WO2023015865A1

WO2023015865A1 - Lidar, method and apparatus for measuring motion speed therefor, and control system

Info

Publication number: WO2023015865A1
Application number: PCT/CN2022/077591
Authority: WO
Inventors: 潘政清; 孙恺; 向少卿
Original assignee: 上海禾赛科技有限公司
Priority date: 2021-08-13
Filing date: 2022-02-24
Publication date: 2023-02-16
Also published as: CN115704897A

Abstract

A lidar, a method and apparatus for measuring motion speed therefor, and a control system. Detection data is obtained by a plurality of transceiver modules, respectively. On the basis of the detection data, the motion speed of a target to be measured is obtained in combination with location information of the transceiver modules. Since there is a preset distance between the plurality of transceiver modules, the obtained motion speed is a vector speed, that is, the motion speed comprises a motion rate and a motion direction angle. The obtaining of the vector speed can more accurately reflect an actual motion condition of said target, and can effectively improve the accuracy and precision of vehicle control.

Description

Laser radar and its method and device for measuring motion speed, and control system

This application claims the priority of the Chinese patent application submitted to the China Patent Office on August 13, 2021, with the application number 202110932808.3, and the title of the invention is "Lidar and its method and device for measuring motion speed, and control system", the entire content of which Incorporated in this application by reference.

technical field

The invention relates to the field of vehicle control, in particular to a laser radar, its method and device for measuring motion speed, and a control system.

Background technique

Autonomous driving is a direction that will have a major impact on human life in the future. A research focus at this stage is the autonomous driving of vehicles. A lot of companies are devoting a lot of resources to invest a lot of R&D resources in this field. The automatic driving system obtains road condition information through the sensor of the perception layer, and then the decision-making layer analyzes and processes the information constructed by the perception layer, and finally controls the subsequent behavior of the vehicle through the execution layer. Among them, lidar has been widely used as a perception sensor for autonomous driving because of its strong distance measurement capability, high resolution, high detection accuracy and accuracy.

In the process of automatic driving, after the system detects various targets, it needs to accurately track these targets, obtain the motion parameters and trajectories of these targets, and then choose accurate driving decisions. To accurately track the target, the system needs to obtain various parameters including the target's position, velocity, acceleration, etc.

One measurement method used in the existing lidar ranging is Time of Flight (ToF). Time-of-flight ranging has the advantages of short laser pulse duration and high instantaneous power, and can simultaneously obtain strong distance measurement capability and high measurement frequency. It is the ranging method adopted by mainstream lidar in the market. The lidar that uses the time-of-flight method for ranging is called ToF radar.

The automatic driving system using ToF radar needs to combine multiple frames of data to perform target perception and target tracking. For one frame of scanning data obtained at a certain moment, the automatic driving system first detects the moving target and determines the position of each moving target; then analyzes the multi-frame scanning data at different times, and then obtains the moving state and trajectory of the moving target . In the case of multi-target tracking, the automatic driving system also needs to pair each target in two adjacent frames of scan data, which needs to solve the problem of new targets appearing and old targets disappearing, and there may be problems such as false alarms and missed detections. Moreover, the detection and processing time of multi-frame scanning data takes a relatively long time, and the problem of insufficient time for decision-making and hedging is likely to occur in sudden emergencies.

Another measurement method for lidar ranging is to use Frequency Modulated Continuous Wave (FMCW) for coherent detection. This type of lidar is called FMCW lidar. FMCW laser radar emits frequency-modulated continuous laser, and obtains the beat signal frequency through the delay of the echo signal, and then calculates the distance and speed of the target. Fig. 1 shows the structural block diagram of the FMCW lidar, and Fig. 2 shows the detection principle of the FMCW lidar. The light source 11 generates high-frequency FM light, a part of the light is amplified by the beam splitter and then transmitted to the transmitter 12, and then sent to the target space. The echo light reflected by obstacles is received by the radar receiver 14, and the other part of the light is used as local oscillator light. Coupled to a mixer 13; the mixer 13 mixes and filters the local oscillator light and the echo light received by the receiver 14; after mixing and filtering, the detector 15 obtains a difference frequency signal; the The difference frequency signal is transmitted to the signal processor 17 for processing through the sampler 16 (such as ADC).

Referring to Figure 2, after the difference frequency signal is sampled and processed, the frequency difference f1 of the falling edge of the echo light and the local oscillator light and the frequency difference f2 of the rising edge can be obtained respectively, and then the distance z and speed v of the obstacle can be calculated according to the following formula.

FMCW lidar can obtain distance and velocity information at the same time with one detection. Moreover, FMCW lidar has the advantage of stronger anti-interference ability, so FMCW lidar is a new direction for autonomous driving perception sensors.

However, the velocity measured by the FMCW lidar is the radial velocity of the target to be measured relative to the lidar, which is inaccurate. Because velocity is a vector. As shown in Figure 3, the radial velocity V _r measured by the FMCW lidar is the projection size of the actual velocity of the target to be measured on the line connecting the target to be measured and the radar, that is, V _r = Vcosα, where α represents the actual velocity of the target to be measured The angle between the direction of motion and the line connecting the target to be measured and the radar. If the actual velocity direction of the target is perpendicular to the direction of motion (i.e. lateral velocity) of the FMCW lidar (i.e. the car), that is, α is close to 90°, then the radial velocity V _r measured by the FMCW lidar is very small, and It cannot accurately reflect the actual motion of the target to be measured. However, in the application of automatic driving, because the emergency situations caused by lateral speed account for more than 90%, cars running red lights, turning vehicles, and pedestrians breaking into the street all need lateral speed to make decisions to avoid danger.

Therefore, there is an urgent need for a more accurate measurement method of moving speed to obtain the vector speed of the target to be measured.

Contents of the invention

The problem solved by the invention is how to obtain the vector velocity of the target to be measured.

In order to solve the above problems, the present invention provides a method for measuring the speed of motion by laser radar, including:

Provide M transceiver modules, wherein, M 2; transmit the jth probe beam and receive the jth echo beam through the ith transceiver module, and form the jth echo beam after the jth probe beam is reflected, wherein, 1 ? Position information and (i, j)th radial velocity; at least based on (a, aj) group of detection data and (b, bj) group of detection data, combined with position information of ath transceiver module and bth transceiver module Position information to obtain the moving speed of the target to be measured, where, 1≦a≦M, 1≦b≦M, 1≦aj≦Na, 1≦bj≦Nb, and a≠b, the ath transceiver module and the bth transceiver module There is a preset distance between modules.

Optionally, before obtaining the moving speed of the target to be measured, the method further includes: judging whether the (a, aj) group of detection data and the (b, bj) group of detection data are identical to the same group of detection data corresponding to the target.

Optionally, the step of judging whether the (a, aj)th group of detection data and the (b, bj)th group of detection data correspond to the same target to be measured includes: according to the position information of the ath transceiver module and the first The position information of the b transceiver module is carried out coordinate conversion, so that the (a, aj) position information in the (a, aj) group of detection data and the (b in the (b, bj) group detection data , bj) position information is converted to the same coordinate system to obtain the (a, aj)th converted position information and (b, bj) converted position information; compare the (a, aj) converted position information with the ( b, bj) converted position information, when the difference between the (a, aj) converted position information and the (b, bj) converted position information is within the preset range, determine the (a, aj) group of detection data and the Groups (b, bj) of detection data correspond to the same target to be tested.

Optionally, the moving speed includes: moving speed and moving direction angle; the step of obtaining the moving speed of the target to be measured includes: according to the (i, j)th position information in the (i, j)th group of detection data and the position information of the i-th transceiver module to obtain the (i, j) radial direction angle; at least according to the (a, aj) radial speed, the (a, aj) radial direction angle, the (b, bj) Radial rate and (b, bj)th radial direction angle, obtaining said motion rate and motion direction angle.

Optionally, the step of transmitting the jth probe beam through the i-th transceiver module includes: obtaining the (i, j)th projection angle, and the (i, j)th projection angle is the jth probe beam emitted by the i-th transceiver module and The included angle of the preset plane; in the step of obtaining the moving speed of the target to be measured, the moving speed in the preset plane is obtained in combination with the (i, j)th projection angle.

Optionally, the step of obtaining the motion velocity in the preset plane includes: obtaining the (i, j)th projection radial velocity according to the (i, j)th radial velocity and the (i, j)th projection angle Speed, the (i, j) projected radial speed is the radial movement speed of the target to be measured in the preset plane; according to the (a, aj) position information, the (b, bj) position information, the (a, aj) projected radial velocity and the (b, bj) projected radial velocity, combined with the position information of the ath transceiver module and the bth transceiver module, to obtain The moving speed of the target to be measured in the preset plane.

Optionally, the preset plane is a horizontal plane; or, the preset plane is a plane whose vertical field of view of the lidar is 0°; or, the lidar has a rotation axis, and the preset A plane is a plane perpendicular to the axis of rotation.

Optionally, the step of transmitting the j-th detection beam through the i-th transceiver module includes: transmitting a Ni-beam detection beam through the i-th transceiver module to perform a frame scan, so as to obtain a frame of scan data of the i-th transceiver module, so A frame of scanning data of the i-th transceiver module includes: Ni groups of detection data.

Optionally, the step of obtaining the moving speed of the target to be measured further includes: performing cosine curve fitting according to multiple sets of detection data to obtain the moving speed of the target to be measured.

