CN103701847A - Onboard network data acquisition and synchronous transmission system - Google Patents
Onboard network data acquisition and synchronous transmission system Download PDFInfo
- Publication number
- CN103701847A CN103701847A CN201310516384.8A CN201310516384A CN103701847A CN 103701847 A CN103701847 A CN 103701847A CN 201310516384 A CN201310516384 A CN 201310516384A CN 103701847 A CN103701847 A CN 103701847A
- Authority
- CN
- China
- Prior art keywords
- data
- packet
- acquisition
- synchronous
- network
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Data Exchanges In Wide-Area Networks (AREA)
Abstract
The invention discloses an onboard network data acquisition and synchronous transmission system. The system comprises an interchanger, a computer connected with the interchanger, a main acquisition unit and an auxiliary acquisition unit, wherein a synchronous clock is arranged on the interchanger; the synchronous clock adopts a GPS (Global Positioning System) time code; the interchanger and the main acquisition unit perform network synchronous acquisition operation of signals and IRIG-B (Inter-Range Instrumentation Group-B) time signal source. The onboard network data acquisition and synchronous transmission system solves the problem of time synchronization of the network data in the process of network acquisition.
Description
Technical field
The present invention relates to a kind of collection and synchronous transmission system of network data, be specifically related to a kind of collection and synchronous transmission system of onboard networks data.
Background technology
Along with the popularization and application in field of aviation measurement and test of networking technology and product, test framework changes multi-channel network image data mode into from traditional single channel PCM (Pulse Code Modulation) data format, makes the collection of data from special-purpose PCM form interface to up-to-date common commercial Network Interface development.The test framework of networking provides good test platform and has accumulated rich experience for the later test of large aircraft, networking measurement has brought many advantages, as: propose to replace the traditional classical PCM way of output with the networking acquisition mode of UDP (User DatagramProtoc01) agreement, increase substantially the data acquisition rate of every sub-acquisition system, make more than total data flow bit rate can reach 60 Mbit/s.The programming of image data, the loading of data and inspection etc. can be undertaken by network mode, do not need special-purpose demodulation card.By Internet Transmission, can also strengthen management, application and the processing of test flight data.The use of networking acquisition mode, also brought the time synchronization problem of network data thereupon, the time synchronization problem that how to solve data in same network packet and heterogeneous networks bag is the problem that cannot avoid and need solution in current field tests, and this problem is directly connected to the calculating of test data.
General Ethernet system gathers structure
Ethernet system forms fairly simple, mainly switch, collector, industrial computer, netting twine etc., consists of.When system works, the unification of IRIG-B time signal source is to each acquisition system time service, each acquisition system the transfer of data collecting in switch, then by switch transfer of data to the industrial computer on aircraft, realize the real-time Transmission, record, analysis of data etc.
Summary of the invention
The invention provides a kind of collection and synchronous transmission system of onboard networks data, it has solved the time synchronization problem of network data in the use of networking acquisition mode.
Technical solution of the present invention is:
The collection of onboard networks data and a synchronous transmission system, comprise switch, the computer being connected with switch, main collector and secondary collector, and its special character is: described switch is provided with synchronised clock, should be synchronised clock GPS time-code; Described switch and main collector carry out Network Synchronization collection signal and the operation of IRIG-B time signal source.
The invention has the advantages that: the time synchronization problem that has solved network data in the use of networking acquisition mode.
Accompanying drawing explanation
Fig. 1 is that the present invention connects schematic block diagram.
Embodiment
Referring to Fig. 1, a kind of collection of onboard networks data and synchronous transmission system, comprise switch, and the computer being connected with switch, main collector and secondary collector, is characterized in that: described switch is provided with synchronised clock, should be synchronised clock GPS time-code; Described switch and main collector carry out Network Synchronization collection signal and the operation of IRIG-B time signal source.
The formation of Ethernet data bag is very flexible, and the parameter in bag can optionally be placed as required.For example: the sample rate of parameters A is 256 times/s, B, the sample rate of D is 128 times/s, C, the sample rate of G is 64 times/s, E, F, H, the sample rate of I is 32 times/s, if these data are placed in same packet, the times of collection of these parameters is different, can draw to draw a conclusion from the sampling period of packet:
1) in moment of starting in sampling period, all channel parameters are sampled simultaneously.
