Kinematics and Robot Design
The KINEMATICS AND ROBOT DESIGN group carries out fundamental research on design, construction, and motion analysis of complex mechanisms and structures. These devices are parallel manipulators, multi-fingered hands, reconfigurable mechanisms, or cooperating robots, to name a few, but they appear in other domains too, as mechanistic models of locomotive organisms, molecular compounds, or nano-structures.
Head of line: Josep Maria Porta
Our activity finds applications in several fields through collaboration with our technological partners
We carry out projects from national and international research programmes.
→ More about our research projects
Robot design and construction
The group designs and constructs innovative mechatronic devices mainly based on parallel architectures. Our developments include the "Wrenchpad" (a six-axis tactile pad), an original air-pumped positioning table, several tensegrity-based robots, a pentaglide, several variations of the Gough-Stewart platform kinematically equivalent the octahedral manipulator, and a twelve degree-of-freedom ameba-like robot.
Position analysis of multi-loop linkages
The group develops techniques for linkage position analysis, i.e., for computing all possible configurations that a linkage can adopt, while respecting the kinematic constraints imposed by its joints. The problem finds applications to robotics (direct and inverse kinematics of serial/parallel robots, cooperative manipulation, and closed-chain motion planning), structural biology (conformational analysis of biomolecules), multibody dynamics (initial position and finite displacement problems), and computer-aided design (variational CAD and assembly positioning). The group works essentially along two different approaches, one based on relaxation techniques (see the CUIK project), and the other based on the deduction of characteristic polynomials using Distance Geometry.
The group also develops methods for closed-chain motion planning. In Robotics, for instance, this problem appears in motion planning for parallel manipulators, in object manipulation with anthropomorphic hands, in constraint-based object positioning, or in surgery or humanoid robots. The problem also appears in Biochemistry, when searching for low-energy paths between different molecular conformations. In all cases, a number of loop-closure constraints give rise to a configuration space of a complex structure on which standard algorithms for motion planning cannot be directly applied. The group addresses this problem using higher-dimensional continuation methods that allow characterizing the configuration space in an incremental way.
Singularities play a prominent role on understanding of a robot's configuration space. