Modelling and simulation of dynamic behaviour of electric motor driven mechanisms

Članak preispituje pojednostavnjene ekvivalentne torzijske modele kao učinkoviti pristup modeliranju i simuliranju dinamičkog ponašanja mehanizama pogonjenih elektromotorom. Naglasak je stavljen na početnu fazu konstruiranja. Gibanje masa je opisano pomoću sustava nehomogenih diferencijalnih jednadžbi drugog reda. Rješenje donosi zakon gibanja kao i funkciju momenta u elastičnim vezama između masa. Posebna pozornost posvećena je preciznom modeliranju karakteristika elektromotora i sila otpora koje djeluju na izvršne dijelove pogonskih mehanizama. Također se razmatra stohastička priroda sila otpora. Cilj je pokazati da kombinacija pojednostavnjenog modela s točnim opisom pogona i opterećenja momentima proizvodi zadovoljavajuće rezultate, koji su, dakle, korisni u unapređivanju procesa konstruiranja. Dva primjera koji uključuju pogonske mehanizme dizalice i rotorskog bagera ilustriraju pristup.The paper reviews simplified equivalent torsional models as an efficient approach to modelling and simulating dynamic behaviour of electric motor driven mechanisms. The focus is put on preliminary design phase. Motion of the masses is described by a system of second-order non-homogeneous differential equations. The solution yields the law of motion as well as the torque function in the elastic bonds between the masses. Special attention is dedicated to accurate modelling of electric motor characteristics and resistant forces acting on executive parts of drive mechanisms. Stochastic nature of resistant forces is also considered. The aim is to demonstrate that the combination of a simplified model with an accurate description of drive and load torques produces satisfactory results, which are, therefore, useful in furthering the design process. Two examples involving drive mechanisms of a crane and a bucket-wheel excavator illustrate the approach