In this article, we present the novel approaches of characterizing and modeling the dynamic hystereses for magnetostrictive actuator. The output vs. input loops of the actuator exhibit dynamic hystereses with the different frequencies and amplitudes of sinusoidal currents. Experimental characterization of the dynamic hysteresis of the magnetostrictive actuator is conducted. Three indexes are quantitatively defined, i.e., loop relative width, loop asymmetry degree, and output nonlinearity degree. The polynomial-modified Prandtl-Ishlinskii（PMPI） and adaptive infinite impulse response（IIR） integrated modeling approach is proposed to perform the dynamic hysteresis identification. Therein, the PMPI model is utilized to describe the hysteresis, while the dynamics is modeled via the IIR model. The parameters of PMPI and IIR model are acquired by the data-fitting and recursive least squares（RLS） algorithm respectively. Experimental characterization results show that the magnetostrictive dynamic hysteresis possesses strong nonlinear and asymmetry. Comparison of theoretical modeling and measurement results demonstrates that the PMPI and adaptive IIR integrated model is effective to describe dynamic hysteresis of the magneostrictive actuator.

In this paper, we study the dynamics properties of the space-based network system which is subject to white noise in a confrontation environment. From the perspective of competition and coexistence, we discuss the balance of three kinds of space-based network systems, including the growth rate and failure rate of spacecraft or satellites in white noise interference systems. First, mathematical tools such as Itô’s formulas are used to derive the balance of the system. Second, we use simple constant coefficient stochastic differential equations to predict and simulate the competition and cooperation of the space-based system, and then the complex system is simplified. Finally, use the discrete method given by Milstein to simulate the solution of the stochastic system. And then, through the numerical simulation, the balance of competition and cooperation of the space-based network system under confrontation environment are proved. In addition, some future research directions are introduced in the conclusions.
© 2021, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

With the increasing of spacecraft launch missions, the number of spacecraft module maintenance tasks also increases, so the path planning link plays a crucial role in the online virtual module maintenance task operation of spacecraft. Since A large amount of qualitative/quantitative method analysis is required in the process of writing the traditional maintenance report, the A^* algorithm is adopted in this paper to search the path for the on-orbit module maintenance task of the spacecraft. Firstly, the abstract model of spacecraft in orbit cabin is built with unity 3 D, and then the search point is controlled to move to the target point based on C#. Finally, in the process of gradually adjusting C# parameters, the optimal parameters are obtained and the path planned by A^* algorithm is displayed. Simulation results show that this method can plan an efficient and safe maintenance path in virtual maintenance environment.

With the increasing of spacecraft launch missions, the number of spacecraft module maintenance tasks also increases, so the path planning link plays a crucial role in the online virtual module maintenance task operation of spacecraft. Since A large amount of qualitative/quantitative method analysis is required in the process of writing the traditional maintenance report, the A∗ algorithm is adopted in this paper to search the path for the on-orbit module maintenance task of the spacecraft. Firstly, the abstract model of spacecraft in orbit cabin is built with unity 3D, and then the search point is controlled to move to the target point based on C#. Finally, in the process of gradually adjusting C# parameters, the optimal parameters are obtained and the path planned by A∗ algorithm is displayed. Simulation results show that this method can plan an efficient and safe maintenance path in virtual maintenance environment.
© 2020 Technical Committee on Control Theory, Chinese Association of Automation.

With the increasing number of agile satellites, the number of on-orbit tasks is also increasing. The task planning for satellite swarm with large scale tasks plays an important role in the management of satellite swarm. Feasible solution finding in a large space composed by the mapping among satellites and tasks is an NP hard problem. Consequently, this paper adopts two-level large neighborhood search algorithm. Firstly, the planning for satellite swarm with large scale tasks is decomposed into a single satellite scheduling problem, and then based on the constraint guided search strategy, neighborhood search is carried out in the solution space. At the same time, in order to improve the search efficiency, a certain scale of population is designed and the PSO algorithm is used to accelerate the convergence. Finally, with the given parameters of satellites and tasks, the algorithm designed in this paper is verified by numerical simulation. The simulation results show that the method can distribute the observation tasks to each satellite evenly without conflict. © 2020 Technical Committee on Control Theory, Chinese Association of Automation.

With the increasing of spacecraft launch missions, the number of spacecraft module maintenance tasks also increases, so the path planning link plays a crucial role in the online virtual module maintenance task operation of spacecraft. Since A large amount of qualitative/quantitative method analysis is required in the process of writing the traditional maintenance report, the A∗ algorithm is adopted in this paper to search the path for the on-orbit module maintenance task of the spacecraft. Firstly, the abstract model of spacecraft in orbit cabin is built with unity 3D, and then the search point is controlled to move to the target point based on C#. Finally, in the process of gradually adjusting C# parameters, the optimal parameters are obtained and the path planned by A∗ algorithm is displayed. Simulation results show that this method can plan an efficient and safe maintenance path in virtual maintenance environment. © 2020 Technical Committee on Control Theory, Chinese Association of Automation.

The demand for high attitude measuring accuracy promotes the key instrument manufacturing method.The Micro-EDM manufacture technique has lots of advantages in instrument surface machining.The surface roughness sensing and imaging is able to provide input to assessment.This paper designs a scheme of surface roughness imaging.The actual experiment results show that the method presented here is able to obtain the precise image of instrument surface.

With the development of space science and technology, the requirements of spacecraft are increasing, and it is significant to research the multi-spacecraft system model. Based on the dual quaternion theory, this paper deduces the coupling kinematics equation of multi-spacecraft, and points out the coupling effect of relative position and attitude. After that, the simulation analysis of 6 kinds of multi-spacecraft is carried out based on the established multi-spacecraft position and orbit integration model, in which the six cases are 5, 15, 25, 35, 45 and 55 satellites respectively. Finally, the correctness and practicability of the model are verified by comparing between Matlab and STK simulation results.

The combined common-view time comparison algorithm for GNSS navigation system is the key technology, The satellite navigation receiver can calculate the delay of signal transmission and transmit time and frequency. Compared with single system CV time comparison algorithm, the combined CV（Common View） time comparison algorithm considers the unification of time and space coordinates of different systems and data processing of time comparison results, and combines Kalman filtering and RTS post smoothing. Using Kalman filtering for the results, this research uses RTS post smoothing on the basis of filtering, in order to improve the precision of time comparison.

This paper deals with the route planning problem for multi-UAVs formation. It provides a method of improved artificial potential field by introducing a longitudinal random factor and B-spline interpolation. The longitudinal random factor is used to solve the problem of falling into local minimum, when the B-spline interpolation is used to smooth the planned route. The simulated results show that the proposed method can solve the route planning problem of multi-UAVs.