Abstract:A general containment control algorithm is proposed for distributed coordinated control of double-integrator dynamics system with multiple leaders. Necessary and sufficient conditions on convergence are presented based on the control gains and system Laplacian eigenvalues. Furthermore, the influences of control gains and the information topology on system convergence rate are investigated. Specifically, the control gains which achieve maximal convergence rate are given, and it is proved by using Weyl theorem that the system convergence rate can be improved by adding information links. Finally, numerical simulations are given to illustrate the main results.

Abstract:A new method is proposed to solve a problem of image restoration which would be degraded by TDICCD irregular sampling process owning to satellite vibrations. Firstly, the rules of image geometric quality degradation is mathematically modeled using unequally spaced fast Fourier transform(USFFT) interpolation, and then a full image degradation model is developed combined with the blurred degradation process. Subsequently, the inverse solution problem of the model equations is transformed into a system of linear equations with a Toeplitz matrix as system matrix on the basis of the USFFT interpolation characteristics. And then the equations can be sovled efficiently. Then, a new method of image restoration is presented, which can implement not only deblurring but also irregular to regular sampling. Finally, the method is verified using simulated standard pattern and real remote sensing images. Experimental results indicate that the proposed method is able to improve the irregularly sampled image effectively, and it has fast computation. The Structural Similarity index between the restored and ideal images is no less than 0.93 in the case of seriously blurred, irregularly sampled and noisy images. The proposed approach can be applied to restore the irregular sampling images owning to on-orbit vibrations effectively.

Abstract:To improve the long-term stability performance, reduce the manual calibration costs and enhance the use efficiency of inertial navigation systems, we propose a prediction and compensation method for the long-term stability of inertial navigation system parameter based on correlation vector machine, in which we choose the mean and standard deviation as the performance indicators. For the mean parameter with a significant change with time in the law, we establish regression modeling for longer storage stability parameter by RVM method, and carry out the performance prediction and calibration parameters compensation for the parameters stability of the shorter storage. The paper presents the modeling forecasting and parameter compensation for the long-term stability of the accelerometer scale factor of the important parameters in the inertial navigation system, the parameter stability mean performance for an interval time of 6 months has improved by 50.90%. This result implies that this method can replace the manual calibration and the use efficiency of inertial navigation systems, and verifies the effectiveness of the proposed method.

Abstract:To increase the operation dexterity of surgical instruments in minimally invasive surgery (MIS), and improve manipulation performance of master-slave control, a novel surgical instrument without coupled motions used in MIS is designed. On the basis of analyzing the formation principle of coupled motions and existing methods of coupled motions elimination, a design method that steel wire crosses the centre of wrist shaft in the radial direction for surgical instrument used in MIS is proposed. The developed instrument has four DOFs and is driven by means of steel wire. Besides that, the instrument can realize quick replacement and useful information record as well. After researching kinematics of surgical instrument and master, master-slave control method for surgical instrument is proposed and experiments platform for master-slave control is established. The experimental results indicate that the position of instrument′s wrist in relation to two fingers remains unchanged in the process of surgical instrument's wrist moving individually, which means that the developed surgical instrument eliminates coupled motions and has good manipulation performance in master-slave control. The design method that steel wire crosses the centre of wrist shaft in the radial direction for surgical instrument used in MIS can eliminate coupled motions, and the developed surgical instrument is beneficial to surgical operation in MIS.

Abstract:Forecasting pedestrian states with the help of video analysis is a significant mean to prevent accidents in public places. An improved Inner-grid Parking Cellular Automata (IPCA) model is proposed to forecast pedestrian state. Motion tracking and scenario modeling are firstly achieved by optical flow method, and then motion states of pedestrian are used to adjust parking time in cellular adaptively to improve forecasting accuracy. Here, the state of an incoming video frame is acquired by analyzing the interaction between micelles, which is provided by the forecasting result of IPCA. After that, a feedback algorithm is employed to revise the forecasting result so that the model could reflect precisely the change of pedestrian state in the scenario. A criterion is also proposed to judge the abnormal state of a video frame, which is collision between two micelles. Compared to other traditional detection methods, IPCA based model has a good ability in predicting the abnormal state ahead of time and obtaining better accuracy.

