Millimeter wave radar triggering method and system

Abstract

The present invention provides a millimeter wave radar triggering method and system, comprising configuring a first millimeter wave radar in front of a toll station and a second millimeter wave radar in the rear, the first millimeter wave radar capturing a radar reflection signal of a target vehicle, generating first reflection surface data of the target vehicle according to the radar reflection signal; constructing a three-dimensional coordinate system, using a finite element analysis method to construct a finite element model of the first reflection surface data based on the three-dimensional coordinate system, and obtaining displacement data of the target vehicle in a lane according to the finite element model; constructing displacement constraints of the finite element model, triggering an ETC fee deduction verification method for the target vehicle scanned by the second millimeter wave radar according to the displacement constraints and the displacement data of the actual detected vehicle in the lane; starting a unified comparison including obtaining ETC tag information through an ETC sensing antenna, a finite element model and license plate data collected by a camera, obtaining an ETC fee deduction verification result, and if the ETC fee deduction verification fails, starting an ETC fee deduction process for the target vehicle.

Description

Technical Field

[0001] The present invention relates to the technical field of highway radars, and in particular to a millimeter wave radar triggering method and system. Background Art

[0002] At present, radars are widely used in fields including transportation, weather monitoring, and aviation navigation. In the existing technology, radars in the field of transportation technology mainly monitor vehicle speed, flow, and violations. At present, highway toll stations have begun to gradually implement the ETC system (electronic toll collection system). The ETC system mainly uses the microwave antenna and electronic tags of the toll station to communicate to achieve high-speed and fast toll release, and uses radar and cameras to monitor the speed and number of vehicles. However, the existing ETC system may misidentify vehicles for toll deduction under special circumstances, such as vehicles in the side lanes cutting in and occupying other vehicles that have been deducted, thereby causing the ETC system to misdeduct fees. In addition, the radars and cameras in the existing technology can only identify vehicle speed and flow, and cannot identify and interact with ETC lane occupancy and deduction information. Summary of the invention

[0003] One of the inventive purposes of the present invention is to provide a millimeter-wave radar triggering method and system, wherein the method and system construct a dual radar system, wherein the front radar is used to detect vehicle speed and vehicle driving status, and the rear radar is used to activate an antenna including a camera and ETC to perform a radar-triggered ETC fee deduction verification method and system, wherein the method and system utilizes the front radar to determine whether there is a possibility of a vehicle cutting in line in the ETC lane, and if there is a possibility of cutting in line, the ETC fee deduction verification method of the rear radar is triggered, so the technical solution of the present invention effectively solves the problem of incorrect deduction objects due to distance and cutting in line during the ETC deduction process.

[0004] Another inventive object of the present invention is to provide a millimeter-wave radar triggering method and system. After obtaining the vehicle entering the ETC lane, the method and system use the front radar reflection signal to construct a finite element model of the corresponding vehicle radar reflection surface, and analyze the displacement data of the target vehicle in the lateral direction of the lane based on the finite element model. The present invention constructs an ETC fee verification method based on the finite element model, including displacement constraints of the target vehicle in the lateral direction of the lane, and triggers the rear radar according to the displacement constraints and the actual displacement data of the target vehicle in the lateral direction of the lane. Therefore, the problem of ETC fee target error is effectively reduced or avoided without additional ETC fee monitoring process steps.

[0005] Another inventive object of the present invention is to provide a millimeter-wave radar triggering method and system, which utilizes the finite element model to perform feature comparison of the radar reflection surface of the target vehicle by the front radar and the rear radar, and is combined with the vehicle sequence for body verification of the target vehicle, and the camera function of the target vehicle license plate is triggered by the rear-trigger camera, and the ETC deduction data is further verified in combination with the license plate number, thereby reducing or avoiding the problem of failure of ETC deduction verification due to the inability of the license plate number to be recognized by the camera in harsh environments.

