Adaptive integral terminal sliding mode control algorithm for hydraulic transformer inner loop position control system based on sensitivity analysis

Hydraulic transformer (HT), known for its significant energy-saving potential, is currently at the forefront of hydraulic research. For HT to function efficiently in the common pressure rail (CPR) hydraulic system, the hydraulic transformer inner loop variable system (HTILVS) must achieve high accuracy and responsiveness. However, parameter uncertainty and external disturbances are the primary issues affecting the HT’s variable control performance. To improve the control accuracy and the speed of the responsiveness of the HTILV system, this study introduces an adaptive integral terminal sliding mode controller (AITSMC) combined with an extended state observer (ESO). First, the system is analyzed for sensitivity. Parameters with higher sensitivity are selected for observation, and the ESO determines the system state variables and flow uncertainties. Then, the integral sliding mode and terminal sliding mode are combined to accelerate error convergence, thereby enhancing the system’s response speed and accuracy. Finally, the comparative experimental results demonstrate that the steady-state error is maintained within 0.01 rad, which confirming the effectiveness of the above method.