RU2800793C2 - Machine with optical measuring device for three-dimensional determination of tool holder position relative to holder and corresponding method of three-dimensional optical measurement - Google Patents

Abstract

FIELD: machine tools.

SUBSTANCE: processing machine includes a processing module equipped with a tool holder and a workpiece holder, as well as an optical measuring device for three-dimensional measurement of the position of the tool holder relative to the workpiece holder, where the optical measuring device comprises an optical system with an imaging system mounted on the workpiece holder, and a three-dimensional target mounted on the tool holder and containing a working face forming a positioning base, which can be located on the optical axis (O) of the optical system. The working face contains the first structure forming a flat base face, which is divided at least into the first section, the surface of which is reflective in accordance with the first reflection parameters, and the second section, the surface of which is reflective in accordance with the second reflection parameters, which differ from the first reflection parameters, and a second structure containing a face tilted relative to the specified flat base face. The specified optical system contains the first shooting system and the second shooting system, and the difference between the focal length of the second shooting system and the focal length of the first shooting system lies in the interval between the minimum distance and the maximum distance separating the base face from the tilted face, and the optical measuring device is made with the possibility of determining, in one stage of shooting the target by means of an optical system, the position in three-dimensional space of the workpiece holder relative to the tool holder.

EFFECT: invention provides the possibility of three-dimensional determination of the relative position of objects in one stage of shooting.

27 cl, 12 dwg

Description

The technical field to which the invention belongs

The present invention relates to the field of machine tools. The present invention also relates to the field of optical measurements of the relative position of the first object and the second object, and in particular the position of the tool holder relative to the workpiece holder in a machine tool.

In the field of machine tools performing, among other things, machining by removing material, there is a need to know exactly the position of the tool holder relative to the workpiece holder in order to provide a machining range corresponding to the machining plan developed during machine setup.

The manufacture of parts by means of machining modules (machining machines), in particular bar automatic machines, automatic lathes, turn-mill centres, milling machines, machining centers and production line machines, usually comprises three separate steps.

At the first stage of setting (or presets), the operator (for example, the operator of a bar machine) determines and checks on the processing module the processing plan, that is, the sequence of operations and axis movements that are necessary to obtain the required workpiece. The operator acts carefully to get the most efficient processing plan, i.e. a plan that makes it possible to process a given part with a minimum of operations, and at the same time avoid conflicts between tools or conflicts with the part. The operator selects the tool to be used and checks the quality of the resulting part, such as surface quality, tolerances, etc.

In the second manufacturing step, a series of parts are produced on a pre-configured machining module with the parameters that were determined during setup. This step is the only manufacturing step; it is often performed for 24 hours a day; while raw material is fed into the processing module by means of a charging device or by means of a workpiece (raw parts) loader.

It may be that the production of a series of parts is interrupted, for example, to replace worn tools, to produce parts of a different type on the same machining module, for machine maintenance, etc., and then production is resumed. In this case, a preparation step is required to apply the settings that were previously defined during configuration. This stage of preparation is faster than setting up.

During this preparation, it is often necessary to replace the tools installed on the machine with another set of tools that is suitable for the upcoming processing. The positioning accuracy of these tools determines the quality of processing, but this positioning is difficult to reproduce at the next stages of preparation.

In addition, during the manufacturing phase, during the processing of new parts, especially over long periods of time, it is quite possible for the position of the tool holder relative to the workpiece holder to drift, in particular due to thermal expansion in machine tools.

State of the art

Therefore, in the machines of the existing state of the art, various technical solutions have been proposed and are being proposed in order to guarantee the correct position of the tool holder relative to the workpiece holder at the manufacturing stage and at the preparation stage, that is, the correct relative position, which corresponds to the relative position of the tool holder and the workpiece holder, which was at the stage settings.

Many in situ measurement methods used in machine tools are designed to measure the relative position of a workpiece or workpiece holder and the tool itself. However, in this case, the measurement of the position of the workpiece or workpiece holder relative to the tool is affected by tool wear and thermal drift in the machine during its operation.

In addition, this type of relative position measurement is usually carried out in two dimensions (in two coordinates), i.e. in two directions, as in document DE 202016004237 U.

Since this determination of the relative position of the workpiece or workpiece holder and the tool is limited to two dimensions (for example, Y and X, respectively, for the lateral and vertical directions), it does not have sufficient completeness to guarantee the correct relative position, so other means of measurement must be used. third coordinate (for example, Z - in the feed/retract direction of the workpiece holder, also called the "material direction"). In this situation, not only the cost of measuring equipment increases, but also the time spent on implementation, which also adds an error due to the use of two measurement series at the same time.

US 2014362387 AA discloses an optical measurement device placed on a tool holder which makes it possible to check that the target object does not interfere with the tool holder. This optical measuring device uses a measuring element with several inclined parts to determine the geometric parameters of the laser measuring device, in particular, the coordinate between the reflected beam sensor and the incident beam emitter. This measuring element is not involved in measuring the position of the tool holder relative to the target object, which may be the part to be machined.

US 2010111630 AA discloses a tool repositioning system for a machine tool, comprising irregularly shaped targets located on the tool, which allows precise optical determination of the position of the tool by means of optical measuring elements whose position is not specified.

US Pat. No. 5,831,734 describes a technical solution in which an optical sensor is attached to a tool holder and determines the position of this tool holder relative to the part to be machined and is provided with a distinct mark (groove).

JP 07246547 proposes a machine tool that is equipped with a reflector mounted on a shaft on which a tool is mounted and a measuring device with multiple laser interferometers that can determine the position of the reflector.

However, these technical solutions do not allow to determine the relative position of the part to be processed and the tool in one shooting stage, so that this one shooting stage provides information that makes it possible to determine this relative position in three-dimensional space.

Also, these technical solutions do not allow for the independence of parameters that change in real time during processing, in particular, tool wear and temperature changes in the tool and/or the working space of the machine that receives the workpiece.

Disclosure of the essence of the invention

One object of the present invention is to provide a technology that enables measurement of the position of a tool holder relative to a workpiece holder and that is free from the limitations of known measurement methods.

Another object of the present invention is to provide a technology that enables measurement of the position of a tool holder relative to a workpiece holder, and which provides a three-dimensional determination of the relative position of the first object and the second object in one survey step.

According to the invention, this problem is solved, in particular, by means of a machining machine comprising a machining module equipped with a tool holder and a workpiece holder, as well as an optical measuring device for three-dimensional measurement of the position of the tool holder relative to the workpiece holder, said optical measuring device comprising an optical system with a system image acquisition mounted on the part holder, and a target mounted on the tool holder and containing a working face forming a positioning base, which can be located on the optical axis of the optical system.

In accordance with the invention, the optical measuring device is configured to determine in three dimensions (in one stage of shooting the target by means of an optical system) the position of the workpiece holder relative to the tool holder. Thus, it is possible to obtain, by shooting the target performed by the optical system, accurate data on the relative position of the tool holder and the workpiece holder. Shooting corresponds to obtaining an image(s) of a target by means of an optical system, namely, receiving, capturing and recording one or more images of a target. In particular, according to one possible variant, the optical system can simultaneously register the first image and the second image of the target. These two images (a pair of images) contain information about the relative position of the target and the optical system, and this information allows you to obtain data on the relative position of the target and the optical system in three directions in space (in particular, X, Y and Z). According to one variant, the optical system is configured to register a sequence of target image pairs.

In particular, the target is positioned so that the rear focal plane of the optical system can be aligned with the working face of the target.

In accordance with one embodiment of the invention, the specified target is three-dimensional, and contains on its working face:

* the first structure forming a flat base face, and

* a second structure containing a face inclined relative to the specified flat base face,

wherein the optical system comprises the first imaging system and the second imaging system, wherein the difference between the focal length of the second imaging system and the focal length of the first imaging system lies in the interval between the minimum distance and the maximum distance separating the base face from the inclined face.

Thus, the optical system can simultaneously determine its position, on the one hand, with respect to the reference face (or the first reference face) by means of the image formed by the first imaging system, and, on the other hand, with respect to at least one zone of the inclined face (or the second reference edge) that is recognized by the image generated by the second imaging system and whose position on the target relative to the base edge is known.

