Journal of Guidance, Control, and Dynamics, Ahead of Print.

Journal of Guidance, Control, and Dynamics, Ahead of Print.

This paper focuses on the use of meta-reinforcement learning for the autonomous guidance of a spacecraft during the terminal phase of an impact mission toward a binary asteroid system. The control policy is replaced by a convolutional-recurrent neural network, which is used to map optical observations collected by the onboard camera to the control thrust and thrusting times. The network is trained

Journal of Guidance, Control, and Dynamics, Ahead of Print.

Path planning for small unmanned aerial systems (SUAS) in the presence of poorly understood and dynamic obstacles is a challenging problem: for example, flight over a spreading wildfire. Evidential information fusion is used to estimate the current wildfire state and the resulting heat aura at flight level. This approach accounts for ignorance, which is a result of conflict among sensors operating

Journal of Guidance, Control, and Dynamics, Ahead of Print.

Journal of Guidance, Control, and Dynamics, Ahead of Print.

Journal of Guidance, Control, and Dynamics, Ahead of Print.

Journal of Guidance, Control, and Dynamics, Ahead of Print.

Understanding and predicting the long-term spin state evolution of defunct satellites and rocket bodies is important for solar radiation pressure modeling, space domain awareness, and active debris removal (ADR). Dynamical modeling and observations indicate that defunct geosynchronous satellite spin states are primarily driven by solar radiation torques via the Yarkovsky–O’Keefe–Radzievskii–Paddack

Mean orbital elements play a significant role in constellation guidance, orbital maintenance, and transfer strategy design. Hence, research on mean orbital elements estimation flourishes with the development of mega-constellation construction, for instance, the Starlink program. This paper investigates the autonomous on-orbit estimation problem of mean orbital elements under the consideration of real-time

This paper investigates the application of the Koopman operator theory to the motion of a satellite about a libration point in the circular restricted three-body problem. Recently, the Koopman operator has emerged as a promising alternative to the geometric perspective for dynamic systems, where the Koopman operator formulates the analysis and dynamic systems in terms of observables. This paper applies

We present a path planning problem for a pursuing unmanned aerial vehicle (UAV) to intercept a target traveling on a circle. The target is cooperative, and its position, heading, and speed are precisely known. The pursuing UAV has nonholonomic motion constraints, and therefore the path traveled must satisfy the minimum turn radius constraints. We consider the class of Dubins paths as candidate solutions

Journal of Guidance, Control, and Dynamics, Ahead of Print.

Journal of Guidance, Control, and Dynamics, Ahead of Print.

This paper presents the first haptically guided cooperative small unmanned aircraft system payload transport system with experimental validation. A team of five quadrotors is connected with individual tethers to an instrumented payload. A user issues haptic guidance commands by applying force on the slung payload. The system estimates user-applied force and direction from inline tension sensors in

Lambert’s problem involves solving the orbits connecting two position vectors with a given flight time. When introducing variations to the input of this problem (that is, terminal positions and the flight time), the output terminal velocities vary in response. The higher-order Lambert problem pursues a higher-order Taylor approximation of the output with respect to the input. Instead of finding a real

In this work angular velocity solutions are presented from accelerometers. Two main formulations are presented. The first is based on using multiple vector sets of accelerometers, and the second is based on using multiple single-axis accelerometers. Linear least-squares approaches are derived for both, along with error-covariance expressions for the angular velocity estimates. Nonlinear least-squares

Spacecraft on-orbit inspection provides a prerequisite for the subsequent autonomous proximity operations. To fulfill the mission, robust constrained control algorithms for relative position tracking and attitude adjustment should be employed to handle the nonlinear coupled dynamics, system constraints, and external disturbances. In this paper, a robust nonlinear model predictive control (NMPC) scheme

Investigating the impact process between the hopping lander and the regolith surfaces is of great significance for the in situ asteroid explorations. The high-efficiency description of the regolith-interaction dynamics of the lander remains to be analyzed. This paper presents a new method for effectively simulating the six-degree-of-freedom motion of the lander when it impacts the regolith at a low

Journal of Guidance, Control, and Dynamics, Ahead of Print.

