Design of BLDC motor controller for electric power wheelchair

We introduce a design and implementation of BLDC motor controller for an electric power wheelchair. The control architecture consists of two layers of feedback control, namely the wheelchair posture control and the wheel velocity control. In the higher level of control architecture, the posture controller works as a reference velocity generator for two wheels. We realize the joystick interface and the posture controller in an 8-bits microcontroller. It is on the lower layer that the velocity controller performs four quadrant operations. For the driving system, a DSP-based BLDC motor controller with three-phase inverter module is especially designed using only three Hall-effect sensors and a single de-link current sensor. The functions of this motor controller include wheel velocity control and torque control. The performance of the control system is experimentally verified.