Vehicle Steering Control Device for Locus Stabilization

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Solution Overview

Problem

When individually correcting the steered angles of right and left wheels during vehicle curvature, existing systems cause fluctuations in the turning state, leading to deviations from the desired travel route, resulting in suboptimal vehicle behavior and energy loss.

Innovation Solution

A control device with a processor that independently controls the steered angles of each wheel by determining and adjusting turning command values based on vehicle behavior state quantities, optimizing the vehicle's behavior to follow a target route, and stabilizing the turning locus through a linkless steer-by-wire system using actuators and sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the steered angles of the right and left steered wheels are individually corrected to improve vehicle behavior and suppress energy loss, then the marginal performance of vehicle behavior is improved and energy loss is suppressed, but the total sum of tire lateral force changes causing fluctuation in the turning state and deviation from the desired travel route

Engineering Contradiction:
Improveenergy loss of steered wheelsVSAvoidstability of turning state
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The control device employs feedback mechanisms by continuously monitoring the actual travel route and vehicle state quantities, then adjusting the steered angles of right and left steered wheels based on the difference between actual and target routes. This closed-loop control ensures that individual wheel angle corrections do not cause cumulative deviations, maintaining stable turning state while achieving energy efficiency.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts steered angles as control parameters based on vehicle speed, steering angle, and desired travel route. By changing the steered angle parameters adaptively rather than using fixed corrections, the system optimizes energy loss suppression while preventing turning state fluctuation and route deviation.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the steered angles of the right and left steered wheels are individually corrected to optimize vehicle behavior, then the marginal performance of vehicle behavior is improved, but the vehicle may deviate from the desired travel route

Engineering Contradiction:
Improvemarginal performance of vehicle behaviorVSAvoidaccuracy of travel route
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The control device continuously compares the actual travel route with the desired travel route and uses this feedback to adjust the steered angles of right and left steered wheels. This ensures that performance optimization through individual wheel correction does not compromise route accuracy, as any potential deviation is detected and corrected in real-time.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary calculations to determine the optimal steered angles for right and left steered wheels based on the desired travel route and current vehicle state. By pre-calculating the necessary angle corrections and applying them proactively, the system maintains both optimized vehicle behavior and accurate route following.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If a linkless steer-by-wire system is used to independently control steered wheels, then ease of operation and adaptability are improved, but device complexity increases

Engineering Contradiction:
Improveindependent control of steered wheelsVSAvoidcomplexity of control system
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent implements a linkless steer-by-wire system that replaces traditional mechanical linkages connecting the steering wheel to steered wheels with electronic control. This substitution enables independent control of right and left steered wheels, improving ease of operation and adaptability, while the electronic architecture manages the inherent complexity through software-based control algorithms.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP3753810B1Control device and turning device
Publication Date: 2023.08.02 JTEKT CORP
  • EP3753810B1 patent drawingFigure 1
  • EP3753810B1 patent drawingFigure 2
  • EP3753810B1 patent drawingFigure 3

AI summary

A control device includes a processor (140). The processor (140) is configured to perform a route acquisition process for acquiring route information indicating a target route of a vehicle. The processor (140) is configured to perform a behavior optimization process for correcting, based on at least one of a plurality of state quantities indicating a behavior of the vehicle during traveling, each of a left turning command value and a right turning command value such that the behavior of the vehicle becomes a target behavior. The processor (140) is configured to perform a locus stabilization process for correcting, based on at least one of the state quantities indicating the behavior of the vehicle during traveling, a steering command value such that the vehicle travels on the target route.