DE102021203972A1 - LiDAR system with mechanical protection - Google Patents

Abstract

The present invention relates to a LiDAR system (1) comprising an emitter unit and a detector unit and a housing (2) in which the emitter unit and the detector unit are arranged. The housing includes (2) an at least partially transparent cover window (3), the LiDAR system (1) being set up to emit a laser beam from the emitter unit for scanning an environment through the cover window (3) and laser light reflected from the environment through to receive the cover window (3) on the detector unit. Known LiDAR systems have only insufficient protection against damage and soiling of the cover window (3). According to the invention, the LiDAR system (1) comprises a hazard detection unit which is set up to activate a mechanical protective device (4) on the housing (2) when a dangerous situation is detected for the LiDAR system (1) in order to protect the cover window (3) at least partially covered on the outside. This can significantly increase the service life of the LiDAR system (1).

Description

The present invention relates to a LiDAR system comprising an emitter unit and a detector unit, and a housing in which the emitter unit and the detector unit are arranged, the housing comprising an at least partially transparent cover window, the LiDAR system being set up to emit a laser beam to be emitted from the emitter unit for scanning an environment through the cover window and to receive laser light reflected from the environment through the cover window at the detector unit.

State of the art

Optoelectronic environment sensors (such as LiDAR systems or environment cameras) experience a significant reduction in performance as soon as their optically active surface becomes dirty during use, for example due to mud, salt films, insects or dust in combination with liquid, or is damaged, for example, by stone chips or scratches. This applies to the cover window of the sensor, which as the outermost layer in front of the sensor optics comes into direct contact with the environment.

The state of the art so far only provides for the detection and/or the subsequent cleaning of dirt from the cover window, as well as an exchange of the sensor or its cover window if the degree of damage is too great. Today's housings of the sensor units of LiDAR systems are often hermetically sealed, so that the cover window cannot simply be exchanged and the LiDAR system or at least one sensor unit with housing (in the case of multiple sensor units in a LiDAR system each with their own housing) in the event of a defect Cover window is a total disposable product. Since the typical LiDAR system in automotive applications is usually specified for a lifetime of 15 years, the alternative to a complete replacement would be a continuous degradation of the system performance, especially for the front-facing and/or lower-mounted sensor units, which e.g. B. are more exposed to flying debris and hail when driving.

From the WO 2017/029775 A1 a system for an autonomous vehicle with LiDAR is known, with a communication interface configured to receive driving environment information and circuitry configured to determine a navigation route based on a degree of reliability of the driving environment information provided by other autonomous vehicles . Information about the quality or danger (particularly falling rocks, weather, etc.) of the route can be included.

WO 2018/197398 A1 and WO 2019/121347A1 disclose sensor systems comprising a LiDAR sensor and a cover partially or completely surrounding the LiDAR sensor with a special combination of materials comprising a thermoplastic composition with high permeability in the infrared range. The composition should also be resistant to weathering and stone chipping.

DE 10 2017 200 795 A1 shows an arrangement as part of a LiDAR device for providing at least one beam with reduced interference reflections, having a mirror, a radiation source and a cover glass to protect the mirror. The cover glass protects against external influences such as dust, dirt, stone chips etc.

Disclosure of Invention

According to the invention, a LiDAR system of the type mentioned is provided, characterized in that the LiDAR system comprises a hazard detection unit which is set up to activate a mechanical protective device on the housing when a dangerous situation for the LiDAR system is detected, in order to at least partially cover the cover window to cover the outside.

Advantages of the Invention

The solution according to the invention has the advantage that, in a dangerous situation, damage to the cover window can be avoided much better. The state of the art has hitherto only been aimed at avoiding certain, previously known dangerous situations through route planning, subsequent cleaning or more resistant cover windows. However, the solution according to the invention allows both damage and contamination to be avoided or at least significantly reduced in significantly more situations and thus to improve the service life itself and the performance development over the service life of a LiDAR system. Maintenance without a complete replacement of a sensor unit can also be made possible if the mechanical protective device, e.g. B. includes replaceable wear elements that are removably attached to the outside of the housing.

