ROS-based intelligent detection system and method for harmonic radar

Abstract

The present invention provides a harmonic radar intelligent detection system and method based on ROS, including: a PC and a harmonic radar detection AGV robot. The harmonic radar detection AGV robot includes: a harmonic radar, a lidar, an MCU central control, and an AGV motion chassis. The PC and the harmonic radar detection AGV robot perform data transmission through local area network communication. The harmonic radar, lidar, MCU central control, and AGV motion chassis perform communication transmission through serial ports. The intelligent harmonic radar based on the ROS system scans the ground, constructs a harmonic radar map, and then performs target detection. The present invention realizes a harmonic radar intelligent scanning system with functions of autonomous positioning, autonomous navigation, and autonomous path planning, improves the efficiency of staff in detecting and positioning hidden targets, and can perform large-range scanning.

Description

Technical Field

[0001] The present invention relates to the technical field of robot detection, and more specifically, to a harmonic radar intelligent detection system and method based on ROS. Background Art

[0002] A harmonic radar is a new type of non-linear node detection radar, which mainly utilizes the harmonic re-radiation characteristics of non-linear targets to identify targets based on the received re-radiation signals of non-linear targets. Traditional harmonic radars generally use handheld scanning, which requires high professionalism of operators and is prone to errors. Moreover, traditional harmonic radars do not have an imaging function, mainly judge based on the energy size of the detected target, have poor three-dimensional sense, and require high professionalism of operators. The present invention combines ROS (Robot Operating System) navigation with a harmonic radar for path planning scanning and three-dimensional imaging, making the harmonic radar map of the presented three-dimensional image more three-dimensional. It can better detect various ground hidden targets, including objects with PN nodes such as eavesdropping devices, electronic fuzes, time bombs, landmines, unexploded bombs, etc., and is applicable to important organs and departments such as national defense, security, public security, and ports.

[0003] Patent document CN106908771B (application number: CN201710081095.8) discloses a method for simulating radar target detection in a pulsed regime in a microwave anechoic chamber: first step, using an intermittent transceiver method to obtain target echo signals; second step, target echo recovery; third step, pulse compression to obtain target information; fourth step, target echo energy compensation information reconstruction. However, this patent's harmonic radar generally uses handheld scanning, which is prone to errors, and does not have an imaging function, mainly judges based on the energy size of the detected target, and has poor three-dimensional sense. Summary of the Invention

[0004] Aiming at the defects in the prior art, the purpose of the present invention is to provide a harmonic radar intelligent detection system and method based on ROS.

[0005] According to the harmonic radar intelligent detection system based on ROS provided by the present invention, it is characterized in that it includes: a PC and a harmonic radar detection AGV robot, and the harmonic radar detection AGV robot includes: a harmonic radar, a lidar, an MCU central control, and an AGV moving chassis;

[0006] The PC and the harmonic radar detection AGV robot perform data transmission through local area network communication, and the harmonic radar, lidar, MCU central control, and AGV moving chassis perform communication transmission through serial ports. The intelligent harmonic radar based on the ROS system scans the ground, constructs a harmonic radar map, and then performs target detection.

[0007] Preferably, the PC is equipped with a ROS robot system, and the mapping, navigation status, and three-dimensional holographic images are displayed through the visualization attack RVIZ.

[0008] Preferably, the measurement distance of the lidar is 25m indoors, the scanning frequency is 16,000 times per second, the angular resolution is 0.3375, and the lidar is placed 20cm above the robot for 360° omnidirectional scanning.

[0009] Preferably, the MCU central control sends motion commands to the vehicle bottom control board, sends acquisition commands to the harmonic radar and the lidar, and receives the odometer information uploaded by the vehicle bottom control board;

[0010] Nodes corresponding to the lidar and the harmonic radar are established according to the data collected by the harmonic radar and the lidar, and the lidar message format provided by the ROS system is used to transmit various types of data to the PC.

[0011] Preferably, the communication mode between the ROS system of the MCU central control and the lidar is a data message. The ROS system sends a request message, and the lidar sends a return message. The request / response mode is adopted between the two, which is initiated by the ROS system first. After the lidar is started, it starts scanning. The ROS system sends a request to the lidar, and the lidar executes relevant command operations after receiving the request.

