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14 pages, 4843 KiB

Open AccessArticle

Integrated Control Scheme for an Improved Disturbance-Free Payload Spacecraft

by Ting Jin, Guohua Kang, Jian Cai, Shaoxia Jia, Jinghua Yang, Xinghua Zhang, Zhenhua Zhang, Long Li and Fangfang Liu

Aerospace 2022, 9(10), 571; https://doi.org/10.3390/aerospace9100571 - 29 Sep 2022

Cited by 7 | Viewed by 1740

Abstract

For a novel disturbance-free payload (DFP) spacecraft, it is difficult to isolate the low-frequency disturbances owing to the umbilical cables, which decreases the pointing accuracy and stability of the payload. In this research, an improved DFP spacecraft and its integrated control scheme are [...] Read more.

For a novel disturbance-free payload (DFP) spacecraft, it is difficult to isolate the low-frequency disturbances owing to the umbilical cables, which decreases the pointing accuracy and stability of the payload. In this research, an improved DFP spacecraft and its integrated control scheme are designed to enhance the pointing accuracy and disturbance attenuation performance. The improved DFP spacecraft consists of a Payload Module (PM), a Support Module (SM), and a Test Mass (TM). The integrated control system is subdivided into three interconnected control loops. An active vibration isolation control loop is used to isolate the PM from disturbances in the high-frequency bands and control the PM to track the attitude of the SM. A drag-free control loop is used to isolate the SM from disturbances in the low-frequency bands and control the SM to track the attitude of the TM. An attitude-pointing control loop is used to control the TM to track the desired attitude. Based on the improved DFP spacecraft and the integrated control system, the payload mounted on the PM can be isolated from disturbances in all of the frequency bands, and its high-level requirements for pointing accuracy and stability can be realized. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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25 pages, 10702 KiB

Open AccessArticle

Self-Organizing Control-Loop Recovery for Predictive Networked Formation Control of Fractionated Spacecraft

by Florian Kempf, Julian Scharnagl, Stefan Heil and Klaus Schilling

Aerospace 2022, 9(10), 529; https://doi.org/10.3390/aerospace9100529 - 20 Sep 2022

Cited by 1 | Viewed by 2120

Abstract

Going beyond the current trend of cooperating multiple small satellites we arrive at fractionated satellite architectures. Here the subsystems of all satellites directly self-organize and cooperate among themselves to achieve a common mission goal. Although this leads to a further increase of the [...] Read more.

Going beyond the current trend of cooperating multiple small satellites we arrive at fractionated satellite architectures. Here the subsystems of all satellites directly self-organize and cooperate among themselves to achieve a common mission goal. Although this leads to a further increase of the advantages of the initial trend it also introduces new challenges, one of which is how to perform closed-loop control of a satellite over a network of subsystems. We present a two-fold approach to deal with the two main disturbances, data losses in the network and failure of the controller, in a networked predictive formation control scenario. To deal with data loss an event based networked model predictive control approach is extended to enable it to adapt to changing network conditions. The controller failure detection and compensation approach is tailored for a possibly large network of heterogeneous cooperating actuator- and controller nodes. The self-organized control task redistribution uses an auction-based methodology. It scales well with the number of nodes and allows to optimize for continuing good control performance despite the controller switch. The stability and smooth control behavior of our approach during a self-organized controller failure compensation while also being subject to data losses was demonstrated on a hardware testbed using as mission a formation control scenario. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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14 pages, 1437 KiB

Open AccessArticle

Angular Trajectory Design for MR-SPS Using Bezier Shaping Approach

by Song Xu, Mingying Huo, Naiming Qi, Wenyu Feng, Tong Lin and Zheng Li

Aerospace 2022, 9(10), 528; https://doi.org/10.3390/aerospace9100528 - 20 Sep 2022

Viewed by 1527

Abstract

Solar power satellite (SPS) is a kind of large-scale on-orbit servicing spacecraft collecting solar energy in space and transmitting energy to the earth. The solar arrays of the SPS must point to the sun to collect enough solar energy and the antenna must [...] Read more.

Solar power satellite (SPS) is a kind of large-scale on-orbit servicing spacecraft collecting solar energy in space and transmitting energy to the earth. The solar arrays of the SPS must point to the sun to collect enough solar energy and the antenna must point to the rectenna on the ground to transmit energy. But due to the limitation of the control effort, accurate solar and earth orientation may not be achieved. This paper focuses on the MR-SPS, and establishes the attitude kinematics and dynamics model of a MW-level MR-SPS. Angular trajectory based on Bezier shaping approach is generated at different time of a year to satisfy the control constraints. The simulation results demonstrate the effectiveness of the proposed method. Even if the control torque is limited to a small amount, the optimal angular trajectory can still ensure high average energy receiving efficiency. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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20 pages, 5223 KiB

Open AccessArticle

Implicit Extended Kalman Filter for Optical Terrain Relative Navigation Using Delayed Measurements

by Stefano Silvestrini, Margherita Piccinin, Giovanni Zanotti, Andrea Brandonisio, Paolo Lunghi and Michèle Lavagna

Aerospace 2022, 9(9), 503; https://doi.org/10.3390/aerospace9090503 - 9 Sep 2022

Cited by 10 | Viewed by 3157

Abstract

The exploration of celestial bodies such as the Moon, Mars, or even smaller ones such as comets and asteroids, is the next frontier of space exploration. One of the most interesting and attractive purposes from the scientific point of view in this field, [...] Read more.

The exploration of celestial bodies such as the Moon, Mars, or even smaller ones such as comets and asteroids, is the next frontier of space exploration. One of the most interesting and attractive purposes from the scientific point of view in this field, is the capability for a spacecraft to land on such bodies. Monocular cameras are widely adopted to perform this task due to their low cost and system complexity. Nevertheless, image-based algorithms for motion estimation range across different scales of complexities and computational loads. In this paper, a method to perform relative (or local) terrain navigation using frame-to-frame features correspondences and altimeter measurements is presented. The proposed image-based approach relies on the implementation of the implicit extended Kalman filter, which works using nonlinear dynamic models and corrections from measurements that are implicit functions of the state variables. In particular, here, the epipolar constraint, which is a geometric relationship between the feature point position vectors and the camera translation vector, is employed as the implicit measurement fused with altimeter updates. In realistic applications, the image processing routines require a certain amount of time to be executed. For this reason, the presented navigation system entails a fast cycle using altimeter measurements and a slow cycle with image-based updates. Moreover, the intrinsic delay of the feature matching execution is taken into account using a modified extrapolation method. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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28 pages, 6290 KiB

Open AccessArticle

Optical Navigation Method and Error Analysis for the Descending Landing Phase in Planetary Exploration

by Rongjun Mu, Peng Wu, Yanpeng Deng and Haofan Song

Aerospace 2022, 9(9), 496; https://doi.org/10.3390/aerospace9090496 - 6 Sep 2022

Cited by 5 | Viewed by 1692

Abstract

To solve the problem of high-precision optical navigation for the descent landing of lunar and planetary probes, an optical navigation method based on the spatial position distribution model is proposed. The method is based on crater detection, and an imaging cosine equivalent mathematical [...] Read more.

