Slip Control Apparatus Torque Calculation for Vehicle Speed Maintenance

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Solution Overview

Problem

Existing slip control apparatuses fail to maintain vehicle speed when slippage occurs at driving wheels, as they either reduce driving torque or apply excessive braking torque, leading to vehicle speed reduction and hindered acceleration.

Innovation Solution

A slip control apparatus and method that calculates and applies driving torque by adding the consumed torque for slippage restraint to the demanded torque, ensuring stable vehicle speed by individually managing driving and braking torque at each wheel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If driving torque is reduced to restrain wheel slippage, then wheel slippage is restrained, but vehicle speed becomes lower than target vehicle speed and acceleration is hindered

Engineering Contradiction:

Improvewheel slippage restraintVSAvoidvehicle speed

Core Design Contradiction:

ReliabilityVSSpeed

Solution Approach 1:

The patent segments the driving torque control by wheel, individually managing torque application to slipping and non-slipping wheels. The torque reducing means operates separately on each wheel based on its slip condition, allowing the non-slipping wheel to maintain full driving torque while the slipping wheel receives reduced torque. This segmentation resolves the contradiction by preventing overall vehicle speed reduction while still restraining slippage at the affected wheel.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies different torque control strategies to different wheels based on their local slip conditions. The torque reducing means selectively reduces driving torque only at wheels experiencing slippage, while maintaining normal torque at wheels with adequate traction. This local quality approach ensures that vehicle speed is maintained through the non-slipping wheels while slippage is restrained only where necessary.

Inventive Principle:

Principle #3Local quality

2Reliability

If braking torque is applied to slipping driving wheel to restrain slippage, then wheel slippage is restrained, but driving torque is consumed and vehicle speed is lowered

Engineering Contradiction:

Improvewheel slippage restraintVSAvoiddriving torque consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

Instead of applying braking torque to the slipping wheel as in conventional systems, the patent inverts the approach by applying driving torque to the non-slipping wheel. The torque applying means provides additional driving torque specifically to wheels with adequate traction, which indirectly restrains slippage at the slipping wheel through the differential mechanism without consuming energy through braking.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent converts the harmful effect of differential torque distribution (which causes slippage) into a beneficial effect by using the same differential mechanism to redirect torque to non-slipping wheels. The differential device, which normally causes slippage by directing torque to the path of least resistance, is instead utilized to transfer torque from slipping wheels to non-slipping wheels, turning the harmful differential action into a beneficial torque redistribution mechanism.

Inventive Principle:

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

3Reliability

If braking torque is applied to non-slipping driving wheel to prevent torque transmission to slipping wheel, then slippage is restrained, but vehicle speed reduction occurs

Engineering Contradiction:

Improveslippage restraintVSAvoidvehicle speed

Core Design Contradiction:

ReliabilityVSSpeed

Solution Approach 1:

The patent inverts the conventional approach of applying braking torque to non-slipping wheels. Instead, the torque applying means applies driving torque to non-slipping wheels, which maintains vehicle speed while the differential mechanism naturally limits torque transmission to slipping wheels. This inversion eliminates the need for braking intervention at non-slipping wheels while still achieving slippage restraint.

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentUS8645041B2Slip control apparatus and slip control method

Publication Date: 2014.02.04 ADVICS CO LTD

AI summary

A slip control apparatus includes a driving torque calculating means calculating driving torque, a driving torque applying means applying the calculated driving torque to driving wheels, and a slip restraining means restraining slippage at each driving wheel when the slippage occurs at each driving wheel, wherein when the slippage occurs at each driving wheel, the driving torque calculating means calculates demanded torque and adds consumed driving torque, which corresponds to the driving torque consumed for restraining the slippage at each driving wheel by the slip restraining means, to the calculated demanded torque to calculate the driving torque.