Patent ID: 6615102
Filing Date: 2003-09-02
Classification: G05B

Abstract:
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.