Transmission Pressure Sensor Control for Altitude Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for operating a transmission device, such as a nine-speed transmission, face challenges in accurately determining changes in operating states due to variations in ambient pressure and altitude, leading to delayed or premature initiation of transmission functions, which affects driving comfort.
Innovation Solution
The method involves using a sensor device upstream of the throttle device to determine pressure signals corresponding to operating pressure, with threshold values calculated from the sum of ambient pressure and a pressure offset, allowing for accurate determination of operating state changes and requested states, thereby improving driving comfort by adjusting hydraulic fluid flow and accounting for pressure delays and resistances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an absolute pressure sensor is used to determine operating pressure, then the pressure signal can be measured, but the measurement precision deteriorates due to ambient pressure variations and altitude changes
Solution Approach 1:
A reference pressure sensor is introduced as an intermediary element to measure ambient pressure separately. This reference measurement acts as a mediator that allows the system to distinguish between ambient pressure variations and actual operating pressure changes, thereby compensating for the harmful effects of ambient pressure on the absolute pressure sensor measurements
Solution Approach 2:
The system changes the parameter being measured by using a differential pressure measurement approach. Instead of relying solely on absolute pressure values, the system measures the difference between absolute pressure and reference (ambient) pressure, which isolates the operating pressure signal from ambient pressure variations and altitude effects
2Ease of operation
If threshold values are used to determine operating state changes, then the control logic is simplified, but the reliability deteriorates due to delayed or premature function initiation
Solution Approach 1:
The system implements feedback by continuously monitoring the pressure signal and comparing it against dynamically adjusted threshold values. The feedback loop allows the control unit to detect when the pressure signal exceeds or falls below thresholds, triggering appropriate responses while compensating for ambient pressure variations through reference sensor data, thereby maintaining both simplicity and reliability
Solution Approach 2:
The threshold values are made dynamic rather than fixed, allowing them to adapt to changing ambient conditions. By adjusting thresholds based on reference pressure measurements, the system maintains accurate operating state detection across varying environmental conditions without complicating the control logic
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 approach ensures more precise control of transmission operations, reducing undersupply issues and maintaining high driving comfort by accurately determining operating state changes and adjusting hydraulic fluid flow, even under varying ambient conditions and after system restarts or downtimes.
Implementation Method 1
through a sensor device upstream of a throttle device, which is connected to a transmission area essentially featuring ambient pressure, a value of a pressure signal corresponding to the operating pressure of a positive-locking shifting element of the transmission device can be determined
Data Source
AI summary
A method for operating a transmission device, which is transferable into different operating states through the actuation of shifting elements, is described. At least one of the shifting elements is designed as a positive-locking shifting element, which is supplied with operating pressure for presenting a defined operating state of the transmission device. Through a sensor device upstream of a valve device, which is connected to a transmission area essentially featuring ambient pressure, a value of a pressure signal corresponding to the operating pressure can be determined. Upon exceeding a threshold value of the pressure signal, currently in the area of the positive-locking shifting element, a change in operating state is determined, and, upon falling short of an additional threshold value of the pressure signal, the reaching of the requested operating state is established. In a non-actuated operating state of the positive-locking shifting element, the pressure in the transmission area is established by the sensor device. Upon the presence of a request for a change in operating state in the area of the positive-locking shifting element, the threshold value and the additional threshold value are determined from the sum of the pressure calculated in the transmission area prior to the presence of the request for the change in operating state and a pressure offset value.