The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper studies the finite time attitude control of a satellite with flexible appendages when the velocity measurements are not available in the condition of external disturbances and model uncertainties. First a dynamic model which considers the coupling effect between the motion of the rigid hub and the deformation of the flexible appendages is build. Then a terminal sliding mode observer is...
A novel model of space electromagnetic docking is established to solve the problem of traditional plume contamination and short service life in this paper. A new modelling technique regarding space electromagnetic docking for CubeSat is proposed. The mathematical model with four core-containing energized solenoids is derived and simplified to the magnetic dipole far-field model of single-turn coil...
The control problem of underactuated spacecraft chaotic attitude motion is investigated based on exponential reaching law in this paper. First, the underactuated spacecraft chaotic attitude system is written in nonlinear equation form with two controls. Once the trajectory planning of angular acceleration is preset, the dynamics equation of angular velocity error can be obtained. Then, the sliding...
The six-degrees-of-freedom relative motion tracking control of a rigid spacecraft is investigated in this paper. In view of the model uncertainties and external disturbances, the relative coupled translational and rotational dynamics are modeled with the aid of the exponential coordinates on the Lie group SE(3). Then, a fast terminal sliding mode controller is designed to make sure the tracking control...
This paper investigates the design method of full order state observer for satellite attitude control system using mixed H2/H∞ optimal approach. A linear system described by state space form is introduced first to state the problem of full order state observer design. The designed observer should meet the requirement of H2 performance and H∞ performance so that the disturbance would influence the...
Due to the space missions' limited budget, microsatellite would be an economical choice, so there has been a great decrease in size and weight. Micro satellite is vulnerable to space environmental disturbances and perturbation of controller. As to the multiplicative perturbation in attitude controller, this paper investigates a robust H∞ controller design with model uncertainties and subject to external...
In order to effectively reduce the volume, mass and cost of the attitude measurement unit (AMU) of the satellite, as well as to ensure that the reliability of the whole system is proper, this paper presents a hardware design method of AMU based on multiple MEMS gyroscopes. Using the modular design method, the scalability of system and the interchangeability between modules are effectively improved...
Guidance is critical for a probe to land on the moon surface successfully. This paper mostly discusses about the guidance law in deceleration process of lunar soft landing. Based on some hypothesis, it creates the dynamics model which is built in the coordinate system of soft landing. Then the suboptimal fuel-consuming guidance law is designed for the purpose of reducing fuel consumption. Output errors...
This paper brings forward a structural damage identification method that integrates energy characteristics of intrinsic mode functions (IMFs) and BP neural networks. This method begins with decomposing acceleration response of structure into the IMFs by EMD and calculates the model energy feature of signal. The input vectors, which are got by combination of IMF model energy feature from the different...
Tree Augmented Naïve Bayes Network (TAN) classifier has shown excellent performance in Machine Learning and Data Mining in spite of the assumption of one- dependence of attributes. This paper proposes a new approach of classification under the possibilistic network (PN) framework with TAN, named tree augmented naïve possibilistic network classifier (TANPC), which combines the advantages of the PN...
In this paper, the relative navigation algorithm of chaser spacecraft with orbit maneuvering is investigated. Based on the relative motion dynamic model and linear relative measurement model, a robust H∞ filter for chaser spacecraft is proposed, which contains affine norm-bounded uncertainties, disturbances, and non-Gaussian noise. The necessary and sufficient conditions for the existence of robust...
This paper presents the Lyapunov-based decentralized adaptive control scheme for a laser beam steering system with a piezo-electric mirror. This controller which this paper designs effectively solves the problem that the piezoelectric steering system is complex dynamics and can not know state of controlled plant. The system uses a decentralized control technology which decouples the interaction of...
This paper mainly provides a modal parameter identification method based on combination of extremum field mean mode decomposition (EMMD) and random decrement technique (RDT), which is applied to structures under ambient excitation. In this method, firstly, a number of intrinsic mode functions (IMFs) are decomposed from acceleration response of structure under ambient excitation by using EMMD. Next,...
Control of relative position and orientation are usually split into two parts in rendezvous and docking missions. It is simple but not precise enough. Based on dual number, this paper derives coupled dynamics equations of two spacecrafts in which the coupling effect of relative position and orientation is indicated. Furthermore, an incremental PID control law is designed to control the coupled system...
The problem of attitude tracking control for rigid satellite is studied in this paper. Based on the dynamic equation and kinematics equation using error quaternion and error angular velocity, a sliding mode controller is initially designed to solve this problem. In order to avoid inherent chattering of sliding mode control and then improve control effect, a disturbance observer is introduced and included...
This paper presents an adaptive model reference scheme for laser-beam steering by an acousto-optic steering system which is a novel nonmechanical control system. The controller this paper designs effectively solves the optical communication system performance worsening problem because of the nonlinearity and the parameters drift of the acousto-optic devices and the pointing error of the satellite...
A fuzzy logic controller is designed for the attitude control of a staring-imaging satellite in LEO. The attitude kinematic and dynamic equations based-on Euler-Angle representations are developed; then, a FLC (Fuzzy Logic Control) law is designed for a staring-imaging satellite; finally, the simulations are performed. Comparing with traditional control methods, the method proposed here has quick...
The paper presents a quaternion-based attitude control algorithm which is subject to control input constraints for rigid spacecrafts. Lyapunov theory is employed to prove the global asymptotic stability of the zero equilibrium points of the close loop system. Also the algorithm is validated by the corresponding hardware-in-the-loop (HIL) simulation using a single-axis air bearing table and other hardware...
The computation of image motion velocity is the premise of high resolution optical imaging. To solve this problem, the model of image motion velocity for spaceborne cameras is established in this paper. The positions of a target and the pixel plane are expressed in the camera coordinate system based on five coordinate systems and multiply coordinate translations. The calculation formulas of target...
Based on the RTPS protocol and the NDDS network messaging middleware, a distributed real-time simulation network of satellite system is developed with Constellation software. Considering the structure feature of actual satellite, the module decomposition technique of distributed simulation is discussed in this paper. And with the RTPS protocol and NDDS network middleware, a synchronous control of...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.