Optical checking system and method for checking a workpiece topography

Abstract

The invention relates to a method for checking a workpiece topography of a workpiece, in particular for checking for macroscopic unevennesses of the workpiece formed by joining or separating processes, using an optical checking system, wherein the checking system comprises a first line laser (61) having a projection axis RL1 pointing in the projection direction and a recording unit (10) having a recording axis RA pointing in the recording direction. The method comprises the steps of positioning the optical checking system and / or the workpiece such that the workpiece topography touches a checking plane at at least one point, generating a first laser line LL1 in the checking plane such that the laser line LL1 is visible on the workpiece topography, recording the workpiece topography by means of the recording unit (10), and assessing the workpiece topography on the basis of the recording of the workpiece topography recorded by the recording unit (10) depending on parameters of the workpiece topography, for example a geometry of the workpiece topography, and a line offset of the first laser line LL1 recorded by the recording device (10).

Description

[0001] Optical inspection system and method for testing a workpiece topography

[0002] The invention relates to a method for testing a workpiece topography in a test plane. Furthermore, the invention relates to an optical testing system or measuring system for testing a workpiece topography, in particular a singular workpiece topography, in a virtual test plane or measuring plane. In particular, the invention relates to an optical testing system for testing spot welds. In particular, the invention relates to an optical testing system for testing the workpiece topography using light structures and recordings of the workpiece topography. In particular, the optical testing system comprises several components, such as a line laser, optionally a point laser, and a recording unit, for contactless testing of the workpiece topography.

[0003] Furthermore, the invention relates to a method for testing, in particular for optical testing, a workpiece topography. The testing system and the method for optical testing of the workpiece topography are preferably suitable for automated use, in particular in production and / or quality control.

[0004] Inspecting workpiece topographies is an important step in component quality assurance and specifically refers to the examination of the surface structure and surface geometry of workpieces to ensure that they meet the specified requirements and tolerances. Workpiece topography inspection is crucial to ensure that workpieces have been manufactured correctly and meet various applications and corresponding safety standards. This is particularly important in the automotive and / or aerospace industries. In particular, the inspection of component connections, such as the inspection of welded joints, is of crucial importance in quality assurance. In the automotive and / or aerospace industries in particular, components are often joined together by welds, for example spot welds, orRiveted joints are joined together, particularly using automated processes. Testing such joints, especially those produced using automated processes, serves to ensure that the joints meet the required strength and quality requirements.

[0005] State-of-the-art testing methods and systems are known that enable the inspection of workpiece topographies. Various techniques are used, such as ultrasonic testing or X-ray testing. These methods are frequently used, especially for inspecting welded joints.

[0006] Ultrasonic testing is a non-destructive testing method in which an ultrasonic probe transmits sound waves into the weld. The reflected sound waves are received and analyzed by the ultrasonic probe or a separate detector to detect irregularities such as voids or cracks. To transmit the sound waves into the workpiece, the ultrasonic probe must be in contact with the workpiece. Poor contact can lead to sound reflections and impair inspection accuracy. Therefore, couplants are often used in this method to improve contact between the ultrasonic probe and the workpiece and enhance sound transmission.

[0007] The process for applying and removing the couplant can be complex, which makes ultrasonic testing time-consuming and only partially suitable for automated testing. In the automotive industry in particular, a car body may have several thousand weld points, which can only be inspected randomly due to the complexity of the process. In X-ray testing, however, X-rays are sent through the workpiece, and an X-ray film or a digital image sensor records the beam attenuation and enables the identification of defects inside the workpiece. In addition to radiation exposure, which can be harmful to health and requires strict radiation protection measures and compliance with safety regulations, the accessibility of the workpiece to be inspected often limits the use of X-ray testing.Therefore, X-ray testing is only suitable to a limited extent for automated use and is only used on a random basis in the automotive industry, for example.

[0008] It is therefore an object of the invention to provide a testing system and a method for testing workpiece topographies, in particular welded joints, which are suitable for automated use.

[0009] The object is achieved by the method according to claim 1 and the subject matter according to claim 15.

[0010] In particular, the task is solved by an optical inspection system or measuring system for testing a workpiece topography, in particular a singular workpiece topography, in a virtual inspection plane E or measuring plane.

[0011] In particular, the inspection system can be used to check whether a workpiece topography is acceptable or not, or to categorize it. The inspection system is particularly suitable for use in the process for testing workpiece topography.

[0012] The virtual test plane is a fictitious plane. The test plane is located at a predetermined distance from the test system. The test plane is understood to be an imaginary reference plane. The test plane can change for individual measurement or test orders.

[0013] The inspection plane can, in particular, touch the surface of the workpiece to be inspected at least at one point. In the method for inspecting the workpiece topography, the inspection plane can, for example, be formed at least partially by the surface of the workpiece and / or the workpiece topography. Both the distance between the inspection plane E and the optical inspection system and their relative positioning can be adjusted, preferably for specific measurement or inspection tasks.

[0014] The optical inspection system is primarily used to inspect welded joints, such as spot welds. However, the optical inspection system can also inspect other workpiece topographies. For example, the inspection system can also inspect solder joints, rivets, screws, bolts, clinch joints, weld beads, grooves, or holes.

[0015] In the context of the invention, the term workpiece topography should be understood to mean, in particular, macroscopic irregularities of the workpiece, such as individual elevations and / or depressions. Such macroscopic irregularities can arise, for example, through joining or separating processes, in particular through welding, soldering, riveting, clinching, milling, or drilling. The workpiece topography can, in particular, be a joining point topography or connection point topography. In particular, the workpiece topography should be understood to mean a point on a workpiece at which the workpiece has been joined or separated. For example, a workpiece topography, in particular a singular workpiece topography, can be formed by a welding point, soldering point, a rivet, a screw, in particular a screw head, a bolt, a weld bead, groove, or bore, in particular a blind bore.

[0016] In particular, a singular workpiece topography should be understood as a visually visible elevation and / or depression in the surface of the workpiece. In particular, the workpiece topography within the meaning of the invention, in particular a singular workpiece topography, should not be understood as the roughness of the surface of the workpiece. The term singular is to be understood in the sense of occurring / occurring sporadically, representing an isolated case or special case. In particular, the term singular is intended to express that the workpiece topography to be tested only takes up a fraction, in particular less than half, preferably less than a quarter, of the workpiece surface. In particular, the term singular does not exclude the occurrence of multiple singular workpiece topographies of the type mentioned on one workpiece.

[0017] For example, the workpiece may be an automobile body that has been joined by means of several hundred spot welds, with each individual spot weld being understood as a singular workpiece topography.

[0018] The optical inspection system preferably comprises a line laser with a projection axis RL1 pointing in the projection direction for generating a laser line LL1 in the inspection plane E. The inspection plane can, in particular, be formed at least partially by the workpiece surface or the workpiece topography. The light emitted by the line laser is preferably visible light, preferably visible to the eye, so that the laser line LL1 can be visible, for example, on a workpiece surface.

[0019] The line laser can, in particular, be a first line laser. The optical inspection system can, in particular, comprise a second line laser. The laser line LL1 generated by the first line laser can be a first laser line LL1. For the sake of simplicity, references to the first line laser and the first laser line LL1 are not intended to be limiting. In particular, unless otherwise stated, the first line laser and the first laser line LL1 can be the only one of this type that the optical inspection system comprises.

[0020] Furthermore, the inspection system preferably comprises a point laser for generating a laser spot P in the inspection plane E. The point laser has a projection axis RP which intersects the inspection plane E into the laser spot P. The light emitted by the point laser is preferably visible light, preferably visible to the eye, so that the laser spot can be visible, for example, on a workpiece surface.

[0021] The inspection system preferably additionally comprises a recording unit with a recording axis RA pointing in the recording direction for optically capturing the test plane E. The recording unit can be a 2D camera, for example, for generating a 2D image. The recording unit can be formed, for example, by a 2D camera that can be focused on the test plane E, in particular on the laser point P in the test plane E. The recording unit can comprise a lens for focusing the recording unit on the test plane, in particular on the laser point P. The lens preferably has a focal length of less than 200 mm, in particular less than 80 mm or less than 50 mm. In particular, the lens can have a focal length of more than 8 mm, in particular more than 18 mm. The lens preferably has a focal length of 20 mm. The lens can be formed in the axial direction between the recording unit and the test plane E.

[0022] The distance between the receiving unit and the test plane E is preferably greater than 100 mm, in particular greater than 200 mm. In particular, the distance between the receiving unit and the test plane E can be less than 400 mm, in particular less than 250 mm.

[0023] The first projection axis RL1 of the first line laser and the projection axis RP of the point laser preferably intersect at an angle a1. In particular, the projection axis RL1 of the first line laser and the projection axis RP of the point laser intersect at the angle a1 in the test plane E. The angle a1 is preferably not equal to 0°. This means that the first line laser and the point laser are preferably aligned within the test system such that the laser point P preferably lies on the first laser line LL1 in the test plane E. In particular, the first line laser and the point laser are aligned such that the first laser line LL1 runs through the laser point P. The absolute value of the angle a1 is preferably greater than 0° and / or less than 90°, in particular less than 60°.

[0024] The recording axis RA of the recording unit and the projection axis RL1 of the first line laser preferably intersect at an angle ß1. In particular, the projection axis RL1 of the first line laser and the recording axis RA of the recording unit intersect at the angle ß1 in the test plane E. The angle ß1 is preferably not equal to 0°. This means that the first line laser and the recording unit are preferably aligned within the test system such that the recording axis RA preferably intersects the first laser line LL1. In particular, the first line laser and the recording unit are aligned such that the recording unit can optically detect the first laser line LL1 at the angle ß1. The absolute value of the angle ß1 is preferably greater than 0°, in particular preferably greater than 20°, in particular greater than 45°. In particular, the absolute value of the angle ß1 can be less than 120°, in particular less than 90°.

[0025] Preferably, the projection axis RL1 of the first line laser, the projection axis RP of the point laser, and the recording axis RA intersect at a point P in the test plane E. Preferably, the point P at which the projection axis RL1 of the first line laser, the projection axis RP of the point laser, and the recording axis RA intersect is equal to the laser point P of the point laser. This means that the laser point P and the first laser line LL1 preferably overlap in the test plane E, with the recording unit focused on the laser point P of the point laser.

