Fuzzy-Type Fast Terminal Sliding-Mode Controller for Pressure Control of Pilot Solenoid Valve in Automatic Transmission

The performance of the pilot solenoid valve (PSV) has a significant impact on the efficiency and service life of an automatic transmission (AT) in automobiles, and it is very difficult to achieve a perfect pressure tracking performance due to the sophisticated combination of mechanical, hydraulic and electromagnetic characteristics inside the PSV. In this paper, based on a nominal nonlinear dynamic model of the PSV including uncertainties and an external disturbance, a fast terminal sliding-mode control (FTSMC) method is developed to achieve tracking precision and robustness in the pressure control of the PSV. To alleviate the chattering phenomenon in the control input signal, fuzzy logic rules are established to tune the switching control coefficient of the control law in FTSMC controller. Compared with the trend-law-based sliding-mode control (TLSMC) method and PID method, the developed fuzzy-type fast terminal sliding-mode control (F-FTSMC) method achieves the shortest settling time, the smallest tracking error at steady state and almost no chattering in the control input by intelligently changing the control law. Simulations and experiments are demonstrated to verify the effectiveness and excellent advantages of the proposed controller.