SENSOR ARRANGEMENT AND METHOD FOR A VEHICLE FOR DETECTING DISTANCE INFORMATION

Description

[0001] The invention relates to a sensor arrangement and a method for a vehicle, in particular for a motor vehicle such as a passenger car or a truck, for detecting distance information. The detection principle can generally be based on detecting light (i.e., electromagnetic radiation) in the visible or non-visible range.

[0002] In the context of vehicles, it is known to capture scenes within or in the surroundings of the vehicle using optical sensors. In particular, it is known to irradiate light with predetermined properties into the scene and to receive light reflected from the scene using a light-sensitive sensor. Based on the received light, measurement signals can be generated, and these can be evaluated to obtain distance information, or in other words, standoff information.

[0003] This information can then be used by various driver assistance systems, as described in

[0002] of the applicant's previously published DE 10 2013 002 671 A1. DE 10 2013 002 671 A1, for example, further discloses, with reference to WO 2008 / 1547361 A1, that existing lighting systems of a vehicle, in particular LED-based lighting systems (see, for example,

[0003] of DE 10 2013 002 671 A1), can be used as a light source for generating and irradiating light, which can then be detected by sensors in reflected form. The lighting system can—also within the scope of the present application—include, for example, a daytime running light, a high beam, a low beam, a turn signal light, a fog light, or the like.

[0004] Furthermore, according to

[0007] and the further detailed description of DE 10 2013 002 671 A1, it was recognized that, in order to shorten the evaluation time and reduce the demands on the sensors, strip-shaped areas can be formed for which distance histograms are determined. Based on these, distance information can then be determined for the intersection points of the strip-shaped areas.

[0005] The present application is based on the findings of DE 10 2013 002 671 A1, in particular its general description, the subject matter described in the claims and, above all, the description of the Figuren 17 bis 22 .

[0006] An introduction to time-of-flight cameras is available from Larry Li, "Time-of-Flight Camera - An Introduction," May 31, 2014, URL: http: / / www.ti.com / lit / wp / sloa190b / sloa190b.pdf. A time-of-flight sensor is available from Rolf Kaufmann et al., "A time-of-flight line sensor: development and application," PROCEEDINGS OF SPIE, September 1, 2004, Vol. 5459, doi:10.1117 / 12.545571, ISSN 0277-786X.

[0007] It was recognized that, despite all this, optimal distance detection cannot be achieved with the teaching of DE 10 2013 002 671 A1.

[0008] The object of the present invention is therefore to further improve the strip-shaped light detection of DE 10 2013 002 671 A1.

[0009] This object is achieved by a sensor arrangement according to claim 1 and a method according to claim 7. Advantageous further developments are specified in the dependent claims. It is understood that the above remarks may also apply to the present invention, unless otherwise stated or apparent.

[0010] In contrast to the solution of DE 10 2013 002 671 A1, which provides for sequential measurement value acquisition for the individual strip-shaped regions, as is evident from the measurement time specifications at the end of

[0067] , the invention provides for the measurement values ​​of the strip-shaped regions to be acquired at least partially simultaneously or in parallel. For example, all strip-shaped regions, or at least 10% of the total provided strip-shaped regions, can be acquired, or in other words, read out, in parallel.

[0011] A measured value can be understood as a measured value generated at a predetermined point in time, and in particular as a measurement signal value obtained for the corresponding strip-shaped area. The measured value or the measurement signal value can also be a value distribution related to a specific point in time. The measured value is preferably one of the distance histograms described above or can be used to generate one.

[0012] An advantage of the disclosed solution is that the observed scene can be captured at least partially and preferably completely simultaneously. The simultaneously captured light, or the measured values ​​simultaneously generated based on it, thus image the scene at the same time. This reduces motion blur, which can occur during sequential capture and simultaneous relative movement between the sensor and the scene. In other words, with the solutions proposed here, motion blur can only occur during the comparatively short parallel exposure time or readout time, whereas with the known solutions, motion blur can occur during the cumulative exposure times for all of the sequentially evaluated strip-shaped areas.

[0013] A further advantage is that the scattered light is more effectively utilized due to the at least partially parallel measurement data acquisition across a majority of the strip-shaped areas. Compared to the previous solution, comparatively short scattered light pulses or pulse trains are now sufficient, with comparatively long pauses between them. This enables savings potential on the hardware side, especially in connection with the lighting sources used.

[0014] It should be noted that for the practical implementation of the teaching of DE 10 2013 002 671 A1, several detection cycles and associated illumination cycles may be necessary, for example, one for the first strip-shaped areas (e.g., in the row direction) and another for the second strip-shaped areas (e.g., in the column direction). With the present solution, however, one detection and illumination cycle may be sufficient, since the light from several strip-shaped areas is detected in parallel.

[0015] In detail, an (optical) sensor arrangement for a vehicle for detecting distance information is proposed, with the features of claim 1 and, among other things, with: an (optical) sensor configured to receive (visible or non-visible) light reflected from a scene in the environment (the sensor arrangement); a (for example electronic) processing unit configured to determine a plurality of first distance histograms as a function of the received light, wherein a respective first distance histogram of the plurality of first distance histograms is assigned a respective first strip-shaped region of the scene, wherein the first distance histogram comprises a strength of reflections in a distance range by objects in the assigned first strip-shaped region; and which is further configured to determine a plurality of second distance histograms as a function of the received light, wherein a respective second distance histogram of the plurality of second distance histograms is assigned a respective second strip-shaped region of the scene, wherein the second distance histogram comprises a strength of reflections in a distance range by objects in the assigned second strip-shaped region; and which is further configured to determine distance information for a region of the scene as a function of the plurality of first distance histograms and the plurality of second distance histograms, wherein the region of the scene comprises an intersection region of one of the first strip-shaped regions with one of the second strip-shaped regions; wherein the strip-shaped regions of the scene each correspond to strip-shaped regions of the sensor, and wherein the sensor arrangement (and in particular its processing unit) is configured to simultaneously determine the light received therein for a plurality of the corresponding strip-shaped regions (or in other words, to read it out and / or to simultaneously determine measured values ​​for the corresponding strip-shaped regions).

[0016] It can therefore be provided that there is an association or correspondence between the areas of a scene, the strip-shaped areas with which the scene is captured, and the strip-shaped areas of or on a sensor. In particular, it can be provided that a scene is captured by means of (e.g. virtual) strip-shaped areas of the type mentioned above, and that these strip-shaped areas are formed or provided by corresponding (corresponding) areas of the sensor and in particular the sensor elements explained below that are present therein. The first and second strip-shaped areas can therefore be virtual, so to speak, but can be traced back to a corresponding grouping or arrangement of sensor elements within the sensor, which divide the scene into correspondingly detectable strip-shaped areas.In particular, the strip-shaped areas can correspond to rows and columns of a matrix-divided sensor (ie the corresponding strip-shaped areas of the sensor can be its rows and columns).

[0017] In general, the sensor can enable a scene to be imaged by means of a two-dimensional detection area which is divided into corresponding strip-shaped areas or which can be assigned to the above-mentioned strip-shaped areas with which the scene is to be captured.

[0018] The sensor can comprise multiple sensor elements, each with at least one photodetector (or photodetector element). The sensor elements can be SiPMs (silicone photomultipliers), which can preferably be constructed from several smaller photodetectors (for example, so-called SPADs - single photon avalanche diodes). Alternatively, the sensor elements can be formed by so-called PIN diodes.

[0019] According to the invention, the photodetectors are arranged in a matrix or grid shape and accordingly, like the sensor in general or a detection area defined thereby, they have a row and a column direction which are perpendicular to one another.

[0020] The determination of received light for the corresponding strip-shaped areas can also be referred to as reading out or evaluating these areas, the latter preferably also comprising the formation of the corresponding distance histograms (or in other words the area-by-area measurement value generation).

[0021] All measured values ​​or measurement signals can generally be determined with time resolution. The sensor arrangement can also comprise a memory device in which the (preferably time-resolved) measurement signals can be stored. The time-resolved signals, which are preferably obtained for each pixel and / or sensor element, can be obtained, preferably simultaneously, as a row- and column-wise, also time-resolved, summed signal. This can then be converted into a distance-resolved signal or a distance histogram using the methods described herein.

[0022] Parallelism or simultaneous readout can be achieved by assigning each strip-shaped area a separate (electrical) line, into which all sensor elements within this strip-shaped area (or within a corresponding strip-shaped area of ​​the sensor) feed their signals. These can be the row and column lines explained below.

[0023] It can be provided that all corresponding strip-shaped areas (of the sensor) can be read out simultaneously, but at least all strip-shaped areas (of the sensor) that correspond to the first or second strip-shaped areas.

[0024] According to a further development, it can be provided that for at least 50% (and preferably at least 25% or at least 10%) of the corresponding strip-shaped areas, the light received therein is determined simultaneously.

[0025] In general, it can also be provided that the corresponding strip-shaped regions of the sensor are divided (e.g., virtually) into regions in which the light received therein is determined simultaneously, and into regions in which the light received therein is not determined simultaneously. Instead, sequential evaluation or readout can be provided in the latter regions.

[0026] In this context, it can further be provided that the regions without simultaneous determination of the received light are located at least partially in (at least) one edge region of the sensor. An edge region of the sensor can be understood, for example, as a row and / or column region (or generally a region) that comprises up to 10% or up to 5% of the total number and / or total area of ​​the rows and / or columns (or generally of the total number and / or total area of ​​the corresponding strip-shaped regions) of the sensor and that is preferably located away from a geometric center of the sensor and, in particular, additionally comprises a row and / or column forming the outermost edge (or generally a strip-shaped region forming the outermost edge).

