Research On Path Tracking Control Method Of The Crablike Robot

In recent years,the shoal zone connecting the ocean and the land has gradually attracted the attention of marine science fields such as seabed resources exploration and development,environmental survey,scientific research,etc.However,the adaptability of traditional robots in the complex wading environment of the region is poor,which further promotes the development of robotic technology adapted to shoal operations.The crab-like robot with amphibious operation ability can play a good role with its own advantages.Whether performing specific tasks or conducting reconnaissance operations,appropriate control methods are needed to ensure that the robot can move accurately and efficiently according to the planned route.In this paper,a crab-like robot with amphibious motion ability is developed based on biological observation and bionic analysis of its structure and function.The path tracking control of the robot is carried out by using Active Disturbance Rejection Control method.Based on bionics,the structure design and motion modeling of the crab-like robot are carried out.By observing and analyzing the physiological structure and motion characteristics of sea crab,the walking foot of five-bar linkage mechanism with series-parallel connection and prototype of seacrab-like robot were designed.The kinematics equation of the walking foot is established,and the forward and inverse kinematics calculation are performed.At the same time,the motion model,differential drive model,whole machine motion model and simplified dynamic model of the crab-like robot are established.Then combined with the global gait of multi-foot robot,the relationship between pose,motion and each drive joint is obtained,and the simulation software is used to verify the rationality of the design scheme and the accuracy of kinematics modeling.Aiming at the kinematic analysis of the crab-like robot to move in amphibious environment,the underwater environment dynamics,the relationship between the body motion and walking foot force and moment in water environment,and the restraint of the robot to withstand submarine friction are analyzed.Intelligent method is applied to global path planning of crab-like robot,and grid method is used to build environment model.The improved ant colony algorithm is used to complete intelligent path planning of crab-like robot.Considering the non-holonomic constraints,mechanical constraints and underwater motion characteristics of the robot,a method of generating temporary path is proposed to meet the requirement of fast walking of the robot in amphibious environment.According to the characteristics and motion model of the crab-like robot system,the traditional line-of-sight navigation strategy is improved,and the output of the reference course angle is adjusted.The error equation of the position and attitude of the crab-like robot during path tracking is established.The path tracking controller of the crab-like robot is designed by using the Active Disturbance Rejection Control Technique.The wavelet neural network is added to the second-order ADRC to improve the performance of ADRC and enhance the anti-interference ability of the whole robot control system.The tracking error,anti-disturbance ability and stability are simulated and analyzed.The path tracking motion of the crab-like robot is simulated,and the positioning error of the control system is simulated and analyzed to verify the correctness,accuracy and anti-disturbance ability of the whole crab-like robot system.The motion simulation of a crab-like robot based on ordinary ADRC and wavelet neural network ADRC is compared and analyzed.The results show that the ADRC based on wavelet neural network has good dynamic characteristics and stronger ability to suppress interference,and has better control effect.