Trajectory Generation for High Speed Pick and Place Robots

Currently parallel robots are finding more and more acceptance in high-speed pick-and-place operations. As for all high-speed mechanisms, vibratory phenomena appear and deteriorate accuracy and dynamic performance at the terminal positions of the pick-and-place path. This paper aims to evaluate the effectiveness of several pick-and-place trajectories in terms of vibration reduction. To address this problem, an elastodynamic model of a five bar mechanism is developed and its behaviour is simulated as it traverses each trajectory. Spectral analysis of the vibrations allows the quality of the vibration reduction to be quantified. The results show that the first and second natural frequencies of the system are excited. It is also shown that long cycle times with smooth motion profiles improve residual error norms, but are outperformed by their discontinuous counterparts when short cycle times are imposed.© 2012 ASME

[1]  Wisama Khalil,et al.  Modeling, Identification and Control of Robots , 2003 .

[2]  A. Segovia,et al.  Comparative study of the different methods of path generation for a mobile robot in a free environment , 1991, Fifth International Conference on Advanced Robotics 'Robots in Unstructured Environments.

[3]  Jorge Angeles,et al.  The isoconditioning loci of a class of closed-chain manipulators , 1998, Proceedings. 1998 IEEE International Conference on Robotics and Automation (Cat. No.98CH36146).

[4]  Dereck S. Meek,et al.  A controlled clothoid spline , 2005, Comput. Graph..

[5]  Peter Eberhard,et al.  DYNAMIC ANALYSIS OF FLEXIBLE MANIPULATORS, A LITERATURE REVIEW , 2006 .

[6]  Ahmed A. Shabana,et al.  Flexible Multibody Dynamics: Review of Past and Recent Developments , 1997 .

[7]  Eric Courteille,et al.  A Systematic Procedure for the Elastodynamic Modeling and Identification of Robot Manipulators , 2010, IEEE Transactions on Robotics.

[8]  Javier García de Jalón,et al.  Kinematic and Dynamic Simulation of Multibody Systems: The Real Time Challenge , 1994 .

[9]  Yutaka Kanayama,et al.  Trajectory generation for mobile robots , 1984 .

[10]  J. Angeles,et al.  Optimization of a Test Trajectory for SCARA Systems , 2008 .

[11]  Damien Chablat,et al.  Stiffness Analysis of Overconstrained Parallel Manipulators , 2009, ArXiv.

[12]  Wisama Khalil,et al.  Modeling, Identification & Control of Robots , 2002 .

[13]  Grigore Gogu,et al.  New Approach for Dynamic Modelling of Flexible Manipulators , 2005 .

[14]  Ashitava Ghosal,et al.  Comparison of the Assumed Modes and Finite Element Models for Flexible Multilink Manipulators , 1995, Int. J. Robotics Res..