Device for testing and / or setting and / or calibrating at least one imaging system

Abstract

The invention relates to a device for testing and / or setting and / or calibrating at least one imaging system, in particular a lidar system, wherein at least one radiation-emitting unit is allocated to the imaging system, wherein by means of the emitted radiation a detection field can be formed, wherein the device has at least one bundling apparatus for bundling the detection field formed by the radiation, wherein the bundling apparatus has at least one optical element which bundles the detection field and is set at a particular angle to the imaging system, wherein the device has at least one radiation unit arranged downstream of the bundling apparatus for orienting the radiation to an entry region of a kaleidoscope, wherein the kaleidoscope has reflection surfaces which face one another and deflect the radiation within the kaleidoscope depending on a particular entry angle of the radiation into the kaleidoscope, and wherein the device has at least one measuring apparatus, adjacent to an exit region of the radiation out of the kaleidoscope, for detecting the radiation exiting the kaleidoscope and / or at least one reflection apparatus for reflecting the radiation exiting the kaleidoscope.

Description

[0001] Device for testing and / or adjusting and / or calibrating at least one imaging system

[0002] The invention relates to a device for testing and / or adjusting and / or calibrating at least one imaging system, in particular a lidar system, wherein at least one radiation-emitting unit is assigned to the imaging system and wherein a detection field can be formed using the emitted radiation. Imaging systems of the type mentioned above, in particular lidar systems (light detection and ranging), are used, for example, for optical distance and speed measurement, for remote measurement of atmospheric parameters, or in a variety of other fields of application. Imaging systems can be active or passive imaging systems. Passive imaging systems can, for example, have a radiation receiver. Active imaging systems can, for example, have a radiation transmitter, i.e., a radiation-emitting unit and a radiation receiver.Imaging systems can include headlights, flashlights, structured light scanners, time-of-flight cameras, or similar devices. The radiation can be coherent or incoherent light. A radiation-emitting unit can be a laser, a light source, or other radiation source. For example, a three-dimensional space can be scanned using radiation. The space scanned by the imaging system is the field of view. Imaging systems, particularly lidar systems, are used, for example, in the control and navigation of autonomous vehicles. Precise setting, calibration, and testing of imaging systems is essential to enable accurate measurements using lidar.For end-of-line testing of imaging systems, for example, extensive test fields can be used, which are modeled on the real conditions of an autonomous vehicle. This sometimes requires large test fields and test setups. This results in a high level of testing effort, making it unsuitable for mass production, i.e., for testing every manufactured imaging system.

[0003] The invention is based on the object of proposing a device and a method for testing and adjusting an imaging system, wherein the test setup has compact dimensions and is designed for the end-of-line test of mass production.

[0004] This object is achieved by a device having the features of patent claim 1 and by a method having the features of patent claim 23. Further developments and advantageous embodiments are specified in the subclaims.

