Research Of Real Time Scheduling Based On The CAN Bus Control Network

Information scheduling in the network control system is mainly related to two areas,namely, control theory and network communication technology. So in order to improve theperformance of networked control system, we can design the control algorithm and thenetwork data scheduling method. Because different nodes of the network informationtransmission right is obtained through the competition for the network access, therefore, thispaper proposes a dynamic hybrid scheduling algorithm to manage information of CAN busnetwork control system. And we design the simulation platform to make the simulationanalysis for the algorithm.This paper firstly describes the message scheduling of networked control systemsconcepts, analyzes the static and dynamic scheduling algorithms and their respectiveadvantages and disadvantages. Then we introduce how to use the TrueTime toolbox, and it isa foundation for the network control system scheduling simulation.Secondly, we study thoroughly the CAN bus in the dynamic scheduling problem, and weuse a detailed analysis for the advantages and disadvantages of the random early discard EDFscheduling algorithms. Based on control and scheduling co-design perspective with theshortcomings of EDF, we puts forward an improved EDF scheduling algorithm, and we useTrueTime simulation software to build simulation model, designing the scheduler, bysimulation results verifying the improved algorithm in reducing delay in terms ofeffectiveness.Finally we introduce the dynamic hybrid scheduling algorithm, under the bandwidthconstrained networks in the presence of emergency information, periodic and nonperiodiccontrol information, analysis and compare the advantages and disadvantages for random ofearly discard scheduling algorithm (EDF)and the cubic function algorithms(RED). In theinformation scheduling process, we want to assure the QOS and QOP respective performancerequirements. Then we combine two kinds of different scheduling strategies together toachieve a dynamic scheduling strategy. Classifying the information waiting to send is thealgorithm, and each kind of information corresponds to different queue, queue managementusing improved RED algorithm, queue internal cycle data using dynamic EDF schedulingalgorithm, nonperiodic data using a static RM scheduling algorithm. By using the QOSscheduler for closed-loop dynamic scheduling, under the simulation results verify that thedynamic hybrid scheduling algorithm that can satisfy the control loop performancerequirements, we guarantee the broadband utilization rate, reducing the data loss, ensuringthat the different types of information in real time, thus improving the overall performance ofnetwork control system.