A method of drawing transmission tower two-dimensional graph based on ObjectARX

The transmission towers are important equipments in power cables, tower commander drawings (also known as two-dimensional graphs) provide comprehensive, accurate drawings for the construction and installation of tower. In this paper, Based on the in-depth study of transmission tower geometry features and design requirements, combined with the knowledge of Computer Graphics, we proposed a drawing algorithm with high performance. By using ObjectARX and MFC, the algorithm can read the 3D tower-modeling data file, automatically generates the two dimensional graph in the format of DWG and displays it in AutoCAD. It greatly improves the efficiency and accuracy of generating tower commander drawings. The main innovation points of this method includes: successfully output the front and side view of tower, diaphragms, arms and legs. If the modeling file includes multi tower bodies and legs, users can choose what to output, single or all, besides, the program can generate a specification-substation table if the length of the specification is too long. At the same time, given that some unit, bolts, flanges have relatively long specifications, we developed an algorithm for automatic collision avoidance. The trials show that: this method satisfies the requirement of engineering design drawing, and has relatively high economic benefit.