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:
Jun. 01, 1993
Filed:
May. 04, 1992
Bruce N Eyerly, Torrance, CA (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
A mixed mode controller (100) for use with a motor having a mechanism (110, 114) for generating a command signal to operate the motor and a first circuit (104) for adjusting the gain of the command signal to provide high speed operation. A second circuit (102) is provided for converting the command signal to a drive signal to excite a winding (106) and to damp the motor. In a preferred embodiment, a step rate signal introduced into the motor controller (100) is operated upon by an accumulator (110) and a memory (114) to generate a voltage command signal. The motor controller (100) includes a low bandwidth current control feedback loop (104) utilized to adjust the gain of the voltage command signal by comparing a command motor current and an actual motor current in a summer circuit (126). The feedback loop (104) provides for automatic gain control of the voltage command signal for yielding high speed operation. The gain-adjusted voltage command signal is thereafter applied to a bipolar voltage driver (102) having high motor damping characteristics. The voltage driver (102) is utilized to control the application of a bus voltage to the motor winding (106) of a stepper motor via a transistor control logic circuit (148). Also included is a time constant correction network (138) for accelerating the settling of variations in the motor current to steady state. Thus, the correction network (138) ensures a rapid response to changes in the commanded motor current.