EP3977218A1

EP3977218A1 - Machining module and machine tool with a unit for detecting the profile of the tool, and method for detecting the profile of the tool

Info

Publication number: EP3977218A1
Application number: EP20731571.4A
Authority: EP
Inventors: Philippe Jacot; Sébastien LAPORTE
Original assignee: LDI Finances SC
Current assignee: Watchoutcorp Sa
Priority date: 2019-06-03
Filing date: 2020-06-03
Publication date: 2022-04-06
Also published as: CA3137237A1; KR20220012303A; US20220250201A1; CH716246A1; WO2020245729A1; TW202111457A; JP7414848B2; CN114026509A; JP2022533695A

Abstract

The invention relates to a material removal machining module (300) for a machine tool, comprising:- a workpiece support (320) which is intended to receive a workpiece (322) to be machined, - a control unit for the workpiece support (308) which is capable of controlling and modifying the position of the workpiece support (320) in the machining module (300), - a tool holder (310) which is intended to receive a tool (312) having an end portion (313) which can be used to machine the workpiece; - a control unit (302) for the tool holder which is capable of controlling and modifying the position of the tool holder (310) in the machining module (300), - a unit for detecting the profile (304) of the tool (312) which is mounted on the tool holder, which unit comprises an optical system (100) which is mounted on the workpiece support (320) and which makes it possible to establish the profile of the end portion (313) of the tool (312) mounted on the tool holder (302).

Description

Machining module and machine tool with a tool profile detection unit, and tool profile detection method

Technical area

The present invention relates to the field of machine tools. The present invention also relates to the field of optical detection of the position of a tool in situ in a machining module, and in particular within a machine tool. The present invention also relates to the field of optical detection of the profile of a tool in situ in a machining module, and in particular within a machine tool. It is in particular a machine tool forming a machining machine by removing material and in particular for a rotating machining step (turning, bar turning, etc.), including a controlled machine tool. digital.

In the field of machine tools, there is a need to know precisely the position of a tool mounted on the tool holder. It is also useful to know the evolution of the wear of this tool. This information is useful in order to ensure a machining range in accordance with the machining plan developed during debugging.

[0003] The manufacture of parts by means of machining modules

(machine tools), in particular of bar turning machines, automatic lathes, turning-milling centers, milling machines, machining centers and transfer machines, typically has three distinct phases:

[0004] In a first development phase (or presetting), the operator (for example a bar turning machine) defines and tests on a machining module the machining plane, that is to say the succession of 'operations and axis movements necessary to obtain the desired workpiece. The operator takes care, for example, to obtain the most efficient possible machining plane, that is to say the one which makes it possible to machine a given part with a minimum of operations and avoiding collisions between tools or with the part. He chooses the tools to be used, and checks the quality of the parts obtained, for example the surface finishes, compliance with tolerances, etc.

[0005] In a second phase of production, a series of parts is produced on the preset machining module, with the parameters defined during the development. This phase is the only productive phase; it is often carried out 24 hours a day, the machining module being supplied with raw material by means of a bar feeder or a loader of slips (raw parts).

[0006] It happens that the production of a series of parts is interrupted, for example to replace worn tools, to produce another type of parts on the same machining module, for machine maintenance, etc., then recovery later. In such a case, a warm-up phase is necessary to apply the parameters defined previously during debugging. This setting up is faster than the focusing.

[0007] When starting up, it is often necessary to replace the tools mounted on the machine with another set of tools suitable for the machining which must be carried out. The precision of the positioning of these tools, but also the rate of wear of these tools, determines the quality of the machining, but these parameters are difficult to reproduce during successive start-ups.

[0008] In addition, during the production phase, it is not impossible to have new parts as and when machining, and in

particular for large series, position drifts between the tool holder and the workpiece support, drifts in particular due to thermal expansion of the machines. Furthermore, the knowledge of the wear of the end portion of the tool which is useful for machining, forming the cutting zone and comprising one or more cutting edges, is

decisive for maintaining machining quality. The evolution of this wear, generally called the wear rate, but which in reality covers different wear processes, sometimes present in combination is not well often never checked, and if it is, it is through an annex installation, which requires additional time for this check and for the disassembly / reassembly of the tool in the machining module.

[0009] Consequently, during the machining process, not only the use of worn tools not suitable for the desired machining of a part, or even the breakage of cutting tools, but also the control of the wear in a dedicated installation separate from the machining module, cause prejudicial effects on the productivity and profitability of the production installations.

It is important to be able to keep the machine parameters resulting in strict compliance with the specifications of the part to be machined, while optimizing the percentage of the production time of the machine tool, but also optimizing the duration of use of each tool. In practice, the sequences of instructions controlling the machine tool are not reviewed or only occasionally, even though the end portion of the tool has, throughout its useful life, a progressive evolution of its profile modifying the geometry and

the location of the cutting edges.

There are many scenarios for changing the profile of the wear of the tool during its use: we can cite for example the flank wear (wear strip on the front face), wear notch, crater wear, wear causing plastic deformation (depression or bulge), formation of a built-up edge, wear creating chipping outside the cutting area, chipping of the cutting edge, wear generating a thermal crack, breakage of the cutting edge.

It may be interesting to assess the wear of the tool not only by the loss of material on its cutting area, but also by monitoring the evolution of the shape of its profile in order to anticipate the type. wear encountered and therefore modify one or more different machining parameters and / or position (s) of the machine tool depending on the type of wear encountered. Thus, for example, in the event of notch wear, it is possible to choose to modify the depth of cut, while in the event of wear by plastic deformation, it is possible to decide to increase the coolant spray rate.

State of the art

Some empirical solutions recommend replacing the tool by number of machined parts. Not only do these solutions not optimize the profitability of the production tool, especially in the case of special tools, expensive or difficult to obtain, but they also do not guarantee the untimely breakage of a tool or the consequences. harmful effects of its wear on the quality of the manufactured part.

[0014] There are systems for evaluating or measuring the wear of cutting tools by probing (with contact) or without contact (visual detection, laser or with an electric field) to validate the integrity or the admissibility of the 'cutting tool (for example a milling cutter or a drill). These checks are carried out outside the process and the machining module, which creates a period of non-production time, incompatible with the needs of mass production. Such techniques are presented in documents US2006021208, CA2071764A1,

US2014233839 or FR2952196.

We can also cite monitoring systems to identify the breakage of a tool, based on the measurement by sensors of signals emitted by the machine tool, in particular the acoustic measurement or the measurement of force (force, torque , effective power ...) on mechanical parts such as cam levers or machine spindles. By comparing the detected signal (vibration, noise, pressure, etc.) with a typical signal previously recorded by the monitoring system during a normal machining cycle, an alert signal can be triggered when the recorded signal deviates too much from the typical signal. [0016] Document US2018111240 describes a solution in which the non-contact measuring device uses a light barrier extending between a light emitting element and a light receiving element, to detect the position of a rotary machining tool. Due to the proximity between the useful portion of the tool and the light emitting and receiving elements, this technology requires means of protection in particular so as not to damage said light emitting and receiving elements with the oil and shavings present in the light.

the environment close to the tool. Moreover, this system makes it possible to know whether the tool touches the light barrier or not, but does not give any information on the precise position or on the profile of the end portion of the tool.

[0017] Document FR2645782 describes a tool breakage control system on a machining center equipped with a numerically controlled machine tool. Two cameras take pictures of the tool before and after machining, and the comparison between the images makes it possible to detect an anomaly on the tool. Document EP3021183 proposes a device integrated in a machine tool, for checking and correcting the position of the cutting edge of a tool on the tool holder via a camera. However, these installations require the use of a repository

additional in the machine tool, namely a reference frame specific to the camera, making it possible to locate the camera in the machine tool and therefore in relation to each of the parts of the machine tool. Such an arrangement potentially generates additional errors in the position of the tool, in particular with respect to the part to be machined.

[0018] Document EP0377374 proposes a system for locating the position of a machining tool relative to the machine tool. A camera is used which compares two perpendicular images of a block template of known position with corresponding images, displayed

later, the tool system.

Document EP2426555 presents an apparatus for detecting the movement of a cutting tool relative to a workpiece. This device has a camera which is fixedly mounted in a part of the machine tool which also includes the workpiece mounted on a chuck and the tool holder.

Also, one can cite the document JPH07246547 which uses a detection system to detect the coordinates of a tool, which is composed of a reflector installed on a tool mounting shaft, and of a measuring device of the type comprising laser interferometers to detect the coordinates of the tool.

It emerges from the foregoing that there is a need for the improved determination (more regular, faster and / or more precise) of the profile of the end portion (useful portion for machining) of a tool in use during stock removal machining.

Brief summary of the invention

An object of the present invention is to provide a machining module that can determine the profile of the end portion of a tool mounted on the tool holder of a machining module. Another object of the invention is to be able to determine

quickly the position or profile, or both the position and the profile, of the end portion of a tool mounted on the tool holder. Thus, we seek to propose a solution making it possible to determine the profile (the position) of the end portion of the tool without dismantling the tool or the tool holder so as not to waste not only time but above all, do not not modify the positioning references of the tool in the tool holder and of the tool holder in the machine tool.

Another object of the present invention is to provide a machining module free from the limitations of known machining modules. [0023] According to the invention, these goals are achieved in particular by means of a machining module by removing material for a machine tool including:

- a workpiece support intended to receive a workpiece,

- a workpiece support control unit capable of controlling and modifying the position of the workpiece support in the machining module,

a tool holder intended to receive a tool having an end portion useful for machining the part mounted on the part support;

- a tool holder control unit capable of controlling and modifying the position of the tool holder in the machining module,

a unit for detecting the profile of the tool mounted on the tool holder, said detection unit comprising an optical system making it possible to determine the profile of said end portion of the tool mounted on the tool holder, in which said optical system is mounted on the workpiece support.

