Final Descent Phase Research Articles

Pilot Control Modeling With Stochastic Periodical Discrete Movement

This paper proposes a novel pilot control model which reflects the following three characteristics of the pilot control behavior: stochastic, periodical, and discrete movement. The focus is on the final descent phase when the pilot controls the aircraft manually based on the flight director commands. The proposed model is developed based on an existing model as well as highly experienced pilot's comments. A flight simulator experiment is conducted and three pilots’ landing data are obtained. The parameters of the pilot model are tuned via a genetic algorithm. The simulation result reveals that the proposed model captures well the characteristics of the data obtained in the simulator experiment and shows a good accordance with actual command tracking capability. The obtained parameters also identify the difference of control strategies between the pilots.

Исследование точностных характеристик комплекса алгоритмов терминального наведения перспективного пилотируемого космического корабля на конечном участке спуска в атмосфере Земли

Исследование точностных характеристик комплекса алгоритмов терминального наведения перспективного пилотируемого космического корабля на конечном участке спуска в атмосфере Земли

Model Predictive Control of Hayabusa2 Probe in the Approach Phase to an Asteroid

A new asteroid exploration spacecraft “Hayabusa2” as a follow on of “Hayabusa” is now in the course of production and experiment in order to launch in 2014. The touchdown of Hayabusa2 can be split into two phases, i.e., the approach phase and the final descent phase. In the approach phase, the spacecraft is guided and controlled by based on the command from the ground station. In contrast, the spacecraft controls its position and attitude by based on the autonomous computation in the final descent phase. This paper presents the application of the Model Predictive Control (MPC) to the approach phase to the asteroid, and verifies the performance and feasibility of this control algorithm through numerical simulations.

Collision dynamics of a visual target marker for small-body exploration

MUSES-C mission is the world first sample and return attempt to or from a near-Earth asteroid. In deep space, it is hard to navigate, guide and control a spacecraft on a real-time basis remotely from the earth, mainly due to the communication delay. Thus, autonomy and robotics technologies are required for final approach and landing to an unknown body. In the final descent phase, cancellation of the horizontal speed relative to the surface of the landing site is essential. During the touchdown and sampling phase, the spacecraft will be navigated relative to the asteroid surface using an optical target marker (TM) placed on the asteroid surface. By using the TM as a reference point, navigation during the landing phase will be much more reliable and precise. Thus, it is important to design a TM with as small a coefficient of restitution as possible to reduce the settling time. To develop a small coefficient of restitution of less than 0.1 in vertical direction, the authors propose a novel TM, which is constructed out of a shell with beads stored internally. To better predict the performance of such a TM, analytical and numerical investigations are performed. The validity and the effectiveness of the proposed method are confirmed and evaluated by numerical simulations and flight results.