Robot Joint Force Detection for Natural Touch Interaction

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Solution Overview

Problem

Conventional robot technologies do not account for interactions when a user touches the robot, lacking a response mechanism to user touch, which is desired for a more natural interaction, especially in animal-type robots.

Innovation Solution

A robot control device and method that includes a detection section to sense external forces on movable parts through joint parameters and a driving control section to manage interactions based on these forces, enabling responses to user touch.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the robot uses conventional operation command response mechanisms, then the robot can respond to explicit commands, but the robot cannot naturally react to user touch interactions

Engineering Contradiction:

Improveinteraction capabilityVSAvoiddetection system complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The joint driving system is designed to serve dual purposes: its primary function of driving the movable part and a secondary function of detecting external forces applied to the movable part. By utilizing the existing joint driving structure for both actuation and sensing, the system achieves touch detection capability without adding separate dedicated sensors, thereby improving interaction versatility while controlling device complexity

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The joint driving system performs self-diagnosis by monitoring its own operational parameters to detect external forces. The system uses its inherent operational data (current, position, velocity) to infer external interactions, eliminating the need for separate detection mechanisms and achieving self-service detection functionality

Inventive Principle:

Principle #25Self-service

2Measurement precision

If the robot adds dedicated force sensors to detect touch, then the robot can accurately detect external forces, but the device complexity and cost increase

Engineering Contradiction:

Improveexternal force detection accuracyVSAvoidsensor system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system replaces dedicated mechanical force sensors with an electronic detection approach using the joint driving system's operational parameters. By substituting physical sensors with electronic monitoring of current, position, and velocity data, the system achieves force detection accuracy while reducing mechanical complexity and sensor requirements

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If the robot responds to all operation commands immediately, then the user can recognize the operation state, but the robot cannot differentiate between intentional commands and accidental touches

Engineering Contradiction:

Improveuser recognition of operation stateVSAvoidtouch interaction capability

Core Design Contradiction:

Ease of operationVSAdaptability or versatility

Solution Approach 1:

The system dynamically adjusts its response behavior based on the detected interaction type. By analyzing the characteristics of external forces (magnitude, duration, position, frequency), the system dynamically determines whether to trigger an operation state or ignore the input as accidental touch, enabling adaptive response that improves both ease of operation and touch interaction capability

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system implements feedback mechanisms where the detected external force characteristics are fed back into the control logic to determine the appropriate response. This feedback loop allows the robot to differentiate between intentional commands and accidental touches by evaluating the nature of the interaction, thereby improving both user recognition and interaction adaptability

Inventive Principle:

Principle #23Feedback

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 the robot to react naturally to user touch, simulating animal-like interactions by varying responses based on touch position, strength, manner, user identity, emotion, and frequency, enhancing user engagement.

Implementation Method 1

a detection section that detects an external force applied to a movable part of a robot, on the basis of a parameter obtained from a joint driving the movable part

Methodology Applied

Scientific EffectForce detection through parameter measurement:

Data Source

PatentUS20250242492A1Robot control device, robot control method, and program

Publication Date: 2025.07.31 SONY GROUP CORP

AI summary

The present disclosure provides a robot control device including a detection section that detects an external force applied to a movable part of a robot, on the basis of a parameter obtained from a joint driving the movable part, and a driving control section that controls an interaction of the robot, according to the detected external force. With this configuration, in a case where a user touches the robot, the robot can perform an interaction according to the touch.