[0006] In order to achieve at least one of the above-mentioned invention objects, the present invention further provides a millimeter wave radar triggering method, the method comprising:

[0007] A first millimeter-wave radar is arranged in front of the toll station and a second millimeter-wave radar is arranged in the rear, wherein the first millimeter-wave radar captures a radar reflection signal of a target vehicle and generates first reflection surface data of the target vehicle according to the radar reflection signal;

[0008] Constructing a three-dimensional coordinate system based on the first millimeter-wave radar, constructing a finite element model including the first reflection surface data based on the three-dimensional coordinate system using a finite element analysis method, and acquiring displacement data including the target vehicle in the lane according to the finite element model;

[0009] Constructing a displacement constraint condition of the finite element model, and triggering a target vehicle ETC fee deduction verification method including a second millimeter-wave radar scan according to the displacement constraint condition and the displacement data of the vehicle actually detected in the lane;

[0010] The ETC fee deduction verification method of the triggered target vehicle is started, including obtaining the ETC tag information through the ETC sensing antenna, comparing the finite element model with the license plate data collected by the camera, and obtaining the ETC fee deduction verification result. If the ETC fee deduction verification fails, the ETC fee deduction process of the target vehicle is started.

[0011] According to one of the preferred embodiments of the present invention, the three-dimensional coordinate system construction method includes: taking the first millimeter-wave radar as the coordinate origin, taking the direction parallel to the lane as the X-axis, taking the direction perpendicular to the lane as the Y-axis, and the height direction as the Z-axis to construct the three-dimensional coordinate system, obtaining the radar reflection signal after the first millimeter-wave radar irradiates the vehicle at a certain beam angle perpendicular to the lane direction, and obtaining the first reflection surface data of the target vehicle, the second millimeter-wave radar and the first millimeter-wave radar have the same beam angle and irradiate perpendicularly to the lane travel direction, and obtain the second reflection surface data of the target vehicle, and the coordinates of the first reflection surface data and the second reflection surface data are converted according to the constructed three-dimensional coordinate system.

[0012] According to another preferred embodiment of the present invention, the finite element model construction method includes: setting units with the same side length and interconnected without overlapping on the first reflecting surface according to the finite element analysis method, calculating the coordinate value of each node in the three-dimensional coordinate system that each unit is connected to other units, and using finite element analysis software to construct point cloud data based on the unit node coordinate values ​​of the three-dimensional coordinate system to obtain the first finite element model of the target vehicle; and setting units with the same side length as the first reflecting surface and interconnected without overlapping on the second reflecting surface according to the finite element analysis method, calculating the coordinate values ​​of the nodes on the second reflecting surface, and obtaining the second finite element model of the target vehicle based on the node coordinate values ​​on the second reflecting surface.

[0013] According to another preferred embodiment of the present invention, the method for calculating the displacement data of the target vehicle includes: obtaining a ternary boundary function F(x, y, z)=\left [ {{\varepsilon}_{1}, {\varepsilon}_{2}} \right ] describing the boundary of the first millimeter-wave radar beam according to the first millimeter-wave radar beam angle ,in and They are two different boundary planes given based on the first millimeter-wave radar beam angle, according to the ternary boundary function F(x,y,z)=\left [ {{\varepsilon}_{1},{\varepsilon}_{2}} \right ] Calculate the Y-axis coordinate values ​​of the point clouds on the finite element model of the target vehicle when they pass through the two boundary planes, and calculate the difference between the Y-axis coordinate values ​​of the two boundary planes of at least two identical point clouds As displacement data, n represents the point cloud identification of the target vehicle, according to the difference And displacement constraints determine whether the current target vehicle triggers the ETC deduction verification method.

[0014] According to another preferred embodiment of the present invention, the method for calculating the displacement data of the target vehicle includes: given the first millimeter wave radar beam angle, two different boundary planes are respectively =[x1,-x1tan(π-θ),z1], =[x2, x2tanθ, z2], where y1=-x1tan(π-θ), y2=x2tanθ, θ is the beam angle with the first millimeter-wave radar as the origin, the X-axis extension direction as 0 angle, and the Y-axis extension direction as the positive angle direction, corresponding to the target vehicle point cloud passing through the plane Solve the three-dimensional coordinate value corresponding to the plane through which the target vehicle point cloud passes Solving the three-dimensional coordinate values; wherein the displacement data of the target vehicle is obtained according to the solved coordinate values =y1-y2=(-x1tan(π-θ)-x2tanθ).

[0015] According to another preferred embodiment of the present invention, the boundary constraint condition includes: setting an upper limit threshold of the displacement data Solve each point cloud n of the target vehicle on the boundary plane and the boundary plane The average of the upper difference , when the average value Greater than the upper limit threshold of the displacement data , then the second millimeter-wave radar, camera and ETC sensing antenna are started to trigger the ETC deduction verification method.

