Patent ID: 6123643
Filing Date: 2000-09-26
Classification: F16D,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) coupled to said engine by a connecting member (16), an inertia brake (19) effective, when activated, to retard rotational speed of said input shaft, and a controller (26) for receiving input signals (24) 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 with logic rules to issue command output signals (28) to transmission system actuators including a transmission actuator (44) effective to shift said transmission, and an inertia brake actuator (19C) effective to actuate said inertia brake, said method including:(a) determining if an upshift from a currently engaged ratio (GR) is indicated;(b) if an upshift from a currently engaged ratio (GR) is indicated:(i) determining if the indicated upshift is feasible without operation of the inertia brake;(ii) if the indicated upshift is feasible without operation of the inertia brake, performing the indicated upshift without operating the inertia brake;(iii) if the indicated upshift is not feasible without operation of the inertia brake, determining if the indicated upshift is feasible with operation of the inertia brake, and(iv) if the indicated upshift is not feasible with operation of the inertia brake, preventing initiation of the indicated upshift;(c) if the indicated upshift is feasible with operation of the inertia brake but is not feasible without operation of the inertia brake, in sequence:(i) determining a value (T.sub.SIM) indicative of a simulated temperature of the inertia brake;(ii) comparing the value to a reference and, if the value exceeds the reference, preventing initiation of the indicated upshift and, if the reference exceeds the value, performing the indicated upshift with operation of the inertia brake.