Optionally, after obtaining a frame of scanning data of the i-th transceiver module, before performing cosine curve fitting, the step of obtaining the moving speed of the target to be measured further includes: judging whether the multiple sets of detection data are consistent with the same target to be measured Corresponding; when judging that the multiple sets of detection data correspond to the same target to be measured, perform cosine curve fitting according to the multiple sets of detection data.

Optionally, the step of providing M transceiver modules includes: providing a laser radar, the laser radar including the M transceiver modules; or, the step of providing M transceiver modules includes: providing multiple laser radars, the multiple A lidar includes the M transceiver modules.

Correspondingly, the present invention also provides a device for measuring motion speed by laser radar, including:

M transceiver modules, wherein, M 2; the i-th transceiver module transmits the j-th detection beam and receives the j-th echo beam, and the j-th detection beam is reflected to form the j-th echo beam, wherein, 1≦i ≦M, 1≦j≦Ni; data module, the data module is suitable for obtaining the (i, j)th group of detection data according to the jth echo beam, and the (i, j)th group of detection data includes : (i, j)th position information and (i, j)th radial velocity; velocity module, said velocity module is suitable for at least according to (a, aj) group detection data and (b, bj) group detection data , and combine the position information of the ath transceiver module and the bth transceiver module to obtain the moving speed of the target to be measured, where 1≦a≦M, 1≦b≦M, 1≦aj≦Na, 1≦bj ≦Nb, and a≠b, there is a preset distance between the ath transceiver module and the bth transceiver module.

Optionally, it also includes: a screening module, which is suitable for judging whether the (a, aj) group of detection data and the (b, bj) group of detection data correspond to the same target to be detected.

Optionally, the screening module includes: a conversion unit adapted to perform coordinate conversion according to the position information of the ath transceiver module and the position information of the bth transceiver module, so that the (a, aj)th group The (a, aj)th position information in the detection data and the (b, bj)th position information in the (b, bj)th group of detection data are transformed into the same coordinate system to obtain the (a, aj)th conversion position information and (b, bj)th conversion position information; a comparison unit adapted to compare said (a, aj)th conversion position information and said (b, bj)th conversion position information, at (a , aj) When the difference between the converted position information and the (b, bj) converted position information is within the preset range, it is judged that the (a, aj) group of detection data and the (b, bj) group of detection data are the same corresponding to the target.

Optionally, the moving speed includes: moving rate and moving direction angle; the speed module includes: a direction angle unit, and the direction angle unit is suitable according to the (i, j)th group of detection data (i, j) j) position information and the position information of the i-th transceiver module, to obtain the (i, j) radial direction angle; a calculation unit, the calculation unit is suitable for at least according to the (a, aj) radial velocity, the ( a, aj) radial direction angle, (b, bj)th radial velocity, and (b, bj)th radial direction angle, to obtain the motion rate and motion direction angle.

Optionally, the speed module is also adapted to obtain the (i, j)th projection angle from the i-th transceiver module, and the (i, j)-th projection angle is the j-th probe beam emitted by the i-th transceiver module and the preset The included angle of the plane; combined with the (i, j)th projection angle, the movement speed in the preset plane is obtained.

Optionally, the velocity module further includes: a projection unit adapted to obtain the (i,jth)th radial velocity and the (i,jth)th projection angle according to the (i,jth)th radial velocity ) projected radial rate, the (i, j)th projected radial rate is the radial movement speed of the target to be measured in the preset plane; the velocity module is suitable according to the (a, aj) ) location information, the (b, bj)th location information, the (a, aj) projected radial velocity and the (b, bj) projected radial velocity, combined with the ath transceiver module and the The position information of the b-th transceiver module is used to obtain the moving speed of the target to be measured in a preset plane.

Optionally, the preset plane is a horizontal plane; or, the preset plane is a plane with a vertical field angle of 0°; or, the lidar has a rotation axis, and the preset plane is vertical to the The plane of the axis of rotation.

Optionally, the i-th transceiver module emits a Ni beam detection beam to perform a frame scan; the data module is suitable for obtaining a frame of scan data of the i-th transceiver module, and a frame of scan data of the i-th transceiver module Including: Ni group detection data.

Optionally, the speed module further includes: a fitting unit adapted to perform cosine curve fitting according to the multiple sets of detection data to obtain the moving speed of the target to be measured.

Optionally, when the discrimination module judges that the multiple sets of detection data correspond to the same target to be measured, the fitting unit performs cosine curve fitting according to the multiple sets of detection data.

Optionally, it includes: one laser radar, the laser radar includes the M transceiver modules; or, includes: multiple laser radars, the multiple laser radars include the M transceiver modules.

In addition, the present invention also provides a control system, the control system is an automatic driving control system, including:

A measuring device, the measuring device is a device for measuring the moving speed of the laser radar of the present invention; a control device, the controlling device is suitable for controlling the vehicle in combination with the moving speed obtained by the measuring device.

Compared with the prior art, the technical solution of the present invention has the following advantages:

The technical scheme of the present invention obtains detection data respectively through a plurality of transceiver modules, and on the basis of the detection data, combines the position information of the transceiver modules to obtain the moving speed of the target to be measured. Since there is a preset distance between the multiple transceiver modules, the obtained moving speed is a vector speed, that is, the moving speed includes a moving speed and a moving direction angle. The acquisition of the vector velocity can more accurately reflect the actual motion of the target to be measured, and can effectively improve the accuracy and precision of vehicle control.

In the optional solution of the present invention, especially for short-distance targets, the detection data is obtained by obtaining one frame of scanning data, and the obtained one frame of scanning data includes one or more i-th groups of detection data, which can be based on multiple The i group of detection data is fitted with a cosine curve to obtain the i-th fitting curve; the movement speed can be obtained according to multiple fitting curves, so as to improve measurement accuracy and reduce measurement error.

In the optional solution of the present invention, the emission angle of the corresponding detection beam can be obtained from the transceiver module as the projection angle; combined with the projection angle, the movement speed in the preset plane can be obtained, thereby converting the movement speed in three-dimensional space into The movement speed in the preset plane can effectively shorten the processing time and improve the processing efficiency. Especially for the field of automatic driving, the preset plane can be the plane that is more interesting for automatic driving, so as to ensure the speed of measurement data processing and the accuracy of measurement results for automatic driving guidance.

Description of drawings

Figure 1 is a structural block diagram of the FMCW lidar;

Figure 2 is the detection principle of FMCW lidar;

Figure 3 is a schematic diagram of the comparison between the radial velocity obtained by the laser radar and the actual velocity of the target to be measured;

Fig. 4 is a schematic flow chart of an embodiment of a method for measuring motion speed by lidar according to the present invention;

Fig. 5 is a structural schematic diagram of the laser radar used in the embodiment of the method for measuring the speed of motion by the laser radar shown in Fig. 4;

Fig. 6 is the functional block diagram of the laser radar adopted by the method embodiment of the laser radar measuring motion speed shown in Fig. 4;

Fig. 7 is a schematic diagram of the optical path structure of the scanning unit in the lidar shown in Fig. 5;

Fig. 8 is a schematic diagram of the principle of obtaining the moving speed of the target to be measured according to the embodiment of the method for measuring the moving speed of the lidar shown in Fig. 4;

Fig. 9 is a step of judging whether the (a, aj) group of detection data and the (b, bj) group of detection data correspond to the same target to be measured in the embodiment of the method for measuring the speed of motion by the lidar shown in Fig. 4 Schematic diagram of the specific process;

Fig. 10 is a schematic flow chart of another embodiment of the method for measuring the speed of motion by the laser radar of the present invention;

Fig. 11 is a schematic diagram of the motion speed in the preset plane in the embodiment of the method for measuring the motion speed by the lidar shown in Fig. 10;

Fig. 12 is a schematic flow chart of another embodiment of the method for measuring motion speed by lidar according to the present invention;

Fig. 13 is a functional block diagram of an embodiment of a device for measuring motion speed by laser radar according to the present invention;

Fig. 14 is a functional block diagram of another embodiment of the device for measuring motion speed by laser radar according to the present invention;

Fig. 15 is a functional block diagram of another embodiment of the device for measuring motion speed by laser radar according to the present invention.

Detailed ways

It can be seen from the background art that the speed measured by the laser radar in the prior art is the radial velocity of the target to be measured relative to the laser radar, and it is difficult to obtain the vector velocity of the target to be measured.

In order to solve the technical problems, the invention provides a method for measuring the speed of motion by laser radar, including:

M transceiver modules are provided, where M≧2; the j-th probe beam is transmitted through the i-th transceiver module and the j-th echo beam is received, and the j-th probe beam is reflected to form the j-th echo beam, wherein, 1≦i≦M, 1≦j≦N _i ; According to the jth echo beam, the (i, j)th group of detection data is obtained, and the (i, j)th group of detection data includes: (i, j) Position information and (i, j) radial velocity; at least based on the (a, aj) group of detection data and the (b, bj) group of detection data, combined with the position information of the a-th transceiver module and the b-th transceiver module The position information of the module to obtain the moving speed of the target to be measured, where, 1≦a≦M, 1≦b≦M, 1≦aj≦N _a , 1≦bj≦N _b , and a≠b, the ath transceiver module There is a preset distance from the bth transceiver module.

