New system of automatic control capable of governing satellite telescopes

A team of Control Engineering researchers at the Public University of Navarra has successfully finalised their work on QFT Multivariable Robust Control of Darwin-type Satellites with large flexible structures, undertaken for the European Space Agency (ESA).

The scientists have designed a new automatic control system capable of governing the Darwin Project satellite telescopes.

The Darwin Project

The European Space Agency is currently developing what is known as the Darwin Project involving the launching into space in 2014 of six satellite telescopes flying in formation. This mission will enable the study of the Universe with hitherto unprecedented precision and depth, improving on current telescopes by several orders of magnitude. Amongst the immediate aims is the search for new planets outside the Solar System and which have possibilities of life on them.

The work developed by the team of researchers at the Public University of Navarra on the design of new control systems for governing satellites in formation attracted the attention of the ESA.

The problem was one of enormous complexity, the remit of the researchers from Navarre requiring the design of a new automatic control system capable of governing satellites in a high-precision manner. In fact, it had to be undertaken with a precision in the order of micro-meters in the orbital three-dimensional position and of milliarcseconds (a 3.6 millionth part of a degree) in each one of the three angles of orientation in space. Moreover, the vibrations introduced by their flexible structures, wind perturbations and gravitational phenomena had to be rejected simultaneously. These specifications were imposed by the enormous precision required of the on-board telescopes whose mission is to probe the furthest points of the Universe with great exactitude.

In developing the research project, two control systems, previously designed for the ESA by an international consortium, were employed. This part of the work involved comparing these with the latest theories on QFT multivariable robust control developed by the research team.

The final results of the project have proved totally satisfactory. The viability of the new QFT developments has been confirmed, improving greatly on the dynamic behaviour of the satellite achieved by previous control theories regarding the twelve evaluation criteria studied.