Abstract:To increase the carrying capacity of hydrostatic extrusion cylinder, sleeve structure was used to offer pre-stress on the inner cylinder by heat interference fit. The stress distribution along the thickness and relationship between thickness combinations and interference gap were studied by finite element method during design of sleeve structure applied in hydrostatic extrusion cylinder. The results show that, for any thickness combinations, as the interference gap increased, the maximum value of equivalent stress first increased and then decreased. The maximum value of equivalent stress located at the inner surface for both inner cylinder and outer cylinder, and as the thickness of inner cylinder increased, the value of equivalent stress at inner surface of inner cylinder increased and that at the inner surface of outer cylinder decreased. In the circle direction sleeve structure leads to compressive stress on the inner cylinder and tensile stress on the outer cylinder. After full loading for inner cylinder, tensile stress caused by internal pressure in the circle direction was offset by pre-stress. When the interference gap and thickness of inner cylinder were 0.15 mm and 35 mm respectively, the value of equivalent stress at inner surface of both inner cylinder and outer cylinder were the same and lowest.

Abstract:The sparse approximation performance of tetrolet transform to the edge and texture of image is much higher than wavelet transform, which makes it suitable for those images that rich in details. However, for the smooth images, its sparse approximation performance is weaker than wavelet transform. Focus on the problem, a novel sparse approximation method that is of some generality is proposed. First, the wavelet transform is conducted to the image, and the polyphase decomposition for each sub-band is operated using p-fold filter and some components are generated, then the PCA is applied to those components. Following, the sparse approximation is conducted to the image after two energy concentration. Secondly, the high-frequency image can be obtained based on the results above, then the tetrolet transform is applied to sparse it. Experimental result shows that, under the same condition, the quality of the reconstructed image obtained by the proposed method is better than that obtained by the wavelet transform and the tetrolet transform, either the subjective or objective quality, which indicates the effectiveness of the proposed method.

Abstract:An approach was proposed to reduce grinding errors and improve meshing performance. Firstly, both a controllable contact path and a high order transmission error（H-TE） curves were designed based on the TCA theory, and the parameters of curves were got by optimizing the minimum amplitude of LTE based on LTCA, and topologically modified tooth of pinion was determined according to movement of the rack generating involute tooth. Secondly, a free-form CNC grinding machine model of five-axis was established and kinematic relationships of the axes were derived. Besides,an error correction model based on a sensitivity analysis of the grinding wheel and the movement of five-axis was determined, and grinding error was established by estimating whether the wheel contact with the pinion, and the corrections were solved by using the PSO optimization algorithm. Finally, an example shows that the optimized higher-order transmission error curves is smooth at the intersect points, and topologically modified tooth is characteristics of more modification and proximal diagonal at engaging-in and engaging-out regions. Besides, a middle concave higher-order transmission error curve makes a smaller LTE amplitude, which helps to reduce vibration；Further more, the parameters of concave depends on working condition, and with the increasing of loads, the optimal parameters value increases. The modified tooth can be efficiently ground by slightly adjusting five-axis movement and the wheel profile according to the solved corrections and then by flat grinding wheel for diagonal correction, which effectively reduce the grinding errors to 2 μm.

Abstract:In order to get the buckling load of deployable structures, stability of linear array deployable structures based on structure of SLE were studied. The paper established a structural instability limit load expression of SLE based on analysis of the elastic deformation of bar, which is applied to the array combination of deployable structure. Then the condition of the stability of this structure is obtained. Results indicate that: Buckling critical load were affected by the bar parameters such as the number of units, bar flexibility and position angle. With the increase of the number of units or the bar flexibility, structural stability gradually reduced; The position angle were affected by unit number, which cannot be used separately as the basis for judging structure instability.Deployable structure stability simulation analysis results and the theoretical analysis results are compared each other, confirming the correctness of the proposed method in this paper because of the experiment data well.

Abstract:A hybrid algorithm which combines the augmented Lagrangian multiplier method with the fish swarm algorithm is presented to solve the problem of constrained nonlinear optimization. The method approximately solves the optimal solution of the augmented Lagrangian function with the fish swarm algorithm, and the solution is applied to update the Lagrangian multipliers and penalty parameters. Stochastic convergence of the artificial fish swarm is analyzed. Compared with an adaptive penalty method for genetic algorithms, simulation results verify the superiority and validity of the proposed hybrid algorithm.