Said target may also meet one or the other or more of the following conditions:

- the flat base face is divided into at least a first section, the surface of which is reflective in accordance with the first reflection parameters, and a second section, the surface of which is reflective in accordance with the second reflection parameters, which differ from the first reflection parameters;

- the surface of the first area is reflective in accordance with diffuse reflection, and the surface of the second area is reflective in accordance with specular reflection;

- the second section is divided in accordance with the sets of local zones located in the first section;

- the surface of the specified inclined face contains relief elements or mirror elements, which are evenly distributed;

- these local zones together form a geometric figure, which is one of the following figures: a quadrilateral, a parallelogram, a rectangle, a square, a rhombus, a regular polygon and a circle;

- these local zones of the second section are formed by islands or segments distributed in the first section;

- these local zones are made of chromium;

- the first structure and the second structure are located on the working face concentric to each other, in particular, the first structure surrounds the second structure;

- local zones of the second section of the first structure form a square that surrounds the second structure;

- the first structure defines the window for the housing containing the specified second structure;

- the second structure is located in the specified body with an inclined edge spaced back from the base edge of the first structure, in particular, located behind the plane bounded by the base edge;

- the surface of the inclined face of the second structure has a streaky structure, in particular, the inclined face of the second structure is covered with one of the following elements: an etched grid, a structured grating or a grid of mirror lines.

In accordance with one embodiment, the surface of the inclined face contains evenly distributed elements of the relief. In accordance with another embodiment, the surface of the specified inclined face contains evenly distributed mirror elements. In both cases, the idea is to be able to position the sloped face, which is roughly flat, in the Z direction orthogonal to the base face. In order to accomplish this, in one case the elements of the relief form surface irregularities or small roughnesses; while the surface of the inclined face, being rough, provides diffuse reflection, which allows the optical system that looks at the target to clearly see part of the inclined face: in particular, these relief elements have a size of more than 700 nm, in particular more than 1 μm, namely, have a size that is larger than the wavelength of the incident light, in this case visible light. Otherwise, inclined plane mirror elements arranged according to the geometry, such as mutually parallel lines located in the Z direction at different positions, are visually distinct from the rest of the surface of the inclined face (which preferably exhibits diffuse reflection). Therefore, the optical system that looks at the target is able to clearly see the portion of the inclined edge with one or more mirror elements.

This three-dimensional target contains on its working face a double structure, respectively forming a first flat base face and a second base face defining a plane inclined relative to the first base face. Such a spatial (three-dimensional) geometry of the target, along with the special and different optical characteristics of the surfaces that respectively form the first reference face and the second reference face, allows for the optical determination of the position of a given target relative to the optical system used in the space of three coordinates X, Y and Z. According to In one embodiment, the optical system used makes it possible to carry out an optical position determination, which actually ends with the measurement of the relative position through a single acquisition step of both the first flat reference face and the second inclined reference face: thus, the measurement consists in simultaneously capturing an image of the first flat reference face. face and the second inclined base face. Such a simultaneous survey may be performed in two, three or more iterations, even n surveys (where n is an integer greater than one, such as a number between two and fifteen). Thus, it is possible to have several images (a series of images), both the first flat base face and the second inclined base face, which makes it possible to process by means of computational algorithms not one image of the first flat base face and the second inclined base face, but a series of such images. , and thus reduce the measurement error.

Specifically, according to one possible embodiment, such imaging(s) of the first flat base facet and the second inclined base facet is performed by an optical system that is used without the need for adjustment, as will be explained below. In this case, there is no special setup that needs to be done in the optical system, which saves a lot of time when measuring the relative position of a 3D target. This technical solution provides a significant advantage compared to existing technical solutions, consisting in the fact that neither several measurement steps are required nor a change in settings, in particular, the focal length of the optical system that looks at the target.

Also, when this target is used to measure the position of the tool holder relative to the workpiece holder, it becomes possible to ensure independence from tool wear and changes in the temperature of the tool and/or the working space of the machine in which the part to be processed is placed by mounting the target on the tool holder.

According to one embodiment, the optical system comprises a first imaging system and a second imaging system, wherein:

- the depth of field of the first imaging system is at least ten times greater than the depth of field of the second imaging system, and

- the optical system is designed in such a way that the optical path of the first imaging system and the optical path of the second imaging system have a common area located on the optical axis of the optical system and containing the rear focal plane of the first imaging system and the rear focal plane of the second imaging system.

Such an optical system can be placed on one of the two objects under consideration (the second object, which is formed by the workpiece holder), and makes it possible, by means of two imaging systems, to simultaneously shoot two sharp images at two closely spaced locations on the other of the two objects (the first object, which is formed by the tool holder), while said two places on the first object are located at slightly different distances from the second object. Such an optical system makes it possible, as will be discussed in more detail below, by means of two images to carry out a three-dimensional determination (ie, in three coordinates) of the position of the first object relative to the second object, which carries the optical system.

According to one possible embodiment, the optical system is configured such that the optical path from the object (the first object) passes through at least part of one of the first or second imaging systems before reaching the other of said imaging systems. Thus, it is possible to have a portion of the optical path as input/output of the optical system that is common to or very close to the first and second imaging systems. In this way, it is not only possible to combine the first and second imaging systems in the same optical system, but also to be able to capture images of two closely spaced locations on the first object, which are separated by a distance of several tens of millimeters, even several millimeters, or distance less than one millimeter.

According to one embodiment, the first and second imaging systems are arranged parallel to each other, and the optical system also includes an optical module located between the first and second imaging systems, and configured to deflect a portion of the light rays passing through at least part of one of the imaging systems. - of the first or second system - to another of the specified imaging systems. According to a possible variant, this optical module is or includes a catoptric (reflective) optical system, for example, a mirror.

This optical system may also meet one or the other or more of the following conditions:

- the focal length of the second imaging system is greater than the focal length of the first imaging system;

- the increase in the first survey system is less than or equal to the increase in the second survey system;

- depth of field (DOF1) of the first imaging system is greater than or equal to 0.8 mm;

- depth of field (DOF2) of the second imaging system is less than or equal to 0.1 mm;

- the first survey system is telecentric and the second survey system is telecentric;

- the first imaging system is configured such that its rear focal plane may coincide with the base face of the first structure;

- the second imaging system is configured such that its rear focal plane can intersect the inclined face of the three-dimensional target;

- the optical device also contains a third imaging system located on the tool holder and configured to determine the orientation of the working face of the target and/or the angular orientation of the tool holder.

The present invention also relates to a method for three-dimensional optical measurement in three orthogonal directions X, Y and Z, respectively, in the three-dimensional space of a machine tool, the positions of the tool holder relative to the workpiece holder, which are in the same line and spaced from each other in the main direction Z, containing steps, by which:

- provide an optical system with an imaging system,

- the specified optical system is installed on the part holder,

- provide a target containing a working face and forming a base for positioning,

- said target is placed on the tool holder,

- the tool holder and the workpiece holder are positioned so that the target can be positioned on the optical axis of the optical system,

- performing one stage of shooting the target, while the optical system is positioned so as to interact with the target, whereby the position of the workpiece holder relative to the tool holder is determined in three-dimensional space.

According to an embodiment of this method, during the shooting phase, the optical system and the target are positioned so that the rear focal plane of the optical system can be aligned with the working face of the target.

