Research On Feedforward Control Method Of Hydraulically Driven Multi Degree Of Freedom Robot

As the economy and science technology constantly develop,the continuous improvement and perfection of the industrial production efficiency are needed.In view of it,enterprises have proposed higher requirements for the high-precision control of complex mechanisms.The advanced control methods that can obtain higher control performance have been searched by researchers for a long time.At present,the relatively advanced solution is the application of control based on dynamics,that is,the application of feedforward and feedback control.In this thesis,the one-and two-degree-of-freedom robot systems will be taken as the research object.The PID control and feedforward control are adopted respectively to conduct the trajectory tracking simulation experiments.From the simulation experiments,the comprehensive contrast of the control performance of the controller is carried out,and the controller with better control performance is selected.Firstly,the robot mechanism and feedforward control are briefly introduced.Since the feedforward control is directly built on the basis of subsystem dynamics,it can be regarded as an effective method to solve the control problems of complex systems.According to the research method of feedforward control based on subsystem dynamics and the structural characteristics of two-degree-of-freedom robot,a complete kinematics and dynamics model is established.The question of how the feedforward control based on subsystem dynamics works on the robot system is further explained.Secondly,the establishment of the mathematical model of the hydraulic drive system and the transformation of transfer function are conducted.In line with the features of PID control and feedforward control,the design of the controllers of the two control methods is made.The construction of a mass block model suitable for two controllers is realized in Amesim,and the simulation is carried out to verify the correctness of the controller design.Then,the design of the kinematic parameters and controller parameters of the robot is conducted in the MATLAB environment,the tools are used to write the program statements,the geometric model and kinematic model of the one-and two-degree-of-freedom robot are built,and the trajectory tracking of the robot is carried out.simulation.In this thesis,the Simulink is used to build a two-degree-of-freedom system model for simulation.The parameters of the feedforward controller are adjusted to achieve a good control effect,and the effectiveness of the feedforward control is verified.After that,the construction of the hydraulic drive one-and two-degree-of-freedom system models is realized in Amesim.The analysis on the control effect of feedforward control is conducted by taking advantage of trajectory tracking experiment.The comprehensive comparison of the control performance of PID control and feedforward control is carried out to illustrate the advantages of feedforward control.Finally,the influence of the control parameters of feedforward control on the tracking effect of the system is considered.The simulation and comparison of three control parameters in feedforward control are conducted to analyze the different effects of different control parameters on the system.