Vehicle Air Dryer Sensor Calibration via Reference Curves
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Solution Overview
Problem
The existing air treatment systems for vehicles face challenges in accurately monitoring humidity due to contamination from lubricating oil substances, leading to inefficient regeneration phases and potential damage to sensors, which results in energy and fuel wastage and limits adaptability to actual operating conditions.
Innovation Solution
An air treatment system that checks the operability of sensors by comparing pressure and humidity/temperature measurement signals, using a combined humidity and temperature sensor to calculate dew point temperature and control regeneration phases, allowing for real-time adaptation and calibration based on reference curves to account for contamination and errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a humidity sensor is used to monitor compressed air humidity for regulating regeneration phases, then energy consumption is reduced by avoiding unnecessary regeneration, but the sensor functionality deteriorates due to contamination from lubricating oil substances
Solution Approach 1:
A reference curve is introduced as an intermediary element that mediates between the contaminated humidity sensor and the control system. The reference curve, established from initial sensor measurements before contamination occurs, serves as a stable reference that filters out the corrupting influence of oil substances. The control system compares current sensor readings against this reference curve to determine actual humidity levels, thereby protecting the control decisions from sensor degradation while maintaining energy-efficient operation.
Solution Approach 2:
The system creates a copy of the ideal sensor behavior through the reference curve. Instead of relying on the deteriorating physical sensor, the system uses the stored reference measurements as a virtual copy of how the sensor should behave under clean conditions. This copying approach allows the system to maintain accurate humidity assessment despite the physical sensor being contaminated, resolving the contradiction between using the sensor for energy savings and protecting it from damage.
2Reliability
If regeneration phases are carried out frequently to ensure dry compressed air, then sensor reliability is maintained by reducing contamination exposure time, but energy consumption increases
Solution Approach 1:
The system implements feedback by continuously comparing current humidity sensor readings against the stored reference curve. This feedback mechanism allows the control system to detect deviations caused by contamination and compensate for them. The feedback loop enables the system to maintain reliable sensor-based control without requiring frequent regeneration phases, thus avoiding the energy penalty while preserving both sensor functionality and control accuracy.
3Device complexity
If operating phases are controlled according to pre-set parameters, then system simplicity is maintained, but adaptability to actual operating conditions deteriorates
Solution Approach 1:
The system introduces dynamics by transitioning from static pre-set parameters to dynamic parameter adjustment based on real-time sensor feedback. The control parameters for regeneration phases are no longer fixed but adapt continuously based on the comparison between current sensor readings and the reference curve. This dynamic approach maintains system simplicity in terms of hardware while achieving high adaptability to actual operating conditions through software-based parameter adjustment.
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 enables precise control of operating phases, reduces energy consumption, and extends sensor lifespan by accurately assessing and correcting measurement deviations, ensuring efficient air treatment while maintaining system reliability.
Implementation Method 1
a measuring device 32 having a temperature sensor 33 for measuring a temperature T and/or a moisture sensor 34 for measuring a moisture content or moisture content F
Implementation Method 2
a pressure sensor 30 or 30a and a second measurement signal S4 from a measuring device 32
Implementation Method 3
the air dryer or the cartridge with drying granulate contained in it absorbs moisture during the conveying phases
Implementation Method 4
The sudden drop in the pressure that occurs when a regeneration phase is initiated essentially leads to an adiabatic expansion of the area behind the air dryer, so that the temperature also drops accordingly
Data Source
Figure 1
Figure 2
AI summary
The air conditioning system (1) has a compressed air inlet for connecting a compressor (2). An air dryer (5) is provided for drying the compressed air entered through the air inlet. A measuring device (32) is arranged in an area (7) after the air dryer for measuring a pressure which is different from the value of the compressed air. A measurement signal (S4) is generated and outputted to a control device (20). An independent claim is also included for a method for verifying the operability of a measuring device in an air conditioning system.