Journal of Unmanned System Technology (JUST, ISSN 2287-7320) is scholarly publication of research work in all relevant areas of unmanned vehicle technologies including dynamics, navigation, guidance, control and its safety verification. The editor welcomes contribution in the form of research article, review paper, brief paper as well as short communication presenting recent progress in the subject area. JUST is an open-access online journal delivered on a responsive web template. JUST is published in collaboration with International Society of Intelligent Unmanned Systems (ISIUS), Center for Unmanned System Studies (CentrUMS)- Institut Teknologi Bandung in Indonesia and Josaphat Microwave Remote Sensing Laboratory (JMRSL), Chiba University in Japan.
A Cooperative Navigation Method of Multiple AUVs for Wide Seafloor Survey –First Performance Evaluation in Sea Environments
This paper reports the sea experimental results and the performance evaluation of the cooperative navigation method of multiple autonomous underwater vehicles (AUVs). AUVs are divided into two groups: moving and landmark. Moving AUVs estimate their states (horizontal positions and heading angles) from their ground velocity, horizontal angular velocity, and acoustical positioning relative to a landmark AUV remaining stationary on the seafloor. A stochastic approach called a particle filter is adopted for state estimation. Each AUV can navigate with small drift over a wide area by alternating the landmark role. When AUVs exchange their landmark roles, they share their estimated states by compressing states with small communication traffic. The method is implemented in two hovering type AUVs (AUV Tri-Dog 1 and AUV Tri-TON 1). The method was evaluated in sea environments in November 2013. The AUVs succeeded in a cooperative navigation, alternately becoming the landmark. It was verified that the implemented method had the ability to perform the wide seafloor survey by only AUVs through sea experiments and post-processing simulation using the experimental results.
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A Comparative Study of Various Topology-based Routing Protocols in VANET
in the last decade, the vehicle flow raises faster than road infrastructure in urban areas. Consequently, traffic problems are increasing affecting people’s safety and comfort. Considering this literature, a various number of solutions is considered to deal with traffic problems using VANET. The most important issues in this field concern providing VANET routing protocols in a high speed environment. In this paper, the topology-based protocols were considered for the study. As known, the topology-based category is divided into three subcategories: reactive, proactive and hybrid. First, the principal characteristics are described and research challenges in VANET environment are discussed. Then, the performance of each topology-based routing protocol is evaluated and described in details. A comparative table of all protocols cited is, also, drawn up comparing protocols to each other. Finally, challenges and issues in topology-based routing protocols were discussed.
Agregation Scheme of Collision Avoidance Control and Formation Forming & Keeping by Topology Switching
A control agregation scheme that combines a collision avoidance controller into a consensus-based formation controller is proposed. The collision avoidance controller part is designed using kinematic model approach, while the consensus-based formation controller part uses consensus algorithm with switching topology to achive non-conflicting control solution between the collision avoidance control part and the formation control part. We also investigate how the change in communication topology affects system’s capability to achieve consensus.
Motion Planning for USV using Classification Capabilities
This paper presents an automatic method to acquire, identify, and track obstacles from an Unmanned Surface Vehicle (USV) location in marine environments using 2D Commercial Of The Shelf (COTS) video sensors, and analyzing video streams as input. The guiding line of this research is to develop real-time automatic identification and tracking abilities in marine environment with COTS sensors. The output of this algorithm provides obstacle’s location in x-y coordinates. The ability to recognize and identify obstacles becomes more essential for USV’s autonomous capabilities, such as obstacle avoidance, decision modules, and other Artificial Intelligence (AI) abilities using low cost sensors. Our algorithm is not based on obstacles characterization. Algorithm performances were tested in various scenarios with real-time USV’s video streams, indicating that the algorithm can be used for real-time applications with high success rate and fast time computation.
