RFID-based berth positioning system and method

Abstract

The invention discloses an RFID-based berth positioning system and method, and relates to the technical field of berth positioning. The system comprises an electronic tag which is used for storing a parking space electronic tag number; the reader is used for activating the electronic tag by transmitting a wireless radio frequency signal and reading the number of the electronic tag; the communication module is used for transmitting the electronic tag number and the number receiving time to the server; and the server is used for storing and processing the received electronic tag numbers and the number receiving time, and carrying out berth positioning according to the berth tag corresponding relation table. According to the technical scheme of the invention, the method can achieve the precise matching of the parking space of the carrier in a parking charging scene, and is higher in application value.

Description

Technical Field

[0001] The present invention relates to the technical field of berth positioning, and in particular to a berth positioning system and method based on RFID. Background Art

[0002] In recent years, with the gradual increase in the number of cars, cars have become an indispensable means of transportation for people's daily travel. The problem of parking difficulties in cities has become more and more serious, especially in busy commercial areas, residential areas and near public transportation hubs. Among them, some vehicles have occupied public parking spaces for a long time, making it difficult for some car owners with temporary parking needs to find vacant parking spaces, which has increased road traffic pressure to a certain extent. In order to solve this problem, various regions have carried out intelligent transformation of urban parking management systems, and improved the turnover rate of urban parking spaces by efficiently managing parking spaces. Among them, mobile video inspection vehicles play a very important role in urban parking management systems. The video inspection vehicle conducts regular inspections of parking spaces, intelligently identifies the license plate numbers of vehicles parked in parking spaces, and automatically generates parking orders, which greatly reduces labor costs compared to traditional road inspections. However, the video inspection vehicle has the problem of inaccurate parking space positioning during use, which can easily cause abnormal parking orders and cause a series of problems. Therefore, the development of a simple and efficient parking space positioning method is imminent.

[0003] Most of the existing berth positioning methods currently have defects in some aspects. For example, the berth positioning method based on GPS, the GPS system used in this method has a large deviation in the positioning data in the application scenario where there are obstructions. At the same time, the implementation of this method requires the device to be able to connect to the Internet in real time, and it will fail in the area with poor network signals; the berth positioning method based on image recognition, the application scenario of this method is relatively limited, it requires obvious text markings on the berth, and subject to this condition, this method is difficult to perform berth positioning work when the lighting conditions are poor or the berth markings are covered by obstructions. Therefore, based on this problem, this application proposes a berth positioning system and method based on RFID. Summary of the invention

[0004] Technical Purpose In order to solve the above problems, the purpose of the present invention is to provide a berth positioning system and method based on RFID, which not only solves the problem of inaccurate berth positioning in the urban berth management system, but also the system and method have a wide range of application scenarios, are not easily interfered by external factors, realize the simplification and automation of berth positioning, improve the accuracy of berth positioning, and avoid the problem of abnormal berth number recognition due to environmental factors.

[0005] Technical Solution In order to achieve the above-mentioned purpose, the present invention provides a berth positioning system and method based on RFID, which activates the electronic tag on the berth by transmitting a wireless radio frequency signal through a reader mounted on a vehicle, and matches the tag data and the berth according to a pre-made berth tag correspondence table, thereby realizing accurate berth positioning.

[0006] In a first aspect, the present invention provides a berth positioning system based on RFID, comprising: An electronic tag, used to store the berth electronic tag number, which is installed on the berth; The reader activates the electronic tag and reads the electronic tag number by transmitting a wireless radio frequency signal; A communication module, used for transmitting the electronic tag number and the time when the number is received to the server; The server is used to store and process the received electronic tag number and the number receiving time, and to locate the berth according to the berth tag corresponding relationship table; The reader and the communication module are built on a carrier.

[0007] Furthermore, the electronic tag is installed on one side of the berth close to the vehicle driving road, and each berth is equipped with at least one electronic tag, which is located at 1 / 3 of the corresponding side of the berth.

[0008] Furthermore, the electronic tag is installed on one side of the berth close to the vehicle driving road, and each berth is equipped with two electronic tags, which are respectively located at 1 / 3 and 2 / 3 of the corresponding side of the berth.

