Angle Encoder Sensor Layout for Tilt and Displacement Measurement

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Solution Overview

Problem

Existing angle measuring devices in machine tools and measuring machines lack the capability to accurately determine the position of an axis of rotation in multiple directions during operation, particularly in terms of precision and handling of tilts and displacements.

Innovation Solution

The angle measuring device comprises two rotatable component groups with a bearing, featuring a scale element with multiple graduations and position sensors arranged with air gaps, along with a compensating clutch for torsional rigidity and axial/radial flexibility, allowing for absolute determination of angular position and displacement measurements with high resolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional angle measuring devices are used, then the angular position can be measured, but the position in multiple directions (tilts and displacements) cannot be determined

Engineering Contradiction:
Improveposition determination accuracyVSAvoidmulti-directional measurement capability
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The angle measuring device is enhanced to perform multiple measurement functions simultaneously. The first position sensor measures angular position while the second position sensor measures radial displacement, and the third position sensor measures axial displacement. This multi-functional approach allows the single device to determine position in multiple directions (angular, radial, and axial) rather than requiring separate measurement systems.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The invention transitions from measuring only angular position (one dimension) to measuring angular position, radial displacement, and axial displacement (three dimensions). By adding position sensors that detect displacements in radial and axial directions, the device achieves multi-directional measurement capability, effectively adding measurement dimensions to the original angular measurement function.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If the position sensor is rigidly connected to the scale element, then angular position measurement is stable, but displacement and tilt measurements cannot be performed

Engineering Contradiction:
Improvemeasurement stabilityVSAvoiddisplacement detection capability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The device is segmented into multiple independent sensing assemblies. The first position sensor is rigidly connected to the scale element for stable angular measurement, while the second and third position sensors are arranged to measure radial and axial displacements respectively. This segmentation allows each sensor to perform its specific measurement function without interfering with the others, maintaining stability for angular measurement while enabling displacement detection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The scale element acts as an intermediary between the first position sensor (for angular measurement) and the second/third position sensors (for displacement measurement). By arranging the sensors at different locations and orientations relative to the scale element, the system can simultaneously measure angular position and displacements without requiring rigid connection between all sensors and the scale element.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If multiple position sensors are added to measure displacements and tilts, then multi-directional position determination is enabled, but device complexity increases

Engineering Contradiction:
Improvemulti-directional measurement capabilityVSAvoidsensor arrangement complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Multiple measurement functions are merged into a single integrated device. The first position sensor on the scale element measures angular position, while the second position sensor measures radial displacement and the third position sensor measures axial displacement. By combining these sensing capabilities in one device rather than using separate measurement systems, the invention achieves multi-directional measurement capability while avoiding the complexity of multiple independent devices.

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

This solution enables precise determination of the axis of rotation's position in multiple directions, correcting for tilts and displacements, thereby enhancing the accuracy and performance of spindles and rotary tables, especially in machining and measuring processes.

Implementation Method 1

a first assembly (2.1), which in turn includes at least one position sensor (2.11) arranged opposite the scale element with an air gap

Methodology Applied
Scientific EffectOptical detection: Light

Data Source

PatentEP3760980B1Angle measuring equipment
Publication Date: 2022.05.18 DR JOHANNES HEIDENHAIN GMBH
  • EP3760980B1 patent drawingFigure 1
  • EP3760980B1 patent drawingFigure 2
  • EP3760980B1 patent drawingFigure 3

AI summary

The invention relates to an angle measuring device comprising a first component group (1), a second component group (2) and a bearing (3). The first component group (1) comprises a scale element (1.1; 1.1'; 1.1") having a first division (1.11; 1.11'; 1.11") and a second division (1.12; 1.12'; 1.12"). The second component group (2) comprises a first assembly (2.1) that includes a position sensor (2.11). The second component group (2) comprises a second assembly (2.2) that includes a first, second, third, fourth, fifth, and sixth position sensors (2.21, 2.22, 2.23, 2.24, 2.25, 2.26), as well as a compensating coupling (2.3). The first division (1.11; 1.11'; 1.11") is defined by the position sensor (2.11) for determining the relative angular position between the component groups (1, 2) detectable. The first division (1.11; 1.11'; 1.11") or a division on the scale element (1.1; 1.1'; 1.11") can be detected by the first, second and third position sensors (2.21, 2.22, 2.23).The second division (1.12; 1.12'; 1.12") is scannable by the fourth, fifth, and sixth position sensors (2.24, 2.25, 2.26) for determining a tilt of the scale element (1.1; 1.1'; 1.1") about a tilting axis (B), wherein the position sensor (2.11) is arranged relative to the position sensors (2.21, 2.22, 2.23, 2.24, 2.25, 2.26) in a torsionally rigid but axially and radially flexible manner. (Figure 3).