阅读说明：本技术 一种基于LoRa的列尾装置及用于该装置的通信方法 (LoRa-based train tail device and communication method for same ) 是由 马赛 陈维明 于 2020-05-30 设计创作，主要内容包括：本发明涉及一种基于LoRa的列尾装置,包括列尾机车台、列尾主机和LoRa网络,列尾机车台和列尾主机通过LoRa网络进行信息交互。本发明还涉及一种用于上述列尾装置的通信方法,该方法分为MAC层部分和应用层部分。MAC层涉及列尾机车台与列尾主机同步及通信时隙的定义,本发明根据通信形式不同将时隙分为三种结构。在每个时隙中列尾机车台执行列尾机车台通信子方法与列尾主机进行通信；列尾主机执行列尾主机通信子方法与列尾机车台进行通信。应用层部分定义了帧类型、帧数据结构和列尾装置应用流程。与现有技术相比,本发明具有功耗低、成本低、体积小、可靠性高、传输距离远等优点。(The invention relates to a train tail device based on LoRa, which comprises a train tail locomotive platform, a train tail host and a LoRa network, wherein the train tail locomotive platform and the train tail host carry out information interaction through the LoRa network. The invention also relates to a communication method used for the train tail device, which is divided into an MAC layer part and an application layer part. The MAC layer relates to the synchronization of a train tail locomotive platform and a train tail host and the definition of communication time slots. The train tail locomotive platform in each time slot executes a train tail locomotive platform communication sub-method to communicate with the train tail host; and the train tail host executes a train tail host communication sub-method to communicate with the train tail locomotive platform. The application layer part defines the frame type, the frame data structure and the application flow of the column tail device. Compared with the prior art, the invention has the advantages of low power consumption, low cost, small volume, high reliability, long transmission distance and the like.)

1. The train tail device based on the LoRa is characterized by comprising a train tail locomotive platform (1), a train tail host (2) and a LoRa network (3); the train tail locomotive platform (1) and the train tail host (2) carry out information interaction through the LoRa network (3).

2. The LoRa-based train tail device according to claim 1, characterized in that the train tail locomotive platform (1) comprises a train tail locomotive platform LoRa module (101), a train tail locomotive platform controller (102), a train tail locomotive platform memory (103), an antenna (104), a train tail locomotive platform power supply module (105) and a train tail control box (106); the train tail locomotive platform LoRa module (101) and the train tail locomotive platform controller (102) are respectively connected with the train tail locomotive platform power module (105); the train tail locomotive platform LoRa module (101), the train tail locomotive platform memory (103) and the train tail control box (106) are respectively connected with the train tail locomotive platform controller (102); the antenna (104) is connected with a train tail locomotive platform LoRa module (101).

3. The LoRa-based train tail device according to claim 2, wherein the train tail locomotive platform power module (105) is connected with a locomotive power supply.

4. The LoRa-based column tail device according to claim 1, characterized in that the column tail host (2) comprises a column tail host LoRa module (201), a column tail host controller (202), a column tail host memory (203), a wind pressure detection module (204) and a column tail host power supply module (205); the train tail host LoRa module (201), the train tail host controller (202) and the wind pressure detection module (204) are respectively connected with the train tail host power supply module (205); the train tail host LoRa module (201), the train tail host memory (203) and the wind pressure detection module (204) are respectively connected with the train tail host controller (202).

5. The LoRa-based train tail device according to claim 4, wherein the wind pressure detection module (204) comprises a wind pressure sensor, an exhaust unit and a wind pipe; the wind pressure sensor and the air exhaust unit are both arranged in the wind pipe; the wind pressure sensor and the air exhaust unit are respectively connected with a train tail host controller (202); and the air pipe is connected with a main air pipe of the train.

6. The LoRa-based train tail device according to claim 4, wherein the train tail host power module (205) is a rechargeable battery.

7. A LoRa-based train tail device according to claim 1, characterized in that the train tail locomotive platform (1) and the train tail host (2) communicate through LoRa communication protocol under LoRa network.

8. A communication method for the train tail device according to claim 1, which is a program embedded in the controller, characterized by comprising a train tail locomotive platform communication sub-method and a train tail host communication sub-method; the train tail locomotive platform is communicated with the train tail host through a train tail locomotive platform communication sub-method; and the train tail host communicates with the train tail locomotive platform through a train tail host communication sub-method.