[0009] Furthermore, the reader activates the electronic tag and reads the electronic tag number by transmitting a wireless radio frequency signal, which specifically includes: the reader continuously transmits a wireless radio frequency signal of a specific frequency to the outside world through a built-in antenna, and the effective scanning range of the wireless radio frequency signal is 1 / 3 of the berth length. When the vehicle travels near the berth, the electronic tag will be activated after entering the range of the wireless radio frequency signal emitted by the reader. After being activated, it transmits the electronic tag number data stored in itself to the reader through the antenna.

[0010] Furthermore, the reader transmits the received electronic tag number and the timestamp when the reader receives the number data to the server through the communication module; the server stores the received data in a memory array and deduplicates the data, and the deduplication process is specifically that when the server receives duplicate data, it only retains the data information received for the first time; the array elements of the memory array follow the first-in-first-out principle.

[0011] Furthermore, the server performs berth positioning according to the berth relationship correspondence table, specifically: if the latest numbering data in the memory array corresponds to the first electronic tag numbering data of the nth berth, then it is judged that the current vehicle is located in the front half of the nth berth; if the latest numbering data in the memory array corresponds to the second electronic tag numbering data of the nth berth, then it is judged that the current vehicle is located in the second half of the nth berth; the judgment standard of the front and rear positions of the berths follows the order of the front and rear positions of the vehicle from the berth with smaller numbers to the berth with larger numbers.

[0012] Furthermore, after receiving the identification result transmitted by the inspection unmanned aerial vehicle, the smart parking management platform pre-judges the current geographical location of the unmanned aerial vehicle. If it is determined that the current geographical location of the unmanned aerial vehicle is not within the area of ​​the parking area, it is determined that the current vehicle is illegally parked. If the geographical location information is consistent, the received identification result is uploaded to the parking space database of the platform for matching. If the matching results of the license plate information and the parking space information are inconsistent, it is determined that the current vehicle occupies the parking space.

[0013] Furthermore, when the vehicle passes the last berth of the current berth sequence, the server periodically queries whether the reception time of the latest array element in the memory array is earlier than the current system time. If the condition is met, it indicates that the numbered data in the memory array has expired. At this time, the server clears the memory array to avoid data misuse.

[0014] Furthermore, the system adopts an RFID system anti-collision scheme based on tag grouping to avoid the signal conflict problem caused by multiple RFID electronic tags entering the reader's radio frequency field range at the same time due to berth layout. It solves the signal conflict problem by grouping the electronic tags and identifying the tags in the tag group in batches according to the binary tree search algorithm.

[0015] Furthermore, the system reduces the impact of multipath effects and radio frequency signal attenuation on RFID system berth positioning through a deep belief network solution, and extracts effective feature information from RFID data so that the system can better adapt to complex indoor and outdoor environments.

[0016] In a second aspect, the present invention further provides a berth positioning method based on RFID, the method is based on the system described in the first aspect, and comprises: Installing electronic tags on berths to store berth numbers; Formulate a correspondence table between electronic tags and berths according to the electronic tag layout; Activate the electronic tag through a reader mounted on the vehicle; The reader receives the number data transmitted by the electronic tag and further transmits it to the server together with the number reception time; The server stores and processes the received electronic tag number and the time when the number is received, and performs berth positioning according to the berth tag correspondence table.

[0017] In a third aspect, the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the aforementioned RFID-based berth positioning method is implemented.

[0018] The present invention activates the electronic tag on the berth by transmitting a wireless radio frequency signal through a reader mounted on a vehicle, and matches the tag data with the berth according to a pre-made berth tag correspondence table, thereby achieving accurate berth positioning; an RFID system anti-collision solution based on tag grouping is used to avoid the signal conflict problem caused by multiple RFID electronic tags entering the reader's radio frequency field range at the same time due to the berth layout; and a deep confidence network solution is used to reduce the impact of multipath effects and wireless radio frequency signal attenuation on RFID system berth positioning. The system and method not only solve the problem of inaccurate berth positioning in the urban berth management system, but also have a wide range of application scenarios, are not easily disturbed by external factors, realize the simplification and automation of berth positioning, improve the accuracy of berth positioning, and avoid the problem of abnormal berth number recognition due to environmental factors.

