Telescope Sim

Dynamic simulation of the a large telescope.

Client: Renowned space engineering company

SCOPE OF THE WORK

The job described in this outline regards the development of a dynamic model that simulates the telescope during controlled surveying and target objects follow-up tasks, taking into account the dynamic interaction between the structural elements.
The main objective was to describe the whole articulated structure dynamics and to characterize the residual vibrations of the cameras and of the primary and secondary mirrors of the tube, in order to determine the effective degree of accuracy of the telescope in normal working conditions.
For this purpose, the motion of the whole structure is simulated by means of a dynamic model implementing the mechanical dynamics equation of the two interactive moving structures, the motors shafts dynamics and the relevant signals filtering and discrete time controls in the MALTLAB/SIMULINK®1 environment.
Simulation runs exemplified typical surveying and tracking missions of the closed loop system. The residual oscillations of the cameras and of the primary and secondary mirrors, after positioning or during follow-up, are investigated and compared with the requirements

1 MATLAB and SIMULINK® are products by Mathworks Inc. (Natick, Mass, USA). They are a powerful mathematical numerical environment and simulation platform, suitable for multidisciplinary models development and implementation both as desktop and real time operation in embedded systems.

JOB OUTLINE

Input data received from the Client

Telescope schematics

Motors and drivers datasheets

Frequency responses of the structures from the FEA models. Response of nodes of interest for different load cases (with longitudinal and angular acceleration and forces applied to the structure)

Main technical activities performed by S.A.T.E.

Model equations implementation in the SIMULINK® environment

Identification of SISO linear models from the frequency responses data

Model validation at different operation conditions

Control system tuning

Closed loop model validation and simulation

Output delivered to the Client

Technical documentation: Final report describing the model equations implemented and the simulations results.

KNOW HOW AND EXPERTISE REQUIRED tO PERFORM THE JOB

The main competences that were needed to perform the job are in the following fields:

  1. Structural dynamics
  2. Non-rigid motion
  3. Control techniques
  4. Data processing and analysis
  5. Advanced use of the MATLAB/SIMULINK® environment