This solution has the particular advantage over the prior art of placing the means for measuring and detecting the end portion of the tool, in situ in the machining module, therefore in the machine. -tool. One of the advantages of this configuration lies in the fact that the measurement or shooting of the end portion of the tool being carried out locally where the machining operations take place, the resulting measurement or image effectively corresponds to the instantaneous reality of the shape / geometry / position of the end portion of the tool without artifacts. Thus, if the tool exhibits deformation due to the local temperature of the machining module, this thermal drift is taken into account, whereas in the event of recourse to a measuring module separate from the machine tool, the tool will have cooled and the measurement will have an artefact due to the change in temperature. Another advantage lies in the fact that since the optical system is attached to the workpiece support, all the spatial referencing between the workpiece support and the tool holder serves as referencing between the optical system and the tool seen by the optical system: the measurement artefact due to the change of reference frame occurring if the tool / tool holder is installed in a measurement module separate from the machine tool is avoided.

[0025] In fact, said detection unit forms a unit for measuring the profile and therefore the wear of the tool which is integrated into the machining module. This arrangement allows in-situ control of tool wear, i.e. within the machining module itself, therefore without removing the tool from the tool holder, and without contact with the tool . For this purpose, said detection unit is placed in the machining module, in particular near the tool holder. In addition, it is understood that placing the optical system, capable of viewing the end portion of the tool mounted on the tool holder, directly on the workpiece support, as an element of the workpiece support, makes it possible to gain in particular in processing time (the optical system is already positioned to detect the end portion of the tool) and in precision (the position of the optical system within the tool holder being known precisely and being fixed, we avoid adding to the determination of the relative position between the optical system and the end portion of the tool an error related to the determination of the relative position between the optical system and the tool holder).

In the present text, the expression "workpiece support" is understood in the sense of "module of the machine tool comprising the elements allowing the assembly and the holding (in particular by clamping) and the

dismantling of the workpiece, as well as the movement of the workpiece in the space of the machining module of the machine tool ”. This part support is generally called a “material spindle”. Also, in the present text, the expression “tool holder” is understood to mean “module of the machine tool comprising the elements allowing the assembly and the holding (in particular by clamping or otherwise) and the dismantling of a tool or several tools, as well as the movement of this (these) tool (s) in the space of the machining module of the machine tool ”.

[0027] Thus, it will not be necessary to base the decision of the

replacing the cutting tool and / or changing the cutting parameters only on mathematical models representing the wear law of the cutting tool and any experimental curves that are not always available, or at all less not existing with the whole range of parameters present. Thanks to the invention, it will also be possible to increase the field explored and therefore the library of experimental curves by integration, for example in a database of data, profile measurements carried out with the machining module according to the invention.

[0028] It is thus possible to optimize in a personalized manner the duration of use specific to each tool, even in a series of similar tools. For example, it will be possible to shorten the useful life of a tool if the evolution parameters of its wear exceed a predefined limit, and this in particular because the reality of the evolution of tool wear is more unfavorable than the theoretical wear model, or to lengthen it if the parameters of evolution of the wear do not exceed the predefined limit because the reality of the wear of the tool is more favorable than the model of theoretical wear.

[0029] In one embodiment, the optical system belongs to an optical measuring device which is configured to allow, by a single step of taking a picture by the optical system, to determine the three-dimensional relative position between the support of the workpiece and the tool holder. In particular, the optical system takes a picture of the tool holder, for example of a specific area of the tool holder and according to one possibility, the optical system takes a picture of a target mounted on the tool holder and forming a positioning reference.

[0030] The present invention also relates to a machine tool comprising a machining module as described in the present text, this machine tool also having a unit for monitoring the wear of the tool which is suitable for calculating the deviation of the profile of the tool from the information supplied by said detection unit. This is a use of the machining module to analyze the condition of the tool and in particular its wear.

Thus, it is understood that it is thus possible from the detection unit and the information provided on the state of the tool during machining, to analyze the state of the tool, its rate of wear, and / or its shape drift, in particular with regard to the cutting zone. [0032] The invention also relates to:

- a method for detecting the position of a tool,

- a method for detecting the profile of a tool, and

a method of detecting the wear of a tool in a machine tool, this tool being mounted on a tool holder in a machining module comprising a workpiece support and a workpiece holder

These methods will be explained and described further in the detailed description.

Brief description of the figures

Examples of implementation of the invention are indicated in the description illustrated by the appended figures in which:

- Figure 1 illustrates in perspective a machining module according to one embodiment of the invention,

- Figure 2 shows in perspective an enlargement of portion II of Figure 1, showing a different tool mounted on the tool holder,

- Figure 3 shows in perspective an enlargement of the end portion of the tool which is useful for machining a part, in a configuration of damage following wear, according to portion III of Figure 2 ,

- Figure 4 illustrates the use of the optical system of the machining module for determining the position and / or the profile of the tool in the tool holder,

- Figure 5 shows in perspective and exploded a tool holder equipped with a three-dimensional target,

- Figure 6 illustrates the use of the optical device of the machining module for determining the measurement in space of the relative position between the tool holder and the workpiece support (also called material spindle)

- Figure 7 is another perspective view corresponding to Figure 6,

- Figure 8 illustrates the optical device in the three-dimensional locating step between the tool holder and the workpiece support, thanks to the three-dimensional target,

- Figure 9 shows the part of Figure 6 corresponding to the tool holder with the three-dimensional target, from the direction IX of Figure 6, or in the direction Z, as seen by the optical system when the target is oriented in the direction of optical system,

- Figures 10, 11 and 12 are three views illustrating the structure of the three-dimensional target, respectively from the front, in perspective and in section, and Figures 13 and 14 are perspective views of the second structure of the target respectively such as in Figures 10, 11 and 12 and according to an alternative embodiment,

- Figures 15A and 15B illustrate the processing of the image generated by the second imaging system of the optical system,

- Figure 16 shows in perspective is another perspective view corresponding to Figure 4 and showing the use of the optical device of the machining module for determining the profile of the end portion of the tool,

- Figure 17 illustrates in perspective and partially a machining module according to another embodiment of the invention,

- Figure 18 illustrates in perspective a variant of the tool holder carrying a series of tools aligned vertically, each tool being oriented along a horizontal axis around which it is rotatably mounted, and - Figure 19 illustrates in perspective a machining module according to yet another embodiment of the invention.

Example (s) of embodiment of the invention

Referring to Figure 1, the machining module 300 comprises a workpiece support 320 and a tool holder 310. The workpiece support 320 can be provided to be removably mounted on the module machining 300, in particular via removable fixing means. As seen in Fig. 1, on the workpiece support 320 is removably mounted a workpiece 322 (a blank bar or slug is shown). The workpiece support 320 comprises what is called a material spindle, namely comprising, for example, a clamp, a mandrel, a bar turning machine, or else a pallet or a pallet holder. The main direction of the workpiece support 320 corresponds to the Z direction. The tool holder 310 can be provided to be removably mounted on the machining module 300, in particular via removable fixing means. As seen in Figure 1, on the tool holder 310 is removably mounted a tool 312 (a tap or a milling cutter is shown in a simplified manner). The tool holder 310 comprises for example a spindle, a carriage or a vice or even a comb. The main direction of the tool holder 310 corresponds to the X direction. In the machining module 300, the vertical direction corresponds to the Y direction, and the three directions X, Y and Z form an orthogonal coordinate system.

A control unit 302 of the tool holder is capable of

order and modify the position of the tool holder 310 in the machining module 300. In the field of mechanical manufacturing and in the present text, the term “control” designates all the hardware and software having the function of giving the movement instructions to all the elements of a machine tool. The machining module 300 also includes a control unit (not shown) for the workpiece support 320. The machining module 300 further comprises a detection unit 304, which detects the position but also the profile of the tool 312 mounted on the tool holder 310. For this purpose, said detection unit 304 comprises an optical system 100 for determining the profile of the end portion 313 of the tool 312 mounted on the tool holder 310 (see Figures 4, 6 and 8). In FIG. 1, the optical axis O of this optical system 100 is shown, from the input face 102 of the optical system. This optical axis O is, in the arrangement of Figure 1, parallel to the Z direction or main direction of the workpiece support 320. Also, preferably, the optical axis O is orthogonal to the direction of the X axis of the workpiece. tool holder 310, as shown in Figure 1. According to the invention, as shown in Figure 1, the optical system 100 is mounted on the workpiece support 320, at least the entire sensor part of the optical system 100, of the components lighting that may be detached from the sensor part of the optical system 100 and therefore placed elsewhere in the machining module 300.

As will be specified later, it is an optical system 100 with shooting, that is to say an optical system capable of generating an image of the profile of the tool by a system of shooting included in the optical system 100. In particular, this optical system 100 comprises a set of optical components and an image acquisition system. Such an image acquisition system makes it possible to take photographs and / or videos, and is for example a camera or a device.

photographic, in particular a digital camera.

In the context of the present invention, an optical system 100 is considered which operates in combination with one or more sources.

bright. Also, it is understood that the shooting system of the optical system 100 according to the invention forms an image sensor. The light source or sources associated with the shooting system of the optical system 100 form emitters of electromagnetic radiation, or

light radiations, the nature of which can be monochromatic, or extending over a range of wavelengths by combining a series of monochromatic electromagnetic radiations (multichromatic light. In one embodiment, the aforementioned light source (s) is (are) not (a) source (s) of laser radiation; and the shooting system of the optical system 100 according to the invention forms an image sensor which does not have or is not associated with a laser emitter.

In the present text, the term "end portion of the tool" is understood to mean the end part of the tool which comprises the zones useful for machining, therefore the cutting zone (s), namely which comprises (nt) the cutting edges defined by intersection between the useful faces and the edges. We find on the enlargement of figure 2, such a portion

313 for the tool 312. In Figure 3, an example of wear of the end portion 313 for a tool other than that of Figure 2, is visible through the wear area 313a distributed between the flank face and the cut face.

In the present text, the term "profile" of the end portion is understood to mean either a two-dimensional representation of the end portion, or a three-dimensional representation of the end portion. For example, this profile can include a line

corresponding to the contour of the end portion of the tool, in projection on a plane or forming an intersection with a plane, in particular a plane orthogonal to the optical axis O of the optical system 100. Also, this profile can form a shape three-dimensional of the end portion 313 of the tool (for example an insert) including the cutting edge (s). Also, this profile can correspond to a three-dimensional shape of the end portion 313 of the tool represented by a series of lines such as a topographic profile.

