Research On Optimized Control Method Of Wall-climbing Robot Based On Steel Wall

Wall climbing robot is a special branch of the robot research field,because of its particularity on the wall,not only greatly expands the scope of application of the machine and can significantly reduce the risk of manual operation.It has an important application in the detection of the petrochemical industry and other large equipment defects in petrochemical storage tank.In this paper,a control system of wall climbing robot is designed which based on the permanent magnetic adsorption theory and the theory of kinematics and dynamics of wheeled wall climbing robot,itshas strong adsorption capacity,high safety performance,flexible movement,small volume and light weight etc..The main research work of this paper is as follows:1.Complete the design of mechanical structure and adsorption mechanism of the wall climbing robot,using variable gap type NdFeB permanent magnetic adsorption structure with sliding bearing strengthen adsorption mechanism stability;completed the design of wall climbing robot control system hardware circuit,using STM32F103C8T6 minimum system as the core of the control system.The system serves as the control center of the system and completes trajectory tracking operations with the assistance of sensors such as the MPU6050.The stepping motor is used to control the adsorption distance to achieve a stable crawling and movement of the wall-climbing robot on the wall surface.2.The finite element 3D model of the permanent magnet adsorption mechanism was established using Ansoft Maxwell finite element analysis software.The steps of material property setting,meshing,solution parameter setting and post-processing were performed.the adsorption force under the conditions of different adsorption spacing and wall material were analyzed,and obtained the adsorption force variation law curve and the magnetic force distribution figure.3.The generalized kinematics equation of the four-wheel-drive wall-climbing robot is obtained through the theory of degree of freedom feature of wheeled mobile robots.The actual kinematics equation of the wall-climbing robot is established in combination with the rigid-body motion relationship;when the wall-climbing robot is moving,the supporting force of the drive wheel,as well as the lateral and radial friction forcesis analyzed,,then combines the moment balance equation,introduces the uncertainty of the system model,and based on the Newton-Euler methodestablished the dynamic equation of the wall-climbing robot in the wall coordinate system.4.Based on the wall-climbing robot kinematics equations,the back-stepping,feedback gain back-stepping,sliding mode controller and incremental PID sliding mode fuzzy controller were designed respectively.Incremental PID sliding mode fuzzy controller passed incremental The PID control method establishes the sliding mode control approach rate,combines the designed sliding surface switching function to obtain the control law,and uses the fuzzy control to adjust the PID parameters.Based on the dynamic equations,the sliding wall adaptive controller and the sliding mode fuzzy adaptive controller are designed,both of which use the kinematic back-stepping controller speed output as the virtual input for sliding mode control and the adaptive method to estimate the uncertain parameters of the dynamic model,both using the Lyapunov function stability criterion The systematically asymptotically stable is proved,but the latter adds a fuzzy control method to adjust the sliding mode gain and improves the convergence time.5.Finally,a wall-climbing robot test system was built and the entire control system was tested.It mainly includes the adsorption force test and the trajectory tracking test.The wall-climbing robot's adsorption force test experiment was completed and compared with the simulation data.The trajectory tracking experiment was completed using the back-stepping control method.