According to the analysis of satellite orbit dynamics,the mathematic description of the trajectory tracking control problem is formulated based on the state space representation of trajectory tracking control systems.A parametric approach is proposed for the satellite trajectory tracking problem by using the eigenstructure assignment theory and the model reference theory of linear systems.A feedback stabilizing controller and a feed-forward tracking controller are built.The designed controllers are applied to the satellite control system and simulation results are given under the hovering over and flying around command signals,which show the effect of the proposed method.

The paper presents a detail test method of electrostatic discharge(ESD)for infrared earth sensor.By analyzing the space environment and the structure characteristics of the satellite in GEO,the surfaces of the satellite exists the possible conditions of ESD.By the ESD experiment,the paper finds the sensitive location of infrared earth sensor easy to be disturbed,and also provides its corresponding measures.

A novel indirect adaptive fuzzy control scheme is proposed for the concerted driving control of six-wheel lunar rover.Based on the Lyapunov theory,it is proven that the designed scheme not only makes the tracking errors converge to a small neighborhood of the origin,but also reduces the tracking errors through increasing the value of designed parameters,and the control accuracy is improved.Simulation results on the concerted driving control of lunar rover verify the efficiency of the approach proposed.

There exist periodic disturbances in the process of elliptical orbit formation maintaining control.In this paper,a linear periodically-varying optimal quadratic regulator is designed by combining the internal model principle with the characteristics of periodically-varying coefficients in dynamics equations.High accuracy of control is achieved by adding the disturbance internal models to the index in the optimal control.Numerical simulations show that the proposed controller containing some disturbance internal models can improve the formation maintaining accuracy a lot for the elliptical orbit.

Measurement error of a star sensor is restricted by varying ambient temperature and solar irradiance.Effect of barrel’s thermal deformation on measurement error of a star sensor is analysed in this paper.The tilting and shifting of the lens caused by barrel’s thermal deformation are calculated for a typical optical system of star sensor.Displacement of star image point and its energy distribution are analyzed.When barrel’s temperatures change uniformly 20℃,measurement errors of the star sensor are about 0.6″ and 0.9″ for cylindrical and conical barrel respectively.When temperature differences of barrel are 30℃,measurement errors are about 2.2″ and 3.3″ for cylindrical and conical barrel respectively.Results show that cylindrical barrel’s thermal stabilization is better than conical barrel’s.

The scanning infrared sensor is used to measure the geocentric vector.Accuracy of the measurements of the geocentric vector is affected by the earth oblateness.This paper discusses the correction algorithms of measurements of the scanning infrared sensor based on earth oblateness and its application in the double-cone scanning infrared earth sensor and then presents a correction algorithm.The simulation shows its validity.

This paper deals with the linear systems with parametric faults.A control strategy based on the linear quadratic form is proposed.It significantly reduces the degradation of performance that results from the time delay needed for the fault tolerant control algorithm.Simulations on an aircraft model show the efficiency of the proposed method.

　Through analyzing fitting curves of software reliability(SR)models,this paper shows that the inherent feature is one of factors affecting adaptability of SR models.Furthermore,a new method for enhancing model adaptability through building model group is put forward.Practices suggest that the above method is feasible.

　A variable structure output feedback control method with disturbance compensation is presented under control torque saturation for the flexible spacecraft.In this method,the variable structure output feedback control suppresses the vibration of flexible appendages,the unknown dynamics and disturbing torques are estimated by an extended state observer and are compensated on line.The simulation results show the method is effective.

This paper investigates the possibility of designing the visualization simulation system for hypersonic vehicle based on STK.A method is presented for creating three-dimensional model of hypersonic vehicle and simulating the space and geography environment.The real time distributed simulation is realized by taking use of the STK/Connect modules.The simulation result shows that the system based on STK satisfies the requirements of task.

A mathematic model of the pressure regulation unit for electric propulsion system is established.Based on the software named Matlab/Simulink,the influence of several important parameters on the system is analyzed.The simulation results show that by applying the bang-bang control,high accuracy and performance can be expected.

A method using finite element analysis in Maxwell 2D/3D is of great benefit to optimal design of solenoid valve and evaluation of scheme.The working current curves and magnetization curves are obtained in this way.By comparison between the test data and simulation results,the analysis method is proved to be effective.

Accurate relative position and velocity determination are required for formation flying of spacecrafts.The comparison of EKF and UKF algorithms for relative navigation based on carrier differential global position system for formation flying is given in this paper.Simulation results indicate that the UKF has better accurate but longer computation time than the EKF since difference of filter’s principles.Both filters are used in practical application for consideration of navigation system redundancy and reliability.

The attitude control problem of low earth orbit(LEO)satellites actuated by magnetorquers only is investigated.By linearizing the nonlinear dynamic and kinematic equations of rigid satellites,a linear periodically time-varing system is obtained.The linear quadratic optimal regulator theory is applied to design an optimal control law for magnetorquers.Simulation results show that the designed optimal magnetic control law can stabilize three-axis attitude of satellites effectively.