[0016] According to another preferred embodiment of the present invention, the distance value l between the first millimeter wave radar and the second millimeter wave radar in the x-axis direction in the three-dimensional coordinate system is obtained, and the point cloud data p=[x n ,y n ,z n ], n is the first millimeter wave radar point cloud identifier, and the point cloud data q=[x m ,y m ,z m ], m is the second millimeter-wave radar point cloud identifier. When the ETC fee deduction verification method is triggered, the feature similarity value is calculated between the point cloud data p of the target vehicle scanned by the first millimeter-wave radar and the point cloud data q scanned by the second millimeter-wave radar for the target vehicle, and a feature similarity threshold is set. If the feature similarity between the point cloud data p and the point cloud data q is greater than the preset feature similarity threshold, the second millimeter-wave radar generates a verification pass message.

[0017] According to another preferred embodiment of the present invention, when the ETC fee deduction verification method is triggered, the camera located at the second millimeter-wave radar is started, the license plate information of the target vehicle is photographed according to the verification pass message generated by the second millimeter-wave radar, and the ETC electronic tag information corresponding to the target vehicle is extracted according to the license plate information, and at the same time, the ETC electronic tag information in the previous ETC deduction data is extracted according to the ETC deduction sequence, and it is determined whether the ETC electronic tag information in the ETC deduction data and the ETC electronic tag information extracted according to the license plate information are consistent. If they are consistent, the verification is passed, and the lifting rod is started to release the target vehicle; if they are inconsistent, the second ETC sensing antenna near the second millimeter-wave radar is started to re-identify the ETC electronic tag information of the target vehicle and execute the ETC deduction process.

[0018] In order to achieve at least one of the above-mentioned invention purposes, the present invention further provides a millimeter-wave radar triggering system, which executes the above-mentioned millimeter-wave radar triggering method.

[0019] The present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program is executed by a processor to implement the above-mentioned millimeter-wave radar triggering method. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Shown is a flow chart of a millimeter wave radar triggering method of the present invention.

[0021] Figure 2 Shown is a schematic diagram of the layout of the radar trigger system in the present invention at a toll station.

[0022] Figure 3 Shown is a schematic diagram of the layout of transmission signals of the first millimeter-wave radar and the second millimeter-wave radar in the present invention.

[0023] Among them, the symbols in the attached figure have the following meanings: O1-first millimeter-wave radar, O2-second millimeter-wave radar, 3-first ETC sensing antenna, 4-second ETC sensing antenna, 5-camera, 6-barrier gate. DETAILED DESCRIPTION

[0024] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0025] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0026] Please refer to Figure 1-Figure 3 The present invention relates to a millimeter wave radar triggering method and system, which are mainly used for automatic toll detection at high-speed toll stations. The method mainly includes the following steps: first, a dual radar system needs to be configured, the dual radar system includes a first millimeter wave radar and a second millimeter wave radar, wherein the first millimeter wave radar is configured at the front side of the vehicle in the driving direction of the ETC lane, wherein the first millimeter wave radar is a trigger radar, which is used to detect the running state of the vehicle entering, and judge whether it is necessary to trigger the ETC deduction verification method according to the running state of the vehicle entering. Further based on the ETC deduction verification method, the second millimeter wave radar is started to perform morphological verification detection on the target vehicle, and the camera is started to recognize the license plate of the target vehicle, and the ETC deduction information is verified by using the binding relationship between the pre-stored license plate information and the ETC electronic tag of the target vehicle. If the verification fails, the ETC deduction process for the target vehicle is started. The present invention can effectively reduce or avoid the correction of the deduction process due to queue cutting between adjacent lanes and ETC recognition errors between vehicles, thereby effectively improving the accuracy of the ETC deduction process.

