Vehicle Shift Control During Power-Supply Failure to Reach Parking
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Solution Overview
Problem
Existing vehicle control systems fail to reliably switch the shift position of the power transmission apparatus from a non-parking position to a parking position during a power-supply failure state, as the fail-safe operation is triggered before the power supply can be switched to a backup source, preventing re-drive of the electric actuator.
Innovation Solution
A control apparatus that includes a shift control portion, a fail-safe portion, a power-supply control portion, and an abnormality-detection stop portion, which temporarily inhibits fail-safe operations during power-supply failures until the power is switched to a secondary power supply, allowing re-drive of the electric actuator after the power switch is completed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the fail-safe operation is executed when an abnormal condition of the electric actuator is detected during power-supply failure, then the safety of the system is improved, but the ability to switch shift position to parking is worsened
Solution Approach 1:
The control apparatus switches the power supply to the electric actuator from the first power supply to the second power supply before executing the fail-safe operation. This preliminary power supply switching ensures that the actuator remains operable during the fail-safe sequence, allowing the shift position to be successfully changed to parking despite the abnormal condition detection.
2Duration of action of moving object
If the power supply is switched to the second power supply during power-supply failure, then the continuity of electric power is improved, but the response time for fail-safe operation is worsened
Solution Approach 1:
The control apparatus performs power supply switching as a preliminary action immediately upon detecting power-supply failure, before the fail-safe operation is executed. This ensures continuous power supply to the actuator without delaying the fail-safe response, as the power switching occurs proactively rather than reactively.
3Object-affected harmful factors
If the electric actuator is inhibited from being re-driven due to abnormal condition detection, then the risk of further damage is reduced, but the ability to complete shift position switching is worsened
Solution Approach 1:
The control apparatus switches the power supply to the second power supply before executing the fail-safe operation that would inhibit re-drive. This preliminary power switching ensures the actuator can complete the necessary movement to achieve parking position before the re-drive inhibition takes effect, thus completing the shift position switching while still protecting against further damage.
Data Source
AI summary
A vehicle control apparatus includes: (a) a shift control portion for controlling switching of a power transmission apparatus between a parking position and a non-parking position; (b) a fail-safe portion for executing a fail-safe operation for inhibiting an electric actuator from being re-driven, when detecting an abnormality of the electric actuator; (c) a power-supply control portion for switching a supplier of an electric power to the electric actuator, from a first power supply to a second power supply, in case of determining a power supply failure of the first power supply; and (d) an abnormality-detection stop portion configured, in case of occurrence of a power-supply failure state of the first power supply during the switching from the non-parking position to the parking position, to stop the fail-safe portion from detecting the abnormality of the electric actuator, until the electric power supplier has been switched to the second power supply.