[0027] An advantage of this variant is that the simultaneous and more precise detection can be reserved for a central area of ​​the sensor and a less precise sequential detection can take place in the peripheral areas, where less relevant events for the vehicle are likely to be observed.

[0028] As already indicated, the sensor comprises a sensor matrix with sensor elements arranged in rows and columns, each of which is configured to receive light, wherein the rows correspond to the first strip-shaped areas of the scene and the columns correspond to the second strip-shaped areas of the scene.

[0029] In general, the sensor, and in particular the sensor elements, can each detect a (light) intensity of the received light. The sensor elements can provide pixel values ​​and / or define individual pixels or image points of the sensor matrix. Simultaneously recorded pixel values, as well as sequentially recorded pixel values ​​related to the same acquisition process, can be considered together and used, for example, to derive common distance histograms.

[0030] The sensor elements in the rows and columns are preferably interconnected (for example, by connecting them to common electrical (signal) lines, and in particular to common row or column lines), and the distance histograms are preferably determined from a total signal from the correspondingly interconnected sensor elements. The interconnection allows the corresponding first and second strip-shaped regions of the sensor to be formed.

[0031] According to an alternative embodiment of the invention, at least those sensor elements whose received light is determined simultaneously each comprise a current mirror arrangement connected to a row line and a column line, to which further current mirror arrangements of other sensor elements are also connected. This makes it possible to summarize the measurement signals obtained for each sensor element row-wise or column-wise and then to form the corresponding distance histograms from these. Furthermore, this variant is particularly suitable when the sensor elements are SiPMs. In general, this is a reliable and inexpensive way to form or detect the strip-shaped regions. The current mirror arrangement can be formed in a conventional manner by two (semiconductor) transistors connected in parallel, for example, and is explained below by way of example with reference to the figures.

[0032] A further variant provides that the sensor elements each comprise at least one PIN detector connected to two resistors to feed the current dropped across them into lines (in particular, a signal line and a row line) associated with the strip-shaped regions. The PIN detector can be connected to a transimpedance amplifier, whose output voltage can be applied to the corresponding resistors.

[0033] According to a further alternative according to the invention, it is provided that at least those sensor elements whose received light is determined simultaneously (i.e., which are read out simultaneously) comprise at least two photodetector elements, each of which receives light (i.e., each of which can be read out or each of which provides a measurement signal), and wherein one of the photodetector elements is connected to a row line and the other to a column line. The photodetector elements can be designed as the above-mentioned SPADS, in particular if the sensor element is a SiPM. In particular, but not limited to the latter case, a sensor element can comprise up to sixteen or up to thirty-two photodetector elements.

[0034] Using this variant, additional hardware elements, such as the current mirror mentioned above, can be eliminated and yet reliable parallel readability of the strip-shaped areas can be achieved.

[0035] Furthermore, it can be provided that more than two photodetector elements are provided per sensor element (for example, sixteen or thirty-two, see above) and these are combined into two preferably equally sized groups, wherein the photodetector elements of one group are connected to a row line and the photodetector elements of one group are connected to a column line, and wherein at least two photodetector elements of one group enclose at least one photodetector element of the other group between them. In other words, the photodetector elements of the two groups can be arranged nested within one another and / or alternately (preferably in the row and column directions). In general, the photodetector elements of the two groups can therefore be arranged in a checkerboard pattern. By means of a corresponding group-like arrangement, a high resolution can be achieved despite dividing individual sensor elements into separate detection areas (ieinto separate photodetector elements).

[0036] The invention further relates to a method for a vehicle for detecting distance information, having the features of claim 7 and including: Receiving light with a sensor that is reflected from a scene in the environment; determining a plurality of first distance histograms as a function of the received light, wherein a respective first distance histogram of the plurality of first distance histograms is assigned a respective first strip-shaped region of the scene, wherein the first distance histogram comprises a strength of reflections in a distance range by objects in the assigned first strip-shaped region; determining a plurality of second distance histograms as a function of the received light, wherein a respective second distance histogram of the plurality of second distance histograms is assigned a respective second strip-shaped region of the scene, wherein the second distance histogram comprises a strength of reflections in a distance range by objects in the assigned second strip-shaped region;Determining distance information for a region of the scene as a function of the plurality of first distance histograms and the plurality of second distance histograms, wherein the region of the scene comprises an intersection region of one of the first strip-shaped regions with one of the second strip-shaped regions; ; wherein the strip-shaped regions of the scene each correspond to strip-shaped regions of the sensor, and wherein for a plurality of the corresponding strip-shaped regions the light received therein is determined simultaneously (or, in other words, a plurality of the corresponding strip-shaped regions of the sensor are read out simultaneously).

[0037] All of the above and below explanations regarding features of the sensor arrangement can also apply to the identically named features of the method. In particular, the method can include any further step and any further feature to provide all of the functions, operating states, or effects described herein in connection with the sensor arrangement. In particular, the method can be carried out with a sensor arrangement according to any of the above and below embodiments.

[0038] According to a further embodiment of the sensor arrangement and the method, the scene is illuminated with a vehicle's LED light source. The LED light source can comprise a vehicle lighting device for illuminating an environment or an interior of the vehicle. The lighting device can comprise, for example, daytime running lights, high beams, low beams, indicator lights, fog lights, or the like. The LED light source can be controlled using a modulation method, and the distance histogram can be determined as a function of the modulation signal and a received signal from the sensor matrix. The modulation method can, for example, comprise a frequency-modulated continuous wave method, in which a frequency with which the LED light source is modulated is changed from an initial frequency to a final frequency over a specific time.The modulation frequency is preferably changed continuously from the initial frequency to the final frequency. Furthermore, a random frequency modulation method can be used as the modulation method, in which a frequency with which the LED light source is modulated is changed randomly or pseudorandomly. Furthermore, the LED light source can be controlled using a single-frequency modulation method, in which a frequency for modulating the LED light source is constant. Finally, the LED light source can be controlled using a pulse modulation method. Depending on the modulation method used, various evaluation methods can be used to determine the distance histograms. For example, correlation methods can be used which correlate a signal used to modulate the LED light source with a received signal from the sensor matrix.In another evaluation method, the modulation signal can be mixed with the received signal, and the distance can be determined as a function of the mixing frequency. The distance histograms essentially represent distance-resolved echograms generated by one or more objects in the strip-shaped detection area. These distance-resolved echograms can be processed into a spatially resolved image using a process similar to that used in a CT scanner, with each location in the image being assigned a corresponding distance. All of the aforementioned methods can also be applied to the simultaneous reading of at least individual strip-shaped areas.

[0039] Because the distance histograms each cover an entire row or column of the scene, fewer coarse-resolution sensors (row or column sensors) are required, or, if a matrix sensor is used, only a few row and column measurements are required instead of measurements for each pixel. Thus, high resolution is possible with fewer sensors or measurements.

[0040] According to the present invention, a device for detecting distance information for a vehicle is further provided. The device comprises a light source designed to illuminate a scene in an environment or within the vehicle. The light source is preferably a lighting device of the vehicle. Furthermore, the lighting device preferably comprises light-emitting diodes for generating the light, since light-emitting diodes can be modulated at a sufficiently high frequency to provide light that can be used for the determination of distance histograms described below. The device further comprises a sensor arrangement of the type mentioned above for receiving light originating from the light source and reflected from the scene.Finally, the device comprises a processing unit which controls the light source and determines a plurality of first distance histograms and a plurality of second distance histograms of the type mentioned above as a function of the received light.

[0041] The present invention will be described in detail below with reference to the drawings. Fig. 1 shows schematically a vehicle and an object in an environment of the vehicle. Fig. 2 shows steps of a method for determining a distance to an object. Fig. 3 shows steps of a method for determining the speed of an object. Fig. 4 shows schematically a circuit of a light-emitting diode light source which is designed to emit light for distance measurement. Fig. 5 shows schematically the arrangement of components of the LED light source of the Fig. 4 in a common semiconductor package. Fig. 6 shows steps of a method for determining the distance of an object. Fig. 7 shows first detection ranges of sensors of a device for determining the position of an object. Fig. 8 shows second detection areas of sensors of a device for determining a position of an object. Fig. 9 shows an overlay of the first and second detection areas of the Fig. 7 und 8 as detected by sensors of a device for determining the position of an object. Fig. 10 shows the second detection areas of the Fig. 8 with an additional blur. Fig. 11 shows the overlay of the first and second detection areas of the Fig. 9 with an additional blurring of the second detection areas. Fig. 12 shows transmitter segments as used by a light source of a device for detecting a position of an object. Fig. 13 shows receiver segments as used by sensors of a device to determine the position of an object. Fig. 14 shows an overlay of the transmitter segments of the Fig. 12 and the receiver segments of the Fig. 13 . Fig. 15 shows a near-field view of transmitter segments generated by a staggered arrangement of transmitter diodes. Fig. 16 shows a far-field view of the transmitter segments of the Fig. 15 . Fig. 17 shows process steps of another method for determining distance information. Fig. 18 shows a scene with an object in a vehicle environment. Fig. 19 shows distance histograms of lines of the scene of the Fig. 18 . Fig. 20 shows distance histograms of columns of the scene of the Fig. 18 . Fig. 21 shows a vehicle that simultaneously measures the distance to a vehicle in front and transmits data. Fig. 22 shows steps of a method for determining a distance of an object and transmitting transmission data. Figur 23 shows a schematic section of an exemplary sensor arrangement according to the invention, which carries out a method according to the invention according to an embodiment.

[0042] In Figur 24 shows a schematic section of a sensor arrangement according to the invention according to a further embodiment.

