Lidar device for a vehicle and method for operating a lidar device

Abstract

The invention relates to a lidar device (10) for a vehicle (100), comprising an optical emission unit (12) having an emission light source for emitting emission light (20); an optical receiving unit (14) having an optical receiving sensor (16); and a controller (18) configured to control the lidar device (10) such that the receiving sensor (16) is ready for reception at a preparation time (TB) dependent on an internal reflection (IR), where the internal reflection (IR) is related to a reflection of the emitted light (20) within the lidar device (10). The application also relates to a vehicle (100) having a lidar device (10), and to a method for operating a lidar device (10).

Description

Technical Field

[0001] The present application relates to a lidar device for a vehicle, a vehicle having the lidar device, and a method for operating the lidar device. Background Art

[0002] Modern vehicles (cars, vans, trucks, motorcycles, etc.) have multiple sensors, and the data of these sensors is used for driver information and / or provided to driver assistance systems. The surrounding environment of the vehicle and other road users is detected by the sensors. Based on the detected data, a model of the vehicle's surrounding environment can be generated, and responses can be made to changes in these vehicle surrounding environments.

[0003] Lidar systems are continuously improved for various functions, such as detecting the surrounding environment information at short and long distances of a vehicle (such as a passenger car or a multi-purpose vehicle). Lidar systems can also be used as sensor systems for driver assistance systems, especially for assistance systems for autonomous or semi-autonomous vehicle control. They can be used in particular to identify obstacles and / or other road users in the front area, rear area or blind spot area of the vehicle. In this case, distance determination is particularly important.

[0004] An important sensor principle for detecting the surrounding environment (such as of a vehicle) in this case is lidar technology (lidar: light detection and ranging). A lidar system includes an optical transmitting unit and an optical receiving unit. The transmitting unit can emit transmitted light. In particular, laser light in the ultraviolet, visible or infrared range can be used as the light in the lidar system. After the emitted light is reflected by an object in the monitoring area of the lidar system's surrounding environment, it can be received by the receiving unit as received light.

[0005] The received light can be evaluated using the transmitted light by the computing unit of the lidar system. In particular, the spatial position and distance of the object where the reflection occurs can be determined. In the current case, the reflected light or the reflected light is understood to be any reflected light, in particular also including the light reflected by scattering or absorption-emission.

[0006] The lidar system can be designed as a flash operation system, namely the so-called flash lidar. Here, a flash lamp can be used to illuminate an area of the surrounding environment, and the receiving unit can be used to detect the received signal reflected on any possible object. A scanning lidar system emits a beam that moves along a scanning direction. A point scanner illuminates an area of the surrounding environment point by point. A line scanner illuminates an area of the surrounding environment line by line.

[0007] A receiver assembly with a photosensitive element is described in DE102017202957A1. The receiver assembly can use the photosensitive element to receive light pulses and output a corresponding received signal, which is used for object detection. The sensitivity of the light sensor element is set via a bias voltage and increased during the measurement period. SUMMARY OF THE INVENTION

[0008] A lidar device for a vehicle includes an optical transmitting unit having a transmitting light source for emitting transmitted light and an optical receiving unit having an optical receiving sensor. A controller of the lidar device is configured to activate the lidar device such that the receiving sensor is ready to receive during a preparation time depending on an internal reflection, where the internal reflection is related to the reflection of the transmitted light within the lidar device.

[0009] Starting from the time of being ready to receive, even very close objects can be measured for distance, position, and / or velocity by the lidar device. Additionally, since complex optical isolation of the transmitting light source and the receiving sensor can be omitted, the lidar device can be constructed more compactly. This is reasonable, for example, in a coaxially constructed lidar device, where the optical elements for the transmitter and the receiver can be used in common.

[0010] In a method for operating the above-described lidar device, the lidar device is activated such that the receiving sensor is ready to receive during a preparation time depending on an internal reflection, where the internal reflection is related to the reflection of the transmitted light within the lidar device. By this method, the detection distance of the lidar device can be extended to very close distances.

