WO2006069748A1

WO2006069748A1 - Device for measurement of an object and method for use of said device

Info

Publication number: WO2006069748A1
Application number: PCT/EP2005/013949
Authority: WO
Inventors: Frank Bartl; Bruno Knobel; Charles Findeisen
Original assignee: Ife Industrielle Forschung Und Entwicklung Gmbh
Priority date: 2004-12-23
Filing date: 2005-12-22
Publication date: 2006-07-06

Abstract

The invention relates to a device for measurement of an object, comprising a measuring platform mounted on gimbals, a distance sensor, at least one imaging system, a moving mirror mounted on the object and a structure mounted on the object, comprising geometrical patterns of lines and adjacent surfaces.

Description

Device for measuring an object and method for using such a device

[01] The invention relates to devices for measuring an object and to methods of using such devices.

[02] In particular, the invention relates to a device for measuring an object with a cardanically mounted measuring platform, a distance meter, at least one imaging system, a triple mirror applied to the object and a structure applied to the object. Such a device is known for example from DE 690 05 106 T2 and EP 0 880 674 Bl.

[03] In the field of surveying, systems are often used that can detect and measure the spatial positions of objects, such as manually guided buttons. It is of particular importance that the process is fast and accurate. The device for the process must be handy and easily portable, but it should also be stable and robust and can be used very reliably even under difficult environmental conditions.

EP 0 880 674 B1 discloses methods which are based on the combination of a distance measurement between the measuring platform and a reflector on the object and the position measurement of several light-emitting diodes on the object by means of a camera with area sensor mounted on the measuring platform.

[05] Suitable reflectors are described in EP 0 880 674 B1 as "reflecting points". These are either "corner cubes" with the property that incident light is reflected back in the same direction, parallel to the incident light beam, or, for example, reflective, circular areas ("dots") on self-adhesive films, which are attached in suitable places.

[06] Distance meters are used to measure the distance between a transmitter and a reflector. The distance meters are based on the transit time measurement of short light pulses, which are directed back into the measuring system by a reflector, or they are based on interferometric methods or they are based on modulated laser light, wherein the distance can be measured as an absolute value by means of phase comparison.

BESTATIGUNGSKOPIE [07] A laser tracker consists of a distance meter whose laser beam is directed in a controlled manner into the room. In this case, both the distance to a reflector unit and the spatial direction of the laser beam are measured and evaluated by means of directional sensors by means of the integrated evaluation unit. The laser beam is aligned so that it falls on the reflector during the distance measurement. This requires that the laser tracker be tracked to the reflector. The patent EP 0 880 674 B1 describes in detail with which sensors this object can be achieved. The measuring platform can track the moving object in the room because it is multi-axially connected to a tripod. The distance between laser tracker and reflector is measured interferometrically, the spatial direction of the laser beam via high-resolution angle encoders. Thus, the spatial position of the reflector with respect to the coordinate system of the measuring head is known. Tracking methods, ie methods in which measured samples are detected in a controlled manner, tracked and at the same time their spatial position or spatial positions are determined, are described, for example, in EP 0 880 674 B1.

[08] An imaging system, hereafter called a camera, consists of a lens system, a two-dimensional sensor, such as a CCD or CMOS sensor, or another photoactive element, such as a position sensing device (PSD). The optics are advantageously equipped with a bandpass filter to receive only the wavelength emitted by the illumination. The sensor can be used in whole or in part.

[09] The invention is based on the object of designing a method of the type mentioned at the outset such that the measuring process can be designed inexpensively, quickly, precisely and in a user-friendly manner by suitable combination of partially established measuring techniques.

[10] This object is achieved in that in a generic device, the structure consists of geometric patterns of lines and limited areas.

[11] It is advantageous if the structure has at least one coarse structure and one fine structure. A particularly advantageous embodiment provides that the fine structure is arranged within the coarse structure. Cumulatively or alternatively, it is proposed that the coarse structure and the fine structure are arranged adjacent to one another. It has proven advantageous if the fine structures are arranged closer to the triple mirror than the coarse structure. Different embodiments show that the structure may consist of several areas which are arranged around the triple mirror. Furthermore, it is advantageous if the patterns become larger with increasing distance to the triple mirror.

[12] It has proved favorable if the structure of geometric patterns has simple, partially rotationally symmetric basic structures together with superimposed more complex structures. [13] A simple embodiment provides that the structure is flat. However, it is advantageous if the structure is three-dimensional, in particular funnel-shaped or cone-shaped. It is particularly advantageous if the structure and the surface of the object have rotationally symmetrical properties.

[14] A variant provides that the structure is self-luminous or at least has a self-illuminating area. Another variant proposes that the structure is not self-luminous and has reflective, absorbent, matt, glossy, phosphorizing or fluorescent materials.

[15] It is advantageous if a fixed focal length imaging system is used.

