DE102020206930A1 - Adjusting a vertical region of interest - Google Patents

Abstract

The present invention relates to an adaptation device (20) for adapting a vertical region of interest (24) within a field of view (22) of a lidar measuring device (16) on a vehicle (10), having: an input interface (28) for receiving of movement data from an inertial sensor (18) with information on a position of the vehicle; an evaluation unit (30) for determining a pitch angle of the lidar measuring device based on the movement data; and a control unit (32) for controlling the lidar measuring device in order to adapt the vertical region of interest based on the determined pitch angle. The present invention further relates to a system (12) for detecting an object (14) in the surroundings of a vehicle (10) and a method for adapting a vertical region of interest (24) within a field of view (22) of a lidar measuring device (16).

Description

The present invention relates to an adjustment device for adjusting a vertical region-of-interest within a field of view of a lidar measuring device on a vehicle. The present invention further relates to a corresponding method and a system for detecting an object in the surroundings of a vehicle.

Modern vehicles (cars, vans, trucks, motorcycles, etc.) have a large number of sensors that provide the driver with information and control individual functions of the vehicle in a partially or fully automated manner. The surroundings of the vehicle and other road users are recorded via sensors. Based on the recorded data, a model of the vehicle environment can be generated and changes in this vehicle environment can be reacted to.

Lidar technology (light detection and ranging) is an important sensor principle for capturing the surroundings. A lidar sensor is based on the emission of light signals and the detection of the reflected light. A distance to the point of reflection can be calculated by means of a transit time measurement. It is also possible to determine a relative speed. Both unmodulated pulses and frequency-modulated signals (chirps) can be used here (frequency-modulated continuous wave lidar, FMCW lidar). A target can be detected by evaluating the received reflections. With regard to the technical implementation of the lidar sensor, a distinction is made between scanning and non-scanning systems. A scanning system is mostly based on micromirrors and a scanning of the environment with a light spot, whereby one speaks of a coaxial system when the transmitted and received light pulses are deflected by the same micromirror. In non-scanning systems, several transmitting and receiving elements are arranged statically next to one another (especially so-called focal plane array arrangement).

In this context, the WO 2018/127789 A1 Lidar systems and methods for detecting and classifying objects are disclosed.

A relevant function of a lidar sensor in the vehicle environment is the detection of obstacles on the road, such as lost cargo, tires or injured people. Particularly injured people and tires can occupy a comparatively small space that is visible from the lidar sensor. When used on a motorway or expressway, such obstacles should be detected in a range of 100 to 300 m. In order to achieve this reliably, a high spatial resolution is necessary. For example, a resolution of 0.05 ° in the horizontal direction and 0.025 ° in the vertical direction may be necessary to ensure that an object is hit by several scanning points.

It does not make sense, or for data processing reasons, not even possible, to scan an entire field of view, which for example can extend from 40 ° to 120 ° in the horizontal direction and from 15 ° to 30 ° in the vertical direction, with such a high resolution. On the one hand, the amount of data that arises would place very high demands on data transmission and data processing and would therefore only be realizable with great effort. On the other hand, such a high resolution would not be necessary in the predominant part of the field of view, in particular in areas with a distance of less than 48 m to 100 m or in the area of the sky above a horizon line. In order to achieve a reliable detection of objects, there are therefore approaches to select a higher resolution than in the remaining field of view in a particularly relevant area (region of interest) within the field of view. However, this relevant area must be selected large enough to ensure that relevant objects are detected with a high degree of reliability. The achievable resolution is therefore limited even with such approaches.

Based on this, the present invention has the task of providing a cost-effectively implementable approach for the reliable detection of objects in the vicinity of a vehicle. In particular, it should be made possible to detect objects lying on the road in the area in front of a vehicle with high reliability.

• einer Eingangsschnittstelle zum Empfangen von Bewegungsdaten eines Inertialsensors mit Informationen zu einer Lage des Fahrzeugs;
• einer Auswerteeinheit zum Ermitteln eines Nickwinkels der Lidar-Messvorrichtung basierend auf den Bewegungsdaten; und
• einer Steuereinheit zum Ansteuern der Lidar-Messvorrichtung, um die vertikale Region-of-Interest basierend auf dem ermittelten Nickwinkel anzupassen.

