Controlling precision stepper motors in flight using (almost) no parts

摘要: This concept allows control of high-performance stepper motors with minimal parts count and flight software complexity. Although it uses a small number common flight-qualified simple algorithms, is capable enough to meet demanding system requirements. Its programmable nature makes trivial implement changes algorithms both during integration & test in flight. Enhancements such as microstepping, half stepping, back-emf compensation, jitter reduction can be tailored the requirements large variety motor based applications including filter wheels, focus mechanisms, antenna tracking subsystems, pointing mobility. The hardware design (using an H-bridge controller IC) was adapted from JPL's MER mission, still operating on Mars. has been fully developed incorporated into MCS instrument MRO, currently Mars orbit. It wheel mechanism linear stage (focus) for AMT instrument. On MCS/MRO, two these circuits elevation azimuth telescope/radiometer assembly, allowing continuously monitor limb Martian atmosphere. Implementation MCS/MRO resulted 4∶1 volume mass required driver electronics (100∶25 square inches PCB space), producing very compact In fact, all are packaged within movable structure. also saved approximately 3 Watts power. Most importantly, enabled its stringent maximum allowable torque disturbance 12