In the recent years, the emergence of drone industry have expanded its utilities purpose in the commercial world. When coupled with computer vision, it can provide useful analysis of the aerial image set taken from the drone, and have since benefited across various industries such as agriculture and land surveillance. For a land surveillance mission, not only does it have the possibility of producing results with higher accuracy, it will also reduce the number of manpower and time required if similar tasks were carried out manually. Singapore is known as a City in a Garden due to the huge amount of greeneries spread across the country. Many of these greeneries consists of large empty grass patch which need maintenance work by hired contractors and visual checks by agency officers every few weeks. With a few thousands site large and small, the amount of manpower required is tremendous. In this paper we propose a solution that can resolve the manpower issue and offer visual analysis through computer vision methods.
Computing Edge Version of Mec Index of Nanostar Dendrimers
Let G be a molecular graph, the edge modified eccentric connectivity index of G is defined as Λ???? (????) = ∑ ???? ????∙ ecc(????) ????∈????(????), where ???????? is the sum of the degrees of neighborhoods of an edge f and ecc(f) is its eccentricity. In this paper an exact formula for the edge modified eccentric connectivity index of a class of nanostar dendrimers was computed.
edge modified eccentric connectivity index
AXI Bus Hardware Accelerator IP for SAR Image Processor Onboard Airborne
This paper presents how a Synthetic Aperture Radar (SAR) image processor based on AXI Bus Hardware Accelerator (HA) IP was proposed and developed. The SAR image processor is targeted for use in an airborne Circularly Polarized SAR (CP-SAR) system. In the processor, The HA IP was built using software and hardware co-design approach to cater for the high computational requirement in the SAR image formation process. The IP core accelerators are based on Advanced eXtensible Interface (AXI) Bus for its highly configurable. In addition, it is easy to get integrated with another IP core through an on-chip bus and low-cost in implementation. The IP core is co-assisted by MicroBlaze softcore processor in order to accelerate the Range Doppler Algorithm (RDA) processing, which is the most commonly used algorithm for SAR image formation. The proposed SAR image processor was implemented on a Xilinx Artix-7 FPGA AC701 Evaluation Kit using multi-core hardware accelerator and configured to work on raw data with segment size of 8192x8192 pixels. Several optimization techniques such as pipelining and parallelization were applied to the initial design to speed up the processing task and to reduce the resource utilization. The functionality of the implemented SAR image processor is validated by processing a raw dataset from recorded by ALOS PALSAR sensor. The results showed that the proposed SAR imaging processor could process SAR raw data in near real-time.
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 diving 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.
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 natural forms 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.
Control of an Unmmaned Underwater Vehicles Using an Optimized LQR Method
This paper presents an optimal control synthesis for an unmanned underwater vehicle using a Multiobjectives Differential Evolution (MODE)-based LQR approach. Although the LQR control is a well-known optimal control method, the optimality of the resulting compensator is a subject of appropriate design parameters’ (Q and R) selection. Considering the complex dynamics nature of an unmanned underwater vehicle, and the need to achieve optimal compromise between several control performance objectives such as time response, control energy minimization and robustness, the conventional LQR design approach is not only potentially challenging, it is time consuming and limits the achievable performance. In this paper, the control problem is formulated as a Multiobjectives optimization problem to search for Pareto-based optimal (sub-optimal) design parameters using a MODE-algorithm. The performance evaluation of the resulting compensator in simulation shows an effective compromise between the conflicting performance objectives, while the design approach is observed to be effective in rapid prototyping and deployment of such vehicle.
The Evolution of Autonomous Vehicles at the National Oceanography Centre
The UK government considers robotics as a key future industry sector and has been an enthusiastic supporter of NOC’s use of marine robotic systems, releasing funds to enable to NOC to build the ‘MARS Innovation Centre’ to build on this leading capability, which opened in Autumn 2015 to act as the UK’s focus for marine autonomous robotic systems. Autonomous systems are steadily becoming more capable, more reliable, and are gaining longer endurance. Costs are falling as new vehicles enter the market, and the supporting sectors such as the insurance industry gain more experience of working with the operators. For unmanned surface vehicles in particular it is likely that costs will fall enough for new users such as marine environmental protection charities or fishing organizations to deploy their own systems. Military use will certainly increase as well. Gradually the dream of replacing a research ship with a robot will be achieved for a wide range of missions, greatly increasing humanity’s knowledge about the global ocean, enabling us to better-manage resources, provide early warning of geohazards or algal blooms, and adapt to changing climate conditions. NOC’s experience will feed into international capacity building and knowledge exchange activities through the UK’s actions in support of UN Sustainable Development Goals and Technology Transfer under the UN Convention on the Law of the Sea. The industry will continue to grow, and soon the idea of autonomy in the ocean will be as normal as the ubiquity of satellite communications, remote sensing and navigation.
