Ultra-high frequency RFID vehicle fixed-point parking method and device for automatic calibration of transmission power

Abstract

Ultra-high frequency RFID vehicle fixed-point parking method with automatic calibration of transmission power. The main control module adjusts the transmission power to the maximum power value for reading work. If no electronic tag is detected within the set time threshold range, the power calibration work is stopped. If the RFID reader can read the content of the electronic tag, the transmission power is gradually reduced according to the set fixed power interval value. After each reduction of the transmission power, the electronic tag is read. When the tag information cannot be read after reducing the transmission power, the corresponding transmission power is recorded, and this is the calibrated power value at this time. After the transmission power is calibrated, every time the user parks the vehicle, the RFID reading and writing module reads the tag with the calibrated power value. If the tag can be read, it means that the corresponding vehicle has been parked in the designated position. If the tag cannot be read, it means that the vehicle has not been parked in the designated position. The present invention provides an efficient and simple method for automatic calibration of transmission power, improving the usability and accuracy of the product.

Description

Technical Field

[0001] The present invention relates to a fixed-point parking device and method based on RFID technology with automatic calibration of ultra-high frequency and transmission power. Background Art

[0002] With the progress of technology and the times, the labor-saving and convenient characteristics of shared electric bicycles have gradually become a more preferred short-distance travel mode for the common people. However, the resulting problems of random parking and random dispatching have seriously affected the city appearance.

[0003] The RFID-based parking solution has the advantages of being unaffected by the parking environment and not requiring power supply from the ground, and can better solve the problem of fixed-point parking of shared electric bicycles. However, in the existing RFID fixed-point parking solutions, low and high frequency bands are mostly used, and the communication distance required for the card reader and the tag is short, the cost is high, and the applicability is low. There are also the following problems in the ultra-high frequency solution. If the RFID transmission power is too large, the induction distance will be too far, resulting in the vehicle not being parked within the fence or not parked at the designated position but the tag can be read, thus misjudging that the vehicle has been parked at the designated position and failing to achieve the purpose of guiding the vehicle owner to park at a fixed point. If the power is low, the detection distance will be too small, resulting in the vehicle owner not being able to detect the tag even if the vehicle is parked at the designated position, thus misjudging that the vehicle has not parked at a fixed point and causing the problem that the vehicle owner cannot park. In addition, when the vehicle stops directly above a certain ground tag at the designated position, the card reader can read the unique tag information, so that the system can count the occupancy of the parking space. If the transmission power of the card reader is too large, the card reader can read multiple tags, resulting in inaccurate statistics of the parking spaces at the parking point, affecting the accuracy of vehicle scheduling or the planning of parking points based on big data analysis. Therefore, before the vehicle is put into use, it is necessary to calibrate the transmission power. However, due to the large variety of shared electric bicycle models and the different installation positions of the card readers, the distances from the installation positions to the ground are different, and the materials, shapes, and thicknesses of the fixed positions of the card readers are different, which will also cause different signal attenuations. In addition, the installation density of the ground tags is different, and the card reader needs to be manually adjusted and calibrated for the transmission power before mass production, which affects the work efficiency, increases the workload, and raises the cost. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: how to design an ultra-high frequency RFID parking device with a frequency band of 900 MHz, whose transmission power can be automatically calibrated according to feedback information.

[0005] The technical solution of the present invention is specifically as follows:

[0006] An ultra-high frequency RFID vehicle fixed-point parking method with automatic calibration of transmission power. The specific steps for calibrating the power adjustment of the RFID card reader are as follows:

[0007] Step 1: The acceleration detection module detects the vehicle motion information and sends the wheel motion information to the main control module; the main control module determines that the vehicle changes from a moving state to a stationary state, and the RFID reader does not store a valid calibration power, then the RFID reader starts to adjust the power calibration;

