Camera of a motor vehicle assistance system and method for manufacturing such an assistance system

Abstract

Method (2) for manufacturing an assistance system for a motor vehicle, comprising a camera (4) comprising an optical module (30) and a camera housing (12) with a first housing half (8) and with a second housing half (10), wherein - the optical module (30) is positioned between the first housing half (8) and the second housing half (10), - the optical module (30) is attached to the first housing half (8) and / or to the second housing half (10) by means of a specific joining technique, in particular by welding, and - the first housing half (8) and the second housing half (10) are joined using the specified joining technique, - wherein, for the creation of the optical module (30), a lens (38) is attached to a profile rail (32).

Description

[0001] The invention relates to a method for producing an assistance system of a motor vehicle, with a camera and a camera of an assistance system of a motor vehicle.

[0002] Motor vehicles incorporate a variety of assistance systems, such as rain sensors, lane departure warning systems, or drowsiness warning systems. Each such assistance system features a camera that, when in operation, captures the windshield, the road surface, or the driver. The captured image is checked for deviations from a specific target state, and if a target state is detected, an actuator is activated, such as a windshield wiper motor, a motor for influencing the steering angle, or an acoustic or visual signaling device.

[0003] The camera typically includes an optical module located within a camera housing for capturing images. To ensure the proper functioning of the assistance system, the optical module must be precisely aligned with the camera housing. Typically, in a first step, the optical module is aligned with a part of the camera housing and secured to it, for example, using screws. This can lead to damage to the optical module due to the comparatively large forces acting on it. The camera housing itself is completed in a subsequent step.

[0004] From the publication DE102012210818A1, a camera module comprising a lens with a lens mount and at least one lens, an image sensor, a support device, and a camera housing is known. The lens is connected to the camera housing, in particular to a first housing part, and is supported by the camera housing. The support device can be fixed, in particular, to the lens or to the first housing part.

[0005] The invention is based on the object of specifying a particularly suitable method for producing an assistance system with a camera and a camera of an assistance system of a motor vehicle, wherein the production time is particularly shortened.

[0006] With regard to the method, the object is achieved according to the invention by the features of claim 1 and with regard to the camera by the features of claim 5. Advantageous further developments and refinements are the subject of the respective subclaims.

[0007] The method is used to manufacture an assistance system for a motor vehicle. The assistance system may be, for example, a rain sensor, a lane departure warning system, a fatigue warning system, an emergency braking system, or a parking aid. The assistance system comprises a camera with an optical module and a camera housing. The optical module is used to capture images and includes electrical and / or electronic components. The camera housing protects the optical module from damage and external influences. For example, the optical module and the camera housing are manufactured simultaneously or at least independently of each other.

[0008] The camera housing itself comprises a first housing half and a second housing half, which are manufactured either simultaneously or independently of each other. For example, both the first and second housing halves are produced by injection molding a plastic. However, it is particularly preferred that the two housing halves consist of a sheet metal that is deep-drawn, particularly for the production of the respective housing halves.

[0009] In a first step, the optics module is positioned between the first housing half and the second housing half. In particular, the optics module is at least partially inserted into an opening in the camera housing, which represents the optical connection between the optics module and the environment to be recorded when the assistance system is in operation. The opening is preferably matched to the optics module and shaped accordingly. For example, insertion takes place in a direction parallel to the optical axis of the optics module, and / or the opening runs parallel to the optical axis of the optics module. In a second step, the optics module is attached to the first housing half using a specific joining technique. Welding is the preferred joining technique, but crimping or flanging are also used. In other words, the optics module is welded, crimped, or flanged to the first housing half.In particular, the optics module and / or the first housing half have corresponding fastening points for this purpose. Alternatively, or in combination with this, the optics module is attached to the second housing half using the specific joining technology.

[0010] In a third step, the first housing half is joined to the second housing half using a specific joining technique. The third step can occur before, after, or simultaneously with the second step. For example, the first housing half is welded to the second housing half, and the optics module is then welded to the first housing half. Alternatively, the optics module is crimped to the second housing half, with the first housing half being crimped to the second housing half at the same time.

