A road vehicle monitoring and height warning system combining traffic radar and 4D millimeter wave radar

Abstract

A road vehicle monitoring and height warning system combining traffic radar and 4D millimeter wave radar comprises a radar sensor detection group, a high pitch resolution antenna array unit, a radar layout architecture unit, a cloud data processing unit and a road warning device unit; the radar sensor detection group comprises a traffic radar and a 4D millimeter wave radar; the high pitch resolution antenna array unit is installed on the 4D millimeter wave radar to provide it with high pitch resolution; the radar layout architecture unit installs the 4D millimeter wave radar on both sides of the road and the traffic radar in the middle of the road, so that the radar sensor detection group can detect the information of all vehicles on the road; the cloud data processing unit processes and integrates data, obtains and transmits the unique ID, speed, position and height information of all vehicles on the road, and performs height discrimination on the vehicles; the road warning device unit is installed on the road, receives an alarm instruction, and provides a vehicle over-height warning. The invention can provide height information of road vehicles.

Description

Technical Field

[0001] The present invention belongs to the technical field of radar detection and radar signal processing, and in particular relates to a road vehicle monitoring and height warning system combining traffic radar and 4D millimeter wave radar, which is used to provide vehicle position, speed and height information. Background Art

[0002] Realizing urban traffic control based on road vehicle information is one of the important applications of intelligent transportation systems. Millimeter-wave radar is widely used in monitoring and obtaining road traffic vehicle information due to its advantages such as high ranging and speed measurement accuracy brought by high bandwidth, and all-weather operation brought by high environmental robustness. However, although commonly used traffic radars or traffic monitoring sensors can obtain vehicle speed and distance information more accurately, they lack the means to obtain vehicle height information, which results in incomplete road vehicle information provided to the intelligent transportation system. Especially in height-restricted sections, the lack of height information perception and road warning of traffic sensors causes traffic jams, vehicle rollovers, falling objects and other traffic safety accidents due to the entry of over-height vehicles, which not only endangers the lives of drivers but also hinders the development and application of intelligent transportation systems. Summary of the invention

[0003] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a road vehicle monitoring and height warning system that combines traffic radar and 4D millimeter-wave radar, so as to make up for the lack of height information in traditional radar systems when acquiring target information and provide vehicle overheight warning for height-restricted sections.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A road vehicle monitoring and height warning system combining traffic radar and 4D millimeter wave radar, comprising:

[0006] Radar sensor detection group, including several traffic radars and several 4D millimeter wave radars, used to obtain the speed, position and height information of all vehicles on the road;

[0007] A high elevation resolution antenna array unit is installed on the 4D millimeter wave radar, and forms a high elevation synthetic aperture in combination with a MIMO transmission mode, thereby providing a high elevation resolution for the 4D millimeter wave radar system;

[0008] A radar layout architecture unit, including two side sections of the road for installing 4D millimeter-wave radars and a central section of the road for installing traffic radars, wherein the layout enables the combination of traffic radars and 4D millimeter-wave radars to detect information of all vehicles on the road;

[0009] The cloud data processing unit is used to receive data detected by traffic radar and 4D millimeter wave radar, obtain and transmit the unique ID, speed, location and altitude information of all vehicles on the road by processing and integrating the data, and perform altitude determination on the vehicles;

[0010] The road warning device unit is installed on the road, receives alarm instructions, and provides vehicle overheight warning.

[0011] In one embodiment, the traffic radar is used to obtain the distance, precise speed, and ID information between the vehicle and the traffic radar; the 4D millimeter wave radar is used to obtain the height, rough speed, and relative distance of the vehicle from the 4D millimeter wave radar; the 4D millimeter wave radar includes:

[0012] The antenna unit uses an array antenna to transmit electromagnetic waves and receive vehicle echo signals;

[0013] A baseband processing unit, used for converting the vehicle echo signal from an analog signal to a digital signal;

[0014] The signal processing unit uses a two-dimensional fast Fourier transform, namely, a distance-dimensional fast Fourier transform and a speed-dimensional fast Fourier transform, to extract the vehicle's height, rough speed and relative distance information from the digital signal.

[0015] In one embodiment, the high elevation resolution antenna array unit comprises:

[0016] The antenna array unit consists of 12 transmitting antennas and 16 receiving antennas. The antenna array transmits electromagnetic waves outward and receives the reflected signals from the vehicle in a wide beam scanning mode of 3° in elevation and 2.5° in azimuth.

