DE102019218932B3 - Determining a relative movement - Google Patents

Abstract

The present invention relates to a device (16) for determining a relative movement between an environment sensor (12) and an object (14), having: an input interface (20) for receiving sensor data from an environment sensor with information on a position and a Doppler speed of a sensor target point the object at a first point in time and at a second point in time; a processing unit (22) for determining a translation and a rotation of the sensor target point between the first point in time and the second point in time based on the sensor data; and a movement unit (24) for determining a relative movement between the environment sensor and the object based on the translation and rotation. The present invention also relates to a method and a system (10) for determining a relative movement between an environmental sensor (12) and an object (14).

Description

The present invention relates to a device for determining a relative movement between an environmental sensor and an object. The present invention also relates to a method and a system for determining a relative movement between an environment sensor and an object.

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.

Radar technology is an important sensor principle. Most of the radar sensors used nowadays in the vehicle sector work as multi-pulse radar sensors (also referred to as chirp sequence radar sensors), in which several frequency-modulated pulses are emitted at short intervals. The radar sensors typically include several transmitting and receiving elements (antenna array) that form virtual channels (Rx / Tx antenna pairs). After preprocessing, the radar sensor then periodically provides a radar target list (also referred to as a point cloud) for further processing. This radar target list includes in particular the parameters distance, radial or Doppler speed and (if available) azimuth and elevation angles for the detected targets and forms the basis for an environment recognition.

Another relevant sensor principle is lidar technology (light detection and ranging). 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. In addition, with modern lidar sensors it is also possible to determine a relative or Doppler speed (so-called FMCW lidar). A corresponding lidar target list can be made available, comparable to a radar sensor.

In the field of driver assistance systems and (partially) autonomous driving, the determination of a relative position of another object in relation to one's own vehicle or to the position of the environment sensor is an important problem. On the one hand, one's own vehicle can be localized in relation to the environment. On the other hand, other objects in the vicinity, such as vehicles or pedestrians, can be localized.

In order to enable the sensor data to be evaluated over several time steps, it is often necessary to establish a relationship between a target list (target point list) that was determined at a first point in time and a target list that was determined at a second point in time (scan matching). . This reference forms the basis for tracking the object or one's own position. In order to establish this reference, in particular an estimation or determination of a relative movement between the environmental sensor and the object can take place and a transformation can be determined. The transformation mostly includes a rotation matrix and a translation vector. A widespread approach is the Iterative Closest Point Approach (ICP), which offers an iterative solution for finding point correspondences between different scans and, based on the correspondence found, determines an optimal transformation. The positions of the different points are considered here.

A disadvantage of previous approaches for determining a relative movement is that inaccuracies can arise due to the high deviations or the sensor inaccuracies of radar or even lidar sensors. Inaccuracies in scan matching can lead to the downstream information processing approaches also delivering incorrect results. Approaches that lead to higher accuracies are often much more computationally expensive and therefore impractical.

The US 2017/0 097 410 A1 discloses a radar system for determining yaw rates of target vehicles. The US 2019/0 107 614 A1 and DE 10 2018 100 632 A1 each disclose a radar method and system for determining the angular position, location and / or speed of a target.

Based on this, the present invention has the task of providing an approach for determining a relative movement between an environmental sensor and an object, which offers a high level of reliability and accuracy and can also be calculated efficiently. In particular, high-precision scan matching should be made possible over several sampling times in order to thereby allow self-localization and / or localization of other objects.

• einer Eingangsschnittstelle zum Empfangen von Sensordaten eines Umgebungssensors mit Informationen zu einer Position und einer Dopplergeschwindigkeit eines Sensorzielpunkts an dem Objekt zu einem ersten Zeitpunkt und zu einem zweiten Zeitpunkt;
• einer Verarbeitungseinheit zum Bestimmen einer Translation und einer Rotation des Sensorzielpunkts zwischen dem ersten Zeitpunkt und dem zweiten Zeitpunkt basierend auf den Sensordaten; und
• einer Bewegungseinheit zum Ermitteln einer Relativbewegung zwischen dem Umgebungssensor und dem Objekt basierend auf der Translation und Rotation.

