In the servo control system of segmented arc permanent magnet synchronous motor (SAPMSM) for large optical telescopes, traditional PID speed controller can no longer meet the high performance required by the system.

In order to further improve the accuracy and anti-interference ability of the motor, this paper proposes a control strategy of an adaptive supertwisting sliding mode controller (ASTSMC) and load torque observer.

The barrier function is used to design the ASTSMC, and the traditional sign function is improved into the relay characteristic function to weaken chattering. Then combine the load observer to compensate the current.

Finally, it is verified through simulation, the results show that compared with traditional super-twisting sliding mode controller (STSMC), in this paper, the strategy proposed has strong interference suppression ability, fast speed response, small overshoot, and can accurately observe the motor load.