A method for remote alarm data transmission in rail transit vehicles

Abstract

This invention discloses a method for transmitting remote alarm data of rail transit vehicles, belonging to the field of rail transit. The method provides a remote alarm data model for rail transit vehicles, featuring a redundancy switching mechanism. The two parties communicating use transmission control protocols such as TCP and UDP, and redundancy switching is performed based on sequence number, timestamp, and timeout judgment. The method is based on symmetric encryption methods such as AES, where the data requester and data responder create the same key. Both parties use this key to encrypt the request message and the vehicle remote alarm data, respectively. The receiving party decrypts the data using the key, and the data requester visualizes the decrypted vehicle remote alarm data. This invention enables reliable encrypted transmission of remote alarm data information of rail transit vehicles, improving the security, availability, confidentiality, and integrity of the transmission process.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rail transit, in particular to a vehicle remote alarm data transmission method in rail transit integrated monitoring. BACKGROUND

[0002] China is in a period of rapid development of rail transit, with the continuous expansion of the network scale, rail transit has become an important part of the urban public transport system. Vehicle remote alarm data is very important in urban rail transit, especially in fully automatic unmanned rail transit, without the participation of train drivers, the operation of the train needs to be completed under the action of the control system, so the monitoring of vehicle remote alarm information needs to be strengthened. The vehicle remote alarm system can automatically collect various data of all vehicles in urban rail transit, such as train fire system, train weight, train door and platform door alignment isolation, train pantograph state and other data. The vehicle remote alarm system transmits data to the integrated monitoring system, the integrated monitoring system integrates vehicle remote alarm information and multi-professional information to provide comprehensive criteria for vehicle dispatching, which is of great significance to ensure the normal work and safe operation of urban rail transit system.

[0003] To realize the vehicle remote alarm information monitoring function of the integrated monitoring system, the vehicle remote alarm system needs to be interconnected, a vehicle remote alarm data model is designed, real-time vehicle remote alarm data is obtained through the transmission control protocol, and the train-mounted equipment and the operation of the train are monitored on the user interface. At the same time, how to improve the security, availability, confidentiality and integrity of the rail transit vehicle remote alarm data transmission process without compromising the timeliness of the data is also a problem to be solved. SUMMARY

[0004] In view of the above problems existing in the prior art, the purpose of the present application is to provide a rail transit vehicle remote alarm data transmission method based on redundant switching and symmetric encryption, a set of vehicle remote alarm data model is designed, in order to meet the requirements of SIL2 level certification, the data transmission between the vehicle remote alarm data requester and the data responder is designed to comply with the EN50159 standard on the application layer protocol, including sequence number, time stamp, timeout judgment, symmetric encryption, redundant switching based on sequence number, time stamp and timeout judgment through the communication link, improving the availability and reliability of rail transit vehicle remote alarm data communication transmission, through the symmetric encryption of data, improving the security, confidentiality and integrity of rail transit vehicle remote alarm data, without compromising the timeliness of the data, ultimately monitoring the train-mounted equipment and the operation of the train on the user interface of the integrated monitoring system.

[0005] In order to achieve the above-mentioned purpose, the technical scheme used by the present application is: based on the object-oriented design method, a set of rail transit vehicle remote alarm information data models containing train number, train online state, fire alarm state, smoke alarm state, fire extinguisher in place state, pantograph state, train door state, date and time, passenger load and other data points are designed as the basic unit of single train, the data requester and the data responder communicate through symmetric encryption and redundant switching mechanism, and the data requester displays the vehicle remote alarm data information obtained by decryption. Specifically, the following steps are included:

[0006] Step 1: Establishing a remote alarm data object of the train according to the defined rail transit vehicle remote alarm information data model;

[0007] Step 2: In order to meet the requirements of SIL2 level certification, the sequence number, time stamp and timeout judgment of the data transmission between the vehicle remote alarm data requester and the data responder are designed, and the vehicle remote alarm data requester and the data responder use the redundant switching mechanism based on the sequence number, time stamp and timeout judgment to communicate through transmission control protocols such as TCP and UDP;

[0008] Step 3: In order to meet the requirements of SIL2 level certification, the data transmission between the vehicle remote alarm data requester and the data responder is symmetrically encrypted, the vehicle remote alarm data requester and the data responder create the same key, and both sides use the key to encrypt the request message and the rail transit vehicle remote alarm information data, and the party receiving the information uses the same key to decrypt the data;

[0009] Step 4: The data requester visualizes the decrypted vehicle remote alarm data.

