Patent ID: 6216075
Filing Date: 2001-04-10
Classification: B60W,F16H,Y10T

Abstract:
A process for determining an operating point of an automatic transmission, especially a continuously variable transmission having a primary pulley and a secondary pulley, the continuously variable transmission having means for detecting input signals which are drawn from a driver vehicle system and are processed at least to one output signal by which is produced within the scope of an operating strategy at least one selected from the group consisting of: a standard of the reduction ratio, a standard of the speed of rotation of an engine, and a standard of a vehicle acceleration, said process comprising the steps of:generating a driving range having a lower and an upper limit (UG, OG);changing an actual operating point standard (Bakt), by calculating an actual acceleration (aakt), a minimum theoretical acceleration (amin) having a highest and lowest value, and a maximum theoretical acceleration (amax) having a highest and lowest value, the actual acceleration, the minimum theoretical acceleration, and the maximum theoretical acceleration are together calculated as a function of an actual engine torque (Mmot) at the actual operating point (Bakt), and as a function of both the lower limit (UG) and the upper limit (OG) of the driving range;determining a driver's desire (afwu) to perform one of accelerate and decelerate;presetting an acceleration (avorg) from actual values of the minimum acceleration (amin) and maximum acceleration (amax) and the driver's desire (afwu);calculating a ratio change per unit time (iVpkt) of the continuously variable transmission from the acceleration (avorg), said ratio change per unit time is guided by the engine speed of rotation (nmot) during the change of ratio.