CN209739079U - Logic control unit for train - Google Patents

Abstract

the utility model relates to a logic control unit for a train, wherein an LCU adopts a hot standby redundancy design and comprises an input module, an output module and two main control modules with redundancy design; the output end of the input module is respectively connected with each main control module, and the output end of each main control module is respectively connected with the output module; the input module collects input direct current voltage information and sends the input direct current voltage information to the main control module; the main control module obtains the direct current voltage signal, calculates and generates a load driving control signal, and sends the load driving control signal to a load through the output module. The input module, the output module and the main control module can be configured to be a two-by-two-out-of-two redundant structure. The utility model discloses each module of system is from taking the self-diagnosis circuit, can realize the fault diagnosis and the redundant switching of each redundant circuit, has improved the reliability of system; the system is configured to be a two-by-two architecture, and the system safety is further improved.

Description

Logic control unit for train

Technical Field

The utility model belongs to the technical field of rail vehicle control system, especially, relate to a logic control unit for train.

Background

The rail train has a large number of relays and other contact control modes, and the devices are connected through cables to form a logic control system for train operation and used for transmitting control signals. The operation of a large and complex electrical system directly affects the train operation safety. However, the relay works for a long time in a high-temperature, humid and vibrating environment, the aging speed is greatly accelerated, faults such as clamping, contact oxidation and the like are easy to occur, and finally, the conduction and the actuation are poor in contact, and even the static head is invalid. According to statistical analysis, more than 60% of vehicle faults are caused by relay faults. The railway trains are various in types and complicated in control signals, and a single-train vehicle uses more than 300 relays and is mostly related to key signals and logics of the trains, so that the requirements on the number, reliability and universality of the signals of a Logic Control Unit (LCU) are high. Aiming at the defect of the existing rail train that a contact logic control mode exists, it is necessary to design an LCU with high reliability and universality.

SUMMERY OF THE UTILITY MODEL

The utility model discloses provide a logic control unit for train on solving above-mentioned not enough basis, this system adopts hot spare redundancy and trouble self-diagnosis design, and improve equipment's reliability can be according to the nimble quantity of configuration input and output circuit of different demands simultaneously, need not to modify the system architecture, the commonality when satisfying equipment and being applicable to different projects.

In order to achieve the above object, the present invention provides a logic control unit for a train, which comprises an input module, an output module and two main control modules with redundant design; the output end of the input module is respectively connected with each main control module, and the output end of each main control module is respectively connected with the output module; the input module is used for acquiring input direct-current voltage information and sending the input direct-current voltage information to the main control module; the main control module is used for acquiring the direct-current voltage signal, calculating to generate a load driving control signal, and sending the load driving control signal to a load through the output module.

Preferably, the input module is configured as 2 input circuits designed for mutual redundancy, and the output module is configured as 2 output circuits designed for mutual redundancy.

Preferably, the input module is configured to have 4 input circuits designed for redundancy, and the output module is configured to have 4 output circuits designed for redundancy, that is, a first output circuit, a second output circuit, a third output circuit, and a fourth output circuit; and a first series circuit consisting of the first output circuit and the second output circuit is connected in parallel with a second series circuit consisting of the third output circuit and the fourth output circuit.

Preferably, the input circuit comprises an input acquisition circuit, and the input acquisition circuit comprises a comparator, a serial-parallel conversion circuit and a photoelectric coupler which are connected in sequence; the input end of the comparator is connected with the DI input port, and the output end of the comparator is connected with the input end of the serial-parallel conversion circuit; the output end of the series-parallel conversion circuit is connected with the input end of a photoelectric coupler, and the output end of the photoelectric coupler is connected with the main control module.

Preferably, the input circuit further comprises an input self-diagnosis circuit, the input end of the input self-diagnosis circuit is connected with the "-" input end of the comparator, and the output end of the input self-diagnosis circuit is connected with the main control module; the input self-diagnosis circuit is used for detecting the conduction state of each path of DI input port according to a preset reference voltage value.

Preferably, the output circuit comprises a switch control circuit, and the switch control circuit adopts a passive switch design and comprises a photoelectric coupler, an MOS driver, an MOS field effect transistor and an overcurrent protection circuit which are connected in sequence; the photoelectric coupler is connected with the main control module, and the output end of the overcurrent protection circuit is connected with the DO output interface; the MOS driver controls the on-off state of the MOS field effect transistor, the output current of the closed MOS field effect transistor is detected, and the overcurrent protection loop carries out overcurrent protection according to the detected output current and feeds back overcurrent information to the main control module.

