The improvements in the iaga contained adding strengthen operator , improving evaluation index of premature , etc . multi - phase homing project , making use of the flight properties of parafoil system in gliding and turning , was simple in control and facile in practice . based on frenet frame , the linear time - variable error equations of parafoil system were built 基于frenet坐標(biāo)系推導(dǎo)和建立了翼傘系統(tǒng)線性時(shí)不變的誤差方程,并運(yùn)用“投影點(diǎn)”的思想來獲得frenet坐標(biāo)系下偏差量的解析近似表達(dá)式,從而設(shè)計(jì)了用于翼傘系統(tǒng)航跡跟蹤的傳統(tǒng)pd控制器和增益調(diào)節(jié)型模糊pd控制器。