KR102385094B1 - Test system for lidar sensor - Google Patents

Abstract

A lidar sensor test system includes: a panel for emitting light from a lidar sensor and reflecting at least a portion of the emitted light; and a computing device which generates a control signal for controlling an operation of the lidar sensor and receives and analyzes data measured by the lidar sensor. The panel is divided into N regions by a plurality of reflection coefficients and properties of a plurality of reflectors, and the properties of the plurality of reflectors are characterized in that they include a diffuse reflector and a retro reflector. Accordingly, a performance test of the lidar sensor can be automatically performed for a plurality of test items.

Description

LIDAR SENSOR TEST SYSTEM

The present invention relates to a lidar sensor test system.

In an autonomous vehicle equipped with a lidar sensor, a defective lidar sensor becomes an important issue for the safety of vehicle occupants.

Therefore, accurately testing the performance of the lidar sensor before the lidar sensor is installed in the vehicle is essential for securing the stability of the autonomous vehicle.

To this end, it is required to develop a test system that can automatically test the performance of the lidar sensor for a number of test items.

Domestic Patent Publication No. 10-2020-0059755: LiDAR sensor verification test simulator (published on May 29, 2020).

The present invention aims to solve the technical problem as described above, and an object of the present invention is to provide a lidar sensor test system capable of automatically performing a performance test of a lidar sensor for a plurality of test items there is.

The lidar sensor test system of the present invention comprises: a panel from which light is emitted from the lidar sensor and reflects at least a portion of the emitted light; and a computing device that generates a control signal for controlling the operation of the lidar sensor and receives and analyzes data measured by the lidar sensor.

The panel is divided into N regions by a plurality of reflection coefficients and properties of a plurality of reflectors, and the properties of the plurality of reflectors include a diffuse reflector and a retro reflector.

Specifically, the lidar sensor includes M sensor pairs, and each of the M sensor pairs is configured to include a radiating element unit and a light receiving element unit for receiving reflected light. In addition, the lidar sensor has a cylindrical shape, rotates at a constant speed during testing, and M radiating element units and M light receiving element units constituting the M sensor pairs are each arranged in a cylindrical height direction. . In addition, it is preferable that the M sensor pairs sequentially operate according to a predetermined order.

In addition, the computing device scans the panel while rotating the lidar sensor and controls to radiate to a plurality of radiation points, receives point cloud data from the lidar sensor, and analyzes the performance of the lidar sensor characterized in that

In addition, the point cloud data may include three-dimensional coordinates of the lidar sensor; the measured intensity of the reflected light; a horizontal angle of the lidar sensor; a distance between the lidar sensor and the panel; measurement time information of the data; and identification information of the corresponding sensor pair.

Specifically, the computing device, using the point cloud data, a first item for analyzing the radiation point of the lidar sensor; a second item for analyzing the operation time of the lidar sensor; a third item for analyzing the angle of the lidar sensor; a fourth item for analyzing a distance between the lidar sensor and the panel; a fifth item for analyzing the measured intensity of the reflected light; and a sixth item for analyzing a time gap between the end time of the operation timing of the last operating sensor pair among the M sensor pairs and the starting time of the operation timing of the first operating sensor pair. It is characterized in that analysis of a plurality of items is performed.

The first item is an analysis item for whether the number of radiation points during the first section of the lidar sensor and the number of radiation points during one rotation of the lidar sensor are abnormal. In addition, the second item is an analysis item for whether the time of the first section and the one rotation time of the lidar sensor are abnormal. In addition, the third item is an analysis item for whether there is an abnormality in the horizontal angle for a specific sensor pair of the lidar sensor and the vertical angle for all sensor pairs during the first section, and the vertical angle of the lidar sensor The direction angle is calculated using the three-dimensional coordinates of the lidar sensor. In addition, the first section is characterized in that it is a section between the start time of one sequential operation timing for all the M sensor pairs to the start time of the next sequential operation timing.

