Transmitting device for a scanning optical detection system of a vehicle, detection system, driver assistance system, method for controlling a beam direction of an optical transmission signal

Abstract

A transmitting device (26) for a scanning optical detection system (12) of a vehicle (10), comprising at least one light source (36) for generating at least one optical transmit signal (32a) and at least one diffractive diffraction unit (38) acting on the at least one transmit signal (32a) for controlling at least one beam direction (40b, 40c) of the at least one transmit signal (32a), characterized in that the at least one diffraction unit (38) is arranged in the beam path of the at least one light source (36) and is adjustable for changing the at least one beam direction (40b, 40c), wherein a far-field opening angle (58), within which a main beam direction (40b) of the diffracted at least one transmit signal (32b) can be moved, defines a far field (62) of the detection system (12) and at least one near-field opening angle (60), within which at least one secondary beam direction (40c) of the bent at least one transmit signal (32c) can be moved,at least one near field (66) of the detection system (12) is specified.

Description

Technical field

[0001] The invention relates to a transmitting device for a scanning optical detection system of a vehicle, with at least one light source for generating at least one optical transmit signal and with at least one diffractive diffraction unit acting on the at least one transmit signal for controlling at least one beam direction of the at least one transmit signal.

[0002] Furthermore, the invention relates to a scanning optical detection system of a vehicle, - with at least one transmitting device, which has at least one light source for generating at least one optical transmit signal and at least one diffractive diffraction unit for controlling at least one beam direction of the at least one transmit signal, - with at least one receiving device for receiving at least one optical receiving signal, which originates from at least one transmitting signal that is reflected by an object in a monitoring area of ​​the detection system, - and with at least one control and / or evaluation device for controlling the at least one transmitting device and / or the at least one receiving device and / or for evaluating received signals received by the at least one receiving device.

[0003] Furthermore, the invention relates to a driver assistance system of a vehicle, - with at least one scanning optical detection system, wherein the at least one detection system - at least one transmitting device, which has at least one light source for generating at least one optical transmit signal and at least one diffractive diffraction unit acting on the at least one transmit signal for controlling at least one beam direction of the at least one transmit signal, - at least one receiving device for receiving at least one optical receiving signal originating from at least one transmitting signal that is reflected by an object in a monitoring area of ​​the detection system, - and at least one control and / or evaluation device for controlling the at least one transmitting device and / or the at least one receiving device and / or for evaluating received signals received by the at least one receiving device, - wherein the driver assistance system includes at least one control and / or evaluation unit for processing object information captured by the at least one detection system.

[0004] Furthermore, the invention relates to a method for controlling at least one beam direction of at least one optical transmission signal of a scanning optical detection system of a vehicle, in which at least one transmission signal is generated and at least one beam direction of the at least one transmission signal is controlled. State of the art

[0005] From US 20160161600 A1, a LIDAR-based system and a method are known which are used for beam shaping and control of laser beams, in which an Optical Phased Array (OPA) Photonic Integrated Circuit (PIC) is used and the detection of laser beams is carried out using photodetectors.

[0006] DE10 2015 105 393 A1 discloses a laser sensor for a motor vehicle with a transmitter for emitting an optical signal and a deflection device with a pivotable mirror element for deflecting the signal at a deflection angle into a monitoring area. A diffractive optical element is arranged in the beam path between the transmitter and the deflection device to split the signal into a plurality of partial beams, the deflection device being designed to deflect the partial beams individually.

[0007] Furthermore, DE 11 2011 103 100 T discloses a lidar imaging device for obtaining a distance representation of a scene. The lidar imaging device comprises a light source for emitting a light beam, a scanning device for scanning the scene with the light beam, and a light sensor for receiving light reflected from the scene. The scanning device includes a spatial light modulator (SLM) configured to display holograms that deflect the light beam in different directions within the scene being imaged.

[0008] US 2016 / 0139266A1 describes a method for imaging a scene that includes the generation of a time-varying optical intensity pattern from at least one continuous wave (CW) light beam.

[0009] Furthermore, US 2008 / 0285010A1 discloses an object detector that projects laser light from a projection part as a detection wave and moves the laser light horizontally and receives reflected waves of the laser light from an object in order to determine the position of the object based on the elapsed time from the time of the projection of the laser light until the reception of its reflection.

