Application And Improvement Of Control Area Network In Control And Mornitoring System

With the demand for networking and intellectualization growing gradually in modern industry, the application range of field continuously extends. As a kind of fieldbus, controller area network(CAN) has high real-time ability and dependability, consequently has a wide range of usage. The thesis mainly discusses aspects of the design and improvement in CAN bus application, under the background of networked control and industrial monitor.Aiming at TTCAN applied to networked control system, considering the effect of sampling period and delay to system performance, constraint condition of control loop delay in bus scheduling is proposed. Genetic algorithm is used to design the scheduling optimization algorithm with delay constraint, and feasibility is verified by simulation. For improvement of aperiodic messages in TTCAN, dynamic centralized scheduling strategy is designed to increase the flexibility, so that aperiodic messages gain maximal arbitration time. Then revised EDF encoding algorithm is designed considering the form of TTCAN matrix cycle, using limited encoding bits to ensure real-time ability to the best and fairness as well. Stateflow toolbox is used to build model of CAN bus, and the above content is verified by real-time simulation under the model. Aiming at CAN applied to industry monitor system, the thought of multi-path parallel CAN is proposed, according to principle of rate matching and method of multilevel communication transforming, hardware design is executed to improve the speed of data collection substantially. Experiment platform is set up to verify the hardware design.