[0011] The receiving sensor includes at least one photosensitive element for receiving, for example, reflected transmitted light reflected on an object in a detection area of the lidar device. A further output signal for use in the vehicle can be generated, for example, by evaluating the transmitted light and the received light by a controller of the lidar device. A cycle having emission of the transmitted light and reception of the reflected light can be referred to as a measurement cycle. The duration of the measurement cycle can be in the range of nanoseconds. The output signal can include information about the distance to the object, the relative velocity of the lidar device with respect to the object, and / or information about the object properties.

[0012] The photosensitive element may include a high-sensitivity optical sensor, such as an avalanche photodiode (APD), which may also be designed as a so-called single-photon avalanche diode (SPAD), also known as Geiger-mode APD. For example, the SPAD or Geiger-mode APD may be designed for the sensitivity of a single photon. However, the threshold may also be set higher, for example, to detect light pulses, for example, to account for background noise. Multiple APDs or SPADs may be assembled to form a so-called silicon photomultiplier (SiPM), where they are interconnected in a field. The individual diodes in this field are also referred to as cells.

[0013] Such high-sensitivity optical sensors have the property that, after being triggered, for example, by a single photon, they have a strongly reduced optical sensitivity for a certain time (dead time), during which they are not ready or hardly ready to receive.

[0014] Internal reflection, also known as back reflection, can occur in a lidar device. Internal reflection can particularly involve the reflection of the emitted light on at least one optical element of the emission unit, the reception unit, and / or the housing (in particular the glass cover of the housing). In particular, at the initial emission of the light, for example, by reflection on the housing, on the emission / reception optical unit, on the optical glass cover, on a possible additional window in front of the system, and / or on other components within the lidar device, these may already cause the triggering of the reception sensor. This can occur in the described lidar device for vehicles because the emitted optical power may be several hundred watts, and a single photon may be sufficient to trigger the reception sensor.

[0015] The controller of the lidar device stimulates the lidar device such that the reception sensor is ready to receive during a preparation time depending on the internal reflection. This offers the advantage that the reception readiness can be shifted to a favorable time within the measurement cycle. For example, the reception readiness can be shifted to a time when the internal reflection within the measurement cycle has decayed. This corresponds to the reception readiness of the reception sensor being shifted to a time when the expected internal reflection has decayed.

[0016] This has the advantage that the light received from the reception readiness of the reception sensor can be used for evaluation and thus, for example, for measurement. This has the advantage that the lidar device can already perform evaluations at short distances and thus, for example, measure distances. The minimum distance that the object to be detected must be away from the lidar device can be chosen to be significantly smaller or can even be completely omitted.

[0017] Therefore, it is possible to omit the data recorded in the first nanosecond in order to suppress incorrect measurements due to internal reflections. Here, the duration of the first nanosecond is generated by the pulse length of the emitted light and the distance covered by the internal reflection within the device. Thus, the minimum distance to the lidar device to be detected can reach several meters. The described lidar device offers the associated advantage that it can be achieved without discarding the reflected emitted light received within the first nanosecond and thus has a shorter minimum distance to the detectable object.

[0018] In addition, the lidar system can more reliably detect so-called blockages. For example, blockages can occur due to contaminants in the optical unit of the device, especially contaminants outside the device, such as on the glass cover of the lidar device. Due to the so-called blockages, the lidar device cannot perform evaluations, such as object detection. Another advantage of the described lidar device is therefore that blockages of the device can be reliably identified because the received light can be directly evaluated from the time of readiness of the receiving sensor.

[0019] In an embodiment, the lidar device is configured to start emitting the emitted light at the emission time, where the readiness time of the receiving sensor depends on the emission time of the emitted light. Here, the emission time of the emitted light can in particular coincide with the readiness time. In other embodiments, the emission time can be before the readiness time, however, here the emission of the emitted light can be controlled, for example, such that full power is first reached at the readiness time.

[0020] The readiness time can also depend on the ambient light intensity and / or the temperature of the receiving sensor and can, for example, be dynamically adapted to these conditions. This allows the lidar device to perform more precise detections and measurements under varying environmental conditions.