[16] In particular when non-self-illuminating structures are used, it is proposed to arrange a light source for illumination, preferably on the measuring platform. However, a scanner can also be arranged for illumination, preferably on the measuring platform. It is advantageous if the scanner deflects a distance meter. Furthermore, it is proposed that the scanner deflects a laser. Finally, it is suggested that the scanner deflect a retroreflective beam of light onto a photosensor on the measurement platform.

[17] A preferred embodiment provides that the distance meter is arranged on the measuring platform.

A particularly advantageous variant provides that the imaging system, a light source and a distance meter is aligned by means of an optical system by the same optics on the object with at least one, preferably three triple mirrors.

A simple rough survey of the position of the object provides that on the measuring platform optical elements such as fish-eye lenses or cassette-like sensors and on the object a light emitter are arranged.

[20] Another device for measuring an object and the structure mounted on the object provides that the structure is formed by at least three spherical wave transmitters and a receiving sensor. Alternatively or cumulatively, it is proposed that an imaging system be formed by at least three receiving sensors and a spherical wave sensor. It is advantageous in each case if a GPS receiver is arranged on the measuring platform and the object.

[21] A method of using a device according to any one of the preceding claims provides that the distance between a point on the measuring platform and the tripple mirror is determined, the angles of the straight lines defined by this point and the triple mirror center point with respect to the coordinate system of the measuring head are determined, a sensor image with the imaging system of the structure attached to the object or parts of the structure is generated, compared with a stored reference image of the structure and the spatial position of the object is determined from it.

[22] In this method, it is advantageous if, prior to the comparison, pixel regions of the sensor image are combined to form a pixel in order to densify the sensor image. Furthermore, it is advantageous if, prior to the comparison, the sensor image is split up into a plurality of partial regions.

[23] In addition, partial areas of the sensor image can each be compared with the corresponding partial areas of the reference image.

[24] The measurement platform, which forms the center of a sphere, and a peripherally moving object provided with corresponding sensors and actuators are interacting in such a way that the spatial position of the object with respect to the coordinate system of the measurement platform can be determined unambiguously. The measuring platform can be moved by two axes of rotation, with angular decoders positioned on a motorized stand, as is the case with a gimbal, so that it can see and measure parts of or all of the enclosing sphere.

[25] The object may be, for example, a probe, which is guided by hand or firmly connected to a higher-level system, such as a robot.

By taking note of the geometry of the moving object can be obtained in a tactile application to the interacting environment their space measurement.

The measuring platform on the stand is stationary in space and without knowledge of the location coordinates or positioned on a movable and controllable via the measuring system track. If the spatial position of the measuring head is determined by additionally attached sensors such as GPS, compass, horizon and solder giving sensors, or distance meters, then absolute measurements in position coordinates of the material to be measured can be calculated in addition to the relative measurement. Together with the mobile application, the measuring volume expands to almost unlimited size.

The device has a measuring head, which consists of a measuring platform, which is freely rotatable on two triples mounted on a tripod, and a freely movable in space, rigid object. The measuring platform and the object to be measured interact in such a way that the spatial position of the object can be uniquely determined. [29] In one case, the measurement platform includes two or more imaging systems, such as cameras, to use triangulation measurement to determine the spatial positions of clearly determinable surface structures on the object, such as luminescent structures. The spatial position of the object and the spatial position of an object point, such as the stylus tip, are calculated by means of the geometric knowledge of the structure and the object.

[30] The surface structures are either non-self-luminous structures, such as reliefs, gray value patterns, color patterns, or self-luminous structures, or a suitable combination of these. The non-self-luminous structures may have a suitable combination of highly reflective, absorbent, matt, glossy, fluorescent or phosphorescent surfaces.

[31] The spatial position of the object is determined by means of classical photogrammetry, an established and reliable method, or by correlation calculation of the entire structure or by a combination of both methods. By suitable use of correlation algorithms, the accuracy in determining the spatial position of the object can be increased. A moving object is thus accurately tracked and its spatial positions precisely detected by determining the spatial position of the searched object in a sequence of images with the help of photogrammetric methods. Furthermore, with this knowledge, correlation calculations in the image sequence can be carried out per camera over the entire image content of the surface structure or over selected subregions of the object. If this method is used iteratively, the solid angles from the photogrammetry can be increased in a further calculation step. Depending on requirements, the process is applied several times. This method makes it possible to achieve high accuracies with simple techniques, in contrast to the known methods mentioned at the outset, which use point-type reflectors and light sources.

[32] In addition to the intrusive systems, the measurement platform can also include a laser scanner. As a result, arbitrarily definable light patterns can be generated on the object surface with a suitable structure of the type mentioned above. Thus, by means of suitable image processing, the spatial position of the object can be determined. A method for stereometric measurement with several cameras on a measuring head combined with a laser scanner for targeted illumination of objects in the room with defined patterns is described in the earlier, German patent application 10 2004 032 643 Al.