[0012] Preferably, the AGV moving chassis includes a vehicle bottom control board, motor encoder wheels, and four omnidirectional wheels for platform positioning, navigation, and obstacle avoidance. When the ROS system of the MCU central control sends a motion command, the AGV moving chassis performs corresponding motions through the PID control algorithm.

[0013] Preferably, the harmonic radar is used for digital modulation waveforms, controls the selection of a random codebook for pulse modulation according to the processing gain setting instruction, and controls the precise adjustment of the transmit signal power by adjusting the output data amplitude according to the transmit power instruction.

[0014] Preferably, the harmonic radar is used for harmonic echo signal processing, including local correlation signal acquisition and preprocessing, second harmonic echo signal acquisition and preprocessing, and third harmonic echo signal acquisition, preprocessing, compression, and target detection.

[0015] According to the intelligent detection method of the harmonic radar based on ROS provided by the present invention, the execution includes:

[0016] Step 1: Start the ROS systems of the MCU central control and the PC, configure the local area network, and establish communication between the MCU central control and the PC through the Secure Shell Protocol;

[0017] Step 2: Initialize the AGV motion chassis, lidar, and harmonic radar. The ROS system of the MCU central control sends a request to the lidar;

[0018] Step 3: The MCU central control sends a motion instruction to the vehicle bottom control board. Through the PID algorithm, it controls the AGV motion chassis to move indoors and uploads the odometer data. At the same time, the ROS system of the MCU central control requests lidar data, and the lidar uploads the collected indoor data in the form of data packets;

[0019] Step 4: The MCU central control receives the transmitted odometer data and lidar data through the subscribed ROS nodes, uses the function packages provided by ROS to construct a grid map, and displays it in a visualization window using the RViz visualization tool in the ROS toolbox on the PC side;

[0020] Step 5: Re-import the established indoor grid map into the ROS system on the PC side, combine the global path planning and local path planning methods for full-coverage path planning, and perform full-path coverage through the bow-shaped search;

[0021] Step 6: When the AGV motion chassis performs the full-traversal path planning method movement, control the harmonic radar to work, collect harmonic radar data, and transmit it back to the ROS system of the MCU central control in the lidar data format;

[0022] Step 7: The MCU central control matches and correlates the transmitted odometer data and harmonic radar data, converts them into a rectangular coordinate system, and transmits them back to the ROS system on the PC side;

[0023] Step 8: After all the indoor maps have been traversed, use the surf function and mesh function of MATLAB, or draw a grid surface, plot the data points in space, connect them into a grid and draw the surface represented by the data points, and finally establish a two-dimensional and three-dimensional harmonic radar map;

[0024] Step 9: According to the harmonic radar map of the three-dimensional map, conduct various detections of ground hidden targets, and end the cruise after the detection is completed.

[0025] Preferably, the odometer information uploaded by the AGV motion chassis includes position, angle, forward speed, and steering speed.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The present invention realizes a harmonic radar intelligent scanning system with functions of autonomous positioning, autonomous navigation, and autonomous path planning, improves the efficiency of detecting and positioning hidden targets by staff, and can perform large-scale scanning;

[0028] 2. The present invention realizes the refined scanning of specific repetitive attention areas of the harmonic radar;

[0029] 3. The present invention establishes an omnidirectional two-dimensional and three-dimensional map of the harmonic radar, enabling the detection of various hidden electronic targets to be visualized, and conducting detection activities more intuitively, quickly, and accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] By reading the following detailed description of the non-restrictive embodiments with reference to the accompanying drawings, other features, objectives, and advantages of the present invention will become more apparent:

[0031] Figure 1 is the architecture diagram of the present invention;

[0032] Figure 2 is the framework diagram of the harmonic radar system;

[0033] Figure 3 is the entire workflow diagram;

[0034] Figure 4 is the schematic diagram of the bow-shaped search path planning;

[0035] Figure 5 is the schematic diagram of the improved path planning. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] The present invention will be described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several changes and improvements can still be made. These all fall within the protection scope of the present invention.

