BR102018007887B1 - CAMERA SYSTEM FOR A VEHICLE, MIRROR REPLACEMENT SYSTEM COMPRISING SUCH CAMERA SYSTEM, AND DRIVER ASSISTANCE SYSTEM INCLUDING SUCH SYSTEM - Google Patents

Abstract

CAMERA SYSTEM FOR A VEHICLE, MIRROR REPLACEMENT SYSTEM COMPRISING SUCH CAMERA SYSTEM, AND DRIVER ASSISTANCE SYSTEM INCLUDING SUCH SYSTEM. A camera system (130) is provided for a motor vehicle (10) comprising a capture unit (30). The capture unit (30) comprises an optical element (301) and an image sensor (303) which is provided with an image sensor surface (304), and is adapted to capture a section of a vehicle environment. The optical element (301) is provided with a distortion with a distortion curve r = f(a), where r is comprised of the distance between a point of the object displayed on the surface of the image sensor (304) and the point of intersection of the optical axis (302) with the surface of the image sensor (304), and a is comprised of the angle between the optical axis (302) of the optical element (301) and the beam incident on the optical element (301) from the point of the object. The distortion curve r = f(a) is provided with, for rw= f (aw) within 0 r rmax, an inflection point aw; rw, for which r = f(aw) = d2r/da 2 (aw) = 0 applies, where rmax is the distance r = f(amax)(...).

Description

FIELD OF INVENTION

[001] The invention relates to a camera system for a vehicle, in particular a commercial vehicle. The invention further relates to a mirror replacement system for a motor vehicle comprising such a camera system, and a driver assistance system for a vehicle comprising such a camera system.

PREVIOUS TECHNIQUE

[002] Currently, the camera system is increasingly used whether or in vehicles, for example, a camera system used in the vehicle in the context of a supplementary system for conventional mirrors, for example, to provide a parking aid for the driver of a passenger vehicle. Furthermore, the camera system is increasingly used in the context of so-called mirror replacement systems, in which mirrors that are prescribed for vehicles, e.g. exterior mirrors (main mirrors), interior mirrors of passenger cars, or Wide body mirrors and front mirrors of commercial vehicles are completely replaced. In such mirror replacement systems, the relevant field of vision, which is generally visible through a mirror, is displayed to the driver of the vehicle permanently and in real time on a monitor or other reproduction unit provided, for example, in the interior of the vehicle. , such that the driver of the vehicle can see the relevant field of view at any time, although no mirror is provided. Furthermore, the vehicle system is used in the context of so-called advanced driver assistance systems (ADAS), in which also data captured by the camera system, e.g. dependent on the respective current driving situation, is displayed to the driver of the vehicle. vehicle, or where captured image data is evaluated in order to control other components of the vehicle, e.g. in the context of distance and/or obstacle detection, road condition detection, lane keeping assist, traffic sign recognition traffic, and the like.

[003] For in-vehicle use, often, whether by legal prescription or due to the intended object and purpose, respectively, of the camera system, specific requirements must be met by the capture device (e.g. camera) of the camera system, for example. with regard to resolution, the angular range to be captured by the camera system, requirements with regard to sharpness in relation to image depth and the like. These requirements, for example allowing the extraction of the desired data from the captured image data, are temporally opposed, so that, for example, at the same time a wide angular range must/must be recorded and simultaneously at least a region/part of the captured angular range, very high resolution and depth of focus must be achieved. Therefore, in a complex in-vehicle camera system, it is generally necessary to provide a plurality of capture units, even if they are directed toward the same or toward overlapping areas around the vehicle, and subsequently combine the image data. captured by a plurality of capture units, for example, in a joint image. Alternatively, by using a plurality of capture units, each capture unit can be assigned its own function with respect to different possibly opposing requirements, and subsequently, the image data captured by the plurality of capture units can be analyzed accordingly. such that from each image, for example for a driver assistance system, the assigned and allocated information are respectively extracted.

[004] In practice, this means that normally, for example in a mirror replacement system, the individual fields of view must be captured respectively by individual capture units, i.e. at least one capture unit per field of vision. For this purpose, the prior art in particular provides in-vehicle camera systems, wherein a plurality of separate image sensors and optics, i.e. separate capture units, are provided, from which image data are subsequently combined by means of sewing. Alternatively, it is also known to provide a common optic with a plurality of image sensors, which are then combined into a larger image sensor surface, thus allowing the capture of a larger image through a common optic, but (several) separate image sensors.

OBJECT OF THE INVENTION

[005] Based on the foregoing, it is an object of the invention to provide a camera system for a vehicle, in which also complex requirements for the quality and range of image data can be implemented in the most flexible way possible by means of a single capture unit comprising a single image sensor with a single image sensor surface and a single optical element. Furthermore, it is an objective to provide a mirror replacement system as well as a driver assistance system capable of implementing, with little effort, complex image capture requirements for the mirror replacement system and the driver assistance system. driver, respectively, through a camera system.

DISPLAY OF THE INVENTION

[006] This object is solved by means of a system comprising the features of claim 1, a mirror replacement system comprising the features of claim 18 and a driver assistance system comprising the features of claim 32 or claim 33. Preferred embodiments are specified in the dependent claims.

[007] In the present report, a camera system that comprises a capture unit that includes an optical element and an image sensor that is provided with an image sensor surface should be understood as a camera system that comprises at least one capture unit as defined in claim 1. Additional capture units may be provided in the context of the camera system, which also either fulfills the requirements of claim 1 or is designed differently, for example, in order to capture fields of view to the left or right of the vehicle. It is essential that the capture unit of the camera system defined in claim 1 comprises exactly one optical element and exactly one image sensor provided with an image sensor surface, and is further adapted as defined in claim 1.

[008] The camera system is based on the idea of adapting the optical element of the capture unit (e.g. camera) in such a way that, on a single image sensor, it is possible to display an area that requires high resolution and a relatively large angle (wide angle) can be captured through the capture unit, and the two can be displayed on an image sensor in a joint manner. An image sensor must be understood as a substantially flat recording surface, wherein the image sensor surface, where the image captured by the optical element is actually represented, is referred to as the image sensor surface. The image sensor surface and the image sensor are, for example, rectangular, that is, the image sensor surface is a rectangular surface with one edge with edge points on two edges of the rectangle, which are parallel to each other . Likewise, the image sensor is generally rectangular and substantially corresponds to the surface shape of the image sensor.

[009] The optical element comprises, for example, an arrangement of a plurality of lenses, which are arranged one after the other and, if necessary, other optical components, and serves to direct the incident light beam to the image sensor and to the surface of the image sensor, respectively, to gather the beam, and so on. The characteristics of the optical element, in particular its distortion, are determined through the selection of lenses and optical components. The optical element is provided with an optical axis, which, in the case of a rotationally symmetric system, is comprised by the system's rotational symmetry axis. In both a rotationally symmetrical system and a system that is not rotationally symmetrical with respect to the optical axis, it is ensured along the optical axis, in any case, that the image taken and the path of the incident light beam through the optical element, respectively, are free from distortion, while, with increasing distance from the optical axis, distortion results, which is a geometric aberration that causes a local change in the image scale. Often the change of scale is a change in magnification with increasing distance of the image point from the optical axis and, in a rotationally symmetric system, rotationally symmetric about a point, the so-called center of distortion, which corresponds to the point of intersection of the optical axis and the image sensor surface. Depending on the optical system, distortion may differ; In a pillow-shaped distortion, for example, the increase is seen to develop towards the edges of the image field, and in a barrel distortion, it decreases towards the edges.

[0010] Furthermore, the optical axis is comprised of the axis along which an incident light beam usually passes through the optical element in an undeflected manner and impinges on the surface of the image sensor.

