Lidar sensor and environment detection system

Abstract

The invention relates to a laser radar sensor and an environmental detection system. The laser radar sensor comprises a window, at least one first and second group of electric conductors, a detection circuit, the window being a light exit and entrance interface of the laser radar sensor, the respective groups of electric conductors having a first conductor and having a second conductor, respectively, the first and second conductors being arranged on and / or in the window electrically insulated from each other, respectively, and being configured as a capacitive sensor, respectively, and being electrically connected with the detection circuit, the first and second groups of electric conductors being arranged at different positions, the detection circuit being configured to generate an electric field between the respective first and second conductors of the respective groups by means of a voltage source, here an alternating voltage, to detect a change of the electric field caused by an object in a vicinity of the window and to determine a position of the object in a plane of the window, and to provide information about the position of the object.

Description

Technical Field

[0001] This invention relates to a lidar sensor and an environmental detection system having such a lidar sensor. Background Technology

[0002] Vehicles that operate with partial and / or high automation are known from the prior art, and these vehicles use various sensors for automatic environmental detection. Key technologies in the field of environmental sensors are optical sensors, such as lidar sensors and camera systems. These are typically encapsulated relative to the environment within a housing. Accordingly, the optical interfaces of these sensors are usually provided through windows integrated into the housing. Crucially for ensuring the functionality of these optical sensors is the ability to automatically identify, and preferably also automatically remove, objects (e.g., dirt, rain, ice, etc.) on the outer surface of the window that affect sensor measurements.

[0003] DE102011081139A1 describes a sensor system for motor vehicles capable of identifying the state of a glass slide, and in particular, the contamination of the glass slide. The glass slide state is detected by altering the electrical properties of a conductive component disposed on and / or in the glass slide.

[0004] EP000002334141A1 describes an electrically heatable transparent glass sheet, which further includes a large-area conductive transparent coating applied to a transparent substrate. This invention particularly relates to a glass sheet having a communication window for use in sensor and camera systems. Summary of the Invention

[0005] According to a first aspect of the invention, a lidar sensor is provided, comprising a window, at least one first group and a second group of electrical conductors, and a detection circuit. The lidar sensor is, for example, a point scanner, a line scanner, or a flash lidar sensor. The lidar sensor is preferably an environmental sensor for a moving vehicle, wherein the moving vehicle is, for example, a road vehicle (e.g., a motorcycle, car, transport vehicle, truck), a rail vehicle, or an aircraft / aircraft and / or a ship, but this does not limit the lidar sensor to application only with moving vehicles.

[0006] For example, a window made of glass and / or transparent plastic serves as the light emission and light incidence interface of a lidar sensor. Corresponding groups of electrical conductors each have a first conductor and a second conductor, which are electrically insulated from each other and arranged on and / or within the window, respectively, and each constitutes a capacitive sensor. Furthermore, the first and second conductors are each electrically connected to a detection circuit.

[0007] Furthermore, the first and second groups of electrical conductors are arranged in different positions. Additionally, the detection circuit is configured to, by means of a voltage source, generate an electric field at least between the corresponding first and second conductors of the corresponding groups, detect changes in the electric field caused by an object in the vicinity of the window, and determine the position of the object on the window surface. The location of the object is indicated, and information about the location of the object is provided. The object is, for example, a contaminant and / or moisture and / or ice, wherein the object is configured to affect the intensity and / or shape of the laser beam emitted and / or received by the lidar sensor.

[0008] The advantage arises from the ability to determine the position of an object within a region of the window surface: measures to remove and / or handle such obstructive objects can be performed selectively, without having to apply them across the entire window surface. This, for example, reduces wear on the window surface or shortens the duration of measures to remove and / or handle such objects. Correspondingly, this advantage is particularly effective when using more than two sets of electrical conductors, enabling the positioning of objects on the lidar sensor window with correspondingly higher accuracy.

[0009] The following shows a preferred extension of the present invention.