[0026] The optical inspection system can comprise a detector for detecting the first laser line LL1, wherein the detector has a detection axis RD1 pointing in the detection direction. The detector can be a first detector, and the inspection system can, for example, comprise a second detector for detecting a second laser line LL2, if present. When reference is made to the first detector below, this is not intended to be restrictive. In particular, the first detector can be the only one of this type that the optical inspection system comprises, unless stated otherwise. The first detector and the first line laser can be formed in a light section sensor, in particular in a first light section sensor. In particular, the first detector and the first line laser can be formed in a common housing.For the sake of simplicity, reference to a first light section sensor is also not intended to be limiting. In particular, unless otherwise stated, the first light section sensor may be the only one of its kind included in the optical inspection system.

[0027] The projection axis RL1 of the first line laser and the detection axis RD1 of the first detector preferably intersect at an angle y1. The angle y1 is preferably not equal to 0°. This means that the first line laser and the first detector are preferably aligned within the test system such that the projection axis of the first line laser RL1 and the detection axis RD1 of the first detector intersect, preferably intersect in the test plane E. In particular, the first detector can be aligned such that it detects the first laser line LL1 in the test plane E. In particular, the first detector can detect the first laser line LL1 at the angle y1. The absolute value of the angle y1 is preferably greater than 0° and / or less than 90°, in particular less than 60°.

[0028] Preferably, the recording axis RA of the recording unit and the projection axis RP of the point laser overlap. In particular, the point laser can be deflected by a deflection device, in particular by a mirror or a prism, so that the projection axis RP of the point laser overlaps the recording axis RA of the recording unit.

[0029] If the deflection device is formed by a mirror, the mirror is preferably semi-transparent, so that the mirror deflects the point laser, in particular the light of the point laser, and the recording unit can continue to optically detect the test plane E through the mirror.

[0030] Preferably, the deflection device is arranged between the test plane E and the

[0031] Recording unit is formed. In particular, the recording axis RA of the recording unit can extend through the deflection device, wherein the recording axis RA is not deflected. If the point laser is deflected by the deflection device, the projection axis RP of the point laser refers to the propagation direction of the point laser after it has been deflected by the deflection device.

[0032] The projection axis RP of the point laser and the recording axis RA of the recording unit can, in particular, enclose an angle £, wherein the angle £ is preferably equal to 0°. In alternative embodiments, the angle £ can, although not preferred, also be different from 0°. Preferably, the recording unit is focused on the laser spot P of the point laser in the test plane E, in particular regardless of the size of the angle £.

[0033] The projection axis RP of the point laser can preferably be perpendicular to the test plane E. At the same time or alternatively, the recording axis RA of the recording unit can be perpendicular to the test plane E. If the projection axis RP of the point laser and the recording axis RA of the recording unit overlap, i.e. if the angle £ between the projection axis RP of the point laser and the recording axis RA of the recording unit is 0°, both the projection axis RP and the recording axis RA are preferably perpendicular to the test plane E.

[0034] If the projection axis RP of the point laser and the recording axis RA of the recording unit overlap, ie the angle £ between the projection axis RP of the point laser and the recording axis RA of the recording unit is 0°, the angle cd at which the first projection axis RL1 of the first line laser and the projection axis RP of the point laser intersect is equal to the angle ß1 at which the recording axis RA of the recording unit and the projection axis RL1 of the first line laser intersect.

[0035] As already mentioned at the beginning, the optical inspection system can comprise a second line laser. The second line laser preferably has a second projection axis RL2 pointing in the projection direction for generating a second laser line LL2 in the inspection plane E. The light emitted by the second line laser is preferably visible light, preferably visible to the naked eye, so that the second laser line LL2 can be visible, for example, on a workpiece surface.

[0036] If the optical inspection system comprises a second line laser, the first line laser and the second line laser are preferably arranged such that the laser line LL1 of the first line laser and the second laser line LL2 of the second line laser intersect at a point P. The first laser line and the second laser line can preferably intersect at a point P in the inspection plane E. The first laser line and the second laser line preferably intersect at the laser point P which the point laser, if present, generates in the inspection plane E. The first laser line LL1 and the second laser line L2 can preferably intersect orthogonally. This means that the first laser line LL1 and the second laser line LL2 are preferably perpendicular to one another, in particular in the inspection plane E.Preferably, the second line laser and the first line laser are arranged in the optical inspection system such that the first laser line and the second laser line intersect in the inspection plane E.

[0037] The projection axis RL2 of the second line laser and the projection axis RL1 of the first line laser preferably intersect at an angle θ. The angle θ is preferably not equal to 0°. The absolute value of the angle θ is preferably greater than 0° and / or less than 180°, in particular less than 120°. Preferably, the angle θ is equal to 90° with a tolerance of 20°.

[0038] In alternative embodiments, the angle θ can also be 0°, so that the first line laser and the second line laser together form a cross line laser. If the first line laser and the second line laser together form a cross line laser, the projection axis RL2 of the second line laser and the projection axis RL1 of the first line laser overlap, with the first laser line LL1 and the second laser line LL2 crossing each other. Preferably, the projection axis RL1 of the first line laser intersects the test plane E at an angle between 90° and 0°. Preferably, the projection axis RL1 of the first line laser intersects the test plane E at an angle that is not equal to 0° and not equal to 90°. Preferably, the projection axis RL2 of the second line laser intersects the test plane E at an angle between 90° and 0°. Preferably, the projection axis RL2 of the second line laser intersects the test plane E at an angle that is not equal to 0° and not equal to 90°.

[0039] The projection axis RL2 of the second line laser can intersect the projection axis RP of the point laser at an angle a2. In particular, the projection axis RL2 of the second line laser and the projection axis RP of the point laser intersect at the angle a2 in the test plane E. The angle a2 is preferably not equal to 0°. This means that the second line laser and the point laser are preferably aligned within the test system such that the laser point P preferably lies on the second laser line LL2. In particular, the second line laser and the point laser are aligned such that the second laser line LL2 runs through the laser point P. The absolute value of the angle a2 is preferably greater than 0° and / or less than 90°, in particular less than 60°.

[0040] The angle a2, at which the projection axis RL2 of the second line laser intersects the projection axis RP of the point laser, can be equal in magnitude to the angle a1 at which the projection axis RL1 of the first line laser intersects the projection axis RP of the point laser. The angle δ, at which the projection axis RL2 of the second line laser and the projection axis RL1 of the first line laser intersect, corresponds in particular to the sum of the angles a1 and a2.

[0041] The projection axis RL2 of the second line laser can intersect the recording axis RA of the recording unit at an angle ß2. In particular, the projection axis RL2 of the second line laser and the recording axis RA of the recording unit intersect at the angle ß2 in the test plane E. The angle ß2 is preferably not equal to 0°. This means that the second line laser and the recording unit are preferably aligned within the test system such that the recording axis RA preferably intersects the second laser line LL2. In particular, the second line laser and the recording unit are aligned such that the recording unit can optically detect the second laser line LL2 at the angle ß2. The absolute value of the angle ß2 is preferably greater than 0°, in particular preferably greater than 20°, in particular greater than 45°. In particular, the absolute value of the angle ß2 can be less than 120°, in particular less than 90°.

[0042] The angle ß2, at which the projection axis RL2 of the second line laser intersects the recording axis RA of the recording unit, is preferably equal in magnitude to the angle ß1, at which the projection axis RL1 of the first line laser intersects the recording axis RA of the recording unit.

[0043] Preferably, the angle ß1 at which the projection axis RL1 of the first line laser intersects the recording axis RA of the recording unit is equal to the angle α1 at which the projection axis RL1 of the first line laser and the projection axis RP of the point laser intersect. In particular, the angle ß2 at which the projection axis RL2 of the second line laser intersects the recording axis RA of the recording unit can be equal to the angle α2 at which the projection axis RL2 of the second line laser intersects the projection axis RP of the point laser.

[0044] Preferably, the projection axis RL2 of the second line laser, the projection axis RL1 of the first line laser, the projection axis RP of the point laser and the recording axis RA intersect at a point in the test plane E. The point preferably corresponds to the laser point P which the point laser generates in the test plane E.

[0045] The optical inspection system can additionally comprise a second detector for detecting the second laser line LL2, wherein the second detector has a detection axis RD2 pointing in the detection direction. The second detector and the second line laser can be formed in a second light section sensor. In particular, the second line laser and the second detector can be formed in a common housing.

[0046] The projection axis RL2 of the second line laser and the detection axis RD2 of the second detector preferably intersect at an angle y2. The angle y2 is preferably not equal to 0°. This means that the second line laser and the second detector are preferably aligned within the test system such that the projection axis RL2 of the second line laser and the detection axis RD2 of the detector intersect, preferably in the test plane E. In particular, the second detector can be aligned such that it detects the second laser line in the test plane E. In particular, the second detector can detect the second laser line at the angle y2. The absolute value of the angle y2 is preferably greater than 0° and / or less than 90°, in particular less than 60°.

[0047] The first line laser, the point laser, the recording unit, and / or the second line laser, if present, can be movable, in particular movably mounted. The first line laser, the point laser, the recording unit, and / or the second line laser, if present, can each be individually movable, in particular movably mounted, or can be jointly movable, in particular movably mounted.

[0048] Preferably, the first line laser, the point laser, the recording unit and the second line laser, if present, are arranged, in particular mounted, in such a way that a movement of the first line laser and / or optionally a movement of the second line laser causes / causes a coordinated movement of the point laser and the recording unit. The coordinated movement of the point laser and the recording unit caused by the movement of the first line laser and / or optionally by the movement of the second line laser preferably occurs with a slight time offset, in particular simultaneously. This means that the first line laser, the point laser, the recording unit and the second line laser, if present, preferably move with a slight time offset, in particular without a time offset.A coordinated movement is preferably understood to mean a sequence of movements or actions in which the first line laser and / or optionally the second line laser executes / executes a movement and the point laser and the recording unit follow this movement. For example, a linear, in particular translational, movement and / or a pivoting movement of the first line laser and / or optionally the second line laser generates the same linear movement and / or pivoting movement of the point laser and the recording unit.

[0049] In particular, the angular relationships between the recording axis RA, the projection axis RL1 of the first line laser, the projection axis RP of the point laser and optionally the projection axis RL2 of the second line laser can be fixed.

