An Intelligent Indirect Dynamic Torque Sensor for Permanent Magnet Brushless DC drives

In this paper, we present a technique for indirect sensing of the dynamic torque feedback signal which is applicable to permanent magnet BLDC drives. This technique is based upon a judicious use of the motor equations, and on parameter estimation methods. It is intelligent in the sense that the technique provides self-calibration at start-up, and it is also possible to extend the technique to overcome effects of parameter drifts by incorporating real-time on-line parameter estimation. The effectiveness of the proposed intelligent indirect dynamic torque sensor has been demonstrated in typical speed and position control experiments where the performance obtained is shown to be superior to that obtained with conventional sinusoidal current controllers.