Preferably, the output circuit further comprises an output self-diagnosis loop, the input end of the output self-diagnosis loop is connected with the output end of the MOS field effect transistor, and the output end of the output self-diagnosis loop is connected to the main control module through a photoelectric coupler; the output self-diagnosis loop is used for detecting the switch state of the MOS field effect transistor and feeding back the detected switch state information to the main control module.

preferably, the train network control system further comprises a communication module, wherein the input end of the communication module is respectively connected with the input end and the output end of the main control module, the output end of the communication module is connected to the train network control system, and the data input and output by the main control module is transmitted to the train network control system.

Preferably, the power supply module converts the bus power supply voltage into an input power supply voltage through DC/DC conversion, and supplies power to the input module, the output module, the main control module and the communication module.

Compared with the prior art, the utility model discloses an advantage lies in with positive effect:

The utility model provides a logic control unit for train, LCU adopts contactless logic control technologies such as opto-coupler and field-dependent transistor (MOSFET), hot standby redundancy design, and through the self-diagnosis function of the system, the fault diagnosis and redundancy switching of each redundancy circuit can be realized, and the reliability of the product is improved; meanwhile, the number of input and output circuits can be flexibly configured according to different requirements, the system structure does not need to be modified, and the universality of the equipment when the equipment is suitable for different projects is met.

(1) The utility model discloses can realize two and take two framework configurations by two, further improve the reliability and the security of system. The input module and the output module can perform real-time self-diagnosis and upload diagnosis data to a train network control system; the output module has an overcurrent protection function, can automatically cut off a switch when outputting short circuit or overcurrent, and upload an overcurrent signal, and can automatically recover after the overcurrent disappears; the input module and the output module are independently designed, are provided with external interfaces, and can be randomly configured according to project requirements; the external communication interface is abundant, can satisfy train MVB or ethernet network deployment requirement, satisfies the communication of car inter-vehicle equipment.

Drawings

Fig. 1 is a structural topology diagram of a Logic Control Unit (LCU) according to the present invention;

Fig. 2 is a block diagram of a system architecture according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a hot standby redundancy design architecture of the LCU of the present invention;

fig. 4 is a schematic diagram of a two-by-two redundancy architecture configured in the present invention.

Fig. 5 is a schematic circuit diagram of the input module of the present invention;

Fig. 6 is a schematic circuit diagram of the output module of the present invention.

Detailed Description

The following further describes embodiments of the present invention with reference to the accompanying drawings.

In the description of the present invention, it is to be understood that the terms "first," "second," and the like are used merely for convenience in describing the present invention and to simplify the description, and are not intended to indicate or imply that the device or element so referred to must be in a particular orientation, constructed and operative in a particular orientation, and are not to be considered as limiting the present invention.

The utility model provides an adopt logic control unit for train of contactless logic control technology design, logic control unit adopt contactless logic control technologies such as opto-coupler and the corresponding pipe in field (MOSFET), replace current relay scheme, through software logic, realize direct control and drive elements such as train contactor and electric empty valve, accomplish various control functions of vehicle. Compared with the traditional relay mode, the contactless logic control unit has the advantages of small size, high reliability and convenience in modification of logic software, can effectively reduce operation and maintenance cost, reduce vehicle faults and risks, improve the reliability and maintenance efficiency of vehicles, improve operation guarantee capability and have very important functions and meanings.

Referring to fig. 1, the logic control unit for train of the present invention includes a main control module, an input module, an output module, a communication module and a power module; the main control module is respectively connected with the input module and the output module, and the communication module is connected with the main control module in parallel; the input module acquires DC110V signals of input equipment such as train buttons, switches and auxiliary contacts of a contactor, and transmits acquired information to the main control module through the CAN bus; the main control module sends an output instruction to the output module through the CAN bus after carrying out logic operation on the information acquired by the input module; the output module sends a driving signal to an external load to control the external load to work according to the received control instruction output by the main control module; the communication module transmits the data input and output by the main control module to a train network control system through MVB/Ethernet; the power supply module converts the DC110V bus power supply voltage into input power supply voltage through DC/DC conversion and supplies power to each module of the logic control unit for the train. The input module comprises two input board cards which are designed in a redundant mode, the output module comprises two output board cards which are designed in a redundant mode, the main control module comprises two main control board cards which are designed in a redundant mode, and the power supply module comprises two power supply board cards which are designed in a redundant mode.

