Torque Converter Control Using Inverse Modeling for NVH Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional vehicle torque converter modeling and control systems only allow for forward direction modeling, leading to inconsistent vehicle acceleration and feel due to the inability to directly control transmission output shaft or wheel torque, resulting in noticeable noise/vibration/harshness (NVH).
Innovation Solution
A control system that includes sensors monitoring vehicle speed, torque request, and transmission gear ratio, using a look-up table to calculate turbine and impeller K-factors, speed ratios, and torque ratios to determine target impeller speed and torque, allowing for direct control of the torque generating system to achieve desired driveline torque and mitigate NVH.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional forward direction torque converter modeling is used, then the control system can operate with existing empirical data, but the ability to directly control transmission output shaft or wheel torque is lost, resulting in inconsistent vehicle acceleration and NVH issues
Solution Approach 1:
The patent inverts the conventional forward direction torque converter modeling approach by implementing backward direction modeling. Instead of calculating impeller torque from turbine torque (forward), the system calculates desired turbine torque from target wheel torque (backward). This inversion enables direct control of transmission output shaft torque by working backwards through the torque converter relationships using the inverse of the conventional torque converter equations, thereby achieving consistent vehicle acceleration and eliminating NVH issues associated with indirect control methods
2Reliability
If conventional torque converter control is used, then the system structure remains simple, but the vehicle acceleration consistency and NVH performance deteriorate
Solution Approach 1:
The patent implements a feedback control mechanism where the controller continuously monitors actual vehicle operating conditions (turbine torque, speed ratios) and compares them with target values calculated from desired wheel torque. The system adjusts impeller torque commands based on the difference between actual and target turbine operating points, ensuring consistent vehicle acceleration. This feedback loop integrates with the backward direction modeling to maintain reliability while managing control complexity through iterative correction rather than overly complex open-loop calculations
Data Source
AI summary
Techniques modeling and controlling a torque converter of a vehicle include accessing a look-up table relating (i) various K-factors of a turbine of the torque converter to (ii) various K-factors of an impeller of the torque converter, speed ratios of the torque converter, and torque ratios of the torque converter, calculating a K-factor of the turbine based on the set of parameters, determining a speed ratio and a torque ratio of the torque converter based on the calculated turbine K-factor using the look-up table, determining a target speed and a target torque for the impeller based on the determined speed and torque ratios of the torque converter, and controlling a torque generating system including the torque converter to achieve the target impeller speed and torque to thereby achieve the torque request at a driveline and mitigate or eliminate noise/vibration/harshness (NVH).