WO2020177076A1

WO2020177076A1 - Detection apparatus initial-state calibration method and apparatus

Info

Publication number: WO2020177076A1
Application number: PCT/CN2019/076995
Authority: WO
Inventors: 吴特思; 陈涵; 许友
Original assignee: 深圳市大疆创新科技有限公司
Priority date: 2019-03-05
Filing date: 2019-03-05
Publication date: 2020-09-10
Also published as: CN111902732A

Abstract

The embodiments of the present invention provide a detection apparatus initial-state calibration method and apparatus. The method comprises: obtaining an echo signal generated by a detection apparatus transmitting a signal to a target scene, said target scene comprising a target reflection object, said transmission signal and said echo signal passing through the first optical device and the second optical device; determining point cloud data of the target reflection object according to the echo signal; according to said point cloud data, calculating a first zero position offset corresponding to the first optical device and a second zero position offset corresponding to the second optical device. Thus fully automatic calibration of the initial state of the detection apparatus can be achieved, improving the efficiency of initial state calibration.

Description

Calibration method and device for initial state of detection device

Technical field

The invention relates to the field of detection technology, in particular to a method and device for initial state calibration of a detection device.

Background technique

Detection devices such as lidar can emit detection signals in different directions, and obtain depth information and reflectivity information of objects based on echoes in different directions. Before the laser radar and other detection devices are officially put into use, in order to overcome the measurement error introduced by the installation error in the installation process of the detection device, and to improve the detection accuracy of the detection device in the working process, it is necessary to perform the initial state of the detection device such as the laser radar. Calibration. In related technologies, when performing initial state calibration for detection devices such as lidar, automatic calibration cannot be achieved, and there is a defect of low efficiency.

Summary of the invention

The embodiment of the present invention provides a method and device for calibrating the initial state of the detection device to improve the efficiency of calibration.

In the first aspect, an embodiment of the present invention provides an initial state calibration method of a detection device, characterized in that the detection device includes a first optical device and a second optical device, and the method includes:

Acquire an echo signal generated by the detection device transmitting a signal to a target scene, the target scene including a target reflector, the transmission signal and the echo signal passing through the first optical device and the second optical device ；

Determining the point cloud data of the target reflector according to the echo signal;

According to the point cloud data, a first zero deviation corresponding to the first optical device and a second zero deviation corresponding to the second optical device are calculated.

In the second aspect, an embodiment of the present invention provides an initial state calibration device of a detection device, which includes at least a memory and a processor; the memory is connected to the processor through a communication bus, and is used to store executable files that are executable by the processor. Computer instructions; the processor is used to read computer instructions from the memory to achieve:

Acquire an echo signal generated by the detection device transmitting a signal to a target scene, the target scene including a target reflector, the detection device including a first optical device and a second optical device, the transmission signal and the echo The signal passes through the first optical device and the second optical device;

In a third aspect, an embodiment of the present invention provides a computer-readable storage medium on which a computer program is stored, and when the program is executed by a processor, the steps of any one of the methods in the first aspect are implemented.

In the embodiment of the present invention, the echo signal generated by the detection device transmitting the signal to the target scene is obtained, the point cloud data of the target reflector is determined according to the echo signal, and the corresponding first optical device of the detection device is calculated according to the point cloud data The first zero position deviation of the second optical device and the second zero position deviation corresponding to the second optical device can automatically calibrate the initial state of the detection device, which has a simpler and more efficient positive effect.

Description of the drawings

In order to more clearly describe the technical solutions in the embodiments of the present invention, the following will briefly introduce the accompanying drawings used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative labor.

Figure 1 is a block diagram of a detection device provided by an embodiment of the present invention;

2 is a schematic structural diagram of a detection device using a coaxial optical path provided by an embodiment of the present invention;

3 is a schematic flowchart of a method for initial state calibration of a detection device provided by an embodiment of the present invention;

FIG. 4 is a schematic flowchart of calculating a first zero deviation corresponding to the first optical device and a second zero deviation corresponding to the second optical device according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of the deviation caused by the installation error of the detection device provided by the embodiment of the present invention;

6 is a schematic diagram of a scene of initial state calibration provided by an embodiment of the present invention;

Fig. 7 is a block diagram of an initial state calibration device of a detection device according to an embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

In order to ensure the accuracy of detection devices such as lidars in the working process, detection devices such as lidars need to be calibrated in the initial state before they are used. Considering that in the prior art, when calibrating the initial state of a detection device such as a lidar, automatic calibration cannot be achieved, and manual calculation and judgment are required, which is inefficient. Based on this, the embodiment of the present invention provides an initial state calibration method and device of a detection device.

The aforementioned detection device may be electronic equipment such as laser radar and laser ranging equipment. In one embodiment, the detection device is used to sense external environmental information, for example, distance information, orientation information, reflection intensity information, speed information, etc. of environmental targets. In one implementation, the detection device can detect the distance between the detection device and the detection device by measuring the time of light propagation between the detection device and the detection object, that is, Time-of-Flight (TOF). Alternatively, the detection device can also use other technologies to detect the distance between the detection object and the detection device, such as a ranging method based on phase shift measurement or a ranging method based on frequency shift measurement. Do restrictions.

For ease of understanding, the working process of distance measurement will be described by an example in conjunction with the detection device 100 shown in FIG. 1.

As shown in FIG. 1, the detection device 100 may include a transmitting circuit 110, a receiving circuit 120, a sampling circuit 130 and an arithmetic circuit 140.

The transmitting circuit 110 may emit a light pulse sequence (for example, a laser pulse sequence). The receiving circuit 120 may receive the light pulse sequence reflected by the object to be detected, and perform photoelectric conversion on the light pulse sequence to obtain an electrical signal. After processing the electrical signal, it may be output to the sampling circuit 130. The sampling circuit 130 may sample the electrical signal to obtain the sampling result. The arithmetic circuit 140 may determine the distance between the detection device 100 and the detected object based on the sampling result of the sampling circuit 130.

Optionally, the detection device 100 may further include a control circuit 150 that can control other circuits, for example, can control the working time of each circuit and/or set parameters for each circuit.