[0017] The antenna array control unit controls the transmission mode of the transmitting antenna in the antenna array unit to obtain a high pitch angle resolution, i.e., 3° ​​in pitch dimension, so as to obtain accurate height information of the vehicle.

[0018] In one embodiment, in the antenna array unit, the transmitting antennas are arranged with a directional dimension spacing of 4λ and a pitch dimension spacing of 8λ, and the receiving antennas are arranged with a directional dimension spacing of λ / 2 and a pitch dimension spacing of λ / 2. The radar adopts a MIMO transmission mode to form a 12×16 virtual antenna array.

[0019] In one embodiment, in the radar layout architecture unit, the two sides of the road are multiple groups of vertical poles distributed on both sides of the road, each group of vertical poles has two, and are symmetrically arranged about the road. Every two 4D millimeter-wave radars form a group and are respectively installed on the two vertical poles in each group, and the beam direction is perpendicular to the driving direction of vehicles on the road. The spacing of the 4D millimeter-wave radars along the driving direction of vehicles on the road enables to cover the entire lane section; the central part of the road is a cross bar set above the road and perpendicular to the driving direction of vehicles. The traffic radar is installed on the cross bar, and the beam direction is parallel to the driving direction of vehicles on the road.

[0020] In one embodiment, the cloud data processing unit includes:

[0021] A data receiving unit, used for receiving all radar data;

[0022] The coordinate conversion and matching unit converts the vehicle distance and precise speed information obtained from the traffic radar and the vehicle height, rough speed and relative distance information obtained from the 4D millimeter-wave radar into a unified coordinate system, and matches the vehicle according to the vehicle information obtained from the traffic radar and the 4D millimeter-wave radar (the 4D millimeter-wave radar will automatically number the vehicle when tracking it), and finally realizes the unification of vehicle ID, vehicle speed, vehicle position and vehicle height information;

[0023] The alarm decision unit determines the height of the road vehicle and gives an alarm instruction based on the prior information of the height limit device;

[0024] Data output unit: outputs information including vehicle ID, vehicle speed, vehicle position and vehicle height to the traffic management department, provides the traffic management department with more complete road vehicle information, and issues alarm instructions to the outside.

[0025] In one embodiment, the coordinate conversion and matching unit matches the frame frequency and frame timestamp of the radar data, converts the radar data in different coordinate systems into a unified coordinate system, and realizes the unification of vehicle speed, distance and height information.

[0026] In one embodiment, the road warning device unit comprises:

[0027] A command receiving unit, used to receive the alarm command given by the cloud processing unit and instruct the road warning device to send a high alarm signal;

[0028] The execution unit completes the corresponding instruction operation according to the received instruction.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1) The present invention adopts 4D millimeter wave radar as a height measuring device, which has high-precision pitch resolution, thereby realizing the acquisition of target speed, distance and height information.

[0031] 2) The present invention proposes a radar layout architecture, which effectively reduces the system cost and ensures that the system can achieve comprehensive detection of vehicle information on the road without adding other sensors and additional installation platforms.

[0032] 3) The present invention solves the deficiency that the traditional detection method can only obtain vehicle speed and distance information, and can accurately obtain vehicle height information to assist in the management of urban traffic conditions.

[0033] 4) The present invention has an early warning service function. When an over-height vehicle is found on the road, the road early warning device will issue an early warning to remind the driver that the vehicle is over-height and needs to take a detour. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a system structure block diagram of the present invention.

[0035] Figure 2 It is a schematic diagram of the system application of the present invention.

[0036] Figure 3 It is a functional block diagram of the radar sensor detection group in the system of the present invention.

[0037] Figure 4 It is a schematic diagram of a high elevation resolution antenna array unit in the system of the present invention.

[0038] Figure 5 It is a schematic diagram of the radar layout architecture unit in the system of the present invention.

[0039] Figure 6 It is a structural block diagram of the cloud data processing unit in the system of the present invention. DETAILED DESCRIPTION

[0040] The embodiments of the present invention are described in detail below with reference to the accompanying drawings and examples.

