Robust auto tool change for industrial robots using visual servoing

ABSTRACT

This work presents an automated solution for tool changing in industrial robots using visual servoing and sliding mode control. The robustness of the proposed method is due to the control law of the visual servoing, which uses the information acquired by a vision system to close a feedback control loop. Furthermore, sliding mode control is simultaneously used in a prioritised level to satisfy the constraints typically present in a robot system: joint range limits, maximum joint speeds and allowed workspace. Thus, the global control accurately places the tool in the warehouse, but satisfying the robot constraints. The feasibility and effectiveness of the proposed approach is substantiated by simulation results for a complex 3D case study. Moreover, real experimentation with a 6R industrial manipulator is also presented to demonstrate the applicability of the method for tool changing.

Keywords:

• Tool change
• robot system
• visual servoing
• sliding mode control

Disclosure statement

No potential conflict of interest was reported by the author(s).

ORCID

Pau Muñoz-Benavent http://orcid.org/0000-0003-4681-183X

J. Ernesto Solanes http://orcid.org/0000-0001-5011-4872

Luis Gracia http://orcid.org/0000-0001-9258-9286

Josep Tornero http://orcid.org/0000-0003-1571-0251

Notes

1 Note that it is assumed that the constraint function ${\phi }_i$ is differentiable around the boundary given by ${\phi }_i=0$.

2 From (6(6) $\ddot{\mathbf{q}}={\ddot{\mathbf{q}}}_c+{\mathbf{d}}_c,$(6) ), it follows that ${\dot{\phi }}_{R,qi}$ (and $\ddot{\mathbf{q}}$) explicitly depends on signal ${\ddot{\mathbf{q}}}_c$, i.e. the sliding manifold has relative degree one with respect to the discontinuous action $\mathbf{u}$, as required by SM theory (Edwards & Spurgeon, 1998).

Additional information

Funding

This work was supported in part by the Ministerio de Economía, Industria y Competitividad, Gobierno de España under Grant BES-2010-038486 and Project DPI2017-87656-C2-1-R.

Notes on contributors

Pau Muñoz-Benavent

Pau Muñoz-Benavent received the B.Sc. degree in industrial engineering, the M.Sc. degree in control systems engineering and the Ph.D. in automation and industrial computer science from the Technical University of Valencia (UPV), Spain, in 2008, 2010 and 2017, respectively. He is currently researcher at the Institute for Design and Manufacturing (IDF) of the UPV. His research interests include visual servoing, computer vision systems and robotic systems.

J. Ernesto Solanes

J. Ernesto Solanes received his B.S. Degree in Industrial Electronics Engineering (2007), B.S. Degree in Industrial Automatics (2009), M.S. Degree in Automatics and Industrial Informatics (2011) and the Ph.D. in Robotics, Automatics and Industrial Informatics (2015), all of them at the Technical University of Valencia (UPV), Spain. He is currently researcher at the Institute for Design and Manufacturing (IDF) of the UPV. His research interests include nonlinear and robust control, computer vision and robotics.

Luis Gracia

Luis Gracia received the B.Sc. degree in electronic engineering, the M.Sc. degree in control systems engineering, and the Ph.D. in automation and industrial computer science from the Technical University of Valencia (UPV), Spain, in 1998, 2000, and 2006, respectively. He is currently Associate Professor at the Department of Systems Engineering and Control (DISA) of the UPV. His research interests include mobile robots, robotic manipulators, and system modelling and control.

Josep Tornero

Josep Tornero received the MS Degree in Systems and Control from the University of Manchester in 1982, and the PhD in Electrical Engineering at the Technical University of Valencia (UPV) in 1985. He has been Visiting Professor at the CIRSSE (NASA Center for Intelligent Robotics Systems for Space Exploration); the Rensselaer Polytechnic Institute at Troy (New York); and at the Department of Mechanical Engineering at the University of California (Berkeley). He is Professor at the Department of Systems Engineering and Control (DISA) of the UPV and responsible for the Institute for Design and Manufacturing (IDF) at the UPV. He is interested in control of robot systems and multirate sampled data systems.