Multi-node mutual positioning method and system in complex environment

Abstract

The invention discloses a multi-node mutual positioning method and system in a complex environment, each node can be set as a master node or a slave node, and the nodes realize a mutual positioning function by transmitting and receiving triangular wave frequency modulation continuous wave signal waveforms; when working in a master node mode, the node is synchronized with working signals of other slave nodes through coarse synchronization and fine synchronization steps, then distance information of the slave nodes is obtained through round-trip flight time calculation, distance information of the slave nodes is obtained through Doppler frequency shift calculation, angle information of the slave nodes is estimated through a DOA method, and positioning of the slave nodes is completed; when the node works in the slave node mode, a to-be-synchronized signal sent by the master node is waited, the to-be-synchronized signal is synchronized with the signal of the master node through the steps of coarse synchronization and fine synchronization, and then the synchronized signal is sent to the master node so that the master node can locate the position of the slave node. According to the method, high-precision mutual positioning among multiple nodes is realized through a working principle of realizing the frequency modulation continuous wave radar among the nodes.

Description

Technical Field

[0001] The present invention belongs to the field of mutual positioning systems for autonomous mobile robots, and in particular relates to a multi-node mutual positioning method and system in a complex environment. Background Art

[0002] As the industrialization process continues to accelerate, autonomous mobile robots (AMRs) can demonstrate excellent characteristics in high-risk, complex, and repetitive tasks, and have broad application prospects in logistics warehousing, automated transportation systems, and even wars. Autonomous mobile robots are regarded as multiple mobile node subsystems. If the subsystems can share information and coordinate with each other, the system as a whole can obtain stronger functions. The information coordination between multiple nodes also greatly increases the working range and working stability of the relevant platform. It can complete tasks in an environment with high time-varying, high dynamics, and high randomness, such as the transportation of important materials, large-scale search and rescue in the wild, and complex and changeable battlefields. Therefore, it is of great significance to study efficient and easy-to-network multi-node mutual positioning algorithms.

[0003] The concept of multi-node mutual positioning was proposed as early as the 1960s. In the early days, multi-node mutual positioning methods mainly used GNSS positioning. In harsh and complex environments, such as when there are a large number of trees or other obstructions, the navigation and positioning capabilities of GNSS will become unstable, and GNSS positioning will not work in indoor environments; positioning can also be achieved by scanning surrounding objects through vision or lidar technology to establish a map. Such systems have excellent positioning accuracy, but they are expensive and easily affected by weather and light, and are not suitable for use in outdoor or indoor environments with smoke, rain and fog; using WIFI or Bluetooth solutions can meet low positioning delays when using RSSI positioning algorithms, and are easy to combine multiple sensor data, but the positioning accuracy it can provide is poor, and it requires additional system assistance, and has low flexibility in complex and changeable environments; therefore, the autonomous mobile robot using the multi-node mutual positioning technology of the radar system does not require additional system assistance, and can achieve local node mutual positioning through the coordination of information from each sensor, and can improve the accuracy and reliability of positioning by improving the redundancy of information through multi-sensor fusion, and can also achieve accurate and stable mutual positioning in outdoor environments with changeable weather or indoor environments full of smoke.

[0004] At present, the main multi-node mutual positioning methods using radar systems include Angle of Arrival (AOA) positioning technology, Received Signal Strength Indication (RSSI) positioning technology, Time of Arrival (TOA) positioning technology, and Time Difference of Arrival (TDOA) positioning technology. Among them, the AOA positioning technology has a simple idea and a small amount of data, but the accuracy is poor; the RSSI positioning method has a low cost and low power, but many factors such as signal reflection, non-line-of-sight error, and antenna gain will have a great impact on this method; using TOA or TDOA technology can achieve high-precision positioning, but it requires the precise clock offset between the mutually positioned nodes to be known, and the angle cannot be measured. Summary of the invention

[0005] The purpose of the present invention is to provide a multi-node mutual positioning method and system in a complex environment. The nodes use a radar system, adopt a linear frequency modulation continuous wave to use the round-trip flight time (RTOF) to measure the distance and speed, and add multiple antennas to use the direction of arrival (DOA) estimation method to measure the angle, so as to achieve high-precision and reliable positioning between multiple nodes, and have good working performance in a complex environment. The node subsystem using the radar system is also flexible and can process multi-sensor data.