To solve the problem of high-precision optical navigation for the descent landing of lunar and planetary probes, an optical navigation method based on the spatial position distribution model is proposed. The method is based on crater detection, and an imaging cosine equivalent mathematical model based on the correspondence of crater objects is constructed. The geometric distribution of the probe spatial position is described to form an Abelian Lie group spatial torus to achieve absolute positioning for parametric optical navigation, Finally, the effect of the measurement error of crater detection on the positioning and attitude of the optical navigation system is discussed, with a fitted ellipse used as a typical analysis object. The effects of different crater distribution configurations and different detection errors on the performance of the proposed optical navigation algorithm are analyzed. The results of Monte Carlo simulation experiments showed that the algorithm proposed in this paper had the advantages of high stability, high accuracy, and good real-time performance, compared with existing methods. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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12 pages, 3360 KiB

Open AccessArticle

Nonlinear Dynamic Modeling of Joints between Solar Panels on Spacecraft

by Shuang Wu, Zhijun Zhao, Dongping Liang, Qunzhi Li and Shougen Zhao

Aerospace 2022, 9(8), 459; https://doi.org/10.3390/aerospace9080459 - 20 Aug 2022

Cited by 2 | Viewed by 1958

Abstract

Multiple linear and nonlinear dynamic parameters of the joints at the root of solar panels and between solar panels on spacecraft, both of which have complex nonlinear dynamic properties, were identified by using the force state mapping method for modeling complex nonlinear joints [...] Read more.

Multiple linear and nonlinear dynamic parameters of the joints at the root of solar panels and between solar panels on spacecraft, both of which have complex nonlinear dynamic properties, were identified by using the force state mapping method for modeling complex nonlinear joints in deployable mechanisms of spacecraft, and the differential equations representing the nonlinear dynamic model of the joints were derived. On the basis of the actual force characteristics of the joints, test systems were developed to investigate the vibration response of the complex nonlinear joints in spacecraft so as to acquire test data necessary for the identification. The relation between the moment and bending angle of the panel root and inter-panel joints on spacecraft was obtained through vibration tests under various frequencies and excitation forces. The validity and effectiveness of the dynamic model have been verified by vibration tests of the joints under pulsed excitation. The parameters identified in this paper reflect the nonlinear stiffness, friction and damping characteristics of the joints. The dynamic model established based on these parameters can describe multiple linear and nonlinear dynamic properties of the joints and can be further applied in modeling and control of the entire spacecraft system. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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18 pages, 2808 KiB

Open AccessArticle

Linear Pseudospectral Method with Chebyshev Collocation for Optimal Control Problems with Unspecified Terminal Time

by Yang Li, Wanchun Chen and Liang Yang

Aerospace 2022, 9(8), 458; https://doi.org/10.3390/aerospace9080458 - 20 Aug 2022

Cited by 2 | Viewed by 1958

Abstract

In this paper, a linear Chebyshev pseudospectral method (LCPM) is proposed to solve the nonlinear optimal control problems (OCPs) with hard terminal constraints and unspecified final time, which uses Chebyshev collocation scheme and quasi-linearization. First, Taylor expansion around the nonlinear differential equations of [...] Read more.

In this paper, a linear Chebyshev pseudospectral method (LCPM) is proposed to solve the nonlinear optimal control problems (OCPs) with hard terminal constraints and unspecified final time, which uses Chebyshev collocation scheme and quasi-linearization. First, Taylor expansion around the nonlinear differential equations of the system is used to obtain a set of linear perturbation equations. Second, the first-order necessary conditions for OCPs with these linear equations and unspecified terminal time are derived, which provide the successive correction formulas of control and terminal time. Traditionally, these formulas are linear time varying and cannot be solved in an analytical manner. Third, Lagrange interpolation, whose supporting points are orthogonal Chebyshev–Gauss–Lobatto (CGL), is employed to discretize the resulting problem. Therefore, a series of analytical correction formulas are successfully derived in approximating polynomial space. It should be noted that Chebyshev approximation is close to the best polynomial approximation, and CGL points can be solved in closed form. Finally, LCPM is applied to the air-to-ground missile guidance problem. The simulation results show that it has high computational efficiency and convergence rate. A comparison with the other typical OCP solvers is provided to verify the optimality of the proposed algorithm. In addition, the results of Monte Carlo simulations are presented, which show that the proposed algorithm has strong robustness and stability. Therefore, the proposed method has potential to be onboard application. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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21 pages, 10856 KiB

Open AccessArticle

Orbital Stability and Invariant Manifolds on Distant Retrograde Orbits around Ganymede and Nearby Higher-Period Orbits

by Qingqing Li, Yuming Tao and Fanghua Jiang

Aerospace 2022, 9(8), 454; https://doi.org/10.3390/aerospace9080454 - 18 Aug 2022

Cited by 9 | Viewed by 2358

Abstract

In the past few years, distant retrograde orbits (DROs) have become increasingly popular due to their conspicuous stability. Nevertheless, it is this characteristic that results in the challenge to the design of transfer orbits into/out of DROs. This paper investigates the DROs around [...] Read more.

In the past few years, distant retrograde orbits (DROs) have become increasingly popular due to their conspicuous stability. Nevertheless, it is this characteristic that results in the challenge to the design of transfer orbits into/out of DROs. This paper investigates the DROs around Ganymede in order to utilize their dynamical characteristics for Jupiter system exploration. In particular, the DRO family is calculated by numerical integration and numerical continuation, higher-period orbits near the DROs are detected using bifurcation theory, and characteristics including orbital stability and invariant manifolds of these orbits are investigated through stability indices and manifold theory. The stability of DROs and the higher-period orbits are first investigated in the circular restricted three-body problem and are then verified in a third-body gravitation perturbation model. The results show that the strong stability of DROs makes it possible to observe the Galilean moons for long periods and that the higher-period orbits that bifurcate from the DROs offer additional insight into the motion of probes approaching/departing from the vicinities of the DROs. Further investigation of the invariant manifolds around higher-period orbits reveals the feasibility of utilizing the DRO family and the nearby unstable structures for multi-target exploration and low-energy transfer between the Galilean moons. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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19 pages, 4920 KiB

Open AccessArticle

A Neural Network Warm-Started Indirect Trajectory Optimization Method

by Jianlin Shi, Jinbo Wang, Linfeng Su, Zhenwei Ma and Hongbo Chen

Aerospace 2022, 9(8), 435; https://doi.org/10.3390/aerospace9080435 - 8 Aug 2022

Cited by 7 | Viewed by 2489

Abstract

The mission of spacecraft usually faces the problem of an unknown deep space environment, limited long-distance communication and complex environmental dynamics, which brings new challenges to the intelligence level and real-time performance of spacecraft onboard trajectory optimization algorithms. In this paper, the optimal [...] Read more.