[0019] Beneficial Effects By implementing the RFID-based berth positioning system and method provided by the present invention, the following technical effects are achieved: (1) The present invention activates the electronic tag on the berth by transmitting a wireless radio frequency signal through a reader mounted on the vehicle, and matches the tag data with the berth according to a pre-made berth tag correspondence table, thereby realizing accurate berth positioning; it has high adaptability to complex environments and can work effectively in a variety of application scenarios, avoiding the influence of external factors on berth number recognition, and further realizing automation; the application of electronic tags enables the berth management system to record and update berth information in real time, thereby improving the efficiency and accuracy of berth management; the electronic tags on the berth are quickly activated through wireless radio frequency signals, realizing automatic data matching, reducing the complexity of manual operations, ensuring the accuracy of berth positioning, and reducing errors caused by human factors.

[0020] (2) The present invention equips the berth with two electronic tags and stores three tag data in the server memory array, thereby enabling the berth management system to more accurately locate the vehicle based on the relationship between the multiple tag data and the berth. Compared with equipping the berth with a single electronic tag, the present invention enables the berth management system to more accurately locate the specific position of the berth where the vehicle is located, thereby improving the accuracy of berth positioning. By recording the tag data in real time in the server, the system has the ability to trace the cause of the error when an abnormal parking order occurs.

[0021] (3) The present invention adopts an RFID system anti-collision scheme based on tag grouping to avoid the signal conflict problem caused by multiple RFID electronic tags entering the reader's radio frequency field range at the same time due to berth layout; it reduces the signal conflict problem between tags and improves the recognition efficiency of the system by grouping RFID tags and applying an anti-collision algorithm in each group; and ensures that each tag group can communicate effectively within the allocated time slot by reasonably allocating communication time slots and frequency resources.

[0022] (4) The present invention reduces the impact of multipath effect and radio frequency signal attenuation on the berth positioning of the RFID system through a deep belief network solution; it improves the accuracy of berth positioning by extracting RFID signal features and learning the nonlinear mapping relationship between signal strength and position information; due to the deep network structure of the deep belief network, the RFID system can have good robustness and reduce the impact of multipath effect and signal attenuation on positioning accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to make the above-mentioned RFID-based berth positioning system and method of the present invention more obvious and easy to understand, the drawings required for use in the specific implementation of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 A schematic diagram showing a berth positioning method based on RFID; Figure 2 A schematic diagram of a berth positioning system based on RFID is shown; Figure 3 A schematic diagram showing the layout of electronic tags; Figure 4 A schematic diagram showing a reader transmitting a wireless radio frequency signal; Figure 5 Schematic diagram showing the effect of the RFID system anti-collision solution based on tag grouping. DETAILED DESCRIPTION

[0025] Embodiment 1: Provided is a berth positioning system and method based on RFID, the berth positioning method is as follows Figure 1 As shown in Figure 1, the berth positioning system is as follows: Figure 2 As shown, the system includes: an electronic tag for storing a berth electronic tag number, which is installed on the berth; a reader, which activates the electronic tag by transmitting a wireless radio frequency signal and reads the electronic tag number; a communication module, which is used to transmit the electronic tag number and the number reception time to the server; the server, which is used to store and process the received electronic tag number and the number reception time, and locate the berth according to the berth tag correspondence table; wherein the reader and the communication module are built on the carrier.

[0026] The RFID-based berth positioning system provided by the present invention specifically includes: Electronic label layout Figure 3 As shown, the electronic tag is installed on one side of the berth close to the vehicle driving road. Each berth is equipped with at least one electronic tag, which is located at 1 / 3 of the corresponding side of the berth. After installation, the electronic tag number and the berth number are recorded and organized into a berth tag correspondence table, as shown in Table 1. After the subsequent reader recognizes the tag, the corresponding berth number can be queried through this table.

[0027] Table 1. Correspondence between electronic tags and berths (partial)

[0028] The electronic tag is installed on one side of the berth close to the vehicle driving road. Each berth is equipped with two electronic tags, which are respectively located at 1 / 3 and 2 / 3 of the corresponding side of the berth.

[0029] The reader activates the electronic tag and reads the electronic tag number by transmitting a wireless radio frequency signal. Specifically, the reader continuously transmits a wireless radio frequency signal of a specific frequency to the outside world through a built-in antenna. The effective scanning range of the wireless radio frequency signal is 1 / 3 of the berth length. When the vehicle travels near the berth, the electronic tag will be activated after entering the range of the wireless radio frequency signal emitted by the reader. After being activated, it transmits the electronic tag number data stored in itself to the reader through the antenna.

