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A cybernetics model of manufacturing execution system(MES CM) was proposed and studied from the viewpoint of cybernetics.Combining with the features of manufacturing system, the MES CM was modeled by"generalized modeling"method that is discussed in large-scale system theory.The mathematical model of MES CM was constructed by the generalized operator model, and the main characteristics of MES CM were analyzed. 相似文献
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The principle of real-time look-ahead was introduced and analysed. An adaptive parametric curve interpolator with a real-time look-ahead function was developed for non-uniform rational B-spline (NURBS) curves interpolation, which considering the maximum acceleration/deceleration of the machine tool. In order to deal with the acceleration/deceleration around the feedrate sensitive corners, the look-ahead function was designed and illustrated. It can detect and adjust the feedrate adaptively. With the help of real-time look-ahead, the acceleration/deceleration can be limited to the range of the machine tool capacity. Thus, feedrate fluctuation is reduced. A NURBS curve interpolation experiment was provided to verify the feasibility and advantages of the proposed interpolator with a real-time look-ahead function. 相似文献
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To solve the resource-constrained multiple project scheduling problem (RCMPSP) more effectively, a method based on timed colored
Petri net (TCPN) was proposed. In this methodology, firstly a novel mapping mechanism between traditional network diagram
such as CPM (critical path method)/PERT (program evaluation and review technique) and TCPN was presented. Then a primary TCPN
(PTCPN) for solving RCMPSP was modeled based on the proposed mapping mechanism. Meanwhile, the object PTCPN was used to simulate
the multiple projects scheduling and to find the approximately optimal value of RCMPSP. Finally, the performance of the proposed
approach for solving RCMPSP was validated by executing a mould manufacturing example. 相似文献
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In textile industry, carding process has decisive influence on produced yarn quality. From the system theoretic point of view, it is marked by stochastic disturbance, long delays, and parameter variation. So, a carding process is difficult to control with traditional control algorithms (such as PID). In this paper, a weighted adaptive generalized predictive control (GPC) law was developed to control such a process. The experimental results show that GPC autoleveller controller could greatly reduce the sliver‘s standard deviation and reject disturbance. 相似文献
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PHEV动力总成控制器硬件在环仿真系统的研究 总被引:1,自引:0,他引:1
对硬件在环仿真系统进行了分析研究,在此基础上以dSPACE系统作为开发平台,构建了并联式混合动力电动汽车(PHEV)的动力总成控制器硬件在环仿真系统,在MATLAB/SIMULINK环境下,建立了并联式混合动力电动汽车的仿真模型,将模型编译到dSPACE系统中,进行接口的设计和监控的工作,建立了硬件在环仿真系统,并对仿真结果进行分析. 相似文献
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The vee-ring is one of the most characteristic features of the fine-blanking process which is derived from the conventional blanking. With the vee-ring, a counter plate and some other working parameters, a component with a precise geometry and smoothly blanked surface can be produced without any major secondary operations. However, these working parameters are always empirically determined or determined by trial-and-error method, which is time-consuming and expensive. In this study, a numerical simulation method was used to analyze the effect of vee-ring factors on product quality, such as distance between vee-ring and punch, vee-ring height and blank holder force, so as to obtain as high clean cut ratio as possible. During the simulation, the model was assumed as axisymmetric one and the workpiece was considered as rigid plastic material, meanwhile the tools were defined as rigid bodies so as to shorten the computational time. A damage model taking into account the influence of hydrostatic stress was used to simulate material fracture in fine-blanking. The result obtained from the simulation indicated that with the help of vee-ring, the metal material near the shear band does not flow with the punch penetration and high compressive stress in the shear band is generated. Consequently, higher clean cut ratio can be obtained with a vee-ring model than the one obtained with a plane blank holder model. Furthermore, the longer the distance between vee-ring and punch is, the higher the height of roll-over becomes. 相似文献