[0043] Fig. 1 shows a vehicle 10 with a device for determining distance information. The device comprises a light source 11, which is designed to illuminate an object 17 in an environment of the vehicle 10. The light source 11 can, for example, comprise a daytime running light, a low beam, a turn signal light, a tail light, a high beam, a fog light, or a reversing light of the vehicle 10. The light source can further comprise one or more light-emitting diodes, which generate light for illuminating the environment of the vehicle 10 or a signaling light, e.g. the light of a turn signal light or a brake light. The light source 11 can furthermore also comprise a lighting device for illuminating an interior of the vehicle 10, such as a dashboard light or a passenger compartment light.The device for determining the distance information further comprises an optical sensor 12 for receiving light reflected from the object 17 and a processing unit 13 coupled to the light source 11 and the sensor 12. If, in the case of the method shown in . Fig. 1 If, in the arrangement shown, the object 17 is located, for example, at a distance 18 in the area in front of the vehicle 10, light 15 emitted by the light source 11 is reflected by the object 17 and received as reflected light 16 by the sensor 12. The operation of the device for determining distance information is explained below with reference to Fig. 2 described.

[0044] Fig. 2 shows a method 20 for the vehicle 10 for determining the distance 18 between the vehicle 10 and the object 17. In step 21, the light source 11 of the vehicle 10 is controlled with a modulated signal. The modulated signal is generated by the processing unit 13. The light 15 emitted by the light source 11 is reflected by the object 17 and received as reflected light 16 by the sensor 12 (step 22). In step 23, a received signal is generated as a function of the received reflected light 16. The received signal can, for example, comprise an analog or digital electrical signal. In step 24, the received signal is combined with the modulated signal in the processing unit 13. For example, the modulated signal and the received signal can be correlated or mixed, as will be described in detail below.The distance 18 to the object 17 is determined in step 25 from a combination signal, for example, a correlation signal or a mixed signal. The distance to the object 17 determined in this way can, for example, be provided to a driver assistance system 14 of the vehicle 10. The driver assistance system 14 can, for example, comprise an adaptive cruise control system, a brake assistance system, a parking assistance system, or a collision warning system. The object 17 can also be located in the interior of the vehicle 10 and illuminated by a corresponding lighting device of the vehicle in the interior, and the reflected light from the object can be received by a corresponding sensor.This makes it possible to determine distances to objects in the interior of the vehicle, for example to recognize gestures of an operating system or, in the event of an accident, to record the current position of an occupant's head in order to trigger appropriate protective mechanisms, such as airbags.

[0045] In order for the previously described method to be used in the vehicle for different driver assistance systems, it may be necessary to use different transmission and reception methods for the different applications. These methods can be selected, for example, depending on the required distance or application. For this purpose, for example, an operating state of the vehicle 10 can be determined and a corresponding transmission and reception method can be selected depending on the operating state of the vehicle, i.e. a corresponding modulation method for generating the modulated signal and a corresponding evaluation method (e.g., mixing or correlating) are selected depending on the operating state. The modulation method can, for example, comprise a frequency-modulated continuous wave method, a random frequency modulation method, a single-frequency modulation method, or a pulse modulation method.These methods will be described in detail below. The operating state of the vehicle may include, for example, a speed of the vehicle, an activation state of a light source of the vehicle, which indicates whether the light source is switched on to illuminate a surrounding area of ​​the vehicle or to output an optical signal, a traveling direction of the vehicle, a previously determined position information or distance information of an object in the surrounding area of ​​the vehicle, weather conditions in the surrounding area of ​​the vehicle, or a type of vehicle assistance device to which the distance information is provided.

[0046] In the frequency-modulated continuous wave method, also referred to as FMCW (Frequency Modulated Continuous Wave) or chirp method, a modulation frequency is changed over a specific time from an initial frequency to a final frequency. Preferably, the modulation frequency is changed continuously from the initial frequency to the final frequency. As will be shown later, the method can be used not only for distance measurement, but also for measuring the speed of the object 17. The generation of modulation signals in which a modulation frequency is changed continuously over a specific time from an initial frequency to a final frequency is known in the art, and therefore the method can be easily implemented, for example, by blanking a synthetically generated waveform.The method can be used to continuously measure the distance 18 to the object 17, making it particularly suitable for light sources 11 that are continuously switched on. Continuously changing the modulation frequency, and thus the transmission frequency of the light source 11, from an initial frequency to a final frequency results in a frequency ramp. By mixing the transmission signal with the reception signal received by the sensor 12, both the distance 18 and the speed of the object 17 can be directly measured. When using light-emitting diodes (LEDs) as the light source 11, which typically have response times of 5-10 nsec, modulation frequencies up to, for example, a maximum of 100 MHz can be used. FMCW modulation can thus, for example, use the transmission frequency from 10 MHz to 100 MHz continuously over a period of, for example, 0.5-400 µsec.When using the frequency-modulated continuous wave (FMCW) method, the distance measurement can be carried out either by means of a frequency mixing or a correlation method.

[0047] When using the frequency-modulated continuous wave method, the transmitted and received signals can be compared to a frequency mixer. An object at a certain distance generates a mixed frequency that is proportional to the distance. The spatial resolution of multiple objects is a function of the resolution of the frequency measurement and thus of the measurement time. Such a frequency mixing method can be implemented, for example, as an analog circuit in an integrated circuit. If, for example, a distance between 0 m and 40 m is to be measured, the light needs to travel this distance back and forth along arrows 15 and 16 of the Fig. 1 approximately 3.3 nsec / mx 40 mx 2 = 264 nsec. This results in a useful signal length for the FMCW signal of approximately 500 nsec. Modulation down to 10 MHz is therefore too small for this method, so that a frequency deviation between 50 and 100 MHz should preferably be used, which is varied linearly over 500 nsec. At a distance 18 of, for example, 25 m between the vehicle 10 and the object 17, the received signal is delayed by 165 nsec compared to the transmitted signal. As previously described, the transmitted signal has a frequency deviation of 50 MHz / 500 nsec = 100 kHz / nsec due to the modulation. With a signal delay of the received signal of 165 nsec, the received signal has a frequency 16.5 MHz lower than the transmitted signal. By mixing the transmitted signal with the received signal, a frequency of 16.5 MHz is obtained at the example distance of 25 m. Generally speaking, this mixing results in a frequency of 0.66 MHz per meter of distance.

[0048] When measuring distance using the frequency-modulated continuous wave method, the transmitted signal and the received signal can also be correlated with each other in order to determine the distance to the object 17 based on a correlation signal thus generated. For this purpose, the modulated signal that was transmitted is correlated with the received signal with a time shift. This results in a correlation maximum at the shift time, which is proportional to the distance 18 of the object 17. Since essentially noisy signals are evaluated, the height of the correlation maximum is a measure of the signal strength, so that different objects 17 can be distinguished. The distance resolution can be determined, for example, by the sampling frequency of the received signal. Several correlation coefficients can be generated to generate the correlation signal.Each of the multiple correlation coefficients is assigned a respective shift time. Each correlation coefficient is formed by correlating the modulated signal, shifted by the respectively assigned shift time, with the received signal. The distance to the object is determined depending on the multiple correlation coefficients, for example, by determining an absolute or local maximum, and the assigned shift times. It is advantageous to utilize a high signal significance in the time domain by using the continuously modulated FMCW signal, which contains many independent frequencies. To achieve a high sampling rate of the received signal, a one-bit conversion, for example, can be advantageous.To generate the binary received signal, the received signal can be generated with a first signal value when the level of the received light falls below a certain intensity, and a received signal with a second signal value can be generated when the level of the received light reaches or exceeds the certain intensity. For this purpose, an amplitude-limiting amplifier can be used, for example, which generates a received signal with unique levels, for example, a binary sequence of zeros and ones, depending on the received light. Since the significance lies in time, hardly any information is lost through this binary conversion, since the significance in the amplitude can be unreliable due to the expected amplitude modulation by the object 17. By reducing the received signal to binary signals, a corresponding correlator can be relatively simple in design and suitable for processing long sequences.This improves the correlation result. If the received signal is digital or binary, it is advantageous for the comparison pattern of the modulated transmitted signal to also be digital. This can be achieved, for example, by using a synthesized digital signal to modulate the light source. This can be generated with consistent quality and only dependent on a transmission clock. If the receive clock is the same as the transmit clock, errors that occur, for example due to temperature drift, can be compensated for. By using the correlation method, long signal sequences can be used. The usable frequency deviation is thus not limited to the signal propagation time for the distance to be measured. As previously described, the method can be implemented purely digitally and is therefore cost-effective.For example, a modulated signal with a length of 50 µsec - 500 µsec can be transmitted, and over this time the frequency can be increased from 10 MHz to 100 MHz. Such a modulated signal can be generated, for example, using a shift register in which a synthetically generated signal is stored. A clock frequency with which the transmitted signal can be clocked out and the received signal clocked in synchronously can be 1 GHz, for example, and is therefore relatively easy to implement. The measurement time of 50 µsec - 500 µsec is so fast for most driver assistance system applications that multiplexing methods are also possible with multi-channel sensors. Furthermore, multiple measurements can be performed and averaged to further improve signal quality.