The mission of spacecraft usually faces the problem of an unknown deep space environment, limited long-distance communication and complex environmental dynamics, which brings new challenges to the intelligence level and real-time performance of spacecraft onboard trajectory optimization algorithms. In this paper, the optimal control theory is combined with the neural network. Then, the state–control sample pairs and the state–costate sample pairs obtained from the high-fidelity algorithm are used to train the neural network and further drive the spacecraft to achieve optimal control. The proposed method is used on two typical spacecraft missions to verify the feasibility. First, the system dynamics of the hypersonic reentry problem and fuel-optimal moon landing problem are described and then formulated as highly nonlinear optimal control problems. Furthermore, the analytical solutions of the optimal control variables and the two-point boundary value problem are derived based on Pontryagin’s principle. Subsequently, optimal trajectories are solved offline using the pseudospectral method and shooting methods to form large-scale training datasets. Additionally, the well-trained deep neural network is used to warm-start the indirect shooting method by providing accurate initial costates, and thus the real-time performance of the algorithm can be greatly improved. By mapping the nonlinear functional relationship between the state and the optimal control, the control predictor is further obtained, which provides a backup optimal control variables generation strategy in the case of shooting failure, and ensures the stability and safety of the onboard algorithm. Numerical simulations demonstrate the real-time performance and feasibility of the proposed method. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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17 pages, 3056 KiB

Open AccessArticle

An Innovative Pose Determination Algorithm for Planetary Rover Onboard Visual Odometry

by Botian Zhou, Sha Luo and Shijie Zhang

Aerospace 2022, 9(7), 391; https://doi.org/10.3390/aerospace9070391 - 19 Jul 2022

Viewed by 1682

Abstract

Planetary rovers play a critical role in space exploration missions, where one of the most fundamental algorithms is pose determination. Due to environmental and computational constraints, real-time pose determinations of planetary rovers can only use low-cost techniques, such as visual odometry. In this [...] Read more.

Planetary rovers play a critical role in space exploration missions, where one of the most fundamental algorithms is pose determination. Due to environmental and computational constraints, real-time pose determinations of planetary rovers can only use low-cost techniques, such as visual odometry. In this paper, by employing the angle-based criterion, a novel pose determination algorithm is proposed for visual odometry, which is suitable for any type of central camera. First, the problem is formulated using the Huber kernel function with respect to the angular residuals. Then, an intermediate coordinate system is introduced between the initial estimation and final refinement. In order to avoid being trapped in periodic local minimums, a linear method is used to further align the reference points between the intermediate and camera coordinate systems. Finally, one step refinement is implemented to optimize pose determinations. The theoretical analysis, the synthetic simulations, and the real experiments show that our proposed algorithm can achieve the best accuracies within similar processing times, compared with the most state-of-the-art algorithms, thereby approving the effectiveness of the proposed algorithm used in planetary rover onboard visual odometry. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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26 pages, 10485 KiB

Open AccessArticle

Design and Analysis of a Novel Floating Docking Mechanism for On-Orbit Refueling

by Zhicheng Sun, Shipeng Li, Huan Zhang, Haiming Lei and Xiaodong Song

Aerospace 2022, 9(7), 365; https://doi.org/10.3390/aerospace9070365 - 7 Jul 2022

Cited by 3 | Viewed by 2591

Abstract

The docking mechanism is a key component for on-orbit refueling technology. In this paper, the design and analysis of a novel floating docking mechanism for on-orbit berthing-based refueling is presented. Compared with traditional berthing and docking, the berthing here is high in success [...] Read more.

The docking mechanism is a key component for on-orbit refueling technology. In this paper, the design and analysis of a novel floating docking mechanism for on-orbit berthing-based refueling is presented. Compared with traditional berthing and docking, the berthing here is high in success rate and low in impact, which is accomplished by stretching out a docking subassembly instead of pulling back the client spacecraft. However, the berthing also has two problems: initial deviations between two spacecraft and an additional force generated by a hard alloy refueling pipe, which both seriously affect the docking operation. Thus, the docking mechanism is designed to have alignment abilities and decrease the additional force as much as possible. Based on the principles above, we introduced spring pins and a helical refueling pipe to design a light, compact, and simple docking mechanism. To further reduce the additional force, we proposed an elliptical-helical pipe and analyzed its mechanical properties. Finally, simulations and experiments were conducted to validate the proposed mechanism. The results show that the proposed mechanism with an elliptical-helical pipe has a high tolerance for linear and angular misalignment and superior dynamic performance during docking. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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15 pages, 4284 KiB

Open AccessArticle

Multisatellite Task Allocation and Orbit Planning for Asteroid Terminal Defence

by Yuelong Luo, Xiuqiang Jiang, Suchuan Zhong, Yuandong Ji and Guohao Sun

Aerospace 2022, 9(7), 364; https://doi.org/10.3390/aerospace9070364 - 7 Jul 2022

Cited by 6 | Viewed by 2401

Abstract

Near-Earth asteroids are a great threat to the Earth, especially potential rendezvous and collision asteroids. To protect the Earth from an asteroid collision, it is necessary to investigate the asteroid defence problem. An asteroid terminal defence method based on multisatellite interception was designed [...] Read more.

Near-Earth asteroids are a great threat to the Earth, especially potential rendezvous and collision asteroids. To protect the Earth from an asteroid collision, it is necessary to investigate the asteroid defence problem. An asteroid terminal defence method based on multisatellite interception was designed in this study. For an asteroid intruding in the sphere of the gravitational influence of the Earth, multiple interceptor satellites are used to apply a kinetic energy impulse to deflect the orbit of the asteroid. First, the effects of planned interception time and planned interception position on the required impulse velocity increment applied to the asteroid are assessed for interception opportunity selection. Second, multiple interceptor satellites are selected to perform the defence task from the on-orbit available interceptor satellite formation. An improved contract net protocol algorithm considering the Lambert orbital manoeuvre is designed to fulfil the task allocation and satellite orbit planning. Finally, simulation experiments demonstrate the rationale and effectiveness of the proposed method, which provides support for asteroid terminal defence technology. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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20 pages, 1620 KiB

Open AccessArticle

The Coupling Orbit–Attitude–Structure Evolution of Rubble-Pile Asteroid with Earth Flyby in the Restricted Three-Body Problem

by Xiangyuan Zeng, Chengfan Feng, Tongge Wen and Qingbo Gan

Aerospace 2022, 9(7), 351; https://doi.org/10.3390/aerospace9070351 - 30 Jun 2022

Cited by 3 | Viewed by 2552

Abstract

Some asteroids flying close to Earth may pose a threat of impact. Among them, the structural and dynamical characteristics of rubble-pile asteroids can be changed because of the tidal force of the Earth in this process. This can provide key information for predicting [...] Read more.

Some asteroids flying close to Earth may pose a threat of impact. Among them, the structural and dynamical characteristics of rubble-pile asteroids can be changed because of the tidal force of the Earth in this process. This can provide key information for predicting the dynamical evolution of potentially hazardous asteroids. In this study, the long-term evolution of the coupling orbit–attitude–structure of these small bodies is presented numerically based on the integration of two models. One is the 3D discrete element method, which models the structure and irregular shape of the rubble-pile asteroid. The other is the dynamical model of the circular restricted three-body problem (CRTBP). This provides a more precise dynamical environment of the asteroid orbital deflection, morphological modification, and attitude angles analysis compared to the frequently adopted two-body problem. Parametric studies on the asteroid evolution were performed focusing on its flyby distance and the bulk porosity. Numerical results indicate that the Earth flyby can form different patterns of modification of asteroids, where the rubble-pile structure can be destructed by considering the bulk porosity. The asteroid orbital deflection and attitude variational trends are also summarized based on the simulations of multi-orbital revolutions. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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17 pages, 2060 KiB

Open AccessArticle

Midcourse Iterative Guidance Method for the Impact Time and Angle Control of Two-Pulse Interceptors

by Yifan Deng, Jinlei Ren, Xu Wang and Yuanli Cai

Aerospace 2022, 9(6), 323; https://doi.org/10.3390/aerospace9060323 - 15 Jun 2022

Cited by 3 | Viewed by 1915

Abstract

To address the need for flexible energy management and impact angle control in the midcourse guidance of modern long-range antiballistic interceptors, an impact time and angle guidance law is designed for the exoatmospheric midcourse flight of antiballistic interceptors, which covers two pulse sections [...] Read more.

