WO2021139919A1

WO2021139919A1 - Lidar sensor and method for optically capturing a field of view

Info

Publication number: WO2021139919A1
Application number: PCT/EP2020/083311
Authority: WO
Inventors: Mustafa Kamil; Thomas Maurer; Annemarie Holleczek
Original assignee: Robert Bosch Gmbh
Priority date: 2020-01-08
Filing date: 2020-11-25
Publication date: 2021-07-15
Also published as: DE102020200098A1

Abstract

A LIDAR sensor (100) for optically capturing a field of view (301), said LIDAR sensor having: a transmitting unit comprising a laser pattern generation unit (101), which is disposed on a stator (114), for transmitting primary light (106) into the field of view (301), the laser pattern generation unit (101) being temperature-stabilised, and the laser pattern generation unit (101) being designed to generate an illumination pattern (304, 305, 306) in the field of view (301), the illumination pattern (304, 305, 306) having a first direction (302) and a second direction (303), the first direction (302) and the second direction (303) running orthogonally relative to each other, and the extent of said illumination pattern (304, 305, 306) along the first direction (302) being greater than the extent of said illumination pattern (304, 305, 306) along the second direction (303); a receiving unit comprising at least one single-photon detector unit (102), which is disposed on the stator (114), for receiving secondary light (107) that has been reflected and/or scattered by an object (113) in the field of view (301); and at least one mirror unit (103) which can rotate about an axis of rotation (104) and is disposed on a rotor, the axis of rotation (104) being oriented parallel to the first direction (302), and wherein the primary light (106) and the secondary light (107) can be coupled out and in perpendicularly to the axis of rotation (104) by means of the mirror unit (103).

Description

description

title

LIDAR sensor and method for optical detection of a field of view

The present invention relates to a LIDAR sensor for optically detecting a field of view and a method for optically detecting a field of view.

State of the art

DE 10 2016219 955 A1 discloses a transmission unit for illuminating an environment, in particular a vehicle, with a laser pattern generation unit, a deflection unit and a control unit, the laser pattern generation unit being set up to generate an illumination pattern in a field of view, the illumination pattern having a first direction and a second Direction, wherein the first direction and the second direction are arranged orthogonally to one another, wherein an extent of the illumination pattern along the first direction is greater than an extent of the illumination pattern along the second direction, and the control unit is set up, the deflection unit at least along the second direction to move so that the illumination pattern is moved at least along the second direction.

Disclosure of the invention

The present invention is based on a LIDAR sensor for the optical detection of a field of view, having a transmission unit with a laser pattern generation unit arranged on a stator for the transmission of primary light into the field of view; and wherein the laser pattern generation unit is temperature-stabilized, and wherein the

Laser pattern generation unit is formed, an illumination pattern in the To generate field of view, wherein the illumination pattern has a first direction and a second direction, wherein the first direction and the second direction are arranged orthogonally to one another, wherein an extension of the illumination pattern along the first direction is greater than an extension of the illumination pattern along the second direction; a receiving unit with at least one single photon detector unit arranged on the stator for receiving secondary light which has been reflected and / or scattered in the field of view by an object; at least one mirror unit rotatable about an axis of rotation and arranged on a rotor, the axis of rotation being oriented parallel to the first direction; and wherein the primary light and the secondary light can be coupled out and in by means of the mirror unit perpendicular to the axis of rotation.

The LIDAR sensor presented here is therefore designed as a macro scanner. A person skilled in the art understands a macro scanner to be an optoelectronic sensor in which a macroscopic unit is rotatably arranged. In the case of the LIDAR sensor presented here, the mirror unit arranged on the rotor can be understood as the macroscopic unit. The field of view (FoV) of the LIDAR sensor can be scanned over time with the primary light. The resolution along one direction of the field of view, in particular along the horizontal direction, can be implemented in fine steps with the aid of an angle measurement. This direction of the field of view, along which the field of view can be scanned, is preferably arranged parallel to the second direction of the illumination pattern.

