Coal mine underground cable long-distance high-speed bus communication method

Abstract

The invention relates to a long-distance high-speed bus communication method for an underground coal mine cable, and belongs to the field of mining safety monitoring communication. According to the method, a two-core mining signal cable is adopted for communication, a 3.3 V level signal is converted into a 12V level signal through a bidirectional level conversion technology, and data transmission is performed by adopting a master-slave communication mode and a monitoring mode, so that the high-speed transmission rate of 4Mbit / s and the transmission distance of more than 5km are realized. Meanwhile, the system adopts a full intrinsic safety design, is suitable for a flammable and explosive environment in an underground coal mine, and improves the safety of communication. The system has the advantages of being long in transmission distance, high in transmission rate, strong in anti-interference capability, high in safety, convenient to deploy and maintain and the like, can be widely applied to various scenes such as safety monitoring, equipment control, data acquisition and the like of an underground coal mine, and provides reliable communication guarantee for safety production of the coal mine.

Description

Technical Field

[0001] The invention belongs to the field of mine safety monitoring communication and relates to a long-distance high-speed bus communication method for underground cables in coal mines. Background Art

[0002] The underground environment of coal mines is complex and there are dangers of flammability and explosion, which puts forward special requirements for communication technology. Traditional underground communication technology in coal mines mainly adopts wired communication methods, including:

[0003] Telephone communication: Voice communication is carried out through telephone lines, the transmission distance is limited, and data cannot be transmitted.

[0004] Wired broadcasting: Voice broadcasting is carried out through broadcasting lines, with limited coverage and inability to achieve two-way communication.

[0005] Industrial Ethernet: Data is transmitted via optical fiber or twisted pair cables, with high transmission rates, but the wiring is complex and the cost is high.

[0006] The above traditional communication technologies have the following limitations:

[0007] Limited transmission distance: The transmission distance of telephone lines and wired broadcasting is limited and cannot meet the needs of large-area coverage in coal mines.

[0008] Low transmission rate: Telephone lines and wired broadcasting cannot transmit data. Although industrial Ethernet has a high transmission rate, the wiring is complex and the cost is high.

[0009] Poor anti-interference ability: The underground environment of coal mines is complex, with electromagnetic interference and mechanical vibration, which poses a challenge to the reliability of communication lines.

[0010] Low safety: Traditional communication lines are flammable and explosive and have low safety.

[0011] In order to overcome the limitations of existing technologies, underground coal mine communication technology is developing in the following directions:

[0012] Wireless communication technology: Wireless communication technology can achieve long-distance transmission without the need for wiring, thus reducing construction costs. Common wireless communication technologies include Wi-Fi, Bluetooth, ZigBee, etc.

[0013] Fiber-optic communication technology: Fiber-optic communication technology has the advantages of high transmission rate, strong anti-interference ability, and high security, and has broad application prospects in underground coal mine communications.

[0014] Safety monitoring technology: The underground safety monitoring system of coal mines can monitor the environmental parameters and safety conditions underground in real time, and transmit the data to the ground through the communication system to provide guarantee for safe production. Summary of the invention

[0015] In view of this, the purpose of the present invention is to provide a method for long-distance high-speed bus communication of underground cables in coal mines. Aiming at the problems existing in RS485 bus communication and optical fiber communication, a mining cable can be connected in series with 32 low-power sensors, with a maximum distance of 5km and a bus bandwidth of 4Mbit / s.

[0016] In order to achieve the above object, the present invention provides the following technical solutions:

[0017] A method for long-distance high-speed bus communication of underground cables in coal mines, the method comprising the following steps:

[0018] Use two-core mining signal cables for communication, one core as the clock line and the other as the data line;

[0019] Adopt bidirectional level conversion technology to convert the 3.3V level signal of the main processor end into a 12V level signal on the transmission line, and realize the signal receiving conversion;

[0020] Using the master-slave communication mode, the master device is responsible for polling the slave device, and the slave device passively responds to the master device;

[0021] In monitoring mode, only one device is allowed to send data on the bus, and other devices are in monitoring state;

[0022] A complete data packet is represented by a start frame, source device address, destination device address, data length, data content, data checksum and end frame.

[0023] A high-speed general purpose input / output (GPIO) interface is used to control the conversion circuit to achieve a certain transmission rate.

[0024] Further, the bidirectional level conversion technology includes:

[0025] Use fast MOS tubes to achieve level conversion;

[0026] The main processor uses a 3.3V level signal;

[0027] The transmission line uses a 12V level signal.