It should be understood that although the detection device shown in FIG. 1 includes a transmitting circuit, a receiving circuit, a sampling circuit, and an arithmetic circuit for emitting a beam for detection, the embodiment of the present application is not limited to this, the transmitting circuit, The number of any one of the receiving circuit, the sampling circuit, and the arithmetic circuit can also be at least two, which are used to emit at least two beams in the same direction or in different directions; wherein, the at least two beams can be emitted simultaneously , It can also be launched at different times. In an example, the light-emitting chips in the at least two transmitting circuits are packaged in the same module. For example, each emitting circuit includes a laser emitting chip, and the dies in the laser emitting chips in the at least two emitting circuits are packaged together and housed in the same packaging space.

In some implementations, in addition to the circuit shown in FIG. 1, the detection device 100 may further include a scanning module 160 for changing the propagation direction of at least one laser pulse sequence emitted by the transmitting circuit.

Among them, the module including the transmitting circuit 110, the receiving circuit 120, the sampling circuit 130, and the arithmetic circuit 140, or the module including the transmitting circuit 110, the receiving circuit 120, the sampling circuit 130, the arithmetic circuit 140, and the control circuit 150 may be referred to as the measuring circuit. The distance measurement module 150 can be independent of other modules, for example, the scanning module 160.

A coaxial optical path can be used in the detection device, that is, the beam emitted by the detection device and the reflected beam share at least part of the optical path in the detection device. For example, after at least one laser pulse sequence emitted by the transmitter circuit changes its propagation direction and exits through the scanning module, the laser pulse sequence reflected by the probe passes through the scanning module and then enters the receiving circuit. Alternatively, the detection device may also adopt an off-axis optical path, that is, the light beam emitted by the detection device and the reflected light beam are respectively transmitted along different optical paths in the detection device. Fig. 2 shows a schematic diagram of an embodiment in which the detection device of the present invention adopts a coaxial optical path.

The detection device 200 includes a ranging module 210, which includes a transmitter 203 (which may include the above-mentioned transmitting circuit), a collimating element 204, a detector 205 (which may include the above-mentioned receiving circuit, sampling circuit, and arithmetic circuit), and an optical path Change element 206. The ranging module 210 is used to emit a light beam, receive the return light, and convert the return light into an electrical signal. Among them, the transmitter 203 can be used to emit a light pulse sequence. In one embodiment, the transmitter 203 may emit a sequence of laser pulses. Optionally, the laser beam emitted by the transmitter 203 is a narrow-bandwidth beam with a wavelength outside the visible light range. The collimating element 204 is arranged on the exit light path of the emitter, and is used to collimate the light beam emitted from the emitter 203, and collimate the light beam emitted from the emitter 203 into parallel light and output to the scanning module. The collimating element is also used to condense at least a part of the return light reflected by the probe. The collimating element 204 may be a collimating lens or other elements capable of collimating light beams.

In the embodiment shown in FIG. 2, the light path changing element 206 is used to combine the transmitting light path and the receiving light path in the detection device before the collimating element 204, so that the transmitting light path and the receiving light path can share the same collimating element, making the light path more compact. In some other implementation manners, the transmitter 203 and the detector 205 may respectively use their own collimating elements, and the optical path changing element 206 is arranged on the optical path behind the collimating element.

In the embodiment shown in FIG. 2, since the beam aperture emitted by the transmitter 203 is relatively small, and the beam aperture of the return light received by the detection device is relatively large, the optical path changing element can use a small-area mirror to combine the emission light path with The receiving light path is combined. In some other implementations, the light path changing element may also use a reflector with a through hole, where the through hole is used to transmit the emitted light of the emitter 203 and the reflector is used to reflect the return light to the detector 205. In this way, the shielding of the back light by the bracket of the small mirror in the case of using the small mirror can be reduced.

In the embodiment shown in FIG. 2, the optical path changing element deviates from the optical axis of the collimating element 204. In some other implementation manners, the optical path changing element may also be located on the optical axis of the collimating element 204.

The detection device 200 further includes a scanning module 202. The scanning module 202 is placed on the exit light path of the distance measuring module 201. The scanning module 202 is used to change the transmission direction of the collimated beam 219 emitted by the collimating element 204 and project it to the external environment, and project the return light to the collimating element 204 . The returned light is collected on the detector 205 via the collimating element 204.

In an embodiment, the scanning module 202 may include at least one optical element for changing the propagation path of the light beam, wherein the optical element may change the propagation path of the light beam by reflecting, refracting, or diffracting the light beam. For example, the scanning module 202 includes a lens, a mirror, a prism, a galvanometer, a grating, a liquid crystal, an optical phased array (Optical Phased Array), or any combination of the foregoing optical elements. In an example, at least part of the optical elements are moving. For example, a driving module is used to drive the at least part of the optical elements to move. The moving optical elements can reflect, refract, or diffract the light beam to different directions at different times. In some embodiments, the multiple optical elements of the scanning module 202 may rotate or vibrate around a common axis 209, and each rotating or vibrating optical element is used to continuously change the propagation direction of the incident light beam. In one embodiment, the multiple optical elements of the scanning module 202 may rotate at different speeds or vibrate at different speeds. In another embodiment, at least part of the optical elements of the scanning module 202 may rotate at substantially the same rotation speed. In some embodiments, the multiple optical elements of the scanning module may also be rotated around different axes. In some embodiments, the multiple optical elements of the scanning module may also rotate in the same direction or in different directions; or vibrate in the same direction, or vibrate in different directions, which is not limited herein.

In one embodiment, the scanning module 202 includes a first optical element 214 and a driver 216 connected to the first optical element 214. The driver 216 is used to drive the first optical element 214 to rotate around the rotation axis 209 to change the first optical element 214. The direction of the beam 219 is collimated. The first optical element 214 projects the collimated light beam 219 to different directions. In one embodiment, the angle between the direction of the collimated beam 219 changed by the first optical element and the rotation axis 209 changes as the first optical element 214 rotates. In one embodiment, the first optical element 214 includes a pair of opposed non-parallel surfaces through which the collimated light beam 219 passes. In one embodiment, the first optical element 214 includes a prism whose thickness varies in at least one radial direction. In one embodiment, the first optical element 214 includes a wedge prism, and the collimated beam 219 is refracted.