To achieve this object, the invention relates in a first aspect to a device for determining a relative movement between an environmental sensor and an object with:

• an input interface for receiving sensor data from an environmental sensor with information on a position and a Doppler velocity of a sensor target point on the object at a first point in time and at a second point in time;
• a processing unit for determining a translation and a rotation of the sensor target point between the first point in time and the second point in time based on the sensor data; and
• a movement unit for determining a relative movement between the environment sensor and the object based on the translation and rotation.

• einer Vorrichtung wie zuvor beschrieben; und
• einem Umgebungssensor zum Detektieren von Objekten in einer Umgebung eines Fahrzeugs.

In a further aspect, the present invention relates to a system for determining a relative movement between an environmental sensor and an object, with:

• a device as previously described; and
• an environment sensor for detecting objects in an environment of a vehicle.

Further aspects of the invention relate to a method embodied in accordance with the device described above 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 executed, causes an execution of the method described herein.

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 device in the dependent claims.

According to the invention, it is provided that sensor data from an environmental sensor are received via an input interface. In particular, data from a radar sensor or a lidar sensor are received which include, on the one hand, a position and, on the other hand, a Doppler velocity of a sensor target point at a first point in time and at a second point in time. The same sensor target point is considered at two (preferably immediately consecutive) points in time. The corresponding determination of a corresponding point at two points in time takes place beforehand, for example by means of a standard approach or by using a further sensor.

The sensor data include, on the one hand, a position and, on the other hand, a Doppler velocity at the two points in time. According to the invention and in contrast to an ICP approach, the Doppler velocity is also taken into account in addition to the position when determining the translation and the rotation of the sensor target point. A relative movement can be described based on the determined translation and rotation. The additional information on the Doppler velocity, which can be provided by both a radar and a lidar sensor, allows a translation and rotation to be determined on the basis of a single point at two points in time. In particular, two successive scans of the environmental sensor are considered. A short time difference enables an approximately constant speed and rotation rate to be assumed without significantly falsifying the result. The determined translation and rotation of the one point can then be used to determine a relative movement of the entire object. The relative movement is calculated in particular in that a corresponding transformation is also determined or carried out for further sensor target points on the object.

Compared to previous approaches in which only the position is used for the scan matching, the additional consideration of the Doppler velocity provided according to the invention enables higher accuracy and reliability. In addition, it is sufficient to consider a single sensor target point at two points in time to fully capture the kinematics. A corresponding transformation can be determined on the basis of a single scan point. In comparison to approaches in which several points are taken as a basis, the approach according to the invention can be calculated much more efficiently. As a result, a reliable and precise detection of a relative movement and a relative position between the environment sensor and the object can be calculated.

In a preferred embodiment, the input interface is designed to receive an azimuth angle, an elevation angle, a distance and a Doppler velocity of the sensor target point at successive sampling times. Sampling times map the scanning frequency with which the environmental sensor is operated. The measurement frequency or update rate of a radar sensor can be 10, for example Hz, so that the time interval between the first point in time and the second point in time is 0.1 seconds. The azimuth, elevation and distance parameters are provided by default. The approach according to the invention can be implemented based on these parameters. However, it is also possible for the sensor data to include position or speed information that has been converted and, in particular, transformed into Euclidean coordinates.

In a preferred embodiment, the processing unit is designed to determine the translation and the rotation of the sensor target point based on a minimization of a mean square deviation of the Doppler velocity of the target point at the two times, preferably using a Gauss-Newton method. It is assumed that there is no acceleration between the points in time. This assumption is particularly possible at high measurement frequencies. The calculation of the mean square deviation can be carried out efficiently, so that the resource requirement remains low. A reliable determination of the translation and the rotation of the sensor target point results.

