초록 ▼

A method for controlling the apply element during a kickdown shift for an electronic automatic transmission system by controlling the turbine speed along a desired slope to adaptively predict how much time remains to fill the apply element after having achieved a predetermined target speed for the t

A method for controlling the apply element during a kickdown shift for an electronic automatic transmission system by controlling the turbine speed along a desired slope to adaptively predict how much time remains to fill the apply element after having achieved a predetermined target speed for the turbine.

대표청구항 ▼

In a vehicle having an engine and a transmission system including an input member, an output member, a torque converter assembly for transmitting torque between the engine and the input member, the torque converter assembly including a turbine, a gear assembly for changing the ratio of torque betwee

In a vehicle having an engine and a transmission system including an input member, an output member, a torque converter assembly for transmitting torque between the engine and the input member, the torque converter assembly including a turbine, a gear assembly for changing the ratio of torque between the input member and output member, a plurality of friction elements for shifting the gear assembly, a fluid actuating device being movable axially for applying at least one friction element, at least one solenoid-actuated valve being movable and having logical operating states (ON and OFF) in response to the presence or absence of electrical power to the valve for directing fluid flow between a fluid source and the fluid actuating device, sensors providing signals indicative of measurement data for predetermined conditions, a controller having memory for processing and storing the signals and predetermined values and providing signals to control the solenoid-actuated valves, a method of controlling the speed change for a kickdown shift, said method comprising the steps of: sensing the speed of the turbine; sensing the speed of the output member; calculating a turbine speed based on the sensed speed of the turbine; calculating an output speed based on the sensed speed of the output member; calculating a target speed based on the calculated output speed; calculating an instantaneous turbine acceleration based on the calculated turbine speed; measuring a time to nearly fill the apply friction element; calculating a kickdown start value based on the time to nearly fill the friction element and a predetermined desired acceleration of the turbine stored in memory; comparing the calculated instantaneous turbine acceleration against the kickdown start value to determine when the calculated instantaneous turbine acceleration exceeds the kickdown start value; and turning ON the friction element by the controller once the calculated instantaneous turbine acceleration exceeds the kickdown start value to control the rate at which the turbine of the torque converter assembly accelerates.