Parallel Switch Steering Control for Abnormality Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing configuration of connecting multiple switches in series for validating lever operations in wheel loaders makes it difficult to determine which switch has an abnormality, leading to inefficiencies in steering device control.
Innovation Solution
A steering device with a first switch and a second switch connected in parallel to the control device, where the first switch sets the steering signal to valid or invalid states, and the second switch conduction changes based on the lever support member's position, allowing the control device to determine abnormal states simply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple switches are connected in series to validate lever operation, then the reliability of preventing misoperation is improved, but the difficulty of detecting which switch has an abnormality increases
Solution Approach 1:
The patent divides the series connection into two separate circuits: a first switch circuit for validating lever operation and a second switch circuit for detecting lever support member position. This segmentation allows independent monitoring of each switch's state, enabling identification of which specific switch has an abnormality while maintaining the reliability benefits of multiple switches.
Solution Approach 2:
The control device acts as an intermediary that receives signals from both switches and determines the operational state based on their combined states. This intermediary processing enables the system to identify abnormal switches by analyzing the signal patterns from each switch independently, rather than having them connected in series where failure points cannot be distinguished.
2Reliability
If multiple switches are connected in series, then the safety against unintentional steering is improved, but the device complexity for determining switch abnormality increases
Solution Approach 1:
The patent segments the switch arrangement into two independent circuits with distinct functions. The first switch circuit validates lever operation while the second switch circuit monitors lever support member position. This segmentation simplifies the determination of switch abnormalities because each circuit can be evaluated independently, reducing the complexity compared to analyzing a series connection where multiple failure points are indistinguishable.
Solution Approach 2:
The control device receives feedback signals from both switches and uses this information to determine the operational state and identify any abnormalities. The feedback mechanism allows the system to monitor each switch's state separately and pinpoint which switch has failed, reducing the complexity of abnormality determination while maintaining safety.
3Reliability
If switches are connected in series, then the validation of lever operation is more reliable, but the time required to diagnose switch abnormalities increases
Solution Approach 1:
The patent segments the switch validation into two separate circuits that can be evaluated independently. The first switch circuit validates lever operation and the second switch circuit monitors lever support member position. This segmentation enables rapid diagnosis of switch abnormalities because the control device can immediately identify which circuit is malfunctioning without having to test each switch in a series connection sequentially.
Solution Approach 2:
The control device receives simultaneous feedback from both switches and processes their states to determine operational validity and identify abnormalities. This feedback mechanism reduces diagnosis time by providing immediate information about which switch has failed, rather than requiring sequential testing of series-connected switches.
Data Source
AI summary
A steering device of a working vehicle includes a lever, a first switch, a lever support member, a second switch, and a control device. The first switch sets a steering signal to be in a valid/invalid state. The lever support member is provided so as to be able to flip up from a certain position of performing tilting operation. The second switch attains conduction when the lever support member is located at the certain position, and attains non-conduction in conjunction with the case where the lever support member is flipped up. The control device sets steering with use of the lever to be valid/invalid. The first switch has a plurality of terminals which respectively attain conduction of a steering signal in accordance with a setting of a valid state and an invalid state and are electrically connected to the control device in parallel with the second switch.