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US 4,070,608 AGranted
Two axes NC system with tool offset
AssigneeThe Superior Electric Company
InventorsHermann Rosshirt, Robert J. Jarosik
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AssigneeThe Superior Electric Company
InventorsHermann Rosshirt, Robert J. Jarosik
Estimating the term…
Tool offset compensation for a commanded path for a two axes NC system that produces movement by axis determination of sequential steps, is provided by having the tool offset the desired value, placing the tool center in the same quadrant as the direction of the commanded path and then making the tool center normal to the beginning of the commanded path. For a linear commanded path, the NC system then produces the commanded path while for an arcuate commanded path, the radius of the movement path produced is made to be the algebraic sum of the commanded path and tool center radii with additional incremental alterations without a corresponding movement being made in the numerical extent of the commanded path to utilize the same numerical extent for controlling the extent of the movement path.
A numerical control system for producing a tool center movement along two axes that is offset a desired value from a commanded path comprising means for producing independent stepwise movement along each axis, means for accepting information of the commanded path, circular path interpolator means for determining the axis on which successive steps are to be produced for an arcuate commanded path, linear path interpolator means for determining the axis on which successive steps are to be produced for a linear commanded path, means for receiving the desired value of the offset, circular tool interpolator means for determining the axis on which successive steps should be taken for an arc having a radius equal to the desired offset value, slope comparator means for causing the tool center to be located on a line normal to the extent of the commanded path at the beginning of the commanded path and ratio interpolator means for causing the extent of the tool center movement to be limited to that commanded by the extent of the commanded path, in which the circular tool interpolator means includes a pair of registers for maintaining the extent that the tool center is offset along each axis, an error register for determining upon actuation the axis on which the next step should be taken and means for maintaining an indication of the direction on each axis of the tool center offset and in which the slope comparator means includes means for comparing the instantaneous extent of the tool center offset with the instantaneous extent of a slope line normal to the beginning of the commanded path, means for sequentially altering either extents and means for terminating the altering when the extents are essentially equal.
A numerical control system for producing a tool center movement along two axes that is offset a desired value from a commanded path comprising means for producing independent stepwise movement along each axis, means for accepting information of the commanded path, circular path interpolator means for determining the axis on which successive steps are to be produced for an arcuate commanded path, linear path interpolator means for determining the axis on which successive steps are to be produced for a linear commanded path, means for receiving the desired value of the offset, circular tool interpolator means for determing the axis on which successive steps should be taken for an arc having a radius equal to the desired offset value, slope comparator means for causing the tool center to be located on a line normal to the extent of the commanded path at the beginning of the commanded path and ratio interpolator means for causing the extent of the tool center movement to be limited to that commanded by the extent of the commanded path and in which the slope comparator means includes means for comparing the instantaneous extent of the tool center offset with the instantaneous extent of a slope line normal to the beginning of the commanded path. means for sequentially altering either extents and means for terminating the altering when the extents are essentially equal, in which the means for sequentially altering the extents includes means for changing the extent having the lesser extent by one step, in which the sequentially altering means includes means for changing the slope line extent including a slope line register for each axis, means for directing the linear path interpolator means to itinerate one step using the reverse values of the extent of the commanded path to determine the axis on which a step should be taken and means for incrementing the slope line register for the axis so determined.
Dependencies are inferred from the claim text.