The laser pattern generation unit has in particular at least one laser. The at least one laser can be designed as a DFB laser (DFB: for Distributed Feedback, DFB), as a DBR laser (DBR: for Distributed Bragg Reflector), as a temperature-stabilized edge or surface emitter or as a temperature-stabilized solid-state laser. A DFB laser or a DBR laser can already be a temperature-stabilized laser. Edge or surface emitters or solid-state lasers can be temperature-stabilized by means of additional units. The fact that the laser pattern generation unit, or in particular the at least one laser, is embodied in a temperature-stabilized manner, can in this way It can be understood that it can be achieved that the properties of the LIDAR sensor, and in particular of the laser pattern generation unit, can be kept stable over an entire operating temperature range of the LIDAR sensor. The operating temperature range of a LIDAR sensor can include a temperature range of -40 ° C to +125 ° C, for example. The temperature stabilization can cause a wavelength of the primary light as a possible property of the laser pattern generation unit to be stable over the operating temperature range. The temperature stabilization can have the effect that the primary light has a very narrow bandwidth over the operating temperature range. It is possible that the laser pattern generation unit neither has to be heated up during start-up nor cooled during operation in order to keep the wavelength of the primary light stable, for example.

The laser pattern generation unit is designed in particular to emit the primary light in a pulsed manner. The laser pattern generation unit is designed in particular to emit the illumination pattern in a pulsed manner. The laser pattern generation unit can thus be designed to emit the primary light as an illumination pattern. The illumination pattern is in particular as a line, a rectangle or a pattern, e.g. B. a checked pattern. In particular, the first direction of the illumination pattern is arranged parallel to a vertical direction of the field of view. In particular, the second direction of the illumination pattern is arranged parallel to a horizontal direction of the field of view. The laser pattern generation unit can have a single laser with high divergence along the first direction of the illumination pattern. The laser pattern generation unit can have a plurality of lasers which are designed to generate the illumination pattern. For this purpose, the plurality of lasers can be arranged in a column, for example. Relatively soon after exiting the LIDAR sensor (immediately or after a few centimeters), a coherent illumination of the field of view with the illumination pattern, which is increasingly homogeneous over the distance to the LIDAR sensor, can arise in the optical path of the transmitter unit. The fact that the laser pattern generation unit is arranged on the stator can be understood to mean that the laser pattern generation unit is arranged in a stationary (or, in other words, stationary) arrangement. The single photon detector unit has in particular at least one single photon detector. The at least one single photon detector can be designed, for example, as a SPAD (for single photon avalanche diode) or as a SiPM (for silicon photon multiplier). In particular, a SiPM detector unit has a large number of SPADs in a special circuit. The single photon detector unit is designed for counting single photons. The single photon detector unit can have a plurality of single photon detector cells. The single photon detector unit can be designed, for example, as a one-dimensional arrangement of a plurality of single photon detector cells. Regardless of which laser emits primary light from a plurality of lasers, a single photon detector cell can receive secondary light, for example in the form of photons. The single photon detector unit can be constructed using BSI technology (BSI: for backside illumination). For this purpose, individual single photon detector cells can be arranged almost without gaps on only extremely small chip areas. The fact that the single photon detector unit is arranged on the stator can be understood to mean that the single photon detector unit is arranged in a stationary manner (or, in other words, also in a stationary manner). In particular, the single photon detector unit is designed to detect a detection pattern which is identical to the illumination pattern. The single photon detector unit receives in particular secondary light from a predetermined section of the field of view in which the primary light was previously emitted by means of the laser pattern generation unit. The transmission of the primary light and the reception of the secondary light preferably take place simultaneously over the predetermined section of the field of view.

The laser pattern generation unit and the single photon detector unit can be arranged separately on the stator. The laser pattern generation unit and the single photon detector unit can be arranged next to one another or one above the other on the stator. The optical path of the transmitting unit between the laser pattern generation unit and the rotatable mirror unit and the optical path of the receiving unit between the rotatable mirror unit and the single photon detector unit can run separately or overlapping, one above the other or next to one another. The optical path of the sender unit and the optical path of the receiving unit can be biaxial, coaxial or partially coaxial with one another.

To drive the rotatable mirror unit, the LIDAR sensor can have an electric drive unit, for example a flat, brushless electric motor. By means of the mirror unit, the primary light can be decoupled from the LIDAR sensor into the field of view, in other words emitted. Secondary light from the field of view can be coupled, in other words received, into the LIDAR sensor by means of the mirror unit. The field of view can in particular have an extension of 120 to 145 ° along a horizontal direction.

