Oblique Plate Capacitor Sensor for 3D Force Torque Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing force and torque sensors require multiple plate capacitors arranged perpendicular to each other to detect forces in three spatial directions, making them complex and inefficient for direction-dependent force and torque detection.

Innovation Solution

The sensor employs at least two obliquely arranged plate capacitors, allowing detection of forces and torques in three spatial directions with fewer capacitors by determining and comparing capacitance changes, and uses an elastic material as a dielectric to enhance capacitance and protect against contamination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple plate capacitors are arranged perpendicular to each other to detect forces in three spatial directions, then the detection capability is improved, but the device complexity increases

Engineering Contradiction:
Improvedetection capabilityVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dimensionality change by arranging plate capacitors obliquely at specific angles (e.g., 45 degrees) relative to the main detection direction instead of perpendicular arrangements. This angular configuration allows two capacitors to detect force components in multiple spatial directions through trigonometric relationships, reducing the total number of capacitors needed while maintaining three-dimensional detection capability.

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

Solution Approach 2:

Each obliquely arranged plate capacitor serves multiple functions: it detects force components along the main detection direction and simultaneously detects force components in deviating directions. This multi-functionality allows a reduced set of capacitors to provide comprehensive spatial force and torque detection that would otherwise require more dedicated sensors.

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

2Measurement precision

If two plate capacitors are arranged at a distance to determine torque, then the torque detection capability is improved, but the device complexity and component count increase

Engineering Contradiction:
Improvetorque detection capabilityVSAvoidcomponent count
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses oblique angular arrangement of plate capacitors to create torque detection capability without requiring spatial separation of capacitors. The angular configuration allows torque to be determined from capacitance changes and their relationships, eliminating the need for distance-based torque measurement arrangements.

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

Solution Approach 2:

The patent combines force detection and torque detection functions into a single integrated sensor structure using obliquely arranged plate capacitors. This merging of functions allows both linear force components and rotational torque to be detected by the same capacitor arrangement, reducing the need for separate detection systems.

Inventive Principle:
Principle #5Merging (Combining)

3Adaptability or versatility

If plate capacitors are arranged obliquely to detect forces in multiple directions, then the detection versatility is improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvedetection versatilityVSAvoidplate arrangement precision
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent specifies particular angular parameters (e.g., 45 degrees) for the oblique arrangement of plate capacitors. By standardizing these angular parameters, the design transforms a potentially complex precision requirement into a manageable geometric specification that can be implemented using standard manufacturing techniques and angle references.

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 enables precise direction-specific detection of forces and torques with reduced component count, improved accuracy, and resistance to electromagnetic interference, while maintaining simplicity in structure and operation.

Implementation Method 1

To measure a force, the capacitance of the plate capacitor is determined, which changes when the force is applied as the plates are moved in relation to one another.

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

uses an elastic material as a dielectric to enhance capacitance and protect against contamination

Methodology Applied
Scientific EffectDielectric: Dielectric

Data Source

PatentEP3889563A1Sensor for detecting a force and / or a torque
Publication Date: 2021.10.06 WELLGO SYST GMBH
  • EP3889563A1 patent drawingFigure 1(a)~1(d)
  • EP3889563A1 patent drawingFigure 2(a)~2(d)
  • EP3889563A1 patent drawingFigure 3(a)~3(b)

AI summary

The invention relates to a sensor (1) for detecting a force and/or a torque, comprising an element (2) for detecting the force and/or torque. The element (2) is arranged in a neutral position when free from the force and/or torque and in a loaded position when subjected to the force and/or torque. The sensor (1) provides a main detection direction for the detection element (2) and includes at least one plate capacitor (3, 4, 5, 6) for detection. According to the invention, the sensor (1) has at least two plate capacitors (3, 4, 5, 6), and the plates of the plate capacitors (3, 4, 5, 6) are arranged at an angle to the main detection direction (X). Preferably, the sensor (1) has at least three, and more preferably at least four, plate capacitors (3, 4, 5, 6).Advantageously, the sensor for the detection element provides two secondary detection directions (Y, Z) which are orthogonal to each other and to the main detection direction (X), and the plates of the plate capacitors (3, 4, 5, 6) are arranged obliquely to the main detection direction (X) and at least one of the secondary detection directions (Y, Z). In one embodiment of the invention, at least two, preferably at least four, of the plate capacitors (3, 4, 5, 6) are arranged parallel to each other, with preferably the plates of one of the plate capacitors (3, 4, 5, 6) being arranged parallel to the plates of one or more of the other plate capacitors (3, 4, 5, 6).