[0010] The invention is based on the objective of designing a transmitting device, a detection system, a driver assistance system and a method of the type mentioned above, in which the transmitting energy of the at least one light source can be used as efficiently as possible. Disclosure of the invention

[0011] According to the invention, this problem is solved in the transmitting device by arranging the at least one diffraction unit in the beam path of the at least one light source and being adjustable to change the at least one beam direction, wherein a far-field opening angle, within which a main beam direction of the diffracted at least one transmitted signal can be moved, defines a far field of the detection system and at least one near-field opening angle, within which at least one secondary beam direction of the diffracted at least one transmitted signal can be moved, defines at least one near field of the detection system.

[0012] According to the invention, the at least one transmitted signal emitted by the light source is diffracted by the at least one diffractive diffraction unit. Due to interference, the diffracted at least one transmitted signal propagates in a principal beam direction and at least one secondary beam direction. At a diffraction angle of 0°, the principal beam direction coincides with the secondary beam direction. The transmitted energy of the at least one transmitted signal is thus divided into a principal transmitted signal with the principal beam direction and at least one secondary transmitted signal with the at least one secondary beam direction, with the larger portion of the transmitted energy being emitted in the principal beam direction.

[0013] Advantageously, the main transmit signal and the at least one secondary transmit signal each contain all the information, in particular phases, frequencies, pulse lengths or the like, of the transmit signal originally emitted by the light source.

[0014] In a vehicle detection system, it is important that objects in the vehicle's lane, i.e., in front of the vehicle in the direction of travel, can be detected at greater distances, particularly on the order of several hundred meters. This allows for early intervention to prevent a collision. In areas adjacent to the vehicle's lane, it is sufficient to detect objects at shorter distances, particularly within a few meters. For the purposes of this invention, the lane is defined as the path the vehicle takes while maintaining its direction of travel, depending on its width.

[0015] According to the invention, the monitoring area is divided into a far field and at least one near field. The far field extends over the vehicle's lane. The at least one near field extends over areas adjacent to the vehicle's lane. To detect objects at greater distances in the far field, a correspondingly long range of the transmitted signal is required, which necessitates a correspondingly high signal energy. Due to the shorter distances, comparatively lower signal energies are sufficient for monitoring the at least one near field. The invention takes advantage of the fact that the transmitted signal of the main signal in the main beam direction is greater than the transmitted energy of the at least one secondary signal in the at least one secondary beam direction. In this way, the transmitted energy sent in the at least one secondary beam direction is also used effectively.In this way, the overall transmission energy of the light source can be used more efficiently to reliably monitor the entire monitoring area, which consists of the far field and at least one near field, with the main transmission signal and at least one secondary transmission signal.

[0016] Advantageously, the detection system can operate using a time-of-flight method. Optical detection systems operating according to the time-of-flight method can be designed and named as Time-of-Flight (TOF), Light Detection and Ranging (LiDAR), Laser Detection and Ranging (LaDAR), or similar systems. In this method, the time of flight is measured from the transmission of a signal, in particular a light pulse, by the transmitting device to the reception of the corresponding reflected signal by a receiving device, and from this, a distance between the detection system and the detected object is determined.

[0017] Advantageously, the detection system can be a scanning system. In this case, a monitoring area can be scanned using transmitted signals. For this purpose, the corresponding transmitted signals, in particular transmit beams, can be steered across the monitoring area with respect to their propagation direction. The diffraction unit can steer the main beam direction within the far field. Simultaneously, at least one secondary beam direction can be steered in the at least one near field. In this way, the entire monitoring area can be scanned with the main transmitted signal and the at least one secondary transmitted signal.

[0018] Advantageously, the detection system can be a laser-based distance measuring system. The laser-based distance measuring system can have at least one laser, in particular a diode laser, as a light source. The at least one laser can transmit pulsed beams as signals. The laser can emit signals in frequency ranges visible or invisible to the human eye. Accordingly, a receiving device can have a detector designed for the frequency of the emitted light, in particular an angle-resolving detector. The laser-based distance measuring system can advantageously be a laser scanner. A monitoring area can be scanned with a laser beam, in particular a pulsed one.