[0005] Essential to the invention is a device for testing and / or adjusting and / or calibrating at least one imaging system, in particular a lidar system, wherein at least one radiation-emitting unit is assigned to the imaging system, wherein a detection field can be formed by means of the emitted radiation, wherein the device has at least one bundling device for bundling the detection field formed by the radiation, wherein the bundling device has at least one optical element arranged at a specific angle to the imaging system and bundling the detection field, wherein the device has at least one radiation directing unit arranged downstream of the bundling device for directing the radiation onto an entrance area of ​​a kaleidoscope, wherein the kaleidoscope has mutually facing reflection surfaces,which deflect the radiation within the kaleidoscope depending on a specific angle of incidence of the radiation into the kaleidoscope, and wherein the device has at least one measuring device connected to an exit region of the radiation from the kaleidoscope for detecting the radiation emerging from the kaleidoscope. The device can have at least one test fixture, which can accommodate the imaging system to be tested. The test fixture can be adapted to the type of system to be tested, in particular the imaging system, and can be interchangeable so that different systems can be tested with the device. However, the device can also be placed in front of a system to be tested without a test fixture. For testing a passive imaging system, the device can comprise a radiation-emitting unit, for example a laser or a similar radiation source.The emitted radiation can be used to test the passive imaging system under investigation. In an active imaging system, the imaging system itself has the radiation-emitting unit. The device has at least one focusing device, which is provided for focusing the detection field formed by the radiation emitted by the imaging system. For example, the detection field can be formed by scanning an area using the radiation-emitting unit of the imaging system in the X and Y directions. The detection field can also be formed, for example, by the radiation received from an area. In this case, it can particularly be laser radiation. The radiation can also be, for example, infrared radiation, coherent or non-coherent light, or the like. The detection field can be focused by the focusing device,particularly in the X-direction and Y-direction. The detection field is thus focused on a smaller area. This makes it possible to examine a larger detection field of the system under test in a compact space. The bundling in the horizontal and vertical planes can be carried out independently of each other, in particular one after the other. For this purpose, the bundling device has optical elements, for example lenses, parabolic mirrors or metamaterial-based surfaces. Moldable mirrors, reflectors or curved surfaces can also be used. Downstream of the bundling device in the beam path is a radiation directing unit with which the radiation emerging from the bundling device can be directed, in particular aligned. The radiation that forms the bundled detection field is directed by the radiation directing unit.directed to the entrance area of ​​a kaleidoscope. The radiation directing unit can, for example, be a controllable mirror so that the radiation can be directed at different angles onto the entrance area of ​​the kaleidoscope. The radiation directing unit can also function as a diaphragm, for example, if the mirror of the radiation directing unit is small compared to the cross section of the emitted radiation, thus preventing unwanted parts of the radiation from being directed into the kaleidoscope. The kaleidoscope has mutually facing reflecting surfaces through which the beam path of the emitted radiation in the kaleidoscope can be extended by reflections from the reflecting surfaces. The length of the radiation path within the kaleidoscope depends on the angle of entry of the radiation into the kaleidoscope. In particular, a kaleidoscope can be formed by a two-dimensional polygon,For example, a triangular or quadrangular imaginary base surface can be formed, which is stretched along the third dimension. The kaleidoscope thus has a polygonal cross-section. The inward-facing inner sides of the lateral surfaces created by the stretching are reflective, whereby the front sides can be open. A hollow space is formed between the lateral surfaces. The kaleidoscope can, in particular, be formed by a geometric body known as a prism, i.e., a spatial body formed by the parallel displacement of a flat polygon in a straight line not lying in this plane. The geometric body is formed only by the lateral surfaces. There are no physical base surfaces, so the front sides are open, and the volume enclosed by the lateral surfaces is formed as a hollow space. The smaller the angle between the imaginary base surface of the kaleidoscope and the incoming radiation,The more reflections occur inside the kaleidoscope and the longer the radiation path becomes, i.e., the length of the path traveled within the kaleidoscope. The angle at which the radiation enters the kaleidoscope determines the length of the radiation path within the kaleidoscope. The radiation path length can therefore be determined by the radiation directing unit. By using the kaleidoscope, different path lengths of the radiation emitted by the system under test can be examined in a small space. The device has at least one measuring device at an exit area of ​​the radiation from the kaleidoscope for detecting the radiation emerging from the kaleidoscope. The measuring device can measure various parameters of the system under test, such as properties of the detection area, properties of the radiation, detection areas of the imaging system, or similar.For example, the measuring device can comprise optical measuring cells, reflectors, and the like. Furthermore, a reflection device can be provided that reflects the radiation emerging from the kaleidoscope back for further evaluation. An evaluation device, in particular a computing device or the like, can be provided to evaluate the radiation detected by the measuring device. The evaluated data can be used for testing and / or adjusting and / or calibrating the imaging system.

[0006] In one development of the invention, the device has at least one test holder for receiving the imaging system to be tested. The device has at least one test holder, which can receive the imaging system to be tested. In particular, the test holder can have connecting means such as clamps or receiving points corresponding to the imaging system, so that the imaging system is firmly held by the test holder. The test holder can be adapted to the type of system to be tested, in particular the imaging system, and can be interchangeable so that different systems can be tested with the device. In particular, the test holder has a bearing for performing a translational movement or a rotational movement.

