CN104833946B - Mine underground motor vehicles personnel are close to automatic sensing system - Google Patents

Abstract

The invention relates to an automatic sensing system for personnel approaching of underground motor vehicles for mines, comprising: a tag worn on the person, a base station, a server, a time synchronizer, a tag control module, and a vehicle control alarm module installed on the vehicle. The server is respectively connected to the time synchronizer, tag control module, vehicle control alarm module and each base station; the time synchronizer is connected to each base station through a cable, and the time synchronization between base stations is realized through a wired method; the tag control module transmits The server's control signal is sent to the tag. The base station collects the tag positioning information wirelessly, and sends the positioning information back to the server through the cable; the server performs tag position calculation and presentation, system self-inspection and equipment management, time synchronization control, alarm signal control and vehicle control. The invention realizes the quick detection of the position between the vehicle and the person, realizes the alarm at both ends of the vehicle and the person at the same time, and can realize fast parking.

Description

Automatic Perception System of Personnel Approaching in Mine Underground Motor Vehicles

technical field

The invention relates to a safety protection system, in particular to an automatic sensing system for personnel approaching of mine underground motor vehicles.

Background technique

Some large vehicles in coal mines, due to the position of the driver in the vehicle, determine that their vision is very poor, they cannot make effective observations, and they are easy to squeeze the surrounding staff; on the other hand, due to the working environment The noise/sight is not good, and the staff cannot effectively detect the arrival of the vehicle, and quickly avoid it.

In the existing technology, regardless of the use of RFID technology or radar technology, the working distance (not less than 100 meters) and two-way alarm cannot meet the needs, and it is easy to form dead angles of the antenna, resulting in missed readings. In the coal mine working face, due to the limitation of the working environment, environmental factors such as noise interference and poor line of sight also greatly affect the application of other technologies. At present, there is no better system that can solve this problem.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies in the prior art, to provide an automatic sensing system for the proximity of mine motor vehicles and personnel, which can realize the collision avoidance function by knowing the positional relationship between people and vehicles through wireless distance measurement and positioning.

According to the technical solution provided by the present invention, the described mine underground motor vehicle personnel approach automatic sensing system includes: a tag worn on the person, and a base station installed on the vehicle, a server, a time synchronizer, a tag control module and a vehicle control module. Alarm module, the server is respectively connected to the time synchronizer, label control module, vehicle control alarm module and each base station; The transmitted data channel sends the control signal of the server to the tag; the tag includes a wireless positioning module connected to the tag MCU, a wireless data transmission module, an alarm module, and a battery. The information is sent back to the server through cable; the server performs label position calculation and presentation, system self-inspection and equipment management, time synchronization control, alarm signal control and vehicle control, and the vehicle control alarm module receives the control signal from the server, and then outputs it to the actuator Alarm control signal or parking control signal.

In the server, according to the actual situation of the vehicle and the layout of the base station, a location database is first constructed. After the base station receives the tag data, the server starts to calculate the final location of each tag and presents it on the display screen in real time.

The alarm signal control and vehicle control functions of the server include:

1) Send the label alarm signal to the label through the label control module;

2) When someone enters the dangerous area, control the sound and light alarm;

3) When someone is very close, the vehicle stop function is activated. If the system is not detected to be safe, the system prohibits the vehicle from starting.

Specifically, the time synchronizer includes a sequentially connected communication interface, a time synchronizer MCU, a signal source, and an amplifier. The time synchronizer MCU first receives a control command from the server, determines whether to start the signal source, and generates a clock signal with a fixed frequency. Then amplify through the amplifier, output multiple synchronization signals, and transmit them to all base stations with cables; after the base station receives the signal, it will be shaped and processed, and then input to the wireless positioning module communicating with the tag to ensure that all base stations use the same time source, time After synchronization, the server can calculate the location.

The length of the connection cable between the time synchronizer and the base station is a fixed value, which can ensure that the time taken for the signal of the time synchronizer to be transmitted to the base station through the cable is equal.

The UWB module is used between the tag and the base station for data transmission and ranging and positioning functions. The tag control module receives the control signal from the server through the RS232 interface, and then sends it to the tag through the wireless data transmission module.