[0021] In an embodiment, the controller of the lidar device intentionally places the receiving sensor in a non-ready-to-receive state before the readiness time. This can be achieved, for example, by triggering a dead time before the readiness time or by intentionally influencing the bias voltage of the receiving sensor. For example, if the receiving sensor includes a field with multiple cells, the average dead time across multiple cells or the maximum value of the dead time in the field can be used. It is also possible to use the full width at half maximum at the tenth maximum value of the dead time in the field, i.e., approximately 10% of the dead time in the field is higher than this value and the other dead times are lower than this value.

[0022] In an exemplary embodiment, the controller is configured to set a preparation time by exciting a receiving sensor, in particular by setting the light sensitivity of the receiving sensor. The reception preparation here depends on the light sensitivity of the receiving sensor. Depending on the type of receiving sensor, the reception preparation can vary gradually with the light sensitivity, or the reception preparation can be provided, for example, when a certain threshold of the light sensitivity is exceeded.

[0023] The setting of the light sensitivity is particularly influenced by the setting of the bias voltage of the receiving sensor. The sensitivity of the receiving sensor can be influenced by the bias voltage, in particular for high-sensitivity optical sensors such as APDs, SPADs, SiPMs. In the present case, the bias voltage of the optical receiving sensors (such as Geiger-mode APDs) can be controlled such that they are only activated after the internal reflection attenuation of the emission light source of the lidar device.

[0024] In an embodiment, the bias voltage of the receiving sensor can initially be set to be below the breakdown voltage, in particular for avalanche photodiodes, such that they are not initially activated. The bias voltage remains below the breakdown voltage and is thus in a deactivated state during the period of internal reflection. Later, after the internal reflection attenuation, the sensor is activated by increasing the bias voltage.

[0025] The reception preparation of the receiving sensor can be switched on or off approximately by means of a so-called switchable bias voltage. For example, during the preparation time, the reception preparation here can be switched on, for example, by setting it to the maximum light sensitivity. Before the preparation time, the reception preparation of the receiving sensor is kept off by means of the corresponding bias voltage. When the reception preparation is off, the internal reflection is thus not received. Then the preparation time is selected such that the internal reflection attenuates. Thus, even for an object very close in front of the sensor, its distance and position can be measured from the time of reception preparation.

[0026] Furthermore, by using the intentional control of the bias voltage, the sensitivity of the optical sensor can optionally be adapted to the expected signal level, and thus, for example, the signal-to-noise ratio can be optimized. In addition to depending on temperature and ambient light, this can also be related to the expected intensity of the received reflection. For example, for an object in the near range of the lidar device, a greater reflection intensity (i.e., light quantity) is expected compared to an object from a very far distance.

[0027] The light sensitivity of the receiving sensor can be adjusted by a corresponding setting of the bias voltage such that the light sensitivity increases during the measurement cycle in order to adapt to the lower-intensity received reflections from more distant objects. Here, the change process of the bias voltage can be determined according to the time sequence of the measurement cycle and the sensitivity characteristics of the receiving sensor.

[0028] During the measurement cycle, the bias voltage can in particular increase decrementally, linearly, quadratically and / or in steps. An increasing decrementally here means that the increase in the light sensitivity during the measurement cycle decreases, i.e., the slope of the light sensitivity curve becomes smaller and smaller. The stepwise change of the bias voltage offers the advantages of a simpler system design and in particular of the circuit design.

[0029] In particular, the intentional setting of the receiving sensor to a state of not being ready to receive before the preparation time can be carried out by optical pre-triggering of one or more photosensitive elements of the receiving sensor. Starting the dead time before the preparation time by optical pre-triggering causes the receiving sensor to be intentionally ready to receive again at the preparation time.

[0030] The pre-triggering by intentionally triggering the light sensor so that the receiving sensor is ready to receive at the preparation time can be achieved, for example, by a time offset of the excitation of the light source and / or by an intentional time profile of the actual light energy of the emitted light.

