Proceedings of International Conference on Intelligent Unmanned Systems
Effects of Eigenmodes, Forward Velocity and Flapping Frequency in Force Generation Mechanisms of a Flapping-Wing MAV
Wind tunnel testing is recurrent for the characterization of the time resolved evolution of the forces acting during a flap cycle of a flapping wing micro aerial vehicle (FWMAV). However, this characterization is often influenced by the lack of knowledge of the typical flapping kinematics and flight regime of the platform, as well as by the effects of attaching a cyclic force system to a force balance. In this regard, the current study analyzes the impact of the previous factors on the sub-flap forces acting longitudinally on a clap-and-fling flapping wing robot. This was done by replicating, in a wind tunnel setup, eight conditions that represent the typical real flight regime of an 17.4g ornithopter. Three force transducer clamping locations are studied, complemented with mechanical impulse and finite element analyses of the natural modes of the structure. The effects of forward flight and flapping frequency are determined by comparing the typical flight conditions with zero free-stream velocity force measurements. It was observed that eigenfrequencies of the ornithopter are close to the first and second harmonics of the flapping frequency for two clamping locations, thus contaminating the force measurements. Furthermore, the forward velocity was found to impact the forces, by affecting the wing shape during flap. An increase in flight velocity reduces the amplitude of the forces acting along the body of the ornithopter (X force). Conversely, the forces along the stroke plane of the wings (Z force) change in phase with an increase in the flight velocity, increasing peak magnitude and the component of Lift force.
A Modified Framework for Longitudinal Dynamic Stability Analysis on Vertical Takeoff of an Insect- Mimicking Flapping-Wing Micro Air Vehicle
In the conventional frameworks for dynamic flight stability analysis, the linearized equations of motion are based on small disturbances from trim condition. This method may be not applicable for vertical takeoff analysis on an insect-mimicking flapping-wing micro air vehicle (FW-MAV) because of two reasons. First, the trim condition is unknown. Second, the initial flight condition, which was at rest on the ground, may be such a large disturbance from the equilibrium that the linearization is invalid. Here, we provide a framework for analyzing the vertical takeoff of an insect-mimicking FW-MAV without acquiring the trim condition. The reference flight condition for disturbances was chosen to be close to the initial flight condition, so that the linearization is applicable. To define the stability derivatives in the equations of motion, the computational fluid dynamics (CFD) software of ANSYS Fluent was used to compute the forces and pitching moments when the FW-MAV operated at various vertical flight speeds and inclined angles from the vertical line. By solving the equations of motion, the behavior of vertical takeoff of the FW-MAV could be analyzed and theoretically reproduced its actual vertical takeoff.
Analysis and Design of Composite Wing Structure of HALE Aircraft
The mission to fly high and very long hour is the specific operating condition of High Altitude Long Endurance (HALE) UAV that require high aspect ratio wing up to 30 to obtain high efficiency aerodynamics. The very flexible wing need to be designed so it can satisfy the deformation and strength criteria. In this research the wing structure of initial version of HALE UAV is designed using carbon composite material. The wing structure is modeled and analyzed using finite element to assess its integrity. The concept of load bearing types of the skin are compared in the analysis. Strength and tip deflection criteria are used to evaluate the wing structure design. The result shows the concept of non-load bearing wing skin will significantly reduce the weight while still can satisfy the strength criteria.
A Smart Ultrasonic Actuator with Multidegree of Freedom for Unmanned Vehicle Guidance Industrial Applications
A smart piezoelectric ultrasonic actuator with multidegree of freedom for unmanned vehicle guidance industrial applications is presented in this paper. The proposed actuator is aiming to increase the visual spotlight angle of digital visual data capture transducer. Furthermore research are still undertaken to integrate the actuator with an infrared sensor, visual data capture digital transducers and obtain the trajectory of motion control algorithm. The actuator consists of three main parts, the stator, rotor and housing unit. The stator is a piezoelectric ring made from S42 piezoelectric material, bonded to three electrodes made from a material that has a close Characteristics to the S42. The rotor is a ball made from steel material. The actuator working principles is based on creating micro elliptical motions of surface points, generated by superposition of longitudinal and bending vibration modes, of oscillating structures. Transferring this motion from flexible ring transducer through the three electrodes, to the attached rotor, create 3D motions. The actuator Design, structures, working principles and finite element analysis are discussed in this paper. A prototype of the actuator was fabricated and its characteristics measured. Experimental tests showed the ability of the developed prototype to provide multidegree of freedom with typical speed of movement equal to 35 rpm, a resolution of less than 5μm and maximum load of 3.5 Newton. These characteristics illustrated the potential of the developed smart actuator, to gear the spotlight angle of digital visual data capture transducers and possible improvement that such microactuator technology could bring to the unmanned vehicle guidance and machine vision industrial applications.
Design and Fabrication of the Muscle Mimicking Composite Actuator for Small Flying Object Using Single Crystal Piezoelectric Material
Studies on muscle mimicking piezo-composite actuators have been increased during the last two decade due to the possibility of various applications for compact lightweight actuators of small unmanned aircraft and biomimetic robots. Piezoelectric materials have been used in a variety of application ranging from shape control of structure, active vibration control of structure to noise suppression due to compact size and good frequency response. The conventional poly-crystal piezoelectric ceramic materials, however, have rather low actuating strains and displacement. In this paper, design and fabrication methods of actuator with single crystal piezoelectric material were investigated to increase actuation strain and displacement.
Formation Control of Humanoid Robots with Obstacle & Collision Avoidance Inspired by SFM
This paper presents a new design for formation control on a group of autonomous humanoid robots with obstacle and collision avoidance ability that inspired by human walking behavior in a pedestrian crowd. This human walking behavior model is known as Social Force Model (SFM) and has been widely used to predict individual movement in a crowd in many variety of situation. We combine consensus algorithm with virtual structure approach for formation control and SFM for obstacle and collision avoidance. In this research, we induced some factors in SFM into consensus equation and then implemented into a group of humanoid robots. The aim of the integration is to create a group of robots that are capable of carrying out its collective tasks while still able to maintain its safety. The use of perception effect, distinct obstacle and collision avoidance function on the algorithm will differentiate algorithm with the others. The attractive feature of this new design is the various behaviors of robots to go back to their initial formation after they avoid obstacles. In the case of robot is trapped in a crowded situation (singularity condition), robot will still trying to look a new position, until it find a condition that allow him to move forward. We verify the proposed algorithm by some simulations and experiments.
A Trajectory Tracking Design of Model Predictive Control for Autonomous Unmanned Helicopters
Autonomous unmanned helicopters represent nonlinear complex systems, have multi mode characteristics and reactive dynamics in their flight missions. To fulfill flight missions completely and safely, model predictive control (MPC) has been considered recently as a tracking control system of autonomous unmanned helicopters especially for small helicopters. In recent years, the tracking control of autonomous unmanned helicopters is required to accomplish a complex trajectory such as in swarm and formation control. Unfortunately, any steady state errors caused by insufficient control system designs may lead to degradation of tracking performances or even failure in tracking mission. The internal model principle (IMP) has been known to produce perfect tracking for control systems. In order to establish good trajectory tracking of autonomous unmanned helicopters, the paper considers the internal model principle for designning the trajectory tracking of model predictive control. Simulation results show that the tracking erros are reduced significantly by selecting the trajectory as combination of modes of the open loop control systems. Autonomous unmanned helicopters represent nonlinear complex systems, have multi mode characteristics and reactive dynamics in their flight missions. To fulfill flight missions completely and safely, model predictive control (MPC) has been considered recently as a tracking control system of autonomous unmanned helicopters especially for small helicopters. In recent years, the tracking control of autonomous unmanned helicopters is required to accomplish a complex trajectory such as in swarm and formation control. Unfortunately, any steady state errors caused by insufficient control system designs may lead to degradation of tracking performances or even failure in tracking mission. The internal model principle (IMP) has been known to produce perfect tracking for control systems. In order to establish good trajectory tracking of autonomous unmanned helicopters, the paper considers the internal model principle for designning the trajectory tracking of model predictive control. Simulation results show that the tracking erros are reduced significantly by selecting the trajectory as combination of modes of the open loop control systems.
Sliding Mode Control Applied to a Qball-X4 UAV
This work is dedicated to the robust tracking problem for a UAV system with external disturbances, the Sliding Mode Control (SMC) strategy is used and tested on a Multi-Input-Multi-Output (MIMO) nonlinear quadrotor helicopter system. For comparison purpose, a LQR controller with integral action is also implemented and tested on a real quadrotor vehicle together with the SM-based controller. The results show that SMC possesses strong robustness for dealing with disturbances and system uncertainties.