[0008] Step 2: According to the rated power parameter value of the RFID reader / writer module, the main control module sets the rated power parameter value as the maximum power value P0, and the main control module adjusts the transmission power to the maximum power value P0 for reading; set the time threshold range T, under the condition that the transmission power is the maximum power value P0, if the electronic tag is not detected within the set time threshold range T, then stop the power calibration work; if the RFID reader can read the electronic tag content, then gradually reduce the transmission power according to the set fixed power interval value, and read the electronic tag each time after reducing the transmission power, and record each transmission power as P i , where i is the order of changing the power. When the transmission power is lowered and the tag information cannot be read, the corresponding transmission power is recorded, and then the mark P n-1 The power value is a calibrated power value and is stored in the RFID reader terminal;

[0009] Step 3: After the transmission power is calibrated, each time the user parks, the RFID reader / writer module uses the calibrated power value P n-1 Read the tag. If the tag can be read, it means that the vehicle is parked at the specified location, that is, the distance between the antenna module of the RFID reader and the electronic tag is the set distance. If the tag is not read, it means that the vehicle is not parked at the specified location, that is, the distance between the antenna module of the RFID reader and the tag exceeds the set value.

[0010] It also includes step 4: the reset condition of the transmission power calibration value is: the power supply of the housing and the external cables is disconnected, and the calibration condition of the transmission power is restarted.

[0011] An ultra-high frequency RFID vehicle fixed-point parking device with automatic calibration of transmission power for implementing the above method comprises an RFID card reader and an electronic tag, wherein the RFID card reader comprises: a main control module and an acceleration detection module, an RFID read / write module, an RFID power amplification module and an RFID antenna module connected thereto, and also comprises a power transmission automatic calibration module, which is communicatively connected to the main control module and performs the steps of power adjustment calibration.

[0012] It also includes a communication module, a positioning module, a vehicle control module and a voice broadcast module connected to the main control module.

[0013] All modules in the above RFID card reader are placed inside the shell, and an external cable module is arranged outside the shell.

[0014] The communication module includes a cellular communication sub-module and a Bluetooth communication sub-module. The communication module uses an NB-IoT communication module or a 4G LET CAT1 communication module. The cellular communication sub-module communicates with the cloud platform of the shared electric bicycle, and the Bluetooth communication sub-module communicates with the mobile phone client.

[0015] The beneficial effects of the present invention are as follows: The ultra-high frequency RFID shared electric bicycle fixed-point parking device and method with automatic calibration of transmission power proposed by the present invention provide an efficient and simple method for automatic calibration of transmission power, improving the usability and accuracy of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is the principle block diagram of the present invention;

[0017] Figure 2 is the flow chart of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0019] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0020] As Figure 1 shown, the ultra-high frequency RFID vehicle fixed-point parking device with automatic calibration of transmission power includes a terminal hardware part and a software part. The hardware part is based on an RFID reader with a frequency band of 900 MHz and an electronic tag with a frequency of 900 MHz. The RFID reader includes a main control module and an acceleration detection module, a communication module, a positioning module, a vehicle control module, an RFID reading and writing module, an RFID power amplification module, an RFID antenna module, and a voice broadcast module connected thereto. All the modules in the above RFID reader are placed inside the housing, and an external cable module is arranged outside the housing. The external cable module is the output cable of the internal functional modules of the housing. The software part is a power transmission automatic calibration module.

[0021] 1) Main control module

[0022] This device uses a single-chip microcomputer as the main control module to detect, process, and output external signals, and is responsible for sending and receiving with the RFID reading and writing module, communication module, positioning module, and external interface. Specifically, the single-chip microcomputer can detect the power-off of the external power supply through a general-purpose I / O via a voltage-dividing circuit, and can obtain the acceleration signal collected by the acceleration detection module through the I / O and I2C interfaces, and then judge the motion and stationary states of the carrier.

[0023] 2) Acceleration detection module

[0024] The acceleration detection module uses a three-axis acceleration sensor to detect the motion state or stationary state of the vehicle.