[0031] In one embodiment, the controller is configured to set the preparation time by triggering a trigger light source, the trigger light of which impinges on the receiving sensor such that the receiving sensor is ready to receive at the preparation time. In particular, the trigger time for providing the trigger of the trigger light source can be before the emission time. In particular, the trigger light of the trigger light source can be used to trigger the dead time in the receiving sensor in the case of not being ready to receive, such that the receiving sensor is then ready to receive at the preparation time.

[0032] Preferably, the trigger light source is designed specifically for light propagation and power such that as many as possible of all the units of the receiving sensor are reached and triggered. The distance between the trigger time and the emission time can advantageously be adjusted during the operation of the lidar device, for example to compensate for temperature effects and / or changes in the background light intensity.

[0033] Alternatively or additionally, the controller can be configured such that it sets the preparation time by exciting the emitted light such that the receiving sensor is ready to receive at the preparation time. This can in particular include a change in the intensity of the emitted light. Here, the intensity of the emitted light can increase during the emission. Here, it is particularly advantageous to emit the emitted light at a lower intensity at the start of the emission. Then, this emitted light of lower intensity impinges on the receiving sensor by internal reflection and causes it to enter a state of not being ready to receive during the dead time. Here, the dead time of not being ready to receive is triggered such that the receiving sensor is then ready to receive at the preparation time. Then, for example, the maximum intensity of the emitted light can be reached at the emission time.

[0034] Preferably, the design here is especially about the emission power at the start, for the triggering unit, such that all units of as many light sensors as possible are reached and triggered. The delay time during which the emitted light starts with a reduced intensity until it reaches the maximum intensity can be advantageously adjusted, for example to compensate for temperature effects and / or changes in the background light intensity. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Exemplary embodiments of the present application are explained and described in more detail below based on the drawings. In the drawings:

[0036] Figure 1 A lidar system having a transmitting and a receiving unit is schematically shown,

[0037] Figure 2 The setting of the light sensitivity of the receiving sensor is schematically shown,

[0038] Figure 3 and 4 A schematic diagram showing internal reflections,

[0039] Figure 5 and 6 The light sensitivity and dead time of the receiving sensor are schematically shown, and

[0040] Figure 7 A vehicle having a lidar system is shown.

[0041] In the drawings, the same reference numerals are used for the same or similar elements. The illustrations in the drawings may not be drawn to scale. DETAILED DESCRIPTION

[0042] Figure 1 A lidar device 10 is schematically shown. The lidar device 10 includes an optical transmitting unit 12 and an optical receiving unit 14 having a receiving sensor 16. The emission process of the emitted light 20 in the transmitting unit 12 and the receiving process of the received light 22 in the receiving unit 14 can be supervised and controlled by a controller 18. The controller 18 can be arranged, for example, on a computing unit having a processor and a memory of the lidar device 10, and can be implemented on such a computing unit, for example, as software.

[0043] The lidar device 10 can be used to detect, and thus sense, stationary or moving objects O in a detection area 30, in particular vehicles, persons, animals, plants, obstacles, road irregularities, in particular potholes or rocks, road boundaries, traffic signs, free space, in particular parking spaces, precipitation, etc. ( Figure 7). The distance to the object O and / or the direction in which the object O is located can be determined, for example, by the controller 18 evaluating the emitted light 20 and the received light 22. Alternatively or additionally, the relative velocity with respect to the object O and / or the nature of the object O can be determined. Information about the nature of the object O can be obtained, for example, by evaluating the intensity of the received light 22.

[0044] The receiving sensor 16 includes photosensitive elements, but preferably includes a plurality of photosensitive elements, which can convert the received light into an electric current that can be read out and evaluated by a downstream circuit. The photosensitive elements of the receiving sensor 16 can be designed, for example, as avalanche photodiodes (APDs), so-called single-photon avalanche diodes (SPADs), or fields of a plurality of interconnected APDs or SPADs, so-called silicon photomultipliers SiPMs. The field of photodiodes can simultaneously receive the received light 22 from multiple directions. The individual photodiodes of the SiPM are also referred to as cells. It can be stipulated that each cell of the SiPM receives the received light 22 from a different direction.

