MINIMUM-TIME CONTROL OF FLEXIBLE SPACECRAFT BY HAMILTONS PRINCIPLE

Modern space vehicles structure requisites are getting more and more s tringent and complex as mission tasks become more sophisticated. This leads to the necessity of developing analysis methods that take into a ccount structure flexibility and the need of reducing manoeuvre time a s much as possible. In this work, a method based on the Hamilton Princ iple in its weak mixed form is developed, in which co-ordinates deriva tives do not appear, but only their virtual variations. The proposed f ormulation is able to take into account system flexibility and saturat ion constraints on control torques and forces. A non-linear variationa l condition is obtained, which can be solved by means of a time-finite -eIement technique to give the minimum-time solutions of the control p roblem. The solutions for slewing manoeuvres are given, along with a n ew solution of the distributed optimal control problem.