Patent ID: 6390949
Filing Date: 2002-05-21
Classification: F16H,Y10T

Abstract:
An apparatus for controlling a power transmitting system of an automotive vehicle, said power transmitting system including (a) an automatic transmission which is shifted up from a presently established lower-gear position to a higher-gear position having a lower speed ratio than said lower-gear position, by an engaging action of a frictional coupling device which is operated by a hydraulic cylinder, and (b) a hydraulic control device for supplying a pressurized fluid to said hydraulic cylinder to effect said engaging action of said frictional coupling device, said apparatus comprising:synchronizing time estimating means for estimating a synchronizing time required for an input speed of said automatic transmission to reach a synchronizing speed of said higher-gear position, in the process of an upshift of said automatic transmission during running of the vehicle in a power-off state in which a vehicle drive force is not transmitted to drive wheels of the vehicle through said automatic transmission; a time data memory storing a predetermined stroking time required for a piston of said hydraulic cylinder to reach an engaging stroke end; and timing determining means operable in response to a command to effect said upshift during running of the vehicle in said power-off state, for comparing said synchronizing time with said predetermined stroking time, and thereby determining a point of time at which a supply of said pressurized fluid to said hydraulic cylinder is initiated.