Reinforcement learning (RL) techniques have been successfully used to find optimal state-feedback controllers for continuous-time (CT) systems. However, in most real-world control applications, it is not practical measure the system states and desirable design output-feedback controllers. This paper develops an online algorithm based on integral RL (IRL) technique a suboptimal controller partially unknown CT linear The proposed IRL-based solves IRL Bellman equation each iteration real time...

Managing fuel in the challenging conditions of zero gravity necessitates a profound grasp fluid dynamics, particularly pivotal role surface tension. This study introduces novel mechanical model to replicate dynamics within partially filled tank gravity. Unlike traditional models, this model, with its six degrees freedom and implication realistic liquid parameters, effectively captures stochastic behavior propellant mass. The accounts for tension effects elastic collisions walls during...

In this paper, the chaotic dynamics in an attitude transitionmaneuver of a coupled slosh–spacecraft with flexible appendage going fromminor axis tomajor spin under influence dissipative effects due to fuel slosh and small constrained undergo only torsional vibration is investigated. The slosh– spacecraftwith aflexible attitudemaneuver carrying sloshing liquid considered amultibody system motion modeled as spherical pendulum. focus paper on way which are coupled. equations derived then...

This paper focuses on the dynamics and control of spacecraft with multiple liquid propellant tanks. The slosh are included by using an improved moving pulsating ball model. model is equivalent mechanical that capable imitating reorientation process, especially for large-amplitude slosh. incorporating a static capillary force effective mass factor. improvements validated previously published experiment results. attitude maneuver implemented momentum transfer technique. designed feedback...

Liquid sloshing within propellant tanks of space vehicles has been a major concern in aerospace engineering. The aim the work this paper is to develop flexible computational framework with high precision simulate three-dimensional large-amplitude liquid Cassini tanks. finite element method adopted solve fluid equations motion an arbitrary Lagrangian–Eulerian (ALE) framework, where characteristic-based split combined fractional step for solving control which ALE kinematic description...

Summary The finite element simulation of liquid sloshing under microgravity is focused on in this paper. For class flows, an important issue to implement the contact angle boundary condition appropriately. A novel method adding infinitely small free‐surface mesh just adjacent line proposed here, which coincides with physical definition angle. This has its orientation determined according angle, and mean curvature at can be computed using orientation. Hence, surface tension force incorporated...

The accurate extraction of model parameters is vital to ensure that the equivalent mechanical can precisely describe dynamic behavior large amplitude liquid sloshing. In this paper, moving pulsating ball (MPBM), which an used represent sloshing, are extracted using a combination computational fluid dynamics (CFD), experimental data, and data-driven algorithms. arbitrary Lagrangian-Eulerian finite element method (ALE-FEM) adopted simulate three-dimension sloshing in tank with high precision....

This paper discusses the coupling dynamics behavior of spacecraft equipped with flexible appendages and liquid propellant tanks. The moving pulsating ball model (MPBM) is used to imitate large-scale motion in a tank. appendage modeled as three-dimensional Bernoulli–Euler beam free end an fixed rigid part spacecraft. Governing equations for beam’s elastic motion, set nonlinear partial differential equations, are discretized into infinite system ordinary by two different methods: assumed mode...

Abstract In this study, the sloshing behaviors and dynamic characteristics of liquid in a horizontal Cassini tank were studied. The forces torques generated by non-equilibrium states experimentally measured with force transducers which have been mounted on experiment platform. experiments mainly focus tank. And effects magnitude frequency external excitations liquid-filling ratios also results show that is highly correlated excitation where small variation leads to complex changes...

In the process of stage separation recoverable liquid launch vehicles, because large amount residual fuel in storage tanks, influence sloshing on safety must be considered. Considering calculation simplicity and operation practicability, Moving Pulsating Ball Model (MPBM) amplitude is introduced into vehicle separation. Combining dynamic equation model with energy relationship during "breathing movement", formula calculating force rigid body derived. Compared calculations commercial CFD...