Method for operating a vehicle lidar sensor with detection of a damage event to the vehicle, lidar sensor, damage detection device and vehicle

Abstract

The invention relates to a method for operating a lidar sensor (4) of a vehicle (1), comprising the steps: emitting optical radiation by means of a transmitter unit (7), wherein at least one transmitting mirror (10) is excited to vibrate in order to emit the optical radiation, receiving the optical radiation reflected in an environment (5) of the vehicle (1) by means of a receiving unit (8), wherein at least one receiving mirror (11) is excited to vibrate in order to receive the reflected optical radiation, checking whether the vibration of the at least one transmitting mirror (10) and / or the vibration of the at least one receiving mirror (11) fulfills a predetermined synchronicity criterion, detecting a damage event of the vehicle (1) by means of checking the synchronicity criterion and outputting a damage signal which describes the damage event.

Description

[0001] The present invention relates to a method for operating a lidar sensor of a vehicle. Furthermore, the present invention relates to a lidar sensor for a vehicle. In addition, the present invention relates to a damage detection device for a vehicle with such a lidar sensor. Finally, the present invention relates to a vehicle with such a damage detection device.

[0002] Lidar sensors are used in modern vehicles and their driver assistance systems to perceive the vehicle's surroundings. For example, lidar sensors are used for highly automated driving. The lidar sensor uses optical radiation, specifically laser light, to measure distances. This allows automated vehicles to create a precise map of their environment.

[0003] A lidar sensor comprises at least one transmitter unit that emits optical radiation into the vehicle's surroundings. The optical radiation reflected from the surroundings or from objects in the vehicle's vicinity returns to the lidar sensor, where it can be received by a receiver unit. Based on the time of flight between the emission of the optical radiation and the reception of the reflected optical radiation, the distance to an object, for example, can then be determined.

[0004] The focus here is particularly on lidar sensors that use micromirrors or so-called MEMS mirrors (MEMS: Micro-Electro-Mechanical System) to emit optical radiation and / or receive reflected optical radiation. Such a micromirror or MEMS mirror comprises, for example, millimeter-sized semiconductor-based mirrors to direct the optical radiation or laser beam in different directions. The lidar sensor can include at least one transmitting mirror for deflecting the emitted optical radiation and at least one receiving mirror for receiving the reflected optical radiation from different spatial directions.

[0005] For a lidar sensor to operate, at least one transmitting mirror and / or at least one receiving mirror must oscillate at a predefined reference frequency. For example, it may be required that the transmitting mirror and the receiving mirror oscillate synchronously. This ensures reliable detection of objects in the vehicle's vicinity. If the vehicle experiences a severe vibration during operation, the synchronization of these mirrors may be disrupted. This asynchronicity is detected, for example, by a corresponding control unit of the lidar sensor.

[0006] The object of the present invention is to demonstrate a solution for how the functionality of a lidar sensor of the type mentioned above can be extended.

[0007] This problem is solved according to the invention by a method, a lidar sensor, a damage detection device, and a vehicle with the features according to the independent claims. Advantageous embodiments of the present invention are specified in the dependent claims.

[0008] A method according to the invention serves to operate a lidar sensor of a vehicle. The method comprises the emission of optical radiation by means of a transmitting unit, wherein at least one transmitting mirror is excited to vibrate in order to emit the optical radiation. Furthermore, the method comprises the reception of the optical radiation reflected in the vicinity of the vehicle by means of a receiving unit, wherein at least one receiving mirror is excited to vibrate in order to receive the reflected optical radiation. The method further comprises checking whether the vibration of the at least one transmitting mirror and / or the vibration of the at least one receiving mirror fulfills a predetermined synchronicity criterion. In addition, the method comprises the detection of a damage event of the vehicle by means of checking the synchronicity criterion and the output of a damage signal that describes the damage event.