The technical scheme of the present invention obtains detection data through a plurality of transceiver modules, and obtains the moving speed of the target to be measured on the basis of the detection data and in combination with the position information of the transceiver modules. Since there is a preset distance between the multiple transceiver modules, the obtained moving speed is a vector speed, that is, the moving speed includes a moving speed and a moving direction angle. The acquisition of the vector velocity can more accurately reflect the actual motion of the target to be measured, and can effectively improve the accuracy and precision of vehicle control.

In the technical solution of the present invention, a plurality of transceiver modules respectively obtain detection data, and in a frame of detection data of at least two transceiver modules, each selects at least one group of qualified detection data, and the aj-th group detection of the a-th detection module Data and the bjth group of detection data of the bth detection module, combined with the position information of the ath transceiver module and the position information of the bth transceiver module, the moving speed of the target to be measured can be obtained; when the number of transceiver modules is more than 3, it can be From a frame of detection data of more than three transceiver modules, at least one group of detection data that meets the conditions is selected, and the moving speed of the target to be measured is obtained by combining the position information of each transceiver module.

In order to make the above objects, features and advantages of the present invention more comprehensible, specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

Referring to FIG. 4 , it shows a schematic flowchart of an embodiment of a method for measuring motion speed by lidar according to the present invention.

As shown in FIG. 4 , step S100 is first performed to provide M transceiver modules, wherein M≧2; and then step S200 is performed to transmit the j-th detection beam and receive the j-th echo beam through the i-th transceiver module. The j detection beam is reflected to form the jth echo beam, wherein, 1≦i≦M, 1≦j≦N _i ; then, step S300 is executed, and the (i, j) group of detection data, the (i, j) group of detection data includes: (i, j) position information and (i, j) radial velocity vri (radial velocity vr1 as shown in Figure 5 and radial velocity vr2).

It should be noted that N _i refers to the number of detection beams emitted by the i-th transceiver module for one frame scanning, that is, the i-th transceiver module emits N _i probe beams for one-frame scanning to obtain the i-th transceiver module One frame of scanning data of the module, the one frame of scanning data of the i-th transceiver module includes: N _i groups of detection data.

The method is a method for measuring motion speed by laser radar. Therefore, in some embodiments of the present invention, the step of providing M transceiver modules includes: providing a laser radar, and the laser radar includes the M transceiver modules.

Referring to FIG. 5 , it shows a schematic structural diagram of the laser radar used in the embodiment of the method for measuring motion speed by the laser radar shown in FIG. 4 .

In some embodiments of the present invention, the step of providing M transceiver modules includes: providing a laser radar, and the laser radar includes: M transceiver modules, that is, the laser radar provided in the step of providing M transceiver modules only includes one light source.

It should be noted that, in the lidar shown in FIG. 5 , the transceiver module includes a scanning unit. FIG. 5 shows two scanning units, namely scanning unit a and scanning unit b, among the M transceiver modules in the lidar.

It should also be noted that the number of transceiver modules in the laser radar used in the method for measuring the moving speed by the laser radar of the present invention can be 2 or more. The present invention does not limit the number of transceiver modules in the lidar.

In some embodiments of the present invention, the lidar is a frequency modulated continuous wave (frequency modulated continuous wave, FMCW) lidar. FMCW lidar can obtain the radial velocity and position information of the target to be measured.

In conjunction with reference to FIG. 6 , FIG. 6 shows a functional block diagram of the FMCW lidar used in the embodiment of the method for measuring motion speed by the lidar shown in FIG. 4 .

Specifically, the process of obtaining the radial velocity and position of the target to be measured by the FMCW lidar is as follows: the frequency-modulated light source 110 generates a linear frequency-modulated continuous original beam; 150 as the local oscillator light, and another part of the original light beam is amplified by the amplification unit 130 as the detection beam, and the detection beam is reflected by the scanning unit (as shown in Figure 7) to the three-dimensional space where the target to be measured is located; After the echo beam formed by the original beam is coupled into the waveguide, it is separated from the detection beam by the beam splitting unit 140, and then transmitted to the frequency mixing unit 150; 160 performs photoelectric conversion; the processing unit (not shown in the figure) calculates the radial velocity and position information of the target to be measured according to the result of photoelectric conversion.

The scanning unit performs two-dimensional scanning by changing the propagating direction of the detection beam, so as to obtain a certain range of field of view. The detection beam generated by the frequency modulation light source 110 is transmitted to the scanning unit through the waveguide, and the detection beam emitted by the waveguide port is deflected by the scanning unit before exiting; the echo beam reflected by the detection target is received by the scanning unit and then coupled to the waveguide. The separation from the detection beam optical path is realized by the beam splitting unit. Wherein, the beam splitting unit 140 may include a circulator, and may also include other splitting elements such as a coupler; the processing unit calculates the diameter of the target to be measured according to the difference frequency and Doppler frequency shift of the local oscillator light and the echo light. speed and position information.

It should be noted that the functional block diagram of the FMCW lidar shown in FIG. 6 is only an example. In other embodiments of the present invention, the light splitting unit may also be arranged downstream of the optical path of the amplification unit, that is, part of the local oscillator light is separated from the original light beam after being amplified, and part of it is output as a detection light beam.

Referring to FIG. 7 , a schematic diagram of the optical path structure of the scanning unit used in the FMCW lidar shown in FIG. 5 is shown.

As shown in FIG. 7 , the scanning unit includes two scanning mirrors 171 and 172 whose axes are perpendicular. The scanning mirror 171 and the scanning mirror 172 may be one-dimensional vibrating mirrors, oscillating mirrors, rotating mirrors and the like. The angular velocities of the motions of the scanning mirror 171 and the scanning mirror 172 are different (that is, if the scanning mirror 171 and the scanning mirror 172 are oscillating mirrors or oscillating mirrors, the deflection speeds of the scanning mirror 171 and the scanning mirror 172 are not equal, if the scanning mirror 171 and the scanning mirror 172 are rotating mirrors, the rotating speeds of the scanning mirror 171 and the scanning mirror 172 are not equal).

Of course, in other embodiments of the present invention, the scanning unit may also include a two-dimensional vibrating mirror for scanning.

It should be noted that, continuing to refer to FIG. 4 , the method of using a laser radar including M transceiver modules to measure the moving speed is only an example. In other embodiments of the present invention, the step of providing M transceiver modules includes: providing multiple laser radars, where the multiple laser radars include the M transceiver modules. Moreover, the M transceiver modules may be evenly distributed in the multiple laser radars, or may be non-uniformly distributed in the multiple laser radars, which is not limited in the present invention.

Moreover, in order to facilitate data fusion, in the embodiment in which multiple laser radars are provided to provide M transceiver modules, the frame rates of the multiple laser radars are the same, so that the multiple laser radars can realize simultaneous detection as much as possible.

The M transceiver modules respectively transmit and receive optical signals to obtain multiple groups of detection data, which are respectively (i, j) groups of detection data, and the (i, j) groups of detection data include: (i, j) position information and (i, j)th radial velocity vri, where 1≦i≦M, 1≦j≦N _i .

It should be noted that, in some embodiments of the present invention, as shown in the figure, the transceiver module includes a scanning unit. Therefore, in the step of obtaining detection data, the position information in the detection data is the information of the position of the scanning unit.

In the method embodiment shown in FIG. 4 and FIG. 5 , in the detection data obtained by transmitting the detection beam and receiving the echo beam through the scanning unit a, the position information is relative to the position information of the scanning unit a; In the detection data obtained by transmitting the detection beam and receiving the echo beam by the scanning unit b, the position information is relative to the position information of the scanning unit b.

Continuing to refer to FIG. 4, after obtaining the detection data, execute step S500, at least according to the (a, aj) group detection data and the (b, bj) group detection data, and combine the position information of the ath transceiver module and the bth transceiver module position information to obtain the moving speed of the target to be measured, wherein, 1≦a≦M, 1≦b≦M, 1≦aj≦N _a , 1≦bj≦N _b , and a≠b, the ath transceiver module and There is a preset distance between the bth transceiver modules.

It should be noted that the present invention does not limit the number of transceiver modules in the lidar. In some embodiments of the present invention, the laser module only includes two transceiver modules, so when step S500 is performed, the ath transceiver module and the bth transceiver module are the transceiver modules in the lidar. In other embodiments of the present invention, the laser module includes more than two transceiver modules, so when step S500 is performed, the ath transceiver module and the bth transceiver module are any two of the two or more transceiver modules that meet the conditions. module.

In other embodiments of the present invention, the laser radar includes 3 or more transceiver modules, so when step S500 is performed, in addition to the (a, aj) group of detection data and the (b, bj) group of detection data, it is also possible to select The (c, cj)th group of detection data, where 1≦c≦M, 1≦cj≦N _c , and combined with the position information of the ath transceiver module, the bth transceiver module and the cth transceiver module, obtain the target’s location speed of movement. The present invention does not limit the number of transceiver modules and the number of transceiver modules corresponding to the selected detection data for obtaining the moving speed of the target to be measured.

Referring to FIG. 8 , it shows a schematic diagram of the principle of obtaining the moving speed of the target to be measured according to the embodiment of the method for measuring the moving speed of the lidar shown in FIG. 4 .

The fields of view of the scanning unit a of the ath transceiver module and the scanning unit b of the bth transceiver module have overlapping areas. The a-th transceiver module and the b-th transceiver module perform a frame detection respectively, and can obtain the detection data of the same target to be tested, that is, the (a, aj)th group of detection data obtained by the a-th transceiver module and the b-th transceiver module. The (b, bj) group of detection data corresponds to the same target to be measured.

