KR102050598B1 - A lidar device capable of preventing interference between vehicles - Google Patents

Abstract

The present invention relates to a lidar device that can prevent the interference between vehicles that can occur between autonomous vehicles,
Lidar device that can prevent the interference between the vehicle according to an embodiment of the present invention,
A transmitter for transmitting a pulse wave coded differently according to a vehicle; A receiver receiving the pulse wave transmitted by the transmitter and reflected by the surface of the object; And a processor configured to determine whether the pulse wave received by the receiver is the same as the coded pulse wave transmitted by the transmitter, and when the pulse wave is the same, calculate a distance from the object using the pulse wave received by the receiver. Include.

Description

Lidar device capable of preventing interference between vehicles

The present invention relates to a lidar device, and more particularly, to a lidar device that can prevent the interference between vehicles that can occur between autonomous vehicles.

A laser (Light Amplification by the Stimulated Emission of Radiation, LASER) generates a stimulated emission of light and amplifies the laser light.

LiDAR (Light Detection and Ranging, LiDAR) is a technology that measures the distance using a laser. It is developed in the form of constructing topographical data for visualizing 3D Geographic Information System (GIS) information and visualizing it. It is applied to such fields.

Recently, it is attracting attention as a core technology while being applied to autonomous vehicles, mobile robots, and drones.

When applied to a vehicle, the rider may perform warning or automatic vehicle control by measuring the distance between vehicles in real time so that the driving vehicle may avoid collision with the front vehicle or minimize impact.

Patent Documents 1 and 2 below disclose object detection sensor technology for detecting an object using a laser.

Patent document 1 includes a laser light source for generating laser light, an image in front of the camera and a laser light generated from the laser light source, and a camera for photographing a front laser light irradiation image, and an image processing apparatus for processing an image captured by the camera. In addition, the image processing apparatus subtracts another image from any one of the front image and the laser light irradiation image, and uses the laser to determine that there is an obstacle when there is a light spot in which the laser light is reflected on the subject. An obstacle sensing device configuration is described.

Patent Literature 2 includes a transmitting unit for transmitting a laser beam, a light receiving unit for receiving a laser beam reflected from an obstacle after being transmitted from the transmitting unit, an obstacle detecting unit for detecting an obstacle using a laser beam received through the light receiving unit, and an obstacle detecting unit The display unit may further include a display unit configured to display the detected obstacles on the screen, and by mounting at least one sensing module (transmitter and receiver) on the wheel of the vehicle, the vehicle may be moved around a wide sensing area without a driving motor for adjusting the angle of transmission of the laser beam. An obstacle sensing device configuration around a vehicle for detecting an obstacle is described.

1 and 2 are diagrams for explaining a problem of the lidar apparatus according to the prior art.

As shown in FIG. 1, a direct interference signal received by another lidar, and an indirect interference signal reflected by another object, may cause amplification or saturate the receiving system, and may cause a ghost target. (Ghost target) can be created.

As shown in FIG. 2, a ghost target is a phenomenon in which an object that does not actually exist appears on the lidar. The interference generated by the same pulse lidar sensor and pulse repetition frequency (PRF) generates a ghost target, and the ghost target is generated. The target moves slowly within its range.

The problem of interference between autonomous vehicles equipped with LiDAR has come to the fore in recent years. Even if the LiDAR scanning method is advanced, the interference between multiple autonomous vehicles is inevitable. Especially at intersections where there are many cars and parking lots, it is likely to cause serious accidents.

1. Republic of Korea Patent Registration No. 10-1296780 2. Korean Patent Registration No. 10-1491289

The present invention has been made to solve the above problems, and an object of the present invention is to provide a lidar device that can prevent the interference between vehicles that can occur between autonomous vehicles.

 Lidar device that can prevent the interference between the vehicle according to an embodiment of the present invention,

A transmitter for transmitting a pulse wave coded differently according to a vehicle; A receiver receiving the pulse wave transmitted by the transmitter and reflected by the surface of the object; And a processor configured to determine whether the pulse wave received by the receiver is the same as the coded pulse wave transmitted by the transmitter, and when the pulse wave is the same, calculate a distance from the object using the pulse wave received by the receiver. Include.

According to one aspect of the invention, the processing unit,

A code generation module for receiving vehicle identification information, generating a vehicle code corresponding to the input identification information, and generating a coded pulse wave by coding a pulse wave using the vehicle code generated by the code generation module; It includes a coding module for transmitting to the transmitter.