To address the need for flexible energy management and impact angle control in the midcourse guidance of modern long-range antiballistic interceptors, an impact time and angle guidance law is designed for the exoatmospheric midcourse flight of antiballistic interceptors, which covers two pulse sections and two coast sections. The problem is described as an optimal control model with discontinuities in the system equations at interior points, and an iterative guidance method is used to efficiently solve the two-point boundary value problem. Simulation results demonstrate the effectiveness of the proposed guidance law; the obtained miss distance accuracy has an order of magnitude of 1 m, and the impact angle accuracy has a 1° order of magnitude while the angle can be achieved. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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12 pages, 3057 KiB

Open AccessArticle

Research on Dual-Arm Control of Lunar Assisted Robot Based on Hierarchical Reinforcement Learning under Unstructured Environment

by Weiyan Ren, Dapeng Han and Zhaokui Wang

Aerospace 2022, 9(6), 315; https://doi.org/10.3390/aerospace9060315 - 10 Jun 2022

Cited by 4 | Viewed by 2503

Abstract

When a lunar assisted robot helps an astronaut turn over or transports the astronaut from the ground, the trajectory of the robot’s dual arms should be automatically planned according to the unstructured environment on the lunar surface. In this paper, a dual-arm control [...] Read more.

When a lunar assisted robot helps an astronaut turn over or transports the astronaut from the ground, the trajectory of the robot’s dual arms should be automatically planned according to the unstructured environment on the lunar surface. In this paper, a dual-arm control strategy model of a lunar assisted robot based on hierarchical reinforcement learning is proposed, and the trajectory planning problem is modeled as a two-layer Markov decision process. In the training process, a reward function design method based on the idea of the artificial potential field method is proposed, and the reward information is fed back in a dense reward method, which significantly reduces the invalid exploration space and improves the learning efficiency. Large-scale tests are carried out in both simulated and physical environments, and the results demonstrate the effectiveness of the method proposed in this paper. This research is of great significance in respect of human–robot interaction, environmental interaction, and intelligent control of robots. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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20 pages, 13785 KiB

Open AccessArticle

Lifetime Extension of Ultra Low-Altitude Lunar Spacecraft with Low-Thrust Propulsion System

by Jingxi Liu, Bo Xu, Chengzhang Li and Muzi Li

Aerospace 2022, 9(6), 305; https://doi.org/10.3390/aerospace9060305 - 3 Jun 2022

Cited by 3 | Viewed by 2610

Abstract

Due to the non-spherical perturbation of the Moon, the lifetime of ultra low-altitude Lunar spacecraft may be quite short. In this paper, we analyze the lifetime of about 50 km-altitude Lunar spacecraft with different initial orbit. The lifetime in low inclination orbits is [...] Read more.

Due to the non-spherical perturbation of the Moon, the lifetime of ultra low-altitude Lunar spacecraft may be quite short. In this paper, we analyze the lifetime of about 50 km-altitude Lunar spacecraft with different initial orbit. The lifetime in low inclination orbits is much shorter than the ones in the near polar orbits. To extend the lifetime and keep the spacecraft in an appropriate range, an orbit maintenance strategy based on low-thrust propulsion system is proposed. The influence of the orbit initial conditions (e.g., semi-major axis, inclination, right ascension of the ascending node) on lifetime extension are discussed and the effect of the low-thrust magnitude in orbit maintenance is analyzed. According to the numerical simulation results, the lifetime of about 50 km-altitude 100 kg Lunar spacecraft with 10 kg fuel and 20 mN thruster can be extended from 7.958 days to over a 109.1725 days, which demonstrates the effectiveness of the strategy. Furthermore, a global perspective for ultra low-altitude Lunar spacecraft lifetime extension problem is provided in this paper, which can be applied to Moon mission designs extensively. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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25 pages, 6828 KiB

Open AccessArticle

Attitude Maneuver and Stability Control of Hyper-Agile Satellite Using Reconfigurable Control Moment Gyros

by Zhi Qu, Gaofei Zhang, Ziyang Meng, Kai Xu, Ruiqin Xu and Jiaojiao Di

Aerospace 2022, 9(6), 303; https://doi.org/10.3390/aerospace9060303 - 3 Jun 2022

Cited by 5 | Viewed by 2808

Abstract

Addressing the problems of insurmountable unknown frictional disturbance and balancing the trade-off between high maneuverability and stability during attitude maneuver are important in low-cost miniaturized single control moment gyro clusters (SGCMGs) for hyper-agile satellite. This paper proposes a new concept of reconfigurable octagonal [...] Read more.

Addressing the problems of insurmountable unknown frictional disturbance and balancing the trade-off between high maneuverability and stability during attitude maneuver are important in low-cost miniaturized single control moment gyro clusters (SGCMGs) for hyper-agile satellite. This paper proposes a new concept of reconfigurable octagonal cone-type SGCMGs by considering practical engineering requirements of hyper-agile satellites. Firstly, the momentum characteristics of typical configurations are quantitatively explained, and the evaluation metrics for SGCMGs based on norm

L_{\infty}

and norm

L_{2}

are defined, respectively. Secondly, a reconfiguration design of SGCMGs from octagonal cone-type into pyramid-type is proposed by analyzing the unknown disturbance mechanism based on SGCMGs. When the hyper-agile satellite is supported to perform fast attitude maneuvers, all units of SGCMGs can work together to output rough and large torque. On the other hand, when the maneuvering ends with stable pointing control, gimbles of one pyramid-type SGCMGs are locked down and fine torque is outputted using another pyramid-type SGCMGs. This will greatly reduce the difficulty of controller design and improve the satellite attitude performance indices. The superiority of the control strategy and selection of the proposed actuator is verified by experiments. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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18 pages, 5998 KiB

Open AccessArticle

Capture Dynamics and Control of a Flexible Net for Space Debris Removal

by Man Ru, Ying Zhan, Bin Cheng and Yu Zhang

Aerospace 2022, 9(6), 299; https://doi.org/10.3390/aerospace9060299 - 1 Jun 2022

Cited by 14 | Viewed by 3956

Abstract

Space debris severely threatens the safety of spacecraft in near-earth orbit. Dragging space debris into the atmosphere to burn is an effective way to remove it. In this paper, the authors focus on capturing irregular and rotating debris via a flexible net. The [...] Read more.