[0050] Preferably, the angular relationship between the detection axis RD1 of the first detector, if present, and the recording axis RA, the projection axis RL1 of the first line laser, and the projection axis RP of the point laser also remains unchanged during a movement of the first line laser. Preferably, the angular relationship between the detection axis RD2 of the second detector, if present, and the recording axis RA, the projection axis RL1 of the first line laser, the projection axis RL2 of the second line laser, and the projection axis RP of the point laser also remains unchanged during a movement of the first line laser.

[0051] This means that preferably, a movement of the first line laser and / or optionally a movement of the second line laser does not change the angular relationships between the individual axes. In particular, the angular relationships between the projection axis RL1 of the first line laser and optionally the projection axis RL2 of the second line laser, the recording axis RA, the projection axis RP of the point laser, and optionally the detection axis of the first detector RD1 remain the same.

[0052] The first line laser, in particular the first light section sensor, the point laser, and the recording unit can, for example, be arranged, in particular mounted, on a common carrier. In particular, the individual components of the test system can be arranged immovably relative to one another on a common carrier. If the individual components are arranged immovably relative to one another on a common carrier, this should be understood in particular as a fixed relationship, in particular an angular relationship, to one another, whereby the relationship can vary between individual measurement tasks or test tasks.

[0053] Additionally, the second line laser, in particular the second light section sensor, can also be arranged, in particular mounted, on the common carrier. A common, mutually immobile arrangement of the components of the inspection system on a carrier has the advantage that all components execute a coordinated movement when the carrier is, for example, pivoted and / or moved translationally. In particular, the individual components move simultaneously when the carrier is, for example, pivoted and / or moved translationally.

[0054] Alternatively, the first line laser, in particular the first light section sensor, the point laser, and the recording unit can be arranged on separate supports, which are arranged, in particular mounted, for movement separately from one another. The support on which the first line laser, in particular the first light section sensor, the point laser, and the recording unit, and optionally the second line laser, in particular the second light section sensor, are arranged, can preferably be mounted as a tool for an industrial robot. In particular, the optical inspection system can form a tool head of an industrial robot. The first light section sensor and / or the second light section sensor can be designed in the form of commercially available light section sensors.

[0055] The deflection device is preferably also formed on the common carrier. In addition, the optical inspection system can comprise an illumination device. The illumination device is preferably formed between the recording unit and the inspection plane E and serves to illuminate the inspection plane E or the workpiece topography to be inspected. The illumination device can preferably be formed by a ring light. The recording axis RA of the recording unit preferably extends centrally through the ring light. The illumination device can also be formed on the common carrier, provided a common carrier is provided. In particular, the recording unit and the illumination device are arranged on a common carrier.

[0056] The invention additionally relates to a method for testing a workpiece topography, in particular a singular workpiece topography, of a workpiece. In particular, the method serves to test a workpiece topography that is at least partially arranged in the test plane. In particular, the invention relates to a method for testing spot welds. The method is preferably carried out using the optical inspection system described above. Components discussed below preferably correspond to the components described above and have their properties.

[0057] The method preferably comprises the following steps: positioning the optical inspection system, recording the workpiece topography using the recording unit, and evaluating the workpiece topography based on the recorded image. The evaluation of the recorded image can be performed, in particular, depending on parameters temporarily stored in a database, for example. If the workpiece topography is a welded joint, the workpiece topography can be evaluated, for example, depending on parameters of the manufacturing process.

[0058] When a database is mentioned in the application, this should not be understood as a limitation to, for example, external or fixed storage. In particular, it should also be understood as the exchange of data between systems. Data can be stored temporarily in the database. For example, data from the manufacturing process can be transmitted directly to the testing system, which then processes it directly. In particular, the database can be formed by a working memory in which the parameters can be stored temporarily.

[0059] The parameters of the manufacturing process can be, for example, preset target values ​​or recorded actual values. For example, the database can contain the target force curve of a welding tool and / or the target current of the welding tool and / or the target resistance curve during welding and / or the target welding time, which are defined in advance for the welding process. Alternatively or additionally, the database can store the actual force curve of the welding tool and / or the actual current of the welding tool and / or the actual resistance curve during welding and / or the actual welding time, which are recorded during the welding process, preferably for each weld joint, in particular for each weld point.

[0060] Other manufacturing process parameters stored in the database can include, for example, material parameters, especially of the welded joint, such as the sheet thickness, the sheet material, or the coating of the sheets to be joined, especially the sheets to be welded. The target position and / or actual position of the joint, especially of the welded joint, especially the weld point position, can also be stored in the database as manufacturing process parameters.

[0061] The method for testing workpiece topography, in particular for testing singular workpiece topography, can be automated. In particular, the method can be carried out downstream of the manufacturing process in production, for example, in the automotive industry. For example, the method for testing workpiece topography can be performed following an automated welding process, in particular a spot weld process.

[0062] The procedure can, for example, be carried out immediately after the

[0063] The optical inspection system can be carried out within a manufacturing process, particularly following a joining or separating process, or in a separate quality assurance step. In particular, the process can be implemented within a production line, for example, within a production line in the automotive industry, as a quality control measure. If the process is carried out immediately after the manufacturing process, the optical inspection system can, for example, follow the manufacturing tool. Alternatively, the process can be carried out separately from the manufacturing process.

[0064] To inspect the workpiece topography, the optical inspection system and / or the workpiece can preferably be positioned or aligned such that the inspection plane touches the workpiece, in particular the workpiece topography, at at least one point. In particular, the optical inspection system and / or the workpiece can preferably be positioned or aligned such that the workpiece topography lies at least partially in the inspection plane. In particular, the inspection system and / or the workpiece can be positioned or aligned such that the inspection plane E forms a tangential plane or sectional plane of the workpiece, in particular the workpiece topography. This means that the inspection plane E preferably touches the workpiece topography at at least one point.

[0065] If the workpiece topography or the workpiece is, for example, a flat plate, the optical inspection system is preferably aligned so that the inspection plane E overlaps with the surface of the workpiece topography.

[0066] In particular, the optical inspection system and / or the workpiece is preferably aligned such that the inspection plane E touches the surface of the workpiece topography at every point if the workpiece topography or the workpiece is, for example, a flat plate.

[0067] The optical inspection system and / or the workpiece are preferably aligned such that the recording unit is substantially perpendicular to the workpiece topography. This means that the optical inspection system is preferably aligned such that the recording axis RA of the recording unit is substantially perpendicular to the workpiece topography. In particular, the inspection system is aligned such that the recording axis RA of the recording unit is substantially parallel to a normal vector of the workpiece topography.

[0068] When, within the scope of the invention, it is stated that the recording axis RA is substantially perpendicular to the workpiece topography, this is to mean that the recording axis RA, at the point at which the recording axis RA intersects the workpiece topography, preferably encloses an angle of 90° ± 20°, in particular an angle of 90° ± 10°, with the surface of the workpiece topography. This means that the recording axis RA can be a straight line which overlaps with the normal vector of the workpiece topography at the point at which the recording axis RA intersects the workpiece topography. In particular, the recording axis RA can intersect with the normal vector of the workpiece topography at the point at which the recording axis RA intersects the workpiece topography at an angle of up to 20°, in particular up to 10°. In particular, the optical inspection system and / or the workpiece are preferably aligned such that the recording axis RA is substantially perpendicular to the inspection plane.

[0069] Preferably, the recording axis RA intersects the workpiece topography at a point at which the test plane touches the workpiece topography.

[0070] The positioning of the optical inspection system and / or the workpiece can be achieved by means of a controller, in particular a robot controller. This means that the optical inspection system and / or the workpiece can be moved to a predetermined location and positioned by means of a controller. If the inspection system is designed, for example, as a tool of a robot arm, the robot arm can be given predetermined coordinates to which the robot arm, in particular the optical inspection system, moves. Alternatively, the workpiece can be transported toward the inspection system, for example, by means of a conveyor system, and thus positioned relative to the inspection system.

[0071] For example, if the process is integrated into a manufacturing process, the optical inspection system can be positioned or aligned using the data from the joining or separating process. If the inspection system follows a manufacturing tool, for example, the inspection system can be positioned or aligned using the manufacturing parameters.

[0072] In the event that the workpiece topography, in particular the weld spot connection, deviates from the expected location, for example due to errors or tolerances in production, the recording unit in particular can detect the workpiece topography so that the testing system can be fine-tuned using the recording unit. In particular, the recording unit can ensure that the testing system detects a workpiece topography. In particular, the recording unit can ensure that the testing system is positioned so that the first line laser and / or the second line laser hits the workpiece topography. In particular, the recording unit can ensure that the point laser hits the workpiece topography, in particular hits the center of the workpiece topography.

[0073] In addition to the robot control, the inspection system can be positioned or aligned using the first light section sensor and / or the second light section sensor, if available, so that the recording axis RA is perpendicular to the workpiece topography.

[0074] If the inspection system comprises, for example, a first light section sensor with a first line laser and a first detector whose projection axis RL1 and detection axis RD1 intersect at an angle y1, the first light section sensor can be used, for example, to align the inspection system such that the recording axis RA of the recording unit is not pivoted about an axis, for example an x-axis, of the workpiece or the workpiece topography.

[0075] If, for example, the inspection system additionally comprises a second light section sensor with a second line laser and a second detector whose projection axis RL2 and detection axis RD2 intersect at an angle y2, the second light section sensor can, for example, be used to align the inspection system so that the recording axis RA of the recording unit is not pivoted about another axis, for example a y-axis, of the workpiece or the workpiece topography.

[0076] For example, the first light-section sensor can be configured to align the inspection system so that the inspection system is not pivoted about the x-axis of the workpiece or the workpiece topography. For this purpose, the first laser line LL1 of the first line laser can, for example, be projected onto the workpiece substantially parallel to the y-axis of the workpiece or the workpiece topography.

[0077] If the inspection system is pivoted about the x-axis relative to the workpiece, in particular relative to the workpiece topography, the first detector will detect the first laser line LL1, for example, as an obliquely rising or falling line instead of a substantially horizontal line. The inspection system can then be pivoted about the x-axis, for example, until the first detector detects the first laser line LL1, for example, as a substantially horizontal line.