As wing designs aim for higher aerodynamic efficiency, the underlying aircraft structure becomes more flexible, requiring additional features to alleviate the loads encountered from gusts and maneuvers. While alleviating loads, it is desirable to minimize the deviations from the original flight trajectory. In this work, a dynamic control allocation method that exploits redundant control effectors for

Journal of Guidance, Control, and Dynamics, Ahead of Print.

Journal of Guidance, Control, and Dynamics, Ahead of Print.

This study presents a comprehensive analysis of biased proportional navigation guidance laws with variable gain in the bias command that achieve stationary target interception with a desired impact angle under the restriction of permissible look angle. More specifically, this study investigates the bias shaping approach, which takes the bias gain function given by a product of factors in range and

Journal of Guidance, Control, and Dynamics, Ahead of Print.

Journal of Guidance, Control, and Dynamics, Ahead of Print.

This paper is concerned with devising nonlinear optimal guidance for intercepting a stationary target with a desired impact time. According to Pontryagin’s maximum principle, some optimality conditions for the solutions of the nonlinear optimal interception problem are established; and the structure of the corresponding optimal control is presented. By employing the optimality conditions, we formulate

A robot with large-degree-of-freedom joints is a promising future space robot capable of adapting to various environments and can perform dexterous tasks with multiple manipulators. The attitude dynamics of a free-flying robot shows nonholonomy, which enables the robot to reorient its attitude by moving its body. However, previous studies were not generally able to handle the nonholonomy, especially

Journal of Guidance, Control, and Dynamics, Ahead of Print.

Journal of Guidance, Control, and Dynamics, Ahead of Print.

Journal of Guidance, Control, and Dynamics, Ahead of Print.

Journal of Guidance, Control, and Dynamics, Ahead of Print.

The sizing of a control moment gyro (CMG) cluster is covered sparsely in literature, but it is of considerable interest to a practicing engineer. In this paper, the sizing of a cluster of four control moment gyros is investigated based on the mission angular momentum requirement of a typical agile spacecraft. The CMG skew angle β and individual CMG angular momentum h are determined as part of the sizing

This paper presents theoretically justified controllers that use relative range and bearing measurements to steer a team of autonomous vehicles, operating without inertial position information, to circular trajectories around a constant-acceleration, constant-velocity, or stationary target. An extended Kalman filter is used to improve the noisy relative measurements and estimate the velocity of the

Inspection or mapping of a target spacecraft in a low Earth orbit using multiple observer spacecraft in stable passive relative orbits (PROs) is a key enabling technology for future space missions. Our guidance and control architecture uses an information gain approach to directly consider the tradeoff between gathered data and fuel/energy cost. The architecture has four components: information estimation

This work develops a factorized version of the partial-update Schmidt–Kalman filter: a partial-update filter that operates on the covariance matrix modified Cholesky factors U (the upper triangular factor) and D (a diagonal factor) rather than on the error covariance matrix P. Effectively, this new formulation combines the well-known numerical stability properties of the UD factorized Kalman filter

Navigation in Global Positioning System–denied environments is notoriously difficult for small unmanned aerial vehicles due to reduction of visible satellites and urban canyon multipath interference. Several existing methods can be used for navigating in a constrained environment, but they often require additional specific sensing hardware for a localization solution or only provide local frame navigation

An optimization algorithm for planning the motion of a humanoid robot during extravehicular activities is presented in this paper. The algorithm can schedule and plan the movements of the two robotic arms to move the humanoid robot by using the handrails present outside the International Space Station. The optimization algorithm considers the eventual constraints imposed by the topology of the handrails

Journal of Guidance, Control, and Dynamics, Ahead of Print.

Journal of Guidance, Control, and Dynamics, Ahead of Print.

This paper is devoted to investigating the fault-tolerant reduced-attitude control problem for boresight reorientation of an uncertain spacecraft subject to pointing and angular velocity constraints. First, the stereographic projection is used to transform this problem to an obstacle avoidance problem on a two-dimensional Euclidean sphere world with circular obstacles. Then, an adaptive fault-tolerant

Journal of Guidance, Control, and Dynamics, Ahead of Print.