[0011] By using a single joining technique, the connection between the optics module and the respective housing half, as well as the connection of the two housing halves to each other, can be performed at the same workstation, requiring only a single tool. Furthermore, no transport between different workstations is required. Furthermore, any curing of an adhesive or cooling after welding can be carried out essentially in parallel, further reducing production time.

[0012] According to the invention, the optics module comprises a lens that is connected to a profile rail. According to the invention, the lens is therefore connected to the profile rail for production. The connection is made directly or indirectly, via further components. In particular, the lens is fastened to a circuit board, which in turn is fastened to the profile rail, in particular by means of screws or an adhesive. Preferably, an image sensor is arranged on the circuit board and in particular connected to it. Alternatively, the image sensor is fastened directly to the profile rail. For assembly, the lens is aligned in particular relative to the image sensor. In a further work step, the lens is suitably connected to the image sensor by means of an adhesive, which prevents any displacement of the image sensor relative to the lens.When the assistance system is in operation, light passes through the lens onto the image sensor, and the electrical voltage generated in this way is read out by other electrical or electronic components on the circuit board. In particular, the profile rail has a C-shaped or U-shaped cross-section, particularly parallel to the optical axis of the lens, which increases the stability of the profile rail. The optics module is expediently connected to the respective housing half using the profile rail. In other words, the profile rail is attached to the assigned housing half using a specific joining technique. By connecting the lens to the profile rail, the lens is stabilized and protected against mechanical stress. Furthermore, aligning the lens with respect to the camera housing is simplified.

[0013] Particularly preferably, a tab is attached to the profile rail during its manufacture. In particular, the profile rail is made from sheet metal and the tab is punched out accordingly. In particular, after punching out of the sheet metal, the tab is bent appropriately. Alternatively, the tab is attached to components of the profile rail, for example by welding or gluing. A recess is made in one of the housing halves, in particular during its manufacture. In particular, the recess is punched out or created by drilling. For example, a C-shaped slot is made in the housing half and, in a further work step, the tongue created in this way is bent to create the recess. For example, the angle is 90° or less, for example between 45° and 30°. The recess is preferably made in the first housing half.In particular, a number of recesses are made, for example in the first housing half, and a corresponding number of tabs are connected to the profile rail.

[0014] To position the optics module between the first and second housing halves, the tab is inserted into the recess. As a result, the profile rail is located inside the housing halves, whereas the tab is partially inside the recess and partially outside the housing halves. As a result, the profile rail is stabilized by the tab and the recess, so that the profile rail can also be attached to the respective housing half after the camera housing is closed. For example, a press fit is created between the tab and the recess, which results in a comparatively stable aligned optics module with respect to the camera housing. Alternatively, a clearance fit is created between the recess and the tab.

[0015] Particularly preferably, the tab has a smaller cross-section than the recess. In other words, a gap is formed between the tab and the recess, and after positioning the optics module between the first and second housing halves, the tab can be moved within the recess. As a result, the profile rail and thus also the optics module can be moved relative to the camera housing. In particular, after inserting the tab into the recess, the optics module is aligned relative to the camera housing by moving the tab within the recess, wherein the optical axis of the optics module is expediently aligned with the optical axis of the camera housing so that they run parallel to one another and correspond. Preferably, the first housing half is joined to the second housing half first.In a further step, the optics module is aligned with the camera housing, with the tab being moved accordingly within the recess. In a subsequent step, the optics module is attached to the housing part in which the recess is made using a specific joining technique. In other words, the alignment (adjustment) of the optics module and the attachment of the optics module only take place after the camera housing has been created. Preferably, each of the housing parts and the profile rail are made from a single sheet of metal, and welding, for example, is chosen as the specific joining technique.

[0016] Alternatively or in combination with this, the tab or tabs, if present, are used as an alignment feature of the camera relative to a camera mount. In this case, preferably before the camera is attached to the camera mount, the camera mount is connected to the motor vehicle and aligned with respect to the latter, this being done suitably at a time independent of the camera installation. When the camera is attached to the camera mount, the tab is positioned with respect to the aligned camera mount, and consequently also the optics module. In this way, the optics module can be aligned with the camera mount in one or more spatial directions without tolerances of the camera housing and / or the connection of the optics module to the camera housing having an influence thereon. The camera mount preferably has a stop surface against which the tab is guided.The stop surface restricts the movement of the tab in at least one direction. Alternatively, the tab can be clipped or locked to a corresponding mating contour of the camera mount.