To achieve this object, the invention relates in a first aspect to an adaptation device for adapting a vertical region of interest within a field of view of a lidar measuring device in a vehicle, with:

• an input interface for receiving movement data from an inertial sensor with information on a position of the vehicle;
• an evaluation unit for determining a pitch angle of the lidar measuring device based on the movement data; and
• a control unit for controlling the lidar measuring device in order to adapt the vertical region-of-interest based on the determined pitch angle.

• einer Lidar-Messvorrichtung an dem Fahrzeug, mit einem Sender zum Aussenden eines Lichtsignals, einem Empfänger zum Empfangen des Lichtsignals nach einer Reflexion an dem Objekt und einer 2D-Scannereinheit zum Abtasten eines Sichtfelds der Lidar-Messvorrichtung;
• einem Inertialsensor zum Erfassen von Bewegungsdaten mit Informationen zu einer Bewegung des Fahrzeugs; und
• einer Anpassungsvorrichtung zum Anpassen einer vertikalen Region-of-Interest innerhalb des Sichtfelds der Lidar-Messvorrichtung wie zuvor beschrieben.

In a further aspect, the present invention relates to a system for detecting an object in the surroundings of a vehicle, with:

• a lidar measuring device on the vehicle, with a transmitter for emitting a light signal, a receiver for receiving the light signal after a reflection on the object and a 2D scanner unit for scanning a field of view of the lidar measuring device;
• an inertial sensor for detecting movement data with information on a movement of the vehicle; and
• an adjustment device for adjusting a vertical region-of-interest within the field of view of the lidar measuring device as described above.

Further aspects of the invention relate to a method embodied in accordance with the adaptation device and a computer program product with program code for performing the steps of the method when the program code is executed on a computer, as well as a storage medium on which a computer program is stored, which when it is on a computer is carried out, causes the method described herein to be carried out.

Preferred embodiments of the invention are described in the dependent claims. It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the respectively specified combination, but also in other combinations or on their own, without departing from the scope of the present invention. In particular, the system, the method and the computer program product can be implemented in accordance with the configurations described for the adaptation device in the dependent claims.

Provision is made for a vertical region of interest to be adapted in the vertical direction based on movement data from an inertial sensor. Movement data from an inertial sensor are received via an input interface. These movement data describe a position of the vehicle, that is to say an orientation of the vehicle with respect to the roadway or with respect to the acceleration due to gravity. On the basis of this, a pitch angle of the lidar measuring device is determined. The lidar measuring device is permanently connected to the vehicle. To this extent, a pitch angle corresponds to a deviation in the alignment of the lidar measuring device from a normal position. In particular, a deviation from the horizon line is described if it is assumed that the lidar measuring device is aligned normally in the direction of the horizon line. On the basis of the determined pitch angle, the lidar measuring device is activated in order to adapt the vertical region of interest. An adaptation is understood to mean, in particular, a shift or also an enlargement or reduction.

In previous approaches, a static region-of-interest or a region-of-interest that can be dynamically adjusted in terms of resolution was used. In contrast, the present approach offers the advantage that a further improved data evaluation can be achieved within a relevant area. Because only the area that is currently relevant is evaluated, it can be evaluated with high reliability. The adaptation of the vertical region of interest based on the position of the vehicle means that only a comparatively small area has to be recorded with high resolution in order to obtain all relevant information. This smaller area can then be recorded with high resolution or with a long range without increasing the requirements for the required data processing performance and communication bandwidth. There is increased reliability in the detection of objects in the vicinity of a vehicle. One advantage of using an acceleration sensor is that the update rate is often ten times higher than the scan rate of a lidar measuring device. For example, an inertial sensor or an acceleration sensor often has an update frequency of 200 Hz to 2 kHz, whereas a lidar measuring device has an image frequency of 10 Hz to 25 Hz. With this much higher sampling frequency, a much faster detection of a braking or acceleration process can be achieved. In addition, the pitch angle of the vehicle or the lidar measuring device can be predicted more reliably and more accurately.

In a preferred embodiment, the control unit is designed to control the lidar measuring device in order to shift the vertical region of interest in the vertical direction by the determined pitch angle. In particular, it is possible for the region of interest to be shifted in the vertical direction in accordance with the current pitch angle. A shift is understood to mean, in particular, a change in the alignment with respect to the vertical axis of the vehicle on which the lidar measuring device is attached. The change is based on the pitch angle. The shift results in the possibility of scanning the relevant area with high resolution.