[0025] 3) Communication module

[0026] The communication module includes a cellular communication sub-module and a Bluetooth communication sub-module. This sub-module can use an NB-IoT communication module or a 4G LET CAT1 communication module. The cellular communication sub-module communicates with the cloud platform of the shared electric bicycle, and the Bluetooth communication sub-module communicates with the mobile phone client. Correspondingly, the communication module also includes a cellular communication antenna and a Bluetooth communication antenna.

[0027] 4) Positioning module

[0028] The positioning module is a satellite positioning module. The satellite positioning module realizes the reception of satellite signals and calculates the position of the device. This module also includes a satellite receiving antenna.

[0029] 5) Vehicle control module

[0030] The vehicle control module is connected to the vehicle power controller, seat lock, and horn through external cables to realize vehicle startup, locking, seat opening and closing, and voice playback.

[0031] 6) RFID reading and writing module

[0032] The RFID reading and writing module is built with a radio frequency transceiver and a digital modem, which is used to modulate digital signals to generate analog signals and demodulate the received analog signals to obtain digital information.

[0033] 7) RFID power amplification module

[0034] The power amplification module amplifies the analog signals generated by the RFID reading and writing module and the received tag analog signals, so that the communication signals can be normally transmitted and received.

[0035] 8) RFID antenna module

[0036] The antenna module is used to convert the wired analog signal generated and amplified by the RFID reading and writing module into a wireless radio frequency signal for transmission, and receive the wireless radio frequency signal emitted by the RFID tag and convert it into a wired analog signal.

[0037] 9) Voice broadcast module

[0038] The voice broadcast module uses voice to remind the vehicle owner of events such as unlocking and successful car return, and warning events such as exceeding the service and abnormal promotion.

[0039] It should be noted that the above main control module, acceleration detection module, communication module, positioning module, vehicle control module, RFID reading and writing module, RFID power amplifier module, RFID antenna module and voice broadcast module are all commercially available hardware modules.

[0040] The present invention adds a power transmission automatic calibration module, and the power transmission automatic calibration module is communicatively connected to the main control module. In the power transmission automatic calibration module, there are two conditions for starting power adjustment: First, the vehicle has not obtained the calibrated transmission power; Second, the vehicle is in a stationary state after moving. That is to say, the scenario where the vehicle obtains the calibrated transmission power is when the vehicle is first placed in the parking space with electronic tags laid, and the specific steps for power adjustment and calibration of its RFID card reader are as follows:

[0041] Step 1: The acceleration detection module detects the vehicle movement information and sends the wheel movement information to the main control module; when the main control module determines that the vehicle changes from the moving state to the stationary state and there is no valid calibrated power stored in the RFID card reader, the RFID card reader starts power adjustment and calibration.

[0042] Step 2: According to the rated power parameter value of the RFID reading and writing module, the main control module sets this rated power parameter value as the maximum power value P0, and the main control module adjusts the transmission power to the maximum power value P0 for reading work. Set the time threshold range T. Under the condition that the transmission power is the maximum power value P0, if no electronic tag is detected within the set time threshold range T, stop the power calibration work; if the RFID card reader can read the electronic tag content, gradually reduce the transmission power according to the set fixed power interval value. After each reduction of the transmission power, read the electronic tag, and record each transmission power as P i , where i is the order of changing the power. When the tag information cannot be read after reducing the transmission power and the corresponding transmission power is recorded, then mark P n-1 The power value is the calibrated power value and is stored in the RFID card reader terminal.

[0043] Step 3: After the transmission power calibration, every time the user parks the car, the RFID reading and writing module uses the calibrated power value P n-1Read the tag. If the tag can be read, it means the corresponding vehicle has been parked at the designated position, that is, the distance between the antenna module of the RFID reader and the electronic tag is the set distance. If the tag cannot be read, it means the vehicle has not been parked at the designated position, that is, the distance between the antenna module of the RFID reader and the tag exceeds the set value. When the set value is exceeded, the main control module sends instructions to the voice broadcast module and the vehicle control module, and then warning or vehicle control operations can be performed according to the settings.