[0027] Specifically, please combine Figure 2 and Figure 3In the present invention, the first millimeter-wave radar O1 and the second millimeter-wave radar O2 are separated by a certain distance, wherein the present invention is also configured with a dual ETC sensing antenna, including a first ETC sensing antenna and a second ETC sensing antenna, the first ETC sensing antenna is arranged behind the first millimeter-wave radar O1, and the position of the first ETC sensing antenna is arranged so that the sensing distance of the first ETC sensing antenna includes the position of the ETC lane emitted by the first millimeter-wave radar O1, but does not include the position of the ETC lane irradiated by the second millimeter-wave radar O2. The second ETC sensing antenna is arranged near the second sensing radar O2, and the second sensing radar O2 is close to the barrier gate of the ETC lane, so that the second ETC sensing antenna can perform the ETC deduction process for the target vehicle according to the scanning verification result of the second sensing radar O2. The present invention is also provided with a camera, which can be arranged between the first millimeter-wave radar O1 and the second millimeter-wave radar O2, for photographing the license plate information of the target vehicle, and verifying the deduction information according to the license plate information of the target vehicle. It is worth mentioning that, since the license plate information is realized based on visible light images, the verification of the license plate information may have certain errors in the recognition of the license plate information in environments such as foggy or snowy nights. Therefore, the verification based on the license plate information in the present invention can be implemented as a verification method. The present invention can also compare the finite element model constructed by the second millimeter wave radar O2 scanning and the finite element model machine constructed by the first millimeter wave radar O1 scanning, calculate the model similarity value, and if the similarity value is greater than the preset similarity threshold as one of the conditions for passing the target vehicle identification verification, further combine the second ETC sensing antenna to perform the ETC deduction information verification operation. It should be noted that the finite element model comparison and the license plate information comparison collected by the camera in the present invention can be selected as one or both of them are satisfied as the conditions for passing the verification. The second ETC sensing antenna and the first ETC sensing antenna are both connected to the ETC electronic tag database, wherein the ETC electronic tag database stores the license plate information, owner information and distance information bound to the corresponding ETC electronic tag, and the ETC electronic tag database can be interconnected with different toll stations to realize the supervision of the distance and deduction information of the corresponding vehicle.

[0028] It is worth mentioning that the core technology of the present invention is to construct a finite element model using the radar reflection surface generated by the radar reflection signal of the target vehicle obtained by scanning the first millimeter-wave radar, and use the finite element model to analyze whether the target vehicle has occupied the lane in the ETC lane, and trigger the verification method of ETC deduction based on the behavior. The specific steps include: first, it is necessary to construct a three-dimensional coordinate system. In the present invention, it is preferred to use the first millimeter-wave radar O1 as the coordinate origin (please refer to Figure 3), with the X axis parallel to the lane driving direction, the Y axis perpendicular to the lane driving direction, and the Z axis in the height direction to construct the three-dimensional coordinate system (such as Figure 3 ), and the beam angle θ of the first millimeter-wave radar scanning needs to be obtained, such as Figure 3 As shown, the beam angle θ in the present invention is defined as the angle between the first millimeter wave radar sensing boundary and the X-axis direction, wherein the emission directions of the first millimeter wave radar and the second millimeter wave radar are both perpendicular to the vertical direction of the ETC lane, and the beam angles of the first millimeter wave radar and the second millimeter wave radar are the same. When the vehicle travels between the two sensing boundaries of the first millimeter wave radar and the second millimeter wave radar, the radar reflection signal on the side of the vehicle will be sensed by the corresponding first millimeter wave radar and the second millimeter wave radar. And in combination with the three-dimensional coordinate system, a reflection surface based on the first millimeter wave radar and the second millimeter wave radar can be constructed. In the present invention, the reflection surface information obtained by scanning the target vehicle by the first millimeter wave radar is constructed by the finite element analysis method, and the displacement value of the target vehicle in the Y-axis direction is calculated based on the finite element model, and the displacement constraint condition in the Y-axis direction is pre-set, so that the displacement value of the target vehicle in the Y-axis direction on the boundary plane calculated by the finite element model satisfies the displacement constraint condition, and if not, the ETC deduction verification process is triggered.

[0029] The finite element model construction method includes: defining the reflection surface of the vehicle passing through the first millimeter wave radar scanning area as the first reflection surface, and setting units with the same side length and interconnected without overlapping on the first reflection surface according to the finite element analysis method. For example, the units can be rectangles or equilateral triangles with the same side length, wherein there is at least one same connection point between each unit and the adjacent unit, and the connection point is a node in the finite element model, which can be calculated according to the side length of the unit and other node coordinates, that is, after obtaining the position information of at least one connection point, the three-dimensional coordinate value of the corresponding node can be obtained according to the geometric connection relationship between different units of the finite element analysis method, and after calculating the coordinate value of each node connected to each other unit in the three-dimensional coordinate system, the finite element analysis software is used to construct point cloud data based on the unit node coordinate value of the three-dimensional coordinate system to obtain the first finite element model of the target vehicle; and according to the finite element analysis method, setting units with the same side length as the first reflection surface and interconnected without overlapping on the second reflection surface, calculating the coordinate values ​​of the nodes on the second reflection surface, and obtaining the second finite element model of the target vehicle according to the node coordinate values ​​on the second reflection surface. Since the same car generally has the same surface, when the first millimeter wave radar and the second millimeter wave radar are scanned in the same way, the point cloud features of the first finite element model and the second finite element model obtained by the finite element analysis method have obvious similarity in the projection direction of the XZ axis constituting surface. The first finite element model and the second finite element model of the present invention can calculate the distance feature between the two finite element model point clouds as the similarity value by coordinate translation. The similarity calculation method is an example of the present invention, and the present invention does not make specific restrictions on this.