[0011] Thus, the camera system for a motor vehicle is based on the idea of actively configuring the distortion of the optical element by the use and selection of specific lens arrangements that form the optical element, so that requirements such as e.g. a wide-angle image, i.e. an image with a huge image angle and an image that is substantially free of distortion or has only little distortion, with high resolution for the desired/requested image parts, can be obtained at the same time. For this purpose, the optical element has a distortion with a distortion curve r = f (α), where r is the distance from a point of the object displayed on the surface of the image sensor to the point of intersection of the optical axis with the image sensor surface, and α is the angle between the optical axis of the optical element and the ray incident on the optical element from the object point. The distortion curve r = f (α) has an inflection point (αw; rw), preferably exactly an inflection point (αw; rw) within 0 < r (α) < rmax, where rmax is the distance r = f (αmax) on the image sensor surface from the optical axis to the edge point of the image sensor surface that is furthest from it. Here, the object is a point from which an incident light beam emanates, which is displayed on the surface of the image sensor by means of the incident light beam passing through the optical element. The angle α between the optical axis of the optical element and the beam incident on the optical element from the object point corresponds to the minimum objective aperture angle required for the respective object point and is hereinafter referred to as the object angle α. In other words, the object angle α is the angle included between the optical axis and the beam of light incident on the optical system from the object point, provided that the object is outside the optical system or optical element. Thus, the angle (90° -α) is the angle between the incident beam at the point where the light beam enters the optical element and a plane that passes through that point and is perpendicular to the optical axis.

[0012] Thus, the object angle α refers to an angle closed by a beam of light incident on the optical element from an object outside the optical element and the optical axis. After passing through the optical element, this object point is correspondingly represented on the surface of the image sensor.

[0013] The distortion curve r = f (α) of the optical element therefore has an inflection point within the surface of the image sensor, to which the second derivative of the distortion curve r = f (α) applies, that is, r'' = f' (α) = 0. Simultaneously, in a coordinate system α, r, in the region between the origin of the distortion curve and the edge point of the image sensor surface furthest from the origin on the surface of the image sensor, the distortion curve has a left-curved part on one side of the turning point and a right-curved part on the other side of the turning point, where a right-curved part (r'' = f' '(α)<0) is present in the region of 0°<α<αw, and a left-curved part (r''=f''(α)>0) is present in the region of αw <α<αmax, where αmax is defined by the limitation of the image sensor surface. αmax is the angle α that corresponds to the maximum distance rmax from the optical axis to the furthest point from the edge of the image sensor. For example, if the optical axis is located centrally on the surface of the image sensor, that is, at the centroid of a substantially rectangular image sensor, then rmax corresponds to the distance from the optical axis on the surface of the image sensor to a point of (arbitrary) edge of the rectangle. If the optical axis is located eccentrically, that is, not at the centroid of the image sensor surface, then rmax is defined by the distance from the optical axis to the edge of the rectangle that is furthest from the optical axis, in the case of a sensor substantially rectangular image. The origin of the coordinate system α, r corresponds to the optical axis on the surface of the image sensor.

[0014] Using the described distortion curve r = f (α) as described, it is possible to achieve a specific or defined, relatively large, distortion-free or substantially distortion-free part with high resolution close to the point of intersection of the optical axis with the distortion curve described previously. image sensor and the optical axis on the image sensor respectively, while simultaneously a large portion of angle can be captured where for larger α, i.e. for object points further away relative to the optical axis, can be achieved a relatively high resolution that is, for example, still sufficient to display, for example, legally prescribed fields of view. Here, it is not necessary to use a capture unit that has extremely high resolution and, consequently, involves large data sets. As a result, no, or only little, post-processing of the image data is required for distortion correction, which could not influence in any way, in particular the increase, the present/existing resolution.

[0015] In particular, the distortion curve that has the shape of an S-curve allows a single image sensor with relatively low resolution to provide an image representation that, with respect to sharpness, resolution and similar requirements, as well as the image region, allows you to capture two fields of view around a commercial vehicle through a single capture unit and display it in the context of a mirror replacement system on a monitor or display unit, even if one of the fields of view is the field of view of a wide-angle mirror. Due to the fact that an image sensor and a capture unit, respectively, with relatively low resolution, it is possible to design the system in an economical and simplified way, since, in a processing unit, which processes data from the capture unit , a reduced volume of data has to be processed and therefore the components that process the volume of data, such as the calculation unit or the working memory of the capture unit, can be designed smaller and thus more rentable. Furthermore, in the case of similar designs of the processing units, the processing speed is higher and the system load is lower respectively, so that on the one hand fast data processing can be realized and on the other hand , the processing unit, in particular the underlying electronic system, heats up less and thus allows simplified heat management.

[0016] In addition to the fact that a single common/joint capture unit can, for example, capture data from two fields of view, it is not necessary to combine data from separate capture units, at least not to the extent that the unit Common capture captures the desired sub areas of the vehicle environment. Furthermore, it is easier to integrate and organize the reduced number of capture units required in the vehicle

[0017] At the same time, by means of the distortion curve, a very high resolution can be achieved where it is required or required, that is, in the highly relevant region in the vehicle's environment, which is within the captured sub-area of the vehicle. vehicle environment. Finally, it is possible to utilize the entire surface of the image sensor so that sufficiently high resolutions can be obtained over the entire surface of the image sensor, such that, if necessary, a part of the image sensor read by a data processing can be shifted/shifted, i.e. altered, on the image sensor. This panning of the reading part can be carried out, for example, depending on the driving situation, or if the vehicle driver wishes to manually adjust the region captured by the capture unit, which region can be displayed on a display unit in the vehicle. This means that it is not necessary to provide a mechanical adjustment of the capture unit to adjust the area/region viewed. This can be done by “shifting” the data from the reading part onto the surface of the image sensor, so that the camera system is more economical and robust, with a reduced probability of failure.

[0018] In a rotationally symmetric optical element, the distortion curve r = f (α) is also rotationally symmetric, that is, identical for all angles β about the optical axis in the image sensor, whose optical axis is displayed as a point. In a non-rotationally symmetrical optical element, it is possible to provide, for different partial angular ranges around the optical axis displayed on the image sensor, different distortion curves r = f (α), i.e. rPx = fβi (α), rβ2 = fβ2 (α)... rβn = fβn (α), which apply to particular partial angular ranges around the optical axis in the image sensor. Basically, the partial angular ranges to which a common distortion curve applies can be arbitrarily large, as long as the arrangements of lenses and other optical components relative to the optical element allow it.

[0019] Preferably, the distortion curve r = f (α) of the camera system has exactly one inflection point (αw; rw) within 0 <r (α) <rmax. This makes it possible to optimize the use of the available image sensor surface in relation to the requirements of the vehicle's camera system, in particular regarding resolution and precision on the one hand and, on the other hand, the angular amplitude of the angle captured by the camera system. .

[0020] According to a particularly preferred embodiment, the gradient r '= dr / dα of the distortion curve r = f (α) in the region of 0 <α <αw is maximum at the origin or at the zero point (r = f ( 0) = 0 ) of the distortion curve. This means that in the immediate proximity of the optical axis at the image sensor surface, the gradient of the distortion curve r = f (α) is maximum, and subsequently decreases towards the inflection point. The maximum of the distortion curve at the zero point does not need to be absolute; however, this condition is not excluded. Normally, it is sufficient that in the displayed part of the distortion curve r = f (α), the distortion curve has a maximum with respect to the region 0° <α <αw at the zero point. This allows the display of a relatively large area around the optical axis or, from the optical axis within this region, it can be displayed with a maximum or relatively large gradient of the distortion curve, in particular relative to conventional distortion curves such such as an equidistant distortion curve. In this case, the distance r for identical angles α is smaller on the surface of the image sensor than in the case of the distortion curve, which has a larger possible gradient in the region of the zero point or immediately at the zero point α = 0 r = 0.

[0021] According to another particularly preferred embodiment, the gradient r '= dr/dα for the distortion curve r = f (α) is minimum at the inflection point (αw; rw). Similar to the largest possible gradient at the zero point of the distortion curve, here too the minimum should be understood as a relative minimum for the displayed part of the distortion curve on the image sensor and not necessarily as an absolute minimum over the entire distortion curve. (virtual) (which is possibly located beyond the image sensor). It is sufficient if the minimum is a minimum in the displayed part and the image sensor surface area respectively, i.e. a minimum in the region 0° <α <αmax.

[0022] It is also preferable that the gradient r '= dr/dα of the distortion curve r = f (α) is in the range 0° <α <αmax for αmax, i.e. maximum at the maximum radius of rmax. This maximum also does not need to be an absolute maximum of the distortion curve. It is sufficient if, in this position, the maximum of the distortion curve for the region αw <α <αmax is located.

