摘要：This article introduces the working principles of a spacecraft hatch including its operating process and moving trajectory. On this basis, an operating mechanism is designed to execute automatic open and close action of the hatch and measure the operating torques. Analysis on the mechanism＇s configuration and topological structure of each phase of movement proves that it is a typical variable freedom mechanism. The mechanism manipulates the hatch in accordance with the moving trajectory requirements through configuration transformation. Kinematic analysis and simulation of some typical configurations show that the velocity differences among mechanism components themselves and the components and their abutting components could exert influences on its working stability during configuration transformation. To solve the problem, stability conditions of configuration transformation are proposed. Appropriate control models are established for the output velocity curves of the driving servo motor and solved based on the stability conditions and rules of movement. Results from another simulation demonstrate that the proposed control models ensure smooth configuration transform and stable operation.

摘要：This paper discusses the problem of design and optimization of low-energy transfer orbit with multi-body environment. A new integrative method is proposed to effectively solve the problem, in which the parameterized patched manifolds in CR3BP(circular restricted three-body problems), the shape-based method with multi-body environment, the homotopic method with multi-body environment, and the low-thrust capturing and descending algorithm with multi-body environment are all included. Firstly, the parameters describing the patched manifolds in CR3 BP are optimized until the least total absolute velocity increment has been got, including the employment of the shape-based method with multi-body environment. Secondly, the low-thrust control laws of the transfer orbit are optimized employing the homotopic method with multi-body environment that transfers the fuel optimization problem to an easier energy optimization problem. Thirdly, the low-thrust descending orbit around Mars is computed using the laws proposed in this paper. As a typical example, the Earth-Mars transfer orbit design is discussed. The results showed that the parameters describing the patched manifolds could be optimized by the DE(differential evolution) algorithm effectively; the homotopic method with multi-body environment could get the optimal value that meets the first order optimality conditions; and the low-thrust descending orbit could effectively be captured by Mars and finally become a circular parking orbit around it by the hypothesis control laws proposed in this paper. It shows that the final fuel cost is much less than the optimal transfer in the patched two-body problems. In conclusion, the method proposed in this paper could effectively solve the low-energy low-thrust optimal control problem in multi-body environment for the future deep space explorations.

摘要：In order to improve the frequency response and anti-interference characteristics of the smart electromechanical actuator(EMA)system,and aiming at the force fighting problem when multiple actuators work synchronously,a multi input multi output(MIMO)position difference cross coupling control coordinated strategy based on double‑closed-loop load feedforward control is proposed and *** this strategy,the singular value method of return difference matrix is used to design the parameter range that meets the requirements of system stability margin,and the sensitivity function and the H_(∞)norm theory are used to design and determine the optimal solution in the obtained parameter stability region,so that the multi actuator system has excellent synchronization,stability and *** the same time,the mathematical model of the integrated smart EMA system is *** to the requirements of point-to-point control,the controller of double-loop control and load feedforward compensation is determined and designed to improve the frequency response and anti-interference ability of single ***,the 270 V high-voltage smart EMA system experimental platform is built,and the frequency response,load feedforward compensation and coordinated control experiments are carried out to verify the correctness of the position difference cross coupling control strategy and the rationality of the parameter design,so that the system can reach the servo control indexes of bandwidth 6 Hz,the maximum output force 20000 N and the synchronization error≤0.1 mm,which effectively solves the problem of force fighting.

摘要：The study of the movement behavior of geckos on a vertical surface, including the measurement and recording of the reaction forces as they move in different directions, plays an important role in understanding the mechanics of the animals' locomotion. This study provides inspiration for the design of a control system for a bionics robot. The three-dimensional reaction forces of vertical surface-climbing geckos (Gekko gecko) were measured using a three-dimensional force-sensors-array. The behavior of gecko as it moved on a vertical surface was recorded with a high speed camera at 215 fps and the function of each foot of a gecko are discussed in this paper. The results showed that the gecko increased its velocity of movement mainly by increasing the stride frequency in the upward, downward and leftward direction and that the speed had no significant relationship to the attachment and detachment times. The feet above the center-of-mass play a key role in supporting the body, driving locomotion and balancing overturning etc. The movement behavior and foot function of geckos change correspondingly for different conditions, which results in safe and effective free vertical locomotion. This research will be helpful in designing gecko-like robots including the selection of gait planning and its control.