In a preferred embodiment, the input interface is designed to receive sensor data with information on positions of further target points on the object at the two times. In addition, the movement unit is designed to determine corresponding further target points at the two times in order to determine the relative movement. The relative movement is determined based on further target points. In particular, a target list with a large number of target points and information on the various target points can be received via the input interface. A corresponding target point is understood to mean the same target point at the second point in time. The same target point is observed at two points in time. In particular, the further target points are correspondingly transformed and an adaptation is made to the target points of the second point in time in order to be able to fully describe the relative movement between the environmental sensor and the object.

In a preferred embodiment, the movement unit is designed to minimize a mean square deviation of the positions and / or Doppler velocities of the further target points at the two points in time, preferably using a Gauss-Newton method. It is possible that the compensation of the movement after the transformation is carried out based on a minimization of a mean square deviation. There is an efficient predictability. In addition, the movement can be determined with high precision. The movement can be fully described.

In a preferred embodiment, the input interface is designed to receive the sensor data from an FMCW radar sensor, which is preferably attached to a vehicle. In particular, a frequency modulated continuous wave radar sensor (FMCW radar sensor) can be used as the environment sensor. Such a radar sensor allows an exact measurement of the angle, the distance and the Doppler speed. The principle of the FMCW radar sensors is the most widely used sensor principle in the automotive sector. The use of the sensor data of an FMCW radar sensor results in a wide range of applicability of the device according to the invention.

In a preferred embodiment, the device according to the invention comprises a relative position unit for determining a relative position of the object in relation to the environment sensor. The input interface is designed to receive sensor data with a first target point list with information on positions of first target points on the object at the first point in time and a second target point list with information on positions of second target points on the object at the second point in time. The relative position unit is designed to generate an accumulated target point list with information on positions of first and second target points on the object at the second point in time. The entries of the first target point list are transformed based on the translation and rotation. The relative position unit is also designed to determine the relative position of the object based on the accumulated target point list. The destination point lists received do not necessarily include the same destination points at different times. There are also new target points added. In order to increase the resolution, an accumulated target point list is generated which includes target points from several points in time. For this it is necessary that the target points are transformed into the same coordinate system. The determined translation and rotation can be used to achieve this transformation. In particular, a corresponding rotation matrix and a translation vector can be generated and used for each point. The transformation takes place in particular into the current sensor-fixed or vehicle-fixed coordinate system. The object recognition or the determination of the relative position can take place with greater accuracy.

A relative movement is understood to mean a movement that the environmental sensor and the object execute in relation to one another. In particular, on the one hand, a movement of the object relative to the ambient sensor and, on the other hand, a Movement of the environmental sensor can be determined relative to the object. As a result, the environmental sensor or a vehicle with an environmental sensor can be self-localized relative to its surroundings and an object in the surroundings can be localized relative to the environmental sensor or relative to the vehicle. An object can be a stationary or a mobile object. In particular, an object can be another vehicle, a pedestrian or an element of the environment, such as a lane boundary or a tree. A translation and a rotation can take place in particular by specifying a rotation matrix and a translation vector. An environmental sensor is, in particular, a sensor whose field of view encompasses the surroundings of a vehicle. An environmental sensor sends out a signal and receives reflections from objects within its field of view. The field of view describes an area within which objects can be detected. In particular, a radar or lidar sensor can be used as the environment sensor, which can measure and provide Doppler information. An environment sensor can comprise several individual sensors which, for example, enable a 360 ° all-round view and can thus record a complete image of the environment. A sensor target point is a single detection of the environmental sensor. An object may have several individual sensor target points. An environment sensor preferably outputs a sensor target list with individual detections, with information given for each individual detection, in particular the angle information (azimuth, elevation), a distance information (ranks) and a radial or Doppler velocity. A relative movement is understood to mean a movement of the object that can be specified by a translation (translation vector) in a point and a rotation (rotation matrix).