[0010] In an advantageous configuration of the lidar sensor of the present invention, the corresponding first and second conductors in the corresponding groups are conductive lines and / or conductive layers. Advantageously, they are arranged linearly, wherein this linear arrangement is preferably achieved in that the corresponding first and second conductors are arranged parallel to each other and alternately with each other. Alternatively, the corresponding first and second conductors are looped. The arrangement can be either (or meandering) or, preferably, circular, in which the corresponding first and second conductors of the respective groups are arranged alternately. Alternatively, the corresponding first and second conductors can be arranged in a grid pattern relative to each other. Furthermore, arrangements different from the variations mentioned herein can also be used for the corresponding first and second conductors associated with current lidar sensors.

[0011] In the case of a grid arrangement of corresponding first and second conductors, they are preferably arranged such that all first conductors are arranged at a first predefined angle, and all second conductors are arranged at a second predefined angle, different from the first predefined angle. In principle, the first and second conductors can be arranged relative to each other at any angle, but are preferably arranged at an angle of 90°. Furthermore, it is conceivable that the grid formed by the first and second conductors can be arranged at different angles with respect to the window surface. In addition to the parallel orientation of the corresponding first and second conductors with respect to the corresponding edges of the window, it is also conceivable that not only the first conductors but also the second conductors are oriented at an angle of 45° or other different angles with respect to the corresponding edges of the window.

[0012] Furthermore, it is possible that the window of a lidar sensor is configured in such a way that it has a flat surface or a surface with a predefined curvature. Therefore, this predefined curvature also includes cylindrical, i.e., wraparound windows.

[0013] Preferably, the corresponding conductors in the first and second groups of electrical conductors are transmissive or substantially transmissive to the light emitted by the lidar sensor, so as not to affect, or only minimally affect, the recognition performance of the lidar sensor. Instead of the transmissive configuration of the corresponding first and second conductors, it is conceivable to use only very thin, non-transmissive or only partially transmissive electrical conductors, which similarly only minimally affect the emitted and / or received laser light of the lidar sensor.

[0014] In the case of a lidar sensor having a cylindrical window (e.g., in the case of a 360° scanner), the corresponding conductors in the first group of electrical conductors and the corresponding conductors in the second group of electrical conductors are preferably constructed in a spiral shape along the circumference of the cylindrical window, wherein the linear, loop-shaped or grid-shaped construction of the corresponding conductors is not explicitly excluded in this configuration of the lidar sensor.

[0015] Particularly preferably, the lidar sensor is configured to apply a voltage, particularly a DC voltage, to a portion or all of the conductors in a corresponding group of electrical conductors, such that the resulting current flow causes heating of the corresponding electrical conductors on the window and their surrounding environment. Thus, the advantage of locating objects on the lidar sensor window can be combined with the advantage of removing ice and / or snow and / or moisture, etc., by heating the window using an arrangement of only one type of electrical conductor. Since the aforementioned DC voltage is used for heating and an AC voltage is used to generate an electric field for capacitive detection of objects near the window, the two functions of the lidar sensor according to the invention can be decoupled using circuitry, so that they do not interfere with each other and can be activated independently accordingly.

[0016] In an advantageous configuration, the lidar sensor is configured to apply voltage to only the conductors in the corresponding group of electrical conductors, in the area located at the object's position, for heating. This provides the advantage that not the entire surface, but only the area of ​​the window actually affected by snow and / or ice and / or moisture, is heated, thus requiring correspondingly less energy consumption for the removal of the interfering object. The manipulation of the corresponding heated area can be achieved, for example, by an analysis processing unit according to the invention, which receives information about the object's position on the window from the detection circuit. Alternatively, it is conceivable that the detection circuit and such analysis processing unit are a single, identical component.

[0017] In a particularly advantageous configuration, the lidar sensor, when using information about the object's location, is configured to: clean the lidar sensor in the area of ​​the object's location; and / or increase the lidar sensor's transmit power and / or receive sensitivity in the area of ​​the object's location. Cleaning of the lidar sensor or its window is performed, for example, by means of a water spray nozzle and / or a compressed air nozzle and / or a wiper. The increased transmit power and / or receive sensitivity of the lidar sensor provides the advantage that (depending on light transmittance) objects in the window area do not need to be removed or immediately removed (e.g., in the case where the lidar sensor does not have a cleaning device), because their interfering effects can be at least partially compensated by the aforementioned countermeasures. The corresponding operation of the lidar sensor's cleaning device and / or the light emitter and / or photodetector is preferably also achieved by means of the aforementioned analysis and processing unit.

