Long Stator Linear Motor Control via Frequency Response Analysis

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Solution Overview

Problem

Long-stator linear motors face challenges in adapting control strategies to individual transport units with varying properties, leading to reduced dynamics and increased maintenance costs due to conservative control approaches that fail to account for differences in load, wear, and frictional forces.

Innovation Solution

A method for determining optimized controller parameters for drive coil controllers based on frequency response analysis, allowing for flexible control adaptations and real-time monitoring of system parameters to adjust for changing conditions, including wear and load states, enabling faster and more precise control interventions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conservative control strategies are used to ensure stable operation across all transport units, then reliability is improved, but dynamics and responsiveness are reduced

Engineering Contradiction:
Improvestable operationVSAvoiddynamics
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The patent applies local quality by determining individual controller parameters for each transport unit based on its specific frequency response characteristics. Instead of using a uniform conservative control strategy for all transport units, the system adapts the control parameters locally to match each unit's actual dynamic properties, thereby achieving both reliability and improved dynamics simultaneously.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If individual control adaptation for each transport unit is implemented, then adaptability is improved, but device complexity increases

Engineering Contradiction:
Improveindividual control adaptationVSAvoidcontrol system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements self-service by enabling each transport unit to determine its own controller parameters through frequency response analysis. The system automatically identifies the dynamic characteristics of each transport unit and computes the appropriate controller parameters without requiring manual configuration or complex external intervention, thus achieving individual adaptation while limiting complexity growth.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If conservative control approaches are used, then ease of operation is improved, but maintenance costs increase due to unaddressed wear and load variations

Engineering Contradiction:
Improvesimple control operationVSAvoidmaintenance costs
Core Design Contradiction:
Ease of operationVSEase of repair

Solution Approach 1:

The patent applies feedback by continuously monitoring the frequency response of each transport unit and using this information to adjust controller parameters. This feedback mechanism enables the system to detect changes in wear and load conditions automatically, allowing for timely maintenance interventions while keeping the control operation simple through automated parameter adaptation.

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 approach enhances the dynamic control of transport units, reduces maintenance needs, and optimizes energy use by allowing for tailored control strategies for each transport unit, improving the overall efficiency and flexibility of long-stator linear motor systems.

Implementation Method 1

By controlling the individual drive coils in the area of the transport unit to regulate the magnetic flux, a propulsive force is generated on the transport unit

Methodology Applied
Scientific EffectMagnetic flux control: Magnetic Field

Implementation Method 2

each drive coil being controlled by a drive coil controller with associated controller parameters by the Drive coil regulators for the drive coils interacting with the transport unit manipulated variables are specified

Methodology Applied
Scientific EffectElectromagnetic interaction: Lorentz Force

Implementation Method 3

In the case of magnetic guidance, guide magnets can be provided on both sides of the transport units, which interact with guide rods arranged opposite one another on the transport path. The guide rods form a magnetic yoke that close the magnetic circuit of the guide magnets.

Methodology Applied
Scientific EffectMagnetic guidance: Magnetic Field

Data Source

PatentEP3251986B1Method for operating a long stator linear motor
Publication Date: 2021.01.27 B&R IND AUTOMATION GMBH
  • EP3251986B1 patent drawingFigure 1
  • EP3251986B1 patent drawingFigure 2
  • EP3251986B1 patent drawingFigure 3~4

AI summary

In order to better adapt the operation of a long stator linear motor to the requirements or the conditions of the individual transport units or the transport route, it is provided that an excitation signal (AS) with a predefined frequency band is superimposed on the manipulated variables (StG) of a drive coil (7, 8) of the long stator linear motor, thereby determining actual variables (IG) of the drive coil control, a frequency response is determined from the manipulated variables (StGAS) superimposed with the excitation signal (AS) and the determined actual variables (IG), and from the frequency response the controller parameters (RP) for this transport unit (Tx) are determined, and the transport unit (Tx) is controlled for movement along the transport route with these determined controller parameters (RP).