[0023] According to a preferred embodiment, the distortion curve that is endowed with the aforementioned characteristic can be realized by a polynomial function. Alternatively, the distortion curve r = f (a) can also be provided by an nth order of groove, i.e., a cross member. That is, it can also be provided as a function that is, step by step, composed of polynomials of nth maximum order. In this case, the polynomial is therefore not provided by a single polynomial, but by a plurality of polynomials that are composed step by step. Another possibility is to provide a Bézier curve, which is a parametrically modeled curve and, therefore, can also meet the requirement of (exactly) an inflection point within the region 0 <r <rmax. These mathematical functions allow relatively simple modeling of the optical element and the optical element distortion curve, respectively.

[0024] According to a particularly preferred embodiment, the centroid of the generally rectangular surface of the image sensor and the point of intersection of the optical axis with the surface of the image sensor and the image of the optical axis on the surface of the image sensor, respectively , are displaced relative to each other. In particular, the optical axis is disposed eccentrically with respect to the surface of the image sensor, i.e. not disposed at the centroid. This allows you to define and model the desired regions of distortion on the surface of the image sensor in a more specific and improved manner, and, if necessary, crop or extract them through a processing unit to display them in a display unit visible to the driver of the vehicle, for example, or in order to evaluate them with regard to specific data. In this way, the region of interest can be selected over almost the entire surface of the image sensor or over the entire surface of the image sensor and can be cropped or read and further processed by the data processing unit.

[0025] Preferably, the optical element is embodied by means of a plurality of lenses arranged in a row and, if necessary, supplemented by other optical components such as, for example, filters. The optical element, for example, comprises at least one lens having a surface other than a partially spherical surface, at least one spherical lens and/or at least one lens with a free-form surface. It is particularly preferable to combine at least two lenses that are different in terms of their characteristics and shapes, as this makes it possible to provide an optical element with (exactly) an inflection point (αw; rw) in its distortion curve r = f (α). If a certain number of rotationally symmetric lenses with different surfaces are arranged in a row one behind the other, this results in a distortion curve r = f (α), which is identical for each angle of rotation β around the optical axis. In this case, the optical element as a whole is therefore rotationally symmetric with respect to its optical axis. This is particularly advantageous if the capture unit also has a substantially rotationally symmetrical requirement, for example with regard to resolution.

[0026] Alternatively, it is also possible to provide an optical element with a distortion that is not rotationally symmetric about its optical axis, so that a first distortion curve rβ1 = f (α) for a rotation angle β1 around the optical axis differs from a second distortion curve rβ2 = f (α) for a rotation angle β2 around the optical axis. Preferably, however, the distortion curves are at least partially, that is, for certain angular ranges around the optical axis, identical or very similar, such that the respective requirements concerning resolution, angular range and similar aspects of certain regions of the captured image can be fulfilled. . Basically, an arbitrary number of distortion curves rβn can be provided. Nevertheless, for a distortion that is not rotationally symmetric, it is sufficient if at least sections with a first distortion curve rβ1 = f (α) and a second distortion curve rβ2 = f (α) are provided, respectively. If rotationally non-symmetrical distortion is desired, it is desirable that the optical element is anamorphic, that is, not rotationally symmetrical in itself, so that, depending on the angle of rotation around the optical axis, different distortion curves are present. It is possible, for example, that one or more of the lenses that form the optical element are anamorphic. Alternatively, for example, an arrangement of individual lenses or optical components of the optical element could be chosen, the arrangement of which is at least partially eccentric with respect to the optical axis of the optical element.

[0027] Furthermore, the camera system preferably comprises at least one processing unit for processing data from the capture unit and/or a display unit for displaying information captured through the capture unit visible to the driver of the vehicle. The processing unit for processing the data may, for example, be provided in the context of a general on-board computer (ECU) of the vehicle, or may be a separate unit provided specifically for the camera system, or may be integrated into the camera system itself. camera system. The display unit is formed, for example, as a monitor, as a plurality of monitors, as a projection onto other components of the vehicle, and the like. In addition to a visual display unit, the display unit can additionally or supplementarily also be implemented as an audio reproduction unit. Furthermore, it can be understood by a display unit which, for example in the context of a driver assistance system, warns the driver only in certain driving situations, which can be effected again by means of a visual display, a signal acoustic or a haptic signal, such as, for example, steering wheel vibration, if an evaluation by the processing unit of the image data captured by the transmission system transmits a corresponding signal to the display unit.

[0028] A particularly preferred use of the camera system is understood to be use in the context of a mirror replacement system. Mirror replacement systems for vehicles have been increasingly used, thus replacing conventional mirrors in the vehicle. The type of mirrors prescribed for a vehicle and therefore which can be replaced in the context of a mirror replacement system is normally defined by legal provisions, in Europe for example by Regulation No. 46 of the United Nations Economic Commission for Europe (UN/ECE) (Addendum 45, Revision 6 currently available). A different matter are so-called additional visual systems, which are not prescribed visual aids that allow supervision of an area that is not required to be permanently and continuously visible to the driver in accordance with a legal provision. An example for this type of additional visual system is understood, for example, in the context of parking assistance, by a reversing camera in a vehicle.

[0029] In many countries around the world, an interior mirror is provided inside the vehicle (according to ECE-R46 “interior mirror group I”) and a (small) main mirror (according to ECE-R46 “group I interior mirror”) and a (small) main mirror (according to ECE-R46 “interior mirror main (small) group III”) on the driver's side, and often also on the passenger's side, are prescribed for passenger vehicles. For commercial vehicles, an interior mirror is generally not prescribed, as unobstructed vision through the rear of the vehicle is generally not possible through the driver's cab. Instead, generally speaking, a main (large) mirror (according to ECE-R46 "main (large) mirror group II") and a wide-angle mirror (according to ECE-R46 "wide-angle mirror" are prescribed). group IV"), as well as other mirrors. Main mirrors are those mirrors that are attached to the outside of the vehicle and can be seen by the driver as exterior mirrors. Depending on country regulations, other mirrors such as, for example, a close-up/close-range mirror (according to ECE-R46 “near mirror/approach group V”) and/or a front mirror (according to ECE -R46 “group VI front mirror”) may be prescribed for commercial vehicles.

[0030] The regions around the vehicle, which must be seen through the different mirrors and therefore must also be seen through a camera monitoring system, are defined/prescribed in the corresponding legal requirements of countries and territories/ individual regions, respectively. Typically, a so-called field of vision is defined, which designates a plane and horizontal part of the road around the vehicle, and which must be visible permanently, at any time and in real time to the vehicle driver.

[0031] The field of view of the interior mirror of a passenger car, for example, is defined in such a way in ECE-R46 that the driver of the vehicle can see a plane and horizontal part of the road, which is located centered on In relation to the central longitudinal plane of the vehicle, it is 20 m wide and extends from the horizon to 60 m behind the vehicle driver's vision. A field of vision for a main rear-view mirror for passenger cars is defined, with respect to the driver's side, in such a way that the driver can see at least a plane and horizontal part of the road, 5 m wide. is bounded on the side of the vehicle by a plane that is parallel to the central longitudinal plane of the vehicle and extends through the outermost point of the driver's side of the vehicle, and which extends from the horizon to 30 m behind the driver's points of vision of the vehicle. The field of view of the main exterior mirror further includes a 1 m wide strip of the road, which is limited on the vehicle side by a plane parallel to the central longitudinal vertical plane of the vehicle and which passes through the outermost point on the driver's side of the vehicle. vehicle and which starts 4 m behind the vertical plane that passes through the vehicle driver's points of vision. A field of view of a passenger side exterior mirror is defined in an analogous manner on the passenger side of the vehicle.

[0032] A field of view of a main mirror (main exterior rear view mirror) on the driver's side (the same applies to the passenger's side) of a commercial vehicle is defined in such a way, for example in ECE-R46, that the driver can see at least a flat, horizontal part of the road, with a width of 4 m, which is limited on the side of the vehicle by a plane that is parallel to a central longitudinal vertical plane of the vehicle and that extends from the horizon up to 20 m behind the vehicle driver's point of view. This field of view further includes a strip of road with a width of 1 m, which is limited on the side of the vehicle by a plane which is parallel to the central longitudinal vertical plane of the vehicle and which passes through the outermost point of the vehicle on the side of the vehicle. driver of the vehicle, and which starts 4 m behind the vertical plane that passes through the driver's points of vision. A field of view of a wide-angle mirror, which is generally only provided in a commercial vehicle and not in a passenger car, is defined in such a way that the driver of the vehicle can see at least a plane and horizontal part of the road, which has a width of 15 m and is limited on the side of the vehicle by a plane which is parallel to the central longitudinal vertical plane of the vehicle and passes through the outermost point on the driver's side of the vehicle, and which extends at least 10 m to 25 m behind the driver's vision. The field of view of the wide-angle mirror further includes a strip of the road, which has an area of 4.5 m and is limited on the side of the vehicle by a plane parallel to the central longitudinal vertical plane of the vehicle and passing through the outermost point on the side. of the driver of the vehicle, and which begins 1.5 m behind the vertical plane that passes through the driver's points of vision.