In this embodiment, two main control modules with redundant designs are adopted, that is, the main control module and the slave control module communicate with each other, the main control module performs logic control under normal conditions, the redundant slave control module monitors the state of the main control module, and when the main control module works abnormally, the slave control module places the main control module in a reset state to perform logic control.

Specifically, the LCU in this embodiment is specifically designed as two sets of control circuits with the same structure and function, i.e., a set a and a set B, as shown in fig. 2; the group A comprises a power supply board A, a main control board A, an input board A and an output board A; the group B comprises a power panel B, a main control panel B, an input panel B and an output panel B, and the circuit design of the power panel, the main control panel, the input panel and the output panel of the software and hardware of A, B is completely consistent. When the LCU adopts the dual-computer hot standby redundancy design, as shown in fig. 3, each input board card is provided with 1 input circuit, that is, the input board card a is provided with an input circuit a, and the input board card B is provided with an input circuit B; each output board card is provided with 1 way of output circuit, namely the output board card A is provided with the output circuit A, and the output board card B is provided with the output circuit B. Namely, the input module is set as 2 input circuits which are designed to be mutually redundant, and the output module is set as 2 output circuits which are designed to be mutually redundant; each input circuit is connected to two masters, and each master is connected to two output circuits, i.e. each master can communicate with A, B two input circuits and A, B two output circuits simultaneously, as shown in fig. 3.

And simultaneously, the utility model discloses can be on the design basis that the heat that figure 3 is shown is equipped with redundancy, according to the concrete demand of system, design for two take two redundancy framework, refer to figure 4 promptly, at this moment, every input board card is provided with 2 ways input circuit, and every output board card is provided with 2 ways output circuit, and the two way output circuit of every output integrated circuit board are parallelly connected after establishing ties. That is, when the LCU is designed as a two-by-two redundant architecture, the input module is set as 4 input circuits which are mutually designed as redundancy, that is, the input board card a is provided with input circuits a1 and a2, and the input board card B is provided with input circuits B1 and B2; the output module is set as 4 output circuits designed as mutual redundancy, namely, the output board a is provided with a first output circuit (namely, the output circuit a1) and a second output circuit (namely, the output circuit a2), and the output board B is provided with a third output circuit (namely, the output circuit B1) and a fourth output circuit (namely, the output circuit B2), namely, each master controller can simultaneously communicate with the four input circuits of a1, a2, B1 and B2 and the two output circuits of a1, a2, B1 and B2. The first series circuit of the output circuit a1 and the output circuit a2 is connected in parallel with the second series circuit of the output circuit B1 and the output circuit B2.

As further shown in fig. 2, fig. 3 and fig. 4, the input ends of the main control board a and the main control board B in the LCU of the present invention are all connected with the input board a and the input board B, and the output ends are all connected with the output board a and the output board B, i.e. the main control board a and the main control board B can receive the information of the input board a and the input board B at the same time and send the information to the output board a and the output board B. In the normal operation process of the LCU, A, B two sets of systems are in a power-on working state at the same time, input signals are collected by two redundant input board cards A, B at the same time, a main control A preferentially selects communication with an input board A and an output board A, a main control B preferentially selects communication with an input board B and an output board B, and a main board performs logic processing and logic output. When the fault diagnosis judges that a certain board card or a certain channel has a fault, the redundant board card and the redundant channel can be automatically switched to. For example, during normal operation, the master control a preferentially selects the input board a for communication, when the master control a detects that the input board a fails, the master control a can switch redundantly to the input board B for communication with the master control a, and similarly, when other boards fail, the master control a can switch between the redundant boards. In this embodiment, the main control board is switched by a single board, and the IO board card is switched by a single redundancy. Specifically, when the system is configured in a hot standby redundancy mode in which each input board card and each output board card are only provided with 1 input/output circuit, as shown in fig. 3; at this time, the 1-path input signal is acquired by each input circuit (input circuit a and input circuit B) on the two redundant input board cards A, B, and the acquired information is transmitted to the main control a and the main control B at the same time, so that cross communication between different systems can be realized. Meanwhile, the system can flexibly configure the number of input and output circuits according to different requirements without modifying the structure of the system; for example, by configuring 4 input and output circuits respectively, and configuring the system as a two-by-two redundant architecture, at this time, when each input board card and each output board card are provided with 2 input/output circuits, as shown in fig. 4, 1 input signal is subjected to information acquisition by two input circuits on two redundant input board cards A, B, that is, 1 input signal is subjected to information acquisition by 4 input circuits (input circuits a1, a2, B1, and B2) and simultaneously transmits acquired information to a master control a and a master control B, so that cross communication between different systems can be realized. And simultaneously, the utility model discloses be not limited to above-mentioned redundant mode configuration, can dispose according to different demands are nimble to commonality when satisfying equipment and being applicable to different projects.