9. The communication method according to claim 8, wherein the train tail locomotive platform communication sub-method comprises:

step 1-1: judging whether downlink data exists or not when the time slot starts, if so, executing the step 1-2, otherwise, executing the step 1-6;

step 1-2: starting a train tail locomotive platform LoRa module (101) to send downlink data, and then executing the step 1-3;

step 1-3: after finishing sending the downlink data, entering a sleep mode, wherein the sleep time is T₁Then performing steps 1-4

Step 1-4: at completion time length T₁After the train tail locomotive station is dormant, configuring a LoRa module (101) module into a receiving state, starting to perform channel detection, and then executing the steps 1-5;

step 1-5: judging whether the uplink reply data sent by the column tail host in the channel is correct lead codes or not, if so, receiving and processing the uplink reply data, and then sleeping to the next time slot, otherwise, directly sleeping to the next time slot;

step 1-6: the train tail locomotive platform directly enters a sleep mode with the sleep time length of T₃Then, executing the steps 1-7;

step 1-7: at completion time length T₃After the train tail locomotive station is dormant, starting a train tail locomotive station LoRa module (101), starting channel detection, and then executing the steps 1-8;

step 1-8: judging whether the channel has a correct lead code of uplink reply data sent by the train tail host, if so, executing the steps 1-9, otherwise, directly sleeping to the next time slot;

step 1-9: receiving and processing uplink reply data, and then performing the processing for a time length of T₂After the dormancy is finished, the train tail locomotive station LoRa module (101) sends downlink response data to the train as the host, and after the sending is finished, the train tail locomotive station LoRa module sleeps to the next time slot.

10. The communication method according to claim 8, wherein the train tail host communication sub-method comprises:

step 2-1: the train tail host is converted from a dormant state to a working state when a time slot starts, a train tail host LoRa module (201) is started to be in a receiving state, and channel detection is started;

step 2-2: judging whether a downlink data correct lead code sent by a train tail locomotive platform is received in a channel, if so, executing the step 2-3, otherwise, executing the step 2-5;

step 2-3: receiving downlink data sent by a train tail locomotive station, processing the data, generating uplink reply data to be sent at the same time, and then executing the step 2-4;

step 2-4: the train tail host enters a sleep mode with the sleep duration of T₁Sending uplink reply data after the dormancy is finished, and then dormancy is carried out to the next time slot;

step 2-5: judging whether the host at the tail of the row has uplink data, if so, executing the step 2-6, otherwise, directly sleeping to the next time slot;

step 2-6: the train tail host enters a sleep mode with the sleep duration of T₃After the dormancy is finished, sending uplink data to a train tail locomotive platform, and then executing the step 2-7;

step 2-7: the train tail host enters a sleep mode with the sleep duration of T₂And then, carrying out channel detection, judging whether the downlink response data sent by the train tail locomotive station is correct boot codes, if so, receiving and processing the downlink response data, and then sleeping to the next time slot, otherwise, directly sleeping to the next time slot.

Technical Field

The invention relates to the technical field of train communication, in particular to a train tail device based on LoRa and a communication method for the train tail device.

Background

With the technical progress and the aim of reducing personnel and increasing efficiency, on the premise of ensuring the operation safety, the railway transportation department replaces the rear air pressure and the exhaust braking operation reported by train rear guard equipment, which is called a train rear device for short, from the nineties of the last century. The communication mode between the train tail host and the train tail locomotive platform adopts 450MHz wireless analog communication, and has the defects of less frequency band resource, short transmission distance, large power consumption, interference between frequency points, poor confidentiality and the like. And then, dual-mode communication of 400MHz frequency band wireless digital communication and GSM-R network communication is gradually adopted for communication among the train tail equipment, so that the transmission distance and reliability of communication are improved, and the problem of communication interruption between the train tail host and the locomotive platform caused by poor communication links is favorably solved.

