System and methods for measuring the profile of a part.

Abstract

The invention relates to a system (100) and several methods for measuring the internal and external profile of a part (50). According to the invention, the measuring system (100) comprises: – a sensor (110) having a probe and a first reference element (130) attached to the probe, said probe and said first reference element (130) having at least one degree of freedom, said sensor (110) being arranged so that said probe is able to follow the internal or external contour of the part (50) while the first reference element (130) is outside the part (50), and – a imaging device (160) able to take an image representing at least a portion of the outside of the part (50) and the first reference element (130) and able to determine the position of the first reference element (130).

Description

technical field

[0001] The present invention relates to the field of measuring the dimensions of an object or part. In particular, the present invention relates to the field of determining the dimensions of an object or part using a sensor (touch or non-touch).

[0002] This type of measurement is used in many fields applying dimensional metrology, including, but not limited to, the machining of parts, particularly by machine tool or any other machining process involving material removal, but also for additive manufacturing. This measurement is also particularly useful for wear control or during maintenance operations.

[0003] In the field of machine tools, there is a need to know precisely the dimensions and / or profile of a part, in order to ensure a machining range conforms to the machining plan developed during the development phase. State of the art

[0004] Various systems for measuring the coordinates of an object in an opto-tactile manner have been proposed, in particular systems comprising a flexible probe.

[0005] Document US2005259271A uses a scanner in the form of a probing head mounted on a flexible probe extension. A first optical system forming a single unit with the scanner detects the position of the probing head in an x, y plane, while a second, independent optical system detects the position of the probing head in the z direction.

[0006] Documents US2016370172A and US2005000102A describe coordinate measuring systems comprising a probing head whose position is tracked by an optical sensor mounted coaxially with the probe. In document US2016370172A, the probe is provided with a flexible extension with a contact element that deviates upon contact with the workpiece and bears a reference mark located in the vertical alignment of the tactile portion of the probe. In document US2005000102A, the coordinate measuring instrument comprises a probing head mounted on an extension and whose position is identified by an optical system whose optical axis is aligned with the probing head.

[0007] In these solutions, it is not possible or not always possible to measure the displacement of the probe head in the three directions of space, in particular if the probe head is hidden, especially in a recess or bore of the part.

[0008] US patent 2009144999A describes a probe for measuring the internal contour of a hollow part. This probe comprises a bar whose lower end carries a probing head that contacts the surface to be measured, and whose upper end emerges from the part and carries a target whose position is located by an optical sensor, in particular a laser sensor. The bar is made movable by mounting it on a spherical joint that also provides one degree of translational freedom. This arrangement requires a support for the spherical joint, which is mounted on the part to be measured, resulting in additional handling. Furthermore, calibrating the probe requires precise and reproducible mounting of the probe / support on the part to be measured.

[0009] Prior art solutions rely on measurements taken with respect to reference points external to the part and the measuring system; that is, intermediate measurements with respect to precision axes are involved in the measurement procedure. This adds steps to the measurement process and leads to the accumulation of uncertainties, or even measurement errors, resulting in a final measurement that is not as precise as desired.

[0010] These solutions therefore do not allow for a device that is quick to set up and use, and above all one that allows for easy measurement of the profile, in particular the internal profile, of an object or part, and in particular of a hollow part.

[0011] Moreover, these solutions are not always sufficiently accurate for certain applications. Brief summary of the invention

[0012] An object of the present invention is to propose a measurement technology enabling a measurement of the profile, and in particular the internal profile of an object or part, free from the limitations of known measurement techniques.

[0013] Another object of the invention is to propose a technology enabling measurement of the profile, and in particular the internal profile of an object or part, which provides a very precise measurement of the portions of a part.

[0014] Another object of the invention is to provide a technology for measuring the profile, and in particular the internal profile of an object or part, in a minimum of measurement steps.

[0015] According to the invention, these objectives are achieved in particular by means of a system for measuring an external profile of a part or an internal profile of a hollow part, comprising: <tb> – <sep>a sensor with a probe having at least one degree of freedom, and a first reference element fixed to the probe, said sensor being arranged so that said probe is able to follow the internal or external contour of the part while the first reference element is outside the part, the probe and <tb> – <sep>a camera capture device capable of taking an image representing at least a portion of the outside of the room and the first reference element.

[0016] This solution has the particular advantage over the prior art of not requiring direct identification of the position of the probe or of a probing head which would be in contact with the profile of the part since it is the first reference element, remaining in all cases outside the part during the measurement, which is able to reproduce the displacement of the probe and which serves as a reference element for determining the position of the point of contact between the face of the part and the probe.

[0017] This occurs firstly when determining the external profile of a part or the internal profile of a hollow part, whether the hollow part is a through opening or a blind hole. Secondly, when determining the internal profile of a part, thanks to the spatial offset between the probe and the first reference element, the probe can be left inside the part, in a hollow portion, while keeping the first reference element outside the part. This allows continued access (for example, optically or by contact) to the first reference element and thus greatly facilitates determining the probe's position by determining the position of the first reference element.

[0018] The probe thus has at least one degree of freedom relative to the part, when the measuring system is stationary, in the position for measuring the profile of a part, and during the movement of the part relative to the measuring system. This possibility of movement of the probe relative to the rest of the measuring system allows it to follow the contour (internal or external profile) of the part to be inspected.

[0019] It is understood that the imaging device has an optical field (or field of view) such that it allows one to see, and therefore to capture, an image comprising both a portion of the exterior of the part and the first reference element. In this way, the acquisition of successive images during the movement of the part relative to the measuring system makes it possible to see, by observing the movement of the first reference element within the field of view, the profile corresponding to this path of the first reference element.

[0020] According to one arrangement, the measuring system further comprises a base and a guiding system connecting the sensor to the base. In this way, controlled movement of the sensor relative to the rest of the measuring system is obtained when the sensor is in a measuring position relative to a workpiece.

[0021] According to one possible arrangement, the guidance system allows a single degree of freedom between the sensor and the base. Thus, a simple measuring system is provided, capable of tracking the variation of the workpiece contour in a direction permitted by the degree of freedom, which is suitable and sufficient in a large number of cases.

[0022] According to another arrangement, said measuring system further comprises a second reference element fixed to the base, said second reference element being positioned so that the imaging device is able to simultaneously view said first reference element, said second reference element, and said portion of the exterior of the part. This arrangement provides, together with the second reference element, a stationary element of the measuring system, serving as a fixed reference frame relative to which the movements of the first reference element, and consequently the movements of the probe, can be visualized (via the imaging device), particularly in at least one direction permitted by the guidance system.

[0023] According to a first embodiment of the invention, the probe is a sensing head capable of following and detecting the internal or external contour of the part by contact. Such a sensing head physically follows the contour of the part to be measured, and in particular the internal contour, which is therefore hidden, during the measurement of the internal contour.

[0024] According to a second embodiment of the invention, the probe is a sensing head capable of tracking and detecting the internal or external contour of the part without contact. For example, but not limited to, it is a probe operating optically, or for example a proximity sensor, or even an electromagnetic or acoustic sensor.

