Motion Control for High-Frequency Relative Positioning Accuracy

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Solution Overview

Problem

Existing motion control systems for apparatuses with multiple movable parts struggle to achieve high accuracy in relative positioning, particularly in high-frequency components, even when using feedback control methods.

Innovation Solution

A motion control apparatus that includes a first and second movable part, a measurement device to measure the motion of the first part, a compensator to generate a manipulated variable based on the measurement and a target value, a generator to produce an observed value for relative motion between the parts, and a calculator to combine outputs from both compensators to improve alignment, with parameter values decided by machine learning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a classic feedback control system (PID controller) is used to control the motion of movable parts, then the control system is simple and easy to implement, but the accuracy of relative positioning (especially high-frequency components) cannot be improved sufficiently

Engineering Contradiction:
Improverelative positioning accuracyVSAvoidcontrol system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The control system is segmented into multiple independent controllers, each responsible for controlling a specific movable part. Each controller independently processes measurement data and generates control signals, allowing parallel operation that improves overall system precision without creating complex interdependencies between controllers

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A synchronization controller acts as an intermediary that receives position information from all movable parts and coordinates their motion. This mediator ensures that all parts maintain precise relative positioning by adjusting their motion based on real-time position feedback, solving the relative positioning accuracy problem without requiring complex direct coupling between all controllers

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If machine learning is introduced to improve control precision, then the accuracy of relative alignment is improved, but the device complexity and computational requirements increase

Engineering Contradiction:
Improverelative alignment accuracyVSAvoidcontrol system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The control system uses real-time measurement data from encoders and other sensors to automatically adjust and optimize control parameters without external intervention. The system self-calibrates by continuously comparing actual positions with target positions and autonomously modifies control signals to maintain optimal alignment accuracy

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

Traditional mechanical alignment mechanisms are replaced with sensor-based measurement systems and software-based control algorithms. Optical encoders, interferometers, and computer vision systems substitute for mechanical alignment tools, enabling non-contact, high-precision measurement and control that reduces mechanical complexity while improving accuracy

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

Data Source

PatentUS12147164B2Motion control apparatus, lithography apparatus, planarization apparatus, processing apparatus, and article manufacturing method
Publication Date: 2024.11.19 CANON KK
  • US12147164B2 patent drawing
  • US12147164B2 patent drawing
  • US12147164B2 patent drawing

AI summary

A motion control apparatus includes a first movable part, a second movable part, a first measurement device for measuring a motion of the first movable part, a first compensator for generating a first manipulated variable based on an output from the first measurement device and a target value for controlling the motion of the first movable part, a generator for generating an observed value concerning a relative motion between the first movable part and the second movable part, a second compensator for generating a second manipulated variable based on the observed value, and a calculator for generating a manipulated variable for driving the first movable part based on an output from the first compensator and an output from the second compensator. For the second compensator, a parameter value for generating the second manipulated variable is decided by machine learning.