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:
Dec. 10, 1996
Filed:
Dec. 07, 1994
Charles W Birchenough, Morton, IL (US);
Kenneth P Liesener, Peoria, IL (US);
Lorne W Tweed, Peoria, IL (US);
Caterpillar Inc., Peoria, IL (US);
Abstract
A control system is provided for a vehicle regulating engine speed during shifts so as to reduce driveline torque and shift shock. The control system includes separate microprocessor based engine and transmission controllers which communicate via a data link. When a shift is initiated, the transmission controller delays a first period of time CTSDELAY sufficient for the transmission to disengage the old gear ratio and then produces a CTSSPEED signal. The transmission controller continues to produce the CTSSPEED signal for a second period of time CTSDUR which corresponds to the time required for the transmission to engage the new gear ratio. The engine controller receives the desired engine speed signal and regulates engine speed into correspondence with the desired speed. During upshifts, the CTSSPEED signal is set to a speed which is a predetermined amount above the synchronization speed of the new gear for an upshift. Conversely, during downshifts, the CTSSPEED is set to a speed which is a predetermined amount below the synchronization speed in the new gear. The control system preferably includes a unit [means] for sensing a lockup time period corresponding to the time required for the transmission to lock up in the new gear ratio. The control system is capable of modifying the second time period CTSDUR as a function of the sensed lockup time period.