Microcomputer implementation of optimal algorithms for closed-loop controlof hybrid stepper motor drives

This paper discusses optimal algorithms for closed-loop control of hybrid s tepper motor drives and their microprocessor implementation. The torque cha racteristics and the optimal control angle of hybrid stepper motor drives w ith added series resistance and reluctant stepper motor drives have been de scribed in detail in the literature. The specific contribution of the prese nt paper to this field of research consists of the analysis of the torque c haracteristics and the optimal control angle of hybrid stepper motor drives with a chopper amplifier and current controller. Analytical expressions fo r the average torque and the optimal control angle of a two-phase hybrid st epper motor with chopper amplifier and current controller have been develop ed. An actual hybrid stepper motor drive and the microcontroller-based impl ementation of the suboptimal and exact optimal control algorithms have been described. The experimental results obtained by positioning a two-phase hy brid stepper motor drive with chopper amplifier, phase current controller, and incremental encoder suggested that the derived optimal control algorith m provided maximum acceleration and minimum positioning time of the hybrid stepper motor drive.