Development of control electronics of a PMBLDC motor for an autonomous rover application in space

The drive system for a space rover application demands for the choice of a motor with low inertia, high power to weight ratio, capacity to develop high acceleration, wide velocity range and high positioning accuracy. Since the control schemes for light weight robot-drive are stringent, the system design and control has become an area of wide research. This paper focuses on the development of controller for a precision actuator as per the requirements of space environment. The design utilizes slotless, coreless PMBLDC motor topology that not only gives high torque to weight ratio and less cogging torque but also limit weight to a few hundred grams. Unlike conventional block commutation scheme, Sinusoidal current commutation SVM controller adopted in this paper reduces torque ripple and controls the motion sequences of robot with high position accuracy and repeatability. The basic drive system design is modeled using Matlab/Simulink environment & is validated with the help of simulation results for confirming the performance characteristics. The results obtained are well within the space requirements which include high torque to inertia ratio, high positioning accuracy, high dynamic response & low detent torque.