[0009] The lidar sensor can detect objects in the vicinity of the vehicle. The lidar sensor's transmitter unit emits optical radiation, particularly laser radiation in the infrared wavelength range. The transmitter unit can include a suitable light source or laser diode for emitting the optical radiation or laser light. Furthermore, the transmitter unit comprises at least one transmitting mirror, which can be a micromirror or MEMS mirror. This transmitting mirror can be set into vibration, allowing the emitted optical radiation to be deflected in different directions. The transmitter unit can also include multiple transmitting mirrors or micromirrors.

[0010] Furthermore, the lidar sensor includes a receiver unit that can receive the optical radiation reflected from the vehicle's surroundings. The receiver unit can also have multiple receiving mirrors. The receiver unit includes at least one receiving mirror, which can preferably be a micromirror or MEMS mirror. Using the at least one receiving mirror, the reflected optical radiation can be detected from different directions and, for example, deflected to a suitable detector for the optical radiation. This detector can, for example, be a laser detector or the like.

[0011] The lidar sensor can also include a corresponding control unit or lidar control unit, by means of which the excitation of the at least one transmitting mirror and / or the at least one receiving mirror can be controlled or regulated to cause oscillation. In particular, it is provided that a corresponding controller or control loop is used to regulate the oscillation of the at least one transmitting mirror and / or the oscillation of the at least one receiving mirror. This controller can be a separate component or implemented by the lidar sensor's control unit.

[0012] The control unit can also check whether the oscillation of at least one transmitting mirror and / or at least one receiving mirror meets the predetermined synchronization criterion. This synchronization criterion can, for example, specify that the at least one transmitting mirror and / or at least one receiving mirror oscillates at a predetermined frequency, or that at least two of these mirrors oscillate synchronously with each other. The lidar control unit can then report an error and degrade the system until the mirrors are moving synchronously again.

[0013] The synchronization criterion may no longer be met, for example, if the lidar sensor or its micromirrors are subjected to shock, acceleration, and / or force. For instance, a severe shock resulting from an accident or collision with an object may disrupt the synchronization of the transmitting and / or receiving mirrors. This asynchrony can then be detected by the lidar sensor or its control unit.

[0014] According to the present invention, the knowledge is utilized that the lidar sensor, which comprises at least one transmitting mirror and / or at least one receiving mirror, can already indirectly detect vibrations or damage events to the vehicle. This information is then used to detect a vehicle rollover more reliably. If the vehicle's lidar sensor detects that the synchronization criterion is no longer met, the damage signal can be output by the lidar sensor's control unit, and further measures can then be initiated as a result of this damage signal, for example, to reduce the effects on the occupants and / or the vehicle itself. Overall, the functionality of the lidar sensor can thus be expanded.

[0015] Preferably, when verifying the synchronicity criterion, the oscillation of at least one transmitting mirror is compared with the oscillation of at least one receiving mirror. Thus, when verifying the synchronicity criterion, it can be checked whether at least one transmitting mirror oscillates synchronously with at least one receiving mirror. If the lidar sensor has at least two transmitting mirrors, it can be checked whether they oscillate synchronously with each other. If the lidar sensor includes at least two receiving mirrors, it can be checked whether they oscillate synchronously with each other. However, it is also conceivable, in principle, to check whether at least one transmitting mirror and / or at least one receiving mirror oscillates synchronously with a predetermined reference frequency.

[0016] As explained earlier, a suitable controller or control loop can be provided to regulate the oscillation of at least one transmitting mirror and / or at least one receiving mirror. The synchronization criterion can then be checked based on the controller's deviation. For example, it can be verified whether the controller deviation exceeds a predetermined limit.