Specifically, the design of each module specific circuit of the LCU of the present invention is shown in fig. 2, 5 and 6, fig. 5 is a schematic circuit diagram of an input circuit, and fig. 6 is a schematic circuit diagram of an output circuit. The specific design of each module of the system is as follows:

With further reference to fig. 2, power panel a supplies power to group a of cards and power panel B supplies power to group B of cards. A. The external power input buses of the B power panel are completely independent from each other, and an independent control switch is arranged at the far end. The communication board is powered by the power supply board A, B at the same time, and can work normally when one power supply board is normal. Namely, the power supply board A supplies power to the main control board A, the input board A and the output board A, and the power supply board B supplies power to the main control board B, the input board B and the output board B. And the system can still maintain the input and output functions after one power panel fails.

Except for the power supply board, all board cards in the LCU communicate with each other through a 2-circuit redundant isolated CAN bus. When one path of CAN bus has unrecoverable fault, the other path of CAN bus is switched redundantly. Only one CAN bus is communicated at the same time, and when the master control board monitors that the CAN bus has a fault, the CAN bus is switched to a redundant CAN communication line.

The communication module is responsible for external MVB, Ethernet, two-way CAN communication, upper computer interface and maintenance, and log recording function. According to the train networking communication type, the input and output signals and the self-diagnosis signal can be sent to a train network control system through the MVB or the Ethernet. Because the communication module is only responsible for the information uploading and the record maintaining function, and has no influence on the control function of the logic control unit, the communication board card in the embodiment adopts a non-redundant design, and the product cost is saved.

The main control module is responsible for internal CAN communication scheduling, logic operation and fault recording. The system comprises two main control modules (CPU) which are mutually redundant, when the main CPU works normally, the slave CPU monitors silently, and the main CPU carries out dispatching and logic operation of CAN communication. The two CPUs are subjected to fault judgment and redundancy switching through hard-wire signals, and the two types of the hard-wire signals are 4, wherein one type of the hard-wire signals is used for pulse life signal transmission, and the other type of the hard-wire signals is used for reset control. When the slave CPU judges the fault of the master CPU through the vital signal or CAN data, the master CPU is reset, and the master function and the slave function are switched.

referring to fig. 5, the input modules are responsible for acquiring 110V input signals, each of the input modules in this embodiment includes A, B two input boards, each of the input boards includes 32 input acquisition channels (DI 01-DI 032), and each of the input channels has a corresponding indicator light. Each board card comprises an independent control chip, the two board cards are mutually redundant, share one external connector and are interconnected through the connectors between the boards. Each input circuit is provided with an input acquisition circuit and a self-diagnosis circuit, the input acquisition circuit comprises a comparator, a serial-parallel conversion circuit and a photoelectric coupler which are connected in sequence, in the embodiment, 32 comparators are specifically arranged, the + input end of each comparator is connected with one DI input port, the minus input end is connected with the self-diagnosis circuit, and the output end is connected with the input end of the serial-parallel conversion circuit; the output end of the series-parallel conversion circuit is connected with the input end of a photoelectric coupler, and the output end of the photoelectric coupler is connected with the main control module; the comparator collects 110V input direct current voltage information of each circuit, outputs the direct current voltage information to the photoelectric coupler after conversion through the serial-parallel conversion circuit, and transmits the direct current voltage information to the main control module after optical coupling isolation. The input end of the input self-diagnosis circuit is connected with the "-" input end of the comparator, the output end of the input self-diagnosis circuit is connected with the main control module, the input self-diagnosis circuit detects the conduction state of each channel of DI input ports according to a preset reference voltage value, in the embodiment, different reference voltage values are set, and the comparator outputs a high-low level value to detect the conduction state of each channel of DI input ports. The design of the input module realizes that A, B two input board cards continuously carry out self-diagnosis in the acquisition process, and simultaneously transmits the acquisition signals and self-diagnosis fault signals to the main control A, B through CAN communication, so as to realize cross communication, the main control A, B compares and judges the redundant signals of A, B two input circuits, and when the signals are inconsistent, the signals are taken according to the self-diagnosis fault signals, so as to control the redundancy switching of the input circuits.