[0006] The technical solution to achieve the purpose of the present invention is: a multi-node mutual positioning method in a complex environment, each node includes a transmitting link, a receiving link, a transceiver antenna, a ZigBee module and a signal processing module; each node can be set as a master node or a slave node, and the nodes realize mutual positioning by transmitting and receiving triangular wave frequency modulation continuous wave signal waveforms;

[0007] When the node works in the master node mode, it synchronizes with the working signals of other slave nodes through the coarse synchronization and fine synchronization steps, and then locates the slave node through the working principle of frequency modulation continuous wave radar; when the node works in the slave node mode, it waits for the synchronization signal sent by the master node, synchronizes with the signal of the master node through the coarse synchronization and fine synchronization steps, and then sends the synchronized signal to the master node so that the master node can locate the position of the slave node; the positioning method includes the following steps:

[0008] Step S1: a master node is set in the node network, and other nodes are set as slave nodes; the ZigBee module of each node is used to make each node work under the same time reference, so as to achieve coarse time synchronization among multiple nodes;

[0009] Step S2: After coarse synchronization, the master node sends the signal to be synchronized to the slave node. The slave node processes the received signal to obtain the time and frequency offset between nodes, and then adjusts the transmission signal of the slave node to make the transmission signal of the slave node accurately synchronized with the local oscillator signal in the master node;

[0010] Step S3: After fine synchronization, the master node receives the transmission signal of the slave node, processes the received signal to obtain the distance, speed and angle information of the slave node to realize the positioning of the slave node.

[0011] A multi-node mutual positioning system in a complex environment is used to implement the above method. The system includes multiple nodes, each of which includes a transmitting link, a receiving link, a transceiver antenna, a ZigBee module and a signal processing module; each node is set as a master node or a slave node, and the nodes realize mutual positioning by transmitting and receiving triangular wave frequency modulation continuous wave signal waveforms;

[0012] When the node works in the master node mode, it synchronizes with the working signals of other slave nodes through coarse synchronization and fine synchronization steps, and then locates the slave node through the working principle of frequency modulation continuous wave radar; when the node works in the slave node mode, it waits for the synchronization signal sent by the master node, synchronizes with the signal of the master node through coarse synchronization and fine synchronization steps, and then sends the synchronized signal to the master node so that the master node can locate the position of the slave node.

[0013] An electronic device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the above method is implemented when the processor executes the program.

[0014] A computer-readable storage medium stores a computer program, which implements the above method when executed by a processor.

[0015] A computer program product comprises a computer program, and the computer program implements the above method when executed by a processor.

[0016] Compared with the prior art, the present invention has the following significant advantages: each node has a receiving and transmitting system, can locate other nodes and can also be located by other nodes, the mutual positioning method between the nodes is equivalent to the work of a secondary radar system, so that the power of the signal received by each node from other nodes is significantly greater than the other noise power, and high-precision wireless local positioning can be achieved. Each node is a wireless local positioning system working between 1GHz and 100GHz. In this wavelength range, the influence of rain, fog and smoke is not serious, and it also has a good working effect in the harsh working environment of agriculture, mining and waste management. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1This is a diagram of an application scenario of a multi-node mutual positioning method in a complex environment according to the present invention.

[0018] Figure 2 This is a specific hardware implementation block diagram of a multi-node mutual positioning method in a complex environment of the present invention.

[0019] Figure 3 This is a flow chart of a multi-node mutual positioning method in a complex environment according to the present invention. DETAILED DESCRIPTION

[0020] The present invention proposes a multi-node mutual positioning method under a complex environment, in which each node includes a transmitting link, a receiving link, a transceiver antenna, a ZigBee module and a signal processing module. Each node works under a triangular wave frequency modulation continuous wave system and has receiving and transmitting functions, and can be set as a master node or a slave node. The nodes realize the mutual positioning function by transmitting and receiving triangular wave frequency modulation continuous wave signal waveforms. When the node works in the master node mode, it synchronizes with the working signals of other slave nodes through coarse synchronization and fine synchronization steps, then obtains the distance information of the slave node through round-trip flight time RTOF calculation, obtains the distance information of the slave node through Doppler frequency shift calculation, estimates the angle information of the slave node through DOA method, and completes the positioning of the slave node; when the node works in the slave node mode, it waits for the synchronization signal sent by the master node, synchronizes with the signal of the master node through coarse synchronization and fine synchronization steps, and then sends the synchronized signal to the master node so that the master node can locate the position of the slave node.

