Shift-by-wire Control Device Maintaining Forward Range
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Solution Overview
Problem
Shift-by-wire type control devices for automatic transmissions face issues with abnormal activation during vehicle travel, leading to reduced driver drivability due to inability to maintain pre-reset states, particularly in distinguishing between neutral and forward ranges.
Innovation Solution
Incorporating an electronic control unit that controls a hydraulic actuated transmission mechanism with solenoids to form a specific forward shift speed when power is interrupted, allowing the automatic transmission to remain in the forward range during abnormal activation, thereby maintaining drivability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the shift range is set to neutral range when vehicle speed exceeds threshold after reset, then occurrence of strange noise is suppressed, but driver's drivability deteriorates due to loss of drive power perception
Solution Approach 1:
The patent changes the control parameter from a fixed neutral-range setting to a variable shift range selection based on detected transmission state. By monitoring whether a specific shift speed is formed in the transmission mechanism, the system dynamically adjusts the post-reset shift range to match pre-reset conditions, thereby maintaining drivability while avoiding noise through intelligent parameter adaptation
Solution Approach 2:
The patent implements a feedback mechanism by detecting whether a specific shift speed is formed in the transmission mechanism after reset. This detection feedback allows the control device to determine the pre-reset shift range and maintain appropriate drivability, converting the harmful noise issue into a controlled state through continuous monitoring and adaptive response
2Device complexity
If the control device uses mechanical position of to-be-operated part for shift range identification, then结构简单性 is maintained, but ability to identify shift range after abnormal activation is lost
Solution Approach 1:
The patent introduces an intermediary detection mechanism that monitors the transmission mechanism's shift speed state. This intermediary feedback allows the control device to infer the shift range without directly relying on mechanical position sensing, thereby maintaining structural simplicity while improving reliability of shift range identification after abnormal activation
Solution Approach 2:
The patent replaces direct mechanical position detection with a hydraulic/control system-based shift speed detection method. By monitoring whether a specific shift speed is formed in the transmission mechanism, the system substitutes mechanical position reliance with a more reliable control-state-based identification method that works effectively after abnormal activation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables continuous forward travel and reduces driver perceived loss of power by determining the pre-abnormal activation shift range and maintaining it post-activation, thus enhancing driver experience.
Implementation Method 1
a hydraulic control device that includes a solenoid and that controls hydraulic pressure supplied to the transmission engagement device, the solenoid operating by receiving power supply
Implementation Method 2
a transmission mechanism including a hydraulic actuated transmission engagement device
Data Source
AI summary
A shift-by-wire type control device whose control target is an automatic transmission including a parking lock mechanism, the shift-by-wire type control device includes an electronic control unit that controls the automatic transmission in response to an instruction to select a shift range when selection of the shift range based on an operation on a to-be-operated part is performed.