# US 6,504,333 B2 · Numerical control apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,504,333 B2 - Document ID: US6504333B2 - Status: Granted - Kind: B2 - Application number: 09/793,486 - Filed: 2001-02-27 - Published: 2001-09-27 - Granted: 2003-01-07 - Earliest claimed: 2000-03-09 - Assignees: Mitsubishi Denki Kabushiki Kaisha - Inventors: Nobuyuki Takahashi; Kiyotaka Kato; Kenji Iriguchi - Web page: https://patentgrep.com/patent/US6504333B2 ## CPC - G05B 19/41: characterised by interpolation, e.g. the computation of intermediate points between programmed end points to define the path to be followed and the rate of travel along that path (G05B19/25, G05B19/31, G05B19/37, G05B19/39, G05B19/40 take precedence) - G05B 2219/34093: Real time toolpath generation, no need for large memory to store values - G05B 2219/34141: B-spline, NURBS non uniform rational b-spline - G05B 2219/43129: Speed as function of curvature, in curves, corners smaller than in straight line - G05B 2219/49111: Cutting speed as function of contour, path, curve - G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G) ## Abstract A numerical control system includes a curved-surface state evaluating unit for forming curved-surface evaluation data of evaluation points by arranging, virtually, the tool on a given scheduled path locus, that serves as the criterion of movement of a tool, to come into contact with a processed surface of a processing object, and by setting a plurality of evaluation points to evaluate the shape of the curved surface, a command speed deciding unit for deciding a command speed appropriately by using a passing speed and other data in the evaluation data, and a tool position data forming unit for calculating quickly a succeeding tool position by utilizing the evaluation data. The operations are performed in real time. ## Claims ### Claim 1 A numerical control apparatus comprising: an evaluating section for forming evaluation data of an evaluation point containing a pointer representing a position of a succeeding clamp point, a path length to the succeeding clamp point, and a passing speed of a process applying portion to be passed through the evaluation point if the evaluation point corresponds to a clamp point, by arranging, virtually, the process applying portion of a system to be numerically controlled on a given scheduled path locus to come into contact with a processed surface of a processing object, and by setting a plurality of evaluation points to evaluate shape of the processed surface, where the clamp point signifies the evaluation point that is decided based on the shape of the processed surface such that the passing speed of the process applying portion passing through the evaluation point is restricted; a command speed deciding section for deciding a command speed at which the process applying portion is moved, by calculating (i) a distance from a current process applying portion position to a closest succeeding evaluation point and then deciding whether a deceleration based on a path length from the current process applying portion position to the succeeding clamp point is necessary, the path length being calculated by reading the path length to the succeeding clamp point in evaluation data of the closest succeeding evaluation point and adding the path length calculated to the distance, (ii) the passing speed in the evaluation data of the clamp point, the passing speed being calculated by employing the pointer in the evaluation data of the closest succeeding evaluation point, and (iii) speed of the current process applying portion; and a process applying portion position data forming section for calculating a process applying portion position by arranging, virtually, the process applying portion to separate from a current process applying portion position by a predetermined distance and to come into contact with the processed surface, and then providing the process applying portion position calculated to the system to be numerically controlled. ### Claim 2 (depends on 1) The numerical control apparatus according to claim 1, wherein the evaluating means picks three successive evaluation points from the evaluation points, and evaluates the processed surface based on a curvature of a circular arc passing through the three points. ### Claim 3 (depends on 1) The numerical control apparatus according to claim 1, wherein respective operations of the evaluating means, the command speed deciding means, and the process applying portion position data forming means are executed in real time. ### Claim 4 A numerical control apparatus comprising: an evaluating section for forming evaluation data of an evaluation point containing a distance to a succeeding evaluation point, by arranging, virtually, a process applying portion of a system to be numerically controlled on a given scheduled path locus to come into contact with a processed surface of a processing object, and by setting a plurality of evaluation points to evaluate shape of the processed surface; a command speed deciding section for deciding a command speed, at which the process applying portion is moved, by deciding whether a deceleration, based on the evaluation data, is necessary; and a process applying portion position data forming section for calculating an evaluation point such that a path length that is a sum of distances obtained by adding successive distances to succeeding evaluation points in the evaluation data of respective evaluation points, exceeds a predetermined length, while using a succeeding evaluation point closest to a current process applying portion position as an initial point, then searching for a process applying portion position that is separated from the current process applying portion position by a predetermined distance, by arranging, virtually, the process applying portion to come into contact with the processed surface while using this evaluation point calculated as a starting point, and providing the process applying portion position found in searching to the system to be numerically controlled. ### Claim 5 (depends on 4) The numerical control apparatus according to claim 4, wherein the evaluating means picks three successive evaluation points from the evaluation points, and evaluates the processed surface based on a curvature of a circular arc passing through the three points. ### Claim 6 (depends on 4) The numerical control apparatus according to claim 4, wherein respective operations of the evaluating means, the command speed deciding means, and the process applying portion position data forming means are executed in real time. ### Claim 7 A numerical control apparatus comprising: an evaluating section for forming evaluation data of an evaluation point containing a pointer representing a position of a succeeding clamp point, a path length to the succeeding clamp point, and a passing speed of a process applying portion to be passed through the evaluation point if the evaluation point corresponds to a clamp point, by arranging, virtually, the process applying portion of a system to be numerically controlled on a given scheduled path locus to come into contact with a processed surface of a processing object, and by setting a plurality of evaluation points to evaluate shape of the processed surface, where the clamp point signifies the evaluation point that is decided based on the shape of the processed surface such that the passing speed of the process applying portion passing through the evaluation point is restricted; a command speed deciding section for deciding a command speed at which the process applying portion is moved, by calculating (i) a distance from a current process applying portion position to a closest succeeding evaluation point and then deciding whether a deceleration based on a path length from the current process applying portion position to the succeeding clamp point is necessary, the path length being calculated by reading the path length to the succeeding clamp point in evaluation data of the closest succeeding evaluation point and adding the path length calculated to the distance, (ii) the passing speed in the evaluation data of the clamp point, the passing speed being calculated by employing the pointer in the evaluation data of the closest succeeding evaluation point, and (iii) speed of the current process applying portion; and a process applying portion position data forming section for calculating an evaluation point such that a path length that is a sum of distances obtained by adding successive distances to succeeding evaluation points in the evaluation data of respective evaluation points, exceeds a predetermined length, while using a succeeding evaluation point closest to a current process applying portion position as an initial point, then searching for a process applying portion position that is separated from the current process applying portion position by a predetermined distance, by arranging, virtually, the process applying portion to come into contact with the processed surface while using this evaluation point calculated as a starting point, and providing the process applying portion position found in searching to the system to be numerically controlled. ### Claim 8 (depends on 7) The numerical control apparatus according to claim 7, wherein the evaluating means picks three successive evaluation points from the evaluation points, and evaluates the processed surface based on a curvature of a circular arc passing through the three points. ### Claim 9 (depends on 7) The numerical control apparatus according to claim 7, wherein respective operations of the evaluating means, the command speed deciding means, and the process applying portion position data forming means are executed in real time.