Vehicle Torque Distribution Hold During Instability Events

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Solution Overview

Problem

Current land vehicle systems face instability issues when modifying torque distribution between driving wheels, leading to wheel slip and uneven rotation speed increases, which existing optimization methods fail to address effectively, particularly in reducing fuel consumption and pollutant emissions.

Innovation Solution

The system maintains current torque distribution and controls the braking system until instability disappears, then authorizes modifications based on estimated grip variations, allowing real-time intervention to prevent further instability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the supervision computer modifies the torque distribution between the first and second trains, then the fuel consumption is reduced and pollutant emissions are limited, but the vehicle instability increases and wheel slip occurs

Engineering Contradiction:
Improvefuel consumptionVSAvoidvehicle stability
Core Design Contradiction:
Use of energy by moving objectVSStability of the object's composition

Solution Approach 1:

The trajectory control device continuously monitors vehicle stability parameters and provides feedback to the supervision computer. When instability is detected, the system adjusts torque distribution in real-time based on this feedback, creating a closed-loop control system that balances fuel efficiency with vehicle stability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The torque distribution between the first and second trains is made dynamic rather than static. The supervision computer continuously adjusts the torque distribution ratio based on real-time vehicle conditions, allowing the system to optimize fuel consumption during stable conditions while rapidly responding to instability events.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the trajectory control device acts quickly to remedy the slip problem on one train, then the wheel slip is corrected, but the rotation speed of wheels on the other train increases sharply

Engineering Contradiction:
Improveslip correctionVSAvoidrotation speed increase
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

When the trajectory control device detects slip on one train, it simultaneously applies preliminary counter-actions to both trains. Instead of solely reducing torque to the slipping wheels, the system also preemptively adjusts torque to the opposite train and applies braking forces to prevent the anticipated sharp speed increase before it occurs.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The trajectory control device performs preliminary actions by pre-adjusting the torque distribution and applying braking forces before the instability fully develops. This proactive approach prevents the chain reaction of slip and sharp speed increases by preparing the system in advance.

Inventive Principle:
Principle #10Preliminary action

3Use of energy by moving object

If the supervision computer modifies torque distribution when the vehicle is already unstable, then the fuel consumption is optimized, but the instability is amplified and control is lost

Engineering Contradiction:
Improvefuel consumptionVSAvoidcontrol stability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The system implements a feedback mechanism where the trajectory control device continuously monitors vehicle stability and communicates with the supervision computer. When instability is detected, the feedback signal prevents the supervision computer from modifying torque distribution, ensuring that fuel optimization does not compromise control stability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The torque distribution control is made dynamic with different operational modes. During stable conditions, the supervision computer optimizes torque distribution for fuel efficiency. During unstable conditions, the system dynamically switches to a stability-priority mode where torque distribution modifications are suspended until stability is restored.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4069539B1Vehicle with torque distribution control in the event of instability, and associated control method
Publication Date: 2023.10.25 STELLANTIS AUTO SAS
  • EP4069539B1 patent drawingFigure 1
  • EP4069539B1 patent drawingFigure 2~3
  • EP4069539B1 patent drawingFigure 4~5

AI summary

A land vehicle (V) comprising: - first (MM1) and second (MM2) power engines supplying torques for the first (T1) and second (T2) wheel sets, - a braking system (SF) acting on the wheels, - a supervising computer (CS) controlling the distribution of torque between the first (T1) and second (T2) sets, and - a path control device (DCT) which, in the event that instability in the vehicle (V) is detected, instructs the supervising computer (CS) to maintain the current torque distribution and controls the braking system (SF) until the instability has passed, and then authorises the supervising computer (CS) to modify the torque distribution.