摘要：This paper studies the problem of suboptimal state-feedback H-two/H-infinity control of stochastic systems with spectrum constraint. Concretely speaking, a mixed suboptimal H-two/H-infinity controller synthesis together with placing the spectrum into a strip region is considered, which is achieved via solving a convex optimization problem.

摘要：Given the institutional similarities between Romania and China in history,its experience in the field of foreign language education reform in colleges and universities can be used for reference in the reform of foreign language teaching of higher education in *** the help of Citespace,this paper presents a visual statistical analysis of 47 SSCI international journal articles on foreign language reform in Romanian universities and gives some suggestions on foreign language education reform in Chinese universities from four aspects:teaching environment,content,technology and cooperation.

摘要：作为目前最有前景的绿氢生产方式,电解水技术被研究者广泛关注.其中,电催化析氧反应(oxygen evolution reaction,OER)作为电解水的半反应,由于其缓慢的四电子转移步骤而成为电解水器件的能量瓶颈.高效的OER催化电极设计是解决该问题的有效方式.本文分析了OER催化剂中氧原子介导的电子重排与活性位点配位不对称性之间的构效关系.通过自发氧化还原反应,将镍离子引入到泡沫镍(NF)表面的FeWO_(4)中,以此破坏FeWO_(4)晶格中FeO_(6)八面体的对称性,并基于此调节Fe位点的电子结构.结构调控促进了钨酸盐适度重构成为具有高OER活性的羟基氧化物.在碱性环境中,具有不对称配位Fe位点的Fe_(0.53)Ni_(0.47)WO_(4)/NF自支撑电极在10 mA cm^(-2)的电流密度下,可获得170 mV的超低过电势,并在1000 mA cm^(-2)的高电流密度下可维持稳定500 h.这种新型OER催化电极为高活性电催化系统的设计提供了新的见解.

摘要：This paper proposes a new loop recovery method to solve the reduced order problem of H∞/ LTR method. The resulted lower order controller shares almost the same performance and robustness as the original H ∞/LTR controller. Further more, this paper develops a new order reduction method: slow-fast mode order reduction (SFMOR) method. This order reduction method is particularly effective for those controllers whose modes can be divided into a slow part and a fast part according to their velocities. Application of these methods to a benchmark example and a certain turbofan engine is described.

摘要：设计基于界面工程的氧/氢析出反应(OER/HER)双功能电催化剂对在高电流密度下同时实现低过电位和稳定的水分解操作至关重要.本文中,我们报告了一种硼化策略以巧妙地定制固定在泡沫铁(IF)上的金属有机框架(MOF).硼原子诱导了Fe-MOF纳米片的结构重构,包括粗糙表面、氧空位以及结晶Fe-MOF和非晶Fe–B之间的面内异质结.面内异质结调节铁位点的d带中心以降低OER/HER能垒.优化的Fe–B/FeMOF/IF在10 m A cm^(-2)下驱动OER和全解水,分别仅需1.44和1.53 V.水分解系统在500 m A cm^(-2)下工作100小时以后的结构变化和性能衰减可忽略不计.该工作为异质结构界面的工程提供了启示,并促进了先进电催化剂的合理设计.

摘要：A distributed relative navigation approach via inter-satellite sensing and communication for satellite clusters is proposed. The inter-satellite link(ISL)is used for ranging and exchanging data for the relative navigation,which can improve the autonomy of the satellite cluster. The ISL topology design problem is formulated as a multi-objective optimization problem where the energy consumption and the navigation performance are considered. Further,the relative navigation is performed in a distributed fashion,where each satellite in the cluster makes observations and communicates with its neighbors via the ISL locally such that the transmission consumption and the computational complexity for the navigation are reduced. The ISL topology optimization problem is solved via the NSGA-Ⅱ algorithm,and the consensus Kalman filter is used for the distributed relative navigation. The proposed approach is flexible to varying tasks,with satellites joining or leaving the cluster anytime,and is robust to the failure of an individual satellite. Numerical simulations are presented to verify the feasibility of the proposed approach.