Flutter is an important phenomenon of aeroelasticity ,also the main cause of airplane destruction . The pit that the flutter speed curve shows in transonic implies flutter is most likely to take place in tran‐sonic stage .In this paper ,double lattice method and ZONA51 method are adopted respectively in subsonic and supersonic ,which are used to compute the flutter speed in the range of transonic .The summarized flutter speed curve reveals the consistency with the phenomenon during the transonic stage . Research methods and conclusions are generally applicable ,and can be used to estimate transonic flutter speed more simply but still accurately .

基于图论理论、变流理论及贝叶斯算法建立环状热网泄漏工况水力模型、预测误差模型.在模拟管网泄漏工况时,将泄漏归结在节点处,将泄漏流量视为该节点流量的一部分,泄漏程度用泄漏面积反映.将由热网泄漏工况水力模型得到的热网泄漏数据库数据作为测量数据,将水力模型的模拟结果作为预测数据,采用预测误差模型计算预测数据的最优估计概率,指导确定泄漏位置.

永磁交流伺服系统的参数自整定功能是高档交流伺服驱动器必备的实用功能,国外先进的交流伺服系统中,该功能已经可以取代手动整定的过程。本文提出了两种不基于模型的PI控制器参数自整定方法,一种对KP和KI参数采用不同的策略加以整定,以提高整定的效率。而另一种采用基于起动过程的转动惯量辨识,结合查表方法整定PI参数。算法简单,具有较强的实用性。

针对交流伺服系统中通常采用的MT法测速在低速时存在的问题,采用了自适应扰动测器以获得低速下的连续转速,并利用波波夫超稳定性理论给出了一种简单的自适应律.该方法能实时观测负载转矩扰动和低速时的连续速度变化,计算量小.仿真和实验结果表明,应用该方法在低速情况下较之传统MT法测速具有良好的控制效果.

By analyzing hardware structure and principle of PLC backup system produced by AB company , the reason of output bump and the failure of data integrity when switchover are explained . To deal with this problem , a method of programming backup program by using high-speed serial link is introduced . An example which is used in blower supervision system for blast furnace is also given .