In one embodiment, the scanning module 202 further includes a second optical element 215, the second optical element 215 rotates around the rotation axis 209, and the rotation speed of the second optical element 215 is different from the rotation speed of the first optical element 214. The second optical element 215 is used to change the direction of the light beam projected by the first optical element 214. In one embodiment, the second optical element 215 is connected to another driver 217, and the driver 217 drives the second optical element 215 to rotate. The first optical element 214 and the second optical element 215 can be driven by the same or different drivers, so that the rotation speed and/or rotation of the first optical element 214 and the second optical element 215 are different, so as to project the collimated light beam 219 to the outside space. Different directions can scan a larger space. In one embodiment, the controller 218 controls the

drivers

216 and 217 to drive the first optical element 214 and the second optical element 215, respectively. The rotational speeds of the first optical element 214 and the second optical element 215 may be determined according to the area and pattern expected to be scanned in actual applications. The

drivers

216 and 217 may include motors or other drivers.

In one embodiment, the second optical element 215 includes a pair of opposite non-parallel surfaces through which the light beam passes. In one embodiment, the second optical element 215 includes a prism whose thickness varies in at least one radial direction. In one embodiment, the second optical element 215 includes a wedge prism.

In an embodiment, the scanning module 202 further includes a third optical element (not shown) and a driver for driving the third optical element to move. Optionally, the third optical element includes a pair of opposite non-parallel surfaces, and the light beam passes through the pair of surfaces. In one embodiment, the third optical element includes a prism whose thickness varies in at least one radial direction. In one embodiment, the third optical element includes a wedge prism. At least two of the first, second, and third optical elements rotate at different rotation speeds and/or rotation directions.

The rotation of each optical element in the scanning module 202 can project light to different directions, such as

directions

211 and 213, so that the space around the detection device 200 is scanned. When the light 211 projected by the scanning module 202 hits the detection object 201, a part of the light is reflected by the detection object 201 to the detection device 200 in a direction opposite to the projected light 211. The return light 212 reflected by the probe 201 is incident on the collimating element 204 after passing through the scanning module 202.

The detector 205 and the transmitter 203 are placed on the same side of the collimating element 204, and the detector 205 is used to convert at least part of the return light passing through the collimating element 204 into an electrical signal.

In one embodiment, an anti-reflection film is plated on each optical element. Optionally, the thickness of the antireflection coating is equal to or close to the wavelength of the light beam emitted by the emitter 203, which can increase the intensity of the transmitted light beam.

In one embodiment, a filter layer is plated on the surface of an element located on the beam propagation path in the detection device, or a filter is provided on the beam propagation path for transmitting at least the wavelength band of the beam emitted by the transmitter and reflecting Other bands to reduce the noise caused by ambient light to the receiver.

In some embodiments, the transmitter 203 may include a laser diode through which nanosecond laser pulses are emitted. Further, the laser pulse receiving time can be determined, for example, the laser pulse receiving time can be determined by detecting the rising edge time and/or the falling edge time of the electrical signal pulse. In this way, the detection device 200 can calculate the TOF using the pulse receiving time information and the pulse sending time information, so as to determine the distance between the detection object 201 and the detection device 200.

The distance and orientation detected by the detection device 200 can be used for remote sensing, obstacle avoidance, surveying and mapping, modeling, navigation, and the like. In one embodiment, the detection device of the embodiment of the present invention can be applied to a mobile platform, and the detection device can be installed on the platform body of the mobile platform. A mobile platform with a detection device can measure the external environment, for example, measuring the distance between the mobile platform and an obstacle for obstacle avoidance and other purposes, and for two-dimensional or three-dimensional mapping of the external environment. In some embodiments, the mobile platform includes at least one of an unmanned aerial vehicle, a car, a remote control car, a robot, and a camera. When the detection device is applied to an unmanned aerial vehicle, the platform body is the fuselage of the unmanned aerial vehicle. When the detection device is applied to a car, the platform body is the body of the car. The car can be a self-driving car or a semi-automatic driving car, and there is no restriction here. When the detection device is applied to a remote control car, the platform body is the body of the remote control car. When the detection device is applied to a robot, the platform body is a robot. When the detection device is applied to a camera, the platform body is the camera itself.

Please refer to FIG. 2, the detection device includes a scanning module 202, and a driver 216 and a driver 217 respectively drive the first optical element 214 and the second optical element 215 to rotate to change the direction of laser emission. The first optical element 214 and the second optical element 215 will introduce zero deviation during the installation process, which are respectively the first zero deviation and the second zero deviation, which will cause errors in scene imaging; the purpose of initial state calibration includes The first zero position deviation and the second zero position deviation respectively corresponding to the first optical element 214 and the second optical element 215 are obtained.

FIG. 3 is a schematic flowchart of a method for calibrating the initial state of a detection device according to an embodiment of the present invention; the detection device includes: a first optical device and a second optical device. The method can be applied to the detection device itself or It is applied to the upper computer and other devices; the method includes the following steps S100-S102:

S100. Obtain an echo signal generated by the detection device transmitting a signal to a target scene, where the target scene includes a target reflector, and the transmitted signal and the echo signal pass through the first optical device and the second optical device. optical instrument.

In this embodiment, the detection device transmits a signal to a target scene, the target scene contains a target reflector, and the target reflector reflects the signal emitted by the detection device, so that the echo signal generated by the target reflector can be obtained. The transmitted signal and the echo signal pass through the first optical device and the second optical device.

S101. Determine point cloud data of the target reflector according to the echo signal.

After obtaining the echo signal of the target reflector, the depth information and angle information of the target reflector can be calculated, and then the point cloud data of the target reflector can be determined.

S102. Calculate a first zero deviation corresponding to the first optical device and a second zero deviation corresponding to the second optical device according to the point cloud data.

In the embodiment of the present application, the echo signal generated by the detection device transmitting the signal to the target scene is obtained, the point cloud data of the target reflector is determined according to the echo signal, and the first optical device corresponding to the detection device is calculated according to the point cloud data The first zero deviation and the second zero deviation corresponding to the second optical device can realize the fully automatic calibration of the initial state of the detection device. Compared with the method of manual calculation and judgment in the calibration process of the prior art, it has more Simple and efficient positive effect.