According to an aspect of the present invention, the code generation module,

The vehicle code may be generated by adjusting an interval between pulses in response to the input identification information.

According to an aspect of the present invention, the code generation module,

The vehicle code may be generated by adjusting a pulse width corresponding to the input identification information.

According to an aspect of the present invention, the code generation module,

The vehicle code may be generated by adjusting an interval and a pulse width between pulses in response to the input identification information.

According to an aspect of the present invention, the code generation module,

The vehicle code may be generated by adjusting the number of pulses in response to the input identification information.

According to an aspect of the present invention, the code generation module,

Generating a portion of the vehicle code by arranging at least one or more of a pulse width and a pulse interval with respect to a part of the input identification information, and generating the remainder of the vehicle code by adjusting and assigning the number of pulses to the rest of the identification information. It is characterized by.

According to an aspect of the present invention, the code generation module,

Generating a part of the vehicle code by arranging at least one or more of a pulse width and a pulse interval with respect to a part of the input identification information, and generating a remainder of the vehicle code by designating a pulse number group for the remainder of the identification information. It is characterized by.

According to one aspect of the invention, the processing unit,

A sampler for sampling a pulse wave received by the receiver to extract a code pattern, a correlation analysis module for performing a correlation analysis method using the extracted code pattern and a vehicle code generated by the code generation module, and the correlation analysis module As a result of the analysis, when the pulse wave received at the receiver is different from the coded pulse wave transmitted at the transmitter, the received pulse wave is noise processed, and the pulse wave received at the receiver is coded pulse transmitted at the transmitter. If the same as the wave, the distance calculation module for calculating the distance to the object using the received pulse wave.

Other specific details of embodiments according to various aspects of the present invention are included in the following detailed description.

According to an embodiment of the present invention, it is possible to distinguish a pulse wave (interference pulse wave) transmitted from another vehicle from a pulse wave reflected from an object after being transmitted from a user's vehicle. Therefore, it is possible to accurately calculate the distance to the object, it is possible to prevent the generation of the ghost target.

1 and 2 are views for explaining the problem of the lidar apparatus according to the prior art.
3 is a view for explaining a schematic operation process of a vehicle with a lidar device according to an embodiment of the present invention.
4 is a diagram illustrating a lidar apparatus according to an embodiment of the present invention.
5 to 11 are views illustrating a vehicle code generated in a code generation module of a lidar device according to an embodiment of the present invention.
12 and 13 illustrate a process performed by the correlation analysis module of the LiDAR apparatus according to an embodiment of the present invention.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present invention, the terms 'comprise' or 'have' are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof. Hereinafter, a lidar device (hereinafter, referred to as a “lidar device”) capable of preventing interference between vehicles according to an exemplary embodiment of the present invention will be described with reference to the drawings.

3 is a view for explaining a schematic operation process of a vehicle with a lidar device according to an embodiment of the present invention, Figure 4 is a view showing a lidar device according to an embodiment of the present invention, 5 to 11 are views illustrating a vehicle code generated in a code generation module of a lidar device according to an embodiment of the present invention, Figures 12 and 13 are views of the lidar device according to an embodiment of the present invention The process performed by the correlation analysis module is illustrated.

As shown in FIG. 3, the lidar apparatus according to an embodiment of the present invention is coded differently according to vehicles so as to prevent lidar interference between autonomous vehicles by lidar transmitted by each autonomous vehicle. Use pulse waves.

The pulse wave transmitted by the lidar device is determined from the plurality of signals (pulse waves) received by the lidar device, and the distance from the object is calculated using the pulse wave, and the remaining pulse waves other than the pulse wave are treated as noise. This prevents lidar interference between autonomous vehicles.

Here, the lidar apparatus according to an embodiment of the present invention will be described by way of example of an autonomous vehicle, but is not necessarily limited to autonomous vehicles, and is applicable to all apparatuses using the lidar apparatus. For example, the present invention can be applied to a mobile robot, a robot cleaner, a drone, or the like using a lidar device.

As shown in FIG. 4, the lidar apparatus according to the embodiment of the present invention includes a transmitter 100, a receiver 200, and a processor 300.

The transmitter 100 transmits coded pulse waves differently according to vehicles on the light source optical axis. The transmitter 100 includes a laser diode 110 that generates pulse waves, a collimating lens 120, and an electronic circuit (not shown) for laser transmission.

