PRODUCING A MEASUREMENT DATA SET BY MEANS OF AN ACTIVE SENSOR SYSTEM

Abstract

An active sensor system (1) has a first and a second emitter unit (2, 2′), as well as a detector unit (3, 3′) and a computing unit (4). The emitter units (2, 2′) are configured to emit respective measurement signals into corresponding emission spatial regions (A1, A2). The detector unit (3, 3′) is configured to generate at least one detector signal on the basis of reflected portions of the measurement signals, and the computing unit (4) is configured to generate a measurement data set on the basis of the at least one detector signal. The computing unit (4) is configured to identify at least one section (T1, T1′, T2) that is shaded with respect to at least one of the emitter units (2, 2′). The computing unit (4) is configured to generate the measurement data set taking into account the section (T1, T1′, T2) and/or to generate correction data for correcting the measurement data set.

Claims

1. An active sensor system having a first emitter unit, a second emitter unit, a detector unit and a computing unit, wherein the first emitter unit is configured to emit a first measurement signal into a first emission spatial region in an environment of the sensor system; the second emitter unit is configured to emit a second measurement signal into a second emission spatial region in the environment; a sensor field of view is given by a first overlapping region of the first emission spatial region with a detector field of view of the detector unit and by a second overlapping region of the second emission spatial region with the detector field of view; the detector unit is configured to generate at least one detector signal on the basis of portions of the first measurement signal and/or of the second measurement signal which are reflected in the sensor field of view; and the computing unit is configured to generate a measurement data set on the basis of the at least one detector signal, wherein the computing unit is configured to: identify, on the basis of the at least one detector signal, at least one section of the sensor field of view which is shaded with respect to the first emitter unit and/or with respect to the second emitter unit; and generate the measurement data set taking into account the at least one section and/or to generate correction data for correcting the measurement data set on the basis of the at least one section.

2. The active sensor system as claimed in claim 1, wherein the computing unit is configured to identify, on the basis of the at least one detector signal, at least one first section of the sensor field of view which is shaded with respect to the first emitter unit and is not shaded with respect to the second emitter unit.

3. The active optical sensor system as claimed in claim 2, wherein the detector unit is configured to generate at least one first detector signal on the basis of portions of the second measurement signal which are reflected by an object in the at least one first section.

4. The active optical sensor system as claimed in claim 3, wherein the computing unit is configured to determine a first signal intensity on the basis of the at least one first detector signal, to modify the first signal intensity according to a predefined first correction rule, and to generate the measurement data set depending on the modified first signal intensity.

5. The active sensor system as claimed in claim 4, wherein the computing unit is configured to determine a measurement point and a confidence value for the measurement point on the basis of the at least one first detector signal, to modify the confidence value according to a predefined second correction rule, and to generate the measurement data set depending on the measurement point and the modified confidence value.

6. The active sensor system as claimed in claim 1, wherein the computing unit is configured to identify, on the basis of the at least one detector signal, at least one second section of the sensor field of view which is shaded with respect to the first emitter unit and is shaded with respect to the second emitter unit.

7. The active sensor system as claimed in claim 1, wherein the detector unit has a first detector with a first field of view and a second detector with a second field of view, and the detector field of view is given by the first field of view and the second field of view.

8. The active sensor system as claimed in claim 1, wherein the active sensor system is one of a lidar system, a radar system, an ultrasonic sensor system.

9. An object characterization system comprising: an active sensor system as claimed in claim 1, and a further computing unit which is configured to characterize an object in the sensor field of view on the basis of the measurement data set or on the basis of the measurement data set and the correction data.

10. The system as claimed in claim 9, wherein the active sensor system the computing unit is configured to: identify, on the basis of the at least one detector signal, at least one first section of the sensor field of view which is shaded with respect to the first emitter unit and is not shaded with respect to the second emitter unit, generate first information for assigning the at least one first section to at least one corresponding first part of the measurement data set and to transmit it to the further computing unit, and characterize the object depending on the first information and/or to initiate a risk-reducing measure depending on the first information.

11. The system as claimed in claim 9, wherein: the computing unit is configured to: identify, on the basis of the at least one detector signal, at least one second section of the sensor field of view which is shaded with respect to the first emitter unit and is shaded with respect to the second emitter unit, generate second information for assigning the at least one second section to at least one corresponding second part of the measurement data set and to transmit it to the further computing unit, and characterize the object depending on the second information and/or to initiate a risk-reducing measure depending on the second information.