[33] If a distance sensor is also attached to the measuring head, the direct distance from the measuring head to the object to be measured can additionally be determined in a supplementary, independent way. The

The method and the device can be used for additional accuracy enhancement for systems with self-illuminating and non-self-luminous surface structures of the objects. As distance sensor Ren come both systems with transit time measurement in question, for which no special reflectors must be attached to the measurement object, as well as systems that require highly reflective areas on the object to be measured, such as triple mirrors. For determining the spatial position of the object provided with a triple mirror, a distance meter and an imaging system are sufficient.

The combination of imaging systems and a distance meter on the measuring platform with triple mirror and self-luminous or non-self-luminous surface structures on the object allows the measurement of the spatial position of the object relative to the measuring head.

[35] If the measuring platform includes a distance meter, which is guided by a camera optics, measuring methods can be used, which use shutter or deflection functions to direct the distance sensor sequentially to several triple mirrors or the like mounted on the measurement object in order to detect the spatial distance on the one hand and the lateral one on the other hand Location of the reflectors to capture with an imaging system. By means of an additionally integrated laser scanner, the reflectors can also be selectively illuminated.

[36] Furthermore, the measuring system may include an expanded light source which illuminates the entire object. The reflectors throw reflected light back through the transmitting optics into the receiving sensors, for example the distance meter or the imaging system. This will replace the laser scanner.

[37] In combination with a laser scanner and a distance meter, a photodiode is sufficient to measure the distances and solid angles to at least three reflectors mounted on the measurement object. By suitable combination of the deflection angle obtained by the laser scanner with the signal of the photosensor so that the spatial position of the object can be determined.

For measuring the position of the object to be measured, it is also possible to use a system consisting of several light sources and time meters distributed in space. In this case, a suitable light signal is sent from the transmitter unit on the measuring platform to the object to be measured. A signal is transmitted via a receiver diode on the object, each with a constant time offset from spatially distributed light sources. In the undisturbed case, these light signals travel as spherical waves to the measuring system, where the transit times are measured by means of sensors at at least three points. With the known signal speeds in the medium between the transmitters and receivers, the corresponding distances can be calculated. By combining all the incoming and determined space distances, a high level of redundancy can be achieved, which increases the measurement accuracy. [39] The evaluation algorithm in the measuring system can be designed to be self-learning or interactive by continuously evaluating the measurement results and returning the adjustment information to the measurement platform. In this way it is possible to exactly determine the trajectory of a moving object in real time.

[40] So that the measuring system has a small size and can therefore be transported conveniently, its construction can be carried out in a telescopic or in a fold-out design.

[41] In order to guarantee the measuring accuracy of the system, the system can be calibrated with an independent third-party system or one can hold a defined object in the measuring volume, which is then calibrated by the measuring system itself. Self-calibration can be achieved automatically in systems with at least two cameras using any flat surface, ie a first-order surface: the system must be placed in a room with a flat surface. Then it looks for a usable plane, creates a specific light pattern and receives the image on all cameras. With suitable software, the calibration is accomplished.

[42] The procedure is to be designed in such a way that the measuring platform with the light-emitting and image-capturing units can be rotated about two axes. Preferably, the measuring platform is gimbal stored and adjusted in two axes. The set relative angular positions are detected very precisely by means of angle decoders.

[43] The discovery of the object is based on known techniques. For example, a camera with a fish-eye lens on the measuring platform can measure the spatial direction to a light-emitting diode on the object with sufficient accuracy so that the measuring platform can be aligned with the object. Another technique consists, for example, in that a GPS receiver is mounted both on the object and on the measuring platform and these communicate with each other, for example by means of WLAN, so that the relative position of the object to the measuring platform is known with sufficient accuracy for the corresponding alignment of the object measurement platform.

The data processing in the camera includes a sequence consisting of a background image without active light source and the subsequent series of images with exposure, an optoelectronic correction for each pixel, as well as statistical information of the image data after the subtraction of the background recording, such as sectoral histograms, histograms per row and column, mean, minima and maxima of gray value information. Depending on the background, the sequence may include a background shot alternating with each shot, or if the background is low or not moving, a background shot may be used for a longer frame of images become. Furthermore, image compression in sub-images with, for example, 4 × 4 or 8 × 8 pixels in the data flow when reading out the images from the sensor is calculated. These subpictures are used to quickly find searched Bildinfoπnationen.

[45] In some known systems of the highest accuracy class, cameras with zoom lenses are used. The focus of these lenses is varied so that the image size of the luminous part of the object is independent of the distance between the camera and the object.

[46] In contrast, the device presented here is based on cameras that have optics with fixed focal lengths. Thus, the field angle of these cameras is constant. In the far field of a camera with a constant field angle, the entire surface structure is typically imaged on the sensor, while in the near field only part of the structure is detected by the sensor. In the far field of the camera, the entire structure is imaged on the sensor, but only the coarser structures are sufficiently resolved by the sensor. In the near field of the camera, the fine structures are sufficiently resolved by the sensor, but only a part of the structure is imaged on the sensor. The image size of the structure varies in such a way with the distance between the camera and the object that only part of the sensor is occupied in the far field, while in the after field the imaged part of the structure occupies the entire sensor. For medium distances between the camera and the object, the structures are adapted accordingly, so that over the entire distance range between camera and object, a sufficiently good resolution can be achieved without transition. Thus, the surface structure consists of areas of different fine structures. Coarse and fine structures can penetrate.