The LIDAR sensor also has, in particular, at least one evaluation unit. The at least one evaluation unit is designed to determine a light transit time of the primary light emitted and the secondary light received again. The distance between the LIDAR sensor and an object in the field of view can be determined, for example, on the basis of a signal transit time (time of flight, TOF). The time-of-flight methods include pulse methods that determine the time at which a reflected laser pulse is received, or phase methods that emit an amplitude-modulated light signal and determine the phase offset to the received light signal. Time-correlated single photon counting (TCSPC) can be implemented for a ToF system.

Advantages of the invention are that compared to two-dimensional scanning LIDAR sensors (for example when using a micromirror) the measuring time or the number of pulses per pixel can be higher. With the LIDAR sensor described here, only one scanning along one direction of the field of view is necessary. In comparison to known LIDAR sensors, the resolution can be increased along at least one direction of the field of view. The resolution along a vertical and / or along a horizontal direction of the field of view can be increased. A very high angular resolution, for example 0.1 * 0.1 °, can be achieved. The field of view can be scanned using a gapless illumination with primary light. The secondary radiation can also be recorded at the same time virtually seamlessly with the help of, for example, a one-dimensional arrangement of several single photon detector cells. This reduces the probability of movement artifacts in the measurement data from the LIDAR sensor. The risk of overlooking objects in the field of view can be reduced. At the same time, the output of the primary light emitted must be significantly lower than, for example, with a LIDAR sensor working according to a flash system. The energy consumption of the LIDAR sensor can be kept low compared to a flash system. The eye safety of the LIDAR sensor can be improved compared to a flash system. In addition, the use of the SPAD or SiPM detectors enables time-correlated single photon counting. By using a one-dimensional arrangement of a plurality of single photon detector cells, the single photon detector unit can be kept small. Such a single photon detector unit requires less energy, generates less waste heat in the device and improves eye safety. The LIDAR sensor has an optimized temperature behavior. The optimized temperature behavior enables the use of a very narrow bandpass filter (e.g. bandwidth <10 nm) in the optical path of the receiving unit. This means that a proportion of useful photons, i.e. photons that can be used to capture the field of view, is greater than a proportion of interfering photons, i.e. photons that interfere with the capture of the field of vision, for example strongly luminous objects, background light or Scattered radiation. The probability that the single photon detector unit will become saturated is greatly reduced. The LIDAR sensor can thus be robust against environmental influences. With changes in the ambient temperature of the LIDAR sensor, but also with other disturbances such as background light, there is little or no change in the measurement properties of the LIDAR sensor. As a result, the LIDAR sensor can also have an increased range that remains the same when the ambient temperature changes. A separation of the optical path of the transmitting unit and the optical path of the receiving unit is not necessary. In this way, for example, the mirror unit can be kept small. The LIDAR sensor can furthermore be particularly flat at least along one extension of its housing. The LIDAR sensor can, for example, have a flat overall height. Also is compared to LIDAR sensors in which, in addition to the mirror unit, active optical components (for example a laser unit or a detector unit) and electrical components (for example an evaluation unit) are rotatably arranged, both temperature stabilization, i.e. thermal management, and energy and data transmission are significantly simplified . The rotatable mirror unit, which can be electrically and optically passive, generally requires no wireless energy transmission, no wireless data transmission and no temperature control.

In an advantageous embodiment of the invention it is provided that an active laser material of the laser pattern generation unit is periodically structured; and wherein the laser pattern generation unit is designed in particular as a DFB laser unit or as a DBR laser unit. Structures with changing refractive indices can form a one-dimensional interference grating or a one-dimensional interference filter. The laser pattern generation unit can be a single DFB or DBR laser unit with an asymmetrical divergence angle. The laser pattern generation unit can alternatively be a one-dimensional arrangement of several DFB laser units or DBR laser units. The advantage of this configuration is that the spectral width of such a laser pattern generation unit is very small. For DFB lasers or DBR lasers, deviations from the set wavelength are, for example, in the range of 10 ⁵ nm. A corresponding laser pattern generation unit thus has very good temperature stabilization. If, on the other hand, a change in the wavelength of the laser pattern generation unit is desired, this can be generated in the case of DFB lasers or DBR lasers by changing the current within a short period of time. This type of wavelength change is much faster than a wavelength change via a change in temperature. In addition, a laser pattern generation unit with the features described here can be inexpensive.

