Real-time end-effector trajectory tracking is applied to a newly developed parallel robotic system with two highly flexible links. In contrast to previous works, which are typically based on offline precalculations or rigid model inversion, a dynamic flexible multibody model is inverted online. As the underactuated system is non-minimum phase, the inverse model needs to be rendered stable for real-time integration. Therefore, three approaches are developed for the considered robot. Firstly, output redefinition is applied by directly weighting the elastic deformations and rotations of the links. Secondly, a small counter weight is attached at an advantageous location on the robot having only a minor influence on the eigenfrequencies. Lastly, the rotational degree of freedom of the end-effector is used to stabilize the internal dynamics of the inverse model with a small motion of a rotary motor. The concepts and real-time applicability are validated within experiments which extends the related literature being highly based on theoretical investigations. The experimental end-effector tracking performance based on the three minimum phase approaches is close to the desired trajectory and clearly outperforms classical rigid body inversion.
Real-time trajectory tracking control of a parallel robot with flexible links
2021-04-01
2-s2.0-85098485080
Article (Journal)
Electronic Resource
English
DDC: | 629 |
Trajectory tracking control of robots with flexible links
Online Contents | 2002
|Modeling and Trajectory Tracking Control of a New Parallel Flexible Link Robot
BASE | 2018
|Trajectory tracking control of mobile robot by time-based spline approach
Online Contents | 2005
|Nonlinear state estimation for trajectory tracking of a flexible parallel manipulator
BASE | 2017
|