Divide 1 second into 500 time slots of 2 milliseconds. During these 2 milliseconds, the tag needs to complete a positioning operation with the base station; according to the location of the tag, dynamically adjust the number of time slots it works: when the tag When the tag is in the safe area, the positioning is completed once per second; when the tag is in the yellow warning area, the positioning is completed 3 times per second; when the tag is in the red warning area, the positioning is completed 7 times per second.

The advantages of the present invention are: the patent realizes the rapid detection of the position between the vehicle and the person, and realizes the alarm at both ends of the vehicle and the person at the same time, the vehicle can stop quickly, and the person can also quickly avoid through the alarm.

Description of drawings

Fig. 1 is a system structure block diagram of the present invention.

Figure 2 is a label structure diagram.

Fig. 3 is a structure diagram of a base station.

Fig. 4 is a functional block diagram of the server.

Figure 5 is a structural diagram of the tag control module.

Fig. 6 is a structural diagram of a time synchronizer.

Fig. 7 is a structural diagram of the vehicle control alarm module.

Figure 8 is a schematic diagram of TWR ranging.

Fig. 9 is a schematic diagram of data transmission in the present invention.

detailed description

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

As shown in FIG. 1 , the system of the present invention includes: a tag 1 , a base station 2 , a server 3 , a time synchronizer 4 , a tag control module 5 and a vehicle control alarm module 6 . The server 3 is respectively connected to the time synchronizer 4, the label control module 5, the vehicle control alarm module 6 and each base station 2; the time synchronizer 4 is connected to each base station 2 through a cable, and the time synchronization between the base stations 2 is realized in a wired manner; The control module 5 sends the control signal of the server 3 to the tag 1 through the data channel of the wireless data transmission.

The tag 1 includes a wireless positioning module connected to the tag MCU, a wireless data transmission module, an alarm module and a battery. Wireless positioning technology can adopt UWB (ultra-wideband) technology, CSS technology or high-precision WiFi technology. The following embodiments take UWB as an example, and the wireless data transmission technology uses 433MHz data transmission as an example.

The base station 2 collects the positioning information of the tag 1 wirelessly, and sends the positioning information back to the server 3 through a cable; the server 3 performs tag position calculation and presentation, system self-inspection and equipment management, time synchronization control, alarm signal control and vehicle control , the vehicle control alarm module 6 receives the control signal from the server 3, and then outputs an alarm control signal or a parking control signal to the actuator.

Each component is described below.

1. Tag 1 is a device worn by workers. Its main functions include: distance measurement and positioning, data transmission, and sound alarm.

As shown in Figure 2, the tag 1 includes: a UWB module connected to the tag MCU, a 433MHz data transmission module, a battery and an alarm module.

MCU (microcontroller) of the tag: implemented by the MCU of Cortex M3, it manages the work of the tag, mainly controlling UWB and data transmission functions;

UWB module: mainly to complete the function of distance measurement and positioning;

433MHz data transmission module: realize receiving data from server 3;

Battery: Powered by high-capacity lithium battery;

Alarm module: it is realized by a sound alarm device.

2. The base station 2 is a device installed on the vehicle. It mainly realizes the collection function of the location information of the tag 1, and transmits the location information to the server 3 through a cable.

As shown in FIG. 3 , the base station 2 includes: a UWB module connected to the MCU of the base station, and a LAN interface.

Base station MCU: realize the management and control of UWB, and forward the data output by UWB to the server through cable;

LAN interface: LAN wired interface, support 10/100M bps rate;

UWB module: Collect positioning data of tags.

The synchronization signal in the figure is only a time synchronization information from the time synchronizer 4 to ensure that the time of all base stations is consistent.

3. The server 3 is the core part of the system, mainly including four functional modules, as shown in Figure 4.

3.1 Position calculation and presentation.

When building the system, it is necessary to first build a location database according to the actual situation of the vehicle and the layout of the base station 2 . After the base station 2 receives the data of the tag 1, it starts to calculate, calculates the final position of each tag, and presents it on the display screen in real time.

