基于运行时验证的无人飞行系统安全威胁检测方法

摘要

无人飞行系统(unmanned aerial system,简称UAS)的软、硬件存在缺陷以及遇到外部恶意攻击,会给UAS的安全性带来极大的威胁.由于UAS的运行环境复杂多变,很多因素在开发过程中难以准确预测,因此,研究有效的运行时安全保证机制具有重要意义.提出了一种基于运行时验证的UAS安全威胁检测方法.首先,对UAS可能遇到的多种安全威胁进行分析,并采用离散时间时序逻辑进行描述,提出相应的UAS-DL语言描述安全监控规约;然后,基于交错自动机提出了自动生成安全威胁监控器的算法,并利用参数化方法实现对多UAS的安全监控.为了提高检测的准确性,进一步研究了将运行时验证和贝叶斯网络推断相结合的方法.采用实际的UAS开发仿真平台Ardupilot进行了实验,并设计了将监控器独立部署在FPGA硬件上的方法,以避免对UAS计算资源的过多占用.实验结果表明,上述方法能够有效地检测UAS的安全威胁.%The defects of the software and hardware in unmanned aerial system and external malicious attack pose a great threat to the security and safety of UAS.Due to the complex running environment of UAS,many factors are difficult to predict accurately in the development process.Therefore,it is of great significance to adopt an effective runtime security and safety guarantee mechanism.This paper proposes a UAS security and safety threat detection method based on runtime verification.Firstly,after analyzing a variety of security and safety threats that UAS may encounter,the paper defines the threats in discrete-time MTL and presents the corresponding UAS-DL language to describe the security and safety monitoring specification.Then an automatic generation algorithm of security and safety threat monitor is introduced based on the alternating automaton,and security and safety monitoring of multi-UAS is implemented by parameterization method.In order to improve the accuracy of the detection,the method of combining runtime verification with Bayesian network inference is also studied.The experiment is carried out with the actual UAS development simulation platform Ardupilot,and monitors are deployed on the field-programmable gate array (FPGA) hardware independently to avoid excessive usage of UAS computing resources.Experimental results show that the proposed method can effectively detect the security and safety threats of UAS.