[0044] Step 4: Considering that after the RFID reader has been calibrated and used, it may need to be repaired or replaced and installed on other vehicle models, the reset problem of the calibrated value of the transmission power must be considered, that is, re-calibration is required. The condition for resetting the calibrated value of the transmission power in the present invention is that the power supply of the housing and the external cable is disconnected. That is, when the maintenance personnel replace the battery, remove and repair the terminal or replace it on other vehicle models, the calibration condition of the transmission power is restarted.

[0045] The above are only the preferred embodiments of the present invention. It should be noted that for those skilled in the art, without departing from the overall concept of the present invention, several changes and improvements can still be made, and these should also be regarded as the protection scope of the present invention.

Claims

1. An ultra-high frequency RFID vehicle fixed-point parking method with automatic calibration of transmission power, characterized in that The specific steps for calibrating the power adjustment of the RFID reader are as follows: Step 1: The acceleration detection module detects the vehicle motion information and sends the wheel motion information to the main control module; when the main control module determines that the vehicle has changed from the moving state to the stationary state and there is no valid calibrated power stored in the RFID reader, the RFID reader starts the power adjustment calibration. Step 2: According to the rated power parameter value of the RFID reading and writing module, the main control module sets this rated power parameter value as the maximum power P0, and the main control module adjusts the transmission power to the maximum power P0 for reading; set the time threshold range T. Under the condition that the transmission power is the maximum power P0, if no electronic tag is detected within the set time threshold range T, stop the power calibration work; if the RFID reader can read the content of the electronic tag, gradually reduce the transmission power according to the set fixed power interval value. After each reduction of the transmission power, read the electronic tag, and record the transmission power each time as P i , where i is the order of changing the power. When the corresponding transmission power is recorded when the tag information cannot be read after reducing the transmission power, then mark P n-1 at this time as the calibrated power value and store it in the RFID reader terminal; Step 3: After the transmission power calibration, every time the user parks the vehicle, the RFID reading and writing module reads the tag with the calibrated power value P n-1 If the tag can be read, it means that the corresponding vehicle has been parked at the designated position, that is, the distance between the antenna module of the RFID reader and the electronic tag is the set distance. If the tag cannot be read, it means that the vehicle has not been parked at the designated position, that is, the distance between the antenna module of the RFID reader and the tag exceeds the set value.

2. The ultra-high frequency RFID vehicle fixed-point parking method for automatic calibration of transmission power according to claim 1, characterized in that: It also includes Step 4: The reset condition for the transmitted power calibration value is that the power supply of the housing and the external cable is disconnected, and the calibration condition of the transmitted power is restarted.

3. An ultra-high frequency RFID vehicle fixed-point parking device for automatically calibrating the transmission power for implementing the method described in claim 1, comprising an RFID reader and an electronic tag, wherein, The RFID reader includes: a main control module and an acceleration detection module, an RFID reading and writing module, an RFID power amplification module, and an RFID antenna module connected thereto, characterized in that: it further includes a power transmission automatic calibration module, the power transmission automatic calibration module is communicatively connected to the main control module, and the power transmission automatic calibration module executes the steps of power adjustment calibration.

4. The ultra-high frequency RFID vehicle fixed-point parking device with automatic calibration of transmission power according to claim 3, characterized in that: It also includes a communication module, a positioning module, a vehicle control module, and a voice broadcast module connected to the main control module.

5. The ultra-high frequency RFID vehicle fixed-point parking device with automatic calibration of transmission power according to claim 3, characterized in that: All the modules in the above RFID reader are placed inside the housing, and an external cable module is arranged outside the housing.

6. The ultra-high frequency RFID vehicle fixed-point parking device with automatic calibration of transmission power according to claim 3, characterized in that: The communication module includes a cellular communication sub-module and a Bluetooth communication sub-module. The communication module uses an NB-IoT communication module or a 4G LET CAT1 communication module. The cellular communication sub-module communicates with the cloud platform of the shared electric vehicle, and the Bluetooth communication sub-module communicates with the mobile phone client.

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