4 is a schematic diagram of a process for calculating a first zero deviation corresponding to the first optical device and a second zero deviation corresponding to the second optical device according to an embodiment of the present invention. In this embodiment, the above-mentioned target reflector may include a single reflector. For example, the single target reflector may be a single total reflection patch. Referring to FIG. 4, the method includes the following steps S201-S205:

S201: Calculate a first angle difference between the first zero deviation and the second zero deviation according to the point cloud data of the single reflector.

Before the initial state calibration of the detection device is performed, the point cloud imaging of the single reflector will be separated due to the installation error of the first optical device and the second optical device of the detection device.

The above step S201 specifically includes the following steps A10-A20:

Step A10: Map each point corresponding to the point cloud data of the single reflector to a two-dimensional plane to obtain two sets of point cloud images of the single reflector. Wherein, the two-dimensional plane includes the plane where the single reflector is located.

In this embodiment, in order to avoid inaccurate calculation of the depth of the target reflector caused by the instability of the echo signal of the target reflector, and to improve the accuracy of calibration, each point corresponding to the point cloud data of a single reflector is mapped to a two-dimensional flat. Specifically, each point corresponding to the point cloud data of a single reflector may be projected onto the plane where the single target reflector is located.

Step A20: Calculate the first angle difference between the first zero deviation and the second zero deviation according to the two sets of point cloud imaging of the single reflector.

Optionally, in the above step A20, calculating the first angular difference between the first zero deviation and the second zero deviation according to the two sets of point cloud imaging of the single reflector includes the following steps A201-A203:

Step A201: Calculate the center point coordinates of the two sets of point cloud imaging of the single reflector.

Step A202: Establish a first objective function based on the center point coordinates of the two sets of point cloud imaging of the single reflector.

Optionally, the above-mentioned first objective function is a function for solving the distance between the center points of the two groups of point cloud imaging under different first angle differences.

Step A203: Minimize the first objective function to obtain a first angle difference between the first zero deviation and the second zero deviation.

In this embodiment, by minimizing the above-mentioned first objective function, the first angle difference that minimizes the distance between the center points of the two sets of point cloud imaging is obtained.

A specific calculation example is given. Assuming that the first zero position deviation is ε ₁ , the second zero position deviation is ε ₂ , and the above-mentioned first angle difference is Δε, the following formula (1):

Δε=ε ₂ -ε ₁ (1)

By solving the following formula (2), Δε is found to minimize the distance between the center points of the two sets of point cloud imaging of a single reflector,

Among them, c ₁ and c ₂ respectively represent the coordinates of the center points of the two sets of point cloud imaging, and d(c ₁ , c ₂ ) represents the distance between the center points of the two sets of point cloud imaging.

S202. Calculate the common deviation of the first zero deviation and the second zero deviation according to the point cloud data on the ground, where the point cloud data on the ground is the point cloud data corrected by the first angle difference .

After calculating the first angular difference Δε between the first zero deviation and the second zero deviation, after correcting the detection device by using Δε, two sets of point clouds of a single reflector are obtained The imaging will converge and no separation occurs; however, the position of the point cloud imaging of the single reflector may have an overall offset relative to the real position. The overall offset is determined by the first zero deviation and Caused by the common deviation of the 20th bit deviation. Therefore, it is also necessary to calculate the common deviation of the first zero deviation and the second zero deviation.

Optionally, in the above step S202, calculating the common deviation of the first zero deviation and the second zero deviation according to the point cloud data on the ground includes the following steps B10-B20:

Step B10: According to the point cloud data on the ground, a normal vector for ground imaging is calculated.

In the case of using a single reflector for calibration, the point cloud data of the ground is obtained, and the normal vector of the ground imaging can be calculated according to the point cloud data of the ground. The point cloud data on the ground is the point cloud data corrected by using the first angle difference Δε.

Step B20: Calculate the common deflection angle of the first zero deviation and the second zero deviation according to the projection of the normal vector of the ground imaging on the plane where the single reflector is located.

For example, after obtaining the normal vector of the ground imaging, the angle between the direction vector and the vertical when the normal vector is projected onto the plane where a single reflector is located is the common deflection angle θ.

S203. Calculate the first zero position deviation and the second zero position deviation according to the first angle difference and the common deviation.

According to the above example, after obtaining the first angular difference Δε and the common deflection angle θ between the first deviation and the second deviation, the first zero deviation ε ₁ =θ and the second zero deviation ε ₂ =θ can be obtained. +Δε.

After the calculation of the above steps S201-S203, the initial state calibration work is basically completed, but because the above calculation process only uses a single reflector for calibration, it may cause over-fitting, resulting in the calculation of other angle directions of the field of view There are errors, so performing secondary calibration on the initial state of the detection device can further improve the calibration effect. Furthermore, in an embodiment of the present application, the aforementioned target reflector further includes a reflector array. For example, the reflector array may be a total reflection patch array. After the above step S203, the method further includes the following steps S204-S205:

S204. Calculate the second angular difference between the first zero deviation and the second zero deviation according to the point cloud data of the reflector array, where the point cloud data of the reflector array is passed through the first zero deviation. A point cloud data corrected by the angle difference and the common deviation.

The foregoing calculation of the second angular difference between the first zero deviation and the second zero deviation based on the point cloud data of the reflector array includes the following steps C10-C20:

Step C10: Map each point corresponding to the point cloud data of the reflector array to a two-dimensional plane to obtain two sets of point cloud images of each reflector in the reflector array.

Similarly, in order to improve the accuracy of calibration, each point corresponding to the point cloud data of the reflector array is mapped to a two-dimensional plane; specifically, the point cloud data of the reflector array can be projected onto the plane where the reflector array is located. in.

Step C20: Calculate the second angle difference between the first zero deviation and the second zero deviation according to the two sets of point cloud imaging of each reflector in the reflector array.

Optionally, the calculation of the second angular difference between the first zero deviation and the second zero deviation based on the two sets of point cloud imaging of each reflector in the reflector array includes the following Steps C201-C203:

Step C201: Calculate the center point coordinates of the two sets of point cloud imaging of each reflector in the reflector array.

Step C202: Establish a second objective function based on the center point coordinates of the two sets of point cloud imaging of each reflector in the reflector array.

Step C203: Obtain a second angle difference between the first zero deviation and the second zero deviation by minimizing the second objective function.