[0028] Further, the bus communication protocol includes:

[0029] Data start frame;

[0030] Source device address;

[0031] Destination device address;

[0032] Data length;

[0033] Data content;

[0034] Data checksum;

[0035] End frame.

[0036] Further, the master-slave device encoding adopts:

[0037] The master device address is encoded as 0;

[0038] The slave devices are numbered sequentially from 1 to 32.

[0039] Furthermore, the process of the master device actively sending data includes:

[0040] The master device generates a periodic clock signal;

[0041] The master device generates a corresponding data signal;

[0042] Receive a clock signal and a data signal from the device;

[0043] The slave device determines the data validity based on the address matching situation;

[0044] The slave device with matching address processes the data, and the slave device with mismatching address discards the data.

[0045] Further, the process of sending data from the device includes:

[0046] After the slave device matches the address, it starts sending data;

[0047] The master device generates a periodic clock signal;

[0048] The slave device generates a data signal on the falling edge of the clock;

[0049] The data signal is transmitted through the cable to the host device.

[0050] Furthermore, the communication method adopts a fully intrinsically safe design and is suitable for underground coal mine environments.

[0051] A coal mine underground cable long-distance high-speed bus communication system, comprising:

[0052] A conversion circuit is connected to the master device and the slave device and is used to realize the conversion between the 3.3V level signal and the 12V level signal;

[0053] The two-core cable for mining is connected to the conversion circuit as a communication medium, one core of which is used as a clock line and the other core as a data line;

[0054] The master device is connected to the conversion circuit and is responsible for polling the slave device, sending data, and receiving data from the slave device;

[0055] The slave device, connected to the conversion circuit, passively responds to the master device and sends data as needed;

[0056] Data protocol is used to standardize data transmission format and communication rules.

[0057] Further, the conversion circuit comprises:

[0058] Fast MOS tube, connected to the master device and the slave device, used to achieve level conversion;

[0059] The pull-up resistor is connected to the MOS tube and is used to pull the high level of the MOS tube to 12V when it is cut off.

[0060] Furthermore, the system adopts a fully intrinsically safe design and is suitable for underground coal mine environments.

[0061] The beneficial effects of the present invention are:

[0062] (1) The present invention adopts two-core cable communication technology, which can achieve a transmission distance of more than 5 km, meeting the needs of large-area coverage in coal mines and overcoming the limitation of short transmission distance of existing communication technologies.

[0063] (2) The present invention adopts bidirectional level conversion technology and high-speed GPIO control technology to achieve a transmission rate of 4 Mbit / s, meeting the needs of data transmission and overcoming the limitation of low transmission rate of existing communication technology.

[0064] (3) The present invention adopts 12V level signal transmission, has strong anti-interference ability, ensures the reliability of communication, and overcomes the limitation of poor anti-interference ability of existing communication technology.

[0065] (4) The present invention adopts a fully intrinsically safe design, which is suitable for the flammable and explosive environment underground in coal mines, improves the security of communications, and overcomes the limitation of low security of existing communication technologies.

[0066] (5) The present invention adopts cable bus transmission, which is simple to deploy and convenient to install and maintain, thereby reducing construction and maintenance costs and improving the deployment and maintenance efficiency of communications.

[0067] (6) The present invention adopts a master-slave communication mode and a monitoring mode to prevent data conflicts and improve the reliability of the communication system.

[0068] (7) The present invention can be applied to various application scenarios such as safety monitoring, equipment control, and data acquisition in coal mines, and has broad application prospects.

[0069] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0071] Figure 1 This is the topology diagram of the long-distance high-speed bus communication network for mining cables;

[0072] Figure 2 It is a bidirectional level conversion circuit diagram;

[0073] Figure 3 It is a schematic diagram of two-core cable communication;

[0074] Figure 4 It is a schematic diagram of bus communication protocol;

[0075] Figure 5 Schematic diagram of master and slave device coding design;

[0076] Figure 6 Schematic diagram of actively sending data to the master device;

[0077] Figure 7 This is a schematic diagram of data transmission from device No. 2. DETAILED DESCRIPTION

[0078] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0079] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0080] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0081] The method adopts cable communication technology to realize sensor communication in coal mines.

[0082] The method adopts two-core cable communication technology, one core cable is used as the clock source, and the other core cable is used as the data source. Communication is performed by writing data at the falling edge of the clock source and reading data at the rising edge of the clock source.

[0083] The method adopts bidirectional level conversion technology to convert the low voltage level signals of the clock source and data source of the ordinary main processor into high voltage level signals suitable for long-distance cable transmission, with the maximum distance reaching 5km.

[0084] This method uses a 3.3V voltage level on the main processor end, which is compatible with ordinary main processors; and a 12V voltage level is used on the transmission line to enhance the anti-interference ability of long-distance transmission.

