摘要
讨论了载体位置、姿态均不受控的飘浮基柔性空间机器人的Terminal滑模控制问题。为讨论既有柔性关节又有柔性臂的欠驱动系统,以一个具有两个柔性关节和一个柔性臂的飘浮基空间机器人为例,首先利用拉格朗日方程并结合系统总质心定义,得到了系统的动力学方程,然后利用奇异摄动法,将柔性空间机器人系统分解为一个柔性空间机械臂子系统和一个柔性关节快变子系统。以此为基础,提出了一种包含柔性空间机械臂子控制项和柔性关节快变子控制项的组合控制器。其中,柔性空间机械臂Terminal滑模子控制项实现了机械臂关节铰期望轨迹的跟踪,柔性关节快变子控制项使得快变子系统稳定在由柔性空间机械臂子控制项产生的机械臂关节轨迹上。系统的数值仿真结果表明,该方法能在抑制柔性关节的柔性振动的同时跟踪上机械臂关节期望轨迹。该控制方案的显著优点为不需要测量、反馈载体的位置、移动速度、移动加速度,同时可保证机械臂关节铰跟踪误差在任意指定有限时间内收敛到零。
A Terminal sliding mode control was proposed for a free-floating space robot.To discuss such an under-actuated flexible-link flexible-j oint space robot,a free-floating space robot with one flexible link and two flexible revolute j oints was presented.The dynamical Lagrange equation was es-tablished by the momentum conservation.And a singularly perturbed model was formulated and used for designing a reduced-order controller,where the system was decoupled into two subsystems （a flexible space manipulator subsystem and a flexible-joint fast subsystem）.A composite controller which consisted of two control components was proposed.A Terminal sliding mode controller was proposed to control the flexible space manipulator subsystem.A flexible-joint fast controller was de-signed to stabilize the flexible-joint fast subsystem around the equilibrium trajectory set up by the flexible space manipulator subsystem under the effects of the Terminal sliding mode controller.A nu-merical simulation was carried out,which confirmed the proposed controller is feasible and effective. The virtue of this control scheme is that the base linear position,the base linear velocity,the base lin-ear acceleration need not be measured.In addition,it is ensured that the tracking errors of the manipu-lator j oints converge to zero in finite time.
出处
《中国机械工程》
EI
CAS
CSCD
北大核心
2015年第7期936-942,共7页
China Mechanical Engineering
基金
国家自然科学基金资助项目(11372073)
福建省自然科学基金资助项目(2010J01003)