[0045] Figure 2 The light sensitivity 24 of a photosensitive element (such as an avalanche photodiode) plotted on the time axis t is shown. The light sensitivity 24 can be set via the bias voltage VB. In the example shown, the bias voltage VB increases step by step during the preparation time TB. This results in an increase in the light sensitivity 24 of the photosensitive element. In the example shown, the light sensitivity 24 of the photosensitive element increases approximately linearly from the preparation time TB. The photosensitive element is ready to receive from the preparation time TB. The relationship between the bias voltage VB and the light sensitivity 24 of the photosensitive element depends on the type of photosensitive element.

[0046] Therefore, the bias voltage VB is controlled over time such that it drops below the breakdown voltage of the photosensitive element during the internal reflection phase, so that the receiving sensor 16 is initially not activated. Then, the bias voltage VB increases above the breakdown voltage of the photosensitive element, so that the receiving sensor 16 can be activated for object measurement. This means that the bias voltage VB changes over time to adjust the light sensitivity of the photosensitive element. This means that the receiving sensor 16 is initially deactivated during the phase in which the internal reflection IR occurs and is then activated by controlling the bias voltage VB. The bias voltage VB can be changed continuously over time to adjust the sensitivity of the light sensor. Additionally, a step change of the bias voltage VB can be performed. For example, the bias voltage VB can be designed to be switchable. The reception readiness of the receiving sensor 16 is turned on or off by means of the so-called switchable bias voltage VB. Alternatively, the bias voltage VB can be realized, for example, by charging a capacitor.

[0047] The light sensitivity of a photosensitive element, in particular an avalanche diode, depends on the bias voltage VB, which can be applied as an overvoltage above the breakdown voltage of the diode. To reduce the light sensitivity of the photosensitive element, the bias voltage can be reduced, in particular to below the breakdown voltage, to deactivate the receiving sensor 16. The bias voltage VB is preferably not reduced too far below the breakdown voltage of the photosensitive element so that the sensitivity can be increased rapidly during the preparation time TB.

[0048] The emitted light 20 is emitted at the emission time TS. This is indicated by an increase in the intensity of the emitted light 20 in Figure 2 . At the time TS, an emitted light pulse is thus emitted. Due to the internal reflection IR of the lidar device 10, the first back-reflection of the received light 22 originating from the internal reflection IR initially reaches the receiving sensor 16. Detecting these internal reflections IR is not desired. Therefore, the preparation time TB is selected such that when the first internal reflection IR impinges on the receiving sensor 16, it is not yet ready to receive. The incidence of the first back-reflection of the received light 22 originating from the internal reflection IR is before the preparation time TB. The bias voltage VB is increased during the preparation time TB such that after the preparation time TB, one or more photosensitive elements of the receiving sensor 16 are ready to receive. After the preparation time TB, subsequent reflections of the emitted light 20 impinge on the receiving sensor 16 as received light 22 at a later time. This reflection can be detected as expected by the lidar device 10 with a receiving sensor 16 that is ready to receive.

[0049] Figure 3 The lidar device 10 is schematically illustrated. The optical transmitting unit 12 emits the emitted light 20. The occurrence of the internal reflection IR is shown by way of example in Figure 3 . A part of the emitted light 20 is reflected on the glass cover AG of the housing of the lidar device 10. A part of these internal reflections IR impinges on the receiving sensor 16. These internal reflections IR are not desired. If the receiving sensor 16 receives these internal reflections IR, its photosensitive elements enter a state during the dead time TZ after reception, in which the photosensitive elements are not ready to receive.