[0025] According to one arrangement, the imaging device comprises a camera and a light source capable of simultaneously illuminating said portion of the exterior of the room and the first reference element. This arrangement allows, in particular when the probe is located in a hollow room and the first reference element is located outside the room, the camera to provide a sufficiently contrasted image.

[0026] According to one arrangement, the camera has a field of view allowing the said portion of the exterior of the room and the first reference element to be seen. This arrangement allows, in particular when the probe is located in a hollow room and the first reference element is located outside the room, the camera to provide an image of the portion of the exterior of the room and the first reference element.

[0027] According to one arrangement, the guidance system includes return means enabling the sensor to return to a rest position relative to the base when the probe is no longer interacting with the internal or external contour of the workpiece. Thus, during interaction between the probe and the workpiece contour, namely probing or contact with support when the probe is a probing head, effective interaction (in particular, effective contact) is ensured, guaranteeing that the probe, and therefore the first reference element, is positioned corresponding to the workpiece contour. If the interaction is non-contact, effective detection between the probe and the first reference element is ensured to allow measurement.Furthermore, when the measurement is performed, these return means allow the sensor, and therefore the probe, to return to a rest position, in which there is no stress (mechanical or otherwise) on the measurement system, particularly on the transmission chain (notably the kinematic chain) between the first reference element and the probe. These return means can take several forms, including, but not limited to, at least one or more of the following: a deformable and elastic element, a spring blade (flat, curved, spiral-shaped, or other), a helical spring, etc.

[0028] According to one arrangement, the guidance system comprises, between the sensor and the base, a sliding link or a tilting link, with mechanical elements, magnetic elements, hydraulic elements...

[0029] The invention also relates to a method for measuring the profile of a part, particularly with the part profile measurement or determination system as described herein. In particular, the invention relates to a method for measuring the internal profile of a part using a measurement system as described herein. According to one embodiment, the method for measuring the profile of a hollow part comprises the following steps: <tb> i) <sep>provision of a sensor with a probe and a first reference element attached to the probe, and a camera capture device, <tb>ii) <sep>supplying a part whose profile we wish to determine, <tb>iii) <sep>sensor placement so that the probe detects a point on the contour of the part while the first reference element is outside the part and within the field of view of the imaging device, iv) triggering the imaging system and forming an image representing at least a portion of the outside of the part and said reference element, <tb> v) <sep>The probe moves relative to the part in a manner that allows it to follow the contour of the part, while the first reference element remains outside the part, performing the same movement. <tb>we) <sep>perform steps iv) and v) for other points on the contour of the part.

[0030] The invention also relates to a method for measuring the external profile of a part, in particular using a measuring system as described herein. According to one possibility, the method for measuring the external profile of a part comprises the following steps: <tb> i) <sep>provision of a sensor with a probe and a first reference element attached to the probe, and a camera capture device, <tb>ii) <sep>supply of a part whose external profile we wish to determine, <tb>iii) <sep>sensor placement such that the probe is outside the part and detects a point on the external profile of the part, while the first reference element is also outside the part and within the field of view of the imaging device. <tb>iv) <sep>triggering the image capture system and forming an image representing at least a portion of the exterior of the room and said reference element, <tb> v) <sep>The probe moves relative to the part in a manner that allows it to follow the outer contour of the part, while the first reference element remains outside the part, performing the same movement. <tb>we) <sep>perform steps iv) and v) for other points on the outer contour of the part.

[0031] In general, the invention also relates to a method for measuring the profile, particularly internal or external, of a part. According to one embodiment, such a method for measuring the profile of a part comprises the following steps: <tb> <sep> <tb> i) <sep>provision of a sensor with a probe and a first reference element attached to the probe, and a camera capture device, <tb>ii) <sep>supplying a part whose profile we wish to determine, <tb>iii) <sep>sensor placement such that the probe detects a point on the contour of the part while the first reference element is outside the part and within the field of view of the imaging device, <tb>iv) <sep>triggering the image capture system and forming an image representing at least a portion of the exterior of the room and said reference element, <tb> v) <sep>The probe moves relative to the part in a manner that allows it to follow the contour of the part, while the first reference element remains outside the part, performing the same movement. <tb>we) <sep>perform steps iv) and v) for other points on the outline of the part.

[0032] According to one provision of either of these measurement methods, the following steps are further carried out: <tb> a) <sep>for each image formed by said shooting device, calculation of the relative position between the first reference element and the portion of the exterior of the room, and <tb> b) <sep>reconstruction of the profile (internal or external) of the part from the said relative positions of the first reference element successively calculated. Brief description of the figures

[0033] Examples of implementation of the invention are given in the description illustrated by the accompanying figures in which: <tb> <sep>Figure 1 illustrates in perspective a first embodiment of the measurement system according to the present invention, <tb> <sep>Figure 2 illustrates the partial cross-sectional view along direction II of Figure 1 of the measuring system according to the first embodiment of the present invention, <tb> <sep>Figures 3 to 5 illustrate, from the front, the different measurement steps with the measurement system shown in Figure 1. <tb> <sep>Figure 6 illustrates in cross-section and front view the principle of using the measurement system of Figure 1 to measure the internal profile of a part. <tb> <sep>Figure 7 illustrates in perspective and schematically the principle of a measurement method with the measurement system according to the first embodiment of the present invention of Figure 1, in the case of measuring the internal profile of a part, <tb> <sep>Figure 8 illustrates, from the front, a variant of the first embodiment of the measuring system according to the present invention. <tb> <sep>Figure 9 represents, in a more schematic front view, the variant of the first embodiment of the measurement system according to the present invention, illustrating the principle of the measurement carried out in the case of an internal part profile, <tb> <sep>Figures 10A and 10B show steps in the measurement process with the variant according to Figure 9 of the first embodiment of the measurement system according to the present invention, <tb> <sep>Figures 11 and 12 schematically represent the general principle of the measurement system according to the present invention, <tb> <sep>Figures 13A and 13B illustrate the measurement steps with a second embodiment of the measurement system according to the present invention, <tb> <sep>Figures 14A and 14B illustrate the measurement steps with a third embodiment of the measurement system according to the present invention, <tb> <sep>Figures 15A and 15B illustrate the measurement steps with a fourth embodiment of the measurement system according to the present invention, <tb> <sep>Figures 16 and 17A to 17F show respectively the image-taking device that can be used in the measurement system according to the invention and the possible processing or analysis steps of the image taken by the image-taking device during the implementation of the measurement method according to the present invention. Example(s) of an embodiment of the invention

[0034] Referring to Figure 1, a sensor 110 according to the present invention is shown in its rest position, without contact with a part to be measured. The sensor 110 comprises a base 112, here in the form of a rigid and virtually undeformable rectangular parallelepiped prism. The largest dimension of this base 112 defines the Y-axis, or measurement axis. Along this Y-axis, a first end 112a (on the right in Figures 1 to 7) and a second end 112b (on the left in Figures 1 to 7) are distinguished on this base 112.

[0035] Directly above the base 112, the sensor 110 includes a support portion 114 having a shape and dimensions close to those of the base 112. This support portion 114 is also rigid and virtually undeformable. Along this Y-axis, a first end 114a (on the right in Figures 1 to 7) and a second end 114b (on the left in Figures 1 to 7) are distinguished on this support portion 114.

