Drive Source Control Device for Vehicle Stability

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Solution Overview

Problem

Existing vehicle drive source control systems face challenges in stabilizing vehicle attitude due to excessive rotation speed and unnecessary yaw moments caused by torque imbalances between left and right drive wheels, leading to potential spin and loss of tire grip, especially during turning or acceleration on uneven surfaces.

Innovation Solution

A drive source control device that includes an overspeed determination module and a correction module to adjust torque command values for the drive sources, reducing the torque of the drive wheel with higher rotation speed and maintaining or decreasing the torque of the drive wheel with lower rotation speed, thereby preventing overspeed and unnecessary yaw moments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If torque difference amplification is applied to achieve smooth turning and suppress vehicle behavior change, then vehicle stability is improved, but drive source rotation speed becomes unbalanced causing overspeed and unnecessary yaw moments

Engineering Contradiction:
Improvevehicle stabilityVSAvoiddrive source rotation speed
Core Design Contradiction:
Stability of the object's compositionVSSpeed

Solution Approach 1:

The control device calculates the rotation speeds of both drive sources and determines whether either exceeds a predetermined threshold. Based on this feedback, the system adjusts torque command values to prevent overspeed while maintaining vehicle stability during turning maneuvers.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts torque distribution between left and right drive sources based on real-time rotation speed conditions. When one drive source approaches overspeed, the control device modifies torque commands to balance rotation speeds, preventing unnecessary yaw moments while maintaining smooth turning capability.

Inventive Principle:
Principle #15Dynamics

2Speed

If torque command values are adjusted to prevent drive source overspeed, then drive source rotation speed is controlled, but vehicle attitude stability deteriorates due to torque imbalance between left and right drive wheels

Engineering Contradiction:
Improvedrive source rotation speedVSAvoidvehicle attitude stability
Core Design Contradiction:
SpeedVSStability of the object's composition

Solution Approach 1:

The control device applies torque reduction only to the drive source that is approaching overspeed, rather than reducing torque to both drive sources. This partial action prevents overspeed of the affected drive source while maintaining sufficient torque balance to preserve vehicle attitude stability.

Inventive Principle:
Principle #16Partial or excessive action

3Speed

If torque is increased to one drive wheel to compensate for overspeed correction, then rotation speed balance is improved, but tire grip is lost due to excessive torque causing spin

Engineering Contradiction:
Improverotation speed balanceVSAvoidtire grip
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The control device continuously monitors rotation speeds and makes gradual, continuous adjustments to torque command values rather than abrupt changes. This continuous control maintains tire grip by preventing torque spikes that would cause spin while ensuring smooth rotation speed balance between drive wheels.

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP3527850B1Drive source control device, and vehicle equipped with said drive source control device
Publication Date: 2022.04.06 NTN CORP
  • EP3527850B1 patent drawingFigure 1
  • EP3527850B1 patent drawingFigure 2
  • EP3527850B1 patent drawingFigure 3

AI summary

Provided is a drive source control device that can suppress increase in the rotation speed of a drive source. This drive source control device (67) includes: an overspeed determination module (68) to determine whether the rotation speed of each of two drive sources (2L, 2R) is overspeed; and a correction module (69) to, when the overspeed determination module (68) determines that the rotation speed of at least one of the drive sources is overspeed, correct command values for outputs of the two drive sources, supplied from a command module (66a). The correction module (69) corrects the command values of the outputs of the two drive sources (2L, 2R) so that the torque of the drive wheel having greater rotation speed decreases from the torque before the correction, and the torque of the drive wheel having smaller rotation speed maintains or decreases from the torque before the correction.