Research On Attitude Control And Path Planning Of The Underwater Spherical Robot BYSP3

This thesis "Research on Attitude Control and Path Planning of The Underwater Spherical Robot BYSQ3" is a follow-up study of the Natural Science Foundation of China Project "Design and Research on an Amphibious Spherical Robot"(No.51175048).This paper deals with the underwater spherical robot BYSQ3 of Beijing University of Posts and Telecommunications.Not only conducting research on attitude control based on modeling in different plane,but also on the method of path planning and course keeping in actual marine environment.The main research contents of this paper are as follows:(1)The mathematical model analysis of the underwater spherical robot BYSQ3 in different plane is completed.The dynamics model is decomposed into three perpendicular planes,including horizontal plane,longitudinal vertical plane and cross vertical plane.Which effectively reduce the computation burden of the modeling analysis and simplify the model.(2)This paper designs an improved fuzzy PID controller,in which the fuzzy control and PID are combined and the three parameters of PID are modified by fuzzy decision.The advance and retreat experiment in horizontal plane was simulated in MATLAB.Besides,the diving and surfacing experiment was simulated in longitudinal vertical.(3)The path planning method of underwater spherical robot in multi-obstacle marine environment is studied.First of all,the marine environment is imitated and obstacles are expanded.The algorithm uses the trunk binary tree structure to construct the path search space and finds a evaluation standard path in the search space.Then the improved particle swarm algorithm is used to optimize the path in sections.This path planning method considere obstacles factors as well as the influence of current size and direction on energy of navigation consumption.(4)To solve the course-keeping problem in actual motion process after path planning,this article puts forward a algorithm based on the backstepping sliding mode control.The detailed theoretical derivation is carried out and the stability of the system is proved by using lyapunov theory.The effectiveness of the control method for the course control of the underwater spherical robot is verified by using MATLAB.(5)It conducts the attitude control experiment and course keeping experiment of the underwater spherical robot BYSQ3.Including pitch angle,yaw angle experiment and the forward motion course-keeping experiment in high or low speed.Gyroscope raw data is recorded and the error sources are analyzed.