[0017] The camera is part of an assistance system of a motor vehicle. By means of the assistance system, traffic flow around the motor vehicle is recorded in particular. The camera comprises a camera housing with a first housing half and a second housing half as well as an optics module. The camera housing serves to protect the optics module, whereas images are recorded using the optics module. The optics module is arranged between the first housing half and the second housing half so that the optics module is protected against external influences by the housing halves. The optics module itself is connected to either the first and / or the second housing half using the same joining technology as the first housing half is connected to the second housing half. The first housing half is preferably welded, crimped or flanged to the second housing half.For this purpose, the first and / or second housing halves preferably have a circumferential collar that is crimped accordingly. Alternatively, a weld seam is applied to the collar, which is in particular essentially circumferential.

[0018] According to the invention, the optics module has a profile rail that is joined to at least one of the housing halves, i.e., fastened to the first and / or second housing half. For example, the profile rail is designed as a flat plate. Suitably, the profile rail is made of a metal or another weldable or flexible material. Preferably, the profile rail is substantially C-shaped, U-shaped, or Z-shaped, which increases its stability. Suitably, the profile rail is made of the same material as the housing half to which the profile rail is joined. In this way, contact erosion is ruled out. Preferably, the two housing halves are made of the same material, so that contact corrosion between the first and second housing halves is also ruled out, wherein in particular the profile rail, if present, is also made of this material.Suitably, the profile rail is made of sheet metal and is preferably a stamped and bent part. The first and / or second housing half is preferably made of sheet metal and is produced, for example, by deep drawing. This reduces the manufacturing costs of the camera, while maintaining a comparatively high level of robustness.

[0019] In particular, the optics module has an image sensor that is connected to the profile rail. The image sensor is, for example, a CCD or CMOS sensor. The image sensor is suitably mounted on a circuit board, which in turn is fastened to the profile rail, for example by means of screws or adhesive. In particular, the optics module has a lens, by means of which light is bundled. In other words, the lens has a converging lens, which is preferably made of a plastic. Suitably, the lens has a lens system with both glass and plastic lenses. The lens is arranged above the image sensor so that the image sensor is suitably illuminated by means of the lens. In this case, the image sensor is located between the lens and the profile rail.As a result, the image sensor is relatively reliably protected from foreign particles or other environmental influences, and the image sensor's recording performance is increased. In a preferred embodiment of the invention, the optics module comprises two or more lenses that are spaced apart from one another. This enables spatial resolution of the images captured by the optics module. For example, the lens is attached to the profile rail and / or the profile rail has a recess within which the lens is at least partially positioned.

[0020] The first housing half expediently has an opening within which the lens is at least partially arranged. In other words, when the camera is in operation, light enters the camera housing through the opening, wherein the light is directed onto the image sensor by means of the lens. Preferably, the camera housing has only a single opening, provided that the optics module only comprises a single lens. As a result, the operation of the image sensor is not affected by stray light or the like. In an alternative embodiment, the optics module has at least a second lens and a second associated image sensor, which are in particular connected to the profile rail. Preferably, the first housing half has two openings, wherein one of the lenses is arranged in each of the openings.

[0021] In particular, the lens is spaced apart from the first housing half. In other words, a gap is formed between the lens and the edge of the opening. This allows the lens to be aligned within the opening and compensates for any distortion of the first housing half.

