QF18D航空双凸极起动/发电机关键特性研究

起动/发电一体化是现代飞机供电系统的主要发展趋势之一。QF18D航空起动/发电机采用的三相双凸极电机具有转子无磁钢无绕组、结构强度高、制造方便、可逆性好等优点,适于高空高速飞行的应用条件。文章首先扼要介绍了QF18D发电及电动工作的结构原理;然后基于有限元仿真和实验验证相结合的方法详细研究了QF18D双凸极直流发电机的空载、短路、外特性和调节特性的特点,主要探讨了换相重叠和电枢反应对电机关键特性的影响机理;最后通过航空涡喷发动机的冷热开车试验验证了QF18D的系统起动性能优越。     

无人机航测技术应用于公路崩滑陡峭地段测量分析

近年来,随着无人机技术和数字摄影测量技术的快速发展,无人机航测技术已经成为一种有效的快速测绘手段.介绍无人机航测数据处理的关键技术,利用无人机航测技术对公路路堤和边坡崩滑进行快速测量,获取测区的3D数字信息,为公路维护管理提供及时有效的测绘资料.     

Study on DSM-based task planning of product cooperative development

The results of analyzing the managerial characteristics and complexity of product cooperative development suggest that task planning is an important aspect for process management of product cooperative development and the method for planning tasks should be able to model the dependency between tasks and iterations during the development process. In this paper, a DSM-based method and its corresponding optimization algorithms are developed. At first the coupled task sets and uncoupled task sets are identified, and the tasks are then optimized by the corresponding algorithms. The optimal tasks plan will reduce the development time and cost. Considering the practical requirements in real world, a Multilayer DSM is proposed, and its information communication techniques between DSM and traversing principle are described in details.