The (a, aj) group of detection data obtained by the a transceiver module includes: (a, aj) radial velocity vr1; the (b, bj) group of detection data obtained by the b transceiver module includes: (b , bj) radial velocity vr2.

As shown in Figure 5 and Figure 8, the radial velocity obtained by the i-th transceiver module is the projection of the velocity vector of the target to be measured in the direction of the line connecting the target to be measured and the scanning unit of the transceiver module, that is, the i-th The (a, aj)th radial velocity vr1 in the (a, aj)th group of detection data obtained by the a transceiver module is the projection of the velocity vector V of the target to be measured in the direction of the line 510a, and the bth transceiver module obtained The (b, bj)th radial velocity vr2 in the (b, bj)th group of detection data is the projection of the velocity vector V of the target to be measured in the direction of the connecting line 510b.

Since there is a preset distance between the ath transceiver module and the bth transceiver module, that is, the positions of the ath transceiver module and the bth transceiver module are not the same, so the radial direction of the ath transceiver module and the radial direction of the bth transceiver module The directions are not the same, and the projections of the velocity vector V of the target to be measured in different radial directions are also different, that is, the (a, aj)th radial velocity vr1 and the (b, bj)th radial velocity vr2 are different. Specifically, the preset distance is greater than or equal to 1 m to ensure accuracy.

On the other hand, the (a, aj) group of detection data obtained by the a-th transceiver module also includes: (a, aj) position information; the (b, bj) group of detection data obtained by the b-th transceiver module also includes : The (b, bj)th position information.

According to the (a, aj) position information and the (b, bj) position information, combined with the pre-stored position information of the ath transceiver module (that is, the position information of the scanning unit a in the ath transceiver module) and The position information of the bth transceiver module (that is, the position information of the scanning unit bj in the bth transceiver module), it can be known that the radial direction of the target to be measured relative to the ath transceiver module is opposite to the target to be measured in the radial direction of the bth transceiver module.

The moving speed is a vector speed, that is, the moving speed includes: moving speed V and moving direction angle; so in the step of obtaining the moving speed of the target to be measured, according to the (a, aj) radial velocity vr1 and the (b , bj) radial velocity vr2, combined with the radial direction of the target to be measured relative to the ath transceiver module, and the radial direction of the target to be measured relative to the bth transceiver module, the moving velocity of the target to be measured is obtained.

As shown in Figure 8, based on the (a, aj) group of detection data obtained by the a-th transceiver module and the (b, bj)-th group of detection data obtained by the b-th transceiver module, the following relationship can be obtained:

v _r1 =V cos(θ ₁ -α) (1)

v _r2 ＝V cos(θ ₂ -α) (2)

Among them, α represents the angle between the motion speed of the target to be measured and the positive direction of the abscissa + x, that is, the motion direction angle of the motion speed; v _r1 represents the radial velocity obtained in the radial direction of the ath transceiver module , that is, the (a, aj) radial velocity vr1; V _r2 represents the radial velocity obtained in the radial direction of the bth transceiver module, that is, the (b, bj) radial velocity vr2; θ1 represents the relative The included angle between the radial direction of the ath transceiver module and the abscissa x; θ2 represents the included angle between the radial direction of the target to be measured relative to the bth transceiver module and the abscissa x.

And θ ₁ and θ ₂ can be respectively obtained according to the radial direction of the target to be measured relative to the ath transceiver module and the radial direction of the target to be measured relative to the bth transceiver module. It can be seen that, by solving the binary linear equations of the calculation formulas (1) and (2) to obtain V and α, the motion velocity V and the motion direction angle α of the motion speed of the target to be measured can be obtained.

It should be noted that in this embodiment, the a-th transceiver module is taken as the origin, and the direction from the a-th transceiver module to the b-th transceiver module is taken as the x-axis, which is perpendicular to the line connecting the a-th transceiver module and the b-th transceiver module and points to the The direction of the target is the y-axis to establish a coordinate system for calculation.

In other embodiments of the present invention, the (c, cj)th group of detection data is also selected, wherein, 1≦c≦M, 1≦cj≦N _c , based on the (c, cj)th group of detection data, the following relationship can be obtained Mode:

v _r3 ＝V cos(θ ₃ -α) (3)

Among them, v _r3 represents the radial velocity obtained in the radial direction of the cth transceiver module, that is, the (c, cj)th radial velocity vr3, θ3 represents the radial direction and abscissa of the target to be measured relative to the cth transceiver module The angle between x.

According to relational formulas (1)-(3), the values of V and α can be obtained, which can be used as the moving speed and moving direction angle of the moving speed of the target to be measured, which can reduce the influence of calculation error and detection error.

Continuing to refer to FIG. 4 , in some embodiments of the present invention, before obtaining the moving speed of the target to be measured, the method further includes: performing step S400, judging the (a, aj)th group of detection data and the (aj)th group of detection data and the ( b, bj) Whether the group of detection data corresponds to the same target to be tested.

Since there is a preset distance between the ath transceiver module and the bth transceiver module, that is, there is a preset distance between the scanning unit of the ath transceiver module and the scanning unit of the bth transceiver module (as shown in Figure 5), it can be seen that, The coordinate system between the scanning unit of the ath transceiver module and the scanning unit of the bth transceiver module is not unified, therefore, it is judged whether the (a, aj) group of detection data and the (b, bj) group of detection data are Before corresponding to the same target to be measured, coordinate transformation is required.

Therefore, with reference to FIG. 9, step S400, the step of judging whether the (a, aj) group of detection data and the (b, bj) group of detection data correspond to the same target to be measured includes: performing step S410, according to The position information of the ath transceiver module and the position information of the bth transceiver module are carried out coordinate conversion, so that the (a, aj) position information in the (a, aj) group of detection data and the (b, bj)th position information (b, bj) position information in the group of detection data is converted to the same coordinate system to obtain (a, aj) converted position information and (b, bj) converted position information; then step S420 is performed to compare the The (a, aj)-th conversion position information and the (b, bj)-th conversion position information, the difference between the (a, aj)-th conversion position information and the (b, bj)-th conversion position information is within a preset range When , it is judged that the (a, aj) group of detection data and the (b, bj) group of detection data correspond to the same target to be measured.

In some embodiments of the present invention, the (a, aj)th transformed position information and the (b, bj) transformed position information are both position information in the world coordinate system, that is, in the step of coordinate transformation, the (a , aj) The (a, aj)th position information in the group of detection data and the (b, bj)th position information in the (b, bj) group of detection data are both converted to the world coordinate system.

In other embodiments of the present invention, the (a, aj)th converted position information may also be the position information in the coordinate system of the bth transceiver module, or the (b, bj)th converted position information may also be the position information of the ath transceiver module The position information under the coordinate system, that is, in the step of coordinate conversion, the (a, aj)th position information and the (b, bj)th position information are converted to the coordinates of a transceiver module in the ath transceiver module and the bth transceiver module Department.

Referring to FIG. 10 , it shows a schematic flowchart of another embodiment of the method for measuring motion speed by lidar according to the present invention.

The difference from the foregoing embodiments is that, in some embodiments of the present invention, the method for measuring the motion speed of the lidar is only interested in the motion of the target to be measured within a preset plane. Therefore, the movement speed in the three-dimensional space can be converted into the movement speed in the preset plane, thereby effectively shortening the processing time and improving the processing efficiency.

In some embodiments of the present invention, the method for measuring the motion speed by the lidar is applied in the field of automatic driving. Since the automatic driving technology mainly focuses on the movement of the target to be measured in the horizontal plane, the preset plane is the horizontal plane, and further is the horizontal plane with the radar as a reference, that is, the plane of the radar coordinate system z=0; or, the preset Let the plane be a plane with a vertical field of view of the laser radar of 0°; or, the laser radar has a rotation axis, and the preset plane is a plane perpendicular to the rotation axis.

Specifically, as shown in FIG. 10 , the step of obtaining the moving speed of the target to be measured includes: performing step S510 first, according to the (i, j)th position information in the (i, j)th group of detection data and the The position information of the i-th transceiver module is obtained to obtain the (i, j) radial direction angle, wherein the (i, j) radial direction angle refers to the direction in which the i-th transceiver device points to the target to be measured; then execute step S520, at least According to the (a, aj) radial velocity, (a, aj) radial direction angle, (b, bj) radial velocity and (b, bj) radial direction angle, the motion rate and motion direction angle.

With reference to FIG. 11 , the step of transmitting the j-th probe beam through the i-th transceiver module includes: obtaining the (i, j)th projection angle γ, and the (i, j-th) projection angle γ is the j-th probe beam emitted by the i-th transceiver module. The angle between the probe beam and the preset plane. Therefore, in the step of obtaining the moving speed of the target to be measured, the moving speed vr// in the preset plane is obtained in combination with the (i, j)th projection angle γ.

It should be noted that, in the step of obtaining the (i, j)th projection angle, the coordinate system is established with the position of the i-th transceiver module as the origin and the direction perpendicular to the preset plane as the z-axis, so the preset The plane is the xoy plane.

