说明：  机器人逆运动学，CCD算法，坐标循环下降算法 相关算法基础：https://sites.google.com/site/auraliusproject/ccd-algorithm 程序运行，看readme
(Inverse kinematics, CCD algorithm, coordinate circulation decline related algorithms underlying algorithms: https: //sites.google.com/site/auraliusproject/ccd-algorithm program is running, see readme)