[0007] In one embodiment of the invention, the test fixture comprises at least one clamping device that is arranged for translational movement, rotational movement, or both translational and rotational movement relative to other components of the device. The translational and rotational movement arrangement ensures precise alignment of the system to be tested, in particular the lidar system, for example, with the focusing device in the device. The test fixture can have a mechanical, electronic, and / or data-conducting interface to the system to be tested.

[0008] In a further development of the invention, at least one sensor is assigned to the test fixture, the focusing device, the radiation directing unit, the kaleidoscope, and / or the measuring device, with which environmental influences on the device or its components can be determined. The sensor(s) can be designed, for example, to measure temperature, air pressure, vibration, or other environmental conditions in order to be able to incorporate the measured values ​​of these environmental conditions into, for example, a calibration or adjustment of the system under test. In a further development of the invention, the focusing device has at least one reflective surface, a lens, or a metamaterial as an optical element.To focus the detection field formed by the radiation emitted by the system under test, the focusing device has, for example, curved reflection surfaces that can focus the detection field independently of one another in the horizontal and vertical planes. Similar effects can be achieved, for example, by using lenses or metamaterials. Deformable mirrors, in particular controllably deformable mirrors, or parabolic mirrors or similar devices can also be provided.

[0009] In one embodiment of the invention, at least one reflection surface is a parabolic mirror. A parabolic mirror allows the radiation emitted by the system under test, forming the detection field, to be focused in both the horizontal and vertical planes.

[0010] In one embodiment of the invention, the reflection surfaces of the focusing device are aligned with one another in such a way that they each act on the detection field formed by the emitted radiation in different planes, in particular, at least one reflection surface is assigned to a horizontal axis of the detection field and at least one reflection surface is assigned to a vertical axis of the detection field. For example, by two reflection surfaces, which can in particular be semi-cylindrically concave at least in sections, the detection field can be focused by a first reflection surface in a horizontal plane and by a second reflection surface in a vertical plane.The decoupled horizontal and vertical focusing reduces the requirements for the optical elements compared to, for example, focusing by a single optical element, such as a parabolic mirror. After exiting the system under test, the radiation is first directed to one reflection surface and then reflected from there to the second reflection surface.

[0011] In one embodiment of the invention, the reflection surfaces of the focusing device are each focused and, at least in sections, substantially cylindrical in shape, in particular rotated 90° relative to one another to align the incident radiation. Reflection surfaces of the focusing device can be formed by focusing, in particular concave, substantially cylindrical, in particular hollow-cylindrical, bodies. The lateral surface sections of the reflection surface are rotated substantially 90° relative to one another in their longitudinal extent. The detection field is focused in a horizontal plane by one reflection surface and subsequently focused in a vertical plane by the other reflection surface. This ensures independent bundling of the dimensions of the detection field.

[0012] In one embodiment of the invention, the bundling device has an internal calibration device, in particular an automatically adjusting self-calibration device. The calibration device ensures precise alignment and adjustment of the bundling device.

[0013] In a further development of the invention, the radiation directing unit is composed of at least one mirror, at least one scanning mechanism, and at least one control unit. The scanning mechanism enables the radiation directing unit to direct the radiation emerging from the bundling device at different angles onto the entry area of ​​the kaleidoscope. This makes it possible to achieve different path lengths of the radiation in the kaleidoscope. For this purpose, the control mirror of the radiation directing unit is pivoted about at least one axis by the scanning mechanism. The scanning mechanism can be implemented, for example, by piezoelectric actuators, servo motors, or the like. The control mirror of the radiation directing unit can be constructed, for example, by a layer structure made of dielectric material or other layer arrangements in order to achieve optimization for different angles of incidence and different wavelengths.Furthermore, the control mirror can be constructed of metamaterials. The scanning speed at which the control mirror is pivoted must be lower than that of the internal scanner of the system under test, in particular the laser scanner of a lidar system under test, which is used to scan the detection field of the imaging system.

[0014] In one embodiment of the invention, the radiation directing unit is rotatable about at least one axis. By rotating the control mirror, different angles of incidence to the kaleidoscope and thus different radiation path lengths within the kaleidoscope can be achieved.

