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121.
《Mechatronics》2014,24(1):23-31
In this paper, energy-saving trajectories are planned for a toggle mechanism driven by a permanent magnet synchronous motor (PMSM). The point-to-point (PTP) trajectory is described by a high-degree polynomial, which satisfies the end conditions of displacement, velocity, acceleration and jerk at the initial and final times. The real-coded genetic algorithm (RGA) method is employed to obtain the mechatronic system’s parameters, and to determine the coefficients of the polynomial, and its fitness function is the inverse of various input energies. The numerical simulations and experiments are compared among several degrees’ polynomials during the whole operation motion. Finally, it is found that the input absolute electrical energy (IAEE) occurs when the highest-degree polynomial is chosen. From the percentage of relative error with respect to the absolute input energy of a 7-degree polynomial, it is found that the percentage of relative error achieves 32% as the degree is 24 with enough for minimum input energy degree. The proposed methodology described in this research has the contribution. It can be applied to any mechatronic system which is required to design a minimum-energy point to point trajectory. 相似文献
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123.
首先介绍了中国移动城域传输网的发展现状,并对城域网内面临的业务承载需求进行了简要分析。此外,基于城域网发展现状及未来业务承载需求提出了基于点、线、面的城域网规划方法。 相似文献
124.
结合河北省地面数字电视广播频率规划研究工作,通过省级、市级单频网规划实例,对地面数字电视频率规划的原则与规划步骤进行了总结,对频率规划所涉及的技术参数和规划方法进行了重点分析,提出了省级地面数字电视频率规划中分别建设省级单频网、市级单频网、县级多频网的规划方案。 相似文献
125.
介绍GOOGLE EARTH地图和PATHLOSS软件在微波网络规划上的各自优缺点,及如何使用GOOGLE EARTH地图进行微波路由规划,视通分析,站址调整和微波中继站设置. 相似文献
126.
D. AnghinolfiM. Paolucci S. SaconeS. Siri 《European Journal of Operational Research》2011,214(3):588-594
In this paper we propose a planning procedure for serving freight transportation requests in a railway network with fast transfer equipment at terminals. We consider a transportation system where different customers make their requests (orders) for moving boxes, i.e., either containers or swap bodies, between different origins and destinations, with specific requirements on delivery times. The decisions to be taken concern the route (and the corresponding sequence of trains) that each box follows in the network and the assignment of boxes to train wagons, taking into account that boxes can change more than one train and that train timetables are fixed.The planning procedure includes a pre-analysis step to determine all the possible sequences of trains for serving each order, followed by the solution of a 0-1 linear programming problem to find the optimal assignment of each box to a train sequence and to a specific wagon for each train in the sequence. This latter is a generalized assignment problem which is NP-hard. Hence, in order to find good solutions in acceptable computation times, two MIP heuristic approaches are proposed and tested through an experimental analysis considering realistic problem instances. 相似文献
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128.
The trajectory planning of redundant robots through the pseudoinverse control leads to undesirable drift in the joint space. This paper presents a new technique to solve the inverse kinematics problem of redundant manipulators, which uses a fractional differential of order α to control the joint positions. Two performance measures are defined to examine the strength and weakness of the proposed method. The positional error index measures the precision of the manipulator's end-effector at the target position. The repeatability performance index is adopted to evaluate if the joint positions are repetitive when the manipulator execute repetitive trajectories in the operational workspace. Redundant and hyper-redundant planar manipulators reveal that it is possible to choose in a large range of possible values of α in order to get repetitive trajectories in the joint space. 相似文献
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为缩短客户从提交订单到领取汽车时间,通过对汽车企业定制化生产供应链要素分析,以订单处理带动生产管理改进.通过改善企业软能力,增强应对市场应变能力,允许一定提前期的订单修改,减少订单处理与等待时间;为适应订单的变化,生产中管理中采用“漏斗模型”,利用粗集理论制定动态生产计划,提高生产效率,达到最终减少客户等待时间目的. 相似文献