Capacitive Robot Guard Potential to Prevent Self-Detection

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Solution Overview

Problem

Industrial and domestic robots, particularly cobots, face self-detection issues due to capacitive electrodes detecting their own electrical components, leading to reduced operational range and potential safety hazards by masking external objects or persons.

Innovation Solution

The robot employs capacitive detection electrodes that are biased to a guard potential, making internal electrical components electrically invisible, thereby avoiding self-detection and maintaining operational range while enhancing detection functionality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If capacitive detection electrodes are used to detect objects and persons in the robot's environment, then safety detection capability is improved, but self-detection of internal electrical components occurs causing operational limitations

Engineering Contradiction:
Improvesafety detection capabilityVSAvoidoperational range
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies equipotentiality by connecting internal electrical components to the guard potential, making them electrically invisible to the capacitive detection electrodes. This eliminates the potential difference between internal components and the detection system, preventing self-detection while maintaining the ability to detect external objects and persons.

Inventive Principle:
Principle #12Equipotentiality

Solution Approach 2:

The guard potential acts as an intermediary between the capacitive detection electrodes and internal electrical components. By introducing this intermediate electrical potential level, the patent isolates internal components from the detection field while allowing external objects to be detected normally.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If capacitive detection electrodes detect electrical components in the robot, then detection sensitivity is improved, but false detection of internal organs occurs

Engineering Contradiction:
Improvedetection sensitivityVSAvoidfalse detection
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

By maintaining internal electrical components at the guard potential, the patent eliminates false detections caused by potential differences. This ensures that only external objects with different potentials are detected, filtering out spurious signals from internal components while preserving detection sensitivity for legitimate targets.

Inventive Principle:
Principle #12Equipotentiality

3Reliability

If the robot blocks operation for safety reasons due to self-detection, then safety is improved, but productivity is reduced

Engineering Contradiction:
ImprovesafetyVSAvoidoperational continuity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The equipotential connection of internal components to the guard potential prevents false safety triggers, allowing the robot to maintain continuous operation without unnecessary shutdowns while still providing genuine safety detection for external objects and persons.

Inventive Principle:
Principle #12Equipotentiality

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 effectively prevents self-detection, ensuring the robot's operational range is not limited and maintaining safety by accurately detecting external objects and persons without interference from internal components.

Implementation Method 1

at least one electronic detection electronics to measure a signal relating to a coupling capacitance, called electrode-object capacitance, between the at least one measurement electrode and a surrounding object

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

at least one electrical biasing means for biasing said at least one measurement electrode to a first alternating electrical potential, different from a general ground potential, at a so-called working frequency

Methodology Applied
Scientific EffectAlternating electrical potential: Alternating Magnetic Field

Implementation Method 3

the at least one biasing means is furthermore arranged to electrically guard at least one electrical member of said sub-part paired, at an alternating electrical potential (VG), called guard, identical or substantially identical to said first potential at said working frequency

Methodology Applied
Scientific EffectParasitic capacitance: Parasitic Capacitance

Data Source

PatentEP3434426B1Robot with capacitive detection means and referenced organ(s) with a guard potential
Publication Date: 2020.02.26 FOGALE NANOTECH SA
  • EP3434426B1 patent drawingFigure 1
  • EP3434426B1 patent drawingFigure 2
  • EP3434426B1 patent drawingFigure 3

AI summary

The invention relates to a robot (300) comprising capacitive sensing electrodes (118), and at least one electrical polarization means (1202) for polarizing the measuring electrodes (118) at a first alternating electrical potential, different from a general ground potential (MG), at a frequency, referred to as the operating frequency. The robot is characterized in that, for at least one sub-part, referred to as the equipped sub-part (104, 114), the outer wall (1041, 1141) of which is non-conductive, said at least one polarization means (1202) is further arranged to maintain the electrical components (1042, 1142) of said equipped sub-part (104, 114) at an alternating electrical potential (VG), referred to as the guard potential, identical or substantially identical to said first potential at said operating frequency.