Testing of ITB Hybrid AUV Bouyancy Engine
As part of ITB Hybrid Autonomous Underwater Vehicle (AUV) research program, we reached the stage of testing of bouyancy engine as a critical component of this vehicle. This paper describes the overview of ITB Hybrid AUV and the role of buoyancy engine in supporting vehicle operation. Step by step testing is described in detail to illustrate the working principle of this important component.
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 mini submarine. The robot is remotely controlled by a pilot. In this ROV tether is usually used to link the robot with devices such as the sea surface energy source, remote control and sensing display. This study started from the stage of modeling the body of the ROV using SolidWorks. Estimation of added mass coefficient and hydrodynamics damping was performed using first principle approach. This leads to development of the equations of motion of ROV describing its salient dynamics. Based on the mathematical model, the ROV motion in 3-D space was investigated by using MATLAB SIMULINK. The stability of the ROV was analyzed and a classical control design was performed using the PID control toolbox.
Bouyancy Engine Design and Test for ITB Hybrid AUV
Hybrid Autonomous Underwater Vehicle is the collaboration concepts between Sea Glider and Autonomous Underwater Vehicle. The specific characteristic of Sea Glider is long endurance, wide range, and limited payload or sensor to support the mission. Different from the AUV as the real surveillance underwater vehicle, they have almost the same payload and emergency system but with limited endurance and range if compared with the Sea Glider system. Dual concepts of these characteristics will be combined. The main mission for this vehicle is adopted in AUV but for submerged and surfacing mode is adopted from Sea glider concepts with their buoyancy engine. This paper describes the step-by-step method to design the buoyancy engine of this hybrid AUV. The laboratory test to validate the design and analysis will also be described.
Progress Status of ITB Hybrid AUV Development
The hybrid AUV has been developed for the last year by Center for Unmanned System Studies (CentrUMS)-ITB. The main concept of this hybrid AUV is to combine the Sea Glider concept and also the common AUV. By the sea glider concept, the buoyancy engine principal has been adopted to support the capability to manipulate the overall dynamic buoyancy from main body vehicle. By this engine, the vehicle has capability to change the state from fully afloat, neutral buoyant and fully submerged. From the common AUV concept, the ultimate survey capability has been adopted. Several sensors for underwater survey will be attached on this vehicle. This research needs multi-year to its completion. Step-by-step method has been carried out to finish the design until testing. In this paper, some progress will be shown according to multi-year project research.
Bi-Dirichlet-type Problems with Polynomial Data in A Unit Sphere in R^3
We studied Bi-Dirichlet boundary value problem of BiLaplace equation. The problem is reformulated as a systems of Laplace-Poisson equation with Dirichlet problems. We utilize an exact algorithms for solving Laplace equations with Dirichlet conditions with polynomial functions data. The algorithm requires differentiation of the boundary function, but no integration.
Joint Decision on Supplier Selection and Trajectory Tracking Control of Multi-Product Inventory System
In this paper, we develop a mathematical model to determine the optimal joint decision for an integrated supplier selection and trajectory tracking control of multi-product inventory system. We develop two models which are a model in an integer quadratic programming for a case when all parameters including the demand of all products are certain and a model in a stochastic integer quadratic programming for a case when the at least one parameter is uncertain (in this research, at least a demand parameter is uncertain with some probability distribution). Some numerical experiments are given to evaluate the models with randomly generated supply chain data. We used multi-stage programming to solve the corresponding optimization problem. From the results, for all cases, the joint decision is obtained i.e. the optimal product volume purchased from each supplier and the inventory level of each product followed the reference level given by the decision maker.
