The paper analyzes the structure of grass ' s vector files and several basic indexes " methods for spatial data . lt also compares the characteristics of the postgis , peegree , openmap , etc . on the other hand , mis paper researches the spatial vector data index arithmetic 除此之外,本課題對于空間矢量數據的索引算法進行了一定的研究,并詳細介紹了r樹模型的基本算法,同其他空間索引算法進行了一定的比較,簡要總結了各種算法的基本特征。
In the paper , the principle and actualizing means of spatial vector control have been systemically discussed and the control software has also been designed . the magnitude of both the rotor flux and the current in torque component have been estimated by using a flux observer , which is developed based on field orientation control principle . the results show that the observer has a good feature due to its speed being calculated without speed sensor or additional hardware 本文對矢量控制的原理、控制方法以及控制實施策略進行了較為系統的分析與研究,利用速度間接觀測理論,建立了異步電機的磁通觀測器,電機的定子磁通和電流的轉矩分量可以通過磁通觀測器估算出來,從而得到電機的轉速,并由此建立了異步電機無速度傳感器矢量控制的理論數學模型和相應的控制算法,在此基礎之上,利用工程中常用的電機專用dsp芯片tms320lf2407作為處理器,對異步電機進行變頻調速控制。
The main technical module of processing gis spatial information of land desertification is designed , which can carry out the spatial overlay of vector data in three periods , extract as well as process attributative information and transform the spatial vector data into visualizing data . the gis database of land desertification is established 本研究設計了土地沙漠化gis空間信息處理的主要技術模塊,即三期矢量數據的空間疊加、屬性的信息提取與處理、空間矢量數據向可視化數據庫的轉化,建立了土地沙漠化gis數據庫。