In addition, the fourth item is an analysis item for whether the corrected distance is abnormal by correcting the distance information of the point cloud data with a correction coefficient for converting the flat panel into a curved surface. In addition, the fifth item is an analysis item for whether the intensity calculated for each area of the panel divided into the N areas is abnormal.

Preferably, the lidar sensor test system of the present invention is synchronized to receive a signal from a satellite according to a Global Navigation Satellite System (GNSS) and transmit a timing signal for operation of the lidar sensor to the lidar sensor signal supply; and a power supply device for supplying power to the lidar sensor, wherein the computing device analyzes the operating current of the lidar sensor using current information input by the power supply device do it with

According to the lidar sensor test system of the present invention, the performance test of the lidar sensor may be automatically performed for a plurality of test items.

1 is a block diagram of a lidar sensor test system according to a preferred embodiment of the present invention.
2 is an exemplary view of a panel according to a preferred embodiment of the present invention.
3 is an explanatory diagram of a lidar sensor according to a preferred embodiment of the present invention.
4 is an explanatory diagram for a first section;
5 is an exemplary view showing pointer cloud data on a plan view.
Fig. 6 is an explanatory view of a method for projecting a panel onto a curved surface;

Hereinafter, a lidar sensor test system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Of course, the following examples of the present invention are not intended to limit or limit the scope of the present invention only to embody the present invention. What can be easily inferred by an expert in the technical field to which the present invention pertains from the detailed description and examples of the present invention is construed as belonging to the scope of the present invention.

First, FIG. 1 shows a configuration diagram of a lidar sensor (S) test system 100 according to a preferred embodiment of the present invention.

As can be seen from FIG. 1 , the lidar sensor (S) test system 100 according to the preferred embodiment of the present invention includes a panel 10 , a 3-axis motor rail 20 , and a motor control device 30 . , an interface device 40 , a power supply device 50 , a synchronization signal supply device 60 , and a computing device 70 .

Here, the panel 10, the three-axis motor rail 20, and the lidar sensor S may be preferably located inside the test room.

The panel 10 emits laser light from a lidar sensor S, and reflects at least a portion of the emitted light.

The panel 10 is preferably divided into N regions by the plurality of reflection coefficients and the properties of the plurality of reflectors. In addition, the properties of the plurality of reflectors may include a diffuse reflector and a retro reflector. Here, N is a natural number of 2 or more.

2 shows an exemplary view of a panel 10 according to a preferred embodiment of the present invention.

As can be seen from FIG. 2, the panel 10 of the present invention has two types of reflection coefficients ( _{FR = 20%, F R =} 80%) and properties of two types of reflectors (Diffuse Reflector, Retro Reflector). It can be divided into 4 areas (①, ②, ③, ④).

A lidar sensor (S) to be tested is mounted on the 3-axis motor rail 20 . In addition, under the control of the motor control device 30, the 3-axis motor rail 20 may move in the X-axis, the Y-axis, and the Z-axis.

The interface device 40 transmits signals from the power supply device 50 , the synchronization signal supply device 60 , and the computing device 70 to the lidar sensor S, and a signal from the lidar sensor S It serves as an interface for transmitting to the computing device (70).

The power supply device 50 serves to supply power to the lidar sensor S. In addition, it is preferable that the power supply device 50 transmits voltage and current information supplied to the lidar sensor S to the computing device 70 .

The synchronization signal supply device 60 receives a signal from a satellite according to a Global Navigation Satellite System (GNSS), and transmits a timing signal for an operation of the lidar sensor S to the lidar sensor S. That is, by using the pulse signal input from the synchronization signal supply device 60, the operation of the lidar sensor (S) is synchronized with the signal from the satellite. Specifically, it is possible to check whether the PPS Lock function of the lidar sensor S is operating by transmitting Ref_PPS/NMEA_msg as a lidar signal so that the lidar sensor S can synchronize. That is, the lidar sensor S may use a pulse signal input from the synchronization signal supply device 60 as a reference clock signal.