In a further advantageous embodiment of the invention it is provided that the laser pattern generation unit is designed as a surface emitter or so-called VCSE laser (English for vertical cavity surface emitting). This allows the LIDAR sensor to be kept inexpensive. Such a laser pattern generation unit can furthermore have a better beam quality of the emitted primary light.

In a further advantageous embodiment of the invention it is provided that the single photon detector unit has a plurality of single photon detector cells; and wherein the plurality of single photon detector cells can be activated simultaneously. The single photon detector cells can be designed as single photon avalanche diodes. The

Single photon detector unit can have a plurality of pixels, at least some pixels each having a plurality of activatable single photon detector cells. A single photon detector cell can be referred to as a subpixel. The LIDAR sensor can furthermore have at least one linker which is designed to link detection signals representing received secondary light from at least two single photon detector cells of a pixel via a combinatorial logic. So-called macropixels are created by linking at least two single photon detector cells of an image point. The pixels of the single photon detector unit can be referred to as macropixels. A single photon detector cell triggers an electrical pulse when a minimal amount of secondary light, for example in the form of photons, falls on a light-intensive area of the single photon detector cell. The amount of secondary light can already be achieved with a single photon detection event, i.e. a single photon. A single photon detector cell can accordingly be very sensitive. The advantage of this embodiment is that the dynamic range of the single photon detector unit can be increased. The image points, i.e. macropixels, enable the use of the otherwise mostly sensitive single photon detector cells. The performance of a pixel can be optimized independently of the optically necessary size. In the case of a defective single photon detector cell of a pixel, not the entire pixel fails. The light yield of a pixel is thus increased in the case of a defective single photon detector cell. With a flexible assignment of the image points to evaluation units of the LIDAR sensor, the area to be evaluated can be adapted to the Single photon detector unit in the subpixel area are made possible. This allows the single photon detector unit to be easily adapted to the transmitter unit of the LIDAR sensor. In addition, both systematic sources of error (e.g. electrical offsets, constant components in the background lighting) and stochastic sources of error (e.g. electrical and thermal noise) can be minimized.

In a further advantageous embodiment of the invention it is provided that the single photon detector unit is designed as a SPAD or SiPM detector unit. In particular, the single photon detector unit has several SPAD single photon detector cells or several SiPM single photon detector cells. Several single photon detector cells can be active at the same time, i.e. receive secondary light at the same time. If the single photon detector unit is designed as a SPAD detector unit, the evaluation of detection signals can take place statistically, for example via a histogram formation. If the single photon detector unit is designed as a SiPM detector unit, the evaluation of detection signals can take place statistically, for example via a histogram formation. Individually detected photons of a macropixel can be assigned to reception times. Such a histogram can be formed in the picosecond to nanosecond range. A reception time of the secondary light can be determined. Optionally, an intensity of the secondary light received can also be determined. Optionally, an original pulse shape of the primary light can also be reconstructed. Due to the illumination pattern, such a statistical evaluation can take place in particular more easily and quickly. The advantage of this embodiment is that, for example, compared to an APD (avalanche photodiode), the output signal does not scale linearly with a number of photons. The output signal is a current (avalanche effect, mass flow of electrons in an electrical field of a PN junction). This output signal is usually tapped as a voltage with the aid of a circuit. An A / D conversion then converts the signal to a selected interface, for example as a binary code. A smaller number of photons is necessary for evaluation. In combination with the linking of at least two single photon detector cells of an image point to form a macropixel improved histogram formation can be achieved with a large number of incoming photons on several SPAD detector units. The ToF per macropixel can be recorded as soon as at least one SPAD single photon detector cell or one SiPM single photon detector cell registers a photon in a macropixel. As a result, a double temporal parallelization of the ToF measurement in a macropixel can be achieved. In addition, a SPAD or SiPM detector unit can be inexpensive. For a SiPM single photon detector cell there is the further advantage that statistics over many pixels can be determined more quickly and without dead time of an individual detector.