• 1 eine schematische Darstellung eines erfindungsgemäßen Systems;
• 2 eine schematische Darstellung einer erfindungsgemäßen Vorrichtung;
• 3 eine schematische Darstellung der Problemstellung des Ermittelns einer Relativbewegung;
• 4 eine schematische Darstellung des erfindungsgemäßen Berechnungsansatzes zum Ermitteln einer Relativbewegung;
• 5 eine schematische Darstellung einer erfindungsgemäß ermittelten Relativbewegung; und
• 6 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 system according to the invention;
• 2 a schematic representation of a device according to the invention;
• 3 a schematic representation of the problem of determining a relative movement;
• 4th a schematic representation of the calculation approach according to the invention for determining a relative movement;
• 5 a schematic representation of a relative movement determined according to the invention; and
• 6th a schematic representation of a method according to the invention.

In the 1 is schematically a system according to the invention 10 for determining a relative movement between an environmental sensor 12th and an object 14th shown. The system 10 includes a device 16 to determine the relative movement and the environmental sensor 12th . In the illustrated embodiment, the device 16 and the environmental sensor 12th in a vehicle 18th integrated. It goes without saying that it is also conceivable that the device 16 and / or the environmental sensor are designed separately.

Like in the 1 shown can have different objects 14th , such as other road users, in particular vehicles, or static objects such as trees, houses or traffic signs, are detected. The environmental sensor 12th can in particular be a radar or lidar sensor.

The approach of the invention is based on the fact that when determining a relative movement between the environmental sensor 12th and object 14th in addition to a position (relative position) of the object determined based on sensor data 14th a Doppler velocity is also included. By taking into account the Doppler velocity, an accurate and efficiently calculable determination of the relative movement based on the observation of a single sensor target point can take place at two successive points in time. In particular in the case of radar detections, in which the position measurement is often faulty, but the Doppler measurement is very accurate, an appropriate determination of movement can take place. Compared to previous scan matching approaches, in which a large number of points have to be taken into account, the approach according to the invention can be calculated more efficiently.

In the 2 is schematically a device according to the invention 16 shown. The device 16 includes an input interface 20th , a processing unit 22nd as well as a movement unit 24 . In the exemplary embodiment shown, the device also includes an (optional) relative position unit 26th . The device according to the invention 16 can, for example, be integrated into a vehicle control device or be designed as part of a driver assistance system or implemented as a separate module. It is possible that the device according to the invention 16 is partially or completely implemented in software and / or hardware. The various units and interfaces can individually or in combination as a processor, processor module or software for a processor.

Via the input interface 20th sensor data from an environmental sensor are received. In particular, data from a radar or an FMCW lidar sensor can be received. Information is received about a position and about a Doppler velocity of a sensor target point on an object at a first point in time and at a second point in time. The assignment between the two points in time or the identification of corresponding points takes place in a preceding step. For this purpose, for example, nearest neighbors methods can be used. In Nearest Neighbors procedures, single or global, corresponding points and / or features are determined. Via the input interface 20th In this respect, preprocessed information is received that ensures that the same point was observed at two different times. The input interface 20th can for example be connected to a vehicle bus system in order to receive the data from the environmental sensor.

In the processing unit 22nd a translation and a rotation of the sensor target point is determined based on the sensor data. This determination is possible based on a single point if the Doppler velocity is also available (at both points in time) and is included in the calculation. In particular, a vector specification for defining the translation and a rotation matrix for defining the rotation of the sensor target point are determined.

In the movement unit 24 a relative movement between the environmental sensor and the object is determined. For this purpose, a corresponding transformation is determined or carried out for various sensor target points of an object, in particular on the basis of the previously determined translation and rotation. In this respect, a relative movement is completely determined. This relative movement can then be used in further processing to localize the environment sensor or the own vehicle, or also to provide localization of an object in the environment of the vehicle. It is possible that the movement unit is also connected to a vehicle bus system in order to transmit the determined relative movement in the form of corresponding parameter information to a further processing unit.

