Wheel-End Torque Control for Smooth HEV Mode and Gear Shifts

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Solution Overview

Problem

In multi-gear four-wheel-drive hybrid electric vehicles, frequent switching of drive modes leads to torque redistribution between front and rear traction motors, causing torque interruption and power loss, compromising vehicle stability and safety.

Innovation Solution

A vehicle torque control method that determines wheel-end torque changes based on driving parameters and correction coefficients, adjusting torque using opposite change trends and step sizes to prevent torque interruption during gear or drive mode changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If drive mode switching is implemented in multi-gear four-wheel-drive HEVs, then adaptability and dynamic performance are improved, but torque interruption and power loss occur during switching

Engineering Contradiction:
Improvedrive mode adaptabilityVSAvoidvehicle stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The control method performs preliminary torque adjustment before drive mode switching occurs. The torque adjustment step size is calculated in advance based on the difference between current and target wheel-end torques, ensuring that torque redistribution is prepared and executed smoothly without interruption or power loss during the switching transition.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements dynamic torque adjustment by calculating torque change amounts and step sizes that adapt to the specific switching scenario. The torque distribution between front and rear traction motors is dynamically adjusted during the drive mode transition, allowing the system to maintain optimal performance while switching between different drive modes.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If gear changes are performed during driving, then speed range and adaptability are improved, but torque redistribution causes power loss

Engineering Contradiction:
Improvespeed range adaptabilityVSAvoidpower loss during gear change
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The control method calculates the required torque adjustment step size before gear change execution. By determining the torque change amount in advance based on the gear transition requirements, the system prepares the torque redistribution in advance, ensuring continuous power delivery and avoiding energy loss during the gear change process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent maintains continuous torque delivery to the wheels during gear changes by smoothly redistributing torque between the front and rear traction motors. The torque adjustment is performed in a continuous manner rather than abruptly, ensuring that the useful action of propelling the vehicle continues without interruption or power loss throughout the gear change.

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP4699878A1Vehicle torque control method and apparatus, and device, storage medium and program product
Publication Date: 2026.02.25 CHERY AUTOMOBILE CO LTD
  • EP4699878A1 patent drawingFigure 1~2
  • EP4699878A1 patent drawingFigure 3~4
  • EP4699878A1 patent drawingFigure 5~6

AI summary

The present disclosure provides a vehicle torque control method and apparatus, a device, a storage medium, and a program product, relating to the field of vehicle control. The method includes: determining at least one of a drive mode or a gear of a vehicle based on a driving parameter of the vehicle; in a case where the at least one of the drive mode or the gear changes, determining a first wheel-end torque change and a second wheel-end torque change based on a requested wheel-end torque, a first wheel-end torque, a second wheel-end torque, and a correction coefficient, wherein a change trend of the second wheel-end torque change is opposite to a change trend of the first wheel-end torque change; and determining a first torque adjustment step size and a second torque adjustment step size based on the first wheel-end torque change, the second wheel-end torque change, and a driving scenario, adjusting a torque of the vehicle using the first torque adjustment step size and the second torque adjustment step size, and controlling movement of the vehicle based on the adjusted torque. This method can improve the stability and safety of the vehicle during driving.