[47] The optical axis of the camera is always aligned to the area with the finest structure. If the object contains a triple mirror, then the area with the finest structure is arranged around it. The triple mirror does not have to be in the center of coarser structures.

[48] The image of the structure on the sensor contains many more pixels with gray scale information than the usual devices with luminous dots. The accuracy of the orientation of the body in space is thus improved. In addition, with the redundant information of the structure, quality statements can be made about the state of the object during the measurement. As a result, deformations on the object provided with structures can be specifically detected. Thus, it is possible, for example, to detect unwanted deformations on the object during the measuring process or to quantitatively detect intentionally caused plastic deformations.

[49] A self-luminous structure is created by a backlight behind a masked structure. This backlight can be a spreader analog be an integrating sphere, so that an approximately homogeneous luminance is generated. Another possibility is the use of self-luminous area displays such as OLED (organic LED) with high contrast and luminance.

[50] Self-luminous structures can also be created by projecting patterns onto the object. The projection unit may be inside or outside the object.

[51] The structure is typically static. However, it can also be dynamic, for example by varying the degree of fineness of the structure or the extent of the illuminated structure by the distance of the object from the camera.

[52] Due to the finite recording time of the sensor for an image, the integration time must be kept short for moving objects. The more accurate the measurement of the body orientation is, the shorter must be either the sensor exposure time or, alternatively, the light pulse of the self-luminous or illuminated structure.

[53] The object structure must meet the required measurement accuracy of the overall system. The accuracy of the orientation determination of an object depends, among other things, on the structure size, the details of the structure, the luminance or illuminance of the structure, the distance camera object or the electro-optical properties of the camera. Three-dimensional structures provide more accurate orientation determination than flat structures.

[54] The following describes a structure that is self-luminous or not self-luminous. The structure should contain a tripple mirror for the distance measurement. The structure consists of self-luminous or non-self-luminous lines with different widths, so that the images on the digital sensor have optimal line widths for the applied subpixel evaluation. The lines used in the evaluation must not be too fine in relation to the pixel size, so that no unwanted moiré effects occur. The structure is formed in three dimensions. It should be noted that the entire structure for all required tilt angle and distances from the camera are sufficiently visible.

[55] The entire structure can serve to verify the inherent integrity and stylus tip. For this purpose, the information of the current structure is continuously compared with the structure before the measurement process. Thus, for example, body deformations can be detected during crash tests of assemblies which are intentionally induced during the measurement. The position of the probe tip with respect to the structure can be checked by means of a suitable movement of the body around the probe tip. To For example, the information of the current structure and the current position of the probe tip with respect to the structure is continuously compared with the corresponding values before the measurement.

[56] An optical bandpass filter must be installed in front of the sensor so that as much of the ambient light as possible is kept away from the sensor. In addition, it should be noted that no light from other system elements such as laser reaches the sensor. Disturbing secondary light scattering can be reduced by differentiating images with and without structure illumination.

[57] The structure surfaces should be sufficiently wear-resistant and covered with a transparent, thin, dirt-repellent layer. As surface material, for example, sapphire is suitable. The protective layer can be Epilame, which has been used successfully in the watch industry for many decades.

[58] The laser beam of the distance meter on the measuring platform is aligned with the center of the triple mirror. The alignment angles of the distance meter refer to the coordinate system of the measuring head. The distance meter determines along the optical axis the distance between a predetermined point on the measuring platform and the center of the triple mirror. Thus, the coordinates of the center of the triple mirror with respect to the coordinate system of the measuring head are known.

[59] The spatial orientation of the object is determined with respect to the now known center of the triple mirror by the evaluation of the sensor image of the structure on the object. The method is based on the comparison (correlation) of the image of the structure with the known reference image of the structure. In the comparison, the structural information is not reduced to a few points that are distinguished by certain symmetries. Rather, the entire image area or partial areas thereof are used directly in the comparison. In the practical implementation of the correlation technique can

[60] 1. the sensor image is condensed by merging pixel regions into one "larger pixel", thus making the total number of "larger pixels" smaller than the number of "normal pixels." For example, squares of the side length become such The further evaluation of the thus condensed sensor image is still based on the direct comparison with the reference image, thus obtaining a first approximation for the parameters of the spatial orientation of the object.

[61]. 2 the sensor image is split into several images that are created by parallel horizontal sections. These distributions allow obtaining a first approximation of the parameters of the Spatial orientation of the structure. Jamming of the parallel of the horizontal sections can also be applied to vertical sections or diagonal cuts,

[62] 3. the sensor image is split into subareas that are all individually correlated with corresponding subregions of the reference image. For example, intersecting lines are evaluated in their entirety and the intersection point is not determined.

