Research On Synchronization And Safe Design For Real-time Ethernet Bus Control System

As an important type of industrial control system,bus control system has been widely and deeply applied in the field of military and civilian manufacturing equipment.Bus control system based on real-time Ethernet communication link has become the mainstream of industrial control system.However,there are few researches on the performance of such systems in China,and there are still some gaps compared with foreign countries.With the increasing requirements of high-performance equipment on response speed,control accuracy and safety,it is urgent to break through the core technologies such as system task scheduling multi-node high-precision synchronization and bus communication security in real-time Ethernet distributed architecture.These core technologies involve many factors such as task time management,communication and protocol transformation,safe function design.How to comprehensively consider these internal factors and improve the real-time,synchronicity,safety and security is the main problem faced by the system.This paper will research on these technical problems.The research work of this paper mainly includes the following aspects:1.According to the development status of industrial control system,the distributed system architecture based on real-time Ethernet bus is carried on the overall discussion.The design scheme for real-time Ethernet bus control system based on typical master-slave architecture is presented.The design methods for each functional module in system are described in detail.The key performance indicators,such as real-time,synchronicity,safety and security of the system,are clarified.It could provide reference and basis for the follow-up research on the key problems of the system.2.Real-time performance of bus control system is the main problem in the field of high-end equipment control.In this paper,the effects of data transmission between master and slaves,multi-task execution time and task delay on the real-time performance of system are analyzed,and the task scheduling and the design of the real-time communication module are researched.For task scheduling,a task scheduling method for real-time Ethernet bus control system is proposed.This method could establish the time relationship among tasks in each control loop and make the control period reduced to a range of hundreds of microseconds.In terms of real-time communication,the real-time communication module in master could make the minimal communication period of system down to 125 microseconds.It could lay a foundation for further research on the high-speed and high-precision synchronization control and safety of system.3.Synchronization performance is an important technical index restricting the improvement of multi-axis linkage control performance.For the field of high-performance equipment control,this paper analyzes the main reasons that affect the performance of system synchronization,and proposes a system synchronization method based on real-time Ethernet which conforms to CANopen protocol.This method considers comprehensively influence of bus communication,protocol transformation and task scheduling on synchronization performance.Based on this method,the minimum synchronization error of the control signals in slaves could reach 100 nanoseconds.The proposed method can be directly applied to multi-node high precision collaborative control of real-time Ethernet bus control system.4.Open bus architecture makes the system vulnerable to information security threats such as illegal network attacks.The communication uncertainty will directly affect the stability of data interaction between master and all slaves.This paper analyzes the main factors that affect the safe communication of the system,and combines SESAMO modeling method to design safe building blocks such as master-slave authentication,communication encryption and data verification,and forms a safe-COE communication architecture that takes into account both safety and security.This architecture can provide a complete solution for the communication security design of distributed system.5.In order to verify the validity of the work in paper,this paper tests the real-time performance and synchronous performance of the system on the established experimental system,and uses formal modeling method to model,simulate and verify the safe communication architecture for this system.The experiment show that,by using the methods of task optimization scheduling,peripheral high-precision synchronous control and safe integration design proposed in this paper,the system has excellent performance in real-time,synchronicity and safety.