Modeling of Multi-Agent System: Equations Appearing in Collision Avoidance Control Methods
Three mainstream approaches of collision avoidance control is discussed: the potential-driven approach, the gyroscopic action approach, and velocity obstacle approach. It is found that the potential-driven approach may also deal with angular motion through the utilization of angular potential field. It is also found that the gyroscopic action approach is actually the angular aspect of the potential-driven approach. The formulation of control solution using velocity obstacle is presented, along with its geometric representation. So far in the discussion, control solution using velocity obstacle approach is most resistant to deadlock situation.
Novel phase error compensation algorithm for direct digital synthesizer chirp generator in synthetic aperture radar
This paper proposes a novel phase error compensation algorithm for the direct digital synthesizer (DDS) chirp generator of high-resolution synthetic aperture radar (SAR). The proposed compensation algorithm adopts the curve fitting method to calculate the error of transmission SAR signal called chirp. In addition, this paper proposes the polynomial modeling method during chirp generation stage to improve spectrum characteristics. The mathematical equations proposed in this paper indicate that the phase shift of chirp in time domain can be eliminated clearly. Simulation results show that the proposed compensation algorithm enhances the peak-to-side lobe ratio (PSLR) and the integrated side ratio (ISLR) up to -0.2068 dB and -0.1091 dB respectively. In addition, spur components have been reduced when compared to the spectrum output of conventional DDS output.
Self-tuning PID Parameters by using NN-GA for Cruise Control System
This paper considers the self-tuning PID parameters by using Neural Network (NN) together with Genetic Algorithm (GA) which is called the NN-GA. The NN-GA is the combination of Neural Network and Genetic Algorithm which is optimized the learning process of NN by using GA. From the simulation results, the NN-GA gives the better transient response i.e., the percent overshoot, the steady state error, the rise time and the settling time when compared with the pure NN, pure GA and PSO.
Aerodynamics Optimization of Propeller-Small Con-trol Surface of HALE UAV using Genetic Algorithm
Currently, High Altitude Long Endurance (HALE) unmanned aerial vehicle has been attracting much attention to researchers. HALE-ITB vehicle have been developed for multiyear program with the purposes of surveillance and communication operating at target altitudes of 60000 feet with endurance more than 12 hours. For starting the program, an initial configuration of the HALE vehicle has been design for a flight at altitude of 20000 feet and 2 hours flight endurance. In order to achieve this mission, the vehicle is designed to have higher aspect ratio of the wing, with lower weight. The determination of location of propellers and small controls on segmented wings become a critical issue due to aerodynamic load and thrust as well as stability of the HALE UAV. The optimum location of the propeller and control position is optimized using Simple Genetic Algorithm. The flow solution around the HALE vehicle is obtained by solving Reynolds Averaged Navier-Stokes equations. As a results, the optimum location of propeller combined with the control surface is obtained when the location is a further forward and lower position and increasing the control surface size. This yields higher aerodynamic characteristics and give better longitudinal stability.