Design of Avionics and Control System of Vertical Take-Off and Landing (VTOL) UAV
In this paper, avionics and control system of Vertical Take-Off and Landing (VTOL) UAV will be presented. The UAV configuration is a hybrid-UAV configuration combining feature of rotary-wing UAV and fixed-wing UAV. There are two topics that will be discussed in this paper. First, avionics system of the UAV including its power system and its peripherals interfacing. Second, control system design of the UAV including flight scenario when the UAV is on transition mode/stage. Rotary-wing UAV configuration has advantages such as easy-and-stable when take-off and landing. Rotary-wing UAV also does not need special area to do take-off and landing. While Fixed-wing UAV configuration has advantages such as high maneuverability and high endurance. This hybrid UAV is designed to obtain all of this advantages.
Motion Deblur Based on the Distributed Optical- Arrays System
In order to alleviate the blur of target caused by the local motion, we have constructed a distributed opticalarrays system with six cameras that consist of three distributed arrays. The target association algorithm using Gaussian Mixture Model (GMM) and template matching is proposed to recognize the same target within inner-array. The motion of target is triangulated after the 3D scene flow is estimated that was used for describe the three-dimensional motion of moving target in the view. Finally, based on linear interpolation, the point spread function (PSF) was estimated to deblur the fuzzy targets. The experiments demonstrate the feasibility and effectiveness of the developed system.
An Effective Detection Method for Video Inter-frame Forgery
The applications of image processing software such as Photoshop, Pro Premiere, challenge the integrity and authenticity of videos. This paper proposes a new method to detect the forgeries of videos. The method is extracting a row (column) of pixels from every frame of a video sequence. Then every continuous four pixel line makes up a pixel belt. The correlation between pixel belts will be calculated by using the histogram intersection method. Finally Box Plot will be used to detect the outliers that exist in correlation coefficients. The outliers are basic judgments of video forgery model. The simulation results show that our method could perfectly detect the forgery and local its position.
Real Time Monocular Visual Odometry using ORB Features in Indoor Environment
Navigation is a key process in many intelligent systems. The most common way to do navigation is using Global Positioning System (GPS). However, in indoor environment, GPS is inaccurate due to multi-path problem. To solve this problem, a dead reckoning system may be implemented. Visual odometry is one of the dead reckoning method which can help solving this problem. Among many types of visual odometry algorithm, feature-based monocular visual odometry algorithm is the one which will be built in this work. The feature detector used in this work is ORB. The features is used for triangulation and the obtained 3D structure will be used as the basic information for poses determination. Pose determination is done by solving PnP problem. After the visual odometry algorithm has been built, the performance of this algorithm is tested. The result of the performance test shows that the visual odometry algorithm can determine the position and orientation with good accuracy.
Effect of Clap-fling in an Insect-like Tailless Flapping-wing Micro Air Vehicle
We report recent research progress in developing a tailless flapping-wing micro air vehicle (FW-MAV) by mimicking the flight of a beetle, Allomyrina Dichotoma. The flapping-wing mechanism was improved to create large flapping wing motions up to 190 degrees by a combination of the four-bar linkage and the pulley-string mechanism. It was able to generate a thrust of 10 to 15 grams while flapping the wings at a flapping frequency of 18 to 22 Hz with a wing area of 17cm2. The measured thrust was about 35-42% larger than the estimated thrust based on the unsteady blade element theory (UBET). The clap-flings at the end of upstrokes and downstrokes were the main source of enhancement in the thrust. Due to the increased thrust, the FWMAV was able to fly by remote control with two sets of fixed stabilizers installed at the top and bottom.
Data-Informed Quasi-Steady Aerodynamic Model of a Clap-and-Fling Flapping Wing MAV
The existence of a simple and still physically representative aerodynamic model, that could be computed from states measured on-board of a flapping wing micro air vehicle would facilitate the development of autonomous ornithopters. In this regard, a phenomenological aerodynamic model of the forces acting on a clap-and-fling flapping wing robot is devised and compared with the real forces measure using a high resolution force sensor in a wind tunnel. This aerodynamic model, implemented using blade-element theory, accounts for the centripetal, translational and rotational circulation, added mass and viscous effects, and uses the real kinematics of the wings, under the assumption of zero camber and linear torsion of rigid wings. Using only the flapping frequency, attitude and forward velocity as inputs, the model was capable of closely reproducing the real force acting perpendicularly to the stroke plane of the wings, the X force, which is the most important Lift force component for the typical flight regimes of this ornithopter.
Design and Development of Compact, Portable, Modular, Rapid Deployment Surveillance UAV System
In open field operations, such as in the mountainous area, the need of small, compact, and portable surveillance system is inevitable, to give the team a scout capability while reducing carried-load significantly. This system is a portable mini unmanned aerial vehicle (UAV) with its mobile Ground Control Systems included. Within this paper, the general design processes are presented from determining DRO, initial sizing, aerodynamics analysis, structure, mechanism, backpack design until flight testing to validate the design. Some simple simulation by XFLR5 and complex simulation CFD are also conducted to predict the almost-real aerodynamics characteristic of UAV. Outdoor flight testing has been conducted and also still on progress for further results.
A Study on Control Surface of Small Flying Object Using Piezo-Composite Actuator
A control surface of wing of a small flying object is usually actuated by servo motor system of electro-magnetic motor. There has been a lot of effort to solve the structural complexity of a system for converting the rotation of a servo motor to a linear actuation motion. We designed the piezocomposite actuator which is a composite laminate structure of the piezoelectric material layer and fiber-reinforced composite material layers. In this paper, a piezo-composite actuator was designed to drive a control surface of wing of small flying object. An all moving control surface actuation method with rotation hinge system and a camber deformation method were designed and tested to observe actuation performances.
Nonlinear Camera Gimbal Visual Servoing Using Command Filtered Backstepping
This paper presents a method for controlling a camera gimbal mechanism that is usually mounted on a fixed-wing unmanned aerial vehicle (UAV). The employment of an image base visual servoing (IBVS) is needed to govern the camera direction always pointing at a target object in a distance using the pan-tilt gimbal mechanism while the fixed-wing UAV flying over the object. Our works are modeling a nonlinear camera gimbal movement and designing a nonlinear adaptive control of command filtered backstepping (CFBS) to manage the movements of an extracted image feature and pan-tilt gimbal mechanism in despite of the radical movements of the UAV itself. Our CFBS design shows the effectiveness of the pan-tilt gimbal IBVS control using software and hardware in the loop simulation (SILS / HILS).
Blocking Force Measurement of a Piezoelectric Stack Actuator Made of Single Crystal Layers (PMN-29PT)
In this paper, we present actuation performance of a piezoelectric stack actuator. The stack actuator was made of 40 single crystal (PMN-29PT) layers with an area of 10x10 mm2, and thickness of 1mm. The stack actuator aims to maximize actuation capability by utilizing the higher piezoelectric strain coefficient in the thickness direction (d33). An electro-conductive adhesive was used for bonding each layer and a thin copper foil (60mm) was inserted in between two layers as an external electrode. In determining d33, the PMN-29PT stack actuator was actuated by applying DC voltage, and actuation displacement was measured by a laser sensor. From the measurement, d33 of the stack actuator was about 2,000 (pm/V). To measure the blocking force of the stack actuator, we built a testing method, where dummy weights can be applied over the top of the actuator and measure its actuation displacement. The measured blocking force turned out to be close to the predicted one, which is about 223 N.
The Research of Quadrotor Flight Control Based on Reinforcement Learning and ADP
This paper studies the application of Lookup-Table reinforcement learning method into the continuous state space control of quadrotor simulator and designs a attitude controller for the quadrotor simulator based on Q-learning; for the improvement of defects concerning difficulty in the learning algorithm’s convergence and low efficiency in learning when Qlearning is faced with large-scale and continuous-space optimized decision, the method of kernel approximate dynamic programming is introduced, Kernel-based Least-Squares Policy Iteration (KLSPI) is proposed, and a controller for the quadrotor simulator is designed based on this algorithm. The experiment shows that the reinforcement learning control method is of fast convergence speed, small steady-state error, strong adaptive ability and good control effect; when dealing with the problem of continuous state space, the Least-Squares Policy Iteration can converge better strategies with fewer training data compared with the traditional method of discretizing state space first.