The optical system 100 is configured to make it possible to detect the profile of the end portion 313 of the tool 312 when the tool holder 310 is in an operational measurement position shown in FIG. 4. In this operational position measurement, the tool holder 310 and the workpiece holder 320 are close to each other. In this operational measurement position, the optical axis O of the optical system 100 can intersect with the end portion 313 of the tool 312, or with the tool 312, or at least sufficiently close to the tool 312 so that the tool 312 is in the field of view of the system optical 100. In other words, in this case, in this operational measuring position, the end of the tool holder 310 is in alignment with the exit (or entry face 102) of the optical system 100. This means that the optical path from the optical system 100 intersects with the end of the tool holder 310 and / or with the tip or more generally the end portion 313 of the tool 312.

In some cases, in the operational measurement position, the smallest distance between the end portion 313 of the tool 312 and the Z axis of the workpiece support is less than 50 cm, or even less than 30cm, and sometimes less than 15cm). Thus, for example, in the operational measurement position, the smallest distance between the end portion 313 of the tool 312 and the Z axis of the workpiece support is between 5 and 50 cm, sometimes between 5 and 30 cm. cm, or between 20 and 30 cm or between 5 and 15 cm.

In certain cases, said operational measurement position corresponds to a position for loading a tool 312 on the tool holder 310: thus, the profile measurement can be carried out as soon as the tool 312 is fitted.

Also, in said operational measurement position, the X axis of the tool holder 310 can have different orientations with respect to the optical axis O of the optical system 100:

- in certain cases, the axis X of the tool holder 310 is orthogonal to the direction of the optical axis O of the optical system 100, as shown in FIG. 1, so that the optical system 100 sees one side of the portion

end and tip of tool 312

- in some cases, the X axis of the tool holder 310 is coaxial or parallel to the direction of the optical axis O of the optical system 100 (case not shown), so that the optical system 100 sees only the tip of the tool 312,

- In yet other cases, the X axis of the tool holder 310 is inclined relative to the optical axis O of the optical system 100 (case not shown by an angle other than zero and different from 90 ° between the axes X and O).

Indeed, according to the machine tool carrying the machining module 300 according to the invention, it is possible to change the orientation of the tool holder 310 and of its axis. X, in particular in the case of a machine tool with five or six axes of movement for the tool holder 310.

Referring now to Figure 4 showing an embodiment of the optical system 100. The optical system 100 includes a first shooting system 110 which is configured so that its image focal plane is able to intersect with the end portion 313 of the tool

312 in said operational measurement position. In addition, the first image acquisition system 110 comprises a first image acquisition system 112 which makes it possible to take an image of the end portion.

313 of the tool 312 in the operational measuring position. In Figures 1 and 4, we also see a light source 140, lateral, close to, optionally mounted on the tool holder 310 in order to constitute a lateral illumination of the end portion 313 of the tool 312 in the operational measurement position.

Other types of light sources, or light sources

Additional can be provided each independently of the other or in addition to one another.

In one embodiment (see Figures 1, 7 and 16), the optical device 10 further comprises a front light source 104 oriented parallel to the optical axis O of the optical system 100 and in the direction of the tool holder 310. This light source 104 can be placed near the optical system 100. This light source 104 is oriented in the direction of the tool 312 in order to constitute a frontal illumination of the end portion 313 of the tool 312 in the position. operational measurement. In particular, as seen in Figures 1, 7 and 16, this front light source 104 is an annular light source surrounding the input face 102 of the optical system 100: in this case, the front light source 104 is coaxial with the optical axis O of the optical system 100. This front light source 104 makes it possible to properly illuminate the surface of the end portion 313 of the tool seen by the optical system 100.

In one embodiment (see Figures 1 and 16), optical device 10 further comprises a rear light source 106 oriented toward optical system 100. This light source 106 is disposed. in order to constitute a rear illumination (“back face”) of the end portion 313 of the tool 312 with respect to the optical system 100 in the operational measurement position. In particular, as seen in Figures 1 and 16, this rear light source 106 is coaxial, preferably aligned with the optical axis O of the optical system 100. In the operational measurement position (see Figure 16) the end portion 313 of the tool is between the entrance face 102 of the optical system 100 and the rear light source 106, so that the end portion 313 of the tool is illuminated from the rear, which increases the contrast of the image taken in the area of the contour of the end portion 313 as seen by the otic system 100.

The optical system 100 also includes a second shooting system 120 with a second image acquisition system 112 which also makes it possible to take an image of the end portion 313 of the tool 312 in the position operational measurement. To this end, the optical path of the first image capture system 210 and the optical path of the second image capture system 120 have a common optical path portion which goes towards and comes from the object viewed by the optical system 100 , in this case the end portion 313 of the tool 312 (see Figures 4 and 16). In another measurement configuration which will be described in relation to FIGS. 6 and 8, it is a target 200 mounted on the tool holder 310 which forms the object looked at, seen by the optical system 100. In the following, we will see The term “object viewed” means in particular either the end portion 313 of the tool 312 mounted on the tool holder, or the target 200. In the operational measurement position, the first image capture system 210 is turned in the direction of the viewed object and forms a camera system aligned with the viewed object, and the second camera system 120 has an optical path 126 which joins with the optical path 116 of the camera system 110 aligned with the 'viewed object and forms a shooting system eccentric with respect to the viewed object, with respect to the optical axis O of the optical system 100, and with respect to the common portion of the optical paths 116 and 126 (aligned with the 'object viewed). The optical axis O is superimposed with the mean radius of the common portion of the first path optical 116 and of the second optical path 126. In this common portion, the sections of the first optical path 116 and of the second optical path 126 are mutually parallel, but not necessarily superimposed.

In the common portion of the optical paths 116 and 126, the optical rays are at least partly coincident or else simply parallel to each other. The second image capture system 120 which is eccentric has an optical path portion 126 internal to this second image capture system 120 which is preferably parallel to the optical axis O. This internal optical path portion 126 is connected to the , or more precisely joined the, optical path 116 of the first image capture system 110 aligned by a dedicated optical module 128, comprising a catoptric optical system such as a mirror 129. In this way, the input of the capture system eccentric view (here the second shooting system 120) is connected to the path or optical path of the aligned shooting system (here the first shooting system 110).

Thus, the optical system 100 comprises an optical module 128 (for example with a catoptric optical element such as a mirror 129) arranged between the first image capture system 110 and the second image capture system 120 and configured to deflect a part of the light rays passing through at least a part of one of the first and the second imaging system towards the other of the first and the second imaging system. The optical system 100 is arranged such that the optical path from the object being viewed (the end portion 313 of the tool 312 in Figures 4 and 16 and the target 200 in Figures 6 and 8) through the optical system 100 passes through at least a portion of one of the first imaging system 110 and the second imaging system 120 (the first imaging system 110 in Figures 4, 6, 8 and 16) before d 'achieve the other of the first imaging system 110 and the second imaging system 120 (the second imaging system 120 in Figures 4, 6, 8 and 16).

Also, in the configuration shown, the first imaging system 110 and the second imaging system 120 are arranged in parallel with respect to each other. Also, in the configuration shown, the first imaging system 110 is mounted directly on the workpiece support 320 and the second imaging system 120 is eccentric with respect to the optical axis of the first imaging system 110 but this may be the case. 'reverse, namely one can have a configuration in which the second shooting system 110 is mounted

directly on the workpiece support 320 and the shooting system 120 is eccentric with respect to the optical axis of the first shooting system 110

In this way, it is understood that when the first shooting system 110 is aligned with the viewed object, the second shooting system 120 also sees the viewed object and can also take a shot. and generate an image of this viewed object. As will now be explained, this image can be used to determine the position of the tool 312 and can be used to determine the profile of the end portion of the tool 312.

Thus, in one embodiment of the invention, there is provided a method for detecting the position of a tool 312 mounted on a tool holder 310 in a machining module 300 comprising a workpiece support 320 and a workpiece carrier 310, comprising the following steps:

i) providing a detection unit 304 in the machining module 300, said detection unit 304 comprising an optical system 100 making it possible to determine the profile of said end portion 313 of the tool 312 mounted on the holder. tool 310, in which the optical system 100 is mounted on the workpiece support 320,

ii) loading the tool 312 into the tool holder 310: this step makes it possible to know the relative position between the tool 312 and the tool holder 310, iii) positioning of the tool holder 310 relative to the workpiece support 320 in an operational measurement position (for example according to the configuration of FIG. 4): this step makes it possible to place the tool 312, and in particular the end portion 313 of the tool 312 or another portion of the tool 312 , visibly by the optical system 100,

iv) activation of said detection unit 304, and v) determination, via the optical system 100, of the position of the tool 312 in the machining module 300.

At this stage, it should be noted again that in the case of the arrangement of the machining module 300 according to the invention and as illustrated in the figures, said optical system 100 is mounted on the workpiece support 320. It is therefore understood that in this way, the taking of a picture by the optical system 100 of the tool 312 (and in particular of its end portion 313) makes it possible to determine not only the relative position between the tool 312 (said end portion 313 of the tool) and the workpiece support 320, but also the relative position between the tool holder 310 and the workpiece support 320.

According to a first possibility concerning said method of detecting the position of the tool, when activating the detection unit 304, it is the first shooting system 110 which is used and therefore c 'is the first image acquisition system 112 which generates one (or more) image (s) of the end portion 313 of the tool 312.

Analysis of this image and in particular of the position of the sharp zone of this image (resulting for example from the arrangement of Figure 4) in the X direction and relative to the edge of the tool as it is seen by the first shooting system 110 makes it possible to know the distance of the tool 312 relative to the optical system 100, therefore the Z position of the tool 313. This image also makes it possible to identify the cutting edge (s) (in projection) such as it (s) is (are) seen by the first shooting system 110. This registration is both in position, in particular with respect to the edge, as well as in geometry ( shape on the image of the line (s) corresponding to the cutting edge (s)).

