Parallel Position Control Scheme of Permanent Magnet DC Motors with a Low-Resolution Sensor

This paper presents a parallel position control of two DC motors simultaneously with a low-resolution hall sensor. To achieve the balanced position control of the geared brushed DC motors, accurate speed and position controls are required. In order to improve the position control performance of the system, a current model speed observer and the back EMF constant adaptive system are implemented in this paper. Using the back EMF estimation and the current model speed observer, the continuous and accurate speed and position can be estimated. The back EMF constant to estimate the DC motor speed is adjusted using the average speed error between the speed observer and the actual speed obtained with the low-resolution hall sensor. The compensation of the position error between the two DC motors can be done using the instantaneous position compensator in the proposed control scheme. The control performance of the dual DC motor system was tested by MATLAB simulation and practical experiments with the manufactured test bench. In the simulation and experiments, the proposed position control scheme shows the improved control performance compared to the conventional control method.