Abstract
A consistent method is presented for solving the so-called general waiter problem, which is to move a tray (mounted at the end-effector of a robot) with a number of loosely placed objects (e.g. cups) as fast as possible such that the objects do not slide at any time. The geometric path of the tray motion is prescribed while the attitude of the tray must vary in order to avoid sliding or tip-over of the objects. The time optimal robot trajectory is determined with a multiple shooting method. For the considered wrist-partitioned robot, the motion is described by the path parameter and the three joint coordinates of the wrist. This 4-parametric description is beneficial for solving the optimal control problem with improved convergence. The optimization takes into account the technical limitations of the robot as well as the limiting friction between objects and tray. Experimental results for a time-optimal motion of a Stäubli RX130L manipulating a tray with 4 cups are presented. A crucial aspect is the use of a model-based control strategy along with the identification of dynamic parameters. Moreover, the basis for any optimization and real-time control is a reliable dynamic model of the robot. Therefore a parameter identification is performed using optimized persistent excitation trajectories.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