According to a second possibility concerning said method of detecting the position of the tool (to be performed as an alternative or in addition to the previous first possibility), when the detection unit 304 is activated, it is the second image acquisition system 120 which is used and therefore it is the second image acquisition system 122 which generates one (or more) image (s) of the end portion 313 of the tool 312. Analysis of this image and in particular of the position of the sharp zone of this image (resulting for example from the arrangement of Figure 4) in the direction X with respect to the edge of the tool as seen by the first shooting system 110 makes it possible to know the distance of the tool 312 with respect to the optical system 100, therefore the Z position of the tool 313. This image also makes it possible to identify the cutting edge (s) (in projection) as it (s) is (are) seen by the second imaging system 120. This registration is both in position, in particular with respect to the edge, and in geometry (shape on the image of the line (or lines) corresponding to I '(to) cutting edge (s)).

Also, in one embodiment of the invention, there is provided a method for detecting the profile of a tool 312 mounted on a tool holder 310, in a machining module 300 comprising a workpiece support 320 and a workpiece carrier 310, comprising the following steps:

i) providing a detection unit 304 in the machining module 300, said detection unit 304 comprising an optical system 100 making it possible to determine the profile of said end portion 313 of the tool 312 mounted on the holder. tool 310, wherein said optical system 100 is mounted on workpiece support 320,

iv) activation of said detection unit 304, and

v) determining, via the optical system 100, the profile of said end portion 313 (or another portion) of the tool 312 mounted in the tool holder 310.

According to a first possibility concerning said method of detecting the profile of the tool 312, during the activation of the control unit. detection 304, it is the first image capture system 110 which is used and therefore it is the first image acquisition system 112 which generates one (or more) image (s) of the end portion 313 of tool 312.

The analysis of this image makes it possible to detect the edge of the tool as seen by the first imaging system 110. This is the edge, namely the contour, of the end portion 312 of the tool 312, seen in projection in the plane (X, Y) orthogonal to the direction Z, itself parallel to the optical axis O of the optical system. Thus, the shape (in this case the contour line) of this edge of the tool 312 provides information on the geometry of the end portion 313 of the tool 312 mounted on the tool holder 31 at the time of setting. of view.

This image also makes it possible to identify the cutting edge (s) (in projection) as it (s) is (are) seen by the first shooting system 110. This registration is both in position, in particular with respect to the edge, as well as in geometry (shape on the image of the line (s) corresponding to I '(to) cutting edge (s).

According to a second possibility concerning said method for detecting the profile of the tool 312 (to be performed as an alternative or in addition to the previous first possibility), when the detection unit 304 is activated, it is the second image capture system 120 which is used and therefore it is the second image acquisition system 122 which generates one (or more) image (s) of the end portion 313 of the tool 312. Analysis of this image makes it possible to detect the edge of the tool as seen by the second imaging system 120. This is the edge, namely the contour, of the end portion 312. of the tool 312, seen in projection in the plane (X, Y) orthogonal to the direction Z, itself parallel to the optical axis O of the optical system. Thus, the shape (in this case the line) of this edge of the tool 312 provides information on the geometry of the end portion 313 of the tool 312 mounted on the tool holder 31 at the time of shooting. . This image also makes it possible to identify the cutting edge (s) (in projection) as it (s) is (are) seen by the second shooting system 120. This registration is both in position, in particular with respect to the edge, as well as in geometry (shape on the image of the line (or lines) corresponding to I '(to) cutting edge (s)). The implementation of such a method of detecting the profile of the tool 312 makes it possible in particular to know the angular orientation of the tool 312 with respect to the X axis of the tool holder, and therefore with respect to to the workpiece support 312, in the operational measurement position, and also makes it possible to verify that the tool 312 is in the desired orientation with respect to the workpiece support in the operational measurement position. Also, the implementation of such a method for detecting the profile of the tool 312 makes it possible to establish the profile and to verify that the tool 312 mounted on the tool holder corresponds to the expected tool (the profile detected corresponds to the expected and predetermined profile), and thus makes it possible to avoid mounting an inadequate tool on the tool holder 310.

In Figure 8, there is shown an optical device 10

comprising an optical system 100 and a three-dimensional target 200 able to cooperate together, according to one embodiment, to perform the three-dimensional measurement of the relative position between the target 200 and the optical system 100. As will be explained below, this measurement allows also to measure the relative position between the tool holder 310 (carrying the target 200) and the workpiece support 320 (carrying the optical system 100), and to deduce therefrom the relative position between the tool 312 (mounted on the holder -tool 310) and part 322 (mounted on the part support 320). In fact, in this measuring position, the target 200 is oriented in the direction of the optical system 100, parallel to a main axis, forming a main horizontal Z direction. To this end, at the output of the optical system 100, the optical path O is orthogonal to a useful face 202 of the target 200.

The target 200 is now described in relation to Figures 8, 10, 11 and 12. The target 200 is in the form of a pellet, here of cylindrical shape of circular section (it could be of square section or the like. ), one side of which forms the useful face 202 for carrying out the measurement. For carrying out the measurement, this useful face 202 is therefore turned towards the optical system 100, and in particular towards the input face 102 of the optical system 100, the Z axis corresponding to the main direction (horizontal in the figures) separating the useful face 202 from the input face 102 of the optical system 100. The surface of the useful face 202 of the target 200 is distributed between a first structure 210 and a second structure 220. The first structure 210 comprises a flat reference face 212 whose surface is smooth and is distributed between a first portion 214 whose surface is reflective with a diffuse reflection and a second portion 216 whose surface is reflective with a specular reflection. More generally, said plane reference face 212 is distributed between at least a first portion (214) whose surface is reflective according to first reflection parameters, and a second portion (216) whose surface is reflective according to second parameters reflection different from the first reflection parameters. In one embodiment, the first portion 214 is coated with a diffusing reflective layer, for example of barium sulphate BaSO4, and the second portion 216 is formed of a reflective layer according to a specular reflection, for example of chromium. In the illustrated embodiment, the second portion 216 consists of several localized zones 217 in the form of circles forming islands arranged within the first portion 214 which is continuous. More generally, the second portion 216 is distributed according to a series of localized zones 217 positioned in the first portion 214. According to one possibility, the localized zones 217 of said second portion 216 are formed of islands or segments distributed in the first portion 214. These localized areas 217 may have other shapes, such as segments or islands other than a circle. These localized zones 217 define between them a figure

geometric belonging to the following list: quadrilateral,

parallelogram, rectangle, square, rhombus, regular polygon and circle. This geometric figure can be a geometric figure with central symmetry. In Figures 10 and 11, twenty-four localized circular areas 217 are arranged in a square. The aim of this first structure 210 is to be able to identify its center C3 precisely using standard vision tools. With the square shape, the two diagonals C1 and C2 of this square intersect at the center of the square. Note that in the measurement position, as shown in Figures 6 to 12, the reference face 212 is disposed parallel to the X and Y directions, forming respectively a vertical direction (an axis) and a transverse horizontal direction (an axis) in the case of the illustrated arrangement.

The second structure 220 has an inclined face 222 relative to the reference face 212: this inclined face 222 is

essentially plane, the mean plane of this inclined face forming with respect to the reference face 212 an acute angle a of between 10 degrees and 80 degrees, for example between 20 and 30 degrees, and preferably of the order of 25 degrees ( see figure 12).

In one embodiment, the surface of this inclined face 222 is not smooth but has relief elements 224 forming surface irregularities either random or else according to a predetermined geometry, for example drawing between them a shape of grid or a network of lines, thus constituting a structured grid (not shown) or a structured network of lines (see FIG. 13). Also, in one embodiment, the surface of the inclined face 222 of the second structure 220 is striated, in particular the surface of the inclined face 222 of the second structure 220 is covered by one of the following elements:

engraved network, structured grid or network of specular lines 225.

Such elements in relief 224 can be protruding or recessed, that is to say set back, relative to the mean plane of the inclined face 222, in particular in the form of small roughness, or any other irregularity of surface. Such elements in relief 224 can be present over the entire surface of the inclined face 222. Such elements in relief 224 can be regularly distributed over the entire surface of the inclined face 222. For example, these elements in relief 224 can form a together

delimiting a grid or network pattern, or more generally a structured surface or a rough surface which makes it possible to diffuse the light reflected on this inclined face 222. The surface of the inclined face 222 of the second structure 222 is for example covered by one of the elements following an engraved network or a structured grid, with a pitch between the patterns of the grid or the network between 5 and 100 micrometers, in particular between 5 and 50 micrometers, and in particular between 8 and 15 micrometers, for example of the order of 10 micrometers.

For example, this inclined face 222 is made of unpolished silicon or ceramic, or unpolished metal or glass, or any other structurable material, and the elements in relief 224 have been obtained by photolithography, machining by removal chips, direct writing, etc ... or any other structuring process. These elements in relief 224 form, for example, depressions and / or projections respectively set back / protruding from the mean plane by a few micrometers or by a few tens of micrometers, in particular between 0.5 micrometers and 50 microns.

micrometers.

[0061] In another embodiment, as illustrated in FIG. 14, the surface of this inclined face 222 is smooth and comprises an array of lines of chrome, or of another material causing a specular reflection of these lines of chrome. which constitute specular elements 225. These specular elements 225 in the form of lines are arranged parallel to each other. In the measuring position, these specular elements 225 in the form of lines or bands are arranged parallel to the Y, Z plane, so that along the inclined surface, in the Z direction, these lines are encountered one by one (i.e. also the case when advancing in direction X). The substrate forming the wafer of the second structure 220 can then be in different materials, including glass or silicon, with on the inclined face 222 a diffusing reflective layer, for example in barium sulphate BaS0 ₄ which alternates with the specular elements. 225 or else which covers the entire surface of the inclined face, with the specular elements 225 arranged above this reflecting layer

diffusing. Such specular elements 225 can be regularly distributed over the entire surface of the inclined face 222. In an exemplary embodiment, these specular elements 225 in the form of lines form a network with a pitch of 25 micrometers, the lines (in particular of chrome). having a width of 12.5 micrometers, equal to the width of

line spacing or portion with diffuse reflection also in the form of lines or bands 12.5 micrometers wide. According to another implementation, a pitch of 10 micrometers or more generally a pitch between 5 and 50 micrometers is used. It should be noted that these specular elements 225 which alternate with the rest of the surface which produces a diffuse reflection, could be in other forms than continuous lines or segments forming bands, in particular broken lines or in dotted lines, patterns such as friezes of dots, circles, triangles, or any other geometric shape.