[0018] According to a second aspect of the invention, an environmental detection system is proposed, the system comprising a lidar sensor as described above. Features, combinations of features, and the resulting advantages are so readily apparent in relation to the features, combinations of features, and advantages stated in conjunction with the first-mentioned aspects of the invention; for the avoidance of repetition, please refer to the embodiments described above. Preferably, such an environmental detection system (e.g., an environmental detection system for a traveling mechanism) is configured to perform analysis and processing of environmental information from the lidar sensor based on information about the position of an object, and / or output alert messages to the user of the environmental detection system. These measures are also preferably implemented using the aforementioned analysis and processing unit. Attached Figure Description

[0019] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The drawings show:

[0020] Figure 1 A schematic view of a lidar sensor according to a first embodiment of the present invention is shown;

[0021] Figure 2A schematic view of a lidar sensor according to a second embodiment of the present invention is shown;

[0022] Figure 3 An exemplary circuit arrangement of a lidar sensor according to the present invention is shown;

[0023] Figure 4 A schematic view of the environmental monitoring system according to the present invention is shown. Detailed Implementation

[0024] Figure 1 A schematic view of a lidar sensor 1 according to a first embodiment of the invention is shown. The lidar sensor 1 has a curved window 10, which is made of glass. Furthermore, the lidar sensor 1 has a detection unit 30, which is electrically connected to a plurality of strip-shaped first electrical conductors 40 and second electrical conductors 45 alternately arranged on the window 10. The electrical conductors 40, 45 are configured as a strip-shaped layer and are transmissive to the laser light generated by the lidar sensor 1 for environmental detection. Adjacent first electrical conductors 40 and second electrical conductors 45 respectively constitute corresponding groups 20, 25, 27, 29 of electrical conductors. The corresponding first electrical conductors 40 and second electrical conductors 45 of the corresponding groups 20, 25, 27, 29 are electrically insulated from each other and are used to generate corresponding electric fields, so as to construct corresponding capacitive sensors through each group 20, 25, 27, 29. In this way, the lidar sensor 1 can record the capacitance change caused by an object 60 on the window 10 and determine the position of the object 60 on the window 10 by means of the detection circuit 30. Here, the object 60 existing in the region of the second group 25 of the electrical conductor is determined.

[0025] This information is advantageously transmitted to an analysis and processing unit 70 that is information technology connected to the detection circuit 30. The analysis and processing unit is configured to improve the receiving sensitivity of the photodetector of the lidar sensor 1 in the region corresponding to the desired position of the object 60.

[0026] Preferably, the respective first electrical conductor 40 and second electrical conductor 45 can be connected to a DC voltage source through their respective ends, so that the surface of the window 10 can be selectively heated in order to selectively remove ice and / or snow on the window 10.

[0027] Figure 2This is a schematic view of the lidar sensor 1 according to a second embodiment of the present invention. Here, the corresponding first and second electrical conductors 40 and 45 are arranged in a grid pattern relative to each other, such that the position of an object 60 possibly attached to the window 10 can be determined with higher accuracy than in embodiment 1, where the position can only be determined individually over the entire area of ​​the group of strip-shaped structures. In contrast, here the position of the object 60 can be determined within the area of ​​the corresponding cross-sections of the first and second electrical conductors 40 and 45.

[0028] Figure 3 An exemplary circuit arrangement of a lidar sensor 1 according to the present invention is shown, comprising a detection circuit 30, a DC voltage source 55, and an AC voltage source 50. Corresponding lines 40, 45 each have resistance and together form a capacitor. In the presence of an object 60 (e.g., a raindrop) in the region of either line 40, 45, the detection circuit 30 records the change in capacitance of this capacitor. This change in capacitance is specifically determined by recording the resulting change in the AC current generated by the AC voltage source 50. The current generated by the DC voltage source 55 in each line 40, 45 is additionally used to heat the corresponding line 40, 45.