[0037] Embodiment:

[0038] As Figure 1 , is the architecture diagram of the intelligent detection method of the harmonic radar based on the ROS system. The system includes a PC terminal and a harmonic radar detection AGV robot. The harmonic radar detection AGV robot includes: a harmonic radar, a lidar, an MCU central control, and an AGV movement chassis.

[0039] The PC terminal and the harmonic radar detection AGV robot use local area network communication for data transmission. The harmonic radar, lidar, MCU central control, and AGV movement chassis use serial communication for transmission. The intelligent harmonic radar based on the ROS system scans the ground to construct a harmonic radar map, and then conducts more accurate and rapid target detection, improving the detection accuracy and expanding the application range.

[0040] Introduce the specific implementation methods of each part:

[0041] PC side: A notebook computer installed with ROS Kinetic Kame robot system and MATLAB, using RVIZ to display mapping, navigation status, and three-dimensional holographic images.

[0042] Lidar: The RPLIDAR A3 lidar from Slan Technology (SLAMTEC) is used. Its measurement distance is 25m indoors, the scanning frequency is 16,000 times per second, and the angular resolution is 0.3375. The lidar is placed 20cm above the robot to ensure 360° omnidirectional scanning. The communication between the ROS system of the MCU and the lidar uses the data message communication method. The ROS system sends a request message, and the lidar sends a return message. The two use a request / response mode, initiated by the ROS system first. After the lidar is started, the core ranging module has already started scanning. The ROS system sends a request to the lidar, and the lidar executes relevant command operations after receiving the request.

[0043] The MCU central control unit sends motion commands to the vehicle bottom control board, and sends acquisition commands to the harmonic radar and the lidar; and receives the odometer information uploaded by the vehicle bottom control board, establishes nodes corresponding to the lidar and the harmonic radar, as well as the amplitude-phase data sensor_msgs / HoloScan of the harmonic radar, and the data of the lidar is the most basic lidar message format sensor_msgs / LaserScan provided for the ROS system; and transmits various types of data to the PC side.

[0044] The AGV motion chassis consists of a vehicle bottom control board, motor encoder wheels, and four omnidirectional wheels, and completes basic functions such as platform positioning, navigation, and obstacle avoidance. When the ROS system of the MCU sends a motion command, the AGV motion chassis performs corresponding motions through the PID control algorithm.

[0045] Figure 2 It is the framework diagram of the harmonic radar system, mainly including two parts: digital modulation waveform generation and harmonic echo signal processing. Among them, the digital modulation waveform selects a random codebook according to the processing gain setting instruction control, then completes pulse modulation, and realizes precise control of the transmitted signal power adjustment through output data amplitude adjustment according to the transmission power instruction control. The harmonic echo signal processing unit includes local correlation signal acquisition and preprocessing, second harmonic echo signal acquisition and preprocessing, third harmonic echo signal acquisition and preprocessing, correlation compression and target detection, etc.

[0046] Figure 3 It is the entire workflow diagram of the intelligent detection method of the harmonic radar based on the ROS system, and its steps are as follows:

[0047] (1) Initialization: Start the MCU and the ROS system on the PC side, configure the local area network, and establish communication between the MCU central control module and the PC side through SSH (Secure Shell).

[0048] (2) Initialize the AGV (Automated Guided Vehicle) moving chassis, lidar, and harmonic radar. The ROS system of the MCU sends a request to the lidar to request data.

[0049] (3) The central control module sends a motion command to the vehicle bottom control board. Through the PID algorithm, it controls the AGV moving chassis to walk indoors and uploads odometer data. At the same time, the ROS system of the MCU requests lidar data, and the lidar uploads the collected indoor data in the form of data packets. The AGV moving chassis uploads odometer information, one is the pose (position and angle), that is, (x, y, θ), and the other is the speed (forward speed and steering speed).

[0050] (4) The central control module receives the transmitted odometer data and lidar data through the subscribed ROS node, uses the slam_gmapping function package provided by ROS to construct a grid map, and displays it in the visualization window of RViz, a visualization tool in the ROS toolbox on the PC.

[0051] (5) Import the established indoor grid map back into the ROS system on the PC side, combine the global path planning and local path planning methods to achieve full-coverage path planning, achieve full-path coverage, and perform a bow-shaped search, searching like plowing the land one by one.

