Design And Motion Characteristics Of PGR-Ⅳ Tube Outer Wall Crawling Robot

Aiming at the problem of long maintenance cycle and difficulty in detecting and maintaining the furnace tubes of slender intersection heating furnace in chemical plants,this paper proposes a crawling robot on the outer wall of the tube using wheel-driven and segmented gravity self-locking technology.The robot can adapt to the load gravity change,pipe bending and pipe diameter change,and has good motion passability and stability.Based on TRIZ theory,this paper analyzes and solves the problems in the field application of PGR-II gravity self-locking tube outer wall crawling robot,sorts out and evaluates the innovative technical scheme,and determines that the design technical scheme of PGR-IV.tube outer wall crawling robot is a segmented tube outer wall crawling robot based on gravity self-locking,and the three-dimensional structure modeling and assembly are completed.Furthermore,the structure of the robot was simplified,the static model was established,the force analysis of the whole,drive and body section of the robot under equilibrium working conditions was carried out,the driving and adhesion conditions of the body were studied,and the finite element check and modal analysis of the main components were carried out,which verified the rationality of the structural design.The virtual prototype model of the robot was established by using the ADAMS dynamic simulation platform,and the dynamic characteristics of crawling on the outer wall of the robot tube were studied.The controllable variables of the body were parameterized,and the influence of the changes of controllable parameters on the crawling and self-locking characteristics of the outer wall of the body tube was analyzed.Aiming at the working scenarios of vertical,curved and variable diameter pipelines,the crawling dynamics of the outer wall of the robot pipe are simulated,and the simulation results show that the current technical scheme can realize the stable crawling of vertical pipelines,and has good adaptability and passability to bending and variable diameter working conditions.The design and analysis of the crawling motion strategy of the outer wall of the robot tube were carried out.Aiming at the gripping control and drive control,the body gripping force control strategy based on fuzzy system controller and the body climbing speed control strategy based on RBF neural network supervised PSO-PID controller are respectively designed.A joint simulation model of ADAMS and Simulink was established.The motion control strategy was simulated and analyzed for the variable path crawling condition.The results show that the robot can complete the gripping force and speed regulation through the information feedback of the fuselage sensor during the crawling process,and adjust the position of the robot’s master-slave lead screw slider and the angle of the auxiliary wheel during the reducer crawling to reduce the horizontal offset of the body section,and at the same time reasonably regulate the speed of the driving wheel,so that the vertical climbing speed of the fuselage is stable at the desired level.