微机控制光学非球面加工

光学非球面加工控制系统是由主机IBM-PC与直接控制(单板机)两级组成的分布式控制系统。IBM-PC完成对非球面面形误差的分析与计算进而自动生成加工程序;单板机控制装置控制抛光机,带动抛光模按加工程序要求,在非球面表面运动。本文主要介绍数控装置的实现,系统安全,断电保护措施以及IBM-PC与单板机双机通讯等。 1.系统的组成及工作原理在光学系统中,应用非球面能够校正像差,改善像质,简化光学系统结构,减轻重量。因而在航空航天光学系统,天文观测,红外技术等诸多方面都有广泛的应用价值。但由于非球面加工与检测的困难,使其应用受到阻碍。对高精度的大型非球面,目前国内一般采用普通研磨抛光法,用刀口仪测量根据阴影图来定性判断误差,在抛光机上,由人工修正抛光模,来控制加工精度。     

New Algorithm to Evaluate the Unreliability of Flow Networks Based on Minimal Cutsets

Several conclusions on minimal cutset are proposed, from which a new algorithm is deduced to evaluate the unreliability of flow networks. Beginning with one unreliability product of the network, disjointed unreliability products are branched out one by one, every of which is selected from the network minimal cutsets. Finally the unreliability of the network is obtained by adding all these unreliability products up.