| Popis: |
The IDSN32 Indian Deep Space Network antenna system commissioned in 2008, is installed at Byalalu, Bangalore and has provided TTC (tracking, telemetry & command) and science data reception support for India's Moon mission “Chandrayaan-I” and Mars Orbiter Mission “Mangalyaan”. The Antenna Control Servo System controls the antenna position in AZ and EL axis to the required pointing and tracking accuracies. The system is designed to meet tracking accuracy of 30mDeg in S band and 15mDeg in X band under the wind conditions of 30 kmph gusting to 45kmph. Tracking accuracy deteriorates in the presence of wind gusts; hence it is required to mitigate effect of wind disturbances to achieve better pointing and tracking accuracies that would be required at higher frequency bands. In order to achieve this, it is proposed to upgrade existing servo system (PI controller) with Advanced controllers, e.g., a Linear Quadratic Gaussian (LQG) controller. The FEM (finite element models) or analytical models due to its many uncertainties / inaccuracies, could not be used to design such controllers hence accurate antenna models are obtained through an experimental approach based on response measurements (System Identification). This paper discusses the system identification experiments carried out for the Azimuth and Elevation axis of IDSN32M Antenna in detail. |