[0052] (6) When the moving chassis performs the complete traversal path planning method movement, at the same time, control the harmonic radar to work, collect harmonic radar data, and transmit it back to the ROS system of the MCU central control module through sensor_msgs / HoloScan.

[0053] (7) The MCU matches and associates the transmitted odometer data and harmonic radar data, converts them into a Cartesian coordinate system, so that the collected harmonic radar data has position information, and transmits it back to the ROS system on the PC side.

[0054] (8) After the entire indoor map has been traversed, use the surf function and mesh function provided by MATLAB, or draw a mesh surface, plot the data points in space and connect them into a mesh, draw a complete surface, and draw the surface represented by the data points, and finally establish a two-dimensional and three-dimensional harmonic radar map.

[0055] (9) Detect various ground hidden targets based on the harmonic radar map of the three-dimensional map.

[0056] (10) End of cruise.

[0057] The configuration of the local area network includes but is not limited to building an unlimited communication channel through portable WIFI, routers, etc., so as to facilitate users to perform remote operation and monitoring.

[0058] The central control module adopts an X86 architecture MCU with an ROS system installed. It is small in size, light in weight, and low in energy consumption. It is suitable for being mounted on a mobile robot platform, receiving odometer information, harmonic radar, and lidar data, and sending motion and collection instructions to the vehicle's bottom control panel, harmonic radar, and lidar.

[0059] The AGV motion chassis, which consists of a vehicle bottom control board, a motor encoder wheel, and four omnidirectional wheels, carries the platform's basic functions such as positioning, navigation, and obstacle avoidance, helping the robot achieve intelligent walking.

[0060] In the complete traversal path planning method, the mobile robot must pass through all points in all target areas to complete full coverage, and the covered paths are continuous and orderly, realizing a search one by one like plowing land.

[0061] The harmonic radar is composed of an antenna, a transmitting RF front end, a receiving RF front end, a system control unit and a data acquisition two-dimensional signal processing system. It is mounted at the bottom of the AGV motion chassis, transmits radar signals, receives transmitted electromagnetic waves, and receives transmitted electromagnetic wave signals.

[0062] The three-dimensional imaging module combines the harmonic radar data with the location information with the map, and uses the three-dimensional map provided by Matlab to draw the harmonic radar map, thereby achieving the purpose of detecting hidden targets.

[0063] Figure 4 This is a schematic diagram of a bow-shaped search path planning method. This path planning method searches the area one by one like a field. This path is standardized, has high scanning efficiency, and can return to the origin after completing the area scan.

[0064] Figure 5 For the improved version of path planning, when there are obstacles, the path can be reasonably arranged to efficiently complete the refined scanning in the area, and the path planning scheme is based on multiple.

[0065] Those skilled in the art know that, in addition to implementing the systems, devices, and their respective modules provided by the present invention in the form of pure computer-readable program code, it is entirely possible to achieve the same program by logically programming the method steps so that the systems, devices, and their respective modules provided by the present invention are implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, embedded microcontrollers, etc. Therefore, the systems, devices, and their respective modules provided by the present invention can be considered as a kind of hardware components, and the modules included therein for implementing various programs can also be regarded as the structures within the hardware components; the modules for implementing various functions can also be regarded as either software programs for implementing the methods or the structures within the hardware components.

[0066] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be combined arbitrarily with each other.