[0036] A deformable and elastic guide system 140 connects the base 112 and the support portion 114 along a Z-axis, or principal axis of the sensor 110, this Z-axis being vertical in the figures and during measurement. The base 112 and the support portion 114 are aligned with each other along the Z-axis in the rest position of the sensor 110.

[0037] In alignment with the main axis Z of the sensor 110, the support portion 114 extends, from its side facing away from the base 112, by a probe 122 and by a rod of a first reference element 131. This probe 122 and this rod of a first reference element 131 are mounted by one of their free ends on the support portion 114. In the rest position, the probe 122 and the rod of a first reference element 131 are parallel to each other and to the main axis Z. The probe 122 and the rod of a first reference element 131 are separated (and equidistant) from each other along the measuring axis Y by a distance Y0 (see Figure 6). Thus, the probing rod 122 and the rod of a first reference element 131 define a plane (Y, Z).

[0038] Thus, in the rest position of the sensor 110, the direction orthogonal to the probing rods 122 and the first reference element 131, and passing through these two rods 122 and 131, is the measurement axis Y. A transverse axis X is defined which is orthogonal to the (Z, Y) plane and orthogonal to the probing rod 122 and to the rod of the first reference element 131. The X, Y, and Z axes define an orthogonal, preferably orthonormal, coordinate system. These rods 122 and 131 are, for example, metallic rods, particularly made of steel.

[0039] The free end (lower end in Figures 1 and 2 to 8) of the probe rod 122 terminates in a probe head 123 forming a probe 120 for the measuring system 100. This probe head 123 is for example made of metal, and in particular of the same metal or metal alloy as the probe rod 122. The probe head 123 is for example (see Figure 6) formed of a sphere with the axis of the probe rod 21 passing through the center of the sphere. In an alternative embodiment visible in figures 1, 3 to 5 and 7, the probing head 123 is formed of a portion of a sphere, in this case a hemisphere, mounted on the side of the free end of the probing rod 122, which is turned towards the rod of the first reference element 131: in other words, the axis of the hemisphere (probing head 123) is oriented along the Y axis.In all cases, the probe head 123 has a portion that protrudes from the probe rod 122, in the Y direction, and towards the rod of the first datum feature 131. That is to say, there is a portion of the probe head 123 that extends beyond the probe rod 122 along the Y axis, this protruding portion of the probe head 123 being oriented towards the datum rod 24 (datum head 25). In this way, as will be seen later, the probe head 123 can be brought into contact with a surface of a workpiece without the probe rod 122 also being in contact with the surface of the workpiece.

[0040] The free end (lower end in Figures 1 and 3 to 8) of the rod of the first reference element 131 terminates in a first reference element 130. This first reference element 130 is, for example, made of metal, and in particular of the same metal or metal alloy as the rod of the first reference element 131. The first reference element 130 is, for example (see Figures 1 to 7), formed of a sphere with the axis of the rod of the first reference element 131 passing through the center of the sphere.

[0041] Thus, in the embodiment shown in Figures 1 to 8, the probing head 123 is mounted on the free end of the probing rod 122, and the first datum element 130 is mounted on the free end of the rod of the first datum element 131. Also, in the embodiment shown in Figures 1 to 8, the probing rod 122 and the rod of the first datum element 131 are of the same length, or more precisely, extend the same length along the Z-axis from the support portion 114. In this way, the probing head 123 and the first datum element 130 are equidistant from the support portion 114 by the same distance Z0 (see Figure 6). In other words, the probing head 123 and the first datum element 130 are below and equidistant from the support portion 114.

[0042] To allow the displacement along the Y-axis of the probing head 123 to be transferred to the first reference element 130, the guide system 140, which connects the support portion 114 to the base 112, is deformable and elastic, at least along the Y-axis. Various embodiments are possible, including one or more elastic elements mounted between the support portion 114 and the base 112. In the embodiments illustrated in Figures 1 to 8, two leaf springs 141, 142 are used as the guide system 140. These two leaf springs 141, 142 are identical and, in the rest position of the sensor 110, are parallel to each other, to the main axis Z, and to the transverse axis X. In other words, the plane of the leaf springs 141, 142 at rest is parallel to the X, Z plane, therefore the plane of the leaf springs 141, 142 at rest is orthogonal to the Y axis.As can be seen in Figure 1, a first leaf spring 141 is mounted between the first end 112a of the base 112 and the first end 114a of the support portion 114. A second leaf spring 142 is mounted between the second end 112b of the base 112 and the second end 114b of the support portion 114. Alternatively, four leaf springs parallel to each other and to the Z and X axes could be used, mounted in pairs, one pair of leaf springs mounted between the first end 112a of the base 112 and the first end 114a of the support portion 114 and another pair of leaf springs mounted between the second end 112b of the base 112 and the second end 114b of the support portion 114.

[0043] With this arrangement, in the rest position of the sensor 110, a frame is formed with the base 112, the support portion 114, and the two leaf springs 141 and 142. This frame forms a rectangle in the (Y, Z) plane in the rest position of the sensor 110, with the length of the rectangle parallel to the Z axis and the width of the rectangle parallel to the Y axis. With this arrangement, in the measurement position of the sensor 110, this rectangle can be deformed as shown in Figure 5. In this situation, the base 112 and the support portion 114 remain parallel to each other and to the Y axis, with an offset dY1 along the Y axis of the support portion 114 and the stems (heads) of the first reference element 131 (130) and the second reference element 151 (150), and the leaf springs 141 and 142 are distorted.In this measurement position, the deformed profile of the leaf springs 141 and 142 comprises in the (X, Z) plane two substantially straight end parts and a central part forming a curve with an inflection point.

[0044] According to the embodiment shown in Figures 1 to 5 and 8, the guide system 140 further comprises a bar 143, the first end 143a (upper end in the figures) of which is fixed rigidly to the base 112 and the second end 143b (lower end in the figures) of which is mounted on the support portion 114 by a sliding connection at least in the Y direction. In this embodiment, the connection between the second end 143b of the bar 140c and the support portion 114 is also sliding in the Z direction, which makes it possible to absorb the deformation of the spring blades 141, 142 or more generally of the guide system 140 in the Z direction.

[0045] In practice, in the arrangement shown in Figures 1 to 5 and 8, the support portion 114 has a groove 114c opposite the base 112, open on the upper face of the support portion 114. As can be seen in Figure 2, the groove 114c has a width 10 sufficient along the X axis to accommodate without movement the free end or second end 143a of the bar 143. As can be seen in Figure 2, the groove 114c has a length L0 along the Y axis to accommodate and allow the movement of the free end or second end 143b of the bar 143 towards the first end 114a or the second end 114b of the support portion 114 over a pre-established maximum distance corresponding to the maximum permissible offset dY1 (dY1max).Thus, if the bar 143 has a cylindrical shape with a circular cross-section of diameter D, the groove 114c has a width 10 equal to or substantially greater than D (10 is between D and 1.05D), and a length L0 equal to D+2(dY1max). This groove 114c is therefore generally elongated along the Y-axis. For example, this groove 114c can be rectangular, oval, or oblong (buttonhole). This groove 114c is either through or blind (blind groove) on the underside of the support portion 114. For example, the maximum permissible offset dY1 (dY1max) is a few millimeters, for example, 2, 5, 7, or 10 millimeters, to the right and left in Figures 2 to 5.

