Improved design and Implementation of Personal Location Beacon
Mi Liao1, Guigen Nie1,2, Jing Zhao1, and Xi He1
1 GNSS Research Center, Wuhan University, Wuhan, China
2 Luojia Laboratory, Wuhan, China
Email: miliao@whu.edu.cn
This letter improves the Personal Location Beacon( PLB), designs and implements a prototype personal maritime emergency radio beacon. Unlike the existing PLB, it is compatible with the traditional global search and rescue system( COSPAS-SARSAT) and BeiDou search and rescue system, the vital signs of people monitoring and reporting functions. After the PLB transmits distress information, the Beidou receiver works. The Beidou receiver receives information from the Rescue Centre and controls whether the PLB transmits the distress information again, reducing unnecessary emissions, thereby reducing the average power consumption of the PLB and extending the working time of the PLB. Measurements show that the current is 79mA in the state of receiving Beidou information, and the 7000mAh 7.4 V lithium battery can send distress messages to COSPAS Rescue Centre and Beidou Rescue Centre 200 times each, and the distress message contains the vital signs of people in distress. The vital sign is the temperature information. Ideally, the 7000mAh 7.4V lithium battery can support the continuous working time of the market for 48 hours.
Introduction:Cospas-Sarsat is a satellite-based positioning system that provides accurate position information data for persons in distress to national search-and-rescue (SAR) authorities[1]. The distress radio for personal use called PLBs( Personal Locator Beacons)[2]. Currently, it is the most successful nonprofit satellite search and rescue system[3]. But it also have limitations. Literature [4] presented the shortage of the COSPAS-SARSAT satellite system. LEOSAR space segment became an ageing component leading to a reduced number of satellites having a SAR payload on-board, and it dose not cover the earth poles. This causes latency in the broadcast of distress beacon information that could reach up to four hours for beacons located near the equator. Therefore, some countries are now considering real-time retransmission of beacon signals using geostationary satellites to eliminate satellite waiting delays [5].
Short Message Communication (SMC) is one of the most feature services of BeiDou Navigation Satellite System (BDS)[6], which is unique from other global navigation satellite system(GNSS). Search and rescue(SAR) service is one of the major services provided by BDS-3 system[7]. Literature [8] applied integrated BDS and GPS navigation system’s precision positioning and SMS( Short Message Service) communication technology to vessel, and solve the problem of vessel navigation, positioning, remote monitoring and commanding. In order to solve the problems of not getting information in time, poor command and incompletely progress while carrying out rescue operations in complex urban environment or wild environment, literature [9] implemented a emergency rescue system by using 5G and BDS. Literature [10] designed a system in dam safety monitoring based on BDS. The above research enrich the application of BDS SMC SAR technology. The joint application of BDS SAR system and COSPAS SAR system can make full use of the advantage of COSPAS SAR system and make up for the shortcomings of COSPAS SAR system. At the same time, human vital signs monitoring is used for personal sea rescue market and transmitted to the monitoring centre through the BDS SMC, which helps the command centre to better control the search, rescue, classification and transfer of people in distress.
Proposed PLB: As shown in Fig. 1, this letter introduces an improved of PLB. It consists of the ultra low standby power circle (which consists of manual switch, water touch switch, reset circuit and switching circuit ), the DC-DC converter, the power, the STM32F413 controller, the BeiDou RDSS module, the RDSS antenna, the COSPAS-SARSAT transmitter( which consist of DDS module, LNA and PA), the 406MHz antenna, the GNSS receiver( which consist of the location system, the time synchronization system and the MEMS system), the GNSS antenna, the life detect sensor, the LEDs, the OLED, the SD card module and the cancel button.