[0033] According to ECE-R46, the field of view of a near or approach mirror is, for example, proportioned so that the driver of the vehicle can see at least one plane and horizontal part of the road outside the vehicle , which is limited by: a plane parallel to the central longitudinal vertical plane of the vehicle and passing through the outermost point on the passenger side of the vehicle; a plane extending parallel to and spaced 2 m from this plane; a plane extending parallel to and 1.75 m behind the plane passing through the vehicle driver's points of view; a vertical plane extending 1 m in front of and parallel to the plane passing through the vehicle driver's points of vision or a plane passing through the furthest point of the vehicle bumper if this plane extends closer than 1 m m in front of the vertical plane extending parallel through the vehicle driver's points of view. In vehicles in which the field of view of a near or approach mirror is captured by a mirror that is attached more than 2.4 m from the ground, or captured by a corresponding pickup device, the described field of view is extended to that the driver can see a flat, horizontal part of the road along the side of the vehicle and outside the above-defined field of vision of a near or approach mirror, which may be rounded at the front with a radius of 2 m, and is limited by the following lines: in the transverse direction of the plane, which extends to a distance of 4.5 m in front of the lateral plane of the vehicle; to the rear, by the plane parallel to a vertical plane extending through the vehicle driver's ocular points and disposed 1.75 m behind this plane; forward by the plane parallel to the vertical plane extending through the driver's points of vision and arranged 3 m in front of this plane.

[0034] According to ECE-R46, the field of vision of a front mirror must be proportioned in such a way that the driver of the vehicle can see/ignore a plane and horizontal part of the road, which is limited by the following planes: a perpendicular transverse plane, through the most advanced point in front of the vehicle, a perpendicular transverse plane extending 2 m in front of this plane; the plane parallel to the central longitudinal vertical plane of the vehicle, which passes through the outermost point on the driver's side of the vehicle, and a plane parallel to the central longitudinal vertical plane of the vehicle, which extends to a distance of 2 m from the outermost point away from the passenger side of the vehicle.

[0035] In the description, if reference is made to fields of vision of a main mirror, a wide-angle mirror, an interior mirror, a close mirror, a front mirror, and the like, the corresponding fields of vision are understood, as defined respectively in the available national regulations, which correspond to the described fields of vision of the mirrors. If there are no corresponding national regulations or definitions available for fields of view, the described dimensions must be considered as a definition for the respective field of view.

[0036] Preferably, the mirror replacement system which, in addition to a processing unit for the data captured by the camera system, preferably comprises a display unit for visibly displaying the information captured by means of the capture unit to the driver, is designed in such a way that the display unit displays data visible to the driver of the vehicle. This can be done, for example, by means of monitors located inside or outside the vehicle, or by means of a projection onto the vehicle's components.

[0037] Preferably, the mirror replacement system is adapted to display on the display unit at least one field of view that is visible to the driver of the vehicle. Specifically, this field of view may be one of the fields of view described previously in the present case.

[0038] According to another preferred embodiment, the mirror replacement system is adapted to capture the field of view of a main mirror and the field of view of a wide-angle mirror on the same side of the vehicle by the common/joint capture system of the system of a common/articulated image sensor, i.e. a single image sensor, and to display the same on the display unit visible to the driver. In particular, due to the characteristic distortion curve of the optical element of the pickup unit, which is a common/joint pickup unit, unique for the field of view of the main mirror and the field of view of the wide-angle mirror, it is possible to provide both the relatively large angle to be displayed, which is necessary for a field of view of a wide-angle mirror of a commercial vehicle, and a suitable resolution, in particular with regard to the field of view of the main mirror and also with regard to respect to depth, i.e. the extent of the field of vision from the main mirror to the rear along the commercial vehicle.

[0039] The same applies if, instead of the main mirror's field of view and the wide-angle mirror's field of view, the field of view of a close range/approach mirror and the field of view of a front mirror are captured at the same time by the common/joint camera system and, in particular, by the single capture unit

[0040] According to a preferred embodiment, if at least two fields of view around the vehicle are displayed visible to the driver and captured by means of the same capture unit, i.e. the same optical sensor and the same image sensor , a first field of view is visibly displayed in a first region of the display unit, and a second field of view is visibly displayed in a second region of the display unit, which is optically separated from the first region. This optical separation can be accomplished, for example, by displaying the first and second fields of view, respectively, on two separate regions of a common monitor, i.e., a common display unit, via the split screen method. If, for example, the fields of view of a main mirror and a wide-angle mirror are captured, the field of view of a main mirror can be displayed in a first region, and the field of a wide-angle mirror can be displayed in a second region located below or above the first part, in which a fixed separation, for example in the form of a bar, or a superimposed optical separation, e.g. a line. That is, out of the captured image data, the processing unit extracts the data to be displayed in the first region and the data to be displayed in the second region. It is therefore clearly recognizable for the driver of the vehicle, where the respective field of vision is displayed. The display of fields of view in a first and second part on the display unit is preferably not changed during operation of the vehicle in relation to the question where a respective field of view is displayed.

[0041] It is preferable that the processing unit is adapted to separate the data or extract the data received from the capture unit, for those to be displayed in the first part of the display unit and the data to be displayed in the second part of the display unit. exhibition. Of course, additional image processing can be carried out by means of the processing unit in such a way that, for example, additional information is superimposed, is pointed out to hazards or, in the context of the entire field of view that is being visibly displayed at all the moments, it is increased or decreased in the respective region, for example, depending on the direction and/or speed of movement.

[0042] Here, it is possible for the data for the first region and the data for the second region to be extracted from overlapping areas on the image sensor, i.e., the area on the image sensor from which the information of the first region is extracted and the area on the image sensor from which information for the second region is extracted overlap, for example in the horizontal direction. After extracting the information from the image sensor, the extracted regions can be digitally enlarged, if necessary, with different scaling factors.

[0043] Instead of displaying two separate regions on the display unit, two fields of view can also be displayed in a single adjacent image on the display unit (panoramic view). This is possible because the data to be displayed is captured through a common image sensor and thus the same optics are used to capture both fields of view, so it is not necessary to combine two different optics with different distortion in a perfect image, which is only possible with considerable additional adjustment and calculation effort. However, the two regions, at least in the direction perpendicular to their (virtual) interface, can be scaled up or down by different scaling factors, e.g. by the same scaling factor in the vertical direction but a different scaling factor in the vertical direction. horizontal.

[0044] Preferably, the processing unit is adapted to adjust, depending on the information captured by a sensor and transmitted by the processing unit such as, for example, the driving direction of the vehicle, the information for the first and/or second region , which is extracted from the data captured by the capture unit, in relation to its position in the image captured by the capture unit on the image sensor. If, for example, the fields of view of a wide-angle mirror and a main mirror of a commercial vehicle are captured by means of the pickup unit, for example, a steering sensor, i.e. a sensor capturing the steering angle, may provide data that prompts the processing unit to adjust the region from which the information displayed to the driver on the display unit is extracted. When driving straight ahead, for example, the information to be displayed may be provided in a first region of the surface of the image sensor to the field of view of the main mirror, while, when driving along a curve, i.e. when turning , information can be provided on a second part of the image sensor surface. The desired visible area is adjusted/updated without actually adjusting the pickup unit. The distortion curve with the inflection point at the surface region of the image sensor allows ensuring the most adequate and appropriate sharpness of the image, even in case the extracted region is displaced on the image sensor. Specifically, the surface reading part of the image sensor is shifted (so-called extraction) to allow the driver to better view the fields of view and, due to the distortion curve of the pickup unit, it can also be sieved so that it can be used without substantial distortion correction or image processing. For this reason, mechanical adjustment of the pickup unit is no longer necessary.

[0045] This can also be used if the vehicle driver wants to manually adjust the virtual mirror implemented by the camera monitor system in a manner analogous to a mirror.