In a further advantageous embodiment of the invention it is provided that the LIDAR sensor furthermore has an evaluation unit which is designed to assign at least one single photon detection event of the single photon detector unit to a time of reception. The evaluation unit can thus be designed to determine a light transit time of the primary light emitted and the secondary light received again. The distance between the LIDAR sensor and an object in the field of view can be determined, for example, on the basis of a signal transit time.

In a further advantageous embodiment of the invention it is provided that the LIDAR sensor has further optical and / or electronic elements, the further optical and / or electronic elements being arranged on the stator. Further optical elements can for example be at least one mirror, in particular at least one fixed mirror, optical filters or optical lenses. Further electronic elements can be, for example, controllable optical elements or at least one control device. For example, the receiving unit can have a more optical wavelength filter as a further optical element. Such an optical wavelength filter can be very narrow-band (bandwidth <10 nm). The advantage of this embodiment is that both the temperature stabilization, i.e. the thermal management, and the energy and data transmission within the LIDAR sensor are significantly simplified. In a further advantageous embodiment of the invention it is provided that the mirror unit is designed as a flat mirror unit with two mirror surfaces aligned parallel to the axis of rotation. The advantage of this embodiment is that it enables a double sampling rate compared to simple playing areas. Compared to LIDAR sensors with polygon mirrors, a better resolution can be achieved, in particular along a horizontal direction of the field of view.

In a further advantageous embodiment of the invention it is provided that the mirror unit with the two mirror surfaces is designed in one piece or that the mirror unit with the two mirror surfaces is designed in several parts. The advantage of the one-piece design is that such a mirror unit is simpler and more cost-effective to manufacture. A multi-part mirror unit has, for example, two flat mirror elements each with a mirror surface, the two mirror surfaces facing away from each other, and an electric drive unit, for example a flat, brushless electric motor, arranged between the two mirror elements. The advantage of the two-part design is that such a mirror unit can be less prone to failure.

In a further advantageous embodiment of the invention it is provided that the primary light and the secondary light can be coupled out and coupled in via an area of the mirror unit which is the same. The advantage of this configuration is that the mirror unit can be kept small. This means that the LIDAR sensor can also be kept small.

The invention is further based on a method for optically detecting a field of view by means of a LIDAR sensor described above with the steps of emitting primary light into the field of view by means of a laser pattern generation unit of a transmission unit arranged on a stator, the laser pattern generation unit generating an illumination pattern in the field of view, and wherein the illumination pattern has a first direction and a second direction, wherein the first direction and the second direction are arranged orthogonally to one another, and wherein an extension of the Illumination pattern along the first direction is greater than an extension of the illumination pattern along the second direction. In a further step, the primary light is decoupled by means of at least one mirror unit rotatable about an axis of rotation and arranged on a rotor, the axis of rotation being aligned parallel to the first direction, and the decoupling taking place perpendicular to the axis of rotation. In a further step, secondary light is coupled in, which was reflected and / or scattered in the field of view by an object by means of the mirror unit, the coupling taking place perpendicular to the axis of rotation. And in a further step, the secondary light is received by means of at least one single photon detector unit of a receiving unit arranged on the stator.

In particular, in the step of coupling out the primary light, the mirror unit is rotated about the axis of rotation. To capture the entire field of view, the rotation can be divided into several angular steps. The field of view can be recorded with a predetermined angular resolution. The number of angular steps required results from the size of the field of view and the angular resolution. For example, a 145 ° field of view can be captured with an angular resolution of 1/10 ° using 1450 angular steps.

drawings

In the following, exemplary embodiments of the present invention are explained in more detail with reference to the accompanying drawings. Identical reference symbols in the figures denote identical or identically acting elements. Show it:

Figure 1 First embodiment of a LIDAR sensor for optical

Detection of a field of view;

Figure 2 Second embodiment of a LIDAR sensor for optical

Detection of a field of view;

FIG. 3 examples of possible illumination patterns;

Figure 4 embodiment of a method for optical detection of a field of view. FIG. 1 shows a plan view of a first exemplary embodiment of a LIDAR sensor 100. The LIDAR sensor 100 has a housing 111. In the present example, this is angular. The housing 111 can be designed as a symmetrical or asymmetrical angular housing. For example, it can be designed as a cuboid, the overall height of which is significantly less than its overall width or overall depth. The housing 111 can be formed from metal. It can have an optical window made of plastic or glass. The optical window can be transparent for primary light 106 and secondary light 107. The optical window can be designed as a flat, vertically inclined or curved surface. The optical window can have an anti-reflective coating.