The computing device 70 generates a control signal for controlling the operation of the lidar sensor S, and serves to receive and analyze data measured by the lidar sensor S. In addition, the computing device 70 may analyze the operating current information of the lidar sensor S by using the current information input by the power supply device 50 .

Figure 3 shows an explanatory view of the lidar sensor (S) according to a preferred embodiment of the present invention.

As can be seen from FIG. 3 , the lidar sensor S of the present invention is composed of M sensor pairs. In addition, each of the M sensor pairs includes a radiating element unit Tx emitting light and receiving reflected light. and a light receiving element unit Rx. Here, M is a natural number of 2 or more.

Each of the radiating element units Tx may mount one or more radiating elements, for example, a laser diode, and each of the light receiving element units Rx may mount one or more light receiving elements. The M sensor pairs can thus be referred to as M channels. For reference, 16 sensor pairs are shown in FIG. 3 .

In addition, the lidar sensor (S) is cylindrical, it is preferable to rotate at a constant speed during the test. In addition, the M radiating element portions Tx and M light receiving element portions Rx constituting the M sensor pairs are each arranged in a cylindrical height direction. In addition, the M sensor pairs are sequentially operated according to a predetermined order.

For example, the number described in FIG. 3 is identification information of the sensor pair, and may sequentially operate in the order of the identification information number.

Specifically, for the M sensor pairs, each sensor pair may sequentially operate according to a predetermined order. That is, a method in which the radiating element unit Tx of one sensor pair emits light, the light receiving element unit Rx of the corresponding sensor pair measures the reflected light, and the radiating element unit Tx of the next sensor pair emits light. Thus, the M sensor pairs can operate sequentially.

In this case, a period between the start time of one sequential operation timing for all M sensor pairs and the start time of the next sequential operation timing is referred to as a first period P1 in the present invention.

4 shows an explanatory diagram of the first section P1.

For example, in the first section P1, the light-receiving element unit Rx of the sensor pair that operates the latest from the start of emission of the emission element unit Tx of the sensor pair that operates first completes light reception, and the first It can be said that it is a period up to the start time of the radiation of the radiation element part (Tx) of the operating sensor pair. If the sensor pair operates sequentially in the order of the identification information, the light receiving element portion Rx of the sensor pair having the last identification information from the emission start time of the emission element portion Tx of the sensor pair having the highest identification information It can be said that it is a section from the completion of light reception to the start time of the emission of the radiation element unit Tx of the sensor pair in which identification information has priority again.

Light is emitted by a plurality of points to the panel 10 by sequential operation of these M sensor pairs, and the reflected light of the plurality of points is measured to constitute point cloud data. That is, the point cloud data means cloud data radiated and measured by M sensor pairs for a plurality of points of the panel 10 .

5 is an exemplary view showing pointer cloud data on a plan view.

For reference, in FIG. 5 , only pointer cloud data for a part of the upper one area of the left side of FIG. 2 is displayed.

The computing device 70 scans the panel 10 while rotating the lidar sensor S and controls it to radiate to a plurality of radiation points, receives point cloud data from the lidar sensor S, and receives the lidar sensor It is characterized by analyzing the performance of (S).

Point cloud data, the three-dimensional coordinates of the lidar sensor (S); the intensity of the measured reflected light; the horizontal angle of the lidar sensor (S); the distance between the lidar sensor (S) and the panel (10); measurement time information of the data; and identification information of the corresponding sensor pair.

Specifically, the computing device 70 may evaluate the performance of the lidar sensor S by analyzing a plurality of items among the following six items. In addition, the computing device 70 may analyze and perform a plurality of items to evaluate the performance of the lidar sensor S, and thus may distinguish good and bad products of the lidar sensor S.

(1) Item 1: Analyze the radiation point of the lidar sensor (S) using the point cloud data sorted according to time information.

