CN114499726A

CN114499726A - Sensor communication method based on TSN (time sensitive network) standard

Info

Publication number: CN114499726A
Application number: CN202011119750.2A
Authority: CN
Inventors: 竜正城
Original assignee: Suzhou Bertai Digital Technology Co ltd
Current assignee: Suzhou Bertai Digital Technology Co ltd
Priority date: 2020-10-23
Filing date: 2020-10-23
Publication date: 2022-05-13

Abstract

A sensor communication method based on TSN (Time-Sensitive Networking) network standard belongs to an improvement scheme in the prior communication technical field, and an information processing unit and a communication processing unit are added between a sensor unit and a sensor interface unit, so that the problems that the sensors in a new and old equipment mixed system cannot realize high-real-Time and high-reliability communication and the problems that the sensors with different communication standards in the same system cannot intercommunicate with each other are solved. The invention of the communication method can be widely used for realizing simultaneous acquisition of physical quantity information and transmission to an upper information processing system which need to carry out high speed and real time on a plurality of signal sources.

Description

Sensor communication method based on TSN (time sensitive network) standard

Technical Field

The invention relates to a sensor communication method based on TSN (time sensitive network) network standard, which can be widely used for realizing simultaneous acquisition of physical quantity information and transmission to an upper information processing system for a plurality of signal sources at high speed and in real time.

Background

1. The existing sensors:

the sensor is a detection device which can sense the physical quantity to be measured and convert the sensed physical quantity into an electric signal or other information in a required form according to a certain rule for output so as to meet the requirements of information transmission, processing, storage, display, recording, control and the like. Sensors are widely used in fields such as industrial production, space development, marine exploration, environmental protection, resource investigation, medical diagnostics, bioengineering, and even cultural relic protection. Every modern project of the modern generation cannot depart from a wide variety of sensors. For example, in modern industrial processes, particularly automated processes, various sensors are used to monitor and control various parameters of the process to operate the equipment in a normal or optimal state to achieve the best quality of the product.

The sensor is a solid-state sensor composed of solid-state elements such as semiconductors, dielectrics, and magnetic materials, in most cases, from the conventional structure-type sensors that sense and convert signals by using changes in structural parameters. In recent years, the development of miniaturization, multi-functionalization, digitalization, intellectualization, systemization and networking is rapidly progressing.

Secondly, as an important component of the sensor, the sensor interface is responsible for the function of information output, and in the development process of the sensor towards multifunction, digitalization, intellectualization, systemization and networking, a means of bidirectional communication with an external system is needed for sending measurement and state information and receiving and processing external commands. In order to realize the corresponding functions, the system is divided into two parts, namely signal processing and communication, wherein the former part is used for realizing the transmission of effective information, preprocessing collected information, storing and packaging data for communication, and the latter part is used for realizing two-way communication according to relevant standards and protocols between an external network or a system. In the aspect of wired communication interfaces, the physical interfaces of the wired communication interfaces comprise standard interfaces such as RJ45, optical fibers, RS232, RS485, RS422, IEEE1394 and the like, and in the aspect of the wired communication interfaces, the wired communication interfaces comprise industrial Ethernet based on TCP/IP such as PROFINET, EtherCAT, POWERLINK, Ethnet/IP, CANopen of field bus type, Modbus, PROFIBUS, CC-Link and the like.

2. The problems existing in the prior art are as follows:

with the development of the current industrial internet, the technical requirements of the sensor and the communication interface thereof, which are important components, are increasing day by day, and in the prior art, the problems of the communication interface of the sensor are mainly embodied in the following three points:

the method solves the problem of interface communication with high real-time performance and high reliability of a sensor in a system with new and old equipment mixed. Communication interfaces such as RS232, RS485, RS422 and the like and communication standards thereof are more applied to some long-term equipment, but the communication protocols thereof cannot meet the existing interface communication requirements of high real-time performance and high reliability.

Secondly, how to solve the problems of data independence and data isolated island caused by sensors with different communication standards in the same system. Aiming at the communication requirements of high real-time performance and high reliability, relatively recent CANopen, Modbus, PROFIBUS and CC-Link modify or add some specific protocols on the basis of standard Ethernet to ensure real-time performance and certainty, non-standard Ethernet thereof causes the communication protocols not to be communicated with each other, data cannot be effectively used, meanwhile, the coordination problem of different data acquisition in the system is difficult to solve, and the communication protocol has defects in usability, interoperability, bandwidth and equipment cost.

