Considering laser radar as the relative navigation sensor during space rendezvous and docking, and special situation in the future, a relative navigation filter algorithm with non-cooperative target eradiating against radar signal is investigated. Considering large calculation mount with high-dimension model, traditional particle filter algorithm is improved, and compared with EKF through simulation. The simulation result shows that the filtering effect of improved particle filter is much better than the EKF, and the calculation mount is largely reduced compared with traditional particle filter.

Most studies of star image location of star sensors are limited in static state conditions at present, however, the star spot is moving during exposure as a result of satellite rotation, thus influencing the location accuracy of the star image center. In this paper the accuracy of star image center location in dynamic state is analyzed for active pixel sensor (APS) based star sensors. First of all, sources of the location errors produced by the centroid algorithm are analyzed, a dynamic accuracy estimation method is proposed, and corresponding formulas are deduced. Then choice of the calculation window and the exposure time influencing the dynamic accuracy is analyzed based on given APS star sensor parameters. Finally, corresponding simulations are made to validate the conclusions.

This paper establishes the model of vernier thrusters for spacecrafts using thrust vector control. The thrust vector control allocation algorithm is proposed based on the analysis of the constraints of vernier thrusters. The sequential quadratic programming based thrust vector control allocation algorithm can minimize the torque errors and thrust errors. Numerical simulation shows that this method can be used to obtain preferable allocation results and the control allocation method is feasible and effective.

This paper presents an integral sliding mode control with adaptive parameters for a class of systems satisfying some conditions when the upper bounds of uncertainties are unknown. The switching function includes the integral of tracking error to avoid assuming that the derivative of desired signal must be known in conventional sliding mode variable structure control. This control approach uses the parameter adaptive algorithm based on the Lyapunov method to make the system reject disturbances. The proposed method is applied to slowly rotating non-cooperative target in an arbitrary elliptical orbit synchronous fly-around position tracking control. Simulation results indicate that the control approach is robust and improves the tracking accuracy considerably.

Autonomous midcourse correction is a key technique to facilitate autonomy of an interplanetary spacecraft. Using B-plane parameters as target parameters and impulse control method combined with linear guidance, an autonomous orbit correction method used during cruise phase of interplanetary orbit is proposed.First, the navigation system periodically determines positions and velocities of the spacecraft. The state is than mapped forward to the B-plane by integrating the dynamics model precisely. If deviation from the desired encounter condition is large enough and isn’t out of the capability of autonomous midcourse correction system, the velocity increment for correction maneuver is computed by using linear guidance formula combined with Newton iteration method. The sensitivity matrix of target parameters relative to control parameters is numeri-cally computed using finite central difference formula. Monte Carlo Simulation shows that this method is capa-ble of guiding the spacecraft to a successful encounter.

By designing a speed and attitude control system based on adaptive neural network compensation，this paper presents a solution of solving the cruise tracking control problem for the stratospheric airship. An adaptive RBFNN (Radial Basis Function Neural Network ) is used to compensate modeling errors, which come from the approximate model applied to a regular linear controller design. The network weight adaptation rule, derived from Lyapunov stability analysis, guarantees that the adapted weight errors and the tracking errors are bounded. The controller design exploits only a little information of model parameters. Simulation results demonstrate the excellent performance and robustness of the controller, even if environmental winds with unknown information exist.

A universal improved nonlinear longitudinal model of a hypersonic vehicle developed by the Langley lab is adopted. For its I/O linearized model, a sliding mode controller is designed. This method can solve the uncertainty problem and it is insensitive to disturbances. The index approach law used to drive the sliding mode to reach the sliding surface is adopted to eliminate the quiver. The simulation results for tracking the height step and velocity step order at cruise condition show that the sliding mode controller with index approach law acquires satisfying tracking ability and strong robustness. The controller can not only track the single height step order or velocity step order accurately, but track the height step order and velocity step order together fleetly with zero error. In addition, the sliding controller with index law is better than the one with sign function in tracking speed and precision. Another result is also proved that the index approach law can eliminate the quiver perfectly.

Analyzing the switching process of Keil C51 in BANK compile mode, this paper proposes a method using a BANK switching technique to solve the problem that only 64K bytes of code space can be accessed in a single-chip computer. On the basis of this analysis this paper presents and validates a design method on software and hardware, thus solving the problem that the typic 8051 only provides 16 address lines for addressing code space in spacecraft equipments.

Deployment and retrieval of a tethered satellite system is the basic issue of its application while the control scheme by varying the tension force of the tether has not been well investigated. In the article the tension force is considered as the control force and discretized in the time domain. The particle swarm optimization optimal algorithm is then used to search the optimal value fitting the optimal index in the feasible zone, thus obtaining the changing law of the control force. This control scheme can make the tethered satellite deploy to the equilibrium position in a short time under the optimal index of least swing and least time. Meanwhile, it is suitable to the retrieval. The simulation results shows this control law costs shorter time and less lateral swing compared with the control law based on varying the speed of deployment and retrieval. So it has some certain advantages.

To study evolving characteristics of a retrograde geosynchronous orbit influenced by major environmental forces, an orbit dynamics model suitable for numerical simulations is given and solved by the advanced RKDP method. Numerical solutions are periodically summed and averaged to get rid of short-periodic-term effects. By analyzing polished data, its orbit characteristics are revealed to us.

Soldering seal is one of the most important processes in the flywheel assembly procedure. Appropriate distribution of temperature field is needed to ensure the quality of the soldering. In this paper, a temperature field of a flywheel is simulated and analyzed. And then, calculated results are compared with experimental data. The results show that calculated results are coincident with experimental data, and the finite element analysis model indicates the temperature field distribution in the soldering process correctly.

A target spacecraft’s orbit must be designed for an orbit rendezvous mission. A new optimization approach is proposed for the mission by bringing both orbit keeping and phasing into effect simultaneously. Orbit keeping is to control the station and the shape of the target orbit, while orbit phasing is to make the initial phase angle desired for rendezvous. In this paper, considering such constraint conditions as the right ascension of ascending node and the inclination coresponding to the chaser spacecraft according to the rendezvous window, the resulting problem for the target orbit design is transformed into a nonlinear program-ming problem,then a sequential quadratic programming method is employed to obtain the solution. The calculation and simulation results show that application of this method not only can meet mission’s requirements with fewer maneuvers, but also can save propellant, so this work is useful for the mission planning of rendezvous and docking.