(2) Item 2: Analyze the operation time of the lidar sensor (S) using the point cloud data sorted according to time information.

(3) 3rd item: Analyze the angle of the lidar sensor (S) using the point cloud data sorted according to time information.

(4) 4th item: Analyze the distance using the point cloud data arranged according to the distance information between the lidar sensor (S) and the panel (10).

(5) Item 5: Analyze the intensity using the point cloud data sorted according to the measured intensity information of the reflected light.

(6) Item 6: Using point cloud data sorted according to time information, between the end of the operation timing of the last operating sensor pair among the M sensor pairs and the start of the operation timing of the first operating sensor pair Analyze the time gap (t1) of

Specifically, the analysis of the first item is the number of radiation points during the first section P1 of the lidar sensor S and the radiation points for a specific pair of sensors during one rotation of 360 degrees of the lidar sensor S It is characterized in that it is carried out by comparing the number of each with the number value set in advance for each. That is, the first item is an analysis item for whether the number of radiation points during the first section P1 is abnormal and whether the number of radiation points during one rotation is abnormal.

In addition, the analysis of the second item may be performed by comparing the time of the first section P1 and the one rotation time of the lidar sensor S with a preset time value for each. That is, the second item is an analysis item for whether the time of the first section P1 and the one rotation time of the lidar sensor S are abnormal.

The analysis of the third item compares the horizontal angle of the sensor pair of the preset identification information of the lidar sensor S and the vertical angle during the first section P1 with the preset angle value for each, respectively. is carried out by That is, the third item is an analysis item for whether there is an abnormality in the horizontal angle of the lidar sensor (S) for a specific sensor pair and the vertical angle of all sensor pairs during the first section (P1). In addition, the vertical angle of the lidar sensor (S) is preferably calculated using the three-dimensional coordinates of the lidar sensor (S).

In the analysis of the fourth item, the distance information of the point cloud data is corrected with a correction coefficient for converting the flat panel 10 into a curved surface, and at least one statistical value for the corrected distance information is set to a preset value. can be carried out in comparison with That is, the fourth item is an analysis item for whether the corrected distance is abnormal. Here, the statistical value may include an average value, a minimum value, and a maximum value.

6 is an explanatory diagram of a method of projecting the panel 10 onto a curved surface.

Forming a panel with a curved surface that can physically position all points at the same distance from the lidar sensor S is preferable when considering the use of the actual lidar sensor S, but there is a difficulty in forming an actual curved panel .

Therefore, the panel 10 is formed as a flat panel, but assuming a curved panel, the light to be emitted to each point of the curved panel is emitted inside the flat panel 10, and the distance is measured by the reflected light for the emitted light . By multiplying this distance by the correction factor, the reflection distance to the curved panel can be calculated. That is, by using the correction coefficient, the radiation information of the flat panel 10 can be projected onto the curved panel.

Analysis of the fifth item is performed by comparing at least one statistical value for intensity information calculated for each area of the panel 10 divided into N areas with a preset value. That is, the fifth item is an analysis item for whether the intensity calculated for each area of the panel 10 divided into N areas is abnormal. Here, the statistical value may include an average value, a minimum value, and a maximum value.

The analysis of the sixth item is at least one statistical value for a time gap t1 between the end time of the operation timing of the last operating sensor pair among the M sensor pairs and the start time of the operation timing of the first operating sensor pair. is compared with a preset value. That is, the sixth item is an analysis item for whether the time gap is abnormal, and it can be said that the M sensor pairs are idle. Here, the statistical value may include an average value, a minimum value, and a maximum value.

As described above, according to the lidar sensor test system 100 of the present invention, it can be seen that the performance test of the lidar sensor S can be automatically performed for a plurality of test items.

