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:
Jul. 13, 1999
Filed:
Oct. 10, 1997
James F Sinnamon, Birmingham, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
An exhaust gas recirculation valve control strategy comprised of learning and continuously updating system operating conditions that affect EGR valve control response, and controlling the EGR valve in response to the learned operating conditions for precise, robust EGR valve control. An adaptive base control signal is learned during an engine operating state where no EGR valve movement is needed, such as during engine idle. The base control signal is then continuously applied to the EGR valve, maintaining the valve at an energized level just below the beginning of valve opening. When a desired degree of opening is determined, the change in control signal is made in reference to the base control signal, reducing the magnitude of the resulting control signal change and control gains necessary to initiate valve movement, enabling faster and more stable EGR control. The base control signal is then periodically adjusted in response to fluctuations in predetermined engine parameters, such as system voltage, manifold air pressure, and EGR operating temperature.