Trajectory planning for elastic structures

• Main Authors: Yao,Chih-Min, 姚志民
• Other Authors: Cheng,Wen-Hon
• Format: Others
• Language: zh-TW
• Published: 1994
• Online Access: http://ndltd.ncl.edu.tw/handle/12231984864040286502

博士 === 國立臺灣大學 === 機械工程研究所 === 82 === The concept of trajectory planning is proposed to treat the motion and vibration control problems for elastic structures with components having large motion and is to be used as a design tool for open loop control. A structure which has the rigid body motion degrees of freedom being completely controlled by joint driving forces is called a joint-actuated structure. The joint space trajectory planning concept for such a structure stems from the special form of the equations of motion when choosing the independent joint coordinates accociated with those joint forces as the independent generalized coordinates of rigid body motion. In this trajectory planning process, the behaviors of rigid body motion and elastic vibration of the whole structure are determined completely from the intergration of one set of equations of motion when those independent joint motions are given. And the algebraic calculation of the other set of equations of motion then determines the required joint driving forces. The variational approach of optimal control theory and parameter optimization method are used to plan the joint space trajectories. The generalized trajectory planning concept, which treats the joint space trajectory planning as its special case, is formed via the inverse dynamics approach. The constraints on zero residual vibration at the final position for the joint space trajectory planning can be relaxed by applying the above generalized trajectory planning method to the linealized model about the states of static equilibrium at the final position such that the performance during motion can be improved. In the simulations, an one-link and a two-link flexible manipulators are used as examples and the methods proposed in this paper are used to plan the optimal trajectories which induce least vibration during motion.