Research On Motion Planning And Vibration Suppression Of Forging Robot

Forging technology is an important technical means in metallurgical industry,but the bad factors such as high temperature,noise,vibration in forging workshop not only affect the physical and mental safety of workers,but also affect the quality of forgings,resulting in enterprise losses.Therefore,forging robots with high efficiency and safety are widely used in forging workshops.However,when forging robot is working,it constantly grabs and transfers forgings,and its multi process movement not only reduces the efficiency,but also may affect other equipment;At the same time,the forging press and other equipment in the forging workshop will inevitably produce impact when working,which will be transmitted to the forging robot through the foundation,and the residual vibration will directly affect the work of the forging robot.In order to solve the above problems,this thesis analyzes the motion control and vibration suppression of forging robot as follows:Firstly,aiming at the process of grasping and transferring the forging,the motion angle of each joint is designed to complete the motion control of the forging robot.By establishing an improved D-H coordinate system for the 6-DOF forging robot,the forward and inverse kinematics equations of the forging machine are obtained;The algorithm of cubic polynomial,quartic trinomial and quintic polynomial trajectory interpolation is studied by using the obtained forward and inverse solutions,and the simulation experiment is carried out in the robtic toolbox of MATLAB r2018 b.Then,in order to suppress the residual vibration,the active and passive hybrid vibration suppression scheme is designed.In the passive control,the half sine pulse excitation of forging press impact in forging environment is obtained through the impact response theory.According to the linear spring assumption of Spone and the rigid flexible coupling characteristics of joint,the three-dimensional structure object of 6-DOF forging robot is established;Metal rubber was selected as the material to analyze its vibration reduction characteristics for residual vibration suppression.The residual vibration suppression of four kinds of metal rubber joint damping with wire diameter of 0.10 mm,0.20 mm,0.25 mm and 0.30 mm was tested by COMSOL platform.After that,in the active control,Lagrange equation is applied to establish the dynamic equation of forging robot;The input shaper is introduced into the open-loop control,and the sliding mode controller with filter is used in the closed-loop control.At the same time,a clonal selection algorithm combining cloud model and reverse learning is designed to optimize the parameters of the sliding mode controller;The stability of the sliding mode controller is analyzed by using Lyapunov function,and the control strategy is tested by Matlab / Simulink software.Finally,numerical test and simulation are carried out for the above key technologies.In the motion control,the quintic polynomial interpolation algorithm is used to make the6-DOF forging robot work faster and more stably according to the desired trajectory;In the passive control,the metal rubber joint damping with wire diameter of 0.25 mm has the best effect on the residual vibration suppression of forging robot;In the active control,an input shaper is introduced into the open-loop control to reduce the amplitude of the input signal by 50%;The closed-loop control uses the sliding mode controller with optimized parameters,and the anti-interference ability reaches 99%,which can effectively suppress the residual vibration of the forging robot.