Multiplexed Sensor Time Correlation Logic Circuit

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Solution Overview

Problem

Existing multiplexed sensor systems for aircraft engines fail to transmit time-correlated sensor signals due to the nature of multiplexing, where only a single sensor signal is received at any given time, preventing simultaneous information from multiple sensors to be sent to the signal processor/controller.

Innovation Solution

A sensor system with a multiplexor connected to time correlation logic circuit via signal conditioning and anti-aliasing filters, which determines and combines current and average values of multiplexed signals to produce time-correlated readings, enabling simultaneous interpretation by the signal processor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of stationary object

If signals from multiple sensors are multiplexed together to reduce weight and costs, then the number of signal wires is reduced, but time-correlated sensor signals cannot be transmitted simultaneously

Engineering Contradiction:
Improveweight of aircraftVSAvoidtime-correlated sensor information
Core Design Contradiction:
Weight of stationary objectVSLoss of information

Solution Approach 1:

The system performs preliminary actions by capturing and storing sensor signal values in memory buffers before processing. Each sensor's signal is sampled and stored with timestamp information, allowing the signal processor to retrieve and correlate these pre-captured values later, thus preserving time-correlated information while using multiplexed wiring.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

A memory buffer acts as an intermediary between the multiplexed sensor signals and the signal processor. The buffer stores incoming sensor values and provides them to the processor in a time-correlated manner, mediating the conflict between multiplexed signal transmission and simultaneous information delivery.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If multiplexing is used to transmit sensor signals over a single wire, then device complexity and wiring costs are reduced, but only single sensor signal values can be received at any given time

Engineering Contradiction:
Improvesignal transmission system complexityVSAvoidtime correlation of sensor data
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

Sensor signals are pre-sampled and stored in memory buffers with associated timing information before being processed. This preliminary capture and storage ensures that even though signals are transmitted sequentially over a single wire, the original time relationships between different sensor readings are preserved for accurate correlation during processing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses timestamp feedback mechanisms where each sampled sensor value is tagged with timing information. This feedback allows the signal processor to correctly associate and correlate sensor readings from different sensors based on their original acquisition times, maintaining reliability despite sequential transmission.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2779136B1Method and apparatus for multiplexed time aligned analog input sampling
Publication Date: 2019.07.24 HAMILTON SUNDSTRAND CORP
  • EP2779136B1 patent drawingFigure 1
  • EP2779136B1 patent drawingFigure 2
  • EP2779136B1 patent drawingFigure 3

AI summary

A sensor system includes a first sensor and a second sensor and a multiplexor having at least two multiplexer inputs connected to the sensors. The output of the multiplexor is connected to a time correlation logic circuit via at least a signal conditioning and anti-aliasing filter, and the output of the time correlation logic is a time correlated sensor reading of the first and second sensor.