Specifically, the step of obtaining the motion velocity in the preset plane includes: according to the (i, j)th radial velocity v _ri and the (i, j)th projection angle γ, obtaining the (i, j)th projection Radial velocity v _{ri //} , the (i, j) projected radial velocity is the radial movement velocity of the target to be measured in the preset plane; according to the (a, aj) position information, The (b, bj)th position information, the (a, aj) projected radial velocity and the (b, bj) projected radial velocity are combined with the ath transceiver module and the bth transceiver module The position information of the module is used to obtain the moving speed of the target to be measured in the preset plane.

That is to say, based on the (a, aj) group of detection data obtained by the a-th transceiver module and the (b, bj)-th group of detection data obtained by the b-th transceiver module, the following relationship can be obtained:

v _r1// ＝V _// cos(θ ₁ -α) (4)

v _{r2 //} ＝V _// cos(θ ₂ -α) (5)

Among them, α represents the angle between the moving speed of the target to be measured in the preset plane and the positive direction of the abscissa + x; v _{r1 //} represents the radial velocity obtained in the radial direction of the ath transceiver module in the preset The projection in the plane, that is, the (a, aj) projected radial rate; v _r2// represents the projection of the radial rate obtained in the radial direction of the bth transceiver module in the preset plane, that is, the (b, bj)th ) projected radial rate; θ1 represents the angle between the radial direction of the target to be measured relative to the a-th transceiver module in the preset plane and the abscissa x; θ2 represents the target to be measured in the preset plane relative to the b-th transceiver module The angle between the radial direction of and the abscissa x. It can be seen that the obtained V _// is also the projection component of the moving speed of the target to be measured in the preset plane.

In other embodiments of the present invention, when the moving speed of the target to be measured is obtained based on the (c, cj) group of detection data of the c-th transceiver module or the detection data of more transceiver modules, V _// can be obtained as the target to be measured The projected component of the motion speed in the preset plane will not be repeated here.

In other embodiments of the present invention, one transceiver module obtains multiple sets of detection data corresponding to the same target to be measured, and uses the multiple sets of detection data to obtain V and α.

Referring to FIG. 12 , it shows a schematic flow chart of still another embodiment of the method for measuring motion speed by lidar according to the present invention.

In some embodiments of the present invention, the step of transmitting the j-th detection beam through the i-th transceiver module includes: performing step S501, transmitting N _i beams of detection beams through the i-th transceiver module to perform a frame scan, so as to obtain the i-th transceiver module One frame of scanning data of the module, the one frame of scanning data of the i-th transceiver module includes: N _i groups of detection data. Wherein, the (i, j)th detection data is obtained according to the i-th transceiver module receiving the j-th echo beam, wherein the j-th echo beam is formed by the j-th detection beam emitted by the i-th transceiver module, 1≦j≦N _i .

It can be seen that the technical solution of the present invention can obtain the motion speed of the target to be measured including the motion rate and the direction angle of motion through one frame of scanning data, thereby effectively improving the speed and accuracy of determining the motion state of the target to be measured.

In some embodiments of the present invention, the method for measuring the motion speed of the laser radar is applied in the field of automatic driving. For a target to be measured, each transceiver module may obtain multiple detection groups corresponding to the target to be measured within one frame. Data, using the above multiple sets of detection data to calculate the moving speed of the target to be measured can effectively reduce the deviation of the result caused by the measurement error.

Specifically, the step of obtaining the moving speed of the target to be measured further includes: performing step S521, performing cosine curve fitting according to multiple sets of detection data, to obtain the moving speed of the target to be measured.

It should be noted that, in order to improve calculation accuracy and control errors, the multiple sets of detection data used for cosine curve fitting must correspond to the same target; and the number of multiple sets of detection data must reach a certain number.

As shown in Figure 12, after performing step S501 to obtain a frame of scanning data of the i-th transceiver module, before performing step S521 to perform cosine curve fitting, the step of obtaining the moving speed of the target to be measured further includes: performing step S511, judging Whether the multiple sets of detection data correspond to the same target to be measured; when judging that the multiple sets of detection data correspond to the same target to be measured, perform cosine curve fitting according to the multiple sets of detection data.

Specifically, the dth transceiver module emits _Nd beams of detection light beams to perform a frame scan to obtain a frame of scan data of the dth transceiver module, and the frame of scan data of the dth transceiver module includes: _Nd groups of detection data, wherein, n1 groups of detection data correspond to a target to be measured; similarly, a frame of scanning data is obtained by emitting _Ne beams of detection beams through the e-th transceiver module to obtain a frame of scan data of the e-th transceiver module , A frame of scan data of the e-th transceiver module includes: N _e groups of detection data, wherein n2 groups of detection data correspond to the target to be measured.

It should be noted that, in some embodiments of the present invention, after the i-th transceiver module performs a frame scan and obtains a frame of scan data, it judges whether the N _i groups of detection data in a frame of scan data correspond to the same target to be measured, thereby Obtaining n _i groups of detection data corresponding to a target to be measured; wherein, it can be judged that the detection data corresponds to the same target to be measured according to the difference of the position information of the n _i groups of detection data being within a preset range.

In some embodiments of the present invention, the coordinate transformation is performed on the N _d groups of detection data and the Ne group of detection data, and the position information difference after conversion according to the _nd groups of detection data and the _{N e} _groups of detection data is within a preset range Within, it is determined that the _nd group of detection data and the _ne group of detection data correspond to the same target to be measured. Further, a clustering algorithm is used to further determine whether the n _d groups of detection data correspond to the same target to be measured, and n1 groups of detection data corresponding to the same target to be measured are obtained; clustering is used for the n _e groups of detection data The algorithm further judges whether it corresponds to the same target to be measured, and obtains n2 sets of detection data corresponding to the same target to be measured. In this way, multiple sets of detection data corresponding to the same target to be measured among the detection data of the multiple transceiver modules are obtained.

The aforementioned calculation formulas (4) and (5) can be regarded as cosine curves determined by the amplitude V _// and the phase α, and the n1 sets of detection data and n2 sets of detection data corresponding to the same target to be measured are distributed in the amplitude On cosine curves that are equal and have the same phase. It can be seen that the amplitude |V _// | and the phase α can be determined by cosine curve fitting based on n1 sets of detection data and n2 sets of detection data.

Specifically, in some embodiments of the present invention, the step of fitting a cosine curve includes: performing cosine curve fitting by using a least square method.

Correspondingly, the present invention also provides a device for measuring speed by laser radar.

Referring to FIG. 13 , it shows a functional block diagram of an embodiment of a device for measuring motion speed by lidar according to the present invention.

The device for measuring the movement speed of the laser radar includes: M transceiver modules 310, wherein M≧2; the i-th transceiver module 310 emits the jth detection beam and receives the jth echo beam, and the jth detection beam is reflected Forming the jth echo beam, wherein 1≦i≦M, 1≦j≦N _i .

The device is a device for measuring motion speed by laser radar. Therefore, in some embodiments of the present invention, the device includes: a laser radar, and the laser radar includes the M transceiver modules 310 .

Referring to FIG. 5 , it shows a schematic structural diagram of the laser radar in the embodiment of the device for measuring motion speed by the laser radar shown in FIG. 13 .

In some embodiments of the present invention, the lidar device for measuring motion speed only includes one lidar with M transceiver modules 310, that is, the lidar in the device includes only one light source.

It should also be noted that the number of transceiver modules in the lidar can be 2 or more. The present invention does not limit the number of transceiver modules in the lidar.

In some embodiments of the present invention, the lidar is an FMCW lidar, that is, the lidar is a frequency modulated continuous wave (frequency modulated continuous wave, FMCW) lidar. FMCW lidar can obtain the radial velocity and position information of the target to be measured.

It should be noted that, for the specific technical solution of the lidar, refer to the descriptions in the foregoing method embodiments, and the present invention will not repeat them here.

It should also be noted that the device includes: one laser radar is only an example. In other embodiments of the present invention, the device may also include: multiple laser radars, where the multiple laser radars include the M transceiver modules. Moreover, the M transceiver modules may be evenly distributed in the multiple laser radars, or may be non-uniformly distributed in the multiple laser radars, which is not limited in the present invention.

Moreover, in order to facilitate data fusion, in the embodiment where the device includes multiple laser radars, the frame rates of the multiple laser radars are the same, so that the multiple laser radars can practice simultaneous detection as much as possible.

M transceiver modules 310 transmit and receive optical signals respectively to obtain multiple groups of detection data, which are respectively (i, j) groups of detection data, and the (i, j) groups of detection data include: (i, j) position information and the (i, j)th radial velocity vri, where 1≦i≦M, 1≦j≦N _i .

It should be noted that, in some embodiments of the present invention, as shown in the figure, the transceiver module includes a scanning unit. Therefore, the location information in the detection data is the location information of the scanning unit.

In the method embodiment shown in Figure 4 and Figure 5, in the detection data obtained by the scanning unit a emitting the detection beam and receiving the echo beam, the position information is the position information relative to the scanning unit a; by In the detection data obtained by the scanning unit b emitting the detection beam and receiving the echo beam, the position information is relative to the position information of the scanning unit b.

Continuing to refer to FIG. 13 , the device further includes: a data module 320, the data module 320 is adapted to obtain the (i, j)th group of detection data according to the jth echo beam, and the (i, j)th The set of detection data includes: the (i, j)th position information and the (i, j)th radial velocity; the velocity module 330, the velocity module 340 is adapted to at least according to the (a, aj)th set of detection data and the (b)th , bj) group of detection data, combined with the position information of the ath transceiver module and the position information of the bth transceiver module, to obtain the moving speed of the target to be measured, wherein, 1≦a≦M, 1≦b≦M, 1≦aj ≦N _a , 1≦bj≦N _b , and a≠b, there is a preset distance between the ath transceiver module and the bth transceiver module.