[0041] In order to solve the problem that the current intelligent transportation system has not considered the vehicle height limit and there is no effective means to monitor the vehicle height, the present invention provides a road vehicle monitoring and height warning system that combines traffic radar and 4D millimeter wave radar. By designing a high pitch resolution antenna array, the 4D millimeter wave radar is guaranteed to have a high angular resolution, so that it has the ability to detect target size, especially target height; by designing the radar layout architecture, the 4D millimeter wave radar is symmetrically installed on both sides of the road according to a specific layout, and combined with the traffic radar, it can achieve comprehensive monitoring of road conditions; the detected data is processed by the cloud data processing unit to obtain the vehicle's unique ID, vehicle position, speed, height and direction information, so that the traffic supervision department can grasp more comprehensive road vehicle information, especially, the alarm decision unit can judge the vehicle height and give an alarm message. In addition, after receiving the alarm command, the alarm system can implement an early warning for over-height vehicles, effectively prevent illegal vehicles from entering, avoid accidents, and further assist urban traffic management.

[0042] Specifically, refer to Figure 1 The road vehicle monitoring and height warning system of the combined traffic radar and 4D millimeter wave radar of the present invention mainly includes a radar sensor detection group, a high pitch resolution antenna array unit, a radar layout architecture unit, a cloud data processing unit and a road warning device unit. The radar sensor detection group is used to obtain the speed, position and height information of the target (i.e., the vehicle on the road), and it includes several traffic radars and several 4D millimeter wave radars. Among them, the high pitch resolution antenna array unit is installed on the 4D millimeter wave radar, controlled by the antenna control unit, and combined with the MIMO transmission mode to form a high pitch synthetic aperture, providing a high pitch resolution for the 4D millimeter wave radar system. The system of the present invention adopts a radar layout architecture unit, installs the 4D millimeter wave radar in a specific layout, and combines the traffic radar to detect vehicle information in combination. For example, it includes two sides of the road and the central part of the road, wherein the 4D millimeter wave radar is installed on both sides of the road, and the traffic radar is installed in the central part of the road. Its layout enables the combination of traffic radar and 4D millimeter wave radar to realize information detection of all vehicles on the road. The cloud data processing unit processes and integrates the data detected by the traffic radar and 4D millimeter wave radar, obtains and transmits the unique ID, speed, location and height information of all vehicles on the road, and performs height judgment on the vehicles. The road warning device unit is installed on the road, receives the alarm command, and provides vehicle overheight warning in the form of pictures, text, sound, lights, etc.

[0043] Reference Figure 2, is the application diagram of this system. The radar sensors of this system are installed on urban roads in a specific layout to fully obtain the speed, position and height information of road vehicles. Specifically, the traffic radar can be installed on the traffic light tower at the intersection, which can obtain the ID information, precise speed and distance between the target and the traffic radar (thus obtaining the precise position of the target). The 4D millimeter wave radar is symmetrically installed on the guardrails on both sides of the road, which can obtain the precise height, rough speed and relative distance of the target from the 4D millimeter wave radar (thus obtaining the precise position of the target). The cloud data processing unit of this system receives all vehicle information data detected by the radar and performs further analysis and processing; through data conversion and matching, the unification of vehicle speed, vehicle position and vehicle height information is achieved; when a vehicle is found to be over-height on the road, an alarm command is output. The road warning device of this system can be installed at a distance in front of the intersection of the height-restricted section. After receiving the alarm command, it will issue a warning to remind the driver of the height restriction ahead.

[0044] Reference Figure 3 In the radar sensor detection group of the present invention, the traffic radar is used to obtain the distance, precise speed, and ID information of the target; the 4D millimeter wave radar system adopts a symmetrically installed 4D millimeter wave radar group to obtain the height, rough speed and relative distance information of the target. The 4D millimeter wave radar of the present invention includes an antenna unit, a baseband processing unit and a signal processing unit. The electromagnetic signal received by the 4D millimeter wave radar passes through the baseband processing unit and the signal processing unit in sequence to obtain the height, rough speed and relative distance information of the target. Specifically, the antenna unit can be in the form of an array antenna, which emits electromagnetic waves and receives vehicle echo signals. The baseband processing unit converts the vehicle echo signal from an analog signal to a digital signal and sends it to the back-end signal processing unit. The signal processing unit uses a 2D fast Fourier transform, i.e., a distance dimension fast Fourier transform and a speed dimension fast Fourier transform, to further process the digital signal, and can extract the rough speed, relative distance, angle, height and other information of the vehicle contained therein, and finally sends this information to the cloud data processing unit for processing.

