Based on the relative motion dynamic model described by C-W equations, and by considering parameter uncertainties characterized by the norm-bounded method and the control input constraints in practice, a robust orbit design approach is proposed for the spacecraft rendezvous engineering. By introducing a Lyapunov function, the design problem is cast into a convex optimization problem subject to linear matrix inequalities. By solving this optimization problem, the robust controllers satisfying the requirements can be designed.

A standard autonomous astronomical navigation method is based on the information of the earth sensor and the star sensor. The extended Kalman filter (EKF) is implemented to estimate the position vector of the spacecraft according to the spacecraft dynamics model and the measurements from these sensors. In order to decrease the estimation error of the filter during orbit maneuvers of the spacecraft, an adaptive robust extended Kalman filter (AREKF) is designed for spacecraft autonomous navigation. The simulation results show that the AREKF can effectively depress the unfavorable effect of thrust uncertainties, and the navigation performance is improved effectively without additional sensors. The estimate of the AREKF is more accurate than ones of the EKF and the adaptive extended Kalman filter (AEKF).

Sensors are important components in a satellite navigation system, so both fault detection and identification for them are of great significance for the reliability improvement of system. In this paper, a sensor fault identification method based on fuzzy logic for the satellite navigation system is presented. First of all, the satellite navigation system is described by the T-S fuzzy model, and then full de-coupled parity equations are applied to detect faults, and a Kalman filter is used to identify fault parameters. Simulation results show that, in case of multiple sensor faults in the navigation system this method can effectively detect them and accurately identify their parameters.

A method for designing attitude stabilization controllers is proposed in this paper for flexible spacecraft without angular velocity measurements. In order to solve the attitude control problem when the angular velocity is not available due to gyro failure or gyroless configuration, a velocity-free attitude regulation controller is proposed in this paper based on quaternion with the global asymptotic stability of the closed loop system proved by combining the Lyapunov direct method with the LaSalle’s theorem. An improved controller is also designed in this paper. Numerical simulations demonstrate the effectiveness of the proposed method.

This paper proposes a fault-tolerant reconfigurable controller for attitude control system of spacecrafts with abrupt changes of centroid. A novel interacting multiple model algorithm, based on the Unscented Kalman filter and a performance index using output residuals, is presented to diagnose the faults. Once a fault is detected and isolated, controller parameters can be reconfigured to compensate the loss of performance and keep the good attitude tracking accuracy of the spacecraft. Numerical simulations validate the effectiveness of the proposed method.

The safety of angular contact ball bearing in CMG under random vibration is investigated. The axial stiffness and radial stiffness of the bearing under both axial force and radial force are derived firstly, then an equivalent linear spring model is established so that the axial force and radial force of the bearing under random vibration can be iteratively obtained using the spectrum analysis of ANSYS. The safety is valuated by comparing radial equivalent static load and axial load with radial base rated static load and limit axial load separately. An analysis of a type of angular contact ball bearing under given input power spectrum density is performed. The result demonstrate that the bearing is safe in any load direction.

Based on varieties of the inertia matrix for a combined spacecraft separated, this paper proposes a adaptive control algorithm. Attitude quaternion is adopted to establish the model of the kind of spacecraft, and based on the Lyapunov stability theory, the algorithm is designed by the backstepping control method. Theoretical analysis proves the algorithm be stable, and the simulation results confirm the effectiveness of the algorithm.

This paper first establishes a satellite orbit dynamics model perturbed by the Earth’s non-spherical gravity, and then develops a numerical orbit propagator programmed by C++ language, with the Runge-Kutta-Fehlberg 7(8) integrator. In this modeling process, the precession, nutation and some other astronomical quantities are considered through two standards released by U.S. Naval Observatory in 1981 and 2005, respectively. By comparing the simulation results with that of the professional software STK, it shows that the magnitudes of position vector differences between these two standards and STK are both not more than the decimeter level, and that of velocity vector differences are both not more than the level of millimeter per second. Therefore, the model and orbit propagator are both prove to be valid, and the difference of orbit propagation caused by referencing the old and new standards is slight.

The measurement accuracy of Sun Sensor is mainly influenced by earth albedo. In this paper, a model about energy attenuation for sunlight incident upon CCD Sun Sensor in large angle is proposed. Through computing peak value of earth albedo irradiance, the influence is correlated with sunlight’s incident angle in theory. For instance, the irradiance produced by earth albedo is comparable to that of the Sun, when the Sun appears in the edge of field of view of CCD Sun Sensor and earth albedo appears in the worst condition. Finally a method about the improvement of structural parameter of Sun Sensor to decrease the influence of earth albedo on Sun Sensor is presented.

Stellar instrument magnitudes are important for star trackers; however, there are not simple and accurate methods to estimate stellar instrument magnitudes. In this paper, a method using color indexes to compute instrument magnitudes is proposed. On the analysis of errors, better data is got by using the improved method. Because the errors are not greater than 0.1 magnitude, the data satisfy requirements of the star sensors.

The structures of various motion simulators for spacecraft’s rendezvous simulation test are discussed with the emphasis on simulators for RVD proximity operation phase in this paper. A new 9-DOF simulator concept of 3+6 type with a cross beam on ground is presented. And then a new 9-DOF simulator concept of 4+5 type is presented. Finally a new concept of simple pose simulator is proposed and this is the only simulator with wider range.

In order to guarantee high-accuracy navigation independent of GPS/GLONASS during long time and long range running, a combined land navigation system using the odometer(OD) and geographic information system(GIS) assisted with the laser-gyro strapdown inertial navigation system(LSINS/OD/GIS) is described in this article. Based on error estimation equation, an automatic zero updating function and odometer parameter calibration and the navigation azimuth error correction by GIS position information synthetically are proposed, using the GIS position information and possible temporary parking states. The results of accuracy verification test are also presented, indicating divergent velocity of main errors has been effectively reduced.

Visualization simulation of satellite orbiting the earth can display the satellite’s orbit and attitude motion intuitionisticly and really. The STK is an important tool for satellite simulation and analysis. It can display 2D and 3D graphics of the satellite. This paper studies the core technique of STK/Connect, makes use of the windows sockets and multi-threads programming technology, and develops the drive program for STK realtime visualization simulation. This drive program receives the data from the telemetry simulator computer according to the UDP protocal, then drives the STK runing through communicatting with the STK’s connect module. Results show that the drive program can realize the realtime simulation for satellites.