In a preferred embodiment, the control unit is designed to control a 2D scanner unit for two-dimensional line-by-line scanning of the field of view of the lidar measuring device. The control unit is preferably for shifting a vertical area corresponding to the vertical region of interest with reduced line spacing within the field of view in FIG Vertical direction formed around the pitch angle. In particular, it is possible to use the adaptation device to control a 2D scanner unit accordingly. This offers the advantage that a line spacing can be changed during operation, so that a resolution can be adapted in the vertical direction. The vertical region-of-interest is an area in which the line spacing is reduced compared to the remaining field of view in order to achieve a higher resolution. Objects can be detected with higher reliability.

In a preferred embodiment, the control unit is designed to move a plurality of adjacent vertical areas with different line spacings within the field of view in the vertical direction by the pitch angle. In particular, it is advantageous if the region of interest is divided into several sub-areas with different resolutions. These sub-areas can be shifted together by the pitch angle. The result is a high resolution within a particularly relevant area, the resolution decreasing both upwards and downwards in the vertical direction. The available capacities in terms of processor performance and data communication are optimally used.

In a preferred embodiment, the evaluation unit is designed to determine the pitch angle based on a static component, which corresponds to a component that cannot be changed during a journey, and a dynamic component, which corresponds to a component that changes during a journey. A static component can in particular be a component that results from loading the vehicle or installing the lidar measuring device. Such a proportion does not change with high frequency while driving. In contrast, a dynamic component can be due to a current driving state or a driving maneuver and in particular a positive or negative acceleration. For example, a braking process changes a pitch angle of the vehicle, which also changes an alignment of the lidar measuring device. By considering the static and dynamic components separately, the evaluation unit can ensure a high level of precision when determining the relevant area or region of interest. Objects can be detected with high reliability.

In a preferred embodiment, the input interface is designed to receive movement data with acceleration data from a longitudinal acceleration sensor for measuring an acceleration of the vehicle in the direction of a longitudinal axis of the vehicle. Additionally or alternatively, the input interface is designed to receive movement data with acceleration data from a 3-axis acceleration sensor for measuring a three-dimensional acceleration vector of the vehicle. Longitudinal acceleration, which can occur, for example, when accelerating or braking, is particularly relevant. This can be recorded in one or three dimensions. If a three-dimensional vector is present, the evaluation unit can determine the pitch angle of the lidar measuring device, in particular based on trigonometric considerations. It goes without saying that previously known parameters with regard to the attachment or mounting of the lidar measuring device on the vehicle can be taken into account here.

In a preferred embodiment, the evaluation unit is designed to determine the pitch angle based on a predefined alignment parameter that describes an alignment of the lidar measuring device in relation to the vehicle. In particular, it is possible for an alignment parameter to be taken into account in addition to the movement data. Such a position can be predetermined, for example, by a mounting position of the lidar measuring device. Depending on the alignment of the lidar measuring device on the vehicle, the pitch angle is determined in a corresponding manner in the evaluation unit in order to enable precise adaptation of the vertical region of interest.

In a preferred embodiment, the input interface is designed to receive the movement data from an inertial sensor of a driver assistance system of the vehicle, in particular an anti-lock braking system. By using data from a sensor that is already on the vehicle, costs can be saved. In any case, various driver assistance systems have acceleration sensors. Their signal is used for the adjustment device to adjust the vertical region-of-interest. There is no need to use a separate, separate sensor, which results in potential cost savings.

In a preferred embodiment, the input interface is designed to receive a distance specification with information on distances between a target point on a roadway in the field of view of the lidar measuring device and the lidar measuring device. The evaluation unit is designed to determine the pitch angle based on the distance specification. The input interface is preferably designed to receive the distance information from the lidar measuring device. In particular, a signal from the lidar measuring device is taken into account when determining the pitch angle. The relevant area within which objects are to be detected includes, in particular, the road surface. This relevant area can be improved can be detected if, in addition to the data from the inertial sensor, data with a distance specification are also taken into account. This allows uphill or downhill slopes to be taken into account in the roadway in front of the vehicle. The inclination of the roadway has an effect on the measurements of the inertial sensor and the movement data due to gravity. Because a distance specification is also included when determining the pitch angle, this effect can in particular be compensated for. In particular, the pitch angle can be adapted accordingly based on the inclination of the roadway. In addition, the measurement of the inertial sensor can be calibrated. This results in greater precision when determining the pitch angle of the lidar measuring device and greater reliability in object detection.