Optionally, the second objective function in this embodiment is a function for calculating the root mean square of the distance between the center points of the two sets of point cloud imaging of all reflectors in the reflector array under different second angle differences. By minimizing the second objective function, the second angular difference between the first zero deviation and the second zero deviation is obtained.

S205. Update the first zero position deviation and the second zero position deviation according to the second angle difference.

For example, it can be understood that when the number of reflectors is multiple, the two sets of point cloud imaging of each reflector need to be brought together, and the second angle difference Δε' is calculated according to the following formula (3),

Among them, n is the number of reflectors, c _i1 , c _i2 respectively represent the coordinates of the center point of the i-th reflector two groups of point cloud imaging, d(c _i1 , c _i2 ) represents the i-th reflector two groups of point cloud The distance between the imaging center points.

Calculate Δε' according to the above method, update the first zero position deviation and the second zero position deviation according to the second angle difference, and finally obtain the first zero position deviation ε ₁ =θ, the second zero position deviation ε ₂ =θ+ε ₁ +Δε'.

After the above calculation process, the calibration of the initial state of the detection device is completed.

Taking into account the installation error of the first optical device and the second optical device of the detection device, the deviation of the first refractive surface of the first optical device relative to the drum and the deviation of the second refractive surface of the second optical device relative to the drum will also be introduced. The installation error of the reflecting mirror of the detection device will introduce the deviation of light incidence. In order to correct the above deviation and further improve the accuracy of the detection device, in an embodiment of the present application, the above method further includes the following step S103:

S103. Calculate the deviation of the first refraction surface of the first optical device relative to the drum, the deviation of the second refraction surface of the second optical device relative to the drum, and the light incident deviation of the detection device according to the point cloud data.

In this embodiment, the target reflector includes a reflector array, and the above step S103 specifically includes the following steps D10-D13:

Step D10: Map each point corresponding to the point cloud data of the reflector array into a two-dimensional plane to obtain two sets of point cloud images of each reflector in the reflector array.

Specifically, in order to improve the accuracy of calculation, each point corresponding to the obtained point cloud data of the reflector array is projected onto the plane where the reflector array is located.

Step D11: Calculate the center point coordinates of the two sets of point cloud imaging of each reflector in the reflector array.

Step D12: Establish a third objective function based on the center point coordinates of the two sets of point cloud imaging of each reflector in the reflector array.

Step D13: Obtain the deviation of the first refraction surface relative to the drum, the deviation of the second refraction surface relative to the drum, and the light incident deviation by minimizing the third objective function.

The third objective function is to calculate all the reflectors in the reflector array under different deviations of the first refraction surface of the first optical device relative to the drum, the deviation of the second refraction surface of the second optical device relative to the drum, and the light incident deviation. The root mean square function of the distance between the center points of the two sets of point cloud imaging. By minimizing the third objective function, the deviation of the first refraction surface of the first optical device relative to the drum, the deviation of the second refraction surface of the second optical device relative to the drum, and the light incident deviation are obtained.

For a more detailed description, referring to FIG. 5, the dotted line indicates the positions of the first optical device, the second optical device, and the drum in an ideal state when there is no installation error. And in an ideal state, the direction vector of the incident light is [1, 0, 0]. When installation errors occur, the incident light will have rotation angles λ _y and λ _z relative to the Y axis and the Z axis. The first optical device and the second optical device of the detection device respectively correspond to the rotating drum. Here, for the convenience of distinction, the rotating drum corresponding to the first optical device is called the first rotating drum, and the rotating drum corresponding to the second optical device Called the second drum. 5, in an ideal state, the normal vector of the first refractive surface 11 of the first optical device 10 is coaxial with the rotation axis of the first drum 12, and the normal vector of the second refractive surface 22 of the second optical device 20 is The vector is coaxial with the rotation axis of the second drum 21. If there is an installation error of the first optical device, the normal vector of the first refraction surface 11 and the rotation axis of the first rotating drum 12 are not on the same axis. At this time, the normal vector of the first refraction surface 11 is relative to the second refraction surface. The theoretical normal vector of 11 has rotation angles β _y1 and β _z1 on the Y axis and the Z axis. If there is an installation error of the second optical device, the normal vector of the second refraction surface 22 and the rotation axis of the second rotating drum 21 are not on the same axis. At this time, the normal vector of the second refraction surface 22 is relative to the second refraction surface. The theoretical normal vector of 22 has rotation angles β _y2 and β _z2 on the Y axis and the Z axis. The rotation angles β _y1 and β _{z1 are} the deviations of the first refraction surface of the first optical device relative to the drum, and the rotation angles β _y2 and β _{z2 are} the deviations of the second refraction surface of the second optical device with respect to the drum. deviation.

By using the following formula (4), the above-mentioned rotation angles λ _y and λ _z , rotation angles β _y1 and β _z1 , and rotation angles β _y1 and β _{z1 are} calculated.

Among them, n is the number of reflectors, c _i1 and c _i2 respectively represent the coordinates of the two sets of point cloud imaging center points of the i-th reflector, and d(c _i1 , c _i2 ) represents the two sets of points of the i-th reflector The distance between the center points of the cloud image.

In this embodiment, the first deviation of the detection device, the second zero deviation, the deviation of the first refractive surface of the first optical device relative to the drum, the deviation of the second refractive surface of the second optical device relative to the drum, and The incident light deviation can further improve the calibration effect of the detection device. The measurement data obtained in the actual working process of the detection device can obtain accurate measurement data after all the above deviations are corrected.

In an optional embodiment of the present invention, the target reflector is a total reflection patch or a pattern formed by spraying a total reflection material, and the target reflector is disposed on the surface of the carrier.

In an optional embodiment of the present invention, the number of the aforementioned target reflectors is multiple, and the distance between adjacent target reflectors is greater than the maximum size of the light spot irradiated on the carrier.

The maximum size of the light spot refers to the dimension with the largest value among all the external dimension parameters of the light spot. For example, when the shape of the light spot is an ellipse, all the dimensions of the light spot include: long axis and short axis, and the maximum size of the light spot refers to the long axis of the light spot; for another example, when the shape of the light spot is circular, The maximum size of the light spot refers to the diameter of the light spot. In this way, it can be ensured that one light spot will not be irradiated on two target reflectors at the same time. Compared with the situation where multiple target reflectors are irradiated by one light spot at the same time, the processing process of the received echo signal by the detection device can be simplified.

