Dynamic Characteristics Analysis And Stability Study Of Joint-Wheel Pole-Climbing Robot

The pole-climbing robot is widely used in the detection and maintenance of pipeline structures such as petrochemical plants,nuclear power plants,power line towers and suspension bridges,so as to improve poor working environment,the inability to ensure personal safety,and low construction efficiency faced by workers.Because the pole-climbing robot exhibits broad application prospects,it has gradually become a hotspot in the research of special robots at home and abroad.In view of the contradiction between the obstacle negotiation and the load of the current pole-climbing robots,a two-stage joint-wheel pole-climbing robot with good obstacle negotiation and load capacity is designed in this paper,which integrates the advantages of joint climbing robot and wheeled climbing robot.It is of good stability,which can actively clamp pipes of different diameters and achieve self-locking.At the same time,it can overcome common kinds of pipeline obstacles.The main research work is as follows:1.The structure,climbing gait,dynamic characteristics and motion stability of different types of pole-climbing robots at home and abroad are compared and analyzed,so the characteristics of different types of pole-climbing modes are summarized.Then a new joint-wheel pole-climbing robot is designed,and the design of main parts is introduced.2.The kinematics and dynamics modeling of the robot are carried out,and the elastic wheel force analysis is carried out based on the steady-state cornering properties.Based on Adams,the overall dynamics model of the pole-climbing robot is established,and the kinematics and dynamics characteristics of the robot are analyzed.3.Using ANSYS Workbench to analyze the free and constrained modes of driving wheel,the frequency range of normal working of the robot is obtained.The static nonlinear finite element analysis of the contact between the driving wheel and the pipe is carried out,therefore,the distribution of the overall stress,strain and normal stress and friction in the contact area are obtained,which verifie the rationality of the driving wheel.Then,the stress distribution of the driving wheel is obtained by the transient dynamic nonlinear finite element analysis of the robot climbing along the axial direction on the vertical pipe.The research conclusions lays a foundation for the optimization of the driving wheel and the research of the robot's motion stability.4.The concept of robot motion stability is put forward,and the axially rotating angle in the climbing process of the robot is selected as the key research object,so the relationship between clamping force,rolling friction coefficient,moving speed and rotating angle and driving torque is obtained.Considering the appropriate clamping force,rolling friction coefficient,moving speed and driving torque,the above parameters are set in Adams to simulate the obstacle negotiation of the robot on conical tube,flange and T-shaped pipe.Finally,the simulation results prove the rationality of the obstacle negotiation ability,load capacity and the overall design.