Parking Steering Angle Correction for Elastic Return After Parking

Solution Overview

Problem

Existing parking assistance devices struggle to maintain a steering angle at 0° or its vicinity after automatic steering due to tire and steering member elastic deformation, leading to unintended steering angle changes.

Innovation Solution

A parking assistance device with a steering device, actuating device, and electronic control unit that performs correction control of the steering angle by anticipating and adjusting for the expected return change, using a storage device to update initial values based on actual return amounts and outside air temperature.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If steered wheels are automatically steered to a straight ahead position after parking completion, then the steering angle should be controlled to 0°, but the steering angle returns in the opposite direction due to elastic deformation of tires and steering members

Engineering Contradiction:

Improvesteering angle control precisionVSAvoidsteering angle stability

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The system performs preliminary action by predicting the elastic deformation return amount before releasing steering force, and pre-adjusts the steering angle to compensate for the expected return. This ensures that when the elastic deformation releases, the steering angle remains at or near 0° instead of returning to the opposite direction.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements feedback by detecting the actual steering angle after parking completion, comparing it with the target angle, and automatically adjusting the steering angle based on the detected return amount. This closed-loop control ensures the steering angle is maintained at 0° despite elastic deformation.

Inventive Principle:

Principle #23Feedback

2Manufacturing precision

If a complicated target path is used to set steering angle to 0° at parking completion, then steering angle control is improved, but the path cannot be set when road width or space around target parking position is limited

Engineering Contradiction:

Improvesteering angle control precisionVSAvoidadaptability to limited space

Core Design Contradiction:

Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The system performs preliminary action by predicting the elastic deformation return amount before releasing steering force, and pre-adjusts the steering angle to compensate for the expected return. This ensures that when the elastic deformation releases, the steering angle remains at or near 0° instead of returning to the opposite direction.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system changes parameters by dynamically adjusting the target steering angle based on detected return amounts and environmental conditions. Instead of using a fixed complicated path, the system modifies steering angle parameters in real-time to achieve 0° control in various space conditions.

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If steering angle correction is performed without considering expected return amount, then control process is simple, but the steering angle cannot be brought closer to target steering angle

Engineering Contradiction:

Improvecontrol process complexityVSAvoidsteering angle control precision

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The system performs preliminary action by predicting the elastic deformation return amount before releasing steering force, and pre-adjusts the steering angle to compensate for the expected return. This ensures that when the elastic deformation releases, the steering angle remains at or near 0° instead of returning to the opposite direction.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements feedback by detecting the actual steering angle after parking completion, comparing it with the target angle, and automatically adjusting the steering angle based on the detected return amount. This closed-loop control ensures the steering angle is maintained at 0° despite elastic deformation.

Inventive Principle:

Principle #23Feedback

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

Enhances the likelihood of achieving a target steering angle by correcting the steering angle proactively, preventing unnecessary corrections, and adapting to actual return changes in steering angle due to tire deformation.

Implementation Method 1

a steering angle of the steered wheels change so as to return in a direction opposite to a direction of the automatic steering due to release of elastic deformation of tires of the steered wheels and steering members

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Data Source

PatentUS12509064B2Parking assistance device

Publication Date: 2025.12.30 TOYOTA JIDOSHA KK

AI summary

A parking assistance device that includes an actuating device that automatically steers steered wheels by actuating a steering device, and an electronic control unit that controls the actuating device, and the electronic control unit is configured to control the actuating device such that a vehicle moves to a target parking position when a command for parking assistance is received, in which the electronic control unit is further configured to perform, when parking has been completed, a first steering angle correction that controls the actuating device such that the steering angle changes by a first target steering angle correction amount toward the side opposite to a present steering angle with respect to a target steering angle.