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:
Oct. 21, 1997
Filed:
Jun. 03, 1996
David Lynn Ehle, Attica, MI (US);
Lisa Marie Unuvar, Flint, MI (US);
Daniel Alexander Crawford, Burton, MI (US);
Timothy Lee Budzier, Davison, MI (US);
Susan Jean Lane, Clarkston, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A vehicle speed control system provides adaptive compensation for compliance in a linking mechanism between a throttle control member and a throttle which creates hysteresis in throttle movement. The system has a vehicle speed sensor, an actuator having an output linked to the throttle control member, an actuator position signal generator and a control responsive to the vehicle speed sensor and the actuator position signal generator for positioning the actuator in closed loop control with a major loop in response to vehicle speed and a minor loop in response to actuator position. The control repeatedly determines when vehicle speed is not within a predetermined range and responds (1) deriving a desired actuator position signal, a present actuator position signal and a position error signal from the difference therebetween, (2) deriving an output position signal from the desired actuator position signal when the position error signal is not zero, (3) modifying the output position signal by a compliance compensation value for actuator movement in a first direction, and (4) activating the actuator to a position corresponding to the output position signal. The control further accumulates the second and subsequent position error signals for actuator movement in the first direction as an accumulated difference value and, when actuator movement is initiated in a second direction, updates the compliance compensation value as a predetermined percentage of the sum of the compliance compensation value and the accumulated difference value.