As part of a transmission unit, the LIDAR sensor 100 has a laser pattern generation unit 101 for emitting primary light 106. The laser pattern generation unit 101 is arranged on a stator 114. The laser pattern generation unit 101 is designed to be temperature-stabilized. For example, an active laser material of the laser pattern generation unit 101 can be designed to be periodically structured for this purpose. For this purpose, the laser pattern generation unit 101 can be designed as a DFB laser unit or as a DBR laser unit. The laser pattern generation unit 101 is also designed to generate an illumination pattern in the field of view of the LIDAR sensor 100. In other words, the laser pattern generation unit is designed to emit primary light 106 as an illumination pattern into the field of view of the LIDAR sensor 100. The illumination pattern here has a first direction and a second direction, the first direction and the second direction being arranged orthogonally to one another. An extension of the illumination pattern along the first direction is greater than an extension of the illumination pattern along the second direction.

The laser pattern generation unit 101 emits primary light 106. The primary light moves along an optical path of the transmission unit in the direction of a mirror unit 103 which can be rotated about an axis of rotation 104. The LIDAR sensor 100 has further optical ones arranged on the stator 114 and / or electronic elements 108 and 109 along the optical path of the transmitter unit. For example, the elements 109 can be optical lenses. In the example, the element 108 is designed as a stationary mirror unit for deflecting the primary light 106 in the direction of the rotatable mirror unit 103. The rotatable mirror unit 103 is arranged on a rotor. Here, the axis of rotation 104 is aligned parallel to the first direction of the illumination pattern. The mirror unit 103 rotates about the axis of rotation 104 along the direction 105. The primary light 106 is coupled out by means of the mirror unit 103 perpendicular to the axis of rotation 104, in this example through the optical window 112. In this way, the primary light 106 is coupled out into the field of view of the LIDAR sensor 100. In the field of view, the primary light 106 can strike an object 113 located there.

The light reflected and / or scattered by such an object 113 can be received as secondary light 107 by the LIDAR sensor 100. For this purpose, the LIDAR sensor 100 has a receiving unit with a single photon detector unit 102 arranged on the stator 114. In particular, after the reflection and / or the scattering, the secondary light 107 is received through the optical window 112 in this example and is coupled in perpendicular to the axis of rotation 104 by means of the mirror unit 103. The secondary light 107 is coupled into the LIDAR sensor 100, in particular into an optical path of the receiving unit. The secondary light 107 moves along the optical path in the direction of the single photon detector unit 102. The LIDAR sensor 100 has further optical and / or electronic elements 108 and 110 arranged on the stator 114 along the optical path of the receiving unit. The elements 110 can be, for example, optical lenses and / or optical filters. In particular, one of the elements 110 can be a very narrow-band optical wavelength filter. In the example, the element 108 is designed as a stationary mirror unit for deflecting the secondary light 107 in the direction of the single photon detector unit 102. The secondary light 107 strikes the single photon detector unit 102. The secondary light 107 can be detected by the single photon detector unit 102 in the form of one or more photons, for example. For this purpose, the single photon detector unit 102 can have several Have single photon detector cells which can be activated at the same time. The single photon detector unit 102 is designed, for example, as a SPAD or SiPM detector unit.

In order to assign at least one single photon detection event to a time of reception, the LIDAR sensor also has an evaluation unit 115. The evaluation unit 115 can be connected to the single photon detector unit 102 in such a way that one or more single photon detection events are sent to the evaluation unit 115 in the form of a detection signal 117. Evaluation unit 115 can also be connected to laser pattern generation unit 101 in such a way that a point in time of the emission of primary light 106 is sent to evaluation unit 115 in the form of a time signal 116. In particular, a point in time of the transmission of a primary light pulse can be sent to the evaluation unit 115 in the form of the time signal 116.