[0078] The second light section sensor can, for example, be configured to align the inspection system such that the inspection system is not pivoted about the y-axis of the workpiece or the workpiece topography. For this purpose, the second laser line LL2 of the second line laser can, for example, be projected onto the workpiece substantially parallel to the x-axis of the workpiece or the workpiece topography. If the inspection system is pivoted about the y-axis relative to the workpiece, in particular relative to the workpiece topography, the second detector will detect the second laser line LL2, for example, as an obliquely rising or falling line instead of a substantially horizontal line. The inspection system can then, for example, be pivoted about the y-axis until the second detector detects the second laser line LL2 as a substantially horizontal line.The step of positioning the inspection system can, in particular, be carried out such that the first laser line LL1 of the first line laser is projected onto the workpiece and / or the second laser line LL2 of the second line laser is projected onto the workpiece. The first detector can detect the first laser line LL1 and / or the second detector can detect the second laser line LL2.

[0079] If, for example, the first detector does not detect the first laser line LL1 as a line running horizontally on average and / or if the second detector does not detect the second laser line LL2 as a line running horizontally on average, the test system can optionally be pivoted such that the second detector detects the second laser line LL2 as a line running horizontally on average and / or that the first detector detects the first laser line LL1 as a line running horizontally on average.

[0080] If the first detector and / or the second detector detect a line that runs horizontally on average, the inspection system with the first light section sensor, the second light section sensor, the point laser and the recording unit can be moved orthogonally and tangentially to the workpiece, if necessary, so that the laser point P lies on the workpiece topography, in particular centrally on the workpiece topography, and the first laser line LL1 and the second laser line LL2 intersect at the point P.

[0081] To avoid errors when checking the workpiece topography, the inspection system should also have a predetermined distance from the workpiece, especially from the workpiece topography. This distance can be set, for example, using the controller, in particular the robot controller. Alternatively or additionally, the distance can be set using the first laser line LL1 and / or optionally using the second laser line LL2 and the laser point P.

[0082] The step of positioning the testing system can additionally include adjusting the distance between the testing system and the workpiece topography. The positioning of the testing system, in particular adjusting the distance between the testing system and the workpiece topography, can in particular be carried out in such a way that the testing system is first positioned so that the laser spot P lies on the workpiece topography. This means that the testing system is preferably aligned, in particular by means of the recording unit, so that the projection axis RP of the point laser intersects the workpiece topography. The testing system is preferably aligned so that the laser spot P lies centrally on the workpiece topography. If the workpiece topography is, for example, an approximately circular spot weld, the testing system is aligned so that the laser spot P lies on the center point of the spot weld.

[0083] The test system can then be aligned so that the first laser line LL1 of the first line laser and / or the second laser line LL2 of the second line laser passes through the laser point P.

[0084] If the optical inspection system is aligned perpendicular to the workpiece topography, for example by the robot controller, an incorrect axial distance between the inspection system and the workpiece topography can result in the first laser line LL1 of the first line laser and / or the second laser line LL2 of the second line laser not passing through the laser point P. This is due in particular to the angle a1 between the projection axis RL1 of the first line laser and the projection axis RP of the point laser or the angle a2 between the projection axis RL2 of the second line laser and the projection axis RP of the point laser.

[0085] By changing the axial distance between the optical inspection system and the workpiece topography, in particular by axially moving the inspection system and / or the workpiece with the workpiece topography, the distance can be adjusted so that the first laser line LL1 of the first line laser and / or the second laser line LL2 of the second line laser runs through the laser point P.

[0086] The first laser line LL1 and optionally the second laser line LL2, if present, and the laser point P can serve as a measure of the correct distance between the testing system and the workpiece, in particular the workpiece topography. The distance is set correctly when the first laser line LL1 and optionally the second laser line LL2, if present, run through the laser point P. If the distance between the testing system and the workpiece, in particular the workpiece topography, is incorrect, the laser point L is not on the first laser line LL1 and / or optionally on the second laser line LL2. In particular, the distance is incorrect if the testing plane of the testing system E does not touch the workpiece or the workpiece topography at a single point or if the testing plane of the testing system E intersects the workpiece or the workpiece topography.This is due in particular to the fixed angular relationship between the projection axis RL1 of the first line laser or optionally the projection axis RL2 of the second line laser and the projection axis RP of the point laser and the resulting fixed distance between the first line laser or the second line laser and the point laser.

[0087] If the inspection system is aligned perpendicularly to the workpiece, in particular to the workpiece topography, and if the inspection system has the correct distance from the workpiece, in particular to the workpiece topography, the recording unit can record the workpiece topography, in particular take a photograph.

[0088] Alternatively, the adjustment of the distance and / or the vertical alignment of the inspection system can be omitted in the positioning step. In particular, the inspection system and / or the workpiece can be positioned such that the first laser line LL1 of the first line laser is projected onto the workpiece and / or that the second laser line LL2 of the second line laser is projected onto the workpiece. Preferably, the first laser line LL1 and the second laser line LL2 are projected onto the workpiece topography such that the first laser line LL1 and the second laser line LL2 intersect, in particular orthogonally intersect, at a point P on the workpiece topography. The point laser and in particular the laser point P can be omitted.If the inspection system and the workpiece, in particular the workpiece topography, are positioned relative to one another in such a way that the first laser line LL1 of the first line laser is projected onto the workpiece, in particular onto the workpiece topography, and / or that the second laser line LL2 of the second line laser is projected onto the workpiece, in particular onto the workpiece topography, the recording unit can record the workpiece topography, in particular photograph it.

[0089] The image of the workpiece topography captured by the acquisition unit can subsequently be evaluated, particularly automatically by a computer, for example, using an AI program. The image can be a 2D image, for example.

[0090] For example, the image can be compared with a large number of images, particularly 2D images, from a database. For example, the database can contain images of workpiece topographies that are to be expected based on the set or occurring production parameters of the manufacturing process and are not faulty. The evaluation of the image should also be understood, for example, as the determination of parameters of the workpiece topography using the image.

[0091] The workpiece topography parameters determined from the image can, for example, be compared with the expected workpiece topography parameters for the respective manufacturing process. The expected workpiece topography parameters can, for example, be stored in a database and / or calculated by the AI ​​program. Alternatively, the image of the workpiece topography recorded by the recording unit can also be evaluated depending on the manufacturing process parameters, without, for example, calculating the expected parameters. In particular, the evaluation can be performed directly based on the recorded workpiece topography parameters and manufacturing parameters, without a direct comparison with target values.In particular, the AI ​​program can be trained with images of workpieces, particularly workpiece topographies, that have been classified as high-quality, as well as with images of workpieces, particularly workpiece topographies that exhibit quality deficiencies. Through this training, the AI ​​program can, in particular, recognize patterns and / or relationships between the parameters of the workpiece topography and / or the line offset and / or the respective manufacturing parameters. This enables the system to evaluate the quality of the workpiece topography and / or categorize it based on a new image and / or manufacturing parameters.

[0092] One aspect of AI-based analysis can be that the AI ​​program has been trained in advance with a collection of images, is being trained, or is trainable. The training data can include a large number of images of different workpiece topographies, which, for example, originate from different manufacturing processes and / or differ in individual parameters of the respective manufacturing process. This allows the AI ​​program to learn, for example, to recognize and / or evaluate various surface features.

[0093] In particular, the AI ​​program can learn to evaluate the workpiece topography depending on manufacturing parameters and / or the parameters of the recorded workpiece topography and / or the recorded line offsets of the first laser line and / or the second laser lines. In particular, the AI ​​program can learn to evaluate the workpiece topography based on the combination of parameters of the workpiece topography and / or the line offsets and / or manufacturing parameters. In particular, the AI ​​program can analyze and / or evaluate relationships between these parameters.

[0094] For example, the Kl can learn to evaluate and / or categorize a recorded workpiece topography, for example when a manufacturing parameter and / or a line offset and / or a parameter of the workpiece topography is undershot or exceeded, in particular to categorize it as OK or not OK.

[0095] In particular, the Kl program can learn to categorize a recorded workpiece topography, for example when a production parameter is exceeded or undershot, independent of, for example, a line offset and / or parameters of the workpiece topography, in particular to categorize it as OK or not OK. Analogously, the Kl program can learn to categorize a recorded workpiece topography, for example when a line offset is exceeded or undershot, independent of, for example, a production parameter and / or parameters of the workpiece topography. Analogously, the Kl program can learn to categorize a recorded workpiece topography, for example when a parameter of the workpiece topography is exceeded or undershot, independent of, for example, a production parameter and / or a line offset.

[0096] In particular, the Kl program may have learned or learn that a workpiece topography is always OK or always not OK when a manufacturing parameter and / or a line offset and / or a parameter of the workpiece topography or a certain combination of individual values ​​is undershot or exceeded.

[0097] In particular, for example, a geometry and / or a depth or height of the workpiece topography can be determined by means of the method for testing the workpiece topography, in particular based on the recording of the recording unit, and can be compared, for example, with expected values ​​for the geometry and / or the depth or height of the workpiece topography for the particularly stored parameters of the manufacturing process.

[0098] The determined values ​​for geometry and / or depth or height can then be compared, for example, with expected values ​​for geometry and / or depth or height. For example, values ​​for the geometry and / or depth or height of the workpiece topography can be stored at least temporarily in the database, which are expected and not erroneous depending on the manufacturing process parameters stored in the database, for example.

[0099] Alternatively or additionally, values ​​for the geometry and / or the depth or height of the workpiece topography can be incorporated into the evaluation of the workpiece topography by the Kl program. For example, by the Kl program calculating values ​​for the geometry and / or the depth or height of the workpiece topography that are to be expected depending on the parameters of the manufacturing process and are not faulty, or by the Kl program considering values ​​for the geometry and / or the depth or height of the workpiece topography in combination with manufacturing parameters in the evaluation of the workpiece topography.

[0100] In particular, the geometry of the workpiece topography can be determined based on the image of the workpiece topography. For example, in a spot weld, the diameter of the weld spot can be determined based on the image from the recording unit and compared, for example, with the expected diameters for the weld spot based on the stored parameters of the manufacturing process.

[0101] In addition or alternatively to the geometry, the recording can also provide information about the depth or height of the workpiece topography and incorporate this into the evaluation of the workpiece topography.