[0015] In one embodiment of the invention, the radiation directing unit acts as a diaphragm between the focusing device and the kaleidoscope. The effect of the diaphragm can be achieved by the size of the control mirror, for example, by preventing peripheral regions of the radiation emerging from the focusing device from being passed on by the control mirror into the kaleidoscope.

[0016] In one embodiment of the invention, the kaleidoscope has a polygon as an imaginary base surface, lateral surfaces adjoin the sides of the imaginary base surface, the lateral surfaces together enclose a cavity at least in sections, the lateral surfaces have reflective surfaces, and the reflective surfaces are arranged on the inward-facing inner sides of the lateral surfaces. A kaleidoscope can be formed by an imaginary two-dimensional base surface, which can be a polygon, that is stretched along the third dimension. For example, the base surface can be triangular or quadrangular, thus the kaleidoscope can have a triangular or quadrangular cross-section. The inward-facing inner sides of the lateral surfaces created by the stretching are reflective. A cavity is formed between the almond surfaces, and the end faces of the kaleidoscope can be open.

[0017] In a further development of the invention, the bundling device, the radiation directing unit, and / or the kaleidoscope have alignment markings. These alignment markings enable precise alignment of the various components to achieve precise beam path guidance.

[0018] In one embodiment of the invention, the measuring device comprises at least one retroreflector. The retroreflector allows the radiation emerging from the kaleidoscope to be reflected back and detected, for example, by a radiation receiver of the imaging system. This allows various parameters and functions of the system under test to be tested.

[0019] In one embodiment of the invention, the measuring device has at least one optical detection element. An optical detection element can be, for example, a photodiode, a photosensor, or the like. This plurality of optical detection elements, which can be arranged, for example, on a grid, can be provided to check, for example, the formation of the detection field.

[0020] In one embodiment of the invention, the device comprises at least one evaluation device for evaluating the radiation detected by the measuring device. The evaluation device can be, for example, a computing device, such as a computing core or the like. The evaluation device can evaluate the detected radiation; in particular, various parameters of the imaging system and the radiation emitted by the imaging system can be detected.

[0021] In a further development of the invention, the surface structure of the reflective surfaces of the kaleidoscope is defined by a mathematical function f(x,y), where x and y lie in a range limited by the horizontal and vertical lengths of the reflective surfaces, and where f(x,y) describes the height profile of the surface structure of the reflective surfaces. The mutually facing reflective surfaces, i.e., the reflective surfaces of the kaleidoscope, can be formed by different surface structures. For example, the reflective surfaces, in particular the mirror surfaces, of the kaleidoscope can be designed as freeform surfaces, curved surfaces, or similar surface shapes. The height profile of the reflective surfaces can be described by a mathematical function f(x,y).The variable x can be limited by the horizontal length of the kaleidoscope's reflecting surfaces, and the variable y can be limited by the vertical length of the reflecting surfaces. The function f(x,y) can be a flat, constant function. However, the function f(x,y) can also be a polynomial function, a series of harmonic functions, or something similar. The reflecting surfaces of the kaleidoscope can be mirrors, for example.

[0022] In a further development of the invention, the measuring device has a reflective, movable target. The target is arranged on a rotating holder, wherein the tangential movement component of the target can be detected by a movement of the radiation. The measuring device has a rotating holder with a reflective target. The radiation, in particular the laser radiation, strikes the rotating target and is deflected by it. The deflection and movement of the deflected laser beam can be used to determine the tangential component of the movement of the movable holder. In particular, a movement component of the target can be detected by a movement of the deflected radiation towards or away from the emitted radiation. For example, a movement of a laser spot generated by the deflected radiation can be detected. This enables Doppler LiDAR systems (LDARs) toDoppler shift Lidar) such as FCMW Lidar systems or RMCW Lidar systems.

[0023] In a further development of the invention, a reflective target is a hologram written using laser radiation. The hologram is designed to resonate with the incident laser radiation, wherein the resonance leads to a three-dimensional reflection that is detectable by the incident laser radiation. A hologram can be recorded using light of one wavelength and thus also detected by a laser of the same wavelength. The light reflection of the hologram has a three-dimensional structure. These can be provided as a target, for example as a reflective target in the measuring device. For example, a vehicle or a person can be recorded as a hologram and serve as a reflective target. A reflective hologram can thus serve as a three-dimensional reflector for the laser radiation, even though the hologram is essentially flat.