Chinese patent CN208585253U discloses a digital dual-mode train tail system based on wireless communication, which includes a train tail locomotive platform installed on a locomotive and a train tail host installed at the tail of the train, and the device uses a GSM-R model, a 400MHz digital channel machine and a router to complete the communication between the train tail host and the train tail locomotive platform, but the device in the patent has the defects of high radio station price, high transmission power consumption, unsatisfactory transmission distance, and interference between station catenary and equipment through practical application.

Disclosure of Invention

The present invention is directed to overcome the above-mentioned drawbacks of the prior art, and provides a low power consumption, low cost, small size, high reliability, and long transmission distance train tail device based on LoRa and a communication method for the device.

The purpose of the invention can be realized by the following technical scheme:

a train tail device based on LoRa comprises a train tail locomotive platform, a train tail host and a LoRa network; and the train tail locomotive platform and the train tail host carry out information interaction through a LoRa network.

Preferably, the train tail locomotive platform comprises a train tail locomotive platform LoRa module, a train tail locomotive platform controller, a train tail locomotive platform memory, an antenna, a train tail locomotive platform power supply module and a train tail control box; the train tail locomotive platform LoRa module and the train tail locomotive platform controller are respectively connected with a train tail locomotive platform power supply module; the train tail locomotive platform LoRa module, the train tail locomotive platform memory and the train tail control box are respectively connected with a train tail locomotive platform controller; the antenna is connected with a train tail locomotive platform LoRa module.

More preferably, the train tail locomotive platform power supply module is connected with a locomotive power supply.

Preferably, the train tail host comprises a train tail host LoRa module, a train tail host controller, a train tail host memory, a wind pressure detection module and a train tail host power supply module; the train tail host LoRa module, the train tail host controller and the air pressure detection module are respectively connected with the train tail host power supply module; the train tail host LoRa module, the train tail host memory and the wind pressure detection module are respectively connected with the train tail host controller.

More preferably, the wind pressure detection module comprises a wind pressure sensor, an exhaust unit and a wind pipe; the wind pressure sensor and the air exhaust unit are both arranged in the wind pipe; the wind pressure sensor and the air exhaust unit are respectively connected with a train tail host controller; and the air pipe is connected with a main air pipe of the train.

More preferably, the train tail host power supply module is a rechargeable battery.

Preferably, the train tail locomotive platform and the train tail host communicate through a LoRa communication protocol under a LoRa network.

A communication method used for the above-mentioned train tail apparatus, including train tail locomotive platform communication sub-method and train tail host computer communication sub-method; the train tail locomotive platform is communicated with the train tail host through a train tail locomotive platform communication sub-method; and the train tail host communicates with the train tail locomotive platform through a train tail host communication sub-method.

Preferably, the train tail locomotive platform communication sub-method comprises the following steps:

step 1-1: judging whether downlink data exists or not when the time slot starts, if so, executing the step 1-2, otherwise, executing the step 1-6;

step 1-2: starting a train tail locomotive platform LoRa module to send downlink data, and then executing the step 1-3;

step 1-3: after finishing sending the downlink data, entering a sleep mode, wherein the sleep time is T₁Then performing steps 1-4

Step 1-4: at completion time length T₁After the train tail locomotive station is dormant, configuring a LoRa module into a receiving state, starting to carry out channel detection, and then executing the step 1-5;

step 1-5: judging whether the uplink reply data sent by the column tail host in the channel is correct lead codes or not, if so, receiving and processing the uplink reply data, and then sleeping to the next time slot, otherwise, directly sleeping to the next time slot;

step 1-6: the train tail locomotive platform directly enters a sleep mode with the sleep time length of T₃Then, executing the steps 1-7;

step 1-7: at completion time length T₃After the train tail locomotive station is dormant, starting a LoRa module of the train tail locomotive station, starting channel detection, and then executing the steps 1-8;

step 1-8: judging whether the channel has a correct lead code of uplink reply data sent by the train tail host, if so, executing the steps 1-9, otherwise, directly sleeping to the next time slot;

step 1-9: receiving and processing uplink reply data, and then performing the processing for a time length of T₂After the dormancy is completed, the LoRa module of the train tail locomotive station sends downlink response data to the column as the host, and after the sending is completed, the train tail locomotive station sleeps to the next time slot.

