Wheel Driving Force Control Using Stiffness-Based Yaw Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional driving force control devices require numerous calibration operations to set appropriate feedback gains, leading to inefficiencies in adjusting the distribution of driving force between vehicle wheels.
Innovation Solution
A driving force control device that acquires steering angle, wheel speed, and vehicle speed to calculate and set driving forces based on a coefficient related to cornering and driving stiffness, reducing the need for extensive calibration by using equations to determine optimal driving forces for each wheel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If feedback control is used to control the distribution of driving force, then the vehicle stability and cornering performance are improved, but an enormous number of calibration operations are required to set the feedback gain
Solution Approach 1:
The patent changes the control parameter from feedback gain (which requires calibration) to driving stiffness (which can be calculated from vehicle parameters). By using driving stiffness as the control parameter in the driving force distribution control, the system maintains vehicle stability without requiring extensive calibration operations.
Solution Approach 2:
The patent replaces the empirical feedback control mechanism with a theoretical calculation-based control mechanism. Instead of using feedback gain that requires calibration, the system uses calculated driving stiffness values based on vehicle parameters to determine driving force distribution, eliminating the need for calibration operations.
2Manufacturing precision
If feedback gain is set through calibration operations, then appropriate driving force distribution is achieved, but the productivity and efficiency of the control system setup is reduced
Solution Approach 1:
The patent changes the approach from setting feedback gain through calibration to calculating driving stiffness from vehicle parameters. This parameter change enables accurate driving force distribution to be achieved through theoretical calculation rather than time-consuming calibration, thereby improving setup efficiency.
Solution Approach 2:
The patent performs preliminary calculation of driving stiffness based on vehicle parameters before actual operation. By pre-calculating the driving stiffness values that will be used in control, the system eliminates the need for calibration operations during setup, improving productivity without sacrificing accuracy.
Data Source
AI summary
A driving force control device for separately controlling a driving force of drive wheels is configured to: acquire a detection value of a steering angle, a speed of the drive wheels, and a speed of the vehicle; set a driving force generated in each drive wheel; control the driving force of each drive wheel so as to become a set driving force; and set a driving force to be generated in at least one pair of the drive wheels, based on a value calculated by multiplying a difference between a speed difference between the a pair of drive wheels corresponding to a target yaw rate estimated from the steering angle and the speed of the vehicle and an acquired speed difference between the one pair of drive wheels by a coefficient based on at least one of a cornering stiffness and a driving stiffness of each drive wheel.