Spindle Deviation Detection Using Laser Beam Splitting

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Solution Overview

Problem

Current methods for determining linear and angular deviations of a workpiece or machine part from a spindle's axis are limited by inaccuracies due to measuring pin distortions, complex setup requirements, and the need for expensive equipment and skilled operators.

Innovation Solution

A method using a laser beam source clamped to the spindle, with optical distances recorded by electronic optical sensors, allowing direct determination of linear deviations and subsequent calculation of angular deviations, minimizing distortion influences and simplifying the measurement process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a measuring pin is used to determine linear deviations, then the measurement method is simple, but the measurement precision is reduced due to production inaccuracies, deformation, and run out of the measuring pin

Engineering Contradiction:
Improvesimplicity of measurement methodVSAvoidaccuracy of deviation measurement
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent replaces the mechanical measuring pin system with an optical laser beam system. The laser beam serves as the measurement reference instead of a physical measuring pin, eliminating mechanical contact and associated errors. The beam splitter and optical sensors create a virtual measurement axis that does not suffer from physical deformation or run out, thereby maintaining simplicity while dramatically improving measurement precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates an optical copy or representation of the measurement axis using laser beams and beam splitters. Instead of relying on the physical integrity of a measuring pin, the system uses multiple laser beams that define a virtual axis through geometric relationships. This optical copying approach eliminates the need for a single precise mechanical reference while maintaining measurement simplicity.

Inventive Principle:
Principle #26Copying

2Measurement precision

If a leveling telescope or autocollimator is used to eliminate measuring pin inaccuracies, then the measurement precision is improved, but the device complexity and setup difficulty increase considerably

Engineering Contradiction:
Improveaccuracy of deviation measurementVSAvoidcomplexity of setup and operation
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the optical measurement system into modular components: a laser source, beam splitters at specific angles, and optical sensors. Each component has a simple function, and they are arranged in a systematic configuration. The beam splitters divide the laser beam into multiple paths that collectively define the measurement axis, allowing precise measurements without requiring complex alignment procedures typical of traditional telescopes or autocollimators.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the fundamental parameter of the measurement system from mechanical alignment (requiring precise physical setup of telescopes) to optical path geometry (defined by fixed beam splitter angles). By using beam splitters mounted at specific angles (e.g., 45 degrees) to the spindle axis, the system establishes measurement references through geometric relationships rather than mechanical adjustment, significantly reducing setup complexity while maintaining high precision.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If a laser interferometer is used to achieve accurate deviation determination, then the measurement precision is improved, but the device complexity and operational requirements increase due to expensive equipment and need for experienced operators

Engineering Contradiction:
Improveaccuracy of deviation measurementVSAvoidcomplexity of equipment and operation
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces expensive, sophisticated laser interferometer equipment with simpler, more accessible optical components. Instead of using complex interferometric arrangements that require specialized knowledge and expensive instrumentation, the system employs basic laser diodes, standard beam splitters, and simple optical sensors. These components are far cheaper, more robust, and easier to operate, eliminating the need for highly experienced operators while maintaining measurement accuracy.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

4Measurement precision

If the optical distance from the spindle is increased to improve measurement accuracy, then the linear deviation determination precision is improved, but the device complexity increases due to the need for multiple sensors at different positions

Engineering Contradiction:
Improveprecision of linear deviation determinationVSAvoidnumber of sensors and their arrangement
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges multiple measurement functions into a single integrated optical system. The beam splitters simultaneously create multiple optical paths that reference different aspects of the spindle axis, and a single sensor can detect deviations by analyzing the combined optical information. This consolidation achieves the precision benefits of multiple measurement distances without requiring physically separate sensors at each position, thereby reducing overall system complexity.

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 approach provides accurate and efficient determination of linear and angular deviations with reduced setup complexity and operational costs, improving measurement precision and ease of use.

Implementation Method 1

a source of a laser beam is clamped to the spindle, and at least at two optical distances from the end of the spindle, points of incidence of the laser beam or its components created by splitting the laser beam by a beam splitter

Methodology Applied
Scientific EffectLaser: Laser

Data Source

PatentEP3029417B1Method of determination and/or continuous determination of a linear and/or angular deviation/deviations of the path or area of a workpiece or a part of the machine from the axis of rotation of its spindle and a detecting device for performing it
Publication Date: 2020.07.01 VUTS AS
  • EP3029417B1 patent drawingFigure 1~2a
  • EP3029417B1 patent drawingFigure 2b
  • EP3029417B1 patent drawingFigure 3

AI summary

The invention relates to a method of determination of a linear deviation (p) and/or (q) and/or angular deviation (β) and/or (γ) of the path and/or plane of a workpiece and/or a machine part from the axis of rotation of the spindle (1), in which a source of the laser beam (2) is clamped to the spindle (1) and at least at two optical distances (b), (c) from the end of the spindle (1) on the path and/or the plane of a workpiece and/or a machine part are successively or simultaneously recorded, or continuously recorded, points of incidence of the laser beam (2) or its components (21), (22), or geometric shapes drawn by the laser beam (2) or by its components (21), (22), whereupon the optical distances (b), (c) change due to the shift of the detecting device (3) and/or its electronic optical sensor/sensors (31), (32) in relation to the end of the spindle (1) by the same value (e) and at the optical distances (b+e), (c+e) thus changed are successively or simultaneously recorded or continuously recorded points of incidence of the laser beam (2) or of its components (21), (22), or geometric shapes drawn by the laser beam (2) or by its components (21), (22). The linear deviation (p) or (q) and/or angular deviation (β) and/or (γ) is then determined or continuously determined from the components of the shift (yb), (yc), or (xb), (xc) of these points of incidence or of the centers of the geometric shapes drawn between the optical distances (b+e) and (c+e) in the respective axis perpendicular to the axis of the spindle (1) rotation, from the difference (a) in the optical distances (b+e) and (c+e), or the difference in the optical distances (b) and (c), from one of the optical distances (b), (b+e), (c), (c+e) from the end of the spindle (1), from the change (e) of the optical distances (b) and (c) from the end of the spindle (1) and from the distance (u), at which the deviation/deviations is/are determined or continuously determined, or from the electronic optical sensor (31). Furthermore, the invention also relates to a detecting device (3) for carrying out this method.