[0010] Further characterized in that: a set of object definitions meeting the requirements of rail transit vehicle remote alarm data transmission are defined, including:

[0011] 1. Vehicle remote alarm data point definition

[0012] Function purpose: define a set of fire alarm state, smoke alarm state, fire extinguisher in place state, pantograph state, train door state, date and time, passenger load and other data point objects;

[0013] 2. Train definition

[0014] Function purpose: define the train object, which includes the number of the train, the name of the train, the online state of the train and other information, and the train object is the parent object of the remote alarm data point object of the train;

[0015] 3. Socket definition:

[0016] Functional purpose: define socket objects, which object attributes include IP address information and port information opened by the data response party, for the request party and the response party of one or more train data to establish a communication connection. In particular, multiple socket objects can be added for redundant communication connection. The socket object is the parent object of the train object.

[0017] Further characterized in that: in order to meet the requirements of SIL2 level certification, the data transmission between the vehicle remote alarm data request party and the data response party is designed for redundant switching based on sequence number, time stamp and timeout judgment. The data request party and the data response party of the remote alarm information of rail transit vehicle agree on a transmission control protocol, such as TCP, UDP, etc., and the two parties of data transmission communicate according to the format of the transmission protocol; the data request party selects one object as the main channel in the redundant socket object according to the IP and port configuration of the object, and sends a communication connection request to the data response party; the rest of the socket objects are used as redundant channels; the data response party receives the communication connection request sent by the data request party, and replies to the communication connection response to establish a communication connection; the data request party sends a vehicle remote alarm data request at regular intervals; the data response party receives the vehicle remote alarm data request and replies to the vehicle remote alarm data response; sequence number, time stamp and timeout judgment are designed in data communication to judge the state of the communication link. If the data request party and the data response party fail to establish a connection or the connection is interrupted, the data request party will select an IP and port configuration of a redundant socket object to send a new communication connection request, and select it as a new main channel after success, and transmit all data through the new main channel.

[0018] 1. Sequence number design

[0019] The data response party of the remote alarm information of rail transit vehicle adds a unique sequence number field seqNumber to the sent vehicle remote alarm data packet, so that even if the vehicle remote alarm data packet is reordered during transmission, the data request party can reorder them through the sequence number. In addition, the sequence number can also be used to detect packet loss: if the sequence number of the vehicle remote alarm data packet received by the data request party has a jump, it means that there is a packet loss, and the current communication link needs to be switched redundantly.

[0020] 2. Time stamp design

[0021] The data response party of the remote alarm information of rail transit vehicle adds a time stamp field timeStamp (total seconds from 00:00:00 on January 1, 1970, Greenwich Mean Time (08:00:00 on January 1, 1970, Beijing Time) to now) to each sent vehicle remote alarm data packet, as the date and time of the vehicle remote alarm data, and also for calculating the delay of the data packet and detecting whether the data packet is overdue.

[0022] 3. Time-out judgment design

[0023] When the data requester of the remote alarm information of the rail transit vehicle receives the data packet, the data update interval T1 from the last received data packet and the link delay interval T2 from the current time are obtained through the time stamp field timeStamp, and the data update interval T1 is compared with the pre-determined maximum update interval T1 max The link delay interval T2 is compared with the pre-determined maximum delay interval T2 max Only when T1≤T1max and T2≤T2max, it is indicated that the data packet is not out of time; otherwise, it is considered that the data packet is out of time, and the redundant switching of the current communication link is required.