Space debris severely threatens the safety of spacecraft in near-earth orbit. Dragging space debris into the atmosphere to burn is an effective way to remove it. In this paper, the authors focus on capturing irregular and rotating debris via a flexible net. The net capture dynamics, including the constitutive dynamics of the flexible net and the nonlinear contact dynamics with the debris, are established to simulate the movements of the flexible net. The debris dynamics, comprising translational and rotational dynamics, are constructed to simulate its motions throughout the whole process. In addition, an active control scheme is applied to designing the controllers of the flexible net. The presented method can be used to simulate the capture and post-capture process of irregular and rotating debris. Moreover, compared with the previous space debris capture mechanism, the presented flexible net can be opened or closed repeatedly; thus, the proposed flexible net has more potential to capture many pieces of debris in one mission. Numerical simulations show that the flexible net has an excellent capture capability with the presented control scheme. The flexible net can capture the debris rotating with an angular velocity of 6.28 rad/s. Moreover, the debris can be fully enveloped and further dragged away along the expected trajectory. The critical indicator results show that the wrapping of the debris is stable; thus, this method is feasible for future missions. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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21 pages, 4647 KiB

Open AccessArticle

Multi-Layer Fault-Tolerant Robust Filter for Integrated Navigation in Launch Inertial Coordinate System

by Jun Kang, Zhi Xiong, Rong Wang and Ling Zhang

Aerospace 2022, 9(6), 282; https://doi.org/10.3390/aerospace9060282 - 24 May 2022

Cited by 3 | Viewed by 1908

Abstract

As to an aerospace vehicle, the flight span is large and the flight environment is complex. More than that, the existing navigation algorithms cannot meet the needs to provide accurate navigation parameters for aerospace vehicles, which results in the decline of navigation accuracy. [...] Read more.

As to an aerospace vehicle, the flight span is large and the flight environment is complex. More than that, the existing navigation algorithms cannot meet the needs to provide accurate navigation parameters for aerospace vehicles, which results in the decline of navigation accuracy. This paper proposes a multi-layer, fault-tolerant robust filtering algorithm of aerospace vehicle in the launch inertial coordinate system to address this problem. Firstly, the launch inertial coordinate system is used as the reference coordinate system for navigation calculation, and the state equation and measurement equation of the navigation system are established in this coordinate system to improve the modeling accuracy of the navigation system. On this basis, a multi-layer, fault-tolerant robust filtering algorithm is designed to estimate and compensate the unknown input in the state equation in real time and adjust the noise variance matrix in the measurement equation adaptively. Simulation results show that the errors about the integrated navigation system output parameters are reduced, through this algorithm, which improves the attitude, velocity and position estimation accuracy of the integrated navigation system. In addition, the algorithm enhances the fault tolerance and robustness of the filtering algorithm. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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21 pages, 2979 KiB

Open AccessArticle

Nonlinear Covariance Analysis-Based Robust Rendezvous Trajectory Design by Improved Differential Evolution Method

by Kai Jin, Zeyang Yin, Yaolin Lei, Yuanlong Zhang and Xiaolong Zhang

Aerospace 2022, 9(5), 277; https://doi.org/10.3390/aerospace9050277 - 21 May 2022

Cited by 1 | Viewed by 2041

Abstract

This paper presents a robust trajectory design method for approaching and rendezvous with a space target considering multi-source uncertainties. A nonlinear covariance analysis method based on the state transition tensor is presented to formulate the propagation of uncertainties including environment parameter uncertainty, actuator [...] Read more.

This paper presents a robust trajectory design method for approaching and rendezvous with a space target considering multi-source uncertainties. A nonlinear covariance analysis method based on the state transition tensor is presented to formulate the propagation of uncertainties including environment parameter uncertainty, actuator error, sensor noise, navigation error and initial state dispersion of the closed-loop GN&C system. Then, the robust trajectory design problem is defined based on the quantified effect of the uncertainties, and an improved self-adaptive differential evolution algorithm is presented to solve the robust trajectory design problem with uncertainties. Finally, four groups of numerical simulations are carried out to show that the designed robust trajectories can satisfy the final state dispersion constraint under multi-source uncertainties. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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18 pages, 3173 KiB

Open AccessArticle

Maneuvering Spacecraft Orbit Determination Using Polynomial Representation

by Xingyu Zhou, Tong Qin and Linzhi Meng

Aerospace 2022, 9(5), 257; https://doi.org/10.3390/aerospace9050257 - 10 May 2022

Cited by 16 | Viewed by 3290

Abstract

This paper proposed a polynomial representation-based method for orbit determination (OD) of spacecraft with the unknown maneuver. Different from the conventional maneuvering OD approaches that rely on specific orbit dynamic equation, the proposed method needs no priori information of the unknown maneuvering model. [...] Read more.

This paper proposed a polynomial representation-based method for orbit determination (OD) of spacecraft with the unknown maneuver. Different from the conventional maneuvering OD approaches that rely on specific orbit dynamic equation, the proposed method needs no priori information of the unknown maneuvering model. The polynomials are used to represent the unknown maneuver. A transformation is made for the polynomials to improve the convergence and robustness. The Extended Kalman Filter (EKF) is used to process incoming observation data by compensating the unknown maneuver using the polynomials. The proposed method is successfully applicated into the OD problem of spacecraft with trigonometric maneuver. Numerical simulations show that the eighth-order polynomials are accurate enough to represent a trigonometric maneuver. Moreover, Monte Carlo simulations show that the position errors are smaller than 1 km, and the maneuver estimated errors are no more than 0.1 mm/s² using the eighth-order polynomials. The proposed method is accurate and efficient, and has potential applications for tracking maneuvering space target. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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19 pages, 2579 KiB

Open AccessArticle

Spaceborne Atom-Interferometry Gravity Gradiometry Design towards Future Satellite Gradiometric Missions

by Zhu Zhu, He Liao, Haibo Tu, Xiaochun Duan and Yanbin Zhao

Aerospace 2022, 9(5), 253; https://doi.org/10.3390/aerospace9050253 - 6 May 2022

Cited by 7 | Viewed by 3052

Abstract

Atom-interferometry gravity gradiometry has been developed as a promising technique for future gravity gradiometric missions after GOCE due to its greater sensitivity in micro-gravity environments and constant performance over the measurement bandwidth. In this paper, a feasible method of spaceborne atom-interferometry gravity gradiometry [...] Read more.

Atom-interferometry gravity gradiometry has been developed as a promising technique for future gravity gradiometric missions after GOCE due to its greater sensitivity in micro-gravity environments and constant performance over the measurement bandwidth. In this paper, a feasible method of spaceborne atom-interferometry gravity gradiometry is proposed by utilizing the free-fall condition of the cold atoms in space. Compared with GOCE, which shows an in-orbit noise performance of 10~20 mE/Hz^1/2, the scheme described in this paper would achieve a high sensitivity of 1.9 mE/Hz^1/2 for gravity gradients measurement by reducing the orbital altitude and optimizing the interrogation time for atom interferometry. The results show that the proposed scheme could significantly augment the spectral content of the gravity field in the degree and order of 280~316 and resolve the global gravity field with an improved accuracy of 0.2 cm@100 km and 0.85 cm@80 km in terms of geoid height, and 0.06 mGal@100 km and 0.3 mGal@80 km in terms of gravity anomaly after 1270 days of data collection. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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26 pages, 8822 KiB

Open AccessArticle

Characterizing an Air-Bearing Testbed for Simulating Spacecraft Dynamics and Control

by Zheng Huang, Wei Zhang, Ti Chen, Hao Wen and Dongping Jin

Aerospace 2022, 9(5), 246; https://doi.org/10.3390/aerospace9050246 - 1 May 2022

Cited by 8 | Viewed by 3643

Abstract

Ground-based testbeds play a critical role in developing and testing different methods of spacecraft dynamics and control. To find the dynamic behavior in such an air-bearing testbed, a detailed characterization of the testbed must be provided via systematic testing approaches. This paper describes [...] Read more.

