Optimization Research On Real-time Performance Of Networked Control System In Car Based On CAN Bus

With the rapid development of the modern automobile, the control mechanismsbecome more and more complex. The traditional way of making electric vehiclesincreased body harness, circuit complexity, the failure rate, and smaller space that acar can be used. Use of the car field bus technology, a body control LAN, andelectrical equipment on the body of distributed control and management of a small carwiring harness can be simply the number of working to improve the system reliabilityand stability. Therefore, the body of network technology for automotive electronicshot content.This paper based on CAN bus automotive network control system, and some keytechnologies are studied. The main research work contains the following.(1) Analysised the automotive network control system development process,technology and application characteristics, Focuseed on the reliability issues of CANbus, and proposed solution strategy.(2) Designed a vehicle control network with a high/low speed CAN bus,implemented the network hardware and software, completed the experimentalplatform. The system’s high-speed network contains a motor control unit, anti-lockbrake unit and power steering unit. The low-speed networks have body controlsubsystem.(3) Proposed a set of network optimization program. Time-triggered technologiesand distributed priority queue with dynamic adjustment is combined in the hybridscheduling algorithm.(4) Established a CAN control network model for real-time analysis andassessment. From the theoretical analysis and experimental verification of theoptimized test both the effectiveness of the program.The basic idea of this hybrid scheduling algorithm is to use a matrix based ontime-triggered bus cycle scheduler management tasks on the packet transmission.With the measures, not only solved the problem of standard CAN protocol in heavynetwork load lower priority message’s infinite delay, but also overcomed theTTCAN’s static scheduling table can not adapt to changes in network parameters, andthe dynamic priority periodic data transmission technology can not guarantee thatdefects in real time. Experimental results show that, on real-time optimization of network efficiency,this paper shows more than10%better compared with the separate TTCANtechnology or dynamic priority technology.