Multiplexed Resistance Reading for Component Characterization

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Solution Overview

Problem

Existing systems for communicating characterization data between electrically connected components, such as fuel metering units and engine controllers, face limitations due to accuracy issues and require complex electronic assemblies that are costly and difficult to design for harsh environments, limiting the amount of coded information that can be transferred and reducing the effectiveness of characterization correction schemes.

Innovation Solution

A system using resistor networks with programmable resistors and a switching network to multiplex resistance values over simpler electrical busses, allowing identification and characterization of components with fewer wires and robustness to withstand harsh environments, enabling efficient communication of characterization data between components like fuel metering units and engine controllers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If sophisticated electronic circuit assemblies (memory devices or personality modules) are used to communicate characterization data, then the amount of coded information available to the FADEC is improved, but the device complexity and cost increase significantly

Engineering Contradiction:
Improveamount of coded informationVSAvoidelectronic circuit assembly complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent extracts the characterization data communication function from complex electronic memory devices and implements it using simple passive resistive circuits. Each resistive circuit contains resistive elements whose resistances are linked together by powers of two, creating a compact binary encoding scheme that can be read by the FADEC through standard ADC resources.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent creates a simplified copy of the characterization data storage function using resistive circuits instead of electronic memory devices. The resistive elements replicate the information storage capability through resistance values that can be sensed and decoded, providing the same functional outcome with much simpler hardware.

Inventive Principle:
Principle #26Copying

2Reliability

If sophisticated electronic circuit assemblies are used for characterization data communication, then the characterization correction scheme effectiveness is improved, but the cost and wiring complexity between FADEC and FMU increase

Engineering Contradiction:
Improvecharacterization correction scheme effectivenessVSAvoidwiring complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the characterization data storage and communication functions into the existing FMU electronic architecture using resistive circuits that can be integrated alongside other FMU components. This eliminates the need for separate sophisticated memory modules and their associated complex wiring, while maintaining the ability to provide correction data to the FADEC.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If complex electronic assemblies are used to survive harsh engine environments, then the reliability in harsh environments is improved, but the device complexity and cost increase

Engineering Contradiction:
Improveharsh environment survival capabilityVSAvoidelectronic assembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses simple resistive circuits that are inherently robust to harsh environments. Resistors are passive components with no moving parts or sensitive electronics, making them naturally resistant to vibration, temperature extremes, and electromagnetic interference common in engine environments, while eliminating the need for complex protective enclosures or shielding.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 solution provides robust, cost-effective identification and characterization of components in harsh environments with reduced wiring complexity, enabling accurate compensation for inaccuracies in fuel metering units and improving overall system performance by allowing more precise communication of characterization data.

Implementation Method 1

a second component comprising a sensor configured to sense a voltage difference between a first bus and a second bus

Methodology Applied
Scientific EffectVoltage sensing: Electric Field

Implementation Method 2

a third component comprising a switching network configured to electrically connect the second bus to the first bus across one or both of the first resistor and the second resistor in response to the first selector signal

Methodology Applied
Scientific EffectElectrical connection switching: Conduction (electrical)

Data Source

PatentEP3556110B1Characterization using multiplexed resistance reading
Publication Date: 2020.11.04 WOODWARD INC
  • EP3556110B1 patent drawingFigure 1
  • EP3556110B1 patent drawingFigure 2
  • EP3556110B1 patent drawingFigure 3

AI summary

The subject matter of this specification can be embodied in, among other things, an identification system includes a first component having a first resistor and a second resistor, a second component having a sensor configured to sense a voltage difference between a first bus and a second bus and a selector signal output port configured to provide a first selector signal and a second selector signal, and a third component having a switching network configured to electrically connect the second bus to the first bus across one or both of the first resistor and the second resistor in response to the first selector signal, and electrically connect the second bus to the first bus across a different one of the first resistor or the second resistor in response to the second selector signal.