The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 01, 1984
Filed:
Nov. 09, 1981
David Friedman, Bedford, MA (US);
Philip Mandel, Burlington, MA (US);
Computervision Corporation, Bedford, MA (US);
Abstract
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.