[63] An advantageous procedure provides the following:

[64] Only a part of the spatial orientation of the object is determined, for example the rotation angle (roll) around the optical axis of the distance meter and that

[65] the structure around the triple mirror is suitable (for example with contrast differences) to measure the roll angle.

[66] In the following, the current state of the art according to EP 0 880 674 Bl and DE 690 05 106 T2 will be explained in greater detail with reference to FIGS. 1 and 2.

Fig. 1 shows a schematic representation of the device for measuring the spatial positions of moving objects. At least one camera and a distance meter are mounted on a gimbal-mounted measuring platform. On the object are a triple mirror as well as active point light sources, such as light emitting diodes,

Fig. 2 shows a schematic representation of a manually guided object (probe).

[67] With reference to the following figures 3 to 13, the invention will be explained in more detail.

FIG. 3 shows a schematic representation of the device for measuring the spatial positions of moving objects. Several gauging systems, such as cameras, are mounted on the gimbal-mounted measuring platform. On the object surface is a self-luminous structure, for example, consisting of straight or curved lines, areas with gray scale gradations or their combinations. This structure is imaged on the stereometrically arranged imaging systems and determines their spatial position with suitable algorithms. The GPS systems and the transceivers on the measuring platform and on the object are used to align the measuring platform with the object at the beginning of the measurement, 4 shows a schematic representation of a self-luminous structure on the object surface,

Fig. 5 shows another embodiment of the inventive arrangement for measuring the

Location of moving objects: At least two imaging systems, a laser scanner consisting of a mirror system and a laser, are mounted on the measuring platform. Any non-self-luminous surface structure, such as a relief or gray pattern of suitable reflective materials, or a combination thereof, which is suitably sequentially illuminated by the laser scanner, is mounted on the object.

Fig. 6 shows another Ausführungsfoπn the inventive arrangement for measuring the

Location of moving objects: At least one imaging system and a distance meter are mounted on the measuring platform. Mounted on the object are a reflector, for example a triple mirror, as well as a self-luminous structure according to FIG. 4,

FIG. 7 shows a further embodiment of the arrangement according to the invention for measuring the spatial positions of moving objects: at least one imaging system, a distance meter and a wide-angle light source are mounted on the measurement platform. On the object, a reflector, for example a triple mirror, and any non-self-luminous structure, as described in Fig. 5, attached,

Fig. 8 shows a further embodiment of the inventive arrangement for measuring the

Location of moving objects: The measuring platform has at least one imaging system and a distance meter aimed at the object by means of a mirror system. The object has the same surface design as in FIG. 6,

Fig. 9 shows a further embodiment of the arrangement according to the invention for measuring the spatial positions of moving objects: On the measuring platform, an imaging system, a distance meter and a wide-beam light source are mounted, all by means of a suitable arrangement of optical elements by the same optics on the object are directed. At least three triple mirrors are attached to the object,

10 shows a further embodiment of the arrangement according to the invention for measuring the spatial positions of moving objects: on the measuring platform there is a distance measurement. and a laser, whose light beams are deflected by a common scanner, and an imaging system, which are directed by a suitable arrangement of optical elements by the same optics on the object. On the object, a self-luminous structure, as described in Fig. 4, and a plurality of triples mounted,

11 shows a further embodiment of the arrangement according to the invention for measuring the spatial positions of moving objects: On the measuring platform are a distance meter and a laser whose light beams are deflected by a common scanner and a photosensor, all by means of a suitable arrangement of optical elements are directed to the object through the same optics. At least three strongly reflecting areas, such as triple mirrors, are mounted on the object,

Fig. 12 shows a further embodiment of the inventive arrangement for measuring the

Location of moving objects: The measuring platform contains a transmitter and at least three receivers for measuring the propagation time of spherical wave fronts, such as

Light pulses or radar waves. On the object a receiver and at least three transmitters are attached and

FIG. 13 shows a schematic representation of the signal sequence for transit time measurements for determining the spatial positions of moving objects.

14 shows a schematic representation of a self-luminous or non-self-luminous structure on the object surface with a rectangular grid pattern. The black colored lines of the grid pattern are places with high brightness and constant luminance or high reflectivity. The areas around the black colored lines absorb the light. In the center of the triple mirror is arranged.

FIG. 15 shows a further schematic representation of a structure on the object surface with a circular grid pattern having the same properties as in FIG. 14.

FIG. 16 shows a further schematic representation of a structure on the object surface with an elliptical lattice pattern having the same properties as in FIG. 14.

FIG. 17 shows a further schematic representation of a structure on the object surface with an octagonal grid pattern with the same properties as in FIG. 14. FIG. 18 shows another schematic representation of a structure on the object surface consisting of eight sectors with cross patterns with the same properties as in FIG. 14.

19 shows a further schematic representation of an object with a stylus tip and a structure on the object surface. The structure on the object surface is an eight-beam

Cross pattern with the same properties as in FIG. 14.