[0021] Preferably, firstly, a time reference is set for multiple nodes that need to be mutually positioned using the ZigBee module to avoid unknown time gaps when multiple nodes start mutual positioning, i.e., the above-mentioned rough synchronization; then, the master and slave nodes that establish the time reference are precisely synchronized, and the slave node performs frequency mixing processing on the received master node signal to obtain an intermediate frequency signal, and then performs FFT operation on the intermediate frequency signal to obtain the frequency value of the upper and lower sweep intermediate frequencies, and the time and frequency offset between the nodes can be calculated by the formula, and then the working frequency and time of the slave node local oscillator signal are adjusted according to the obtained time and frequency offset so that the working signals of the slave node and the master node are precisely synchronized. In step S3, the relative position, speed, and angle between the nodes are measured by the method of triangular wave frequency modulation continuous wave system to realize the positioning of the slave node by the master node. After completing the precise synchronization between nodes, the master node converts the transmission mode to the receiving mode, and the slave node converts the receiving mode to the transmission mode. The master node can then start locating the positions of other slave nodes. After receiving the signal from the slave node, the master node obtains the distance information of the slave node by calculating the round-trip flight time of the signal. The speed information of the node can be obtained through the Doppler frequency shift of the intermediate frequency signal. The master node with multiple receiving antennas can obtain the angle information of the node through DOA. Each node can work in the master node mode to locate other nodes, or work in the slave node mode to be located by the master node, so as to realize the mutual positioning of multiple nodes.

[0022] Preferably, it is necessary to perform precise synchronization of the signals between the master and slave nodes through step S2. This is because different nodes work under different system clock crystals, and the working signals of the master and slave nodes will have time and frequency offsets. After the slave node receives the signal to be synchronized from the master node, it obtains the intermediate frequency signal by mixing, and performs FFT operation and peak search on it to detect the frequency value f1 of the upper sweep intermediate frequency signal and the frequency value f2 of the lower sweep intermediate frequency signal. The corresponding relationship between the two intermediate frequency signal frequency values ​​f1, f2 and the time and frequency offsets Δt, Δf between the nodes is:

[0023] f1=Δf+Δf a -μΔt

[0024] f2=Δf+Δf a +μΔt

[0025] in Derivation of the formula can obtain the specific formula for calculating time and frequency offset:

[0026]

[0027] Where T is the sweep period, B is the sweep bandwidth, Δf a It is the known frequency offset of the slave node local oscillator signal relative to the master node to prevent negative frequencies from appearing in the intermediate frequency signal of the signal that is swept up and down.

[0028] Preferably, after fine synchronization, the triangular wave frequency modulation continuous wave system can be used to locate the slave node. The working signal of the slave node at this time has only a signal propagation delay t compared with the local oscillator signal of the master node. d Therefore, the slave node transmits the synchronized signal to the master node, and the master node can calculate the distance between the nodes by signal processing and using the round-trip flight time (RTOF) of the signal. The synchronization signal received by the master node has a 2t difference with the initial transmission signal. d The master node performs FFT operation and peak search on the intermediate frequency signal to detect the frequency value f of the upper and lower sweep intermediate frequency signals. up 、f dn The time with RTOF is 2t d The specific relationship is:

[0029]

[0030] The formula for obtaining the specific distance information of the master node from the slave node is:

[0031]

[0032] Where c is the speed of light, and the distance information of the node can be obtained through the frequency value f up or dn get.

[0033] Furthermore, for the frequency spectrum between the master and slave nodes with relative speed, there will be a Doppler frequency shift f D , then the intermediate frequency signal frequency value f of the upper and lower sweep frequencies obtained by the master node is up 、f dn The time with RTOF is 2t d The specific relationship becomes:

[0034]

[0035] Therefore, the specific formula by which the master node can calculate the distance and speed information of the slave node is:

[0036]

[0037] where f l The starting frequency of the node's frequency sweep.

[0038] For a master node with multiple receiving antennas, the DOA method can be used to measure the angle of the slave node relative to the master node. Different DOA methods are used for different antenna arrays, specifically: Bartlett Beamforming, Capon Beamforming, MUSIC Beamforming and other methods. The master node can obtain the specific angle information of the slave node by performing beamforming estimation on the obtained signal. Each node can work in the master node mode to locate other nodes, or work in the slave node mode to be located by the master node, so as to realize the mutual positioning of multiple nodes.

