Electrostatic Sensor Reference Capacitance Control

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Solution Overview

Problem

Existing electrostatic sensors with multiple detection areas face challenges in improving operability due to inaccuracies in determining operations caused by fluctuations in parasitic capacitance from environmental factors and noise.

Innovation Solution

The electrostatic sensor employs a control device that detects electrostatic capacitance between an operated member and electrodes, determines operations based on differences in capacitance, and dynamically adjusts the reference capacitance to differentiate between changes caused by environmental factors and noise, thereby enhancing accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the reference electrostatic capacitance is dynamically changed based on capacitance changes in detection areas, then the sensor adapts to environmental fluctuations, but noise may cause inappropriate reference changes leading to inaccurate operation determination

Engineering Contradiction:

Improveadaptation to environmental fluctuationsVSAvoidoperation determination accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent combines the capacitance change data from multiple detection areas and applies a majority vote mechanism to determine whether to update the reference electrostatic capacitance. By merging information from multiple areas, the system can distinguish between environmental fluctuations (affecting multiple areas similarly) and noise (affecting areas differently), thus improving both adaptability and measurement precision

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The system implements a feedback mechanism where the determination result from multiple detection areas is used to control whether the reference electrostatic capacitance is updated. The feedback loop ensures that reference capacitance changes only occur when environmental fluctuations are confirmed across multiple areas, preventing noise-induced inappropriate changes while maintaining adaptability to genuine environmental changes

Inventive Principle:

Principle #23Feedback

2Measurement precision

If the reference electrostatic capacitance is held constant, then noise-induced inappropriate changes are prevented, but the sensor cannot adapt to genuine environmental fluctuations

Engineering Contradiction:

Improveoperation determination accuracyVSAvoidadaptation to environmental fluctuations

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent introduces dynamic control of the reference electrostatic capacitance based on the determination results from multiple detection areas. The reference capacitance transitions between held constant and updated states according to whether environmental fluctuations or noise is detected, enabling the system to adapt to genuine environmental changes while maintaining stability against noise

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

A feedback mechanism controls the reference electrostatic capacitance update based on the majority vote result from multiple detection areas. When environmental fluctuations are detected (majority of areas show similar capacitance changes), the reference capacitance is updated; when noise is detected (areas show different changes), the reference capacitance is held constant, achieving both adaptability and precision

Inventive Principle:

Principle #23Feedback

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 improves the sensor's ability to accurately distinguish between valid operations and environmental noise, ensuring reliable operation even under conditions of fluctuating parasitic capacitance, thus enhancing the overall operability of the sensor.

Implementation Method 1

a detection device configured to detect an electrostatic capacitance between an operated member having a plurality of detection areas and an electrode having areas associated with the detection areas respectively

Methodology Applied

Scientific EffectElectrostatic capacitance: Capacitance

Implementation Method 2

an electrostatic sensor equipped with an operated member (a member to be operated) having a plurality of detection areas

Methodology Applied

Scientific EffectElectrostatic field: Electric Field

Data Source

PatentUS11467700B2Electrostatic sensor, control device, and non-transitory computer-readable medium

Publication Date: 2022.10.11 KK TOKAI RIKA DENKI SEISAKUSHO

AI summary

A detection device is configured to detect an electrostatic capacitance between an operated member having a plurality of detection areas and an electrode having areas associated with the detection areas respectively. A control device is configured to determine whether an operation is performed to each of the detection areas based on whether a difference between the electrostatic capacitance and a reference electrostatic capacitance exceeds a threshold range, and to change the reference electrostatic capacitance based on a change in the electrostatic capacitance. The control device holds the reference electrostatic capacitance in a case where different changes in the electrostatic capacitance are detected between the detection areas.