[0024] Further features are that, in order to meet the requirements of SIL2 level authentication, symmetric encryption design is performed on the data transmission between the data requester and the data responder of the vehicle remote alarm. The data requester and the data responder of the remote alarm information of the rail transit vehicle agree on a symmetric encryption method such as AES, and the same key is created by both parties; the data requester encrypts the request message using the key and sends it to the data responder, and the data responder decrypts the received request message using the key; the data responder encrypts the vehicle remote alarm information data using the key and sends it to the data requester, and the data requester decrypts the received vehicle remote alarm information message using the key.

[0025] Further features are that the data receiver displays the decrypted remote alarm data of the rail transit vehicle in real time on a visual interface or saves it to a historical database.

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

[0027] 1. The present application designs a vehicle remote alarm data model for the storage and display of the remote alarm information of the rail transit vehicle, and realizes the basis of the vehicle remote alarm information transmission;

[0028] 2. The present application designs the compliance of the EN50159 standard on the application layer protocol for the data transmission between the data requester and the data responder of the vehicle remote alarm, and improves the availability and reliability of the remote alarm data communication transmission of the rail transit vehicle by using the communication link of the sequence number, time stamp and time-out judgment for redundant switching;

[0029] 3、The application carries out the compliance design of EN50159 standard on the application layer protocol for the data transmission between the vehicle remote alarm data request party and the data response party, improves the security, confidentiality and integrity in the process of the data transmission of the track traffic vehicle remote alarm data through the symmetric encryption of the communication data, and does not damage the timeliness of the data, and finally realizes the monitoring of the on-board equipment of the train and the running condition of the train on the user interface of the integrated monitoring system. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 The object definition relationship diagram is designed for the object based design method of the embodiment.

[0031] Figure 2 The flowchart of the vehicle remote alarm data redundant encryption transmission function implementation of the embodiment is shown.

[0032] Figure 3 The diagram of the symmetric encryption and decryption of the vehicle remote alarm information data using the key of the embodiment is shown. DETAILED DESCRIPTION

[0033] The specific embodiment of the application is described in further detail below in combination with the drawings and the embodiment. The following examples are used to illustrate the application, but do not limit the scope of the application. The embodiment is based on the object-oriented design method, and a group of track traffic vehicle remote alarm information data models including train number, train online state, fire alarm state, smoke alarm state, fire extinguisher in place state, pantograph state, train door state, date and time, passenger load and other data points are designed for a single train as a basic unit. The data request party and the data response party communicate through the symmetric encryption method and the redundant switching mechanism. The data request party displays the decrypted vehicle remote alarm data information. Specifically, the following steps are included.

[0034] Step 1: Establishing the remote alarm data object of the train according to the defined track traffic vehicle remote alarm information data model;

[0035] Step 2: In order to meet the requirements of SIL2 level certification, the sequence number, time stamp, timeout judgment design is carried out for the data transmission between the vehicle remote alarm data request party and the data response party. The vehicle remote alarm data request party and the data response party use the redundant switching mechanism based on the sequence number, time stamp and timeout judgment, and communicate through transmission control protocols such as TCP, UDP, etc.

[0036] Step 3: To meet the requirements of SIL2 certification, the data transmission between the vehicle remote alarm data requester and the data responder is designed for symmetric encryption. The vehicle remote alarm data requester and the data responder create the same key, and both parties use the key to encrypt the request message and the rail transit vehicle remote alarm information data, respectively. The party receiving the information uses the same key to decrypt the data.

[0037] Step 4: The data requester visualizes the decrypted vehicle remote alarm data.