The laser diode 110 is an optical element for generating a pulse wave, the collimating lens 120 is an optical lens for condensing the pulse wave generated through the laser diode, it is located behind the laser diode.

The coded pulse wave is generated by the processor 300 to be described later and transmitted to the transmitter 100, and the transmitter 100 receiving the pulse transmits a pulse of a predetermined period on the light source optical axis. The transmitter 100 may transmit, for example, a pulse having a short pulse width of ns (nano second), ps (pico second), or lower to the light source optical axis, and the pulse width or period is necessarily limited thereto. It doesn't happen.

The receiver 200 receives the pulse wave transmitted from the transmitter 100 and reflected by the object A. FIG. The receiver 200 includes a condenser lens 210 for condensing the pulse wave reflected by the object A, a light receiving sensor 220 for acquiring the pulse wave through the condenser lens 210, and an optoelectronic amplification circuit (not shown). It includes. In addition, a band pass filter (not shown) may be provided between the condenser lens 210 and the light receiving sensor 220 to transmit only pulse waves of a wavelength band transmitted from the transmitter 100 and not transmit pulse waves of other wavelength bands. Can be.

The pulsed wave passing through the condenser lens 210 converts an optical signal into an electrical signal through the light receiving sensor 220 and an optoelectronic amplifying circuit (not shown). The light receiving sensor 220 may be, for example, an avalanche photo diode (APD).

The processor 300 calculates a distance from the object using the pulse wave received by the receiver 200. The processor 300 determines whether the pulse wave received by the receiver 200 is the same as the coded pulse wave transmitted by the transmitter 100, and when the processor 300 is identical, the object using the pulse wave received by the receiver 200. Calculate the distance between and. If the pulse wave received by the receiver 200 is different from the coded pulse wave transmitted by the transmitter 100, the processor 300 noise-processes the received pulse wave.

To this end, the processor 300 includes a code generation module 310, a coding module 320, a sampler 330, a correlation analysis module 340, and a distance calculation module 350.

The code generation module 310 receives the identification information of the vehicle and generates a vehicle code corresponding to the input identification information. Here, the identification information may be a unique identification number of the vehicle, and may be, for example, a vehicle number, a chassis number, a resident registration number of the vehicle owner, a driver's license number of the vehicle owner, and the like. Of course, the present invention is not limited thereto and may be all user information that can be identified because duplicate registration such as an e-mail account of a vehicle holder is impossible.

The code generation module 310 may generate a vehicle code by adjusting an interval between pulses in response to the input identification information. The code generation module 310 may generate a vehicle code using a pulse code having an interval set according to a predetermined rule with respect to elements constituting identification information such as letters and numbers. In the following description, the character is explained in the case of Hangul, for example, but is not limited to Hangul, it is also applicable to the unique characters of each country, such as the English alphabet, Hiragana.

For example, when the identification information is a vehicle number, as shown in FIG. 5, pulse intervals corresponding to the numbers 0 to 9 and Korean consonants and vowels are allocated, and pulse intervals are arranged corresponding to the vehicle number. By doing so, a vehicle code can be generated. For each number and letter, set the pulse intervals so that they do not overlap. At this time, the pulse width may be set equally.

In addition, the code generation module 310 may generate a vehicle code by adjusting a pulse width in response to the input identification information. The code generation module 310 may generate a vehicle code using a pulse code whose width is set according to a predetermined rule with respect to elements constituting identification information such as letters and numbers.

For example, as illustrated in FIG. 6, a vehicle code may be generated by allocating pulse widths corresponding to the numbers 0 to 9 and Korean consonants and vowels, and arranging the pulse widths corresponding to the vehicle numbers. . Set the pulse width so that it does not overlap for each number and character. At this time, the pulse interval may be set equally.

In addition, the code generation module 310 may generate a vehicle code by adjusting an interval and a pulse width between pulses in response to the input identification information. In the case of adjusting the pulse interval and the pulse width, one of the pulse interval and the pulse width may be assigned to a character and the other may be assigned to a number to generate a vehicle code.