The movement of the mechanical protection device can be fully or partially driven and/or after the release of a holding device direction by gravity or a magnetic force or a mechanical biasing force.

Preferably, elements of the mechanical protection device are interchangeably attached to the housing, such as. B. a protective layer to enable replacement after damage to the protective device.

• - keine Beschädigungsdetektion ist erforderlich,
• - kein Austausch des Abdeckfensters ist erforderlich,
• - kein Unterschied zwischen BOL (Beginn of life) und EOL (End of life) Performance der Sensoreinheit, d.h. Aufrechterhaltung der optischen Performance der Sensoreinheit über die Lebensdauer,
• - keine mechanische Beschädigung des Glases / Kunststoffs des Abdeckfensters, d. h. die Lebensdauer einer (z. B. hydrophoben) Beschichtung wird signifikant erhöht,
• - der Schutzmechanismus ist unabhängig von Sensortyp und -Hersteller z. B. kann ein Fremdsensor als verschlossene „Blackbox“ geschützt werden, ohne beispielsweise NDA-Verletzungen (NDA = non-disclosure agreement, engl. Verschwiegenheitsvereinbarung) zu begehen. Kein Eingriff in den Sensor ist notwendig, sondern es wird nur eine spezifizierte Schnittstelle zur Ansteuerung benötigt,
• - mechanische Schutzeinrichtung funktioniert sowohl bei stehendem als auch bei fahrendem Ego-Fahrzeug,
• - die mechanische Schutzeinrichtung bietet auch Schutz vor Frost (z. B. Zerkratzen durch eine sich bildende Eisschicht) bei längerem Stand an kalten Orten,
• - die mechanische Schutzeinrichtung bietet einen Schutz vor Alterung durch Sonnenbestrahlung an sonnigen Orten,
• - die mechanische Schutzeinrichtung bietet einen Schutz vor Salzfilmen an meeresnahen Orten,
• - die mechanische Schutzeinrichtung bietet einen Schutz vor mechanischer Beschädigung bei böswilliger Beschädigung oder Parkremplern,
• - die mechanische Schutzeinrichtung erlaubt eine schnellere Entfrostung bei aktivierter Heizung, d.h. schnellstmögliche Herstellung der Funktionalität nach Tau oder Frost ist möglich, wenn die mechanische Schutzeinrichtung in der Parksituation aktiviert war,
• - eine optische Anpassung des LiDAR-Einbauortes an Wagenlackfarbe im Stillstand / Parkmodus und integrierte Abdeck- bzw. Abschiedszeremonie bei Verlassen des Fahrzeuges ist möglich.

Further advantages of the invention are:

• - no damage detection is required,
• - no replacement of the cover window is required,
• - no difference between BOL (beginning of life) and EOL (end of life) performance of the sensor unit, ie maintaining the optical performance of the sensor unit over the service life,
• - no mechanical damage to the glass / plastic of the cover window, i.e. the service life of a (e.g. hydrophobic) coating is significantly increased,
• - the protective mechanism is independent of the sensor type and manufacturer, e.g. For example, a third-party sensor can be protected as a locked "black box" without, for example, violating the NDA (NDA = non-disclosure agreement). No intervention in the sensor is necessary, only a specified interface is required for control,
• - mechanical protective device works both when the ego vehicle is stationary and moving,
• - the mechanical protection device also offers protection against frost (e.g. scratching by a layer of ice forming) when standing in cold places for a long time,
• - the mechanical protection provides protection against aging caused by solar radiation in sunny places,
• - the mechanical protection device provides protection against salt films in places close to the sea,
• - the mechanical protection device provides protection against mechanical damage in the event of malicious damage or parking bumps,
• - the mechanical protective device allows faster defrosting when the heating is activated, i.e. the fastest possible restoration of functionality after dew or frost is possible if the mechanical protective device was activated in the parking situation,
• - An optical adaptation of the LiDAR installation location to the vehicle paint color when stationary / parking mode and an integrated covering or farewell ceremony when leaving the vehicle is possible.

