基于Stewart平台的星上微振动主动隔离/抑制

针对星上微振动主动隔离/抑制的要求,以VCM(voice coil motor)作动器Stewart平台为控制装置,通过对其动力学模型解耦将控制转化为SISO(single input single output)问题;分析了Skyhook控制方法的隔振效果及其对抑振的局限性,在控制系统中加入了PFF(positive force feedback)控制回路,并引入加速度反馈环节以提高系统的鲁棒稳定性,形成一种振动主动隔离/抑制控制方法;利用Stewart平台的单杆开展了基础扫频激励和负载单频直接干扰共同作用下的S-DOF(single degree of freedom)微振动主动隔离/抑振控制实验,建立了Stewart平台刚/柔混合动力学模型并通过仿真研究了6-DOF振动主动隔离/抑振控制效果。实验和仿真结果表明:该方法可实现良好的振动主动隔离/抑制效果且性能稳定。     

Tuning rules for robust FOPID controllers based on multi-objective optimization with FOPDT models

In this paper a set of optimally balanced tuning rules for fractional-order proportional-integral-derivative controllers is proposed. The control problem of minimizing at once the integrated absolute error for both the set-point and the load disturbance responses is addressed. The control problem is stated as a multi-objective optimization problem where a first-order-plus-dead-time process model subject to a robustness, maximum sensitivity based, constraint has been considered. A set of Pareto optimal solutions is obtained for different normalized dead times and then the optimal balance between the competing objectives is obtained by choosing the Nash solution among the Pareto-optimal ones. A curve fitting procedure has then been applied in order to generate suitable tuning rules. Several simulation results show the effectiveness of the proposed approach.     

烧结混合料加水的模糊自适应分数阶PI~λD~u控制

烧结混合料加水系统具有大滞后、模型复杂的特性,且客观环境中存在干扰因素,传统的控制方法很难取得理想的控制效果。分数阶PIλDu控制器比常规PID控制器多了两个可调参数,具有更好的控制效果。在分析分数阶微积分的基础上,给出了分数阶微积分的数字实现,用分数阶PIλDu控制代替常规PID控制,结合模糊控制,首次提出了一种针对烧结混合料加水系统的模糊自适应分数阶PIλDu控制方法,利用模糊逻辑实现分数阶PIλDu控制参数的在线调整。并用MATLAB/simulink进行建模仿真。仿真结果验证该控制算法的有效性,能取得较好的控制效果。     

反冲过滤器在洗煤厂污水处理中的应用

利用可编程序控制器S7-200作为主控制器,配合反冲过滤器实现了洗煤厂污水的重复利用。可以有效地降低水资源浪费,降低生产成本,提高洗煤作业的环保水平。     

计算机控制的铣床数控系统设计

设计了基于Windows环境下主从式的开放式铣床数控系统。硬件系统采用NC嵌入IPC的开放式体系结构。软件系统采用模块化设计,开发了人机交互界面、数控代码解释、程序查错、数据预处理等功能模块。开放式结构的运用体现了系统开放性、灵活性的特点。     

Experimental analysis of battery charge regulation in photovoltaic systems

The influence of charge regulation on batteries for stand‐alone photovoltaic systems is analysed in relation to two factors: battery lifetime and the daily energy service supplied. The regulation thresholds adjusted in the charge controller (for disconnection and reconnection), in overcharge and deep discharge conditions, determine the whole system operation. Laboratory testing procedures are proposed and applied to different components of the photovoltaic rural electrification market. Finally, technical recommendations for charge regulation of lead–acid batteries are presented. Copyright © 2003 John Wiley & Sons, Ltd.