基于完好性与连续性风险的最优垂直保护门限计算

Calculation of Optimal Vertical Protection Level Based on Integrity Risk and Continuity Risk

为降低飞行器精密垂直引导进近过程中的完好性风险和连续性风险,使接收机自主完好性监测(RAIM)算法能提供水平方向和垂直方向上的完好性保障,提出一种基于多假设解分离的RAIM算法来求解最优垂直保护门限(VPL)。在满足全球导航卫星系统(GNSS)完好性和连续性的前提下,优化GNSS系统对各假设故障模式的完好性风险和连续性风险分配,得到最优VPL。仿真结果表明,与传统基于斜率的RAIM算法相比,该算法能够提供更精确的VPL值,提高了系统可用性,并且随着卫星故障先验概率不断增大仍具有较好的鲁棒性。

In order to reduce the integrity risks and continuity risks in the process of precision vertical guidance of aircraft,and make the Receiver Autonomous Integrity Monitoring （RAIM） algorithm provide the horizontal and vertical integrity for security,this paper proposes a Multiple Hypothesis Separation Solution （MHSS）-based RAIM algorithm to solve Vertical Protection Level（VPL）.The algorithm is based on the premise that the integrity and continuity of the Global NAvigation Satellite System （GNSS） can be met,and the optimal Vertical Protection Level（VPL） is obtained by optimizing the allocation of the integrity budgets and the continuity risks in each hypothesis failure mode.Simulation results show that the proposed algorithm can provide a more accurate VPL value and increase the availability of the system compared with the traditional slope-based RAIM algorithm.It also has good robustness with the increasing prior probability of satellite failure.