It should be noted that the present invention does not limit the number of transceiver modules in the lidar. In some embodiments of the present invention, the laser module only includes two transceiver modules, that is, the ath transceiver module and the bth transceiver module. In other embodiments of the present invention, the laser module includes more than two transceiver modules, and the a-th transceiver module and the b-th transceiver module are any two of the two or more transceiver modules that meet the conditions.

In other embodiments of the present invention, the laser radar includes 3 or more transceiver modules, that is, the laser radar also includes: the cth transceiver module; therefore, except for the (a, aj) group of detection data and the (b, bj ) group of detection data, the speed module 330 can also select the (c, cj)th group of detection data, where 1≦c≦M, 1≦cj≦N _c , and then combine the ath transceiver module, the bth transceiver module and The position information of the cth transceiver module is used to obtain the moving speed of the target to be measured. The present invention does not limit the number of transceiver modules and the number of transceiver modules corresponding to the selected detection data for obtaining the moving speed of the target to be measured.

Referring to FIG. 8 , it shows a schematic diagram of the principle of obtaining the moving speed of the target to be measured in the embodiment of the device for measuring the moving speed of the lidar shown in FIG. 13 .

The fields of view of the scanning unit a of the ath transceiver module and the scanning unit b of the bth transceiver module have overlapping areas. The ath transceiver module and the bth transceiver module respectively perform a frame detection, and the data module 320 can obtain the detection data of the same target to be measured, that is, the (a, aj)th group of detection data and the bth group of detection data obtained by the ath transceiver module The (b, bj)th group of detection data obtained by the transceiver module corresponds to the same target to be measured.

The (a, aj)th group of detection data obtained by the data module 320 through the ath transceiver module includes: (a, aj) radial velocity vr1; the data module 320 obtained by the bth transceiver module The obtained (b, bj)th group of detection data includes: (b, bj)th radial velocity vr2.

With reference to Fig. 5 and Fig. 8, the radial velocity obtained by the i-th transceiver module is the projection of the velocity vector of the target to be measured in the direction of the line connecting the target to be measured and the scanning unit of the transceiver module, that is, the i-th The (a, aj)th radial velocity vr1 in the (a, aj)th group of detection data obtained by the transceiver module is the projection of the velocity vector V of the target to be measured in the direction of the line 510a, and the bth transceiver module obtained The (b, bj)th radial velocity vr2 in the (b, bj)th group of detection data is the projection of the velocity vector V of the target to be measured in the direction of the connecting line 510b.

On the other hand, the (a, aj)th group of detection data obtained by the data module 320 through the ath transceiver module also includes: the (a, aj)th position information; the data module 320 obtained by the bth transceiver module The (b, bj)th group of detection data also includes: (b, bj)th position information.

According to the (a, aj) position information and the (b, bj) position information, combined with the pre-stored position information of the ath transceiver module (that is, the position information of the scanning unit a in the ath transceiver module) and The position information of the bth transceiver module (that is, the position information of the scanning unit bj in the bth transceiver module), the speed module 340 can obtain the radial direction of the target to be measured relative to the ath transceiver module , and the radial direction of the target to be measured relative to the bth transceiver module.

The motion speed is a vector speed, that is, the motion speed includes: motion velocity V and motion direction angle; so the speed module 340 is based on the (a, aj)th radial velocity vr1 and the (b, bj)th radial velocity vr2, combining the radial direction of the target to be measured with respect to the a-th transceiver module and the radial direction of the target to be measured with respect to the b-th transceiver module, to obtain the moving speed of the target to be measured.

With reference to Fig. 8, based on the (a, aj) group detection data obtained by the a transceiver module and the (b, bj) group detection data obtained by the b transceiver module, the following relationship can be obtained:

v _r1 =V cos(θ ₁ -α) (1)

v _r2 ＝V cos(θ ₂ -α) (2)

And θ ₁ and θ ₂ can be respectively obtained according to the radial direction of the target to be measured relative to the ath transceiver module and the radial direction of the target to be measured relative to the bth transceiver module. It can be seen that, the velocity module 340 obtains V and α by solving the binary linear equation of formula (1) and (2), that is, the velocity of motion V and the direction of motion of the target to be measured can be obtained. alpha.

It should be noted that, in this embodiment, in the process of solving the calculation formula, the speed module 340 is based on the a-th transceiver module as the origin, and the direction from the a-th transceiver module to the b-th transceiver module as the x-axis, perpendicular to the The a-th transceiver module is connected to the b-th transceiver module and the direction pointing to the target to be measured is the y-axis to establish a coordinate system for calculation.

v _r3 ＝V cos(θ ₃ -α) (3)

In the case of complete and accurate detection, V and α obtained according to relational expressions (1)～(3) should be equal, but there is a certain deviation or error in the detection of lidar, then according to relational expressions (1)～( 3), a set of V and α values can be obtained by combining two by two, and the average value of multiple sets of |V| and α values can be used as the motion velocity V and motion direction angle α of the motion speed of the target to be measured, which can be reduced The effect of probing errors.

Continuing to refer to FIG. 13 , in some embodiments of the present invention, the device further includes: a screening module 330, the screening module 330 is suitable for judging the (a, aj)th group of detection data and the (b, bj)th group Whether the group detection data corresponds to the same target to be tested.

Since there is a preset distance between the ath transceiver module and the bth transceiver module, that is, there is a preset distance between the scanning unit of the ath transceiver module and the scanning unit of the bth transceiver module (as shown in Figure 5), it can be seen that, The coordinate system between the scanning unit of the ath transceiver module and the scanning unit of the bth transceiver module is not unified, therefore, in addition to judging the (a, aj) group of detection data and the (b, bj) group of detection data Whether they correspond to the same object to be measured, the screening module 330 needs to perform coordinate transformation.

As shown in FIG. 4 , the screening module 330 includes: a conversion unit 331, and the conversion unit 331 is adapted to perform coordinate conversion according to the position information of the ath transceiver module and the position information of the bth transceiver module, so that the ( The (a, aj) position information in the a, aj) group of detection data and the (b, bj) position information in the (b, bj) group of detection data are transformed into the same coordinate system to obtain the (a , aj) conversion position information and (b, bj) conversion position information; comparison unit 332, said comparison unit 332 is suitable for comparing said (a, aj) conversion position information and said (b, bj) conversion position information Position information, when the difference between the (a, aj)th converted position information and the (b, bj) converted position information is within the preset range, judge the (a, aj)th group of detection data and the (b, bj)th group of detection data The group of detection data corresponds to the same target to be measured.

In some embodiments of the present invention, the (a, aj)th conversion position information and the (b, bj)th conversion position information are both position information in the world coordinate system, that is, the conversion unit 331 makes the (a, aj)th conversion position information The (a, aj)th position information in the ) group of detection data and the (b, bj)th position information in the (b, bj) group of detection data are both converted to the world coordinate system.

In other embodiments of the present invention, the (a, aj)th converted position information may also be the position information in the coordinate system of the bth transceiver module, or the (b, bj)th converted position information may also be the position information of the ath transceiver module The location information in the coordinate system, that is, the conversion unit converts the (a, aj)th location information and the (b, bj)th location information to the coordinate system of one of the ath transceiver module and the bth transceiver module.

Referring to FIG. 14 , it shows a functional block diagram of another embodiment of the apparatus for measuring motion speed by lidar according to the present invention.

In some embodiments of the present invention, the method for measuring the motion speed by the lidar is applied in the field of automatic driving. Since the automatic driving technology mainly focuses on the movement of the target to be measured in the horizontal plane, the preset plane is a horizontal plane; or, the preset plane is a plane whose vertical field of view of the lidar is 0°; Alternatively, the lidar has a rotation axis, and the preset plane is a plane perpendicular to the rotation axis.

Specifically, as shown in FIG. 14 , the speed module 340 includes: a direction angle unit 341, and the direction angle unit 341 is adapted to use the (i, j)th position information and The position information of the i-th transceiver module obtains the (i, j) radial direction angle, wherein the (i, j) radial direction angle refers to the direction in which the i-th transceiver device points to the target to be measured; the calculation unit 343, The calculation unit 343 is adapted to be at least based on the (a, aj)th radial velocity, the (a, aj)th radial direction angle, the (b, bj)th radial velocity and the (b, bj)th radial direction angle , to obtain the motion rate and motion direction angle.

11, the velocity module 340 is also adapted to obtain the (i, j)th projection angle γ from the i-th transceiver module 310, and the (i, j)-th projection angle γ is the first i-th transceiver module 310 transmitted j is the angle between the detection beam and the preset plane; combined with the (i, j)th projection angle γ, the movement speed in the preset plane is obtained. Therefore, the velocity module 340 is suitable for combining the (i, j)th projection angle γ to obtain the movement velocity vr// in the preset plane.

It should be noted that, in the process of obtaining the (i, j)th projection angle γ by the velocity module 340, a coordinate system is established with the position of the i-th transceiver module as the origin and the direction perpendicular to the preset plane as the z-axis, Therefore, the preset plane is the xoy plane.