[0024] In a further development of the invention, a beam splitter is arranged in the beam path after at least one module for diverting at least a portion of the radiation, and each beam splitter is assigned a detection device and / or an evaluation device and / or a reflection element. Beam splitters can divert portions of the radiation after a module of the measuring device, such as after the bundling device or the kaleidoscope, for example, in order to characterize the radiation.

[0025] In a further development of the invention, at least one material is arranged in the beam path within the kaleidoscope, wherein the material is transparent to the radiation, wherein the material has light scattering elements for scattering the laser light. A material or an object consisting of the material can be arranged in the beam path of the radiation, in particular the laser radiation, in the kaleidoscope. The material is transparent to the radiation, in particular to the laser radiation. It can be, for example, glass plates processed by means of laser radiation. Scattering elements, which can be generated by means of a laser, for example, are arranged in the material volume. The scattering elements can be microscopic and distributed according to a predetermined pattern or randomly in the material volume.The scattering elements scatter the incoming radiation, allowing controlled backscattering of the radiation toward the radiation source. This allows various weather conditions, such as those in which a lidar system under test would be operated, to be simulated. The scattering elements can thus simulate raindrops, snow, or even fog.

[0026] The invention further relates to a method for testing and / or adjusting and / or calibrating at least one imaging system, in particular a lidar system, wherein at least one radiation-emitting unit is assigned to the system, wherein a detection field can be formed by means of the emitted radiation, wherein the length of the radiation path of the radiation forming the detection field is extended and wherein the extension of the radiation path can be described by at least one iterated function. In particular, the method is designed to be carried out with the previously described device of the preceding claims. The method is provided for testing and / or adjusting and / or calibrating an imaging system, such as a headlight, a flashlight, a structured light scanner, a time-of-flight camera, a lidar system or the like.An active imaging system can be configured to emit radiation, for example, coherent or incoherent light, using a radiation-emitting unit. For testing a passive imaging system, the device can comprise a radiation-emitting unit, for example, a laser or a similar radiation source. The emitted radiation can be used to test the passive imaging system under investigation. In an active imaging system, the imaging system itself comprises the radiation-emitting unit. The emitted radiation forms a detection field. A device according to the invention, which has a focusing device, can focus the radiation forming the detection field. The focusing device can reduce the detection field, particularly in the X and Y directions.The detection field is therefore focused on a smaller space. This makes it possible to examine what would otherwise be a larger detection field of the system under test in a compact space. After focusing, the radiation forming the focused detection field is forwarded, for example, using a radiation directing unit. In order to be able to examine different radiation path lengths of the emitted radiation, the radiation path of the radiation emitted, for example, by the system under test is extended in a small space. The aim here is for the extension of the beam path to be describable by at least one iterated function. An iterated function is a function obtained by combining another function with itself a certain number of times.Starting from an initial function, the result of applying a specific function is used again as input to the function, and this process is repeated accordingly. For example, the number of iterations can be used to describe an extension of the radiation path due to reflections, in particular multiple reflections, of the radiation on reflected surfaces. The radiation path extension based on iterated functions enables an investigation of the emitted radiation to examine the system under test at different radiation path lengths in a small space. In a further development of the invention, the detection field formed by the emitted radiation is focused by means of at least one focusing device.To focus the detection field formed by the radiation emitted by the system under test, the focusing device has, for example, curved reflection surfaces that can focus the detection field independently of one another in the horizontal and vertical planes. Similar results can be achieved, for example, by using lenses or metamaterials. Deformable mirrors, in particular controllable, deformable mirrors or parabolic mirrors, can also be provided.