12. A method for generating a measurement data set by means of an active sensor system the method comprising: emitting a first measurement signal into a first emission spatial region in an environment of the sensor system and emitting a second measurement signal into a second emission spatial region in the environment; providing a sensor field of view by a first overlapping region of the first emission spatial region and by a second overlapping region of the second emission spatial region with the detector field of view; generating at least one detector signal on the basis of portions of the first measurement signal and/or of the second measurement signal which are reflected in the sensor field of view; generating the measurement data set on the basis of the at least one detector signal; and identifying, on the basis of the at least one detector signal, at least one section of the sensor field of view which is shaded with respect to the first emitter unit and/or is shaded with respect to the second emitter unit, wherein the measurement data set is generated taking into account the identified at least one section and/or correction data for correcting the measurement data set are generated on the basis of the at least one section.

13. The method as claimed in claim 12, further comprising: identifying, on the basis of the at least one detector signal, at least one first section of the sensor field of view which is shaded with respect to the first emitter unit and is not shaded with respect to the second emitter unit is identified; and/or on the basis of the at least one detector signal, at least one second section of the sensor field of view which is shaded with respect to the first emitter unit and is shaded with respect to the second emitter unit is identified.

14. A method for characterizing objects by an active sensor system, comprising: generating a measurement data set by the active sensor system according to the method as claimed claim 12; and characterizing an object in the sensor field of view on the basis of the measurement data set or on the basis of the measurement data set and the correction data.

15. (canceled)

Description

[0108] In the figures:

[0109] FIG. 1 shows a schematic representation of an exemplary embodiment of an object characterization system according to the improved concept and of an active sensor system according to the improved concept; and

[0110] FIG. 2 shows a schematic representation of a further exemplary embodiment of an object characterization system and of an active sensor system according to the improved concept.

[0111] FIG. 1 schematically shows an object characterization system 1′ according to the improved concept, which has an active sensor system 1 according to the improved concept. For example, the active sensor system 1 is designed as a lidar system in the present case.

[0112] The active sensor system 1 has a first emitter unit 2 and a second emitter unit 2′, which are arranged at spatially different positions. For example, the emitter units 2, 2′ can be installed at different positions in a motor vehicle 6. In addition, the sensor system 1 has a detector unit 3.

[0113] The emitter units 2, 2′ can be designed as infrared laser light sources, for example. The detector unit 3 can include one or more avalanche photodiodes, APDs, for example.

[0114] The sensor system 1 also has a computing unit 4 which can be designed as a control and processing unit, for example. For example, the computing unit 4 can actuate the emitter units 2, 2′ and/or the detector unit 3.

[0115] The emitter units 2, 2′ and the detector unit 3 can have corresponding driver circuits, for example, or such driver circuits can be included in the computing unit 4.

[0116] The computing unit 4 can actuate the emitter units 2, 2′ so that the first emitter unit 2 emits first measurement signals into a first emission spatial region A1 and the second emitter unit 2′ emits second measurement signals into a second emission spatial region A2.

[0117] The detector unit 3 has a detector field of view D, that is to say in particular can only detect light that runs from the detector field of view D in the direction of the detector unit 3.

[0118] The first emission spatial region A1 overlaps the detector field of view D in a first overlapping region SF1 and the second emission spatial region A2 overlaps the detector field of view D in a second overlapping region SF2. Points in space that are either in the first overlapping region SF1 or in the second overlapping region SF2 form a sensor field of view SF of the active sensor system 1.

[0119] In other words, the sensor system 1 can basically recognize objects that are located in the sensor field of view SF. If an object O1 is located, for example, in the first overlapping region SF1 but not in the second overlapping region SF2, the object can reflect the first measurement signals and the detector unit 3 can detect these reflected portions. The same applies analogously to objects that are located in the second overlapping region SF2 but not in the first overlapping region SF1.

[0120] Objects O4, O3, O4, which are located both in the first and in the second overlapping region SF1, SF2, can in principle be reached by the first measurement signal and by the second measurement signal, can reflect said signals, and the detector unit 3 can detect the corresponding reflections.

[0121] However, if an object O1 is located in the sensor field of view SF, this object O1 may shade a first section T1 with respect to the first emitter unit 2 or the second emitter unit 2′. If there are a plurality of objects O1, O2 in the sensor field of view SF, this can also lead to second spatial regions T2 in which there is shading with respect to both emitter units 2, 2′.