Specifically, as shown in FIG. 14, the velocity module 340 further includes: a projection unit 342, which is suitable for according to the (i, j)th radial velocity v _ri and the (i, jth) ) projection angle γ, to obtain the (i, j) projected radial velocity v _ri// , the (i, j) projected radial velocity is the radial movement velocity of the target to be measured in the preset plane ; The calculation unit 343 is suitable for according to the (a, aj)th position information, the (b, bj)th position information, the (a, aj)th projected radial velocity and the (b, bj) Projecting the radial velocity, combining the position information of the a-th transceiver module and the b-th transceiver module to obtain the moving velocity of the target to be measured in the preset plane.

That is to say, based on the (a, aj) group of detection data obtained by the a-th transceiver module and the (b, bj)-th group of detection data obtained by the b-th transceiver module, the calculation unit 343 can obtain the following relationship:

v _r1// ＝V _// cos(θ ₁ -α) (4)

v _{r2 //} ＝V _// cos(θ ₂ -α) (5)

Among them, α represents the angle between the moving speed of the target to be measured in the preset plane and the positive direction of the abscissa + x; v _{r1 //} represents the radial velocity obtained in the radial direction of the ath transceiver module in the preset The projection in the plane, that is, the (a, aj) projected radial rate; v _r2// represents the projection of the radial rate obtained in the radial direction of the bth transceiver module in the preset plane, that is, the (b, bj)th ) projected radial rate; θ1 represents the angle between the radial direction of the target to be measured relative to the a-th transceiver module in the preset plane and the abscissa x; θ2 represents the target to be measured in the preset plane relative to the b-th transceiver module The angle between the radial direction of and the abscissa x. The speed module 340 obtains V _// by solving the simultaneous binary linear equation of formulas (4) and (5), which is also the projection component of the moving speed of the target to be measured in the preset plane.

In other embodiments of the present invention, when the moving speed of the target to be measured is obtained based on the (c, cj) group of detection data of the c-th transceiver module or more detection data of more transceiver modules, multiple V _// can be obtained and obtained The average value is used as the projected component of the moving speed of the target to be measured in the preset plane, and will not be repeated here.

Referring to FIG. 15 , it shows a functional block diagram of another embodiment of the apparatus for measuring motion speed by laser radar according to the present invention.

In some embodiments of the present invention, the i-th transceiver module (not shown in the figure) emits N _i probe beams to perform a frame scan; the data module (not shown in the figure) is suitable for obtaining the i-th transceiver One frame of scanning data of the module, the one frame of scanning data of the i-th transceiver module includes: N _i groups of detection data. Wherein, the (i, j)th detection data is obtained according to the i-th transceiver module receiving the j-th echo beam, wherein the j-th echo beam is formed by the j-th detection beam emitted by the i-th transceiver module, 1≦j≦N _i .

In some embodiments of the present invention, the device for measuring motion speed by lidar is applied in the field of automatic driving. Especially for short-distance, large-volume targets to be measured (such as short-distance buses, etc.), relative to the lidar, its vertical pitch angle is relatively large, that is, within the vertical field of view, the The range covered by the target to be measured is relatively large, and the use of data at different vertical angles can effectively reduce the deviation of the results caused by measurement errors.

Based on the same resolution, for close-range targets to be measured (for example, within 50m or within 20m), the data module can obtain more detection data groups of the same target to be measured, for example, a vehicle can detect Hundreds of sets of detection data, that is, these hundreds of sets of detection data correspond to the same target to be measured. It can be seen that the speed module 340 can effectively reduce measurement errors and improve calculation accuracy through comprehensive processing of multiple sets of detection data corresponding to the same target to be measured. Moreover, the method of comprehensively processing multiple sets of detection data to reduce measurement errors has high judgment accuracy and is more suitable for use scenarios on urban roads.

Specifically, as shown in FIG. 15, the speed module 340 further includes: a fitting unit 344, which is adapted to perform cosine curve fitting according to the multiple sets of detection data to obtain the target to be measured. speed of movement.

In order to improve calculation accuracy and control errors, the multiple sets of detection data used for cosine curve fitting must correspond to the same target; and the number of sets of the multiple sets of detection data must reach a certain number.

Therefore, as shown in FIG. 12 , when the screening module 330 judges that the multiple sets of detection data correspond to the same target to be measured, the fitting unit 344 performs cosine curve fitting according to the multiple sets of detection data.

Specifically, the d1th transceiver module emits N _d1 probe beams to perform a frame scan, and the data module obtains a frame of scan data of the d1th transceiver module, and a frame of scan data of the d1th transceiver module includes: N _{The d1} group of detection data, wherein, the n1 group of detection data corresponds to a target to be measured; similarly, the e1th transceiver module emits a N _e1 detection beam to perform a frame scan, and the data module obtains the e1th transceiver module. One frame of scanning data, the one frame of scanning data of the d1-th transceiver module includes: N _e1 sets of detection data, wherein n2 sets of detection data correspond to the target to be measured.

It should be noted that, in some embodiments of the present invention, the device further includes: a screening module 330, after the i-th transceiver module performs a frame scan and obtains a frame of scan data, the screening module 330 is suitable for judging a frame of scan data Whether the N _i groups of detection data in are corresponding to the same target to be measured, so as to obtain n _i groups of detection data corresponding to a target to be measured. Specifically, the discrimination module 330 may determine that the detection data correspond to the same target to be detected according to the difference of the position information of the n _i groups of detection data within a preset range.

In some embodiments of the present invention, the screening module 330 performs coordinate transformation on the N _d sets of detection data and the Ne set of detection data, and according to the position information difference after conversion between the _nd sets of detection data and the _{n e} _sets of detection data If the value is within a preset range, it is determined that the _nd group of detection data and the _ne group of detection data correspond to the same target to be measured. Further, the screening module 330 adopts a clustering algorithm to the n _d groups of detection data to further judge whether they correspond to the same target to be measured, and obtain n1 groups of detection data corresponding to the same target to be measured; The n _e groups of detection data use a clustering algorithm to further judge whether they correspond to the same target to be measured, and obtain n2 groups of detection data corresponding to the same target to be measured. In this way, multiple sets of detection data corresponding to the same target to be measured among the detection data of the multiple transceiver modules are obtained.

The aforementioned calculation formulas (4) and (5) can be regarded as cosine curves determined by the amplitude V _// and the phase α, and the n1 sets of detection data and n2 sets of detection data corresponding to the same target to be measured are distributed in the amplitude On cosine curves that are equal and have the same phase. Therefore, the fitting unit 344 performs cosine curve fitting based on the n1 group of detection data and the n2 group of detection data respectively, and can obtain corresponding calculation formulas (4) and (5) respectively; the speed module 340 obtains according to the fitting The calculation formulas (4) and (5) can then determine the amplitude V _// and phase α. Specifically, in some embodiments of the present invention, the fitting unit 344 uses the least square method to fit the cosine curve.

In addition, the present invention also provides a control system, and the control system is an automatic driving system.

Specifically, the control system includes: a measuring device and a control device; wherein the measuring device is a device for measuring the moving speed of the laser radar of the present invention; the controlling device is suitable for controlling the vehicle in combination with the moving speed obtained by the measuring device.

The measuring device is the device for measuring the speed of motion by laser radar of the present invention, so the specific technical solution of the measuring device refers to the description of the embodiment of the device for measuring motion speed by laser radar, and the present invention will not repeat them here.

Since the measuring device detects the target to be measured through two or more transceiver modules separated by a preset distance, the motion of the target to be measured can be obtained on the basis of one frame of data through the functional relationship between the motion speed and the detection data. The speed can avoid the decision-making delay problem caused by multi-frame data processing, and can effectively improve the detection and calculation speed.

Moreover, in some embodiments, the measuring device can obtain the moving speed of the target to be measured by fitting curves of multiple sets of detection data in one frame of scanning data. The comprehensive processing of multiple groups of detection data corresponding to the same detection target can effectively reduce measurement errors and improve calculation accuracy; the reduction of the measurement device error can effectively improve the judgment accuracy of the control system, so that all The above control system is more suitable for the usage scenarios of urban roads.

To sum up, the technical solution of the present invention obtains detection data through multiple transceiver modules, and on the basis of the detection data, combined with the position information of the transceiver modules, the moving speed of the target to be measured is obtained. Since there is a preset distance between the multiple transceiver modules, the obtained moving speed is a vector speed, that is, the moving speed includes a moving speed and a moving direction angle. The acquisition of the vector velocity can more accurately reflect the actual motion of the target to be measured, and can effectively improve the accuracy and precision of vehicle control. In the optional solution of the present invention, especially for short-distance targets, the detection data is obtained by obtaining one frame of scanning data, and the obtained one frame of scanning data includes one or more i-th groups of detection data, which can be based on multiple The i group of detection data is fitted with a cosine curve to obtain the i-th fitting curve; the movement speed can be obtained according to multiple fitting curves, so as to improve measurement accuracy and reduce measurement error. In the optional solution of the present invention, the emission angle of the corresponding detection beam can be obtained from the transceiver module as the projection angle; combined with the projection angle, the movement speed in the preset plane can be obtained, thereby converting the movement speed in three-dimensional space into The movement speed in the preset plane can effectively shorten the processing time and improve the processing efficiency. Especially for the field of automatic driving, the preset plane can be the horizontal plane that is more interesting for automatic driving, so as to ensure the measurement accuracy and measurement speed at the same time.