Simulation and Dynamics Analysis of Remotely Operated Vehicle (ROV) Using PID Controller For Pitch Movement
ROV (Remotely Operated Vehicle) is a type of underwater robot that resembles a ship. The robot is controlled by a pilot who controls the remote control. In this ROV tether as a link robot using the device as a source of energy on the surface of the ocean, remote control and sensing display. This study starts from the stage of modeling the body of the ROV using SolidWorks 2014. Estimation of added mass coefficient and estimation of damping hydrodynamics with manual calculation that very important to enter in the simulation. Thus construct equations of mathematical modeling to dynamics with MATLAB SIMULINK to generate 3 DOF motion of the ROV and then, stability analysis ROV using command and GUI in MATLAB with PID control is needed. Creating a world in language VRML files using software V-Realm Builder 2.0 and connect it to the ROV dynamics conditions in MATLAB SIMULINK. Then simulation of the ROV using sl3d toolbox contained in MATLAB 2013b and dynamics analysis of the ROV vision of ROV thruster force is modeled as the input plots generated Signal Builder with position and velocity about time.
Single Chip Controller Design for Piezoelectric Actuators Using FPGA
The piezoelectric actuating device that consist of piezoelectric material is known for large power density with simple structure. It can generate large force than the conventional actuator and it has also wide bandwidth with fast response in a compact size. To control the piezoelectric actuator, we need analog signal conditioning circuit as well as digital microcontrollers. Conventional microcontrollers are not equipped with analog part and need digital to analog converters in addition to the embedded analog to digital converters, which makes the system bulky compared with the small size of the piezoelectric devices. To overcome these weaknesses, we are developing single-chip controller that can handle analog and digital signals simultaneously using mixed signal FPGA technology. We used the Smart Fusion FPGA device that integrates ARM®Cortex-M3, analog interface and FPGA fabric in a single chip and offering full customization. It gives more flexibility than traditional fixed-function microcontrollers with the excessive cost of soft processor cores on traditional FPGAs. In this paper we introduce the design of a single chip controller using mixed signal FPGA, Smart Fusion device. To demonstrate its performance, we implemented a PID controller and PWM generator in the FPGA fabric. PWM generator and PID controller showed the effective regulation of a simple 1st order plant.
UAV Target Tracking Based on Improved TLD Algorithm
When tracking UAV targets in complex environments, it requires to realize online tracking. At the same time, the target may be obscured and lost in some frames. In order to overcome these problems, the TLD(Tracking Learning and Detecting) algorithm containing tracking module, learning module and detecting module is improved. In the framework of improved algorithm, detection module based on the method of building targets neighborhood constructs the scan windows. Also a location prediction module based on Kalman filter is introduced. The experimental results show that the improved TLD algorithm can be applied to the case of target obscured with high recognition rate and low error detection rate. At the same time, it has good real-time performance and can satisfy the demands of general online tracking system.
Multi-Plat IRST Tracking System with Radar Assistance
In the multi-target tracking field, the infrared sensor of the Unmanned Aerial Vehicle (UAV) has a very good concealment because it don’t emit energy to the surveillance area. Due to the lack of range information, the traditional method of multi-plat infrared sensor search and tracking (IRST) system use cross location to realize target localization and tracking, but the tracking accuracy becomes poor when maneuvering targets appear. While the radar can receive both the range and bearing measurements which can ensure the tracking accuracy. So, the proposed algorithm facing to the UAV system combines the accuracy of radar with the concealment of IRST, and use the current statistical model to track the maneuvering target. This algorithm propose the policy of the radar on/off and track evaluation algorithm. The measurements of radar are introduced to initial tracks and modify the error tracks. Simulation results demonstrate the effectiveness of the algorithm.
Local Minima Consistent Identification Method to Accelerate Multiagent Reinforcement Learning
This paper presents a novel method in accelerating Multiagent Reinforcement Learning called Local Minima Consisten Identification or LMCI. Incorporating LMCI in Multiagent Reinforcement Learning Algorithms will successfully accelerate the learning convergence. This method scales down the state space iteratively by distinguishing insignificant states from the significant one and then eliminating them while learning, which aggressively reduces the scale of the state space in the following learning episodes. This method is generally applicable for varying Multiagent Reinforcement Learning algorithms such as Multiagent Q() and Multiagent SARSA() in order to solve multiagent task challenges or general multiagent learning with large scale state space characteristic.
Collision Avoidance System for Unmanned Aerial Vehicle (UAV)
A collision avoidance flight guidance and control is developed to be implemented in a small UAV system. The obstacle avoidance system is designed to be an integral part of the autonomous flight control system, such that the UAV has ability to manage its maneuvers and flight trajectory during particular missions. The avoidance system has to be able to adjust the flight path in case potential collision with other flying vehicles is detected. The algorithm principally works by compute new waypoints at each time step for correcting the original ones. In the proposed approach, once a potential flight path conflict (collision) is detected, an ellipsoid zone is attributed to the conflicting vehicle. Then the UAV system will compute new trajectory avoiding the conflicting flight path by determining contact points on the boundary of the moving ellipsoid at each particular time steps. The contact points computation considers the relative positions and velocity vectors between the UAV and the conflicted fying vehicle. Based on the obtained avoiding waypoints, a flight guidance and a flight control systems are designed to steer the UAV following the suggested path. The controller principally works by driving the cross-track and course angle errors of the UAV flight, relative to the desired path, to zero, through performing Bank to Turn (BTT) maneuvers. The system generates corrective commands, based on the error information, and transforms it into a heading change via roll maneuver. The roll maneuver controller is designed using LQR technique such that it can provide an appropriate roll dynamics of the UAV. Simulation results will be presented and analyzed to investigate the performance of the proposed system.
Relative Position-based Collision Avoidance System for Swarming UAV Applications
This paper presents the development of quadrotor unmanned aerial vehicle (UAV) for close proximity swarming applications that is capable of quad-directional collision avoidance with obstacles through the implementation of relative position-based cascaded PID position and velocity controllers. A collision avoidance algorithm that decides evasive maneuvers in two dimensional flight by the means of net error calculation is developed. Sensor fusion of ultrasonic (US) and infrared (IR) sensors is performed to obtain a reliable relative position data of obstacles which then fed into collision avoidance controller (CAC) for generating necessary response in terms of attitude commands. Flight tests performed in both indoor and outdoor environments proved the capability of UAV to avoid collisions with the obstacles and dummy non-flying UAVs that existed at a closer distance in its four primary directions of detections during flight successfully.
Vision Based UAV Formation Sense and Avoid System
With the increasing use of airspace and the wide application of unmanned aerial vehicles (UAV), the Sense And Avoid (SAA) problem has attracted more and more attention. This paper presents a solution for the SAA of UAV formation equipped with optical sensors. We introduce the stereo vision theory combined with the UAV formation to calculate the position of the targets. The tracking of target is resolved by adopting multi-model (MM) theory so as to solve the problem of the target maneuver. Also during the avoidance, we introduce ellipsoid security region as the safety region and use the flight angle to re-configure the formation’s flight. The simulation results show the effectiveness of this method. In the end, we described our test platform which is used to test the vision based SAA algorithm.
Fast Matching Method for Aerial Image Based on Topological Characteristics
Image feature extraction and matching is a hot topic in UAV vision navigation. Simulating human visual cognitive process that we see the entire object first and then the parts, Euler-SIFT image matching method is proposed to improve the probability of aerial image matching. In the experiment, we compared the matching time and success rate of SIFT method, Euler vector method and Euler-SIFT method. The results show that our approach performs best in UAV vision navigation application.
Preliminary Numerical Analysis of The Effects of Rear Fin-Shape on The Oscillating Propulsion Performance
Performance of the oscillating fin with different rear shapes has been analyzed in the present work. Preliminary analysis was performed by using numerical simulations on the interaction between fluid and solid model. Involved rear fin-shapes were based on nature form of caudal fin of fish such as round, truncate, fork and lunate. From the present result, the rear-shapes affect the optimum performance of the fin such as thrust production, represented by cruising speed, and efficiency. The effects determine suitable mission for each rear-shape such as short, medium, or long cruising endurance. Further numerical study on the effect of material elasticity of the fin, represented by cupping shape of the fin, was also performed. The characteristics of cupping shape increases thrust production of the oscillating fin for impulse thrust generator such as round and truncate rear-shapes.
