Vehicle Control Circuits for Synchronized Restart After Power Latch
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Solution Overview
Problem
In steer-by-wire systems, when a vehicle is powered on while power latch control is being performed after being powered off, the control arithmetic units may recognize powering-on at different timings due to varying wiring resistance, leading to mismatched start timings and potential unintended arithmetic results or state transitions.
Innovation Solution
A control device with multiple control circuits that start only after all circuits have recognized the vehicle's powering-on, ensuring synchronized start timings. This is achieved through mutual confirmation processes among the control circuits, using flags to determine when all circuits have recognized powering-on.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If control arithmetic units operate independently after powering on during power latch control, then each unit can start its operation, but the start timings become mismatched leading to unintended arithmetic results or state transitions
Solution Approach 1:
The patent applies preliminary action by having control arithmetic units enter a standby state after powering on, before actually resuming operation. Each unit determines whether to enter standby based on voltage comparison, and the unit with the earliest resume timing enters standby to wait for other units. This preliminary standby action prevents mismatched operations while maintaining fast resumption capability.
Solution Approach 2:
The patent uses feedback mechanisms where control arithmetic units monitor system voltage and compare it against reference values to determine their operational state. The units exchange information about their resume timings and adjust their operation accordingly, with later units waiting for confirmation from earlier units before resuming. This feedback loop ensures synchronized operation while maintaining productivity.
2Reliability
If control arithmetic units wait for all units to recognize powering-on before starting, then synchronized start timing is achieved, but operation resumption is delayed
Solution Approach 1:
The patent applies preliminary action by having control arithmetic units perform voltage comparison and determine their resume timing in advance, then enter a standby state rather than waiting passively. The unit with the earliest calculated resume timing enters standby and prepares to resume first, while other units prepare to follow. This preliminary preparation enables fast, synchronized resumption without delayed waiting.
Solution Approach 2:
The patent implements dynamic operation where control arithmetic units can transition between different states (operation, standby, suspension) based on real-time voltage conditions and mutual confirmation. Rather than a static wait-all-units approach, the system dynamically adjusts which unit operates when, allowing the earliest-ready unit to resume first while ensuring others follow in proper sequence, thus maintaining both speed and synchronization.
Data Source
AI summary
A control device for a vehicle includes a plurality of control circuits configured to control a control object by starting in response to powering-on of a vehicle and to perform power latch control for continuing to be supplied with electric power in a predetermined period in response to powering-off of the vehicle. Each of the control circuits is configured to perform starting after all of the control circuits have recognized the powering-on of the vehicle in a case where the vehicle is powered on while the power latch control is being performed after the vehicle has been powered off.