Nowadays, radio frequency identification (RFID) technology has been widely used in logistics, warehousing, urban transportation, medicine, and other fields due to its advantages of fast identification speed, low cost, and high security. The multitag collision problem causes the reader to fail to complete the identification of the tags in its coverage in time, thus seriously affecting the work efficiency of the entire RFID system. Therefore, the study of an efficient multitag identification algorithm is the basic premise to ensure the industrial application of RFID. Aiming at the problems of the low slot utilization rate of the existing DFSA algorithm in a large-scale tag recognition environment, we proposed a dynamic frame slotting anticollision algorithm based on tags prefix grouping called G-DFSA. G-DFSA uses the tag prefix to recognize the tag set and constructs the probe frame based on the grouping. Then, the slot statistics results of the probe frame are used to process the frames whose frame length does not match the number of tags. As shown in the simulation results, the system efficiency of the proposed algorithm is still close to the theoretical optimal throughput rate of DFSA algorithm 0.368 in the large-scale tag set. Compared with the existing methods, G-DFSA has obvious advantages in system throughput.

Radio frequency identification technology by transmitting radio waves to the target area and attaching to the object battery-free RFID tags. It can accomplish the fast, timely, and accurate acquisition of the relevant data of the object without touching the identified object. In practical applications, there may be problems where products that have not been warehoused are missing, which we call missing unknown tag problem. The existing missing tag identification methods are not well suited to the scene, and the missing tag identification method containing unknown tags only takes into account the problem of known tags and unknown tags appearing in the same area, and cannot solve the problem of these missing unknown tags. Therefore, we propose a priority based strategy for missing unknown tag identification (PMUTI), which improves the identification process by means of the priority strategy. The method of sequential marking for unknown tags that have been missing is convenient for warehouse managers to make quick judgment and processing. The experimental results show that the PMUTI outperforms existing methods.

Time-delay chaotic systems with multiple positive Lyapunov exponents have been extensively studied in the field of information security. This paper proposes a new four-dimensional time-delay Lorenz system and its chaotic synchronization through the Lyapunov–Krasovskii theory. The sufficient conditions for the stability of the new chaotic system are obtained by the Routh–Hurwitz criterion, and the control parameters are found to have a significant impact on the speed of synchronous convergence. Furthermore, oscillation circuit simulation is essential for contributing the chaotic system to practical applications. Accordingly, the circuits of the chaotic time-delay system and its coupled synchronous control circuit are innovatively designed by Multisim. Experiment results illustrate the behaviors of various attractors in the new time-delay Lorenz system and the effectiveness of the proposed asymptotic synchronous method.