Ground-based testbeds play a critical role in developing and testing different methods of spacecraft dynamics and control. To find the dynamic behavior in such an air-bearing testbed, a detailed characterization of the testbed must be provided via systematic testing approaches. This paper describes a planar air-bearing testbed to develop control methods in spacecraft on-orbit operations. This testbed has an almost frictionless surface and can be used to simulate two-dimensional motions in the microgravity environment, with one rotational and two translational degrees of freedom (DOF). The hardware and software architectures of the testbed are presented in detail and key parameters are characterized by a series of systematic test approaches. In addition, a new visual navigation method was designed as an alternative to the external visual system. Finally, two typical case studies are presented to demonstrate the performance of the developed testbed. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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22 pages, 2175 KiB

Open AccessArticle

Optimization of Geostationary Orbit Transfers via Combined Chemical–Electric Propulsion

by Shihai Yang, Bo Xu and Xin Li

Aerospace 2022, 9(4), 200; https://doi.org/10.3390/aerospace9040200 - 7 Apr 2022

Viewed by 3440

Abstract

For geostationary orbit transfers, a long duration is required using electric propulsion and a large propellant mass is needed with chemical propulsion. Hybrid transfers can achieve a balance between the fuel consumption and transfer time. In this paper, a trajectory optimization method is [...] Read more.

For geostationary orbit transfers, a long duration is required using electric propulsion and a large propellant mass is needed with chemical propulsion. Hybrid transfers can achieve a balance between the fuel consumption and transfer time. In this paper, a trajectory optimization method is proposed for time-fixed minimum-fuel orbital transfer with combined chemical–electric propulsion. The necessary conditions and transversality conditions related to impulsive burns are derived theoretically with Pontryagin’s maximum principle. The long-duration geostationary orbit transfer is a many-revolution transfer, and is solved with the homotopic approach from the short-duration transfer problem. The variation in fuel consumption with transfer time is nearly linear, and the variation in the magnitude of impulsive burn is exponential. A simple model is presented for the estimation of fuel consumption and magnitude of impulsive burn with given transfer time, specific impulse of propulsion system and low-thrust magnitude. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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23 pages, 6760 KiB

Open AccessArticle

Orbit-Injection Strategy and Trajectory-Planning Method of the Launch Vehicle under Power Failure Conditions

by Yin Diao, Jialun Pu, Hechuan Xu and Rongjun Mu

Aerospace 2022, 9(4), 199; https://doi.org/10.3390/aerospace9040199 - 7 Apr 2022

Cited by 2 | Viewed by 3295

Abstract

Aiming at the problem of autonomous decision making and trajectory planning (ADMTP) for launch vehicles under power failure conditions, the target degradation order strategy (TDOS) and the trajectory online planning method were studied in this paper. Firstly, the influence of power failure on [...] Read more.

Aiming at the problem of autonomous decision making and trajectory planning (ADMTP) for launch vehicles under power failure conditions, the target degradation order strategy (TDOS) and the trajectory online planning method were studied in this paper. Firstly, the influence of power failure on the orbit-injection process was analyzed. Secondly, the TDOS was proposed according to the mission attribute, failure mode, and multi-payload combination. Then, an online planning method based on the adaptive target update iterative guidance method (ATU-IGM) and radial basis neural network (RBFNN) was proposed, where the ATU-IGM adopted the basic TDOS criterion for generating optimal orbit-injection samples and online guidance instructions, and the RBFNN was used for orbit-injection samples training and online generation of orbital missions. Finally, the comparative simulation analysis was performed under multi-failure conditions. The results showed that the TDOS proposed in this paper could meet the requirements of the mission decision making under different failures, target orbit types, orbit-injection methods, and payload compositions. The online trajectory-planning capability deviation was less than 5%, and the mission decision-making and trajectory-planning time were less than 10 ms. This study provides theoretical support for autonomous decision making and planning of space launch missions. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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23 pages, 1717 KiB

Open AccessArticle

Geostationary Station-Keeping of Electric-Propulsion Satellite Equipped with Robotic Arms

by Chengzhang Li, Bo Xu, Wanmeng Zhou and Qibo Peng

Aerospace 2022, 9(4), 182; https://doi.org/10.3390/aerospace9040182 - 28 Mar 2022

Cited by 4 | Viewed by 4368

Abstract

We propose two approaches based on feedforward control and model-predictive control, respectively, to solve the station-keeping problem of an electric-propulsion geostationary Earth orbit (GEO) satellite, whose thrusters are mounted on two robotic arms on its anti-nadir face. This novel configuration enables a wider [...] Read more.

We propose two approaches based on feedforward control and model-predictive control, respectively, to solve the station-keeping problem of an electric-propulsion geostationary Earth orbit (GEO) satellite, whose thrusters are mounted on two robotic arms on its anti-nadir face. This novel configuration enables a wider range of thrust direction, making it possible to regard the thrust direction as control variables. To solve this control problem, we present the quick feedforward controller (QFFC) and the fuel-optimal model predictive controller (FOMPC). The QFFC is developed based on the analysis of GEO dynamics and the thruster configuration. The FOMPC applies an optimization algorithm to solve the nonlinear model predictive control (NLMPC) problem with the initial value given by the QFFC. Numerical simulations suggest that both controllers could achieve stable station-keeping over multiple objective elements with fewer thrusters and fewer maneuvers. The QFFC has higher control accuracy and lower computational requirements than the FOMPC, whereas the FOMPC could significantly save fuel consumption. The robustness assessment and other discussions of the controllers are also presented. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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21 pages, 6242 KiB

Open AccessArticle

A Beam Search-Based Channel Allocation Method for Interference Mitigation of NGSO Satellites with Multi-Beam Antennas

by Haojie Zhang, Di Ren and Fanghua Jiang

Aerospace 2022, 9(4), 177; https://doi.org/10.3390/aerospace9040177 - 23 Mar 2022

Cited by 7 | Viewed by 4871

Abstract

In the past few years, non-geostationary orbit (NGSO) satellite communication constellations have regained popularity due to their conspicuous advantages. Nevertheless, with more NGSO satellites getting involved in communications, the spectrum resources should become much more scarce. Multi-beam high throughput satellite and spectrum sharing [...] Read more.

In the past few years, non-geostationary orbit (NGSO) satellite communication constellations have regained popularity due to their conspicuous advantages. Nevertheless, with more NGSO satellites getting involved in communications, the spectrum resources should become much more scarce. Multi-beam high throughput satellite and spectrum sharing are two major techniques in communication design. The two techniques can significantly mitigate interference and highly augment the capacity of the communication system. Thus, they are commonly used in satellite communication systems nowadays. With a massive number of NGSO satellites comprising the communication system and moving in their orbits, interference scenarios are pretty complex. In this article, the relationship between the level of interference and the beam distance is deduced. Moreover, for beams with different tilting angles, the different off-axis angles may correspond to the same beam distance, which is directly related to the interference level. Through the interference analysis, we propose a channel allocation method that uses a beam search algorithm to optimize the channel allocation problem and achieves outstanding time efficiency. The performance of the proposed method is validated by a coexisting scenario of the geostationary orbit and NGSO satellite communication systems. The results show that the level of interference can be largely mitigated, and the capacity of communication systems is significantly augmented. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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16 pages, 3790 KiB

Open AccessArticle

Observability Analysis and Improvement Approach for Cooperative Optical Orbit Determination

by Yan Luo, Tong Qin and Xingyu Zhou

Aerospace 2022, 9(3), 166; https://doi.org/10.3390/aerospace9030166 - 18 Mar 2022

Cited by 8 | Viewed by 2780

Abstract

Cooperative orbit determination (OD) using inter-spacecraft optical measurements is an important technology for space constellation missions. In this paper, the observability of a two-spacecraft cooperative OD system is investigated. The influence of geometric configuration on the observability is analyzed, and two special unobservable [...] Read more.