[0102] If the workpiece topography is, for example, a rise or depression in the workpiece, for example in the form of a

[0103] Weld spot connection, the recording unit for the first laser line LL1 and / or the second laser line LL2, if present, records a line offset in the area of ​​the workpiece topography. In particular, the recording unit for the first laser line LL1 and / or the second laser line LL2, if present, can detect a line offset in the area of ​​the workpiece topography. In particular, the first laser line LL1 and / or the second laser line LL2, if present, as well as any line offset in the area of ​​the workpiece topography can be seen in the recording of the recording unit. This line offset is a measure of the elevation and / or depression of the workpiece in the area of ​​the workpiece topography. This information about the height or depth of the workpiece topography can additionally be incorporated into the evaluation of the workpiece topography.

[0104] In particular, the line offset can be compared with a line offset expected for the manufacturing process, such as the previously described comparison of the geometry parameters. The line offset can, in particular, be a parameter of the workpiece topography.

[0105] For example, if the workpiece topography involves a spot weld joint, the image from the acquisition unit can be compared with numerous images of spot weld joints from a database. For example, the database can contain images of spot weld joints that are expected to be non-defective based on the parameters of the welding process and / or the workpiece material. Alternatively or additionally, only expected parameters of the spot weld joint can be stored and / or calculated by the Kl program.

[0106] Alternatively or additionally, for example, the diameter and / or the depth or height of the weld joint can be determined using the method and compared with expected values ​​for the diameter and / or the depth or height of the weld joint for the recorded manufacturing parameters.

[0107] For example, values ​​for the diameter and / or the depth or height of the spot weld connection can be stored in the database or calculated by the Kl program, which are to be expected depending on the parameters of the welding process and the material of the workpiece and are not incorrect.

[0108] The parameters for spot welding can, for example, be the settings and parameters that are determined and / or recorded during the welding process to ensure the quality and reliability of the weld. If the image of the workpiece topography recorded by the welding unit deviates from the images stored for these production parameters, or if the workpiece topography parameters determined from the image deviate too significantly from the workpiece topography parameters expected for these production parameters, for example, if the spot weld connection is too large or too small in diameter, the workpiece topography, especially the spot weld connection, can be considered non-standard.

[0109] The invention is presented below in the form of aspects. The aspects are formulated in the form of claims and can replace or advantageously develop these claims. Features formulated in the aspects can supplement or advantageously develop the subject matter or method of the invention:

[0110] Aspect #1 : Optical inspection system for checking a workpiece topography in a virtual inspection plane E comprising:

[0111] 1.1. at least one line laser (61) with a projection axis RL1 pointing in the projection direction for generating a laser line LL1 in the test plane E,

[0112] 1 .2. optionally a point laser (40) with a projection axis RP intersecting the test plane E for generating a laser point P in the test plane E, and

[0113] 1 .3. a recording unit (10) with a recording axis RA pointing in the recording direction for optically recording the test plane E, wherein

[0114] 1.4. the projection axis RL1 of the line laser (61) and the projection axis RP of the point laser (40), if the point laser (40) is present, intersect at an angle a1, and

[0115] 1 .5. the recording axis RA of the recording unit (10) and the projection axis RL1 of the line laser (61) intersect at an angle ß1, and wherein

[0116] 1.6. the projection axis RL1 of the line laser (61), the recording axis RA and preferably the projection axis RP of the point laser (40) intersect at one point, preferably at the laser point P, in the test plane E. Aspect #2: Optical inspection system according to one of the preceding aspects, wherein the optical inspection system is provided for inspecting a welded joint, spot welded joint, clinched joint, screwed joint, soldered joint, riveted joint or bolted joint.

[0117] Aspect #3: Optical inspection system according to one of the preceding aspects, wherein the optical inspection system comprises the point laser (40) and the recording axis RA of the recording unit (10) and the projection axis RP of the point laser (40) overlap each other.

[0118] Aspect #4: Optical inspection system according to one of the preceding aspects, wherein the point laser (40) is preferably deflected by a deflection device (41), in particular by a mirror or a prism, so that the projection axis RP of the point laser (40) overlaps with the recording axis RA of the recording unit (10).

[0119] Aspect #5: Optical inspection system according to one of the preceding aspects, wherein the optical inspection system comprises the point laser (40) and the projection axis RP of the point laser (40) is perpendicular to the inspection plane E.

[0120] Aspect #6: Optical inspection system according to one of the preceding aspects, wherein the recording axis RA is perpendicular to the inspection plane E.

[0121] Aspect #7: Optical inspection system according to any one of the preceding aspects, wherein

[0122] 7.1 . the line laser (61 ) is a first line laser (61 ) and the laser line LL1 is a first laser line LL1 and

[0123] 7.2. the test system comprises a second line laser (71) with a projection axis RL2 pointing in the projection direction for generating a second laser line LL2 in the test plane E,

[0124] 7.3. the first line laser (61) and the second line laser (71) are arranged such that the first laser line LL1 of the first line laser (61) and the second laser line LL2 of the second line laser (71) intersect at the point. Aspect #8: The optical inspection system according to the preceding aspect, wherein the optical inspection system comprises the point laser (40) and the first line laser (61) and the second line laser (71) are arranged such that the first laser line LL1 of the first line laser (61) and the second laser line LL2 of the second line laser (71) intersect at the laser point P of the point laser (40).

[0125] Aspect #9: Optical inspection system according to aspect 7, wherein the first line laser (61) and the second line laser (71) are arranged such that the first laser line LL1 of the first line laser (61) and the second laser line LL2 of the second line laser (71) intersect orthogonally at the point, in particular at the laser point according to aspect 8.

[0126] Aspect #10: Optical inspection system according to one of the preceding aspects, wherein the optical inspection system comprises the point laser (40) and

[0127] 10.1. the projection axis RL2 of the second line laser (71) and the projection axis RL1 of the first line laser (61) intersect at an angle ö,

[0128] 10.2. the projection axis RL2 of the second line laser (71) and the projection axis RP of the point laser (40) intersect at an angle a2, and

[0129] 10.3. the recording axis RA of the recording unit (10) and the projection axis RL2 of the second line laser (71) intersect at an angle ß2, and wherein

[0130] 10.4. the projection axis RL2 of the second line laser (71), the projection axis RL1 of the first line laser (61), the projection axis RP of the point laser (40) and the recording axis RA intersect at the laser point P in the test plane E.

[0131] Aspect #11: Optical inspection system according to one of the preceding aspects, wherein the line laser (61) and a detector (62) for detecting the laser line LL1, which has a detection axis RD1 pointing in the detection direction, are formed in a light section sensor (60) and the projection axis RL1 of the line laser (61) and the detection axis RD1 of the detector (62) intersect at an angle y1.

[0132] Aspect #12: Optical inspection system according to one of the preceding aspects, wherein the second line laser (71) according to one of aspects 7 to 10 and a second detector (72) for detecting the second laser line LL2, which has a detection axis RD2 pointing in the detection direction, are formed in a second light section sensor (70) and the projection axis RL2 of the second line laser (71) and the detection axis RD2 of the second detector (72) intersect at an angle y2.

[0133] Aspect #13: Optical inspection system according to one of the preceding aspects, wherein the first line laser (61), optionally the point laser (40), the recording unit (10) and optionally the second line laser (71) according to one of aspects 7 to 10 or 12 are movable, in particular movably mounted, and wherein a movement of the first line laser (61) and / or optionally a movement of the second line laser (71) causes / causes a coordinated movement of the point laser (40) and the recording unit (10).

[0134] Aspect #14: Optical inspection system according to one of the preceding aspects, wherein the angular relationships between the recording axis RA, the projection axis RL1 of the first line laser (61), optionally the projection axis RP of the point laser (40) and optionally the projection axis RL2 of the second line laser (71) according to one of aspects 7 to 10 or 12 are fixed.

[0135] Aspect #15: Optical inspection system according to one of the preceding aspects, wherein the first line laser (61), in particular the first light section sensor (60) according to aspect 11, optionally the point laser (40), the recording unit (10), and optionally the second line laser (71) according to one of aspects 7 to 114, in particular the second light section sensor (70) according to aspect 12, are arranged on a common carrier. Aspect #16: Optical inspection system according to the preceding aspect, wherein the carrier can be mounted as a tool of an industrial robot.

[0136] Aspect #17: Optical inspection system according to one of the preceding aspects, wherein the recording unit (10) is a 2D camera which is focused on the point P.

[0137] Aspect #18: Optical inspection system according to the preceding aspect, wherein the 2D camera is focused on the laser point P of the point laser (40).

[0138] Aspect #19: Optical inspection system according to one of the preceding aspects, wherein an illumination device (50) for illuminating the inspection plane E is formed between the recording unit (10) and the inspection plane E.

[0139] Aspect #20: Optical inspection system according to one of the preceding aspects, wherein a ring light for illuminating the inspection plane E is formed between the recording unit (10) and the inspection plane E.

[0140] Aspect #21 : Method for testing a workpiece topography of a workpiece, by means of the optical inspection system according to one of aspects 1 to 20, comprising the steps

[0141] 21 .1 . Positioning the optical inspection system,

[0142] 21 .2. Recording the workpiece topography using the recording unit (10),

[0143] 21 .3. Evaluation of the workpiece topography based on the recording of the workpiece topography.

[0144] Aspect #22: Method according to the preceding aspect, comprising the step of positioning the optical inspection system so that the inspection plane E forms a tangential plane of the workpiece topography.

[0145] Aspect #23: Method according to one of the two preceding aspects, comprising the step of detecting the workpiece topography using the recording unit (10). Aspect #24: Method according to one of the three preceding aspects, wherein the method is for testing a spot weld connection, welded connection, clinch connection, screw connection, soldered connection, riveted connection, or bolted connection.

[0146] Aspect #25: Method according to one of the four preceding aspects, wherein the step of evaluating the workpiece topography takes place as a function of parameters of the manufacturing process stored in a database.

[0147] Aspect #26: Method according to one of the five preceding aspects, wherein the optical inspection system is aligned, in particular by robot control, such that the recording axis RA is substantially perpendicular to the workpiece topography.

[0148] Aspect #27: Method according to one of the six preceding aspects, wherein the optical inspection system comprises the point laser (40) and the step of positioning the inspection system occurs such that the laser point P lies on the workpiece topography.

[0149] Aspect #28: Method according to one of the seven preceding aspects, wherein the optical inspection system comprises the point laser (40) and the step of positioning the inspection system occurs such that the first laser line LL1 of the first line laser (61) and / or the second laser line LL2 of the second line laser (71) pass through the laser point P.