[0122] FIG. 1 shows an example of a situation in which a first object O1 is located in the first overlapping region SF1, but outside the second overlapping region SF2. A first section T1, which is shaded with respect to the first emitter unit 2, results accordingly. For example, a second object O2 is located within the first and second overlapping regions SF1, SF2 and also within the first section T1. The second object O2 therefore cannot be reached by the first measurement signal, but can be reached by the second measurement signal. On a side of the second object O2 that is remote from the second emitter unit 2′, however, there is now a second section T2 of the sensor field of view SF which is shaded both with respect to the first emitter unit 2 and with respect to the second emitter unit 2′, with the result that a third object O3, which is located in this second section T2, cannot be detected by the sensor system 1.

[0123] However, in the present example, the second object O2 also generates a further first section T1′ which is shaded with respect to the second emitter unit 2′, but not with respect to the first emitter unit 2. FIG. 1 shows, by way of example, a fourth object O4 which is located in the further first section T1′. This object can be detected by the sensor system 1 by virtue of the first measurement signal being reflected by the object O4 and the corresponding reflections being able to be detected by the detector unit 3.

[0124] It is pointed out that the objects O1, O2, O3, O4 shown in FIG. 1 only serve to illustrate different situations with regard to different shading events. Even if the object O1 is in the first emission spatial region A1, but not in the detector field of view D, shading, e.g. of the object O2 with respect to the first emitter unit 2, can be identified via position information on O2 relative to the emitter unit 2′ and the detector unit 3.

[0125] The detector unit 3 generates at least one detector signal on the basis of the reflected portions of the first and/or the second measurement signal, which are detected by the detector unit 3.

[0126] The computing unit 4 can identify the first sections T1, T1′ or the second section T2 on the basis of the at least one detector signal. The computing unit 4 can generate a measurement data set, in particular a lidar point cloud, on the basis of the at least one detector signal, taking into account the at least one section T1, T1′, T2. Alternatively or additionally, the computing unit can generate correction data for correcting the measurement data set on the basis of the sections T1, T1′, T2.

[0127] The computing unit 4 can transmit the measurement data set and/or the correction data to the further computing unit 5. The further computing unit 5 is configured, for example, to recognize or characterize one or more of the objects O1, O2, O3, O4 on the basis of the measurement data set and/or on the basis of the correction data or to carry out further processing.

[0128] A further exemplary embodiment of the system 1′ or of the sensor system 1 is shown in FIG. 2.

[0129] The sensor system 1 in FIG. 2 contains a further detector unit 3′, which is designed analogously to the detector unit 3, for example. The detector units 3, 3′ can also be understood together as a common detector unit.

[0130] As explained with reference to FIG. 1, the detector unit 3 has a first detector field of view D1 and the further detector unit 3′ has a second detector field of view D2. The union of the detector fields of view D1, D2 forms the detector field of view D here.

[0131] As a result, the detection range of the sensor system 1 is further increased. Otherwise, the explanations regarding the sensor system 1 in FIG. 1 apply here analogously.

[0132] As described, the problem of shading in active sensor systems 1 having a plurality of emitter units 2, 2′ can be countered by means of the improved concept.

[0133] The amplitudes of the detector signals, i.e. their signal strength, are reduced by the shading. This can affect the characterization of the objects O1, O2, O3, O4. For example, image processing or machine vision algorithms, such as algorithms based on artificial intelligence methods, would have to recognize shading by other objects in advance. In order to simplify the complexity of the problem, the improved concept provides for the characteristics of shaded regions to be corrected.

[0134] For this purpose, for example, a measure of the signal strength or a variable applied thereto or based thereon can be used.

[0135] In a situation as illustrated in FIGS. 1 and 2, the shading is evaluated, viewed from the sensor system 1, in particular from the front to the rear. In other words, the computing unit 4 first recognizes the first object O1, corrects the characteristics in the shaded region T1, then recognizes the object O2 and corrects the characteristics for the further shaded region T1 and the second section T2.

[0136] The sections T1 and/or T2 can be communicated to the further computing unit 5 separately from one another or together as regions of low trustworthiness and/or reduced performance.

[0137] According to the improved concept, the detector signals, for example, are therefore generated first, then the objects that shade certain sections T1, T1′, T2 are recognized. Corresponding correction values for the confidence or for the signal strength can then be calculated or read in and the characteristics, i.e. in particular signal strength or confidence values, in the shaded regions T1, T1′, T2 can be corrected using the computing unit 4.

[0138] The further computing unit 5 can then further process the corrected measurement data or the measurement data set in a correspondingly reliable manner.