Vehicle Torque Compensation for Split-Road Brake LSD Control

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Solution Overview

Problem

Existing vehicle control systems fail to maintain the desired longitudinal acceleration on split road surfaces due to limitations in driving torque output, leading to the need for additional driver input.

Innovation Solution

A vehicle control apparatus that calculates and compensates for lost driving torque on split road surfaces by adding a correction torque to the driver's request torque, using brake LSD control to manage wheel slip and maintain desired acceleration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If brake LSD control is applied to prevent wheel slip on split road surface, then wheel slip is reduced, but driving torque is lost due to braking torque applied to the first driving wheel

Engineering Contradiction:

Improvewheel slip controlVSAvoiddriving torque

Core Design Contradiction:

ReliabilityVSPower

Solution Approach 1:

The patent converts the harmful effect of braking torque (which reduces driving torque) into a beneficial compensation mechanism. The control apparatus calculates the driving torque lost due to brake LSD control and adds this lost torque back to the target driving torque, thereby converting the negative impact into a corrected output that maintains both wheel slip control and adequate driving torque

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The control apparatus implements a feedback mechanism by calculating the driving torque lost due to braking torque and using this information to adjust the target driving torque. The control unit continuously monitors the brake LSD control state and compensates for torque loss in real-time, ensuring the output driving torque matches the driver's intent while maintaining wheel slip control

Inventive Principle:

Principle #23Feedback

2Reliability

If upper limit on target driving torque difference is limited according to driver request torque, then wheel slip is controlled, but longitudinal acceleration of the vehicle is reduced

Engineering Contradiction:

Improvewheel slip controlVSAvoidlongitudinal acceleration

Core Design Contradiction:

ReliabilityVSSpeed

Solution Approach 1:

The patent transforms the limiting effect (which reduces longitudinal acceleration) into a compensatory mechanism. By calculating the driving torque lost due to the upper limit constraint and adding this compensation to the target driving torque, the system maintains wheel slip control while restoring the longitudinal acceleration that would otherwise be lost

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The control apparatus dynamically adjusts the target driving torque parameter based on the calculated torque loss. When brake LSD control is active and the upper limit constraint is applied, the system changes the target driving torque parameter by adding the compensation amount, thereby maintaining performance despite the constraint

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12528363B2Control apparatus for vehicle, control system for vehicle, and control method for vehicle

Publication Date: 2026.01.20 ASTEMO LTD

AI summary

A control apparatus for a vehicle includes an addition portion that outputs a post-compensation driver request torque, which is acquired by adding a driving torque (a loss compensation driving torque) lost due to a braking torque provided to a wheel on a low-μ road surface side according to a BLSD request hydraulic pressure calculated by a BLSD request hydraulic pressure calculation processing portion to a driver request torque calculated by a driver request torque calculation processing portion, to a motor.