In the optionally provided relative position unit 26th an accumulated target point list can be generated. This accumulated target point list includes information on positions of target points that were recorded at different times. The target points are transformed into a uniform, preferably sensor-fixed, coordinate system in order to enable a common evaluation. In this respect, the resolution is increased, so to speak, by considering several time steps.

an einem Objekt 14 dargestellt. Der Punkt ${\overrightarrow{p}}_0$

ist ein beliebiger Punkt im Raum (typischerweise das Drehzentrum des Objektes), auf den man die Geschwindigkeit ${\overrightarrow{v}}_i$

des Punktes ${\overrightarrow{p}}_i$

beziehen kann. Die Darstellung ist dabei als vogelperspektivische Ansicht (Draufsicht) in kartesischen Koordinaten in einem xy-Koordinatensystem zu verstehen. Das Koordinatensystem entspricht insoweit einer Draufsicht auf eine Situation in einer Umgebung eines (eigenen) Fahrzeugs, wobei sich der Umgebungssensor (am Fahrzeug) an der Nullposition befindet. Für die Geschwindigkeiten in den beiden Punkten am Objekt 14 gilt: $${\overrightarrow{v}}_i={\overrightarrow{v}}_o+\omega \times \left({\overrightarrow{p}}_i-{\overrightarrow{p}}_o\right).$$

In the 3 are schematically two points ${\overrightarrow{p}}_0,{\overrightarrow{p}}_i$

on an object 14th shown. The point ${\overrightarrow{p}}_0$

is an arbitrary point in space (typically the center of rotation of the object) on which the speed is applied ${\overrightarrow{v}}_i$

of the point ${\overrightarrow{p}}_i$

can relate. The representation is to be understood as a bird's-eye view (top view) in Cartesian coordinates in an xy coordinate system. In this respect, the coordinate system corresponds to a top view of a situation in the surroundings of a (one's own) vehicle, with the surroundings sensor (on the vehicle) being at the zero position. For the speeds in the two points on the object 14th applies: $${\overrightarrow{v}}_i={\overrightarrow{v}}_O+\omega \times \left({\overrightarrow{p}}_i-{\overrightarrow{p}}_O\right).$$

für die die euklidischen Koordinaten x und y, die Drehrate ω, die Beschleunigungen ẋ bzw. ẏ sowie den Winkel θ. Ausgehend von den fünf Unbekannten (ẋ₀, ẏ₀, ẋ₀, ẏ₀ und ω) ergibt sich, dass mindestens drei Bedingungen notwendig sind. Diese Gleichung ist somit ohne weitere geometrische Informationen nicht lösbar.This results in the radial speed ṙ _i $${\dot{r}}_i=\left({\dot{x}}_O-\omega \left(y_i-y_O\right)\right)cOs\left({\theta }_i\right)+\left({\dot{y}}_O-\omega \left(x_i-x_O\right)\right)sin\left({\theta }_i\right)$$

for the Euclidean coordinates x and y, the rate of rotation ω, the accelerations ẋ and ẏ and the angle θ. Based on the five unknowns (ẋ ₀ , ẏ ₀ , ẋ ₀ , ẏ ₀ and ω) it follows that at least three conditions are necessary. This equation cannot be solved without further geometric information.

stattdessen der Momentanpol ${\overrightarrow{p}}_{icr}$

(Englisch: Instant Center of Rotation) verwendet wird, verschwindet der lineare Anteil ${\overrightarrow{v}}_o.$

Damit reduziert sich die Gleichung zu $${\overrightarrow{v}}_i=\omega \times \left({\overrightarrow{p}}_i-{\overrightarrow{p}}_{icr}\right)$$

was nur noch drei Unbekannte Größen aufweist. Die Radialgeschwindigkeit lässt sich dann wie folgt schreiben: $${\dot{r}}_i=\omega y_{icr}cos\left({\theta }_i\right)-\omega x_{icr}sin\left({\theta }_i\right)$$

