Research On Electro-hydraulic Servo Loading Control System Of Main Rotor Joint Bearing Testing Machine

Helicopter main rotor joint bearing testing machine needs to simulate the joint bearing in the work of the real movement and load,to achieve integrated service life evaluation of bearing life test.The test load control system adopts the electro-hydraulic servo loading control system.Since the test requires a long time,uninterrupted simulation of real force changes and dynamic real load,it is necessary to solve the rapidity of the dynamic load spectrum response with the electro-hydraulic loading system.The traditional PID is widely used in engineering practice,but it does not meet the high performance requirements of the test load of the test machine under complex conditions.According to the requirements of the load design of the main rotor joint bearing,this paper presents a multi-channel passive electro-hydraulic servo loading control system with hydraulic cylinder as the dynamic actuator to simulate the real motion and load of the joint bearing.And the mathematical model of loading system is established.ADRC does not depend on the exact mathematical model of the controlled object,and does not need to model and measure the disturbance.By designing the ESO,the disturbance and state information of the system are estimated.By designing the TD,State information and its differential signal are tracked,to solve the load system response speed and overshoot control contradiction.Because of these characteristics of the ADRC,it is applied to the system of this paper.Through simulation,it is proved that in the case of external conditions,The control effect in the loading system is better than the bilinear TD modification of "linear PID" control,the system’s response speed,anti-jamming ability and robustness are improved significantly.Finally,combined with the requirements of loading control of the joint bearing test machine,the load spectrum and the motion spectrum of the joint bearing are tested by the intelligent control of the measurement and control system,and the test data are collected,analyzed and saved.