Fig. 20 shows a schematic representation of intersecting lines. The black colored lines or areas are places with high brightness and constant luminance or high reflectivity. The non-blackened areas absorb the light.

FIG. 21 shows a further schematic representation of a structure arranged around the triple mirror with the same properties as in FIG. 14.

FIG. 22 shows a further schematic illustration of a structure arranged around the triple mirror with the same properties as in FIG. 14.

FIG. 23 shows a further schematic illustration of a structure arranged around the triple mirror with the same properties as in FIG. 14.

FIG. 24 shows a further schematic illustration of a structure arranged around the triple mirror with the same properties as in FIG. 14.

FIG. 25 shows a further schematic representation of a structure arranged around the triple mirror with the same properties as in FIG. 14.

FIG. 26 shows a further schematic illustration of a structure arranged around the triple mirror and consisting of sectors. The black-colored sectors are places with high brightness and constant luminance or high reflectivity. The non-black colored sectors absorb the light. The coordinate system with center in the triple mirror center point shows the alignment angles.

[68] The devices shown schematically in Figures 1 and 2 are representative of the prior art and are used for non-contact measurement of the spatial position of an object 10 with respect to a measuring head 1. A measuring platform 6 is mounted, for example on a tripod 2 and in front of the object 10 posed. The measuring platform 6 is stored at 3 single or multi-axis. With motorized adjustment 5 arbitrary solid angles can be approached on the sphere. The positions of the measuring platform 6 are detected by exact angle decoder 4. At least one imaging system 7 with preferably a CCD area sensor and a distance meter 8 are mounted on the measurement platform 6. On the object 10, which is preferably formed as a button with the probe tip 13, as shown in FIG. 2, there are at least three light emitting diodes 12 and a triple mirror 11. The spatial position of the object is determined by the distance between the distance meter 8 and the Trippelspiegel 11 and the image information of the imaging system 7 of the LEDs determined.

[69] The apparatus shown schematically in Fig. 3 shows the essential elements of the invention for measuring the spatial positions of moving objects 10, such as buttons with the probe tip 13. On the two-axis, preferably gimbal, mounted measuring platform 6 at 3 are several imaging Systems 7, such as cameras, attached. On the object surface 10 is a self-luminous structure 14, for example consisting of straight or curved lines of finite thickness, surfaces with gray scale patterns or combinations thereof, as shown in Fig. 4. This structure 14 is imaged onto the stereometrically arranged imaging systems 7. With appropriate algorithms, the spatial position of the structure 14 and with the geometric knowledge and the spatial position of the probe tip 13 are determined.

[70] The device shown schematically in FIG. 5 shows another embodiment of the arrangement according to the invention for measuring the spatial positions of moving objects. At least two imaging systems 7, a laser scanner consisting of a mirror system 18 and a laser 17 with the optics 21, are now mounted on the measurement platform. On the object 10, a non-self-luminous structure 19 is mounted, which is illuminated by the laser scanner 17, 18 sequentially in a suitable manner.

[71] The apparatus shown schematically in FIG. 6 shows a further embodiment of the arrangement according to the invention for measuring the spatial positions of moving objects. Now at least one imaging system 7 and a distance meter 8 are mounted on the measuring platform. On the object 10, a reflector 11, for example, a triple mirror, and a self-luminous structure 14 as shown in FIG. 4 are attached.

[72] The apparatus shown schematically in FIG. 7 shows a further embodiment of the arrangement according to the invention for measuring the spatial positions of moving objects. Now are on the

Measuring platform 6 at least one imaging system 7, a distance meter 8 and a wide-beam

Light source 22 is mounted, which are directed by means of the optics 21 to the object 10. On the object 10, a reflector 11, such as a triple mirror, and any non-self-luminous structure 19 are mounted.

[73] The apparatus shown schematically in FIG. 8 shows a further embodiment of the arrangement according to the invention for measuring the spatial positions of moving objects. At least one imaging system 7 and a laser 17 directed onto the object 10 by means of a scanner 18 and the optics 21 and a distance meter 8 are now mounted on the measuring platform 6. On the object 10, a reflector 11, such as a triple mirror, and a suitable combination of self-luminous 14 and non-self-luminous structures 19 are attached.

[74] The apparatus shown schematically in FIG. 9 shows a further embodiment of the arrangement according to the invention for measuring the spatial positions of moving objects. Now are on the

Measuring platform 6, an imaging system 7, a distance meter 8 and a wide-angle light source 22 are mounted, which are all directed by a suitable arrangement of optical elements 26 through the same optics 21 to the object 10. At least three triple mirrors 11 are mounted on the object 10.

The distance meter 8 is directed sequentially by means of alignment of the measuring platform 6 on the individual triple mirror 11.