2) parameter that in the sampling period, sample rate is greater than is once equal interval sampling.
3) parameter arranging in packet is only in all sampling just outwards transmissions after finishing.
4) only after the sampling period finishes, send packet, there is no At All Other Times data packet transmission.
To the structural analysis of Ethernet data bag, can find out, Ethernet data bag is only after all data acquisitions are complete, just data are exported in unification, all the other times are being waited for, therefore have some queries: during end cycle, send packet, if whether the whether feasible packet of the larger this method of data volume can lose network in the sampling period, in idle condition, should how could utilize fully the efficiency of Internet Transmission the higher parameter of sample rate repeatedly can be sent in sampling period process in batches
Determining with concrete application of type of data packet and quantity is closely related.The type of definition ethernet format definition packet is quite flexible.If packets of information is very large, the time delay that the collection of data, packing and transmission produce is also long, even exceeds the scope (for example using telemetry system) of entire system performance.If lost packets can be lost bulk information.The long sampling period also means that the time that system is recovered from of short duration power down process also can be long.If packet is too little, certainly will need to increase the number of packets of information, cause the information (as packet header file or filename) of relevant communications protocol ratio shared in the whole sampling period excessive, the efficiency of transmission of network is reduced.
When determining the sampling period, should take into full account type and the valid data amount of data/address bus, as RS-322/422, ARINC429, MILSTD.1553B and audio signal sample information etc., they have transmission cycle separately.Too large or too little (comparing with bus parameter turnover rate) all will cause obliterated data in sampling period.If the parameter gathering contains bus data or serial data, the frequency in sampling period should be greater than the renewal rate of bus or serial data.In actual use, the size of packets of information should be limited in 200 to 1000 data words, the packet header file word that comprises packet and valid data word.The number of each sampling period packets of information should be limited between 1 to 16.The number of specifying information bag is looked the kind of total parameter amount and parameter sampling speed and is determined.The calculating of its number should be as the criterion by the number of times that each cycle gives out a contract for a project.Such as the packets of information having sends repeatedly in one-period.The kind of valid data sample rate should be limited in 4 kinds of left and right, and sample rate is higher certainly, and the packets of information that each sampling period sends is more.It is unpractical that every kind of sample rate is all worked out to a packets of information, can only be sample rate low to high leaning on, data word few to many leaning on.Its principle is to reduce as far as possible the quantity of packets of information.In actual use, the rules of arrangement of packet is:
1) data that mail to different destinations should be encapsulated in different pieces of information bag;
2) high-speed sampling and low speed sampling should be encapsulated in different packets;
3) parameter that need carry out correlation computations is placed on same collection port as far as possible;
4) the packet sending speed for up not for down of packet;
5) will to take transmitting apparatus and receiving equipment performance be foundation to the length of data packet number and packet.
Synchronous acquisition order at same collection port collection signal because carrying out, the net synchronization capability of collection signal is determined by corresponding acquisition module characteristic, as: digital signal acquiring is exactly to digital signal buffer memory, transmission, and it postpones greatly about 8 one 10 stoves (testing equipment: 429 buses of the Hibernian ACRA KAM500 of company collecting device, 1553B bus test version card).Analog signal is different, analog signal is buffer memory, transmission etc. after frequency overlapped-resistable filter, A/D conversion, Finite Impulse Response filter, because digital filtering causes the delay that the signal of different frequency is produced different (take KAM500 analog signal plug-in unit KAD/ADC/014 be example), measurements and calculations the results are shown in Table l.The new cycle starts the sampling period and starts to send packet { 3 send packet bursts send packet horsefly to send packet 23 to send packets from for different analog signals, and it postpones greatly about 4.15～595.7793 ms (sample rate is between 32～4096 Hz).In analog signal and numeral, carry out correlation computations, the lower error causing of sample rate is larger, even can not use.As: flight is controlled and flight quality is calculated with the 2 weeks/s of frequency sweep frequency that takes a flight test, and is equivalent to asynchronous 7.20 the phase delay that just may cause of signal of 1 ms correspondence 0.720,10 ms, and this can accept reluctantly to data processing.But if postpone 20 ms, phase delay may reach 150 left and right, this is unacceptable, and the minimum requirements of parameter time delay is 10 ms, is preferably 5 ms.And for the synchronous error between analog signals, depend on the size of retardance between them, for its delay of signal of same sample rate, be 10～15 stoves.Therefore, by the synchronous error that reduces that different sampling structures can be a large amount of is set.
