Capacitive Sensor Noise Correction with Adaptive Sampling Timing
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Solution Overview
Problem
Capacitive touch sensors face challenges in noise rejection, leading to increased sampling requirements that slow response times and degrade signal quality, as existing solutions lack active noise tuning capabilities and are limited by static optimization techniques.
Innovation Solution
The system actively optimizes signal-to-noise ratio by real-time tuning of waveform timing and digital filters, using noise measurement techniques such as running averages or interquartile range to adjust oversampling and timing parameters, thereby minimizing noise at the acquisition stage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple samples are taken to verify the result and reject noise, then noise rejection capability is improved, but response time increases and system performance degrades
Solution Approach 1:
The patent applies dynamics by making the sampling rate adjustable rather than fixed. The system dynamically changes the sampling rate based on detected noise conditions, allowing it to sample at higher rates when noise is present and at lower rates when the environment is quiet, thus resolving the contradiction between noise rejection and response time
Solution Approach 2:
The patent changes the sampling rate parameter based on noise detection. By monitoring noise levels and adjusting the sampling rate accordingly, the system can optimize between taking multiple samples for noise rejection versus maintaining fast response time, directly addressing the technical contradiction
2Ease of operation
If a fixed sampling rate is used, then the system is simple to operate, but performance degrades at certain noise frequencies
Solution Approach 1:
The system transitions from a static fixed sampling rate to a dynamic adaptive sampling rate that automatically adjusts based on detected noise conditions. This maintains ease of operation while improving signal quality across varying noise frequencies
Solution Approach 2:
The patent implements feedback by continuously monitoring noise levels and using this information to adjust the sampling rate. This closed-loop approach ensures the system automatically adapts to different noise frequencies without user intervention, maintaining both simplicity and performance
Data Source
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AI summary
A system (702) for reducing noise in a sensor measurement system includes a noise detector (806) for detecting noise in capacitive to digital conversion measurements; a noise correction module (808) operably coupled to the noise detector and configured to dynamically modify one or more delays associated with a sampling waveform (input 802); and a noise filter (804) for filtering the sampling waveform.