[0046] We refer to figures 3 to 5, showing the sensor 110 in the case of measuring the external profile of a part 50, therefore of a face 51 of the part forming an external face 51.

[0047] More generally, such a method for measuring the external profile of a part comprises the following steps: <tb> a) <sep>We provide a 110 sensor, <tb> b) <sep>We provide a part 50 whose external profile we wish to determine, namely the measurement of the profile of face 51 (external face), <tb> c) <sep>a shooting device 160 (external sensor as in figure 7) is provided, capable of determining the position of the first reference element 130, (here, as seen in figure 3, the sensor 110 is in the rest position, with the support portion 114 and the base 112 in the initial position, aligned one above the other along the Z axis) <tb> d) <sep>the probing head 123 is placed against the external face 51, while the first reference element 130 remains at a distance from said part 50 (movement according to arrow F1 of figure 3, by bringing the sensor 110 and the external face 51 of the part 50 closer together, along the Y axis, to reach the intermediate position of figure 4 in which the guiding system 140 is not deformed) <tb> e) <sep>The sensor 110 is moved so that the probing head 123 remains in contact with the external face 51 of the part, with the base 112 moving relative to the support portion 114 and relative to the part 50 along the Y axis (movement according to arrow F1 in Figure 4, with the base 112 of the sensor 110 moving relative to the part along the Y axis by a distance dY1, to reach the measurement position of the sensor 110), and <tb> f) <sep>The position of the first reference element 130 is identified by said camera 160, which makes it possible to determine the position of the probing head 123 on the face 51 of the part 50, and <tb> g) <sep>The sensor 110 is moved so that the probe head 123 comes to another location on the external face 51 of the part 50, keeping contact between the probe head 123 and the external face 51 of the part 50 (in Figure 5, vertical movement along the Z axis as indicated by arrow F2, but this can be a movement along the X direction and / or the Y direction depending on the geometry of the part 50), then steps f) and g) are repeated until the end of the determination of the external profile (or portion of the external profile) of the part 50.

[0048] In the case of a hollow part 50 (bore, recess, hole, light, housing 52), a similar procedure is carried out, placing the probing head 123 of the probe 120 against the inner face 54 of the part 50 while the first reference element 130 remains outside the part 50, as explained in relation to Figures 6 and 7. In Figure 6, the part 50 has a through hole 52 as a housing and in Figure 7, the part has a blind hole 52 as a housing.

[0049] In this case, such a method for measuring the internal profile of a part 50 comprises the following steps (see Figures 6 and 7): <tb> a) <sep>We provide a 110 sensor, <tb> b) <sep>We provide a hollow part 50 whose internal profile we wish to determine (internal face 54 of the housing 52), <tb> c) <sep>A shooting device 160 (external sensor as in Figure 7) is provided, capable of determining the position of the first reference element 130. <tb> d) <sep>the probing head 123 is placed inside said hollow part 50, with the probing head 123 against the inner face 54, while the first reference element 130 remains outside said hollow part 50 (here, as seen in figure 6, the sensor 110 is in the rest position, with the support portion 114 and the base 112 in the initial position, aligned one above the other along the Z axis), <tb> e) <sep>The sensor 110 is moved so that the probing head 123 enters (or remains) in contact with the inner face 54 of the part 50, and <tb> f) <sep>The position of the first reference element 130 is identified by said camera 160, which makes it possible to determine the position of the probing head 123 in the part 50, and <tb> g) <sep>The sensor 110 is moved to another location on the inner face 54 of the part 50, keeping contact between the probing head 123 and the inner face 54 of the part 50, then steps f) and g) are repeated until the end of the determination of the internal profile of the part 50.

[0050] The shooting device 160 (external sensor) is used to locate and determine the position of the first reference element 130, each time the sensor 110 is moved relative to the face 51 or 54 of the part 50 to be measured, i.e. when the probing head 123 has moved on the face to be measured 51 or 54. For this purpose, the shooting device 160 includes an optical sensor. In this case, we can take a shooting device 160 whose optical axis O is arranged orthogonally to the (Y, Z) plane (see figure 7), in order to be able to detect the displacements of the first reference element 130 (and therefore indirectly of the probing head 123) along the Y axis. Such a shooting device 160 is for example formed of an optical system, in particular a centered optical system, comprising a set of optical components and an image acquisition system.Such an image acquisition system allows for taking photographs and / or videos, and is, for example, a camera or photographic device, particularly a digital camera.

[0051] The camera 160 has intrinsic properties that allow it to have a field of view 162 that covers the first reference element 130. Figure 6 shows the projection in the (Y, Z) plane of the field of view 162, or solid angle, through which the camera 160 is sensitive to electromagnetic radiation (light). In the case shown in Figure 6, the field of view 162 of the camera 160 includes the first reference element 130, and it also covers or encompasses the part 50, or at least the portion of the part 50 comprising the face to be measured 54 (inner face 54).

[0052] According to another embodiment illustrated in Figure 8, the sensor 110' further comprises a second reference element 150 rigidly mounted to the base 112 and located near the first reference element 130 (in front of and above the first reference element 130 in the arrangement of Figure 8). More specifically, the stem of the second reference element 151 is fixed to the side of the base 112 forming the first end 112 of the base and is located directly above the first end of the support portion 114 and the first reference element 130. Also, the shape and length of the stem of the second reference element 151, which rigidly connects the base 112 to the second reference element 150, are arranged to avoid any contact and collision between the first reference element 130 and the second reference element 150.In this embodiment example, the second reference element 150 is a sphere of similar size to the sphere constituting the first reference element 130.

[0053] Thanks to this second reference element 150, the offset along the Y-axis of the probing head 123 can be detected. This offset (not shown) is due to the bending of the probing rod 122 when the probing head 123 is pressed against a surface to be measured 51 or 54. In this case, in the measurement methods described above, a second reference element 150 is also provided, mounted rigidly to the base 112 and located near the first reference element 130. During measurement step f), the relative displacement (particularly along the Y-axis) between the first reference element 130 and the second reference element 150 is also detected in this second reference element, and this relative displacement is taken into account in determining the position of the probing head 123. It is therefore understood that the field of view 162 of the imaging device 160 also includes the second reference element. 150.

[0054] Such a second reference element 150 is also useful for measuring the external profile because the same phenomenon of bending along the Y axis of the probe rod 122 is likely to occur, and this always without the existence of any bending of the rod of the first reference element 131 since the first reference element 130 is not in contact with a surface, therefore is not subjected to a support which could generate a restoring force from the surface and therefore a bending deformation of the rod of the first reference element 131.