Synchronous acquisition order at different acquisition port processing signal because carrying out, the net synchronization capability of collection signal is except the synchronous error that comprises unified collection port, also to comprise different port and send the time error between acquisition, as: in No. 1 port, a certain data packet sending speed is 32 times/s, in No. 2 ports, a certain data packet sending speed is 1024 times/s, wherein data dependent errors depends on the time interval of giving out a contract for a project between them, is 32 ms.If the rules of arrangement according to packet, according to the data error requirement of related operation, improve the packet sending speed of parameter, can greatly reduce the correlated error of data, as: different port sample rate is all set to 1024 Hz, between its digital signal, error is about 1 ms, and between digital signal and analog signal, error is about 18.5 ms.Simultaneously, the packet producing according to the rules of arrangement of packet, make packet network transmission time ask and be more evenly distributed, when reducing synchronous error, the packet loss of data in the unit interval is greatly improved, as: it is example that three KAM500 of take gather networking port, each port has the packet (32 of 4 different rates, 64,128,256 Hz), if only comprise the signal of 800 same frequencys in each bag, in l s, can send 1440 packets, by non-volatile recording, analyze, the packet loss of packet is every 38 rain 1 time; Same structure, just in same packet, the sample frequency of signal is more, and by non-volatile recording statistical analysis, the packet loss of data is every 6 min 1 time, and its reason is packet more chaotic the causing that distribute on the time of giving out a contract for a project.Time synchronized between the network packet that different acquisition terminal sends be by unified time source to terminal time service, carry out synchronously, as shown in Figure l, the defect that such test exists: the correlation that can only ensure the time in same sampling terminal, cannot guarantee the temporal correlation of each data in different terminals, can not be as theoretical basis to the tighter sampling parameter of different terminals data dependence requirement.How to ensure that distinct device different terminals carries out by unified beat the key that data sampling is whole network test system success or failure, has provided the improved concrete grammar of Ethernet Data Acquisition System below.
How the improvement of Ethernet Data Acquisition System ensures the correlation of data between synchronization different acquisition port, is the basis of related data test of flying in a large number.The key of problem is that whole test macro has a synchronised clock, this synchronised clock sends and requires synchronous acquisition order one temporal information and pulse per second (PPS) to each collecting device, it is benchmark that the rising edge of pulse per second (PPS) is take in synchronous acquisition order, all collection channels all gather the data of synchronization, store transmission, between pulse per second (PPS), press equal interval sampling, according to temporal information in packet, just can ensure the correlation of different acquisition devices collect data.Because whole system is to be based upon in local area network (LAN), the synchronous acquisition order of different acquisition equipment can only come from the network switching equipment.At present, the world has been formulated and has been met Network Synchronization and require IEEE mono-1588 agreements, and Hibernian ACRA company has developed corresponding product.The temporal information of the data based network packet of network collection is carried out corresponding fusion, processing.