Abstract:To design and control furnace roller better, heat loss law of water-cooled furnace roller which surface coat is composed of heat-resistant alloy or asbestos fibers before and after improvement was studied by mathematical models. After analyzing the problems of traditional roller hearth furnace, the improvement reason and key point were pointed out. Heat transfer models for cooling process of two kinds of rollers were established and solved with iteration planning algorithm based on Newton search. Then, the relation between water flow velocity (uw), inlet water temperature (tw-in) and roller cross section temperatures, outlet water temperature (tw-out), water temperature rise (Δtw), cooling water heat absorption (Qw) was studied. The conclusions and recommendations are mainly as follows: 1) Roller cross section temperatures, tw-out, Δtw decrease with the increase of uw. The water critical velocity (uwcv) of two kinds of furnace rolls is 0.07 m／s and 0.09 m／s respectively, and when uw is larger than uwcv, turbulent flow occurs. Considering less water scale and water treatment system cost, tw-out should be under 45 ℃ and Δtw should be less than 10 ℃. So suitable uw should be 0.4～0.8 m／s and 0.2～0.6 m／s, when cooling water is entire turbulent flow, cooling efficiency is high, and Δtw is small, above which energy consumption increase greatly and uselessly, but Qw almost remains unchanged. 2) Qw of asbestos fibers roller is small and 78％ of heat-resistant alloy roller when cooling water is entire turbulent flow. Application result indicates that consumption of per ton steel is greatly reduced after the improvement and optimization control of furnace rollers, of which the reason is that production is greatly increased due to not grinding rollers, except for optimal control, fiber furnace roller heat loss is small.

Abstract:Two-dimensional rolling process is modeled and analyzed by nonlinear finite element software called ABAQUS for understanding the law of changing of rolling parameters and strip tensile stress distribution in asymmetrical rolling process. There are three asymmetry factors about rolling process, drive mode, contact friction lubrication conditions between work roll and strip, asynchronous rolling mode. The effect of the asymmetry factors on the tensile stress distribution of strip, roll force and roll torque is analyzed. The effect of the asymmetry factors on the shape of strip and rolling process is compared and assessed. Simulation results show that all the asymmetry factors can make the tensile stress distribution in thickness direction of strip asymmetrical and change the mechanics parameter of temper rolling process obviously. Compared with the corresponding symmetry rolling process, some asymmetry factors can reduce the roll force and roll torque in different degree. Therefore, the advantages and disadvantages of asymmetric rolling process factors both exist from different perspective.

Abstract:According to the driving cycle of heavy off-road vehicles, the brake power and energy permutation is analyzed, and the performance requirement for the hybrid energy storage system(HESS) is achieved based on the brake energy recovery rate and motor parameters. The parameter matching method for the HESS is proposed and by which the instance calculation for the hybrid propulsion system of 21 tons class vehicles is carried out, and the performance of the HESS with Li-ion cells and ultra capacitors is discussed too. The instance calculation and the test results indicate that the designed HESS can meet the requirement of the total performance of the HEV and the brake energy recovery, the volume and weight answer for the restriction of the top design of the HEV. The designed HESS with ultra capacitors can increase the transient power volume greatly and the brake performance and the brake energy recovery rate are enhanced remarkably.

Abstract:To avoid the difficulties in the kinematics and dynamic analysis, development of control system, and so on brought by the existence of coupling in the parallel mechanism, a novel two degrees of freedom (DOF) rotational decoupled parallel mechanism (DPM) is proposed. The mobility and motion feature of this 2-DOF rotational DPM is analyzed with the constraint screw method, and the number of mobility is calculated by using the Modified Kutzbach-Grübler criterion. The inverse and forward displacement problems of the proposed DPM are solved according to the geometrical relationship. The expression of the Jacobian matrix is deduced with the relational expression between the input and output parameters of the mechanism. And according to the expression of the Jacobian matrix, the decoupled feature of the proposed parallel mechanism is validated. Aiming at different selection of the drive, the singular configuration of the mechanism is analyzed according to the Jacobian matrix. The contents of this paper enrich the configurations of the decoupled parallel mechanisms and should be useful for the further application of the parallel mechanisms.

Abstract:To improve the design level and R＆D efficiency of large-span inflatable structure, an optimization method combining FEM with genetic algorithms is applied to design optimization of large span inflatable structure. A FEM model of the inflatable structure is established, calculated and analyzed with the FEM software ABAQUS, then the model is optimized with genetic algorithms and the optimal solution is obtained after breeding and evolution. From the analysis results, there are uniform stress distribution on skin material, higher average stress levels on each accessory structure, a high material utilization and the weight 3 928 kg of whole structure in the optimal solution. According to the optimal solution, the sample is processed and tested, and it can safely work under all conditions. The minimum safety distance of rotor wingtip is 1.09 m, and the minimum vertical safety distance is 1.67 m, which are consistent with the results of FEM. The test results are almost consistent with the analysis, and the optimization program meets the practical requirements well.

