X-Y Motion Platform Accuracy via Visual Feedback Compensation

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Solution Overview

Problem

Conventional X-Y motion platforms suffer from inaccuracies due to motor, screw rod, assembly, and environmental errors, limiting system accuracy to 10µm to 50µm, and require stringent assembly and device selection to improve accuracy.

Innovation Solution

A method and system that uses a calibration board and industrial lens to capture images of calibration points, calculate actual position coordinates, and adjust the motion control system for motion compensation, reducing the need for precise assembly and device selection by providing feedback for accurate motion control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional X-Y motion platform with step motor and screw rod is used, then device complexity is reduced, but system accuracy deteriorates to 10µm to 50µm due to motor errors, screw rod errors, assembly errors and return-to-zero errors

Engineering Contradiction:
Improvesystem accuracyVSAvoiddevice complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent introduces a camera to capture images of the worktable position and uses image processing to detect actual position. This visual feedback system compares actual position with commanded position and generates correction signals to compensate for errors, thereby improving system accuracy without requiring high-precision mechanical components

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces mechanical measurement methods with optical measurement using a camera and image processing. Instead of relying on mechanical encoders or grating rulers, the system uses visual detection to measure worktable position, substituting mechanical sensing with optical sensing to achieve higher accuracy

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If stricter requirements are laid on assembly and device selection to improve accuracy, then system accuracy is improved, but device complexity and cost increase

Engineering Contradiction:
Improvesystem accuracyVSAvoidassembly requirements
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The system performs self-calibration and self-correction by automatically capturing images, processing them to detect position errors, and generating correction signals. The system compensates for its own errors including assembly errors and motor errors without requiring external calibration procedures or manual adjustment

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent changes the measurement parameter from mechanical position encoding to optical image coordinates. By transforming position measurement into image processing domain, the system can achieve high precision measurement without stringent mechanical assembly requirements

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If linear motor and high-accuracy screw rod are employed to improve accuracy, then system accuracy reaches ±10µm, but device complexity and cost increase

Engineering Contradiction:
Improvesystem accuracyVSAvoiddevice complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent substitutes mechanical precision components (linear motors and high-accuracy screw rods) with optical measurement and visual feedback. Instead of relying on precision mechanical drives, the system uses camera-based position detection and software-based error compensation to achieve comparable or superior accuracy with simpler mechanical components

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Manufacturing precision

If grating ruler and marble platform are used to improve accuracy, then system accuracy reaches ±5µm, but device complexity increases and return-to-zero errors persist due to grating ruler jitter interference

Engineering Contradiction:
Improvesystem accuracyVSAvoiddevice complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces grating ruler-based mechanical measurement with optical image processing. By using a camera to capture and analyze images of position markers on the worktable, the system eliminates the need for grating rulers and marble platforms, thereby avoiding their associated complexities and return-to-zero errors

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

Improves system accuracy by reducing movement errors and relaxing requirements for assembly and device selection, achieving higher precision with ordinary components and eliminating return-to-zero errors.

Implementation Method 1

industrial lens to capture images of calibration points

Methodology Applied
Scientific EffectOptical imaging: Lens

Data Source

PatentEP3091405B1Method, device and system for improving system accuracy of x-y motion platform
Publication Date: 2018.09.12 ALEADER VISION TECH
  • EP3091405B1 patent drawingFigure 1
  • EP3091405B1 patent drawingFigure 2
  • EP3091405B1 patent drawingFigure 3~4

AI summary

Disclosed are a method, a device and a system for improving system accuracy of an X-Y motion platform, and the method includes: taking a picture of a preset calibration board synchronously as a controlled equipment on an X-Y motion platform moves, and analyzing the picture to obtain pixel coordinates of a calibration point in the picture, where the preset calibration board is taken as a reference; acquiring actual coordinates of the calibration point on the calibration board, and calculating actual position coordinates of the controlled equipment on the X-Y motion platform from the actual coordinates and the pixel coordinates of the calibration point; and adjusting a motion control system of the X-Y motion platform according to the actual position coordinates, to control the motion of the X-Y motion platform to perform motion compensation for the controlled equipment. With the technical solution of the invention, the system accuracy can be improved, and the requirements for assembly and device selection can be reduced.