【作者】 应舜安；

【导师】 林桐；

【作者基本信息】 福州大学 ， 固体力学， 2005， 硕士

【摘要】 本文主要研究一种驱动冗余平面并联柔性机械臂的动力学建模,以及结合采用压电陶瓷驱动器来抑制柔性臂振动的控制方法。用第一类拉格朗日(Lagrange)方法建立了一种驱动冗余平面并联柔性机械臂的动力学模型,消去拉格朗日乘子,对复杂的并联柔性机械臂数学模型进行化简、整理,使得为串连柔性机械臂提出的控制策略能应用于这种并联柔性机械臂,为驱动冗余平面并联柔性机械臂实现高速、高精度控制奠定了理论基础。通过数值仿真,验证了冗余驱动的优点:冗余驱动可使并联机构避开工作空间内部的奇异点,提高并联机构的刚度和精度,冗余驱动还有抑制振动的作用。采用压电陶瓷驱动器来抑制柔性并联机械臂的残余振动。因此,当柔性并联机械臂的末端执行器要求快速、精确定位时,系统的残余振动能快速减弱。对柔性机构进行轨迹控制的主要任务是让机构的末端执行器跟踪期望轨迹,同时要抑制柔性臂振动,防止柔性臂的振动影响跟踪精度。施加给驱动关节的驱动力矩,难以既让杆件作大范围刚性运动又抑制柔性臂振动。本文用基于刚性模型的控制器控制杆件的刚性运动,把刚性模型当作标称模型,采用压电陶瓷驱动器抑制柔性臂振动,使柔性系统与标称模型之间的偏差稳定在一定范围内,实现了系统的鲁棒稳定,并在保证控制精度的前提下减小了实时控制的计算量,提高了控制效率。更多还原

【Abstract】 This thesis presents the research work about dynamic modeling of a planar flexible parallel manipulator with redundant actuation, and control of the manipulator with several approaches and using PZT for vibration attenuation. The Lagrangian formulation is used to derive the equations of motion of the flexible-link parallel manipulator with redundant actuation. The constraint forces are eliminated and obtain the minimum number of equations of motion. Based on the dynamic model, many dynamic control algorithms designed for serial flexible manipulators can be applied to the parallel flexible manipulators. Many advantages of redundant actuation are confirmed by numerical simulation. Redundant actuation can eliminate singularities, and improve the stiffness and accuracy of parallel manipulators. For flexible parallel mechanism, redundant actuation can damp vibration of flexible-link. Piezoelectric actuators are used for residual vibration attenuation, resulting in high positioning accuracy and fast movements. The aim of trajectory tracking control of flexible mechanism is high tracking accuracy and simultaneous vibration attenuation. It is not easy for active joints to control the stiff movements of flexible manipulators and damp vibration simultaneously. In this thesis, the torque provided by active joints is responsible for stiff movements of a flexible parallel manipulator, rigid model of the manipulator is regarded as the nominal system. PZT is used to damp vibration of flexible-link, making the error between flexible manipulator and nominal system small, resulting in stability of the system. The control scheme reduces the time of calculating for real time control.更多还原