[0017] Furthermore, it is advantageous if the severity and / or type of damage event can be identified based on the synchronicity criterion. For example, the severity of the damage event can be estimated based on the deviation of the oscillation of at least one transmitting mirror and / or at least one receiving mirror from the reference frequency. When using a controller, the severity of the damage event can be identified based on the controller deviation. Based on the controller deviation or the amplitude of the asynchronicity, the type of damage event can then also be identified. Thus, for example, a distinction can be made between a minor collision and a serious accident. In this way, the damage signal output by the lidar sensor can also provide information describing the severity and / or type of the damage event.

[0018] Furthermore, the system may include the ability to determine the spatial direction in which the oscillation of the transmitting mirror and / or the receiving mirror deviates when verifying the synchronization criterion. Based on the design of the transmitting mirror and / or the receiving mirror, as well as the asynchrony, it is possible, for example, to identify the spatial direction in which a force or acceleration acts on the lidar sensor and thus on the vehicle. This allows for differentiation between forces acting longitudinally or vertically along the vehicle. Using this information, it is then possible, for instance, to distinguish whether the vehicle drove over a pothole or whether a rear-end collision occurred.

[0019] In particular, it is provided that at least one transmitting mirror and / or at least one receiving mirror oscillates at a frequency in the range of several kilohertz. During operation of the control loop, sampling can thus take place at a sampling rate or frequency significantly higher than the oscillation frequency of at least one transmitting mirror and / or at least one receiving mirror. This allows deviations in synchronization or failure to meet the synchronization criterion to be detected within a short period of time, thereby providing very rapid information about a potential vehicle malfunction.

[0020] A lidar sensor according to the invention for a vehicle is configured to emit optical radiation by means of a transmitter unit, wherein the lidar sensor excites at least one transmitting mirror to vibrate in order to emit the optical radiation. Furthermore, the lidar sensor is configured to receive the optical radiation reflected in the vicinity of the vehicle by means of a receiver unit, wherein the lidar sensor excites at least one receiving mirror to vibrate in order to receive the reflected optical radiation. The lidar sensor is also configured to check whether the vibration of the at least one transmitting mirror and / or the vibration of the at least one receiving mirror fulfills a predetermined synchronization criterion. In addition, the lidar sensor is configured to detect a damage event of the vehicle by checking the synchronization criterion and to output a damage signal that describes the damage event.

[0021] The vehicle's lidar sensor can consist of a laser range finder with one transmitting mirror and one receiving mirror. Alternatively, the lidar sensor can have two laser range finders, each with one transmitting mirror and three receiving mirrors. Such a lidar sensor then comprises eight micromirrors.

[0022] Another aspect of the invention relates to a damage detection device for a vehicle. This damage detection device comprises a lidar sensor according to the invention. Furthermore, the damage detection device includes a computing unit configured to output a control signal depending on the damage signal output by the lidar sensor. The computing unit can, for example, be a control unit of the vehicle. The computing unit can have at least one processor. A control signal can be output by means of the computing unit, which can be used, for example, to control the vehicle's safety systems. As a result of the control signal, restraint systems of the vehicle, such as airbags, seatbelt pretensioners, or the like, can be activated.

[0023] Preferably, the damage detection device includes a collision sensor for detecting the damage event. In principle, the damage detection device can be used to detect damage events or collisions involving the vehicle and, depending on the detected damage event, to initiate damage mitigation measures. The collision sensor in the damage detection device can be, for example, an acceleration sensor, a force sensor, or the like. In addition to this known collision sensor, information from the lidar sensor can now be used to detect and / or characterize the damage event. This improves the reliability of damage event detection.

[0024] Furthermore, it is advantageous if the damage detection device has an output unit for providing information about the detected damage event to the vehicle's driver. This is particularly suitable if, for example, a minor rear-end collision, a parking bump, or driving over a pothole is detected as the damage event. In this case, the driver can, for example, be informed via the output unit that the lidar sensor may be damaged and that they should visit a repair shop if necessary.

[0025] A vehicle according to the invention comprises a damage detection device according to the invention. The vehicle is in particular designed as a passenger car.

