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US 6,615,102 B1Granted
Process and system for compensating static errors on numerically controlled machine tools
AssigneeFidia S.p.A.
InventorGiuseppe Morfino
Life of this patent
Estimating the term…
Abstract
A system and a process are described for performing the Static Error Compensation on numerically controlled machine tools. The process comprises the steps of: connecting a measuring laser device (5) to a numerically controlled machine tool (1); automatically sending a point 0 of the machine (1) to the laser device (5); sending commands for taking m measure points of the machine (1) from the control (3) to the laser device (5); automatically detecting the measure points and sending consolidated data from the laser device (5) to the control (3); producing a model of static errors of the machine (1); executing the Static Error Compensation depending on said produced model.
Claims21
Process for performing a Static Error Compensation on machines, particularly numerically controlled machine tools, comprising the following steps:
- a. connecting a measuring laser device (5) to a control device (3) of a numerically controlled machine (1);
- b. positioning a reflector (7) of said measuring laser device (5) in a point whose absolute distance is known, said point being called point 0 for measures, and automatically sending the point 0 of said machine (1) from said control device (3) to said measuring laser device (5);
- c. sending a command for taking a measure point of said machine (1) from said control device (3) to said measuring laser device (5);
- d. automatically detecting said measure point by said measuring laser device (5) after n times from which no variations from said point occurred;
- e. sending data regarding said point of said machine (1) detected by said measuring laser device (5) to said control device (3);
- f. repeating the previous steps from c) to e) for m measure points;
- g. producing a model of static errors of said numerically controlled machine (1);
- and
- h. executing a Static Error Compensation (SEC) depending on said produced model,
- wherein said step (g) of producing a model comprises the following steps:
- g1. determining the sizes of small elementary cubes (volume elements=voxels) through a procedure based on FFT techniques that determines the minimum voxel size with which the geometric operation of machine (1) is described;
- g2. acquiring static errors;
- g3. collecting values of static errors for all voxel vertexes into which the working volume for machine (1) has been divided;
- and wherein said step (h) of executing a SEC depending on said produced model comprises the following steps:
- h1. providing an error table containing the static errors values in predetermined positions of the machine (1);
- h2. based on said error table, computing and then compensating the static errors of the machine (1), with such a compensation speed as to be able to perform the compensation of a static error in a useful period in order to produce a better geometric behaviour of the machine (1) with respect to the case of lack of compensation;
- h3. acquiring the values of the measuring system aboard the machine;
- h4. processing, based on the values contained in said error table, the static error value corresponding to the current position of the machine provided through the acquiring step.
15 more elements
System for performing a Static Error Compensation on machines, particularly numerically controlled machine tools, comprising:
- a numerically controlled machine (1);
- a control device (3) connected to said machine (1) and adapted to control the operation of said machine (1);
- and
- a measuring laser device (5) assembled on a numerically controlled bi-rotating head (8), said measuring leaser device (5) being connected to said control device (3), a reflector (7) of said measuring laser device (5) being positioned in a point whose absolute distance is known, said point being-called point 0 for measures;
- characterised in that said control device (3) is adapted to perform the following steps:
- automatically sending the point 0 of said machine (1) to said measuring laser device (5);
- sending a command for taking a measure point of said machine (1) to said measuring laser device (5);
- automatically detecting said measure point by said measuring laser device (5) after n times from which no variations from said point occurred;
- receiving data regarding said point of said machine (1) detected by said measuring laser device (5);
- repeating the previous steps for m measure points;
- producing a model of static errors of said numerically controlled machine (1);
- and
- executing a Static Error Compensation (SEC) depending on said produced model,
- and in that said control device (3) comprises calibration means adapted to perform the step of producing a model, said step comprising the following sub-steps:
- determining the sizes of small elementary cubes (volume elements=voxels) through a procedure based on FFT techniques that determines the minimum voxel size with which the geometric operation of machine (1) is described;
- acquiring static errors;
- collecting values of static errors for all voxel vertexes into which the working volume for machine (1) has been divided;
- and in that said control device (3) comprises static error compensation means that are adapted to perform the step of executing a SEC depending on said produced model, said step comprising the following sub-steps:
- providing an error table containing the static errors values in predetermined positions of the machine (1);
- based on said error table, computing and then compensating the static errors of the machine (1), with such a compensation speed as to be able to perform the compensation of a static error in a useful period in order to produce a better geometric behaviour of the machine (1) with respect to the case of lack of compensation;
- acquiring the values of the measuring system aboard the machine;
- processing, based on the values contained in said error table, the static error value corresponding to the current position of the machine provided through the acquiring step.
19 more elements
Dependencies are inferred from the claim text.