Research On Position And Force Anti-disturbance Control Of Valve-controlled Asymmetric Cylinder Loading System

As a common load simulator,the valve controlled asymmetric cylinder loading system has the advantages of large power to mass ratio,strong bearing capacity and small working area,and has been widely used in aerospace,weapon research and development,product testing and other occasions.However,due to the defects of being easily affected by disturbance,time-varying hydraulic system parameters,slow loading speed and so on,it not only has higher requirements for its control ability,but also seriously restricts the application of valve controlled asymmetric cylinder loading system in more fields.This paper takes the valve-controlled asymmetric cylinder loading system as the research object,compensates and controls the disturbance existing in the system,improves the control accuracy at the same time,and finally improves the overall control performance of the system.In this paper,the output position and output force control of the valve-controlled asymmetric cylinder loading system are studied,and the effectiveness of the control strategy in this paper is verified on the established experimental platform.The main contents of this paper are as follows:(1)The working process of the valve controlled asymmetric cylinder loading system is analyzed,and the system is modeled according to its composition principle.The mathematical model between the piston rod displacement of the hydraulic cylinder and the control current of the servo valve is obtained,as well as the mathematical model between the output force of the system and the control current of the servo valve is analyzed,and some characteristics of the system are analyzed.(2)In terms of the position control of the valve-controlled asymmetric cylinder loading system,aiming at the unknown disturbance and model uncertainty in the system,a position control strategy based on linear active disturbance rejection control algorithm was proposed,and the fourth-order observer and third-order control rate of the system were derived,so as to realize the observation and compensation of the total disturbance.The position controller is verified by MATLAB and AMESim.(3)In terms of output force control of valve-controlled asymmetric cylinder loading system,aiming at the problems of slow loading speed,weak anti-interference ability and low loading accuracy in the system,a control strategy based on the combination of RBF neural network and PID control algorithm is proposed to identify the system information and actively compensate the disturbance through real-time online adjustment of control parameters.The force controller is verified by MATLAB and AMESim.(4)Build a hardware-in-the-loop experiment platform of the valve-controlled asymmetric cylinder loading system based on x PC Target real-time system,and verify the effectiveness of position control and force control of the valve-controlled asymmetric cylinder loading system by using this platform.