Steering Lock Position Detection Using Digital and Analog Sensors

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Solution Overview

Problem

Existing steering lock devices face inaccuracies in detecting the unlock position of the lock member, which can hinder proper control of the lock and unlock states, leading to potential security issues and operational inefficiencies.

Innovation Solution

The steering lock device incorporates a position detector with both digital and analog output types, utilizing a first unlock detecting portion for binary signals and a second unlock detecting portion with a parabolic output waveform to accurately determine the unlock position by analyzing the positional relationship and changes in the detection signals, ensuring precise identification of the lock member's position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a digital output type position detector is used to detect the unlock position, then the device structure is simple, but the detection accuracy is insufficient

Engineering Contradiction:
Improvedevice structureVSAvoiddetection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent combines a digital output type position detector and an analog output type position detector into a single integrated position detection system. The digital detector provides basic position information with simple structure, while the analog detector provides precise position information. By merging both detection types and using their outputs together in the control unit, the system achieves both structural simplicity and high detection accuracy.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of operation

If only a digital output type position detector is used, then the device is simple to operate, but the unlock position cannot be accurately detected

Engineering Contradiction:
Improveoperation simplicityVSAvoidunlock position detection accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The control unit acts as an intermediary that processes signals from both the digital output type position detector and the analog output type position detector. It integrates the simple operation interface benefit of digital detection with the precise measurement capability of analog detection, automatically determining the unlock position based on combined signal analysis without requiring complex user intervention.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If an analog output type position detector is used alone, then the detection accuracy is high, but the device complexity increases

Engineering Contradiction:
Improveposition detection accuracyVSAvoiddetector structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The position detection function is segmented into two parts: a digital output type position detector for basic position detection and an analog output type position detector for precise position detection. This segmentation allows each detector to be optimized for its specific function, with the digital detector maintaining structural simplicity and the analog detector providing measurement precision, while the control unit coordinates both segments.

Inventive Principle:
Principle #1Segmentation

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 configuration significantly enhances the accuracy of detecting the unlock position, preventing erroneous state changes and ensuring secure vehicle operation by correctly determining the lock member's position, even in the presence of disturbances or sensor abnormalities.

Implementation Method 1

Japanese Laid-Open Patent Publication No. 2012-25269 describes the arrangement of magnetic sensors at a lock position and an unlock position to detect whether the lock member is located in the lock position or the unlock position.

Methodology Applied
Scientific EffectMagnetic field detection: Magnetic Field

Data Source

PatentEP3300964B1Steering lock device
Publication Date: 2019.05.01 KK TOKAI RIKA DENKI SEISAKUSHO
  • EP3300964B1 patent drawingFigure 1
  • EP3300964B1 patent drawingFigure 2
  • EP3300964B1 patent drawingFigure 3~4

AI summary

A steering lock device (1) includes a position detector (27) that detects a position of a lock member (12). The position detector (27) includes a first unlock detecting portion (27b) of a digital output type that detects that the lock member (12) is located in an unlock position from a positional relationship with a detected portion (28) and a second unlock detecting portion (27c) of an analog output type that detects that the lock member (12) is located in an intermediate position, which is between a lock position and the unlock position, from a positional relationship with the detected portion (28). A position determination portion (31) determines whether or not the lock member (12) is located in the unlock position based on a detection signal (Sb) of the first unlock detecting portion (27b) and a detection signal (Sc) of the second unlock detecting portion (27c), which has a parabolic output waveform that changes in accordance with movement of the lock member (12).