In an optional embodiment of the present invention, the surface of the above-mentioned carrier is flat, and the carrier includes a wall or a flat plate.

In an optional embodiment of the present invention, the distance between the carrier and the detection device is greater than a preset distance.

Optionally, in order to ensure the accuracy of the calibration calculation, the distance between the carrier and the detection device is set to be greater than or equal to 8 meters.

The actual calibration scene can be referred to as shown in Figure 6. The detection device 60 transmits a signal to the surface of the carrier 61 where the target reflector is located. The target reflector reflects the light wave signal, and the detection device receives the echo signal. The detection device or other equipment For example, the host computer obtains the echo signal, determines the point cloud data of the target reflector according to the echo signal, and performs calibration of the initial state of the detection device according to the point cloud data according to the above-mentioned method.

As shown in FIG. 7, an embodiment of the present invention provides an initial state calibration device 700, which includes at least a memory 702 and a processor 701; the memory 702 is connected to the processor 701 via a communication bus 703, and is used for storing The computer instructions executable by the processor 701; the processor 701 is configured to read computer instructions from the memory 702 to implement:

Acquire an echo signal generated by the detection device transmitting a signal to a target scene, the target scene including a target reflector; the detection device includes a first optical device and a second optical device, the transmission signal and the echo signal pass through The first optical device and the second optical device;

Optionally, the target reflector includes a single reflector, and the processor 701 is calculating the first zero offset corresponding to the first optical device and the first zero deviation corresponding to the second optical device according to the point cloud data. When the 20-bit deviation, it is specifically used for:

Calculating a first angle difference between the first zero deviation and the second zero deviation according to the point cloud data of the single reflector;

Calculating a common deviation between the first zero deviation and the second zero deviation according to ground point cloud data, where the ground point cloud data is point cloud data corrected by the first angle difference;

According to the first angle difference and the common deviation, the first zero position deviation and the second zero position deviation are calculated.

Optionally, the aforementioned processor 701 is specifically configured to: when calculating the first angle difference between the first zero deviation and the second zero deviation according to the point cloud data of the single reflector:

Mapping each point corresponding to the point cloud data of the single reflector into a two-dimensional plane to obtain two sets of point cloud images of the single reflector;

Calculating a first angle difference between the first zero deviation and the second zero deviation according to the two sets of point cloud imaging of the single reflector;

Wherein, the two-dimensional plane includes the plane where the single reflector is located.

Optionally, the above-mentioned processor 701 specifically uses the first angle difference between the first zero deviation and the second zero deviation according to the two sets of point cloud imaging of the single reflector. in:

Calculating the center point coordinates of the two sets of point cloud imaging of the single reflector;

Establishing a first objective function based on the center point coordinates of the two sets of point cloud imaging of the single reflector;

By minimizing the first objective function, the first angle difference between the first zero deviation and the second zero deviation is obtained.

Optionally, the aforementioned processor 701 is specifically configured to: when calculating the common deviation of the first zero deviation and the second zero deviation according to the point cloud data on the ground:

According to the point cloud data of the ground, the normal vector of the ground imaging is calculated;

According to the projection of the normal vector of the ground imaging on the plane where the single reflector is located, a common deflection angle of the first zero deviation and the second zero deviation is calculated.

Optionally, the target reflector further includes a reflector array, and the processor 701 calculates the first zero deviation and the second zero deviation according to the first angle difference and the common deviation. , Specifically used for:

According to the point cloud data of the reflector array, the second angle difference between the first zero deviation and the second zero deviation is calculated, and the point cloud data of the reflector array is through the first angle Point cloud data corrected by the difference and the common deviation;

The first zero position deviation and the second zero position deviation are updated according to the second angle difference.

Optionally, the aforementioned processor 701 is specifically configured to calculate the second angular difference between the first zero deviation and the second zero deviation according to the point cloud data of the reflector array:

Mapping each point corresponding to the point cloud data of the reflector array into a two-dimensional plane to obtain two sets of point cloud images of each reflector in the reflector array;

Calculating a second angular difference between the first zero deviation and the second zero deviation according to the two sets of point cloud imaging of each reflector in the reflector array;

Wherein, the two-dimensional plane includes the plane where the reflector array is located.

Optionally, the processor 701 calculates the second angular difference between the first zero deviation and the second zero deviation according to the two sets of point cloud imaging of each reflector in the reflector array When value, specifically used for:

Calculating the center point coordinates of the two sets of point cloud imaging of each reflector in the reflector array;

Establishing a second objective function based on the center point coordinates of the two sets of point cloud imaging of each reflector in the reflector array;

The second angular difference between the first zero deviation and the second zero deviation is obtained by minimizing the second objective function.

Optionally, the aforementioned processor 701 is further configured to read computer instructions from the memory to implement:

According to the point cloud data, the deviation of the first refraction surface of the first optical device relative to the drum, the deviation of the second refraction surface of the second optical device relative to the drum, and the light incident deviation of the detection device are calculated.

Optionally, the target reflector includes a reflector array, and the processor 701 is calculating the deviation of the first refractive surface of the first optical device relative to the drum and the second optical device of the detection device based on the point cloud data When the deviation of the second refraction surface relative to the drum and the deviation of light incidence, it is specifically used for:

Establishing a third objective function based on the center point coordinates of the two sets of point cloud imaging of each reflector in the reflector array;

By minimizing the third objective function, the deviation of the first refractive surface relative to the drum, the deviation of the second refractive surface relative to the drum, and the light incident deviation are obtained.

Optionally, the above-mentioned target reflector is a total reflection patch or a pattern formed by spraying a total reflection material, and the target reflector is arranged on the surface of the carrier.

Optionally, there are multiple target reflectors, and the distance between adjacent target reflectors is greater than the maximum size of the light spot irradiated on the carrier.

Optionally, the surface of the above-mentioned carrier is flat, and the carrier includes a wall or a flat plate.

Optionally, the distance between the aforementioned carrier and the detection device is greater than a preset distance.

Optionally, the aforementioned initial state calibration device includes a detection device or a host computer.

