Vehicle Seat Capacitance Compensation Under Heating Interference
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Solution Overview
Problem
Capacitive sensors with interdigitated electrodes on vehicle seats are often disturbed by the operation of heating systems, leading to unreliable detection of seat occupancy due to complex and unreliable electronic circuits.
Innovation Solution
A method involving adaptive and continuation compensation of capacitance values measured by interdigitated electrodes, with a learning phase to adjust compensation values, and a phased compensation approach to enhance detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If heating system is activated to provide thermal comfort, then temperature comfort is improved, but capacitance measurement accuracy deteriorates due to interference
Solution Approach 1:
The controller receives a warning signal indicating the heating system will be activated and applies adaptive compensation in advance during an initial phase. This preliminary action allows the system to prepare for the upcoming interference from the heating system, adjusting compensation values before the full thermal interference occurs, thereby maintaining measurement accuracy while the heating system operates.
Solution Approach 2:
The system dynamically changes the compensation parameter based on the heating system state. When heating is activated, the controller modifies the capacitance compensation values through adaptive compensation during an initial phase and continuation compensation during a continuation phase. This parameter adjustment compensates for the thermal interference effect, allowing accurate occupancy detection despite the heating system operating at elevated temperatures.
2Difficulty of detecting and measuring
If complex electronic circuits are used for occupancy detection, then detection capability is improved, but reliability deteriorates
Solution Approach 1:
The patent introduces an intermediary compensation mechanism between the capacitive sensor and the occupancy detection logic. Instead of relying on complex electronic circuits alone, the system uses a compensation value that mediates the effect of heating interference on the capacitance measurement. This intermediary approach simplifies the electronic circuit requirements while maintaining reliable detection by mathematically compensating for thermal effects.
Solution Approach 2:
The controller implements a feedback mechanism by continuously monitoring capacitance values and applying adaptive compensation based on the heating system state. The system adjusts compensation values in response to measured capacitance changes, creating a closed-loop feedback system that improves reliability. This feedback approach replaces complex open-loop electronic circuits with a simpler, more reliable adaptive compensation algorithm.
3Measurement precision
If adaptive compensation is applied continuously, then measurement accuracy is improved, but energy consumption increases
Solution Approach 1:
The system implements periodic action by dividing the heating operation into distinct phases: an initial phase with adaptive compensation and a continuation phase with continuation compensation. The controller switches between different compensation strategies based on the phase, rather than applying maximum adaptive compensation continuously. This periodic approach maintains measurement accuracy during critical transition periods while reducing energy consumption during stable operating conditions.
Solution Approach 2:
The system applies partial compensation rather than excessive continuous compensation. During the initial phase, adaptive compensation is applied to establish accurate baseline measurements, but during the continuation phase, the system uses a simpler continuation compensation with a constant value. This partial action approach provides sufficient compensation to maintain accuracy without the excessive energy consumption of continuous high-level adaptive compensation.
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
Enhances the reliability and accuracy of seat occupancy detection by minimizing interference from heating systems, using a controller to apply adaptive and continuation compensation to capacitance values.
Implementation Method 1
capacitive sensors with interdigitated electrodes mounted on a seat of a vehicle... capacitance values measured by the capacitive sensors
Implementation Method 2
the seat being equipped with a heating system... warning signal indicating an operating or non-operating state of the heating system
Data Source
AI summary
The present disclosure relates to a method for processing capacitance values generated by capacitive sensors with interdigitated electrodes supported by a seat of a vehicle.