[0030] The reader further transmits the received electronic tag number and the timestamp when the reader receives the number data to the server through the communication module; the server stores the received data in a memory array and performs deduplication processing on the data, and the deduplication processing is specifically that when the server receives duplicate data, it only retains the data information received for the first time; the array elements of the memory array follow the first-in-first-out principle.

[0031] The server performs berth positioning according to the berth relationship correspondence table, specifically: if the latest number data in the memory array corresponds to the first electronic tag number data of the nth berth, then it is judged that the current vehicle is located in the front half of the nth berth; if the latest number data in the memory array corresponds to the second electronic tag number data of the nth berth, then it is judged that the current vehicle is located in the second half of the nth berth; the judgment standard of the front and rear positions of the berths follows the order of the front and rear positions of the vehicle from the berth with smaller numbers to the berth with larger numbers.

[0032] When the vehicle passes the last berth of the current berth sequence, no new electronic tag number data will be read into the memory array of the server before the vehicle enters a new berth sequence. The server cleans up the number data in the memory array to avoid the last set of number data being reused, and to avoid the position of subsequent vehicle movements being continuously determined by the system as the second half of the last berth. Specifically, the server periodically queries whether the reception time of the latest array element in the memory array is earlier than the current system time by 600ms. If the condition is met, it indicates that the number data in the memory array has expired. At this time, the server clears the memory array to avoid data misuse.

[0033] The reader transmits a radio frequency signal such as Figure 4As shown in the figure, the vehicle equipped with an RFID reader travels along the outside of the berth, and its driving direction is from right to left, passing through berths 1, 2, 3 and 4 in sequence. At berth 1, the reader has passed berth P101, but has not reached berth P102. At this time, the memory array stores two tag data of berth P101, which are DF11 and DF01 in sequence. According to the berth relationship table, the corresponding berth number is P101. Therefore, it is determined that the vehicle is located at berth P101 and has not reached berth P102. The system outputs the berth positioning result as berth P101. When the vehicle moves from position 1 to position 2, the reader reads the first tag data DF02 of berth P102. At this time, the tag data stored in the memory array are DF02, DF11 and DF01 respectively. According to the berth relationship table, the berth number corresponding to DF02 is P102, and the berth number corresponding to DF11 and DF01 is P101. At this time, it is determined that berth P101 is the last berth passed by the vehicle. The current vehicle is located in the front half of berth P102, and the system outputs the berth positioning result as berth P102. When the vehicle moves from position 2 to position 3, the reader reads the second tag data DF12 of berth P102. At this time, the tag data stored in the memory array are DF12, DF02 and DF11 respectively. According to the berth relationship table, the berth number corresponding to DF12 and DF02 is P102, and the berth number corresponding to DF11 is P101. At this time, it is determined that berth P101 is the last berth passed by the vehicle. The current vehicle is located in the second half of berth P102, and the system outputs the berth positioning result as berth P102. When the vehicle moves to the left from position 4, the reader reads the first tag data DF03 of the P103 berth. At this time, the tag data stored in the memory array are DF03, DF12 and DF02. According to the berth relationship table, the berth number corresponding to DF03 is P103, and the berth numbers corresponding to DF12 and DF02 are P102. At this time, P102 is determined to be the last berth passed by the vehicle. The current vehicle is located in the front half of the P103 berth, and the system outputs the berth positioning result as the P103 berth. The berth determination method for subsequent positions is a cycle of the above-mentioned situations.

[0034] The system uses an RFID system anti-collision solution based on tag grouping to avoid signal collision problems caused by multiple RFID electronic tags entering the reader's radio frequency field range at the same time due to berth layout, such as Figure 5As shown, it can be seen that after adopting the anti-collision scheme of the present invention, the conflict rate can be significantly controlled. The signal conflict problem is solved by grouping the electronic tags and identifying the tags in the tag group in batches according to the binary tree search algorithm. Specifically, the RFID tags in the berth area are grouped, and the possibility of signal conflict is reduced by keeping the number of tags in each group within a certain range; a specific communication time slot is allocated to each tag group, and an ALOHA-based algorithm is applied in each tag group to allocate time slots in a random manner to reduce conflicts between tags; when the reader detects a signal conflict, the conflicting tags are rescheduled or selected according to the rules of the anti-collision algorithm until the conflict is resolved; after successfully identifying each tag, the relative position of the tag is calculated by receiving the signal strength indication value, thereby realizing berth positioning.