[0085] The method adopts a master-slave communication mode, where both the master and slave devices have unique addresses, the master device is responsible for polling the slave device, and the slave device passively responds to the master device.

[0086] This method uses the monitoring mode, where only one device is allowed to send data on the bus, and other devices are in the monitoring state and only read the data on the bus. When the write data permission is obtained, the data is written on the data line.

[0087] The method uses a start frame, a source device address, a destination device address, a data length, a data content, a data check code and an end frame to represent a complete data packet.

[0088] The method adopts a high-speed GPIO control conversion circuit, and the transmission rate can reach 4Mbit / s.

[0089] System composition:

[0090] This invention patent mainly includes conversion circuits, mining cables, master / slave devices and data protocols. Figure 1 This is the topology diagram of the long-distance high-speed bus communication network for mining cables.

[0091] Detailed design:

[0092] 1. Bidirectional level conversion design

[0093] The main processor uses a 3.3V level, the transmission line uses a 12V level, and bidirectional level conversion is achieved through fast MOS tubes.

[0094] When S1 is at a low level, the MOS tube Q1 is turned on, S1 and S2 are turned on, and the S2 end is pulled down to 0V, realizing low-level transmission over long distances in the cable.

[0095] When S1 is at a high level, the MOS tube Q1 is turned off, and the S2 end is pulled up to a 12V high level by the pull-up resistor, realizing high-level transmission over long distances of the cable.

[0096] When the cable is at a low level, S2 is at a low level, the parasitic diode inside the MOS tube is turned on, pulling S1 down to a low level, and then the MOS tube is turned on, S1 and S2 are turned on, the output end is pulled down to 0V, and the device end is realized at a low level.

[0097] When the cable is at a high level, S2 is at a high level, the MOS tube Q3 is turned off, and the S1 end is pulled up to a high level by the pull-up resistor, achieving a high level on the device end.

[0098] Figure 2 This is a bidirectional level conversion circuit diagram.

[0099] 2. Design of two-core cable communication for mines

[0100] The system uses a two-core cable for mine communication, one core cable is used as the clock source, and the other core cable is used as the data source. Communication is carried out by writing data on the falling edge of the clock source and reading data on the rising edge of the clock source. The clock source is periodically generated by the master device, and the data source is generated by the writing device. The main processor end is 3.3V level, and the transmission line is 12V level.

[0101] Figure 3 This is a schematic diagram of two-core cable communication.

[0102] 3. Bus communication protocol design

[0103] The data transmitted on the bus is transmitted in a fixed data format. A complete data packet contains the data start frame, source device address, destination device address, data length, data content, data check code, and end character.

[0104] Figure 4 This is a schematic diagram of the bus communication protocol.

[0105] 4. Master and slave device coding design

[0106] A unified address coding is used for the devices on the bus. The address coding of the master device is 0, and the slave devices are numbered from 1 to 32.

[0107] Figure 5 Schematic diagram of the master-slave device encoding design.

[0108] 5. Design of the master device actively sending data

[0109] Cable communication uses the master device to actively send data. The master device's clock source generates a periodic clock signal, and the master device's data source generates a corresponding data signal. Through the two-core cable transmission, all slave devices will receive the clock signal and data signal at the same time. The slave device will only consider it as valid data and process it when the address matches, otherwise it will be discarded.

[0110] Figure 6 The master device actively sends data, and the address matching diagram of the slave device numbered 2.

[0111] 6. Design of sending data from device

[0112] After the slave device matches the address, it starts to send data. The clock pin of the master device generates a periodic clock signal. At the same time, the slave device generates a data signal from the data sending pin at the falling edge of the clock. The data signal is transmitted through the data line of the cable and reaches the master device. Figure 7 Design a schematic diagram for sending data from device No. 2.

[0113] Example 1: Coal Mine Underground Environment Monitoring System

[0114] The system consists of the following parts:

[0115] Main equipment: Located on the ground, responsible for collecting underground environmental data, processing and displaying it.

[0116] Slave equipment: located underground, including temperature sensors, humidity sensors, methane sensors, etc., used to collect environmental data underground.

[0117] Conversion circuit: located between the master device and the slave device, realizes the conversion between 3.3V level signal and 12V level signal.

[0118] Two-core cable for mining: connects master equipment, slave equipment and conversion circuits as a communication medium.

[0119] Working principle:

[0120] The master device converts the collected environmental data into 12V level signals through the conversion circuit and sends them to the slave device through the cable.

[0121] After receiving data from the device, the 12V level signal is converted into a 3.3V level signal and processed.