Abstract:This paper proposes a scalable, reconfigurable, general test system design oriented the spacecraft electronic system. The design employs open flexible test system design method. Common test interfaces are integrated into classified modules with FPGA as control core, which ensures the reconfigurability of hardware. Software utilizes modularized pattern. Application program interacts with the operating system through transfer layer which ensures reusability of software. All modules can be combined into three local testing machine models using the PC/104 PLUS and Ethernet. The optical fiber transmission technology is employed to combine all the local testing machine models into a distributed testing system. This system is compatible, universal, and secure. Vacuum tank test and multi-device joint test show that the system is competent for all kinds of electronic system testing in different scenarios.

Abstract:With the development of Social Media, web mining analysis has been regarded as one of hot research topics. Traditional single task regression builds models for each task, which ignores the sharing information among tasks in the occasion of multi-variable prediction. Therefore, this paper used multi-task regression mining method, and managed to analyze the pattern between user’s personality and network behavior. This study collected a sample set of 335 RenRen users and 563 Weibo users through online test invitation. Using multi-task regression, the final prediction accuracy is 87％ or more. The result means that multi-task regression works better then single task regression for multi-variable modeling.

Abstract:To eliminate the common mode input in the the micromachined gyroscopes, a novel architecture of the micromachined gyroscope is proposed in this paper. The structure of the MEMS is designed to be symmetrical, and two-degree of freedom (DOF) oscillators are utilized in both drive-mode and sense-mode. Driving force actuates two driving masses to move with anti-phase in drive-mode. The novel architecture consists of identical left and right tines, which provides immunity to common mode input of environmental variations. To avoid the coupling between drive-mode and sense-mode, the drive-mode suspensions are introduced in sense-mode. The gyroscope is designed to be double-decoupled structure. Compared to the drive-mode of the proposed gyroscope, the gain of frequency response is increased by about 30 dB in the sense-mode. The bandwidth of drive-mode and sense-mode are 250 Hz and 310 Hz respectively. The gyroscope can provide stable gain and phase in the operational frequency region, and provide immunity to common mode input of environmental variations.

Abstract:Aiming at the problems that the faults of NPP’s main coolant pump are difficult to recognize effectively during their early phases, and that DST can only solve single fault diagnosis in the identification framework without serious conflict, this paper proposes a diagnosis model for main coolant pump’s concurrent fault fusion in early phases, based on DSmT. Taking advantage of DSmT, multiple independent proofs are used to conduct fusion decision, and obtain the results of main pump fault and concurrent fault diagnosis. On the simulation machine of nuclear power plant, main coolant pump was simulated and verified, and the results show that this method can improve the accuracy of recognition of main pump’s current faults during early phases, and reduce the uncertainty of the diagnosis.

Abstract:Based on the basic characteristics of core competitiveness of scientific research institutes, this paper analyzed the key factors affecting the core competitiveness of scientific research institutes, constructed the evaluation model of the core competitiveness of scientific research institutes from the perspective of strategic management, resource support capabilities, technology innovation, organizational management capabilities, and then used Entropy-Topsis evaluation model to evaluate 26 typical scientific research institutes’ core competitiveness, drew the construction level of the core competitiveness of scientific research institutes at this stage, cleared a path to enhance the core competitiveness, and provided a theoretical basis and practical guidance of scientific research institutes core competence evaluation and optimization construction.

Abstract:For the edges between objects and background in an image are intertwined or their common boundaries are vague as well as the textures of objects and background are similar, a new method based on graph theory and closed-form solution was proposed. First, it uses closed-form solution to initially separate the objects from background roughly, then, to extract the detailed information of inter objects, it applies an improved graph-based algorithm to obtain the final image segmentation results. The test results show that the algorithm of matting avoids aliasing of foreground and background and the improved graph-based algorithm increases segmentation accuracy by 6％~12％ effectively. Compared to the traditional algorithms such as region merging, ordinary graph, and thresholding, the new algorithm has the better accuracy and effect, therefore it has the significant superiority.