检索结果-南通市图书馆

Optimizing the Qusai-static Folding and Deploying of Thin-Walled Tube Flexure Hinges with Double Slots

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2014年第2期27卷 279-286页

作者： YANG Hui DENG Zongquan LIU Rongqiang WANG Yan GUO Hongwei State Key Laboratory of Robotics and system Harbin institute of Technology

The thin-walled tube flexure（TWTF） hinges have important potential application value in the deployment mechanisms of satellite and solar array, but the optimal design of the TWTF hinges haven＇t been completely solved, which restricts their applications. An optimal design method for the qusai-static folding and deploying of TWTF hinges with double slots is presented based on the response surface theory. Firstly, the full factorial method is employed to design of the experiments. Then, the finite element models of the TWTF hinges with double slots are constructed to simulate the qusai-static folding and deploying non-linear analysis. What＇s more, the mathematical model of the TWTF flexure hinge quasi-static folding and deploying properties are derived by the response surface method. Considering of small mass and high stability, the peak moment of quasi-static folding and deploying as well as the lightless are set as the objectives to get the optimal performances. The relative errors of the objectives between the optimal design results and the FE analysis results are less than 7%, which demonstrates the precision of the surrogate models. Lastly, the parameter study shows that both the slots length and the slots width both have significant effects to the peak moment of quasi-static folding and deploying of TWTF hinges with double slots. However, the maximum Mises stress of quasi-static folding is more sensitive to the slots length than the slots width. The proposed research can be applied to optimize other thin-walled flexure hinges under quasi-static folding and deploying, which is of great importance to design of flexure hinges with high stability and low stress.

关键词： design optimization quasi-static folding and deploying flexure hinges thin-walled tube response surface method,numerical simulation

Method for Analyzing Articulated Torques of Heavy-duty Six-legged Robot

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2013年第4期26卷 801-812页

作者： ZHUANG Hongchao GAO Haibo DING Liang LIU Zhen DENG Zongquan State Key Laboratory of Robotics and system Harbin Institute of Technology

The accuracy of an articulated torque analysis influences the comprehensive performances of heavy-duty multi-legged robots. Currently, the extremal estimation method and some complex methods are employed to calculate the articulated torques, which results in a large safety margin or a large number of calculations. To quickly obtain accurate articulated torques, an analysis method for the articulated torque is presented for an electrically driven heavy-duty six-legged robot. First, the rearmost leg that experiences the maximum normal contact force is confirmed when the robot transits a slope. Based on the ant-type and crab-type tripod gaits, the formulas of classical mechanics and MATLAB software are employed to theoretically analyze the relevant static torques of the joints. With the changes in the joint angles for the abductor joint, hip joint, and knee joint, variable tendency charts and extreme curves are obtained for the static articulated torques. Meanwhile, the maximum static articulated torques and the corresponding poses of the robot are also obtained. According to the poses of the robot under the maximum static articulated torques, ADAMS software is used to carry out a static simulation analysis. Based on the relevant simulation curves of the articulated torques, the maximum static articulated torques are acquired. A comparative analysis of the maximum static articulated torques shows that the theoretical calculation values are higher than the static simulation values, and the maximum error value is approximately 10%. The proposed method lays a foundation for quickly determining accurate articulated torques to develop heavy-duty six-legged robots.

关键词： heavy-duty six-legged robot articulated torque MATLAB static simulation analysis ADAMS

Integrated evaluation approach for node importance of complex networks based on relative entropy

在线全文

学校读者我要写书评

暂无评论

Journal of systems Engineering and Electronics 2016年第6期27卷 1219-1226页

作者： Bin Chen Zhixue Wang Chen Luo institute of Command Information system PLA University of Science and Technology

Evaluating the node importance correctly is a crucial issue for complex networks research. If a network has multiple or ambiguous morphological features, the evaluation result of an individual index may be unilateral. Meanwhile, the results may be inconsistent if different indexes are adopted simultaneously. To solve the problem, an integrated approach is proposed based on relative entropy. In this approach, a system of multiple indexes is constructed firstly. Then each evaluation result of an individual index is handled into a discrete distribution. Finally an optimal integrated evaluation solution is obtained by linear programming. This approach has a well-formed theoretic basis and an easilycalculated procedure, which can be used in a variety of complex networks. Experimental results show that the proposed approach is more effective than other different methods proposed in some literatures. © 2016 Beijing institute of Aerospace Information.