According to an embodiment not shown, the inclined face 222 of the second structure 220 carries point and projecting elements in relief 224, in the form of small mounds or pins, which are distributed in rows parallel to each other, the elements of relief 224 being offset from one row to another, to form a staggered pattern. According to another embodiment not illustrated, the inclined face 222 of the second structure 220 carries projecting relief elements 224 in the form of segments parallel to each other and at an equal distance in two series intersecting at 90 ° to each other. . This set of raised elements 224 constitutes a grid pattern. Note that this grid can be formed of two series of segments parallel to each other, with series of intersecting segments at an angle other than 90 ° from each other. In Figures 10 to 13, the inclined face 222 of the second structure 220 bears relief elements 224 recessed in the form of a series of segments parallel to each other and equidistant from each other along the X direction: these elements in relief 224 in this case form grooves. This direction X is therefore orthogonal to the direction of the segments forming the elements in relief 224.

In the embodiment of Figure 14, the surface of the inclined face 222 of the second structure 220 is therefore covered by a network of specular lines 225, namely continuous bands parallel to each other whose surface has properties specular reflection. Thus, in some of the aforementioned cases, and in particular those of Figures 13 and 14, the surface of the inclined face 222 of the second structure 220 is striated.

According to the embodiments shown for the target 200, the patch delimiting the target 200 comprises on its useful face 202 the first structure 210 which occupies most of the surface of the useful face 202, and within the first structure 210, an area reserved for the second structure 220. In this situation, the first structure 210 surrounds the second structure 220. More precisely, the localized areas 217 of the second portion 216 of the first structure 210 define a square which surrounds the second structure 220. According to one possible arrangement, and in the case of the embodiments of the target 200 as shown, the first structure 210 and the second structure 220 are arranged on the useful face 202 in a concentric manner relative to one another. to the other. Furthermore, as in the cases shown, the first structure 210 defines an opening 218 for a housing 219 housing said second structure 220, which is for example disposed on a wafer having the inclined face 222. When the wafer is housed in the housing 219 of the first structure 210, its inclined face 222 is turned towards the outside of the housing 219, towards the opening 218. In this case, the second structure 220 is disposed in said housing 219 with the inclined face 222 which is is set back with respect to the reference face of said first structure 210: this means that the inclined face 22, therefore the second structure 220 is arranged behind, behind the plane delimited by the reference face 212 (with respect to the direction main Z, see FIG. 11), in housing 219, for example from 0.05 to 2 millimeters or else of the order of 0.15 millimeters. According to another possibility, not shown, the second structure 220 is disposed forward, in front of the plane delimited by the reference face 212. According to yet another possibility, not shown, the second structure 220 is disposed on either side of the plane delimited by the reference face 212, namely a part of the inclined face 222 is disposed behind and the other part of the inclined face 222 is disposed forward, relative to the reference face 212. In order to protect the first structure 210 and the second structure 220 from the environment (dust, oil, shocks, etc.), as can be seen in FIG. 12, the target 200 comprises a protective plate 230 in a transparent material , in particular glass, covering the first structure 210 and the second structure 220 on the side of the useful face 202.

According to one possible implementation, as shown in FIG. 12, the target 200 comprises, in the form of a stack, the following elements. A bottom wall 231 is surmounted by a plate 232 formed by a plate hollowed out in its center in order to delimit the housing 219 delimited by the opening 218 on the side of the useful face 202. The plate 232 is surmounted by the protection 230 closing the housing 219. The whole is surrounded by a cylindrical wall 234 retaining the entire target 200. The protection plate 230 comprises The second structure 220 is for example a silicon wafer housed in the housing 219 with the inclined face 222 (bearing the elements in relief 224 or specular elements 225) turned towards the useful face 202. The face of the plate 232 turned towards the useful face 202 comprises a reflecting layer 233 according to two zones as described above respectively in relation with the first portion 214 (reflecting surface according to a diffuse reflection) and the second portion 216 (reflecting surface according to a specular reflection, in particular in the form of local elements ss 217).

Furthermore, the target 200 can be equipped with an RFID (radio frequency identification) type chip, not shown, in order to allow the storage and reading of a unique identifier and of data relating to the target 200 and possibly also in connection with a tool holder 310 (see Figures 1 and 5) on which the target 200 is intended to be mounted. These data can include, for example, in particular, the reference of this tool holder 310 and other information related to the use of this tool holder 310 (for example its serial number, its type, its setting relative to the material center. or workpiece support 320, the number of times it has been used ...). In FIGS. 5, 9 and 16, the target 200 (and the possible RFID chip) is mounted on the portion of the tool holder 310 forming a clamp. Referring now to Figure 8 to present the optical system 100 associated with the target 200 which has just been described to together form an optical device 10 allowing the measurement of the relative position between two objects in the three directions of the space, and thus the relative position between the workpiece support 320 and the tool holder 310 or the relative position between the workpiece 322 and the tool 312. In particular, we consider an orthogonal space (possibly

orthonormal) in a Cartesian coordinate system X, Y and Z, which is direct in the figures). This optical system 100 is intended to take simultaneously, during the same sequence of shots, both an image of the first structure 210 of the target 200 and at the same time an image of the second structure 220 of the target 200. According to the present text, this simultaneous shooting of the two images is carried out without focusing, which allows a great speed of execution of this shooting. Others

characteristics, linked in particular to the specific structure of the target 200 which has just been described, also allows maximum precision. The applicant company has produced an optical three-dimensional measuring device 10 in accordance with the present description which achieves in half a second or less a repeatable relative measurement with an accuracy of one micrometer or less.

The optical system 100 comprises the first shooting system 110 and the second shooting system 120. According to one possible arrangement, said optical system 100 is arranged so that the difference between the focal length of the second system of 120 and the focal length of the first shooting system 110 is between the minimum distance and the maximum distance separating the reference face 212 from the inclined face 202. According to another possible arrangement, the depth of field DF01 of the first shooting system 110 is much greater and in particular at least 10 times greater than the depth of field DF02 of the second shooting system 120. For example the depth of field DF01 of the first shooting system 110 is between 10 and 10,000, or even between 100 and 5,000 greater than the DF02 depth of field of the second shooting system 120. Among the various possibilities, the DF01 depth of field of the first shooting system 110 is greater than or equal to 0.8 millimeter, or it is between 0.5 and 5 millimeters, or it is between 0.8 and 3 millimeters, or it is between 1 and 2 millimeters. Also, according to various possibilities, the depth of field DF02 of the second shooting system 120 is less than or equal to 0.1 millimeter, or it is between 5 and 50 micrometers, or it is between 8 and 30 micrometers, or well it is between 10 and 20 micrometers.

According to one embodiment, the first shooting system 110 is configured so that its image focal plane F1 is capable of

correspond to the reference face 212 of the first structure 210, and the second shooting system 120 is configured so that its image focal plane F2 is able to intersect with the inclined face 222 of the three-dimensional target 200.

This allows, when the object viewed by the optical system 100 is the target 200, it is possible for the first image capture system 110 to naturally and without further adjustment, its focus on the entire reference face. 212 of the first structure 210 in a range of distance between the target 200 and the first shooting system 110 which can vary over a few millimeters. In parallel, the second shooting system 120 is able to naturally and without any other adjustment, its focusing on the portion of the inclined face 222 of the second structure 210 which is at the distance from the second shooting system. 120 corresponding to the focal length of the second image capture system 120. According to one possibility, the magnification of the first image capture system 210 is smaller than the magnification of the second image capture system 220.

In one possible configuration, the optical system 100 is arranged so that the optical path of the first shooting system 110 and the optical path of the second shooting system 120 have a common section placed on the optical axis O of the optical system 100 and comprising the image focal plane F1 of the first system of 110 and the image focal plane F2 of the second image capture system 120. In this case, preferably, the optical system 100 is arranged such that the optical path from the object passes through at least a portion of the image. one of the first and second shooting system 120 before reaching the other of the first and second shooting system 120.

According to one possible arrangement, the first image acquisition system 112 of the first image capture system 110 and the second image acquisition system 122 of the second image capture system 120 are synchronized in order to take simultaneously a first image by the first image capture system 110 and a second image by the second image capture system 120. In this case, it is understood that the target and the optical system 100 belong to an optical device 10 for measurement which is configured to allow by a single step of shooting the target 200 by the optical system 100 to determine the three-dimensional relative position between the support of the workpiece 310 and the tool holder 320. Also, in this case, this single step of shooting the end portion 313 of the tool mounted on the tool holder 310 by the optical system 100 to determine the profile of the end portion 312 of the tool 312 mounted on the holder tool 310, and notam ment the three-dimensional profile of the end portion 312 of the tool 312 mounted on the tool holder 310.

As already explained above, to allow simultaneous access to the vision of the target 200 by the first shooting system 210 and by the second shooting system 220, the latter

present a portion of a common optical path which goes towards and comes from the object viewed by the optical system 100, in this case the target 200 (see FIGS. 6 and 8) after mounting the target 200 on the tool holder 310 and mounting the optical system 100 on the workpiece support 320. For this purpose, in the operational measurement position, the first image pickup system 210 is turned in the direction of the useful face 202 of the target 200 and forms a camera system. shot aligned with the target 200, and the second pickup system 120 has an optical path 126 which joins the optical path 116 of the shooting system 110 aligned with the target 200 and forms a shooting system eccentric with respect to the target 200, with respect to the optical axis O of the optical system 100, and with respect to the portion common optical paths 116 and 126 (common portion aligned with the target). In other words, the optical path of the shooting system aligned with the target 200 is substantially perpendicular to the reference face 212.