[0030] In one of the preferred embodiments of the present invention, the present invention needs to calculate whether the target vehicle enters the ETC channel from the side lane when the vehicle enters the sensing range of the first ETC sensing antenna. The present invention obtains a ternary boundary function F(x,y,z)=\left [ {{\varepsilon}_{1},{\varepsilon}_{2}} \right ] describing the boundary of the first millimeter-wave radar beam according to the first millimeter-wave radar beam angle. ,in and They are two different boundary planes given based on the first millimeter-wave radar beam angle, please refer to Figure 3, the boundary plane set in the present invention is perpendicular to the XY plane of the three-dimensional coordinate system, and has a beam angle of θ with the extension direction of the X-axis. According to the three-dimensional boundary function F(x,y,z)=\left [ {{\varepsilon}_{1},{\varepsilon}_{2}} \right ] Calculate the Y-axis coordinate values ​​of the point clouds on the finite element model of the target vehicle when they pass through the two boundary planes, and calculate the difference between the Y-axis coordinate values ​​of the two boundary planes of at least two identical point clouds As displacement data, n represents the point cloud identification of the target vehicle, according to the difference And displacement constraints determine whether the current target vehicle triggers the ETC deduction verification method.

[0031] Specifically, the method for calculating the displacement data of the target vehicle includes: given the first millimeter wave radar beam angle, two different boundary planes are respectively =[x1,-x1tan(π-θ),z1], =[x2, x2tanθ, z2], where y1=-x1tan(π-θ), y2=x2tanθ, θ is the beam angle with the first millimeter-wave radar as the origin, the X-axis extension direction as 0 angle, and the Y-axis extension direction as the positive angle direction, corresponding to the target vehicle point cloud passing through the plane Solve the three-dimensional coordinate value corresponding to the plane through which the target vehicle point cloud passes Solving the three-dimensional coordinate values; wherein the displacement data of the target vehicle is obtained according to the solved coordinate values =y1-y2=(-x1tan(π-θ)-x2tanθ). The displacement data of the target vehicle The overall displacement of the target vehicle's radar reflection surface is calculated by finite element analysis, and combined with the displacement constraint condition, it can effectively predict whether the vehicle is cutting in line within the sensing range of the first millimeter-wave radar.

[0032] The boundary constraints include: setting the upper limit threshold of displacement data , solve each point cloud n of the target vehicle on the boundary plane and the boundary plane The average of the upper difference , when the average value Greater than the upper limit threshold of the displacement data , then the second millimeter-wave radar, camera and ETC sensing antenna are started to trigger the ETC deduction verification method.

[0033] Obtain the distance between the first millimeter-wave radar and the second millimeter-wave radar in the x-axis direction of the three-dimensional coordinate system l , and respectively obtain the point cloud data p=[x n ,y n ,z n ], n is the first millimeter wave radar point cloud identifier, and the point cloud data q=[x m ,y m ,z m ], m is the second millimeter wave radar point cloud identifier, when the ETC fee deduction verification method is triggered, the feature similarity value is calculated between the point cloud data p of the target vehicle scanned by the first millimeter wave radar and the point cloud data q of the target vehicle scanned by the second millimeter wave radar, wherein the point cloud data q=[x m ,y m ,z m ]'s x-coordinate is translated in the positive direction l Then get the point cloud data q l =[x m +l ,y m ,z m ], and calculate the point cloud data q l =[x m +l ,y m ,z m ] is the point cloud coordinate value on the XZ projection plane, and the point cloud data p=[x n ,y n ,z n ] The point cloud coordinate value on the XZ projection plane, and the coordinate Euclidean distance calculation formula is used to calculate the similarity value between the point clouds on the two-dimensional plane, wherein the Euclidean distance formula is a prior art and the present invention will not go into details therein, and a feature similarity threshold is set. If the feature similarity between the point cloud data p and the point cloud data q is greater than the preset feature similarity threshold, the second millimeter wave radar generates a verification pass message.