[0150] Aspect #29: Method according to one of the eight preceding aspects, wherein the optical inspection system comprises the point laser (40) and the step of positioning the inspection system occurs such that the laser point P is centered on the workpiece topography.

[0151] Aspect #30: Method according to one of the nine preceding aspects, wherein the

[0152] Workpiece topography is additionally evaluated based on a line offset of the first laser line LL1 and / or the second laser line LL2 detected by the recording device (10).

[0153] Aspect #31: Method according to the preceding aspect, wherein the line offset is a measure of an elevation and / or depression of the workpiece in the region of the workpiece topography.

[0154] Aspect #32: Method according to any one of the eleven preceding aspects, wherein the optical inspection system comprises the point laser (40) and the step of positioning the inspection system comprises the following steps:

[0155] 32.1 .Projection of the first laser line LL1 of the first line laser (61) onto the workpiece and projection of the second laser line LL2 of the second line laser (71) onto the workpiece,

[0156] 32.2. Detection of the first laser line LL1 by the first detector (62) and detection of the second laser line LL2 by the second detector (72),

[0157] 32.3. optionally pivoting the first light section sensor (60) so that the detector (62) detects the first laser line LL1 as a line running horizontally on average, and / or optionally pivoting the second light section sensor (70) so that the second detector (72) detects the second laser line LL2 as a line running horizontally on average,

[0158] 32.4. coordinated translational movement of the first light section sensor (60), the second light section sensor (70), the point laser (40) and the recording unit (10) orthogonal and / or tangential to the workpiece, so that the laser point P lies on the workpiece topography, in particular centrally on the workpiece topography, and the first laser line LL1 and the second laser line LL2 intersect at the laser point P.

[0159] Aspect #33: Method according to one of the twelve preceding aspects, wherein the recording of the workpiece topography is evaluated as a function of parameters of the manufacturing process stored in the database and wherein the stored parameters are the force curve of a welding tool and / or the current intensity of the welding tool and / or resistance curve during welding and / or the welding time and / or material parameters of a welded joint, such as sheet thickness, sheet material or coating of the welded sheets, and / or a welding point position.

[0160] The invention will be explained in more detail below using exemplary embodiments. Features disclosed in the exemplary embodiments advantageously develop the subject matter of the claims and the embodiments explained above. They show:

[0161] Figure 1: a schematic representation of an optical inspection system;

[0162] Figure 2a: a schematic representation of a workpiece topography in the correct

[0163] Distance to the test system;

[0164] Figure 2b: a schematic representation of a workpiece topography at the wrong distance from the inspection system;

[0165] Figure 3: a schematic representation of the recording unit and a first

[0166] line laser;

[0167] Figure 4a: a schematic representation of a workpiece being scanned around the x-axis with a first light section sensor;

[0168] Figure 4b: a schematic representation of a workpiece not wasted around the x-axis with a first light section sensor;

[0169] Figure 5a: a schematic representation of a workpiece wasted around the y-axis with a second light section sensor;

[0170] Figure 5b: a schematic representation of a workpiece not wasted around the y-axis with a second light section sensor;

[0171] Figure 6: a schematic representation of the angular relationships between the

[0172] point laser and a line laser;

[0173] Figure 7: a schematic representation of the angular relationships between the

[0174] Projection axis RP of the point laser and the recording axis RA of the recording unit.

[0175] Figure 1 shows a schematic representation of an optical inspection system for inspecting a workpiece topography. The optical inspection system is aligned in Figure 1 such that the inspection plane E forms a tangential plane of the workpiece topography to be inspected. This means that the inspection plane of the inspection system touches the workpiece topography at least at one point. In particular, the inspection plane of the inspection system corresponds to the inspection plane of the workpiece, or the surface of the workpiece, or the workpiece topography, at least partially corresponds to the inspection plane of the inspection system.

[0176] The workpiece topography can, in particular, be a spot weld connection, as schematically illustrated in Fig. 1, for example. The inspection system comprises a first line laser 61 with a projection axis RL1 pointing in the projection direction for generating a first laser line LL1 in the inspection plane E. Furthermore, the optical inspection system comprises a second line laser 71 with a projection axis RL2 pointing in the projection direction for generating a second laser line LL2 in the inspection plane E. The second line laser 71 is optional. Thus, the inspection system can also be configured without the second line laser 71.

[0177] The first line laser 61 can, as schematically illustrated in Figures 4a and 4b, form a light section sensor 60 together with a first detector 62 for detecting the laser line LL1, which has a detection axis RD1 pointing in the detection direction. Accordingly, instead of the first line laser 61 shown in Figure 1, the inspection system can comprise a first light section sensor 60, which is formed from the first line laser 61 and the first detector 62.

[0178] The second line laser 71 can, as schematically illustrated in Figures 5a and 5b, form a light section sensor 70 together with a second detector 72 for detecting the laser line LL2, which has a detection axis RD2 pointing in the detection direction. Accordingly, instead of the second line laser 71 shown in Figure 1, the inspection system can comprise a second light section sensor 70, which is formed from the second line laser 71 and the second detector 72.

[0179] The optical inspection system further comprises a point laser 40 with a projection axis RP intersecting the inspection planes E for generating a laser spot P in the inspection plane E. The point laser 40 is preferably also optional. The point laser 40, in particular the projection axis RP, preferably intersects the inspection plane E at a 90° angle, with a tolerance of ± 20°, in particular ± 10°, being permissible. The light emitted by the point laser 40 is preferably visible light, so that the laser spot P can be visible, for example, on a workpiece surface.

[0180] Furthermore, the optical inspection system comprises a recording unit 10 with a recording axis RA pointing in the recording direction for optically detecting the inspection plane E. The recording axis preferably intersects the inspection plane E at a 90° angle, whereby a tolerance of ± 20°, in particular ± 10°, is permissible. In particular, the recording axis RA is perpendicular to the inspection plane E. The recording unit 10 can be formed, for example, by a 2D camera. The recording unit 10 is focused in particular on the laser point P of the point laser 40.

[0181] A bandpass filter 20 and / or a lens 30 can additionally be provided in the axial direction between the recording unit 10 and the test plane E. The bandpass filter 20 can be used to allow signals in a specific frequency range to pass through, while suppressing or attenuating signals outside this range. In particular, the bandpass filter 20 can be used to emphasize or suppress certain frequency components when capturing the test plane E.

[0182] The objective lens 30 can be configured to focus the recording unit 10 on the laser point P. In particular, the objective lens 30 can be adjusted so that the light structures generated by the point laser 40, the first line laser 61, and optionally by the second line laser 71 are sharply captured by the recording unit 10 at a predetermined distance. In particular, the focal length of the objective lens 30 can be adjusted so that its focus coincides with the laser point P. The objective lens 30 can be an optical objective lens, which can comprise, for example, lenses, mirrors, or diffraction gratings. Furthermore, the optical inspection system comprises a deflection device 41 designed to deflect the light of the point laser 40 such that the projection axis RP of the point laser 40 strikes the inspection plane E perpendicularly. The deflection device 41 is preferably formed in the axial direction between the recording unit 10 and the inspection plane E.If the point laser 40 is deflected by the deflection device 41, the projection axis RP of the point laser 40 refers to the propagation direction of the point laser 40 after it has been deflected by the deflection device 41.

[0183] The deflection device 41 can be formed, for example, by a mirror or a prism. If the deflection device 41 is formed by a mirror, the mirror is preferably semi-transparent, so that the mirror deflects the point laser 40, in particular the light from the point laser 40, and the recording unit 10 can continue to optically capture the test plane E through the mirror.

[0184] As can be seen in Figure 1, the projection axis RP of the point laser 40 and the recording axis RA of the recording unit 10 overlap. In particular, the deflection device 41 deflects the light of the point laser 40 such that the projection axis RP and the recording axis RA overlap. This means that the projection axis RP and the recording axis RA are coaxial with each other and do not form an angle.

[0185] In alternative embodiments, as shown in Figure 7, for example, the point laser 40' can be designed such that its projection axis RP strikes the test plane E without a deflection device 41. The point laser 40', in particular the projection axis RP, can enclose an angle of less than 90° with the test plane E. This means that the projection axis RP is not perpendicular to the test plane E. In this case, the projection axis RP of the point laser 40' and the recording axis RA of the recording unit 10 enclose an angle £ with each other. The angle £ between the projection axis RP and the recording axis RA should be as small as possible, preferably less than 20°, in particular preferably less than 10°.If the optical inspection system, as shown in Figure 1, has a first line laser 61 and a second line laser 71, the projection axis RL1 of the first line laser 61 and the projection axis RL2 of the second line laser 71 intersect at an angle θ. Furthermore, the first laser line LL1 of the first line laser 61 and the second laser line L2 of the second line laser 71 intersect at the laser point P in the inspection plane E. Preferably, the first laser line LL1 of the first line laser 61 and the second laser line LL2 of the second line laser 71 intersect at an angle of 90°. This means that the first laser line LL1 and the second laser line LL2 preferably intersect at the laser point P.

[0186] As can be seen in Fig. 1, the projection axis RP of the point laser 40, the projection axis RL1 of the first line laser 61, the projection axis RL2 of the second line laser 71 and the recording axis RA of the recording unit preferably intersect at the laser point P in the test plane E.

[0187] As shown, for example, in Fig. 6, the first projection axis RL1 of the first line laser 61 and the projection axis RP of the point laser 40 intersect at an angle a1. In particular, the projection axis RL1 of the first line laser and the projection axis RP of the point laser intersect at an angle a1 in the test plane E. The angle a1 is preferably not equal to 0°. This means that the first line laser 61 and the point laser 40 are aligned within the test system such that the laser point P in the test plane E lies on the first laser line LL1.

[0188] Even if not shown in more detail, the projection axis RL2 of the second line laser 71 and the projection axis RP of the point laser 40 intersect at an angle α2 in the test plane E. The angle α2 is preferably not equal to 0°. This means that the second line laser 71 and the point laser 40 are aligned within the test system such that the laser point P in the test plane E lies on the second laser line LL1. The angles α1 and α2 can be of equal magnitude. The magnitude of the angle α1 and / or the angle α2 is preferably greater than 0° and / or less than 90°, in particular less than 60°. As shown, for example, in Fig. 6, the recording axis RA of the recording unit 10 and the projection axis RL1 of the first line laser 61 intersect at an angle β1 in the test plane E. The angle β1 is not equal to 0°.This means that the first line laser 61 and the recording unit 10 are aligned within the test system such that the recording unit 10 can optically detect the first laser line LL1 at the angle ß1.