[0019] The invention is used in a vehicle, in particular a motor vehicle. Advantageously, the invention can also be used in a land vehicle, in particular a passenger car, truck, bus, motorcycle, or the like. The invention can also be used in autonomous or at least partially autonomous vehicles.

[0020] The detection system can advantageously be connected to, or be part of, at least one electronic control unit of the vehicle, in particular a driver assistance system and / or a chassis control system and / or a driver information system and / or a parking aid. In this way, the object data detected by the detection device, in particular the distance, orientation and / or relative speed of an object relative to the vehicle, can be transmitted to the control unit and used to influence driving functions, in particular speed, braking, steering and / or the output of a warning and / or alert signal, especially for the driver.

[0021] In an advantageous embodiment, at least one diffraction unit can comprise or consist of an optical phased array, an adjustable optical grating, or the like. An optical phased array (OPA) can be used to control the phase of light waves transmitted through or reflected from a two-dimensional surface of adjustable surface elements. The OPA allows the light to be diffracted, thus setting the beam direction of transmitted signals in the form of light waves. Diffraction using an OPA can be achieved with lower energy losses compared to reflection at a mirror, particularly a micromechanical mirror.

[0022] In a further advantageous embodiment, at least one diffraction unit can be configured to reflect or transmit with respect to the at least one transmitted signal. A reflective configuration allows for lower energy losses compared to a transmitting configuration. A transmitting configuration has the advantage that the light source and the at least one diffraction unit can be arranged one behind the other in front of the monitored area.

[0023] In a further advantageous embodiment, the at least one light source can include or consist of at least one laser. A laser can generate coherent light with high energy density. Furthermore, a laser can precisely transmit signals. Advantageously, a laser can generate corresponding light pulses as transmission signals.

[0024] In a further advantageous embodiment, the beam profile of the at least one transmitted signal emanating from the at least one light source and the profile of a diffractionally active surface of the at least one diffraction unit can be matched to achieve maximum energy efficiency. Thus, a cross-section of the transmitted signal emanating from the at least one light source can correspond to a cross-section of the active surface of the at least one diffraction unit. In this way, the active surface can be fully illuminated at all diffraction angles without any part of the transmitted signal radiating past the active surface and being lost to the system.

[0025] In contrast, with a conventional rotating mirror, the illuminated area changes depending on the angle of rotation, so that either at smaller angles of rotation some of the light energy shines past the mirror or at larger angles of rotation some part of the mirror surface is not illuminated.

[0026] In a further advantageous embodiment, the far-field opening angle can be approximately between 10° and 30°, in particular approximately 22°, and / or the at least one near-field opening angle can be approximately between 12° and 60°, in particular approximately 40°. In this way, a correspondingly large far field and a larger near field can be scanned.

[0027] In a further advantageous embodiment, the at least one far field can lie within the at least one near field. In this way, the at least one far field can extend in the center, particularly in front of the vehicle in the direction of travel. The at least one near field can extend beyond the far field to the right and left when viewed in the direction of travel.

[0028] Furthermore, the problem with the detection system is solved according to the invention by the fact that - which is arranged in the beam path of at least one light source and is adjustable to change at least one beam direction, - where a far-field opening angle, within which a principal beam direction of the diffracted at least one transmitted signal can be moved, defines a far field of the detection system - and at least one near-field opening angle within which at least one side ray direction of the diffracted at least one transmitted signal can be moved, at least one near field of the detection system is specified.

[0029] In an advantageous embodiment, the at least one receiving device can have at least one angle-resolving optical receiver. In this way, the at least one receiving device can determine the direction from which the at least one received signal originates. Thus, the at least one received signal can be assigned to the corresponding beam direction, in particular the main beam direction or the at least one secondary beam direction. The direction of the detected object relative to the detection system can therefore be determined more easily and / or more accurately.

[0030] In a further advantageous embodiment, the at least one receiving device can receive at least one received signal from at least one transmitted signal in a main beam direction and at least one received signal from at least one transmitted signal in at least one secondary beam direction, particularly simultaneously. In this way, the detection system can also detect multiple objects or a correspondingly spatially extended object. Thus, an object in the far field and an object in the near field can be detected, particularly simultaneously.

