A5070392086- Spacecraft Dynamics and Control
- Astro and Planetary Science
- Space Satellite Systems and Control
- Aerospace Engineering and Control Systems
- Spacecraft Design and Technology
- Advanced Control Systems Optimization
- Stability and Control of Uncertain Systems
- Spacecraft and Cryogenic Technologies
- Aerospace Engineering and Energy Systems
- Inertial Sensor and Navigation
- Gas Dynamics and Kinetic Theory
- Guidance and Control Systems
- Adaptive Control of Nonlinear Systems
- Bayesian Methods and Mixture Models
- Advanced Optimization Algorithms Research
- Optimization and Variational Analysis
- Adaptive optics and wavefront sensing
- Process Optimization and Integration
- Robotic Path Planning Algorithms
- Sparse and Compressive Sensing Techniques
- Solar and Space Plasma Dynamics
- Stellar, planetary, and galactic studies
- Geophysics and Gravity Measurements
- Modular Robots and Swarm Intelligence
- Capital Investment and Risk Analysis
Purdue University West Lafayette
2022-2024
Australian National University
2024
American Institute of Aeronautics and Astronautics
2023-2024
Jet Propulsion Laboratory
2022
University of Colorado Boulder
2019-2021
NSF National Center for Atmospheric Research
2021
The University of Tokyo
2016-2017
Asteroid exploration is a pertinent challenge due to the varying complexity of their dynamical environments, shape and communication delays distance. Thus, autonomous navigation methods are continually being developed improved in current research enable safe exploration. These often involve using horizon-based Optical Navigation (OpNav) determine spacecraft's location, which reliant on visibility horizon. It critical ensure reliability this measurement such that spacecraft may maintain an...
Spacecraft operations are influenced by uncertainties such as dynamics modeling, navigation, and maneuver execution errors. Although mission design has traditionally incorporated heuristic safety margins to mitigate the effect of uncertainties, particularly before/after crucial events, it is yet unclear whether this practice will scale in cislunar region, which features locally chaotic nonlinear involves frequent lunar flybys. This paper applies chance-constrained covariance steering...
Dynamical environments around small celestial bodies are complex and uncertain, leading to highly perturbed, uncertain orbital motions in their proximity. Under such complexity uncertainty, mission designers need plan robust guidance control of the spacecraft orbit meet some requirements derived from objectives as precise science observation campaigns. To develop a planner for under this paper presents stochastic optimal approach design policies that minimize expected effort while ensuring...
OMOTENASHE and EQUULEUS are two 6-U CubeSats by JAXA The University of Tokyo to be launched in 2019 onboard NASA's Exploration Mission 1. This paper presents the nominal trajectories an overview mission analysis work approaches. trajectory exploits Earth -Sun -Moon dynamics capture spacecraft into a libration orbit around L2 point, using only -10 m/s deterministic Av. cost complexity, however, driven statistical maneuvers because expected limited performances determination (because ground...
The present paper extends the classically studied chance-constrained optimal control to incorporate continuous-time chance constraints. While classical approaches provide risk guarantees only at discretized epochs, it is essential for most physical systems have guarantees; especially important unstable systems. This develops a new approach enforce by leveraging notion of Cumulative Lyapunov Exponent, which measures cumulative stabilities Linear Time-Varying (LTV) solution method finds...
With appropriate control algorithms, solar radiation pressure (SRP) can be effectively used for orbit around small celestial bodies. In contrast to the historical treatment of SRP as a disturbance at weak gravity environment, present paper finds active spacecraft attitude promising control. An optimal law is developed SRP-based control, where complex reflection model considered make applicable realistic surface models. The demonstrated with numerical simulations on an asteroid landing...
Any space trajectories are subject to state uncertainty due imperfect knowledge, random disturbances, and partially known dynamical environments. Ideally, such associated risks must be properly quantified taken into account in the process of trajectory design, ensuring a sufficiently low risk causing hazardous events. To bridge gap between ideal goal current practice mission this paper extends Lawden's primer vector theory develops solution method solve problem low-thrust optimization under...
This paper proposes an algorithm that solves non-convex optimal control problems with a theoretical guarantee for global convergence to feasible local solution of the original problem. The proposed extends recently successive convexification (SCvx) address its key limitation: lack feasibility main idea is incorporate SCvx iteration into algorithmic framework based on augmented Lagrangian method enable while retaining favorable properties SCvx. Unlike SCvx, our approach iterates both...
This paper describes development strategies and on-orbit results of the attitude determination control system (ADCS) for world's first interplanetary micro-spacecraft, PROCYON, whose advanced mission objectives are optical navigation or an asteroid close flyby. Although earth-orbiting micro-satellites already have ADCSs practical missions, these cannot be used micro-spacecraft due to differences in space environments their orbits. To develop a new ADCS, four issues discussed: initial Sun...
This paper will provide an introduction and overview of Area-of-Effect Softbots (AoES), which are currently in development under a Phase 2 NASA Innovative Advanced Concepts (NIAC) project. AoES designed to operate proximity to, on the surface of, small asteroids support mining planetary defense missions. Their unique design capabilities dependent incorporation soft, compliant, lightweight materials. have large area-to-mass ratio allows them take advantage peculiarities dynamical environment...
View Video Presentation: https://doi.org/10.2514/6.2022-1627.vid Solar sailing is an emerging technology that harnesses solar radiation pressure to propel spacecraft, providing the potential enable longer-duration, higher Delta-V missions. To ensure successful missions, mission designers need design trajectories are robust against uncertainty due navigation error, control and unplanned transition safe mode. Based on deterministic stochastic approaches, this study develops frameworks under...
This paper presents a robust path-planning framework for safe spacecraft autonomy under uncertainty and develops computationally tractable formulation based on convex programming. We utilize chance-constrained control to formulate the problem. It provides mathematical solve sequence of policies that minimizes probabilistic cost constraints with user-defined confidence level (e.g., safety 99.9% confidence). The enables planner directly state distributions operational uncertainties while...
We address the problem of finite-horizon control a discrete-time linear system, where initial state distribution follows Gaussian mixture model, terminal must follow specified distribution, and inputs obey chance constraints. show that, throughout time horizon, distributions are fully characterized by mixtures. then formulate cost, distributional constraint, affine/2-norm constraints on control, as convex functions decision variables. This is leveraged to chance-constrained path planning...