Hall-Effect Control Switch Sensing Across Rotational Joints

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Solution Overview

Problem

Existing control input devices for teleoperated systems face challenges in providing reliable data and power transmission across rotational joints, particularly for control switches that require continuous rotation, leading to complexity and space constraints.

Innovation Solution

A control input device with a passive magnet as a first sensor element and a Hall effect sensor array on a base member to detect the position of a switch contact portion independently of the rotational orientation, allowing continuous rotation without the need for power or data transmission across the joint.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If control switches are positioned on the rotating portion to allow continuous rotation, then the rotational degree of freedom is maintained, but data and power transmission to and from the rotating portion becomes difficult

Engineering Contradiction:

Improvecontinuous rotation capabilityVSAvoiddata and power transmission system

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces mechanical data and power transmission mechanisms with a magnetic field-based sensing system. A magnet is mounted on the rotating portion and a Hall effect sensor on the stationary base, eliminating the need for slip rings or flexible cables that would be required for traditional electrical transmission across the rotational joint.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The magnetic field serves as an intermediary between the rotating portion and the stationary base. The magnet generates a magnetic field that penetrates through the rotational joint without physical contact, allowing the Hall effect sensor to detect switch positions without requiring direct electrical or mechanical connection across the rotating interface.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If traditional sensor systems are used across rotational joints, then power and data can be transmitted, but the system complexity and space requirements increase

Engineering Contradiction:

Improvepower and data transmissionVSAvoidsensor system space

Core Design Contradiction:

ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent eliminates mechanical transmission components (slip rings, flexible cables, connectors) by using a non-contact magnetic field-based sensing system. This substitution dramatically reduces the space required for the sensor system while maintaining reliable signal transmission across the rotational joint.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If control switches require communication across the rotational joint, then functionality is maintained, but the system becomes more complex and less robust

Engineering Contradiction:

Improveswitch communication functionalityVSAvoidcommunication system

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces complex communication mechanisms with a simple magnetic field sensing system. The magnet on the rotating portion and Hall effect sensor on the base create a robust, maintenance-free communication channel that requires no physical connection across the rotational joint, eliminating wear, friction, and connection failure issues.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

Enables reliable detection of switch positions and orientations across rotational joints, reducing complexity and space requirements while maintaining robust and cost-effective operation.

Implementation Method 1

Methodology Applied

Scientific EffectHall effect: Hall Effect

Data Source

PatentEP3840681B1Control switch position sensing across a rotational joint

Publication Date: 2025.10.01 INTUITIVE SURGICAL OPERATIONS INC

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AI summary

Implementations relate to control switch position sensing across a rotational joint. In some implementations, a control input device includes a base member and a roll member rotatable about a central axis with respect to the base member in a roll degree of freedom. A switch contact portion is rotatable with the roll member and moveable to multiple positions in a switch degree of freedom. A first sensor element is coupled to and moveable with the switch contact portion and can be a passive element. A base sensor element is coupled to the base member and configured to sense a proximity of the first sensor element to the base sensor element, and to output a signal indicative of a current position of the switch contact portion in the switch degree of freedom independently of a rotational orientation of the roll member in the roll degree of freedom.