According to this method, one or more or more of the following conditions may be provided:

- the specified target is three-dimensional, and contains on its working face:

* the first structure forming a flat base face, divided into at least:

- the first area, the surface of which is reflective according to diffuse reflection, and

a second portion whose surface is reflective according to specular reflection, and

* a second structure containing a face inclined relative to the specified flat base face,

- said optical system comprises a first imaging system and a second imaging system, in which:

- the depth of field of the first imaging system is at least ten times greater than the depth of field of the second imaging system, while

- the specified optical system, on the one hand, is made in such a way that the optical path of the first imaging system and the optical path of the second imaging system have a common area containing the rear focal plane of the first imaging system and the rear focal plane of the second imaging system, and, on the other hand, so that the difference between the focal length of the second imaging system and the focal length of the first imaging system lies in the interval between the minimum distance and the maximum distance separating the base face from the inclined face,

- the tool holder and the workpiece holder are arranged in such a way that, on the one hand, the focal length of the first imaging system allows the back focus of the first imaging system to be placed on the first target structure, and, on the other hand, the focal length of the second imaging system allows the back focus of the second imaging system to be placed systems on the second target structure,

- at the stage of shooting by means of the optical system, at least one step of simultaneous shooting by means of the first shooting system of the optical system and by means of the second shooting system of the optical system is performed, thereby for each stage of shooting through the optical system, on the one hand, the first shooting system forms the first image of the target , providing the ability to determine on the base face the position of the second section relative to the first section, which gives, firstly, the first part of information about the relative position of the target and the first shooting system in the X direction, and, secondly, the second part of the information about the relative position of the target and the first imaging system in the Y direction, and, on the other hand, the second imaging system forms a second image of the target, containing a sharp section corresponding to the location of the inclined edge of the second structure, which gives the third part of the information about the distance between the target and the second imaging system in the Z direction.

According to another possible embodiment, the second section of the flat base face is divided into a number of local zones located on the first section, while when the first imaging system forms the first image of the target, the position of the local zones of the second section on the base face is determined, which gives part of the information about the relative position of said local areas and the first imaging system, which makes it possible to obtain a measurement result of the relative position in the Y direction and in the X direction.

Brief description of the drawings

Examples of the invention are indicated in the following description, illustrated by the accompanying drawings, in which:

fig. 1 shows a three-dimensional measurement device which comprises a three-dimensional target according to the invention and an optical system;

fig. 2A illustrates the use of the 3D measurement device of FIG. 1 in a machine according to the invention for measuring in space the position of a tool holder relative to a workpiece holder (also referred to as a material spindle);

fig. 2B shows part of FIG. 2A corresponding to a tool holder with a three-dimensional target as viewed in the direction IIB of FIG. 2A, i.e. in the Z direction as the optical system "sees" it when the target is directed towards the optical system;

fig. 3A, 3B and 3C are three views illustrating the construction of a three-dimensional target according to the invention, respectively, front view, perspective view and sectional view; and fig. 3D and 3E show a perspective view of a second target structure corresponding to FIG. 3A, 3B and 3C according to the embodiment;

fig. 4A and 4B illustrate the processing of an image formed by the second pickup system of the optical system;

fig. 5 is a perspective and exploded view of a tool holder equipped with a three-dimensional target according to the invention;

fig. 6 illustrates the mounting of a 3D optical measurement device on a tool holder according to the invention.

Implementation of the invention

In FIG. 1 shows an optical device 10 comprising an optical system 100 and a three-dimensional target 200 that can interact with each other in order to perform a three-dimensional measurement of the relative position of the target 200 and the optical system 100. In fact, at this measurement position, the target 200 is oriented in the direction of the optical system 100 in parallel the main axis forming the main horizontal direction Z. To this end, at the output of the optical system 100, the optical path O is orthogonal to the working face 202 of the target 200.

The target 200 will be further described with reference to FIG. 1, 3A, 3B and 3C. The target 200 is in the form of a cylindrical tablet with a circular cross section (the target may have a square or other cross section), in which one side forms a working face 202 for making measurements. Therefore, to carry out measurements, this working face 202 is rotated in the direction of the optical system 100, in particular, in the direction of the input face 102 of the optical system 100, while the Z axis corresponding to the main direction (horizontal direction in the figures) separates the working face 202 from the input face 102 optical system 100.

The surface of the working face 202 of the target 200 is divided into a first structure 210 and a second structure 220. The first structure 210 includes a flat base face 212 which is smooth and is divided into a first region 214 which is reflective according to diffuse reflection and a second region 216 which is reflective according to specular reflection. In one embodiment, the first region 214 is coated with a diffusely reflective layer, such as barium sulfate BaSO ₄ , and the second region 216 is formed with a specularly reflective layer, such as a chromium layer. According to the depicted embodiment, the second section 216 is made in the form of several local zones 217 in the form of circles forming "islands" located within the first section 214, which is continuous. These local zones 217 may be of a different form, for example, they may have the form of segments or "islands" of a different shape than circular. These local zones 217 together form a geometric figure - one of the following list: quadrilateral, parallelogram, rectangle, square, rhombus, regular polygon and circle. This geometric figure can be a figure with central symmetry. In FIG. 3A and 3B, twenty-four circular local areas 217 are arranged in a square pattern. The purpose of the first structure 210 is to accurately recognize the center C3 using standard video tools. In the case of a figure of the "square" type, two diagonals C1 and C2 of the specified square intersect in its center. It should be noted that when measuring the position as shown in FIG. 1-3 and 5, the base face 212 is arranged parallel to the X and Y directions, respectively forming a vertical direction (axis) and a transverse horizontal direction (axis) in the case of the arrangement as shown.

The second structure 220 includes a face 222 inclined relative to the base face 212; while this inclined face 222 is practically flat, and the median plane of this inclined face forms with respect to the base face 212 an acute angle a, lying in the range of 10°-80°, for example, an angle of 20°-30°, and preferably an angle of the order of 25° ( see Fig. 3C).

According to one embodiment, the surface of a given sloped face 222 is not smooth, but contains terrain elements 224 that create surface irregularities that are either random or have a predetermined geometry, for example, together form a lattice or grid of lines, thus forming a structured lattice ( not shown) or a structured grid of lines (see Fig. 3D).

Such relief features 224 may be in the form of protrusions or recesses, i. e. may stand back from the median plane of the inclined face 222, in particular in the form of a slight roughness or any other surface irregularity. Such features 224 may be present on the entire surface of the sloped face 222. Such features may be uniformly distributed over the entire surface of the slope 222. For example, these features 224 may form a line that delimits the pattern of a lattice or grid, or more generally , a structured surface, or a rough surface that makes it possible to obtain sufficient scattering of the light reflected from the inclined facet 222. The surface of the inclined facet 222 of the second structure 220, for example, is covered with one of the following: an etched grid or a structured grating, in which the distance (pitch) between the elements lies in the range of 5-100 µm, in particular in the range of 5-50 µm, including 8-15 µm, for example, has the order of 10 µm.

For example, this slanted face 222 is made of unpolished silicon or ceramic or unpolished metal or glass or any other material that allows structure to be obtained, while the relief elements 224 are obtained by photolithography, chip removal, direct shaping. drawing (inscription), or in any other way that allows you to form a structure. Said relief elements 224 form, for example, recesses and/or protrusions, which are respectively spaced back from the median plane and/or protrude beyond the median plane by several microns or several tens of microns, in particular by 0.5-50 µm.

According to another embodiment, as shown in FIG. 3E, the surface of this sloping face 222 is smooth and contains a grid of lines of chromium or other material that provides mirror reflection to said lines of chromium, which form mirror elements 225. Said mirror elements 225 in the form of lines are parallel to each other. In the measuring position, said mirror elements 225 in the form of lines or stripes are arranged parallel to the Y, Z plane, so that along the inclined face in the Z direction, said lines meet one after the other (the same is observed when moving in the X direction). The substrate forming the plate of the second structure 220 may be made of various materials, including glass or silicon, with a diffusely reflective layer on the inclined face 222 made, for example, of barium sulfate BaSO ₄ , which alternates with the mirror elements 225, or which covers the entire the surface of the inclined face, and the mirror elements 225 are located on top of this diffusely reflective layer. According to an exemplary embodiment, these mirror elements 225 in the form of lines form a grid with a pitch of 25 µm. In this case, these lines (in particular, from chromium) have a width of 12.5 μm equal to the width of the gaps between the lines or areas of diffuse reflection, which also have the form of lines or stripes with a width of 12.5 μm. According to another embodiment, a 10 µm pitch is used, or more generally, a pitch in the range of 5-50 µm. It should be noted that the reflective elements 225 that interleave with the rest of the diffuse reflection surface may have a shape other than solid lines or segments forming stripes; in particular, it can be broken lines, figures such as dotted borders, circles, triangles, or any other geometric shapes.