When used as a reference point for speed ${\overrightarrow{v}}_i$

instead the momentary pole ${\overrightarrow{p}}_{icr}$

(English: Instant Center of Rotation) is used, the linear portion disappears ${\overrightarrow{v}}_O.$

This reduces the equation to $${\overrightarrow{v}}_i=\omega \times \left({\overrightarrow{p}}_i-{\overrightarrow{p}}_{icr}\right)$$

which only has three unknown quantities. The radial velocity can then be written as follows: $${\dot{r}}_i=\omega y_{icr}cOs\left({\theta }_i\right)-\omega x_{icr}sin\left({\theta }_i\right)$$

For the three unknown variables ω, x _icr and y _icr, only two are required Boundary conditions. In this respect, it is possible, based on the additional consideration of the Doppler velocity, to completely determine the relative movement between the environmental sensor and the object or the kinematics of an object for the presence of only two points.

dargestellt, wobei Messungen der Position und Dopplergeschwindigkeit zu den Zeitpunkten k und k + 1 vorliegen. Für die Radialgeschwindigkeit ṙ_i,k zum ersten Zeitpunkt gilt $${\dot{r}}_{i,k}=\omega y_{icr}cos\left({\theta }_{i,k}\right)-x_{icr}\omega sin\left({\theta }_{i,k}\right).$$

In the 4th is a schematic of the approach according to the invention for determining the translational and rotational speed of the sensor target point ${\overrightarrow{p}}_i$

with measurements of the position and Doppler velocity at times k and k + 1. The following applies to the radial speed ṙ _{i, k} at the first point in time $${\dot{r}}_{i,k}=\omega y_{icr}cOs\left({\theta }_{i,k}\right)-x_{icr}\omega sin\left({\theta }_{i,k}\right).$$

The following applies to the radial speed ṙ _{i, k + 1} at the second point in time $${\dot{r}}_{i,k+1}=\omega y_{icr}cOs\left({\theta }_{i,k+1}\right)-x_{icr}\omega sin\left({\theta }_{i,k+1}\right).$$

The relationship applies to the circle segment φ covered, based on the distances c and d $$\phi =\frac{\omega }{T}=2{\text{tan}}^{-1}\left(\frac{c}{2d}\right)$$

die Geradengleichung $$y_{icr}=m{x}_{icr}+b$$

_{In addition, y icr} results for the y position at the momentary pole ${\overrightarrow{p}}_{icr}$

the straight line equation $$y_{icr}=m{x}_{icr}+b$$

für die Iterationsschritte n und n+1, den Parametervektor β sowie die Jacobimatrix J.On the basis of this, the mean square error can then be minimized over the two Doppler velocities. One possible solution is to use the Gauss-Newton method $$\begin{array}{c}{\beta }_{n+1}={\beta }_n-{\left(J_n^T{J}_n\right)}^{-1}r\left({\beta }_n\right)\\ {\beta }_n=x_{icr}\end{array}$$

for the iteration steps n and n + 1, the parameter vector β and the Jacobian matrix J.

In the 5 is shown schematically how, based on the determined translation and rotation, the relative movement between the environmental sensor and the object 14th can be calculated. As shown, the object will 14th observed in the sensor-fixed coordinate system of the environmental sensor at a first point in time t at a different point than at a second point in time t + 1. The corresponding transformation can take place based on an indication of a translation vector and a rotation matrix. In this respect, the specific translation and rotation is used to determine the relative movement between the environmental sensor and the object and between the two points in time.

In the 6th a method according to the invention for determining a relative movement between an environmental sensor and an object is shown schematically. The method comprises the steps of receiving S10 sensor data from an environment sensor, determining S12 a translation and a rotation and determining S14 a relative movement between the environment sensor and the object. The method can in particular be implemented in software that is executed on a vehicle control device. It is also possible for the method to be carried out in an environment sensor, in particular in a radar and / or lidar sensor.