[0034] When the ETC fee deduction verification method is triggered, the camera located at the second millimeter-wave radar is started, and the license plate information of the target vehicle is photographed according to the verification pass message generated by the second millimeter-wave radar, and the ETC electronic tag information of the corresponding target vehicle is extracted according to the license plate information, and at the same time, the ETC electronic tag information in the previous ETC fee deduction data is extracted according to the ETC fee deduction sequence, and it is determined whether the ETC electronic tag information in the ETC fee deduction data is consistent with the ETC electronic tag information extracted according to the license plate information. If they are consistent, the verification is passed, and the lifting rod is started to release the target vehicle; if they are inconsistent, the second ETC sensing antenna near the second millimeter-wave radar is started to re-identify the ETC electronic tag information of the target vehicle and execute the ETC fee deduction process.

[0035] The embodiments disclosed in the present invention, the process described above with reference to the flowchart can be implemented as a computer software program. The embodiments disclosed in the present invention include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program contains a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through the communication part, and / or installed from a removable medium. When the computer program is executed by the central processing unit (CPU), the functions defined in the method of the present application are executed. It should be noted that the computer-readable medium described in the present application can be a computer-readable signal medium or a computer-readable storage medium or any combination of the two. The computer-readable storage medium can be, for example, but not limited to, a system, device or device of an electrical, magnetic, optical, electromagnetic, infrared segment, or semiconductor, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to, electrical connections with one or more wire segments, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In the present application, a computer-readable storage medium may be any tangible medium containing or storing a program that may be used by or in conjunction with an instruction execution system, apparatus, or device. In the present application, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, which carries a computer-readable program code. Such propagated data signals may be of various types, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device. The program code contained on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless segments, wire segments, optical cables, RF, etc., or any suitable combination thereof.

[0036] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present invention. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0037] Those skilled in the art should understand that the embodiments of the present invention described and shown in the drawings are only examples and do not limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and explained in the embodiments. Without departing from the principles, the implementation methods of the present invention may be deformed or modified in any way.

Claims

1. A millimeter wave radar triggering method, characterized in that: The method comprises: A first millimeter-wave radar is arranged in front of the toll station and a second millimeter-wave radar is arranged in the rear, wherein the first millimeter-wave radar captures a radar reflection signal of a target vehicle and generates first reflection surface data of the target vehicle according to the radar reflection signal; Constructing a three-dimensional coordinate system based on the first millimeter-wave radar, constructing a finite element model including the first reflection surface data based on the three-dimensional coordinate system using a finite element analysis method, and acquiring displacement data including the target vehicle in the lane according to the finite element model; Constructing a displacement constraint condition of the finite element model, and triggering a target vehicle ETC fee deduction verification method including a second millimeter-wave radar scan according to the displacement constraint condition and the displacement data of the vehicle actually detected in the lane; The ETC fee deduction verification method of the triggered target vehicle is started, including obtaining the ETC tag information through the ETC sensing antenna, comparing the finite element model with the license plate data collected by the camera, and obtaining the ETC fee deduction verification result. If the ETC fee deduction verification fails, the ETC fee deduction process of the target vehicle is started.

2. A millimeter wave radar triggering method according to claim 1, characterized in that: The three-dimensional coordinate system construction method includes: taking the first millimeter-wave radar as the coordinate origin, taking the direction parallel to the lane as the X-axis, taking the direction perpendicular to the lane as the Y-axis, and the height direction as the Z-axis to construct the three-dimensional coordinate system, obtaining the radar reflection signal obtained by irradiating the vehicle with a certain beam angle perpendicular to the lane driving direction by the first millimeter-wave radar, and obtaining the first reflection surface data of the target vehicle, the second millimeter-wave radar and the first millimeter-wave radar have the same beam angle and irradiate perpendicularly to the lane driving direction, and obtain the second reflection surface data of the target vehicle, and transform the coordinates of the first reflection surface data and the second reflection surface data according to the constructed three-dimensional coordinate system.

