Vehicle Seat Pressure Sensing With Temperature-Humidity Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle seat occupant monitoring systems face challenges in accurately measuring pressure due to variability in temperature and humidity, leading to imprecise data and long response times, which are inadequate for real-time monitoring in autonomous vehicles.
Innovation Solution
Incorporating temperature and humidity sensors with capacitive sensors in contact with foam to measure pressure, where the capacitance variation is compensated based on temperature and humidity readings, allowing for precise pressure measurement independent of environmental changes, and using a controller to filter out vibrations and improve signal-to-noise ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If capacitive sensors are used to measure pressure on foam, then measurement sensitivity is improved, but measurement precision deteriorates due to temperature and humidity variability
Solution Approach 1:
The system uses temperature and humidity sensors to continuously monitor environmental conditions and feeds this information back to the controller. The controller then applies compensation algorithms to adjust the pressure measurements from capacitive sensors, eliminating the negative impact of temperature and humidity variability and maintaining reliable measurements under changing environmental conditions.
Solution Approach 2:
The system changes the measurement parameters by incorporating temperature and humidity sensors alongside capacitive sensors. By measuring multiple physical parameters (capacitance, temperature, humidity) and using them together in compensation calculations, the system converts the problematic environmental variability into useful compensation data, transforming the measurement approach from direct pressure sensing to environmentally-compensated pressure sensing.
2Measurement precision
If compensation algorithms are implemented to correct temperature and humidity effects, then measurement accuracy is improved, but device complexity increases
Solution Approach 1:
The controller serves multiple functions: it processes signals from capacitive sensors, reads temperature and humidity sensor data, executes compensation algorithms, and outputs corrected pressure measurements. By making the controller multi-functional, the system avoids adding separate dedicated compensation hardware, thereby improving measurement accuracy while limiting the increase in overall device complexity.
Solution Approach 2:
The system merges the pressure sensing function with environmental monitoring and compensation processing into an integrated measurement system. The capacitive sensors, temperature sensors, and humidity sensors are combined in a coordinated measurement approach, and their data processing is merged within a single controller that handles all sensing and compensation operations, reducing the need for separate complex subsystems.
3Loss of information
If multiple sensors are integrated for comprehensive monitoring, then measurement completeness is improved, but response time increases
Solution Approach 1:
The system implements continuous simultaneous measurement of pressure, temperature, and humidity by all sensors, with the controller continuously processing data from all three sensor types. This continuous multi-parameter monitoring ensures complete physiological data capture without sequential delays, maintaining rapid response times while achieving comprehensive measurement coverage.
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 solution enables accurate, real-time pressure measurement and compensation, enhancing the monitoring of vehicle seat occupants with rapid response times suitable for level 3 and 4 autonomous vehicles, providing enriched physiological data and improved safety features.
Implementation Method 1
a measurement system comprising at least one capacitive sensor in contact with the foam and adapted for measuring pressure exerted on the foam by a user... at least one electrode forms a capacitor with the foam. Thereafter, even a slight compression of the foam causes a movement of the at least one electrode, which is measurable. The determination of a distance variation is obtained from the capacitance of the capacitor
Implementation Method 2
The determination of a distance variation is obtained from the capacitance of the capacitor, where the value of the capacitance varies proportionally with the permittivity of the dielectric medium between the sensor and the foam
Implementation Method 3
a seat comprises at least one temperature and/or humidity sensor... a compensation suited to the measured pressure is determined based on a temperature and/or a humidity provided by the at least one temperature and/or humidity sensor
Implementation Method 4
a seat comprises at least one temperature and/or humidity sensor... a compensation suited to the measured pressure is determined based on a temperature and/or a humidity provided by the at least one temperature and/or humidity sensor
Implementation Method 5
at least one electrode forms a capacitor with the foam. Thereafter, even a slight compression of the foam causes a movement of the at least one electrode, which is measurable
Data Source
AI summary
A seat comprising a temperature or a humidity sensor, a foam and a measurement system comprising a capacitive sensor in contact with the foam and adapted for measuring pressure exerted on the foam by the user, a compensation suited to the measured pressure being determined based on a temperature or a humidity provided by the temperature or the humidity sensor.