Wheel Speed Sensor Signal Segmentation for High-Resolution Encoders

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Solution Overview

Problem

Conventional vehicular wheel speed sensors lack the resolution needed for accurate control in autonomous vehicles, requiring replacement of magnetic encoders with industrial rotary encoders that are costly, unsafe, and difficult to mass-produce, especially in harsh environments.

Innovation Solution

A measuring sensor system that uses two magnetic detectors to generate low and high-resolution rotation data signals from existing magnetic encoders, allowing for precise wheel speed and direction measurement without replacing the encoder, with the high-resolution data providing enhanced control capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a magnetic encoder with a large number of teeth or magnetic pole pairs is used to achieve high resolution measurement, then the measurement precision is improved, but the device complexity and manufacturing cost increase

Engineering Contradiction:
Improvewheel rotation speed and direction measurement resolutionVSAvoidmagnetic encoder structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the measurement function into two parts: the magnetic encoder provides basic position information with a moderate number of pole pairs, while the signal processing unit segments the measurement task by generating multiple virtual pulses from each actual encoder pulse through phase-shifted signal processing, achieving high resolution without increasing encoder complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary signal processing unit that acts as a mediator between the magnetic encoder and the control system. This unit processes the encoder signals through phase shifting and combination to generate high-resolution measurement data, avoiding the need to modify the encoder structure itself

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If an industrial rotary encoder is replaced for high resolution measurement, then the measurement precision is improved, but the reliability and ease of manufacture deteriorate due to harsh vehicle environments and complex assembly processes

Engineering Contradiction:
Improvewheel rotation speed and direction measurement resolutionVSAvoidproduct safety in high temperature and humidity environments
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent makes the existing magnetic encoder system self-sufficient by enhancing its signal processing capabilities rather than replacing it. The system processes its own output signals through phase-shifting techniques to achieve high resolution, eliminating the need for external industrial encoders and their associated environmental protection requirements

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent changes the signal processing parameters (phase shifts, pulse generation timing) rather than the physical encoder parameters. By manipulating the temporal and phase characteristics of the encoder signals, the system achieves high resolution measurement without altering the encoder's physical structure or environmental requirements

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If an industrial rotary encoder is replaced for high resolution measurement, then the measurement precision is improved, but the ease of manufacture deteriorates due to complicated coating operations and assembly processes

Engineering Contradiction:
Improvewheel rotation speed and direction measurement resolutionVSAvoidproduct assembly process
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent merges the signal processing functions directly into the existing encoder system or control unit. By combining the basic encoder with enhanced signal processing capabilities in a single integrated approach, the system eliminates the need for separate industrial encoders and their complex coating and assembly processes

Inventive Principle:
Principle #5Merging (Combining)

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 accurate and safe vehicle control with higher resolution wheel speed and direction measurement without replacing the magnetic encoder, simplifying production and reducing costs by using existing components.

Implementation Method 1

a first magnetic detector configured to detect a magnetic field induced from the magnetic encoder and output a strength value of the magnetic field as a first electrical signal

Methodology Applied
Scientific EffectMagnetic field detection: Hall Effect

Data Source

PatentEP3608677B1High resolution bearing sensor and IC chip for multipole pair magnetic pulse ring
Publication Date: 2024.08.14 ILJIN ENTERPRISE CO LTD
  • EP3608677B1 patent drawingFigure 1~2
  • EP3608677B1 patent drawingFigure 3
  • EP3608677B1 patent drawingFigure 4

AI summary

A measuring sensor for measuring a rotation speed and a rotation direction of a magnetic encoder in a vehicle wheel may comprise: a first magnetic detector configured to detector a magnetic field induced from the magnetic encoder and output a strength value of the magnetic field as a first electrical signal; a second magnetic detector configured to detect a magnetic field induced from the magnetic encoder and output a strength value of the magnetic field as a second electrical signal; a first output signal generator configured to generate and output first rotation data including information indicating a rotation speed of a wheel on the basis of the first electrical signal; and a second output signal generator configured to generate second rotation data including information indicating a rotation speed of the wheel on the basis of the second electrical signal. The information indicating the rotation speed of the wheel in the second rotation data may have a resolution that is higher than that of the information indicating the rotation speed of the wheel in the first rotation data.