[0055] In the case of this variant of the first embodiment, the method for measuring the internal profile of a part 50 comprises the following steps (see Figures 9, 10A and 10B: <tb> a) <sep>A 110' sensor is provided as described previously, <tb> b) <sep>We provide a hollow part 50 whose internal profile we wish to determine (internal face 54 of the housing 52), <tb> c) <sep>A shooting device 160 (external sensor as in Figure 9) is provided, capable of determining the relative position between the first reference element 130 and the second reference element 150. <tb> d) <sep>the probing head 123 is placed inside said hollow part 50, with the probing head 123 against the inner face 54, while the first reference element 130 and the second reference element 150 remain outside said hollow part 50 (here, as seen in Figure 10A, the sensor 110' is in the rest position, with the support portion 114 and the base 112 in the initial position, aligned one above the other along the Z axis, as well as the first reference element 130 and the second reference element 150 aligned one above the other along the Z axis on a reference line R), <tb> e) <sep>The sensor 110 is moved relative to the part 50 along the Y-axis (arrow F1, Figure 10B) so that the probing head 123 enters (or remains) in contact with the inner face 54 of the part 50: this generates a support force (arrow A) of the first reference element 130 against the inner face 54 and deforms the spring blades 141 and 142 with an opposite displacement of the same magnitude (arrow F3) of the support portion 114 relative to the base 112, this generates a Y-direction offset dY1 of the first reference element 130 relative to the second reference element 150 (Figure 10B), and <tb> f) <sep>The position of the first reference element 130 relative to the second reference element 150 is identified by said camera 160, which makes it possible to determine the position of the probing head 123 in the part 50, and <tb> g) <sep>The sensor 110' is moved in the Z direction (vertical direction) to another location on the inner face 54 of the part 50, maintaining contact between the probing head 123 and the inner face 54 of the part 50. Steps f) and g) are then repeated until the internal profile of the part 50 has been determined. In this way, as shown in Figure 9, a measurement line M representing the internal contour of the inner face 54 is constructed point by point as the first reference element 130 is successively positioned. It is understood that the vertical reference line R passing through the second reference element 150 (for example, through its center or another point) is used as a reference, and that the measurement line M is a transposition outside the part 50 of the line C (Figure 9) of the internal contour (internal profile) to be measured.

[0056] In this first embodiment, the measuring system 100 or 110' comprises a parallel deformation structure including, one above the other in parallel, the base 112 and the support portion 114 which are undeformable, and the two spring blades 141 and 142 which are deformable along the horizontal Y direction. This makes it possible to define a measuring axis, here the Y axis, and to apply a support force of the probing head 123 on the part 50. This support force depends on the characteristics of the spring blades 141 and 142 (length, width, thickness) and their deformation.

[0057] In this first embodiment, but also in general, the invention allows, as can be seen in figure 11, to follow very precisely the internal (or external) contour of the part 50 along the internal face 54 (external 52), by the probing head 123 of the probe 120 which remains in contact with the part 50.In the embodiments presented, the reconstruction and tracking of the contour is carried out in the vertical direction Z (orientation of the measurement line M and the contour line C to be reconstructed), but it is possible to perform this reconstruction and tracking of the contour in another direction, in particular a horizontal direction, for example in the X direction, or another direction in the (X, Y) plane, or even in one of these directions for a portion of the contour and then in a second of these directions to change the portion of the contour and return to the first of these directions to visualize this new portion of the contour. Despite the fact that this probing head 123 is invisible from outside the part 50, the invention makes it possible to visualize its movement via the first reference element 130.The guidance system 140 allows the probing head 123 to move relative to the base 112 in one or more directions.

[0058] The invention allows, via the image-capture device 160, which is arranged with a field of view 162 including the first reference element 130 and the outer contour of the part and / or the second reference element 150, for successive images to be taken during the movement of the first reference element 130 and for its relative position to be measured with respect to the part (or with respect to the second reference element 150). These images make it possible to form, point by point, the measurement line M, which reconstructs the line C of the internal contour to be measured. This is made possible because the measurement system transfers the movement of the probing head 123, as it follows the internal (or external) contour of the part, and therefore the internal (or external) profile of the part, to the first reference element 130, which is outside the part.The measurement line M in Figure 9 corresponds to the internal profile of the part along the vertical Z direction at a location (a point) on the part (housing 52) in a horizontal plane parallel to the (X, Y) plane. To reconstruct the entire internal (external) profile of the part, namely the entire surface of the internal (external) face 54 (52), the measurement steps must be repeated to reconstruct another measurement line M' passing through another location (a point) on the part (housing 52) in this horizontal plane parallel to the (X, Y) plane, and so on for the required number of points. Reconstructing the measurement line M amounts to reproducing, outside the part 50, the contour of a "slice" of the part 50 in a plane parallel to the vertical Z axis. By also reconstructing other slices, the juxtaposition of the measurement lines M, M', etc., in three-dimensional space is obtained by adding images.

[0059] A preliminary calibration step is performed to determine the exact relative position between the first reference element 130 and the position of the probing head 123. This allows the measurement line M to be transferred to obtain the line C of the internal contour to be measured, which is invisible from outside the part. For this purpose, depending on one possibility, an image of the sensor 110 or 110' is taken with the imaging device 160, without the part 50, in order to define the relative position of the first reference element 130 and the probing head 123 in the rest position of the sensor 110 or 110'.

[0060] The sensor 110 or 110' can be held by its base 112 by a gripping member or a support member (shown schematically in Figure 12) and moved by any displacement system such as an articulated arm controlled by control systems and motorized shafts 170 in order to allow relative displacement between the sensor 110 or 110' and the part 50 according to: <tb> – <sep>a horizontal movement along the Y axis as indicated by arrow F1 in Figure 12, and / or <tb> – <sep>a vertical movement along the Z axis as indicated by arrow F2 in Figure 12.

[0061] Reference is now made to Figures 13A and 13B, which represent a measuring system 200 according to a second embodiment of the invention. In this case, the elements of the measuring system 200, similar to those of the first embodiment presented previously (measuring system 100), bear a reference symbol which is that of the first embodiment increased by a value of 100. A sensor 210 is found comprising: <tb> – <sep>a support portion 214 extending vertically downwards from a probing rod 222 carrying at its free end a probing head 223 and in parallel a first reference element rod 231 carrying at its free end the first reference element 230, <tb> – <sep>a base 232 extending vertically downwards from a rod 251 of a second reference element carrying at its free end a second reference element 250. A variant not shown might not include this second reference element 250.

[0062] The support portion 214 and the base 212 are placed one in front of the other with a guide system 240 allowing rotational movement between them around an axis P parallel to the horizontal direction X. This direction X is orthogonal to the horizontal measurement direction Y separating the probing head 223 and the first reference element 230. For this purpose, the guide system 240 can have several designs, and in particular include a shaft (not shown) parallel to the axis P and positioned vertically above the probing head 223. This shaft passes through the support portion 214 and the base 212, and is fixed relative to one of the two support portion 214 and the base 212.The guide system 240 further includes a spiral spring (not shown) with an axis parallel to axis P (possibly coaxial with axis P) surrounding the shaft, with its inner end fixed to the shaft and its outer end fixed to the other of the two support portions 214 and the base 212. This rotational movement (see arrow F3 in Figures 13A and 13B) is facilitated by the presence of a weight 241 connected to the outside of the support portion 214, with an offset along the Y direction between the support portion 214 and the weight 241. Thus, this weight 241 serves as a counterweight to the assembly formed by the probe head 223 and the first reference element 230. The mass of this weight 241, as well as the distance L1 separating it from the shaft, and therefore from the probe head 223, can be modified to form an adjustable lever arm. .

