Mobile and aerial manipulation

Autonomous aerial manipulation

The Robotics Research Group has currently three Phd researchers working on aerial manipulators, sponsored by FWO (Fund for Scientific Research- Flanders) project G04041N, "Autonomous manipulation using a flying robot" .

The goal of the project is

• performing manipulation tasks using an autonomous quadrotor,
• applying the sensor-based framework for task specification and control, developed in our research group, to the autonomous quadrotor and
• robust control of the quadrotor during manipulation task execution.

The three Phd researchers involved are Steven Bellens, Dominick (Nick) Vanhienen and Jon Verbeke:

• Steven Bellens will provide generic functions for manipulation tasks, using the
  quadrotor as-is and as an iTaSC user
• Dominick Vanthienen will advance iTaSC (General software framework compliant with 5C’s and with maximal
  reusability) in able to implement the acceleration-resolved control scheme and to formulate the
  quadrotor problem in this general framework. Moreover, Nick will extend the degrees of freedom of the quadrotor and implement complex manipulation tasks.
• Jon Verbeke focuses on the development of a new platform,
  specifically designed for constraint robust navigation in an agricultural setting.

The main research platform used is a Pelican quadrotor from AscTec GmbH. A Draganflyer XPro and a Parrot AR.Drone are also part of our squadron, mainly used for student projects.

Mobile manipulation with the PR2

The Robotics Research Group takes part in the Willow Garage Beta Program, in which we recieved a PR2 platform. The main contributions of our research group to the program are:

• OROCOS-ROS integration
• Using Blender for visualisation and simulation of the PR2
• Demonstrating the Unified Framework for Task Specification, Control and Coordination for Mobile Manipulation on the PR2

The capabilities of the OROCOS-ROS integration was demonstrated by the haptic coupling of the PR2 with a Kuka LWR arm and Youbot platform [4].

The Unified Framework (iTaSC-Skill framework)  is a general software framework compliant with 5C’s (separation of concerns) and with maximal reusability. iTaSC stands for instantaneous Task Specification using Constraints, which is developed at the K.U.Leuven during the past years [1,2,3].The framework generates motions by specifying constraints in geometric, dynamic or sensor-space between the robots and their environment. These motion specifications constrain the relationships between objects (object frames) and their features (feature frames).

This framework was demonstrated with a human-PR2 co-manipulation task, in which a human and a PR2 together pick up a plate (or other object like a table) and move it from one room to another [5].

• [1] J. De Schutter, T. De Laet, J. Rutgeerts, W. Decre, R. Smits,E. Aertbelien, K. Claes, and H. Bruyninckx. Constraint-based task specification and estimation for sensor-based robot systems in the presence of geometric uncertainty. The International Journal of Robotics Research, 26(5):433–455, 2007.
• [2] W. Decre, R. Smits, H. Bruyninckx, and J. De Schutter. Extending iTaSC to support inequality constraints and non-instantaneous task specification. In Proceedings of the 2009 IEEE International Conference on Robotics and Automation, pages 964–971, Kobe, Japan, 2009.
• [3] J. Rutgeerts. Constraint-based task specification and estimation for sensor-based robot tasks in the presence of geometric uncertainty. PhD thesis, Department of Mechanical Engineering, Katholieke Universiteit Leuven, Belgium, 2007.
•  [4] K. Buys et Al., Haptic coupling with the PR2 as a demo of the OROCOS - ROS - Blender integration, The IEEE/RSJ International Conference on Intelligent Robots and Systems, San Fransisco, September 2011
• [5] D. Vanthienen et Al., iTaSC as a unified framework for task specification, control and coordination, demonstrated on the PR2, PR2 beta program workshop, The IEEE/RSJ International Conference on Intelligent Robots and Systems, San Fransisco, September 2011