Capacitance Sensor Noise Detection via Cumulative Sum
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Solution Overview
Problem
Existing operation input detection devices face challenges in accurately distinguishing between genuine operation inputs and external noise, particularly due to the high computational demands of noise separation methods like Fourier transforms, which can increase calculation load.
Innovation Solution
An operation input detection device comprising an operation input detection unit, a change amount accumulation unit, a section variation amount calculating unit, and a noise determination unit, which accumulates and analyzes sensor output changes over a predetermined sampling period to differentiate between genuine inputs and noise based on threshold values, thereby reducing computational load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Fourier transform is used to separate external noise from sensor output, then noise separation reliability is improved, but calculation load increases
Solution Approach 1:
The patent replaces the complex Fourier transform method with a simple cumulative sum calculation that accumulates absolute differences of sensor output values. This 'cheap' computational approach achieves sufficient noise detection without the heavy computational burden of Fourier transform, effectively discarding the need for complex mathematical operations while maintaining practical reliability.
Solution Approach 2:
The patent substitutes the mathematical signal processing mechanism (Fourier transform) with a simpler arithmetic accumulation mechanism. By calculating the cumulative sum of absolute differences and comparing it against a threshold, the system replaces complex frequency domain analysis with straightforward time domain arithmetic, significantly reducing calculation load while maintaining noise detection capability.
2Measurement precision
If Fourier transform is used to separate external noise, then detection accuracy is improved, but processing time increases
Solution Approach 1:
The patent employs a computationally inexpensive cumulative sum method that requires minimal processing time. By accumulating absolute differences of sensor values and comparing against a threshold, the system achieves rapid noise detection without the time-consuming Fourier transform calculations, effectively using a 'cheap' computational approach that processes data quickly.
Solution Approach 2:
The patent skips the intermediate frequency domain analysis step of Fourier transform and directly computes the cumulative sum of absolute differences in the time domain. This rushing through the detection process using simple arithmetic operations significantly reduces processing time while still achieving sufficient detection accuracy for practical applications.
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 enables accurate detection of operation inputs while limiting increases in calculation load, effectively reducing erroneous recognition caused by external noise and enhancing the reliability of the detection process.
Implementation Method 1
a sensor output of a capacitance sensor that changes when a detection subject moves toward and away from the operation input unit
Data Source
AI summary
An operation input detection device includes an operation input detection unit, a change amount accumulation unit, a section variation amount calculating unit, and a noise determination unit. The operation input detection unit detects an operation input on an operation input unit based on a sensor output of a capacitance sensor. The change amount accumulation unit accumulates a change amount of the sensor output in a determination section. The change amount of the sensor output is a difference of a detection value of the sensor output detected as each sampling timing from a previous value of the sensor output. The section variation amount calculating unit calculates a section variation amount of the sensor output.