In a preferred embodiment, the evaluation unit is designed to determine the pitch angle based on a previously known height of the lidar measuring device on the vehicle above the roadway. In particular, a height of the lidar measuring device on the vehicle above the roadway is helpful for a trigonometric observation based on a distance specification. By additionally taking this information into account, the accuracy in determining the pitch angle can be further improved.

In a preferred embodiment, the evaluation unit is designed to determine the pitch angle based on an application of a stochastic filter, in particular a Wiener filter or a Kalman filter, with a predefined system model over several time steps. By using a stochastic filter, errors can be prevented and individual inaccurate or noisy measurements can be countered. The accuracy is improved and the reliability is increased.

In a preferred embodiment, the input interface is designed to receive curve data with information on cornering of the vehicle. The evaluation unit is designed to determine a relevant azimuth angle range based on the curve data. The control unit is designed to control the lidar measuring device in order to adapt a horizontal region of interest based on the ascertained azimuth angle range. In this respect, in addition to the vertical adjustment, an adjustment is also made in the horizontal direction. For this purpose, curve data are used that can include, in particular, data from an inertial sensor or steering angle data with information on a current steering angle of the vehicle. Based on this data, an adaptation of the region-of-interest in the horizontal direction can also be carried out in a manner analogous to the adaptation in the vertical direction. For example, when a vehicle drives around a curve, the region of interest is shifted in the direction of the planned trajectory. This results in a further improved selection and adaptability of the relevant area. It avoids that data is collected in less relevant areas and ties up capacities. This means that most of the available processor power and communication bandwidth can be used for the relevant area. Objects can be detected with higher reliability.

A field of view or a field of view of a lidar measuring device corresponds to an area that can be seen by the lidar measuring device. In particular, the field of view is defined by specifying an angle in the vertical direction (elevation angle) and an angle in the horizontal direction (azimuth angle). A vertical resolution corresponds to a resolution in the vertical direction within this field of view. A vertical resolution can in particular be specified in the form of a scanning angle increment. A scanning angle increment corresponds in particular to a line spacing in the case of a line-by-line scanning of the field of view. Basically, resolution is preferably to be understood as an angle specification between two adjacent rows or columns when the field of view is scanned by the 2D scanner unit in the horizontal (horizontal resolution) or vertical direction (vertical resolution). A horizontal or vertical area or a horizontal / vertical region-of-interest corresponds to a cutout or section of the field of view in the corresponding direction. A vertical region of interest corresponds, for example, to a field of view section within a specific elevation angle range. The region of interest corresponds in particular to an area of the field of view that is considered to be particularly relevant. The surroundings of a vehicle include in particular an area in the surroundings of the vehicle that is visible from the vehicle.

• 1 eine schematische Darstellung eines Fahrzeugs mit einem System zum Detektieren eines Objekts;
• 2 eine schematische Darstellung einer Anpassungsvorrichtung zum Anpassen einer vertikalen Region-of-Interest;
• 3 eine schematische Darstellung eines Sichtfelds bei zeilenweiser Abtastung;
• 4 eine schematische Darstellung einer Anpassung einer vertikalen Region-of-Interest innerhalb des Sichtfelds;
• 5 eine schematische Darstellung einer Lidar-Messvorrichtung;
• 6 eine schematische Darstellung eines Ansatzes zum Anpassen einer vertikalen Region-of-Interest; und
• 7 eine schematische Darstellung eines erfindungsgemäßen Verfahrens.

The invention is described and explained in more detail below using a few selected exemplary embodiments in connection with the accompanying drawings. Show it:

• 1 a schematic representation of a vehicle with a system for detecting an object;
• 2 a schematic representation of an adjustment device for adjusting a vertical region-of-interest;
• 3 a schematic representation of a field of view with line-by-line scanning;
• 4th a schematic representation of an adaptation of a vertical region-of-interest within the field of view;
• 5 a schematic representation of a lidar measuring device;
• 6th a schematic representation of an approach to adjusting a vertical region-of-interest; and
• 7th a schematic representation of a method according to the invention.

In the 1 is schematically a vehicle 10 with one system 12th for detecting an object 14th in an environment of the vehicle 10 shown. The representation corresponds to a side sectional view of the situation. The object 14th can for example be a car tire, a vehicle part lying on the road or a person. The system 12th comprises a lidar measuring device 16 , an inertial sensor 18th as well as an adapter 20th . In the illustrated embodiment, the system is 12th arranged within the vehicle or integrated into the vehicle. The lidar measuring device 16 is for example in the area of a bumper of the vehicle 10 assembled. The adjustment device 20th and the inertial sensor 18th are for example in a control unit or in the lidar measuring device 16 integrated. It goes without saying that it is also possible that the lidar measuring device 16 who have favourited the adapter 20th and / or the inertial sensor 18th are carried out separately and are integrated, for example, in a mobile device.

