Capacitive Sensor Electrode Evaluation With Variable Charging Pulses
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Solution Overview
Problem
High-frequency cyclical charging of capacitive sensor electrodes generates undesired alternate electromagnetic fields, violating electromagnetic radiation norms and requiring stringent construction and operation standards.
Innovation Solution
The method involves varying the charging pulse durations during capacitive sensor electrode evaluation, reducing frequency-dependent irradiation peaks by spreading energy density across a wider frequency range, allowing for more flexible configuration and faster evaluation while adhering to normative requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high-frequency cyclical charging is used to ensure reliable evaluation in sufficiently short time, then evaluation speed is improved, but electromagnetic radiation increases causing normative violations
Solution Approach 1:
The patent applies dynamics by making the charging frequency variable rather than fixed. The control device adjusts the charging frequency dynamically based on evaluation requirements, allowing the system to operate at lower frequencies when possible to reduce electromagnetic radiation, while still achieving reliable evaluation within acceptable time frames.
Solution Approach 2:
The patent changes the parameter of charging frequency from a constant high value to a variable parameter that can be adjusted. By modifying the frequency parameter adaptively, the system achieves both reduced electromagnetic radiation and maintained evaluation reliability, resolving the contradiction between speed and radiation levels.
2Productivity
If high charging frequencies are used to reduce evaluation time, then productivity is improved, but device complexity increases due to stringent construction and operation standards
Solution Approach 1:
The patent simplifies device complexity by changing the operating parameter from fixed high frequency to variable frequency. This allows the control device to select optimal frequencies that meet evaluation requirements without consistently operating at maximum frequencies, thereby reducing the stringency of construction and operation standards needed.
Solution Approach 2:
By implementing dynamic frequency adjustment, the system avoids the need for complex fixed high-frequency design requirements. The control device can adaptively select frequencies, reducing the complexity of construction and operation standards while maintaining high productivity when needed.
3Device complexity
If fixed charging frequency is used to simplify control, then device complexity is reduced, but adaptability decreases when different evaluation conditions require different frequencies
Solution Approach 1:
The patent implements dynamics by providing a control device that can adjust charging frequency based on different evaluation conditions. This dynamic capability allows the system to adapt to various requirements while maintaining relatively simple control architecture, resolving the contradiction between simplicity and adaptability.
Solution Approach 2:
The control device is designed with multi-functionality, capable of operating at multiple frequency levels to满足不同 evaluation conditions. This universal design allows a single device to handle both simple and complex evaluation scenarios, improving adaptability without proportionally increasing complexity.
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 reduces electromagnetic radiation issues, enabling the use of higher frequencies for evaluation, increasing speed, and allowing for flexible configuration and cost-effective implementation by adapting control electronics.
Implementation Method 1
The sensor electrode forms a capacity with a reference electrode
Implementation Method 2
the electrostatic properties of the entire system are changed
Implementation Method 3
the sensor electrode is coupled to a charging circuit for a coupling duration tK. During the coupling of the sensor electrode with the charging circuit, the sensor electrode is partially or completely filled with an electric charge
Data Source
AI summary
A method for evaluating a capacity value of a capacitive sensor electrode includes an evaluation process, which includes performing a charging process of a sensor electrode, and evaluating a parameter, which depends on the capacity value of the sensor electrode. A first charging pulse duration tL,1 for the charging process includes a first coupling duration tK,1 and a first decoupling duration tE,1 with tL,1=tK,1+tE,1, of a first coupling and decoupling cycle. A second charging pulse duration tL,2, includes a second coupling duration tK,2 and a second decoupling duration tE,2 with tL,2=tK,2+tE,2, of a second coupling and decoupling cycle immediately following the first coupling and decoupling cycle. These differ from each other by a first pulse duration difference ΔtL,1.