Preferably, the train tail host communication sub-method includes:

step 2-1: the train tail host is converted from a dormant state to a working state when a time slot starts, a train tail host LoRa module is started to be in a receiving state, and channel detection is started;

step 2-2: judging whether a downlink data correct lead code sent by a train tail locomotive platform is received in a channel, if so, executing the step 2-3, otherwise, executing the step 2-5;

step 2-3: receiving downlink data sent by a train tail locomotive station, processing the data, generating uplink reply data to be sent at the same time, and then executing the step 2-4;

step 2-4: the train tail host enters a sleep mode with the sleep duration of T₁Sending uplink reply data after the dormancy is finished, and then dormancy is carried out to the next time slot;

step 2-5: judging whether the host at the tail of the row has uplink data, if so, executing the step 2-6, otherwise, directly sleeping to the next time slot;

step 2-6: the train tail host enters a sleep mode with the sleep duration of T₃Go to sleepAfter finishing, sending uplink data to the train tail locomotive platform, and then executing the step 2-7;

step 2-7: the train tail host enters a sleep mode with the sleep duration of T₂And then, carrying out channel detection, judging whether the downlink response data sent by the train tail locomotive station is correct boot codes, if so, receiving and processing the downlink response data, and then sleeping to the next time slot, otherwise, directly sleeping to the next time slot.

Compared with the prior art, the invention has the following advantages:

firstly, the power consumption is low: the train tail device adopts a low-power-consumption miniaturized design, is provided with a low-power-consumption LoRa module, and has the transmitting power of only 50mW, the minimum transmitting power of the conventional locomotive platform is 5W, and the transmitting power of the conventional host is 3W.

Secondly, the reliability is high: the train tail device adopts the LoRa communication module, so that the anti-interference performance is improved, and meanwhile, the invention also provides a communication method for the train tail device.

Thirdly, the cost is low: the train tail device adopts the LoRa communication module, the market price of the changed module is far lower than that of the existing 400MHz digital radio station, 450MHz digital radio station and GSM-R communication module, and the manufacturing cost of the device is greatly reduced.

Fourthly, the transmission distance is long: the train tail locomotive platform and the train tail host machine are communicated through the LoRa network, the receiving sensitivity reaches-148 dBm, the receiving sensitivity is obviously superior to-110 dBm of the existing equipment, and the communication distance is greatly increased.

Drawings

FIG. 1 is a schematic block diagram of a train tail device according to the present invention;

FIG. 2 is a schematic structural diagram of a train tail device according to the present invention;

FIG. 3 is a flow chart of a train tail locomotive communication sub-method of the present invention;

FIG. 4 is a flow chart of a train tail host communication sub-method according to the present invention;

FIG. 5 is a schematic diagram illustrating the connection and disconnection process between the train tail locomotive platform and the train tail host according to the embodiment of the present invention;

FIG. 6 is a data transmission process between a train tail locomotive platform and a train tail host according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of a time slot structure when a train tail locomotive platform sends data and a train tail host receives data according to an embodiment of the present invention;

FIG. 8 is a schematic diagram of a time slot structure when a train tail host sends data and a train tail locomotive platform receives data according to an embodiment of the present invention;

fig. 9 is a schematic time slot structure diagram of the train tail host and the train tail locomotive station having no data transmission in the embodiment of the present invention.

The reference numbers in the figures indicate:

1. train tail locomotive platform, 2, train tail host computer, 3, loRa network, 101, train tail locomotive platform loRa module, 102, train tail locomotive platform controller, 103, train tail locomotive platform memory, 104, antenna, 105, train tail locomotive platform power module, 106, train tail control box, 201, train tail host computer loRa module, 202, train tail host computer controller, 203, train tail host computer memory, 204, wind pressure detection module, 205, train tail host computer power module.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, shall fall within the scope of protection of the present invention.

A train tail device based on LoRa, the structure of which is shown in fig. 1 and fig. 2, comprising: a train tail locomotive platform 1, a train tail host 2 and a LoRa network 3.

