Research On AUV Intelligent Obstacle Avoidance Strategy

In recent years,with the rapid development of computer,automatic control,artificial intelligence,microelectronics and other technologies and the improvement of refined operation requirements,autonomous underwater vehicle(AUV)has made remarkable progress in underwater survey,marine research and other fields.AUV integrates the mechanical structure,sensors,conversion and propulsion,inertial navigation,power supply system,troubleshooting control and other system professional technologies.Its technical indicators are far beyond the general driverless car,and it is the wind vane of electrical engineering and automatic control.In order to meet the needs of complex underwater environment and precise control of AUV attitude,a new AUV system is designed in this paper.The obstacle is identified by sonar,and the obstacle avoidance strategy is formulated to achieve accurate obstacle avoidance of AUV.There are four propellers in the tail of the system,which are arranged in X-shape;four propellers have no rudder;four propellers and fairings in the tail are controlled to realize attitude adjustment.Finally,according to the design requirements,a prototype of AUV is made,and the accuracy and effectiveness of the AUV system are verified by MATLAB simulation and underwater experiment.First of all,this paper briefly introduces the main technical specifications of the new AUV and the structure of the system,including sonar system,control and communication system,attitude adjustment system.Then,the working principle of each component structure of the system is described.The system identifies obstacles through sonar,and transmits information to the control system.The control system sends instructions to the attitude adjustment system according to the control strategy.The attitude adjustment system controls the motor to complete the direction change of AUV,and finally achieves the goal of avoiding obstacles.Secondly,aiming at the obstacle avoidance task of AUV,the model of AUV system is simulated by MATLAB,including virtual obstacle model,controlled object model,motion direction model,obstacle recognition model,motion endjudgment model,etc.According to the established model,an obstacle avoidance strategy based on PID controller is designed.After that,the feasibility of obstacle avoidance system is verified by setting single or multiple obstacles in Matlab platform.The simulation results show that the proposed obstacle avoidance strategy and the designed controller have good effectiveness and can achieve the expected goal.Finally,the AUV prototype is designed,which is composed of the main control hardware platform and software control system based on stm32f722.The equipment of the obstacle avoidance control system is debugged and tested in the pool and by the river.Through the underwater experiment,the good performance of the whole obstacle avoidance system is verified,which meets the needs of the actual project.