[0031] The receiver can convert the received signals into a form usable by the control and / or evaluation unit. In particular, the optical received signals can be converted into electronic signals.

[0032] Furthermore, the problem is solved according to the invention in the driver assistance system by the fact that - which is arranged in the beam path of at least one light source and is adjustable to change at least one beam direction, - where a far-field opening angle, within which a principal beam direction of the diffracted at least one transmitted signal can be moved, defines a far field of the detection system - and at least one near-field opening angle within which at least one side ray direction of the diffracted at least one transmitted signal can be moved, at least one near field of the detection system is specified.

[0033] Furthermore, the object of the invention is achieved in the method by sending the at least one transmit signal to at least one diffractive diffraction unit and diffracting the at least one transmit signal in at least one beam direction with the at least one diffraction unit, wherein the at least one diffraction unit is adjusted and thereby pivots a main beam direction of the diffracted at least one transmit signal within a far-field opening angle and pivots at least one secondary beam direction of the diffracted at least one transmit signal within a near-field opening angle.

[0034] Furthermore, the features and advantages described in connection with the inventive transmitting device, the inventive detection system, the inventive driver assistance system, and the inventive method, and their respective advantageous embodiments, apply to each other accordingly, and vice versa. The individual features and advantages can, of course, be combined with one another, potentially resulting in further advantageous effects that go beyond the sum of the individual effects. Brief description of the drawings

[0035] Further advantages, features, and details of the invention will become apparent from the following description, in which an embodiment of the invention is explained in more detail with reference to the drawing. The person skilled in the art will expediently consider the features disclosed in the drawing, the description, and the claims individually and combine them into meaningful further combinations. The drawing schematically shows Fig. 1 a motor vehicle with a driver assistance system and a scanning optical detection system for monitoring a monitoring area in the direction of travel in front of the motor vehicle; Fig. 2. A functional diagram of the motor vehicle with the driver assistance system and the detection system from the Fig. 1; Fig. 3. A detailed representation of a diffractive diffraction unit of a transmitter device of the detection system from the Fig. 1 and Fig. 2; Fig. 4 an amplitude-diffraction angle diagram of a diffraction unit from the Fig. 3 diffracted light transmission signal; Fig. 5. A top view of a monitoring area of ​​the detection system from the Fig. 1 to Fig. 2 in an exemplary swiveling phase of a beam direction of the transmitted signal, wherein a main beam direction of a transmitted signal points in the direction of a main axis of the detection system; Fig. 6 an amplitude-diffraction angle diagram of the transmitted signal from the Fig. 5; Fig. 7 the top view of the monitored area from the Fig. 5 in a further pivoting phase of the beam direction of the transmitted signal, wherein the main beam direction of the transmitted signal is inclined relative to the main axis and a secondary beam direction of the transmitted signal points away from the main beam direction on the opposite side of the main axis; Fig. 8 the amplitude-diffraction angle diagram of the transmitted signal from the Fig. 7; Fig. 9 the top view of the monitored area from the Fig. 5 and Fig. 7 in another pivoting phase of the beam direction of the transmitted signal, where here the main beam direction and the secondary beam direction with respect to the main axis in comparison to the Fig. 7 are mirrored; Fig. 10 the amplitude-diffraction angle diagram of the transmitted signal from the Fig. 9.

[0036] In the figures, identical components are labelled with the same reference symbols. embodiment(s) of the invention

[0037] In the Fig. Figure 1 shows a motor vehicle 10 in the form of a passenger car in a front view. The motor vehicle 10 has a scanning optical detection system 12, for example in the form of a laser scanner. The detection system 12 is, for example, arranged in the front bumper of the motor vehicle 10. With the detection system 12, a vehicle, for example, in the Fig. 2. The indicated monitoring area 14 in the direction of travel 16 in front of the motor vehicle 10 is monitored for objects 18. The detection system 12 can also be located elsewhere on the motor vehicle 10 and oriented differently. The objects 18 can be, for example, other vehicles, persons, obstacles, road surface irregularities such as potholes or stones, road boundaries, or the like. In the Fig. 2 is an object 18, exemplified as a checkered rectangle. Fig. Figure 2 is otherwise merely a functional diagram of some components of the motor vehicle 10 and the detection system 12, which does not serve spatial orientation.