[0189] Although not shown in detail, the recording axis RA of the recording unit 10 and the projection axis RL2 of the second line laser 71 also intersect at an angle ß2 in the test plane E. The angle ß2 is not equal to 0°. This means that the second line laser 71 and the recording unit 10 are aligned within the test system such that the recording unit 10 can optically detect the second laser line LL2 at the angle ß2. The angles ß1 and ß2 can be equal in magnitude. The magnitude of the angle ß1 and / or the angle ß2 is preferably greater than 0° and / or less than 90°, in particular less than 60°.

[0190] If the measuring system or the inspection system comprises the first light section sensor 60 with the first line laser 61 and the first detector 62 instead of the simple first line laser 61, the projection axis RL1 of the first line laser 61 and the detection axis RD1 of the first detector 62 intersect at an angle y1, as shown by way of example in Figures 4a and 4b. The angle y1 is not equal to 0°. This means that the first line laser 61 and the first detector 62 are aligned within the inspection system such that the projection axis of the first line laser 61 and the detection axis RD1 of the first detector 62 intersect in the inspection plane E, and the first detector 62 detects the first laser line LL1 at the angle y1.

[0191] If the inspection system comprises the second light section sensor 70 with the second line laser 71 and the second detector 72 instead of the simple second line laser 71, the projection axis RL2 of the second line laser 71 and the detection axis RD2 of the second detector 72 intersect at an angle y2, as shown by way of example in Figures 5a and 5b. The angle y2 is not equal to 0°. This means that the second line laser 71 and the second detector 72 are aligned within the inspection system such that the projection axis of the second line laser 71 and the detection axis RD2 of the second detector 72 intersect in the inspection plane E, and the second detector 72 detects the second laser line LL2 at the angle y2.

[0192] The method for testing a workpiece topography will be described below with reference to Figures 1 to 6. The method preferably comprises the following steps: positioning the optical inspection system so that the inspection plane E touches the workpiece topography at least at one point, recording the workpiece topography using the recording unit 10, and evaluating the workpiece topography based on the recording of the workpiece topography.

[0193] To inspect the workpiece topography, the optical inspection system, as shown in Figure 1, is preferably positioned such that the inspection plane E forms a tangential plane of the workpiece, in particular the workpiece topography. This means that the inspection plane E preferably touches the workpiece topography at at least one point. If the workpiece topography is itself a plane, for example, the inspection plane E can overlap with it and thus touch it at several points. If the workpiece topography is a spot weld, the inspection plane E preferably touches the spot weld at its lowest point.

[0194] The optical inspection system is preferably aligned such that the recording unit 10 is perpendicular to the workpiece topography. This means that the optical inspection system is aligned such that the recording axis RA of the recording unit 10 is substantially perpendicular to the workpiece, in particular to the workpiece topography.

[0195] The positioning of the optical inspection system can be done using robot control. This means that the optical inspection system is moved to a predetermined location and aligned using a controller.

[0196] In addition to the robot control, the inspection system can be aligned using the first light section sensor 60, as shown in Figures 4a and 4b, and / or the second light section sensor 70, as shown in Figures 5a and 5b.

[0197] In the following, only the positioning of the inspection system using the first light-section sensor 60 will be discussed with reference to Figures 4a and 4b. Positioning using the second light-section sensor 70 can be performed in the same way as positioning using the first light-section sensor 60, with the inspection system, or rather the workpiece, merely being pivoted about a different axis of the coordinate system.

[0198] Figure 4a shows the first light section sensor 60 in the spatially fixed xyz coordinate system, with the projection axis RL1 of the first line laser 61 aligned parallel to the z-axis. The detection axis RD1 of the first detector 62 is aligned at an angle y1 to the projection axis RL1. The detector 62 thus detects the first laser line LL1 at the angle y1. The first line laser 61 projects the first laser line LL1 onto the workpiece essentially parallel to the y-axis.

[0199] For the sake of simplicity, the workpiece is shown in Figures 4a and 4b as a cuboid without workpiece topography and is pivoted about the x-axis in Figure 4a. This means that the surface of the workpiece facing in the z-direction forms an angle with the xy-plane of the coordinate system. Due to the pivoting of the workpiece about the x-axis, the workpiece has a distance dL1 at its rear end from the first line laser 61 that is smaller than the distance DL1 that the workpiece has at its front end from the first line laser 61.

[0200] Due to the different distance, the line laser hits the rear end of the workpiece earlier than the front end. Due to the pivoting of the workpiece around the x-axis, the first detector 62 detects the first laser line LL1 not as a horizontal line in the y-direction of the coordinate system, but as an obliquely rising line in the yz-direction.

[0201] The step of positioning the inspection system can be carried out such that the first laser line LL1 of the first line laser 61 is projected onto the workpiece, and the first detector 62 detects the first laser line LL1. If the first detector 62 does not detect the first laser line LL1 as a horizontally running line on average, as shown in Figure 4a, the inspection system and / or the workpiece can be pivoted about the x-axis until the first detector 62 detects the first laser line LL1 as a horizontally running line on average, as shown, for example, in Figure 4b.

[0202] In Figure 4b, the workpiece is pivoted about the x-axis by a distance compared to Figure 4a, such that the surface of the workpiece facing in the z-direction is aligned parallel to the xy-plane of the coordinate system. This means that the workpiece is pivoted about the x-axis by a distance compared to Figure 4a, such that its front end and rear end are at the same distance dL1 = DL1 from the first line laser 61. The first line laser 61 and the first detector 62 are positioned the same with respect to the spatially fixed coordinate system as in Figure 4a. The first detector 62 therefore detects a horizontal line. This makes it possible to determine that the workpiece is not pivoted about the x-axis.

[0203] If a pivoting about the y-axis is to be detected, the inspection system also requires a second light section sensor 70, which projects the second laser line LL2 onto the workpiece essentially parallel to the x-axis, as shown in Figures 5a and 5b.

[0204] If the inspection system additionally comprises the second light section sensor 70, as shown in Figures 5a and 5b, the optical inspection system can additionally detect a pivoting about the y-axis of the coordinate system and pivot the inspection system and / or the workpiece in an analogous manner until the second detector 72 detects the second laser line LL2 as a line running horizontally on average in the x-direction.

[0205] To avoid errors when checking the workpiece topography, the distance of the inspection system to the workpiece, in particular the workpiece topography, should be adjusted so that the inspection plane E touches the workpiece, in particular the workpiece topography, at least at one point. In particular, the distance between the optical inspection system and the workpiece topography should be adjusted so that the inspection plane E forms a tangential plane to the workpiece topography.

[0206] The distance of the inspection system to the workpiece topography can be adjusted, for example, using the laser point P (if present), the first laser line LL1, and / or the second laser line LL2 (if present). The first laser line LL1 and optionally the second laser line LL2 (if present), and the laser point P can serve as a measure of the correct distance between the inspection system and the workpiece, in particular the workpiece topography.

[0207] By changing the axial distance between the optical inspection system and the workpiece topography, in particular by axially moving the inspection system and / or the workpiece with the workpiece topography relative to each other, the distance can be adjusted such that the first laser line LL1 of the first line laser 61 and / or the second laser line LL2 of the second line laser 71 passes through the laser point P, as shown in Figure 2a. In particular, the distance is adjusted such that the first laser line LL1 and the second laser line LL2 intersect at the laser point P.

[0208] If the distance between the inspection system and the workpiece, in particular the workpiece topography, is incorrectly set, ie the inspection plane E does not touch the workpiece or the workpiece topography or intersects it, the laser point P on the workpiece is not located on the first laser line LL1 on the workpiece and / or optionally on the second laser line LL2 on the workpiece, as shown in Figure 2a.

[0209] If the inspection system is aligned perpendicularly to the workpiece, in particular to the workpiece topography, and if the inspection system is at the correct distance from the workpiece, in particular to the workpiece topography, in particular if the inspection plane E is tangent to the workpiece or the workpiece topography, the recording unit 10 can record, in particular photograph, the workpiece topography. The recording unit 10 can also take a picture of the workpiece topography without the previously described positioning of the inspection system and / or the workpiece topography.

[0210] The evaluation of the workpiece topography, in particular the weld spot quality, can be carried out by recording the workpiece topography by a computer, for example using a Kl program, or in alternative versions by an operator.

[0211] If the workpiece topography is, for example, a spot weld joint, the image from the recording unit 10 can be compared with a plurality of images of spot weld joints from a database, particularly using a computer. For example, the database can contain images of spot weld joints or parameters of spot weld joints that are to be expected and not faulty depending on the set welding parameters of the welding process and the workpiece material. The expected parameters of the spot weld joints can be calculated alternatively or additionally by the Kl program.

[0212] If the recording of the recording unit 10 of the workpiece topography deviates too much from the recordings stored for these production parameters or the parameters of the spot weld connection, for example if the spot weld connection is too large or too small in diameter, the workpiece topography, in particular the spot weld connection, can be assessed as not being in order.

[0213] In addition to comparing the image captured by the recording unit 10, information collected by the recording unit 10 regarding the depth or height of the workpiece topography can also be used to evaluate the workpiece topography. As shown in Figure 3, the recording unit 10 detects the first laser line LL1 and / or the second laser line LL2, which is not shown in Figure 3, as a height profile of the workpiece topography. This is due to the projection axis RL1 or RL2 intersecting the recording axis RA at an angle ß1 or ß2.

[0214] As can be seen in Figure 3, for example, the first laser line LL1 detected by the recording unit 10 exhibits a line offset in the central region of the workpiece topography. This line offset is a measure of the elevation and / or depression of the workpiece in the area of ​​the workpiece topography. This information about the height or depth of the workpiece topography can also be incorporated into the evaluation of the workpiece topography.

[0215] Figures 2a and 2b show the first laser line LL1 and the second laser line LL2 detected by the recording unit 10 in a simplified form, i.e., without any bevel in the area of ​​the rise of the workpiece topography. Figures 2a and 2b show a simplified image of the image taken by the recording unit 10 of the workpiece topography. The evaluation of the workpiece topography can preferably be performed using both the image in Figures 2a and 2b.