[0049] The modulated signal used to control light source 11 can also be generated using a random frequency modulation method. A transmission frequency from a frequency band is randomly varied over a specific time period. This method is also referred to as Random Frequency Modulation (RFM). The previously described correlation method can be used in a comparable manner to determine the distance to object 17. The random frequency modulation method offers very high immunity to interference, for example, against scattered light and other measurement methods. Furthermore, multiple measurement channels can be measured simultaneously, since corresponding crosstalk from other measurement channels is suppressed by the correlation analysis. The modulation frequencies and the duration of the transmission signal can be selected in a comparable manner to those of the frequency-modulated continuous wave method.The random frequency modulation method can therefore be used in particular when several light sources illuminate a scene or a room simultaneously and measurements are to be taken with all of them at the same time. For example, measurements can be carried out with all headlights of the vehicle 10 simultaneously using the random frequency modulation method. Each light source is given its own significant signature, which can then be differentiated using the correlation method. Furthermore, data encoded in the modulation signal can be transmitted to other vehicles or receivers at the roadside at the same time. For continuous distance measurement, continuous control of the light source 11 is required, so this method is particularly suitable for light sources that are permanently switched on, such as daytime running lights or headlights when driving at night.The previously described frequency-modulated continuous wave method and the previously described random frequency modulation method can also be used in combination. For example, due to the better signal quality, the frequency-modulated continuous wave method can be used first. If interference is detected, such as light sources from other vehicles, the system can switch to the random frequency modulation method. Likewise, the system can switch, at least temporarily, to the random frequency modulation method if data transmission is required. The light source 11 and the sensor 12 can be used equally well for the frequency-modulated continuous wave method and the random frequency modulation method.

[0050] In the method for determining the distance to the object 17, a single-frequency modulation method can also be used to generate the modulated signal for controlling the light source 11. The single-frequency modulation method uses a constant modulation frequency and is therefore particularly simple to implement. In contrast, however, it can be relatively easily disrupted by fog, spray, dust or external light sources and can therefore be used in particular in applications where such disruptions cannot occur, for example due to the installation location, or where a temporary failure can be tolerated, such as in distance measurement in the interior or in parking aids where measuring too close has no negative consequences and the low speed of the vehicle means the necessary distances are small or spray development is insignificant.For continuous distance measurement, the single-frequency method also requires a permanently active light source, so that the single-frequency method can preferably be used in conjunction with, for example, daytime running lights or the vehicle's low beam headlights. A distance determination, i.e. an evaluation of the single-frequency modulation method, can be traced back to a phase measurement, which determines a phase difference between the modulated signal and the received signal. For example, the phase measurement can be carried out by comparing the received signal with the modulated signal digitally using an AND operation. Suitable typical modulation frequencies are, for example, in the range of 5-20 MHz. In this range, the unambiguousness of the phase evaluation based on the single-frequency modulation can be ensured.

[0051] Finally, a pulse modulation method can be used to generate the modulated signal for controlling the light source 11. This pulse modulation method can be used, in particular, even when the light source 11 is switched off. The short light pulses of the pulse modulation method can be designed so that they are invisible or barely visible to the observer. When a light source is switched on, the pulse modulation method can also be used by configuring the light source for the pulse duration, or in other words, by generating "negative" light pulses. The pulse modulation method is therefore particularly suitable where measurements are to be taken at a low measurement frequency of, for example, 10 to 100 Hz, and the light used for measurement should not be visible.Light sources, such as a low beam, a turn signal, a tail light, a brake light, or a reversing light, which are not switched on at the time of measurement, can be switched on with short pulses with a length of, for example, 10 to 100 nsec, which are not noticed by a human observer due to the low average power. When the light sources are switched on, the light can be switched off for a short period of time, for example, 10 to 100 nsec, creating a negative light pulse that can also be detected by the sensor 12. The distance 18 to the object 17 can be determined using the pulse modulation method, for example, using the correlation method described above. In particular, a pulse modulation can be used which consists of a pulse sequence that has a high temporal significance over non-uniform pulse intervals.The received signal generated as a function of the received light can in turn be correlated with the modulated signal, or alternatively, a mathematical description of the pulse can serve as a correlation pattern for the pulse modulation. The received signal can be sampled across the measurement distance. Using an oversampling method, several such echograms can be recorded and summed as a distance histogram. Pulse analysis can then be used to detect echo pulses and, for example, to determine a precise distance 18 using a center of gravity measurement. The method is suitable for both positive and negative pulses.

[0052] As already mentioned in connection with the frequency-modulated continuous wave method, in addition to the distance 18 to the object 17, a speed of the object 17 can also be determined. This will be explained below with reference to Fig. 3 be described in detail. Fig. 3 shows a method 30 for determining a speed of the object 17. In step 31, the light source 11 of the vehicle 10 is controlled with a frequency-modulated signal. In step 32, the reflected light 16 emitted by the light source 11 and reflected by the object 17 in the surroundings of the vehicle 11 is received. In step 33, a received signal is generated as a function of the received light 16. In step 34, a difference frequency between a frequency of the frequency-modulated signal with which the light source 11 was controlled and a frequency of the received signal is determined by mixing the two signals. On the basis of the mixed signal, i.e., as a function of the difference frequency, speed information of the object 17 is determined in step 35.The frequency-modulated signal can be generated, in particular, according to the previously described frequency-modulated continuous-wave method, in which the modulation frequency of the frequency-modulated signal is changed from an initial frequency to a final frequency over a specific time period. As previously described, distance information about the object 17 can also be determined depending on the received signal and the frequency of the frequency-modulated signal, for example, by mixing the signals or correlating the signals. The frequency of the frequency-modulated signal is preferably in a range of 10 to 200 MHz.

[0053] The method will be described in detail below using a frequency-modulated continuous wave (FMCW) modulation as an example. With FMCW modulation, a continuous frequency sweep of, for example, 10 MHz to 100 MHz is modulated in 40 microseconds. A distance of 200 meters between vehicle 10 and object 17 results in a shift of 1.32 µs or 2.97 MHz. A relative velocity of v results in a further mixing sequence according to the Doppler formula: f = c c + ν ⋅ f 0 where f is the modulation frequency, f 0 is the frequency of the received signal, and c is the speed of light. The following table shows the Doppler frequency shift for different object velocities.

[0054] The table shows that the Doppler frequency depends on the modulation frequency. A higher modulation frequency also leads to a higher Doppler frequency. The FMCW modulation can therefore be modified, for example, so that the frequency is modulated from 10 MHz to 100 MHz in 20 µs, and then the frequency is held at 100 MHz for a further 20 µs. The Doppler frequency can then be measured at 100 MHz, for example. The Doppler frequency can be determined directly, for example, by mixing the transmitted frequency with the received frequency. For practical reasons, however, the Doppler frequency can alternatively be determined by mixing the received signal with another signal whose frequency differs from the frequency of the frequency-modulated transmitted signal by a predetermined value.For example, the received signal can be compared or mixed with a signal that has a frequency 100 kHz lower than the frequency-modulated transmitted signal. This results in Doppler frequencies between 100,000 and 100,024 Hz for speeds between 0 and 260 km / h in the example shown in the table. These significantly higher frequencies are easier to measure and can be generated within a measurement time of, for example, 20 µs.

[0055] As previously described, the light source 11 of the vehicle 10 is to be modulated, for example, in a frequency range of 10 MHz to 100 MHz. Light-emitting diode light sources that use semiconductor light-emitting diodes to generate the light 15 are particularly suitable for this purpose. In particular, light-emitting diodes that generate ultraviolet or blue light have such a wide modulation bandwidth. For color conversion into white light or other colored light components, such as red or green light, these light-emitting diodes can additionally have phosphor coatings that convert ultraviolet light or blue light into other colored light. The high-frequency light for distance measurement or speed measurement is, in particular, the blue light of the light-emitting diodes. The currents through the light-emitting diodes are in the range of several amperes in order to achieve corresponding illumination ranges.To achieve efficient modulation, the LED control system must be designed accordingly. Fig. 4 shows a light-emitting diode light source 40, which is also referred to as a modulation circuit and which has a corresponding design. The light-emitting diode light source 40 comprises a light-emitting diode 41, a switching element 42, and an energy storage element 43. The light-emitting diode 41 can, as previously described, preferably comprise a light-emitting diode that generates blue light or at least has a blue light component. The switching element 42 can, for example, comprise a transistor, in particular a field-effect transistor. The energy storage element can, for example, comprise a capacitor. The switching element 42 is controlled by a modulated signal 44. A power supply comprises a ground connection (GND) 45 and a power supply connection (Vcc) 46.When the switching element 42 switches on due to control by the modulated signal 44, a current flows from the supply voltage connection 46 through the LED 41 to the ground connection 45 and, in addition, a further current of a charge stored in the energy storage element 43 flows from a first connection 47 through the switching element 42 and the LED 41 to a second connection 48 of the energy storage element 43. Due to the high switching frequencies, a design with the shortest possible lines, particularly between the elements 41, 42 and 43, is desirable so that the inductance of the lines is as low as possible and thus losses, susceptibility to interference and, in particular, radiated interference are as low as possible. When the switching element 42 is off, the energy storage element 43 is charged by the supply voltage 46 and the ground connection 45.When the switching element 42 is switched on, the energy storage element provides a very large current through the LED 41 for a short period of time. Therefore, the connections between the energy storage element 43, the switching element 42, and the LED 41, in particular, should be kept as short as possible. If the lines in the circuit comprising the LED 41, switch 42, and energy storage element 43 become too long, they represent an inductance that "resists" any current change. This requires a very high voltage to generate modulation, which represents a rapid current change. Even a few millimeters of line length can have a significant impact. The energy stored in the lines during modulation is partially absorbed in the lines and converted into heat, while another portion is radiated as interference.For example, to generate 10 W of light with the LED 41, a current of approximately 10 amperes is required through the LED 41. If the light pulse is to be 50 nsec long, for example, approximately 200 volts are required for a wired structure in which the LED 41, the switching element 42 and the capacitor 43 are arranged as separate elements on a printed circuit. Accordingly, an energy requirement of 200 V x 10 A x 50 nsec = 0.1 mJ is required. For a structure using SMD technology, for example, 60 V and 10 A are necessary, ie, an energy requirement of 30 µJ. In an optimized structure, which is described below in conjunction with . Fig. 5 However, as will be shown, only 8 V and 10 A are required, i.e., an energy consumption of 4 µJ. In all cases, approximately 40 W are absorbed in the light-emitting diode 41. Thus, the efficiency in the optimized design is 50%, in the SMD design approximately 6%, and in the wired design on a printed circuit board, the efficiency is only 2%.

