Additive Manufacturing NC Control for Velocity-Supply Synchronization
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Solution Overview
Problem
In additive manufacturing, errors in material supply and beam velocity transitions during acceleration and deceleration processes affect machining accuracy, leading to suboptimal performance even with conventional techniques.
Innovation Solution
A numerical control device that analyzes machining program transitions for the moving velocity of the machining head and material supply, calculates specific movement sections for acceleration and deceleration, and adjusts material supply commands to maintain constant relations between velocity and supply rate, ensuring precise control during additive manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional runway paths are set with constant velocity for machining head movement, then the machining process can be simplified, but machining accuracy deteriorates due to errors in material supply and beam velocity transitions during acceleration and deceleration
Solution Approach 1:
The patent applies dynamics by transitioning from constant velocity movement to dynamically adjusted velocity profiles. The machining head velocity is continuously adjusted based on real-time feedback from position detectors and material supply sensors, allowing smooth acceleration and deceleration while maintaining precise control over the relationship between head movement, material supply rate, and beam output. This dynamic control resolves the contradiction by enabling both process flexibility and high machining accuracy.
Solution Approach 2:
The patent implements feedback control systems that continuously monitor the actual position of the machining head, the rate of material supply, and the beam output. These feedback signals are used to adjust the velocity profile in real-time, compensating for deviations caused by acceleration and deceleration. The feedback mechanism ensures that the material supply rate and beam output remain synchronized with the actual head velocity, thereby maintaining machining accuracy while allowing dynamic velocity changes.
2Productivity
If the machining head velocity is changed during acceleration and deceleration, then productivity can be improved, but machining accuracy deteriorates due to errors in the relation between moving velocity and material supply amount
Solution Approach 1:
The patent enables dynamic velocity adjustment during machining operations, allowing the machining head to accelerate and decelerate smoothly without compromising accuracy. The velocity profile is continuously optimized based on the machining program requirements, enabling higher productivity through reduced idle time at constant velocity while maintaining precise control over the velocity-material supply-beam output relationship throughout the dynamic transitions.
Solution Approach 2:
The patent dynamically changes multiple parameters simultaneously - velocity, material supply rate, and beam output - in coordinated fashion during acceleration and deceleration phases. These parameter changes are governed by pre-calculated profiles that ensure the ratios between velocity and material supply rate remain constant, thereby maintaining machining accuracy while enabling productive velocity transitions.
3Productivity
If material supply rate is increased to match higher machining head velocity, then productivity improves, but machining accuracy deteriorates due to response performance limitations of the material supply source
Solution Approach 1:
The patent implements preliminary action by pre-calculating and pre-positioning material before velocity changes occur. The system anticipates upcoming acceleration or deceleration phases based on the machining program and adjusts the material supply rate in advance, compensating for the response lag of the material supply source. This ensures that the material is ready at the correct rate when the velocity change occurs, maintaining machining accuracy without limiting productivity.
Solution Approach 2:
The patent applies dynamics to the material supply system by enabling continuous, smooth adjustment of the material supply rate in response to velocity changes. The material supply mechanism is controlled dynamically to match the actual head velocity profile, with acceleration and deceleration rates optimized to overcome the inherent response limitations of the supply source while maintaining the critical velocity-supply rate relationship for machining accuracy.
4Manufacturing precision
If the beam output is adjusted to match the machining head velocity, then machining quality improves, but device complexity increases due to synchronization requirements between beam source and movement control
Solution Approach 1:
The patent merges the control of beam output with the velocity control system by integrating the beam power adjustment mechanism into the existing motion control architecture. The beam source controller receives velocity profile commands from the motion controller and automatically adjusts beam output in real-time based on the actual head velocity feedback. This merging eliminates the need for separate, complex synchronization systems while maintaining high machining quality through coordinated velocity-beam output control.
Solution Approach 2:
The patent implements feedback control where the actual velocity of the machining head is continuously measured and used to adjust the beam output in real-time. The feedback loop ensures that the beam power remains proportional to the actual velocity, maintaining consistent energy density and machining quality regardless of velocity changes. This feedback mechanism simplifies the overall control architecture by using the existing velocity measurement infrastructure rather than requiring additional sensing and coordination systems.
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 enables high machining accuracy by synchronizing material supply and beam output with the machining head's movement, improving the overall precision and quality of the additive manufacturing process.
Implementation Method 1
a beam source emitting a beam; irradiation of the beam; locally melting a material using a beam emitted from a machining head
Implementation Method 2
a machining head to be moved; movement path along which a machining head is to be moved; moving velocity of the machining head
Implementation Method 3
a material supply source; supply amount of the material; adding the molten material to a workpiece
Implementation Method 4
an operation mechanism owned by the additive manufacturing apparatus; processes for acceleration and deceleration in driving the operation mechanism
Data Source
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AI summary
A numerical control device (1) includes: a program analyzing unit (22) that analyzes a transition of a moving velocity of a machining head relative to a workpiece and a transition of a supply amount of a material supplied to an irradiation position of a beam on the basis of a machining program (20); a movement distance calculating unit (25) that calculates a first distance on the basis of a result of analysis performed by the program analyzing unit (22), the first distance being a length of a first movement section to a first position at which addition of the material to the workpiece is started, the first movement section being a section through which the machining head is moved while the head is accelerated; and a condition command generating unit (27) that generates a supply command to increase the supply amount of the material per hour from zero to a command value according to a machining condition while the machining head is moved through the first movement section.