3.2 Alarm function.

There are three main alarm functions:

1) Send the alarm signal of tag 1 to tag 1 through the tag control module 5;

2) When someone enters the dangerous area, control the sound and light alarm;

3) When someone is very close, the vehicle stop function is activated. If the system is not detected to be safe, the system prohibits the vehicle from starting.

3.3 System self-test and equipment management.

The system self-inspection is mainly to automatically detect whether all the equipment of the positioning system are working normally. If it is abnormal, the system will prompt an alarm, and decide whether to start the vehicle according to the alarm level;

Device management mainly manages/configures/upgrades all devices in the system.

3.4 Time synchronization control.

After the system starts and completes the self-test, the control time is started synchronously, and the positioning calculation is started.

4. The time synchronizer 4 implements time synchronization between the base stations 2 in a wired manner.

As shown in FIG. 6 , the time synchronizer 4 includes a serially connected RS232 communication interface, a time synchronizer MCU, a signal source and an amplifier. The time synchronizer 4 first receives the control command from the server 3, and decides whether to start the signal source. After the signal source is amplified by the amplifier, it outputs a plurality of synchronization signals, and transmits the synchronization signals to each base station 2 by wire.

The present invention adopts wired time synchronization, generates a fixed-frequency clock signal through a time signal generator, then amplifies it through an amplifier, and transmits it to all base stations with cables. The radio frequency module ensures that all base stations use the same time source, and position calculation can only be performed after time synchronization.

In order to make the system installation easier, in this system, the length of the cable between the time synchronizer and the base station is a fixed value to ensure that the time it takes for the signal of the time synchronizer to be transmitted to the base station through the cable is equal.

5. The tag control module 5 mainly sends the ranging coordination function of the server 3 to the tag 1, and realizes the sending function through the data channel of the wireless data transmission module.

As shown in Fig. 5, the tag control module 5 includes an RS232 interface connected to the MCU and a 433MHz data transmission module. The tag control module 5 is a wireless transmission control channel, which receives the control signal from the server 3 through the RS232 interface, and then sends it to the tag 1 through the 433MHz data transmission module.

6. The vehicle control alarm module 6 realizes the vehicle control function and the alarm control function. In an emergency, the server 3 sends out an alarm signal, and the vehicle control alarm module 6 realizes an audible and visual alarm. In an emergency, the parking function is realized.

As shown in Figure 7, the vehicle control alarm module 6 receives the control signal from the server 3 through the RS232 interface, and the MCU then outputs the control signal to the "alarm control" and "parking control" actuators.

In the present invention, the UWB module is used between the tag 1 and the base station 2 to perform data transmission and distance measurement and positioning functions. In this system, the IR-UWB ranging function is used to calculate the distance between the tag 1 and a specific base station 2. Since the IR-UWB uses a pulse method, the accuracy of the ranging is very high. TWR (Two way Range) method for distance measurement, the accuracy is within 10 cm, and the distance can exceed 100 meters. Ensure the availability of system applications.

For the method of TWR ranging, refer to FIG. 8 .

Electromagnetic wave flight time = (2T _RR -T _sp -2T _SR +T _RP +T _RF -T _SF )/4

Distance between two points = speed of light * electromagnetic wave flight time.

In this way, the error caused by the time processing at both ends of the distance measurement can be eliminated, and high-precision distance measurement can be achieved.

In the present invention, the fusion of TDoA and TWR ranging technologies is adopted. In the way of TDoA to achieve positioning, in order to obtain better positioning accuracy, the base station must be located around, and the tag must be located in the middle of the base station, so that the hyperbolic algorithm can be used to obtain the position of the tag. However, if TWR ranging is used to achieve positioning, the tag needs to complete ranging with all base stations, which takes a long time and the number of tags that the system can accommodate is limited. Through the fusion of these two technologies, through the transformation of time and distance, the limitations of various problems such as positioning accuracy/base station erection/number of tags are solved.