[0039] The present invention realizes high-precision mutual positioning between multiple nodes by implementing the working principle of frequency-modulated continuous wave radar between nodes, which makes up for the shortcomings of existing multi-node mutual positioning technology that is easily affected by environmental weather, has poor positioning accuracy, is easily affected by non-line-of-sight errors and antenna gain factors, has high requirements on the synchronization accuracy of clock units between nodes, and has low flexibility of the positioning node subsystem.

[0040] It is easy to understand that according to the technical solution of the present invention, without changing the essential spirit of the present invention, a person skilled in the art can imagine various embodiments of the present invention. Therefore, the following specific embodiments and drawings are only exemplary descriptions of the technical solution of the present invention, and should not be regarded as the whole of the present invention or as a limitation or limitation of the technical solution of the present invention. On the contrary, the purpose of providing these embodiments is to enable those skilled in the art to understand the present invention more thoroughly. The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the innovative concept of the present invention.

[0041] Combination Figure 1 , a multi-node mutual localization scene graph is introduced to apply this method, where one node is set as the master node to locate the positions of the other three slave nodes at the center.

[0042] In a further embodiment, in combination Figure 2, introduces the specific hardware reference used to implement the method. First, a transmitting antenna 1 and 8 receiving antennas 3 are required. The transmitting component of the node includes a radio frequency module 8 for adjusting the specific parameters of the transmitting signal, and a signal modulation module 2 for generating the radio frequency signal; the receiving component includes a mixer 4 for mixing the receiving signal and the local oscillator signal to obtain an intermediate frequency signal, a low-pass filter 5 for filtering out the high-frequency signal, and an intermediate frequency amplifier 6 for amplifying the processed signal. Both the receiving and transmitting channels need to be added with a switch 7 controlled by a ZYNQ chip 10; the intermediate frequency signal passes through the intermediate frequency amplifier 6 and then is collected by an 8-way ADC chip 9. The collected data will be FFT-operated in the ZYNQ chip 10, and the data will be stored in the DDR RAM 13 for further processing; the ZYNQ chip performs peak detection by reading the FFT data results after the operation, and performs step S2 synchronization and step S3 positioning by adjusting the radio frequency module 8 and the transceiver conversion switch 7; the Zigbee module 11 controls each node system to work under the same time reference; at the same time, the hardware circuit also needs a power supply module 14 to make the circuit work stably to provide the system with a clock crystal oscillator 12.

[0043] In a further embodiment, in combination Figure 3 , the specific implementation process of the multi-node mutual positioning method is as follows: two or more nodes to be positioned define a time reference through the ZigBee module to achieve the purpose of rough synchronization between the master and slave nodes, and then the master node sends a frequency sweep signal to the slave node to start the synchronization step. After receiving the signal, the slave node performs: 1. AD acquisition and FFT operation on the intermediate frequency signals of the upper and lower frequency sweeps; 2. Peak detection on 2×8 signal spectra; 3. According to the formula, the average time and frequency offset is calculated to achieve the purpose of accurate synchronization with the master node signal. The above signal processing is performed within the predefined signal processing time. After reaching the predefined signal processing time, the slave node sends a synchronization signal to the master node. After receiving the signal, the master node performs: 1. AD acquisition and FFT operation on the intermediate frequency signals of the upper and lower frequency sweeps; 2. Peak detection on 2×8 signal spectra; 3. According to the formula, the distance and speed information of the slave node is calculated; 4. The angle information of the slave node is estimated according to the phase in the 8 spectra to achieve the purpose of locating the position of the slave node.

[0044] The present invention can realize high-precision mutual positioning between multiple nodes in a complex environment by only performing synchronization and measurement positioning once through multiple nodes working in a linear frequency modulation system, and the infrastructure is simple, low cost and easy to maintain. The method has the advantages of fast detection speed, long detection distance, no weather influence, strong environmental adaptability, etc.

[0045] The present invention is further described in detail below with reference to specific embodiments.

