Research On Coupling Dynamics Of Cable And Inspection Robot In Vibration Environment

The cable inspection robot is a professional service robot used to replace the inpectors to detect the surface damage and internal broiken wires of the cable-stayed bridge,thereby reducing the risk and cost of manual inspection,and improving the quality and efficiency of the inspection.However,as the span of cable-stayed bridge becomes longer,highly flexible and length cables may produce different forms of vibration under the action of wind loads and ground moving vehicles.Through vibration experiments in this paper,it is found that the robot skids when the cable exceeds a certain frequency and amplitude of vibration,which will affect the quality and efficiency of the detection.It is very important to reduce the impact of vibration on the stability of the cable inspection robot.This paper proposes a spring-magnetorheological damping coupling force loading mechanism to improve the climbing stability of the robot.This mechanism can be used in cable inspection robots or other rope climbing robots that use springs to provide clamping force.The shearing magnetorheological damper designed in the paper can make the robot produce a smaller damping force and make the spring deform quickly when surmounting obstacles.The paper uses ANSYS to simulate and analyze the internal magnetic field of the damper,and obtain the relationship between current and magnetic induction.The Sigmoid model is used to establish the mechanical model of the damper,and the mechanical performance of the damper is obtained,which verifies the rationality of the damper designed in this paper.Firstly,the paper establishes the dynamic model of the cable and the robot system for study the influence of cable vibration on the climbing stability of the cable detection robot.The vibration response equations of the cable are derived base on the Hamilton's principle.The dynamic equations of the robot are derived base on the Newton-Euler method.The rigid-flexible coupling dynamic relationship between the robot and the cable system is built with the auxiliary coordinate system.Then,the dynamic equations are solved by the fourth-order Runge-Kutta method.Based on the calculation results,the influence of the cable vibration and the vibration suppression performance of the different stiffness and damping of the spring-magnetorheological damping coupling force loading mechanism under the wind is simulated and analyzed.In this paper,a vibration experiment device is built to test the climbing stability of the robot under the condition of cable vibration.The experiment and test results show that the amplitude of the cable has little effect on the climbing stability of the robot,while the vibration frequency has little effect on the climbing stability of the robot.