In this system, the data transmission adopts the wireless transmission mode of 433MHz to realize the function of issuing data and commands from the server 3 to the tag 1. The 433MHz data transmission module of tag 1 only needs to have a receiving function, and the tag control module 5 only needs to have a sending function, which simplifies the design of the system. If Tag 1 has any data to be uploaded, it can be directly uploaded in the positioning message through UWB. Refer to Figure 9 for specific implementation. That is, the data upload in the system adopts the UWB method, and the data downlink adopts the 433MHz digital transmission method, which greatly simplifies the complexity of the system design and improves the reliability of the system.

The specific implementation of the system will be described in two aspects as follows: system construction and positioning.

1. System construction is divided into system installation and system configuration.

There are two main aspects of system installation, one is the installation of equipment on the vehicle, and the other is the pairing of people and tag 1. Except label 1, all other equipment is installed on the vehicle.

Among the equipment installed on the vehicle, the base stations 2 need to be distributed around the vehicle according to the actual situation. If possible, it is better that all the base stations 2 are on the same plane.

System configuration includes:

1. Anchor configuration is mainly to configure the location of the base station, especially relative to the specific location of the vehicle, the calculation accuracy and location installation have a great correlation. The other is the configuration of network parameters.

2. Label configuration is mainly to associate with people and establish a one-to-one correspondence.

3. System alarm area configuration, configure the alarm area according to the needs, the system can configure multiple levels, at least with "non-alert area" / "yellow alarm area" / "red alarm area". Define these areas. When label 1 is in a different area, the strategy needs to be adjusted dynamically.

2. The system positioning process is as follows:

1 System self-test.

After the system is powered on, the system starts self-test. The system self-check mainly includes the following aspects:

1) Server 3 system software self-test, configuration confirmation is normal;

2) Whether the self-check of the base station is normal, open the heartbeat and establish an association with the server;

3) Server 2 sends a time synchronization command to time synchronizer 4;

2 Passenger and vehicle position detection and vehicle start.

After the time synchronization of the system is enabled, the position of tag 1 can be detected by the base station, but server 2 needs to allocate time slots through the tag control module 5 to determine the working time slot and working frequency of each tag. The server then calculates the position of each tag relative to the vehicle.

If someone is found staying in the red warning area, the vehicle will not be able to start unless the person leaves the red warning area. When the system confirms that it is safe, the indicator light will show that the vehicle can be started.

3 system dynamic positioning.

In the subsequent normal operation stage of the system, the tag 1 sends a positioning and ranging message to the base station 2, the server calculates the position of the tag 1, and dynamically adjusts the working frequency and time slot of the tag 1 through the tag control module 5. When encountering an emergency, the server sends an alarm through the vehicle control alarm module 6, including: the three-color light alarm on the body, and the buzzer alarm on label 1; when the alarm is found to be invalid, the system needs to use the vehicle control alarm module 6 Automatic parking.

Some implementation details of the system are described and analyzed below.

1. Wired time synchronization.

Due to the limitations of the system, the base stations are arranged around the car, and no base station can achieve wireless visibility to all base stations (there are obstacles in the middle), so the wired time synchronization method is adopted to ensure that the time synchronization accuracy between base stations is higher than 0.01ns . This will only bring a very small distance error, which meets the requirements of the system accuracy.

2. High precision.

In this system, the positioning accuracy can reach within 0.3 meters. High precision is mainly guaranteed by the following technologies:

1) High-precision wired time synchronization, the system wired time synchronization accuracy reaches 0.01 ns, and the converted distance is 3 mm;

2) High-precision distance measurement, using TWR method for distance measurement, the distance measurement accuracy reaches 3 cm (10,000 times of distance measurement, standard deviation is 2.5 cm)

3) Algorithm guarantee. In the system, multiple filtering is used to ensure more accurate positioning data.

However, due to the wireless positioning, it will be affected by some environments, such as the occlusion of the human body, which will reduce the positioning accuracy of the system. The overall positioning accuracy is 0.3 meters.

3. Time division scheduling.

In this system, the concept of TD (time division) is introduced, and 1 second is divided into 500 time slots, each time slot is 2 milliseconds, within these 2 milliseconds, tag 1 needs to complete a positioning operation with the base station. At the same time, according to the position of the label, the number of time gaps for its work is dynamically adjusted. When it is in the safe area, it completes 1 positioning per second; when the tag is in the yellow warning area, it completes 3 positionings per second; when it is in the red warning area, it completes 7 positionings per second.