In the representation of the 1 the field of view is dashed 22nd the lidar measuring device 16 indicated. The field of view 22nd can for example include an opening angle of 46 ° in the horizontal direction and 38 ° in the vertical direction. Within the field of view there is a region of interest 24 which corresponds to an area which is particularly relevant for the detection of obstacles and for the decisions of a partially autonomous or autonomous vehicle. This region of interest 24 represents part of the field of view 22nd The area of the road, for example, is particularly relevant 26th . The object 14th on the roadway 26th should be detected with the highest possible reliability. In the example shown, the region of interest includes 24 the entire field of view in the horizontal direction 22nd .

In order to reliably detect objects, it should be within the region of interest 24 a high resolution can be ensured. Outside the region of interest, the lidar measuring device 16 work with reduced resolution or do not evaluate any data at all. It is provided that the vertical position or also the extent of the region-of-interest 24 within the field of view 22nd by means of the adapter 20th based on the data from the inertial sensor 18th is adjusted (adjustment of the vertical region-of-interest). It is particularly advantageous if the region of interest 24 exactly symmetrical about a pitch angle plane of the vehicle, which is orthogonal to the vertical axis of the vehicle and parallel to the roadway 26th runs, is arranged.

It is proposed, based on the consideration of the data of the inertial sensor, a pitching movement of the vehicle 10 or the associated lidar measuring device 16 by adjusting the region of interest 24 to compensate. The relevant area should be within the region-of-interest 24 being held.

It is particularly advantageous if the inertial sensor (in particular an inertial sensor unit with a multi-axis acceleration sensor and multi-axis rotation rate sensor) directly measures a pitching movement of the lidar measuring device. If, for example, in the case of a truck with a flexible driver's cab, the lidar measuring device 16 is attached to the driver's cab, it is advantageous if the inertial sensor is also attached to the driver's cab. When the lidar measurement device 16 is rigidly connected to the vehicle, the inertial sensor can also be arranged at another point in or on the vehicle.

In the 2 is schematically the adjustment device 20th shown. The adjustment device 20th includes an input interface 28 , an evaluation unit 30th as well as a control unit 32 . The adjustment device 20th can for example be integrated into a lidar measuring device or also into a vehicle control device or a driver assistance system. The units and interfaces of the adapter 20th can be implemented partially or completely in hardware and / or in software.

Via the input interface 28 movement data of the inertial sensor with information on a position of the vehicle are received. A position of the vehicle is understood to mean, in particular, an orientation of the vehicle in relation to the acceleration due to gravity. A position corresponds to an alignment in three-dimensional space. The movement data can include, in particular, data from a three-axis acceleration sensor or also data from a longitudinal acceleration sensor that measures an acceleration of the vehicle in the direction of a longitudinal axis of the vehicle. The input interface 28 is directly connected to a corresponding sensor. For example, the movement data can also be received by an inertial sensor that is already integrated in the vehicle. In particular, the data from a driver assistance system, for example an anti-lock braking system, of the vehicle can be used. The input interface 28 can to Data reception can be linked to a bus system of the vehicle, for example.

In the evaluation unit 30th a pitch angle of the lidar measuring device is determined based on the received movement data. This is done in the evaluation unit 30th For example, based on a previously known height of the lidar measuring device on the vehicle above the roadway and based on a predefined alignment of the lidar measuring device in relation to the vehicle on the basis of a trigonometric consideration, a pitch angle is calculated.

In the evaluation unit 30th the pitch angle can be determined based on a static component and a dynamic component. The static part corresponds to a part that does not change during a journey. For example, a loaded car may require an adjustment of the vertical region-of-interest from the outset in order to compensate for a change in the orientation of the lidar measuring device due to the load. In contrast to this, the dynamic component corresponds to a component that changes during the journey. In particular, the dynamic component can result from braking and acceleration maneuvers. When braking, the vehicle is pushed into the front shock absorbers, causing it to nod. A lidar measuring device on the vehicle also performs this pitching movement, which changes its alignment with respect to the roadway. In order to determine or estimate the pitch angle, it is advantageous if the evaluation unit 30th is designed to apply a stochastic filter. In this way, in particular, smoothing and compensation of outliers can be achieved. A Wiener filter or a Kalman filter is advantageously used. Such a filter is applied over several time steps, using a previously known or predefined system model that transfers a state from one point in time to the next. In particular, the pitch angle can be estimated by means of such a filter.

