Research On The Real-Time Secheduling And User Experience Of High-Reliability Construction Vehicles Bus System

Because of the character of the Construction Vehicles’workplace and working nature, the requests of security, reliability and real-time performance of the construction vehicles are extremely harsh. Adopting bus control technology and vehicle networked technology can effectively reduce vehicle wiring harness, enhance the speed of information transfer and the system reliability, as well as reduce the failure frequency of the construction vehicles. When the system scale increases bigger and bigger, the electronic control unit gets more and more, the CAN BUS self-characteristic and its problem during the process of node networked would cause the communication time-delay and data packet dropout in the Construction Vehicles System based on CAN Bus, even affect the real-time and reliability, result in the decrease of user experience. Against these existed problems, a research is studied on the real-time performance, the scheduling and the user experience of Construction Vehicles.Combining with the own characteristics of the vehicle, a suitable CAN BUS architecture is proposed, as well as the research and analysis on the Application Layer protocol-SAE J1939is done in this thesis. On the basis of this, the analysis of the system real-time performance is done, and two kinds of real-time solutions are proposed to improve the real-time performance of the Construction Vehicles network:the improved time-division scheduling solution and the dynamic priority promotion solution. Then, the improved time-division scheduling solution is selected and a time-division scheduling strategy based on master-slave structure is proposed, changing the multi-master structure system into Master-slave structure system. The global clock is imported to system, the improved average-loading algorithm is used to generate the schedule table. In the simulation environment CANoe, the simulation platform of the construction vehicle electronic equipment subnet is established, and the time-division scheduling strategy based on the master-slave structure is achieved on this simulation platform. At the last part, a discuss of how to improve the user experience under vehicle cab environment is done, based on the summarize of the current Construction Vehicles bus system.The results of the simulation on the CANoe environment demonstrate that the loa rate of the Construction Vehicles bus system is getting more balanced after adopted the scheduling strategy, and there is no data latency or packet losses. All this work improves the real-time performance and reliability of the Construction Vehicles Bus System.