The evaluation unit 115 can also be designed as a control unit 115. For this purpose, the adjustment unit 115 can be connected to the laser pattern generation unit 101, to the single photon detector unit 102 and / or to the rotor of the rotatable mirror unit 103. This is the case in the example in FIG. The control unit 115 can send a control signal 119 to the laser pattern generation unit 101 to control the laser pattern generation unit 101. The control unit 115 can also send a control signal 120 to the single photon detector unit 102 for controlling the single photon detector unit 102. The control unit 115 can also send a control signal 121 to the rotor of the rotatable mirror unit 103 to control the rotation of the mirror unit 103.

The mirror unit 103 in FIG. 1 is designed as a flat, one-piece mirror unit 103 with two mirror surfaces 122 and 123 aligned parallel to the axis of rotation 104.

FIG. 2 shows a plan view of a second exemplary embodiment of a LIDAR sensor 100. This second exemplary embodiment is very similar to the first exemplary embodiment, which is why only the differences below are referred to is received. What was said in the description of FIG. 1 applies to all components that are not discussed again below. Thus, in FIG. 2, the laser pattern generation unit 101 and the

Single photon detector unit 102 arranged one above the other on the stator 114, in contrast to the exemplary embodiment from FIG. 1, in which the laser pattern generation unit 101 and the single photon detector unit 102 are arranged next to one another on the stator 114. In addition, in contrast to the exemplary embodiment from FIG. 1, the mirror unit 103 in FIG. 2 is designed as a flat, multi-part mirror unit 103 with two mirror surfaces 122 and 123 aligned parallel to the axis of rotation 104. The mirror unit 103 here has two flat mirror elements 201 and 202, each with a mirror surface 122 and 123, respectively. The two mirror elements 201 and 202 are arranged parallel to one another. The two mirror elements 201 and 202 are arranged in such a way that the two playing surfaces 122 and 123 point away from one another. An electric drive unit can be arranged between the two mirror elements 201 and 202.

FIG. 3 shows examples 304, 305 and 306 of possible illumination patterns in a field of view of a LIDAR sensor 100 described in FIGS. 1 and 2, for example. Each of the illustrated illumination patterns 304, 305 and 306 has a first direction 302 and a second direction 303, the first direction 302 being arranged to the second direction 303 orthogonally to one another. The first direction 302 of the illumination pattern can correspond to a direction of the field of view 301, in particular the vertical direction. The second direction 303 of the illumination pattern can correspond to a direction of the field of view 301, in particular the horizontal direction. The extent of each illumination pattern 304, 305 and 306 is greater along the first direction 302 than an extent of each illumination pattern 304, 305 and 306 along the second direction 303. Illumination pattern 304 is designed as a line. For such an illumination pattern 304, for example, the rotatable mirror unit of the LIDAR sensor can be designed one-dimensional. A high sampling rate and / or redundant sampling of the field of view 301 can be implemented by means of the illumination pattern 304. The illumination pattern 305 is designed as a broader line or rectangle. With such a Illumination pattern 305, the single photon detector unit of the LIDAR sensor could be designed as an elongated two-dimensional detector unit. For example, the single photon detector unit could be formed from two one-dimensional arrangements of a plurality of single photon detector cells arranged directly next to one another. The illumination pattern 305 offers the advantage that the field of view 301 can be scanned faster, more redundantly or statistically deeper. The illumination pattern 306 is designed as a pattern consisting of the two rectangles 306-1 and 306-2. The illumination pattern 306 can also be referred to as a vertical line with high-contrast gaps. The illumination pattern 306 can be used to achieve an improved trend capability on the single photon detector unit of the LIDAR sensor. In addition, the illumination pattern 306 is advantageous for eye safety.

FIG. 4 shows, as an exemplary embodiment, the method 400 for optically detecting a field of view by means of a LIDAR sensor described above. The method starts in step 401. In step 402, primary light is emitted into the field of view by means of a laser pattern generation unit of a transmission unit arranged on a stator, the laser pattern generation unit generating an illumination pattern in the field of view, and the illumination pattern having a first direction and a second direction wherein the first direction and the second direction are arranged orthogonally to one another, and wherein an extent of the illumination pattern along the first direction is greater than an extent of the illumination pattern along the second direction. In step 403, the primary light is decoupled by means of at least one mirror unit rotatable about an axis of rotation and arranged on a rotor, the axis of rotation being aligned parallel to the first direction, and the decoupling taking place perpendicular to the axis of rotation. In step 404, secondary light is coupled in that has been reflected and / or scattered in the field of view by an object by means of the mirror unit, the coupling taking place perpendicular to the axis of rotation. In step 405, the secondary light is received by means of at least one single photon detector unit of a receiving unit arranged on the stator. The method 400 ends in step 406.

