Advances of Surface Control Methodologies for Flexible Space Reflectors

With the advances in deployable membrane technologies, the possibility of developing large, lightweight reflectors has greatly improved. However, to achieve the required accuracy, precision surface control is needed. The goal of this research was to investigate the feasibility of applying distributed polyvinylidene fluoride actuators and domain control on a flexible reflector and address some of the technical challenges. An analytical model of the integrated reflector–actuator system was developed. A Kapton reflector with polyvinylidene fluoride actuators was experimentally tested and compared with the model. A new least-squares control law is designed to ensure optimal solutions are derived in a rigorous manner when constraints are applied. The model is exercised using individually controlled polyvinylidene fluoride actuators on a large-scale reflector under thermal load. Although the results are promising with the large number of actuators applied, the major challenge is that it is unrealistic to have the same number of power supplies as actuators in actual applications. To resolve this issue, a new optimization methodology was developed, designated as the en masse elimination algorithm, which finds the global optimal solution that groups the actuators to match the limited number of power supplies and achieve minimum surface error.