[0046] Depending on the requirements, a single vehicle sensor can be used as a sensor, or a combination of at least two vehicle sensors can be used, e.g. functionally identical sensors on different sides of the vehicle (e.g. wheel sensors ) or different sensors.

[0047] Likewise, a sensor other than a sensor indicating the vehicle's driving direction may cause/trigger the displacement of the region of extracted information on the surface of the image sensor.

[0048] According to a preferred embodiment, in a mirror replacement system, the arrangement of the optical axis of the pickup unit, in particular the optical element of the pickup unit, is oriented in such a way that it intersects the field of view or a of the fields of vision. Preferably, if the captured and displayed fields of view are the fields of view of a main mirror and a wide-angle mirror, the optical axis intersects the field of view on a flat horizontal portion of the road at an intersection with a maximum distance of 5 m for a lateral boundary line of the vehicle, wherein the lateral boundary line is comprised of a line of intersection of a plane parallel to the central longitudinal plane of the vehicle, which passes through the outermost or outermost lateral point of the vehicle . For this reason, it is possible that a segment of straight line of vision, which passes through this crossing point, and which is limited by the limitation of the field of view of the main mirror, is located in the region of the distortion curve that is curved towards the right, i.e. in the region for which the second derivative of the distortion curve is less than 0 (r '' = f '' (α) <0). Here, the inflection point of the distortion curve is preferably located beyond this straight line segment of view. Compared to conventional distortion curves, it is possible for this region to cover a relatively large area on the image sensor for an angle α of the incident light beam and thus can be displayed with high resolution.

[0049] According to a preferred embodiment, the mirror replacement system is adapted to capture part of the vehicle through the capture unit and display the same on the display unit visible to the driver of the vehicle. This allows the driver to easily orient himself and, especially in commercial vehicles, to have a good overview of the commercial vehicle's spatial situation and possible obstacles.

[0050] Alternatively or in addition to a mirror replacement system, the camera system can be used for an advanced driver assistance system (ADAS). Here, it is possible to evaluate the captured information, for example, in relation to other information in the vehicle's environment, for example, the presence of road lines, traffic signs, other road users and the like, and, for example, provide this information for an adaptive cruise control system (ACC, ADR, STA), an emergency braking assistant (ABA), an active lane keeping assistant (LKA, LKAS), lane change assistant or similar, which form part of or constitute the driver assistance system (ADAS), and provide corresponding outputs to other components of the vehicle through a control unit.

[0051] According to a particularly preferred embodiment, the camera is directed forward when viewed from a forward driving direction of the vehicle. This is particularly advantageous for automatic distance control or similar. Additionally, information captured by a driver assistance system may be sent and/or displayed to a driver, either in the context of a mirror replacement system or in the context of another assistance system. It is possible, for example, to issue corresponding warning signals via audio signals, tactile signals or the like, for example vibration of a steering wheel, to the driver and to warn the driver, for example, against a dangerous situation. Brief Description of the Drawings

[0052] Next. The invention is described exemplarily by means of the attached drawings, in which:

[0053] Figure 1 is a schematic view of a mirror replacement system using a camera system according to the invention;

[0054] Figure 2 is a perspective view of a commercial vehicle with a camera system in accordance with the invention;

[0055] Figure 3 is a simplified sectional view of the essential components of the camera system;

[0056] Figure 4 is a perspective view of the essential components of the camera system, in accordance with Figure 3;

[0057] Figure 5 illustrates a sectional, perspective, schematic view of an embodiment of a structure of the optical element of the capture unit of the camera system;

[0058] Figure 6 is another sectional perspective view of the detailed structure of the optical element of the camera system capture unit;

[0059] Figure 7 shows the distortion curve of the optical element of the capture unit in a coordinate system α, r;

[0060] Figure 8 shows the first derivative of the distortion curve of the optical element of the capture unit of the capture system;

[0061] Figure 9 shows the second derivative of the distortion curve of the optical element of the camera system's capture unit;

[0062] Figure 10a shows the distortion curve of the optical element of the camera system's capture unit compared to conventional distortion curves.

[0063] Figure 10b is a detail of Figure 10a that shows the distortion curves around the origin of the distortion curve;

[0064] Figure 11 is a schematic view of the image sensor of the capture unit, where fields of view of a main mirror and a wide-angle mirror are illustrated in accordance with Figure 2;

[0065] Figure 12 shows details of the distortion curve of the capture unit of the camera system of the embodiment illustrated in Figure 11;

[0066] Figure 13 is a schematic top view of a commercial vehicle, which schematically shows the movement of a region to be illustrated depending on the vehicle's driving situations; It is

[0067] Figure 14 is a schematic view of an image sensor surface of the capture unit of the camera system, which illustrates the deviation / displacement of the regions of interest according to Figure 13 on the image sensor surface.

Description of Preferred Embodiments

[0068] Figure 1 shows a schematic view of a mirror replacement system 100, for example, for a commercial vehicle. The mirror replacement system 100 may be integrated into a driver assistance system, or may be used in the form of a separate mirror replacement system 100. The mirror replacement system 100 comprises a camera system 130, a processing unit 120, and the display unit 110. Image data captured by the camera system 130 is provided to the processing unit 120 which, after processing appropriate, provides this image data to the display unit 110 to display the same visibly to a driver of the vehicle. The mirror replacement system 100 may be further coupled with one or more vehicle sensors 140, which also provide data to the processing unit 120, such as, for example, the current driving state (steering angle, driving speed , driving direction) of the vehicle, which data is taken into account by the processing unit 120 when processing the data received from the camera system 130. Alternatively, the vehicle sensor(s) 140 could (m) be coupled directly with the camera system 130, such that the camera system is controlled directly dependent on the data received by the sensor(s) 140 of the vehicle. For this reason, it is also possible for the processing unit 120 to output data to control the camera system 130 to the camera system 130.

[0069] The processing unit 120 may be provided in the form of a processing unit separate from the camera system 130, for example in the form of a vehicle on-board computer, or, alternatively, it may be integrated within of the camera system 130. The display unit 110 is, for example, comprised of a monitor provided in the vehicle, where the data provided by the processing unit 120 is displayed visibly to the driver of the vehicle. Alternatively, instead of a monitor provided in the vehicle, a display unit connected to the outside of the vehicle could be provided, for example in the mirror region of conventional vehicles. Furthermore, the display unit could be implemented in the form of a projection onto a vehicle structure component within the vehicle. With respect to the display unit 110, it should be noted that, in addition to the illustrated inclusion, wherein a monitor is provided for displaying the data provided by the processing unit 120, also a plurality of separate monitors or display units may constitute the display unit 110. visualization. Depending on the requirements, these monitors can be proportioned identically or differently.

[0070] Furthermore, in particular if used in the context of a driver assistance system (ADAS), and in particular its processing unit 120, it is linked to other information or control components of the vehicle 150, if necessary, These components may be driver display units, audio message units, or components that directly control the vehicle, for example steering assistance.

[0071] The camera system 130 comprises at least one capture unit 30, which will be described in greater detail below; it may, however, also comprise a plurality of capture units 30 of the type described above. Furthermore, other capture units 31 may be provided, which do not necessarily have to meet the requirements imposed on the capture unit 30. For this reason, it is possible for the processing unit 120, as indicated in Figure 1, to directly receive data of images from the individual capture units 30 and 31, respectively, instead of receiving image data from the camera system 130. For this reason, the processing unit 120 can also provide control signals directly to the individual capture units 30 , 31.

[0072] Figure 2 shows a perspective view of a commercial vehicle 10 that is provided with a mirror replacement system 100 according to Figure 1. Consequently, one or more pickup units 30 are mounted on the commercial vehicle 10. As illustrated in Figure 2 the exemplary mirror replacement system 100, which is mounted on the vehicle, is adapted to capture a field of view 11 from a main mirror and a field of view 12 from a wide-angle mirror by means of the capture 30, and present the same in the driver's cabin of the vehicle 10 visible to the driver of the commercial vehicle 10. In Figure 2, the field of view 11 of a main mirror and the field of view 12 of a wide-angle mirror are illustrated schematically by dashed lines (the field of view 11 of a main mirror by long dashes, the field of view 12 of a wide-angle mirror by shorter dashes) on the flat road surface next to the vehicle 10.

