Task level robot programming using prioritized non-linear inequality constraints

In this paper, we propose a framework for prioritized constraint-based specification of robot tasks. This framework is integrated with a cognitive robotic system based on semantic models of processes, objects, and workcells. The target is to enable intuitive (re-)programming of robot tasks, in a way that is suitable for non-expert users typically found in SMEs. Using CAD semantics, robot tasks are specified as geometric inter-relational constraints. During execution, these are combined with constraints from the environment and the workcell, and solved in real-time. Our constraint model and solving approach supports a variety of constraint functions that can be non-linear and also include bounds in the form of inequalities, e.g., geometric inter-relations, distance, collision avoidance and posture constraints. It is a hierarchical approach where priority levels can be specified for the constraints, and the nullspace of higher priority constraints is exploited to optimize the lower priority constraints. The presented approach has been applied to several typical industrial robotic use-cases to highlight its advantages compared to other state-of-the-art approaches.

[1]  S. Sathiya Keerthi,et al.  A fast procedure for computing the distance between complex objects in three-dimensional space , 1988, IEEE J. Robotics Autom..

[2]  Pieter Abbeel,et al.  Finding Locally Optimal, Collision-Free Trajectories with Sequential Convex Optimization , 2013, Robotics: Science and Systems.

[3]  Alois Knoll,et al.  Prioritized motion-force control of multi-constraints for industrial manipulators , 2015, 2015 IEEE International Conference on Robotics and Biomimetics (ROBIO).

[4]  Alois Knoll,et al.  Analysis and semantic modeling of modality preferences in industrial human-robot interaction , 2015, 2015 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS).

[5]  Alois Knoll,et al.  Intuitive instruction of industrial robots: Semantic process descriptions for small lot production , 2016, 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS).

[6]  Alois Knoll,et al.  Constraint task-based control in industrial settings , 2009, 2009 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[7]  Giuseppe Oriolo,et al.  Kinematically Redundant Manipulators , 2008, Springer Handbook of Robotics.

[8]  Oussama Khatib,et al.  A unified approach for motion and force control of robot manipulators: The operational space formulation , 1987, IEEE J. Robotics Autom..

[9]  M. Powell.  A Direct Search Optimization Method That Models the Objective and Constraint Functions by Linear Interpolation , 1994 .

[10]  Olivier Stasse,et al.  Real-time (self)-collision avoidance task on a hrp-2 humanoid robot , 2008, 2008 IEEE International Conference on Robotics and Automation.

[11]  Siddhartha S. Srinivasa,et al.  CHOMP: Gradient optimization techniques for efficient motion planning , 2009, 2009 IEEE International Conference on Robotics and Automation.

[12]  Tsuneo Yoshikawa,et al.  Manipulability of Robotic Mechanisms , 1985 .

[13]  John Hallam,et al.  Definition and initial case-based evaluation of hardware-independent robot skills for industrial robotic co-workers , 2014, ISR 2014.

[14]  Markus Rickert,et al.  Efficient Motion Planning for Intuitive Task Execution in Modular Manipulation Systems , 2011 .

[15]  Alois Knoll,et al.  Constraint-based task programming with CAD semantics: From intuitive specification to real-time control , 2015, 2015 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS).

[16]  Alois Knoll,et al.  Scene Perception and Recognition in industrial environments , 2013, ISVC 2013.

[17]  M. Chung,et al.  A constrained optimization approach to resolving manipulator redundancy , 1996 .

[18]  Éric Marchand,et al.  A redundancy-based iterative approach for avoiding joint limits: application to visual servoing , 2001, IEEE Trans. Robotics Autom..

[19]  Oussama Khatib,et al.  Whole-Body Dynamic Behavior and Control of Human-like Robots , 2004, Int. J. Humanoid Robotics.

[20]  Joris De Schutter,et al.  Constraint-based Task Specification and Estimation for Sensor-Based Robot Systems in the Presence of Geometric Uncertainty , 2007, Int. J. Robotics Res..

[21]  Giorgio Metta,et al.  Prioritized motion-force control of constrained fully-actuated robots: "Task Space Inverse Dynamics" , 2014, Robotics Auton. Syst..

[22]  Pierre-Brice Wieber,et al.  Hierarchical quadratic programming: Fast online humanoid-robot motion generation , 2014, Int. J. Robotics Res..

[23]  Joris De Schutter,et al.  Geometric Relations Between Rigid Bodies (Part 1): Semantics for Standardization , 2013, IEEE Robotics & Automation Magazine.

[24]  W. Eric L. Grimson,et al.  Handey: A robot system that recognizes, plans, and manipulates , 1987, Proceedings. 1987 IEEE International Conference on Robotics and Automation.

[25]  Enric Celaya,et al.  A Relational Positioning Methodology for Robot Task Specification and Execution , 2008, IEEE Transactions on Robotics.

[26]  Alois Knoll,et al.  An ontology for CAD data and geometric constraints as a link between product models and semantic robot task descriptions , 2015, 2015 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS).

[27]  Joris De Schutter,et al.  Extending iTaSC to support inequality constraints and non-instantaneous task specification , 2009, 2009 IEEE International Conference on Robotics and Automation.

[28]  Friedrich M. Wahl,et al.  Manipulation Primitives - A Universal Interface between Sensor-Based Motion Control and Robot Programming , 2011, Robotic Systems for Handling and Assembly.