The focus of this paper is the design and development of an automatic system for microassembly. The automatic processing is made possible by (i) the development of a machine vision algorithm to identify the targets an...
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The focus of this paper is the design and development of an automatic system for microassembly. The automatic processing is made possible by (i) the development of a machine vision algorithm to identify the targets and end-effectors, (ii) an uncalibrated visual servoing algorithm to lead the end-effector to grasp the micro-pieces and then assemble the target. The experimental results demonstrate that this prototype microassembly system is effective and practicable for automatic microassembly applications.
A time-based nested partition （NP） approach is proposed to solve resource-constrained project scheduling problem （RCPSP） in this paper. In iteration, one activity is selected as the base point of which the finish ...
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A time-based nested partition （NP） approach is proposed to solve resource-constrained project scheduling problem （RCPSP） in this paper. In iteration, one activity is selected as the base point of which the finish time interval calculated by CPM is divided into two parts to form two subregions on the basis of the promising region of the last iteration. Then sampling is taken in both subregions and the surrounding region to determine the promising region and aggregate the other as the surrounding region of this iteration so that whether the backtracking or the moving operation being performed is determined. Double justification is also performed in iteration to improve the results. The results of numerical tests on PSPLIB show the effectiveness and time-efficient of the proposed NP method.
Presently pneumatic muscles (PMs) are used in various applications due to their simple construction, lightweight and high force to weight ***, pneumatic muscles are facing various problems due to their nonlinear chara...
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Presently pneumatic muscles (PMs) are used in various applications due to their simple construction, lightweight and high force to weight ***, pneumatic muscles are facing various problems due to their nonlinear characteristic in various mechanical *** model of PM is nonlinear and *** this paper, a Lyapunov-based control (LBC) approach is proposed for the control of *** on the nonlinear characteristic of PM, a dynamic model of the PM actuator with pulling a mass against gravity is *** objectives are both a regulation and an asymptotic tracking of a desired *** analysis based on Lyapunov method with respect to our proposed control law is *** simulation results show the validity, effectiveness and enhancing robustness of the proposed method.
We prove that Fv(3,5;6) = 16, which solves the smallest open case of vertex Folkman numbers of the form Fv(3,k;k + 1). The proof uses computer algorithms.
We prove that Fv(3,5;6) = 16, which solves the smallest open case of vertex Folkman numbers of the form Fv(3,k;k + 1). The proof uses computer algorithms.
Landing footprint of an entry vehicle provides critical information for mission planning. Conventional methods calculate it through solving a family of multi-constraints optimal control problems. It is difficult to so...
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Landing footprint of an entry vehicle provides critical information for mission planning. Conventional methods calculate it through solving a family of multi-constraints optimal control problems. It is difficult to solve. To generate the boundary of it, we proposed a new scheme based on differential evolution(DE). Utilizing DE's parallelism, each run generates one side instead of one point of the boundary. To get the full boundary, just need run the algorithm two times. The algorithm's merits include accurate, fast, not relying on simplification of the system, all control variables are under consideration and facilitating parallel programming.
It is difficult to guide the entry vehicle to prescribed area due to the disperse of environment and kinematics. Through predicted residual range at the current state based on drag acceleration, we developed a predict...
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It is difficult to guide the entry vehicle to prescribed area due to the disperse of environment and kinematics. Through predicted residual range at the current state based on drag acceleration, we developed a predictor-corrector guidance law which doesn't need iteration to figure out the reference trajectory. Then using extended state observer based controller to track the reference trajectory. We use several missions(under various disperse conditions) to test the guidance law. Simulation results demonstrated that the guidance law is able to achieve the prescribed terminal conditions under various perturbations in the aerodynamic coefficients, the density of the atmosphere and the mass of the vehicle.
This paper presents an active disturbance rejection guidance method using quadratic transition for the atmospheric ascent guidance problem. The quadratic transition is designed from the current flight states with a re...
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This paper presents an active disturbance rejection guidance method using quadratic transition for the atmospheric ascent guidance problem. The quadratic transition is designed from the current flight states with a reference trajectory planned off-board. For any states error, the solution of the designed quadratic transition converges to the reference trajectory. The guidance command is obtained from the derivative of the designed quadratic transition. For the unknown modeling error, the guidance command is compensated using the estimated disturbances from the extended state observer. Computer simulation for GHV (Generic Hypersonic Air Vehicle) model, which includes initial states error and modeling error, shows great accuracy and effectiveness of this guidance method.
We develop an effective method for improving the segmentation result based on the Multi-Stencils Fast Marching method (MSFM). In MSFM, the gradient information of the image plays a vital role for calculating edges. It...
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A new defect detection algorithm base on Support Vector Data Description (SVDD) is proposed. A fabric texture model is built on the gray-level histogram of textural fabric image. Two Gray-level Co-occurrence Matrix (G...
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This paper investigates adaptive flocking of multi-agent systems (MASs) with a virtual leader. All agents and the virtual leader share the same intrinsic nonlinear dynamics, which satisfies a locally Lipschitz conditi...
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