The control unit 32 serves to control the lidar measuring device. The control unit 32 be connected to a vehicle bus system and communicate with the lidar measuring device via this. It is also possible that the control unit 32 is directly connected to the lidar measuring device. The control unit 32 serves to carry out or initiate the corresponding adjustment of the region of interest.

In the 3 is schematic the field of view 22nd the lidar measuring device shown from the perspective of the lidar measuring device. The field of view 22nd denotes the area that can be scanned by the lidar measuring device, for example by means of several scanning lines 34 . Within the field of view 22nd there is an object 14th . In addition, the road runs 26th within the field of view 22nd to the horizon line 36 . In the representation of the 3 are the different scan lines 24 essentially parallel to the horizon line 36 or aligned parallel to a transverse axis of the vehicle and are at a constant distance from one another. It goes without saying that column-by-column scanning would also be conceivable.

The representation of the 4th corresponds to the representation in 3 , the roadway, the horizon line and the object not being shown for the sake of clarity. It is intended to be within the field of view 22nd a region of interest 24 is adjusted in the vertical direction. In particular, an adaptation by a shift is indicated in the illustration. An adaptation is also understood to mean a change in the resolution. In the illustrated embodiment in the 4th are the scan lines 34 within the region of interest 24 arranged at a smaller distance from each other. The resolution within the region of interest is therefore higher than in the remaining field of view. With a corresponding control it is possible to adjust the distance between the scanning lines 34 to vary from each other. The adaptation device can be used to control the distance between the scan lines 34 decrease within a certain range. By changing the spacing of the spacing lines accordingly 34 can be the region-of-interest 24 within the field of view 22nd can be moved vertically (up and down).

It goes without saying that a number of different zones with different resolutions can also be provided in a corresponding manner. For example, a maximum resolution can be provided within a first region of interest with 0.025 ° vertical resolution in a central area. In a second region of interest directly next to it, an area with a reduced vertical resolution of 0.05 ° can be provided. In a third region of interest directly following the second region of interest, a further reduced resolution of 0.1 ° can be provided.

The adaptation of the region of interest then preferably includes the adaptation of all three sub-areas.

In the 5 is a schematic of an exemplary structure of a lidar measuring device 16 shown. The lidar measuring device 16 includes a transmitter 38 for emitting a light signal and a receiver 40 for receiving the light signal after reflection on the object. The transmitter 38 is in particular designed as a laser source which emits a pulsed or a frequency-modulated signal (chirp signal). The recipient 40 is designed in particular as a photodetector.

Furthermore, the lidar measuring device comprises 16 a 2D scanner unit 42 to scan the field of view of the lidar measuring device 16 to feel. The 2D scanner unit 42 can in particular be designed as a microelectromechanical system (MEMS). It is also possible to use a galvanometer. A micromirror is activated in order to transmit the light signal in different positions and to receive corresponding detections of the different positions. In particular, the field of view of the lidar measuring device becomes 16 scanned line by line. There is preferably a fast horizontal axis and a slow vertical axis, each of which can be controlled by associated actuators. The 2D scanner unit 42 offers in particular a corresponding control interface in order to be able to control the vertical and horizontal movement of the mirror. In particular, it can be specified for the axes which angle is to be used between two rows or columns. If, for example, a higher resolution or a smaller line spacing is to be used within a region of interest, this can be achieved by a modification in the control of the vertical axis. In particular, the angle can be reduced during the deflection between two time steps or between two lines.

Furthermore, the lidar measuring device comprises 16 a combination unit 44 . In the illustrated embodiment in the 5 is the combination unit 44 designed as a circulator. The fact that for the transmitted light signal and for the received light signal between the 2D scanner unit 42 and the combination unit 44 the same path is used, the illustrated lidar measurement device is used 16 also referred to as a coaxial lidar measuring device or as a coaxial lidar measuring device.

In the 6th an embodiment of the approach for adjusting the vertical region-of-interest is shown schematically. In particular, the interaction of the various units involved is shown in a preferred embodiment of the approach for adapting the vertical region of interest. It is understood that the various units in the 6th are optional and it is also possible to only access information from a few selected units.