[0073] Furthermore, in Figure 2, the direction of forward movement is indicated by an arrow D. All directions specified in this description, i.e., front, rear, left, right, and so on, refer to in the forward direction of the vehicle.

[0074] The field of view 1 of the main mirror, which is illustrated in Figure 2, extends from a lateral boundary line 13 of the vehicle in a lateral direction away from the vehicle and rearward. The lateral boundary line 13 is a line defined by the intersection of the flat horizontal road with a plane parallel to the central longitudinal line (not shown) of the vehicle, and passing through, in a lateral direction, the outermost point of the vehicle.

[0075] The optical axis 302 of the optical element 301 (Figures 3, 4) of the capture unit 30, which is, for example, provided by a camera, extends in the lateral direction at an angle with respect to the central longitudinal plane of the vehicle and the road surface such that it intersects the field of view 11 of a main mirror on the road surface. This means that the intersection point S or crossing point of the optical axis 302 and the road surface are within the field of view 11 of a main mirror in the embodiment shown in Figure 2. Preferably, the intersection point S is located 6 m behind the capture unit 30 when viewed in the longitudinal direction of the vehicle, more preferably in the range of 4 to 5 m.

[0076] Furthermore, in Figure 2, a straight line of sight segment 14 is illustrated by means of thin dotted lines, which straight line of sight segment is defined by the line segment of a line perpendicular to the side boundary line 13 and passing through the intersection at point S of the optical axis 302 and the road surface, which is located within the field of view area 11 of the main mirror.

[0077] Next, the pickup unit 31 of the camera system 130 is described in more detail with reference to Figures 3 and 4, which schematically show the beam path through an optical element schematically illustrated in a sectional and perspective view. (cut), respectively, as well as through Figures 5 and 6, which schematically show embodiments of an optical element structure.

[0078] The optical element 301 and the image sensor 302 form the essential components of the capture unit 30 for the camera system of a motor vehicle. As can be seen in Figures 3 and 4, in the present embodiment, the optical element 301 is substantially rotationally symmetric about the optical axis 302. This means that any beam of light incident on the pickup unit 30 from an object point to be displayed at an identical angle, for example α1, with respect to the optical axis 302, is displayed on the surface of the image sensor 304 rotationally symmetric about the optical axis with identical distortion. Angle α, hereinafter also referred to as object angle α, corresponds to an angle that is the angle of incidence of the light beam on an optical element 301, having an incidence surface (virtually not illustrated) perpendicular to the optical axis 302. Consequently, any beam of light incident at object angle α1 is displayed on the image sensor surface 304 with a distance r1 to the optical axis 302. Here, the image sensor surface 304 is the surface that is actually proportioned for display within the entire image aperture/aperture angle of the optical element 301, i.e., the surface of the image sensor 302, which is suitable for display, and which faces the optical element 301.

[0079] Figures 3 and 4 schematically illustrate the beam paths through the optical element 301 and their respective displays on the surface of the image sensor 304 of the image sensor 303 at distances r1, r2,..., rn for different angles of object α1, α2,... an. Since, in the illustrated embodiment, the optical element 301 is rotationally symmetrical, the distance r1, r2,..., rn and the beam path through the optical element 301 are also rotationally symmetrical with respect to the optical axis 302. The axis optic 302 for which α = α0 = 0°, r = r0 = 0 strikes the surface of the image sensor 304 at the origin of a distortion curve (α = 0; r = 0) of a coordinate system α, r.

[0080] The optical element 301, which, as illustrated schematically in Figures 5 and 6, is composed of a lens system and, if necessary, other optical components, and comprises a plurality of rotationally symmetric lenses that are arranged in a row one behind the another has a distortion curve called r = f (α), which is a geometric image error of the optical element, causing a local change in the image scale. Due to the rotational symmetry of the optical element 301, the distortion curve r = f (α) of the embodiment illustrated in Figures 3 and 4 is also rotationally symmetric about the optical axis 302.

[0081] An embodiment of the lens arrangement is illustrated in Figure 5. Here, the seven lenses 314 to 320 are arranged in a line in the incident light path (from left to right in Figure 5). Lens 314 is a spherical convex-concave lens, lens 315 is a spherical convex-concave lens. Lens 316 is formed by a spherical concave-convex lens, lens 317 by a free-form lens (spherical lens) having a convex-concave surface and a concave surface, lens 318 is a spherical bi-convex lens, the lens 319 is a spherical lens having a convex surface and a concave-convex surface, and the lens 320 is a spherical lens that is provided with a concave surface and a convex-concave surface. The free-form surfaces of the lenses 317 and 320 are also rotationally symmetrical, so that the optical element 301 of the embodiment of Figure 5, which is formed by the seven lenses, is rotationally symmetrical about the optical axis 302. In the embodiment of Figure 6 , a sensor protection glass 305 and an infrared filter 329 can be provided in front of the image sensor 303 (see the embodiment of Figure 6). Also in this case, the optical element 301 is provided with the schematically indicated beam path, as well as a distortion curve r = f (α) having an inflection point in the region 0 <r <rmax.

[0082] In the alternative embodiment of the optical element 301 illustrated in Figure 6, the optical element 301 comprises eight lenses 306, 307, 308, 309, 310, 311, 312, 313 arranged in a line along the path of the incident beam. light (from left to right in Figure 6). In the order in which the incident light passes the lens on its way to the image sensor 303, the lens 306 is a convex-concave spherical lens, the lens 307 is a convex-concave spherical lens, the lens 308 is a concave- convex, lenses 309 and 310 are, respectively, spherical bi-concave lenses, lens 311 is a spherical bicubic lens, lens 312 is a free-form lens (spherical lens) having a rotationally symmetrical convex-concave surface and a convex, and lens 313 is a concave-spherical spherical convex lens. Furthermore, a sensor protection glass 305 as well as an infrared filter 329 are provided as additional optical components in front of the image sensor 303. By means of such a lens arrangement, the incident light, as illustrated exemplarily for some beams in Figure 6, it is directed and deflected by the optical element 301. For this reason, and due to the respective lens arrangement, the optical element 301 as a whole has the distortion curve r = f (α), which has a inflection point in the image sensor surface region 304 0 <r <rmax.

[0083] Both the optical system illustrated in Figure 5 and the optical system illustrated in Figure 6 comprise an aperture 303 as another component. Additional filters, openings, and the like may be provided if necessary. The lenses can be formed, for example, from glass (especially spherical lenses) or from synthetic material. Different materials can be combined when necessary. Furthermore, the lenses may be provided with, for example, a vapor-deposited metallic coating or a different coating, which generally has no influence on the refraction of light, but serves only to influence dispersion, eliminate unwanted reflection, and the like. .

[0084] Most of the lenses 307 to 320 of the embodiments illustrated in Figures 5 and 6 are comprised of lenses that are provided with at least one partially spherical surface. For example, lenses 312, 317 and 320, however, are so-called spherical lenses, which have at least one surface that is not partially spherical. Although not illustrated in Figures 5 and 6, by selecting suitable lenses that are not rotationally symmetric about the optical axis 302, it is also possible to form the optical element 301 anamorphic, such that the optical element is provided with a distortion curve that is not rotationally symmetric about the optical axis.

[0085] By means of the exemplary lens arrangements illustrated in Figures 5 and 6, rotationally symmetric r = f (α) distortion curves of the optical element can be generated, which are a function of r = f (α) having an inflection point (αw; rw) within the maximum distance rmax, which is the maximum distance of a point on the surface of the Image sensor 304 relative to the optical axis 302 on the surface of the Image sensor 304. to reach the inflection point on the region of 0 <r (α) <rmax for the distortion curve r = f (α), for αw corresponding to a radius rw on the surface of the image sensor 304, which is smaller than rmax, the following shall apply: = f '' (αw) = d2r / dα2 (α = αw) = 0; r '' = f '' (α) <0 for 0 <α <αw; r '' = f '' (α) > 0 for αw <α <αmax. This type of distortion curve, which can, for example, be obtained by arranging the optical element according to Figures 5 and 6, is illustrated schematically in Figure 7. Its first derivative is illustrated in Figure 8 and its second derivative is illustrated in Figure 9.

