Adaptive integral-type second-order nonsingular terminal sliding mode control of permanent magnet linear synchronous motor

An adaptive integral-type second-order nonsingular terminal sliding mode control approach is proposed to address the stability concerns in the control system of a permanent magnet linear synchronous motor (PMLSM), which is susceptible to uncertainties and load disturbances. This method utilizes second-order nonsingular terminal sliding mode control based on sliding mode control theory to ensure finite time convergence of the system. An integral second-order sliding mode surface is defined to eliminate the steady-state error caused by uncertain factors. Additionally, an adaptive mechanism estimates the upper bound of uncertainties, resulting in a parameter-turning terminal sliding mode tracking controller that improves the system's anti-interference capability and reduces the sliding mode chattering phenomenon. The proposed adaptive integral-type second-order nonsingular terminal sliding mode controller is developed without assuming prior knowledge of the upper bound of uncertainties. Experimental results demonstrate superior antiinterference capability, position tracking accuracy, convergence speed, and effective chattering suppression compared to traditional second-order nonsingular terminal sliding mode control methods that rely on assumed upper bounds of uncertainties.