Experimental Study on the Performance of a Double-pump Hybrid Actuator
In this paper, a double-pump design has been investigated, to achieve high output blocking force of hybrid piezoelectric-hydraulic actuator. Connection method and driving method, key design factors, were considered. Among four kinds of combinations, three kinds of double-pump designs were carried out. A manual valve system was installed for switching of a series and parallel modes. Input signals were controlled by LabVIEW program for an 1800 phase difference of cross driving method). In order to ensure the same performance between the two pumps, two same piezo-stacks and amplifiers were used. The results showed that an outstanding maximum blocking force was measured as 3009N, when using cross driving-series connection combination was used with 200Hz pumping frequency.
Performance Analysis on Biomimetic Fin With Cupping Base and Cupping Ratio Variation
Research on fish locomotion has been widely conducted since the last two decades, but the effect of fish tail cupping shape when swimming is rarely discussed in detail [2][3][4]. In this paper, a model is proposed for a rounded shape caudal fin with a rear profile made to simulate a cupping phenomenon shape. The models are made to simulate cupping phenomenon in various cupping parameter setting. The model is then used to run a CFD simulation to find their respective cruising speed, where drag equals thrust produced. Performance parameter that will be observed in this paper is thrust generated, based on the cruising speed and efficiency. From the data obtained we can figure out the relation between performance and cupping parameters. The result is expected to help future research or optimization of existing fin designs. Other performance category such as efficiency and noise generation is not included in this paper.
Application of RRT Algorithm to Unmanned Ground Vehicle Motion Planning and Obstacle Avoidance
This report presents an application of Randomized Rapidly-exploring Tree (RRT) algorithm to unmanned ground vehicle motion planning and obstacle avoidance. Dynamics and kinemics of the vehicle are presented. A pure-pursuit motion controller is discussed. General structure of the RRT algorithm, including node selection, tree expansion, and path generation is introduced. After a feasible path is found, certain optimization efforts are included to shorten the overall length of the path. Experimental tests using real ground vehicle are demonstrated. Based on the test results, the motion planning and obstacle avoidance strategies proposed in this paper proves to be effective.
Development of CentrUMS ITB SWASH Model Controller
The control system of the SWASH (Small Waterplane Area Single Hull) is needed for the SWASH to get its stability when it operates. The main purpose of the controlling is to get the vehicle operates in the desired depth. There are some factor that must be considered during reading the vehicle depth. The vehicle can get any pitch or roll angle during operation. This cause the reading of the depth different. SWASH will operate in the ocean for the future. The surface of the ocean water is not flat. It has wave that has peak and valey. This paper disusses how to make the vehicle can handle those situations.
Auto-Disturbances Rejection Control Design of Brushless DC Motor Drive Based on Plunger Pump Hydraulic System
In the brushless direct current motor driving plunger pump hydraulic system, overload and load sudden change will happen in starting period and speed stable working time. An auto-disturbance rejection controller composed by TD, ESO and NLSEF is designed to solve those problems. At starting, the output speed will reach the setting value with no overshoot in a short time. A very small speed oscillation will occur when large load sudden change during work area. The experimental results show the controller ensure very good robustness and adaptability under starting and load disturbance.
Adaptive Feed forward Controller Applied for Active Engine Mount System
An active engine mount (AEM) system presented in this paper reduces the transmission of engine vibration to the chassis and the noises in the passenger cabin. To accomplish this goal, an adaptive feed forward control algorithm was employed to the AEM system. This proposed algorithm reduces the response time of control signal and improves the inherent delayed control output in the feedback algorithm by calculating reference signals obtained from vibration sources. Based on the modeling of AEM system, the simulation result confirms how well the proposed control algorithm performs to reduce the transmitted vibrations from engine to the chassis.
Track Segment Association Based on Expectation-Maximization Algorithm for Joint Estimate and Identification
Modern target tracking system are facing the challenge of track breakages frequently. The track segment association (TSA) technique for judging the identitiy of two fractured tracks is becoming increasingly important because the continual tracking performance is important because the continual tracking performance is important for intelligence report. In this paper, we propose one consider a common situation of track breakages due to target maneuver with turn motion. The coordinated turn maneuver was described by the turn rate. The estimation of maneuvering model parameter and stitching start time and end time (namely, start and end time of maneuver) both are needed by the fact that these two problems are critical for TSA and coupled with each other. A novel schema with the tought of joint estimate and identification of stitching time and model parameter are presented based on the expectation-maximization (EM) algorithm. The simulation shows the effect of the proposed method in broken tracks reduction and track continuity improvement.
Overview the Challenges of Noninvasive Glucose Monitoring Techniques
Nowadays, the number of people with diabetes is increasing rapidly. Diabetes patients are required regular monitoring and continuous blood glucose to control their situation. However, the current measures are not convenient. The research and development of non-invasive technology is inevitable. This paper presents overview of the diabetes problem, the current invasive measures and details on the methodology for the future. Definitions, comparisons, collation would be discussed and evaluated. The non–invasive methods also has many things to discuss and clear up. The article will help clarify these points as above. While advances have been made, the reliability and the calibration of noninvasive instruments could still be improved, and more studies carried out under different physiological conditions of metabolism, bodily fluid circulation, and blood components are needed.
Designing an Expert System for Ragi Cultivation
The cultivation of cereals like ragi, jowar, wheat varies from region to region. So due to this there is a ambiguity and confusion among the farmers by comparing the other region farmers yield, cultivation schedule etc. So this leads to be taken into consideration an advisory committee should advice the suitable requirement for farmers. In this connection we have designed an expert system for our region of ragi cultivation. This expert system advises the former cultivation schedule as per the soil, irrigation timing, diseases prevention and eradication. The designed system have been tested in various atmospheric condition for soil and disease conditions. The results are quite encouraging.
A De-ghosting Technique for Passive Coherent Location With Transmitter Origin Uncertainty
Passive Coherent Location (PCL) has attracted attention of many researchers for its advantages such as low cost, covert operation, and low vulnerability to electronic countermeasures in air defense system. However, in cases such as transmitters of a single frequency network(SFN) are used, it is not a trivial problem to resolve signals of multiple transmitters reflected from multiple targets, which adds another dimension of uncertainty into data association. To address such transmitter-object-measurement 3D data association problem, many effective assignment-based algorithms are proposed. Nevertheless, research shows that in multidimensional assignment based algorithms, candidate assignment tree building consumes about 95% of the time. Consequently, it is necessary to develop proper de-ghosting techniques with less time consumption. The major contribution of this paper is that we propose a distribution geometry of stations based de-ghosting strategy, by taking such information into consideration, we can easily decrease the scale of the candidate assignment tree with very little time consumption, which will surely lighten the burden of data association. Both theoretical analysis and simulation are provided to demonstrate the feasibility and effectiveness of our algorithm.
Re-STOL Micro Ornithopterswith Four Strategies for Improvement
Regarding to the 20-cm wingspan flapping microair-vehicles (MAVs) or ornithopters, how to prolong the operation time and improve the flight control is very critical to their roadmap of development. Based on using the available technology and commercial transducer devices, this work presents four new features of ornithopters and proves them feasible. The 1st feature is repeatable short take-off and landing (re-STOL) so that the ornithopter can stop flapping in the air and automatically falls on the ground with resetting to the good gesture of take-off. The 2nd feature is to recharge the onboard Lithium battery by flexible photo-voltaic (PV) thin film on the tail. Recharging can be done either during flight or on the ground if the background light intensity is enough for PV devices to work. The 3rd feature is toward the semi- or fully autonomous flight control of ornithopters. It is realized by integrating gramweighted microelectronic devices including Arduino-based micro-processors, MEMS inertial measurement units (IMUs) and mini servo actuators. Longitudinal pitching control and altitude control are proposed herein. The 4th feature is to develop new flapping mechanisms with large flap angle and no phase lag between two flapping wings. The above four newly developed features of ornithopters can preliminarily solve their current four shortcomings, i.e., vulnerable to gust wind, short flight endurance, hard to autonomously control and small payload, to great extent.
Design of Retract Mechanism for VTOL UAV Propeller
The objective of this mechanism is give Vertical Take-Off and Landing (VTOL) capability for fixed wing type UAV. In order to make effective when UAV fly in long range, propeller should be hidden at the body of UAV. However when UAV want to hover, take-off, or landing propeller should be shown. So, we need a mechanism to move the propeller automatically. This paper will discuss on designing the retractable rear propeller mechanism that cause minimum retraction force, and some of detail calculation.
Design and Manufacturing of UAV Backpack
The UAV Backpack is a good concept for spying and aerial documentation device. The design of the UAV backpack is compact and modular to make it easy to be carried by one person. The material used was EPP foam laminated by fiber reinforced composite. The manufacturing process of this concept is vacuum infusion process. The ultimate tensile test of the prototype (GFRP) is 330.45 MPa. The prototype succeed to fly for 23 min at average 60 km/h with belly landing at 45 km/h and survived.