Referring to fig. 6, in this embodiment, each output module includes 2 output boards, each output board includes an independent control chip, and the two boards are redundant to each other, share one external connector, and are interconnected through an inter-board connector. Each output board card comprises 16 DO output channels (DO 1-DO 16), and each output channel is provided with a corresponding indicator light. Each DO output channel is provided with a switch control circuit and an output self-diagnosis circuit, the embodiment adopts a passive switch design, and the switch control circuit comprises a photoelectric coupler, an MOS driver, an MOS field effect transistor and an overcurrent protection circuit which are sequentially connected; the photoelectric coupler is connected with the main control module, and the output end of the overcurrent protection circuit is connected with the corresponding DO output interface; the input end of the output self-diagnosis loop is connected with the output end of the MOS field effect transistor, and the output end of the output self-diagnosis loop is connected to the master control through a photoelectric coupler. The main control receives information of the input module, calculates and generates a load driving control signal, sends the load driving control signal to an MOS driver of a 16-channel DO output channel after optical coupling isolation, the MOS driver controls the closing or the opening of a corresponding MOS field effect transistor, the MOS driver simultaneously detects output current after the closing of the MOS field effect transistor, and when the output current is detected to be overlarge (namely, exceeds a designed threshold current value), the overcurrent protection circuit carries out overcurrent protection according to the detected output current and feeds back overcurrent information to the main control. Meanwhile, the corresponding output self-diagnosis loop detects the actual switch state of the MOS field effect transistor and feeds back the detected switch state information to the main control, and the main control compares and judges the self-diagnosis signal of each DO output channel with the output load driving control signal to generate the self-diagnosis fault information of the corresponding output board card. The main control compares and judges the redundancy signals of the A, B two output circuits, and when the signals are not consistent, the signals are picked according to the self-diagnosis fault information to control the redundancy switching of the output circuits. In the embodiment, the output module adopts a passive switch design, the MOS field effect transistor is used for switching control, the driving current can reach 2A, the driving voltage can reach 300V, the driving requirements of different levels of 24V and 110V of the train are met, and all channels are designed to be completely isolated in a non-common mode.

the utility model discloses accessible configuration input and output module's jumper resistance realizes that two take two to get two system architecture designs. Each input/output module consists of four sets of independent and redundant circuits, the input module can vote by two times or two times, and the output module can be connected in series and in parallel, so that the fault that the single-path output cannot be disconnected is avoided. Two sets are a group and a single group is provided with independent fault diagnosis modules, and fault diagnosis is carried out on the plate pieces in the group, so that the reliability of the system is further improved. The input module can be configured into a 2-by-2-to-2 mode, 1 input signal is acquired by each 2-path acquisition circuit on the two redundant input board cards, and the master control board cards are compared pairwise to obtain a signal; the output module can be configured into a 2-by-2 selection 2 mode, 2 paths of DO circuits of the single board are connected in series and then connected in parallel with 2 paths of DO circuits of the redundant board cards, 1 input signal is acquired by 2 paths of acquisition circuits on the two redundant input board cards respectively, and the main control board compares every two signals and then acquires the signal.

Meanwhile, the utility model discloses well input module and output module all are provided with self-diagnostic circuit, input self-diagnostic circuit and output self-diagnostic circuit promptly, carry out real-time self-diagnosis to upload the diagnostic data to TCMS; the output module is provided with an overcurrent protection circuit, can automatically cut off a switch when outputting short circuit or overcurrent, and uploads an overcurrent signal, and can automatically recover after the overcurrent disappears; the input module and the output module are independently designed, are provided with external interfaces, and can be randomly configured according to project requirements. The system has rich external communication interfaces, CAN meet the MVB or Ethernet networking requirements of the train, contains external 2-way CAN communication, CAN meet the communication of equipment between the trains, and reduces the wiring of the train.

