Study On Key Technology Of Active Collision Avoidance For Underwater Vehicle

Design of active collision avoidance system is one of the core issues in the area of no-cable unmanned underwater vehicle (UUV) and intelligent underwater vehicle (AUV).The issue stems from an actual R & D projects commissioned by a company. The aim of the project is to develop a kind of unmanned underwater vehicle which is used to monitor the depth of the fairways under the jurisdiction of the company timely. When the vehicle measures in accordance with the established routes, obstacles may occur anytime in the planned route, the vehicle must have therefore taken the capabilities of active collision avoidance. The issue is an important component of the vehicle—research on active collision avoidance system. The collision avoidance system's main function is to set down the collision avoidance plan based on the on-line obstacles information received from four sonar on the front, back, right and left directions of the vehicle, in the certain risk circumstances of collision, the system provides the necessary collision avoidance information to the control system, finally the control system completes collision avoidance actively.The reliability of sonar detection is essential to the whole collision avoidance system. First of all, my issues designs a set of practical experimental programs from the sonar measurement accuracy, open angle accuracy, the impact of sonar detection accuracy of surface and underwater sonar measurements, as well as disturbance, sonar range design and other aspects, conducts on-site laboratory tests and analysis of the experimental data, to assess the performance of ESE-50 sonar, test results show that the sonar can be used for initiative collision avoidance of the underwater vehicle. Then AT89S51 is used as the control core to design and develop a sonar data acquisition and storage system through the serial port expansion chip—GM8125,to achieve the acquisition and storage of four-way(front, back, right and left) serial sonar data at the same time. In the part of collision avoidance strategic planning, firstly establish Cartesian coordinate system in the fairway, based on the four-way boat sonar detection capability, taking the head direction of the boat, the current direction, the direction and distance information of barriers as known parameters, develop a new method of determining the new navigation points. Considering the most possible collision circumstances, then designs corresponding collision avoidance strategy. Finally the whole collision avoidance strategy is implemented through software program, and simulated in the SCM system simulation. The simulation results show that the collision avoidance strategy plan can achieve simple collision avoidance for the vehicle in the fairway environment.