Vehicle Shift Control After Momentary Power Interruption

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Solution Overview

Problem

Existing vehicle control devices face issues with unintended shift position switching due to momentary interruptions in the control-device electric-power source, leading to potential misalignment with the driver's intended shift position.

Innovation Solution

The control device incorporates a shift-switching control portion that performs initial position learning processes only after a driver-initiated shift operation, setting reference positions for the actuator based on encoder counts, and temporarily holds the power transmission in a neutral position during interruptions to prevent unintended shifts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If initial position learning process is performed automatically when vehicle electric-power source is switched on, then the actuator reference position is set correctly, but unintended shift position switching occurs after momentary interruption of control-device electric-power source

Engineering Contradiction:

Improveshift position control reliabilityVSAvoiddriver's intended shift position

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The system performs preliminary action by detecting momentary interruptions and preparing to execute initial position learning process only when necessary (after interruption and before driver operation). This resolves the contradiction by proactively identifying the problematic condition and preparing an appropriate response that prevents unintended shift positioning while respecting driver intent.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses feedback by monitoring the state of the control-device electric-power source and detecting momentary interruptions. Based on this feedback, the shift-switching control portion decides whether to perform initial position learning or wait for driver operation, thereby preventing unintended shift positioning while ensuring correct reference position setting when needed.

Inventive Principle:

Principle #23Feedback

2Ease of operation

If initial position learning process is delayed until driver shift operation, then unintended shift switching is prevented, but actuator reference position may not be set correctly after power interruption

Engineering Contradiction:

Improvedriver's intended shift positionVSAvoidshift position control reliability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The system performs preliminary detection of momentary interruptions and prepares the appropriate response (performing or delaying initial position learning) before the driver operates the shift device. This ensures that when the driver does operate the shift device, the actuator reference position is already correctly set, eliminating the need to choose between the two conflicting approaches.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from power source status detection to dynamically adjust the timing of initial position learning. When a momentary interruption is detected, the system feedback-indicates that initial learning should be performed before driver operation; when no interruption occurs, it feedback-indicates that learning should wait for driver operation, thus resolving the contradiction adaptively.

Inventive Principle:

Principle #23Feedback

3Reliability

If actuator reference position is set after momentary interruption, then correct shift positioning is achieved, but storage requirements increase

Engineering Contradiction:

Improveshift position accuracyVSAvoidstorage capacity

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The system uses self-service by utilizing the existing encoder component already present in the actuator to perform position learning. The encoder provides the necessary position information without requiring additional storage capacity, as the learning process uses real-time encoder feedback rather than storing reference positions in memory.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system replaces what would traditionally require storage (memory of reference positions) with a mechanical/electrical sensing approach using the encoder. Instead of storing reference position data, the system uses the encoder to detect and learn positions in real-time, substituting storage requirements with sensing capabilities.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS11215281B2Control device for vehicle

Publication Date: 2022.01.04 TOYOTA JIDOSHA KK

AI summary

A control device for a vehicle including (i) a power transmission device, (ii) a shift operation device that is to be operated by a driver of the vehicle to an operation position corresponding to a shift position of the power transmission device, and (iii) a switching device for switching the shift position of the power transmission device through actuation of an actuator. The control device is configured, upon occurrence of a momentary interruption of a control-device electric-power source that is supplied with an electric power from a vehicle electric-power source, to not perform an initial position learning process for setting a reference position of the actuator, until a shift switching operation for switching the shift position of the power transmission device is performed by a driver of the vehicle.