And thirdly, how to solve the problem of complex and high-freedom data communication which is necessary for more intelligent sensors and is possibly brought in the future. From the output of primary analog quantity data information to the output of digital quantity signals in the current digital conversion, the increase of data quantity in a communication period caused by the improvement of data precision and the increase of complexity of a data structure caused by the intelligent development of a sensor are expected in the future, and the requirements need a communication technology with higher degree of freedom to realize.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a sensor communication method based on a TSN (time sensitive network) network standard.

By adopting a TSN (Time-Sensitive Networking) network standard at a communication interface of the sensor, the real-Time performance and the reliability of standard Ethernet communication under the condition of not increasing or replacing the existing hardware are improved, and the problems of low Time synchronism of a plurality of groups of sensors on information communication and limited data architecture freedom under different application occasions are solved.

The invention adopts the following technical scheme:

1. and an information processing unit and a communication processing unit are added between the sensor unit and the sensor interface unit. The information processing unit is used for information acquisition of the sensor unit or processing of control information, and has the functions of signal conditioning, data shaping, data storage and the like. The communication processing unit is used for processing information communication facing the interface unit, and comprises a data packet and communication processing.

2. In the communication processing unit, the following communication design requirements are met by adopting the following modes:

the universality is as follows: the method meets the respective existing requirements of a distributed peer-to-peer architecture of standard Ethernet and a polling/bundling frame technology adopted by a deterministic network by adopting a Virtual Local Area Network (VLAN) conforming to IEEE802.1Q, and enables the network to exert respective advantageous functions.

Real-time performance: real-time transmission of high-priority data is ensured through PTP time synchronization and taprio flow channel configuration.

Expansion (compatibility): the compatibility of the data frame is realized by encapsulating other protocol data frames into real-time data packets while supporting OPC UA, MQTT protocol and the like by using a protocol supporting a network layer and a transport layer.

3. The system adopts an independent communication protocol structure design to realize real-time communication with different grade requirements in the network, and directly addresses based on the MAC address, and ensures that data completes a real-time data transmission task within a determined time interval through a real-time channel.

4. A user-defined data frame architecture is adopted to define the data type and determine the field length of the transmission data, and data communication is realized according to different application occasions.

After the existing sensor communication method is adopted, the following advantages can be realized:

1. on the premise of the existing standard Ethernet bandwidth performance, the communication speed of the highest nanosecond level is realized, so that the high real-time performance and the high reliability of the communication between the sensor and an external network and an upper system are achieved.

2. Time synchronization on information communication of multiple groups of sensors is realized, and complete state detection and control at a system level are provided.

3. The self-defining degree of the communication data architecture is improved, the self-defining of the data architecture different from the existing communication protocol or field bus is realized, and the sensor is efficiently applied to sensors in different occasions.

FIG. 1 shows the basic structure of a sensor for the communication method of the present invention

FIG. 2 is a structural design of a protocol stack of the communication method of the present invention

FIG. 3 is a self-defined data frame structure of the communication method of the present invention

FIG. 4 is a graph of error statistics for the number of transmitted communications sampled within a unit period for the communications method of the present invention

FIG. 5 is a graph of error statistics for transmitted communication data sampled in a unit period of a communication method of the present invention

Detailed Description

On the premise of adopting the invention, the sensor of the Hall current is used for sampling data from the machine tool equipment, and the test result of real-time and reliability verification is obtained when the data is transmitted to an external network (system) by taking 1ms as a period. In the whole system test:

1.4 groups of independent sensors are adopted to simultaneously transmit data;

2. framing the acquired data according to the custom data frame, wherein the byte capacity of each transmission is 1400;

3. the sensor data uploading period is 1 ms.

From the test results it follows: an information processing unit and a communication processing unit based on a Time-Sensitive network (TSN) network standard are added in the existing sensor, and after improvement and transplantation of a Time synchronization function are added, the following test targets can be completely achieved:

1.4 data time strict synchronization between the sensors;

2. in the test of more than ten million times of communication, the error in the sampling period of 1ms is stably less than 35 nanoseconds;

3. the frame loss phenomenon is not observed in the complete test process, and the requirement of high reliability can be met

In fig. 4 and 5, partial results of the experimental results at any time period are shown.

Claims

1. A sensor communication method is characterized in that the communication method conforms to the TSN (Time-Sensitive Networking) standard, and can realize simultaneous physical quantity information acquisition and transmission to an upper information processing system for a plurality of signal sources at high speed and in real Time.

2. The sensor communication method according to claim 1, wherein an information processing unit for information acquisition of the sensor unit or processing of control information and a processing communication processing unit for information communication to the interface unit are incorporated between the sensor unit and the sensor interface unit.

3. The method of claim 2, wherein the information processing comprises signal processing, signal conditioning, data shaping, and data storage functions.

4. The sensor communication method according to claim 2, wherein the communication processing comprises data packet packing and communication processing functions.