Research On Vibration Characteristics Analysis And Suppression Methods Of Cooperative Robot

To meet the individual needs of the majority of small and medium-sized enterprises,cooperative robot,with its light and quick,low-cost configuration features favored by the Market.However,due to the joint flexibility effect and link flexibility effect,the robot has vibration phenomena during operation and after stopping.This kind of vibration not only seriously affects the positioning accuracy of the cooperative robot,but also considerably reduces its efficiency.Therefore,it is necessary to suppress this adverse vibration.This article takes the collaborative robot EC66 developed by Beijing Elite Technology Co.,Ltd.as the research object and conducts in-depth research on its vibration suppression.The main research contents are as follows:(1)Establish the dynamic model of the cooperative robot: For the EC66 cooperative robot,The Newton Euler method based on spinor theory is used to build the dynamic model of robot considering the influence of joint flexibility.After that,the inertia parameters of each joint of the robot are obtained by using the CAD parameter identification method in Solid Works software.Moreover,to understand the modal vibration information of the robot,based on the modal analysis of the cooperative robot in the ANSYS software,the first six modal vibration frequencies of the cooperative robot are obtained,which lays the foundation for the subsequent vibration suppression of the cooperative robot.(2)Measurement and analysis of vibration parameters of the cooperative robot: in this paper,the acceleration signals of each joint are detected by the MEMS sensor MPU6500 which has been integrated into the joint of cooperative robot,and preprocess these acceleration signals through internal calibration,filtering and other processes.Then use the fast Fourier transform to get the system vibration frequency and other parameters,and finally test it on the actual robot.Use loading and unloading as a typical action to measure the robot signal and get the frequency,which provides a parameter basis for the subsequent design of the vibration suppression controller of the cooperative robot.(3)Process vibration suppression of the cooperative robot: Aiming at the vibration of the cooperative robot during operation,this paper uses the Backstepping control theory to suppress it.One-joint and three-joints cooperative robots are taken as research objects,designing the corresponding backstep controller and PID controller respectively according to their dynamic model,and the vibration suppression effects of the two control methods are compared.Finally,the effectiveness and superiority of the backstepping control method in the vibration suppression of the cooperative robot are verified by Matlab simulation.(4)Residual vibration suppression of the cooperative robot: Aiming at the residual vibration of the cooperative robot,this paper uses the input shaping method to suppress it.The MNIS-ZV negative input shaper is improved on the basis based on the traditional input shaper,which improves the system response speed while reducing the residual vibration and reduces the system delay.Afterward,to solve the shortcomings that the open-loop control of the input shaper cannot correct errors and the anti-interference ability is weak,this paper proposes a closed-loop control method combining the MNIS-ZV negative input shaper and the backstepping control to suppress the residual vibration of the cooperative robot Finally,the Matlab software is used to simulate the control method and verify the effectiveness of the scheme.In summary,this paper designed relevant vibration suppression methods respectively to solve process vibration and residual vibration for the cooperative robot EC66 and achieved good suppression effect.It achieves the expected goal of the paper and provides a theoretical reference for further vibration suppression research.