[0122] The slave device converts the collected environmental data into 12V level signals as needed and sends them to the master device through a cable.

[0123] After receiving the data, the master device converts the 12V level signal into a 3.3V level signal, and processes and displays it.

[0124] Example 2: Coal Mine Underground Equipment Control System

[0125] The system consists of the following parts:

[0126] Main equipment: located on the ground, responsible for controlling the equipment underground, such as ventilators, drainage pumps, etc.

[0127] Slave device: Located underground, responsible for receiving control instructions and controlling the equipment.

[0128] Conversion circuit: located between the master device and the slave device, realizes the conversion between 3.3V level signal and 12V level signal.

[0129] Two-core cable for mining: connects master equipment, slave equipment and conversion circuits as a communication medium.

[0130] Working principle:

[0131] The master device converts the control command into a 12V level signal through a conversion circuit and sends it to the slave device through a cable.

[0132] After receiving the instruction from the device, the 12V level signal is converted into a 3.3V level signal and the device is controlled according to the instruction.

[0133] The slave device converts the operating status of the device into a 12V level signal and sends it to the master device through the cable.

[0134] After receiving the data, the master device converts the 12V level signal into a 3.3V level signal, and processes and displays it.

[0135] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A method for long-distance high-speed bus communication of cables in underground coal mines, characterized in that: The method comprises the following steps: Use two-core mining signal cables for communication, one core as the clock line and the other as the data line; Adopt bidirectional level conversion technology to convert the 3.3V level signal of the main processor end into a 12V level signal on the transmission line, and realize the signal receiving conversion; Using the master-slave communication mode, the master device is responsible for polling the slave device, and the slave device passively responds to the master device; In monitoring mode, only one device is allowed to send data on the bus, and other devices are in monitoring state; A complete data packet is represented by a start frame, source device address, destination device address, data length, data content, data checksum and end frame. A high-speed general purpose input / output (GPIO) interface is used to control the conversion circuit to achieve a certain transmission rate.

2. The method for long-distance high-speed bus communication of underground cables in coal mines according to claim 1, characterized in that: The bidirectional level conversion technology includes: Use fast MOS tubes to achieve level conversion; The main processor uses a 3.3V level signal; The transmission line uses a 12V level signal.

3. The method for long-distance high-speed bus communication of underground cables in coal mines according to claim 1, characterized in that: The bus communication protocol includes: Data start frame; Source device address; Destination device address; Data length; Data content; Data checksum; End frame.

4. The method for long-distance high-speed bus communication of underground cables in coal mines according to claim 1, characterized in that: The master-slave device encoding adopts: The master device address is encoded as 0; The slave devices are numbered sequentially from 1 to 32.

5. The method for long-distance high-speed bus communication of underground cables in coal mines according to claim 1, characterized in that: The process of the master device actively sending data includes: The master device generates a periodic clock signal; The master device generates a corresponding data signal; Receive a clock signal and a data signal from the device; The slave device determines the data validity based on the address matching situation; The slave device with matching address processes the data, and the slave device with mismatching address discards the data.

6. The method for long-distance high-speed bus communication of underground cables in coal mines according to claim 1, characterized in that: The process of sending data from the device includes: After the slave device matches the address, it starts sending data; The master device generates a periodic clock signal; The slave device generates a data signal on the falling edge of the clock; The data signal is transmitted through the cable to the host device.

7. The method for long-distance high-speed bus communication of underground cables in coal mines according to claim 1, characterized in that: The communication method adopts a fully intrinsically safe design and is suitable for underground coal mine environments.

8. A coal mine underground cable long-distance high-speed bus communication system, characterized by: include: A conversion circuit is connected to the master device and the slave device and is used to realize the conversion between the 3.3V level signal and the 12V level signal; The two-core cable for mining is connected to the conversion circuit as a communication medium, with one core as the clock line and the other as the data line; The master device is connected to the conversion circuit and is responsible for polling the slave device, sending data, and receiving data from the slave device; The slave device, connected to the conversion circuit, passively responds to the master device and sends data as needed; Data protocol is used to standardize data transmission format and communication rules.

9. The long-distance high-speed bus communication system for underground cables in coal mines according to claim 8, characterized in that: The conversion circuit comprises: Fast MOS tube, connected to the master device and the slave device, used to achieve level conversion; The pull-up resistor is connected to the MOS tube and is used to pull the high level of the MOS tube to 12V when it is cut off.

10. The coal mine underground cable long-distance high-speed bus communication system according to claim 8, characterized in that: The system adopts a fully intrinsically safe design and is suitable for underground coal mine environments.

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