propeller and small control surface position
Implementation of a PID-Control Algorithm on a Hardware Quadcopter System using dSPACE Platform
Whilst different techniques have been explored for designing quadcopters, like other helicopters, the onus of navigating quadcopters rest upon using an efficient controller for controlling all its available DOF. Designing a rugged and robust universal control-system for quadcopter, in the face of environmental disturbances and uncertainties, are challenging task for control-engineer. It is universally agreed that simulation and software models are not exact representation of physical systems and their behaviors. This paper goes behind modeling and simulations of quadcopters and it controller; it present a real-time hardware demonstration of a quadcopter and it controller. In this paper a quadcopter and a PID-controller were modeled mathematically and designed in MATLAB/ SIMULINK. A hardware quadcopter prototype was also constructed. A real-time implementation of the PID-Control algorithm on the hardware Quadcopter by dSpace1104 R&D controller-board; via the quadcopter Simulink model
Analysis of Vivaldi, Rectangular, Bow-tie, and Quasi-Yagi Antenna Performance for S-Band FMCW-SAR on UAV Platform
Frequency Modulated Continuous Wave (FMCW) radar uses continuous signal that can change its frequency along the measurement in its detection process. The developed FMCW radar will be combined with Synthetic Aperture Radar (SAR) technology that uses signal processing algorithm to improve the resolution of the output image beyond the limitation of physical antenna and will be mounted on the Unmanned Aerial Vehicle (UAV). On this paper, the performance of Vivaldi, rectangular, bow-tie, and quasi-Yagi antenna will be analyzed to determine which antenna is best used in the developed system. The developed FMCW-SAR radar has an operating frequency of 2.4 GHz (S-Band) and requires an operating bandwidth of 80 MHz to send and receive the continuous signal. All of the developed antennas are made using FR4 Epoxy material with permittivity of 4.3 and height of 1.6 mm and each of it was able to meet these specifications. For the developed FMCW radar system, rectangular antenna will be chosen to be improved with consideration of the available space for installation of the antenna.
Techniques for Quadcopter modeling and Design: A Review
Quadcopters modelling research has cease or almost at a halt, compared to its controller counterpart, which has received all the attention and continue to receives more research attention. While controller design seems to be viewed as a way of addressing the inherent problems peculiar to quadcopters by ways of controlling it, it no surprising to see that a lot of previous research failed to address this inherent practical problem. This paper reviews the most effective techniques widely used by researchers for modelling & designing quadcopters only and not it controller. Rotor modelling in conjunction with aerodynamic effect, parametric identifications were reviewed and analysed. As a demonstration, a quadcopter modelled was developed via voltage manipulation approach for this review, likewise PID controller. Taylor-series first-order approximation was used to linearize the developed non-linear model so that linear PID controller can be used to test the model. This model the author envisage to discuss with Mathwork Inc. for its incorporated as into the Matlab software as a quadcopter Simulink-block; for which different controllers can be directly interfaced to (with little as required design modification to the helicopter block model or no modification at all). This, the author believes will aid further study of the inherent research problems associated with quadcopter.
Conventional Unmanned Aerial Vehicle (UAV) formation requires radio communication between the UAVs and the ground control station. However, noise and interruption in the communication links may result in severe consequences. In this paper, vision-based line formation is introduced to eliminate the problems mentioned earlier. Individual UAV with a camera on-board can detect its neighboring UAVs by implementing the concept of the Histogram of Oriented Gradients (HOG) descriptors and cascade classifiers. Image processing such as removal of shadow is applied to improve the detection rates. Upon successful detection, the Leader-Follower formation theory is applied to allow the follower UAV to distinguish and follow the path of the leader UAV. Lastly, to control the movement of the UAVs, a flight controller is designed and implemented on Simulink, based on the line formation requirements.
