Patent ID: 6409629
Filing Date: 2002-06-25
Classification: F16H,Y10T

Abstract:
A method for controlling automatic upshifting in a vehicular automated mechanical transmission system (10) for a vehicle comprising a fuel-controlled engine (12), a multiple-speed mechanical transmission (14) having an input shaft (18) driven by said engine, a friction upshift brake (26) for selectively retarding rotation of said input shaft, and a controller (28) for receiving input signals (30) including one or more of signals indicative of engine speed (ES), engaged gear ratio (GR) and vehicle speed (OS), and to process said input signals in accordance with logic rules to issue command output signals (32) to transmission system actuators including a transmission actuator (52) effective to shift said transmission and a brake actuator (26A) effective to operate said brake, said logic rules including rules for:(a) establishing upshift feasibility criteria whereby upshifts into a target gear ratio are considered feasible only if, under sensed vehicle operating conditions, said criteria is satisfied, and (b) determining if upshifts under consideration with use of said brake are feasible, said method characterized by the steps of: (i) establishing a maximum allowable temperature (TEMPMAX) for said brake; (ii) determining a predicted brake temperature (TEMPp) at completion of an upshift under consideration using said brake; (iii) comparing said maximum allowable temperature to said predicted brake temperature; and (iv) if said predicted brake temperature exceeds said maximum allowable brake temperature (TEMPp>TEMPMAX), then not commanding said upshift under consideration using said brake.