Design Of The Key Personnel Monitoring System Based On Smart Tags

In today’s increasingly vital social problems, there are a lot of lonely elderly in need ofcare in the nursing home, a large number of new-born infants in need of medical care in thehospitals, and moreover, the criminals in need of real-time supervision in the prisons. Thesethree urgent problems can be attributed to one type, which is the supervision of key personnel.The traditional way of supervising by hiring a lot of caregivers, is money-consuming as wellas energy-consuming, moreover, it cannot guarantee to be real-time and accuracy. Thus, it isurgent that we should look for a new type of monitoring.This paper focused on the issue of the key personnel monitoring by building a complexsystem combined by both hardware and software. For the hardware part, a dual-band RFIDsmart tags was designed as a tool, while for the software part, RSSI-based the LANDMARCpositioning algorithms and regional localization algorithm were implemented. The papermainly discussed the following six categories: dual-band smart tags design, the LANDMARCpositioning algorithm research and improvement, acquisition and improvement of thereceived signal strength, regional positioning algorithm and its algorithm expansion theory,the smart tag anti-collision design and smart tags low-power design, and PC software design.By building a monitoring system based on dual-band smart tags, the system accomplishedlocalization for key personnel, vital signs monitoring, real-time management, falling-off alarmand other functions. Compared with the traditional single-frequency electronic tags, dual-bandsmart tags have temperature detection feature and MEMS accelerometer detection function.Thus, it can be worn on the person to be monitored to detect of vital signs and state of motion,and transferred the basic information the tag number, real-time signs of life via radiofrequency communication. More importantly, the dual-band smart tags have twonon-interfering communication band, which could combine two separate bands and twodifferent localization algorithms to achieve the grading positioning. The first-class regionallocation positioning uses position estimation algorithm positioning process without ranging. Itcan only be estimated to be positioned personnel area to narrow the scope of positioning, andlays the foundation for the second-level positioning.On the other hand, the second-level positioning uses RSSI-based the LANDMARCpositioning algorithm. This algorithm is accurate in ranging and is directly achieved withinthe raging results area, which can reduce the traverse scan time and improve the positioningefficiency. In addition, the system conducted a multiplex frequency division method to avoid collision, and solved the collision problem of a reader recognize multiple dual-band smarttags at the same time. The smart tags low-power design was achieved and verified byoptimizing the tags control chip and RF chip operating modes working processes. Finally, atest of the system performance and PC terminal function is conducted.The analysis results showed that the number of pins that can be accommodated by thepresent system is more than200. In the interior open environment, the positioning accuracy ofthe system can reach1m, if the indoor environment is complex with more obstacles, thepositioning accuracy will decrease, but can still remain within2meters with the temperaturemeasurement accuracy up to0.1degrees Celsius, the accelerometer test results being obvious;PC software module working normally to ensure personnel management and localizationfunctions. The above researches indicate that key personnel monitoring system based on thesmart tag proposed in this paper has a theoretical guidance and practical value.