Claims

Expectations

1. LIDAR sensor (100) for optical detection of a field of view (301) having:

• a transmission unit with a laser pattern generation unit (101) arranged on a stator (114) for emitting primary light (106) into the field of view (301); and wherein the laser pattern generation unit (101) is temperature-stabilized, and wherein the

The laser pattern generation unit (101) is designed to generate an illumination pattern (304, 305, 306) in the field of view (301), the illumination pattern (304, 305, 306) having a first direction (302) and a second direction (303), wherein the first direction (302) and the second direction (303) are arranged orthogonally to one another, an extent of the illumination pattern (304, 305, 306) along the first direction (302) being greater than an extent of the illumination pattern (304, 305, 306) along the second direction (303);

A receiving unit with at least one single photon detector unit (102) arranged on the stator (114) for receiving secondary light (107) which has been reflected and / or scattered in the field of view (301) by an object (113);

• at least one mirror unit (103) rotatable about an axis of rotation (104) and arranged on a rotor, the axis of rotation (104) being aligned parallel to the first direction (302); and wherein the primary light (106) and the secondary light (107) can be coupled out and in by means of the mirror unit (103) perpendicular to the axis of rotation (104).

2. LIDAR sensor (100) according to claim 1, wherein an active laser material of the laser pattern generation unit (101) is periodically structured; and wherein the laser pattern generation unit (101) is designed in particular as a DFB laser unit or as a DBR laser unit.

3. LIDAR sensor (100) according to claim 1 or 2, wherein the single photon detector unit (102) has a plurality of single photon detector cells; and wherein the plurality of single photon detector cells can be activated simultaneously.

4. LIDAR sensor (100) according to one of the preceding claims, wherein the single photon detector unit (102) is designed as a SPAD or SiPM detector unit.

5. LIDAR sensor (100) according to one of the preceding claims further comprising an evaluation unit (115) which is designed to assign at least one single photon detection event of the single photon detector unit (102) to a time of reception.

6. LIDAR sensor (100) according to one of the preceding claims having further optical and / or electronic elements (108, 109, 110), wherein the further optical and / or electronic elements (108, 109, 110) on the stator (114 ) are arranged.

7. LIDAR sensor (100) according to one of the preceding claims, wherein the mirror unit (103) is designed as a flat mirror unit (103) with two mirror surfaces (122, 123) aligned parallel to the axis of rotation (104).

8. LIDAR sensor (100) according to claim 7, wherein the mirror unit (103) is formed in one piece with the two mirror surfaces (122, 123) or wherein the mirror unit (103) is formed in several parts with the two mirror surfaces.

9. LIDAR sensor according to one of the preceding claims, wherein the primary light (106) and the secondary light (107) can be coupled out and coupled in via an area of the mirror unit (103) which is identical.

10. The method (400) for the optical detection of a field of view by means of a LIDAR sensor according to one of claims 1 to 9 with the steps:

Emission (402) of primary light into the field of view by means of a laser pattern generation unit of a transmission unit arranged on a stator, the laser pattern generation unit generating an illumination pattern in the field of view, and the illumination pattern having a first direction and a second direction, the first direction and the second Direction are arranged orthogonally to one another, and wherein an extent of the illumination pattern along the first direction is greater than an extent of the illumination pattern along the second direction; Decoupling (403) of the primary light by means of at least one mirror unit rotatable about an axis of rotation and arranged on a rotor, the axis of rotation being aligned parallel to the first direction, and the decoupling taking place perpendicular to the axis of rotation; Coupling in (404) secondary light which has been reflected and / or scattered in the field of view by an object by means of the mirror unit, the coupling taking place perpendicular to the axis of rotation; and

• Receiving (405) the secondary light by means of at least one single photon detector unit of a receiving unit arranged on the stator.