[0027] In a further development of the method, the bundling of the detection field takes place by means of the bundling device one after the other in different planes, in particular bundling takes place in a horizontal axis of the detection field and in a vertical axis of the detection field independently of one another. For example, one reflection surface can be assigned to a horizontal axis of the detection field and one reflection surface to the vertical axis of the detection field. By means of two reflection surfaces, which can in particular be hollow, cylindrical and concave at least in sections, the detection field can, for example, be bundled by a first reflection surface in a horizontal plane and bundled by a second reflection surface in a vertical plane. By decoupled horizontal and vertical bundling, the requirements for the optical elements, for example a bundling by a single optical element, are reduced.After exiting the system to be tested, the radiation is first directed onto one reflective surface and reflected from there onto the second reflective surface in order to achieve bundling, first in a horizontal and then in a vertical plane. In a further development of the method, the length of the radiation path of the radiation forming the detection field is extended by means of at least one kaleidoscope, and the length of the radiation path is adjusted by the angle of incidence of the radiation into the kaleidoscope. The radiation forming the bundled detection field is directed onto the entrance area of ​​a kaleidoscope by means of a radiation directing unit. The kaleidoscope has mutually facing reflective surfaces through which the radiation path of the emitted radiation in the kaleidoscope can be extended by reflections from the reflected surfaces.The length of the radiation path within the kaleidoscope depends on the angle at which the radiation enters the kaleidoscope. In particular, a kaleidoscope can be formed by a two-dimensional polygon, for example a triangular or quadrangular imaginary base surface, which is stretched along the third dimension. The inward-facing inner sides of the lateral surfaces created by the stretching are reflective. A cavity is formed between the lateral surfaces. The smaller the angle between the imaginary base surface of the kaleidoscope and the incoming radiation, the more reflections occur inside the kaleidoscope and the longer the radiation path becomes, i.e. the length of the path traveled by the kaleidoscope. The angle at which the radiation enters the kaleidoscope therefore determines the length of the radiation path in the kaleidoscope.

[0028] The drawings illustrate an embodiment of the invention, from which further essential features of the invention may emerge. Identical parts are provided with the same reference numerals throughout the figures of the drawings. They show:

[0029] Figure 1: a schematic representation of essential components of a device according to the invention; Figure 2: a schematic representation of a bundling device of the device according to the invention according to Figure 1 in a perspective view;

[0030] Figure 3: a schematic representation of a bundling device of the device according to the invention according to Figure 1 in side view;

[0031] Figure 4: a schematic representation of a kaleidoscope of the device according to the invention; and

[0032] Figure 5: a schematic representation for calculating a distance to be covered within the kaleidoscope according to Figure 4.

[0033] Figure 1 shows a device according to the invention comprising a test holder 1, a bundling device 2, a radiation directing unit 3, a kaleidoscope 4, a measuring device 5, and an evaluation unit 6. The test holder 1 is designed and provided for clamping a laser beam emitting unit 7 of an imaging system to be tested, in particular a lidar system. The laser beam emitting unit 7 is arranged relative to the other components in such a way that the emitted radiation passes successively first through the bundling device 2, then through the radiation directing unit 3, and finally through the kaleidoscope 4, and the radiation A strikes the measuring device 5. The measuring device 5 is formed in the illustration by a number n of measuring cells 8, 8', wherein each of the measuring cells 8, 8' is coupled to the evaluation unit 6, i.e., measurement data is forwarded accordingly to the evaluation unit 6.

[0034] What is essential for the invention is the combination of the bundling device 2 with the radiation directing unit 3 and the kaleidoscope 4, by means of which larger distances for the laser beam A can be simulated in accordance with real conditions.

[0035] Figures 2 and 3 show the bundling device 2 in detail, which is shown in Figure 2 in a perspective view and in Figure 3 in a side view. The bundling device in Figure 2 is formed by a lens system 9 arranged upstream in the beam direction and two cylindrical, concavely curved reflective surfaces 10, 10'. The cylindrical, concavely curved reflective surfaces 10, 10' are aligned with one another in such a way that the central axes assigned to the cylindrical curvatures are set at a right angle to one another. The reflective surfaces 10, 10' thus bundle the incident radiation A in different planes and focus the detection field of the imaging system formed by the radiation onto a smaller area. The radiation A can be guided past a camera detector 11, 12 after the output.Using the camera detectors 11, 12, the correct alignment of the reflection surfaces 10, 10' relative to each other can be checked and adjusted based on the determined values. The camera detector 12, located at the output of the bundling device 2, is connected to the radiation directing unit 3, to which the laser beam A is fed.

