A data transmission system and data transmission method based on can switch network

Abstract

The invention discloses a data transmission system based on CAN switching network, comprising a CAN ring network module for collecting real-time status data of each platform gate and transmitting it to a CAN switching network module, for receiving the real-time status data and converting the real-time status data It is suitable for sending the data information of the Ethernet transmission module to the CAN transfer module of the Ethernet transmission module, the Ethernet transmission module for transmitting the data information to the PSC, the PSC, PSA for processing the data information and the display information The CAN ring network module is composed of several CAN ring networks, each CAN ring network includes several CAN nodes, the CAN node includes a DCU, and the DCU and the sliding door are used to collect real-time status data. The invention provides a data transmission system based on CAN switching network, which uses double CAN ring network inside and double network cable communication outside, realizes data and communication sharing, and improves the reliability of the system.

Description

technical field [0001] The invention relates to the field of rail transit data transmission, in particular to a data transmission system and data transmission method based on CAN switching. Background technique [0002] The subway platform door is an important part of the urban rail transit field. There are two types of vehicles commonly used in subway vehicles: Type A and Type B. There are 5 sets of doors in each compartment of the A-type car, and 4 sets of doors in each compartment of the B-type car. The number of groups is 4 groups, 6 groups, 8 groups and so on. The number of sliding doors in the platform door is consistent with the number of subway train compartment doors. Each sliding door corresponds to a set of platform door controllers (DCU). Each set of DCU needs to collect various status information of the door and upload it to The central control system (PSC) of the platform door, such as a 6-group B-type car on one side of the platform door, requires 24 sets o...

AI Technical Summary

Problems solved by technology

[0011] 1) If the working voltage provided by the power supply system is not normal, it will make some electronic control modules not work properly for a short time, which will make the whole CAN bus system unable to work

[0012] 2) When there is a short circuit, open circuit of the communication line or a change in the physical properties of the line, the communication signal is attenuated or distorted, which will cause multiple electronic control units to be abnormal and make the CAN bus system unable to work

[0013] 3) Since the node is the electronic control module in the CAN bus system, the failure of the node is the failure of the electronic control module, which includes software failure and transmission protocol or software program defects or conflicts, so that the communication of the CAN bus system is chaotic or unable to work , this kind of failure will generally appear in batches, and the hardware failure is generally the failure of the electronic control module chip or integrated circuit, causing the CAN bus system to fail to work normally.

[0014] 4) A large number of data uploads make the CAN bus load rate higher, and the higher the load rate, the greater the probability of communication delays in low-priority nodes.

According to experiments, when the load rate is 30%, the average message transmission time of the high priority node is almost the same as the theoretical transmission time; while the low priority node has a delay of about 20%; when the load rate reaches 60% Under normal circumstances, the node with the highest priority has a delay of at least 25%, and the delay of the lowest priority has reached 4 times, which cannot meet real-time performance at all; when the average utilization rate of the bus reaches more than 70%, the communication of the bus will be Congestion may occur, and in extreme cases, error frames may occur

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