Journal of Guidance, Control, and Dynamics, Ahead of Print.

Journal of Guidance, Control, and Dynamics, Ahead of Print.

Journal of Guidance, Control, and Dynamics, Ahead of Print.

Control law design for flexible aircraft with coupled flight and structural dynamics is currently a challenge. If not correctly addressed during control law design, the aeroservoelastic coupling can negatively affect the lateral-directional stability of the aircraft. In this context, this paper describes a methodology for the design of a stability augmentation system for the Instituto Tecnológico de

In-orbit relative navigation between a networked swarm of centimeter-scale femto-spacecraft would add considerable value to a range of space mission concepts and applications, such as for multipoint sensing and distributed sparse aperture interferometry. For a swarm of networked femto-spacecraft, relative position determination would be possible by inferring coarse range estimates from the received

In this paper, a neural-adaptive, prescribed-performance trajectory controller is proposed to stabilize a flexible cable-towed aerial-recovery drogue subjected to actuator constraints, unmeasurable cable tensions, and airflow disturbances. The towed drogue’s six-degree-of-freedom (6-DOF) dynamics are formulated in a nominal affine nonlinear form based on the flexibly cable-drogue system’s dynamics

This paper addresses the fault-tolerant optimal attitude control problem for a rigid spacecraft with external disturbance, model uncertainties, and actuator faults. Firstly, the incremental nonlinear control technology is used to simplify the attitude control system into an incremental nominal model with a synthetic uncertainty/fault term that is estimated by a nonsingular terminal sliding mode disturbance

Asteroid exploration has been attracting more attention in recent years. Nevertheless, we have just visited tens of asteroids, whereas we have discovered more than 1 million bodies. As our current observation and knowledge should be biased, it is essential to explore multiple asteroids directly to better understand the remains of planetary building materials. One of the mission design solutions is

Homing guidance requires maintaining the target lock-on condition within the seeker’s field of view (FOV). This paper aims at developing a unified FOV-limited guidance framework from which a variety of two-dimensional (2D) and three-dimensional (3D) guidance laws can be derived. First, the unified method for 2D homing guidance is established by augmenting an arbitrary baseline guidance law with a biased

Aiming at de-tumbling a non-cooperative space target safely and efficiently, an eddy brake approach utilizing multiple high-temperature superconducting (HTS) coils is proposed in this paper. The configuration design criteria of HTS coil are constructed first to guarantee the validity of the eddy brake method. Then, considering that each HTS coil is mounted on a servicing satellite, the desired position

Journal of Guidance, Control, and Dynamics, Ahead of Print.

This paper presents a novel approach to the robust solution of optimal impulsive control problems under aleatory and epistemic uncertainty. The novel approach uses belief Markov decision processes to reformulate the control problem in terms of uncertainty distributions, called beliefs, rather than the realizations of the system states. This formulation leads to the definition of a belief optimal control

The problem of optimal trajectory planning with nonconvex collision avoidance constraints is discussed in this paper. The trajectory planning algorithm aims to generate a feasible trajectory with specified performance indexes to reduce collisions of aerospace vehicles in the presence of second-order smooth obstacles. The algorithm design that manages such mission scenarios is challenging because of

In this work, an orbit determination algorithm suitable for CubeSats onboard implementation is developed, which simulates optical autonomous navigation accomplished by a stand-alone platform. An extended Kalman filter featuring line-of-sight acquisitions of planets is selected as the state estimator, and its performances are tested on a Raspberry Pi, whose characteristics are comparable to a miniaturized

Journal of Guidance, Control, and Dynamics, Ahead of Print.

Journal of Guidance, Control, and Dynamics, Ahead of Print.

The proposed Laser Interferometer Space Antenna (LISA) mission features a three-satellite constellation realizing a long-arm interferometer designed to observe gravitational waves emitted by a multitude of stellar, galactic, and possibly cosmic sources not accessible to ground-based detectors. In support of maximizing LISA’s scientific return, this paper presents an on-orbit excitation and estimation