Tunnel personnel location system

Introduction of Positioning System

Brief Introduction of Technological Advancement

UWBLOC positioning system uses a technology based on UWB carrier-free communication principle to achieve positioning. UWBLOC technology uses nanosecond to microsecond non-sinusoidal narrow pulse to transmit data. By transmitting very low power signals over a wide spectrum, UWBLOC can achieve data transmission rates ranging from hundreds of Mbit/s to several Gbit/s in a range of about 300 meters.

UWBLOC technology has strong anti-jamming performance, high transmission rate, large system capacity and very small transmission power. UWBLOC system transmits very small power, communication equipment can be used less than 1 mW transmission power to achieve communication. Low transmitting power greatly prolongs the working time of power supply. Moreover, the effect of electromagnetic radiation on human body will be very small if the transmitting power is small

The Location System can achieve the highest positioning accuracy of 10 cm, millisecond delay real-time display of personnel position.

UWBLOC signals almost do not interfere with wireless devices operating at the same frequency. UWBLOC signals have very strong penetration ability and can be positioned accurately in indoor and underground space, such as tunnels and pipelines, while GPS positioning system can only work within the visual range of GPS positioning satellites. Unlike GPS providing absolute geographical position, UWBLOC pulse positioner can give relative position. In addition, UWBLOC wireless locator is cheaper.

 Positioning principle

As shown in the following figure, the UWBLOC base station needs to be installed on the tunnel wall. The staff wears the UWBLOC tag. The tag is an active beacon. The tag sends a signal pulse in every second. The base station receives the signal pulse. The distance between the tag and the base station can be calculated by the time when the pulse reaches the base station. At last, the real-time position of the staff can be obtained through complex signal processing.

It should be noted that the antenna of the signal base station should be far away from the metal occlusion object, because the metal object will reflect the pulse signal, which will lead to the signal loss when the base station can not receive the signal pulse from the label, thus leading to the failure of location.

When installing a base station, it is necessary to determine the distance between each base station and the entrance, so as to calculate the distance between the personnel and the entrance accurately.

System Topology Diagram

Cable transmission mode is a communication scheme designed for long distance tunnel. Base stations are connected by transceivers. Transceivers transmit data to the server of the tunnel monitoring center through optical fibers. The location coordinates of each location beacon are obtained by real-time operation of the personnel location engine software installed on the server. Managers can view the real-time position of the personnel through the display, and can also transfer the data of all base stations to the positioning engine server of the monitoring center. The information such as the name of the staff member, duty, the time of entry and exit of the tunnel are displayed on the LED display screen at the tunnel entrance.

UWBLOC pulse wireless communication is used between beacon and base station. The staff can wear the beacon on their hands or fix it on the safety helmet.

Basic function introduction

1. Locate the location information of each person accurately and display the information on the electronic map of the monitoring center.

2. Automatic attendance statistics function can automatically record the names ,position and the time of entering and display these information on the large LED screen in the monitoring center.

3. Track playback function, the system supports querying the movement track of any person in a certain period of time, and can look back at the last stop position of each person in the event of a safety accident.

Power supply for the base station

UWBLOC base station support standard POE power supply.

POE power supply is shown in the picture below:

Power supply for the location label

As shown in the picture below, the positioning label is powered by lithium batteries. If the lithium batteries are running down, the label will flash the red light to remind you that the lable need to be charged, and it can be charged by the USB data line. Usually it can be fully charged within 2 hours and the green light will be on when it is fully charged.

Installation for the base station

The installation height of the positioning base station should be as high as possible, and away from occlusion, and the distance between the two base stations should not be greater than 300 meters (100 meter for this project). This is to ensure that the location label can communicate with at least two base stations at the same time in order to locate.

Base station antennas need to be installed vertically and downwards.

During installation, the coordinates of each base station should be determined, and the tunnel portal should be used as the origin.

Base station specification

Location label specification