100: lidar sensor test system
10: panel
20: 3-axis motor rail
30: motor control unit
40: interface device
50: power supply
60: synchronization signal supply
70: computing device
S: lidar sensor

Claims (12)

In the lidar sensor test system,
a panel for emitting light from the lidar sensor and reflecting at least a portion of the emitted light; and
A computing device that generates a control signal for controlling the operation of the lidar sensor and receives and analyzes data measured by the lidar sensor;
The lidar sensor includes M sensor pairs,
The lidar sensor is cylindrical and rotates at a constant speed during testing,
The computing device scans the panel while rotating the lidar sensor and controls to radiate to a plurality of radiation points, receives point cloud data from the lidar sensor, and analyzes the performance of the lidar sensor,
The computing device, using the point cloud data, a first item for analyzing the radiation point of the lidar sensor; a second item for analyzing the operation time of the lidar sensor; a third item for analyzing the angle of the lidar sensor; a fourth item for analyzing a distance between the lidar sensor and the panel; a fifth item for analyzing the measured intensity of the reflected light; and a sixth item for analyzing a time gap between an end time of an operation timing of a last operating sensor pair among the M sensor pairs and a starting time of an operation timing of the first operating sensor pair; analysis of many of the items,
The test system, characterized in that M is a natural number of 2 or more. According to claim 1,
The panel is
It is divided into N regions by the plurality of reflection coefficients and the properties of the plurality of reflectors,
The properties of the plurality of reflectors are,
Includes a diffuse reflector and a retro reflector,
wherein N is,
A test system, characterized in that it is a natural number greater than or equal to 2. According to claim 1,
Each of the M sensor pairs is configured to include a radiating element unit and a light receiving element unit for receiving reflected light,
M radiating element units and M light receiving element units constituting the M sensor pairs are respectively arranged in a cylindrical height direction,
The M sensor pairs are sequentially operated according to a predetermined order. delete According to claim 1,
The point cloud data is
three-dimensional coordinates of the lidar sensor;
the measured intensity of the reflected light;
a horizontal angle of the lidar sensor;
a distance between the lidar sensor and the panel;
measurement time information of the data; and
A test system comprising a; identification information of the corresponding sensor pair. delete According to claim 1,
The first item is
An analysis item for whether or not the number of radiation points during the first section of the lidar sensor and the number of radiation points during one rotation of the lidar sensor is abnormal,
The first section is
The test system, characterized in that it is a period between the start time of one sequential operation timing for all the M sensor pairs and the start time of the next sequential operation timing. According to claim 1,
The second item is
An analysis item for whether the time of the first section and the time of one rotation of the lidar sensor is abnormal,
The first section is
The test system, characterized in that it is a period between the start time of one sequential operation timing for all the M sensor pairs and the start time of the next sequential operation timing. According to claim 1,
The third item is,
An analysis item for whether there is an abnormality in the horizontal angle for a specific sensor pair of the lidar sensor and the vertical angle for all sensor pairs during the first section,
The vertical angle of the lidar sensor is,
It is calculated using the three-dimensional coordinates of the lidar sensor,
The first section is
The test system, characterized in that it is a period between the start time of one sequential operation timing for all the M sensor pairs and the start time of the next sequential operation timing. According to claim 1,
The fourth item is
The test system, characterized in that it is an analysis item for whether the corrected distance is abnormal by correcting the distance information of the point cloud data with a correction coefficient for converting the flat panel into a curved surface. According to claim 1,
The fifth item is,
It is an analysis item for whether the intensity calculated for each area of the panel divided into N areas is abnormal,
wherein N is,
A test system, characterized in that it is a natural number greater than or equal to 2. According to claim 1,
The test system is
a synchronization signal supply device for receiving a signal from a satellite according to a Global Navigation Satellite System (GNSS) and transmitting a timing signal for operation of the lidar sensor to the lidar sensor; and
A power supply for supplying power to the lidar sensor; further comprising,
The computing device,
A test system, characterized in that the operating current of the lidar sensor is analyzed by using the current information received by the power supply device.

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