Autonomous Underwater Vehicle Analysis

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Abstract : This paper presents a practical implementation for simulating the pitching and yawing motions of an autonomous underwater vehicle (AUV) and its consequent control using an ARM based SBC Friendly ARM mini2440. A rotary encoder and adxl303 triple axis accelerometer has been used to measure the position and acceleration respectively. The emphasis of this paper is given on the interfacing of the sensors with Friendly ARM mini2440 and the resultant control algorithm implemented on the embedded platform to control the designed testbench. The control algorithm implemented is PID control. It is to be noted that the entire project was done to study the movements of an underwater vehicle and the ensuing control strategies and the prototype …show more content…
Introduction: Autonomous Underwater Vehicles have emerged as a key research area, mainly in the fields of deep sea surveillance. AUVs are being extensively used by the oil and gas industry for sea floor mapping, and also as a means to study deep sea bio-diversity. With the advancement of robotics and control engineering theories, it has been possible to make underwater vehicles more and more autonomous, enabling them to operate with minimal human intervention.
Though many advanced control techniques have been developed, and shown to work very well theoretically, their practical implementation in real time systems is still an open field of research. In this paper we present a practical implementation scheme of PID control strategy on a system which has been mechanically modelled to simulate the basic movements of an underwater vehicle. The movements which have been simulated in this study are the pitching and the yawing or the heading movements. The mechanics of an underwater vehicle have been related with the system under study and has been presented in section 2. Adxl 330 sensors have been used in this project. This is basically a triple axis accelerometer, whose readings have been
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The kernel can be compiled using the command # make zImage Follow steps 1 to 6 to activate other adc channels thereby creating a new c source code file each time. Figure 5: Bottom up flowchart of hardware-software integration

Figure 6: Flowchart representation of application program
4. Control System Design: The most important part of designing a controller is to find a proper mathematical model representing the entire system. It is desired from the control system design aspect, that the pitching and yawing movements of the vehicle be completely decoupled. The generic block diagram of the subsystems is as given below

Figure 7: Block diagram representation of the control system
The actuators used for this project are dc motors. The mathematical model of the motors has been derived, without considering the motor inductance. The load driven by the motor is the vehicle mass for the pitch subsystem. The load driven by the heading control motor is the sum of the support link mass and the mass of the pitch subsystem. Figure 8: Simulink block diagrams for yaw and pitch subsystems Figure 9: Response of the pitch subsystem to step

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