Dynamic Digital Input Filtering for Noise-Resistant Discrete I/O

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Solution Overview

Problem

Industrial control systems face challenges in differentiating signal levels due to electrical noise, which can cause false readings, and existing solutions struggle to balance impedance to minimize noise while managing power consumption and heat dissipation effectively.

Innovation Solution

A Dynamic Digital Input Filtering system that dynamically adjusts the input impedance of logic devices in response to changing electrical noise environments, using impedance adjusting circuits and algorithms to monitor and control impedance levels, thereby optimizing power efficiency and signal integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the impedance of the logic device is reduced to minimize the effects of electrical noise, then the noise immunity is improved, but the power consumption and heat dissipation increase

Engineering Contradiction:
Improvenoise immunityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements dynamic impedance adjustment by switching between high-impedance and low-impedance states based on detected signal conditions. The logic device monitors for false transitions caused by electrical noise and only switches to low-impedance mode when noise is detected, rather than maintaining low impedance continuously. This dynamic approach resolves the contradiction by providing noise immunity only when needed, while maintaining power efficiency during normal operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the impedance parameter dynamically based on operating conditions. A controller monitors the digital input signal for false transitions indicative of electrical noise interference and adjusts the impedance parameter accordingly - switching to low impedance when noise is detected and returning to high impedance when noise is absent. This parameter change strategy allows the system to optimize between noise immunity and power consumption based on real-time conditions.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the impedance is continuously kept low to ensure signal integrity in noisy environments, then the signal reliability is improved, but the power consumption increases and heat dissipation worsens

Engineering Contradiction:
Improvesignal integrityVSAvoidheat dissipation
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The system dynamically adjusts impedance based on detected noise conditions rather than maintaining a static low-impedance state. The controller monitors for false signal transitions and only switches to low-impedance mode when electrical noise is detected, thereby maintaining signal integrity only when necessary. This dynamic behavior reduces continuous power consumption and heat dissipation while preserving signal reliability when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements a feedback mechanism where the controller monitors the digital input signal for false transitions caused by electrical noise. Based on this feedback, the controller automatically adjusts the impedance state - switching to low impedance when noise-induced false transitions are detected and returning to high impedance when the signal is clean. This feedback-driven approach ensures signal integrity is maintained only when necessary, optimizing the balance between reliability and energy loss.

Inventive Principle:
Principle #23Feedback

3Use of energy by moving object

If the impedance is increased to reduce power consumption, then the power efficiency is improved, but the ability to differentiate signal levels in noisy environments deteriorates

Engineering Contradiction:
Improvepower efficiencyVSAvoidsignal differentiation
Core Design Contradiction:
Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The patent employs dynamic impedance switching to overcome the limitations of static high-impedance design. The system operates in high-impedance mode during normal conditions to maintain power efficiency, but automatically switches to low-impedance mode when electrical noise is detected through monitoring of false signal transitions. This dynamic adjustment ensures that signal differentiation capability is preserved when needed while maintaining power efficiency during clean signal conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The impedance parameter is changed dynamically based on detected noise conditions. The controller monitors the input signal for false transitions and adjusts the impedance parameter accordingly - maintaining high impedance for power efficiency during normal operation and switching to low impedance when noise interference is detected. This parameter change strategy allows the system to optimize between power efficiency and signal differentiation capability based on real-time environmental conditions.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3185424B1System and method for dynamic digital input filtering
Publication Date: 2021.10.06 SCHNEIDER ELECTRIC USA INC
  • EP3185424B1 patent drawingFigure 1~2
  • EP3185424B1 patent drawingFigure 3
  • EP3185424B1 patent drawingFigure 4

AI summary

A dynamic digital filtering system for detecting electrical noise in a discrete I/O circuit. The dynamic digital filtering system has a controller (70) for monitoring the logic signal produced by a logic device (66) monitoring a remote I/O device. The logic device (66) includes a circuit for dynamically adjusting the impedance across a power terminal (46) and a terminal (54) receiving a binary signal from the I/O device. Upon a change of state of the monitored logic signal the controller commands the impedance adjusting circuit to momentarily change its input impedance to determine if the binary signal responsible for the monitored change of state of the logic signal was true or false. If the monitored logic signal does not change state during the momentary change in impedance the binary signal will be verified as "true". If the monitored logic signal does change state during the momentary change in impedance the binary signal will be considered as "false".