[75] The apparatus shown schematically in FIG. 10 shows a further embodiment of the arrangement according to the invention for measuring the spatial positions of moving objects. Now arranged on the measuring platform 6 are a distance meter 8 and a laser 17, whose light beams are deflected by a common scanner 18, and an imaging system 7, all of which are directed by a suitable arrangement of optical elements 26 through the same optics 21 onto the object 10 are. On the object 10 are a self-luminous structure 14, as described in Fig. 4, and a plurality of triple mirrors

11 attached.

[76] The apparatus shown schematically in FIG. 11 shows a further embodiment of the arrangement according to the invention for measuring the spatial positions of moving objects. Now on the measuring platform 6, a distance meter 8 and a laser 17, whose light beams are deflected by a common scanner 18, and a photosensor 23 are mounted, which are all directed by a suitable arrangement of optical elements 26 through the same optics 21 to the object 10 , At least three highly reflective areas, such as triple mirrors 11, are mounted on the object 10.

[77] The apparatus shown schematically in FIG. 12 shows a further embodiment of the arrangement according to the invention for measuring the spatial positions of moving objects. Now there are on the Messplattfoπn 6 a transmitter 27 and at least three receivers 28/1, 28/2, 28/3 at runtime spherical wave fronts, such as light pulses or radar waves. On the object 10, a receiver 23 and at least three transmitters 24/1, 24/2, 24/3 are mounted. However, any number of transmitters 24 / n and receivers 28 / n considered suitable may also be used (with n = 1, 2, 3,...).

[78] FIG. 13 schematically shows the signal sequence for transit time measurements for determining the spatial positions of moving objects. The transmitter 27 of the measuring platform 6 emits at a time interval 35 light pulses, which are received at a time interval 29 from the mounted on the object 10 receiver 23. Each of these received by the receiver 23 light pulse triggers at the transmitters 24/1, 24/2, 24/3 of the object 10 at a time offset at intervals 30, 34, etc. light pulses from the installed on the measuring platform 6 receivers 28/1, 28/2, 28/3 are received and at each of these receivers 28/1, 28/2, 28/3 at intervals 31, 32, 33 trigger light signals, which are used for the transit time measurement of spherical wave fronts. The pulses following each such light pulse of the transmitter 27 at the transmitters 24 and receivers 28 are shown in FIG. 13 only for the first light pulse 27.

[79] The diagram of FIG. 13 refers by way of example to a device with three transmitters 24/1, 24/2, 24/3 on the object 10 and with three receivers 28/1, 28/2, 28/3 on the measuring platform 6. According to the invention, however, any other number of transmitters 24 / n and receivers 38 / n considered suitable can be used.

FIGS. 14 to 26 show some embodiments of the self-luminous structure 14 or non-self-luminous structure 19 with a combination of geometrical patterns 15 and gray value patterns 16 on the object 10. In this case, a triple mirror 11 is always integrated. The optical axis of the camera is always aligned during the measurement on the triple mirror. Thus, the fine pattern areas 39 for the near field are arranged around the tripple mirror. The coarser the pattern 40-42, the farther away these areas are from the triple mirror. Near the tripple mirror, a zone 43 with a combination of fine to very coarse patterns can also be used to increase the accuracy of the orientation. Orientation aids 44 integrated in the structure are symmetry-breaking, geometric elements.

[81] The structure 14 can be flat or three-dimensional. Three-dimensional structures allow a higher accuracy in the orientation of the object than flat structures. The boundaries 45 and 46 may be in the same plane. However, the boundary 46 may also be wholly or partially outside the plane containing the boundary 45. [82] The circular grid pattern in FIG. 15 may be flat. A three-dimensional structure may have the shape of a funnel or a cone. The circular grid pattern thus lies on the mantle surface of a funnel or cone thus formed with the tripple mirror in the funnel center or on the apex of the cone. Analogously, the above explanations for FIG. 15 also apply to FIGS. 14, 16 to 25.

A further three-dimensional structure can be formed by the sectors 47 lying in the plane in FIG. 18 and the sectors 48 being formed as inclined planes. The sectors 48 touch the plane at area 45 and continuously increase to the boundary 46. Sectors 47 and 48 are planar substructures. Alternatively, the sectors 48 may descend continuously behind the plane spanned by the sectors 47. The areas 49 between the sectors 47 and 48 may also be formed as inclined planes with corresponding geometric patterns. This allows a further increase in the accuracy of the orientation of the object.

FIG. 19 shows a possible embodiment of an object 10 with a measuring tip 13, which is provided with a three-dimensional structure comprising eight sectors 47 and 48 and a triple mirror 11. The sectors are equipped with the patterns 39 to 42. The black lines and crosses 39 to 42 are areas of constant luminance and high brightness or high reflectivity. The marks 44 serve as the orientation of the structure. Each of the eight sectors has a flat surface. Four of the eight sectors 47 lie in the same plane as the area 45 next to the triple mirror 11. The other four sectors 48 are inclined at a certain angle with respect to the plane. These sectors 48 represent inclined planes analogously as in FIG. 18. The regions 49 between the sectors 47 and 48 can also be formed as inclined planes with corresponding geometric patterns. This allows a further increase in the accuracy of the orientation of the object.

