The first stage of system development is the stage of function design and system simulation test. In this stage, the function design of the target product is completed first, and then the simulation test of the function is completed by means of simulation. The simulation test at this stage is called SiL (Software in the Loop, software). In-loop simulation) test, that is, the environment data of the control logic operation process is provided through the simulation model to verify whether the output result of the control logic meets the requirements of the user’s demand description, and the design of the control algorithm independent of hardware is realized at this stage. The commonly used software tools in this stage are ASCET-MD of ETAS, LabVIEW of NI, Simulink and Stateflow of Mathworks, etc. The control algorithm validated by the SiL test will enter the second stage of development.