Positioning Device Crossing Transmitter Coils for Uniform Field

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing position measuring devices face challenges with low sensitivity due to high electrical resistance in the transmitter winding arrangement, leading to a weak electromagnetic field and inconsistent signal strengths across individual elements, which affects measurement accuracy and sensitivity.

Innovation Solution

The transmitter winding arrangement is designed with two groups of serpentine conductor tracks that cross each other, allowing for adjustable resistance and ensuring all surfaces are exposed to a uniform magnetic field, while receiver coils are arranged to maximize sensitivity and accuracy through series and parallel connections, and strategic placement to minimize edge effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If transmitter coils are connected in series to ensure uniform current flow, then measurement accuracy is improved, but the total resistance becomes too high and the electromagnetic field becomes too weak

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidelectromagnetic field strength
Core Design Contradiction:
Measurement precisionVSPower

Solution Approach 1:

The transmitter winding arrangement is divided into multiple groups of coils (first group, second group, etc.), where coils within each group are connected in series to ensure uniform current flow, while the groups themselves are connected in parallel to reduce total resistance. This segmentation allows the system to benefit from both series and parallel connection advantages.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different parts of the transmitter winding arrangement have different connection topologies: individual coils within a group are connected in series (for uniform current), while groups are connected in parallel (for reduced resistance). This local differentiation of connection quality resolves the contradiction between uniform current distribution and sufficient field strength.

Inventive Principle:
Principle #3Local quality

2Power

If transmitter coils are connected in parallel to increase electromagnetic field strength, then sensitivity is improved, but current distribution becomes non-uniform and measurement accuracy deteriorates

Engineering Contradiction:
Improveelectromagnetic field strengthVSAvoidmeasurement accuracy
Core Design Contradiction:
PowerVSMeasurement precision

Solution Approach 1:

The transmitter winding arrangement is segmented into multiple groups where coils within each group maintain series connection for uniform current, while groups are paralleled for increased field strength. This segmentation preserves current uniformity at the coil level while achieving parallel connection benefits at the group level.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The connection topology varies locally: series connection within groups ensures uniform current distribution, while parallel connection between groups increases overall field strength. This local quality differentiation allows simultaneous achievement of both uniformity and strength.

Inventive Principle:
Principle #3Local quality

3Power

If conductor track width is reduced to decrease resistance, then sensitivity is improved, but manufacturing precision becomes more difficult to control

Engineering Contradiction:
Improveelectromagnetic field strengthVSAvoidconductor track width tolerance
Core Design Contradiction:
PowerVSManufacturing precision

Solution Approach 1:

Instead of changing the conductor track width (which has tight manufacturing tolerances), the patent changes the connection topology parameter - using series-parallel combination of multiple coils. This allows resistance reduction through increased number of parallel paths rather than through decreased individual track width, avoiding manufacturing precision issues.

Inventive Principle:
Principle #35Parameter changes

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 sensitivity and accuracy of the position measuring device by ensuring uniform current flow across all transmitter surfaces and optimizing the electromagnetic field strength, while reducing interference from external fields and edge effects.

Implementation Method 1

An alternating current is fed into the transmitter winding arrangement, which currents are primarily induced in the elevations of the measuring standard, which influence the alternating electromagnetic field of the transmitter winding arrangement depending on the position of the scanning device relative to the measuring standard. An alternating voltage is induced in the receiver winding arrangement by said electromagnetic alternating field

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

An alternating voltage is induced in the receiver winding arrangement by said electromagnetic alternating field, which is dependent on the position of the measuring scale relative to the scanning device

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2302328B1Positioning device with multiple crossing transmitter coil assembly
Publication Date: 2014.09.24 ROBERT BOSCH GMBH
  • EP2302328B1 patent drawingFigure 1~2
  • EP2302328B1 patent drawingFigure 3~4
  • EP2302328B1 patent drawingFigure 5~6

AI summary

The position measuring device has a transmitter coil arrangement (40) with two groups (51) and multiple transmitter conductive strips (52a to 52e). The transmitter conductive strips of a group run parallel to each other in each case. The position measuring device crosses the transmitter conductive strips of the both groups in such a manner that it limits transmitting surfaces (46a to 46f). The transmitting surface is arranged between the two adjacent crossing positions (53).