Control Strategy Research Of Two-axis Hydraulic Angle Vibration Table

Based on the NSFC (Natural Science Foundation of China)-"vibration control of the large scale structural dynamic testing system based on the multiple shaking tables" develop the control strategy of two-axis hydraulic angle vibration test system., which is be theoretically and experimentally researched.Vibration simulation is widely used in the detection of the reliability of different kinds of products by using specific vibration simulation device and vibration control technology to simulate the vibration environment while product is under transported and used. The purpose of vibration simulation control strategy’s research is to improve the dynamic response and control precision of the random vibration environment simulation system.Reference signal of random vibration simulation system is generally given by random wave or PSD (power spectral density). This paper studies random wave representation and PSD replication algorithm of random vibration control respectively. The servo control system is used to realize the DOF control of vibration table, i.e., to convert the DOF drive signals to hydraulic displacement drive signals. By using three-state-control strategy to solve low natural frequency, low damping ratio of the vibration table’s servo system. Three-state-controller can extend acceleration frequency band, improve the stability of the system. By using the freedom synthesis and decomposing matrix to achieve DOF control.For the large deviations between response signal and desired input signal with only servo control system and the replicated time domain wave can not fully represent the characteristics of random vibration environment, an adaptive inverse controller is proposed to add in the outer loop of the servo control system to compensate the drive signal in time, to minimize the deviation between response signal and input signal, thus to replicate reference waveform accurately.Based on the principle of vibration control system proposed PSD replication algorithm to iterative compensate the driven signal, to identify frequency response function of the system. By adopting time domain randomization to convert frequency domain driven spectrum to time domain driven signal, to reproduce reference PSD in high precision. The proposed control strategies in this paper are modeled and simulated through Matlab/Simulink. The realtime computer control system, which is used to test and verify the proposed control strategies, is developed based on on XPC Target host-target technology. The experimental results verify the simulation results, indicate the effectiveness of proposed control strategies.