For example, as illustrated in FIG. 7, the numbers 0 to 9 allocate pulse intervals corresponding thereto, and the Korean alphabet consonants and vowels allocate corresponding pulse widths to correspond to vehicle numbers. The vehicle code can be generated by arranging the widths. For each number and letter, set the pulse interval and pulse width so that they do not overlap. That is, different pulse intervals and the same pulse width are assigned to each number, and different pulse widths and the same pulse interval are set for the characters, respectively. The pulse widths commonly assigned to numbers and the pulse widths representing characters should not overlap. Similarly, pulse intervals commonly assigned to characters and pulse intervals representing numbers do not overlap.

In the case of a Korean vehicle number as shown in FIG. 7, a pulse width representing a letter is represented between two digits + one letter + four digits and is disposed between pulse intervals representing a number.

On the other hand, the identification information is arranged in a form of letters and numbers, the vehicle code generated in the code generation module 310 is not necessarily arranged in the order. For example, as shown in FIG. 8, only six numbers may be arranged in the original order, and characters may be arranged at the front or the rear. That is, when the vehicle number is "01 is 2345", the vehicle code may be generated such that it is "012012" or "012345".

In addition, the number of pulses of the vehicle code generated in the code generation module 310 does not necessarily have to match the number of letters and numbers. Part of the identification information may be arranged at least one or more of the pulse width and the pulse interval to generate a portion of the vehicle code, the remainder of the identification information may be assigned the number of pulses to generate the remainder of the vehicle code.

For example, in FIG. 9A, "2345" generates a vehicle code by arranging at least one of a corresponding pulse width and a pulse interval, and "01" allocates one pulse to the vehicle code. The generated one is illustrated. (B) of FIG. 9 is a case in which the vehicle number is "04 is 2345", "ga 2345" is the same as that of FIG. 9 (a), but "04" indicates that the vehicle code is generated by allocating four pulses. To illustrate.

On the other hand, when generating the vehicle code by allocating the number of pulses, if the number of the vehicle code is large, there is a problem that too many pulses are used. To compensate for this, when generating a code using a pulse number, the number 0 to 9 may be divided into a plurality of groups, and then a vehicle code may be generated by specifying a pulse number for the number belonging to the group. At this time, a different pulse width is designated for each number.

For example, divide the numbers 0 to 9 into two groups, each of which is a group member of 0 to 5, 6 to 9, and assign one pulse number to the first group (numbers 0, 1, 2, 3, and 4). In the second group (numbers 5, 6, 7, 8, and 9), two pulses can be designated. At this time, the pulse width of the number 0 may be set to 1.0 ns and the pulse width of the number 9 may be set to 1.9 ns by increasing the pulse width by 0.1 ns each time 1 is increased.

In summary, the following [Table 1].

number 0 One 2 3 4 5 6 7 8 9 Pulse width (ns) 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 Number of pulses One 2

Of course, the pulse number designation as shown in the above table is just one example and may be set differently from this.

10 illustrates a case where a vehicle code is generated by allocating a pulse number. The vehicle number illustrated in FIG. 10 is “5222345”, and “ga2345” generates at least one of a pulse width and a pulse interval corresponding thereto as shown in FIG. 9. "52" generates a vehicle code by allocating the number of pulses. According to the table, the number 5 has a pulse number of 2 and a pulse width of 1.5 ns, the number 2 has a pulse number of 1 and a pulse width of 1.2 ns. Accordingly, as shown in FIG. 10, part of the vehicle number “52” generates a part of the vehicle code by allocating two pulses having a pulse width of 1.5 ns and one pulse having a pulse width of 1.2 ns. The vehicle code is completed by combining with the vehicle code corresponding to.

FIG. 11 is a diagram for comparing a case where there is a pulse number group designation for a number and a case where there is no number. 11A and 11C show no pulse number group designation, and FIGS. 11B and 11D show pulse number group designation. As shown in (c) of FIG. 11, since 90 pulses must be allocated to code “90”, many pulses are used. In this case, it is preferable to designate a pulse number group as shown in Fig. 11D, and generate a vehicle code by varying the pulse width of each number.

The coding module 320 generates a coded pulse wave by coding the pulse wave using the vehicle code generated by the code generation module 310. The generated coded pulse wave is transmitted to the transmitter 100.

The sampler 330 extracts a code pattern by sampling the pulse wave received by the receiver 200 so that the correlation analysis module 340 can perform the correlation analysis method.

