Vehicle Start Controller Signal Redundancy
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Solution Overview
Problem
Vehicle system start controllers face reliability issues in turning the ignition switch on and off due to failures in hold circuits and analog signal circuits, leading to improper vehicle system operation and potential unintended stopping or failure to start.
Innovation Solution
A vehicle system start controller with a decision circuit that compares main and sub IG instruction signals to determine the ignition switch's state, using a combination of signal generation circuits, vehicle state detection, and failure detection to ensure reliable operation by preventing unnecessary stopping and detecting failures, thereby ensuring the ignition switch can be turned on and off reliably.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If a hold circuit is used to maintain the IG signal at the high level, then the vehicle system can remain running, but the ignition switch cannot be turned off reliably when the hold circuit fails
Solution Approach 1:
The patent divides the single IG signal path into two separate signal generation circuits (main and sub) that independently generate IG instruction signals. This segmentation allows the system to compare signals from different sources and detect failures in either circuit, resolving the contradiction by providing redundancy while maintaining operation continuity.
Solution Approach 2:
The patent implements a feedback mechanism where the decision circuit continuously compares the main IG instruction signal with the sub IG instruction signal. When a discrepancy is detected, the system uses vehicle state information (shift position, brake status) to determine the actual ignition switch state and provides feedback to correct the signal, ensuring reliable ignition switch control even when one circuit fails.
2Reliability
If the IG signal is fixed at the low level due to ignition switch failure, then the vehicle system cannot be started, but adding complex detection circuits increases system complexity
Solution Approach 1:
The decision circuit serves multiple functions: it compares the main and sub IG instruction signals, determines the actual ignition switch state based on vehicle context, and generates the correct IG output signal. This multi-functionality resolves the contradiction by providing comprehensive failure detection and correction without requiring separate dedicated circuits for each function.
Solution Approach 2:
The patent introduces vehicle state information (shift position, brake status) as an intermediary to help the decision circuit determine the actual ignition switch state when signal discrepancies occur. This intermediary information provides context that resolves ambiguities without adding complex direct detection circuits to the ignition switch itself.
3Duration of action of stationary object
If the hold circuit fixes the logical level at the high level, then the vehicle system cannot be stopped, but this creates unintended continuous operation
Solution Approach 1:
The patent performs preliminary comparison of the main and sub IG instruction signals before generating the final IG output. By checking for discrepancies in advance and using vehicle state information to determine the intended ignition switch state, the system prevents unintended continuous operation while maintaining operation duration when properly commanded.
Solution Approach 2:
The patent makes the IG signal generation dynamic by continuously comparing signals from two independent circuits and adjusting the output based on real-time vehicle state information. This dynamic approach allows the system to adapt to failures and correct unintended continuous operation while maintaining operation when properly commanded, resolving the contradiction between duration and harmful factors.
Data Source
AI summary
Start/stop decision circuit receives main and sub IG instruction signals from a hold circuit and a sub line, respectively, and if the signals match in logic, the start/stop decision circuit follows the main IG instruction signal's logic to determine whether an ignition switch is turned on/off. If the main and sub IG instruction signals attain the high and low levels, respectively, and a logic discrepancy is thus caused, and a condition is established for speculating that the vehicle is parked and therefrom a decision is made that the vehicle system will be stopped with high probability, then the start/stop decision circuit determines that the ignition switch is turned off, and start/stop decision circuit detects that the hold circuit has an ON failure and subsequently the start/stop decision circuit stops the vehicle system.