[0045] The high pitch resolution antenna array unit of the present invention comprises an antenna array unit and an antenna array control unit. The antenna array unit is composed of 12 transmitting antennas and 16 receiving antennas. The antenna array transmits electromagnetic waves outward in a wide beam scanning mode of 2 to 3° in pitch dimension and 2.5° in direction dimension and receives the reflected signal of the vehicle. The antenna array control unit controls the transmission mode of the transmitting antenna in the antenna array unit to obtain a high pitch angle resolution, i.e., a pitch dimension of 2 to 3°, thereby obtaining accurate height information of the vehicle.

[0046] Reference Figure 4In the antenna array unit of the present invention, the transmitting antennas are arranged with a directional dimension spacing of 4λ and a pitch dimension spacing of 8λ, and the receiving antennas are arranged with a directional dimension spacing of λ / 2 and a pitch dimension spacing of λ / 2. The radar adopts the MIMO transmission mode to form a 12×16 virtual antenna array.

[0047] Reference Figure 5 In the radar layout architecture unit of the present invention, the central part of the road is a crossbar set above the road and perpendicular to the direction of vehicle travel. The traffic radar is installed on the crossbar, and the beam direction is parallel to the direction of vehicle travel on the road, accurately detecting the speed and distance information of the vehicle. The two sides of the road are multiple groups of vertical poles distributed on both sides of the road or existing guardrails on both sides of the road. Each group of vertical poles has two, and can be symmetrically arranged about the road. Every two 4D millimeter-wave radars form a group, which are symmetrically installed on the two vertical poles of each group or on both sides of the road guardrail, and the beam direction is perpendicular to the direction of vehicle travel on the road. The spacing of the 4D millimeter-wave radar along the direction of vehicle travel on the road enables the entire road section to be covered. For example, the entire road section is covered with a spacing of 200 meters, and the road section is detected in a wide beam scanning mode of 2-3° in pitch dimension and 2.5° in direction dimension to accurately obtain the height information of the vehicle. The traffic radar and the 4D millimeter-wave radar are combined for detection to obtain the speed, position and height information of the vehicle.

[0048] Reference Figure 6The cloud data processing unit of the present invention includes: a data receiving unit, a coordinate conversion and matching unit, an alarm decision unit and a data output unit. The data receiving unit collects data detected by radars at different locations. Due to the different installation locations of traffic radar and 4D millimeter wave radar, the location information detected by different radars for the same vehicle is different. Through the coordinate conversion and matching unit, the frame frequency and frame timestamp of the radar data are matched, and the data in the two coordinate systems (i.e., the vehicle distance and precise speed information obtained from the traffic radar and the vehicle height, rough speed and relative distance information obtained from the 4D millimeter wave radar) are converted to a unified coordinate system. When tracking the target, the radar will number the target and match the vehicle according to the detected vehicle information, and finally realize the unification of vehicle ID, vehicle speed, vehicle position and vehicle height information. The alarm decision unit judges the height of the road vehicle and gives an alarm instruction based on the prior information of the height limit device. If the height of the vehicle does not exceed the road height limit, the vehicle drives normally; if the height of a vehicle exceeds the road height limit, the system will send the warning instruction to the warning device on the road through the data output unit to remind the driver that the vehicle is overheight and needs to detour in advance. The warning instruction includes at least vehicle information (mainly vehicle ID, such as license plate number) and instruction content, and may also include vehicle speed, vehicle position and vehicle height. Optional forms include: license plate number + "height limit at xx meters ahead, your vehicle has exceeded the height, please detour in advance". In addition, the data output unit will also send vehicle information on the road to the traffic management department, so that the traffic management department can grasp more comprehensive road vehicle information and better assist urban traffic management.

[0049] The road warning device unit of the present invention includes a command receiving unit and an execution unit, wherein the command receiving unit receives the alarm command given by the cloud processing unit to instruct the road warning device to send a high alarm signal; the execution unit completes the corresponding instruction operation according to the received command.

