Showing papers by "Zoran Vukić published in 2007"
01 Jan 2007
TL;DR: In this paper, an identification method based on induced self-oscillations, which has proved to be applicable to underwater vehicles, is presented, and an error analysis for the proposed method is presented.
Abstract: Given the fact that AUV dynamics change depending on the payload, finding a mathematical model in a rather small period of time is quite important. Classical openloop identification methods give accurate parameter identification, but are also time consuming. In the paper we present an identification method based on induced self-oscillations, which has proved to be applicable to underwater vehicles. In addition to that, an error analysis for the proposed method is presented. Experimental results obtained on an underwater vehicle are given and compared to the results obtained using open-loop identification algorithms.
21 citations
27 Jun 2007
TL;DR: The work presented in this paper deals with the process of transfer function identification by using self-oscillation method (autotuning identification method) in a general matrix form and some modifications are introduced.
Abstract: The work presented in this paper deals with the process of transfer function identification by using self-oscillation method (autotuning identification method). The algorithm is given in a general matrix form and some modifications are introduced. The modifications of the algorithm include augmentation of the initial algorithm for Type k systems, systems with delays and discrete-time systems. The paper also includes simulation examples which describe the introduced modifications. Apart from being rather simple, this method is applicable to real systems. Its greatest advantage is quick identification of a transfer function (depends on the system).
15 citations
18 Jun 2007
TL;DR: In this article, the authors presented the procedure for identification of coupled mathematical models for underwater vehicles, with the use of a simple laboratory apparatus that consists of a Webcam placed above the experimental pool.
Abstract: The paper presents the procedure for identification of coupled mathematical models for underwater vehicles. The procedure is performed with the use of a simple laboratory apparatus that consists of a Webcam placed above the experimental pool. The video recording of the underwater vehicle in motion is then analyzed in order to obtain relative speeds within the camera frame. The experiment uses a simple maneuver which excites the vehicle in all controllable directions (in the horizontal plane). The results have shown that even though the system under observation is nonholonomic, the sway motion occurs due to coupling. This allows for determination of dynamic model in uncontrollable directions. The experimental data also show which terms in a general dynamic model can be omitted when dealing with micro underwater vehicles, in order to preserve the simplicity.
13 citations
01 Jan 2007
TL;DR: The architecture of autonomization of the VideoRay Pro II ROV together with its technical specifications is presented and a procedure for open-loop identification of the nonlinear yaw model is presented.
Abstract: The Automarine Module is a simple cost effective method for transforming underwater remotely operated vehicles (ROVs) into autonomous underwater vehicles (AUVs), with minimum development time, and with no ROV circuit alteration. This paper presents architecture of autonomization of the VideoRay Pro II ROV together with its technical specifications. The paper also presents a procedure for open-loop identification of the nonlinear yaw model. Analytical expressions that are used for model identification are also provided.
12 citations
27 Jun 2007
TL;DR: This paper shows, on the basis of extensive simulated experiments, that such a trajectory planner based on virtual potentials, guarantees good extendibility, scalability and performance in a hard-real-time hardware-in-the-loop system.
Abstract: This paper deals with an analysis of applicability, capabilities, benefits and pitfalls of using a virtual potential field approach to autonomously planning trajectories in non-communicating autonomous underwater vehicles (AUV-s). Virtual potentials represent an approach to this problem with cross-layer design features. Examples of different layers of control that can be achieved with the same fundamental approach are: obstacle-avoidance, energy-optimal trajectories, forming up with other moving agents, controlled formation fragmentation into well-posed sub-formation etc. This paper shows, on the basis of extensive simulated experiments, that such a trajectory planner based on virtual potentials, guarantees good extendibility, scalability and performance in a hard-real-time hardware-in-the-loop system.
11 citations
TL;DR: In this article, a trajectory planner for an autonomous, non-communicating submerged vehicle (AUV) is proposed based on virtual potentials, an approach that guarantees good extendibility, scalability and performance in a hard-real-time hardware-in-the-loop system.