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 examples 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 after using the present invention and after carefully analyzing 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 some measures in several different dependent patent claims should not be understood to mean that a combination of these measures cannot also be used advantageously. A computer program can be stored / distributed on a non-volatile data carrier, for example on an optical memory or on a semiconductor drive (SSD). A computer program can be distributed together with hardware and / or as part of hardware, for example by means of the Internet or by means of wired or wireless communication systems. Reference signs in the patent claims are not to be understood as restrictive.

List of reference symbols

10

system

12th

Environmental sensor

14th

object

16

contraption

18th

vehicle

20th

Input interface

22nd

Processing unit

24

Movement unit

26th

Relative position unit

Claims (10)

Device (16) for determining a relative movement between an environment sensor (12) and an object (14), the object comprising a stationary or mobile object comprising a vehicle, pedestrian or an element of the environment comprising a lane boundary or a tree, with: an input interface (20) for receiving sensor data from an environmental sensor with information on a position and a Doppler velocity of a sensor target point on the object at a first point in time and at a second point in time, with corresponding sensor target points and / or features being identified; a processing unit (22) for determining a translation and a rotation of the sensor target point between the first point in time and the second point in time based on the sensor data; and a movement unit (24) for determining a relative movement between the environment sensor and the object based on the translation and rotation comprising a movement of the object relative to the environment sensor and a movement of the environment sensor relative to the object, the relative movement being determined by an adaptation to the sensor target points of the takes place at the second time. Device (16) after Claim 1 wherein the input interface (20) is designed to receive an azimuth angle, an elevation angle, a distance and a Doppler velocity of the sensor target point at successive sampling times. Device (16) according to one of the preceding claims, wherein the processing unit (22) for determining the translation and the rotation of the sensor target point based on a minimization of a mean square deviation of the Doppler velocity of the target point at the two times, preferably using a Gauss-Newtonian Procedure, is formed. Device (16) according to one of the preceding claims, wherein the input interface (20) is designed to receive sensor data with information on positions of further target points on the object (14) at the two times; and the movement unit (24) is designed to determine corresponding further target points at the two points in time in order to determine the relative movement. Device (16) after Claim 4 wherein the movement unit (24) is designed to minimize a mean square deviation of the positions and / or Doppler velocities of the further target points at the two points in time, preferably using a Gauss-Newton method. Device (16) according to one of the preceding claims, wherein the input interface (20) is designed to receive the sensor data from an FMCW radar sensor, which is preferably attached to a vehicle (18). Device (16) according to one of the preceding claims, with a relative position unit (26) for determining a relative position of the object (14) in relation to the environment sensor (12), wherein the input interface (20) is designed to receive sensor data with a first target point list with information on positions of first target points on the object at the first point in time and a second target point list with information on positions of second target points on the object at the second point in time; the relative position unit is designed to generate an accumulated target point list with information on positions of first and second target points on the object at the second point in time, the entries of the first target point list being transformed based on the translation and rotation; and the relative position unit is designed to determine the relative position of the object based on the accumulated target point list. System (10) for determining a relative movement between an environmental sensor (12) and an object (14), comprising: a device (16) according to any preceding claim; and an environment sensor for detecting objects in the vicinity of a vehicle (18). Method for determining a relative movement between an environmental sensor (12) and a Object (14), the object comprising a stationary or mobile object comprising a vehicle, pedestrian or an element of the environment comprising a lane boundary or a tree, with the steps of: receiving (S10) sensor data from an environmental sensor with information on a position and a Doppler speed a sensor target point on the object at a first point in time and at a second point in time; Determining (S12) a translation and a rotation of the sensor target point between the first point in time and the second point in time based on the sensor data, with corresponding sensor target points being identified, comprising nearest neighbors method; and determining (S14) a relative movement between the environment sensor and the object including a movement of the object relative to the environment sensor and a movement of the environment sensor relative to the object by an adaptation to the sensor target points of the second point in time based on the translation and rotation. Computer program product with program code for performing the steps of the method according to Claim 9 when the program code is executed on a computer.

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