In particular, as illustrated in Figures 6 and 8, the first shooting system 210 is turned towards the useful face 202 of the target 200, namely that the first shooting system 210 is oriented perpendicular to the useful 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 perpendicular to the useful face 202 (and therefore to the reference face 212) of the target 200. In this configuration, as seen in FIGS. 6 and 8, the optical axis O and the common portion of the optical paths 116 and 126 are parallel to the main direction Z, and are orthogonal to the transverse directions X and Y, as well as to the plane X, Y.

[0076] In one embodiment, the focal length of the second image capture system 120 is greater than the focal length of the first image capture system 110. For example, the difference between the focal length of the second capture system 120 and the focal length of the first image capture system 110 is between 0.5 and 5 millimeters.

In one embodiment, the magnification of the first imaging system 110 is less than or equal to the magnification of the second imaging system 120. For example, the magnification of the first imaging system 110 is between 0.2 and 1 times the magnification of the second image capture system 120. For example, the magnification of the first image capture system 110 is between 0.3 and 0.8, or else between 0.4 and 0.6, preferably around 0.5 times the magnification of the second shooting system 120.

In the embodiment of Figures 6 and 8, the optical system 100 further comprises the aforementioned light source 140 in relation to Figures 1 and 4, oriented in the direction of the tool holder 310 and adapted to be oriented in direction of the three-dimensional target 200, this light source 140 being arranged so as to be able to constitute a lateral illumination of the three-dimensional target 200. For this purpose, this light source 140 is arranged eccentrically and inclined with respect to the path optics 116 + 126 of the optical system 100. In particular, the light rays of the light source 140 form with the reference face 212 of the target an angle such as their specular reflection on the surfaces

reflective of the target, and in particular on the localized areas 217, generates reflected light rays which do not penetrate into the optical system 100. Likewise, when the inclined face 222 comprises specular elements 225, the reflection of the light rays from the source light 140 on these specular elements 225 does not penetrate the optical system 100.

According to one embodiment, the first shooting system 210 used and the second shooting system 220 used are

telecentrics. As a reminder, telecentricity is a characteristic of an optical system in which all the main rays (the central ray of each beam of rays) which pass through the system are

practically collimated and parallel to the optical axis. In the case of telecentric optics, the concept of depth of field is replaced by that of working distance. According to another embodiment, the first camera system 210 used and the second camera system 220 used are not or not both telecentric. In the case where they are both telecentric, they can also be used to measure the geometric characteristics of the tools arranged on the tool holder 310 as already described previously or in the remainder of this text. In one embodiment, the machining module 300 comprises the target 200 described above, which is mounted on the tool holder 310 (see FIG. 1). This target 200 comprises the useful face 202 which forms a positioning reference capable of being placed in the optical axis O of the optical system 100 when the tool holder is in a predetermined angular position around its axis X (after rotation according to the arrow R of Figure 1) and in a predetermined axial position along its X axis (see Figures 6, 7 and 8), forming a referencing position of the tool holder 310 relative to the workpiece support 320. In this position of referencing, the target 200 is arranged so that the image focal plane of the optical system 100 can be coincident with the useful face 202 of the target. In particular, but in a nonlimiting manner, in this referencing position, the target 200 is arranged so that the image focal plane F1 of the first shooting system 110 of the optical system 100 can be merged with the useful face 202 of the image. target (see FIG. 12), and so that the image focal plane F2 of the second image capture system is able to intersect with the inclined face 222 of the target 200 (the focal length of the second image capture system 120 ) is able to place the image focal point F2 of the second shooting system 120 on the second structure 220 of the target 200).

Referring now to Figures 1 and 6 to expose the three-dimensional optical measurement method between the target 200 and the optical system 100, in the case of a machine tool whose machining module 300 comprises an optical device 10. We take as reference directions X, Y and Z those of the machine tool, in particular the frame of the machine tool, which gives a vertical direction X (or first transverse axis), a main horizontal direction Z ( or main axis) and a lateral horizontal direction Y (or second transverse axis). The target 200 is placed on the tool holder 310 (see FIG. 5): the tool holder 310 extends in a main horizontal direction, corresponding to the X axis, with the possibility of rotating around this X axis. to this end, part of the tool holder 310, for example the collet, has housings on its

periphery, usually dedicated to the assembly of the

tightening / loosening of the clamp, in which we can put the target 200, possibly associated with an RFID chip as described above.

Furthermore, the optical system 100 is mounted on the workpiece support 320 (see FIG. 1) and receiving the workpiece 322. The workpiece support 320 extends in its main horizontal direction, corresponding to the Z axis, with the possibility of rotating around this Z axis. Then, the workpiece support 320 and the tool holder 310 are placed in a close position, prior to a machining step, placing the tool 312 and the workpiece 322 nearby from each other, in a relative measuring position. The positioning of the target 200 on the tool holder 310 and the positioning of the optical system 100 on the workpiece support 320 allow that in this relative measurement position, the target 200, and more precisely the reference face 202, can be placed in the extension of the optical axis O of the optical system 100 (note that this optical axis O is parallel to the direction Z). Thus, the reference face 202 of the target 200 is turned towards the input face 102 of the optical system 100.

As in the case shown in Figure 1, the optical device 10 further comprises a third shooting system 130 disposed on the tool holder 310 and configured to identify the orientation of the useful face 202 of the target 200 and / or the angular orientation of the rotating part of the tool holder 310, in particular around the X axis. An additional preliminary step of positioning the target 200 is carried out before the step of simultaneous shooting. with said optical system 100, according to which:

the tool holder 310 and the workpiece support 320 are placed so that the useful face 202 of the three-dimensional target 200 is located in the optical path O of the optical system 100. In particular, the third taking system can be used. view 130 to identify the angular orientation of the target 200 with respect to the rotating part of the tool holder 310, therefore with respect to the X axis, which makes it possible to modify, if necessary, the angular orientation of the rotating part of the tool holder 310 (see arrow R in FIG. 6), and thus place the target 200 so that its useful face 202 is turned in the direction of the optical system 100. The relative measuring position is obtained in which when the target 200 is oriented towards the optical system 100 as explained previously in the case of FIGS. 6 and 8: in this case, the Z direction extends between the target 200 and the optical system 100.

In one embodiment, the optical device 10 further comprises a third imaging system 130 disposed on the tool holder 310 and configured to locate the angular orientation of the tool holder 310 around its X axis. in the presence of a target 200, this third imaging system 130 also or only makes it possible to identify the orientation of the useful face 202 of the target 200 around the X axis of the tool holder 310.

When the optical device 10 is used for the first time, namely the optical system 100 and an associated target 200, respectively mounted on a workpiece support 320 and on a tool holder, an additional, prior step must be carried out , spatial referencing of the position of the target 200 relative to the tool holder 310 which carries the target 200 in the three directions X, Y and Z. It should be noted that we obviously know the parameters of the optical system 100, to namely the first image capture system 110 and the second image capture system, including their focal length. At this stage, it may be mentioned that when the working space of the machining module 300 is confined and maintained at a constant temperature, this thermal stability generates dimensional stability for the optical device 10 and therefore of its parameters.

It is recalled that the measurement of the relative position

three-dimensional between the target 200 and the optical system 100 is used in the case of a machine tool to ultimately know the relative three-dimensional position in X, Y and Z between the tool holder 310 and the workpiece support 320.

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

During this step of spatial referencing of the position in the three directions X, Y and Z of the target 200 (calibration of the optical device 10), for example with the arrangement of FIGS. 6 and 9, a socket is activated view by the optical system 100, which generates on the one hand the

generation by the first image acquisition system 112 of the first image capture system 110 of a first image of the entire useful face 202 of the target 200 with the entire reference face 212 which is clear and on the other hand the generation by the second image acquisition system 122 of the second image capture system 120 of a second image of the entire inclined face 222 of the target 200 with only a clear area in the form of a horizontal strip. This first image comprises the image of the localized zones 217, here delimiting a square (see figure 10), so that the processing of the first image generates the diagonals C1 and C2 of the square and makes it possible to identify the center C3 of the square . Thus, since the position of the optical axis O on the first image is known, the

determination of the position of the center C3 of the square makes it possible to know the position in X and in Y of the target 200 with respect to the optical axis O, but also on the one hand with respect to a reference mark 314 in the X direction on the door tool 310 and on the other hand with respect to a mark 316 in the Y direction on the tool holder 310. Indeed, as can be seen in FIGS. 6 and 9, a face of the tool holder is used as an X reference. 310 which is orthogonal to the X axis, for example resulting from a shoulder re-entering along a section of the tool holder 310, visible as a line in the first image and forms said reference mark 314 in the X direction (see FIG. 9 ). In addition, as seen in Figures 6 and 9, a dimension of the tool holder 310 close to the target 200, which is

orthogonal to the X axis, and in the case shown which is the width (parallel to the Y direction) of the tool holder 310 close to the target 200, for example the diameter when this portion of the tool holder 310 is cylindrical by circular section; this dimension forms said mark 316 in the Y direction (see FIG. 9).

In parallel, the processing of the second image is carried out, an example of which is visible in FIG. 15A. By analyzing the local contrast of this second image (see FIG. 15B showing contrast curves as a function of the position in X), the position X0 in the vertical direction X of the sharp zone of the second image is determined. This analysis is carried out via an algorithm making it possible to determine the sharpest pixels of the image. As the inclination of the inclined face 222 is known, there is a correspondence curve between X and Z of this inclined face 222, specific to the target 200. Thanks to this correspondence curve, knowledge of the position X0 ( see FIG. 15A and 15B) makes it possible to deduce therefrom the position Z0 of the inclined face 222 on the optical axis O, and therefore the position in Z of the target 200 with respect to the optical system 100. Furthermore, the relative position in Z of the optical system 100 with respect to the workpiece support 320 is known by a measuring ruler (not

shown) arranged along the Z axis on the workpiece support 320 and which supports the optical system 100. Likewise, the relative position in Z of the target 200 with respect to the reference mark 314 of the tool holder 310 is known.

