Control of Permanent Magnet Synchronous Motor in EMA System Based on Superhelical Membrane Observer without Position Sensors

In electromechanical actuation systems, if the position sensor of a permanent magnet synchronous motor fails, it may adversely affect the safe and stable operation of the system. To address this critical issue, a sensor-less control method based on a hyperbolic sliding mode observer is proposed. This method integrates the hyperbolic sliding mode observer into the three-loop control system of the electromechanical actuator based on sliding mode control principles. The sigmoid function is used to reduce the chattering phenomenon of traditional sliding mode observers, and a Lyapunov function is constructed to prove its stability. Simulations are conducted using the Simulink software platform, and the results indicate that the designed observer can provide high-precision estimates of rotor position and speed, achieving sensor-less control of the system. This provides a theoretical basis for fault-tolerant control of position sensors in permanent magnet synchronous motors within electromechanical actuation systems.