Vehicle Control Apparatus Torque Rate Moderation

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Solution Overview

Problem

Electric vehicles experience fluctuations during acceleration from a low-speed state, particularly after gear shifting from drive to reverse or reverse to drive, due to abrupt changes in drive torque, leading to passenger discomfort.

Innovation Solution

A vehicle control apparatus with a detection and control system that moderates the rate of increase in drive torque by using sensors to detect vehicle speed, shift position, and drive torque, and adjusts the torque accordingly based on predetermined thresholds to prevent fluctuations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the drive torque of the electric motor is increased to improve acceleration performance, then the acceleration capability is improved, but the vehicle fluctuates and passenger comfort deteriorates at low-speed acceleration after gear shifting

Engineering Contradiction:
Improveacceleration capabilityVSAvoidvehicle fluctuation
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The control apparatus changes the rate of increase in drive torque based on vehicle speed parameters. When vehicle speed is at or below a predetermined low-speed threshold, the control apparatus limits the rate of increase in drive torque to a predetermined value, preventing abrupt torque changes that cause vehicle fluctuation. When vehicle speed exceeds the threshold, the normal torque increase rate is restored, maintaining acceleration performance.

Inventive Principle:
Principle #35Parameter changes

2Loss of time

If the rate of increase in drive torque is increased to improve acceleration response, then the acceleration response is improved, but vehicle fluctuations occur conspicuously at low-speed state

Engineering Contradiction:
Improveacceleration response timeVSAvoidvehicle stability
Core Design Contradiction:
Loss of timeVSStability of the object's composition

Solution Approach 1:

The control apparatus dynamically adjusts the torque increase rate based on real-time vehicle speed conditions. The system switches between two torque control modes: a limited increase rate mode when vehicle speed is at or below the predetermined low-speed threshold, and a normal increase rate mode when vehicle speed exceeds the threshold. This dynamic adaptation maintains acceleration response while preventing fluctuations at low speeds.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If gear shifting from drive to reverse or reverse to drive is enabled at low vehicle speed, then the versatility of the vehicle is improved, but abrupt changes in forward or backward acceleration occur causing passenger discomfort

Engineering Contradiction:
Improvegear shifting capabilityVSAvoidabrupt acceleration change
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The control apparatus applies preliminary anti-action by detecting when the vehicle is in a low-speed state (at or below the predetermined threshold) and proactively limiting the rate of increase in drive torque before gear shifting occurs. This preventive measure counteracts the potential abrupt acceleration changes that would occur during gear shifting from drive to reverse or reverse to drive, thereby maintaining passenger comfort while preserving gear shifting versatility.

Inventive Principle:
Principle #9Preliminary anti-action

Data Source

PatentEP3620322B1Vehicle control apparatus
Publication Date: 2022.07.20 MITSUBISHI MOTORS CORP
  • EP3620322B1 patent drawingFigure 1
  • EP3620322B1 patent drawingFigure 2
  • EP3620322B1 patent drawingFigure 3

AI summary

A vehicle control apparatus (1,1a) includes a detection section (2), a control section (4). The detection section (2) is configured to detect vehicle information including a vehicle speed of a vehicle (10) driven by an electric motor (12) and drive torque of the electric motor (12). The control section (4) is configured to moderate a rate of increase in the drive torque at the time of acceleration with respect to a rate of increase set in advance on the basis of a detection result of the detection section (2) on condition that the vehicle speed of the vehicle (10) is less than or equal to a predetermined speed and the drive torque is greater than or equal to a predetermined threshold.