Open AccessThe article studies dynamics of rotor on active magnetic bearings within the mathematical model development of rotor in artificial ventricle. The problem of stabilization of rigid titanium rotor with magnetic inserts on active magnetic bearings is analyzed.
The relevance of the research field is caused by high percent of people who are suffering from heart disease. The purposes of work are to create a mathematical model of the rigid rotor and position its center to meet specified requirements for displacement of no more than 0.2 millimeter while rotating with the speed from 5 000 rpm to 10 000 rpm in constant blood flow. The work of AMBs is based on the principle of active magnetic pendant of ferromagnetic solid. The stabilization in adjusted position is accomplished by magnetic forces, which affect the solid from the control electromagnets.
The article presents initial data, design scheme, assumptions accepted to solve the problem and derivation of dynamic equation of rotating rigid rotor on AMBs. The decentralized control of magnetic pendant was implemented. The PD control – proportional differential control - was chosen as the base of control system. Its application is widespread due to the simplicity, industrial use and operation stability. The use of decentralized control in dynamics modeling of a rigid rotor in AMBs is physically occurred and has some advantages. One of the most important advantages is the calculation of control parameters by selection of appropriate values of rigidity and damping parameters.
The analysis of rotor dynamics was conducted in MATLAB© software package.
The modeling was performed to allow observing the system action while the parameters were varied.
The conducted research showed that to meet the specified requirements of maximal rotor displacement no more than 0.2 mm the following values of coefficients were required:
and
The stabilization of the rotor axis position is provided in 10 and 0.5 seconds, respectively, for oscillation from to m with specified values of gains.
From the gains obtained, parameters of magnetic bearings can be estimated and desirable ones can be selected on the basis of specified constructional and technical requirements for rotor operation.
The conducted work supposes further research of the rotor position issue to improve the offered development.