[0050] During this dead time TZ, the reflection of the emitted light 20 on an object O outside the lidar device 10 cannot be received by the receiving sensor 16. Therefore, in Figure 3 and Figure 4In an exemplary embodiment, a trigger light source TL is provided. The trigger light source TL can emit trigger light 28 onto the receiving sensor 16. Due to the trigger light 28, when the trigger light 28 is received, the photosensitive elements of the receiving sensor 16 initially enter a state in which they are not ready to receive during the dead time TZ. The dead time TZ is selected such that it coincides with the incidence of the internal reflection IR on the receiving sensor 16. After the internal reflection IR decays and after the dead time TZ ends, the receiving sensor 16 is thus ready to receive during the preparation time TB. Therefore, the trigger time TT at which the trigger light source TL is triggered is preferably selected such that the dead time TZ of the photosensitive elements of the receiving sensor 16 triggered by the trigger light 28 ends and the receiving sensor 16 is ready to receive during the preparation time TB.

[0051] Figure 4 shows a lidar device 10 having a trigger light source TL based on Figure 3 an exemplary embodiment. Figure 4 The internal reflection IR is shown, which can occur on two surfaces of the glass cover AG within the glass cover AG. The optical emission unit 12 emits the emission light 20. A part of the emission light 20 is reflected as an internal reflection IR within the glass cover AG of the lidar device 10 and is incident on the receiving sensor 16 as the internal reflection IR. These internal reflections IR incident on the receiving sensor 16 are also not desired because, as referred to in Figure 3 it triggers the dead time TZ of the photosensitive elements of the receiving sensor 16. Therefore, a trigger light source TL is provided, which emits trigger light 28 onto the receiving sensor at the trigger time TT such that as many of all the units as possible are irradiated by the trigger light 28.

[0052] Figure 3 and Figure 4 the functions of the exemplary embodiment are shown by way of example in Figure 5 The light sensitivity 26 of the optical elements of the receiving sensor 16 is shown by way of example. In the example shown, the state EB of the photosensitivity 26 refers to the reception readiness of the photosensitive elements, and the state NEB refers to the non-reception readiness of the photosensitive elements. In the example shown, the dead time TZ of the photosensitive elements is triggered by the trigger light 28 at the trigger time TT. During the dead time TZ, the photosensitive elements are in the non-reception ready state NEB. At the emission time TS, i.e., after the trigger time TT, the intensity of the emission light 20 increases such that the measurement cycle begins. Shortly after the emission light pulse of the emission light 20 ends, the reception readiness is reached during the preparation time TB. In the example shown, the preparation time TB coincides with the end of the dead time TZ. The preparation time TB is selected here such that it occurs after the internal reflection IR decays. After the preparation time TB, the photosensitive elements of the receiving sensor 16 are ready to receive the reflections on the object O and detect these objects O.

[0053] Figure 6 Schematically shows the operating mode of another embodiment of the present application. In the example shown, the intensity of the emitted light 20 increases at the emission time TS. This increase initially occurs to a lesser extent, such that since this emitted light 20 has a lower intensity and is incident on the receiving sensor 16, internal reflections occur in the lidar device. This triggers the dead time TZ in the photosensitive element of the receiving sensor 16 and causes the photosensitive element to enter the not-ready-to-receive state NEB. At the preparation time TB, the light sensitivity 26 of the photosensitive element returns to the ready-to-receive state EB.

[0054] Now, the invention of the emitted light 20 with a higher and especially full intensity occurs with a delay. It occurs such that the full intensity of the emitted light 20 is first reached after the emission time TS but before the preparation time TB of the photosensitive element of the receiving sensor 16 reaches the reception readiness EB.

[0055] Therefore, when the receiving sensor 16 is in the not-ready-to-receive state NEB during its dead time TZ, the internal reflection IR is incident on the receiving sensor 16. The preparation time TB only occurs thereafter, and the receiving sensor 16 is in the ready-to-receive state EB to receive the reflection on the object O in the detection area 30 of the lidar device 10.

[0056] Figure 7 Schematically shows a vehicle 100, such as a passenger car. The lidar device 10 is arranged in the front area of the vehicle 100. The emitted light 20 and the received light 22 can be evaluated by the controller 18 for the detection, distance determination, and / or speed determination of the object O located in the detection area 30.

