Feedback Local Optimality Principle Applied to Rocket Vertical Landing (VTVL)

Vertical landing is becoming popular in the last 15 years, a technology known under the acronym VTVL, Vertical Takeoff and Vertical Landing. The interest in such landing technology is dictated by possible cost reductions, which impose spaceship’s recycling. The rockets are not generally designed to perform landing operations, rather their design is aimed at takeoff operations, guaranteeing a very high forward acceleration to gain the velocity needed to escape the gravitational force. In this chapter, a new control method based on Feedback Local Optimality Principle, named FLOP, is applied to the rocket landing problem. The FLOP belongs to a special class of optimal controllers, developed by the mechatronic and vehicle dynamics lab of Sapienza, named Variational Feedback Controllers (VFC), that are part of an ongoing research and are recently applied in different field: nonlinear system and marine and terrestrial autonomous vehicles, multi-agent interactions, and vibration control. This chapter is devoted to show the robustness of the nonlinear controlled system, comparing the performances with the LQR, one of the most acknowledged methods in optimal control.