Robust speed control of brushless DC motor using adaptive input-output linearisation technique

A robust speed control scheme for a brushless DC (BLDC) motor using an adaptive input-output linearisation technique is presented. By using this technique, the nonlinear motor model can be linearised in Brunovski canonical form, and the desired speed dynamics can be obtained based on the linearised model. This control technique, however, gives an undesirable output performance under the mismatch of the system parameters and load conditions caused by the incomplete linearisation. For the robust output response, the disturbance torque and flux linkage will be estimated by a model reference adaptive technique. The adaptation laws are derived by the Popov's hyperstability theory and positivity concept. The proposed scheme is implemented on a BLDC motor using the software of DSP TMS320C30 and the effectiveness is verified through the comparative simulations and experiments. Indexing terms: Bnishless DC motor, Input-output linearisation. Model reference adaptive system, Speed control