基于流向控制的消息传递协作定位算法OA

To address cooperative localization of mobile target nodes,a flow-direction controlled posterior linearized message passing is proposed using time of arrival(TOA)and Doppler frequency shift(DFS)measurements.First,a joint posterior distribution of position-velocity for all target nodes is constructed and the corresponding factor graph of the distribution is designed.Then,a posterior linearization method is applied to linearize the nonlinear measurement model.Subsequently,a node classification mechanism is proposed to control the direction of message passing in the factor graph,thereby suppressing the propagation of inaccurate messages and mitigating the resulting positioning errors and computational overhead.Finally,iterative mes-sage passing and belief updates are performed to estimate the positions and velocities of all target nodes.Simulation results show that,under a measurement noise level of 1,when the target nodes start moving from the first time instant,the probability that the position estimation error of the proposed algorithm is within 1.5 m reaches 95%,whereas those of the two benchmark algorithms are 62%and 20%,respectively.Meanwhile,the probability that the velocity estimation error of the proposed algorithm is within 0.2 m/s reaches 99%,compared with 72%and 84%for the two benchmark algorithms,respectively.In addition,the running time of the proposed algorithm is reduced by approximately 27%and 34%relative to the two benchmark algorithms,respectively.