[0026] The preferred embodiments and their advantages presented with reference to the method according to the invention apply accordingly to the lidar sensor according to the invention, to the damage detection device according to the invention, and to the vehicle according to the invention.

[0027] Further features of the invention will become apparent from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown in the figures alone, can be used not only in the combinations specified, but also in other combinations or on their own, without departing from the scope of the invention.

[0028] The invention will now be explained in more detail with reference to preferred embodiments and the accompanying drawings. These show: Fig. 1 a schematic representation of a vehicle which has a damage detection device with a lidar sensor; and Fig. 2 A schematic representation of the lidar sensor, which has a transmitter unit and a receiver unit.

[0029] Fig. Figure 1 shows a schematic representation of a vehicle 1, which in this case is a passenger car. The vehicle 1 includes a damage detection device 2 by means of which, as explained in more detail below, a damage event on the vehicle 1 can be detected. The damage detection device 2 includes a lidar sensor 4 by means of which objects 6 in the vicinity 5 of the vehicle 1 can be detected. An object 6 in the vicinity 5 of the vehicle 1 is shown schematically below.

[0030] The lidar sensor 4 comprises a transmitter 7, which can emit optical radiation or laser light. Furthermore, the lidar sensor 4 comprises a receiver 8, which can receive the optical radiation reflected by the object 6 in the environment 5. Based on the time of flight between the emission of the optical radiation and the reception of the reflected optical radiation, a distance between the lidar sensor 4 (or the vehicle 1) and the object 6 can then be determined.

[0031] Fig. Figure 2 shows a schematic representation of the transmitter unit 7 and the receiver unit 8 of the lidar sensor 4. The transmitter unit 7 includes a light source 9 for emitting the optical radiation or laser light. The light source 9 can, for example, be a suitable laser diode. Furthermore, the transmitter unit 7 includes a reflector 10 for deflecting the optical radiation emitted by the light source 9. The reflector 10 is designed as a so-called micromirror or MEMS mirror. The reflector 10 serves to deflect the optical radiation into different solid angle regions in the vicinity 5 of the vehicle 1.

[0032] The receiver unit 8 of the lidar sensor 4 comprises a receiving mirror 11, which is also designed as a micromirror or MEMS mirror. This receiving mirror 11 serves to receive the optical radiation reflected from different solid angle regions in the vicinity 5 of the vehicle 1 and to direct it to a detector 12 of the receiver unit 8. The detector 12 can, for example, be designed as a laser detector.

[0033] During operation of the lidar sensor 4, both the transmitting mirror 10 and the receiving mirror 11 oscillate at a predetermined reference frequency. A control loop can be provided for this purpose by means of a control unit 13 of the lidar sensor 4, by means of which both the transmitting mirror 10 and the receiving mirror 11 are excited to oscillate, whereby the mirrors 10 and 11 are excited to oscillate in such a way that they oscillate synchronously with each other. During operation of the vehicle 1 or while the vehicle 1 is in motion, vibrations, forces, or accelerations can act on the lidar sensor 4. These effects can lead to asynchrony of the oscillations of the transmitting mirror 10 and the receiving mirror 11. This means that a predetermined synchronicity criterion regarding the oscillation of the transmitting mirror 10 and the receiving mirror 11 is no longer met, or the transmitting mirror 10 no longer oscillates synchronously with the receiving mirror 11.

[0034] This detection of the asynchrony between the transmitting mirror 10 and the receiving mirror 11 is used to detect damage to or from vehicle 1. In the event of a collision with an obstacle or an accident involving vehicle 1, forces, accelerations, or vibrations occur at the lidar sensor 4, which can be detected by the control unit 13 as asynchrony between mirrors 10 and 11. The lidar sensor 4 and the control unit 13 can then output a damage signal describing this event.

