A Cascade Approach for Global Trajectory Tracking Control of Underactuated AUVs

A global trajectory tracking controller is presented for underactuated AUVs with only surge force and yaw moment in the horizontal plane. A transformation is introduced to represent the tracking error system into a cascade form. The global and uniform asymptotic stabilization problem of the resulting cascade system is reduced to the stabilization problem of two subsystems by use of the cascade approach. For the stabilization of the subsystem involving the yaw moment, a control law is proposed based on the feedback linearization method. Another subsystem is stabilized by designing a fuzzy sliding mode controller which can offer a systematical means of constructing a set of shrinking-span and dilating-span membership functions. In order to demonstrate the practicability of the proposed controller, control constraints, parameter uncertainties, and external disturbances are considered according to practical situation of AUVs. Simulation results show very good tracking performance and robustness of the proposed control schemes.     

决策在会外

中国人开会,其实在开会前已经在私下里对事情进行沟通。即便是重大决策,也会采取主要领导“碰头”私下商量的方式,确定个初步方案,来供与会人参考。     

疏肝解郁胶囊合经颅磁刺激治疗脑卒中后抑郁症60 例临床观察

目的：探讨疏肝解郁胶囊联合经颅磁刺激（TMS）治疗脑卒中后抑郁症的效果。方法：将120 例脑卒中后抑郁症患者随机分为治疗组和对照组，每组各60 例。2组均行常规康复训练，对照组采用经颅磁刺激治疗，治疗组在对照组的基础上加疏肝解郁胶囊治疗。2组均治疗6周后观察综合疗效、汉密尔顿抑郁自评量表（HAMD-17）评分、匹兹堡睡眠指数量表（PSQI）评分、简易精神状态量表（MMSE）评分。结果：总有效率治疗组与对照组分别为96.67%（58/60）、73.33%（44/60），2组比较，差异有统计学意义（P＜0.05）；2组HAMD-17评分、PSQI评分、MMSE评分治疗前后组内比较及治疗后组间比较，差异均有统计学意义（P＜0.05）。结论：疏肝解郁胶囊联合经颅磁刺激治疗脑卒中后抑郁症患者，疗效显著，值得临床推广应用。