Actuation Control of Trailer Mover Using the Nonlinear Disturbance Observer

This paper presents an actuator motor control scheme of the electric mover for the non-powered trailer. The actuator motor of the electric mover drives the traction roller in the forward and reverse direction to attach and detach the traction roller to the trailer wheel. Because the trailer motion depends on the wheel motion transferred from the mover roller, the contacting strength of the mover roller is very important to keep the constant traction power transmission. This paper presents sensorless speed estimation and non-linear disturbance observer to improve the constant traction power transmission performance. The proposed actuator motor control scheme determines the braking position by the estimated disturbance torque to press the trailer wheel. To estimate the disturbance torque of the actuator motor, the actual motor speed has to be detected. The sensorless estimation scheme obtains the actuator motor speed in the proposed method. Then, the estimated actuator motor speed is used to observe the nonlinear disturbance torque of the roller to the trailer wheel. The observed disturbance torque shows the starting mechanical friction and the reflected disturbance torque from the trailer tire well. The observed disturbance torque is used to determine the stop position of the mover roller to keep the constant friction between the roller and the trailer wheel.