[0038] Further: Define a set of object definitions that meet the requirements of rail transit vehicle remote alarm data transmission, such as Figure 1 As shown, including:

[0039] 1. Vehicle remote alarm data point definition

[0040] Function purpose: Define a set of train online status, fire alarm status, smoke alarm status, fire extinguisher in place status, pantograph status, train door status, date and time, passenger load, etc. Data point objects;

[0041]

[0042] 2. Train definition

[0043] Function purpose: Define train object, which includes train number, train name, train online status, etc. Information, train object is the parent object of the train remote alarm data point object;

[0044]

[0045] 3. Socket definition:

[0046] Function purpose: Define socket object, object attributes include IP address information and port information opened by data responder, used for communication connection between one or more train data requesters and responders. In particular, multiple socket objects can be added for redundant communication connection. Socket object is the parent object of train object;

[0047]

[0048] Further: As shown in Figure 2As shown, in order to meet the requirements of SIL2 level certification, the data transmission between the vehicle remote alarm data requester and the data responder is designed to be redundant switching based on sequence number, timestamp, and timeout judgment. The data requester and the data responder of the rail transit vehicle remote alarm information agree on a transmission control protocol, and the two parties of data transmission communicate according to the format of the transmission protocol; the data requester selects one object in the redundant socket object as the main channel, and sends a communication connection request to the data responder through the IP and port configuration of the object, and the remaining socket objects are used as redundant channels; the data responder receives the communication connection request sent by the data requester, and replies with a communication connection response to establish a communication connection; the data requester sends a vehicle remote alarm data request at regular intervals; the data responder receives the vehicle remote alarm data request and replies with a vehicle remote alarm data response; sequence number, timestamp, and timeout judgment are designed in the data communication to judge the state of the communication link, and if the data requester and the data responder fail to establish a connection or the connection is interrupted, the data requester will select an IP and port configuration of a redundant socket object to send a new communication connection request, and after success, it will be selected as a new main channel, and all data will be transmitted through the new main channel.

[0049] 1. Sequence number design

[0050] The data responder of the rail transit vehicle remote alarm information adds a unique sequence number field seqNumber to the sent vehicle remote alarm data packet, so that even if the vehicle remote alarm data packet is reordered during transmission, the data requester can reorder them through the sequence number. In addition, the sequence number can also be used to detect packet loss: if the sequence number of the vehicle remote alarm data packet received by the data requester has a jump, it means that there is packet loss, and the current communication link needs to be switched redundantly.

[0051] 2. Timestamp design

[0052] The data responder of the rail transit vehicle remote alarm information adds a timestamp field timeStamp (total seconds from 00:00:00 on January 1, 1970, Greenwich Mean Time (08:00:00 on January 1, 1970, Beijing Time) to the present) to each sent vehicle remote alarm data packet, as the date and time of the vehicle remote alarm data, and also for calculating the delay of the data packet and detecting whether the data packet is overdue.

[0053] 3. Timeout judgment design

[0054] When the data requester of the remote alarm information of the rail transit vehicle receives the data packet, the data update interval T1 from the last received data packet and the link delay interval T2 from the current time are obtained through the time stamp field timeStamp, and the data update interval T1 is compared with the predetermined maximum update interval T1 max The link delay interval T2 is compared with the predetermined maximum delay interval T2 max Only when T1≤T1max and T2≤T2max, it is indicated that the data packet is not overdue; otherwise, it is considered that the data packet is overdue, and the redundant switching of the current communication link is required.

[0055] Further, in order to meet the requirements of SIL2 level authentication, symmetric encryption design is performed on the data transmission between the data requester and the data responder of the vehicle remote alarm. The data requester and the data responder of the remote alarm information of the rail transit vehicle agree on a symmetric encryption method AES, and the same key AES_Key is created by both parties for data transmission; as shown in the figure, the data requester encrypts the request message using the key and sends it to the data responder, and the data responder decrypts the received request message using the key; the data responder encrypts the vehicle remote alarm information data using the key and sends it to the data requester, and the data requester decrypts the received vehicle remote alarm information message using the key. Figure 3

[0056] Further, the decrypted rail transit vehicle remote alarm data is displayed in real time on a visual interface or saved to a historical database by the data requester of the vehicle remote alarm.