Train tail locomotive platform 1: the train tail locomotive platform power supply control system comprises a train tail locomotive platform LoRa module 101, a train tail locomotive platform controller 102, a train tail locomotive platform memory 103, an antenna 104, a train tail locomotive platform power supply module 105 and a train tail control box 106, wherein the train tail locomotive platform LoRa module 101 and the train tail locomotive platform controller 102 are respectively connected with the train tail locomotive platform power supply module 105, the train tail locomotive platform LoRa module 101, the train tail locomotive platform memory 103 and the train tail control box 106 are respectively connected with the train tail locomotive platform controller 102, and the antenna 104 is connected with the train tail locomotive platform LoRa module 101.

The train tail locomotive platform power module 105 is directly connected with a locomotive power supply and directly supplies power through the locomotive power supply.

Train tail host 2: the train tail host machine LoRa module 201, the train tail host machine controller 202, the train tail host machine memory 203, the wind pressure detection module 204 and the train tail host machine power module 205, the train tail host machine LoRa module 201, the train tail host machine controller 202 and the wind pressure detection module 204 are respectively connected with the train tail host machine power module 205, and the train tail host machine LoRa module 201, the train tail host machine memory 203 and the wind pressure detection module 204 are respectively connected with the train tail host machine controller 202.

The wind pressure detection module 204 comprises a wind pressure sensor, an air exhaust unit and a wind pipe, wherein the wind pressure sensor and the air exhaust unit are both installed in the wind pipe, the wind pressure sensor and the air exhaust unit are respectively connected with the train tail host controller 202, and the wind pipe is connected with a train main wind pipe.

In this embodiment, the train tail host power supply 205 is a rechargeable battery, specifically a lithium ion rechargeable battery.

The train tail locomotive platform 1 and the train tail host 2 in this embodiment communicate through an LoRa communication protocol under an LoRa network.

The LoRa communication module with low power consumption is selected for the LoRa module 201 of the train tail host in this embodiment.

The embodiment also relates to a communication method for the train tail device, which is divided into an MAC layer part and an application layer part, wherein the MAC layer part relates to synchronization between the train tail locomotive platform and the train tail host and definition of communication time slots, the embodiment divides the time slots into three structures according to different communication forms, and as shown in fig. 7 to 9, the train tail locomotive platform performs a train tail locomotive platform communication sub-method in each time slot to communicate with the train tail host; and the train tail host executes a train tail host communication sub-method to communicate with the train tail locomotive platform. The application layer part defines the frame type, the frame data structure and the application flow of the column tail device.

The train tail locomotive platform communication sub-method is embedded in the train tail locomotive platform controller 102, and the train tail host computer communication sub-method is embedded in the train tail host computer controller 202.

The process of connecting and disconnecting the train tail locomotive platform and the train tail host is shown in fig. 5, and the process of transmitting data between the train tail locomotive platform and the train tail host is shown in fig. 6. In this embodiment, the MAC layer protocol for communication between the train tail locomotive platform 1 and the train tail host 2 is as follows:

the frame sent to the train tail host by the train tail locomotive platform is downlink data; the frame sent to the train tail locomotive platform by the train tail host is uplink data. A pair of communicated train tail locomotive platforms and a train tail host select the same and fixed center frequency and bandwidth for data transceiving. The MAC layer divides uplink and downlink transmissions into time slots of fixed time length. The time slot is divided into three types, namely, a train tail locomotive platform sends downlink data and a train tail host sends uplink reply data, the train tail host sends the uplink data and the train tail locomotive platform sends the downlink reply data, and the train tail locomotive platform and the train tail host do not have data to send. Fig. 7 to 8 are schematic diagrams of time slot structures when a train tail locomotive platform sends data and a train tail host receives data, a train tail host sends data and a train tail locomotive platform receives data, and neither the train tail host nor the train tail locomotive platform sends data, respectively.

The column tail host in each time slot executes a communication process according to a column tail host communication sub-method;

and the train tail locomotive station executes a communication process according to the train tail locomotive station communication sub-method.

In a time slot, after receiving the downstream data of the train tail locomotive station, the train tail host needs to send the upstream reply data in the time slot.

In a time slot, after receiving the uplink data of the train tail host, the train tail locomotive station needs to send downlink response data in the time slot.

And the data frames sent by the train tail host and the train tail locomotive station in the time slot consist of a lead code and a frame load.

