Vehicle Operation Device Reference Circuit Failure Detection
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Solution Overview
Problem
Existing operation devices for vehicles face challenges in reliably determining the failure of contact switches due to transient periods and half-pressed states, leading to potential erroneous failure detection and safety issues.
Innovation Solution
The operation device incorporates a configuration with a reference contact circuit and multiple output contact circuits, where the reference contact circuit turns on earlier than the output contact circuits, allowing for accurate failure detection and reducing the influence of rattling, and can continue operation even if one contact circuit fails, using a determination unit to assess the state of each contact circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a monitor signal line is used to detect switch abnormalities, then fixation and disconnection can be detected, but transient periods and half-pressed states cause erroneous failure detection
Solution Approach 1:
The patent segments the monitoring function by introducing a dedicated reference contact circuit separate from the output contact circuits. This reference circuit provides a baseline signal that allows the system to distinguish between transient states (where reference and output circuits show consistent behavior) and actual failures (where inconsistencies occur), thereby improving measurement precision without sacrificing reliability.
Solution Approach 2:
The reference contact circuit acts as an intermediary element that mediates between the switch input and the failure detection logic. By comparing the reference circuit's signal with the output circuits' signals, the system can filter out erroneous detections caused by transient periods and half-pressed states, achieving both high reliability and precision in failure detection.
2Reliability
If multiple contact circuits are monitored simultaneously, then comprehensive failure detection is achieved, but the complexity of determining contact states increases
Solution Approach 1:
The patent divides the contact circuits into two distinct groups: reference contact circuits and output contact circuits. This segmentation simplifies the determination logic by establishing a clear comparison framework - the reference circuits serve as a baseline against which output circuits are measured. This structured approach enables comprehensive monitoring while keeping the complexity manageable through systematic organization.
Solution Approach 2:
The system implements feedback by continuously comparing the states of reference contact circuits with output contact circuits. This feedback mechanism allows the determination unit to automatically identify inconsistencies indicating failures without requiring complex manual analysis, achieving comprehensive detection with controlled complexity through automated comparison logic.
3Productivity
If the movable contact moves from initial position to end position, then all contact circuits should turn on, but rattling causes transient periods where contacts are in uncertain states
Solution Approach 1:
The patent merges the monitoring function into the existing contact circuit structure by adding reference contact circuits that move with the same movable contact. This integration allows the system to monitor multiple circuits simultaneously without requiring separate monitoring mechanisms, maintaining fast response speed while improving reliability through redundant monitoring that can filter out transient instability caused by rattling.
Data Source
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AI summary
An operation device (1) includes three contact circuits (20) each of which includes fixed terminals (21, 22) and a slider (23) as a movable contact that selectively changes a state between the fixed terminals (21, 22) to an ON state or an OFF state, a determination unit (30) to which the contact circuits (20) are connected, and an operation signal generation unit (40) that outputs a signal indicating that an operation unit (10) is in a state of ON operation. In response to an ON operation performed on the operation unit (10), the slider (23) moves from an initial position (P1) where all contact circuits (20) are in an OFF state to an end position (P3) where all contact circuits (20) are turned on. Assuming that one of the contact circuits (20) is a reference contact circuit (20A) and the others are output contact circuits (20B, 20C), the reference contact circuit (20A) is provided such that a distance from the initial position (P1) to a position (P2) where the reference contact circuit (20A) is turned on is smaller than that for the output contact circuits (20B, 20C).