[0038] The detection system 12 operates according to a light pulse time-of-flight method. With the detection system 12, for example, the distance, direction, and speed of the object 18 relative to the motor vehicle 10 can be determined.

[0039] The detection system 12 is part of a driver assistance system 20 or can be connected to it. The driver assistance system 20 can, for example, support the driver of the motor vehicle 10. For instance, the motor vehicle 10 can drive or park at least partially autonomously with the help of the driver assistance system 20. The driver assistance system 20 can influence driving functions of the motor vehicle 10, such as engine control, braking, or steering, or issue instructions or warning signals. For this purpose, the driver assistance system 20 is connected to functional devices 22 in a regulating and / or controlling manner. Fig. Figure 2 shows two exemplary functional devices 22. These functional devices 22 could be, for example, an engine control system, a brake system, a steering system, a chassis control system, or a signal output system.

[0040] The driver assistance system 20 has an electronic control unit 24 with which corresponding electronic control and regulation signals can be transmitted to and / or received and processed by the functional units 22.

[0041] The detection system 12 comprises a transmitter 26, a receiver 28, and an electronic control and evaluation unit 30. Pulsed optical signals 32 can be transmitted into the monitoring area 14 using the transmitter 26. The signals 32 are reflected by the object 16 and returned to the detection system 12 as corresponding pulsed optical signals 34. The distance to the object 16 is determined by the electronic control and evaluation unit 30 from the time of flight of light, i.e., the time between the transmission of the signal 32 and the reception of the corresponding signal 34.

[0042] The control and evaluation unit 30 is connected to the control unit 24 via signal technology. Depending on object information from the detection system 12, the control unit 24 can control / regulate driving functions of the motor vehicle 10.

[0043] For the invention it is not essential whether electrical control and / or evaluation devices, such as the control unit 24, the control and evaluation unit 30, an engine control unit of the motor vehicle 10 or the like, are integrated in one or more components or component groups or are at least partially realized as decentralized components or component groups.

[0044] The transmitting device 26 comprises a light source 36 and a diffractive diffraction unit 38. The light source 36 is, by way of example, configured as a laser. The diffraction unit 38 is, by way of example, an optical phased array (OPA). It is known that with an OPA, the direction of the transmitted signal 32b, 32c emitted by the diffraction unit 38 can be set by appropriately controlling the phase of the transmitted signal 32a in the form of a light wave.

[0045] In the Fig. Figure 3 shows a schematic detail view of the diffraction unit 38. The diffraction unit 38 is used in transmitting mode as an example. Alternatively, the diffraction unit 38 can also be used reflectively. The beam profile of the transmitted signal 32a from the light source 36 and the profile of an active surface 42 of the diffraction unit 38 are matched such that the incoming transmitted signal 32a completely illuminates the active surface 42.

[0046] With the diffraction unit 38, the incoming transmitted signal 32a is diffracted by adjustable diffraction elements 44 of the diffraction unit 38 such that part of the transmitted energy of the transmitted signal 32a is sent as the main transmitted signal 32b in a main beam direction 40b and part of the transmitted energy of the transmitted signal 32a is sent as a secondary transmitted signal 32 in a secondary beam direction 40c into the monitoring area 14. A further, smaller portion of the transmitted energy is allocated to, for example, two additional secondary transmitted signals 32d, 32e, which are directed, for instance, into the Fig. 8 and Fig. Figure 10 shows that at a diffraction angle of 0°, the main beam direction 40c and the secondary beam direction 40c coincide. Depending on the design of the diffraction unit 38 and the wavelength λ of the transmitted signal 32a, more than three secondary signals 32c, 32d, 32e, or fewer, may be relevant.