[0022] A circuit board is expediently arranged within the camera housing, by means of which the images captured by the image sensor are processed and evaluated. The circuit board is suitably contacted to the image sensor by means of a foil conductor. For this purpose, the foil conductor is, for example, soldered directly to the image sensor or a bond is created between them. Alternatively, the foil conductor is electrically contacted to a circuit board on which the image sensor is mounted, for example by soldering or a connector. In a further embodiment, the circuit board is designed as a foil circuit board, which is in particular integral with the foil conductor. Due to the arrangement of the circuit board within the camera housing, it is possible to create the camera as a module and to supply standardized data to an interface, regardless of the design of the image sensor used.The comparatively short connections also essentially rule out faulty transmission, while the connection is comparatively simple and robust. If the camera housing is made of a metallic material, the influence of any external electrical or magnetic fields is also excluded or at least reduced. The foil conductor requires comparatively little space, and the flexible connection means that the signal connection is not interrupted even in the event of relative movement of the circuit board with respect to the image sensor, for example due to vibration of the camera housing. In addition, the foil conductor enables a comparatively free choice of the mounting angle of the optics module with respect to the circuit board, as well as tolerance compensation.

[0023] Preferably, the circuit board, which is electrically contacted with the image sensor by means of the foil conductor, is held between the first and second housing halves. In other words, a frictional connection is realized between the first housing half, the circuit board, and the second circuit board. For this purpose, the first and / or second housing half preferably has a corresponding clamping section, in particular in the form of a collar, against which the circuit board rests. For assembly, the circuit board is placed against the corresponding receptacle of the first or second housing half, and in a further step, the remaining housing half is connected to this housing half to create the camera housing. As a result, the circuit board is in direct mechanical contact with both housing halves. Due to this attachment, no further fastening means such as screws, clips, or the like are necessary, thus reducing material costs.The circuit board is also attached in one step when joining the two housing halves, so that the production time is further reduced.

[0024] Preferably, the optics module is attached to the camera housing at three points. In particular, the optics module has the profile rail, which is connected to the camera housing at three points. The connection points are comparatively small, each having an area of ​​less than 1 cm. 2 , 0.5 cm 2 or 0.25 cm 2Preferably, the contact points are designed essentially as points. In particular, two of the contact points are located at opposite ends of the camera housing, with the third point preferably being spaced from a straight line connecting these two contact points. This increases the stability of the optics module with respect to the camera housing. In particular, when the assistance system is assembled, the contact points are located on the top side of the camera housing as well as on the left and right sides. Due to the connection of the optics module to the camera housing by means of three defined contact points, the alignment of the optics module is essentially independent of external influences, such as the movement of the motor vehicle along a rough road. In other words, the alignment of the optics module is maintained.

[0025] Preferably, at least one of the housing halves has a recess within which a tab of the optics module is at least partially arranged. The tab is shaped like an extension and projects outwards from the interior of the camera housing. The recess is suitably created as a punched-out section, which reduces manufacturing costs and time. If the optics module has the profile rail, the tab is suitably connected to the profile rail and preferably molded onto it. Preferably, at least a clearance fit is created between the tab and the recess so that movement of the tab within the recess is possible provided the optics module is not rigidly connected to the housing half. The direction of movement is preferably perpendicular to the direction in which the tab is inserted into the recess.During production, a defined starting point for the optics module is thus created, by means of which the optics module can be aligned with respect to the camera housing even when the camera housing has already been completely manufactured. In particular, the alignment of the optics module with respect to the camera housing and the adjustment of the optical axis of the optics module take place after production of the camera housing, with the optics module being moved with respect to the camera housing by exerting force on the tab. The optics module expediently has a number of such tabs, in particular three tabs. This improves the alignment of the optics module with respect to the camera housing. Expediently, the optics module is connected to the camera housing at three points, each of these points having one of the tabs and one of the recesses.

[0026] When the camera is mounted, the recess is ideally closed by the tab. For example, after the optics module has been aligned, the tab is bent, crimped, or welded to close the recess. This prevents foreign particles from entering the camera housing after the optics module has been correctly aligned, thus increasing its service life. It also prevents contamination of the image sensor, if present.

[0027] Alternatively, or in combination with this, when the assistance system is assembled, the tab or tabs, if present, are guided against a stop surface, preferably against a number of stop surfaces corresponding to the number of tabs, of a camera mount that is attached, for example, to a vehicle body. In other words, the tab rests against the stop surface. Consequently, the optics module is aligned with respect to the camera mount, with tolerances of the camera housing having no influence on this. Alternatively, the tab is clipped or latched to a corresponding mating contour of the camera mount.