According to an embodiment that is not shown in the drawings, the sloping face 222 of the second structure 220 bears a region that bulges forward the elements 224 of the relief in the form of small ridges or wedges distributed in mutually parallel rows, while the elements 224 of the relief are mutually offset from one row to another to get a stepped figure. According to another embodiment, which is not shown in the drawings, the slanted face 222 of the second structure 220 bears segment-shaped raised features 224 that are parallel to each other and equidistant and correspond to two series intersecting at 90° to each other. Such a set of relief elements 224 forms a lattice pattern. It should be noted that this grating can be formed by two series of mutually parallel segments that intersect each other at an angle other than 90°. In FIG. 3A, 3B, 3C and 3D, the sloped face 222 of the second structure 220 bears embossments 224 which are recessed in a series of segments that are parallel to each other and spaced at equal distances from each other in the X direction: these embossments 224 form grooves in this case. . Therefore, the direction X is orthogonal to the direction of the segments that form the elements 224 relief.

Therefore, in the embodiment shown in FIG. 3E, the surface of the inclined facet 222 of the second structure 220 is covered with a grid of specular lines 225, namely, mutually parallel solid strips, the surface of which has the property of specular reflection.

Thus, in some of the cases mentioned above, and in particular those illustrated in FIG. 3D and 3E, the surface of the sloped face 222 of the second structure 220 has a banded structure.

In accordance with the embodiments presented for the target 200, the tablet that defines the target 200 contains on its working face 202 the first structure 210, which occupies the majority of the surface of the working face 202, and within the first structure 210, the area occupied by the second structure 220. In this situation, the first structure 210 surrounds the second structure 220. More precisely, the local zones 217 of the second section 216 of the first structure 210 form a square that surrounds the second structure 220. In accordance with one possible condition, and in the case of the embodiments of the target 200 presented in the drawings, the first the structure 210 and the second structure 220 are located on the working face 202 concentric to each other. Moreover, as in the illustrated embodiments, the first structure 210 defines a window 218 for the body 219 containing the second structure 220, which is, for example, placed on a plate that has an inclined edge 222. When the plate is placed in the body 219 of the first structure 210 , its sloped edge 222 is rotated outward from the housing 219, towards the window 218. In this particular case, the second structure 220 is located in the housing 219 so that the sloped edge 222 is set back from the base face of the first structure 210: this means that the sloped edge 222, and hence the second structure 220, are located behind, behind the plane bounded by the base face 212 (relative to the main direction Z, see Fig. 3B) in the body 219, and are spaced back, for example, by 0.05-2 mm or approximately 0.15 mm. According to another possible option, which is not shown in the drawings, the second structure 220 is placed in front of the plane bounded by the base face 212. According to another possible option, which is also not shown in the drawings, the second structure 220 is located on each side of the plane bounded by the base edge 212, namely, part of the inclined edge 222 is located behind, and the other part of the inclined edge 222 is located in front of the base edge 212.

In order to protect the first structure 210 and the second structure 220 from the environment (dust, oil, shock, etc.), as can be seen in FIG. 3C, the target 200 includes a protective plate 230 of a transparent material, in particular glass, covering the first structure 210 and the second structure 220 from the side of the working face 202. In accordance with one possible embodiment, as shown in FIG. 3C, target 200 contains the following items as a package. The bottom wall 231, on top of which the top plate 232 is installed, in the center of which a cutout is made, limiting the body 219, limited from the side of the working face 202 by a window 218. From above, the top plate 232 is covered with a protective plate 230, which closes the body 219. All these elements are together surrounded by a cylindrical wall 234 that holds the entire target 200. The second structure 220 is, for example, a silicon wafer enclosed in a housing 219 with an inclined face 222 (which bears relief elements 224 or mirror elements 225) turned in the direction of the working face 202. plate 232, facing the working face 202, contains a reflective layer 233 in the form of two zones, as discussed above with respect to the first section 214 (reflective surface in accordance with diffuse reflection) and the second section 216 (reflective surface in accordance with specular reflection ), in particular in the form of local elements 217).

In addition, the target 200 may be equipped with RFID (RFID, Radio Frequency identification) (not shown) to allow storage and reading of a unique identifier and data relating to the target 200 and related to the first object, which is supposed to be target 200, in particular the tool holder 310 (see FIGS. 5 and 6): for example, reference information on the tool holder 310 and other information associated with the use of this tool holder (for example, its serial number, type, its settings relative to the center of the material of the workpiece holder, the number of times the tool holder is used, etc.).

Further, according to FIG. 1, an optical system 100 will be considered associated with the target 200 just described, which together form an optical measurement device 10 that allows measurement of the relative position of two objects in three spatial directions. In particular, the orthogonal space is considered in the Cartesian coordinate system X, Y and Z, which is indicated in the drawings. This optical system 100 is designed to simultaneously capture, in the same sequence of shooting, both the image of the first structure 210 of the target 200 and the image of the second structure 220 of the target 200. According to the present description, this simultaneous shooting of two images is carried out without adjustment, which gives a high speed such shooting. Other properties, in particular related to the special design of the target 200 discussed above, also allow maximum accuracy to be achieved. The 3D optical measurement device 10 according to the present invention is capable of reproducibly measuring the relative positions of objects with an error of 1 µm or less in % of a second or faster.

This optical system 100 includes a first imaging system 110 and a second imaging system 120. According to one embodiment, said optical system 100 is configured such that the difference between the focal length of the second imaging system 120 and the focal length of the first imaging system 110 lies between a minimum distance and the maximum distance separating the base facet 212 from the inclined facet 222. According to another embodiment, the depth of field (DOF1) of the first imaging system 110 is much larger, in particular at least ten times the depth of field (DOF2) of the second imaging system 120. For example, the depth of field DOF1 of the first imaging system 110 exceeds the depth of field DOF2 of the second imaging system 120 is 10-10,000 times, or 100-5,000 times. Among the different possible characteristics: the depth of field DOF1 of the first imaging system 110 is greater than or equal to 0.8 mm, or in the range of 0.5-5 mm, or in the range of 0.8-3 mm, or in the range of 1-2 mm. Also among other possible characteristics: the DOF2 depth of field of the second imaging system 120 is less than or equal to 0.1 mm, or is in the range of 5-50 µm, or in the range of 8-30 µm, or in the range of 10-20 µm.

This allows the first imaging system 110 to focus naturally and without other adjustments on the entire base face 212 of the first structure 210 in the range of distances between the target 200 and the first imaging system 110, which may vary within a few millimeters. In parallel, the second imaging system 120 can naturally and without other adjustments focus on a portion of the inclined edge 222 of the second structure 210, which is located at a distance from the second imaging system 120, which corresponds to the focal length of the second imaging system 120. According to one possible option, the increase in the first imaging system system 210 is less than the magnification of the second camera system 220.

Each imaging system according to the present description (the first imaging system 210 and the second imaging system 220) corresponds to an optical system, in particular, a centered optical system containing a set of optical elements and an imaging system. Such an imaging system enables the acquisition of photographs and/or videos, and is, for example, a camera or a photographic apparatus, in particular a digital camera. According to one exemplary embodiment, the first imaging system 112 of the first imaging system 110 and the second imaging system 122 of the second imaging system 120 are synchronized to simultaneously capture the first image by the first imaging system 110 and the second image by the second imaging system 120.

In order for the first imaging system 210 and the second imaging system 220 to simultaneously view the target 200, these systems have a common portion of the optical path, which is directed forward and originates from the object monitored by the optical system 100; in this case, the target 200 (see Fig. 1 and 2) is installed on the first object, and the optical system 100 is installed on the second object. To this end, in the measurement position, the first imaging system 210 is rotated in the direction of the working face 202 of the target 200, and forms an imaging system aligned with the target 200, while the second imaging system 120 has an optical path 126 that meets the optical path 116 of the first imaging system. 110 aligned with the target 200 and forms a survey system that is offset from the target 200 from the optical axis O of the optical system 100, and from the common portion of the optical paths 116 and 126 (aligned with the target). In other words, the optical path of the imaging system, aligned with the target 200, is essentially perpendicular to the base face 212. The optical axis O is aligned with the middle beam of the common section of the first optical path 116 and the second optical path 126. In this common section, the segments of the first optical path 116 and of the second optical path 126 are mutually parallel, but not necessarily aligned with each other.

