Rotational Angle Sensor Dynamic Range Calibration

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Solution Overview

Problem

Existing rotation angle sensor systems face limitations in resolution and usability due to limited measurement angle intervals, which can lead to incorrect signal interpretation and reduced flexibility in installation positions, especially when dealing with vehicle deflections caused by wear or stone chips.

Innovation Solution

A rotation angle sensor system that maintains internal resolution by using a one-to-one mapping of the digital output signal over a maximum angle interval of 0° to 360°, ensuring uncomplicated signal processing and flexibility in installation positions, with a measurement angle interval that can cover up to 360° without ambiguity and includes a discontinuity only at its edges for clear signal interpretation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the measurement angle interval is limited to a small range (e.g., -45° to +45°), then the resolution of the output signal can be maintained at 2^12 bits, but the system cannot handle excessive vehicle deflections and requires frequent recalibration

Engineering Contradiction:
Improveoutput signal resolutionVSAvoidmeasurement angle range
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent implements a dynamic measurement angle interval that automatically adapts to the actual vehicle deflection range. The system determines the minimum and maximum angles from calibration data and sets the measurement interval dynamically, allowing the sensor to handle both small and large deflections without requiring fixed limited ranges or recalibration

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the parameter of measurement angle interval based on calibration results. By storing minimum and maximum angles and using them to define the valid output signal range, the system adapts its measurement parameters to match actual vehicle conditions, resolving the contradiction between fixed resolution and variable measurement needs

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the measurement angle interval is extended to cover large deflections, then the system can handle excessive vehicle deflections, but the output signal may exceed valid ranges leading to incorrect interpretation

Engineering Contradiction:
Improvemeasurement angle rangeVSAvoidsignal interpretation accuracy
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The system uses calibration feedback to establish the valid output signal range. By determining minimum and maximum angles during calibration and using these values to define the valid signal interval, the system ensures that output signals remain within interpretable ranges while accommodating large deflections, preventing incorrect signal interpretation

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary calibration to determine the minimum and maximum angles before normal operation. This preliminary action establishes the valid output signal range in advance, ensuring that during actual operation, even with large deflections, the output signals remain within the pre-determined valid range for accurate interpretation

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If the zero position is fixed during installation, then the output signal can be simplified, but the system lacks flexibility in installation positions and requires precise alignment

Engineering Contradiction:
Improveoutput signal processingVSAvoidinstallation flexibility
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The patent implements a dynamic zero position that is determined during calibration rather than being fixed during installation. The system automatically adapts to the actual installation position by determining the zero angle from calibration data, eliminating the need for precise alignment while maintaining simplified output signal processing through automatic range adjustment

Inventive Principle:
Principle #15Dynamics

4Measurement precision

If the internal resolution is maintained at high levels, then measurement precision is improved, but data degradation occurs with conventional interfaces due to electromagnetic interference and long cable runs

Engineering Contradiction:
Improveinternal resolutionVSAvoidelectromagnetic interference
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent extracts only the necessary portion of the high-resolution internal data for output. By determining the valid output signal range based on actual measurement needs and transmitting only this reduced data set, the system maintains high internal resolution for accurate measurement while reducing transmitted data to levels that are immune to electromagnetic interference and cable run degradation

Inventive Principle:
Principle #2Taking out (Extraction)

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

The solution allows for full utilization of internal resolution without restricting the measurement angle interval, preventing incorrect signal interpretation and enabling flexible installation and operation, even with excessive vehicle deflections, by ensuring each output signal value corresponds to a specific angle, thus enhancing the system's usability and accuracy.

Implementation Method 1

a magnetic encoder rotates with the motion sensor, and its angular position is detected by a Hall effect sensor or another type of sensor

Methodology Applied
Scientific EffectHall effect: Hall Effect

Data Source

PatentEP3347680B1Rotational angle sensor system having variable measurement angle range
Publication Date: 2021.04.14 CONTINENTAL TEVES AG & CO OHG
  • EP3347680B1 patent drawingFigure 1a
  • EP3347680B1 patent drawingFigure 1b
  • EP3347680B1 patent drawingFigure 2

AI summary

The invention relates to a rotational angle sensor system comprising: a rotatably mounted movement sensor; a sensor that is designed to detect a rotation of the movement sensor, wherein the rotation occurs at a measurement angle interval (∆α); an evaluation electronics system designed to receive an analogue signal from the sensor and to digitalise same using an internal resolution, and to emit a digital output signal (D(α)) reporting the rotation detected by the sensor, characterised in that the resolution of the digital output signal (D(α)) for a measurement angle interval (∆α) of less than or equal to 360° is the same size as the internal resolution.