Heterogeneous Safety-critical Computer Design Based On VxWorks And QNX Real-time Operating Systems

The rail transportation operation control system is a safety-critical system that guarantees the safe operation of trains.As the key component of the safety-critical system,the safety-critical computer can guarantee the system-oriented safety state in the event of a system failure.At present,safety-critical computer commonly adopts the homogeneous hardware and operating systems,and there are still safety risks in the face of common cause failure.Therefore,it is of great theoretical significance and application value to study the design method of heterogeneous safety-critical computer(HSC).In this thesis,firstly,based on the analysis of the effect of common cause failure on the reliability and safety of homogeneous safety-critical computer,a general design scheme of safety-critical computer with heterogeneous software and hardware is proposed.The theoretical analysis of the reliability of the proposed scheme is carried out simultaneously.Then,the hardware platform of the HSC is built,and the device driver based on two real-time operating systems is developed.On this basis,the design method of the HSC platform software is researched emphatically and the platform software is completed based on VxWorks and QNX respectively.Finally,testing of the HSC is carried out.Research work of this thesis focuses on the following:(1)The structure and operation mechanism of homogeneous 2oo3 safety-critical computer platform are given.The reliability and safety model of the homogeneous safety-critical computer with common cause failure are established based on Markov process.Moreover,the effect of common cause failure on the reliability and safety of the homogeneous safety-critical computer platform is analyzed.(2)Drawing on the design experience of homogeneous 2oo3 safety-critical computer,a general design scheme of HSC is proposed.On the basis,the reliability model of the HSC under special maintenance strategy is established.High reliability of the HSC is proved by comparing with homogeneous safety-critical computer platform.(3)Based on the existing hardware in the laboratory,the hardware platform of the HSC is built.Aiming at the interface requirement of the HSC,the hardware interface design is completed by using programmable logic resources,and the device driver software of the corresponding interface is developed based on VxWorks and QNX real-time operating systems.(4)On the basis of the established HSC hardware platform,the design technology of the HSC platform software is mainly studied,including key technologies such as inter-system synchronization,data voting and inter-system communication.Besides,the platform software is developed based on VxWorks and QNX real-time operating systems.(5)The simulation testing environment is built,the synchronization,voting and other functions of the HSC are tested,and satisfactory test results are achieved.