[0047] The main beam direction 40b and the secondary beam direction 40c are defined by their respective diffraction angles 48b and 48c, which are exemplified in the Fig. 7 and Fig. Figure 9 shows the diffraction angles 48b and 48c. These angles refer to a principal axis 50 of the transmitting device 26, which, for example, represents the optical axis of the diffraction unit 38. In the illustrated embodiment, the principal axis 50 is perpendicular to a radiation face of the diffraction unit 38.

[0048] The diffraction angles 38b and 38c are defined by the phase shift caused by the diffraction elements 44 of the diffraction unit 38. By appropriately adjusting the diffraction elements 44, the main beam direction 40b and the secondary beam direction 40c can be set, preferably pivoted. The diffraction angles 38b and 38c are naturally related.

[0049] In the Fig. Figure 4 shows a schematic amplitude-diffraction angle diagram of an exemplary main transmit signal 32b and a secondary transmit signal 32c emerging from the diffraction unit 38.

[0050] The beamwidths b of the main transmitted signal 32b and the secondary transmitted signal 32c depend on the number N of diffraction elements 44 and the wavelength λ of the transmitted signal 32a. The following relationship is known: b=1.03 λ / N.

[0051] The main transmitted signal 32b and the secondary transmitted signal 32c are surrounded by an envelope 52. A width be1 at the base of the envelope 52 and a width be2 of the envelope 52 at mid-height are each dependent on the wavelength λ and a respective width d of the diffraction elements 44. The following relationships are known: be1=2.44 λ / d be2=1.03 λ / d.

[0052] During diffraction, the transmitted energy of the incoming signal 32a is distributed between the respective main signals 32b and the secondary signals 32c, depending on the diffraction angles 38b and 38c. The larger portion of the transmitted energy is allocated to the main signal 32b, and the smaller portion to the secondary signals 32c and any other secondary signals.

[0053] In the Fig. 5, Fig. 7 and Fig. Figure 9 shows three exemplary swivel phases of the main beam direction 40b and the secondary beam direction 40c. The main beam direction 40b and the secondary beam direction 40c are swiveled back and forth in a swivel plane to scan the monitored area 14. The swivel plane corresponds, for example, to the drawing plane in the Fig. 5, Fig. 7 and Fig. 9.

[0054] To scan a far field 62, the main beam direction 40b is pivoted back and forth between two far-field limit angles 54 in a main beam pivot direction 70c. The far-field limit angles 54 are located symmetrically on opposite sides of the main axis 50 in the pivot plane.

[0055] Due to the relationship between the main beam direction 40b and the secondary beam direction 40c, the secondary beam direction 40c is simultaneously pivoted back and forth between two near-field limit angles 56 in a secondary beam pivot direction 70c to scan a near field 66. The near-field limit angles 56 are located symmetrically on opposite sides of the main axis 50 in the pivot plane. The main beam pivot direction 70b and the secondary beam pivot direction 70c are naturally opposite in direction.

[0056] The far-field limit angles 56 define a far-field opening angle 58. Similarly, the near-field limit angles 56 define a near-field opening angle 60. In the present embodiment, the far-field opening angle 58 is, for example, 20°. The near-field opening angle 60 is, for example, 40°. The far field 62 therefore extends within the near-field 66 in the vicinity of the detection system 12.

[0057] The far field 62 extends to a distance 64 of, for example, approximately 200 m from the detection system 12. The near field 66 extends to a distance 68 of, for example, approximately 20 m. The far field 62 covers the lane of the vehicle 10. Any objects 18 present there must be detected early, i.e., at a greater distance, to prevent potential collisions. The near field 66 covers areas diagonally in front of the vehicle 10, adjacent to the lane of the vehicle 10. Any objects 18 present there pose a lower collision risk, so it is sufficient if they are detected later, i.e., at a shorter distance.

[0058] The main signal 32b, which has the higher signal energy and therefore a greater range, is used to scan the far field 62. The slightly weaker secondary signal 32c is used to scan the near field 66. The distribution of the transmission energy due to diffraction between the main signal 32b and the secondary signal 32c can be used advantageously to increase the overall opening angle for monitoring the surveillance area 14 without losing any information about any objects 14.