The lidar measuring device 16 particularly shows the components of the 5 illustrated lidar measuring device. The measured distance information is stored in a processing unit 46 further processed. In particular, the collected distance information is combined with corresponding direction information from the control unit 32 connected. The ones in the processing unit 46 The point cloud generated can then serve as input for corresponding object recognition functionalities.

In the control unit 32 In the example shown, a control signal for the lidar measuring device is thus generated 16 generated. In particular, a signal is generated by means of which the light signal is deflected in a corresponding elevation and azimuth direction. The control unit 32 can, for example, generate a signal based on which a scanning process of a new frame is then initiated in the lidar measuring device.

Based on the point cloud of the processing unit 46 can in a corresponding pitch angle estimation unit 48 furthermore a determination of the pitch angle of the lidar measuring device 16 relative to the roadway based on a detection of the roadway at a distance of, for example, 5 to 20 m. The pitch angle estimation unit 48 use or determine a model of the roadway in order to combine several detections at several different distances to form a probable roadway surface. The pitch angle can be estimated based on a single distance measurement and a mounting height of the lidar measuring device above the roadway. It is also possible that the pitch angle is estimated based on angle and distance differences between several measurements of the road surface in front of the vehicle, for example at distances of 5 m, 7 m and 10 m.

The inertial sensor 18th is designed in particular for measuring an acceleration in the direction of travel and for measuring a rotary movement that corresponds to a pitching movement. In particular, a six-axis MEMS inertial sensor can be used, which can determine a three-dimensional acceleration and a three-dimensional rotary movement (inertial measuring unit, IMU).

In the evaluation unit 30th becomes a pitch angle of the lidar measuring device 16 definitely. In particular, a probable inclination of the lidar measuring device 16 in the next frame of the lidar measurement device 16 be predicted. On the one hand, the movement data of the inertial sensor serve as the basis 18th and on the other hand, the output data of the pitch angle estimation unit 48 . In particular, in the evaluation unit 30th a configurable prediction filter, for example a Wiener filter or an adaptive filter such as a Kalman filter, can be used for this purpose. About such a Prediction filter, a probable future pitch angle can be determined or predicted based on a measurement of accelerations over several time steps and a system model that also includes a model of the vehicle dynamics. Additionally or alternatively, a second prediction filter can be used which makes a prediction based on the output of the pitch angle estimation unit 48 undertakes. An advantage of the additional use of the pitch angle estimation unit 48 lies in the fact that a reliable estimate can also be made when the roadway rises or falls.

In summary, a vertical adjustment of the region of interest can take place on the one hand with a static portion and on the other hand with a dynamic portion. Data from an inertial sensor can be used for both static and dynamic adjustments. Point cloud data from the lidar measuring device can be used, in particular, to compensate for static changes and to calibrate an inertial sensor.

In the 7th a method according to the invention for adapting a vertical region of interest within a field of view of a lidar measuring device in a vehicle is shown schematically. The method comprises the steps of receiving S10 movement data, determining S12 a pitch angle and activating S14 of the lidar measuring device. The method can in particular be implemented in software that is executed on a lidar measuring device or in a vehicle control unit.

The invention has been comprehensively described and explained with reference to the drawings and the description. The description and explanation are to be understood as an example and not restrictive. The invention is not limited to the disclosed embodiments. Other embodiments or variations will become apparent to those skilled in the art using the present invention and a careful analysis of the drawings, the disclosure, and the following claims.

In the claims, the words “comprising” and “having” do not exclude the presence of further elements or steps. The undefined article “a” or “an” does not exclude the presence of a plural. A single element or a single unit can perform the functions of several of the units mentioned in the patent claims. An element, a unit, an interface, a device and a system can be implemented partially or completely in hardware and / or in software. The mere mention of a few measures in several different dependent patent claims should not be understood to mean that a combination of these measures cannot also be used advantageously. Reference signs in the patent claims are not to be understood as restrictive.