Cooperative orbit determination (OD) using inter-spacecraft optical measurements is an important technology for space constellation missions. In this paper, the observability of a two-spacecraft cooperative OD system is investigated. The influence of geometric configuration on the observability is analyzed, and two special unobservable configurations are identified. Then, an approach to improve the observability by involving an additional spacecraft is proposed. Comparative analysis of system observability shows that an extra spacecraft in the system could change the coplanar and symmetric configuration and improve the observability of the cooperative OD system. Monte-Carlo simulations are carried out, and results verify the observability improvement conclusion. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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19 pages, 3611 KiB

Open AccessArticle

Constrained Motion Planning of 7-DOF Space Manipulator via Deep Reinforcement Learning Combined with Artificial Potential Field

by Yinkang Li, Danyi Li, Wenshan Zhu, Jun Sun, Xiaolong Zhang and Shuang Li

Aerospace 2022, 9(3), 163; https://doi.org/10.3390/aerospace9030163 - 17 Mar 2022

Cited by 25 | Viewed by 6579

Abstract

During the on-orbit operation task of the space manipulator, some specific scenarios require strict constraints on both the position and orientation of the end-effector, such as refueling and auxiliary docking. To this end, a novel motion planning approach for a space manipulator is [...] Read more.

During the on-orbit operation task of the space manipulator, some specific scenarios require strict constraints on both the position and orientation of the end-effector, such as refueling and auxiliary docking. To this end, a novel motion planning approach for a space manipulator is proposed in this paper. Firstly, a kinematic model of the 7-DOF free-floating space manipulator is established by introducing the generalized Jacobian matrix. On this basis, a planning approach is proposed to realize the motion planning of the 7-DOF free-floating space manipulator. Considering that the on-orbit environment is dynamical, the robustness of the motion planning approach is required, thus the deep reinforcement learning algorithm is introduced to design the motion planning approach. Meanwhile, the deep reinforcement learning algorithm is combined with artificial potential field to improve the convergence. Besides, the self-collision avoidance constraint is considered during planning to ensure the operational security. Finally, comparative simulations are conducted to demonstrate the performance of the proposed planning method. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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16 pages, 22713 KiB

Open AccessArticle

Finite-Time Distributed Leaderless Cooperative Guidance Law for Maneuvering Targets under Directed Topology without Numerical Singularities

by Xiaofei Dong and Zhang Ren

Aerospace 2022, 9(3), 157; https://doi.org/10.3390/aerospace9030157 - 13 Mar 2022

Cited by 5 | Viewed by 2457

Abstract

A new distributed leaderless cooperative guidance algorithm is suggested for multi-directional saturation strikes against maneuvering targets. First, the finite-time disturbance observer (FDO) is used to estimate the target’s unknown maneuvers. After that, the guidance laws along the line-of-sight (LOS) direction and the LOS [...] Read more.

A new distributed leaderless cooperative guidance algorithm is suggested for multi-directional saturation strikes against maneuvering targets. First, the finite-time disturbance observer (FDO) is used to estimate the target’s unknown maneuvers. After that, the guidance laws along the line-of-sight (LOS) direction and the LOS normal direction are designed separately based on the finite-time consensus theory. The proposed guidance law could satisfy both impact time and LOS angle constraints. Numerical singularities due to feedback linearization are avoided by nonlinear stability analysis. Finally, the effectiveness of the proposed cooperative guidance law is proved by numerical simulation arithmetic. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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14 pages, 4757 KiB

Open AccessArticle

Bifurcations of Periodic Orbits in the Gravitational Field of Irregular Bodies: Applications to Bennu and Steins

by Yongjie Liu, Yu Jiang and Hengnian Li

Aerospace 2022, 9(3), 151; https://doi.org/10.3390/aerospace9030151 - 8 Mar 2022

Cited by 3 | Viewed by 2333

Abstract

We investigate the topological types and bifurcations of periodic orbits in the gravitational field of irregular bodies by the well-known two parameter analysis method. Results show that the topological types of periodic orbits are determined by the locations of these two parameters and [...] Read more.

We investigate the topological types and bifurcations of periodic orbits in the gravitational field of irregular bodies by the well-known two parameter analysis method. Results show that the topological types of periodic orbits are determined by the locations of these two parameters and that the bifurcation types correspond to their variation paths in the plane. Several new paths corresponding to doubling period bifurcations, tangent bifurcations and Neimark–Sacker bifurcations are discovered. Then, applications in detecting bifurcations of periodic orbits near asteroids 101955 Bennu and 2867 Steins are presented. It is found that tangent bifurcations may occur three times when continuing the vertical orbits near the equilibrium points of 101955 Bennu. The continuation stops as the Jacobi energy reaches a local maximum. However, while continuing the vertical orbits near the equilibrium points of 2867 Steins, the tangent bifurcation and pseudo period-doubling bifurcation occur. The continuation can always go on, and the orbit ultimately becomes nearly circular. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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14 pages, 11231 KiB

Open AccessArticle

Event-Triggered Attitude-Tracking Control for a Cableless Non-Contact Close-Proximity Formation Satellite

by Jirong Qi, He Liao, Yufei Xu, Zhu Zhu and Chaolan You

Aerospace 2022, 9(3), 138; https://doi.org/10.3390/aerospace9030138 - 4 Mar 2022

Cited by 4 | Viewed by 2802

Abstract

The cablelessness of non-contact close-proximity formation satellites can fundamentally avoid the influence of non-contact interface coupling effects and can further enhance the attitude pointing accuracy and stability of the payload module (PM). However, it also brings the problem of limited on-board resources and [...] Read more.

The cablelessness of non-contact close-proximity formation satellites can fundamentally avoid the influence of non-contact interface coupling effects and can further enhance the attitude pointing accuracy and stability of the payload module (PM). However, it also brings the problem of limited on-board resources and system latency. In this paper, an event-triggered attitude tracking controller of the support module (SM) that avoids the Zeno phenomenon was proposed. The update time of the control signal was determined by the event-triggering mechanism based on intermediate variables, thus, reducing the communication burden and actuator asynchrony between the two modules. The feasibility and effectiveness of the proposed approach was demonstrated by numerical simulations. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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21 pages, 8163 KiB

Open AccessArticle

Satellite Cluster Formation Reconfiguration Based on the Bifurcating Potential Field

by Wanying Gao, Kehang Li and Chunling Wei

Aerospace 2022, 9(3), 137; https://doi.org/10.3390/aerospace9030137 - 4 Mar 2022

Cited by 5 | Viewed by 2975

Abstract

The satellite cluster formation reconfiguration has received considerable attention in recent years. However, the traditional centralized control methods are challenging to apply to satellite clusters because of the enormous fuel consumption, and few studies have addressed the mathematical characterization of satellite clusters. This [...] Read more.