Claims

1. A harmonic radar intelligent detection system based on ROS, characterized in that, it includes: A PC and a harmonic radar detection AGV robot, and the harmonic radar detection AGV robot includes: a harmonic radar, a lidar, an MCU central control, and an AGV movement chassis; The PC and the harmonic radar detection AGV robot perform data transmission through local area network communication. The harmonic radar, lidar, MCU central control, and AGV movement chassis perform communication transmission through serial ports. The intelligent harmonic radar based on the ROS system scans the ground to construct a harmonic radar map, and then performs target detection; The process of the intelligent harmonic radar based on the ROS system scanning the ground to construct a harmonic radar map is as follows: Step 1: Start the ROS systems of the MCU central control and the PC, configure the local area network, and establish communication between the MCU central control and the PC through the Secure Shell protocol; Step 2: Initialize the AGV movement chassis, lidar, and harmonic radar. The ROS system of the MCU central control sends a request to the lidar; Step 3: The MCU central control sends a movement instruction to the vehicle bottom control board. Through the PID algorithm, it controls the AGV movement chassis to walk indoors and uploads odometer data. At the same time, the ROS system of the MCU central control requests lidar data, and the lidar uploads the collected indoor data in the form of data packets; Step 4: The MCU central control receives the transmitted odometer data and lidar data through the subscribed ROS nodes, uses the function packages provided by ROS to construct a grid map, and displays it in a visual window form using the RViz visualization tool in the ROS toolbox on the PC; Step 5: Re-import the established indoor grid map into the ROS system of the PC, combine the global path planning and local path planning methods to perform full-coverage path planning, and perform full-path coverage through the bow-shaped search; Step 6: When the AGV movement chassis performs the complete traversal path planning method movement, control the harmonic radar to work, collect harmonic radar data, and transmit it back to the ROS system of the MCU central control in the lidar data format; Step 7: The MCU central control matches and associates the transmitted odometer data and harmonic radar data, converts them into a rectangular coordinate system, and transmits them back to the ROS system of the PC; Step 8: After the entire indoor map has been traversed, use the surf function and mesh function of MATLAB, or draw a grid surface, plot the data points in space, connect them into a grid, and draw the surface represented by the data points. Finally, establish a two-dimensional and three-dimensional solid harmonic radar map; Step 9: According to the harmonic radar map of the three-dimensional map, perform various detections of ground hidden targets, and end the cruise after the detection is completed.

2. The harmonic radar intelligent detection system based on ROS according to claim 1, characterized in that, The PC is equipped with a ROS robot system, and displays the mapping, navigation status, and three-dimensional holographic images through the visual attack RVIZ.

3. The harmonic radar intelligent detection system based on ROS according to claim 1, characterized in that, The measurement distance of the lidar is 25 m indoors, the scanning frequency is 16,000 times per second, the angular resolution is 0.3375, and the lidar is placed 20 cm above the robot for 360° omnidirectional scanning.

4. The ROS-based intelligent detection system of harmonic radar according to claim 1, characterized in that the MCU central control sends motion instructions to the vehicle bottom control board, sends acquisition instructions to the harmonic radar and the lidar, and receives the odometer information uploaded by the vehicle bottom control board; Nodes corresponding to the lidar and the harmonic radar are established according to the data collected by the harmonic radar and the lidar, and the lidar message format provided by the ROS system is used to transfer various types of data to the PC side.

5. The ROS-based intelligent detection system of harmonic radar according to claim 1, characterized in that The communication mode between the ROS system of the MCU central control and the lidar is through data packets. The ROS system sends a request packet, and the lidar sends a return packet. The request / response mode is adopted between the two, initiated by the ROS system first. After the lidar is started, it begins to scan and work. The ROS system sends a request to the lidar, and the lidar executes relevant command operations after receiving the request.

6. The ROS-based intelligent detection system of harmonic radar according to claim 1, characterized in that The AGV moving chassis includes a vehicle bottom control board, motor encoder wheels and four omnidirectional wheels for platform positioning, navigation and obstacle avoidance. When the ROS system of the MCU central control sends a motion instruction, the AGV moving chassis performs corresponding motions through the PID control algorithm.

7. The ROS-based intelligent detection system of harmonic radar according to claim 1, characterized in that The harmonic radar is used for digital modulation waveforms, controls the selection of a random codebook for pulse modulation according to the processing gain setting instruction, and controls the precise adjustment of the transmitted signal power by adjusting the output data amplitude according to the transmission power instruction.

8. The ROS-based intelligent detection system of harmonic radar according to claim 1, characterized in that The harmonic radar is used for harmonic echo signal processing, including local correlation signal acquisition and preprocessing, second harmonic echo signal acquisition and preprocessing, and third harmonic echo signal acquisition, preprocessing, compression and target detection.

9. The ROS-based intelligent detection system of harmonic radar according to claim 1, characterized in that The odometer information uploaded by the AGV moving chassis includes position, rotation angle, forward speed and steering speed.

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