Electromagnetic Pinning Control for Linear Mover Position Holding

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Solution Overview

Problem

Existing motion control systems in linear drive systems face challenges in maintaining the precise position of movers without mechanical coupling, as they are prone to movement due to external disturbances, electronic noise, and position drift, which can lead to overheating and damage, and require complex and costly mechanical structures or inefficient motor control routines.

Innovation Solution

A control system that utilizes electromagnetic pinning by regulating the current in the linear drive system's coils to maintain the mover's position, using a d-q reference frame to manage forces and resist external disturbances, eliminating the need for mechanical coupling and reducing noise sensitivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a mechanical structure is used to lock the mover in place, then the mover position stability is improved, but the device complexity and cost increase

Engineering Contradiction:
Improvemover position stabilityVSAvoiddevice complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent replaces mechanical locking structures with an electromagnetic field-based control system. The controller regulates current in the coils to generate electromagnetic forces that counteract external disturbances and maintain mover position, eliminating the need for mechanical pins, linkages, or other physical locking mechanisms.

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

Solution Approach 2:

The system dynamically adjusts electrical parameters (current magnitude and phase) in response to detected position deviations or disturbance forces. By changing the current parameters supplied to the coils, the electromagnetic force is modulated to maintain position stability without mechanical intervention.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If a mechanical structure is used to lock the mover in place, then the mover position stability is improved, but the manufacturing cost increases

Engineering Contradiction:
Improvemover position stabilityVSAvoidmanufacturing cost
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The patent replaces mechanical locking structures with an electromagnetic field-based control system. The controller regulates current in the coils to generate electromagnetic forces that counteract external disturbances and maintain mover position, eliminating the need for mechanical pins, linkages, or other physical locking mechanisms.

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

3Device complexity

If the motor control routine is used to maintain mover position, then the mechanical structure is simplified, but the system reliability decreases due to overheating and damage risks

Engineering Contradiction:
Improvedevice complexityVSAvoidsystem reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The system continuously monitors mover position and uses this feedback to adjust the current supplied to the coils. The controller detects position deviations caused by external disturbances and dynamically modifies the electromagnetic force to counteract these disturbances, maintaining position stability without excessive current buildup.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system proactively applies electromagnetic forces to counteract external disturbance forces before they can cause significant position deviations or damage. By detecting or anticipating disturbance forces (such as gravity on inclined tracks or forces from external actuators), the controller pre-adjusts the current to prevent problematic situations.

Inventive Principle:
Principle #9Preliminary anti-action

4Stability of the object's composition

If the mover is held at a fixed position using conventional control, then the position is maintained, but the system is sensitive to electronic noise and position drift

Engineering Contradiction:
Improveposition maintenanceVSAvoidposition precision
Core Design Contradiction:
Stability of the object's compositionVSMeasurement precision

Solution Approach 1:

The system continuously monitors mover position and uses this feedback to adjust the current supplied to the coils. The controller detects position deviations caused by external disturbances and dynamically modifies the electromagnetic force to counteract these disturbances, maintaining position stability without excessive current buildup.

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

This solution effectively holds the mover at a desired position with improved precision and reduced risk of overheating or damage, eliminating the need for mechanical structures and enhancing system reliability and efficiency.

Implementation Method 1

The track is made up of a number of track segments that, in turn, hold individually controllable electric coils. Successive activation of the coils establishes a moving electromagnetic field that interacts with the movers and causes the mover to travel along the track.

Methodology Applied
Scientific EffectElectromagnetic field interaction: Electromagnetic Induction

Implementation Method 2

A control system that utilizes electromagnetic pinning by regulating the current in the linear drive system's coils to maintain the mover's position, using a d-q reference frame to manage forces and resist external disturbances.

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentEP4300809A1System and method for electromagnetic pinning and hybrid control of a linear drive system
Publication Date: 2024.01.03 ROCKWELL AUTOMATION TECH INC
  • EP4300809A1 patent drawingFigure 1
  • EP4300809A1 patent drawingFigure 2~4
  • EP4300809A1 patent drawingFigure 5~6

AI summary

A system and method for holding position of a mover in an independent cart system includes receiving a current feedback signal corresponding to a current present in at least one coil for a linear drive system in the independent cart system. A motion command for the mover is received, where the motion command defines a desired position along a track of the independent cart system to which the mover is to travel. An electromagnetic pinning control mode is disabled while controlling operation of the at least one mover to the desired position and enabled when the at least one mover is at the desired position.