[0063] In this case, the probe 220 (sensing head 223 at the free end of the sensing rod 222) is connected to the fixed part of the measuring system by a guide system 240 allowing only rotation about an axis P orthogonal to the Y direction of the measurement. It is therefore, in this instance, a pivoting guide system 240.

[0064] A pendulum-type structure is thus formed which operates in the same way as the sensor 110' of the first embodiment and allows a measurement axis to be defined along the Y direction. This structure ensures a constant and extremely low contact force A of the probing head 223 on the inner face 54 (or outer face 51) of the workpiece, regardless of the deformation of the spiral spring. In this case, the guide system 240 allows one degree of freedom of the probe 220, which is a rotational movement around the axis P, parallel to the X axis. The use of this sensor 210 in conjunction with a camera 160 makes it possible to create a workpiece profile measurement system according to a measurement method identical to that already described in relation to the first embodiment.

[0065] Reference is now made to Figures 14A and 14B, which represent a measuring system 300 according to a third embodiment of the invention. In this case, the elements of the measuring system 300, similar to those of the first embodiment presented above, bear a reference symbol which is that of the first embodiment increased by a value of 200. A sensor 310 is found comprising: <tb> – <sep>a support portion 314 extending vertically downwards from a probing rod 322 carrying at its free end a probing head 323 and in parallel by a first reference element rod 331 carrying at its free end the first reference element 330, this support portion 314 has a general L shape with the rod of the L oriented along the vertical direction Z and the base of the L parallel to the direction Y and carrying the probing head 323 and the first reference element 330. <tb> – <sep>a base 312 extending vertically downwards from a rod 351 of a second reference element carrying at its free end a second reference element 350. A variant not shown might not include this second reference element 350.

[0066] The support portion 314 and the base 312 are movable relative to each other in the direction of the horizontal measuring axis Y, according to a translational movement. Here, the base 312 has a stirrup shape, in particular an inverted U shape, with the base of the U parallel to the Y direction and the two arms of the U parallel to the Z direction. One of the two arms of the U of the base 312 extends through the rod 351 of the second reference element and through the second reference element 350. Two guide pieces parallel to each other and to the Y direction connect the two arms of the U to allow the translational movement of the support portion 314. More precisely, a rail 344 forms the first guide piece in the form of a rod which preferably has a circular cross-section and on which the support portion 314 is mounted at a through opening in the portion of the rod of the L.Also, a slide 345 forms the second guide piece in the form of a rod parallel to the rail 344. To cooperate in translation with the slide 345, this other portion of the L-shaped rod has, for example, a notch to partially surround the slide 345 or a through opening forming a passage for the slide 345.

[0067] In order to exert a support force (arrow A) by the probing head 323 on the inner (or outer) face 54 (51) of the part which is for example oriented in the vertical direction and to allow the return to the rest position (figure 14A) of the support portion 314 relative to the base along the Y axis, two compression springs 346 and 347 are used, forming means for returning the support portion 314. These springs 346 and 348 are mounted on the rail on either side of the support portion 314. These springs 346 and 348 have one end in contact and bearing on the support portion 314 (one spring for each face) and one end in contact and bearing on the base 312 (each spring bearing on a different arm of the U of the base 312). These are, for example, as in the example shown in figures 14A and 14B, two helical springs 346 and 347.In the example shown in Figures 14A and 14B, there are two springs 346 and 347 of the same length and the same resistance to compression per unit length, which places the rest position (see Figure 14A) of the support portion 314 between the two arms (ends along the measurement direction Y) of the base 312. However, the geometric and / or physical characteristics of each spring 346 and 347 can be adapted according to specific requirements.It is understood that in this arrangement, the support force A of the probing head 323 on the part 50 depends on the deformation of the springs: thus in the case of figure 14B, the probing head 323 presses on the internal face 54 of the part 50, in the area on the right of the figure on a portion of the vertical internal face 54, as seen by the camera; In this case, the sensor 310 has been offset in translation to the right relative to the part 50, which has moved the support portion 314 relative to the base 312 to the left by the distance dY1 (see figure 14B) and put the first spring 346 located to the left of the support portion 314 under compression (more). This offset dY1 is found between the first reference element 330 attached to the support portion 314 and the second reference element 350 attached to the base 312.

[0068] Reference is now made to Figures 15A and 15B, which represent a measuring system 400 according to a fourth embodiment of the invention. In this case, the elements of the measuring system 400, similar to those of the measuring system 300 according to the third embodiment presented previously, bear a reference symbol, which is that of the third embodiment increased by a value of 100. A sensor 410 is found comprising: <tb> – <sep>a portion of support 414 extended vertically downwards by a probing rod 422 carrying at its free end a probing head 423 and in parallel by a first reference element rod 431 carrying at its free end the first reference element 430, this portion of support 414 has a general shape of a horizontal U with the base of the U oriented along the vertical direction Z, the upper branch of the U oriented along the direction Y and the lower branch of the U (carrying the probing head 423 and the first reference element 430) also oriented parallel to the direction Y. <tb> – <sep>a base 412 extending vertically downwards from a rod 451 of a second reference element carrying at its free end a second reference element 450. A variant not shown might not include this second reference element 450.

[0069] The support portion 414 and the base 412 are movable relative to each other in the direction of the measurement axis, which is this time the vertical axis Z, according to a translational movement. Here, the base 412 also has a stirrup shape, in particular a horizontal U shape, with the base of the U parallel to the vertical Z and the two arms of the U parallel to the direction of the Y axis; the opening of the U in the support portion 414 is oriented towards the base 412; the opening of the U in the base 412 is oriented towards the support portion 414; One of the two arms of the U of the base 412 (lower arm) extends through the rod 451 of the second reference element and through the second reference element 450, and is partially disposed in the housing delimited by the support portion 414, while at least in projection in the plane of figure 15A or 15B, that is to say seen in direction X by the shooting device 160 (not shown).Two parallel guide pieces, aligned in the Z direction, connect the two arms of the U-shaped base 412 to allow the translational movement of the support portion 414. More specifically, a rail 444 forms the first guide piece in the form of a rod, preferably with a circular cross-section, on which the support portion 414 is mounted at a through-hole in the other arm of the U-shaped base 412 (the upper arm). A slide 445 forms the second guide piece in the form of a rod parallel to the rail 444. To cooperate in translation with the slide 445, this other portion of the other arm of the U-shaped base 412 (the upper arm) has, for example, a notch to partially surround the slide 445 or a through-hole forming a passage for the slide 445.

