Torque converter slip control based on motor torque during transient events

Abstract

The invention provides torque converter slip control based on motor torque during transient events. A hybrid vehicle is provided with an engine, an electric drive motor, a battery, an automatic transmission with a torque converter having a bypass clutch, and a powertrain controller dynamically adjusting the torque converter slip to balance fuel economy and drivability during a transient torque request by using motor torque to satisfy the transient torque and applying feed forward control of the fluid pressure in the bypass clutch based on the motor torque and feedback control of the slip to maintain torque converter torque ratio substantially constant during the transient event.

Description

technical field [0001] The present invention relates to controls for a hybrid vehicle comprising a power train having an engine, an electric motor with a power source, a torque converter with a bypass clutch and a plurality of stepped ratio gears An automatic transmission, the powertrain is controlled by a powertrain controller that generates a command to bypass clutch fluid pressure based on electric machine operation to maintain a target slip during a transient event. Background technique [0002] In a conventional engine-powered vehicle with an automatic transmission, a transmission controller manages the operation of the torque converter. The torque converter has a bypass clutch that manages torque transfer between the torque converter's impeller and turbine. The bypass clutch provides three modes of bypass clutch operation, and torque multiplication can occur based on the amount of slip between the impeller side and the turbine side. In open mode, the torque converter...

AI Technical Summary

Problems solved by technology

However, feed-forward control predicts the operation of the system based on engine torque estimates, but the difficulty of accurately estimating engine torque values ​​during, for example, tip-in events and the timing delay of the feedback circuit interferes with micro-slip control Precise control of swipes during events

Hybrid vehicles add powertrain because hybrid vehicles include monitoring and control of the engine, traction motor, or both as power sources in the powertrain, as well as monitoring and control of clutches and additional sensors and actuators system control complexity

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