Robot Shape Measurement Using Single-Shaft Light Scanning

Solution Overview

Problem

Existing shape measurement technologies using multi-joint robots face accuracy issues due to complex and heavy multi-joint probes, which limit measurement precision and require additional drive shafts, and using simple probes with fixed emission directions on multi-joint robots results in insufficient movement accuracy.

Innovation Solution

A shape measurement device employing a multi-joint robot with a non-contact distance measuring sensor that scans objects using measurement light emitted from a fixed direction, driven by a single selected shaft of the robot, minimizing additional drive shafts and enhancing accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a multi-joint probe is used to measure surfaces facing various directions, then the adaptability to different surface orientations is improved, but the device complexity and weight increase, reducing measurement accuracy

Engineering Contradiction:

Improveadaptability to different surface orientationsVSAvoidprobe structure complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The measurement system is segmented into two independent parts: a simple fixed-direction probe attached to a multi-joint robot for positioning, and a separate control system that calculates measurement directions. This segmentation allows the robot to handle positioning while the control system handles orientation calculations, avoiding the need for a complex multi-joint probe structure.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A direction calculation unit acts as an intermediary between the robot controller and the distance measuring sensor. This intermediary calculates the appropriate measurement directions based on the measured surface normal directions and communicates them to the sensor, enabling the simple probe to achieve multi-directional measurement capability without structural complexity.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If a multi-joint probe is used to measure surfaces facing various directions, then the adaptability to different surface orientations is improved, but the probe weight increases, reducing movement accuracy

Engineering Contradiction:

Improveadaptability to different surface orientationsVSAvoidprobe weight

Core Design Contradiction:

Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The measurement system is segmented into two independent parts: a simple fixed-direction probe attached to a multi-joint robot for positioning, and a separate control system that calculates measurement directions. This segmentation allows the robot to handle positioning while the control system handles orientation calculations, avoiding the need for a complex multi-joint probe structure.

Inventive Principle:

Principle #1Segmentation

3Device complexity

If a simple probe with fixed emission direction is attached to a multi-joint robot, then the device complexity is reduced, but the measurement accuracy is limited by the robot's movement accuracy

Engineering Contradiction:

Improveprobe structure complexityVSAvoidsurface measurement accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

A direction calculation unit acts as an intermediary between the robot controller and the distance measuring sensor. This intermediary calculates the appropriate measurement directions based on the measured surface normal directions and communicates them to the sensor, enabling the simple probe to achieve multi-directional measurement capability without structural complexity.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The measurement direction parameters are dynamically changed based on the surface normal directions detected during scanning. Instead of physically reorienting the probe through complex mechanical joints, the system changes the emission direction parameters through computational control, allowing the simple probe to adapt to various surface orientations while maintaining measurement accuracy.

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

The solution allows for high-precision shape measurement without additional drive shafts, reducing errors and vibration, and maintaining accurate scanning trajectories.

Implementation Method 1

a non-contact distance measuring sensor 160...emits measurement light...measure the shape of the object

Methodology Applied

Scientific EffectLight: Light

Data Source

PatentUS20250354802A1Shape measurement device and shape measurement method

Publication Date: 2025.11.20 HITACHI HIGH TECH CORP

AI summary

When a multi-joint robot is adopted in a shape measurement device, the shape of an object is measured with high accuracy without adding an additional drive shaft to the multi-joint robot. The shape measurement device includes a multi-joint robot having a plurality of drive shafts and a non-contact distance measuring sensor attached to the multi-joint robot, in which the multi-joint robot drives only a predetermined single shaft among the plurality of drive shafts to scan an object with measurement light emitted from the non-contact distance measuring sensor.