CN102932740B - An underground personnel positioning search and rescue system - Google Patents

Abstract

The invention discloses an underground personnel positioning search and rescue system. The system includes: a positioning server, a monitoring terminal, a wired communication subsystem, a wireless communication base station, a positioning device and a search and rescue device; the wired communication subsystem mainly includes an optical fiber, an optical splitter and a wireless switch; The wireless communication base station mainly includes equipment such as explosion-proof box, power supply, backup battery, wireless access equipment and antenna; the wireless communication base station is installed at a certain distance underground, and the wireless communication base station is connected to the positioning server on the well through a wired communication subsystem; the positioning device and wireless communication The base station communicates through wireless; the positioning server realizes personnel positioning through the positioning device carried by the underground staff, and the positioning device sends information such as the user's location and ID number to the positioning server at regular intervals; the search and rescue device can directly communicate with the positioning device wirelessly; the search and rescue system It can locate the position of trapped persons, avoid ineffective work, save precious rescue time, and improve rescue efficiency. The positioning search and rescue system is a comprehensive system that integrates underground personnel tracking and positioning, dispatch management, and post-disaster search and rescue.

Description

An underground personnel positioning search and rescue system

technical field

The invention relates to an underground personnel positioning search and rescue system. The invention specifically relates to technical fields such as WI-FI wireless communication and wireless positioning.

Background technique

Downhole personnel positioning is an important measure for safe production. Over the years, people have used various methods to detect the location of underground personnel. When an accident occurs in a mine, the positioning system can provide an important reference for personnel search and rescue. But the current positioning and search and rescue system has the following deficiencies.

At present, the actual use is mainly based on radio frequency identification technology (RFID). RFID uses radio frequency to carry out non-contact two-way communication to achieve the purpose of identification and exchange data. Different from other contact identification technologies, the RFID system can realize automatic identification and position monitoring of people or objects in different states without contact between the radio frequency card and the reader. A typical radio frequency identification system mainly includes two parts: a radio frequency card and a reader. Using RFID has the following problems:

1. The RFID communication distance is limited, and the farthest barrier-free communication distance of the active RFID card is 80 meters;

2. The RFID card reading and writing equipment has a large volume and is not easy to carry.

3. It is not convenient for two-way communication.

The positioning system based on wireless sensor network, such as Zigbee positioning system, has the following problems in the actual use underground:

1. The networking of Zigbee wireless sensor network needs the support of network core equipment coordinator and router. If the network core equipment, especially the coordinator, is damaged, the network will be completely paralyzed. Unable to support search and rescue positioning.

2. The communication of Zigbee wireless sensor network must have network support, point-to-point communication is not supported. When there is no network support, the positioning terminal cannot communicate with other devices.

3. It is impossible to know the current activity status of the trapped person.

"Ad hoc network" is a special self-organizing peer-to-peer multi-hop mobile communication network formulated by the IEEE802.11 standard committee. In the Ad hoc network, nodes have the ability to forward messages, and communication between nodes may go through The forwarding of multiple intermediate nodes, that is, multi-hop (MultiHop), is the most fundamental difference between Ad hoc networks and other mobile networks. The nodes coordinate with each other through layered network protocols and distributed algorithms, realizing the automatic organization and operation of the network. Therefore, it is also called MultiHop Wireless Network, Self Organized Network or Infrastructureless Network. Most WI-FI wireless network modules support Ad hoc networks at the same time.

Contents of the invention

The purpose of the present invention is to provide a positioning and search and rescue system capable of accurately locating underground personnel and having the function of searching for the position of trapped personnel and the function of two-way communication when an accident occurs in a mine, personnel are trapped, and fixed communication facilities are damaged and unable to work. system.

The underground personnel positioning search and rescue system of the present invention includes: a positioning server, a monitoring terminal, a wired communication subsystem, a wireless communication base station, a positioning device and a search and rescue device; the wired communication subsystem mainly includes an optical fiber, an optical splitter and a wireless switch; the wireless communication base station mainly includes Including explosion-proof box, power supply, backup battery, wireless access equipment, antenna isolator and antenna; install a wireless communication base station at a certain distance underground, and connect the wireless communication base station to the wireless switch and positioning server on the well through optical fiber; the positioning device and wireless communication base station Through wireless communication; the positioning server realizes personnel positioning through the positioning device carried by the underground staff, and the positioning device sends information such as the location, identity and activity status of the user to the positioning server at regular intervals; the positioning device and the search and rescue device are connected through Ad hoc networking. Realize wireless communication;

The search and rescue device components include: processor, wireless communication, buttons, storage, display screen, LED indicator light, buzzer, temperature sensor and power supply circuit; the specific process of search and rescue of the search and rescue device is as follows:

1. Initialize the system, set the communication unit to have the Ad hoc networking function, and enable the IP address assignment function;

2. After the search and rescue device successfully organizes the Ad hoc network, TCP/IP or UDP communication is started. When the search and rescue device reaches the communication distance of the positioning device, the positioning device automatically connects to the search and rescue device, and automatically establishes a TCP/IP or LDP communication link;

3. After the link is successfully established, the positioning device regularly detects the signal field strength of the search and rescue device.