Through time-division scheduling, the capacity of the system is guaranteed, and at the same time, the safety of the tag wearers is also guaranteed.

4. High capacity.

In this system, the capacity of the system label can reach 256 (of course, no more than 20% enter the yellow alarm area, and no more than 10% enter the red alarm area). The high capacity is mainly guaranteed by the above technologies:

1) Time division scheduling;

2) Integration of TDoA and TWR positioning technology.

5. Low cost and high reliability.

In this system, the system is implemented with an extremely simple single-chip solution. Compared with radar and other technologies, the system cost is lower, and there is no dead angle in system coverage.

Claims (5)

1. The personnel approach automatic sensing system for underground motor vehicles in mines is characterized by: a tag (1) worn on the personnel, a base station (2), a server (3), and a time synchronizer (4) installed on the vehicle ), the tag control module (5) and the vehicle control alarm module (6), the server (3) is respectively connected to the time synchronizer (4), the tag control module (5), the vehicle control alarm module (6) and each base station ( 2); the time synchronizer (4) connects each base station (2) through a cable, and realizes the time synchronization between the base stations (2) through a wired method; the label control module (5) connects the server (3) to the server (3) through the data channel of wireless data transmission The control signal is sent to the tag (1); the tag (1) includes a wireless positioning module connected to the tag MCU, a wireless data transmission module, an alarm module and a battery, and the base station (2) collects tags (1) through wireless Positioning information, and send the positioning information back to the server (3) via cable; the server (3) performs label position calculation and presentation, system self-inspection and equipment management, time synchronization control, alarm signal control and vehicle control, vehicle control alarm module (6) Receive the control signal from the server (3), and then output the alarm control signal or parking control signal to the actuator; In the server (3), according to the actual situation of the vehicle and the layout of the base station (2), the location database is constructed first, and after the base station (2) receives the data of the tag (1), the server (3) starts to calculate the The final position of the vehicle is displayed on the display screen in real time; The alarm signal control and vehicle control functions of the server (3) include: 1) Send the label alarm signal to the label (1) through the label control module (5); 2) When someone enters the dangerous area, control the sound and light alarm; 3) When someone is very close, the vehicle stop function is activated, and the system prohibits the vehicle from starting if the system is not detected to be safe; The time synchronizer (4) includes a sequentially connected communication interface, time synchronizer MCU, signal source and amplifier. The time synchronizer MCU first receives a control command from the server (3), decides whether to start the signal source, and generates a fixed frequency The clock signal is then amplified by the amplifier to output multiple synchronous signals, which are transmitted to all base stations (2) by cables; after the base station (2) receives the signal, it is shaped and processed, and then input to the wireless positioning device communicating with the tag (1) The module ensures that all base stations use the same time source, and the server (3) can perform position calculation only after the time is synchronized. 2. The automatic sensing system for personnel approaching of mine underground motor vehicles according to claim 1, characterized in that the length of the connecting cable between the time synchronizer (4) and the base station (2) is a fixed value. 3. The automatic sensing system for personnel approaching of mine underground motor vehicles according to claim 1, characterized in that, the UWB module is used between the tag (1) and the base station (2) for data transmission and distance measurement and positioning functions. 4. The automatic sensing system for personnel approaching of mine underground motor vehicles according to claim 1, characterized in that, the tag control module (5) receives the control signal from the server (3) through the RS232 interface, and then transmits the control signal through wireless data transmission Module sends to tag (1). 5. The automatic sensing system for personnel approaching of mine underground motor vehicles according to claim 1, characterized in that 1 second is divided into 500 time slots of 2 milliseconds, and within these 2 milliseconds, the tag (1) needs to Complete a positioning operation with the base station (2); dynamically adjust the number of time slots for its work according to the different positions of the tag (1): when the tag (1) is in a safe area, complete one positioning per second; when When the tag (1) is in the yellow warning area, the positioning is completed 3 times per second; when the tag (1) is in the red warning area, the positioning is completed 7 times per second.