Research On The Control Strategy Of The Electro-hydraulic Servo Sinusoidal Vibration For The Automotive Parts

The electro-hydraulic servo vibration test equipment can simulate many kinds of vibration environment such as sine, random and so on, which can be applied to detect the resonance frequency and fatigue life of the automobile components. The sine vibration test is a typical form of vibration, which is widely used in the vibration environment simulation experiment, but in sine acceleration process control, the sine acceleration signals often exist amplitude error, phase lag and the harmonics, which will decrease the precision. For this purpose, the paper further studied the strategy of the harmonic cancellation strategy and the amplitude-phase control strategy for the sinusoidal vibration test.Firstly, according to the mechanism parameters of the electro hydraulic servo sinusoidal vibration test equipment, this paper established nonlinear mathematical model of the servo system based on primitive equation, the model considered nonlinear part such as friction, this model, which is the basis for the following simulation, can accurately reflect the actual situation. Then, the paper analyzes the mechanism of the hydraulic servo system, and designs the three state controller based on the linearization model..To solve the amplitude error and phase lag problem of the output sine acceleration signal, this paper research the amplitude-phase control strategy, which is the based on system identification and offline iterative, meanwhile, this paper research the other amplitude phase control strategy which based on LMS algorithm. After the simulation of two kinds of control strategies, this paper analysis the two algorithms.To solve waveform distortion problems of the output sine acceleration signal in the process of test. This paper analysis the factor from two aspects,which is time-varying factor and nonlinear factor of hydraulic servo control system, then this paper explores the options for the harmonic suppression scheme. In order to cancellate the harmonic, this paper researchs the adaptive harmonic suppression control strategy based on LMS algorithm.In order to verify the control strategy is correct, this paper developed adaptive amplitude-phase controller and adaptive harmonic suppression controller based on rapid control prototyping technology, and the experiment result is satisfacted, which indicate that the conclusion obtained in the simulation is right.