Cable Detection Robot Variable Stiffness Variable Damping Loading Mechanism Research On Vibration Damping Methods

Cable detection robot is a special robot for damage detection of cable cables of cable-stayed bridges,which replaces traditional manual detection and can effectively reduce detection costs and improve detection efficiency.However,in the high-altitude cable detection operation,the robot has to face the cable vibration caused by high-altitude wind load,and most detection robots use coil springs with immutable stiffness coefficients as the loading and vibration damping mechanism of the robot.Vibration caused by the inevitable deformation of the spring will make the robot loading force fluctuation,resulting in the roller and cable surface friction change,resulting in slippage phenomenon,in order to avoid the above situation,it is necessary to design a new loading mechanism and control algorithm,according to the cable vibration output appropriate loading force,improve the robot climbing stability.Firstly,this paper studies the influence of cable vibration on the climbing stability of the robot through indoor vibration experiment,analyzes the causes of the slipping phenomenon,and further analyzes the relationship between the loading force provided by the loading mechanism and the friction between the roller and the surface friction of the cable with theory,and obtains the friction required for the stable climb of the robot.In order to improve the climbing stability of the robot,the influence of variable damping and variable stiffness on the vibration damping performance of the robot was analyzed,and a robot coupling loading mechanism with variable damping and variable stiffness was proposed.The vibration response of the cable under the influence of high-altitude wind load and robot climbing was explored,and the influence of variable stiffness variable damping loading mechanism on the climbing stability of the robot was further explored.Secondly,based on the variable stiffness variable damping mechanism,a new coupling loading mechanism with coupling magnetorheological damper and nitrogen gas spring is designed,and the output damping force of the magnetorheological damper is continuously adjustable,and the output mechanical model of the magnetorheological damper is established.Nitrogen gas springs are used instead of ordinary coil springs to give full play to the characteristics of basically constant spring output spring pressure.The ball screw is used to control the support angle of the nitrogen gas spring between the loading mechanism to change the stiffness of the loading mechanism and realize the design of the active variable damping variable stiffness of the loading mechanism.In order to meet the detection needs of the detection robot staying on the cable and the emergency avoidance ability to cope with the harsh environment,the low-power self-locking mechanism of the robot is designed.Finally,this paper builds an experimental platform for coupled loading mechanism to test the mechanical properties of the new loading mechanism.Simulink is used to build a simulation experimental model of a new coupled loading mechanism,and the fuzzy PID adaptive control algorithm is adopted to adjust the PID parameters according to the vibration of the cable to improve the performance of the new coupled loading mechanism.The control effect of fuzzy PID adaptive control algorithm and PID control algorithm was compared.Simulation experiments show that for the robot-cable system,the fuzzy PID adaptive control algorithm can adjust the parameters in real time according to the climb situation,and has a good dynamic effect.Finally,a robot-cable coupling system vibration experimental platform is built to test the climbing stability of the robot using the new coupling loading mechanism in the cable vibration environment.Experiments show that the new coupling loading mechanism changes the output damping force by changing the input magnetorheological damper current,changes the stiffness of the loading mechanism by changing the support angle of the nitrogen gas spring,controls the output loading force,and reduces the robot speed fluctuation to less than 7% when the vibration frequency is 10 Hz and the amplitude is 4mm,which improves the climbing stability and damping performance of the robot.