3. A millimeter wave radar triggering method according to claim 1, characterized in that: The finite element model construction method includes: setting units with the same side length and interconnected without overlapping on the first reflecting surface according to the finite element analysis method, calculating the coordinate value of each node in the three-dimensional coordinate system where each unit is connected to other units, and using finite element analysis software to construct point cloud data based on the unit node coordinate values ​​in the three-dimensional coordinate system to obtain the first finite element model of the target vehicle; and setting units with the same side length as the first reflecting surface and interconnected without overlapping on the second reflecting surface according to the finite element analysis method, calculating the coordinate values ​​of the nodes on the second reflecting surface, and obtaining the second finite element model of the target vehicle according to the node coordinate values ​​on the second reflecting surface.

4. The millimeter wave radar triggering method according to claim 1, characterized in that: The method for calculating the displacement data of the target vehicle includes: obtaining a ternary boundary function F(x, y, z) describing the boundary of the first millimeter wave radar beam according to the first millimeter wave radar beam angle = ,in and are two different boundary planes given based on the first millimeter-wave radar beam angle, according to the ternary boundary function F (x, y, z) = Calculate the Y-axis coordinate values ​​of the point clouds on the finite element model of the target vehicle when they pass through the two boundary planes, and calculate the difference between the Y-axis coordinate values ​​of the two boundary planes of at least two identical point clouds As displacement data, n represents the point cloud identification of the target vehicle, according to the difference And displacement constraints determine whether the current target vehicle triggers the ETC deduction verification method.

5. A millimeter wave radar triggering method according to claim 4, characterized in that: The method for calculating the displacement data of the target vehicle includes: given the first millimeter wave radar beam angle, two different boundary planes are respectively =[x1,-x1tan(π-θ),z1], =[x2, x2tanθ, z2], where y1=-x1tan(π-θ), y2=x2tanθ, θ is the beam angle with the first millimeter-wave radar as the origin, the X-axis extension direction as 0 angle, and the Y-axis extension direction as the positive angle direction, corresponding to the target vehicle point cloud passing through the plane Solve the three-dimensional coordinate value corresponding to the plane through which the target vehicle point cloud passes Solving the three-dimensional coordinate values; wherein the displacement data of the target vehicle is obtained according to the solved coordinate values =y1-y2=(-x1tan(π-θ)-x2tanθ).

6. A millimeter wave radar triggering method according to claim 5, characterized in that: The displacement constraint condition includes: setting the upper limit threshold of the displacement data , solve each point cloud n of the target vehicle on the boundary plane and the boundary plane The average of the upper difference = , when the average value Greater than the upper limit threshold of the displacement data , then the second millimeter-wave radar, camera and ETC sensing antenna are started to trigger the ETC deduction verification method.

7. A millimeter wave radar triggering method according to claim 6, characterized in that: Obtain the distance between the first millimeter-wave radar and the second millimeter-wave radar in the x-axis direction of the three-dimensional coordinate system l , and respectively obtain the point cloud data p=[x n ,y n ,z n ], n is the first millimeter wave radar point cloud identifier, and the point cloud data q=[x m ,y m ,z m ], m is the second millimeter-wave radar point cloud identifier. When the ETC fee deduction verification method is triggered, the feature similarity value is calculated between the point cloud data p of the target vehicle scanned by the first millimeter-wave radar and the point cloud data q scanned by the second millimeter-wave radar for the target vehicle, and a feature similarity threshold is set. If the feature similarity between the point cloud data p and the point cloud data q is greater than the preset feature similarity threshold, the second millimeter-wave radar generates a verification pass message.

8. The millimeter wave radar triggering method according to claim 1, characterized in that: When the ETC fee deduction verification method is triggered, the camera located at the second millimeter-wave radar is started, the license plate information of the target vehicle is photographed according to the verification pass message generated by the second millimeter-wave radar, and the ETC electronic tag information of the corresponding target vehicle is extracted according to the license plate information, and at the same time, the ETC electronic tag information in the previous ETC fee deduction data is extracted according to the ETC fee deduction sequence, and it is determined whether the ETC electronic tag information in the ETC fee deduction data is consistent with the ETC electronic tag information extracted according to the license plate information. If they are consistent, the verification is passed, and the lifting rod is started to release the target vehicle; If they are inconsistent, the second ETC sensing antenna near the second millimeter-wave radar is activated to re-identify the ETC electronic tag information of the target vehicle and execute the ETC deduction process.

9. A millimeter wave radar trigger system, characterized in that: The system executes a millimeter wave radar triggering method as described in any one of claims 1-8.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and the computer program is executed by a processor to implement a millimeter-wave radar triggering method as described in any one of claims 1-8.

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