4. The positioning device sends field strength information, its own identity number and vibration state information obtained by the vibration sensor to the search and rescue device through the communication link with the search and rescue device.

5. After the search and rescue device receives the information sent by the positioning device, it calculates the distance according to the signal field strength. The formula of field strength and distance is a reference empirical formula, and the relevant parameters are obtained through on-site measurement, as follows:

$\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; 10</span>}}^{\frac{\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; Rd</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; \&delta;</span>}}}{\mathrm{<span\; class="notranslate">\; 10</span>}\mathrm{<span\; class="notranslate">\; no</span>}}}$

In the formula, A is the power of the received signal when the signal propagates 1m away;

n is the propagation factor, also known as the loss index, and its value depends on the propagation environment of the wireless signal;

Rd is the signal strength of the wireless base station received by the positioning device, that is, the RSSI value;

X _δ is a Gaussian normal random variable with zero mean

6. The LCD screen of the search and rescue device displays the signal field strength and estimated distance, the identity number of the positioning device, and the vibration sensor induction status information of the trapped person. The search and rescue personnel can comprehensively judge the activity status of the trapped person according to the vibration status information, which is convenient for implementation corresponding search and rescue measures.

7. The search and rescue device indicates the distance between the search and rescue device and the trapped person through sound and light. After receiving the information sent by the positioning device carried by the trapped person, it emits sounds and lights with different frequency intervals according to the calculated distance. The higher the frequency of short sound and light flashing, the user can know the distance of the trapped person by listening to the sound or observing the light flashing without looking at the LCD display screen, so as to improve the efficiency of search and rescue work. When multiple positioning devices are found, the closest one is used as the target indication.

8. Two-way communication between the search and rescue device and the positioning device, that is, when the positioning device passes the communication link with the search and rescue device, the search and rescue device can send information to the positioning device carried by the trapped person, and the trapped person can also use the positioning device to send information to the search and rescue device .

9. Temperature detection, there is a temperature sensor inside the positioning device, with temperature detection function, real-time temperature can be displayed on the LCD display

10. Upload the search and rescue records, and upload the search and rescue records to the positioning server in the area where the communication facilities are not damaged and the wireless network communication is normal.

Features of the invention

1. The self-organizing network of search and rescue devices and positioning devices carried by trapped persons does not require the support of any other fixed infrastructure network facilities. Each node coordinates its own behavior through layered protocols and distributed algorithms, and can quickly, efficiently and automatically form a network for communication. It has high search sensitivity.

2. The Ad hoc network composed of search and rescue devices and positioning devices carried by trapped persons is a dynamic network. Network nodes can move anywhere, the network structure changes at any time, and nodes can join and leave the network at any time, which is convenient for mobile work and continuous search.

3. The search and rescue device not only locates the position of the trapped person, but also knows the life activity status of the trapped person, avoids ineffective work, saves precious rescue time, and improves rescue efficiency.

Description of drawings

Figure 1 Schematic diagram of positioning search and rescue system positioning work

Figure 2 Schematic diagram of the search and rescue work of the positioning search and rescue system

Figure 3 Block diagram of the hardware structure of the search and rescue device

Figure 4 System block diagram of the search and rescue device

Figure 5 Workflow diagram of the search and rescue device

Figure 6 Work flow chart of connecting the positioning device to the search and rescue device

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1 and Figure 2, the composition of the positioning search and rescue system includes:

The underground personnel positioning search and rescue system includes: a positioning server (1), a wired communication subsystem, a wireless communication base station (2), a positioning device (3) and a search and rescue device (6). The wired communication subsystem is the backbone network of the entire positioning search and rescue system, and the wired communication subsystem uses optical fiber as the main transmission medium. The wired communication subsystem also includes network management equipment such as an optical splitter and a wireless switch (5). The wireless communication base station is installed at a certain distance underground, and the wireless communication base station is connected to the server on the well through optical fiber. The main function of the wireless communication base station is WI-FI wireless access. The wireless communication base station includes explosion-proof boxes, power supplies, backup batteries, wireless access equipment, antenna isolators and antennas. The wireless access device is called AP (Access Point) in the standard WI-FI network. It is responsible for the wireless terminal device to access the wired Ethernet, and the WI-FI wireless LAN covers each roadway through the wireless communication base station. Each AP is allocated with a service set identifier SSID and a different physical address. The positioning system distinguishes different wireless communication base stations according to the identification of the AP. The wireless communication base station supports cross-region roaming of wireless terminal equipment. As a positioning reference point, the location information and identification information of the wireless communication base station are stored in the positioning server and the storage subsystem of the positioning device, providing a basis for positioning calculations. As a standard WI-FI terminal equipment, the positioning device is connected to the WI-FI wireless local area network to communicate with the uphole positioning server. The positioning server is responsible for system communication management, data storage and providing personnel and equipment information services for monitoring terminals. Production management personnel access the positioning server through the monitoring terminal (4) to realize real-time monitoring of underground staff and related equipment. The monitoring terminal has functions such as map display, staff location and data display query, staff location statistics, and historical location tracking query. The geographic information platform can use the MapX mapping component. The mine map is a vector map of the two-dimensional profile of the roadway, and the map file is in the MapInfo format.

Figure 2 is a schematic diagram of the search and rescue work of the positioning and search and rescue system. When the fixed communication access equipment fails, the search and rescue device (6) and the positioning device (3) establish an Ad hoc network, and the search and rescue device organizes the network to assign an IP address to the positioning device.

In the embodiment shown in Figure 3, the hardware composition of the search and rescue device includes the following parts:

1. Processor (306) selects the MSP430F147 single-chip microcomputer of TI company. This model is a 16-bit RISC structure, with 32kFlash, 1kRAM; and has 5 low power consumption modes, rich on-chip peripheral modules, flexible clock system and many other advantages. MSP430 can work at a low voltage of 1.8-3.6V, and the system uses a working voltage of 3.3V. MSP430F147 built-in precision is 12 A/D converters of 200kps. 1-bit nonlinear differential error, 1-bit nonlinear integral error, 4 analog-to-digital conversion modes.

2. The WI-FI communication (307) part includes the WI-FI communication module and antenna. The WI-FI communication module adopts the iChip series encrypted networking control chip CO2128 of ConnectOne Company as the core product. The module includes a radio frequency module, communication An interface module, a state control and detection module and a memory; the antenna adopts a directional antenna.

3. The button (304) control circuit is composed of 4 buttons, using an independent button-type keyboard, combined with the display interface of the display screen, to realize the switching of various functions and states.

4. The storage (305) chip adopts one piece of 24C512. Since the positioning device only uses one memory chip, the chip selection address does not need to be set, so the chip selection pins of the 24C512 are all grounded. 24C512 uses I2C bus communication, and uses two standard I/O interfaces plus pull-up resistors to connect SCL and SDA pins to realize communication control between the processor and the memory chip.

5. The LCD display (301) adopts a two-line dot matrix liquid crystal display module, which has the characteristics of low power consumption and wide supply voltage range. The viewing area size: 60.5×18.0mm, 54.8×18.3mm. The O port transmits display data to the liquid crystal module, and drives and controls the liquid crystal module through four I/O ports.

6. The LED indicator light (302) adopts two SMD LEDs, which are red and green respectively. The green is used as a system status indicator, which includes power indicator and charging indicator, etc., and the red LED is used as a status indicator, and the status includes information indicator, search indicator and distance indication, etc.

7. The buzzer (303) adopts a passive buzzer.

8. The hardware part of the temperature sensor (310) includes a temperature sensitive resistor and a whist bridge. The resistance of the temperature-sensitive resistor changes, and the temperature-sensitive resistor is used as one of the bridge arm resistances to directly convert the change in resistance into a change in bridge voltage. The core of the ADC12 module of MSP430147 is shared, and the acquisition input is completed separately through the analog switch at the front end. Therefore, the bridge arm where the temperature-sensitive resistor is located can be connected to any one of the 12 AD analog input ports to detect the change of the bridge voltage. . MSP430F147 MCU A/D conversion reference reference voltage can use the reference reference voltage input externally, or the reference reference voltage generated by the internal reference voltage generator, and the A/D conversion setting can be completed by setting the ADC12CTL control register. Since the use of the internal reference voltage of the single-chip microcomputer will increase the power consumption of the processor, in consideration of the power saving design of the device, an external reference voltage is selected to ensure the working time of the device. The detected signal also needs to be filtered by software through the processor.