关键词： Entropy Linear programming

Analysis on the Performance of the SLIP Runner with Nonlinear Spring Leg

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2013年第5期26卷 892-899页

作者： YU Haitao LI Mantian CAI Hegao State Key Laboratory of Robotics and system Harbin Institute of Technology

The spring-loaded inverted pendulum(SLIP) has been widely studied in both animals and ***,the majority of the relevant theoretical studies deal with elastic leg,the linear leg length-force relationship of which is obviously conflict with the biological observations.A planar spring-mass model with a nonlinear spring leg is presented to explore the intrinsic mechanism of legged locomotion with elastic *** leg model is formulated via decoupling the stiffness coefficient and exponent of the leg compression in order that the unified stiffness can be scaled as convex,concave as well as linear *** apex return map of the SLIP runner is established to investigate dynamical behavior of the fixed *** basin of attraction and Floquet Multiplier are introduced to evaluate the self-stability and initial state sensitivity of the SLIP model with different stiffness *** numerical results show that larger stiffness exponent can increase top speed of stable running and also can enlarge the size of attraction domain of the fixed *** addition,the parameter variation is conducted to detect the effect of parameter dependency,and demonstrates that on the fixed energy level and stiffness profile,the faster running speed with larger convergence rate of the stable fixed point under small local perturbation can be achieved via decreasing the angle of attack and increasing the stiffness *** perturbation recovery test is implemented to judge the ability of the model resisting large external *** result shows that the convex stiffness performs best in enhancing the robustness of SLIP runner negotiating irregular *** research sheds light on the running performance of the SLIP runner with nonlinear leg spring from a theoretical perspective,and also guides the design and control of the bio-inspired legged robot.

关键词： spring-loaded inverted pendulum legged locomotion apex return map nonlinear spring

An optimized run-length based algorithm for sparse remote sensing image labeling

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2022年第4期18卷 663-677页

作者： Shen-shen Luan Bo-wen Cheng Shuai Jiang Yu-hang Wu Zong-ling Li Ji-yang Yu institute of Spacecraft system Engineering Haidian DistrictBeijingChina

Labeling of the connected components is the key operation of the target recognition and segmentation in remote sensing *** conventional connected-component labeling(CCL) algorithms for ordinary optical images are considered time-consuming in processing the remote sensing images because of the larger size.A dynamic run-length based CCL algorithm(Dy RLC) is proposed in this paper for the large size,big granularity sparse remote sensing image,such as space debris images and ship *** addition,the equivalence matrix method is proposed to help design the pre-processing method to accelerate the equivalence labels *** result shows our algorithm outperforms 22.86% on execution time than the other algorithms in space debris image *** proposed algorithm also can be implemented on the field programming logical array(FPGA) to enable the realization of the real-time processing on-board.

关键词： Connected-component labeling Label equivalence resolving Hardware implementation Equivalence matrix On-board processing

Design and Dynamic Model of a Frog-inspired Swimming Robot Powered by Pneumatic Muscles

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2017年第5期30卷 1123-1132页

作者： Ji-Zhuang Fan Wei Zhang Peng-Cheng Kong He-Gao Cai Gang-Feng Liu State Key Laboratory of Robotics and system Harbin Institute of Technology

Pneumatic muscles with similar characteristics to biological muscles have been widely used in robots, and thus are promising drivers for frog inspired robots. How- ever, the application and nonlinearity of the pneumatic system limit the advance. On the basis of the swimming mechanism of the frog, a frog-inspired robot based on pneumatic muscles is developed. To realize the indepen- dent tasks by the robot, a pneumatic system with internal chambers, micro air pump, and valves is implemented. The micro pump is used to maintain the pressure difference between the source and exhaust chambers. The pneumatic muscles are controlled by high-speed switch valves which can reduce the robot cost, volume, and mass. A dynamic model of the pneumatic system is established for the sim- ulation to estimate the system, including the chamber, muscle, and pneumatic circuit models. The robot design is verified by the robot swimming experiments and the dynamic model is verified through the experiments and simulations of the pneumatic system. The simulation results are compared to analyze the functions of the source pressure, internal volume of the muscle, and circuit flow rate which is proved the main factor that limits the response of muscle pressure. The proposed research provides the application of the pneumatic muscles in the frog inspired robot and the pneumatic model to study muscle controller.