In particular, as shown in FIG. 1 and 2, the first imaging system 210 is rotated in the direction of the working face 202 of the target 200, in other words, is oriented perpendicular to the working face 202 of the target 200. This means that the optical axis O and the common portion of the optical paths 116 and 126 are aligned with the target 200 and are located at right angles to the working face 202 (and hence the base face 212) of the target 200. With this configuration, as can be seen in FIG. 1 and 2, optical axis O and the common portion of optical paths 116 and 126 are parallel to the main Z direction and orthogonal to the X and Y transverse directions and the X, Y plane.

In the common area of the optical paths 116 and 126, the optical beams at least partially merge with each other, or are simply parallel to each other. The second imaging system 120, which is offset, has a portion of the optical path 126 (inside the second imaging system 120) which is preferably parallel to the optical axis O. of the imaging system 110 aligned by means of a specialized optical module 128 containing a catoptric (reflective) optical system, such as a mirror 129. Thus, the input of the offset imaging system (in this case, the second imaging system 120) is associated with the trajectory of the optical path of the aligned optical imaging system ( in this case the first camera system 110).

More generally, one of the first survey system 110 and the second survey system 120 is rotated in the direction of the working face 202 of the target 200, and forms a survey system aligned with the target 200, while the other survey system from the first survey system 110 and the second survey system 120 has an optical path 126 that meets the optical path 116 of the imaging system 110 aligned with the target 200 to form an offset imaging system. This means that said other imaging system has an optical axis that passes through the sloped edge 222, i.e. through the second structure 220 of the target 200. Also, the first shooting system 110 and the second shooting system 120 are arranged parallel to each other. In addition, the optical system also includes an optical module 128 (for example, with a catoptric optical system such as a mirror) located between the first imaging system 110 and the second imaging system 120, and configured to deflect a portion of the light rays passing through at least part of one from the first and second survey systems towards the other from the first or second survey systems. Conversely, the optical system 100 is designed in such a way that the optical path from the observed object (target 200 in Fig. 1 and 2) due to the optical system 100 passes through at least part of one of the first imaging system 110 and the second imaging system 120 (the first survey system 110 in Figures 1 and 2) before reaching the other of the first survey system 110 and the second survey system 120 (second survey system 120 in Figures 1 and 2).

According to one embodiment, the focal length of the second imaging system 120 is greater than the focal length of the first imaging system 110. For example, the focal length difference between the second imaging system 120 and the first imaging system 110 is in the range of 0.5 mm to 5 mm.

According to one embodiment, the magnification of the first imaging system 110 is less than or equal to that of the second imaging system 120. For example, the magnification of the first imaging system 110 is 0.2-1 that of the second imaging system 120. For example, the magnification of the first imaging system 110 is in the range 0 .3-0.8 or 0.4-0.6 magnification of the second imaging system 120, and is preferably about 0.5 of the magnification of the second imaging system 120.

In the embodiment depicted in FIG. 1 and 2, the optical system 100 also includes a light source 140 oriented in the direction of the three-dimensional target 200. The light source 140 is positioned to provide side illumination of the target 200. To this end, this light source 140 is positioned off-center, and tilted relative to the optical path 116+126 of the optical system 100. In particular, the light rays from the light source 140 form an angle with the base face 212 of the target, so that their specular reflection from the reflective surfaces of the target, and in particular, local zones 217, forms reflected light rays that are not enter the optical system 100. Similarly, when the inclined face 222 includes mirror elements 225, the reflection of light rays coming from the light source 140 from these mirror elements 225 does not enter the optical system 100.

According to one embodiment, the first usable survey system 210 and the second usable survey system 220 are telecentric. As a reminder, telecentricity is the characteristic of an optical system whereby all of the main beams (the center beam of each beam) that pass through the system are nearly collimated and parallel to the optical axis. In the case of telecentric optics, the concept of depth of field is replaced by the concept of working distance. According to another embodiment, the first usable survey system 210 and the second usable survey system 220 are not telecentric, or both are not telecentric. In the case where both systems are telecentric, they can also be used to measure the geometry of the tools located on the tool holder 310.

Further, according to FIG. 2A-6, a method for three-dimensional optical measurement of distances between the target 200 and the optical system 100 will be discussed in the case of a processing machine, in which the processing module 300 includes an optical device 10. The base directions X, Y and Z are the base directions of the processing module, in particular the coordinate system processing module that gives the vertical direction X (or the first transverse axis), the main horizontal direction Z (or the main axis) and the transverse horizontal direction Y (or the second transverse axis). The target 200 is placed on the tool holder 310, which serves as the first object (see Fig. 5): the tool holder 310 extends in the main horizontal direction, which corresponds to the X axis, with the possibility of rotation around the X axis. To this end, part of the tool holder 310 , for example, a clip, has recesses on its peripheral surface, typically designed to receive a grip/release tool, and into which a target 200, possibly associated with an RFID chip, as previously discussed, can be placed. In addition, the optical system 100 is mounted on the workpiece holder 320, which serves as the second object (see FIG. 6) and receives the workpiece 322 to be processed. The workpiece holder 320 extends along its main horizontal direction corresponding to the Z-axis and is rotatable about the Z-axis. the part were in close proximity to each other, in the position of measuring the relative position. The location of the target 200 on the holder 310 of the tool and the location of the optical system 100 on the holder 320 of the part allows, in this position of measuring the relative position, to position the target 200, or rather the base face 202, on the continuation of the optical axis O of the optical system 100 (it should be noted that the specified optical axis O parallel to the Z direction). Thus, the base face 202 of the target 200 is rotated in the direction of the input face 102 of the optical system 100.

As shown in FIG. 6, the optical device 10 also includes a third imaging system 130 located on the tool holder 310 and configured to determine the orientation of the working face 202 of the target 200 or the angular orientation of the rotating part of the tool holder 310, in particular with respect to the X axis. 200 is performed before the simultaneous shooting step with the optical system 100, according to which:

- the tool holder 310 and the part holder 320 are positioned so that the working face 202 of the spatial target 200 is on the optical axis O of the optical system 100. In particular, the third imaging system 130 can be used to determine the angular orientation of the target 200 relative to the rotating part of the tool holder 310, and therefore relative to the X axis, which makes it possible to change (if necessary) the angular orientation of the rotating part of the tool holder 310 (see arrow R in Fig. 6), and thus the location of the target 200 so that the working face 202 is rotated in the direction of the optical system 100. The position of the measurement relative position is obtained when the target 200 is oriented in the direction of the optical system 100, as discussed above with respect to Figs 1 and 2A: in this case, the Z direction passes between the target 200 and the optical system 100.

When first using the optical device 10 (namely, the optical system 100 and the associated target 200), respectively mounted on the workpiece holder 320 (or more generally on the second object), and on the tool holder 310 (or more generally - on the first object), a preliminary additional step of spatially referencing the position of the target 200 relative to the tool holder 310 (in a more general sense, the first object) must be performed, which links the target 200 with the three directions X, Y and Z. It should be noted that, obviously , the parameters of the optical system 100, namely the first imaging system 110 and the second imaging system 120 are known, including their focal lengths. At this stage, it can be noted that when the working space of the processing module 300 is limited and maintained at a constant temperature, its thermal stability determines the stability of the dimensions of the optical device 10 and, therefore, its parameters.

It is worth recalling that the three-dimensional measurement of the relative position of the target 200 and the optical system 100 is used in the case of a machine tool in order to ultimately know in the form of X, Y and Z coordinates the spatial relative position of the tool holder 310 (or more generally the first object) and the holder 320 details (or more generally - the second object).