The correlation analysis module 340 performs a correlation analysis method using the code pattern extracted from the sampler 330 and the vehicle code generated by the code generation module 310 to transmit the pulse wave received from the receiver 200 to the transmitter 100. It is determined whether or not it is the same as the coded pulse wave transmitted from the. Correlation analysis is a technique that analyzes the correlation between two pulse waves.The correlation between the pulse intervals or the pulse widths between two pulse waves is a causal relationship between two pulse waves (either the same type of pulse wave or the different type of pulse wave). ).

For example, as shown in FIG. 12, the pulse interval or pulse width of the coded pulse wave P1 transmitted from the transmitter 100 and the pulse wave P2 reflected from the object received from the receiver 200 may be determined. Contrast analysis determines that the two pulse waves P1 and P2 coincide with each other in the preset similarity range. On the other hand, as shown in FIG. 13, when the pulse intervals (or pulse widths) of the two pulse waves P1 and P3 are different, it is determined that the two pulse waves P1 and P3 do not coincide. That is, the pulse wave P3 is not a pulse wave received by the coded pulse wave reflected from the object, but is determined as an interference pulse wave transmitted from a lidar device of another vehicle and received by the receiver.

The distance calculation module 350 noise-processes the received interference pulse wave when the pulse wave received by the receiver 200 is an interference pulse wave as a result of the analysis of the correlation analysis module 340. If the pulse wave received by the receiver 200 is the same as the coded pulse wave transmitted from the transmitter, the distance calculation module 350 calculates the distance from the object using the received pulse wave. Calculate

According to the lidar device capable of preventing the interference between the vehicle according to an embodiment of the present invention as described above, the pulse wave transmitted by the user and reflected from the object and received from the pulse wave transmitted from another vehicle (interference pearl Spa) can be distinguished. Therefore, it is possible to accurately calculate the distance to the object, it is possible to prevent the generation of the ghost target.

As mentioned above, although an embodiment of the present invention has been described, those of ordinary skill in the art may add, change, delete or add components within the scope not departing from the spirit of the present invention described in the claims. The present invention may be modified and changed in various ways, etc., which will also be included within the scope of the present invention.

100: transmitter 200: receiver
300: processor 310: code generation module
320: coding module 330: sampler
340: correlation analysis module 350: distance calculation module

Claims (9)

A transmitter for transmitting a pulse wave coded differently according to a vehicle;
A receiver receiving the pulse wave transmitted by the transmitter and reflected by the surface of the object; And,
A processor configured to determine whether the pulse wave received by the receiver is the same as the coded pulse wave transmitted by the transmitter, and calculating the distance from the object using the pulse wave received by the receiver, if the same is the same. But
The processing unit receives the vehicle identification information and generates a vehicle code corresponding to the input identification information, if the number of pulse waves required to represent the vehicle identification information is a predetermined number or less, generates a vehicle code based on the number of pulses, And a code generation module for generating a vehicle code based on the pulse width and the number of pulses when the number of pulse waves necessary for indicating the vehicle identification information is greater than or equal to a predetermined number.
Lidar device that can prevent interference between vehicles.
According to claim 1,
The processor may include a coding module configured to generate a coded pulse wave by coding a pulse wave using the vehicle code generated by the code generation module and to transmit the coded pulse wave to the transmitter.
Lidar device that can prevent interference between vehicles.
According to claim 1,
The pulse width corresponds to a character included in the vehicle identification information.
Lidar device that can prevent interference between vehicles.
According to claim 1,
The code generation module generates a vehicle code based on the number of pulses corresponding to the number included in the vehicle identification information when the number of pulse waves required to represent the vehicle identification information is less than or equal to a predetermined number.
Lidar device that can prevent interference between vehicles.
According to claim 1,
The code generation module generates a vehicle code based on the number of pulses allocated to a group to which the number of pulse waves belongs when the number of pulse waves required for representing the vehicle identification information is greater than or equal to a predetermined number.
Lidar device that can prevent interference between vehicles.
delete delete delete The method according to claim 1, The processing unit,
A sampler for sampling a pulse wave received by the receiving unit to extract a code pattern;
A correlation analysis module for performing a correlation analysis method using the extracted code pattern and the vehicle code generated by the code generation module;
As a result of the analysis of the correlation analysis module, when the pulse wave received at the receiver is different from the coded pulse wave transmitted at the transmitter, the received pulse wave is noise processed, and the pulse wave received at the receiver is transmitted at the transmitter. A distance calculation module for calculating a distance to the object using the received pulse wave when the same as the coded pulse wave
Lidar device that can prevent the interference between the vehicle comprising a.

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