[0029] Figure 4 A schematic view of an environmental monitoring system according to the present invention is shown. The environmental monitoring system includes a lidar sensor 1, which is connected to an analysis and processing unit 70 in terms of information technology. The analysis and processing unit 70 is configured to analyze and process the measurement signals generated by the lidar sensor 1 and determine the environment of the lidar sensor 1 based on the measurement signals. Based on information generated by the lidar sensor 1 regarding the location of pollutants present on the window 10 of the lidar sensor 1, the analysis and processing unit 70 is configured to increase the transmission power of the lidar sensor 1 in that area to compensate for signal attenuation caused by pollutants. Furthermore, the analysis and processing unit 70 is configured to output a corresponding prompt message to the user of the environmental monitoring system via a display 80 when it is not possible to compensate for pollutants by increasing the transmission power.

Claims

1. A lidar sensor (1), comprising: Window (10), At least one first group (20) and a second group (25) of electrical conductors. Detection circuit (30) in, The window (10) is the light emission interface and light incidence interface of the lidar sensor (1). The corresponding groups (20, 25) of electrical conductors each have a first conductor (40) and a second conductor (45), the first conductor and the second conductor respectively The sensors are arranged electrically insulated from each other on the window (10) and / or inside the window and are respectively constructed as capacitive sensors. Electrically connected to the detection circuit (30), The first group (20) and the second group (25) of the electrical conductors are arranged in different positions from each other. The detection circuit (30) is configured to, An electric field is generated between the corresponding first conductor (40) and second conductor (45) of the respective groups (20, 25) by means of a voltage source (50). The change in electric field caused by an object in the vicinity of the window (10) is detected, and the position of the object (60) within the plane of the window (10) is determined. Provide information about the location of the object (60).

2. The lidar sensor (1) according to claim 1, wherein, The first conductor (40) and the second conductor (45) of the corresponding groups (20, 25) are relative to each other. Linear, or Ring, or Grid Arranged conductive lines and / or conductive layers.

3. The lidar sensor (1) according to claim 2, wherein, The corresponding first conductor (40) and the corresponding second conductor (45) are arranged in a grid-like arrangement such that all first conductors (40) are arranged at a first predefined angle, and all second conductors (45) are arranged at a second predefined angle different from the first predefined angle.

4. The lidar sensor (1) according to any one of claims 1 to 3, wherein, The window (10) It has a flat surface, or It has the following surface: the surface has a predefined curvature.

5. The lidar sensor (1) according to any one of claims 1 to 3, wherein, The corresponding conductors (40, 45) in the first group (20) and the second group (25) of the electrical conductors are transmissive to light emitted by the lidar sensor (1).

6. The lidar sensor (1) according to any one of claims 1 to 3, wherein, The lidar sensor (1) has a cylindrical window (10), and The corresponding conductors (40, 45) in the first group (20) of the electrical conductors and the corresponding conductors (40, 45) in the second group (25) of the electrical conductors are respectively constructed in a spiral shape along the circumference of the cylindrical window (10).

7. The lidar sensor (1) according to any one of claims 1 to 3, wherein, The lidar sensor (1) is configured to apply a voltage to some or all of the conductors (40, 45) in a corresponding group (20, 25) of electrical conductors, such that the resulting current flow causes heating of the corresponding electrical conductors (40, 45) on the window (10) and their surrounding environment.

8. The lidar sensor (1) according to claim 7, wherein, The lidar sensor (1) is configured to apply voltage to conductors (40, 45) in the region of the object (60) in the corresponding group (20, 25) of electrical conductors for heating purposes.

9. The lidar sensor (1) according to claim 7, wherein, The voltage is a DC voltage.

10. The lidar sensor (1) according to any one of claims 1 to 3, wherein, The lidar sensor (1) is configured to use information about the location of the object (60) for... Cleaning of the lidar sensor (1) is performed in the area of ​​the location of the object (60), and / or Increase the transmit power and / or receive sensitivity of the lidar sensor (1) in the region of the location of the object (60).

11. An environmental monitoring system, said environmental monitoring system comprising a lidar sensor (1) according to any one of claims 1 to 10, wherein, The environmental detection system is configured to, based on information about the location of the object (60) Matching the analysis and processing of environmental information of the lidar sensor (1), and / or The system will output a notification message to the user of the environmental monitoring system.

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