[0036] The illustration in Figure 3 further shows that radiation A strikes the reflection surface 10 at an angle between 45° and 90°, is focused in a first plane, and is projected onto the second reflection surface 10', onto which the laser beam A strikes at an angle of approximately 45° and is again focused in a further plane perpendicular to the previous plane. The detection field of the imaging system formed by the emitted radiation A is then focused onto a smaller area, and the radiation is fed to the radiation directing unit 3.

[0037] Finally, Figure 4 shows a detailed view of the function of the kaleidoscope 4. The kaleidoscope 4 has lateral surfaces 16, 16', 16", 16'" arranged at right angles to one another, which form internally mirrored reflection surfaces at which the incident radiation A is reflected and deflected depending on a specific angle of incidence. In Figure 4, the radiation A shown forms a total of four complete helices, with the radiation A per helix striking each of the lateral surfaces 16, 16', 16", 16'" once before the radiation A is guided out of the kaleidoscope 4 at a predetermined exit region 15. Both the exit region 15 and the entry region 14 of the radiation A are assigned to the opposite imaginary base surfaces of the kaleidoscope 4.

[0038] Figure 5 shows an example of how the path length of the radiation A striking the lateral surfaces 16, 16', 16", 16'" is calculated. The individual lateral surfaces 16, 16', 16", 16'" have a width a, whereby the radiation strikes the lateral surfaces 16, 16', 16", 16'" in the middle and travels a path length I = a / 2 between two lateral surfaces 16, 16', 16", 16'" in each case. This then means that the path length per helix is ​​calculated from I = 4a / 2 = ax 2 x 2. This results in a path length per helix of ~ 2.83a. In a next step, the total path length GL can be calculated using the path length I and a factor n corresponding to the number of path lengths within the kaleidoscope 4. The formula used is that factor n = (total path length GL) / (path length I). Assuming dimensions of the lateral surfaces 16, 16', 16", 16'" of kaleidoscope 4 of a = 60 cm and n = 18, this results in a total path length GL > 30 m.

Claims

Patent claims 1. Device for testing and / or adjusting and / or calibrating at least one imaging system, in particular a lidar system, wherein at least one radiation-emitting unit is assigned to the imaging system, wherein a detection field can be formed by means of the emitted radiation, wherein the device has at least one bundling device (2) for bundling the detection field formed by the radiation (A), wherein the bundling device (2) has at least one optical element which is set at a specific angle to the imaging system and bundles the detection field, wherein the device has at least one radiation directing unit (3) arranged downstream of the bundling device (2) for directing the radiation (A) onto an entrance region (14) of a kaleidoscope (4), wherein the kaleidoscope (4) has mutually facing reflection surfaces (16, 16').16", 16'"), which deflect the radiation (A) within the kaleidoscope (4) as a function of a specific angle of incidence of the radiation (A) into the kaleidoscope (4), and wherein the device has at least one measuring device (5) adjoining an exit region (15) of the radiation (A) from the kaleidoscope (4) for detecting the radiation (A) emerging from the kaleidoscope (4) and / or at least one reflection device for reflecting the radiation (A) emerging from the kaleidoscope (4).

2. Device according to claim 1, characterized in that the device has at least one test holder (1) for receiving the imaging system to be tested.

3. Device according to claim 2, characterized in that the test holder (1) has at least one clamping device which is arranged to be translationally movable, rotationally movable or translationally and rotationally movable relative to other components of the device.

4. Device according to one of claims 2 or 3, characterized in that the test holder (1), the bundling device (2), the radiation directing unit (3), the kaleidoscope (4) or the measuring device (5) is assigned at least one sensor with which environmental influences on the device or its components can be determined.

5. Device according to one of claims 1 to 4, characterized in that the bundling device (2) has at least one reflection surface (10, 10'), a lens or a metamaterial as an optical element.

6. Device according to claim 5, characterized in that at least one reflection surface (10, 10') is a parabolic mirror.

7. Device according to claim 5, characterized in that the reflection surfaces (10, 10') of the bundling device (2) are aligned with each other in such a way that they each act in different planes on the detection field formed by the emitted radiation, in particular at least one reflection surface (10) is assigned to a horizontal axis of the detection field and at least one reflection surface (10') is assigned to a vertical axis of the detection field.

