Cabin Humidity Estimation Using a Particulate Matter Sensor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for determining relative humidity in a motor vehicle's passenger compartment require complex electronic resources and additional sensors, which are challenging to install due to spatial constraints, especially in electric vehicles.
Innovation Solution
A method that utilizes a particulate matter sensor equipped with temperature and relative humidity sensors to calculate relative humidity by linking it to partial pressure of water through thermodynamic formulas, eliminating the need for an additional humidity sensor by estimating air temperature in the passenger compartment from the sensor's temperature and dissipated power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If additional humidity sensors are installed to measure relative humidity in the passenger compartment, then measurement precision is improved, but device complexity and spatial requirements increase
Solution Approach 1:
The patent makes the particulate matter sensor perform multiple functions: its primary function of detecting particulate matter concentration and an additional function of determining relative humidity through thermodynamic calculations using temperature and humidity parameters from the same sensor
Solution Approach 2:
The patent combines the humidity measurement function with the existing particulate matter sensor by integrating temperature and relative humidity sensing capabilities into the same device, eliminating the need for separate dedicated humidity sensors
2Measurement precision
If dedicated humidity sensors are added to the vehicle, then relative humidity monitoring capability is improved, but installation difficulty increases due to spatial constraints
Solution Approach 1:
The existing particulate matter sensor is made multi-functional by adding the capability to measure temperature and relative humidity parameters, allowing it to serve both particulate matter detection and humidity monitoring purposes
Solution Approach 2:
The particulate matter sensor uses its own integrated temperature and humidity sensors to generate the data needed for relative humidity determination, eliminating the need for external dedicated humidity sensing equipment
3Measurement precision
If complex electronic processing resources are allocated for humidity data processing, then relative humidity determination accuracy is improved, but device complexity and electronic resource requirements increase
Solution Approach 1:
The patent replaces complex electronic processing systems with thermodynamic calculation methods, using established thermodynamic relationships and formulas (such as the Bertrand-Dupré formula) to determine relative humidity from temperature and humidity parameters
Solution Approach 2:
The patent transforms the measurement approach by changing from direct humidity sensing to indirect determination through thermodynamic parameter relationships, using temperature and partial pressure of water vapor to calculate relative humidity through established thermodynamic equations
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 allows the particulate matter sensor to determine relative humidity effectively, reducing the number of sensors needed and simplifying the installation process, thereby improving passenger compartment air quality monitoring without additional hardware.
Implementation Method 1
a parameter reflecting a specific humidity of the air from a relative humidity of the air and a temperature of the air in a sensor integrating at least one temperature sensor
Implementation Method 2
one relative humidity sensor, preferably a particulate matter sensor
Implementation Method 3
a saturated vapor pressure at the air temperature in the particulate matter sensor is determined by a Bertrand-Dupré thermodynamic formula, so as to deduce therefrom the value of the partial pressure of water in the air
Data Source
Figure 1~2
Figure 3~5
AI summary
The invention relates to a method for determining a relative humidity of the air in a motor vehicle passenger compartment, comprising the following steps: - determining a parameter reflecting a specific humidity of the air from a relative humidity (HR1) of the air and a temperature (T1) of the air in a sensor integrating at least one temperature sensor and one relative humidity sensor, - calculating the relative humidity (HR2) of the air in said passenger compartment of the motor vehicle from said parameter and a temperature (T2) of the air in the passenger compartment.