Research On Trajectory Tracking Control Of Steel Structure Building Inspection Flexible Robot

Traditional steel structure building monitoring methods have the problems of time-consuming,labor-intensive,incomplete and inaccurate detection.Therefore,this paper uses a magnetic adsorption flexible flaw detection robot for steel structure health monitoring.This flexible flaw detection robot has two front and rear car body parts,each of which has two powerful magnetic wheels,which are driven by differential speed,and the front and rear car bodies are connected by a flexible and deformable flexible steel belt.Such a structure enables the robot to have the ability to overcome various spatial structural obstacles,and detect different parts of the steel structure by carrying related equipment.Flaw detection robot is a mobile robot with special structure and function.Trajectory tracking control is one of its basic tasks and the key to research.Based on the structural characteristics of flexible robots and the mechanical analysis of flexible steel strips,a trajectory tracking error model for flexible flaw detection robots is proposed in this paper.Based on this system model,a new and improved sliding mode controller is designed,which solves the problems of complex control structure,unsatisfactory tracking speed and insufficient tracking accuracy of the steel structure flaw detection robot in trajectory tracking control.The research work and results of this article are as follows:1.Firstly,from the perspective of the structural characteristics of the flexible flaw detection robot,the motion shape of the robot is analyzed,and the front and rear car bodies are regarded as two-wheel-drive mobile robots respectively,and its kinematics model is established according to non-integrity constraints.The flexible robot is characterized by the flexibility of the steel belt connecting the front and rear car bodies.Based on the theory of elastic mechanics,the relationship between the deformation of the steel belt and the motion of the front and rear car bodies is analyzed.Based on the Euler Bernoulli beam equation,the speed constraint equation between the front and back of the flexible robot is established.The kinematic model of the mobile robot and The velocity constraint equation establishes the trajectory tracking error model of the flexible robot as a whole.2.Aiming at the problem of trajectory tracking control of flexible flaw detectionrobot,it is concluded that the flaw detection robot system is a complex coupled system with multiple inputs and multiple outputs.A sliding mode control method is proposed to realize the robot trajectory tracking.First,a backstepping design method is used to design a trajectory tracking controller based on the traditional sliding mode approach law.Based on the analysis of the shortcomings of the traditional sliding mode reaching law,an improved sliding mode reaching law is proposed,and a new trajectory tracking controller is designed by using this sliding mode reaching law.Then the stability analysis of the improved sliding mode controller is carried out to verify the stability of the controller.After decoupling the front and rear vehicle body linear velocity and angular velocity control output from the trajectory tracking controller,the rotational speed control amount of the front and rear vehicle body driving wheels is obtained,and then the digital PID regulator is used to control the rotational speed of the driving wheels,and finally the robot trajectory tracking control is realized.3.ATMega128 high-performance processor is used as the core to build the control system hardware platform of the flaw detection robot.Aiming at the characteristics of the flexible robot,a scheme is proposed in which the control system circuit board is mounted on the front and rear car bodies,respectively,and a frame diagram of each functional module is constructed.The robot control system mainly includes a core control module,an input-output module,a power module,and a wireless communication module.The PCB was drawn according to the schematic diagram of the control system,and the circuit board was processed to make the robot control system.4.The trajectory tracking simulation of a flexible flaw detection robot was performed with a sliding mode controller based on the traditional approach law and a sliding mode controller based on the improved approach law.By comparing and analyzing the simulation results of the two,it is verified that the improved sliding mode controller can realize the trajectory tracking of the flexible flaw detection robot,and is more stable,the tracking speed is more block,the tracking accuracy is higher,and the control performance is better.Based on the designed control system,a prototype experimental platform for a steel structure flaw detection robot was built,and the effectiveness of the digital PID wheel speed controller was verified on this platform.