[0035] Embodiment 2: On the basis of the above-mentioned embodiment, a deep belief network solution is added to reduce the impact of multipath effect and radio frequency signal attenuation on RFID system berth positioning, which extracts effective feature information from RFID data so that the system can better adapt to complex indoor and outdoor environments; Among them, it is necessary to collect the RSSI values ​​of the electronic tags and normalize the collected RSSI data to eliminate the signal strength differences in different environments to ensure data consistency; and build a fingerprint database by recording the coordinates of its known position to provide a basis for subsequent algorithm training and positioning.

[0036] Design a deep belief network structure, including an input layer, multiple hidden layers, and an output layer; initialize network parameters, including weight matrices and bias vectors, where the weight update formula is:

[0037] in, Represents the updated weights from the hidden layer to the output layer; represents the current weight from the hidden layer to the output layer; Represents the learning rate, which controls the step size of weight update; Represents the partial derivative of the loss function with respect to the weights, indicating how to adjust the weights to reduce the error.

[0038] The restricted Boltzmann machine is used for layer-by-layer pre-training and feature extraction; each restricted Boltzmann machine layer can be regarded as a feature extractor and is trained using the following formula:

[0039] in, Represents a given hidden layer state Below, visible unit The probability of being 1; Represents the Sigmoid function, which is used to convert input into probability; Represents the weights connecting visible units and hidden units; Represents the state of the hidden layer unit; Represents the bias term, which affects the baseline value of probability.

[0040] Based on the pre-training, the network is fine-tuned using labeled data to optimize the network parameters. The mean square error is used as the loss function in the fine-tuning process:

[0041] in, represents the mean squared error, which measures the difference between the model prediction and the actual value; represents the expected output, i.e., the target value in the training data; Represents the actual output of the network, that is, the result predicted by the model.

[0042] During positioning, the RSSI data of the tag to be located is collected, features are extracted through the network, and matched with the feature database obtained in the training phase to estimate the position of the tag to be located.

[0043] The particle swarm optimization algorithm is used to further optimize the parameters of the restricted Boltzmann machine to improve the accuracy and efficiency of the positioning system. In the particle swarm optimization algorithm, the particle position and velocity update formula is as follows:

[0044]

[0045] in, Indicates Particles in time speed; Indicates Particles in time speed; represents the cognitive coefficient, which affects the tendency of the particle to move toward its best historical position; and Represents a random number between 0 and 1, used to increase the randomness of the algorithm; Represents particles The best position in history; represents the social coefficient, which affects the tendency of particles to move to the optimal position of the population; represents the global optimal position of the population; Represents particles In time location; Represents particles In time to the new location.

[0046] For example, the average RSSI value of 4 RFID readers to one tag in a parking lot is: , , and ; Train the deep belief network by normalizing these values; Assume that there is only one restricted Boltzmann machine with 4 visible units and 10 hidden units. The weights and biases are updated during training. The initial weights and biases are randomly set, for example: Distributed in the interval [0, 0.1]; visible unit bias ; Hidden unit bias Distributed in the interval [0, 0.1]; Using the contrast divergence method, the weight update after one iteration: Assuming the learning rate is ; The data expectation is 0.5; The reconstruction expectation is 0.3, then the weight update is:

[0047] If the initial weight is 0.05, the updated weight is:

[0048] Assume there are 5 particles, the position of each particle represents the weight in the deep belief network, and the velocity update and position update are as follows: The initial particle position and velocity are set randomly; Inertia Weight ; Cognitive coefficient ; Social coefficient ; Random number ; Random number ; Update speed and position:

[0049]

[0050] The effect of the deep belief network solution is shown in Table 2: Table 2. Summary of the effects of deep belief network solutions

[0051] As shown in Table 2, the model optimized by the deep belief network scheme provides predicted coordinates that are closer to the true location and reduces the positioning error. This shows that the deep belief network scheme can significantly improve the accuracy of the RFID-based berth positioning method.

[0052] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable non-transient storage media containing computer-usable program code.

[0053] The present invention can provide computer program instructions to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce means for implementing the system.

[0054] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device that implements the functions of the system.

[0055] These computer program instructions may also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable device provide steps for implementing the functions of the system.

