Computer simulation of the «engine - working machine» mechanical system

There was investigated the application for the purpose of diagnosing the technical condition of the unit, the internal combustion engine (ICE) - the working machine (WM) of advanced computer models of internal combustion engines with the additional function of determining the technical condition of machines (mechanisms) driven by the internal combustion engine. The mechanical system «ICE-working machine» is considered as a three- and two-mass system with lumped parameters. Equations of equilibrium moments are made that act on the selected concentrated masses, taking into account various nonlinearities (dry and viscous friction, dead zone, etc.), elasticity of the shafts and joints. The block diagrams of the ICE-PM system in the form of transfer functions are given. A computer simulation of this system was carried out with the presentation of the obtained computer structural diagrams and graphs of dynamic processes (angular velocities and shaft accelerations, etc.). Introducing into these schemes the values of the parameters characteristic of a specific unit ICE-PM by varying the values of different moments, it is possible in the static and dynamic modes to evaluate their influence on the technical state of ICE-PM. The use of a computer model allows to take into account the influence of these factors on informative diagnostic signals reflecting the technical condition of the internal combustion engine, since the level of signals characterizing the power indicators of the internal combustion engine is significantly higher than the level of signals reflecting elasticity and nonlinearity. The developed computer block diagram can be directly used in diagnostic complexes based on microprocessor systems, microcontrollers and microcomputers for diagnosing internal combustion engines and working machines under operational conditions.

ICE - working machine, non-linearity, elasticity of shafts and connections, computer simulation