Claims

1. A road vehicle monitoring and height warning system combining traffic radar and 4D millimeter wave radar, characterized in that: include: Radar sensor detection group, including several traffic radars and several 4D millimeter wave radars, used to obtain the speed, position and height information of all vehicles on the road; The traffic radar is used to obtain the distance, precise speed, and ID information between the vehicle and the traffic radar; the 4D millimeter wave radar is used to obtain the height, rough speed, and relative distance of the vehicle from the 4D millimeter wave radar; A high elevation resolution antenna array unit is installed on the 4D millimeter wave radar, and forms a high elevation synthetic aperture in combination with a MIMO transmission mode, thereby providing a high elevation resolution for the 4D millimeter wave radar system; A radar layout architecture unit, including two side sections of the road for installing 4D millimeter-wave radars and a central section of the road for installing traffic radars, wherein the layout enables the combination of traffic radars and 4D millimeter-wave radars to detect information of all vehicles on the road; The cloud data processing unit is used to receive data detected by traffic radar and 4D millimeter wave radar, obtain and transmit the unique ID, speed, location and altitude information of all vehicles on the road by processing and integrating the data, and perform altitude determination on the vehicles; The road warning device unit is installed on the road, receives the alarm command, and provides vehicle overheight warning; Wherein, the high elevation resolution antenna array unit comprises: The antenna array unit consists of 12 transmitting antennas and 16 receiving antennas. The antenna array transmits electromagnetic waves outward and receives the reflected signals from the vehicle in a wide beam scanning mode of 3° in elevation and 2.5° in azimuth. The transmitting antennas are arranged with a azimuth spacing of 4λ and an elevation spacing of 8λ, and the receiving antennas are arranged with a azimuth spacing of λ / 2 and an elevation spacing of λ / 2. The radar adopts MIMO transmission mode to form a 12×16 virtual antenna array. The antenna array control unit controls the transmission mode of the transmitting antenna in the antenna array unit to obtain a high pitch angle resolution, i.e., a pitch dimension of 3°, thereby obtaining accurate height information of the vehicle; The cloud data processing unit includes: A data receiving unit, used for receiving all radar data; The coordinate conversion and matching unit converts the vehicle distance and precise speed information obtained from the traffic radar and the vehicle height, rough speed and relative distance information obtained from the 4D millimeter-wave radar into a unified coordinate system, and matches the vehicle according to the vehicle information obtained from the traffic radar and the 4D millimeter-wave radar, ultimately unifying the vehicle ID, vehicle speed, vehicle position and vehicle height information; The alarm decision unit determines the height of the road vehicle and gives an alarm instruction based on the prior information of the height limit device; Data output unit: outputs information including vehicle ID, vehicle speed, vehicle position and vehicle height to the traffic management department, provides the traffic management department with more complete road vehicle information, and issues alarm instructions to the outside.

2. The road vehicle monitoring and height warning system combining traffic radar and 4D millimeter wave radar according to claim 1 is characterized in that: The 4D millimeter wave radar includes: The antenna unit uses an array antenna to transmit electromagnetic waves and receive vehicle echo signals; A baseband processing unit, used for converting the vehicle echo signal from an analog signal to a digital signal; The signal processing unit uses a two-dimensional fast Fourier transform, namely, a distance-dimensional fast Fourier transform and a speed-dimensional fast Fourier transform, to extract the vehicle's height, rough speed and relative distance information from the digital signal.

3. The road vehicle monitoring and height warning system combining traffic radar and 4D millimeter wave radar according to claim 1 is characterized in that: In the radar layout architecture unit, the two sides of the road are multiple groups of vertical poles distributed on both sides of the road, each group of vertical poles has two, and are symmetrically arranged about the road. Every two 4D millimeter-wave radars form a group and are respectively installed on the two vertical poles in each group, and the beam direction is perpendicular to the driving direction of vehicles on the road. The spacing of the 4D millimeter-wave radars along the driving direction of vehicles on the road enables to cover the entire lane section; the central part of the road is a cross bar set above the road and perpendicular to the driving direction of vehicles. The traffic radar is installed on the cross bar, and the beam direction is parallel to the driving direction of vehicles on the road.

4. The road vehicle monitoring and height warning system combining traffic radar and 4D millimeter wave radar according to claim 1 is characterized in that: In the coordinate conversion and matching unit, the frame frequency and frame timestamp of the radar data are matched, and the radar data in different coordinate systems are converted into a unified coordinate system to achieve the unification of vehicle speed, distance and height information.

5. The road vehicle monitoring and height warning system combining traffic radar and 4D millimeter wave radar according to claim 1 is characterized in that: The road warning device unit comprises: A command receiving unit, used to receive the alarm command given by the cloud processing unit and instruct the road warning device to send a high alarm signal; The execution unit completes the corresponding instruction operation according to the received instruction.

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