Advantageous developments of the invention are specified in the dependent claims and described in the description.

In one embodiment, the mechanical protective device is set up to move at least one protective layer in front of the cover window when a dangerous situation is detected. A protective layer enables the cover window to be covered as completely as possible in relation to the environment and thus the best possible protection. The protective layer is preferably a flexible (e.g. bendable and/or rollable) protective layer, in particular made of a plastic. The protective layer can be guided, for example, in one or two guide rails on the housing. However, guide rails can also be used in other configurations of the mechanical protective device.

The protective layer is preferably at least partially transparent. As a result, the LiDAR system can continue to operate even while the mechanical protective device is activated, albeit possibly with reduced performance due to interference in the light path through the (possibly dirty/damaged) protective layer. The protective layer preferably consists of a transparent plastic.

It is preferred if the mechanical protective device is set up to move two interacting protective layers in front of the covering window when a dangerous situation is detected. As a result, the entire covering window can be covered more quickly or a certain redundancy can be achieved if the protective layers can at least partially overlap in the covering position. The protective layers can be guided in independent, staggered guide rails. This allows double coverage to be achieved. Alternatively, the protective layers can be guided in common guide rails, which means that double coverage is not possible, since both protective layers ideally abut one another at the end edges in the covering position, but protection against failure and faster coverage can still be achieved compared to just one protective layer.

At least one protective layer preferably rests against a further outer wall of the housing in the non-activated position, or at least one protective layer is in the non-activated position at least least partly rolled up. Both solutions allow the protective layer to be arranged in a space-saving manner and the at least one protective layer to be activated and moved quickly into a covering position.

• - von einem Mikrophon gelieferte Umgebungsgeräuschdaten,
• - von einem Beschleunigungssensor gelieferte Beschleunigungsdaten,
• - von einem Navigationssystem gelieferte Standortdaten und / oder Kartendaten,
• - aus den Daten der Detektoreinheit des LiDAR-Systems ermittelte 3D-Punktenwolken-Informationen aus der sich nähernde Gefahrenquellen erkannt wurden,
• - von einem Temperatursensor gelieferte Temperaturdaten,
• - per Mobilfunk und / oder GPS bereitgestellte Wetterinformationen
• - von einem Geschwindigkeitssensor gelieferte Geschwindigkeitsdaten insbesondere zur Erkennung eines Stillstands,
• - vom LiDAR-System sowie von externen Sensoren gelieferte Daten zur Erkennung von Umgebungsobjekten wie insbesondere LiDAR-Umgebungsdaten Ultraschalldaten, Kameradaten, Radardaten,
• - von einer externen Steuereinheit gelieferte Fahrzeugsituationsdaten.

It is preferred if the hazard detection unit includes one or more of the following data in order to detect a hazard situation:

• - Ambient noise data provided by a microphone,
• - acceleration data provided by an accelerometer,
• - location data and/or map data supplied by a navigation system,
• - 3D point cloud information determined from the data of the detector unit of the LiDAR system, from which approaching sources of danger were recognized,
• - temperature data provided by a temperature sensor,
• - weather information provided by mobile phone and/or GPS
• - speed data supplied by a speed sensor, in particular for detecting a standstill,
• - Data supplied by the LiDAR system and external sensors for the detection of surrounding objects, such as in particular LiDAR surrounding data, ultrasound data, camera data, radar data,
• - vehicle situation data supplied by an external control unit.