[0056] Fig. 5 shows the optimized design of the LED light source 40. The LED light source 40 comprises the LED 41, the switching element 42, and the energy storage element 43. The switching element 42 is coupled in series with the LED 41. The energy storage element 43 is coupled in parallel to the series connection of the LED 41 and the switching element 42. When the switching element 42 switches on, a current path is switched through the LED 41, which runs from a first terminal 47 of the energy storage element 43 via a first line section 50 to the switching element 42 and from there via a second line section 51 to the LED 41. The current path runs via a third line section 52 to the second terminal 48 of the energy storage element 43. As in the Fig. 5 As shown, the elements 41, 42 and 43 are arranged in a common housing 54. In other words, the semiconductor elements 41 and 42 as well as the capacitor 43 are accommodated in the common housing 54 without their own housing. This allows the lengths of the connections 50 to 52 to be designed correspondingly short. For example, the entire current path connecting the energy storage element 43, the light-emitting diode 41 and the switching element 42 can have a length of less than 12 mm. Preferably, the length of the current path is shorter than 9 mm. Each of the connections 50, 51 and 52 can be, for example, 1 to 3 mm. The connections 50 to 52, together with the connections 44 to 46, can form a so-called leadframe, which on the one hand provides the external connections 44 to 46 of the light-emitting diode light source 40 and on the other hand provides the connections 50 to 52 for coupling the elements 41 to 43.Due to the short connection lengths of the connections 50 to 52, a high efficiency of the LED light source 40 can be achieved. Several LED light sources can be realized in the housing 54 by arranging several LEDs 41, switching elements 42, and energy storage devices 43 on a common leadframe in the common housing 54. The LED 41 can generate light with a wavelength of less than 760 nm, preferably less than 500 nm, i.e., in particular, blue light. Furthermore, a phosphor coating can be provided in the housing 54, which converts ultraviolet light or blue light generated by the LED 41 into light of a different color.The light-emitting diode light source 40 or several of the light-emitting diode light sources 40 can be used in a lighting device 11 of the vehicle 10, for example to illuminate an environment of the vehicle 10 or to generate a light signal, such as a turn signal or a brake light.

[0057] In the methods and devices described above, existing lighting devices of the vehicle, such as low beam headlights, fog lights, turn signals, brake lights, or reversing lights, were used to generate a modulated light signal that is reflected by an object in the vehicle's surroundings and received by a sensor on the vehicle. From the received signal of the sensor and the knowledge of the modulated signal with which the vehicle's lighting device was controlled, a distance or speed of the object can be determined. Since the primary function of the lighting device is to illuminate the vehicle's surroundings or to emit a light signal, such as a turn signal or a brake signal, a method 60 will be described below that simultaneously ensures the determination of distance information.For this purpose, an operating state of the vehicle is first detected in step 61. The operating state of the vehicle can, for example, be a target state for the vehicle's lighting device, which indicates whether the lighting device should be switched on or off. Detecting the operating state can further comprise determining an ambient brightness in an environment or within the vehicle or determining a distance measuring range for which the distance information is to be determined. Depending on the operating state thus determined, a modulated transmission signal is generated in step 62. For example, a first modulated transmission signal can be generated if the target state for the lighting device indicates that the lighting device should be switched on.Furthermore, a second modulated transmission signal can be generated, which is inverted to the first modulated transmission signal, if the target state indicates that the lighting device should be switched off. For example, when the lighting device is switched off, a modulated transmission signal can be generated which comprises short light pulses whose energy is insufficient to be seen by an observer. Conversely, if the lighting device should be switched on, a modulated transmission signal can be generated which switches the lighting device off for short pulses that are so short that they are not noticed by an observer, thus making the lighting device appear to be continuously switched on. In step 63, the lighting device 11 of the vehicle 10 is controlled with the generated transmission signal.In step 64, reflected light 16 is received, which was emitted as light 15 by the illumination device 11 and reflected by the object 17. Depending on the received light 16, a received signal is generated in step 65. In step 66, the received signal is combined with the transmitted signal, and in step 67, the distance to the object 17 is determined from the combination.

[0058] The amount of light that cannot be seen by an observer depends, among other things, on the overall brightness of the vehicle's surroundings and the contrast in the transmission plane. During the day, considerably larger amounts of light can be emitted by the lighting device, which go unnoticed by an observer, than at night. Typically, the signal-to-noise ratio is considerably worse during the day due to the sun's stray light, so that higher transmission powers are necessary during the day than at night. During the day, for example, powers of up to 2 mJ can be emitted, which go unnoticed by an observer. The method can therefore be used to set an average power of the modulated signal depending on the operating state, in particular ambient brightness. Furthermore, the transmission energy can be set depending on a distance measuring range for which the distance measuring information is to be determined.This depends, for example, on the requirements of an application that uses the distance information. A driver assistance system for adaptive cruise control or a collision avoidance system may require a larger distance measuring range than a parking system.

[0059] The modulated transmission signal can, for example, comprise a pulse-modulated signal. The pulse-modulated signal can have a pulse duration in the range of 1 to 500 ns, preferably 10 to 100 ns. The frequency at which the pulses of the pulse-modulated signal are repeated can be in the range of 1 to 1,000 Hz, preferably 10 to 100 Hz.

[0060] The vehicle's lighting system can, for example, comprise the previously described LED light source or multiple LEDs. With white LEDs, the primary blue light component can be used as the modulation carrier. This is modulated at high frequency with the modulated transmission signal and remains in the spectrum of the white LED. The phosphor of the LED cannot follow the rapid modulations because it is generally sluggish. This creates a uniformly bright light that is white to the human eye, while the blue component exhibits the desired modulation.

[0061] Depending on the operating state of the vehicle and the modulated transmission signal, another lighting device of the vehicle can be controlled. For example, the vehicle 10 is traveling on a country road and a driver assistance system, such as adaptive cruise control, is switched on. The headlights of the vehicle are switched off. Therefore, a modulated transmission signal is generated which comprises short-term light pulses. This can be used to provide distance information to an object in front of the vehicle for the adaptive cruise control system. Switching on a driving light of the vehicle is therefore not necessary, i.e. not all of the energy needs to be made available for all of the LED bulbs of the vehicle's headlights, which can be particularly advantageous for an electric vehicle. The adaptive cruise control system in particular requires a large measuring range.If, as previously described, the headlights are switched off during the day, the high beam can be used with high energy to emit measurement pulses that have a long range. If, however, the vehicle is driving in the dark, the high beam is modulated by briefly reducing its brightness to enable a long measurement range. However, if an oncoming vehicle is approaching in the dark, the high beam cannot be operated to avoid dazzling the driver of the oncoming vehicle. In this case, the LEDs of the low beam can be modulated by briefly reducing their brightness to determine distance information. At the same time, the LEDs of the high beam can be modulated with short pulses to determine distance information without dazzling oncoming traffic.In other words, some LEDs are briefly switched on (in this case, the LEDs for the off high beam) and others are briefly switched off (in this case, the LEDs for the low beam). This allows for a long measuring range without the high beam LEDs dazzling or disturbing oncoming vehicles.

[0062] In the methods and devices described above, a distance of the object 17 or a speed of the object 17 was determined using a lighting device 11 already present on the vehicle 10, such as a low beam, a daytime running light, or a high beam of the vehicle 10. The following describes how, using the methods described above, additional position information, i.e., additional directional information, of the object 17 with respect to the vehicle 10 can be determined.

[0063] According to one embodiment, the sensor 12 of the vehicle 10 comprises at least two first sensors for receiving light generated by the vehicle's light source 11 and reflected from a scene including the object 17 in the vehicle's surroundings. Each of the at least two first sensors is assigned a respective first detection area of ​​the scene. The first detection areas are arranged in a row in a first direction. Fig. 7 shows 15 first detection areas, which are assigned to 15 first sensors. The 15 first detection areas are arranged in a horizontal direction. Two of the 15 first detection areas are designated by reference numerals 71 and 72. The sensor 12 further comprises at least two second sensors for receiving light reflected from the scene, wherein each of the at least two second sensors is assigned a respective second detection area of ​​the scene. The second detection areas are arranged in a row in a second direction. The second direction is different from the first direction. In Fig. 8 Two second detection areas 81 and 82 are shown, which are arranged in a row in a vertical direction. In addition, further detection areas are shown in Fig. 8 which are also arranged in pairs in a row in the vertical direction, for example the two third detection areas 83 and 84. The processing unit 13 is designed to determine a position of the object 17 in the surroundings of the vehicle 10 depending on signals from the first and second sensors. One of the first detection areas, for example the area 71, is partially superimposed on one of the second detection areas, for example the area 81. One of the first detection areas, i.e. the area 71, can additionally be partially superimposed on another of the second detection areas, for example the area 82, as shown in Fig. 9 is shown. The third detection areas 83, 84, which are monitored by corresponding third sensors, can be arranged such that one of the first detection areas, for example the detection area 71, is partially superimposed on one of the second detection areas, for example the area 81, on another of the second detection areas, for example the area 82, on one of the third detection areas, for example the area 83, and on another of the third detection areas, for example the area 84.

