Vehicle Driving Force Control for Heave Reduction in In-Wheel Motors

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Solution Overview

Problem

Existing driving force control methods for in-wheel motor type vehicles are limited in reducing vertical displacement (heave vibration) of the vehicle body, especially when the suspension structure has a relatively small anti-squat angle, which restricts the effectiveness of reducing vertical displacement.

Innovation Solution

A driving force control method that adjusts the front wheel driving force and rear wheel driving force, in conjunction with the application of friction braking force, to lift or lower the vehicle body, enhancing the reduction of vertical displacement by modifying the net driving force distribution beyond the conventional adjustment range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If suspension structure has small anti-squat angle, then vehicle structure is simplified, but effectiveness of reducing vertical displacement is restricted

Engineering Contradiction:

Improvesuspension structureVSAvoidvertical displacement reduction effectiveness

Core Design Contradiction:

Device complexityVSStability of the object's composition

Solution Approach 1:

The invention replaces the mechanical suspension-based anti-squat mechanism with an active control system that uses independent wheel force adjustment. Instead of relying on the mechanical anti-squat angle provided by the suspension geometry, the system uses electronic control to adjust driving and braking forces on each wheel, thereby achieving vertical displacement reduction without requiring a complex suspension structure.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the control parameters from passive suspension geometry (anti-squat angle) to active wheel forces (driving and braking forces). By dynamically adjusting the magnitude and direction of forces applied to each wheel, the system can compensate for the limited anti-squat angle and achieve effective vertical displacement control regardless of the suspension structure.

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method significantly improves the reduction of vertical displacement and vehicle body lift/lowering effectiveness, even in vehicles with suspension structures that have limited anti-squat angles, by optimizing the cooperative process involving front and rear wheel braking and driving forces.

Implementation Method 1

adjustment of at least one of the front wheel driving force and the rear wheel driving force

Methodology Applied

Scientific EffectForce: Force

Implementation Method 2

application of friction braking force to at least one of the front wheel and the rear wheel

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS12187135B2Driving force control method and driving force control device

Publication Date: 2025.01.07 NISSAN MOTOR CO LTD

AI summary

A driving force control method controls front wheel driving force and rear wheel driving force by a front wheel motor connected to a front wheel of a vehicle and a rear wheel motor connected to a rear wheel, respectively. The driving force control method includes: executing a cooperative process of lifting up or lifting down a vehicle body by cooperation of adjustment of at least one of the front wheel driving force and the rear wheel driving force and application of friction braking force to at least one of the front wheel and the rear wheel.