For the effect of motion of target , a method of isar motion compensation based on scattering center tracking is used . for the difficulty of getting echo signal of bistatic isar of moving target , a method of simulating moving target using turntable data is used . finally the imaging results by using simulating data based on scattering center tracking show the effectiveness of the methods 针对目标的运动对双站逆合成孔径雷达成像质量的影响,运用基于散射重心跟踪的isar运动补偿方法来消除目标运动对成像质量的影响,并针对双站isar运动目标回波获取的困难,运用一种用转台数据模拟运动目标回波的方法来获得仿真数据,最后用仿真数据验证了基于散射重心跟踪法的双站isar运动补偿的正确性。
According to the gjb 2077 - 94 and the requirement of automatic radio of haige communication co . , a new way of bit synchronization is put forward . this article discusses the design of 8 - fsk modulating and demodulating , signal detection , and fec encoding , based on the technique of bit synchronization . ale module is optimized and mended in its application , because it is a module of automatic radio of the company 本文根据gjb2077 - 94短波自适应通信系统自动线路建立规程和海格通信公司短波自适应电台对ale模块的具体需求，采用了一种新的位同步方法：能量跟踪法，并在此基础上提出了8fsk调制解调，信号检测，前向纠错编码的具体实现方法。
In this paper point to point control , constant frequency control and up and down frequency control are studied , in which current lagging loop control method is used to restrict over currents . and using flux tracking method , position open loop , position close loop control system are also studied . and research results indicate that larger current ripples are restricted by means of subdividing space vectors 本文以永磁同步电动机为研究对象，分别对同步电动机的点动控制、恒频控制以及升降频控制进行了分析与研究，研究中采用了电流滞环控制方法，可有效地限制过电流现象；此外采用磁链跟踪法对位置开环和位置闭环的步进控制系统分别进行了探讨与研究，研究表明，采用矢量细分后，可有效地减小电流波动。
It can be used in any complex environment , can locate all paths from transmitter to receiver which avoid redundant calculation , and it is a standard 3 - d forecast model ; in addition , it is a point to point ray tracing method based on specular theory which do n ' t carry out the receive test ; furthermore the model adopt the reverse arithmetic which exert the tree concept in data frame and establish a virtual fountain tree permanently , the proagmme can back - search the virtual fountain tree when it is running . these operation increase the calculate speed and it result in the higher receive efficiency and precision . the thesis design a programme to compare the prediction results based on ray tracing method of virtual fountain tree between the measurement results and prediction results based on the other transmittion models . the comparsion result indicate the new model is a better model 它可应用于任何复杂的传播环境中，能找到发射机到接收机之间的所有电波传播路径而无须冗余的计算，是一种准三维的预测模型；另外，从本质上讲，它仍然是一种基于镜像理论的点对点的射线跟踪法，所以它无须进行接收测试；而且由于采用了反向算法，运用数据结构中多叉树的概念，先确定需要计算的场点位置，找出所有能从源点到达场点的射线，并且可一次性建立一个虚拟源树，以后每次的计算只要通过对该树进行后序遍历即可，大大提高了运算速度，因而有较高的接收效率与精度。本文对该模型进行了相应的仿真，并将其预测结果与实测结果以及基于cost231经验性模型和基于强力射线跟踪确定性模型的预测结果进行了比较，结果表明了该模型的优越性。
In addition , the performance criterion is respectively described , and the torque ripple at low - speed is analyzed in this paper . according to a method to adjust the duty ratio coefficient , we select a torque track with adaptation fuzzy controller to simulate . the experimental results show that the control strategy proposed can acquire better control effect 针对直接转矩控制系统在低速运行时依然存在的转矩脉动大、运行性能差的问题进行研究分析，结合传统的固定采样周期控制方法，提出一种基于自适应模糊转矩跟踪法，调节电压矢量占空因子，进行仿真研究，改善了系统的低速性能。
There are 6 types of 551 algorithms available , they are : geometric division , algebraic iteration , trace , lattice , analytics and trigonometry methods . but none of them has completely reached a good balance between efficiency and precision , because the research was done either from one side of versatility or merely the other side of precision . at present , trace method is considered a relatively better method with higher precision and better stability 到目前为止，提出的求交算法大致有六种，即：几何分割法、代数迭代法、跟踪法、网格法、解析法和三角法；但任何一种方法都没有解决好求交问题中速度与精度的有效统一，因为有的算法侧重于通用性，有的却只注重精度问题。
