Dual-Motor Torque Vectoring Under Battery and Grip Limits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing torque vectoring systems in electric vehicles can destabilize driving on roads with varying friction coefficients, leading to reduced driving force and stability, particularly when one wheel encounters a low-friction surface.
Innovation Solution
A vehicle system with dual motors and a torque vectoring mechanism that adaptively distributes torque between wheels based on battery state of charge, motor rotational speed, and temperature, using a controller to manage power and torque limits to stabilize driving.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If torque vectoring control is applied to ensure stability during driving on curves, then driving stability is improved, but battery charge/discharge power limits are exceeded and motor torque limits are violated
Solution Approach 1:
The patent implements dynamic adjustment of torque distribution between wheels based on real-time battery state of charge (SoC) and motor operational status. The controller continuously monitors battery SoC levels and motor torque limits, adapting the torque vectoring control parameters to ensure stability while respecting powertrain constraints. This dynamic control strategy allows the system to maintain driving stability across varying operating conditions without exceeding battery charge/discharge power limits or motor torque capabilities.
2Stability of the object's composition
If different torque is applied to left and right wheels for torque vectoring, then driving stability on curves is improved, but torque distribution becomes unbalanced leading to potential wheel slip or instability on low-friction surfaces
Solution Approach 1:
The patent applies local quality by differentiating torque application to individual wheels based on their specific operating conditions. The controller independently calculates optimal torque commands for each wheel considering local factors such as wheel speed, battery SoC, and motor torque limits. This localized torque control enables the system to provide torque vectoring for stability while preventing excessive torque differences that could cause wheel slip on low-friction surfaces, thereby maintaining both stability and adhesion reliability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enhances driving stability by reducing torque differences between wheels on surfaces with varying friction, maintaining driving force and stability through adaptive torque distribution.
Implementation Method 1
a first motor driver configured to convert power output from the battery in response to the first torque command to control a driving current of the first motor
Implementation Method 2
a second motor driver configured to convert power output from the battery in response to the second torque command to control a driving current of the second motor
Data Source
AI summary
A vehicle includes a battery, a first motor configured to provide a first wheel and a second wheel with a driving force, and a second motor configured to provide the first wheel and the second wheel with different rotational forces. The vehicle also includes a controller configured to output a first torque command and a second torque command, a first motor driver and a second motor driver configured to convert power output from the battery in response to, respectively, the first torque command for the first motor and the second torque command for the second motor. The controller is configured to determine a torque limit of the first motor based on a state of charge (SoC) of the battery and a rotational speed of the first motor and a torque limit of the second motor based on the SoC of the battery and a rotational speed of the second motor.