By performing this operation multiple times, each time modifying the Z distance of the workpiece support 310 relative to the tool holder 320 (for example by moving back or by advancing the workpiece support 310), it is thus possible to reconstitute the three-dimensional image of the inclined face 222 of the target 200, and have a reference base forming a map for the three-dimensional coordinates of the inclined face 222 of the target 200 with respect to the tool holder 310. Finally, c 'is the entire useful face 202 of the target 200 (reference face 212 and inclined face 222) which is spatially referenced in the three directions X, Y and Z with respect to the tool holder 310.

Then, the actual measurement can be carried out whenever necessary during the operations of using the machining module. 300 equipped with this target 200 and this optical system 100, not disassembled in the meantime in order to maintain the precision of the measurement of the spatial referencing described above. For this purpose, one is for example with the arrangement of FIG. 6. One carries out, if necessary, a rotation of the workpiece support 320 around its axis of rotation which is parallel to the axis X (see arrow R in FIG. 1), in order to align the target 200 with the optical system 100. Then, a shooting is activated by the optical system 100, which generates on the one hand the generation by the first image acquisition system 112 of the first shooting system 110 of a first image of the entire useful face 202 of the target 200 with the entire reference face 212 which is clear and, on the other hand, the generation by the second acquisition system of images 122 of the second imaging system 120 of a second image of the entire tilted face 222 of the target 200 with only a sharp area as a horizontal stripe

corresponding to the focal length of the second image capture system 120. The analysis of this first image allows, as explained

previously, to identify the center C3 of the square formed by the localized elements 217, and thus the position in X and in Y of the target 200 with respect to the optical axis O, and also with respect to the tool holder 310. L ' analysis of the second image and in particular of the position of the sharp zone of the second image (as in Figure 6) along the direction X makes it possible to know the position in Z, therefore the distance, of the target 200 with respect to the system optical 100. Indeed, for the second image, as we know the Z position of each pixel of the image of the inclined face 222 relative to the references 314 and 316 on the tool holder 310, it is possible to measure very quickly the Z position of the target 200 and therefore of the tool holder 310.

It is understood from the above that in this way, we measure very quickly, only by analyzing the two images generated by the optical system 100, and without wasting time that would require an adjustment or a focusing of this. optical system 100, the position in X, Y and Z of the target 200 relative to the optical system 100 and starting from the tool holder 310 relative to the workpiece support 320. This is possible because we know the position in X, Y and Z of the optical system 100 with respect to the part support 320 which supports it. We can do this referencing of the center material (workpiece support 320) with respect to the tool holder 310 for example by mounting a probe on the tool holder 310 then in a first referencing step in the X direction come into contact with the point of the probe on the optical system 100 d 'on the one hand and on the material support 320 on the other hand, which gives the difference in the X direction between the optical system 100 and the optical system 100. By carrying out these probing steps again after placing the axis of the tool holder 310 parallel to the Z axis of the workpiece holder, the deviation in the Z direction between the optical system 100 and the optical system 100 can be obtained.

In the event of thermal drift, for example expansion of the different parts of the machining module, this measurement procedure makes it possible to overcome the effect of thermal expansion.

This procedure can be used for determining the position or the profile of the end portion 313 of the tool 312 mounted on the tool holder 310 by the optical system 100, as explained below. We proceed according to the above explanations in relation to the

spatial referencing of the position in the three directions X, Y and Z of the target 200 relative to the optical system 100, with the difference of placing no longer the target 200 but the end portion 313 of the tool 312 in the optical axis O of the optical system (see Figures 4 and 16). In this case, it will be understood that during the activation of the detection unit 304, both the first image capture system 110 and the second image capture system 120 which are both used (in particular from simultaneously) and therefore it is both the first image acquisition system 112 and the second image acquisition system 112 which generate one (or more) image (s) of the end portion 313 of tool 312.

In fact, in this measuring position, the end portion 313 is arranged so that the image focal plane F1 of the first imaging system 110 of the optical system 100 can be merged with a portion of the surface of the portion d. 'end 313, and so that the image focal plane F2 of the second imaging system is adapted to intersect with a portion of the surface of the end portion 313: thus, the focal length of the second imaging system. view 120 is suitable for placing the image focus F2 of the second shooting system 120 on a portion of the surface of the end portion 313.

Thus, it is understood that the image taken by the second shooting system 120 allows the clear zone to have precise information on the distance along the Z axis from the position of the end portion 313 of the tool 312 with respect to the optical system 100 (and therefore of the workpiece support 320) and the image taken by the first imaging system 110 is an image of the entire visible face of the end portion 313 of tool 212 with all or a large part of this image being sharp. This image of the end portion 313 taken by the first image capture system 110 makes it possible to provide a map of this portion.

end 313 of the tool 212, including viewing the line of the edge of this end portion 313 of the tool 212 seen in projection along the Z axis and forming the profile or part of the profile of this portion of end 313.

Thus, according to a third possibility concerning the method for detecting the profile of the tool 312, as presented above, during the activation of the detection unit 304, it is (at least the and in some case only) the first image capture system 110 which is used and therefore it is the first image acquisition system 112 which generates one (or more) image (s) of the end portion 313 of the tool 312.

The analysis of this image makes it possible to detect the edge of the tool as seen by the first imaging system 110. This is the edge, namely the contour, of the end portion 312 of the tool 312, seen in projection in the plane (X, Y) orthogonal to the direction Z, itself parallel to the optical axis O of the optical system. Thus, the shape (in this case the line) of this edge of the tool 312 resulting from the image taken by the first imaging system 110 provides information on the geometry of the end portion 313 of the tool. 312 mounted on the tool holder 31 at the time of shooting. This image also makes it possible to identify the cutting edge (s) (in projection) as it (s) is (are) seen by the first shooting system 110. This registration is both in position, especially with respect to the edge, than in geometry (shape on the image of the line corresponding to the cutting edge). It is understood that these shooting operations of the end portion 313 of the tool can be repeated several times after a rotation along the X axis of the tool holder 310, in particular a rotation of a few degrees or 10 at 20 °, to have different shots of the end portion 313 from the optical system 100, at different angles. All these images allow a three-dimensional reconstruction of the shape (of the profile) of the end portion 313 of the tool 312.

Also, in one embodiment of the invention, there is provided a method for detecting the wear of a tool 312 in a machine tool, in which the method for detecting the profile is implemented. of the tool as described above (according to one or other of the implementation possibilities described above), which generates information (including at least one image) representative of the profile of the end portion 313 of the tool in a first state, and which further comprises the following steps:

vi) performing machining steps with said tool 312, whereby a tool 312 is obtained with an end portion 313 of the tool having a modified profile (second state or new profile), and

vii) positioning the tool holder 310 relative to the workpiece support 310 in said operational measurement position (for example according to the configuration of FIG. 4),

viii) activation of said detection unit 304, and

ix) determination, via the optical system 100, of the modified profile of said end portion 313 of the tool 312 mounted in the tool holder 310 (for example for checking the position and / or orientation of the cutting profile, or for example to check the nature of the cutting tool and therefore that it is the category of cutting tool required for the upcoming machining operation), and

x) establishing a state of wear of the tool, from the profile and the modified profile of said end portion 313 of the tool.

Thus, in this case, the comparison of the information related to the image (or to the images) of the end portion 313 of the tool in its first state and in its second state, makes it possible to determine, follow and to qualify tool wear, including rate of wear, type of wear, speed of wear. This procedure makes it possible, for example, to construct a wear curve as the image is taken in parallel with the use of the tool, in particular for a first tool of a series of identical tools. With each new tool in this series of identical tools, we can redo the wear curve from the information linked to the images taken, or adapt the wear curve already established in order to form a wear chart for this type of wear. 'tools. In this way, when using the ^nth tool of this series of identical tools, it is possible to take less frequent images and all the same by comparison with the wear curves or the wear chart. previously obtained, see the trend and therefore anticipate the wear to come with this tool, which makes it possible, on the one hand, to modify the settings of the machine tool accordingly for new parts manufactured with this tool or for the new machining passes still to be made with the current part and on the other hand anticipating / deciding whether or not to change the tool for the next part.

This is also used to qualify the good (bad) state of the tool by checking and validating (or invalidating) that after the machining steps implemented, the tool having the modified profile has a new geometry which always corresponds to that required by the specifications.

Furthermore, the implementation of such a method for detecting the wear of the tool 312 also makes it possible in particular to know

the angular orientation of the tool 312 with its modified profile, relative to the X axis of the tool holder, and therefore relative to the workpiece support 312, in the operational measurement position, and also makes it possible to verify that the The tool 312 with its modified profile is in the desired orientation relative to the workpiece support 310 in the operational measurement position. Also, the implementation of such a method for detecting the wear of the tool 312 makes it possible to establish the profile and to verify that the tool 312 mounted on the tool holder corresponds to the expected tool (the detected profile corresponds to the expected and predetermined profile), and thus makes it possible to avoid mounting a tool in an inadequate state on the tool holder 310. In one embodiment, there is provided a machine tool equipped with a machining module as described in particular, this machine tool also comprises a unit for monitoring the wear of the tool 306 (FIG. 1 ) which is capable of calculating the deviation of the profile of the tool from the information supplied by said unit 304 for detecting the profile of the tool 312. In particular, in this machine tool, said unit for monitoring the wear of the tool 306 allows, when said deviation of the profile of the end portion 313 of the tool 312 exceeds a deviation

predetermined, that the modified profile (new profile) of said end portion 313 of the tool 312 mounted on the tool holder 310, detected by said detection unit 304, is used to recalculate the machining parameters. These machining parameters include in particular information for the movement of the tool holder 310, which is transmitted to said control unit of the tool holder 302. In particular, if this deviation of the profile exceeds a threshold deviation then the information related to the new one. tool profile are used to recalculate machining parameters including modified information for the movement of the tool holder 310, which is transmitted to said tool holder control unit 302. Thus, said holder control unit tool 302 receives this modified information, which makes it possible to adapt the machining steps according to the measurement of the profile of the tool by the detection unit 304.

