Planar Positioning Apparatus Area Scale Extension
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Solution Overview
Problem
Existing planar positioning apparatuses have a limited range of displacement and actuating power in the Z direction, with restricted lateral displacement due to their position sensor system design.
Innovation Solution
The introduction of an area scale that extends beyond the window between the coil and magnet arrangement, placed directly on the magnet or coil arrangement, made from non-magnetic materials like glass or aluminum alloys, which provides an enlarged position detection range and is supported by holding means to maintain parallel configuration without bending or waviness, and a chessboard-like magnet arrangement with optimized magnetic field alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the area scale is extended beyond the window in the stator or rotor, then the position detection range is enlarged and displacement range is increased, but the structural complexity and potential for deformation increase
Solution Approach 1:
The area scale is divided into multiple segments or sections that can be independently supported by multiple holding means distributed across the stator or rotor surface. This segmentation allows each segment to be independently controlled for parallelism while collectively providing an extended position detection range beyond the window area.
Solution Approach 2:
The area scale extends in the lateral dimension beyond the window boundary, transforming the position detection from a localized window-based measurement to an extended area-based measurement. This dimensional extension enables larger displacement range while the holding means provide support in the vertical dimension to maintain parallelism.
2Length of moving object
If the area scale is made larger to increase displacement range, then the position detection capability is improved, but the rigidity and stability of the scale may deteriorate
Solution Approach 1:
The enlarged area scale is divided into multiple regions supported by distributed holding means, which prevents the entire large structure from bending or deforming. Each localized segment maintains its rigidity while being supported at multiple points, allowing the overall system to achieve both large displacement range and maintained rigidity.
Solution Approach 2:
Different regions of the area scale have locally optimized properties - the scale material and thickness can be varied in different zones to provide appropriate rigidity where needed while maintaining the overall extended structure. The holding means are strategically positioned to provide local support where deformation would most likely occur.
3Measurement precision
If non-magnetic materials like glass or aluminum alloys are used for the area scale, then the magnetic field is not disturbed and positioning precision is maintained, but the manufacturing complexity increases
Solution Approach 1:
The area scale serves multiple functions simultaneously: it provides the position detection surface, acts as a non-magnetic barrier that protects the magnetic field from distortion, and serves as a mounting substrate for the holding means. Using a standardized non-magnetic material like glass or aluminum alloy simplifies the overall design by consolidating these functions into a single component.
Solution Approach 2:
The material selection shifts from magnetic materials to non-magnetic materials (glass, aluminum alloys), changing the magnetic parameter of the scale from magnetic to non-magnetic. This parameter change eliminates magnetic field distortion while the holding means and mounting procedures are designed to accommodate these specific materials, balancing manufacturing complexity with performance benefits.
4Measurement precision
If holding means are added to maintain parallel configuration of the area scale, then the position measurement accuracy is improved, but the device complexity increases
Solution Approach 1:
The holding means are integrated with the existing stator or rotor structure rather than being added as separate external components. The holding means may be combined with the window structure, the scale mounting surface, or existing mechanical features, thereby providing parallelism control without significantly increasing overall device complexity.
Solution Approach 2:
The area scale and holding means are designed to self-align or self-maintain parallel configuration through their geometric design and mounting features. The holding means may incorporate self-centering features or geometric constraints that automatically ensure parallelism without requiring complex active control mechanisms, thereby improving measurement accuracy while minimizing added complexity.
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 configuration enhances the displacement range and actuating power in the Z direction while maintaining precision, allowing for larger displacement and improved mechanical rigidity without disturbing the magnetic field, thus enabling more robust and precise positioning.
Implementation Method 1
a stator which comprises a coil arrangement consisting of flat coils... an evaluation and control device for evaluating position signals of the position measuring head and for controlling the application of current to the coil arrangement
Implementation Method 2
a rotor which is arranged opposite the stator in the operating state of the positioning apparatus and which has a planar magnet arrangement comprising a plurality of rows of magnets
Implementation Method 3
at least one position measuring head, which is arranged within the stator or rotor in the operating state of the positioning apparatus, for detecting the position of the rotor relative to the stator
Data Source
AI summary
The invention relates to a planar positioning apparatus, comprising a stator which comprises a coil arrangement consisting of flat coils, a rotor which is arranged opposite the stator in the operating state of the positioning apparatus and which has a planar magnet arrangement comprising a plurality of rows of magnets, wherein the plane which is spanned by the planar magnet arrangement is arranged parallel to the plane of the coil arrangement, at least one position measuring head, which is arranged within the stator or rotor in the operating state of the positioning apparatus, for detecting the position of the rotor relative to the stator, an area scale which is fixed to the rotor or to the stator in a specific position, and an evaluation and control device for evaluating position signals of the position measuring head and for controlling the application of current to the coil arrangement for controlling the position of the rotor with respect to the stator. The stator or the rotor has at least one window for making the area scale visible for the position measuring head, wherein the area scale extends beyond the window between the coil and magnet arrangement, is placed directly on at least one section of the magnet or the coil arrangement, consists of a material which does not influence the magnetic field between the stator and the rotor, and has associated holding means for ensuring a parallel configuration in relation to the rotor and stator over the entire extent of said area scale.