| New energy vehicles attract people’s more and more attention.For the new energy vehicles using electromotor as power device,the EMI test is significant.With the current EMI detection technology and equipment the staff used,this article,“A Characteristic Frequency Scanning System of EMI for New Energy Vehicles Based on Finite State Machine”,studies EMI characteristic frequency scanning technology,finite state machine transfer analysis and its model and system integration,software realization,making EMI characteristic frequency scanning more convenient and possessing engineering significance.This research work was supported by the Guangzhou Science and Technology Project(No.201504010037).This paper designs the EMI characteristic frequency scanning system architecture,realizes the finite state machine modeling and simulation of the EMI characteristic frequency scanning system,establishes the characteristic frequency scanning system of the new energy vehicle based on the finite state machine,and verify the system function as well as its rapidity through experiments.The main work of the thesis includes:(1)This paper introduces the architecture of EMI characteristic frequency scanning system,analyzes the process and function of EMI test,discusses the causes of data transmission delay error,and puts forward the unified technology of EMI characteristic frequency scanning data for new energy vehicles based on time stamp.(2)The construction and simulation of EMI model based on finite state machine is studied.Based on the idea of finite state machine,this paper puts forward the modeling idea of initializing the instrument,sending and receiving data commands into a finite state,and establishing a finite state machine model.And the finite state machine model is applied to the Petri model.The model is analyzed from the aspects of accessibility,safety and activity by using HIPS simulation software.(3)This paper designs and realizes the characteristic frequency scanning system of the new energy vehicle based on the finite state machine.The LabVIEW is used to structure and modularize the EMI characteristic frequency scanning system to realize the functions of instrument initialization,parameter setting,data storage and display.Through the design experiment,the function and fastness of the characteristic frequency scanning system of the new energy vehicle EMI characteristic based on the finite state machine are verified.Complete the system verification experiment,verify that the system can achieve the detection of characteristic frequency amplitude,data acquisition,data storage,to determine the test results,data integration and other related functions;complete the system fast experiment to verify the system in time-consuming significantly reduced(average Time-consuming 61.77s),more time than commercial software(average time-consuming 152.61s)to meet the engineering requirements. |