Design and Prototyping of an Autonomous Un-Guided Vehicle (AuGV) for Hazardous Areas Usage: Moon Rover Space Exploration Vehicle Prototyping
This paper present the design and prototyping of an AuGV capable of navigating & avoiding obstacles in its path whilst it simultaneously calculate the shortest or best route to achieve the primary task for which it is designed for, i.e. deploying it solar-panel on locating a spot of brightest light intensity. While most AGV (Autonomous Guided Vehicle) journal papers focuses on simulations and abstract ideas, this paper focuses on the development of an actual working prototype (with emphasizes on hardware such as controller, subsystems as well as the various communication protocols which were incorporated to link the various the subsystems together and to effectively transfer data and information control). Decentralized embedded system solution was used to achieve the objectives of this project; while the test environment, obstacles in path, etc. are not known to the AGV neither were they incorporated in the programming of the AGV controller. A fully functioning prototype was built, tested and it results presented herein as well as video demonstration
Light-Sensing & Deployment of Solar-panel
SAR Image Processing Based on the LEON3 Multiprocessor for CP-SAR onboard Microsatellite
The SAR imaging processor is an essential part in SAR system to produce the final SAR image quality that used for various remote sensing applications. In this paper, we propose the design and describe the development of onboard SAR image processor based on LEON3 softcore multiprocessor implemented on FPGA board. The proposed SAR image processor is targetted to used for future onboard Unmanned Aerial Vehicle (UAV) and microsatellite of Josaphat Microwave Remote Sensing Laboratory (JMRSL). The system-on-chip (SoC) approach has been used for highly configurable, easy to integrate with other IP core through an AMBA on-chip bus and low-cost implementation. The open hardware LEON3 multiprocessor has been configured to meet the system requirement to aim at high-performance processing. The implementation of the proposed SAR image processing is targetted on an Altera Cyclone IV FPGA family and Xilinx Artix-7 FPGA AC701 Evaluation Kit. The RDA algorithm is implemented as software to run on the LEON3 Multiprocessor, and the functionality validated using the ALOS PALSAR raw data. The preliminary results show that the functionality of the system successfully works and can compress the SAR raw data into an SAR image, whereas the processing speed needs to be improved. The proposed design promises to answer the problem of SAR image processing in the future with a low price.
Implementation and Testing of Low Power FMCW S-Band Radar System Design for Small UAV
Abstract—The paper importantly discuss about design of low power Frequency Modulated Continuous Wave (FMCW) S-Band (~2.3GHz) radar system, and then the implementation and testing procedure. The main system of FMCW S-Band radar consists of a ramp generator, a Radio Frequency (RF) System, and an audio amplifier. The ramp signal is generated from IC XR-2206 (modulator). This ramp signal is connected to a voltage-controlled oscillator (VCO), one part of RF system, to produce a chirp signal with varying frequencies as a result of inclined voltage signal (ramp signal) generated by modulator. Besides VCO, in RF system there are also signal amplifier (either for transmitting signal or receiving signal), splitter signal (for transmitting purpose) and mixer (for receiving purpose). Audio amplifier consists of a gain stage/amplifier and two-stages 15 KHz active Low-Pass Filter (LPF) which are applied to process the signal from RF mixer’s output before being acquired through audio jack. At the front end of the system, two Vivaldi Antennas with 4dBi gain are installed and act as transmitter and receiver. The system is tested to detect simple corner reflectors placed in an area. The future application of this light weight and low power FMCW radar system is able to be mounted on a small Unmanned Aerial Vehicle (UAV) to do myriad tasks such as forest survey, crop monitoring, and reconnaissance.
Design, Manufacture and Testing of Unmanned Ground Vehicle for Field Service Operation
This paper was describe the concept, modelling, simulation, fabrication and testing of an Unmanned Ground Vehicle (UGV). This UGV was to be used in field service operation. It had to be able to operate in hazardous environment and various terrain. In our work, we had developed a small vehicle equipped with belt track and flipper that can be controlled remotely.
Arduino-Based Altitude and Heading Control of a Flapping Wing Micro-Air-Vehicle
This paper presents the development of hardware module to perform versatile flight controls of flapping wing micro air vehicles (FWMAVs) or ornithopters. Firstly the authors survey the developed avionics, including the configurations of full integration and with discrete components, respectively for flight and control of FWMAVs in the literature. MEMS micro-barometers and micro-compass are frequently interfaced with a microcontroller to determine the altitude and orientation of FWMAVs. Herein a custom-developed printed-circuit-board (PCB) is also integrated with an inertial-measurement-unit (IMU) and a barometer to obtain constant altitude of the air vehicle. The heading of the FWMAV is controlled using a micro-compass with reference to magnetometer direction in the IMU. Simulation and hardware testing were carried out using an ATmega-328Pmicro-controller onboard. The result confirms that the proposed control system can be adopted to control the FWMAVs efficiently some comments on the necessity of integration about the control avionics are also addressed.