Optionally, the aforementioned detection device includes at least one of the following: laser radar, millimeter wave radar, and ultrasonic radar.

An embodiment of the present invention also provides a computer-readable storage medium on which a computer program is stored, and when the program is executed by a processor, the steps of the method are realized.

For the device embodiment, since it basically corresponds to the method embodiment, the relevant part can refer to the description of the method embodiment. The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in One place, or it can be distributed to multiple network units. Some or all of the modules may be selected according to actual needs to achieve the objectives of the solutions of the embodiments. Those of ordinary skill in the art can understand and implement it without creative work.

It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply one of these entities or operations. There is any such actual relationship or order between. The terms "include", "include", or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements that are not explicitly listed. Elements, or also include elements inherent to such processes, methods, articles, or equipment. If there are no more restrictions, the element defined by the sentence "including a..." does not exclude the existence of other same elements in the process, method, article, or equipment including the element.

The methods and devices provided by the embodiments of the present invention are described in detail above. Specific examples are used in this article to illustrate the principles and implementations of the present invention. The descriptions of the above embodiments are only used to help understand the methods and methods of the present invention. Core idea; At the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation and the scope of application. In summary, the content of this specification should not be construed as a limitation of the present invention .

Claims

A method for calibrating an initial state of a detection device, wherein the detection device includes a first optical device and a second optical device, and the method includes:

Acquire an echo signal generated by the detection device transmitting a signal to a target scene, the target scene including a target reflector, the transmission signal and the echo signal passing through the first optical device and the second optical device ；

Determining the point cloud data of the target reflector according to the echo signal;

According to the point cloud data, a first zero deviation corresponding to the first optical device and a second zero deviation corresponding to the second optical device are calculated.
The method according to claim 1, wherein the target reflector includes a single reflector, and the first zero deviation corresponding to the first optical device and the first zero deviation are calculated according to the point cloud data. The second zero deviation corresponding to the two optical devices includes:

Calculating a first angle difference between the first zero deviation and the second zero deviation according to the point cloud data of the single reflector;

Calculating a common deviation between the first zero deviation and the second zero deviation according to ground point cloud data, where the ground point cloud data is point cloud data corrected by the first angle difference;

According to the first angle difference and the common deviation, the first zero deviation and the second zero deviation are calculated.
The method according to claim 2, wherein the first angle difference between the first zero deviation and the second zero deviation is calculated according to the point cloud data of the single reflector ,include:

Mapping each point corresponding to the point cloud data of the single reflector into a two-dimensional plane to obtain two sets of point cloud images of the single reflector;

Calculating a first angle difference between the first zero deviation and the second zero deviation according to the two sets of point cloud imaging of the single reflector;

Wherein, the two-dimensional plane includes the plane where the single reflector is located.
The method of claim 3, wherein the first angle between the first zero deviation and the second zero deviation is calculated according to the two sets of point cloud imaging of the single reflector Differences, including:

Calculating the center point coordinates of the two sets of point cloud imaging of the single reflector;

Establishing a first objective function based on the center point coordinates of the two sets of point cloud imaging of the single reflector;

The first objective function is minimized to obtain the first angle difference between the first zero deviation and the second zero deviation.
The method according to claim 2, wherein the calculating the common deviation of the first zero deviation and the second zero deviation according to the point cloud data of the ground comprises:

According to the point cloud data of the ground, the normal vector of the ground imaging is calculated;

According to the projection of the normal vector of the ground imaging on the plane where the single reflector is located, a common deflection angle of the first zero deviation and the second zero deviation is calculated.
The method according to claim 2, wherein the target reflector further comprises a reflector array, and in the calculation of the first zero deviation and the total deviation according to the first angular difference and the common deviation After the second zero deviation, it also includes:

According to the point cloud data of the reflector array, the second angle difference between the first zero deviation and the second zero deviation is calculated, and the point cloud data of the reflector array is passed through the first zero deviation. Point cloud data corrected by the angle difference and the common deviation;

The first zero position deviation and the second zero position deviation are updated according to the second angle difference.
8. The method according to claim 6, wherein the calculation of the second angular difference between the first zero deviation and the second zero deviation based on the point cloud data of the reflector array ,include:

Mapping each point corresponding to the point cloud data of the reflector array into a two-dimensional plane to obtain two sets of point cloud images of each reflector in the reflector array;

Calculating a second angular difference between the first zero deviation and the second zero deviation according to the two sets of point cloud imaging of each reflector in the reflector array;

Wherein, the two-dimensional plane includes the plane where the reflector array is located.
The method according to claim 7, wherein the calculation of the first zero deviation and the second zero deviation based on two sets of point cloud imaging of each reflector in the reflector array The second angle difference between, including:

Calculating the center point coordinates of the two sets of point cloud imaging of each reflector in the reflector array;

Establishing a second objective function based on the center point coordinates of the two sets of point cloud imaging of each reflector in the reflector array;

The second angular difference between the first zero deviation and the second zero deviation is obtained by minimizing the second objective function.
The method of claim 1, wherein the method further comprises:

According to the point cloud data, the deviation of the first refraction surface of the first optical device relative to the drum, the deviation of the second refraction surface of the second optical device relative to the drum and the light incident deviation of the detection device are calculated.
The method according to claim 9, wherein the target reflector comprises an array of reflectors, and the first refractive surface of the first optical device of the detection device is calculated relative to the rotating drum according to the point cloud data. The deviation, the deviation of the second refraction surface of the second optical device relative to the drum, and the deviation of light incidence include:

Mapping each point corresponding to the point cloud data of the reflector array into a two-dimensional plane to obtain two sets of point cloud images of each reflector in the reflector array;

Calculating the center point coordinates of the two sets of point cloud imaging of each reflector in the reflector array;

Establishing a third objective function based on the center point coordinates of the two sets of point cloud imaging of each reflector in the reflector array;

