During the process of obstacle expression , geometrical predigestions and improvements are carried out with the structure characters of obstacle polygon . a new method of vertex judgement - tangent way is proposed during polygon vertex judgement in this paper . it conquers the limitation of traditional plans , which is the same with either obstacle vertex judgement 在障礙物表達(dá)中,研究了障礙物多邊形的構(gòu)造,并對(duì)其進(jìn)行了幾何簡(jiǎn)化和改進(jìn);針對(duì)多邊形頂點(diǎn)判斷問題,提出了一種新的頂點(diǎn)判別法?切線法,該方法克服了傳統(tǒng)法的缺陷,對(duì)任一障礙物都適用。