[0070] In order to exert a support force (arrow A) by the probing head 423 on a portion of the inner (or outer) face 54 (51) of the part which is oriented for example in the horizontal direction and to allow the return to the rest position (figure 15A) of the support portion 414 relative to the base 412 along the vertical axis Z, two compression springs 446 and 447 are used, forming return means for the support portion 412. These springs 446 and 448 are mounted on the rail 444 on either side of the upper arm of the support portion 414. These springs 446 and 448 have one end in contact with and bearing on the support portion 414 and one end in contact with and bearing on the base 412 (each spring bearing on a different arm of the base 412). These are, for example, as in the example shown in figures 15A and 15B, two helical springs 446 and 447.In the example shown in Figures 15A and 15B, there are two springs 446 and 447 of the same length and the same resistance to compression per unit length, which places the rest position (see Figure 15A) of the support portion 414 between the two arms (ends along the measurement direction Z) of the base 412. However, the geometric and / or physical characteristics of each spring 446 and 447 can be adapted according to specific needs.It is understood that in this arrangement, the support force A of the probing head 423 on the part 50 depends on the deformation of the springs: thus in the case of figure 15B, the probing head 323 presses on the internal face 54 of the part 50, in the area on the right of the figure, which has a re-entrant shoulder, on a portion of horizontal surface which is here as seen by the camera device; In this case, the sensor 410 has been offset upwards in the Z direction relative to the part 50, which has displaced the support portion 414 relative to the base 412 downwards by the distance dZ1 (see figure 15B) and put the second spring 447 located under the upper arm of the support portion 414 into (further) compression. This offset dZ1 is found between the first reference element 430 attached to the support portion 414 and the second reference element 450 attached to the base 412.

[0071] As schematically represented in Figure 16, a camera 160 used in the measurement system according to the invention, for example according to one of the embodiments shown in the figures and described above, comprises: <tb> – <sep>A camera and a set of lenses allow the focal plane of this camera 160 to be placed on the part 50 and on the first reference element 130 (230, 330, 430), and also, if necessary, on the second reference element 150 (250, 350, 450). In order to improve the contrast of the image taken by the camera 160, in its field of view 162, a light source 164 is placed in a backlighting configuration, as shown in Figure 16. In this way, the object(s) present in the field of view 162 (of the camera) of the shooting device 160 is / are placed between the shooting device 160 and the light source 164. This backlighting gives an image such as that of figure 17A (for a portion of a sphere which is for example the probing head), with a gradient of grey or dark / light between the part and the outside of the part.Processing this image (figures 17B to 17F) allows us to obtain an image after processing I which allows us to very precisely delimit the position of the contour of this or these objects visible by the shooting device 160 (figure 17F).

[0072] In the foregoing, a technique has been described in which the determination of the position of the first reference element 130 (and where applicable the position of the second reference element 150) is carried out optically by the camera 160. The present invention can also be applied to the determination of the position of the first reference element 130 (and where applicable the position of the second reference element 150) in another way, and in particular by contact between another type of sensor and the first reference element 130 and where applicable the position of the second reference element 150).It should be noted that when the determination of the position of the first reference element 130 and, where applicable, of the position of the second reference element 150, is carried out optically, this avoids an additional deformation of the rod 131 (151) of the first (second) reference element 130 (150) and therefore a shift of the first (second) reference element 130 (150) which would alter the measurement.

[0073] Common features can be noted between all or part of these embodiments. In particular, between the measuring system of the first embodiment 100, the second embodiment 200 and the third embodiment 300, said guiding system 140, 240, 340 is a flexible system at least along the Y direction. In the case of the measuring system of the fourth embodiment 400, said guiding system 440 is a flexible system at least along the Z direction.

[0074] Also, in particular between the measurement system of the first embodiment 100, the second embodiment 200, the third embodiment 300 and the fourth embodiment 400, one or more of the following provisions A to I apply(s) for a sensor also the subject of the present invention or for a measurement system comprising such a sensor:

[0075] *Arrangement A: the sensor forms a mechanical probing device suitable for use in determining the internal profile of a part 50, comprising: <tb> – <sep>a base, <tb> – <sep>a support portion elastically connected to the base by a guiding system, <tb> – <sep>a probing head mounted via a probing rod on the support portion, <tb> – <sep>a reference head mounted via a reference rod on the support portion, in which: <tb> – <sep>The reference head and the probing head are located on the side of the support portion opposite said base. <tb> – <sep>The reference rod and the probing rod are arranged in a Y, Z plane, being, in the rest position of the device, parallel to each other and to a Z direction.

[0076] *Arrangement B: said guidance system is arranged so that when the probing head enters and remains in contact with a surface of the part, a relative displacement between the probing head and the base is at least partially transmitted to the reference head via the guidance system.

[0077] *Disposition C: said guidance system is arranged so that when the probing head enters and remains in contact with a surface not parallel to the Y, Z plane, any relative displacement between the probing head and the base along the Y direction is at least partially transmitted to the reference head via the guidance system.

[0078] *Disposition D: said guide system comprises at least one spring-forming element. In particular, the guide system comprises two parallel leaf springs connecting said support portion to said base, the plane of each leaf spring being, in the rest position of the device, orthogonal to the Y direction.

[0079] *Arrangement E: the probing head is mounted on the free end of the probing rod and the reference head (first reference element) is mounted on the free end of the reference rod.

[0080] *Arrangement F: the probing rod and the reference rod are of the same length

[0081] *Arrangement G: device further comprising a calibration indicator (second reference element) fixedly mounted to the base and located near the reference head. This calibration indicator (second reference element) makes it possible to detect the Y (or Z, or X) offset of the probing head.

[0082] *Arrangement H: a measuring system includes such a mechanical probing device and an external device with an external sensor (such as, for example, a shooting device) capable of determining the position of the reference head (first reference element).

[0083] *Arrangement I: such a measurement system in which the external sensor is an optical device with an optical sensor, whose optical axis is arranged orthogonally to the (Y, Z) plane.

[0084] The first embodiment 1100, the second embodiment 200, the third embodiment 300, and the fourth embodiment 400 of the measuring system as described above include a mechanical sensor and are therefore examples of a contact profile determination technology. However, the measuring system according to the present invention can also be a non-contact system.

[0085] Such a measuring system 40 according to the present invention can be fitted to a measuring bench, a workpiece inspection station during machining, and can even be integrated as a module of a machine tool. Reference numbers used in the figures

[0086] X Transverse axis Y Measuring axis Z Main axis (vertical) Y0 Distance separating the probe stem from the stem of the first datum feature Z0 Distance separating the probe head and the first datum feature from the support portion dY1 Offset between the base and the support portion in the measuring position l0 Groove width 114c L0 Groove length 114c F1 Deflection (sensor displacement 110) F2 Deflection (sensor displacement 110) F3 Deflection (displacement of the support portion relative to the base 112) A Deflection (support force of the first datum feature 130 on the part 50) R Datum line (vertical line passing through the second datum feature 150) M Measuring line of the internal profile of the inner face 54 C Line following the internal profile to be measured 50 Part 51 Face to be measured (outer face) 52 Housing (hole, bore ...) 54 Face to be measured (inner face) 100 Measuring system (first embodiment) 110 Sensor 110' Sensor 112 Base 112a First end 112bSecond end 114 Support portion 114a First end of the support portion 114b Second end of the support portion 114c Groove 120 Probe 122 Probe rod 123 Probe head 130 First reference element 131 Rod of the first reference element 140 Guide system 141 First spring blade 142 Second spring blade 143 Bar 143a First end of the bar 143b Second end of the bar 150 Second reference element 151 Rod of the second reference element 160 Shooting device 162 Field of view of the shooting device 164 Light source I Image after processing 200 Measuring system (second embodiment) 210 Sensor 212 Base 214 Support portion 220 Probe 222 Probe rod 223 Probe head 230 First reference element 231 Rod of the first reference element 240 Guiding system 241 Weight 250 Second reference element 251 Rod of the second reference element P Rotation axis between 214 and212 L1 Lever arm length 300 Measuring system (third embodiment) 310 Sensor 312 Base (stirrup-shaped) 314 Support portion (L-shaped sliding carriage) 320 Probe 322 Probe rod 323 Probe head 330 First reference element 331 Rod of the first reference element 340 Guide system 344 Rail 345 Slide 346 First helical spring 347 Second helical spring 350 Second reference element 351 Rod of the second reference element 400 Measuring system (third embodiment) 410 Sensor 412 Base (stirrup-shaped) 414 Support portion (U-shaped sliding carriage) 420 Probe 422 Probe rod 423 Probe head 430 First reference element 431 Rod of the first reference element 440 Guide system 444 Rail 445 Slide 446 First helical spring 447 Second helical spring 450 Second reference element 451 Rod of the second reference element< / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb> < / sep> < / tb>

