Abstract
An ion engine is one of the most advantageous thrusters for orbit transfer of space vehicles or station keeping of large and long life satellite because of its high specific impulse. The ion engine system includes the ion engine, power supply unit and command interface unit, then the compatibility and interaction between them are important problems. A simulation system is necessary for a design tool at its development phase and for prediction means at the space operation.
The ion engine is a nonlinear and multivariable system which is controlled by 10 power supplies. Its operation characteristics are dependent on the thermal condition of several components, propellant particle density and power supply characteristics. Thermal model which is the dominant factor of the dynamics is derived. Most plasma models are described generally by rational polynomials and their unknown parameters are identified by the steepst descent method. Each model is identified individually and is integrated. Param-eters of the integrated models are adjusted from the view of the total system response. The computer aided parameter tuning method is employed and it takes effect to increase accuracy of the simulation. This simulation system is applied and compared with the real system. The improvement procedures of the ion engine system are presented for the application example of the simulation system.
