Modelling,simulation and identification of an engine air path electromechanical actuator

This paper deals with the modelling and the identification of an electromechanical Diesel engine actuator. The studied Bosch GPA-S actuator is designed for swirl/tumble flaps to control the air amount entering into the cylinder. This study aims to design a complete simulator that reproduces, with sufficient accuracy, the actuator dynamics taking into account the effects of the friction phenomenon. Hence, an overview of the actuator structure and its operation principle is first given. Then, its mathematical model as well as the nonlinearity, related to its behaviour, is discussed. Next, three identification procedures, which allow estimating both the system parameters and the friction model coefficients, are introduced. Finally, simulation results, using MATLAB, and experimental results, using LabVIEW, are presented demonstrating the effectiveness of the proposed techniques.     

蝶阀加工及装配工艺的研究

传统工艺加工阀体、活门时，对机床的性能要求较高，一般为数控镗床。介绍了一种采用普通镗床加工阀体、活门的工艺方法及蝶阀在厂内装配的工艺方法。     

Integrating neural network technology and noise analysis

The integrated use of neural network and noise analysis technologies offers advantages not available by the use of either technology alone. The application of neural network technology to noise analysis offers an opportunity to expand the scope of problems where noise analysis is useful and unique ways in which the integration of these technologies can be used productively. The two-sensor technique, in which the responses of two sensors to an unknown driving source are related, is used to demonstration such integration. The relationship between power spectral densities (PSDs) of accelerometer signals is derived theoretically using noise analysis to demonstrate its uniqueness. This relationship is modeled from experimental data using a neural network when the system is working properly, and the actual PSD of one sensor is compared with the PSD of that sensor predicted by the neural network using the PSD of the other sensor as an input. A significant deviation between the actual and predicted PSDs indicate that system is changing (i.e., failing). Experiments carried out on check valves and bearings illustrate the usefulness of the methodology developed.     

引进型国产300MW汽轮机窜轴事故分析及防止对策

通过引进型国产300MW汽轮机在启动试运中出现的一次窜轴事故,根据计算机追忆打印的有关图表、数据分析了产生事故的原因,并提出了为防止类似事故重演应采取的措施和建议。经采取措施后该机组多次又在相同情况下启机,已安全运行。说明分析正确,措施得当,值得同类型机组借鉴。     

机电排灌工程管理之我见

机电排灌工程是丘陵、滨湖地区的主要灌溉设施，必须建立适应市场经济的管理新机制，确保工程良性运行和巩固发展，满足不断发展的工农业生产需要。     

阀控式铅酸蓄电池的维护

对阀控式铅酸式蓄电池的维护工作进行了初步探讨。     

加强设备管理 防止阀门泄漏

分析了润滑油加氢装置阀门产生泄漏的原因，针对存在的问题，提出了防止阀门泄漏的方法，确保了装置“两年一修”的长周期安全运行。     

摇臂参数设计方法

建立了中小功率内燃机常用摇臂参数化设计模型。采用可变参数构成摇臂结构，并作结构的有限元网络，此后再进行有限元分析，计算出摇的质量、刚度、转动惯量 力。使摇臂的设计归结为几个主要参数的优选。实例分析表明，计算值和实测值基本相符，优选出的摇避设计优于原设计。     

双瓣止回阀阀瓣强度分析及优化设计

通过对双瓣止回阀阀瓣的有限元分析,介绍了有限元分析法在阀门强度和刚度分析方面的应用。     

An improved bacterial foraging algorithm for combined static/dynamic environmental economic dispatch

Economic dispatch is carried out at the energy control center to find out the optimal output of thermal generating units such that power balance criterion is met, unit operating limits are satisfied and the fuel cost is minimized. With growing environmental awareness and strict government regulations throughout the world, it has become essential to optimize not only the total fuel cost but also the harmful emissions, both, under static as well as dynamic conditions. The static environment economic dispatch finds the optimal output of generating units for a fixed load demand at a given time, while the dynamic environmental economic dispatch schedules the output of online generators with changing power demands over a certain time period (normally one day) so as to minimize these two conflicting objectives, simultaneously. In this paper, the price penalty factor approach is employed for simultaneous minimization of cost and emission. The generator ramp rate constraints, non-convex and discontinuous nature of cost function and the large number of generators in practical power plants, make this problem very difficult to solve. Here, a fuzzy ranking approach is employed to identify the solution which offers the best compromise between cost and emission objectives.