In this description, the three directions X, Y, and Z are, for example, the axes of the machine tool processing unit 300. Thus, the Z direction can be defined as the main axis, namely the main horizontal direction separating the first object (tool holder 310) from the second object (workpiece holder 320). The X direction may be defined as the vertical direction (or more generally the first transverse axis), and the Y direction may be defined as the transverse horizontal direction (or more generally the second transverse axis. In one embodiment, the holder 310 tool rotates about an axis parallel to the X direction.

At this stage of spatial reference of the position of the target 200 in the three directions X, Y and Z (calibration of the optical device 10), for example, in the scheme corresponding to Fig. 2A and 2B, shooting by means of the optical system 100 is activated, which leads, on the one hand, to the formation by the first imaging system 112 belonging to the first shooting system 110 of the first image of the entire working facet 202 of the target 200 with the entire base facet 212 that is imaged. sharply, and on the other hand to the formation of the second imaging system 122 belonging to the second imaging system 120, the second image of the entire inclined edge 222 of the target 200 with a single sharply imaged zone in the form of a horizontal strip. Said first image contains an image of local areas 217, which in this case define a square (see FIG. 3A), so that the processing of the first image gives the diagonals C1 and C2 of the square, and makes it possible to determine the center C3 of the square. Thus, since the position of the optical axis O in the first image is known, determining the position of the center C3 of the square makes it possible to know in X coordinates and Y coordinates the position of the target 200 relative to the optical axis O, but also, on the one hand, relative to the anchor point 314 in the X direction on tool holder 310, and, on the other hand, relative to the anchor point 316 in the Y direction on the tool holder 310. In fact, as can be seen in FIG. 2A and 2B, the surface of the tool holder 310 that is orthogonal to the X axis is used as the reference in the X direction, for example, formed by a shoulder on the body of the tool holder 310, which appears as a line in the first image, and whose surface forms the anchor point 314 in the X direction. In addition, as can be seen in FIG. 2A and 2B, the dimension of the tool holder 310 in the vicinity of the target 200 that is orthogonal to the X axis and which in the depicted case is the width (parallel to the Y direction) of the tool holder 310 in the vicinity of the target 200 is used as the reference in the Y direction, for example, the diameter when this part of the tool holder 310 is cylindrical with a circular section; this dimension (gauge) forms the anchor point 316 in the Y direction.

In parallel, a second image is processed, an example of which is seen in FIG. 4A. By analyzing the local contrast of this second image (see Fig. 4B, which shows contrast curves depending on the position in X coordinates), the position X0 of the sharpened zone of the second image in the vertical X direction is determined. This analysis is performed by an algorithm that makes it possible to determine the sharpest image pixels. Since the slope of the sloped edge 222 is known, a correspondence curve is obtained between X and Z of a given sloped edge 222 specific to the target 200. Due to this correspondence curve, knowing the position X0 (see FIGS. 4A and 4B) makes it possible to obtain the position Z0 of the sloped edge 222 from this. on the optical axis O, and hence the Z position of the target 200 relative to the optical system 100. In addition, the Z position of the optical system 100 relative to the workpiece holder 320 is known from the data of a measuring ruler (not shown), which is located along the X axis on workpiece holder 320, and which supports the optical system 100. Similarly, the Z position of the target 200 relative to the anchor point 314 of the tool holder 310 is known.

By repeatedly performing this operation, each time changing the distance along the Z coordinate of the workpiece holder 320 relative to the tool holder 310 (for example, by retracting or feeding the tool holder 310), it is thus possible to reconstruct the three-dimensional image of the inclined face 222 of the target 200, and obtain a reference base, which in Cartesian coordinates displays the inclined face 222 of the target 200 relative to the holder 310 of the tool. Ultimately, it's all about the working edge 202 of the target 200 (base edge 212 and slant edge 222), which is spatially anchored in the three X, Y, and Z directions relative to the tool holder 310.

Then, whenever it is necessary in the operations of using the processing module 300 equipped with the target 200 and the optical system 100, the actual measurement can be performed without disassembling the system between measurement points in order to maintain the spatial reference measurement accuracy that was explained above. For this purpose, for example, the circuit of FIG. 2A. If necessary, the tool holder 310 is rotated about its axis of rotation, which is parallel to the X axis (see arrow R in FIG. 6) to align the target 200 with the optical system 100. on the one hand, to the formation by the first imaging system 112 of the first imaging system 110 of the first image of the entire working face 202 of the target 200 with the entire base face 212, which is in the field of sharpness, and, on the other hand, to the formation by the second imaging system 122 of the second of the second imaging system 120 of the second image of the entire inclined face 222 of the target 200 with only one sharply depicted zone in the form of a horizontal strip corresponding to the focal length of the second imaging system 120. The analysis of the first image makes it possible, as mentioned above, to determine the center C3 of the square formed by the local elements 217, and thus, in X coordinates and in Y coordinates, determine the position of the target 200 with respect to the optical axis O as well as with respect to the tool holder 310. Analysis of the second image, and in particular the position of the sharply imaged area of the second image (as in Fig. 2A) in the X direction, makes it possible to determine this position in Z coordinates, and hence the distance of the target 200 relative to the optical system 100. In fact, with regard to the second image Since the Z position of each image pixel of the sloping edge 222 relative to the anchor points 314 and 316 of the tool holder 310 is known, it is possible to measure the Z position of the target 200 and hence the tool holder 310 very quickly.

From the foregoing, it should be understood that in this way, solely by analyzing the two images formed by the optical system 100, without wasting time for adjusting or adjusting the optical system 100, the position of the target 200 relative to the optical system 100 in the X, Y and Z coordinates can be very quickly measured, starting from the position of the tool holder 310 relative to the workpiece holder 320. This is possible because the position of the optical system 100 relative to the workpiece holder 320 is known in X, Y, and Z coordinates.

The present description also relates to an optical system for three-dimensional measurement of the relative position of the first object and the second object, on which the specified optical system is supposed to be installed, containing the first imaging system and the second imaging system, in which:

- the depth of field of the first imaging system is at least 10 times greater than the depth of field of the second imaging system, and

- the optical system is designed in such a way that the optical path of the first imaging system and the optical path of the second imaging system have a common area containing the rear focal plane of the first imaging system and the rear focal plane of the second imaging system.

The present description also relates to a method for three-dimensional optical measurement, respectively, in the three orthogonal directions X, Y and Z of the relative position of the first object and the second object, which are aligned in one line and spaced from each other in the main Z direction, in which:

- provide a three-dimensional target that forms the base for positioning and contains on the working face:

* the first structure forming a flat base face, divided into at least:

- the first area, the surface of which is reflective in accordance with the first reflection parameters, and

- a second section, the surface of which is reflective in accordance with the second reflection parameters, which differ from the first reflection parameters, and

* the second structure containing the face inclined relative to the specified flat base faces;

- provide an optical system containing the first imaging system and the second imaging system, in which:

- the depth of field of the first imaging system is at least 10 times greater than the depth of field of the second imaging system, and

- the optical system is made, on the one hand, in such a way that the optical path of the first imaging system and the optical path of the second imaging system have a common area containing the rear focal plane of the first imaging system and the rear focal plane of the second imaging system, and, on the other hand, such so that the difference between the focal lengths of the second imaging system and the first imaging system lies in the interval between the minimum distance and the maximum distance separating the base face from the inclined face,

- the specified three-dimensional target is placed on the first object so that, on the one hand, the focal length of the first imaging system allows you to place the image focus of the first imaging system on the first target structure, and, on the other hand, the focal length of the second imaging system allows you to place the image focus of the second imaging system systems on the second target structure,

- the specified optical system is placed on the second object,

- at least one simultaneous shooting is carried out by means of the first shooting system belonging to the optical system and by means of the second shooting system belonging to the optical system, and thus for each shooting performed by means of the optical system, on the one hand, the first shooting system forms the first image of the target , which makes it possible to determine the position of the second section relative to the first section on the base face, which gives, firstly, the first part of information about the position of the target relative to the first shooting system in the X direction, and, secondly, the second part of information about the position of the target relative to the first of the shooting system in the Y direction, and, on the other hand, the second shooting system forms a second image of the target, containing a sharply imaged area corresponding to the location of the inclined edge of the second structure, which gives the third part of the information about the distance between the target and the second shooting system in the Z direction.