Visual Estimation of UAV Landing Attitude Based on Adaboost
In the process of UAV autonomous landing, with reference to the independent designed landmark, visual navigation system using Adaboost classifier based on Haar features can recognize the landmarks in a wide variety of complex environments. A method for estimating the attitude of UAV in autonomous landing is put forward according to the camera imaging principle, and then the derivation is given in the following. In the end of this paper, the effectiveness of the proposed algorithm is verified by simulation examples.
UAV Sense and Avoid with ADS-B, Simulation and Experiment
ADS-B is regarded as a promising fashion on UAV SAA application. In this article, we proposed simulation and HIL platforms to test ADS-B based SAA functions, trials are carried out with real on-the-air ADS-B data. In the simulation, we build the simulation scenario with ArcGIS, and we use a small ADS-B receiver to collect airspace traffic status to generate a real UAV flying environment. In the experiment setup, we use both ADS-B In and ADS-B Out to carry out the SAA function with two small quadrotors. Both the simulation and experiment has shown the advantages of information sensing and collision resolution towards SAA scnarios, with higer precision, wider range as well as better stability.
Design of Diver Propulsion Vehicle Ganendra RI-1 Using SolidWorks Flow Simulation
A diver propulsion vehicle DPV, also known as an underwater propulsion vehicle or underwater scooter is an item of equipment used by scuba diving and rebreather divers underwater to increase the range. Simulation studies produce data in the form of comparison between DPV without tunnel, with side tunnel, bottom tunnel. The results are presented as data containing surface pressure, environmental pressure, cut plot speed, and 3 dimensional flow velocity and drag force. From the data analysis, we found that the side tunnel design provide the overall best performance to achieve desired vehicle specification.
Control Allocation Scheme for Aircraft with Redundant Control Effectors
Modern aircrafts may exploit more complex control effectors (surfaces), some of which are designed as redundant effectors. Redundant control effectors can give alternatives to provide required control moment in different situation/condition. This redundancy means that different combination of control effectors action can be generated for resulting a particular maneuvers or corrections. Hence, the redundancy may provide some degree of flexibility in controlling the attitude and maneuver of the aircraft. In this paper a control allocation scheme using weighting matrix is explored and evaluated. The weighting matrix can be viewed as a control signal distributor which may assign the responsibility of generating particular control moment to different control effectors, hence some preferred effectors can be assigned. Further, the weighting matrix implemented here can be computed and adapted to condition of the effectors, in terms of their current ability to track the control signal. In case of one of the control effectors is degrading, then the control task for that particular effector will be assigned to other effectors, within their performance limits, to push the system in producing the required actions (maneuvers). Using this scheme, a way of anticipating effectors faults, by redistributing the control signals to different effectors, can be achieved. The scheme is developed and simulated on an aircraft model with canard configuration which may provide redundant effectors in longitudinal channel. The developed scheme is simulated for providing particulars attitude control actions in longitudinal channel under different conditions. In this case, the scheme shows its ability to generate the required moment to track the control command using different combination of control effectors. Further some effectors faults are also simulated to evaluate the redistributing behavior of the scheme. It can be seen that when one of the effectors is degraded/faulted, the weighting matrix is adapting and automatically redistributing the control command to other effectors, hence the desired response can still be maintained. The scheme is also improved so that it can handle actuator lag by introducing an augmented matrix and linear transformation from control input into virtual control input.
Automatic Load Alleviation Simulation During Boom Refueling for UAV
In recent years, a number of algorithms of automatic load alleviation (ALA) for UAV boom refueling were developed, but most works are usually conducted without considering the force caused by the steering angle of spherical joint. Aimed at the problem, this paper proposes a method of fractional order sliding-mode control to restrict the force caused by the steering angle of spherical joint. Firstly, considering nonlinear characteristics, a refueling boom model is built. Secondly, a force model and reference command generator is constructed. Then, a control law based on fractional order sliding-mode control is designed to restrict the force caused by the steering angle of spherical joint using the variable structure control theory and the Lyapunov stability theory. Finally, simulation is carried out to verify the designed control law. Simulations show that the proposed fractional order slidingmode controller achieves good performance.
Embedded system design for A Maximum Power Point Tracking Controller for Traffic Light System Powered by Photovoltaic
Photovoltaic traffic light system is a significant application of renewable energy source. The develop the system use solar energy as an alternative effort of local authority to reduce expenditure for paying fees to power supplier which the power comes from conventional energy source. Since photovoltaic modules still have relatively low conversion efficiency, An alternative control of maximum power point tracking (MPPT) method applied to the traffic light system. MPPT is intended to catch up the maximum power at daytime in order to charge the battery at the maximum rate in which the power from the battery is intended to be used at night time or cloudy day. MPPT is actually a dc-dc converter that can step up or down of voltage in order to achieve the maximum power using Pulse Width Modulation (PWM) control. In this work, we design a MPPT using Microcontroller PIC16F877. Where this microcontroller will compare the voltage and current from PV system, and convert the new voltage and current to get maximum power output. Based on experiment, we obtained the voltage of operation use MPPT is at 16.454 V, this value had error 2.6%, if we compared with Maximum power point voltage of PV module that is 16.9V, based on this result then this MPPT control work successful to deliver the power from PV module to battery maximally.
Geometry and Structural Design of Tidal Current Turbine
Tidal energy is an attractive source of renewable energy since it is regular and predictable. Due to this fact, various types of tidal turbines have been developed to explore renewable energy technology. In this study, a tidal current turbine is designed using hydrofoil NACA 63-424 for 5 m long blades to extract 200 kW. Using the blade element-momentum theory (BEMT), the blade geometry was optimized such that the turbine demonstrates a maximum power coefficient at a tip speed ratio (TSR) of 4.5. We also analyzed pitch control for the turbine to maintain consistent power generation at various inflow velocities. With the current blade design, we computed forces and moments acting on the blades by applying the BEMT to design stiffness of the blade structure. In order to reduce the risk of cavitation at the design stage, we also conducted cavitation analysis using the pressure coefficients computed by ANSYSFluent. The analysis showed that the blade will not experience cavitation. Finally, we could judge that the suggested composite blade structure has enough stiffness and strength for the expected loading condition through the finite element analysis.
Design and Manufacturing an Explosive Ordinance Disposal Robot Chassis
This paper describes the development of a lightweight chassis and drivetrain of an Explosive Ordnance Disposal Robot. It defines the design methodology of selecting the correct specification of a robot to define a general concept of the robot. The chassis and drivetrain movement concept is described and a finite element analysis is achieved to validate the strength of the robot under intermediate payloads.
Flexible Wing of HALE UAV using Two-way Fluid Structure Interaction Method
Numerical simulation of flexible High Altitude Long Endurance Unmanned Aerial Vehicle (HALE UAV) wing using two-way fluid structure interaction (FSI) method is presented. The HALE wing is designed with high aspect ratio. This configuration intended to reduce the vehicle induced drag and reduces the lift-loss at wingtip which caused by wingtip vortex. But the structure of the wing itself becomes more elastic that be able to give large deformation when the aerodynamic loads applied. This deformation causes the change of aerodynamic loads distribution on the wing. Then this provides a new deformation to the wing structure and vice versa. This interaction in a couple process called as fluid structure interaction (FSI) will be simulated using ANSYS 15.0 software for HALE wing. The unsteadiness and viscous flows at low speed are evaluated using the solution of time-dependent Reynolds Averaged Navier-Stokes (RANS) with SST k-ω turbulent model. In addition, multi-block structured grids are generated to provide more accurate viscous result and to anticipate negative volume of the mesh which may occur due to the wing deformation during simulation. Five different simulations with variation of material characteristics including Young's modulus and Poisson's ratio are carried out. The results include global aerodynamic characteristics at various material characteristics.
Design of Separate Lift and Thrust Hybrid Unmanned Aerial Vehicle
Hybrid UAV is a new platform of UAV which is integrating fixed wing and multirotor to get vertical takeoff and landing capability with high range and long endurance. Thus it has the benefit of both fixed wing and multirotor platform. The design methodology of hybrid UAV is resembled fixed wing aircraft with modification at some part due to augmentation of multirotor. This Hybrid UAV has been manufactured and on testing phase.