10 citations
Proceedings Article•
01 Jan 2007
TL;DR: In this article, the authors presented the procedure for identification of coupled mathematical models for underwater vehicles, with the use of a simple laboratory apparatus that consists of a webcam placed above the experimental pool.
Abstract: The paper presents the procedure for identification of coupled mathematical models for underwater vehicles. The procedure is performed with the use of a simple laboratory apparatus that consists of a webcam placed above the experimental pool. The video recording of the underwater vehicle in motion is then analyzed in order to obtain relative speeds within the camera frame. The experiment uses a simple maneuver which excites the vehicle in all controllable directions (in the horizontal plane). The results have shown that even though the system under observation is nonholonomic, the sway motion occurs due to coupling. This allows for determination of dynamic model in uncontrollable directions. The experimental data also show which terms in a general dynamic model can be omitted when dealing with micro underwater vehicles, in order to preserve the simplicity.
4 citations
01 Jan 2007
TL;DR: In this paper, the authors present a low cost way for underwater vehicle positioning in places like pools, tanks, water towers etc. The developed application calculates a 2D position using only a simple scanning sonar and a digital compass.
Abstract: A major percentage of underwater operations takes place in structured environments. This article presents a low cost way for underwater vehicle positioning in places like pools, tanks, water towers etc. The developed application calculates a 2D position using only a simple scanning sonar and a digital compass. A user interface has also been designed for this purpose. Various modes of sonar scanning were tested in a circular pool and the analysis of the results is presented here.
4 citations
01 Jan 2007
TL;DR: In this paper, the authors explored the forming-up, robustness of the ensuing formation and coordinated movement of autonomous, non-communicating submerged vehicles planning their trajectories using a virtual potential fields method.
Abstract: This paper explores the forming-up, robustness of the ensuing formation and coordinated movement of autonomous, non-communicating submerged vehicles (AUV) planning their trajectories using a virtual potential fields method The behavior and characteristic merits and problems of the proposed scheme, which plans the trajectory on the basis of AUV kinematics is tested in 2D simulations A brief commentary on further avenues of research and improvement in order to make the method applicable to hardware-in-the-loop usage is given
3 citations
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TL;DR: The ROV simulator was developed as modular structure with the possibility of connecting signals received from the real ROV to the simulator, and the kinematics of the ROV was implemented for simulator needs.
Abstract: The ROV simulator was developed as modular structure with the possibility of connecting signals received from the real ROV. Programming language VRML helped in developing a 3D model of the ROV and the interaction between the ROV and the virtual world has been achieved. The kinematics of the ROV was implemented for simulator needs. The simulator menu offers different virtual environments. The simulator has different additional possibilities such as: gripper management, realistic illumination and camera manipulations.
3 citations
01 Jan 2007
TL;DR: The Automarine Module as mentioned in this paper is a cost effective method for transforming underwater remotely operated vehicles (ROVs) into autonomous underwater vehicles (AUVs), with a minimum development time needed.
Abstract: The Automarine Module is a cost effective method for transforming underwater remotely operated vehicles (ROVs) into autonomous underwater vehicles (AUVs), with a minimum development time needed. An existing ROV can easily be transformed in an AUV with no alteration of its interior, thus retaining the ROV mode of operation by simply disconnecting the module. The Automarine autonomization module described here has been developed for the VideoRay Pro II ROV, and the same idea can easily be applied on any other ROV.
02 Jul 2007
TL;DR: The behavioural cloning approach is applied to design the vehicle controller and virtual obstacle is used also in the goal position reaching of the autonomous vehicle in environments with unmoving obstacles.
Abstract: The problem of dynamic path generation for the autonomous vehicle in environments with unmoving obstacles is presented. Generally, the problem is known in the literature as the vehicle motion planning. In this paper the behavioural cloning approach is applied to design the vehicle controller and virtual obstacle is used also in the goal position reaching. In behavioural cloning, the system learns from control traces of a human operator. To learn from control traces the machine learning algorithm and neural network algorithms are used. The goal is to find the controller for the autonomous vehicle motion planning in situation with infinite number of obstacles.