In the embodiment shown in Figure 4, the system composition of the search and rescue device includes:

1. The acquisition subsystem (401), responsible for the acquisition of device input signals, including: temperature information acquisition, vibration sensor sensing signal acquisition, voltage acquisition step counting calculation and button action acquisition.

2. The positioning subsystem (402), responsible for collecting the signal field strength from the surrounding WI-FI access point to the module from the WI-FI communication module, and combining the step length of the wearer according to the field strength signal and the location information of the access point The position of the positioning device is obtained through the calculation of the number of steps, and is uploaded to the positioning server through the communication subsystem.

3. The communication subsystem (403), responsible for the communication between the device and the system and external equipment, including WI-FI wireless communication control and UART communication control.

4. The display subsystem (404), responsible for driving the LCD screen of the device and displaying information.

5. The control subsystem (405), responsible for controlling hardware units such as the buzzer, LED, LCD backlight, and power supply of the device to realize their respective functions.

6. The storage subsystem (406), responsible for controlling the communication between the device and the storage chip, and realizing data storage and reading operations.

Figure 5 is a work flow diagram of the search and rescue device. After the system is initialized, the search and rescue device automatically searches for a positioning device (501). The search and rescue device has an Ad hoc networking function. When the search and rescue device reaches the communication distance of the positioning device, the search and rescue device assigns an IP to the positioning device Address (502), the search and rescue device accepts the connection of the positioning device (503), opens the communication service and establishes a communication link (504), after the link is established successfully, the positioning device regularly detects the signal field strength of the search and rescue device, and the positioning device passes through the connection with the search and rescue device The communication link of the search and rescue device sends field strength information and its own identity number (505). After the search and rescue device receives the information sent by the positioning device, it analyzes and obtains the signal field strength of the search and rescue device detected by the positioning device, and substitutes the field strength into the empirical formula Calculate the distance between the search and rescue device and the positioning device (506); there is a temperature sensor inside the search and rescue device, which has a temperature detection function, and regularly monitors the ambient temperature (507); the identity number of the signal field strength positioning device and the positioning device sensed by the LCD screen display The last activity time of the user, the search and rescuer can use this as a reference for judging the activity state of the trapped person; the search and rescue device sends out sounds and lights with different interval frequencies (508) according to the distance from the positioning device, and the shorter the distance, the sound and light flicker frequency The higher the height, the user can know the distance of the trapped person by listening to the sound or observing the flickering of the light without looking at the LCD display, so as to improve the efficiency of search and rescue work; the LCD display shows real-time temperature; the search and rescue device has a clock function, which can Displaying the current time in real time enables the wearer to grasp the accurate time in real time. Search and rescue personnel can set the search and rescue device to the upload record state (509) through the LCD screen display prompts and operation buttons. Set it as a common WI-FI network terminal node mode, the search and rescue device searches for nearby wireless communication base stations that are working normally, and if found, it will automatically connect to the WI-FI network, connect to the TCP service port of the positioning server and send unuploaded search records in TCP mode (512 ), when all the records are uploaded, the WI-FI communication module is automatically restored and transferred to the Ad hoc networking working mode (513), and continues to search for the positioning device (501).

In the embodiment shown in Figure 6, the positioning device automatically searches for a special search and rescue device and calls for help in the TCP connection communication mode. The device acts as a client to connect to the fixed IP address and port of the positioning server, and the positioning server uses a fixed IP address and fixed port for the server side, and the uplink and downlink information is transmitted based on the TCP link channel. When there is no data transmission on the link channel, the positioning device should send a link detection data packet (603) every time S (602) to maintain the TCP connection, and the system starts timing when the link detection data packet is sent out for more than time K and is not received When the reply (604) is received, the link detection packet (603) is sent again immediately; if no reply is received after sending R times (605) continuously, the link is determined to be invalid, and the data sender actively disconnects the connection (614) and repeats TCP Connection process (601); if TCP fails to connect successfully, then reconnect to the network, if it is still not connected to the network (606) for more than G times, it will automatically enter the distress search mode (608), and the communication subsystem sets the WI-FI communication module Enter the search and rescue device state, in which the positioning device supports Ad hoc networking; if the number of unsuccessful TCP connections (606) between the positioning device and the positioning server does not reach G times, a prompt message will be displayed on the LCD screen, and the user can Often press the specific function key of the positioning device to manually control the positioning device to enter the rescue mode (608); when the positioning device searches for the signal of the nearby search and rescue device, it will join the Ad hoc network organized by the search and rescue device, and automatically obtain the IP address assigned by the search and rescue device. TCP connects to the search and rescue device (610), detects the signal field strength of the search and rescue device (611), sends information such as field strength, positioning device identity, and last vibration time to the search and rescue device through the TCP connection channel (612), and after the interval time H (613) Repeat the process of detecting field strength (611) and sending information (612); if the positioning device does not detect the search and rescue device signal, then repeat the sound and light call for help (609) to continue searching for the search and rescue device signal. The positioning server as the data receiver can also actively detect the link at regular intervals. If it does not receive the uploaded data or the link detection data packet from the positioning device over time S1, it will determine that the link is invalid and actively disconnect from the positioning device. Parameters S, K, R, G, H, S1 can be set according to the link conditions.