The Investigations of Horizontal and Vertical Resistance for the Swimmer Delivery Vehicle on Submerged Condition
This paper is concentrated on the investigation of horizontal and vertical drag/resistance of submerged Swimmer Delivery Vehicle (SDV). For initial estimation, the resistance investigation was carried out by Computational Fluid Dynamics (CFD) approach using a CFD code called Tdyn. Navier-Stoke Solver was used in Tdyn to solve the fluid flow. The k-ω shear-stress-transport (SST) model was selected for turbulence model. The investigation were carried out at several speeds from 1 to 6 knots for horizontal direction and from 1 to 3 knots for vertical direction with main dimension 4 x 2 x 1,24 m or 1 : 1 scale with single-phase of fluid. The results of calculation show that the horizontal direction drag is 873,42 N at 6 knot and the vertical direction drag is 7659 N at 3 knot. The resistance of 3 knot vertical direction is higher than horizontal direction with very far distance because of the different of frontal area that to be faced with fluid of the swimmer delivery vehicle. 1 knot speed was considered as maximum vertical direction speed because its resistance is 520 N.
Controll of Unmanned Small Scale Helicopter: A Review
Controller design has been identified as one of the major activity in small scale unmanned helicopter development. Several approaches have been reported with varying degree of achievement and performance both in simulation and real-time implementation. This paper presents a survey of relevant research on control of the unmanned helicopter. The objective is to provide summary of the state of the art approaches in control design for the system with respect to modeling and implementation issues regarding flight control system. The unmanned helicopter flight control components and objectives are introduced first. Several model based and non-model based control design methods are presented with a view to highlight the strength and weakness of each of them. Conclusion is made with summary of the current trend, challenges and future direction in the control of unmanned helicopter.
Extremum Seeking Control for Autonomous Rotorcraft
In recent times, multirotors Unmanned Aerial Vehicles (UAVs) have fascinated researchers because of their high maneuverability to carry out complex autonomous missions. Most of these vehicles use on-board Proportional-Integral-Derivative (PID) controller for the stabilization of the vehicle during flights. However, it is well known that the effectiveness of PID controller is limited due to poor (online) tuning. In this paper, we propose the combination of PID controller and Extremum Seeking Control to provide tracking control to an autonomous quadrotor. Extremum Seeking (ES), a nonmodel-based optimization method, iteratively modifies state feedback control (SFC) parameters through a cost function so that the output can be optimized. ESC is used to provide online tuning to the controller. The performance of the designed controller is then evaluated through simulations. The results show the effectiveness and robustness of the ES controller for tracking through waypoints.
Microcontroller-based for Development an Inverter for 500W Residential Wind Generator
In this project, an inverter circuit with suitable control scheme design was developed using Microcontroller PIC16F887. The circuit was to be used with a selected topology of Wind Energy Conversion System (WECS) to convert electricity generated by a 500W direct-drive permanent magnet type wind generator which is typical for residential use. From single phase AC output of the generator, a rectifier circuit is designed to convert AC to DC voltage. Then a DC-DC boost converter is used to step up the voltage to a nominal DC voltage suitable for domestic use. The proposed inverter then will convert the DC voltage to sinusoidal AC. The duty cycle of sinusoidal Pulse-Width Modulated (SPWM) signal controlling switches in the inverter was generated by a microcontroller. The lab-scale experimental rig involves simulation of wind generator by running a geared DC motor coupled with 500W wind generator where the prototype circuit was connected at the generator output. The experimental circuit produced single phase 240V sinusoidal AC voltage with frequency of 50Hz. Measured total harmonics distortion (THD) of the voltage across load was 4.0% which is within the limit of 5% as recommended by IEEE Standard 519-1992.
The Development of Turbojet Based on Turbocharger
This paper explains the process of developing a small turbojet engine based on an available turbocharger. As a study case, turbocharger Turbonetics T70 was chosen as the engine’s compressor and turbine core while the combustion chamber was separately designed and manufactured. An engine performance analysis, with an assumed components efficiencies and pressure losses was done to determine the engine’s thrust at sea level static condition. From the analysis, it was found that the engine produces maximum thrust of 208 N at 105,800 rpm. The compressor pressure ratio (CPR), turbine inlet temperature (TIT) and air mass flow at its maximum thrust are 4.23; 1,260.4 K and 0.4931 kg/s respectively. After all parts were completely built, the engine was assembled and several functional tests were conducted. The objective of the test was not to measure the thrust but to find out whether the engine can perform a self sustains operation or not. The tests results show that the idle speed is around 52,000 rpm with the idle exhaust gas temperature (EGT) is about 1,053 K. The maximum speed achieved during functional test is 80,000 rpm. In the future, performance tests will be conducted to investigate the engine’s thrust, specific fuel consumption and efficiencies.
Vaporizer Design for T70 Turbocharger-Based Turbojet Combustion Chamber Using CFD Analysis Method
This report discuss about vaporizer design for turbocharger-based combustion chamber. The purpose of designing vaporizer for combustion chamber is to modify a turbocharger to become a turbojet. Later on, the modified turbocharger could be used as propulsion system on a small aerial vehicle. T70 turbocharger compressor and turbine data charts were obtained from the manufacturer, meanwhile for the other dimensions were obtained from direct measurement. The design process was based on reference book entitled "Gas Turbine Combustion". During the design process, Computational Fluid Dynamics (CFD) numerical simulation was also being done with the help of ANSYS as the CFD software. For the CFD simulation, k-epsilon, eddy dissipation, and P1 was used as the turbulence model, combustion model, and radiation model respectively. The simulation results were then compared with the previous design for further improvement of the design. This iteration process keeps going untuk the design parameters were achieved. The final combustion chamber design is 30 cm long with 80 cm diameter using the tubular/can type with vaporizer. Simulation result showed that the total pressure loss was 19%, pattern factor <2%, and liquid fuel was fully vaporized. The total pressure loss was still to high, but in terms of flow uniformity and evaporation conditions, the result was up to the design target.
Design and Analysis of Low Speed Vertical Axis Type Sea Current Turbine
The Needs on renewable energy sources that are environmentally friendly and sustainable lately become a central issue in every country. Indonesia as an archipelago country with the most of area is coverage by ocean, have some advantage to utilize it. The one of the potential energy source is from sea current . Sea current have more advantages than another source on the ocean, especially on the most predictable of the characteristic. The main mechanism of sea current dominated by the gravity force between earth and moon, or common known as tides mechanism. The goal for this research is how to design the most effective and efficient power generation system by sea current turbine that can operate on slow water current speed. This paper will discuss how to design and analysis vertical axis type of sea current turbine. Some of the design aspect will be described on this paper.
Development of Quicklook Processor for Circularly Polarized Synthetic Aperture Radar onboard GAIA-II Microsatellite
Synthetic Aperture Radar sensor produce large amount of raw data and requires high amount of computing resources to process the data into full resolution image. Although most SAR application requires high-resolution image, there are cases where low-resolution is also important, for example when browsing from large collection of raw data to find the area of interest. A quick-look SAR processor for L-band Circularly Polarized Synthetic Aperture radar sensor onboard GAIA-II microsatellite is developed to produce low-resolution images and enable rapid preview of CP-SAR images on commodity of the shelf computer system. The algorithm is based on modified Range-Doppler processing with sub-aperture data processing. The result is validated using actual raw data from JERS SAR that has similar characteristics with GAIA-II CP SAR sensor.
Development of Spaceborne Antenna for Circular Polarized SAR using Kevlar Honeycomb Core
Our laboratory develops microsatellite onboard Circular Polarized Synthetic Aperture Radar (CPSAR) that has an advantage of compactness and low power requirement. Additionally the transmission of CP microwave is not affected by Faraday rotation effect in the ionosphere, comparing to linear polarized systems especially at the L band. The CP-SAR onboard small satellite is required to be lightweight and resistant to heat and shock. This paper presents a development of circular polarized microstrip antenna using Kevlar honeycomb core as the substrates. The results show good characteristics of the antennas except the axial ratio. The reason of insufficient axial ratio is assumed as fabrication error of the radiator and microstripline.
'SMART' Cane Project for the Visually Imapaired: Of a Direction Guidance System using GPS
In the present time, travelling had been essential necessary for many people. People travel for various reasons, such as study, job, meet someone, buy groceries, leisure and so on. This task has been made easier with technology such as car, motor, and aircraft. However, the same thing cannot be apply for the visually impaired persons. Without the ability to see their surroundings, they are unable to know their own positions. Usually, the visually impaired person navigates through a familiar place using either the white cane or the guide dog, or the combination of both. But this will only be useful if they want to go to familiar area. There are various devices that can help them to travel to unfamiliar place, but these devices are expensive. Since most of the visually impaired persons are in the low-income category, sophisticated gadgets are out of the question. In this project the aim is to develop an affordable ‘smart’ cane to integrate the Global Positioning System into the white cane, so that it can help the visually impaired persons to be more independent, increase their confidence level and help them to lead a better life. Since the device will be attached to the cane, it must be portable, easy to carry, lightweight and compact. This is done by using the Raspberry Pi, a credit-card sized single-board computer.