Claims

1. A berth positioning system based on RFID, characterized in that: include: An electronic tag, used to store the berth electronic tag number, which is installed on the berth; The reader activates the electronic tag and reads the electronic tag number by transmitting a wireless radio frequency signal; A communication module, used for transmitting the electronic tag number and the time when the number is received to the server; The server is used to store and process the received electronic tag number and the number receiving time, and to locate the berth according to the berth tag corresponding relationship table; The anti-collision module based on tag grouping is used to avoid the signal conflict problem caused by multiple RFID electronic tags entering the reader's radio frequency field range at the same time due to the berth layout. It solves the signal conflict problem by grouping the electronic tags and identifying the tags in the tag group in batches according to the binary tree search algorithm; The deep belief network module is used to reduce the impact of multipath effects and radio frequency signal attenuation on the RFID system berth positioning. It extracts effective feature information from RFID data so that the system can better adapt to complex indoor and outdoor environments; The reader and the communication module are built on a carrier.

2. The RFID-based berth positioning system according to claim 1, characterized in that: The electronic tag is installed on one side of the berth close to the vehicle driving road. Each berth is equipped with at least one electronic tag, which is located at 1 / 3 of the corresponding side of the berth.

3. The RFID-based berth positioning system according to claim 1, characterized in that: The reader activates the electronic tag and reads the electronic tag number by transmitting a wireless radio frequency signal. Specifically, the reader continuously transmits a wireless radio frequency signal of a specific frequency to the outside world through a built-in antenna. The effective scanning range of the wireless radio frequency signal is 1 / 3 of the berth length. When the vehicle travels near the berth, the electronic tag will be activated after entering the range of the wireless radio frequency signal emitted by the reader. After being activated, it transmits the electronic tag number data stored in itself to the reader through the antenna.

4. The RFID-based berth positioning system according to claim 1 or 3, characterized in that: The reader further transmits the received electronic tag number and the timestamp when the reader receives the number data to the server through the communication module; the server stores the received data in a memory array and performs deduplication processing on the data, and the deduplication processing is specifically that when the server receives duplicate data, it only retains the data information received for the first time; the array elements of the memory array follow the first-in-first-out principle.

5. The RFID-based berth positioning system according to claim 4, characterized in that: The server performs berth positioning according to the berth relationship correspondence table, specifically: if the latest number data in the memory array corresponds to the first electronic tag number data of the nth berth, it is determined that the current vehicle is located at the front half of the nth berth; If the latest number data in the memory array corresponds to the second electronic tag number data of the nth berth, it is judged that the current vehicle is located in the rear half of the nth berth; the judgment standard of the front and rear positions of the berths follows the front and rear position sequence of the vehicle from the berth with smaller numbers to the berth with larger numbers.

6. The RFID-based berth positioning system according to claim 5, characterized in that: When the vehicle passes the last berth of the current berth sequence, the server periodically queries whether the reception time of the latest array element in the memory array is earlier than the current system time. If the condition is met, it indicates that the number data in the memory array has expired. At this time, the server clears the memory array to avoid data misuse.

7. The RFID-based berth positioning system according to claim 1, characterized in that: The method for solving the signal conflict problem by the anti-collision module based on tag grouping includes: grouping the RFID tags in the berth area, and reducing the possibility of signal conflict by keeping the number of tags in each group within a certain range; allocating a specific communication time slot for each tag group, and allocating the time slots in each tag group in a random manner; when the reader detects a signal conflict, rescheduling or selecting the conflicting tags according to the anti-collision rules until the conflict is resolved; after successfully identifying each tag, calculating the relative position of the tag by receiving the signal strength indicator value.

8. A berth positioning method based on RFID, characterized in that: The method is implemented based on the system according to any one of claims 1 to 7: The method comprises: Installing electronic tags on berths to store berth numbers; Formulate a correspondence table between electronic tags and berths according to the electronic tag layout; Activate the electronic tag through a reader mounted on the vehicle; The reader receives the number data transmitted by the electronic tag and further transmits it to the server together with the number reception time; The server stores and processes the received electronic tag number and the time when the number is received, and performs berth positioning according to the berth tag correspondence table.

9. A computer-readable storage medium, wherein a computer program is stored in the computer-readable storage medium, characterized in that: When the computer program is executed, the RFID-based berth positioning method according to claim 8 is implemented.

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