Edge-Detecting Logic Circuit for Separate Sensor Signal Recognition

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Solution Overview

Problem

Classical DC-based OR-gates are unable to detect individual signals at input contacts separately, as they become submerged into a single output, which is a limitation in applications like modern vehicle safety systems where individual signal detection is necessary.

Innovation Solution

A logic circuit with a sub-circuit for signal edge detection and high-pass filters connected to each input contact, allowing the detection of individual signal edges and discrimination between non-overlapping signals by converting step-shaped signals into peaked signals with adjustable decay-time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a classical DC-based OR-gate is used, then the circuit complexity is low, but the ability to detect individual signals separately is lost

Engineering Contradiction:
Improvesignal detection precisionVSAvoidcircuit complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the signal processing function into separate components: individual high-pass filters for each input contact and a shared edge detection sub-circuit. This segmentation allows each input signal to be processed independently through its own filter, enabling individual signal detection while sharing common detection resources to control overall complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces high-pass filters as intermediary components between the input contacts and the edge detection sub-circuit. These filters transform step-shaped input signals into peaked signals, serving as a mediator that enables the edge detection circuit to distinguish between individual signals that would otherwise be submerged in the classical OR-gate output.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of information

If high-pass filters are added to each input contact, then individual signal detection is enabled, but the device complexity increases

Engineering Contradiction:
Improvesignal information retentionVSAvoidcircuit complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent applies segmentation by providing each input contact with its own high-pass filter, ensuring that signal information from each contact is preserved independently. This prevents information loss that would occur in a classical OR-gate where all signals are combined before detection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the temporal parameter of the signals by using high-pass filters to convert step-shaped signals into peaked signals with shorter duration. This parameter transformation allows the edge detection circuit to resolve individual signals that arrive close in time, retaining signal information that would otherwise be indistinguishable.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If the decay-time of peaked signals is reduced, then temporal resolution is improved, but the ability to detect closely spaced signals is limited

Engineering Contradiction:
Improvetemporal resolutionVSAvoidsignal detection reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent adjusts the decay-time parameter of the high-pass filters to optimize the balance between temporal resolution and detection reliability. By carefully selecting the filter time constants, the system achieves sufficient temporal resolution to distinguish closely spaced signals while maintaining reliable detection through the shared edge detection sub-circuit.

Inventive Principle:
Principle #35Parameter changes

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

Enables the detection of individual signals even when they arrive close in time, improving the OR-logic behavior to distinguish separate signals based on temporal resolution, enhancing the capability of restraint control systems in vehicles.

Implementation Method 1

each respective high-pass filter is realised by a capacitive coupling between the respective input contact and the single signal input

Methodology Applied
Scientific EffectCapacitive coupling: Capacitance

Data Source

PatentEP4422073A1Logic circuit, restraint control system, and vehicle
Publication Date: 2024.08.28 VEONEER SWEDEN SAFETY SYST AB
  • EP4422073A1 patent drawingFigure 1
  • EP4422073A1 patent drawingFigure 2
  • EP4422073A1 patent drawingFigure 3

AI summary

A logic circuit (1) with plural input contacts (2) has a sub-circuit (5) for signal edge detection. The sub-circuit (5) has a single signal input (4) coupled to each of the input contacts (2) and produces an output signal (6) in response to a signal edge at the single signal input (4). A restraint control system (110) for a vehicle (100) is configured to trigger one or more restraints in response to the output signal (6). In a vehicle (100) one or more sensors (121, 122) are coupled to the restraint control system (110); some of the sensors (122) may be coupled to the restraint control system (110) via a data processing device (130).