Torque Budgeting for Vehicle Yaw Control and Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional torque vectoring systems in electric vehicles face challenges in dynamically controlling wheel torques for improved yaw response and stability, particularly at high speeds, due to delays in feedback signals and oscillations caused by noise in yaw rate measurements.
Innovation Solution
A system that transforms operator intentions into electrical magnitudes and frequencies, using a torque budgeting apparatus to distribute torque among independent field-oriented motor control circuits, adjusting torque targets based on attainable torque, user operations, and vehicle characteristics, with sensors providing real-time slip and skid information to adaptive torque control circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If torque vectoring is used to improve yaw response and stability, then vehicle handling is improved, but delays in feedback signals and oscillations occur due to noise in yaw rate measurements
Solution Approach 1:
The patent implements a feedback mechanism where the controller continuously monitors yaw rate measurements and adjusts torque distribution in response to detected oscillations. The system uses the measured yaw rate as feedback to identify oscillatory conditions and modifies the torque vectoring control accordingly, creating a closed-loop control system that responds to actual vehicle behavior.
Solution Approach 2:
The patent converts the harmful effect of noisy yaw rate measurements into a beneficial control mechanism. By detecting oscillations through the noisy measurements and using them as input signals, the system applies counteracting torque adjustments that dampen the oscillations. The noise that would normally degrade control reliability is instead utilized to trigger corrective actions that improve stability.
2Speed
If torque is dynamically assigned among wheels to improve yaw control, then responsiveness is improved, but system complexity increases
Solution Approach 1:
The patent segments the torque control function into independent wheel-level control units, each capable of receiving and executing torque commands from the central controller. This segmentation allows parallel processing of torque assignments to different wheels, improving response speed while distributing the computational burden across multiple independent control channels rather than requiring a monolithic control system.
Solution Approach 2:
The patent implements dynamic torque assignment where the controller continuously adjusts torque distribution among wheels based on real-time vehicle state measurements including yaw rate, steering angle, and wheel speeds. The system transitions from static torque vectoring to dynamic adaptive control, allowing the torque distribution to change rapidly in response to varying driving conditions and oscillatory states.
Data Source
AI summary
A circuit budgets torque among independent field-oriented motor control circuits. A desired vehicle yaw turning moment is received from an operator control input. The circuit determines a positive or negative torque target for each electrically powered drive wheel and transmits it to an adaptive field-oriented motor control circuit which provides voltage magnitude and voltage frequency to a poly-phase synchronous alternating current electric motor. When wheel loading, limited traction, or stability prevents any motor from attaining the torque target, that data is returned to the budgeting circuit and torque budget is adjusted for all adaptive field-oriented motor control circuits. Varying numbers of powered wheels are assigned torque depending on vehicle dynamics. Performance of the vehicle can be adapted to driver capabilities. A vehicle may serve as a driving simulator for diverse vehicles.