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Xu N.,Shanghai University | Zhang Z.,Shanghai University | Zhang H.,Shanghai University | Lv T.,Shanghai University | And 2 more authors.
Key Engineering Materials | Year: 2012

In the process of vacuum casting, non-uniform flow front velocity about pouring material will lead to casting non-uniform shrinkage and warping deformation. Ideal filling pattern should make pouring material fill into the mold cavity with uniform flow front velocity. Give an optimization method of vacuum casting process, optimize the filling velocity in the filling process by combining numerical simulation and optimization method, and make the flow front velocity of pouring material uniform in the filling process, further reduce the warping deformation of casting. The example shows that the optimal model and the given solution algorithm is feasible. © (2012) Trans Tech Publications, Switzerland. Source

Li H.,Shanghai University | Li H.,Shanghai Key Laboratory of Mechanical Automation and Robotics | Luo J.,Shanghai University | Luo J.,Shanghai Key Laboratory of Mechanical Automation and Robotics | And 3 more authors.
Przeglad Elektrotechniczny | Year: 2012

Vision System is important for autonomous robot. In this paper, a robot bionic vision system, which has the function of the human eye movements, is developed to solve the problem of vision instability during robot working. Firstly, according to the eyeball structure and eye movement characteristics, the mechanism of the bionic eye with three degree of freedom (DOF) is designed by using a spherical parallel manipulator. Because it will be applied in a rough environment, natural frequency of vibration and the maximum deformation of the bionic eye mechanism is gained based on finite-element method(FEM). Then, the control system of the bionic vision is established based on a oculomotor control model, which can compensate the visual error caused by the dynamic changes of the robot attitude and tracking target position. In addition, a bionic vision embedded system with a standard video data interface is developed. Finally, some simulation and physical robot experiments are conducted in harsh environments, and the test results confirm the effectiveness of this bionic vision system. It is also shown that the controller based on oculomotor control model is robust even with external disturbance. Source

Lou W.,Shanghai University | Yao Y.,Shanghai Key Laboratory of Mechanical Automation and Robotics | Huang X.,Shanghai University | Cheng M.,Shanghai University | Hu Q.,Shanghai Key Laboratory of Mechanical Automation and Robotics
Advance Journal of Food Science and Technology | Year: 2013

This study presents a novel algorithm for assembling cell pore structure to enhance the connectivity of porous medium used in the medical science. Firstly based on sample learning, the designed cell pore structure is assembled and thus the parametric pore model can be established. Then the model is optimized by using random decision forests as evaluator and KD tree as the nearest neighbor searching area in the high dimensional space. Finally the parametric model can be transformed to solid model for evaluating the robustness of the proposed algorithm with the aid of the second development platform of UG. The test verifies that the proposed method can assemble and optimize the established cell pore model and thus significantly improve the correlation among cell models and successfully solve the difficult problem that the connectivity among cell models can't easily be controlled. © Maxwell Scientific Organization, 2013. Source

Lv T.,Shanghai University | Zhang H.,Shanghai University | Liu Y.,Shanghai University | Liu Y.,Shanghai Key Laboratory of Mechanical Automation and Robotics | And 2 more authors.
Key Engineering Materials | Year: 2012

Considering that the problem of traditional process parameters setting in vacuum casting machine is of long period, high cost and inferior quality stability, a kind of hybrid intelligent decision model which combined with case-based reasoning, neural network and fuzzy reasoning were established. First, use the case-based reasoning technology to extract the similar case from the case database. Then, use the initial parameters to run the mould trial. Finally, use the fuzzy reasoning technology to optimize the initial parameters according to the product defects. Based on the above-mentioned intelligence model, the related hardware and software system was established. The actual practice proved that the system is effective and can be used in practical production. © (2012) Trans Tech Publications, Switzerland. Source

Luo J.,Shanghai University | Luo J.,Shanghai Key Laboratory of Mechanical Automation and Robotics | Li H.,Shanghai University | Chen J.,Shanghai University | And 4 more authors.
Journal of Computers | Year: 2011

Motion targets tracking techniques is one of the most important aspects in the fields of mobile robot research under unknown environments. To solve the problem of unstable vision resulted from the uncertainties, a method of active compensation for robot visual was proposed based on the principle of bionic eye movements. According to oculomotor neural circuits, an adaptive oculomotor control model of eye movements was established, and the model includes that VOR, smooth purisuit and compound eye movements. In order to verify the model's performance, some simulation experiments ware conducted in different environment. Simulation results show that the model can be active compensation of visual error caused by the dynamic variation of the robot attitude and the tracking target location. Finally, physical robot experiments results also confirm the effectiveness of the control model. Compared with the conventional camera, this new one can solve the problem of unstable vision. © 2011 ACADEMY PUBLISHER. Source

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