A method of controlling a rotational speed of a motor of an electric bed includes the following steps. (A) Use a sensor to detect rotation of the motor, set a predetermined rotational speed of the motor in a microcontroller, and use the microcontroller to calculate actual rotational speeds of the motor. (B) Use the microcontroller to calculate an average actual rotational speed of the motor at each of sampling time points in a predetermined period. (C) Use the microcontroller to compare the average actual rotational speed of the motor with the predetermined rotational speed to obtain a difference signal. (D) Input the difference signal to a driver circuit to adjust the rotational speed of the motor until the average actual rotational speed of the motor is equal to the predetermined rotational speed. In this way, the motor of the electric bed can approximately rotate in the predetermined rotational speed.

The present disclosure is directed to motor system for a multi-RET actuator system. The motor system includes a rotor configured to rotate within an interior cavity of a stator, a drive shaft coupled to the rotor and to a drive assembly of the multi-RET actuator system, an annular disc surrounding the stator, the annular disc is coupled to the rotor such that rotation of the rotor causes simultaneous rotation of the annular disc, a plurality of spaced apart magnets embedded within the annular disc, a HALL effect sensor, and a motor speed controller in communication with the rotor and the HALL effect sensor. Methods for controlling the position and speed of a motor system are also described herein.