One or more of these sensors or sources of information may be part of the LiDAR system or part of a vehicle in which the LiDAR system is installed. The threat detection unit of the LiDAR system can include a local control unit in the LiDAR system or the housing of a/each sensor unit. Ambient noise data can provide indications of the beginning of falling rocks, grit or dirt on the road, hail or similar hazardous situations. Acceleration data can provide an indication of the severity of a hazardous situation, e.g. B. if the driver brakes hard when a potentially dangerous situation is identified (a small amount of debris flying around is detected with a microphone/lidar point cloud), since this is e.g. B. can greatly increase the amount of flying debris (e.g. from the tires of the vehicle in front). Vehicle situation data can e.g. B. include the standstill of the vehicle, so that, for example, automatically or instructed by the user during a parking process, the mechanical protection device is activated. However, this can also depend on other parameters, e.g. B. only when parking in the open air or when snow / hail etc. are forecast (with access to external weather data) or the temperature measured by the temperature sensor is below a certain threshold (e.g. below 5°C or below 0°C Etc.).

In the non-activated position, the mechanical protective device is preferably pretensioned by a holding mechanism and is set up such that when the mechanical protective device is activated, the holding mechanism is released and the mechanical protective device automatically moves into the covering position. This solution allows the cover window to be covered quickly and regularly reduces power consumption, since any drive that may be present for the mechanical protective device is then only activated when the mechanical protective device (or e.g. a protective layer) is deactivated and moved back into the non-activated position must be active. The holding mechanism can e.g. B. include a spring mechanism or a magnetic mechanism.

In one embodiment, the mechanical protective device comprises a protective mechanism which, when activated, automatically moves into the covering position under the influence of gravity. An example of such a protective mechanism is a so-called Nuremberg scissors, i.e. a kind of self-deploying lattice. Although such a mechanism does not usually cover the cover window as evenly, depending on the design, it tends to be more resistant than a protective layer, in particular to larger objects such as in the case of falling rocks or hail.

The mechanical protective device preferably comprises a drive unit which is set up to move the mechanical protective device back into a non-activated position after it has been activated. However, the drive unit can also be set up to move the mechanical protective device from the non-activated position into the covering position when it is activated. For example, if two cooperating protective layers are used, it may be necessary that one or both protective layers are also driven when moving to the covering position, e.g. B. in a protective layer against gravity or protective layers that are performed substantially horizontally. Alternatively, the mechanical protective device can also be moved back manually after activation back into a non-activated position can be provided if the most cost-effective system is desired.

It is preferred if the mechanical protective device comprises a magnetic return mechanism which is set up to move the mechanical protective device back into a non-activated position after activation. The magnetic return mechanism may comprise an electromagnet adapted to e.g. B. to overcome a spring force until the mechanical protection device can be held in the non-activated position by a holding mechanism until the next activation. It is also possible to combine a spring mechanism for activation with the protective device with an electric motor for retracting the protective device.

The LiDAR system can also include a number of sensor units, each with a LiDAR unit in separate housings, in which case all or just some of the housings can/can have mechanical protective devices.

The invention also relates to a vehicle comprising a LiDAR system according to one of the above embodiments, the vehicle preferably being an at least partially self-driving passenger vehicle or truck. The vehicle can be a motor vehicle, in particular a road-bound motor vehicle, for example a passenger car or a truck or a two-wheeler.

character list

• 1 eine erste Ausführungsform eines erfindungsgemäßen LiDAR-Systems in Seitenansicht,
• 2 eine zweite Ausführungsform eines erfindungsgemäßen LiDAR-Systems in Seitenansicht,
• 3 eine dritte Ausführungsform eines erfindungsgemäßen LiDAR-Systems in Seitenansicht,
• 4 eine vierte Ausführungsform eines erfindungsgemäßen LiDAR-Systems in Seitenansicht,
• 5 eine fünfte Ausführungsform eines erfindungsgemäßen LiDAR-Systems in Frontansicht,
• 6 eine sechste Ausführungsform eines erfindungsgemäßen LiDAR-Systems in Frontansicht.

Exemplary embodiments of the invention are explained in more detail with reference to the drawings and the following description. Show it:

• 1 a first embodiment of a LiDAR system according to the invention in side view,
• 2 a second embodiment of a LiDAR system according to the invention in side view,
• 3 a third embodiment of a LiDAR system according to the invention in side view,
• 4 a fourth embodiment of a LiDAR system according to the invention in side view,
• 5 a fifth embodiment of a LiDAR system according to the invention in front view,
• 6 a sixth embodiment of a LiDAR system according to the invention in front view.