The previous descriptions and explanations have been given for an embodiment of the machining module 300 with a tool holder 310 extending along the X axis which is horizontal, with a Y axis of the machining module 300 which is vertical, with a tool 312 rotating about an axis parallel to the X axis, and a tool holder 310 mobile along the X axis. According to another embodiment visible in FIG. 17, it is implemented according to the invention a machining module 300 with a tool holder 310 extending along the X axis which is vertical with a Y axis of the machining module 300 which is horizontal, still with a tool 312 rotating around a axis parallel to the X axis, and a tool holder 310 mobile along the X axis. According to another embodiment visible in FIGS. 18 and 19, a machining module 300 is implemented according to the invention with a tool holder 310 'carrying a series of tools 312, 312', 312 ", 312 '" parallel to each other and aligned in the Y direction (vertical). Each tool 312, 312 ', 312 ", 312"' of the series of tools extends along the X axis which is horizontal, each tool 312, 312 ', 312 ", 312'" being rotary (arrow A) around an axis parallel to the X axis via a rotating part of the tool holder 310 '(for example a spindle) which carries one of the tools 312, 312', 312 ", 312 '"; the tool holder 310 ′ being movable in translation along the X axis and along the Y axis, and preferably also in rotation about the vertical Y axis (arrow B). This embodiment makes it possible to continue machining by passing from one to the other of the tools 312, 312 ', 312 ", 312'". In this case, the tool holder 310 ′ is equipped with more than one (at least one) target 200, possibly associated with an RFID chip as explained above. In the case shown in Figure 18, two targets 200 are arranged on the rear part of the tool holder 310 'which is not rotatable about an axis parallel to the X axis. shown) one target 200 per tool 312, 312 ', 312 ", 312'" at the rotating part of the tool holder 310 '(for example a spindle) which carries one of the tools 312, 312', 312 ", 312 '".

Reference numbers used in figures

X Vertical direction (first transverse axis)

Y Lateral horizontal direction (second transverse axis)

Z Main horizontal direction (Main axis)

C1 Diagonal

C2 Diagonal

C3 Center

a Angle of the inclined face

R Arrow for toolholder and target rotation

10 Optical device

100 Optical system

O Optical axis

102 Entrance face of optical system

104 Front ring light source

106 Rear light source

110 First shooting system

DOF1 Depth of field of the first shooting system

F1 Image focal plane of the first imaging system

112 First image acquisition system

116 Optical path of the first imaging system

120 Second camera system

F2 Image focal plane of the second imaging system

DOF2 Depth of field of the second camera system

122 Second image acquisition system

126 Optical path of the second imaging system

128 Optical module with catoptric optical system

129 Mirror

130 Third camera system

140 Light source (side illumination)

200 Three-dimensional target

202 Useful side

210 First structure

212 Reference face First portion (reflective surface according to diffuse reflection)

Second portion (reflective surface according to specular reflection)

Localized areas

Opening

Housing

Second structure

Inclined face

Relief elements

Specular elements

Transparent protection plate

bottom wall

Platinum

Reflective layer

Cylindrical wall

Machining module

Tool holder control unit

Tool profile detection unit

Tool wear monitoring unit

Workpiece support control unit

Toolbox

'' Multi-spindle tool holder

Tool

'Tool

”Tool

'”Tool

Tool end portion

a Wear zone

X mark on the tool holder

Y-mark on the tool holder

Workpiece support or material spindle

Workpiece (material)

Claims

1. Machining module (300) by removing material for a machine tool comprising:

- a workpiece support (320) intended to receive a workpiece (322), - a workpiece support control unit (308) capable of controlling and modifying the position of the workpiece support (320) in the module d 'machining (300),

- a tool holder (310) intended to receive a tool (312) having an end portion (313) useful for machining the part mounted on the part support;

- a tool holder control unit (302) capable of controlling and modifying the position of the tool holder (310) in the machining module (300),

- a unit for detecting the profile (304) of the tool (312) mounted on the tool holder, said detection unit (304) comprising an optical system (100) making it possible to determine the profile of said end portion ( 313) of the tool (312) mounted on the tool holder (302), wherein said optical system (100) is mounted on the workpiece holder (320).

2. A machining module (300) according to claim 1, wherein said optical system (100) is configured to enable said profile to be detected when the tool holder (310) is in an operational measurement position.

3. A machining module (300) according to claim 2, wherein said optical system (100) comprises a first image pickup system (110) which is configured so that its image focal plane is adapted to intersect with the image. end portion of the tool (322) in said position

operational measurement.

4. Machining module (300) according to one of claims 1 to 3, wherein said optical system (100) comprises an optical axis (O) orthogonal to the direction of the X axis of the tool holder (310).

5. Machining module (300) according to one of claims 1 to 4, wherein the optical system (100) belongs to an optical device (10) for measuring which is configured to allow, by a single shooting step by the optical system (100) to determine the relative position

three-dimensional between the workpiece support (320) and the tool holder (310).

The machining module (300) according to claim 5, wherein said optical measuring device (10) is configured to further enable, by a single step of taking a picture of the end portion of the tool (322). ) mounted on the tool holder (310) by the optical system (100) to determine the profile of the end portion of the tool (312) mounted on the tool holder (310).

7. Machining module (300) according to one of claims 5 and 6, wherein said optical device (10) for measurement further comprises a front light source (104) oriented parallel to the optical axis (O). from the optical system (100) and towards the tool holder (310).

8. The machining module (300) according to one of claims 5 to 7, wherein said optical device (10) for measurement further comprises a rear light source (106) oriented towards the optical system (100).

9. Machining module (300) according to one of claims 1 to 8, wherein said machining module (300) further comprises a target (200)

belonging to the optical device (10), said target being mounted on the tool holder (310) and comprising a useful face (202) forming a positioning reference able to be placed in the optical axis (O) of the optical system (100) ) when the tool holder is in a predetermined angular position around its axis (X) and in an axial position

predetermined along its axis (X), forming a position of

referencing of the tool holder (310) relative to the workpiece support (320).

10. The machining module (300) according to claim 9, wherein the target (200) is a three-dimensional target (200) comprising on a useful face (202):

* a first structure (210) defining a plane reference face (212), and

* a second structure (220) having an inclined face (222) relative to said flat reference face (212),

and wherein said optical system (100) comprises a first imaging system (110) and a second imaging system (120), wherein the difference between the focal length of the second imaging system (120) and the focal length of the first camera system (110) is between the minimum distance and the maximum distance separating the reference face (212) from the inclined face (222).

11. Machining module (300) according to one of claims 9 and 10, wherein said optical device (10) for measuring further comprises a light source (140) oriented in the direction of the tool holder (310), said light source (140) being arranged so as to be able to constitute a lateral illumination of the three-dimensional target (200).

12. Machining module (300) according to one of claims 1 to 11, wherein the optical system (100) comprises a first shooting system (110) and a second shooting system (120), in which :

- the depth of field of the first imaging system (110) is at least 10 times greater than the depth of field of the second imaging system (120), and in which

- the optical system (100) is arranged so that the optical path of the first imaging system (110) and the optical path of the second imaging system (120) have a common section placed on the optical axis ( O) of the optical system (100) and comprising the image focal plane of the first imaging system (110) and the image focal plane of the second imaging system (120).

13. Machining module (300) according to claims 10 and 12, wherein;

- the first imaging system (110) is configured so that its image focal plane is able to correspond to the reference face (212) of the first structure (210), and

- the second shooting system (120) is configured so that its image focal plane is able to intersect with the inclined face (222) of the three-dimensional target (200).

14. Machining module (300) according to one of claims 1 to 13, wherein the optical device (10) further comprises a third imaging system (130) arranged on the tool holder (310) and configured. to mark the angular orientation of the tool holder (310) around its axis (X).

15. Machine tool comprising a machining module (300) according to one of claims 1 to 14, said machine tool further comprising a tool wear monitoring unit (306) which is capable of calculating the deviation of the tool profile from the information provided by said detection unit (304).

16. Machine tool according to the preceding claim, wherein said tool wear monitoring unit (306) allows, when said deviation of the profile of the tool exceeds a predetermined deviation, that the modified profile of said portion. end of the tool (312) mounted on the tool holder (3s10), detected by said detection unit (304), is used to recalculate the machining parameters, said machining parameters comprising information for the movement of the tool holder (310), which are transmitted to said tool holder control unit (302).

17. Method for detecting the position of a tool (312) mounted on a tool holder (310) in a machining module (300) comprising a workpiece support (320) and a tool holder (310), comprising the following steps:

i) providing a detection unit (304) in the machining module (300), said detection unit (304) comprising an optical system (100) for determining the profile of said end portion (313) of the tool (312) mounted on the tool holder (310), wherein said optical system (100) is mounted on the workpiece holder (320),

ii) loading the tool (312) into the tool holder (310),

iii) positioning of the tool holder (310) relative to the workpiece support (320) in an operational measurement position,

iv) activation of said detection unit (304), and

v) determination, via the optical system (100), of the position of the tool (312) in the machining module (300).

18. Method of detecting the profile of a tool (312) mounted on a tool holder (310), in a machining module (300) comprising a workpiece support (320) and a tool holder (310), comprising the following steps:

ii) loading the tool (312) into the tool holder (310),

iv) activation of said detection unit (304), and

v) determining, via the optical system (100), the profile of said end portion (313) of the tool (312) mounted in the tool holder (310).

19. Method for detecting the wear of a tool in a machine tool, in which the method for detecting the profile of the tool according to claim 18 is implemented, and which further comprises the following steps:

vi) performing machining steps with said tool (312), whereby a tool (312) is obtained with an end portion (313) having a modified profile, and

vii) positioning the tool holder (310) relative to the workpiece support (320) in said operational measuring position,

viii) activation of said detection unit (304), and

ix) determining the modified profile of said end portion (313) of the tool (312) mounted in the tool holder (310), and x) establishing a state of wear of the tool, from the profile and the modified profile of said end portion (313) of the tool.