[0046] Example

[0047] Multiple nodes applying the method have the same composition structure; each node includes a transmitting component, a receiving component, and a digital signal processing module; the transmitting component includes a transmitting antenna for radiating a transmitting signal, a radio frequency module and a signal modulation module for configuring the parameters of the transmitted signal, and a transmitting switch for turning on or off the transmitting signal; the receiving component includes a receiving antenna for receiving a signal transmitted by another positioning unit, a mixer for mixing the received signal to obtain an intermediate frequency signal, a filter and an amplifier for filtering out unnecessary signals and amplifying the intermediate frequency signal, and a receiving switch for turning on or off the receiving signal; the digital signal processing module includes controlling a ZigBee module for coarse synchronization, a crystal oscillator module for providing a clock reference signal for a chip and a radio frequency module, a RAM module for storing and reading data, and a power supply module for power management of the entire node; the digital signal processing module is also connected to the radio frequency module, and is used to control the radio frequency module, accurately synchronize the two positioning systems, condition and process the intermediate frequency signal, and control the transmission and reception state conversion of the node.

[0048] In this embodiment, all nodes adopt the frequency modulated continuous wave system. This method includes multiple nodes. During positioning, the master node sends information to other located slave nodes, performs step S1 rough synchronization, and after the working time base is established between the nodes, the master node sends the modulated signal to be synchronized to the slave node to perform step S2 fine synchronization. After receiving the signal, the slave node performs signal processing to obtain the time and frequency offset relative to the master node. The slave node adjusts the transmission signal of its own work. After the predefined signal processing time ends, the slave node sends the accurately synchronized signal to the master node. After receiving the signal, the master node performs step S3 positioning, performs distance positioning of the slave node based on the RTOF method, estimates the speed of the slave node based on the Doppler frequency shift method, and estimates the angle of the slave node based on the DOA. The master node can achieve the positioning of the slave node through three steps. Each node can be used as a master node to obtain the location information of other nodes to achieve multi-node mutual positioning.

[0049] In this embodiment, the transmitting and receiving antennas use patch antennas with the same structure. The total length of the patch antenna unit is 6 cm, the node working signal has a center frequency of 24 GHz, a bandwidth of 250 MHz, and a sweep frequency of 1 ms. The AD sampling rate is 8 MHz, and the maximum measurable distance range is 2.4 km.

[0050] To sum up, the present invention provides a multi-node mutual positioning method in a complex environment, which makes up for the shortcomings of the existing multi-node mutual positioning technology, such as being easily affected by environmental weather, having poor positioning accuracy, being easily affected by non-line-of-sight errors and antenna gain factors, having high requirements for the synchronization accuracy of clock units between nodes, and having low flexibility of the positioning node subsystem.

[0051] The above description is only a preferred specific implementation of the present invention, but the protection scope of the present invention is not limited thereto.

[0052] Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the protection scope of the present invention.

[0053] It should be understood that in order to simplify the present invention and help those skilled in the art understand the various aspects of the present invention, in the above description of the exemplary embodiments of the present invention, the various features of the present invention are sometimes described in a single embodiment or described with reference to a single figure. However, the present invention should not be interpreted as the features included in the exemplary embodiments are all necessary technical features of the patent claims.

[0054] It should be understood that the modules, units, components, etc. included in the device of an embodiment of the present invention can be adaptively changed to be set in a device different from the embodiment. The different modules, units, or components included in the device of the embodiment can be combined into one module, unit, or component, or they can be divided into multiple sub-modules, sub-units, or sub-components.

Claims

1. A multi-node mutual positioning method in a complex environment, characterized in that: Each node includes a transmitting link, a receiving link, a transmitting and receiving antenna, a ZigBee module and a signal processing module; each node can be set as a master node or a slave node, and the nodes can realize mutual positioning by transmitting and receiving triangular frequency modulated continuous wave signal waveforms; When the node works in the master node mode, it synchronizes with the working signals of other slave nodes through the coarse synchronization and fine synchronization steps, and then locates the slave node through the working principle of frequency modulation continuous wave radar; when the node works in the slave node mode, it waits for the synchronization signal sent by the master node, synchronizes with the signal of the master node through the coarse synchronization and fine synchronization steps, and then sends the synchronized signal to the master node so that the master node can locate the position of the slave node; the positioning method includes the following steps: Step S1: a master node is set in the node network, and other nodes are set as slave nodes; the ZigBee module of each node is used to make each node work under the same time reference, so as to achieve coarse time synchronization among multiple nodes; Step S2: After coarse synchronization, the master node sends the signal to be synchronized to the slave node. The slave node processes the received signal to obtain the time and frequency offset between nodes, and then adjusts the transmission signal of the slave node to make the transmission signal of the slave node accurately synchronized with the local oscillator signal in the master node; Step S3: After fine synchronization, the master node receives the transmission signal of the slave node, processes the received signal to obtain the distance, speed and angle information of the slave node to realize the positioning of the slave node.