[0216] Reference symbol

[0217] 10 Recording unit

[0218] 20 bandpass filters

[0219] 30 lens

[0220] 40 point lasers

[0221] 41 Deflection device

[0222] 50 lighting equipment

[0223] 60 first light section sensor

[0224] 61 first line laser

[0225] 62 first detector

[0226] 70 second light section sensor

[0227] 71 second line laser

[0228] 72 second detector

[0229] M Test plane P Point

[0230] Ln first laser line

[0231] LL2 second laser line

[0232] Rn projection axis of the first line laser

[0233] RDI detection axis of the first line laser

[0234] RL2 Projection axis of the second line laser

[0235] RD2 Detection axis of the second line laser

[0236] Rp projection axis of the point laser

[0237] RA Recording axis of the recording unit ai Angle between the projection axis of the first line laser and the projection axis of the point laser ßi Angle between the recording axis of the recording unit and the projection axis of the first line laser

[0238] 02 Angle between projection axis of the second line laser and projection axis of the point laser ß2 Angle between recording axis of the recording unit and projection axis of the second line laser y1 Angle between projection axis of the first line laser and detection axis of the first detector y2 Angle between projection axis of the second line laser and projection axis of the first line laser ö Angle between projection axis of the first line laser and the projection axis of the second line laser s Angle between recording axis of the recording unit and projection axis of the point laser

Claims

Claims 1 . Method for testing a workpiece topography of a workpiece, in particular for testing macroscopic unevenness of the workpiece formed by joining or separating processes, using an optical testing system, the testing system comprising: 1.

1. a first line laser (61) with a projection axis RL1 pointing in the projection direction, and 1 .

2. a receiving unit (10) with a receiving axis RA pointing in the receiving direction, the method comprising the steps: 1 .

3. Positioning the optical inspection system and / or the workpiece so that the workpiece topography touches a test plane at least at one point, 1 .

4. Generating a first laser line LL1 in the test plane so that the laser line LL1 is visible on the workpiece topography, 1 .

5. Recording the workpiece topography using the recording unit (10), 1 .

6. Evaluation of the workpiece topography based on the image of the workpiece topography recorded by the recording unit (10) as a function of parameters of the workpiece topography, for example a geometry of the workpiece topography, and a line offset of the first laser line LL1 recorded by the recording device (10).

2. Method according to the preceding claim, wherein the recording unit (10) is a 2D camera and the recording generated by the recording unit is a 2D image recording.

3. Method according to one of the preceding claims, wherein the optical inspection system and / or the workpiece is aligned, in particular by a control system, for example a robot control system, such that the The receiving axis RA forms an angle of 90° ± 20°, in particular an angle of 90° ± 10°, with the surface of the workpiece topography.

4. Method according to one of the preceding claims, wherein the workpiece topography is a raised area and / or depression in the workpiece formed by a joining or separating process.

5. Method according to one of the preceding claims, wherein the optical inspection system comprises a second line laser (71) with a projection axis RL2 pointing in the projection direction and wherein the method comprises the step of generating a second laser line LL2 in the inspection plane, so that the first laser line LL1 of the first line laser (61) and the second laser line LL2 of the second line laser (71) intersect at one point, in particular intersect orthogonally.

6. Method according to one of the preceding claims, wherein the optical inspection system comprises a point laser (40) and the step of positioning the inspection system is carried out in such a way that the laser point P lies, preferably centrally, on the workpiece topography and the first laser line LL1 of the first line laser (61) and / or the second laser line LL2 of the second line laser (71) according to the preceding claim run / runs through the laser point P.

7. Method according to one of the preceding claims, wherein the workpiece topography is evaluated based on a line offset of the first laser line LL1 and / or the second laser line LL2 according to one of claims 4 to 5, detected by the recording device (10), wherein the line offset is a measure of an elevation and / or depression of the workpiece in the region of the workpiece topography.

8. Method according to one of the preceding claims, wherein the evaluation of the workpiece topography is carried out automatically, for example by a computer, in particular by means of a Kl program.

9. Method according to one of the preceding claims, wherein the recording of the workpiece topography is evaluated as a function of parameters of the manufacturing process stored, in particular temporarily, in a database.

10. Method according to one of the preceding claims, wherein in the step of evaluating the workpiece topography the workpiece topography is categorized, for example into small, large, OK, not OK, deep, high and / or flat.

11. Method according to one of the preceding claims, wherein in the step of evaluating the workpiece topography the determined parameters are compared with expected parameters of the workpiece topography for the manufacturing process.

12. Method according to one of the preceding claims, wherein in the step of evaluating the workpiece topography the diameter and / or the depth or height of the workpiece topography is / are determined and compared with expected values ​​for the diameter and / or the depth or height of the workpiece topography for recorded manufacturing parameters of the manufacturing process.

13. Method according to one of the preceding claims, wherein the recording of the workpiece topography is evaluated as a function of parameters of the manufacturing process stored in a database, in particular temporarily, and wherein the stored parameters are the force curve of a welding tool and / or the current intensity of the welding tool and / or resistance curve during welding and / or the welding time and / or material parameters of a welded joint, such as sheet thickness, sheet material or coating of the welded sheets, and / or a welding point position.

14. Method according to one of the preceding claims, wherein the optical inspection system comprises a point laser (40), in particular the point laser (40) according to claim 4, a first light section sensor (60) with the first line laser (61) and a first detector (62) and a second light section sensor (70) with a second line laser (71), in particular the second line laser (71) according to one of claims 3 to 5, and a second detector (72), and the step of aligning the test system comprises the following steps: 14.1 . Projection of the first laser line LL1 of the first line laser (61) onto the workpiece and projection of the second laser line LL2 of the second line laser (71) according to one of claims 4 to 9 onto the workpiece, 14.

2. Detection of the first laser line LL1 by the first detector (62) and detection of the second laser line LL2 by the second detector (72), 14.

3. optionally pivoting the first light section sensor (60) so that the detector (62) detects the first laser line LL1 as a line running horizontally on average, and / or optionally pivoting the second light section sensor (70) so that the second detector (72) detects the second laser line LL2 as a line running horizontally on average, 14.

4. coordinated translational movement of the first light section sensor (60), the second light section sensor (70), the point laser (40) and the recording unit (10) orthogonal and / or tangential to the workpiece, so that the laser point P lies on the workpiece topography, in particular centrally on the workpiece topography, and the first laser line LL1 and the second laser line LL2 intersect at the laser point P.

15. An optical inspection system for use in the method according to any one of claims 1 to 9, comprising: 15.1 .at least the first line laser (61) with a projection axis RL1 pointing in the projection direction for generating the first laser line LL1 in the test plane E, 15.

2. optionally a point laser (40) with a projection axis RP intersecting the test plane E for generating a laser point P in the test plane E, and 15.

3. the recording unit (10) with the recording axis RA pointing in the recording direction for the optical recording of the test plane E, whereby 15.

4. the projection axis RL1 of the line laser (61) and the projection axis RP of the point laser (40), if the point laser (40) is present, intersect at an angle a1, and 15.

5. the recording axis RA of the recording unit (10) and the projection axis RL1 of the first line laser (61) intersect at an angle ß1, and wherein 15.

6. the projection axis RL1 of the line laser (61), the recording axis RA and preferably the projection axis RP of the point laser (40) intersect at one point, preferably at the laser point P, in the test plane E.

16. Optical inspection system according to the preceding claim, wherein the optical inspection system comprises the point laser (40) and the recording axis RA of the recording unit (10) and the projection axis RP of the point laser (40) overlap each other and wherein the point laser (40) is preferably deflected by a deflection device (41), in particular by a mirror or a prism, so that the projection axis RP of the point laser (40) overlaps with the recording axis RA of the recording unit (10).

17. Optical inspection system according to one of the three preceding claims, wherein 17.

1. the test system comprises a second line laser (71) with a projection axis RL2 pointing in the projection direction for generating a second laser line LL2 in the test plane E, 17.

2. the first line laser (61) and the second line laser (71) are arranged such that the first laser line LL1 of the first line laser (61) and the second laser line LL2 of the second line laser (71) intersect, in particular orthogonally intersect, at the point, preferably at the laser point P of the point laser (40), if present.

18. Optical inspection system according to one of the four preceding claims, wherein the first line laser (61) and a first detector (62) for detecting the first laser line LL1, which has a detection axis RD1 pointing in the detection direction, are formed in a light section sensor (60) and the projection axis RL1 of the line laser (61) and the detection axis RD1 of the detector (62) intersect at an angle y1 and / or wherein a second line laser (71), in particular the second line laser according to claim 14, and a second detector (72) for detecting the second laser line LL2, which has a Detection axis RD2 pointing in the detection direction, are formed in a second light section sensor (70) and the projection axis RL2 of the second line laser (71) and the detection axis RD2 of the second detector (72) intersect at an angle y2.

19. Optical inspection system according to one of the five preceding claims, wherein the first line laser (61), optionally the point laser (40), the recording unit (10) and optionally the second line laser (71) according to claim 13 are movable, in particular are movably mounted, and wherein a movement of the first line laser (61) and / or optionally a movement of the second line laser (71) causes / causes a coordinated movement of the point laser (40) and the recording unit (10).

20. Optical inspection system according to one of the six preceding claims, wherein and wherein preferably the angular relationships between the recording axis RA, the projection axis RL1 of the first line laser (61), optionally the projection axis RP of the point laser (40) and optionally the projection axis RL2 of the second line laser (71) are fixed.

21. Optical inspection system according to one of the seven preceding claims, wherein the first line laser (61), in particular the first light section sensor (60) according to claim 15, optionally the point laser (40), the recording unit (10) and optionally the second line laser (71) according to one of claims 14, in particular the second light section sensor (70) according to claim 15, are arranged on a common carrier and wherein the carrier can preferably be mounted as a tool of an industrial robot.

22. Optical inspection system according to one of the eight preceding claims, wherein the recording unit (10) is a 2D camera which is focused on the point P, preferably on the laser point P of the point laser (40), if present, and wherein an illumination device (50), in particular a ring light, for illuminating the inspection plane E is preferably formed between the recording unit (10) and the inspection plane E.

Images