Embodiments of the invention

1 until 6 show six different embodiments of a LiDAR system 1 according to the invention, each comprising an emitter unit and a detector unit (each not shown), which are arranged in a housing 2. The housing 2 includes an at least partially transparent cover window 3. The LiDAR system 1 is set up to emit a laser beam from the emitter unit for scanning an environment through the cover window 3 and to receive laser light reflected from the environment through the cover window 3 at the detector unit.

The LiDAR system 1 now includes a danger detection unit that is set up to activate a mechanical protective device 4, 5, 6 on the housing 2 when a dangerous situation is detected for the LiDAR system 1 in order to at least partially cover the cover window 3 to the outside. This allows the cover window z. B. in front of an approaching rockfall 7, as in 1 until 4 displayed, protected.

In the 1 until 5 Embodiments are shown in which the mechanical protective layer 4, 5 is set up to move at least one protective layer 4, 5 in front of the cover window 3 when a dangerous situation is detected. The embodiments of 1 , 2 , 3 , 4 , 5 each have a protective layer 4, while the embodiment of 2 is set up to move two cooperating protective layers 4, 5 in front of the cover window 3. Cooperating can alternatively to the embodiment of 2 also mean an overlapping of the protective layers 4, 5, for example to achieve greater protection or to create redundancy in the event of a possible failure (jamming, cracking, etc.) of one of the protective layers. The arrows at the end of the protective layers 4, 5 or next to them respectively illustrate their direction of movement upon activation.

In particular, in the first embodiment of the 1 is the protective layer 4 in non-activated position on another outer wall of the housing (here the top of the housing 2).

In the third and fourth embodiment of the 3 and 4 a protective layer 4, 5 is at least partially rolled up in the non-activated position.

In the second embodiment of the 2 it is left open how the two cooperating protective layers 4, 5 are each arranged in the non-activated position, of course both the solutions corresponding 1 (Applying to the other outside of the housing 2) or the 3 (at least partially rolled up) are conceivable.

4 and 5 show embodiments in which the mechanical protective device 4, 5 is pretensioned in the non-activated position by a holding mechanism and is set up such that when the mechanical protective device 4, 5 is activated, the holding mechanism is released and the mechanical protective device 4, 5 automatically moves into moves the covering position. In 4 two possible positions of the protective layer 4 during activation are shown (dashed or with a dash-dot line). The protective layer 4 is not here as in 1 and 2 lowered (or raised) but is further rolled up in its partially rolled-up state in an angular increment until a holding mechanism (e.g. a rubber tongue) is released and the protective layer 4 suddenly moves against the cover window 3 . This happens e.g. B. analogous to a so-called duck foot mechanism with flap stick method.

6 1 shows a sixth embodiment in which the mechanical protective device 4, 5 comprises a protective mechanism 6 which, when activated, automatically moves into the covering position under the influence of gravity. An example of such a protective mechanism is a so-called Nuremberg scissors, i.e. a kind of self-expanding lattice as in 6 indicated in partially deployed position. Such a mechanism does not usually cover the cover window 3 as evenly as a protective layer 4, 5, but depending on the configuration it tends to be more resistant than a protective layer 4, 5, in particular to larger objects such as in the case of falling rocks or hail.

1 and 5 12 show drive units 8, 9, 10 which are set up to move the mechanical protective device 4, 5, 6 into the covering position upon activation and/or to move it back into a non-activated position after activation. For the sake of simplicity, this is not shown in the other embodiments. 1 shows a drive unit 8, which may include an electric motor 8, for example, and guide rails z. B. along the top of the housing 2 and on the side of the cover window 3 and an indicated deflection roller on the edge of the housing 2. 5 12 shows a drive unit 9, 10, which includes a magnetic reset mechanism 9, which is set up to move the protective layer 4 (shown here in broken lines) after activation back into a non-activated position. A spring 10 is biased in a non-activated position to provide a motive force upon activation to move the protective layer 4 to the covering position. Here too, for example, two protective layers 4 are conceivable, e.g. B. in the given representation from the right. Two drive units 9, 10 can also be provided per protective layer 4, here z. B. also on the top of the housing 2 for a more even exertion of force.