The satellite cluster formation reconfiguration has received considerable attention in recent years. However, the traditional centralized control methods are challenging to apply to satellite clusters because of the enormous fuel consumption, and few studies have addressed the mathematical characterization of satellite clusters. This research aims to propose a mathematical characterization method for satellite clusters and investigate the formation reconfiguration control of satellite clusters. This study provided the five-element characterization method to represent the cluster characteristics and internal correlation characteristics of orbiting satellite clusters. In addition, a control method based on bifurcating potential fields was proposed to realize satellite cluster formation’s dynamic migration and rapid reconfiguration. A cluster with 50 satellites was simulated to verify the feasibility and effectiveness of the proposed formation control algorithm. The results show that various formation topologies were achieved by simply changing the bifurcation parameter and configuration adjustment parameters. The five descriptive elements of the satellite cluster can intuitively and effectively reflect the running state of the satellite cluster. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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22 pages, 5081 KiB

Open AccessArticle

Autonomous Trajectory Generation Algorithms for Spacecraft Slew Maneuvers

by Andrew Sandberg and Timothy Sands

Aerospace 2022, 9(3), 135; https://doi.org/10.3390/aerospace9030135 - 3 Mar 2022

Cited by 62 | Viewed by 7811

Abstract

Spacecraft need to be able to reliably slew quickly and rather than simply commanding a final angle, a trajectory calculated and known throughout a maneuver is preferred. A fully solved trajectory allows for control based off comparing current attitude to a time varying [...] Read more.

Spacecraft need to be able to reliably slew quickly and rather than simply commanding a final angle, a trajectory calculated and known throughout a maneuver is preferred. A fully solved trajectory allows for control based off comparing current attitude to a time varying desired attitude, allowing for much better use of control effort and command over slew orientation. This manuscript introduces slew trajectories using sinusoidal functions compared to optimal trajectories using Pontryagin’s method. Use of Pontryagin’s method yields approximately 1.5% lower control effort compared to sinusoidal trajectories. Analysis of the simulated system response demonstrates that correct understanding of the effect of cross-coupling is necessary to avoid unwarranted control costs. Additionally, a combination of feedforward with proportional derivative control generates a system response with 3% reduction in control cost compared to a Feedforward with proportional integral derivative control architecture. Use of a calculated trajectory is shown to reduce control cost by five orders of magnitude and allows for raising of gains by an order of magnitude. When control gains are raised, an eight orders of magnitude lower error is achieved in the slew direction, and rather than an increase in control cost, a decrease by 11.7% is observed. This manuscript concludes that Pontryagin’s method for generating slew trajectories outperforms the use of sinusoidal trajectories and trajectory generation schemes are essential for efficient spacecraft maneuvering. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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24 pages, 5385 KiB

Open AccessArticle

Discrete-Time Attitude Tracking Synchronization for Swarms of Spacecraft Exploiting Interference

by Peiran Li, Xin Wen, Mohong Zheng, Haiying Liu, Dizhi Long and Yuping Lu

Aerospace 2022, 9(3), 134; https://doi.org/10.3390/aerospace9030134 - 3 Mar 2022

Cited by 1 | Viewed by 2100

Abstract

The attitude tracking synchronization control of an orbit-predetermined leader–follower spacecraft swarm for the space moving target is discussed in this paper. The information exchange between all spacecraft is assumed to be discrete in time and on the undirected connected graph. Moreover, due to [...] Read more.

The attitude tracking synchronization control of an orbit-predetermined leader–follower spacecraft swarm for the space moving target is discussed in this paper. The information exchange between all spacecraft is assumed to be discrete in time and on the undirected connected graph. Moreover, due to the demand for saving communication resources, wireless interference has been utilized, which allows all the neighbors of a spacecraft to access the same channel frequency spectrum simultaneously. Then the backstepping control algorithm is designed to let the spacecraft

(β, A)

-practically stably synchronize their states and track a time-varying trajectory in the presence of unknown fading channels. Finally, simulation is provided to verify that using the proposed control scheme, the attitude tracking synchronization can be achieved with high precision. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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18 pages, 1404 KiB

Open AccessArticle

Design of a Low-Cost Air Bearing Testbed for Nano CMG Maneuvers

by Charalampos Papakonstantinou, Georgios Moraitis, Vaios Lappas and Vassilis Kostopoulos

Aerospace 2022, 9(2), 95; https://doi.org/10.3390/aerospace9020095 - 12 Feb 2022

Cited by 8 | Viewed by 4336

Abstract

In this paper, a low-cost, miniature spacecraft attitude control simulator is presented for testing miniature actuators such as Nano Control Moment Gyroscopes (CMGs) for simple maneuvers. The experimental setup is composed by an attitude control system (ACS) that mainly consists of a four-CMG [...] Read more.

In this paper, a low-cost, miniature spacecraft attitude control simulator is presented for testing miniature actuators such as Nano Control Moment Gyroscopes (CMGs) for simple maneuvers. The experimental setup is composed by an attitude control system (ACS) that mainly consists of a four-CMG cluster in a pyramid configuration and a custom-made air bearing. The one-degree-of-freedom (DoF) air bearing is fabricated to reproduce the frictionless conditions of a nano-satellite in orbit. The ACS is made exclusively using low-cost commercial-off-the-shelf (COTS) components, whilst the air bearing is made using 3D-printed parts. Both hardware and software implementations are described in detail and the performance of the developed simulator is evaluated by two maneuver experiments. Despite the manufacturing imperfections, the ACS is capable of providing higher angular velocities than previously presented in the literature while following the theoretical or simulation data. The results indicate that it is possible to manufacture a low-cost, miniature actuator such as a CMG, using COTS components to demonstrate the operation of an agile nano-satellite. Any deviations from the theoretical values are addressed and several improvements are discussed to further enhance the performance of the air bearing testing platform. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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Review

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22 pages, 3629 KiB

Open AccessReview

A Review of Spatial Robotic Arm Trajectory Planning

by Ye Dai, Chaofang Xiang, Yuan Zhang, Yupeng Jiang, Wenyin Qu and Qihao Zhang

Aerospace 2022, 9(7), 361; https://doi.org/10.3390/aerospace9070361 - 6 Jul 2022

Cited by 28 | Viewed by 9043

Abstract

With space technology development, the spatial robotic arm plays an increasingly important role in space activities. Spatial robotic arms can effectively replace humans to complete in-orbit service tasks. The trajectory planning is the basis of robotic arm motion. Its merit has an essential [...] Read more.

With space technology development, the spatial robotic arm plays an increasingly important role in space activities. Spatial robotic arms can effectively replace humans to complete in-orbit service tasks. The trajectory planning is the basis of robotic arm motion. Its merit has an essential impact on the quality of the completed operation. The research on spatial robotic arm trajectory planning has not yet formed a broad framework categorization, so it is necessary to analyze and deeply summarize the existing research systematically. This paper introduces the current situation of space obstacle avoidance trajectory planning and motion trajectory planning. It discusses the basic principle and practical application of the spatial robotic arm trajectory planning method. The future development trend has also been prospected. Full article

(This article belongs to the Special Issue Recent Advances in Spacecraft Dynamics and Control)

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