In order for space-based sensors operating at various wavelengths to perform measurements with the highest accuracy and stability, the platforms on which these sensors are typically mounted must not be subjected to any deformations or stresses. In addition to the existing, mostly passive methods of structural stabilization through the use of appropriately designed materials or constructions, research in the field of smart structures has in recent years developed and investigated methods of active control. In these active approaches, sensors measure changes, such as occurring stresses or temperature gradients, compared to a reference state. With the help of a mathematical model of the structure, these changes can be analyzed and evaluated in order to achieve a specific controlled response through special actuators on this structure. One such patented approach involves actively controlling deformations in the micrometer range caused by changes in thermal boundary conditions by selectively introducing heat based on temperature measurements at selected points of this structure. In this work, this specific approach is experimentally validated. To achieve this, the existing mathematical-theoretical FEM model with filter and controller is modified for a real application, and an experimental setup for demonstrating the approach under laboratory conditions in a thermal vacuum chamber is developed. In a first step, it is shown that the theoretical assumptions underlying the approach, involving the use of transfer functions between the change in heat input at one location of the structure and the resulting temperature change at any other location of the structure, are accurate. Furthermore, it is demonstrated that the reconstruction of the temperature field of the structure based on thermal modes is possible. In a second step, it is proven that by appropriately adjusting the system parameters of the closed filter and controller loop, this approach enables a reduction in the displacement of selected points on the structure to as little as one-sixth of the uncontrolled reference displacements for various types of disturbances. Thus, it has been demonstrated that this method can achieve stability criteria for space-based, highly precise measurement techniques which have not been possible with purely passive methods thus far.    «

In order for space-based sensors operating at various wavelengths to perform measurements with the highest accuracy and stability, the platforms on which these sensors are typically mounted must not be subjected to any deformations or stresses. In addition to the existing, mostly passive methods of structural stabilization through the use of appropriately designed materials or constructions, research in the field of smart structures has in recent years developed and investigated methods of activ...    »