Digital controller for servo-valve of 6-DOF shaking table based on TMS320F2812

In this paper, an analysis of the principle of the shaking table is carried out and a digital servo-valve controller for three-axis six-DOF shaking table based on TMS320F2812 is designed. The result was compared with the analogue controller. AD598 is selected as the modulator-demodulator to condition the displacement signal of the servo-valve main spool.AD7665 is adopted to acquire the conditioned signal. DAC7744 is used as the generator of the driving signal for the servo-valve. The user command signal transfers to the digital controller through CAN bus from the upper computer. Based on mathematical model of the servo-valve, PID control law is designed to adjust the control system and a speed feedback signal method applied to expand the bandwidth of the control system. Through the discrete transfer function of the control system, software is programmed to test the digital controller. Test results show that the digital controller is easy to implement and has strong anti-jamming capacity. Additionally, it can overcome bad consistency of hydraulic cylinder when the shaking table vibrates at high frequency.