Although the invention has been illustrated and described in more detail by means of preferred exemplary embodiments, the invention is not restricted by the disclosed examples and other variations can be derived therefrom by a person skilled in the art without departing from the protective scope of the invention.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• WO 2017/029775 A1 [0004]
• WO 2018/197398 A1 [0005]
• WO 2019/121347 A1 [0005]
• DE 102017200795 A1 [0006]

Claims (10)

LiDAR system (1) comprising: - an emitter unit and a detector unit, - a housing (2) in which the emitter unit and the detector unit are arranged, the housing (2) comprising an at least partially transparent cover window (3), the LiDAR system (1) is set up to emit a laser beam from the emitter unit for scanning an environment through the cover window (3) and to receive laser light reflected from the environment through the cover window (3) on the detector unit, characterized in that the LiDAR The system (1) comprises a hazard detection unit which is set up to activate a mechanical protective device (4, 5, 6) on the housing (2) around the cover window (3) at least when a dangerous situation is detected for the LiDAR system (1). partially covered on the outside. LiDAR system (1) after claim 1 , wherein the mechanical protective device (4, 5, 6) is set up to move at least one protective layer (4, 5) in front of the cover window (3) when a dangerous situation is detected. LiDAR system (1) after claim 2 , wherein the mechanical protective device (4, 5, 6) is set up to move two interacting protective layers (4, 5) in front of the cover window (3) when a dangerous situation is detected. LiDAR system (1) according to any of the above claims 2 or 3 , wherein at least one protective layer (4, 5) rests against a further outer wall of the housing in the non-activated position or at least one protective layer (4, 5) is at least partially rolled up in the non-activated position. LiDAR system (1) according to one of the preceding claims, wherein the danger detection unit includes one or more of the following data in order to detect a dangerous situation: - Ambient noise data provided by a microphone, - acceleration data provided by an accelerometer, - location data and/or map data supplied by a navigation system, - 3D point cloud information determined from the data of the detector unit of the LiDAR system (1) from which approaching sources of danger were identified, - temperature data provided by a temperature sensor, - weather information provided by mobile phone and / or GPS, - speed data supplied by a speed sensor, in particular for detecting a standstill, - Data supplied by the LiDAR system (1) and external sensors for the detection of surrounding objects, such as in particular LiDAR surrounding data, ultrasound data, camera data, radar data, - vehicle situation data supplied by an external control unit. LiDAR system (1) according to one of the preceding claims, wherein the mechanical protection device (4, 5, 6) is prestressed in the non-activated position by a holding mechanism and is set up such that when the mechanical protection device (4, 5, 6) the holding mechanism is released and the mechanical protection device (4, 5, 6) automatically moves into the covering position. LiDAR system (1) according to one of the preceding claims, wherein the mechanical protective device (4, 5, 6) comprises a protective mechanism (6) which, when activated, moves automatically into the covering position under the influence of gravity. LiDAR system (1) according to any one of the preceding claims, wherein the mechanical protective device (4, 5, 6) comprises a drive unit (8, 9, 10) which is adapted to the mechanical protective device (4, 5, 6). to move back to a non-activated position after an activation. LiDAR system (1) according to one of the preceding claims, wherein the mechanical protection device (4, 5, 6) comprises a magnetic reset mechanism (9) which is set up to reset the mechanical protection device (4, 5, 6) after activation move to a non-activated position. Vehicle comprising a LiDAR system (1) according to one of the preceding claims, wherein the vehicle is preferably an at least partially self-driving passenger vehicle or truck.

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