Design of Rack-Pinion Mechanism for Insect Mimicking Flapping-Wing Micro Air Vehicle
In this work, we present a simple but robust flapping-wing mechanism, which is able to flap with a large flapping angle range. In the design, a combination of the Scotchyoke and rack-pinion mechanisms was employed to convert the rotational motion of a motor into a large flapping motion. Three gear ratios 12:1, 16:1 and 20:1 were considered in this study. A series of flapping tests were conducted to find out a gear ratio for which the flapping frequency and the power consumption are optimal. From these experimental results, the gear ratio 16:1 was identified and then used in performance tests. The proposed mechanism was compared to a pulley-string mechanism in terms of thrust generation and power consumption. The flapping system based on the rack-pinion mechanism showed improvement in the flapping frequency and thrust-to-power ratio.
The Study on Stability and Seakeeping Characteristics of the Swimmer Delivery Vehicle in Surfacing Condition
Swimmer Delivery Vehicle (SDV) is a portable surface and submersible military instrument designed to transport diver from a combat swimmer unit or naval Special Forces underwater, over long distances. Although SDV usually carry a pilot, co-pilot, and combat swimmer team and their equipment, however it is possible only for two persons which are the pilot and co-pilot as the combat swimmer team. The paper has focused on the study of stability and seakeeping characteristics of the swimmer delivery vehicle for two persons in surfacing condition. The intact stability characteristics will be investigated at the various load cases and weight distribution configurations which are influenced by the heavy battery locations. Regarding the seakeeping performance analysis, the Bretschneider or ITTC formula with 2 parameters will be adopted as the wave spectrum at the wave parameters defined from the operational environment. The influence of the parameters on the stability and seakeeping of the swimmer delivery vehicle are presented and discussed.
Operation Design of CentrUMS-ITB SWASH Vehicle
As archipelago country, the needs of Marine Vehicles have increased day by day according to the utilization benefits and minimum risk during the operation [1]. Some of the main task has proved just only carried by Marine Unmanned Vehicle. One of them is an Unmanned Surface Vehicle (USV). Which has the ability to do a good observation at sea level or below sea level. This vehicle has a feature in the design, which is where the most of the structure placed under the surface, only part of the Main mast that appear on the surface. This type of Marine vehicle is called the Semisubmersible Marine vehicle. By the wetted area characteristic, this vehicle can known as Small Waterplane Are Single Hull (SWASH). This vehicle must have good condition whether on docking condition or Operation condition. The Main task for this vehicle is as a Unmanned Marine Surveillance Agent. This paper will discuss the operational design and control mode of this vehicle. Some of the detail calculation to determine the characteristic of this vehicle will be discussed on the part of this paper.
Design, Kinematic Modeling and Implementation of Integrated Flapping Wing Micro Aerial Vehicle Flight Platform
Advanced technological development of aerial robot, requires the engineers to develop renewable flying mechanism. Flapping wing micro aerial vehicle (MAV) inspired by the flying ability of birds and insects. Electro-mechanical design of flapping wing MAV, kinematic modeling and the integration are successfully implemented. Small and lightweight robot design also successfully implemented to get a platform that can fly and maneuver easily. Crank-shaft mechanism as the flapping mechanism and modelling to achieve particular flap frequency is implemented in this robot. Biplane wing configuration and the tail are designed to obtain a stable platform. Control system of the robot getting feedback from the inertial measurement unit (IMU) sensor. The data is processed by a microprocessor with stabilization algorithm which is then fed to the actuator. Flight test showed that the robot can fly up to 90 seconds in the air with the forward speed up to 4 m/s. Integrated systems of flapping wing MAV is also equipped with a camera and ground control station as a data telemetry center for flight attitude parameters monitoring function and real-time sensing purposes.
Distributed Flight Array of Autonomous Flying Vehicles
Vertical Take-off and Landing vehicles (VTOL) have gained widespread popularity among researchers in aerial vehicles because of the unique capabilities they possess such as vertical stationary flight and maneuverability due to their inherent dynamic nature. This has resulted in many beneficial and unique applications for both military and civilian purposes. Despite heightened interest in VTOL vehicles, research in this area until now has focused almost exclusively on rotorcraft platforms such as Quadrotors. Very little research has been performed in extending the design of VTOL vehicles to a multirotor platform consisting of individual flight modules using distributed control. In this project, a multi-rotor platform consisting of modular flight vehicles using distributed control has been designed which has been designated the Distributed Flight Array (DFA). The individual modules are able to communicate and coordinate with each other to fly in a variety of flight formations either as individual units flying in formation in a coordinated fashion or as larger units by physically combining and docking with each other. A distributed strategy for hover control based on the physical parameters of the DFA formed the basis of the flight control of the DFA. An estimator was used to obtain the state of the system. The unique design of the Distributed Flight Array gives it many unique advantages over conventional rotorcrafts such as significantly greater resilience to catastrophic on-board failure, greater optimization and flexibility.
Combustor Design for Turbocharger Turbojet Engine
This research explains several variation designs of the combustion chamber for a turbojet engine based of T70 turbocharger. T70 turbocharger engines are widely used in vehicles, especially cars. The problem that often occurs in the combustion chamber is the non-uniform flow which makes a pressure loss. The other problem is no combustion occurs in the primary zone, but it occurs in the dilution zone until the outlet engine nozzle. The method performed in this research is hot flow CFD simulation in combustion chamber using ANSYS 14 software. The aim of this research is to make an optimum combustion chamber design which has minimum pressure loss, a small pattern factor, and turbine inlet temperature (TIT) that does not exceed limit of the material. Flow analysis on each variation designs is performed to find the best flow patterns. A good flow pattern will follow some certain conditions such as presence of air circulation and sufficient air mass flow in each zone. The analytical methods that used to consider the initial design target are turbine inlet temperature, pattern factor, mass flow distribution, and pressure loss. In this combustion chamber design, the TIT target is less than 1260 Kelvin, pattern factor is less than 0.2, mass flow passing through the snout is 8.0 percent, primary is 12 percent, secondary is 30 percent, dilution is 45 percent, cooling is 5 percent, and pressure loss is less than 8%. Result of the simulation shows that TIT is 1201.7 K, pressure loss is 19.82 percent, pattern factor is 0.44 and mass flow passing through the snout is 2.7 percent, primary is 12.3 percent, secondary is 20.2 percent, dilution is 45.8 percent, and cooling is 18.95 percent.
A Single-on-Chip for Onboard SAR Imaging Processor Based on the LEON3
This paper described the design and development of onboard SAR imaging processor based on LEON3 softcore processor implemented on FPGA board. The SAR imaging processor will be used for future onboard microsatellite and Unmanned Aerial Vehicle (UAV) of Josaphat Microwave Remote Sensing Laboratory. The system-onchip (SoC) approach has been chosen for highly configurable, easy to integrate with other IP core through an on-chip bus and low cost implementation. The open hardware LEON3 processor has been configured to meet the system requirement to aim at high performance processing. The target implementation of System-on-Chip is on an Altera Cyclone IV FPGA family. The RDA algorithm for SAR image processing is implemented in software on LEON3 Processor by using C language. The system testing is done by using the data ALOS PALSAR. The experimental results show that the system’s functionality successfully works. The system can convert raw image data into a SAR image but processing speed needs to be improved. The proposed design promises to solve the problem of SAR image processing in the future with a low price.
Development of Synthetic Aperture Radar Onboard UAV, Aircraft and Microsatellite
This paper introduces the progress of synthetic aperture radar (CP-SAR) development for unmanned aerial vehicle (UAV, JX series), Aircraft (Boeing 737-200) and microsatellites (GAIA series). This sensor will be employed to monitor global land deformation in the future.
Thermal Imaging-Based Human Emotion Detection: GLCM Feature Extraction Approach
Recent studies in artificial intelligence and robotics proved the ability of social intelligence in robots. However, it has become increasingly apparent that social and interactive skills are necessary requirements in any application areas and contexts where robots is needed to interact and collaborate with other robots or humans. In order to develop an emotionally intelligent robot, the issues on how to perceive human emotion (affective) states and how to manifest the robot’s emotion should be addressed. In this paper, we presented an efficient method for thermal image feature extraction using the Gray Level Co-occurrence Matrix (GLCM) technique. By analysing the heat pattern on the facial skin, this work attempt to investigate the suitability of the thermal imaging technique for affect detection. The findings of this study indicate thermal imaging as an alternative, contactless and noninvasive method for appraising human emotional states.
