DEVICE AND METHOD FOR GENERATING TEST DATA FOR TESTING A DISTANCE DETERMINATION IN AN OPTICAL TIME-OF-FLIGHT MEASUREMENT

Abstract

A device for generating test data for testing a distance determination during an optical runtime measurement, comprising:

A test pattern generator, which is set up to generate a chronological sequence of test events, so as to provide the latter to a test histogram channel for generating time-correlated test histogram data for testing the distance determination during the optical runtime measurement.

Claims

1. A device for generating test data for testing a distance determination during an optical runtime measurement, comprising: A test pattern generator, which is set up to generate a chronological sequence of test events, so as to provide the latter to a test histogram channel for generating time-correlated test histogram data for testing the distance determination during the optical runtime measurement.

2. The device according to claim 1, wherein a time distance between two times of two chronologically sequential test events in the generated chronological sequence of test events is based upon a time resolution of the optical runtime measurement.

3. The device according to claim 2, wherein the chronological sequence of test events is generated based upon at least one input parameter.

4. The device according to claim 2, wherein the input parameter is an image counter.

5. The device according to claim 2, wherein the input parameter is a line index of a receiving matrix.

6. The device according to claim 2, wherein the input parameter is a system time.

7. The device according to claim 2, further comprising: A hash generator, which is set up to generate a bit vector from the input parameters, and apply a hash function to the latter, so as to generate a binary sequence.

8. The device according to claim 7, wherein the chronological sequence of test events is further generated based upon the binary sequence.

9. The device according to claim 1, wherein the test events in the chronological sequence of test events are identical.

10. A measuring device for testing a distance determination during an optical runtime measurement, comprising: A device for generating test data for testing a distance determination during an optical runtime measurement, said device comprising a test pattern generator, which is set up to generate a chronological sequence of test events, so as to provide the latter to a test histogram channel for generating time-correlated test histogram data for testing the distance determination during the optical runtime measurement; and at least one test histogram channel, which is set up to receive the chronological sequence of test events generated by the test pattern generator, and generate time-correlated test histogram data based thereupon.

11. The measuring device according to claim 10, wherein the test histogram channel provides the generated time-correlated test histogram data to a peak detection unit, which determines distances therefrom.

12. The measuring device according to claim 11, further comprising: A test unit, which is set up to receive the distances determined by the peak detection unit and receive times of the chronological sequence of test events, so as to determine nominal distances from these times.

13. The measuring device according to claim 12, wherein the test unit is further set up to generate an error signal based upon a deviation between the determined distances and the nominal distances.

14. The measuring device according to claim 13, wherein the error signal is generated based upon a deviation that lies outside of a tolerance range

15. A method for generating test data for testing a distance determination during an optical runtime measurement, comprising: Generation of a chronological sequence of test events, so as to provide the latter to a test histogram channel for generating time-correlated test histogram data for testing the distance determination during the optical runtime measurement.

Description

[0083] Exemplary embodiments of the invention will now be exemplarily described with reference to the attached drawings, in which:

[0084] FIG. 1 illustrates a coding of times of a chronological sequence of test events;

[0085] FIG. 2 illustrates an exemplary embodiment of a system for an optical runtime measurement in a block diagram; and

[0086] FIG. 3 illustrates an exemplary embodiment for a method of generating test data for testing a distance determination during an optical runtime measurement in a flowchart.

[0087] FIG. 1 illustrates the coding of times of the chronological sequence of test events.

[0088] The horizontal axis in the diagram on FIG. 1 is a distance (time). The vertical axis is dimensionless, and only serves to illustrate the times. The vertical dashes show the distance (point in time) at which a test event is generated.

[0089] In this exemplary embodiment, a binary sequence comprised of three bits is generated by a hash generator (not shown). The binary sequence was determined by applying a hash function to a bit vector, which was generated from an image counter and a line index. The first bit of the binary sequence is equal to 0, the second and third bit are each equal to 1. The time distance between the test events is constant, and corresponds to a distance of 1 m. No test event is generated at the starting point, and a synchronization event (first test event) is generated at 1 m. Based upon the binary sequence, a second test event is generated at 3 m, a third test event at 4 m, and a fourth test event at 6 m.

[0090] FIG. 2 illustrates the exemplary embodiment of system 1 for the optical runtime measurement in a block diagram.

[0091] The system 1 for the optical runtime measurement is a LIDAR system, and operates as follows: A pulse generator 2 outputs an electronic start signal for starting the optical runtime measurement. In response to the electronic start signal, a transmitting system 3 sends out a light pulse, which is reflected on an object 4. The reflected light reaches a receiving system 5, which has a receiving matrix (not shown) with light-detecting receiving elements (here SPADs) arranged in 128 lines and 256 columns. In response to the incident light, the light-detecting receiving elements generate electrical signals, which are received by a histogram channel 6. The histogram channel 6 also receives the electronic start signal for synchronization, and generates time-correlated histogram data based upon the received electrical signals.

[0092] A device 7 generates a chronological sequence of test events parallel to the optical runtime measurement. In this exemplary embodiment, the test events are identical, and generated at times according to FIG. 1. The device 7 receives the electronic start signal at a test pattern generator 8 for synchronization. The device 7 further has a hash generator, which generates the binary sequence from FIG. 1 based upon an image counter and a line index. The hash generator 9 transfers the binary sequence to the test pattern generator 8, which generates the chronological sequence of test events based upon the binary sequence. The latter is transferred by the test pattern generator 8 to a test histogram channel 10, which generates time-correlated test histogram data based upon the received chronological sequence of test events. The test histogram channel 10 receives the electronic start signal for synchronization.

[0093] In this exemplary embodiment, a switch 11 switches between the time-correlated histogram data and the time-correlated test histogram data once the image counter has again increased by four. If the switch 11 allows the time-correlated histogram data through, they are transferred to a peak detection unit 12, which determines object distances from the time-correlated histogram data. Another switch 13 switches the determined object distances to a processor 14, which generates a three-dimensional image of the object 4 from the object distances.

[0094] If the switch 11 allows the time-correlated test histogram data through, they are transferred to the peak detection unit 12, which determines distances from the time-correlated test histogram data. The switch switches the determined distances to a test unit 15. The test unit 15 receives the times of the chronological sequence of test events from the test pattern generator, and determines nominal distances therefrom. The test unit 15 compares the determined distances and the nominal distances, and outputs an error signal.

[0095] In a flowchart, FIG. 3 illustrates the exemplary embodiment for the method 20 of generating test data for testing the distance determination during the optical runtime measurement.

[0096] A chronological sequence of test events is generated at 21, so as to provide them to a test histogram channel for generating time-correlated test histograms for testing the distance determination during optical runtime measurement, as explained herein.

REFERENCE LIST

[0097] 1 System [0098] 2 Pulse generator [0099] 3 Transmitting system [0100] 4 Object [0101] 5 Receiving system [0102] 6 Histogram channel [0103] 7 Device [0104] 8 Test pattern generator [0105] 9 Hash generator [0106] 10 Test histogram channel [0107] 11, 13 Switch [0108] 12 Peak detection unit [0109] 14 Processor [0110] 15 Test unit [0111] 20 Method [0112] 21 Generation of a chronological sequence of test events, so as to provide the latter to a test histogram channel for generating time-correlated test histogram data for testing the distance determination during the optical runtime measurement