Claims

1. A measuring system (100; 200; 300; 400) for the external profile of a part (50) or the internal profile of a hollow part (50), comprising: – a sensor (110, 110'; 210; 310; 410) with a probe (120; 220; 320; 420) having at least one degree of freedom, and a first reference element (130; 230; 330; 430) integral with the probe (120; 220; 320; 420), said sensor (110, 110'; 210; 310; 410) being arranged so that said probe (120; 220; 320; 420) is able to follow the internal or external contour of the part (50) while the first reference element (130; 230; 330; 430) is outside the room (50), and – a camera-taking device (160) capable of taking an image representing at least a portion of the outside of the room (50) and the first reference element (130; 230; 330; 430).

2. Measurement system (100; 200; 300; 400) according to claim 1, further comprising a base (112; 212; 312; 412) and a guidance system (140; 240; 340; 440) connecting the sensor (110, 110'; 210; 310; 410) with the base (112; 212; 312; 412).

3. Measurement system (100; 200; 300; 400) according to claim 2, wherein said guidance system (140; 240; 340; 440) permits a single degree of freedom between the sensor (110, 110'; 210; 310; 410) and the base (112; 212; 312; 412).

4. Measurement system (100; 200; 300; 400) according to claim 2 or 3, further comprising a second reference element (150; 250; 350; 450) integral with the base (112; 212; 312; 412), said second reference element (150; 250; 350; 450) being placed so that the shooting device (160) is able to simultaneously see said first reference element (130; 230; 330; 430), said second reference element (150; 250; 350; 450) and said portion of the outside of the part (50).

5. Measurement system (100; 200; 300; 400) according to any one of claims 1 to 4, wherein the probe (120; 220; 320; 420) is a probing head capable of following and detecting the internal or external contour of the part (50) by contact.

6. Measurement system (100; 200; 300; 400) according to any one of claims 1 to 4, wherein the probe (120; 220; 320; 420) is a sensing head capable of following and detecting the internal or external contour of the part (50) without contact.

7. Measurement system (100; 200; 300; 400) according to any one of claims 1 to 6, wherein the image-capturing device (160) comprises a camera and a light source capable of simultaneously illuminating said portion of the exterior of the part (50) and the first reference element (130; 230; 330; 430) 8. Measurement system (100; 200; 300; 400) according to claim 7, wherein the camera has a field of view (64) allowing said portion to be seen from outside the part (50) and the first reference element (130; 230; 330; 430).

9. Measurement system (100; 200; 300; 400) according to any one of claims 1 to 8, wherein the guidance system (140; 240; 340; 440) includes return means enabling the sensor (110, 110'; 210; 310; 410) to return to a rest position relative to the base (112; 212; 312; 412) when the probe (120; 220; 320; 420) is no longer interacting with the internal or external contour of the part (50).

10. Measurement system (100; 200; 300; 400) according to any one of claims 1 to 9, wherein the guidance system (140; 240; 340; 440) comprises between the sensor (110, 110'; 210; 310; 410) and the base (112; 212; 312; 412) a sliding link or a tilting link.

11. A method for measuring the internal profile of a hollow part (50), comprising the following steps: i) providing a sensor (110, 110'; 210; 310; 410) with a probe (120; 220; 320; 420) and a first reference element (130; 230; 330; 430) attached to the probe (120; 220; 320; 420), and a camera (160), ii) providing a hollow part (50) whose internal profile is to be determined, iii) positioning the sensor (110, 110'; 210; 310; 410) so that the probe (120; 220; 320; 420) is inside the part (50) and detects a point on the internal profile of the part (50) while the first reference element (130; 230; 330; 430) is outside the part (50) and in the field of view of the camera (160), iv) triggering of the camera system and formation of an image representing at least a portion of the outside of the part (50) and said reference element, v) movement of the probe (120; 220; 320;420) inside the part (50) in a movement allowing the probe (120; 220; 320; 420) to follow the internal contour of the part (50), while the first reference element (130; 230; 330; 430) remains outside the part (50) making the same movement, vi) perform steps iv) and v) for other points of the internal contour of the part (50).; 12. A method for measuring the external profile of a part (50), comprising the following steps: i) providing a sensor (110, 110'; 210; 310; 410) with a probe (120; 220; 320; 420) and a first reference element (130; 230; 330; 430) attached to the probe (120; 220; 320; 420), and a camera (160), ii) providing a part (50) whose external profile is to be determined, iii) positioning the sensor (110, 110'; 210; 310; 410) so that the probe (120; 220; 320; 420) is outside the part (50) and detects a point on the external profile of the part (50) while the first reference element (130; 230; 330; 430) is also outside the part (50) and in the field of view of the camera (160), iv) triggering of the camera system and formation of an image representing at least a portion of the outside of the part (50) and said reference element, v) movement of the probe (120; 220; 320;420) relative to the part (50) according to a movement allowing the probe (120; 220; 320; 420) to follow the external contour of the part (50), while the first reference element (130; 230; 330; 430) remains outside the part (50) by performing the same movement, vi) perform steps iv) and v) for other points of the external contour of the part (50).; 13. Method for measuring the profile of a part (50), comprising the following steps: i) providing a sensor (110, 110'; 210; 310; 410) with a probe (120; 220; 320; 420) and a first reference element (130; 230; 330; 430) attached to the probe (120; 220; 320; 420), and a camera (160), ii) providing a part (50) whose profile is to be determined, iii) positioning the sensor (110, 110'; 210; 310; 410) so that the probe (120; 220; 320; 420) detects a point on the contour of the part (50) while the first reference element (130; 230; 330; 430) is outside the part (50) and in the field of view of the camera (160), iv) triggering of the camera system and formation of an image representing at least a portion of the outside of the part (50) and said reference element, v) movement of the probe (120; 220; 320; 420) relative to the part (50) in a movement allowing the probe (120; 220; 320;420) to follow the contour of the part (50), while the first reference element (130; 230; 330; 430) remains outside the part (50) by performing the same movement, vi) perform steps iv) and v) for other points of the contour of the part (50).; 14. Measurement method according to any one of claims 11 to 13 wherein the following steps are further carried out: a) for each image formed by said shooting device (160), calculation of the relative position between the first reference element (130; 230; 330; 430) and the portion of the outside of the part (50), and b) reconstruction of the profile of the part (50) from said relative positions of the first reference element (130; 230; 330; 430) successively calculated.