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51.
INVESTIGATION ON KANE DYNAMIC EQUATIONS BASED ON SCREW THEORY FOR OPEN-CHAIN MANIPULATORS 总被引:4,自引:0,他引:4
IntroductionDynamicsofroboticmanipulatorsisthebasisofdynamiccontrolandmechanicaldesignofroboticmanipulators.Dynamicanalysisofrobotscanemploytheapproachesoftheoreticalmechanicsanddynamicequationsofanalyticalmechanics,suchasNewton_Eulerdynamicequations,Lagrange_Eulerdynamicequations ,Routhequation ,Appellequation ,andKaneequations.Theultimateresultsarethesamewhenweinvestigateononekindofmotionsaboutoneobjectivebydifferentdynamicequations,butthespeedandquantitiesofcomputationoftheseequationsare… 相似文献
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The character of reorganization of the short-range order and the scale structure during the ordering of glass forming melts is elaborated based on the results of diffraction and microscopic investigations of the ordered and glassy alloys in tellurium-germanium systems. For this purpose cooling curves reflecting the formation processes of structural levels in real time are analyzed and the effective activation energies are estimated. 相似文献
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Magnetic bunch compressor is one of the key technologies on the path to next generation accelerator driven facilities. In this paper we report the design principles and the first experimental research of the bunch compressor developed at Chinese Academy of Engineering Physics (CAEP). The length of the bunch after compressor is found to be about 0.7 ps (rms) and the peak current exceeds 500 A when operated in the optimized condition. The sensitivity of the bunch length on the phase of the acceleration field and magnetic field of the bunch compressor was also measured and analyzed. 相似文献
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通过对国产典型产品比较发现,双级螺杆式压缩机COP值高于双级活塞式压缩机。在-35℃/35℃典型工况下,平均COP值高11.4%,最大增加了18.3%。实例分析表明,不同方案配置的电机功率差别很大。活塞机比螺杆机方案电机总功率明显偏大,平均大20%,差别最大的总功率增加了42%。因此,在制冷系统设计选型阶段,应对压缩机不同选型方案COP及电机功率进行优化,应认真核算实际需要的电机功率。对于年运行≥3000小时的系统,应选用Y2-E或者YX系列高效节能型电动机。 相似文献
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This study reports the comparison of heat transfer and friction factor characteristics of helical screw inserts in Al2O3–water and carbon nano-tube–water nano-fluids through a straight pipe in transition regime with constant heat flux boundary condition. Experiments were carried out by using 0.15% volume concentration of Al2O3–water and carbon nano-tube–water nano-fluid with helical tape inserts of twist ratio, TR = 1.5, 2.5, and 3. The thermal performance of helical screw tape inserts with the carbon nano-tube–water nano-fluid is found -to be higher when compared to the Al2O3–water nano-fluid. In addition, the maximum enhancement in heat transfer was obtained for the carbon nano-tube–water nano-fluid with helical tape inserts of twist ratio 1.5. The increase in pressure drop of the Al2O3–water nano-fluid with helical screw tape inserts is found to be higher compared to the carbon nano-tube–water nano-fluid helical screw tape inserts at lower value of twist ratio. 相似文献
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The interaction between a screw dislocation and an interfacial cruciform crack and collinear linear cracks under loads at infinity was investigated. General solutions of complex potentials to this problem were derived by using complex potential theory. As illustrative examples, the closed form solution for a screw dislocation interacting with an interfacial cruciform crack and a linear crack is obtained. The stress intensity factor and critical stress intensity factor for dislocation emission are also calculated. The results show that the shielding effect increases with the increase of the shear modulus and the distance between the two cracks, but it decreases with the increase of dislocation azimuth and the distance between the dislocation and the cruciform crack tip. The critical loads at infinity for dislocation emission increase with the increment of the emission angle, the distance the two cracks and the vertical length of the cruciform crack. 相似文献