2. The method for mutual positioning of multiple nodes according to claim 1, characterized in that: After the coarse synchronization sets the time base between nodes, the working signals between the master and slave nodes need to be precisely synchronized. After the slave node receives the signal to be synchronized from the master node, it obtains the intermediate frequency signal by mixing, and performs FFT operation and peak search on it to detect the frequency value f1 of the upper sweep intermediate frequency signal and the frequency value f2 of the lower sweep intermediate frequency signal; the corresponding relationship between the two intermediate frequency signal frequency values ​​f1 and f2 and the time Δt and frequency offset Δf between nodes is as follows: f1=Δf+Δf a -μΔt f2=Δf+Δf a +μΔt in The formula is derived to obtain the specific formula for calculating time and frequency offset: Where T is the sweep period, B is the sweep bandwidth, Δf a It is the known frequency offset of the slave node's local oscillator signal relative to the master node. After obtaining the time Δt and frequency offset Δf, the slave node adjusts the frequency and time of its own local oscillator signal so that the working signals of the slave node and the master node are precisely synchronized.

3. The multi-node mutual positioning method according to claim 2, characterized in that: Positioning steps After fine synchronization, the master node switches the transmission mode to the receiving mode, and the master node can start to locate the positions of other slave nodes; the slave node switches the receiving mode to the transmission mode, and the working signal of the slave node at this time is only delayed by the signal propagation time t compared with the local oscillator signal of the master node. d Therefore, the slave node transmits the synchronized signal to the master node, and the master node can calculate the distance between nodes by signal processing and using the round-trip flight time of the signal. The synchronization signal received by the master node has a 2t difference with the initial transmission signal. d The master node performs FFT operation and peak search on the intermediate frequency signal to detect the frequency value f of the upper and lower sweep intermediate frequency signals. up 、f dn The time with RTOF is 2t d The specific relationship is: The formula for obtaining the specific distance information of the master node from the slave node is: Where c is the speed of light, and the distance information of the node is transmitted through the frequency value f up or dn get.

4. The multi-node mutual positioning method according to claim 3, characterized in that: For the intermediate frequency signal spectrum between the master and slave nodes with relative speed, there will be a Doppler frequency shift f D , then the intermediate frequency signal frequency value f of the upper and lower sweep frequencies obtained by the master node is up 、f dn The time with RTOF is 2t d The specific relationship becomes: The specific formula for the distance and speed information of the slave node relative to the master node is: where f l The starting frequency of the node's frequency sweep.

5. The multi-node mutual positioning method according to claim 4, characterized in that: For a master node with multiple receiving antennas, the DOA method is used to measure the angle of the slave node relative to the master node. The master node can obtain the specific angle information of the slave node by performing beamforming estimation on the obtained signal. Each node can work in the master node mode to locate other nodes, or work in the slave node mode to be located by the master node, so as to achieve mutual positioning of multiple nodes.

6. A multi-node mutual positioning system in a complex environment, characterized in that: Used to implement the method described in any one of claims 1 to 5, the system includes multiple nodes, each node includes a transmitting link, a receiving link, a transceiver antenna, a ZigBee module and a signal processing module; each node is set as a master node or a slave node, and the nodes realize mutual positioning function by transmitting and receiving triangular wave frequency modulated continuous wave signal waveforms; When the node works in the master node mode, it synchronizes with the working signals of other slave nodes through coarse synchronization and fine synchronization steps, and then locates the slave node through the working principle of frequency modulation continuous wave radar; when the node works in the slave node mode, it waits for the synchronization signal sent by the master node, synchronizes with the signal of the master node through coarse synchronization and fine synchronization steps, and then sends the synchronized signal to the master node so that the master node can locate the position of the slave node.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the method according to any one of claims 1 to 5 are implemented.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method according to any one of claims 1 to 5 are implemented.

9. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 5 are implemented.

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