The utility model discloses a LCU adopts integrated processor and MOSFET semiconductor power switch to replace the relay of traditional train, and more traditional relay design, logic control is more accurate and reliable, and failure diagnosis and maintenance are more high-efficient and convenient. The dual-computer hot standby redundancy is adopted, the working group A and the hot standby group B are powered on and start self-checking at the same time, and input and output feedback information and the working state of a detection system are continuously monitored; when faults of power supply faults, loss of life signals, output short circuit/open circuit feedback and the like of a certain group of LCU control systems are detected, related abnormal module functions are closed, automatic switching of redundant modules is achieved, and train operation is not affected during switching. The main control module is single-board integral redundancy switching, and the input module and the output module can realize single-way redundancy switching, so that the reliability and the safety of the system are further improved. The system is composed of two independent hardware systems, automatic switching of working groups when the equipment is in fault is realized by matching with software, self-diagnosis is carried out on the system, and the diagnosis data is uploaded to the TCMS in real time, so that real-time monitoring of the working state of the LCU is realized, and storage, analysis and the like can be carried out through the software according to the fault diagnosis data. The utility model discloses a contactless design reduces the contact trouble, and redundant design guarantees that arbitrary single-point fault system can normally work, has improved the train reliability. The system is provided with a diagnosis module, faults can be quickly judged through diagnosis signals, the system is convenient to modularize design and maintain, and train maintainability is improved. Meanwhile, the number of the input modules and the number of the output modules can be configured according to different requirements, the system structure does not need to be modified, and the universality of the system when the system is suitable for different projects is met.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in other forms, and any person skilled in the art may use the above-mentioned technical contents to change or modify the equivalent embodiment into equivalent changes and apply to other fields, but any simple modification, equivalent change and modification made to the above embodiments according to the technical matters of the present invention will still fall within the protection scope of the technical solution of the present invention.

Claims (9)

1. A logic control unit for a train is characterized by comprising an input module, an output module and two main control modules with redundant designs; the output end of the input module is respectively connected with each main control module, and the output end of each main control module is respectively connected with the output module; the input module is used for acquiring input direct-current voltage information and sending the input direct-current voltage information to the main control module; the main control module is used for acquiring the direct-current voltage signal, calculating to generate a load driving control signal, and sending the load driving control signal to a load through the output module.

2. The train logic control unit according to claim 1, wherein the input module is configured as 2 input circuits designed to be redundant to each other, and the output module is configured as 2 output circuits designed to be redundant to each other.

3. The logic control unit for train according to claim 1, wherein the input module is configured as 4 input circuits designed to be redundant to each other, and the output module is configured as 4 output circuits designed to be redundant to each other, namely, a first output circuit, a second output circuit, a third output circuit and a fourth output circuit; and a first series circuit consisting of the first output circuit and the second output circuit is connected in parallel with a second series circuit consisting of the third output circuit and the fourth output circuit.

4. The train logic control unit according to any one of claims 2 to 3, wherein the input circuit comprises an input acquisition circuit, and the input acquisition circuit comprises a comparator, a serial-parallel conversion circuit and a photoelectric coupler which are connected in sequence; the input end of the comparator is connected with the DI input port, and the output end of the comparator is connected with the input end of the serial-parallel conversion circuit; the output end of the series-parallel conversion circuit is connected with the input end of a photoelectric coupler, and the output end of the photoelectric coupler is connected with the main control module.

5. The logic control unit for train as claimed in claim 4, wherein the input circuit further comprises an input self-diagnosis circuit, the input end of the input self-diagnosis circuit is connected with the input end of the comparator "-" and the output end of the input self-diagnosis circuit is connected with the main control module; the input self-diagnosis circuit is used for detecting the conduction state of each path of DI input port according to a preset reference voltage value.

6. The logic control unit for the train as claimed in claim 2, 3 or 5, wherein the output circuit comprises a switch control circuit, the switch control circuit adopts a passive switch design, and comprises a photoelectric coupler, a MOS driver, a MOS field effect transistor and an overcurrent protection circuit which are connected in sequence; the photoelectric coupler is connected with the main control module, and the output end of the overcurrent protection circuit is connected with the DO output interface.

7. The logic control unit for the train according to claim 6, wherein the output circuit further comprises an output self-diagnosis circuit, an input end of the output self-diagnosis circuit is connected with an output end of the MOS field effect transistor, and an output end of the output self-diagnosis circuit is connected to the main control module through a photoelectric coupler; the output self-diagnosis loop is used for detecting the switch state of the MOS field effect transistor and feeding back the detected switch state information to the main control module.

8. The logic control unit for train as claimed in claim 1, further comprising a communication module, wherein the input end of the communication module is connected to the input end and the output end of the master control module respectively, the output end of the communication module is connected to the train network control system, and the data input and output by the master control module is transmitted to the train network control system.

9. The logic control unit for trains of claim 8, further comprising a power supply module, wherein the power supply module converts the bus power voltage into an input power voltage through DC/DC conversion, and supplies power to the input module, the output module, the main control module and the communication module.