Torque Converter Feedforward Control for Electrified Powertrain Speed
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Solution Overview
Problem
Conventional solutions for controlling input speed in electrified powertrains with a torque converter are inefficient due to high calibration efforts and failure to account for variations, leading to suboptimal performance and increased closed-loop control effort.
Innovation Solution
An adaptive feedforward control system that monitors operating parameters of the electrified powertrain, determines desired input speed, minimum and maximum torques for the torque converter, and calculates a final feedforward torque to control the electric motor, utilizing an adaptive FTC map or model generated by a Kalman filter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional heuristic techniques are used to compute optimal load torque, then the control system can maintain steady forward torque, but high calibration effort is required
Solution Approach 1:
The control system performs self-calibration by using the Kalman filter to adaptively identify torque converter parameters during normal operation. The system continuously updates its own model based on measured operating data, eliminating the need for extensive external calibration procedures while maintaining reliable torque control
Solution Approach 2:
The Kalman filter implements a feedback mechanism that continuously compares measured operating parameters with model predictions, automatically adjusting the torque converter model parameters to match actual system behavior. This adaptive feedback loop replaces manual calibration with automated parameter identification
2Speed
If modeling from wheel to actuator is used to control input speed, then transmission input speed can be regulated, but variations are not accounted for causing closed-loop controller wind-up
Solution Approach 1:
The feedforward control component calculates the required actuator torque in advance based on the desired transmission input speed and the adaptively identified torque converter model. This preliminary torque calculation accounts for torque converter variations before the control action is applied, preventing closed-loop wind-up by providing accurate anticipatory control
Solution Approach 2:
The torque converter model parameters are dynamically adapted using the Kalman filter to reflect real-time operating conditions. This dynamic parameter adjustment ensures the feedforward control remains accurate across varying operating points, maintaining controller stability without wind-up
3Ease of operation
If conventional control methods are used in electrified powertrains with torque converters, then basic operation is maintained, but performance and responsiveness are suboptimal
Solution Approach 1:
The patent replaces conventional mechanical control approaches with an adaptive control system that uses Kalman filter-based parameter identification and feedforward torque calculation. This substitution of adaptive algorithms for traditional mechanical control methods significantly improves powertrain performance and responsiveness while maintaining ease of operation
Data Source
AI summary
An adaptive feedforward control method for an electrified powertrain including a torque converter includes determining a desired input speed for a torque converter based on the set of operating parameters of the electrified powertrain, determining minimum and maximum torques for an impeller of the torque converter based on the set of operating parameters of the electrified powertrain, determining a raw feedforward torque for the torque converter impeller based on the desired input speed for the torque converter and a speed of a turbine of the torque converter, determining a final feedforward torque for the torque converter impeller based on the raw feedforward torque for the torque converter impeller and the minimum and maximum torques for the torque converter impeller, and controlling an electric motor of the electrified powertrain based on the final feedforward torque for the torque converter impeller.