The flow of the train tail locomotive communication sub-method is shown in fig. 3, and comprises the following steps:

step 1-1: judging whether downlink data exists or not when the time slot starts, if so, executing the step 1-2, otherwise, executing the step 1-6;

step 1-2: starting a train tail locomotive platform LoRa module 101 to send downlink data, and then executing the step 1-3;

step 1-3: after finishing sending the downlink data, entering a sleep mode, wherein the sleep time is T₁Then performing steps 1-4

Step 1-4: at completion time length T₁After the train tail locomotive station is dormant, configuring a LoRa module 101 module into a receiving state, starting to perform channel detection, and then executing the steps 1-5;

step 1-5: judging whether the uplink reply data sent by the column tail host in the channel is correct lead codes or not, if so, receiving and processing the uplink reply data, and then sleeping to the next time slot, otherwise, directly sleeping to the next time slot;

step 1-6: the train tail locomotive platform directly enters a sleep mode with the sleep time length of T₃Then, executing the steps 1-7;

step 1-7: at completion time length T₃After the train tail locomotive station is dormant, starting a train tail locomotive station LoRa module 101, starting channel detection, and then executing the steps 1-8;

step 1-8: judging whether the channel has a correct lead code of uplink reply data sent by the train tail host, if so, executing the steps 1-9, otherwise, directly sleeping to the next time slot;

step 1-9: receiving and processing uplink reply data, and then performing the processing for a time length of T₂After the dormancy is completed, the LoRa module of the train tail locomotive station sends downlink response data to the column as the host, and after the sending is completed, the train tail locomotive station sleeps to the next time slot.

The process of the train tail host communication sub-method is shown in fig. 4, and includes:

step 2-1: the train tail host is switched from a dormant state to a working state when a time slot starts, a train tail host LoRa module 201 is started to be in a receiving state, and channel detection is started;

step 2-2: judging whether a downlink data correct lead code sent by a train tail locomotive platform is received in a channel, if so, executing the step 2-3, otherwise, executing the step 2-5;

step 2-3: receiving downlink data sent by a train tail locomotive station, processing the data, generating uplink reply data to be sent at the same time, and then executing the step 2-4;

step 2-4: the train tail host enters a sleep mode with the sleep duration of T₁Sending uplink reply data after the dormancy is finished, and then dormancy is carried out to the next time slot;

step 2-5: judging whether the host at the tail of the row has uplink data, if so, executing the step 2-6, otherwise, directly sleeping to the next time slot;

step 2-6: the train tail host enters a sleep mode with the sleep duration of T₃After the dormancy is finished, sending uplink data to a train tail locomotive platform, and then executing the step 2-7;

step 2-7: the train tail host enters a sleep mode with the sleep duration of T₂And then, carrying out channel detection, judging whether the downlink response data sent by the train tail locomotive station is correct boot codes, if so, receiving and processing the downlink response data, and then sleeping to the next time slot, otherwise, directly sleeping to the next time slot.

When the train tail host 2 receives correct train tail locomotive station preamble data at the beginning of a time slot, the time of receiving the preamble is used as the clock synchronization time. The channel listening window may be greater than the preamble transmission time in each frame. The receiver starts listening to the channel relatively earlier than the sender sends the preamble, and the receiver ends listening to the channel relatively later than the sender sends the preamble; to ensure complete reception of the preamble data.

The protocol of the communication application layer of the train tail host and the train tail locomotive platform is as follows:

the uplink and downlink data frame structure is shown in table 1.

TABLE 1 upstream and downstream data frames

The data frame types are shown in table 2.

TABLE 2 data frame types

Serial number	Data frame name	Data direction	Description of the invention
				1	Establishing a connection request	Downstream
2	Establishing a connection reply	Uplink is carried out
				3	Disconnection request	Downstream
4	Disconnect reply	Uplink is carried out
				5	Query wind pressure	Downstream
6	Wind pressure response	Uplink is carried out
				7	Air exhaust command	Downstream
8	Air exhaust response	Uplink is carried out
				9	Wind pressure alarm	Uplink is carried out
10	Wind pressure alarm confirmation	Downstream
				11	Battery under-voltage alarm	Uplink is carried out
12	Battery under-voltage alarm confirmation	Downstream

The length of the uplink and downlink data frames is fixed to 29 bytes, wherein the preamble is 2 bytes, and the frame load data is 27 bytes in total. And the downlink data and the uplink data in the same time slot are consistent in frame number.

