在繞線這個領域，找到一個不與障礙物相交之直角史坦納樹是一個基本的問題。現在的設計內通常都含有許多直角的障礙物，例如區塊型模組、矽智財模組及預先繞線好的網路。因此，建造出一個不與障礙物相交的直角史坦納樹變成了一個很實際的問題。在這篇論文中，我們提出了一個很快速且穩定的演算法來解決此問題。我們分別使用了一個以分割作基礎的方法和使用螞蟻演算法為基礎的方法去建造一個不與障礙物相交的史坦納樹。除此之外，兩個簡單的演算法被用來將史坦納樹垂直水平化及加以改進線段長度。從我們的實驗結果可以看出，我們的演算法可以在很小的執行時間內找到很好的結果，即使是對於較大的測資，如接點和障礙物的個數都大於一百，我們的演算法依然可以做到。

In routing, finding a rectilinear Steiner minimal tree (RSMT) is a fundamental problem. Today’s design often contains rectilinear obstacles, like macro cells, IP blocks, and pre-routed nets. Therefore obstacle-avoiding RSMT (OARSMT) construction becomes a very practical problem. In this thesis we present a fast and stable algorithm for this problem. We use a partitioning based method and an ant colony optimization based method to construct obstacle-avoiding Steiner minimal tree (OASMT). Besides, two heuristics are proposed to do the rectilinearization and refinement to further improve wirelegnth. The experimental results show our algorithm achieves good wirelength results and the runtime is very small even for the larger cases each of which has both the number of terminals and the number of obstacles more than 100.

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