[0059] In the Fig. Figure 5 shows a pivoting phase with a principal diffraction angle 48b of 0°. The principal beam direction 40b therefore lies on the principal axis 50. The transmitted energy of the transmit signal 32a falls on the principal transmit signal 32b. In the Fig. Figure 6 shows an amplitude-diffraction angle diagram where the normalized amplitude of the main transmit signal 32b is shown against the diffraction angle.

[0060] In the Fig. 7 is a swiveling phase after the swiveling of the main beam direction 40b from the Fig. 5 in the direction of rotation 70b, viewed in the direction of travel 16 to the right, and correspondingly to the rotation of the secondary beam direction 40c to the left. In this rotation phase, the main diffraction angle 48b is approximately 5°. The secondary diffraction angle 48c of the secondary transmitted signal 32c is approximately -17°. The transmission energy of the incoming transmitted signal 32a is distributed here between the main transmitted signal 32b and the secondary signal 32c, with the larger energy share falling on the main transmitted signal 32b. In the Fig. Figure 8 shows the corresponding amplitude-diffraction angle diagram.

[0061] In the Fig. 9 is a further swiveling phase after the swiveling of the main beam direction 40b starting from the swiveling phase Fig. 7 in the opposite direction of rotation 70b, viewed in the direction of travel 16 to the left, and the associated rotation of the secondary beam direction 40b to the right. In this rotation phase, the principal diffraction angle 48c is approximately -5° and the secondary diffraction angle 48c is approximately +17°. In the Fig. Figure 10 shows the corresponding amplitude-diffraction angle diagram.

[0062] Furthermore, in the Fig. 8 and Fig. 10 Two further spurious transmission signals 32d and 32e are shown as examples, which have a negligible part of the transmission energy and which are transmitted to areas outside the monitoring area 14.

[0063] Depending on the direction of the beam, the main transmit signal 32b and / or the secondary transmit signal 32c are reflected at the object 18 and sent back as corresponding received signals 34.

[0064] The receiving device 32 detects the received signals 34 as an angle function, allowing the direction of the object 18 relative to the detection system 12 to be determined. From the signal travel time, the distance and, due to the Doppler effect, the velocity of the object 18 relative to the detection system 12 can be determined.

[0065] The object information is transmitted by the control and evaluation unit 30 to the control unit 24 of the driver assistance system 20, thus controlling the corresponding driving functions. Because the monitoring area 14 is monitored simultaneously in two directions – except at a diffraction angle of 0° – overall monitoring is improved, particularly becoming more efficient and / or faster. The transmission energy is advantageously distributed and utilized, allowing for the use of less overall transmission energy. Alternatively, the same transmission energy can be used to monitor a greater distance to the detection system 12.

