Automatic Transmission Parking Lock Emergency Release Detection
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Solution Overview
Problem
Existing automatic transmission devices with parking lock systems lack a reliable method to detect when the emergency release device has been used to deactivate the parking lock, leading to uncertainty about the operational state of the parking lock device.
Innovation Solution
A method that utilizes a position sensor to determine if the selector shaft has been moved outside the operating position range, with additional checks on the distance covered and the hydraulic valve's current deviation, to confirm the actuation of the emergency release device and ensure the parking lock is deactivated.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the emergency release device is used to deactivate the parking lock, then the parking lock is deactivated and the vehicle can be driven, but the system cannot reliably detect that the emergency release has been activated
Solution Approach 1:
The control unit continuously monitors the position of the selector shaft and compares it against the expected position range. When the selector shaft position deviates from the normal range, the system generates feedback indicating emergency release activation, allowing reliable detection of the emergency release state without adding complex sensors
Solution Approach 2:
The position sensor acts as an intermediary element that indirectly detects emergency release activation. Instead of directly sensing the emergency release device state, the system uses the selector shaft position as a mediator to infer whether the emergency release has been activated, simplifying the detection mechanism
2Measurement precision
If the selector shaft position is continuously monitored to detect emergency release activation, then detection reliability improves, but the complexity of the detection system increases
Solution Approach 1:
The position sensor serves multiple functions: it monitors the selector shaft position for normal operation, detects emergency release activation, and provides feedback for control decisions. By making the position sensor multi-functional, the system achieves precise emergency release detection without adding dedicated detection components
Solution Approach 2:
The existing position sensor and control unit perform the emergency release detection function as part of their normal operation. The control unit uses its existing processing capabilities to analyze position data and detect emergencies, allowing the system to self-monitor without requiring additional detection hardware or processing resources
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
This method allows for reliable detection of the emergency release device's activation, preventing unintentional locking and ensuring the parking lock is properly deactivated, thereby avoiding erroneous detection and maintaining the vehicle's operational state.
Implementation Method 1
a hydraulic device with a hydraulic cylinder and a hydraulic piston arranged therein, wherein the hydraulic piston can be displaced in the hydraulic cylinder by means of a pressure present in the hydraulic cylinder
Implementation Method 2
a position sensor detects a position of the selector shaft, which is outside the operating position range
Data Source
AI summary
The invention relates to a method for operating an automatic transmission apparatus (1) with a parking lock device (2), wherein the parking lock device (2) has a hydraulic apparatus (3) with a hydraulic cylinder (4) and a hydraulic piston (5) which is arranged therein and can be secured in at least two positions by means of a locking apparatus (7), and an emergency unlocking apparatus (12), wherein the hydraulic piston (5) is operatively connected to a switching shaft (6) of the parking lock device (2), and a pressure can be set in the hydraulic cylinder (4) by means of a hydraulic valve (9), and wherein the switching shaft (6) can be moved within an operating position range by means of the hydraulic apparatus (3). In this context there is provision that when the emergency unlocking apparatus (12) is actuated, the switching shaft (6) is moved into a position which lies outside the operating position range, and that an operating state of the emergency unlocking apparatus (12) is checked, wherein an activated emergency unlocking apparatus (12) is detected if, over a specific time period, a position sensor detects a position of the switching shaft (6) which lies outside the operating position range and/or if a distance travelled by the switching shaft (6) and detected by means of the position sensor exceeds a limiting value. The invention further relates to an automatic transmission apparatus (1).