As previously explained, the optical system thereby synchronously forms the first image and the second image. In addition, the optical system 100 forms the first image and the second image without any adjustment, which makes it possible to shoot immediately and without loss of time.

The present description also relates to a processing machine containing the above-described optical target, while the processing machine contains the above-described optical system. The present description also relates to a machining machine, comprising a machining module equipped with a tool holder and a workpiece holder, as well as an optical measuring device for three-dimensional measurement of the position of the tool holder relative to the workpiece holder; wherein the optical measuring device contains the specified optical system mounted on the part holder, and the target, which is mounted on the tool holder and contains a working face that forms the base for positioning, which can be located on the optical axis of the optical system. For example, the specified optical measuring device is made with the ability to determine in three-dimensional space the relative position of the workpiece holder and the tool holder in one stage of shooting the target by means of an optical system. Also, according to a possible embodiment, the target is positioned so that the rear focal plane of the optical system coincides with the working face of the target.

The present description also relates to a system for three-dimensional optical measurement of the location of the first object relative to the second object, containing:

- an aggregate containing the first object and the second object,

- an optical measuring device, discussed in the present description, in which:

- the first imaging system is designed in such a way that its rear focal plane can coincide with the base face of the first structure, and

- the second imaging system is designed in such a way that its rear focal plane can intersect the inclined face of the three-dimensional target. In accordance with the second option, compatible with the first option discussed above or taken separately, the optical measuring device is such that:

- the focal length of the first imaging system allows you to place the focus of the image on the first structure of the target,

- the focal length of the second imaging system allows you to place the focus of the image on the second target structure.

The specified unit is, for example, a piece of equipment, a machine tool, a module, in particular a scientific or technical module containing a first object and a second object that can be moved relative to each other, and for which it is necessary to bind their relative position in three-dimensional space. For example, the assembly is a machining machine or a machining module with a tool holder or one of the tool holders as the first object, and with a workpiece holder that carries the workpiece to be processed (bar, blank, etc.) as the second object. According to another example, the assembly is a block for mounting electronic components on a printed circuit board, while the first object is the holder of the printed circuit board, and the second object is a clamp or other tool for installing the electronic component. According to yet another example, the assembly is a cell culture module for seeding a series of wells on microplates, wherein the first object is a microplate holder and the second object is a device holder for injecting cells to be cultured.

The present invention also relates to a method for three-dimensional optical measurement, respectively, in three orthogonal directions X, Y and Z of the position of the first object relative to the second object, which are aligned in one line and spaced from each other in the main Z direction, comprising the steps of:

- provide a three-dimensional target that forms the base for positioning and contains on the working face:

* the first structure forming a flat base face, divided into at least:

- the first area, the surface of which is reflective in accordance with the first reflection parameters, and

- a second section, the surface of which is reflective in accordance with the second reflection parameters, which are different from the first reflection parameters, and

* a second structure containing a face inclined relative to the specified flat base face,

- providing an optical system comprising a first imaging system and a second imaging system, wherein

- the specified three-dimensional target is placed on the first object in such a way that, on the one hand, the focal length of the first imaging system allows you to place the focus of the image of the first imaging system on the first target structure, and, on the other hand, the focal length of the second imaging system allows you to place the focus of the image of the second shooting system systems on the second target structure,

- the specified optical system is placed on the second object,

- at least one simultaneous shooting is carried out by means of the first shooting system belonging to the optical system and by means of the second shooting system belonging to the optical system, and thus for each shooting performed by means of the optical system, on the one hand, the first shooting system forms the first image of the target , which makes it possible to determine the position of the second section relative to the first section (in particular, the position of local zones on the base face), which gives, firstly, the first part of the information about the position of the target relative to the first imaging system in the X direction, and, secondly, the second part of the information about the position of the target relative to the first imaging system in the Y direction, and, on the other hand, the second imaging system forms a second image of the target, containing a sharply imaged area corresponding to the location of the inclined face of the second structure, which gives the third part of the information about the distance between the target and the second camera system in the Z direction.

For this, according to one possible embodiment, the depth of field (DOF1) of the first imaging system is at least ten times greater than the depth of field (DOF2) of the second imaging system. In addition, in accordance with another possible embodiment, taken alone or in combination with the previous possible embodiment, the specified optical system is performed in such a way that the optical path of the first imaging system and the optical path of the second imaging system have a common area, including the rear focal plane the first imaging system and the rear focal plane of the second imaging system. In addition, in accordance with another possible embodiment, taken alone or in combination with one or both of the previous possible options, the specified optical system is performed in such a way that the difference between the focal length of the second imaging system and the focal length of the first imaging system is in the interval between the minimum distance and the maximum distance separating the base face from the sloped face.

By means of this method, it is possible to obtain spatial geometric information associated with the (first) base face and with the inclined face (or second base face) of a three-dimensional target, which makes it possible, on the basis of said information, to infer the position in the three spatial directions X, Y and Z of the first object relative to the second object. Prior to this, a three-dimensional binding of the target position with respect to the first object will be performed, and a three-dimensional binding of the position of the optical system with respect to the second object.

It is important to note that, according to one embodiment, capturing or imaging by each capturing system of the optical system is performed without adjusting the corresponding capturing system. Indeed, it is precisely the position (in the three directions X, Y, Z) of the survey system relative to the object that the survey system is looking at (and, consequently, both the position of the first survey system relative to the base face and the position of the second survey system relative to the inclined target face) and optical properties, and, in particular, a very different depth of field of the imaging systems belonging to the optical system, makes it possible to simultaneously form two images: respectively, the base face and the inclined face. The analysis of these two images (even two series of images) makes it possible to obtain information about the position of the target relative to the optical system along the X coordinate (this X direction corresponds, for example, to height), along the Y coordinate (this Y direction corresponds, for example, to the horizontal lateral displacement) and along the Z coordinate (this Z direction corresponds, for example, to the main horizontal distance), and hence information about the relative position in three-dimensional space of the first object that carries the three-dimensional target and the second object that carries the optical system.

According to one embodiment of the method, after placing a three-dimensional target on the first object and placing the optical system on the second object, an additional step is performed to determine the spatial position of the target in X, Y and Z coordinates relative to the first object by means of the optical system.

According to one possible embodiment of the method, the second section of the flat base face is divided into a number of local zones located on the first section, while the first image formed by the first imaging system makes it possible to determine the position of the local zones of the second section on the base face, which provides information about the relative the location of said local areas and the first imaging system, allowing relative measurement in the Y direction and X direction.

List of reference symbols

X - Vertical direction (first transverse axis)

Y - Lateral horizontal direction (second transverse axis)

Z - Main horizontal direction separating the first object from the second object (major axis)

C1 - Diagonal

C2 - Diagonal

C3 - Center

α - Inclined face orientation angle

R - Arrow showing rotation of tool holder and target

10 - Optical system

200 - 3D target

202 - Working face

210 - First structure

212 - Base face

214 - First section (with diffuse reflection surface)

216 - Second section (with mirror reflection surface)

217 - Local zones

218 - Window

219 - Body

220 - Second structure

222 - Inclined edge

224 - Relief elements

225 - Mirror elements

230 - Transparent protective plate

231 - Bottom wall

232 - Top plate

233 - Reflective layer

234 - Cylindrical wall 100 Optical system

O - Optical axis

102 - Entrance face of the optical system

110 - First filming system

DOF1 - Depth of field of the first imaging system

F1 - Rear focal plane of the first imaging system

112 - First imaging system

120 - Second filming system

F2 - Rear focal plane of the second imaging system

DOF2 - Depth of field of the second imaging system

122 - Second imaging system

126 - Optical path of the second filming system

128 - Optical module with catoptric optical system

129 - Mirror

130 - Third filming system

140 - Light source (side illumination)

300 - Processing module

310 - Tool holder (first object)

312 - Tool

314 - Anchor point of the tool holder along the X coordinate

316 - Anchor point of the tool holder along the Y coordinate

320 - Part holder or material spindle (second object)

322 - Workpiece (material).