List of reference symbols

10

vehicle

12th

system

14th

object

16

Lidar measuring device

18th

Inertial sensor

20th

Adjustment device

22nd

Field of view

24

Region of Interest

26th

roadway

28

Input interface

30th

Evaluation unit

32

Control unit

34

Scan line

36

Horizon line

38

Channel

40

recipient

42

2D scanner unit

44

Combination unit

46

Processing unit

48

Pitch angle estimation unit

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed 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 2018/127789 A1 [0004]

Claims (15)

Adaptation device (20) for adapting a vertical region-of-interest (24) within a field of view (22) of a lidar measuring device (16) on a vehicle (10), having: an input interface (28) for receiving movement data from an inertial sensor (18) with information on a position of the vehicle; an evaluation unit (30) for determining a pitch angle of the lidar measuring device based on the movement data; and a control unit (32) for controlling the lidar measuring device in order to adapt the vertical region-of-interest based on the determined pitch angle. Adaptation device (20) according to Claim 1 , wherein the control unit (32) is designed to control the lidar measuring device (16) in order to shift the vertical region of interest in the vertical direction by the determined pitch angle. Adaptation device (20) according to one of the preceding claims, wherein the control unit (32) is designed to control a 2D scanner unit for two-dimensional line-by-line scanning of the field of view (22) of the lidar measuring device (16); and is preferably designed to move a vertical region corresponding to the vertical region of interest (24) with a reduced line spacing within the field of view in the vertical direction by the pitch angle. Adaptation device (20) according to Claim 3 wherein the control unit (32) is designed to move a plurality of adjacent vertical regions with different line spacings within the field of view (22) in the vertical direction by the pitch angle. Adaptation device (20) according to one of the preceding claims, wherein the evaluation unit (30) for determining the pitch angle based on a static component, which corresponds to a component that cannot be changed during a journey, and a dynamic component, which corresponds to a component that changes during a journey, is trained. Adaptation device (20) according to one of the preceding claims, wherein the input interface (28) for receiving movement data is designed with acceleration data of a longitudinal acceleration sensor for measuring an acceleration of the vehicle (10) in the direction of a longitudinal axis of the vehicle; and or is designed with acceleration data of a 3-axis acceleration sensor for measuring a three-dimensional acceleration vector of the vehicle. Adaptation device (20) according to one of the preceding claims, wherein the evaluation unit (30) is designed to determine the pitch angle based on a predefined alignment parameter that describes an alignment of the lidar measuring device (16) in relation to the vehicle (10). Adaptation device (20) according to one of the preceding claims, wherein the input interface (28) is designed to receive the movement data from an inertial sensor (18) of a driver assistance system of the vehicle (10), in particular an anti-lock braking system. Adaptation device (20) according to one of the preceding claims, wherein the input interface (28) is designed to receive a distance specification with information on distances between a target point on a roadway (26) in the field of view (22) of the lidar measuring device (16) and the lidar measuring device, the evaluation unit (30) is designed to determine the pitch angle based on the distance specification; and the input interface is preferably designed to receive the distance information from the lidar measuring device. Adaptation device (20) according to Claim 9 , wherein the evaluation unit (30) is designed to determine the pitch angle based on a previously known height of the lidar measuring device (16) on the vehicle (10) above the roadway (26). Adaptation device (20) according to one of the preceding claims, wherein the evaluation unit (30) is designed to determine the pitch angle based on an application of a stochastic filter, in particular a Wiener filter or a Kalman filter, with a predefined system model over several time steps. Adaptation device (20) according to one of the preceding claims, wherein the input interface (28) is designed to receive curve data with information on cornering of the vehicle; the evaluation unit (30) is designed to determine a relevant azimuth angle range based on the curve data; and the control unit (32) is designed to control the lidar measuring device (16) in order to adapt a horizontal region-of-interest (24) based on the ascertained azimuth angle range. System (12) for detecting an object (14) in the vicinity of a vehicle (10), comprising: a lidar measuring device (16) on the vehicle, with a transmitter (38) for emitting a light signal, a receiver (40) for receiving the light signal after a reflection on the object and a 2D scanner unit (42) for scanning a field of view ( 22) the lidar measuring device; an inertial sensor (18) for detecting movement data with information on a movement of the vehicle; and an adjustment device (20) for adjusting a vertical region-of-interest (24) within the field of view of the lidar measuring device according to one of the preceding claims. Method for adapting a vertical region of interest (24) within a field of view (22) of a lidar measuring device (16) on a vehicle (10), comprising the steps: Receiving (S10) movement data from an inertial sensor (18) with information on a position of the vehicle; Determining (S12) a pitch angle of the lidar measuring device based on the movement data; and Activation (S14) of the lidar measuring device in order to adapt the vertical region-of-interest (24) based on the determined pitch angle. Computer program product with program code for performing the steps of the method according to Claim 14 when the program code is executed on a computer.

Images