关键词： Frog-inspired robot Pneumatic muscle High-speed switch valve Pneumatic model

Topology Structure Synthesis and Analysis of Spatial Pyramid Deployable Truss Structures for Satellite SAR Antenna

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2014年第4期27卷 683-692页

作者： WANG Yan DENG Zongquan LIU Rongqiang YANG Hui GUO Hongwei State Key Laboratory of Robotics and system Harbin Institute of Technology

Many attentions for structural synthesis are paid to planar linkages and parallel mechanisms, while design novel pyramid deployable truss structure（PDTS） of satellite SAR mainly depends on experience of designer. To design novel configuration of PDTS, a two-step topology structure synthesis and analysis approach is proposed. Firstly, a conceptual configuration of PDTS is synthesized. Weighted graph and weighted adjacency matrix are established to realize topological description for PDTS. Graph properties are then summarized to distinguish differentia between PDTS and other type structures. According to graph properties, a procedure for synthesis conceptual configuration of PDTS is presented. Secondly, join relationship of components in a PDTS is analyzed. Kinematic chain and corresponding incidence/adjacency matrix are employed to analyze join relationship of PDTS. Properties and simplified rules of kinematic chain are extracted to construct kinematic chain. A procedure for construction kinematic chain of PDTS is then established. Finally, with this two-step approach all 11 rectangular pyramid deployable structures whose folded state is planar are discovered and their kinematic chains are constructed. Based on synthesis results, a novel deployable support structure for satellite SAR is designed. The proposed research can be applied to obtain some novel PDTSs, which is of great importance to design some novel deployable support structures for satellite SAR antenna.

关键词： structural synthesis deployable truss structure spatial linkage graph theory SAR antenna

On Modeling Drilling Load in Lunar Regolith Simulant

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2018年第1期31卷 41-52页

作者： Qi-Quan Quan Chong-Bin Chen Zong-Quan Deng Jun-Yue Tang De-Wei Tang State Key Laboratory of Robotics and system Harbin Institute of Technology

Drilling and coring, as effective ways to obtain lunar regolith along the longitudinal direction, are widely applied in the lunar sampling field. Conventionally, modeling of drill-soil interaction was divided into soil cutting and screw conveyance processes, ignoring the differences in soil mechanical properties between them. To improve the modeling accuracy, a hypothesis that divides the drill-soil interaction into four parts: cuttings screw conveyance, cuttings extruding, cuttings bulldozing, and in situ simulant cutting, is proposed to establish a novel model based on the passive earth pressure theory. An iterative numerical calculation method is developed to predict the drilling loads. A drilling and coring testbed is developed to conduct experimental tests. Drilling experiments indicate that the drilling loads calculated by the proposed model match well the experimental results. The proposed research provides the instructions to adopt a suitable drilling strategy to match the rotary and penetrating motions, to increase the safety and reliability of drilling control in lunar sampling missions.

关键词： Lunar regolith drilling Lunar regolith simulant Drill-simulant interaction Screw conveyance

Simulation design of fuze warhead system of air defense missile at very low altitude

在线全文

学校读者我要写书评

暂无评论

Journal of systems Engineering and Electronics 2017年第3期28卷 572-584页

作者： Qi Zhao Guangyu Du Bin Zhang Yanbin Zhai Yuruo Shi Beijing institute of Electronic system Engineering Beijing 100854China

A novel simulation method for fuze warhead system (FWS) at very low altitude flight is proposed to solve adaptability issues of the traditional one in the naval battle. Firstly, a simulation system framework is presented. Then the detailed implementation of a novel general fuze model, a novel sea echo model and a novel warhead dynamic effectiveness power field algorithm including the simulation system are presented. Finally, simulation results show good performance of the proposed method. The proposed method can simulate the echo signal when the complex fuze antennas detect target and the sea at the same time, and can truly reflect the target positions hit by the warhead fragments. The proposed method can solve the existing problems in the FWS simulation system.

关键词： fuze warhead system (FWS) simulation fuze warhead matching sea echo fragment trajectory drifting