[0035] This damage signal, which is output by the lidar sensor, can then be used by the damage detection device 2 of the vehicle 1, which is located in Fig.Figure 1 is shown schematically. The damage detection device 2 comprises a computing unit 3, which is connected to the lidar sensor 4 for data transmission. Thus, the damage signal from the lidar sensor 4 can be transmitted to the computing unit 3 of the damage detection device 2. Using the computing unit 3, the damage event on the vehicle 1 can then be characterized based on the damage signal. The severity and type of the damage event can also be determined based on the damage signal. Thus, for example, a distinction can be made between a minor parking bump, a rear-end collision, or a serious collision.

[0036] Furthermore, the damage detection device 2 includes a collision sensor 14, which serves to detect damage to the vehicle 1. The collision sensor 14 is, for example, an acceleration sensor, which is commonly used in damage detection devices 2. In the damage detection device 2, the signal from the collision sensor 14 can be validated, for example, by the damage signal from the lidar sensor 4. Depending on the detected damage or collision, a control signal can then be output by the processing unit 3, which in turn initiates protective measures for the occupants of the vehicle 1. Such protective measures can include, for example, the activation of airbags, the activation of seat belt tensioners, the activation of the brakes of the vehicle 1, or the like. Reference symbol list 1 vehicle 2 Damage detection device 3 Computing equipment 4 Lidar sensors 5 Environment 6 objects 7 transmitter unit 8 receiver unit 9 Light source 10 transmission mirrors 11 reception mirrors 12 Detector 13 Control unit 14 Collision sensor

Claims

[1] Method for operating a lidar sensor (4) of a vehicle (1), comprising the steps: - Emitting optical radiation by means of a transmitting unit (7), wherein at least one transmitting mirror (10) is excited to oscillate in order to emit the optical radiation, - Receiving the optical radiation reflected in an environment (5) of the vehicle (1) by means of a receiving unit (8), wherein at least one receiving mirror (11) is excited to oscillate in order to receive the reflected optical radiation, and - Check whether the oscillation of the at least one transmitting mirror (10) and / or the oscillation of the at least one receiving mirror (11) fulfills a predetermined synchronicity criterion, characterized by - Detecting a damage event of the vehicle (1) by checking the synchronicity criterion and - Outputting a damage signal that describes the damage event. [2] Method according to claim 1, characterized by , that when checking the synchronicity criterion, the oscillation of the at least one transmitting mirror (10) is compared with the oscillation of the at least one receiving mirror (11). [3] Method according to claim 1 or 2, characterized by , that the severity and / or type of the damaging event is identified by checking the synchronicity criterion. [4] Lidar sensor (4) for a vehicle (1) which is designed to: - to emit optical radiation by means of a transmitting unit (7), wherein the lidar sensor (4) excites at least one transmitting mirror (10) to oscillate in order to emit the optical radiation, - to receive the optical radiation reflected in an environment (5) of the vehicle (1) by means of a receiving unit (8), wherein the lidar sensor (4) excites at least one receiving mirror (11) to oscillate in order to receive the reflected optical radiation, and - to check whether the oscillation of at least one transmitting mirror (10) and / or the oscillation of at least one receiving mirror (11) fulfills a predetermined synchronicity criterion, characterized by , that the lidar sensor (4) is also configured to - to identify a damage event of the vehicle (1) by checking the synchronicity criterion and - to issue a damage signal that describes the damage event. [5] Damage detection device (2) for a vehicle (1) comprising a lidar sensor (4) according to claim 4 and a computing device (3), wherein the computing device (3) is configured to output a control signal depending on the damage signal output by the lidar sensor (4). [6] Damage detection device (2) according to claim 5, characterized by , that the damage detection device (2) has a collision sensor (14) for detecting the damage event. [7] Damage detection device (2) according to claim 5 or 6, characterized by , that the damage detection device (2) has an output unit for outputting information about the detected damage event to a driver of the vehicle (1). [8] Vehicle (1), in particular passenger car, comprising a damage detection device (2) according to any one of claims 5 to 7.

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