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排序方式: 共有463条查询结果,搜索用时 16 毫秒
51.
激光直写设备超精密平稳驱动技术的研究   总被引:1,自引:1,他引:0  
在二元光学激光直写设备中,主轴的速度稳定性是影响光刻精度的主要原因之一。提出采用机电混合滤波器消除电机的轴向振动和径向振动对系统的影响,提高主轴系统瞬时运动的平稳性。利用鉴相器输出的频差与相差和主轴电机的速度对锁相调速系统的结构进行优化。同时,利用神经网络改善锁相环系统的非线性特性,并采用模糊参数自调整方法调节控制器的参数。结果表明使用机电混合滤波器可使主轴的轴向与径向振动小于20nm,采用改进的锁相环控制可大大提高主轴的调速范围,并改善其动态性能。  相似文献   
52.
Jun  Gang  Sheng  Jian   《Automatica》2008,44(12):3093-3099
A novel optimal Finite Word Length (FWL) controller design is proposed in the framework of μ theory. A computationally tractable close-loop stability measure with FWL implementation considerations of the controller is derived based on the μ theory, and the optimal FWL controller realizations are obtained by solving the resulting optimal FWL realization problem using linear matrix inequality techniques.  相似文献   
53.
A multivariable analog system can be controlled by a sampled-data compensator. A conic sector that can be used to analyze the closed-loop stability and robustness of this feedback system is presented in this letter.  相似文献   
54.
In this paper we discuss a real-life case study to optimize the logistics network for the collection of containers from end-of-life vehicle dismantlers in the Netherlands. Advanced planning concepts, such as dynamic assignment of dismantlers to logistic service providers, are analyzed using a simulation model. Based on this model, we periodically solve a vehicle routing problem to gain insight into the long-term performance of the system. The vehicle routing problem considered is a multi-depot pickup and delivery problem with alternative delivery locations. A special characteristic of the problem is the limited vehicle capacity of two containers. We solve this problem with a heuristic based on route generation and set partitioning.  相似文献   
55.
为避免基于Riccati方程求解移动域控制问题时复杂的矩阵求逆运算,提出一种基于离散Hopfield网络(DHNN)的移动域控制策略.对每个离散时刻,通过建立DHNN能量函数与移动域线性二次(LQ)性能指标间的等价关系,在线构建相应时刻的DHNN,理论设计能够保证该网络具有稳定性,而且由其稳态输出可获得移动域控制输入.应用于倒立摆平衡控制的仿真实验说明了论文提出的移动域控制策略的正确性及与滚动优化思想相结合实现无限域闭环最优控制的可行性.  相似文献   
56.
一种实用的开关磁阻电机驱动控制器设计   总被引:1,自引:0,他引:1  
徐仲春  马瑞卿  刘亚  王灿 《微电机》2007,40(2):44-47
针对三相6/4结构开关磁阻电动机,介绍了一种基于AT89C51单片机的驱动控制系统。详细阐述了系统的组成,重点介绍了速度闭环方法和功能实现电路。实验结果表明,该系统具有良好的快速正/反转、连续调速和闭环稳速功能。  相似文献   
57.
Control of reactive distillation process for production of ethyl acetate   总被引:1,自引:1,他引:1  
In this paper, plant-wide control for the production of ethyl acetate using reactive distillation is studied. Four important issues are considered in developing control schemes, including: (1) economics; (2) steady-state deviation of key product purities; (3) controllability in terms of degree of oscillation and settling time; and (4) feasible region of disturbances for effective control. Starting with two basic control schemes that have been studied before, new control schemes are developed to improve the operability of the process. These new control schemes have evolved from the basic schemes by making a trade-off between optimal design and control or by selecting sensor locations using closed-loop sensitivity analysis. It is found that, while being subjected to fluctuations in the composition of the acid feed or in the production flow-rate, sensor location based on traditional open-loop sensitivity causes a larger overshoot and steady-state deviation of key product purities. Sensor location on the basis of a closed-loop sensitivity analysis provides a better alternative for feedback control. The resulting scheme for control is found to be effective in reducing the steady-state deviation and in promoting good control performance.  相似文献   
58.
非正则线性系统的闭环P型迭代学习控制   总被引:3,自引:0,他引:3  
迭代学习控制是改善具有重复运行性质过程的跟踪性能的有效方法。开环迭代学习控制学习周期长,在迭代学习的初期容易出现不稳定和高增益的现象。对非正则系统的迭代学习控制,需要采用高阶微分学习律。该文针对一类非正则线性定常连续系统,讨论了闭环P型迭代学习控制律,给出并证明了闭环P型迭代学习控制律的收敛性条件的两个定理,解决了非正则系统的P型迭代学习控制问题。仿真实例说明闭环迭代学习律的有效性和快速性。  相似文献   
59.
廖旭志 《宽厚板》2004,10(4):30-33
本文论述了西门子6RA70装置在双边剪夹送辊传动系统中的应用,解决了夹送辊不同步而出现的钢板走偏问题。  相似文献   
60.
This paper studies coordinated scheduling of production and logistics for a large-scale closed-loop manufacturing system by integrating its manufacturing and recycling process. In addition to the forward manufacturing process, different recycling units in reverse recycling process are also studied. A decentralized network is designed to formulate the coordinated scheduling problem as a mixed integer programming model with both binary and integer variables. As the problem for closed-loop manufacturing is large-scale and computational-consuming in nature, the model is divided into integer variable sub-models and complex binary variable sub-models for preprocessing and reprocessing respectively. An iterative solution approach by Benders decomposition is developed to accelerate the solving efficiency in large-scale case by updating custom constraints. A case study is conducted to investigate the managerial implications of the decentralized network for the closed-loop manufacturing system. Computational experiments demonstrate the validity and efficiency of the proposed iterative solution approach for the large-scale scenarios.  相似文献   
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