Claims (1)
1. the collection of onboard networks data and a synchronous transmission system, comprise switch, and the computer being connected with switch, main collector and secondary collector, is characterized in that: described switch is provided with synchronised clock, should be synchronised clock GPS time-code; Described switch and main collector carry out Network Synchronization collection signal and the operation of IRIG-B time signal source.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310516384.8A CN103701847A (en) | 2013-10-28 | 2013-10-28 | Onboard network data acquisition and synchronous transmission system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310516384.8A CN103701847A (en) | 2013-10-28 | 2013-10-28 | Onboard network data acquisition and synchronous transmission system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN103701847A true CN103701847A (en) | 2014-04-02 |
Family
ID=50363243
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310516384.8A Pending CN103701847A (en) | 2013-10-28 | 2013-10-28 | Onboard network data acquisition and synchronous transmission system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103701847A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103973386A (en) * | 2014-05-23 | 2014-08-06 | 哈尔滨工业大学 | Time aligning method for 1553B data and ADC data in data collecting system |
| CN106851686A (en) * | 2017-01-22 | 2017-06-13 | 郑州信工智能化系统有限公司 | Realization method and system with time bias data collection radio MAC protocol |
| CN109842575A (en) * | 2017-11-27 | 2019-06-04 | 中国航空工业集团公司西安航空计算技术研究所 | A kind of big tolerance sample circuit of 429 bus receiving nodes |
| CN112907782A (en) * | 2021-02-18 | 2021-06-04 | 江西洪都航空工业集团有限责任公司 | Multisource multi-type data playback device based on time synchronization |
-
2013
- 2013-10-28 CN CN201310516384.8A patent/CN103701847A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103973386A (en) * | 2014-05-23 | 2014-08-06 | 哈尔滨工业大学 | Time aligning method for 1553B data and ADC data in data collecting system |
| CN103973386B (en) * | 2014-05-23 | 2016-09-28 | 哈尔滨工业大学 | 1553B data and the time unifying method of adc data in a kind of data collecting system |
| CN106851686A (en) * | 2017-01-22 | 2017-06-13 | 郑州信工智能化系统有限公司 | Realization method and system with time bias data collection radio MAC protocol |
| CN106851686B (en) * | 2017-01-22 | 2020-03-31 | 郑州信工智能化系统有限公司 | Method and system for realizing wireless MAC protocol with time compensation data acquisition |
| CN109842575A (en) * | 2017-11-27 | 2019-06-04 | 中国航空工业集团公司西安航空计算技术研究所 | A kind of big tolerance sample circuit of 429 bus receiving nodes |
| CN109842575B (en) * | 2017-11-27 | 2021-08-03 | 中国航空工业集团公司西安航空计算技术研究所 | 429 bus receiving node large-tolerance sampling circuit |
| CN112907782A (en) * | 2021-02-18 | 2021-06-04 | 江西洪都航空工业集团有限责任公司 | Multisource multi-type data playback device based on time synchronization |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108965171B (en) | Industrial wireless WIA-PA network and time sensitive network conversion method and device | |
| CN112866075B (en) | In-band network telemetering method, system and related device for Overlay network | |
| CN104717150B (en) | Switch and packet discarding method | |
| Carneiro et al. | Flowmonitor: a network monitoring framework for the network simulator 3 (ns-3) | |
| CN109194433B (en) | High-precision time service method based on gigabit AFDX (avionics full Duplex switched Ethernet) network | |
| CN105099828B (en) | A kind of implementation method of high performance network tester | |
| WO2022100411A1 (en) | Method for measuring forwarding time characteristics of tsn, and terminal | |
| US8248926B2 (en) | Packet rate detection apparatus and method | |
| CN102571479B (en) | Method, device and system for measuring time delay | |
| CN109089029B (en) | FPGA-based Gige Vision interface image transmission system and method | |
| CN103701847A (en) | Onboard network data acquisition and synchronous transmission system | |
| CN101414963A (en) | Method and apparatus for automatic topological discover and resource management in PBB TE network | |
| CN103746937A (en) | Data acquisition service bus system applied to smart power distribution network and implementation method thereof | |
| CN102215102A (en) | Method and applications of network monitoring data packet with timestamp | |
| CN108833366B (en) | Control frame compression method based on AS6802 protocol | |
| CN113036930B (en) | Power grid data communication management system | |
| CN105162726B (en) | Long-range SV data transmissions and delay compensation method based on E1 links | |
| CN112671598B (en) | Special algorithm hardware module for electric power suitable for electric power system control protection device | |
| CN101800777A (en) | Open network data acquisition method and device, and monitoring system based on device | |
| CN103633741A (en) | Intelligent substation sampled value network data switching method and device | |
| CN113141279A (en) | Switch mesh test system and method | |
| CN112803970A (en) | System and method for monitoring power line broadband carrier communication system of whole network | |
| CN205404700U (en) | Take multi -functional FPGA acquisition unit of time reference output | |
| CN116582603A (en) | Low-voltage station clock level data acquisition method based on HPLC+HRF communication | |
| CN102790663B (en) | Full-hardware network interface applied to very long baseline interferometry (VLBI) hardware related processor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20140402 |