[0064] The position determination of the object 17 using the superimposed detection areas, as described above, will be described in detail below. In comparison, it should be noted that with non-superimposed detection areas, with, for example, five detection areas, only five different position areas for the object 17 can be distinguished. By superimposing the detection areas, as described in Fig. 9 However, as shown, eight different position ranges for the object 17 can be distinguished using the detection ranges 71 and 81-84. If only the sensor assigned to one of the detection ranges 81-84 detects the object 17, the object 17 is located in a range that is assigned to the corresponding sensor and which does not overlap the range assigned to the sensor 71. Thus, four different ranges for the object 17 can already be distinguished. If the object 17 is detected in one of the ranges 81-84 and additionally in the range 71, the object 17 must be located in one of the four overlap ranges, which result from the overlap of the range 81 with the range 71, the range 82 with the range 71, the range 83 with the range 71 or the range 84 with the range 71. As a result, four further position ranges for the object 17 can be distinguished.If the sensors are arranged in such a way that the . Fig. 7 und 8 The detection areas shown can be monitored separately, can be monitored by the Fig. 9 The superposition shown can be achieved by using the required 15 first sensors for the areas of Fig. 7 and the 16 sensors for the areas of Fig. 8 A total of 56 different areas can be realized in which object 17 can be detected separately.

[0065] The second detection areas can, in turn, additionally overlap in the vertical direction and additionally overlap in the horizontal direction with further detection areas, for example, the third overlap areas 83, 84. This can be achieved, for example, by a so-called "blurring" of the associated sensors. Fig. 10 shows the previously described overlap of the second, third and further detection areas. In combination with the first detection areas of the Fig. 7 Thus, a variety of different areas can be provided for determining the position of the object 17, as shown in Fig. 11 By overlapping the first detection areas, the resolution of the position determination of the object 17 can be further increased, but for reasons of clarity this is not shown in Fig. 11 is not shown. The Fig. 9 and 11 further show that, particularly in the center, i.e., in the area where the horizontally and vertically arranged detection areas overlap, a particularly high resolution can be achieved for determining the position of the object 17. This can be advantageously used for many driver assistance systems of a vehicle, since a high resolution is particularly advantageous when the vehicle is traveling straight ahead, while a lower resolution in the peripheral area can generally be tolerated.

[0066] The coverage areas of the Fig. 7-11 are perpendicular to the measuring direction, ie perpendicular to arrow 16 of the Fig. 1 .

[0067] In connection with the Fig. 12-14 a further possibility is presented for determining position information of the object 17 in relation to the vehicle 10.

[0068] The lighting device 11 of the vehicle 10 has at least a first light source and a second light source. The first and second light sources can be controlled independently of one another. The first light source is designed to illuminate a first illumination area of ​​a scene in an environment or within the vehicle 10. The second light source is designed to illuminate a second illumination area of ​​the scene. The first illumination area is different from the second illumination area. Fig. 12 Several illumination areas 121-127 are shown. For example, the first illumination area can be area 121 and the second illumination area can be area 122. The sensor 12 comprises at least a first sensor and a second sensor for receiving light reflected from the scene. A first detection area of ​​the scene is assigned to the first sensor, and a second detection area of ​​the scene is assigned to the second sensor. The first detection area is different from the second detection area. Fig. 13 Six detection areas 131-136 are shown. The first detection area can be, for example, area 131 and the second detection area can be, for example, area 132. The processing unit 13 controls the first and second light sources and, if appropriate, further light sources to generate the illumination areas 123-127 and determines a position of the object 17 in the surroundings of the vehicle 10 depending on signals from the first and second sensors and, if appropriate, further sensors which are assigned to the detection areas 133-136, and depending on the control of the light sources. The areas 121-127 and 131-136 lie, for example, in the plane of the arrows 15 and 16 of the Fig. 1 .

[0069] The detection areas can, for example, be arranged aligned with the illumination areas, ie the detection area 131 corresponds substantially to the illumination area 121, the detection area 132 corresponds substantially to the illumination area 122, etc. Each of the detection areas can have a predetermined angular range, for example 10° or, as in the Figuren 12 und 13 shown, 20°. The segments formed in this way can be scanned one after the other using a so-called time-division multiplexing method. Since the distance measuring methods described above, in particular the frequency-modulated continuous wave method or random frequency modulation method, allow distance measurements within a segment to be carried out within a very short time, for example within 50 µsec, the entire angular range covered by the segments can be scanned in a very short time. If, for example, an angular range of 120° is to be scanned in 10° segments, the entire angular range can be scanned in 600 µsec with a measuring time of 50 µsec per segment. Even with a longer measuring time of 500 µsec, the entire angular range of 120° can be scanned in 6 ms.Typical applications of driver assistance systems require measurement times in the range of 30 ms–50 ms, allowing for sufficiently fast sampling. The sampling resolution can be improved by using segments that overlap halfway rather than equipping each angle segment with a corresponding transmitter and receiver. Fig. 14 shows such an overlap of the illumination areas 121-127 with the detection areas 131-136. Both the illumination areas and the detection areas each cover an angular range of 20°. The offset overlap of the illumination areas 121-127 with the detection areas 131-136 results in twelve 10° segments, which can be scanned with seven light sources and six sensors. The segments can be arranged side by side, since a time-division multiplexing method is used, meaning crosstalk from one segment to a neighboring segment is not relevant. Only one pair of transmitter and receiver is operated at a time, so that it is clearly possible to determine in which segment a signal occurs. In other words, the first detection area 131 covers a partial area of ​​the first illumination area 121 and a partial area of ​​the second illumination area 122.The second detection area 132 comprises a further sub-area of ​​the second illumination area 122. The second detection area 132 is separate from the first illumination area 121.

[0070] From the previously linked to the Figuren 12-14 With the arrangement of illumination areas and detection areas described above, additional information for estimating visibility can be obtained if detection areas that are not assigned to a lighting area at all are evaluated simultaneously. For example, for a distance measurement, the light source for illumination area 121 and the sensor for detection area 131 are operated. This results in a measuring segment in the overlap area between illumination area 121 and measurement area 131. At the same time, or in a time-division multiplex process, a sensor assigned to detection area 136 is queried. If this sensor also reports a distance signal based on the light emitted for illumination area 121, this can only arise from secondary scattered light.If, as here, signals occur in distant illumination areas and detection areas, it is due to very thick fog, for example. If the segments are closer together, for example, if detection area 133 provides a distance signal, measurable secondary scattering occurs even at lower particle densities. By evaluating areas at different distances, the fog can be assessed very accurately. From this, the current visibility can be estimated.

[0071] For segmented illumination of the surroundings of vehicle 10, as previously described, multiple light sources are required. For this purpose, for example, multiple light-emitting diodes from, for example, a low beam or, in particular, from a daytime running light having a linear structure can be used. To achieve a uniform appearance, particularly with linear daytime running lights, spaced-apart light-emitting diodes in the daytime running light can be connected together in groups and illuminate a respective illumination area. Intermediate light-emitting diodes can illuminate further illumination areas. In other words, for example, the first light source used to generate the illumination area 121 can comprise at least a first light-emitting diode and a second light-emitting diode.A second light source, which illuminates the illumination area 122, can also comprise at least one light-emitting diode or a plurality of light-emitting diodes. The first and second light-emitting diodes of the first light source and the light-emitting diode of the second light source are arranged in a row, with the light-emitting diode of the second light source being arranged between the first and second light-emitting diodes of the first light source. Since the brightness of the light-emitting diodes can vary during distance measurement, this offset arrangement can ensure that these differences in brightness are not perceived by an observer. Alternatively, however, it can also be used to create an interesting design effect if the differences in brightness are visible to an observer.

[0072] Fig. 15 shows a near field of illumination areas due to a staggered arrangement of LEDs. A light strip 151 comprises 21 LEDs. The light strip 151 can, for example, be a light strip of a daytime running light and have a length of, for example, 42 cm. The light strip 151 illuminates seven illumination areas or segments, each with an angle of 20°. Each segment is generated by three LEDs spaced 14 cm apart. Fig. 15 The segments illuminated by the individual LEDs are shown. The far field of the segments generated by the LEDs of the light strip 151 is shown in Fig. 16 Here, the approximately 20° illumination areas 121-127 are clearly visible.

[0073] Various vehicle assistance systems may require image information of the vehicle's surroundings, providing a high-resolution image of a scene in front of the vehicle from the vehicle's perspective. Each area or pixel of the image information is assigned a corresponding distance value to an object in that area. This image information may be necessary, for example, to detect obstacles above or below a certain area, such as obstacles on the roadway such as speed bumps that cannot be crossed. Fig. 17 shows a method 170 for determining such distance information. In step 171, the scene in the surroundings of the vehicle is illuminated. The method 170 can be used not only outside the vehicle, but also inside the vehicle, for example to recognize gestures of a driver. The light reflected from the scene is received by the sensor 12 of the vehicle 10. In step 172, a plurality of first distance histograms are determined as a function of the received light. A respective first distance histogram of the plurality of first distance histograms is assigned a respective first strip-shaped region of the scene. The first distance histogram comprises an intensity of reflections in a distance range by objects in the assigned first strip-shaped region. In step 173, a plurality of second distance histograms are determined as a function of the received light.A respective second distance histogram of the plurality of second distance histograms is assigned a respective second strip-shaped region of the scene. The second distance histogram comprises a strength of reflections in a distance range by objects in the assigned second strip-shaped region. In step 174, a distance is determined for a region of the scene as a function of the plurality of first distance histograms and the plurality of second distance histograms. The region of the scene comprises an intersection region of one of the first strip-shaped regions with one of the second strip-shaped regions. The first strip-shaped regions are preferably parallel to one another along their longitudinal direction, and the second strip-shaped regions are preferably parallel to one another along their longitudinal direction.The longitudinal direction of the first strip-shaped regions is preferably perpendicular to the longitudinal direction of the second strip-shaped regions. The first strip-shaped regions can comprise rows of the scene in front of the vehicle or inside the vehicle, and the second strip-shaped regions can comprise columns of the scene. To determine the plurality of first distance histograms and the plurality of second distance histograms, the sensor 12 can comprise a receiver matrix in which rows and columns can be selectively interconnected, such that a received signal is generated either from the sum of all elements in a column or from the sum of all elements in a row. All rows and columns can then be measured individually.The distance measurements can be performed, for example, using one of the previously described methods by appropriately modulating the vehicle's light source and correlating or mixing the received signal from one of the rows or columns with the transmitted signal for the lighting device 11. The receiver matrix can, for example, have 300 rows and 700 columns, i.e., a total of 1,000 rows and columns. With a measurement time per row or column of, for example, 50 µsec, these 1,000 measurements can be performed in 50 ms, whereby, according to the explanations below, at least partially and preferably completely simultaneous measurement of all rows and columns is provided in the present case.

