Method and apparatus for controlling stepper motors

摘要

A method and apparatus for controlling a stepper motor involves the generation of command currents which drive the stepper motor and provided critical damping of the natural resonance of the stepper motor. Digital error signals are developed by selectively combining a position signal and a digital velocity signal which is derived from a feedback signal proportional to velocity. In one embodiment, the digital error signals are converted into command currents for driving the stepper motor in such a manner as to achieve damping of the motor's natural resonance. In an anternative embodiment, the digital error signals and feed forward acceleration signals and/or feed forward velocity signals are converted into command currents for driving the stepper motor so as to achieve damping of the motor's natural resonance, as well as correction for positional errors induced by either velocity or acceleration.