Claims (9)

1. An underground personnel positioning search and rescue system, comprising: a positioning server, a monitoring terminal, a wired communication subsystem, a wireless communication base station, a positioning device and a search and rescue device; the wired communication subsystem includes an optical fiber, an optical splitter and a wireless switch; the wireless communication base station includes Explosion-proof box, power supply, spare battery, wireless access equipment, antenna isolator and antenna; install a wireless communication base station at a certain distance underground, and connect the wireless communication base station to the wireless switch and positioning server on the well through optical fiber; the positioning device and the wireless communication base station pass through Wireless communication; the positioning device is used for positioning and human activity detection; the positioning device regularly sends the location, identity number and activity status information of the user to the positioning server; the positioning device communicates with the search and rescue device when the wired communication network and wireless communication base station fail The Ad hoc networking mode realizes wireless communication; the work of the search and rescue device includes the following steps: the processor of the search and rescue device controls the wireless communication module to realize automatic Ad hoc networking, accepts the wireless connection of the positioning device or the rescue device carried by the underground personnel, and assigns it IP address; receive the field strength information and ID number between the search and rescue device and the search and rescue device sent by the positioning device; calculate the distance from the positioning device according to the field strength information; display the distance of the positioning device, the ID number and the usage sensed by the positioning device through the display screen The time of the last activity of the victim; the sound and light indicate the distance between the search and rescue device and the trapped person, and emit sounds and lights with different frequency intervals according to the calculated distance; the search and rescue device and the positioning device send text messages to each other; upload search and rescue records. 2. The underground personnel positioning search and rescue system as claimed in claim 1, characterized in that: the positioning device is used to locate and detect the user's activity status, and in the case of normal communication with the positioning server, regularly sends the user's position information, identity number and activity status. 3. The underground personnel positioning search and rescue system as claimed in claim 1, characterized in that: when the positioning device fails to connect to the inherent wireless network for a period of time, it automatically connects to the Ad hoc network organized by the search and rescue device, and sends a field message to the search and rescue device. Strong information, identity number and the latest activity time information, so that the search and rescue system can obtain the location, identity number and activity status of the trapped person. 4. The underground personnel positioning search and rescue system according to claim 1, wherein the search and rescue device includes: a processor, a wireless communication component, a key, a memory, a display screen, an LED indicator light, a temperature sensor and a power supply circuit. 5. The underground personnel positioning search and rescue system according to claim 1, characterized in that: the search and rescue device receives the information sent by the positioning device, analyzes and obtains the field strength information and the identity number between the search and rescue devices, and displays it on the display screen. 6. The underground personnel positioning search and rescue system as claimed in claim 1 is characterized in that: the search and rescue device calculates the distance between the search and rescue device and the positioning device according to the field strength Rd sent back by the positioning device, and the formula is as follows: $\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; 10</span>}}^{\frac{\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; Rd</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; \&delta;</span>}}}{\mathrm{<span\; class="notranslate">\; 10</span>}\mathrm{<span\; class="notranslate">\; no</span>}}}$ In the formula, A is the power of the received signal when the signal propagates 1m away; n is the propagation factor, also known as the loss index, and its value depends on the propagation environment of the wireless signal; Rd is the signal strength of the wireless communication base station received by the positioning device, that is, the RSSI value; X _δ is a Gaussian normal random variable with zero mean. 7. The underground personnel positioning search and rescue system as claimed in claim 1, wherein the search and rescue device displays the distance of the positioning device, the ID number and the time of the latest vibration sensed by the positioning device through the LCD, thereby judging the current positioning device user activity status. 8. The underground personnel positioning search and rescue system as claimed in claim 1, characterized in that: the search and rescue device indicates the distance between the search and rescue device and the trapped personnel through sound and light, and sends out sounds and lights at different interval frequencies according to the calculated distance. The higher the near frequency. 9. The underground personnel positioning search and rescue system according to claim 1, wherein the search and rescue device uploads search and rescue records to the positioning server in a normal area of wireless network communication.