[0086] As illustrated in Figure 7, in a coordinate system α,r, an inflection point (dw; rw) is present in the region [0; rmax]. Furthermore, at a specific object angle α = α2 = αw, the second derivative (Figure 9) of the distortion curve is zero, that is, it has a zero crossing at αw. As illustrated in Figure 9, in front of the inflection point, that is, in the region of 0° <α <αw, the second derivative of the distortion curve r = f (α) is negative; for the region αw <α <αmax, the distortion curve is positive. This means that, as can be seen in Figure 7, the distortion curve r(α) is curved to the right in a first region of 0° < α < αw, and curved to the left in a second region of αw < α < αmax.

[0087] The origin of the coordinate system α, r in Figure 7, that is, r = 0 mm, α = 0°, corresponds to the optical axis point 302 on the image sensor. rmax is the maximum distance that a point on the image sensor can have from the optical axis 302. If, in a rectangular image sensor, the optical axis is centered, that is, arranged at the centroid, and the rectangular image sensor has lengths of edge a, b, is applicable . If the optical axis is not arranged centrally on the image sensor, the distance rmax is comprised of the distance between the optical axis 302 on the surface of the image sensor 304 to the farthest corner of the surface of the image sensor 304.

[0088] Figures 10a and 10b show, also in the coordinate system α, r, the distortion curve r = f (α) for an optical element 301 of the capture unit 30 in comparison with various prior art distortion curves. Figure 10b shows an enlarged section Z in the origin region of the coordinate system α, r. The distortion curve r = f (α) with an inflection point (αw; rw) in the region of 0 <α <αmax, is illustrated by a solid line and marked by f1. f2 signals a gnomonic (distortion-free) distortion curve, f3 a stereographic distortion curve, i.e. a conformal distortion curve, f4 an equidistant distortion curve, f5 an equal area distortion curve and f6 a distortion curve spelling. The focal distances in relation to the distortion curves are selected so that all distortion curves pass through the point (αw, rw).

[0089] As can be seen in Figure 10a and Figure 10b, the distortion curve f1 has an inflection point at (αw; rw), where the curvature of the distortion curve changes curve to the right (in the region 0 < α < αw) for left turns (in the region of αw <α <αmax). Furthermore, as can be seen in particular from Figure 10b, the gradient of the distortion curve f1 in the interval close to the origin of the coordinate system α, r is large, in particular compared to the other distortion curves. This means that a relatively large space for displaying a relatively small angle is provided on the image sensor 303, which makes the area in this region can be displayed with high resolution. Furthermore, the gradient of the distortion curve r = f1 (α) at the inflection point (αw; rw) is minimal, that is, at the inflection point itself and in its proximity, a relatively low gradient is present. Finally, for αmax, the gradient of the distortion curve is preferably maximum or relatively large, as can be particularly observed from the illustration in Figure 10a.

[0090] A distortion curve as illustrated in Figures 7 to 10b, is, for example, described by a polynomial function . Alternatively, a spline function may describe the distortion curve, said spline function being a partial polynomial function, that is, a function consisting of a plurality of polynomial parts/units, or a Bézier curve, which is a mathematically formulated curve (numerically generated curve).

[0091] With reference to Figure 11 and Figure 12, a visualization of the field of views 11, 12 for the commercial vehicle 10 (Figure 2) is shown, which are captured by means of the camera system 130, on the surface of the image sensor 304. The surface of the image sensor 304 of the image sensor 303 illustrated in Figure 11 is rectangular with side lengths a and b of the rectangle. As can be seen in Figure 11, in the illustrated embodiment, the optical axis 302 is disposed eccentrically with respect to the surface of the image sensor 304, that is, beyond the centroid of the surface of the image sensor 304. Specifically, the optical axis 302 is eccentric with respect to side a of the rectangular image sensor surface 304. This results in a maximum distance r3 = rmax from the optical axis 302 on the image sensor surface 304 to the farthest corners of the image sensor surface. image 304. Furthermore, according to Figures 10a and 10b, the rays that have the optical axis 302 as their center are illustrated, which pass through the inflection point of the distortion curve r = f (α) (r2 = rw), a radius rSB corresponding to the maximum distance from the optical axis 302 to the edge of the sensor surface parallel to the side line a; a radius rSH corresponding to the maximum distance from the optical axis 302 on the sensor surface 304 to the edge of the sensor surface parallel to the sensor edge b; as well as a radius r1, which corresponds to a first illustrated radius r1 with an angle ai, as illustrated in Figures 10a and 10b. Furthermore, in Figure 11, the image displayed 11' of the field of view 11 of the main mirror (see Figure 2), as well as the image displayed 12' of the field of view 12 of the wide-angle mirror (see Figure 2), are illustrated. as well as an image displayed 15' from the horizon. As can be seen, specifically the image 11 'of the field of view 11 of the main mirror is largely within a region located within the radius r1, such that this region within the radius r1 is displayed with increased resolution compared to the curves of distortions normal to the prior art. Furthermore, the entire image displayed 12' of the field of view 12 of the wide-angle mirror can be imaged on the same image sensor with the same optical element. It is not necessary to provide a second optical sensor and/or a second image sensor and subsequently combine the image for display.

[0092] Furthermore, in Figure 11, the image displayed 14 'of the straight line of sight segment 14 is illustrated (see Figure 2). As can be seen in Figure 11, this line segment extends substantially parallel to a side edge of the image sensor surface 304 (side edge a).

[0093] In Figure 12 this image displayed 14' of the straight line of sight segment is also represented in the coordinate system α, r, in addition to the image displayed of the distortion curve r = f1 (α). It is clearly recognizable that the entire width of the image displayed from the field of view 11 of the main mirror is within the region of 0 <α <αw, which is in the region of the distortion curve r = f (α) which is curved to the right and , therefore, involves high resolution (specifically when compared to the distortion curves of conventional optical systems).

[0094] In the presently described embodiment, where the camera system 130 is used in a vehicle mirror replacement system 100, a processing unit 120 of the mirror replacement system 100 may subsequently evaluate the image data captured by the mirror sensor. camera. image 303, and displaying the same, for example, on a monitor, visible to a driver located, for example, in the driver's cab of a commercial vehicle. In the present embodiment, separate regions are read for the field of view 11 of a main mirror and the field of view 12 of a wide-angle mirror and, in accordance with a preferred embodiment (not illustrated), displayed to the driver in separate regions of the unit. display size 110. Separate regions can be provided on a common monitor or on separate monitors. Therefore, it is possible to model the usual appearance of a main mirror and a wide-angle mirror for the driver of the commercial vehicle. If the camera system 130 is, for example, used in the context of a driver assistance system, surface regions of interest may also be evaluated with respect to specific environmental information (e.g., road lines, traffic signs, other road users, and the like) by a processing unit and, depending on the information captured and determined, it can be interfered with in the converter control system, a note or information can be indicated to the driver, and the like.

[0095] In a mirror replacement system 100, as previously described in the present case, it is further possible, depending on the driving situation of the automobile, for example, a commercial vehicle 10, to extract data to be displayed to the driver on the mirror. Visualizing 100 different regions of the surface of the image sensor 304, that is, evaluating different parts of the surface of the image sensor 304 at different times during the driving operation. This is described exemplarily with reference to Figures 13 and 14.

[0096] Figure 13 shows a top view of a commercial vehicle during forward or forward driving, in which the field of view 11 of a main mirror and the field of view 12 of a wide-angle mirror are illustrated schematically. . Figure 14 illustrates, also for forward driving, the surface of the image sensor 304 with the image displayed 11' of the field of view 11 and the image displayed 12' of the field of view 12. As has already been explained previously, during normal straight ahead, the region 21' for illustrating/displaying the field of view 11 of the main mirror and for providing the driver with a view of the field of view 11 of the main mirror, respectively, is extracted from the data on a first part of the surface of the image sensor 304. If the driving situation changes, it may happen that, whilst the alignment of the pickup unit 30 in the vehicle does not change, the region of interest changes from the original region of interest 21 to the displaced/deflected region 22. This This may be the case if a vehicle, in particular a commercial vehicle with a trailer, drives along curves or carries out a maneuvering process. In this case, the region of interest, which corresponds to the field of view 11 of the main mirror, as illustrated in Figure 13, moves to region 22. By means of the camera system 130 comprising the capture unit 30 which includes the optical element 301, which has the distortion curve r = f (α) of the type described above, it is also possible to shift the region on the surface of the image sensor 304, from which the region's image sensor data is extracted, such that 14, image data from a region 22' on the surface of the image sensor 304 is extracted. This is possible without losing the necessary precision of the image data, i.e. in particular the resolution, as the distortion curve r = f (α) can provide the necessary resolution and distortion in all regions from which the data can be obtained. extracted, without the need for data-in-processing. Thus, the field of view 11 and its displayed image 11', respectively, can be updated corresponding to the driving situation. A mechanical adjustment of the capture unit 30 is not required. Instead, the adjustment can be performed solely by extracting data from the image data of the image sensor 304 in selected regions.