8. Device according to one of claims 5 to 7, characterized in that the reflection surfaces (10, 10') of the bundling device (2) are each focusing and at least partially substantially cylindrical in shape, in particular are rotated offset by 90° to one another for aligning the incident radiation.

9. Device according to one of claims 1 to 8, characterized in that the bundling device (2) has at least one internal calibration device, in particular an automatically adjusting self-calibration device.

10. Device according to one of claims 1 to 9, characterized in that the radiation directing unit (3) is composed of at least one mirror, at least one scanning mechanism and at least one control unit.

11. Device according to one of claims 1 to 10, characterized in that the radiation directing unit (3) is designed to be rotatable about at least one axis.

12. Device according to one of claims 1 to 11, characterized in that the radiation directing unit (3) functions as a diaphragm between the bundling device (2) and the kaleidoscope (4).

13. Device according to one of claims 1 to 12, characterized in that the kaleidoscope (4) has a polygon as an imaginary base surface, that lateral surfaces adjoin the sides of the imaginary base surface, that the lateral surfaces together enclose a cavity at least in sections, that the lateral surfaces have reflection surfaces (16, 16', 16", 16'") and that the reflection surfaces (16, 16', 16", 16'") are arranged on the inward-facing inner sides of the lateral surfaces.

14. Device according to one of claims 1 to 13, characterized in that the bundling device (2), the radiation directing unit (3) and / or the kaleidoscope (4) has alignment markings.

15. Device according to one of claims 1 to 14, characterized in that the measuring device (5) has at least one retroreflector.

16. Device according to one of claims 1 to 15, characterized in that the measuring device (5) has at least one optical detection element.

17. Device according to claims 1 to 16, characterized in that the device has at least one evaluation device (6) for evaluating the radiation (A) detected by means of the measuring device (5).

18. Device according to claim 1 to 17, characterized in that the surface structure of the reflection surfaces (16, 16', 16", 16'") of the kaleidoscope (4) is defined by a mathematical function f(x,y), where x and y lie in a range limited by the horizontal and vertical length of the reflection surfaces (16, 16', 16", 16'") and where f(x,y) is the height profile describing the surface structure of the reflection surfaces (16, 16', 16", 16'").

19. Device according to one of claims 1 to 18, characterized in that the measuring device (5) has a reflective movable target, that the target is arranged on a rotating holder, wherein the tangential movement component of the target can be detected by a movement of the radiation (A).

20. Device according to one of claims 1 to 19, characterized in that a reflecting target is a hologram written by means of laser radiation, that the hologram is resonant to the wavelength of the incident laser radiation, wherein the resonance leads to a three-dimensional reflection which is detectable by the incident laser radiation.

21. Device according to one of claims 1 to 20, characterized in that in the beam path after at least one module a beam splitter is arranged for diverting at least a portion of the radiation and that each beam splitter is assigned a detection device and / or an evaluation device and / or a reflection element.

22. Device according to one of claims 1 to 21, characterized in that at least one material is arranged in the beam path within the kaleidoscope (4), wherein the material is transparent to the radiation (A), wherein the material has light scattering elements for scattering the radiation (A).

23. Method for testing and / or adjusting and / or calibrating at least one imaging system, in particular a lidar system, wherein at least one radiation (A) emitting unit (3) is assigned to the imaging system, wherein a detection field can be formed by means of the emitted radiation (A), wherein the length of the radiation path of the radiation (A) forming the detection field is extended and wherein the extension of the radiation path can be described by at least one iterated function.

24. Method according to claim 23, characterized in that the detection field formed by the emitted radiation (A) is bundled by means of at least one bundling device (2).

25. Method according to claim 24, characterized in that the bundling of the Detection field is carried out successively in different planes by means of the bundling device (2), in particular that bundling in a horizontal axis of the detection field and in a vertical axis of the detection field takes place independently of one another.

26. Method according to one of claims 23 to 25, characterized in that the length of the radiation path of the radiation (A) forming the detection field is extended by means of at least one kaleidoscope (4) and that the length of the radiation path is adjusted by the angle of entry of the radiation (A) into the kaleidoscope (4).

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