جستجوی مقالات مرتبط با کلیدواژه « booster landing » در نشریات گروه « مکانیک »

In this paper, optimal guidance law design considering fixed final state and time for the final phase booster landing problem of a spacecraft or launch vehicle is investigated and studied. This guidance law, not only satisfied a specific optimality criterion, but it also has the least sensitivity to the initial state’s deviations; which is due to the inclusion of the nonlinear terms in the mathematical modeling using the high order expansions method. The main goal of this research, is to investigate the development and to augment the capability of the high order expansions method for guidance law design. Different implementations of this approach including the differential algebra high order, the generating function based high order and vectorized high order expansions methods have been investigated. After reviewing the implementation concepts of the high order expansions method, the effectiveness of this method has been studied. Then a 3-dimensional booster landing problem has been chosen as the case study and after extracting the mathematical model and nominal optimal solution, the sensitivity variables have been extracted up to the 3rd order. Afterwards, to investigate the performance of the designed guidance law, the Monte Carlo simulations have been performed and it has been shown that the designed guidance law on the basis of the Taylor series and high order expansions method has a good accuracy and is a valuable alterative to the nominal trajectory tracking guidance approach.

In this research the main goal is to compare the performance of Vectorized High Order Expansions and SDRE method for vertical landing of booster. To this end, at first a comprehensive study of references related to both Vectorized High Order and SDRE method has been performed. Then, the Vectorized High Order Expansions method and the implementation in optimal control problems has been introduced. After that, the SDRE method has been reviewed briefly, and the landing problem has been solved using both methods. To evaluate the performance, a set of various simulations have been performed for both methods and with respect to different initial deviations. By means of simulation results, the performance of both method is studied with regard to landing point errors. To achieve this, statistical results of terminal state errors have been calculated for both method with respect to different initial deviation to evaluate and compare both method, quality-wise.