SUMMARY
This paper proposes the localization of unknown nodes based on the centroid iteration algorithm. It uses the range-free localization method and proposes the iteration stopping criterion for centroid iteration algorithm and node localization flow chart according to the location of the unknown nodes based on the plane enclosed by N beacon nodes and those where the received signals of the unknown node are gradually weakened, and finally achieves the accurate localization of unknown communication nodes. Simulation results show that with the proportion of beacon nodes increasing, the relative error of calculation is gradually reduced; when the proportion of beacon nodes remains the same, with the radio range of the node increasing, the relative error of localization gradually decreases. When the radio range is small (R=15m, R=20m), with the proportion of beacon nodes increasing, the relative error of localization increases instead of decreasing. Compared with other three traditional centroid localization algorithms, the algorithm proposed in this paper can achieve the minimum relative localization error at different radio ranges. Under this algorithm, the localization is accurate and highly resistant to RSSI errors. Calculation results show that the optimal radio range R = 30m.