[0057] The above embodiments only illustrate the technical idea of the present application, and cannot limit the protection scope of the present application. Any modification made according to the technical idea of the present application on the basis of the technical scheme falls within the protection scope of the present application.​

Claims

1. A method for transmitting remote alarm data of a rail transit vehicle, characterized in that: The method comprises the following steps: Step 1: establishing a remote alarm data object of a train according to a defined rail transit vehicle remote alarm information data model; A set of object definitions meeting the requirements of rail transit vehicle remote alarm data transmission, comprising: Data points: defining train online status, fire alarm status, smoke alarm status, fire extinguisher in place status, pantograph status, train door status, date and time, and passenger load data point objects; Train: defining a train object, the train object attributes including train number and train name information, and the train object being a parent object of the train remote alarm data point objects; Socket: defining a socket object, the socket object attributes including IP address information and port information opened by a data response party, and being used for establishing a communication connection between a data request party and the data response party, and a plurality of socket objects need to be defined for redundant communication connections; Step 2: performing sequence number, timestamp and timeout judgment design on data transmission between the data request party and the data response party, and the data request party and the data response party using a redundant switching mechanism based on the sequence number, timestamp and timeout judgment to communicate through a TCP or UDP transmission control protocol; The timeout judgment design specifically comprises: When the data request party of the rail transit vehicle remote alarm information receives a data packet, obtaining a data update interval T1 from the last received data packet and a link delay interval T2 from the current time through a timestamp field timeStamp, and comparing the data update interval T1 with a pre-determined maximum update interval T1max and comparing the link delay interval T2 with a pre-determined maximum delay interval T2max; only when T1≤T1max and T2≤T2max, it is indicated that the data packet is not overdue; otherwise, it is considered that the data packet is overdue, and the redundant switching of the current communication link is needed; Step 3: performing symmetric encryption design on data transmission between the data request party and the data response party, the data request party and the data response party creating the same key, and both parties respectively encrypt the request message and the rail transit vehicle remote alarm information data using the key, and the party receiving the information decrypts the data using the same key; Step 4: the data request party visually displaying the decrypted vehicle remote alarm data; In step 2, the data request party selects one object in the redundant socket objects as a main channel, and sends a communication connection request to the data response party through the IP and port configuration of the object, and the remaining socket objects are used as redundant channels; the data response party receives the communication connection request sent by the data request party, replies to a communication connection response, and establishes a communication connection; the data request party sends a vehicle remote alarm data request at a regular time; the data response party receives the vehicle remote alarm data request, and replies to a vehicle remote alarm data response; In the data communication, the sequence number, time stamp, timeout judgment design is carried out, the state of the communication link is judged, if the data request party and the data response party connection establishment fails or the connection is interrupted, the data request party will select an IP, port configuration of a redundant socket object to send a new communication connection request, and select it as a new main channel after success, and transmit all data through the new main channel; The sequence number design is specifically: The data response party of the rail transit vehicle remote alarm information adds a unique sequence number field seqNumber to the sent vehicle remote alarm data packet, when the vehicle remote alarm data packet is reordered in the transmission process, the data request party can reorder them through the sequence number; if the sequence number of the vehicle remote alarm data packet received by the data request party has a jump, it means that there is a packet loss, and the current communication link needs to be switched redundantly.

2. The remote alarm data transmission method for rail transit vehicles according to claim 1, characterized in that: The time stamp design is specifically: The data response party of the rail transit vehicle remote alarm information adds a time stamp field timeStamp to each sent vehicle remote alarm data packet, as the date and time of the vehicle remote alarm data, and also for calculating the delay of the data packet and detecting whether the data packet is overdue.

3. The method of claim 1, wherein the method further comprises: The step 3 is specifically, the data request party and the data response party of the rail transit vehicle remote alarm information agree on a symmetric encryption method, and the data transmission parties create the same key; the data request party uses the key to encrypt the request message and sends it to the data response party, and the data response party uses the key to decrypt the received request message; the data response party uses the key to encrypt the vehicle remote alarm information data and sends it to the data request party, and the data request party uses the key to decrypt the received vehicle remote alarm information message.

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