[0057] The detection area 30 is located in front of the front area of the vehicle 100. Therefore, in the example shown, the area in front of the vehicle 100 in the traveling direction can be monitored. The lidar device 10 can also be arranged in other areas of the vehicle 100, such as in the rear area and / or the lateral area. A plurality of lidar devices 10 can also be arranged on the vehicle 100, especially also in the corner areas of the vehicle 100.

[0058] With the scanning lidar device 10, the detection area is continuously scanned by the emitted light 20. This is indicated by the Figure 7 arrow in. With a flash lidar, the detection area can be illuminated simultaneously in whole or in part.

Claims

1. A lidar device (10) for a vehicle (100), having an optical transmitting unit (12) having a transmitting light source for transmitting transmitted light (20), an optical receiving unit (14) having an optical receiving sensor (16), and A controller (18), the controller (18) being configured to energize the lidar device (10) such that the reception sensor (16) is ready to receive during a preparation time (TB) that depends on an internal reflection (IR), wherein, the internal reflection (IR) is related to the reflection of the transmitted light (20) within the lidar device (10).

2. The lidar device according to claim 1, wherein, The internal reflection (IR) is related to the reflection of the transmitted light on at least one optical element of the transmitting unit (12), the receiving unit (14) and / or the housing (AG).

3. The lidar device according to claim 1 or 2, wherein The lidar device (10) is configured to start transmitting the transmitted light (20) at a transmission time (TS), wherein the preparation time (TB) depends on the transmission time (TS) of the transmitted light.

4. The lidar device according to any one of the preceding claims, wherein, The preparation time (TB) depends on the ambient light power and / or temperature of the receiving sensor.

5. The lidar device according to any one of the preceding claims, wherein, The excitation of the lidar device by the controller (18) includes placing the receiving sensor (16) in an unprepared-to-receive state (NEB) before the preparation time (TB).

6. The lidar device according to any one of the preceding claims, wherein, The controller (18) is configured to set the preparation time (TB) by exciting the receiving sensor (16), in particular by setting the light sensitivity (24, 26) of the receiving sensor (16).

7. The lidar device according to claim 6, wherein, The controller (18) is configured to set the light sensitivity (14) by setting the bias voltage (VB) of the receiving sensor (16).

8. The lidar device according to claim 7, wherein, The bias voltage (VB) increases during the measurement period, and the increase occurs in particular decrementally, linearly, quadratically and / or stepwise.

9. The lidar device according to claim 6 or 7, wherein, The bias voltage (VB) is achieved by charging a capacitor.

10. The lidar device according to any one of the preceding claims, wherein, The controller (18) is configured to set the preparation time (TB) by triggering a trigger light source (TL), the trigger light (18) of which is incident on the receiving sensor (16) such that the receiving sensor (16) is ready to receive at the preparation time (TB).

11. The lidar device according to claim 10, wherein, The trigger time (TT) for providing the trigger of the trigger light source (TL) is before the transmission time (TS).

12. The lidar device according to any one of the preceding claims, wherein, The controller (18) is configured to set the preparation time (TB) by exciting the transmitted light (20) such that the receiving sensor (16) is ready to receive at the preparation time (TB).

13. The lidar device according to claim 12, wherein, The excitation of the transmitted light (20) includes a change in the intensity of the transmitted light (20), in particular an increase in the intensity of the transmitted light during transmission.

14. A motor vehicle (100) having a lidar device (10) as claimed in any one of the preceding claims.

15. A method for operating a lidar device (10), the lidar device (10) having an optical transmitting unit (12) and an optical receiving unit (14), the optical transmitting unit (12) having a transmitting light source for emitting transmitted light (12), the optical receiving unit (14) having an optical receiving sensor (16), wherein, The lidar device (10) is excited such that the receiving sensor (16) is ready to receive at a preparation time (TB) depending on the internal reflection (IR), wherein the internal reflection (IR) is related to the reflection of the transmitted light (20) within the lidar device (10).

Images