Before the train tail host 2 and the train tail locomotive platform 1 are connected, the same communication frequency is set for the two devices. And inputting the serial number of the train tail host to be connected to the train tail locomotive platform.

After the connection is established, the train tail host 2 and the train tail locomotive station 1 continuously listen to the channel and receive wireless data. The trail locomotive platform 1 first sends a "establish connection request" command. After receiving the connection establishment request type frame, the train tail host 2 stores the train tail locomotive station number and replies a connection establishment response type frame if the received train tail locomotive station number is the locomotive station to be connected. And the train tail locomotive station starts to execute the train tail locomotive station communication sub-method to communicate with the train tail host by taking the time of sending the command frame of establishing the connection request as a time slot. The train tail host 2 starts to execute the train tail host communication sub-method to communicate with the train tail locomotive station by taking the time when the command frame of 'establishing connection request' is received as a time slot. After the train tail locomotive platform 12 receives the connection establishment response frame, if the serial numbers of the train tail locomotive platform 1 and the train tail host 2 are correct, the serial number of the train tail host is stored. And after the train tail locomotive platform sends the type frame of 'establishing connection request', if the response frame is not received within 20 seconds, the train tail locomotive platform is sent again.

If the train tail locomotive platform 1 needs to inquire the wind pressure state of the train tail host 2, a wind pressure inquiry type frame is sent to the train tail host at the beginning of the time slot. After receiving the data, the train tail host 2 inquires the wind pressure and sends information such as battery voltage of the train tail host, signal intensity and signal to noise ratio of the received downlink data frame and the like to the 'wind pressure response' uplink data frame according to a specified frame format.

If the train tail locomotive platform 1 needs the train tail host 2 to execute air exhaust, an air exhaust command type frame is sent to the train tail host at the beginning of the time slot. And after receiving the data, the train tail host 2 executes air pipe exhaust operation, and sends the information of battery voltage of the train tail host, signal strength and signal to noise ratio of the received downlink data frame and the like to an 'exhaust response' uplink data frame according to a specified frame format. And after the train tail locomotive platform sends the air exhaust command type frame, if the response frame is not received within 20 seconds, the response frame is sent again.

When the wind pressure of the train main air pipe is lower than a set value, the train tail host 2 sends a wind pressure alarm type frame to the train tail locomotive platform in a time slot. And after the train tail locomotive platform 1 receives the data frame, displaying alarm information, and replying a 'wind pressure alarm confirmation' data frame to the train tail host 2. And after the train tail host 2 receives the data frame of 'wind pressure alarm confirmation', stopping sending the alarm information to the train tail locomotive platform 1. The train tail host 2 sends the wind pressure alarm data every 20 seconds until receiving the wind pressure alarm confirmation data frame.

When the battery voltage of the train tail host 2 is lower than a set value, the train tail host 2 sends an undervoltage alarm type frame to the train tail locomotive platform once. And after the train tail locomotive platform 1 receives the data frame, displaying alarm information, and replying an under-voltage alarm confirmation data frame to the train tail host 2. And after the train tail host 2 receives the data frame of the undervoltage alarm confirmation, stopping sending the alarm information to the train tail locomotive platform 1. The train tail host 2 sends the data of 'under-voltage alarm' once every 20 seconds until it receives the data frame of 'wind pressure alarm confirmation'.

If the train tail locomotive platform 1 needs to be disconnected from the train tail host 2, the train tail locomotive platform 1 firstly sends a disconnection request command. After receiving the disconnection request type frame, the train tail host 2 deletes the stored train tail locomotive station number and replies a disconnection response type frame if the received train tail locomotive station number is the locomotive station number stored therein. After the train tail host 1 receives the disconnection response frame, if the train tail locomotive platform and the train tail host are the stored numbers, the stored train tail host number is deleted. After transmitting the "disconnection request" type frame, the train end locomotive platform 1 retransmits the frame if it does not receive the response frame within 20 seconds.

While the invention has been described with reference to specific embodiments, the invention is not limited thereto, and various equivalent modifications and substitutions can be easily made by those skilled in the art within the technical scope of the invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.