[0097] These advantages are obtained by using at least one capture unit 30 that comprises an optical element 301 having a distortion curve r = f (α), which has an inflection point within the maximum distance from a point on the surface image sensor 304 to the optical axis 302 on the surface of the image sensor 304.

[0098] It is explicitly established that all features set forth in the description and/or claims are intended to be set forth separately and independently of each other for the purpose of original disclosure, as well as for the purpose of restricting the claimed invention regardless of the composition of the invention. the characteristics in the embodiments and/or claims. List of reference numbers 10 commercial vehicle 11 field of view of a main mirror 12 field of view of a wide-angle mirror 13 side boundary line 14 straight line of the segment of view 11' image (displayed) of the field of view 11 12' image (displayed) of the field of view 12 14' image (displayed) of the straight line of the segment of vision 14 15' image (displayed) of the horizon line 21' extracted part 22' extracted part 30 capture unit 31 capture unit element optical optical axis image sensor image sensor surface sensor protection glass lens lens lens lens lens lens lens lens lens lens lens lens lens lens lens infrared filter aperture mirror replacement system display unit processing unit camera system sensor of vehicle control device distortion curve distortion curve f2 distortion curve (no distortion, gnomonic) f3 distortion curve (conformation, stereographic) f4 distortion curve (equidistant) f5 distortion curve (equal area, orthographic) f6 distortion curve distortion (orthographic) fβi distortion curve a lateral edge of the image sensor surface b lateral edge of the image sensor surface D direction of forward movement of the vehicle S point of intersection α object angle of incident light β angle of rotation around the optical axis r distance from a point on the surface of the image sensor to the optical axis

Claims (21)

1. Mirror replacement system, wherein the mirror replacement system is part of a commercial vehicle (10), and comprising a camera system (130), wherein the camera system comprises a capture unit (30) which includes an optical element (301) and an image sensor (303) that is provided with an image sensor surface (303) and adapted to capture a section of a vehicle environment, characterized in that the optical element (301) is endowed with a distortion with a distortion curve r = f (α), where r is the distance that goes from an object point represented on the surface of the image sensor (304) to the point of intersection of the optical axis (302) with the surface of the image sensor (304), and α is the angle between the optical axis (302) of the optical element (301) and the beam incident on the optical element (301) from the object point, the distortion curve r = f(α) for rw = f (αw) is provided with an inflection point (αw; rw) within 0 < r < rmax, for which r'' = f''' (αw) = d2r applies /dα 2(αw) = 0, where rmax is the distance r = f(αmax) on the image sensor surface (304) from the optical axis (302) to the furthest boundary point on the image sensor surface. image (304), and for the curvature of the distortion curve, the following applies: r'' = f'' (α) < 0 for 0°< α < αw r'' = f'''(α) > 0 for αw < α < αmax; and further comprising a processing unit (120) for processing data from the capture unit (30) and/or a display unit (110) for displaying information captured by the capture unit (30) visible to the driver of the vehicle, in that the capture unit (30) is adapted to capture at least one of the field of view (11) of a main mirror, or the field of view (12) of a wide-angle mirror on one side of the commercial vehicle, or the field of view of a proximity mirror, or the field of a frontal mirror, the capture unit (30) being preferably adapted to capture both the field of view (11) of a main mirror and the field of view (12) of a wide-angle mirror on the same side of the commercial vehicle (10), in which the optical axis (302) of the optical element (301) of the capture unit (3) crosses the field of view (11, 12) or one of the fields of vision (11, 12), in which the optical axis (302) of the optical element (301) intersects one of the fields of view (11, 12) at an intersection point (S) at a maximum distance of 5 m to a line lateral limit line of the vehicle, wherein the lateral limit line (13) is a line of intersection of a plane parallel to the central longitudinal plane of the vehicle, which plane passes through an outermost lateral point of the vehicle, with the road horizontal plane. 2. Mirror replacement system according to claim 1, characterized in that the distortion curve r = f(α) is provided with exactly one inflection point (αw; rw) within 0 < r < rmax. 3. Mirror replacement system, according to claim 1 or 2, characterized in that the gradient r' = dr/dα of the distortion curve r = f(α) is maximum in the region 0°< α < αw under the point zero r = f(0) = 0 of the distortion curve. 4. Mirror replacement system according to any one of claims 1 to 3, characterized in that the gradient r' = dr/dα of the distortion curve r = f(α) is minimum at the inflection point r = f(αw ) = rw of the distortion curve. 5. Mirror replacement system according to any one of claims 1 to 4, characterized in that the gradient r' = dr/dα of the distortion curve r = f(α) is maximum in the region αw < α < αmax to αmax (r = f(αmax) = rmax) of the distortion curve. 6. Mirror replacement system according to any one of claims 1 to 5, characterized in that the distortion curve r = f(α) is comprised of a polynomial function . 7. by a function Polynomial system. mirror replacement, according to any one of claims 1 to 6, characterized in that the distortion curve r = f(α) is comprised 8. One-function Groove System. mirror replacement, according to any one of claims 1 to 7, characterized in that the distortion curve r = f(α) is comprised 9. by a Bézier curve. Mirror replacement system according to any one of claims 1 to 8, characterized in that the centroid of the image sensor area (304) and the point of intersection of the optical axis (302) with the image sensor surface (304 ) do not coincide, in particular the optical axis (302) is arranged eccentrically with respect to the surface of the image sensor (304). 10. Mirror replacement system according to any one of claims 1 to 9, characterized in that the optical element (301) includes at least one lens that is provided with a shape other than a partial sphere. 11. Mirror replacement system according to any one of claims 1 to 10, characterized in that the optical element (301) includes at least one spherical lens. 12. Mirror replacement system according to any one of claims 1 to 11, characterized in that the optical element (130) includes at least two lenses that are different from each other. 13. Mirror replacement system, according to any one of claims 1 to 12, characterized in that the optical element (103) is provided with a rotationally symmetrical distortion with respect to its optical axis (302), so that the distortion r = f(α) are identical for each rotation angle β around the optical axis (302). 14. Mirror replacement system according to any one of claims 1 to 12, characterized in that the optical element (301) is provided with a distortion that is not rotationally symmetric with respect to its optical axis (302), so that a first distortion curve r1 = f (α) for a rotational angle β1 about the optical axis differs from a second distortion curve r2 = f (α) for a rotational angle β2 about the optical axis. 15. Mirror replacement system, according to claim 14, characterized in that the optical element (301) is anamorphic. 16. Mirror replacement system according to any one of claims 1 to 15, characterized in that the mirror replacement system is adapted to display at least two fields of vision around the vehicle visible to the driver, where preferably a first field of view is visible in a first region of the display unit, and a second field of view is visible in a second region of the display unit, which second region is optically separated from the first region. 17. Mirror replacement system, according to claim 16, characterized in that the mirror replacement system is adapted to capture information from the two fields of vision (11, 12) by means of a common capture unit (30) /joint of the camera system (130), and the processing unit (120) be adapted to separate and extract the data received from the capture unit (30) into information to be displayed in the first region of the display unit and in the second region of the display unit, respectively. 18. Mirror replacement system according to any one of claims 1 to 17, characterized in that the mirror replacement system is adapted to visually display the information captured by the capture unit (30), and is further adapted to display at at least one field of view, which is located on a flat horizontal portion of the road surrounding the vehicle (10), in the display unit (110) for the driver of the vehicle. 19. Mirror replacement system according to any one of claims 1 to 18, characterized by a segment of the straight line of vision (14) perpendicular to the lateral limit line (13), which line segment passes through the point of intersection (S) and is limited by the limitation of the field of view of the main mirror, it is in the region of the distortion curve r = f(α) for 0° < α < αw with r'' = f''(α) < 0. 20. Mirror replacement system according to claim 19, characterized in that the inflection point (αw; rw) is beyond the straight line segment of vision (14). 21. Driver assistance system, characterized by comprising a mirror replacement system as defined in any one of claims 1 to 20.