Claims

[1] Transmitting device (26) for a scanning optical detection system (12) of a vehicle (10), with at least one light source (36) for generating at least one optical transmit signal (32a) and with at least one diffractive diffraction unit (38) acting on the at least one transmit signal (32a) for controlling at least one beam direction (40b, 40c) of the at least one transmit signal (32a), characterized by, that the at least one diffraction unit (38) is arranged in the beam path of the at least one light source (36) and is adjustable to change the at least one beam direction (40b, 40c), wherein a far-field opening angle (58), within which a principal beam direction (40b) of the diffracted at least one transmitted signal (32b) can be moved, defines a far field (62) of the detection system (12) and at least one near-field opening angle (60), within which at least one secondary beam direction (40c) of the diffracted at least one transmitted signal (32c) can be moved, defines at least one near field (66) of the detection system (12). [2] Transmitting device according to claim 1, characterized by , that at least one diffraction unit (38) comprises or consists of an optical phased array, an adjustable optical grating or the like. [3] Transmitting device according to claim 1 or 2, characterized by, that at least one diffraction unit (38) is designed to reflect or transmit with respect to the at least one transmit signal (32a). [4] Transmitting device according to any of the preceding claims, characterized by that the at least one light source (36) has or consists of at least one laser. [5] Transmitting device according to any of the preceding claims, characterized by , that a beam profile of the at least one transmitted signal (32a) coming from the at least one light source (36) and the profile of a diffraction-active surface (42) of the at least one diffraction unit (38) are adapted to each other to achieve maximum energy efficiency. [6] Transmitting device according to any of the preceding claims, characterized by, that the far-field opening angle (58) is approximately between 10° and 30°, in particular approximately 22°, and / or that at least one near-field opening angle (60) is approximately between 12° and 60°, in particular approximately 40°. [7] Transmitting device according to any of the preceding claims, characterized by , that at least one far field (62) lies within at least one near field (66). [8] Scanning optical detection system (12) of a vehicle (10), - with at least one transmitting device (26) which has at least one light source (36) for generating at least one optical transmitting signal (32a) and at least one diffractive diffraction unit (38) acting on the at least one transmitting signal (32a) for controlling at least one beam direction (40b, 40c) of the at least one transmitting signal (32a), - with at least one receiving device (28) for receiving at least one optical receiving signal (34) originating from at least one transmitting signal (32b, 32c) reflected by an object (18) in a monitoring area (14) of the detection system (12), - and with at least one control and / or evaluation device (30) for controlling the at least one transmitting device (26) and / or the at least one receiving device (28) and / or for evaluating received signals (34) received by the at least one receiving device (28), characterized by , that - which is arranged in the beam path of the at least one light source (36) and is adjustable to change the at least one beam direction (40b, 40c), - wherein a far-field opening angle (58), within which a main beam direction (40b) of the diffracted at least one transmitted signal (32b) can be moved, defines a far field (62) of the detection system (12) - and at least one near-field opening angle (60) within which at least one side-ray direction (40c) of the diffracted at least one transmitted signal (32c) can be moved, at least one near field (66) of the detection system (12) is specified. [9] Detection system according to claim 8, characterized by , that the at least one receiving device (28) has at least one angle-resolving optical receiver. [10] Detection system according to claim 8 or 9, characterized by, that the at least one receiving device (28) can receive at least one received signal (34) from at least one transmitted signal (32b) in a main beam direction (40b) and at least one received signal (34) from at least one transmitted signal (32c) in at least one secondary beam direction (40c), in particular simultaneously. [11] Driver assistance system (20) of a vehicle (10), - with at least one scanning optical detection system (12), wherein the at least one detection system (12) - at least one transmitting device (26) which has at least one light source (36) for generating at least one optical transmitting signal (32a) and at least one diffractive diffraction unit (38) acting on the at least one transmitting signal (32a) for controlling at least one beam direction (40b, 40c) of the at least one transmitting signal (32a), - at least one receiving device (28) for receiving at least one optical receiving signal (34) originating from at least one transmitting signal (32b, 32c) reflected by an object (18) in a monitoring area (14) of the detection system (12), - and at least one control and / or evaluation device (30) for controlling the at least one transmitting device (26) and / or the at least one receiving device (28) and / or for evaluating received signals (34) received by the at least one receiving device (28), - wherein the driver assistance system (20) comprises at least one control and / or evaluation unit (24) for processing object information acquired by the at least one detection system (12), characterized by , that - which is arranged in the beam path of the at least one light source (36) and is adjustable to change the at least one beam direction (40b, 40c), - wherein a far-field opening angle (58), within which a main beam direction (40b) of the diffracted at least one transmitted signal (32b) can be moved, defines a far field (62) of the detection system (12) - and at least one near-field opening angle (60) within which at least one side-ray direction (40c) of the diffracted at least one transmitted signal (32c) can be moved, at least one near field (66) of the detection system (12) is specified. [12] Method for controlling at least one beam direction (40b, 40c) of at least one optical transmit signal (32a) of a scanning optical detection system (12) of a vehicle (10), wherein at least one transmit signal (32a) is generated and at least one beam direction (40b, 40c) of the at least one transmit signal (32a) is controlled, characterized by , that the at least one transmit signal (32a) is sent to at least one diffractive diffraction unit (38) and with the at least one diffraction unit (38) the at least one transmit signal (32a) is diffracted in at least one beam direction (40b, 40c), wherein the at least one diffraction unit (38) is adjusted and thereby a main beam direction (40b) of the diffracted at least one transmit signal (32b) is pivoted within a far-field opening angle (58) and at least one secondary beam direction (40c) of the diffracted at least one transmit signal (32c) is pivoted within a near-field opening angle (60).

Images