Optimal allocation of risk probability based on improved PSO algorithm

Abstract

The continuity risk and integrity risk in the traditional advanced receiver autonomous integrity monitoring (ARAIM) algorithm are equally distributed to all visible satellites, which leads to a relatively conservative vertical protection level (VPL) calculation, and a method to optimize the allocation of risk probability based on the improved particle swarm algorithm is proposed. The improved particle swarm algorithm takes the risk probability allocation strategy as the particle of the algorithm, takes the weighted sum of the vertical protection level VPL as the adaptive function of the algorithm, improves the search capability of the algorithm through nonlinear dynamic adjustment of the inertia weights, and improves the convergence speed of the algorithm through adaptive adjustment of the learning factor, which enables the algorithm to globally perform a stochastic search within the given range to ensure that the algorithm can be more precisely track down the risk probability assignment method that optimizes the VPL value, thus achieving the purpose of improving the availability of ARAIM system. The experimental results show that the proposed method is able to optimize the calculation of VPL and improve the availability of the ARAIM algorithm in both single and dual systems for integrity monitoring.