Laser Plotter Axis Prediction for Precise Bus-Based Laser Timing

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Solution Overview

Problem

Conventional laser plotter designs require high hardware and software engineering effort due to direct connections between laser control modules and position sensors, limiting the use of standardized industrial buses and leading to suboptimal synchronization of laser activation with axis positions.

Innovation Solution

A method utilizing a mathematical-physical model of the mechatronic axis system to estimate future axis positions, allowing synchronization with standardized industrial buses by calculating positions at future times, thus enabling precise laser activation without direct sensor connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If direct connection between laser control module and position sensors is used, then laser activation timing is precise, but hardware and software engineering effort increases

Engineering Contradiction:
Improvelaser activation timing precisionVSAvoidhardware and software engineering effort
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent introduces an intermediary calculation unit that computes future axis positions based on current position data and motion parameters. This intermediary layer enables standardized industrial buses to be used while maintaining precise laser activation timing, as the calculated future positions allow the laser control module to trigger at the correct time without direct sensor connections.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system performs preliminary calculations of future axis positions before the actual laser activation occurs. By computing where the axis will be at future time points based on current motion state, the system prepares the laser control in advance, enabling precise timing without requiring continuous direct feedback from position sensors during operation.

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If standardized industrial bus is used, then device complexity is reduced, but sampling time is too long for precise laser synchronization

Engineering Contradiction:
Improvestandardized component usageVSAvoidsampling time delay
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The system performs preliminary calculations of future axis positions at each sampling moment, projecting where the axis will be at subsequent time points. This allows the laser control module to activate at precisely the right moment based on pre-calculated positions, compensating for the long sampling time of standardized industrial buses.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces the direct mechanical/electrical connection between position sensors and laser control with a computational model. Instead of relying on fast direct signal transmission, the system uses mathematical calculations based on motion parameters (velocity, acceleration, jerk) to predict future positions, substituting physical signal speed with computational prediction accuracy.

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

3Adaptability or versatility

If position data is transmitted at sampling times, then industrial bus compatibility is achieved, but laser must be activated much too early without future position estimation

Engineering Contradiction:
Improveindustrial bus compatibilityVSAvoidlaser activation timing accuracy
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The system performs preliminary calculations of future axis positions at each sampling moment, projecting where the axis will be at subsequent time points. This allows the laser control module to activate at precisely the right moment based on pre-calculated positions, compensating for the long sampling time of standardized industrial buses.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system creates a computational model (copy) of the axis motion behavior using current position, velocity, acceleration, and jerk parameters. This model replicates the expected future motion trajectory, allowing the laser control to follow the predicted path without direct real-time sensor feedback, thus maintaining precision while using standardized buses.

Inventive Principle:
Principle #26Copying

Data Source

PatentEP4487186B1Method for operating a laser plotter for cutting, engraving, marking, and/or inscribing a workpiece, and laser plotter for engraving, marking, and/or inscribing a workpiece
Publication Date: 2025.12.03 TROTEC LASER LTD
  • EP4487186B1 patent drawingFigure 1
  • EP4487186B1 patent drawingFigure 2
  • EP4487186B1 patent drawingFigure 2a

AI summary

The invention relates to a laser plotter and a method for operating a laser plotter (1) for cutting, engraving, marking, and/or inscribing a workpiece (7), wherein at least one radiation source (4) in the form of a laser (5, 6) is used in a housing (3) of the laser plotter (1), and when the beam source (4) is activated, a laser beam (10) is deflected to a focusing unit (12) via deflecting elements (11). A control process is carried out by a control unit (13) of the basis of the set parameters and/or a loaded job (18), and preferably a working table (9) or a working area (8) is captured via at least one camera (23) in order to record an inserted workpiece (7). The data, in particular the job (18), is received by a computing unit (27) and a calculation for planning the path is carried out offline by the computing unit (27) or externally by a cloud solution or components (15). The path planning process and additional data are then transferred to a PLC (26a) or a soft PLC (26b), from which the individual target data, in particular the path plan and additional data, such as the speed for example, is then transmitted to at least one module (29, 30, 31) for controlling the axis and the laser via an industrial bus (25, 28), in particular an etherCAT bus, in steps during the scanning cycles or scanning times (40). During the cyclical scanning times (40), at least the detected position and speed information, in particular the axis positions (41) and speeds, are transmitted from the axis module (29, 30) to the laser control module (31), and in response thereto, an estimation (39) or calculation (39) of one or more future axis positions (42) at future points in time (43) is carried out by means of the laser control module (31) or by a universal board, in particular a universal Trotec board, in order to activate a control signal for controlling the laser, in particular in order to activate the laser (5, 6) at the specified estimated axis position (42) of the focusing unit (12), in a timely manner.