Stepper Motor Encoder Feedback for X-ray Positioning

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Solution Overview

Problem

Existing X-ray systems lack precise and intuitive control over the movement of X-ray sources and detectors, often resulting in imprecise positioning and potential unintentional movements due to manual force applications.

Innovation Solution

The integration of a stepper motor system with an incremental rotary encoder allows for precise control of the X-ray source and detector movements by converting manual forces into angular position changes, using encoder signals to determine position deviations and control the motor for accurate alignment and movement support.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual force is applied to move the X-ray source and detector, then ease of operation is improved, but positioning precision deteriorates due to unintentional movements

Engineering Contradiction:
Improvemanual controlVSAvoidpositioning precision
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The system continuously monitors the angular position of the rotor shaft using an incremental rotary encoder and compares it with the reference angular position. When a position deviation is detected (indicating manual force application), the control unit automatically activates the stepper motor to support the movement, ensuring precise positioning while maintaining ease of operation.

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If a stepper motor is used to control movement, then positioning precision is improved, but device complexity increases

Engineering Contradiction:
Improvepositioning precisionVSAvoidcontrol system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The control system automatically detects manual force application through the encoder's position deviation signal and self-activates the stepper motor to support the movement. This self-service mechanism eliminates the need for complex external control interfaces, reducing operational complexity while maintaining high positioning precision.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If an incremental rotary encoder is used to detect position, then measurement precision is improved, but electronic complexity increases

Engineering Contradiction:
Improveangular position detection precisionVSAvoidelectronic complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The incremental rotary encoder provides continuous feedback on the rotor shaft's angular position. The control unit uses this feedback to detect position deviations caused by manual force and automatically adjusts the stepper motor operation accordingly, achieving high measurement precision with minimal electronic complexity.

Inventive Principle:
Principle #23Feedback

4Ease of operation

If the rotor shaft angular position changes in response to external force, then ease of operation is improved, but control reliability deteriorates due to unintentional movements

Engineering Contradiction:
Improvemanual movement controlVSAvoidmovement control reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system uses the incremental rotary encoder to provide real-time feedback on rotor shaft position. When position deviation exceeds a threshold (indicating intentional manual force), the control unit activates the stepper motor to support controlled movement. This feedback mechanism distinguishes between intentional and unintentional movements, maintaining both ease of operation and control reliability.

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 enables high-resolution, accurate, and intuitive control of X-ray system components, preventing unintentional movements and allowing for precise positioning with reduced electronic complexity, while supporting both manual and motor-driven movements.

Implementation Method 1

at least one incremental rotary encoder, which is coupled with the rotor shaft of the stepper motor and configured to generate an encoder signal in accordance with the change of the angular position of the rotor shaft

Methodology Applied
Scientific EffectAngular position detection:

Implementation Method 2

at least one stepper motor, which is configured to move the first structure relative to the second structure, the stepper motor comprising a rotor shaft

Methodology Applied
Scientific EffectElectromagnetic conversion:

Implementation Method 3

a control unit, which is configured to determine, based on the encoder signal, a position deviation signal characterizing a deviation of the angular position of the rotor shaft from a reference angular position of the rotor shaft and to control the stepper motor to rotate the rotor shaft dependent on the position deviation signal

Methodology Applied
Scientific EffectFeedback control: Feedback

Data Source

PatentEP3075317B1X-ray system and method for operating an x-ray system
Publication Date: 2017.09.20 AGFA HEALTHCARE NV
  • EP3075317B1 patent drawingFigure 1
  • EP3075317B1 patent drawingFigure 2~4
  • EP3075317B1 patent drawingFigure 5

AI summary

The invention relates to an X-ray system and an according method for operating an X-ray system comprising: a first structure (11, 17), on which an X-ray source and/or an X-ray detector is provided; a second structure (14); at least one stepper motor (40), which is configured to move the first structure (11, 17) relative to the second structure (14, 15), the stepper motor (40) comprising a rotor shaft (41) which is coupled with the first structure (11, 17) such that when a user exerts an external force (F) on the first structure (11, 17) an angular position of the rotor shaft (41) is changed in accordance with the exerted external force (F); at least one incremental rotary encoder (50), which is coupled with the rotor shaft (41) of the stepper motor (40) and configured to generate an encoder signal in accordance with the change of the angular position of the rotor shaft (41); and a control unit (60), which is configured to determine, based on the encoder signal, a position deviation signal characterizing a deviation of the angular position of the rotor shaft (41) from a reference angular position of the rotor shaft (41) and to control the stepper motor (40) to rotate the rotor shaft (41) dependent on the position deviation signal such that the stepper motor (40) supports a movement of the first structure (11, 17) relative to the second structure (14) in accordance with the exerted external force (F).