传统接收机自主完好性监测(Receiver Autonomous Integrity Monitoring,RAIM)算法采用完好性风险最小准则确定判决门限,其过于保守的门限求解方式增加了航空用户的连续性风险。针对不同航空用户完好性需求的差异,提出了一种基于最小总风险代价函数的RAIM门限优化算法,以假设检验中漏检与误警概率之和作为总风险代价函数,在兼顾导航所需性能及RAIM可用性的前提下,最小化总风险代价函数,以此确定RAIM优化门限,实现完好性与连续性风险间的权衡。仿真结果表明,经过最小总风险代价函数权衡,可合理降低用户连续性风险,并使其具备在伪距域中判定RAIM可用性的能力。
Traditional Receiver Autonomous Integrity Monitoring( RAIM) algorithm uses integrity risk minimum criterion to determine the threshold,the threshold solving method is too conservative and may increase the risk of the continuity to aviation users. In view of the differences between the aviation users' integrity requirements,a RAIM threshold optimization algorithm based on minimum total risk cost function is proposed. Taking the sum of false alarm probability and missed detection probability in hypothesis test as the total risk cost function,on the premise of ensuring RNP and RAIM availability,the total risk cost function is minimized to determine the RAIM optimize threshold and achieve the trade-off between integrity and continuity. The simulation results show that after the minimum total risk cost function trade-off,the continuity risks of users can be reasonably reduced,and the RAIM availability can be judged in the pseudorange domain.