By minimizing the third objective function, the deviation of the first refractive surface relative to the drum, the deviation of the second refractive surface relative to the drum, and the light incident deviation are obtained.
The method according to claim 1, wherein the target reflector is a total reflection patch or a pattern formed by spraying a total reflection material, and the target reflector is disposed on the surface of the carrier.
The method according to claim 11, wherein the number of the target reflector is multiple, and the distance between adjacent target reflectors is greater than the maximum size of the light spot irradiated on the carrier.
The method according to claim 11, wherein the surface of the carrier is flat, and the carrier includes a wall or a flat plate.
The method according to claim 11, wherein the distance between the carrier and the detection device is greater than a preset distance.
An initial state calibration device of a detection device, characterized in that it includes at least a memory and a processor; the memory is connected to the processor through a communication bus, and is used to store computer instructions executable by the processor; The device is used to read computer instructions from the memory to realize:

Acquire an echo signal generated by the detection device transmitting a signal to a target scene, the target scene including a target reflector, the detection device including a first optical device and a second optical device, the transmission signal and the echo The signal passes through the first optical device and the second optical device;

Determining the point cloud data of the target reflector according to the echo signal;

According to the point cloud data, a first zero deviation corresponding to the first optical device and a second zero deviation corresponding to the second optical device are calculated.
The apparatus according to claim 15, wherein the target reflector comprises a single reflector, and the processor is calculating the first zero deviation and the corresponding first optical device based on the point cloud data When the second zero position deviation corresponding to the second optical device is specifically used for:

Calculating a first angle difference between the first zero deviation and the second zero deviation according to the point cloud data of the single reflector;

Calculating a common deviation between the first zero deviation and the second zero deviation according to ground point cloud data, where the ground point cloud data is point cloud data corrected by the first angle difference;

According to the first angle difference and the common deviation, the first zero deviation and the second zero deviation are calculated.
The device according to claim 16, wherein the processor calculates the first zero deviation between the first zero deviation and the second zero deviation according to the point cloud data of the single reflector. When the angle difference is used, it is specifically used for:

Mapping each point corresponding to the point cloud data of the single reflector into a two-dimensional plane to obtain two sets of point cloud images of the single reflector;

Calculating a first angle difference between the first zero deviation and the second zero deviation according to the two sets of point cloud imaging of the single reflector;

Wherein, the two-dimensional plane includes the plane where the single reflector is located.
The device according to claim 17, wherein the processor calculates the difference between the first zero deviation and the second zero deviation according to the two sets of point cloud imaging of the single reflector. When the first angle difference is used, it is specifically used for:

Calculating the center point coordinates of the two sets of point cloud imaging of the single reflector;

Establishing a first objective function based on the center point coordinates of the two sets of point cloud imaging of the single reflector;

By minimizing the first objective function, the first angular difference between the first zero deviation and the second zero deviation is obtained.
The device according to claim 16, wherein the processor is specifically configured to: when calculating the common deviation of the first zero deviation and the second zero deviation according to the point cloud data on the ground:

According to the point cloud data of the ground, the normal vector of the ground imaging is calculated;

According to the projection of the normal vector of the ground imaging on the plane where the single reflector is located, a common deflection angle of the first zero deviation and the second zero deviation is calculated.
The device according to claim 16, wherein the target reflector further comprises a reflector array, and the processor calculates the first zero deviation according to the first angle difference and the common deviation After the deviation from the second zero position, it is specifically used to read computer instructions from the memory to realize:

According to the point cloud data of the reflector array, the second angle difference between the first zero deviation and the second zero deviation is calculated, and the point cloud data of the reflector array is through the first angle Point cloud data corrected by the difference and the common deviation;

The first zero position deviation and the second zero position deviation are updated according to the second angle difference.
The device according to claim 20, wherein the processor calculates the second difference between the first zero deviation and the second zero deviation based on the point cloud data of the reflector array. When the angle difference is used, it is specifically used for:

Mapping each point corresponding to the point cloud data of the reflector array into a two-dimensional plane to obtain two sets of point cloud images of each reflector in the reflector array;

Calculating a second angular difference between the first zero deviation and the second zero deviation according to the two sets of point cloud imaging of each reflector in the reflector array;

Wherein, the two-dimensional plane includes the plane where the reflector array is located.
The device according to claim 21, wherein the processor calculates the first zero position deviation and the second zero position according to two sets of point cloud imaging of each reflector in the reflector array The second angle difference between the deviations is specifically used for:

Calculating the center point coordinates of the two sets of point cloud imaging of each reflector in the reflector array;

Establishing a second objective function based on the center point coordinates of the two sets of point cloud imaging of each reflector in the reflector array;

The second angular difference between the first zero deviation and the second zero deviation is obtained by minimizing the second objective function.
The apparatus according to claim 15, wherein the processor is further configured to read computer instructions from the memory to implement:

According to the point cloud data, the deviation of the first refraction surface of the first optical device relative to the drum, the deviation of the second refraction surface of the second optical device relative to the drum and the light incident deviation of the detection device are calculated.
The device according to claim 23, wherein the target reflector comprises a reflector array, and the processor is calculating the first refraction surface of the first optical device of the detection device based on the point cloud data. When the deviation of the relative drum, the deviation of the second refraction surface of the second optical device relative to the drum, and the deviation of light incidence, it is specifically used for:

Mapping each point corresponding to the point cloud data of the reflector array into a two-dimensional plane to obtain two sets of point cloud images of each reflector in the reflector array;

Calculating the center point coordinates of the two sets of point cloud imaging of each reflector in the reflector array;

Establishing a third objective function based on the center point coordinates of the two sets of point cloud imaging of each reflector in the reflector array;

By minimizing the third objective function, the deviation of the first refractive surface relative to the drum, the deviation of the second refractive surface relative to the drum, and the light incident deviation are obtained.
The device according to claim 15, wherein the target reflector is a total reflection patch or a pattern sprayed from a total reflection material, and the target reflector is disposed on the surface of the carrier.
The device according to claim 25, wherein the number of the target reflector is multiple, and the distance between adjacent target reflectors is greater than the maximum size of the light spot irradiated on the carrier.
The device according to claim 25, wherein the surface of the carrier is flat, and the carrier comprises a wall or a flat plate.
The device according to claim 25, wherein the distance between the carrier and the detection device is greater than a preset distance.
The device according to claim 14, wherein the device comprises: a detection device or an upper computer.
The device according to claim 29, wherein the detection device comprises at least one of the following: laser radar, millimeter wave radar, and ultrasonic radar.
A computer-readable storage medium having a computer program stored thereon, wherein the program is executed by a processor to implement the steps of the method according to any one of claims 1-14.