X-band UAV-SAR System Design Using Wideband Chirp Signal Generator
Synthetic aperture radar (SAR) is an active sensor that is operated using the moving platforms such as satellite, aircraft, or unmanned aerial vehicle (UAV). As a kind of imaging radar, it uses microwave to detect the target in remote area. Due to the characteristics of microwave, the SAR can be operated regardless of the weather conditions. Also, it offers highresolution images of targets by utilizing the wide-bandwidth transmit signal. Due to the features of SAR, it is widely used in several area such as surveillance, land monitoring, urban managing, disaster monitoring etc. To conduct the continuous monitoring for some specific areas, the SAR payloads are loaded on UAV and operated recently. Several UAV-SARs exist already in research fields and practical uses (e.g. AirMOSS of NASA). These platforms usually perform its missions on 1-2 km above the ground. The specifications of the recent UAV-SARs and the conceptual design of the proposed UAV-SAR are listed in Table 1 [1]. To achieve the high-resolution, the SAR system uses a linear frequency modulated (LFM) signal called chirp. As the bandwidth of transmit signal is inverse proportional to the resolution, the SAR system requires wide-bandwidth signal to offer the better performance. There are several types of chirp signal generators: memory-map based type, signal generators using frequency multipliers, direct digital frequency synthesizer (DDFS) type, and parallel DDFS type. The memory-map based chirp signal generator stores the predefined chirp waveform in the PROM or other memory devices and loads the signal using the counter. It has the advantage of high-precision output. However, it requires the large sized ROM to store the wide-bandwidth signal and hard to update the predefined signal especially the SAR is operated in space mission. Compared to the previous one, the DDFS generates only the phase of the signal using registers and full-adders. Next, it combines the phase signal and the amplitude signal that is stored look-up table (LUT). When DDFS generates the desired signal, it controls the frequency control word (FCW). The fast switching speed, less memory dependency, simple structure, easy configurability, and etc. are the features of DDFS. However, as this system truncates the I/O bits between the phase signal generator and LUT, the signal characteristics are degraded due to the spurs. The signal generator using frequency multiplier is proposed to realize the wide-bandwidth signals. First, it generates the relatively narrow band signal. Next, using the frequency multiplier and band-pass filter (BPF), it expands the bandwidth of transmit signal. Using the frequency multiplier, SAR system can achieve the wide-bandwidth with simple structure. However, as the bandwidth of signal is multiplied with the hardware, also the residual noise of the signal gets larger. In this paper, the parallelized DDFS type chirp signal generator is presented. The signal generators are operated based on a digital circuit. Therefore, the baseband output bandwidth of the presented signal generation methods is limited due to the clock frequency of the devices. However, by using the multiple memory and the high-speed multiplexer, the parallelized DDFS can generate the wide-bandwidth chirp signal with relatively low clock frequency. As the recent SAR system requires the high-resolution images, the SAR system equipped with wideband signal generator is also needed. In this paper, the conceptual design for X-band UAV SAR and the parallelized DDFS chirp signal generator for the wideband chirp pulse (up to 800 MHz) have been proposed. Using the circular polarization, the proposed SAR system can be used to full-polarimetric SAR. Also, due to the wideband chirp pulse, the SAR system can offer the images of sub-meter resolution.
Mathematical Modelling of Hexacopter System: A Port-Hamiltonion Approach
This paper describes the mathematical modelling of unmanned aerial vehicle (UAV) of multirotor system based on energy-preserving of port-controlled Hamiltonian (PCH) approach. In this paper, a model of UAV or hexacopter consist of six rotors, with three pairs of counter-rotating fixed-pitch blades is used to derive the basic mathematical modelling of the system. This model then can be used to develop proper method for stabilization and trajectory control of the hexacopter system. The model is based on the total energy in the system and is separated into subsystem which utilized the exist interconnections. The main advantages of this PCH approach due to preservation of the nonlinearity of the model by using port-controlled Hamiltonian system and the energy balance in the system can be attained by shaping the internal energy while stabilizing the system.
Machine Vision-based for Development a Sun Tracking using Intelligent Algorithm
Two degree of freedom (DOF) of light tracking system using fuzzy logic control is presented in this paper. The fuzzy control for light tracking system (FLTS) uses a webcamera as a vision sensor, two PC sound cards as output signal controller, and two DC motors as a pan-tilt driver mechanism. The Fuzzy logic controller to control the camera panel angles of light tracking system is designed. Two fuzzy controllers are proposed, one for each motor to produce proper PWM in order to track the light source. A typical FLC includes three basic components, an input signal fuzzification, a fuzzy engine, and an output signal defuzzification. The Fuzzy controller input parameters (Xcp,Ycp) and variation of duty cycle output parameters are used to generate the optimal pulse-width-modulated (PWM) to track the light source, such that PWM is generated under different operating conditions to drive the motors. The motors will react accordingly when they receive signal from the sound card to make sure the camera always focuses on the centroid of the light source. The system tested at different locations. The data which were obtained by experiment were able to show a validity of the proposed controller.
Variable-Pitch Propeller Design for “Stingray 500” Quad Copter in Hovering Condition
Propeller is one of the thrust generating devices that is widely used in flying vehicle exists in the world. Despite its old aged first discovery, propeller still has its advantages over the newer thrust devices. This research focuses on designing a propeller of the quad copter Stingray 500 with variable-pitch propeller system for a surveillance mission, which was originally for aerobatics purpose. Surveillance requires a flying vehicle to hover as long as possible in a designated area, so that the mission changes will be carried out by replacing the current propeller into a more efficient propeller in hovering condition. After conducting an analysis of the current propeller in hovering conditions with various pitch angle, propeller design is conducted with three types of airfoil. By using momentum-blade element theory for propellers, propeller analysis and design is done. In this research, designing a small-sized propeller is strongly influenced by its airfoil lift coefficient value that affected the value of the Reynolds number. If the lift coefficient is too large, propeller will have thin chord distributed along the span. This causes the Reynolds number to become small and the airfoil aerodynamic efficiency go down. Even though an airfoil has a high efficiency in every Reynolds number compared to the other airfoils, the propeller design results will have a bad performance if that happens. Also when designing a hovering mission propeller, the span wise twist angle generated along the propeller differs a little on the span wise angle of attack when compared to a just straight propeller blade, so it can be considered a cheaper manufacturing cost.
Dynamic Characteristics and Components Selection Strategy of a Railway Vehicle Quarter Car Suspension
Suspension system is a mechanism which isolates the vehicle body from road shocks and unwanted vibrations. A basic suspension system usually consists of spring, damper, rods, and ball joints in both automotive and railway transportation. The primary aim of this project is to design and develop a smallscale test rig of quarter car railway vehicle for suspension system. This paper describes the research investigation, the technical design procedure and component selection strategy of the completed suspension system. The rig design and motion analysis has been done by using Solidworks motion study to find out the dynamic characteristic of the system such as estimation of torque requirement, vehicle body and bogie acceleration, vehicle body and bogie displacement based on the selected parameters and track input.
Simulation and Experimental Study of Formation Control of Multi Humanoid Robots
Distributed formation control of multi humanoid robot system with obstacle avoidance and collision avoidance are presented. The architecture consists of several layers, namely consensus tracking, consensus based formation control, behaviour and physical robot layers. The formation control system was simulated in MATLAB software before it was implemented to humanoid NAO Aldebaran robots. In the experimental study the visual odometry was used to track the robots’ position and their moving direction. The result of the experiment showed that the distributed formation control design was succeed in directing the robots into their planned formation, avoiding obstacles, and avoiding collisions among themselves with certain communication topology, shape of formation, obstacles’ position and their number.
Metro Kapsul, A New Elevated Public Transportation System For Big City
A lot of new big cities have experienced an accute traffic jam due to lack of anticipation on increasing number of vehicles on the limited length of roads they have. Adding new road or widening the existing road will be a costly solution on cities where the cost of land are already very high. An elevated public transportation system or underground train will be an alternatif solutions, but the cost to build such systems are also very high. In case of the elevated public transportation system, the construction cost of the elevated track ussually making the biggest portion of the total invesment. In this paper a new automatic control of the movement of the trains in the group that have been patented, and how this will reduce significantly the costruction cost of the elevated track will be explained.