[0028] An embodiment of the invention is explained in more detail below with reference to a drawing. In the drawings: Fig. 1 schematically shows a method for producing an assistance system with a camera, Fig. 2 perspective view of the camera in an exploded view, Fig. 3 perspective view of the camera in a sectional view, and Fig. 4 the camera in a top view.

[0029] Corresponding parts are provided with the same reference numerals in all figures.

[0030] In Fig. 1 schematically shows a method 2 for producing an assistance system for a motor vehicle. The assistance system is a lane keeping assistant for warning a driver of the motor vehicle before leaving a lane. The assistance system comprises the camera 4 shown in the following figures. In a first step 6, a first housing half 8 and a second housing half 10 of a camera housing 12 are created. For this purpose, the second housing half 10 is punched from a sheet metal, wherein the cross section of the second housing half 10 is essentially L-shaped perpendicular to a first direction 14 and cuboid-shaped perpendicular to a second direction 16. In a third direction 18, the cross section is C-shaped. The edge of the second housing half 10 is formed by means of a circumferential collar 19.

[0031] The shape and manufacturing method of the first housing half 8 essentially corresponds to that of the second housing half 10. However, the shorter leg of the L-shape, running in the third direction 18, is thickened to form a stop surface 20. Two openings 22 are made in the stop surface 20. Furthermore, three recesses 24 are punched into the first housing half 8, two of the recesses 24 being located on opposite sides in the first direction 24 in the region of the connection of the two legs of the L-shaped cross-section. The remaining recess 24 is arranged on the free end of the L-shaped cross-section, essentially in the middle between the two remaining recesses 24. In the edge region, the first housing half 8 has an overlap 26 corresponding to the collar 19.

[0032] In a second step 28, an optical module 30 is created. For this purpose, a profile rail 32 is punched from the sheet metal of the first and second housing halves 8, 10, the cross-section of which is U-shaped perpendicular to the first direction 14. The leg of the U-shape located at the bottom in the third direction 18 is extended in the first direction 14, forming two tabs 34. In other words, the two tabs 34 are integrally formed on the profile rail 32. The central region of the remaining U-leg extending in the second direction 16 forms a third tab 34.

[0033] Two printed circuit boards 34 are attached to the middle leg of the profile rail 32, forming the U-shape. Each printed circuit board 34 mounts an image sensor 36 in the form of a CMOS chip. During production, the printed circuit boards 34 are screwed to the profile rail 32. Furthermore, the image sensors 36 are each covered by a lens 38, which is glued to the profile rail 32. Each of the image sensors 36 is electrically connected to a foil conductor 40 via the respective printed circuit board 34.

[0034] In a third step 42, the optics module 30 is positioned between the first housing half 8 and the second housing half 10, wherein the tabs 34 formed on the profile rail 32 are inserted into the corresponding recesses 24 of the first housing half 8. Here, the lenses 38 of the optics module 30 are partially arranged within the openings 22 of the first housing half 8, with play between each of the lenses 38 and the respectively associated opening 22. As a result, the lenses 38 protrude through the openings 22. In addition, the foil conductors 40 are plugged into corresponding plugs 44 of a substantially C-shaped printed circuit board 46. The printed circuit board 46 is placed onto the collar 19 of the second housing half 10, and this assembly is engaged behind by means of the overlap 26 of the first housing half 8. As a result, the printed circuit board 46 is held between the first and second housing halves 8, 10, as shown in Fig.3, so that the circuit board 46 is secured against accidental removal.

[0035] In a fourth step 48, the optics module 30 is aligned with respect to the camera housing 12. In this case, the two lenses 38 are moved within the openings 22 such that the optical axes of the lenses 38 lie on the desired optical axes. For this purpose, for example, a test image arranged in front of the camera housing 12 is captured using the image sensors 36, and a reference image is created from this. The optics module 30 is moved until the reference image corresponds to the test image. For this purpose, each of the tabs 34 is moved accordingly within the respective recess. In other words, the tabs 34 are engaged and, by means of these, the profile rail 32 and consequently also the lenses 38 are moved accordingly. Since the tabs 34 are integral with the profile rail 32, detachment of the tabs 34 from the profile rail 32 is excluded.