[84] The basic geometric elements of self-luminous structures can be lines 50 with constant radiance and high brightness (Figure 20). The area 51 around these glowing lines is not bright. Alternatively, the bars 51 may not be self-luminous. Now they are embedded in luminous areas 52. The luminous areas 52 are surrounded by non-luminous areas 51.

[85] For non-self-luminous structures, the lines 50 are of high reflectivity (Figure 20). The area 51 around these reflective areas absorb the light. Alternatively, the bars 51 may be absorbent and the area 52 may be high reflectivity.

[86] Figures 21 to 26 show further possible structures on the object surface. All of the structures shown in FIGS. 14 to 26 are based on the structures 14 and 19. [87] The spatial position of the object is determined by correlation of the known structure with the measured structure. Neither the entire structure nor parts of it are reduced to a geometric point.

[88] Instead of determining all the components of the object position, it is also possible to supplement other possible detection systems only certain components of the spatial position, such as the rotation of the object about the axis (roll in FIG. 26), that of the distance meter 8 and the triple mirror 11 is defined.

Claims

claims:

1. A device for measuring an object with a gimbal-mounted measuring platform, a distance meter, at least one imaging system, a mounted on the object triple mirror and a mounted on the object structure, characterized in that the structure consists of geometric patterns of lines and limited areas ,

2. Device according to claim 1, characterized in that the structure has at least one coarse structure and a fine structure.

3. Device according to claim 1 or 2, characterized in that the fine structure is arranged within the coarse structure.

4. Apparatus according to claim 2 or 3, characterized in that the coarse structure and the

Fine structure are arranged adjacent to each other.

5. Device according to one of claims 2 to 4, characterized in that the fine structure is arranged closer to the triple mirror than the coarse structure.

6. Device according to one of the preceding claims, characterized in that the structure consists of several areas which are arranged around the tripple mirror.

7. Device according to one of the preceding claims, characterized in that the

Patterns get larger with increasing distance to the triple mirror.

8. Device according to one of the preceding claims, characterized in that the

Structure of geometric patterns has simple partially rotationally symmetric basic structures together with superimposed complex structures.

9. Device according to one of the preceding claims, characterized in that the structure is flat.

10. Device according to one of the preceding claims, characterized in that the

Structure is funnel-shaped or cone-shaped.

11. Device according to one of the preceding claims, characterized in that the structure is three-dimensional.

12. Device according to one of the preceding claims, characterized in that the structure and the surface of the object have rotationally symmetric properties.

13. Device according to one of the preceding claims, characterized in that the

Structure is self-luminous or has at least one self-luminous area.

14. Device according to one of the preceding claims, characterized in that the structure is not self-luminous and having reflective, absorbent, matte, glossy, phosphorescent or fluorescent materials.

15. Device according to one of the preceding claims, characterized in that a fixed focal length imaging system is used.

16. Device according to one of the preceding claims, characterized in that for illumination, preferably on the measuring platform, a light source is arranged.

17. Device according to one of the preceding claims, characterized in that for illumination, preferably on the measuring platform, a scanner is arranged.

18. The device according to claim 17, characterized in that the scanner deflects a distance meter.

19. Device according to Speech 17, characterized in that the scanner deflects a laser.

20. The device according to spoke 17, characterized in that the scanner deflects a retroreflective light beam to a photosensor on the measuring platform.

21. Device according to one of the preceding claims, characterized in that the distance meter is arranged on the measuring platform.

22. Device according to one of the preceding claims, characterized in that the imaging system, a light source and a distance meter is aligned by means of an optical system by the same optics on the object with at least one, preferably three triple mirrors.

23. Device according to one of the preceding claims, characterized in that optical elements such as fish-eye lenses or cassette-type sensors and on the object a light emitter are arranged on the measuring platform.

24. An apparatus for measuring an object with a structure mounted on the object, characterized in that the structure by at least three spherical wave transmitter and a

Receiving sensor is formed.

25. An apparatus for measuring an object with a structure mounted on the object, characterized in that an imaging system is formed by at least three receiving sensors and a spherical wave transmitter.

26. Device according to one of claims 24 or 25, characterized in that a GPS receiver is arranged on the measuring platform and the object.

27. Method for using a device according to one of claims 1 to 23, in which the distance between a point on the measuring platform and the triple mirror is determined, the angles of the straight lines defined by this point and the triple mirror center point, determined with respect to the coordinate system of the measuring head be a sensor image with the imaging

System of the attached to the object structure or parts of the structure is generated, compared with a stored reference image of the structure and the spatial position of the object is determined therefrom.

28. The method according to claim 27, characterized in that prior to the comparison pixel regions of the sensor image are combined to form a pixel in order to densify the sensor image.

29. The method according to claim 27 or 28, characterized in that before the comparison, the sensor image is split into a plurality of subregions.

30. The method according to any one of claims 27 to 29, characterized in that partial areas of the sensor image are each compared with the corresponding portions of the reference image.