Claims (47)

1. A machining machine comprising a machining module equipped with a tool holder and a workpiece holder, as well as an optical measuring device for three-dimensional measurement of the position of the tool holder relative to the workpiece holder, said optical measuring device comprising an optical system with an imaging system mounted on the workpiece holder, and a three-dimensional target mounted on a tool holder and containing a working face forming a base for positioning, which can be located on the optical axis (O) of the optical system, and the working face contains a first structure forming a flat base face, which is divided into at least a first section , the surface of which is reflective in accordance with the first reflection parameters, and the second section, the surface of which is reflective in accordance with the second reflection parameters, which differ from the first reflection parameters, and the second structure containing a face inclined relative to the specified flat base face, while the specified optical system contains the first shooting system and the second shooting system, and the difference between the focal length of the second shooting system and the focal length of the first shooting system lies in the interval between the minimum distance and the maximum distance separating the base face from the inclined face, and the optical measuring device is made with the possibility of determining, in one stage of shooting the target by means of an optical system, the position in three-dimensional space of the workpiece holder relative to the tool holder. 2. The processing machine according to claim 1, wherein the surface of said first portion is reflective according to diffuse reflection and the surface of said second portion is reflective according to specular reflection. 3. The processing machine according to claim 1, wherein the second section is divided in accordance with sets of local zones located in the first section. 4. The processing machine according to claim 1, wherein the surface of the sloping face contains relief elements or mirror elements that are uniformly distributed. 5. The processing machine according to claim 3, wherein said local zones together form a geometric figure, which is one of the following figures: a quadrilateral, a parallelogram, a rectangle, a square, a rhombus, a regular polygon, and a circle. 6. The processing machine according to claim 3, wherein the local zones of said second section are formed by islands or segments distributed over the first section. 7. The processing machine according to claim. 1, in which the first structure and the second structure are located on the working face concentric to each other. 8. The processing machine according to claim 1, wherein the first structure surrounds the second structure. 9. The processing machine according to claim 3, wherein the local zones of the second section of the first structure form a square that surrounds the second structure. 10. A processing machine according to claim 1, wherein the first structure defines a window for a housing containing said second structure. 11. The processing machine according to claim 10, wherein the second structure is located in said housing with an inclined edge spaced back from the base edge of the first structure. 12. The processing machine according to claim 1, wherein the surface of the inclined edge of the second structure is striped, in particular, the surface of the inclined edge of the second structure is covered with one of the following: an etched grid, a structured grating, or a grid of mirror lines. 13. Processing machine according to claim. 1, in which the target also contains a plate of transparent material, in particular glass, covering the first structure and the second structure from the side of the working face. 14. Processing machine according to claim 1, wherein the optical measuring device also includes a light source oriented in the direction of the three-dimensional target, said light source being positioned to provide side illumination of the three-dimensional target. 15. Processing machine according to claim. 1, in which the optical system contains the first filming system and the second filming system, while: - the depth of field of the first imaging system is at least ten times greater than the depth of field of the second imaging system, and - the optical system is designed in such a way that the optical path of the first imaging system and the optical path of the second imaging system have a common area located on the optical axis (O) of the optical system and containing the rear focal plane of the first imaging system and the rear focal plane of the second imaging system. 16. Processing machine according to claim 15, wherein the optical system is configured such that the optical path from the object passes through at least part of one of the first and second imaging systems before reaching the other of said first and second imaging systems. 17. Processing machine according to claim. 15, in which the first and second filming systems are parallel to each other, and the optical system also includes an optical module located between the first and second filming systems, and configured to deflect part of the light rays passing at least through a part of one of the first and second survey systems to another of said first and second survey systems. 18. Processing machine according to claim 15, wherein the focal length of the second imaging system is greater than the focal length of the first imaging system. 19. Processing machine according to claim 15, wherein the magnification of the first imaging system is less than that of the second imaging system. 20. The processing machine according to claim 15, wherein the depth of field (DOF1) of the first imaging system is greater than or equal to 0.8 mm. 21. The processing machine according to claim 15, wherein the depth of field (DOF2) of the second imaging system is less than or equal to 0.1 mm. 22. The processing machine according to claim 15, wherein the first survey system is telecentric and the second survey system is telecentric. 23. Processing machine according to claim. 1, in which the optical system contains the first filming system and the second filming system, while: - the depth of field of the first imaging system is at least ten times greater than the depth of field of the second imaging system, and - the optical system is designed in such a way that the optical path of the first imaging system and the optical path of the second imaging system have a common area located on the optical axis (O) of the optical system and containing the rear focal plane of the first imaging system and the rear focal plane of the second imaging system, and when this: - the first imaging system is designed so that its rear focal plane can correspond to the base face of the first structure, and - the second imaging system is designed in such a way that its rear focal plane can intersect the inclined face of the three-dimensional target. 24. Processing machine according to claim 15, wherein the optical device also includes a third imaging system located on the tool holder and configured to determine the orientation of the working face of the target and/or the angular orientation of the tool holder. 25. A method for three-dimensional optical measurement, respectively in three orthogonal directions X, Y and Z in the three-dimensional space of a processing machine, of the position of the tool holder relative to the workpiece holder, which are aligned and spaced from each other in the main Z direction, comprising steps in which: - providing an optical system with an imaging system, said optical system comprising a first imaging system and a second imaging system, - the specified optical system is installed on the part holder, - provide a three-dimensional target containing a working face that forms the base for positioning, and the specified working face contains * the first structure forming a flat base face, divided into at least: - the first area, the surface of which is reflective in accordance with the first reflection parameters, and - a second section, the surface of which is reflective in accordance with the second reflection parameters, which differ from the first reflection parameters, and * a second structure containing a face inclined relative to the specified flat base face, and the difference between the focal length of the second imaging system and the focal length of the first imaging system lies in the interval between the minimum distance and the maximum distance separating the base face from the inclined face, - said target is placed on the tool holder, - the tool holder and the workpiece holder are positioned so that the target can be positioned on the optical axis (O) of the optical system, and so that, on the one hand, the focal length of the first imaging system allows the back focus of the first imaging system to be placed on the first target structure, and , on the other hand, the focal length of the second imaging system makes it possible to place the back focus of the second imaging system on the second target structure, - performing one stage of shooting the target using an optical system located so that it can interact with the target, whereby the position of the holder of the part to be processed relative to the tool holder is determined in three-dimensional space, and at the indicated stage of shooting by means of the optical system, at least one simultaneous shooting by means of the first imaging system of the optical system and by means of the second imaging system of the optical system, thus for each shooting by means of the optical system, on the one hand, the first imaging system forms the first image of the target, making it possible to determine the position of the second section relative to the first section on the base face , which gives, firstly, the first part of information about the relative position of the target and the first shooting system in the X direction, and, secondly, the second part of the information about the relative position of the target and the first shooting system in the Y direction, and also, on the other hand , the second imaging system generates a second target image containing a sharp portion corresponding to the location of the inclined face of the second structure, which provides a third of the information about the distance between the target and the second imaging system in the Z direction. 26. The method according to claim 25, in which: - said surface of the first region is reflective according to diffuse reflection, and - said surface of the second section is reflective in accordance with specular reflection, - moreover, in the specified optical system, the depth of field of the first imaging system is at least ten times greater than the depth of field of the second imaging system, while - the specified optical system is designed in such a way that the optical path of the first imaging system and the optical path of the second imaging system have a common area containing the rear focal plane of the first imaging system and the rear focal plane of the second imaging system. 27. The method according to claim 25, in which the second section of the flat base face is divided into a number of local zones located on the first section, while when the first shooting system forms the first image of the target, the position of the local zones of the second section on the base face is determined, which gives part of the information about the relative position of said local areas and the first survey system, which makes it possible to obtain a measurement result of the relative position in the Y direction and in the X direction.

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