[0036] In a fifth step 50, the two housing halves 8, 10 are welded together, with a weld seam (not shown in detail) being created along the free end of the collar 19 of the second housing half 10 and along the free end of the overlap 26 of the first housing half 8. Here, the tabs 34 are also welded to the first housing half 8, so that the optics module 30 is attached to the first housing half 8 at three points 52. Furthermore, the recesses 24 are closed, preventing foreign particles from penetrating the camera housing 12 through the recesses 24. Due to the attachment of the optics module 30 at three connection points 52, the camera 4 has a comparatively high degree of flexibility. In other words, twisting of the camera housing 12 does not lead to a change in the alignment of the optics module 30.In addition, the resulting camera 4 exhibits low manufacturing tolerances due to the comparatively late alignment of the optics module 30. The lenses 38 and the image sensors 36 also retain their relative alignment to one another even when the camera housing 12 is subjected to vibration.

[0037] The invention is not limited to the exemplary embodiment described above. Rather, other variants of the invention can also be derived therefrom by those skilled in the art without departing from the scope of the invention. In particular, all individual features described in connection with the exemplary embodiment can also be combined with one another in other ways without departing from the scope of the invention. List of reference symbols 2 procedures 4 Camera 6 first step 8 first housing half 10 second housing half 12 camera bodies 14 first direction 16 second direction 18 third direction 19 collars 20 stop surface 22 Opening 24 recess 26 Assault 28 second step 30 optics module 32 profile rail 34 circuit board 36 image sensor 38 lens 40 foil conductors 42 third step 44 plugs 46 circuit board 48 fourth step 50 fifth step 52 junction point

Claims

[1] Method (2) for producing an assistance system of a motor vehicle, with a camera (4) which has an optical module (30) and a camera housing (12) with a first housing half (8) and with a second housing half (10), in which - the optical module (30) is positioned between the first housing half (8) and the second housing half (10), - the optical module (30) is attached to the first housing half (8) and / or to the second housing half (10) by means of a specific joining technique, in particular by welding, and - the first housing half (8) and the second housing half (10) are joined by means of the specific joining technique, - wherein a lens (38) is connected to a profile rail (32) to create the optical module (30). [2] Method (2) according to claim 1, characterized bythat a tab (34) is attached to the profile rail (32) and a recess (24) is made in one of the housing halves (8, 10), wherein the tab (34) is inserted into the recess (24) for positioning the optical module (30). [3] Method (2) according to claim 2, characterized by that the optical module (30) is aligned with respect to the camera housing (12), wherein the tab (34) is moved relative to the recess (24), and / or that the optical module (30) is aligned with respect to a camera holder, wherein the tab (34) is guided in particular against a stop surface of the camera holder. [4] Camera (4) of an assistance system of a motor vehicle, with an optical module (30) arranged between a first housing half (8) and a second housing half (10) of a camera housing (12), wherein the first housing half (8) and the second housing half (10) are connected by means of the same joining technology as the optical module (30) and the first housing half (8) and / or the second housing half (10), characterized by that the optical module (30) has a profile rail (32) made of the same material as the two housing halves (8,10), in particular sheet metal, which is joined to at least one of the housing halves (8,10). [5] Camera (4) according to claim 4, characterized by that an image sensor (36) is connected to the profile rail (32), which is covered by means of a lens (38) which is arranged at least partially within an opening (22) of the first housing half (8), wherein the lens (38) is in particular spaced apart from the first housing half (8). [6] Camera (4) according to claim 5, characterized by that a printed circuit board (46) is arranged within the camera housing (12), which is electrically contacted with the image sensor (36) by means of a foil conductor (40), wherein the printed circuit board (46) is held in particular between the two housing halves (8, 10). [7] Camera (4) according to one of claims 4 to 6, characterized by that the optical module (30) is attached to the camera housing (12) at three points (52). [8] Camera (4) according to one of claims 4 to 7, characterized by that the first housing half (8) and / or the second housing half (10) has a recess (24), in particular a punched-out portion, wherein a tab (34) of the optical module (30) is at least partially arranged within the recess (24), wherein in particular the recess (24) is closed by means of the tab (32).

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