Although the present invention is disclosed above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, so the protection scope of the present invention should be based on the scope defined in the claims.

Claims

A method for measuring motion speed by laser radar, characterized in that, comprising:

Provide M transceiver modules, where M≧2;

The i-th transceiver module transmits the j-th probe beam and receives the j-th echo beam, and the j-th probe beam is reflected to form the j-th echo beam, where 1≦i≦M, 1≦j≦N i ;

According to the jth echo beam, the (i, j)th group of detection data is obtained, and the (i, j)th group of detection data includes: the (i, j)th position information and the (i, j)th radial direction rate;

At least according to the (a, aj) group of detection data and the (b, bj) group of detection data, combined with the position information of the ath transceiver module and the position information of the bth transceiver module, the moving speed of the target to be measured is obtained, wherein, 1≦a≦M, 1≦b≦M, 1≦aj≦N a , 1≦bj≦N b , and a≠b, there is a preset distance between the ath transceiver module and the bth transceiver module.
The method according to claim 1, wherein before obtaining the moving speed of the target to be measured, the method further comprises: judging the (a, aj)th group of detection data and the (b, bjth) group ) whether the group detection data correspond to the same target to be tested.
The method according to claim 2, wherein the step of judging whether the (a, aj) group of detection data and the (b, bj) group of detection data correspond to the same target to be measured comprises:

According to the position information of the ath transceiver module and the position information of the bth transceiver module, coordinate transformation is performed, so that the (a, aj)th position information in the (a, aj)th group of detection data and the (b, aj)th group of detection data and the (b, bj) The (b, bj) position information in the group of detection data is converted to the same coordinate system, and the (a, aj) conversion position information and the (b, bj) conversion position information are obtained;

Comparing the (a, aj)th conversion position information with the (b, bj)th conversion position information, the difference between the (a, aj)th conversion position information and the (b, bj)th conversion position information is in the preset When it is within the range, it is determined that the (a, aj) group of detection data and the (b, bj) group of detection data correspond to the same target to be measured.
The method according to claim 1, wherein the speed of motion comprises: speed of motion and angle of motion direction;

The step of obtaining the moving speed of the target to be measured comprises:

Obtain the (i, j)th radial direction angle according to the (i, j)th position information in the (i, j)th group of detection data and the position information of the ith transceiver module;

According to at least (a, aj)th radial velocity, (a, aj) radial direction angle, (b, bj)th radial velocity and (b, bj)th radial direction angle, obtain said motion rate and angle of motion.
The method according to claim 1 or 4, wherein the step of transmitting the j-th probe beam through the i-th transceiver module comprises: obtaining the (i, j) projection angle, and the (i, j) projection angle is The included angle between the jth detection beam emitted by the ith transceiver module and the preset plane;

In the step of obtaining the moving speed of the target to be measured, the moving speed in a preset plane is obtained in combination with the (i, j)th projection angle.
The method according to claim 5, wherein the step of obtaining the movement speed in the preset plane comprises:

According to the (i, j) radial velocity and the (i, j) projection angle, the (i, j) projected radial velocity is obtained, and the (i, j) projected radial velocity is the Describe the radial movement speed of the target to be measured in the preset plane;

According to the (a, aj)th position information, the (b, bj)th position information, the (a, aj)th projected radial velocity and the (b, bj)th projected radial velocity, combined The position information of the a-th transceiver module and the b-th transceiver module is used to obtain the moving speed of the target to be measured in the preset plane.
The method according to claim 5, wherein the preset plane is a horizontal plane;

Alternatively, the preset plane is a plane whose vertical field of view of the lidar is 0°;

Alternatively, the lidar has a rotation axis, and the preset plane is a plane perpendicular to the rotation axis.
The method according to claim 2 or 3, wherein the step of transmitting the jth detection beam through the i-th transceiver module comprises: transmitting N i beams of detection beams through the i-th transceiver module to perform a frame scan to obtain the One frame of scan data of the i-th transceiver module, the one-frame scan data of the i-th transceiver module includes: N i groups of detection data.
The method according to claim 8, wherein the step of obtaining the moving speed of the target to be measured further comprises:

According to multiple sets of detection data, cosine curve fitting is performed to obtain the moving speed of the target to be measured.
The method according to claim 9, wherein after obtaining a frame of scan data of the i-th transceiver module, before performing cosine curve fitting, the step of obtaining the moving speed of the target to be measured further comprises:

Judging whether the multiple sets of detection data correspond to the same target to be measured; when judging that the multiple sets of detection data correspond to the same target to be measured, performing cosine curve fitting according to the multiple sets of detection data.
The method according to claim 1, wherein the step of providing M transceiver modules comprises: providing a laser radar, the laser radar including the M transceiver modules;

Alternatively, the step of providing M transceiver modules includes: providing multiple laser radars, the multiple laser radars including the M transceiver modules.
A device for measuring the speed of motion by laser radar, characterized in that it comprises:

M transceiver modules, where M≧2;

The i-th transceiver module transmits the j-th probe beam and receives the j-th echo beam, and the j-th probe beam is reflected to form the j-th echo beam, wherein, 1≦i≦M, 1≦j≦N i ;

A data module, the data module is adapted to obtain the (i, j)th group of detection data according to the jth echo beam, and the (i, j)th group of detection data includes: (i, j)th position information and the (i, j)th radial velocity;

A speed module, the speed module is adapted to obtain at least according to the (a, aj) group of detection data and the (b, bj) group of detection data, combined with the position information of the ath transceiver module and the position information of the bth transceiver module The moving speed of the target to be measured, wherein, 1≦a≦M, 1≦b≦M, 1≦aj≦N a , 1≦bj≦N b , and a≠b, between the ath transceiver module and the bth transceiver module There is a preset distance between them.
The device according to claim 12, further comprising: a screening module adapted to judge whether the (a, aj)th group of detection data and the (b, bj)th group of detection data are Corresponding to the same target to be tested.
The device according to claim 13, wherein the screening module comprises:

A conversion unit, the conversion unit is adapted to perform coordinate conversion according to the position information of the ath transceiver module and the position information of the bth transceiver module, so that the (a, aj)th group of detection data in the (a, aj)th group The position information and the (b, bj)th position information in the (b, bj)th group of detection data are converted to the same coordinate system, and the (a, aj)th converted position information and the (b, bj)th converted position are obtained information;

a comparison unit adapted to compare said (a, aj)th conversion location information with said (b, bj)th conversion location information, and said (a, aj)th conversion location information with said (b, bj)th ) when the difference between the converted position information is within a preset range, it is determined that the (a, aj) group of detection data and the (b, bj) group of detection data correspond to the same target to be measured.
The device according to claim 12, wherein the movement speed comprises: movement rate and movement direction angle;

The velocity module includes:

A direction angle unit, the direction angle unit is adapted to obtain the (i, j)th path according to the (i, j)th position information in the (i, j)th group of detection data and the position information of the i-th transceiver module direction angle;

a calculation unit adapted to be based on at least the (a, aj)th radial velocity, the (a, aj)th radial direction angle, the (b, bj)th radial velocity and the (b, bj)th radial Direction Angle, get the motion rate and motion direction angle.
The device according to claim 12 or 15, wherein the velocity module is further adapted to obtain the (i, j) projection angle from the i-th transceiver module, and the (i, j) projection angle is the i-th projection angle The included angle between the jth detection beam emitted by the transceiver module and the preset plane; combined with the (i, j)th projection angle, the movement speed in the preset plane is obtained.
The apparatus of claim 16, wherein the velocity module further comprises:

a projection unit adapted to obtain the (i,j)th projected radial velocity according to the (i,j)th radial velocity and the (i,j)th projection angle, the (ith , j) projected radial velocity is the radial movement velocity of the target to be measured in the preset plane;

The velocity module is adapted to be based on the (a, aj)th position information, the (b, bj)th position information, the (a, aj)th projected radial velocity and the (b, bj)th Projecting the radial velocity, combined with the position information of the a-th transceiver module and the b-th transceiver module, obtains the moving velocity of the target to be measured in a preset plane.
The device according to claim 16, wherein the preset plane is a horizontal plane;

Alternatively, the preset plane is a plane with a vertical viewing angle of 0°;

Alternatively, the lidar has a rotation axis, and the preset plane is a plane perpendicular to the rotation axis.
The device according to claim 12, wherein the i-th transceiver module emits N i probe beams to scan a frame; the data module is suitable for obtaining a frame of scan data of the i-th transceiver module, so A frame of scanning data of the i-th transceiver module includes: N i groups of detection data.
The apparatus of claim 19, wherein the velocity module further comprises:

A fitting unit, the fitting unit is suitable for performing cosine curve fitting according to multiple sets of detection data to obtain the moving speed of the target to be measured.
The device according to claim 20, wherein when the discrimination module judges that the multiple sets of detection data correspond to the same target to be measured, the fitting unit performs cosine curve fitting according to the multiple sets of detection data.
The device according to claim 12, characterized in that, comprising: a lidar, the lidar comprising the M transceiver modules;

Alternatively, it includes: multiple laser radars, where the multiple laser radars include the M transceiver modules.
A control system, the control system is an automatic driving control system, characterized in that it includes:

A measuring device, the measuring device is the device for measuring the movement speed of the lidar according to any one of claims 12-22;

control means adapted to control the vehicle in conjunction with the speed of movement obtained by the measuring means.