CNC Axis Transition Control for Non-Tangential Contour Paths
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Solution Overview
Problem
Existing methods for machining with non-tangential contour paths result in reduced path speed and increased machining time due to required 'speed jumps' of individual axes, especially in operations like turning or milling, where block transitions are common.
Innovation Solution
Implementing a technology clock with a period different from the interpolation clock (IPO clock) to specify acceleration periods and maximum velocities for axes, allowing for smoother transitions and maintaining high path speed without axis slowdowns during block changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If speed jumps are required for non-tangential contour paths, then path speed can be maintained, but axis synchronization is compromised and vibrations increase
Solution Approach 1:
The patent applies preliminary action by pre-calculating and pre-positioning axes during an acceleration period before the block transition point. The numerical control device determines a transition maximum velocity and acceleration period in advance, allowing axes to be prepared for the upcoming discontinuous transition. This preliminary preparation enables smoother coordination when the actual transition occurs, reducing synchronization issues and vibrations while maintaining path speed.
2Reliability
If axes are slowed down during block transitions, then synchronization is improved, but machining time increases
Solution Approach 1:
The patent applies dynamics by implementing a technology clock with a different period than the interpolation clock, allowing dynamic adjustment of acceleration periods and transition maximum velocities. This dynamic timing mechanism enables the system to optimize axis coordination during block transitions without requiring complete speed reduction, thereby maintaining higher path speeds and reducing machining time while still achieving proper synchronization.
3Device complexity
If acceleration period is tied to interpolation clock period, then control is simplified, but flexibility in optimizing transitions is limited
Solution Approach 1:
The patent applies segmentation by separating the control timing into two distinct clocks: the interpolation clock for path generation and the technology clock for acceleration control. This segmentation allows each clock to operate independently with optimized parameters for its specific function, providing flexibility in transition optimization without complicating the overall control structure. The technology clock can be configured with a different period to match specific machine characteristics and transition requirements.
Data Source
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AI summary
The invention relates to an operating method for a machine (2), wherein, even for a trajectory (P) which is determined by a parts program with multiple block transitions with a non-tangential contour, a high trajectory speed (vP) and an accompanying short operating time are achieved. According to the invention, for at least one first position-controlled axis (X), an acceleration duration (TD1, TD2, TD3) can be specified that differs from a first period duration (T1, T2, T3, T4), wherein a transition maximum acceleration can be specified for the first position-controlled axis (X), wherein a transition maximum speed (vX,m3) is determined for the first position-controlled axis (X) in such a way that, with a movement of the first position-controlled axis (X) with the transition maximum speed (vX,m3) using the transition maximum acceleration, the speed (vx) of the first position-controlled axis (X) has the value of zero at the end of the acceleration duration (TD1, TD2, TD3), and wherein the travelling movement is determined in such a way that the speed (vx) of the first position-controlled axis (X), at the transition from a first trajectory section (P1) to a second trajectory section (P2), does not exceed the transition maximum speed (vX,m3).