[0074] A distance-resolved echogram, a so-called distance histogram, is now available for each row or column. This can be processed into a pixel-resolved image using a process similar to that used in a CT scanner. To reduce processing effort, a specific region of interest can be selected using the same process. The corresponding receiver elements of the receiver matrix are interconnected for this region, and only this region is observed and evaluated.

[0075] Switching between different areas to be evaluated is possible dynamically and can thus be adapted to different driving situations.

[0076] The procedure described above is described below with reference to the Fig. 18 bis 20 be described using an example. Fig. 18 shows a scene in the surroundings of the vehicle. A vehicle 182 is located on a roadway 181. The scene is divided into a plurality of areas in a matrix. In the Fig. 18 In the example shown, the scene is divided into 14 rows and 19 columns, resulting in a total of 266 areas. This small number of rows and columns has been omitted for clarity in the Fig. 18 bis 20 Practical implementations may, for example, have at least 100 rows and at least 200 columns, preferably 300 rows and 700 columns. The sensor 12 therefore preferably comprises a sensor matrix with a corresponding row and column resolution. The lighting device 11 of the vehicle 10 illuminates the Fig. 18 The scene is preferably illuminated with an LED light source, and the analysis is performed using one of the previously described modulation methods, such as the frequency-modulated continuous wave method, the random frequency modulation method, the single-frequency modulation method, or the pulse modulation method. By connecting the receiver matrix in rows or columns, range-resolved echograms are generated for the rows and columns.

[0077] Fig. 19 shows corresponding distance-resolved echograms for the 14 lines of the scene of the Fig. 18 The echogram for the fifth line from the bottom of the scene of Fig. 18 will be described in detail below. The echogram for this fifth line is shown in Fig. 19 marked with the reference number 191. As can be seen from Fig. 19 As can be seen, the echogram shows an increased signal level in the range from 60 to 110 meters. Conversely, in the range from 10 to 60 meters and in the range from 110 to 150 meters, there is essentially no signal level. This means that there is at least one object in the fifth column in the range from 60 to 110 m. However, there may be several objects in this range. Where the object is located in the horizontal direction, i.e. in which column area the object is located, can be determined from the echogram. Fig. 19 not apparent.

[0078] Fig. 20 shows corresponding echograms for the 19 columns of the scenes of the Fig. 18 . In this context, for example, column 6 from the left shows the Fig. 18 which are in the Fig. 20 is marked with reference numeral 201. The echogram 201 of the sixth column indicates that one or more objects are located within a range of 60 to 110 meters. The echogram of the columns, in turn, contains no information about the distribution of the objects within the column.

[0079] From the totality of the echograms, for each of the 266 individual areas of the scene, the Fig. 18 Corresponding distance information to objects in the scene can be determined. Area-specific information can be obtained, for example, using a two-dimensional Fourier transform from the distance-resolved echograms of the rows and columns.

[0080] The distance-resolved echograms in the Fig. 19 and 20are dimensionless and can, for example, display a relative size that shows what percentage of the row or column-shaped area represents a respective distance from the vehicle.

[0081] With both pulse modulation and random frequency modulation (RFM), it is possible to encode information into the transmitted signal 15 that can be decoded by a receiver. This information can be used, for example, for communication between vehicles, so-called car-to-car communication, or for communication between the vehicle 10 and an infrastructure object, such as a traffic light or a traffic control system. Fig. 22 shows a method 220 with which digital information can be transmitted simultaneously with a distance measurement. Fig. 21 shows the vehicle 10 as well as another vehicle 210 and an infrastructure object 211. With the Fig. 22 In the method 220 described above, a distance between the vehicles 10 and 210 can be measured simultaneously and information, in particular digital information, can be transmitted to the vehicle 210 or the infrastructure object 211.

[0082] In step 221, a modulated signal is generated as a function of transmission data to be transmitted by the vehicle 10. In step 222, the light source 11 of the vehicle 10 is controlled with the modulated signal. In step 223, light 16, which was emitted as light 15 by the light source 11 and reflected by the vehicle 210 or another object in the surroundings of the vehicle 10, is received. In step 224, a received signal is generated as a function of the received light. The received signal can, for example, comprise an analog electrical signal or a digital signal. In step 225, the received signal is combined with the modulated signal, for example using the correlation method described above, and in step 226, the distance between the vehicle 10 and the vehicle 210 is determined from a combination signal of this combination.The modulation method for generating the modulated signal can, in particular, comprise a random frequency modulation method or a pulse modulation method. In the frequency modulation method, a modulation frequency is changed depending on the transmitted data. In the pulse modulation method, a pulse spacing or pulse length is changed depending on the transmitted data. The modulated signal can also be generated depending on random data.

[0083] The data to be sent by the vehicle 10 is thus transmitted in the modulation of the transmission signal. For example, as in Fig. 21 As shown, a bit sequence 213 can be transmitted from the vehicle 10 to both the preceding vehicle 210 and the infrastructure object 211 using the modulated transmission signal, as shown by the light propagation arrows 15 and 212. Receivers in the vehicle 210 or in the infrastructure object 211 can receive and demodulate the modulated transmission signal, and thus recover and further process the transmission data 213. The encoding of the transmission data 213 into the modulated transmission signal will be described in detail below using a pulse modulation method and a random frequency modulation (RFM) method as examples.

[0084] In the pulse modulation method, light pulses are sent at a pulse repetition rate. This rate is typically long compared to the pulse length of the light pulses. Since a constant pulse repetition rate can be disadvantageous for distance measurement, the spacing between pulses can be varied within a certain range, for example to avoid beat states. To transmit data, for example, this variation in the spacing between pulses can be divided into a static component and a systematic component. For example, pulses with a length of 50 nsec and a pulse repetition rate of 25 kHz, i.e. 40 µsec, can be used. To measure a distance in the range of up to 250 m, for example, a pulse spacing of 250 m x 6.6 nsec / m x 2 = 3.3 µsec should not be exceeded. This makes it possible to vary the pulse spacing between 3.3 µsec and 76 µsec.For a system with a time-of-flight distance measurement and a base timing of 25 snec, there are 2,936 possible variations. Of these, 512 can be used, for example, to transmit 9 bits. Of these, 6 bits can contain the transmitted data, and the remaining 3 bits can be statistically varied. Thus, the interval between pulses fluctuates by 12.8 µsec from 33.6 to 46.6 µsec. Thus, 6 bits of transmitted data can be transmitted every 40 µsec, achieving a net data rate of 150 kbit / sec.

[0085] With random frequency modulation (RFM), for example, frequencies from 10 MHz to 100 MHz can be varied within 40 µs. In a random frequency modulation method without data transmission, several frequencies are randomly selected from this frequency band, which are then modulated one after the other, thus resulting in a frequency sequence that is significant for the measurement. For the transmission of the transmitted data, the frequency selection is no longer random; sondern includes at least a systematic component. For example, frequencies can be synthesized from the 10 to 100 MHz band in frequency steps of 10 kHz. This allows for 9,000 different frequencies. Of these, 512 can be used as significant frequencies, resulting in a frequency spacing of approximately 175 kHz for each piece of information. A typical frequency modulation receiver can easily distinguish frequencies of 50 kHz, so the transmitted information can be easily decoded if a frequency spacing of 50 kHz or more is maintained. This leaves 125 kHz or ± 62.5 kHz for random variation to reduce interference.

[0086] In Figur 23 A schematic section of an exemplary sensor arrangement according to the invention is shown, which carries out a method according to the invention according to one embodiment. A sensor 290 can be seen, which comprises a plurality of individual sensor elements 300, each of which provides measurement signals in the form of an intensity value from received light.

[0087] The sensor elements 300 are arranged in a matrix. Consequently, there is a row and column direction indicated by a coordinate system, with the rows in Fig. 23 labeled Z and columns S. A section of three rows and three columns is shown as an example, although a significantly higher number may be provided (see previous examples). A position of the pixels or sensor elements 300 may be specified via row and column coordinates, as shown in Fig. 23 shown as an example.

[0088] Each row Z and each column S forms a strip-shaped area of ​​the type described herein, so that distance histograms are formed accordingly row-by-row and column-by-column. Furthermore, each sensor element 300 provides a measurement signal that can be read out in both the row and column directions in the manner described below, in particular to form the distance histograms formed row-by-column.

[0089] The sensor elements 300 are constructed similarly. However, the components of the sensor elements 300 explained below are not provided with a separate reference symbol for each sensor element 300.

[0090] Each sensor element 300 comprises a photodetector element 302 in the form of a SiPM 302. The SiPM 302 generates an electrical measurement signal based on the received light or light intensity. The measurement signal is to be considered both row-wise and column-wise for each sensor element 300 (i.e., contribute to the distance histograms formed row-wise and column-wise, respectively). For this purpose, each SiPM 302 is connected to a row line 304-308 and to a column line 310-314.

[0091] The signals present simultaneously on the row lines 304 - 308 and on the column lines 310 - 314 can be used to form the distance histograms row by row and column by column.

[0092] The connection to the row lines 304-308 and to the column lines 310-314 is established via a current mirror 316, which, in addition to the example shown, is formed by a conventional circuit of two semiconductor transistors 318. One of the semiconductor transistors 318 supplies the column lines 310-314, and the other supplies the row lines 304-308.

[0093] This structure represents a simple and reliable variant to enable the desired simultaneous determination of received light for sensor elements 300 in the strip-shaped areas or, more precisely, in the individual rows Z and columns S.

[0094] In Figur 24 A schematic section of a sensor arrangement 290 according to the invention is shown according to a further exemplary embodiment. Sensor elements 300 arranged in a matrix are again shown (not all of them are provided with a corresponding reference numeral), but their internal structure is only indicated very roughly and only in a selected and schematically outlined partial area 319.

[0095] Each sensor element 300 is shown as comprising a plurality of photodetector elements 320, 340, which are grouped together in two groups. More specifically, a first group of photodetector elements 320, shown in light, and a second group of photodetector elements 340, shown in dark, are shown. Each group may comprise, for example, sixteen individual photodetector elements 320, 340. The photodetector elements 320, 340 may be configured in the form of the SPADS discussed above, which are combined to form or comprise one or more SIPMs.

[0096] It can be seen that the photodetector elements 320, 340 of the individual groups are arranged in a checkerboard pattern, so that two consecutive photodetector elements 320, 340 of one group in the column and row directions each sandwich a photodetector element 320, 340 of the other group. The photodetector elements 320, 340 of the individual groups are thus arranged alternately in the column and row directions.

[0097] The photodetector elements 320 of one group provide a measurement signal that is applied to a row line (see row line 304 marked as an example). The photodetector elements 340 of the other group provide a measurement signal that is applied to a column line (see row line 310 marked as an example).

[0098] This ensures that, without additional hardware components in the form of the current mirror or other amplification circuits (which can also be provided optionally), the measurement signal of a sensor element 300 can be read out both row by row and column by column and, in particular, simultaneously.

[0099] Out of Figur 24 It also becomes clear once again that measurements are carried out for each row Z (exemplarily represented as Z 1 of Z m ) and each column S (exemplarily represented as S 1 of S m ) and, in particular, the described column- and row-wise distance histograms are formed.

[0100] Finally, in Figur 24It is also indicated that the sensor arrangement 290 can be divided into a sensor 291, which comprises the sensor elements 300 and thus the units that provide the measurement signals. The column- and row-wise distance histograms, however, can be determined by a processing unit 292, indicated by way of example, whose function has already been explained in connection with the other figures above and which can be designed in a generally similar manner to these figures.

[0101] For the sake of completeness, it should be mentioned that the outermost sensor elements 300 of rows P 1,1 to P n,1 and P 1,m to P n,m as well as columns P n,1 to P n,m and P 1,1 to P 1,m (and optionally also other adjacent rows and columns) are edge regions in which, instead of simultaneous detection or triggering of the corresponding sensor elements 300, sequential detection or triggering could also occur. This is based on the idea that relevant objects will presumably be detected less frequently in these regions than, for example, in a central region of the matrix-shaped sensor element arrangement. List of reference symbols

[0102] 10Vehicle 11Light source 12Optical sensor 13Processing unit 14Driver assistance system 15Light 16Reflected light 17Object 18Distance 20Procedure 21-25Step 30Procedure 31-35Step 40LED light source 41LED 42Switching element 43Energy storage element 44Modulated signal 45Ground connection 46Power supply connection 47First connection 48Second connection 50-52Connections 54Housing 60Procedure 61-67Step 71, 72Detection area 81-84Detection area 121-127Illumination area 131-136Detection area 151Light band 170Procedure 171-174Step 181Roadway 182Vehicle 191Echogram 201Echogram 210Vehicle 211Infrastructure object 212Light processing arrow 213Transmission data 220Procedure 221-226Step 291Sensor 292Processing unit 300Sensor element SSColumns ZRows 302SiPM 320, 340Photodetector element 304-308Row line 310-314Column line 316Current mirror 318Semiconductor transistors 319Subarea

Claims

1. Sensor arrangement (290) for a vehicle (10) for acquiring distance information, comprising: - a sensor (291) which is configured to receive light (16) reflected from a scene in the surrounding region; - a processing unit (292) which is configured to determine a plurality of first distance histograms (191) depending on the received light (16), wherein a particular first distance histogram (191) of the plurality of first distance histograms (191) is assigned a particular first strip-shaped region of the scene, wherein the first distance histogram (191) comprises a strength of reflections in a distance range by objects in the assigned first strip-shaped region; and which is further configured to determine a plurality of second distance histograms (201) depending on the received light (16), wherein a particular second distance histogram (201) of the plurality of second distance histograms (201) is assigned a particular second strip-shaped region of the scene, wherein the second distance histogram (201) comprises a strength of reflections in a distance range by objects in the assigned second strip-shaped region; wherein the distance histograms are distance-resolved echograms; and which is further configured to determine distance information for a region of the scene depending on the plurality of first distance histograms (191) and the plurality of second distance histograms (201), wherein the region of the scene comprises an intersection region of one of the first strip-shaped regions with one of the second strip-shaped regions; wherein the strip-shaped regions of the scene each correspond to strip-shaped regions of the sensor (291), wherein the sensor arrangement (290) is configured to simultaneously determine the light received in a plurality of the corresponding strip-shaped regions, wherein the sensor (291) comprises a sensor matrix with sensor elements (300) arranged in rows (Z) and columns (S), each of which is configured to receive light (16), wherein the rows (Z) correspond to the first strip-shaped regions of the scene and the columns (S) correspond to the second strip-shaped regions of the scene, and wherein at least one of the following variants is further provided: I) at least those sensor elements (300) of which the received light (16) is determined simultaneously each comprise a current mirror arrangement (316) which is connected to a row line (304-308) and to a column line (310-314), to which further current mirror arrangements (316) of other sensor elements (300) are also connected; II) at least those sensor elements (300) of which the received light (16) is determined simultaneously each comprise at least two photodetector elements (320, 340) each receiving light (16), and one of the photodetector elements (320, 340) is connected to a row line (304-308) and the other to a column line (310-314).

2. Sensor arrangement (290) according to claim 1, wherein the sensor (291) is configured to simultaneously determine the light (16) received in at least 50% of the corresponding strip-shaped regions.

3. Sensor arrangement (290) according to claim 1 or 2, wherein the corresponding strip-shaped regions of the sensor (291) are divided into regions in which the light (16) received therein is determined simultaneously, and into regions in which the light (16) received therein is not determined simultaneously.

4. Sensor arrangement (290) according to claim 3, wherein the regions without simultaneous determination of the received light (16) lie at least partially in an edge region of the sensor (291).

5. Sensor arrangement (290) according to any of the preceding claims, wherein the sensor elements (300) in the rows (Z) and columns (S) are each interconnected and the distance histograms are determined from a total signal of correspondingly interconnected sensor elements (300).

6. Sensor arrangement (290) according to alternative II) of claim 1, wherein more than two photodetector elements (320, 340) are provided and these are combined into two groups, wherein the photodetector elements (320, 340) of one group are connected to a row line (304-308) and the photodetector elements (320, 340) of one group are connected to a column line (310-314), and wherein at least two photodetector elements (320, 340) of one group enclose at least one photodetector element (320, 340) of the other group between them.

7. Method for a vehicle (10) for acquiring distance information, comprising: - controlling a light source 11; - receiving, with a sensor (291), light (16) reflected from a scene in the surrounding region; - determining a plurality of first distance histograms (191) depending on the received light (16), wherein a particular first distance histogram (191) of the plurality of first distance histograms (191) is assigned a particular first strip-shaped region of the scene, wherein the first distance histogram (191) comprises a strength of reflections in a distance range by objects in the assigned first strip-shaped region; - determining a plurality of second distance histograms (201) depending on the received light (16), wherein a particular second distance histogram (201) of the plurality of second distance histograms (201) is assigned a particular second strip-shaped region of the scene, wherein the second distance histogram (201) comprises a strength of reflections in a distance range by objects in the assigned second strip-shaped region; wherein the distance histograms are distance-resolved echograms; - determining distance information for a region of the scene depending on the plurality of first distance histograms (191) and the plurality of second distance histograms (201), wherein the region of the scene comprises an intersection region of one of the first strip-shaped regions with one of the second strip-shaped regions; wherein the strip-shaped regions of the scene each correspond to strip-shaped regions of the sensor (291), wherein for a plurality of the corresponding strip-shaped regions the light (16) received therein is determined simultaneously, wherein the sensor (291) comprises a sensor matrix with sensor elements (300) arranged in rows (Z) and columns (S), each of which is configured to receive light (16), wherein the rows (Z) correspond to the first strip-shaped regions of the scene and the columns (S) correspond to the second strip-shaped regions of the scene, and wherein at least one of the following variants is further provided: - at least those sensor elements (300) of which the received light (16) is determined simultaneously each comprise a current mirror arrangement (316) which is connected to a row line (304-308) and to a column line (310-314), to which further current mirror arrangements (316) of other sensor elements (300) are also connected; - at least those sensor elements (300) of which the received light (16) is determined simultaneously each comprise at least two photodetector elements (320, 340) each receiving light (16), and one of the photodetector elements (320, 340) is connected to a row line (304-308) and the other to a column line (310-314).

8. Device for acquiring distance information for a vehicle, comprising: a light source configured to illuminate a scene in a surrounding region or within the vehicle, a sensor arrangement according to any of claims 1 to 6 for receiving light which originates from the light source and has been reflected from the scene, and a processing unit configured to control the light source and to determine a plurality of first distance histograms and a plurality of second distance histograms according to any of claims 1 to 6 depending on the received light.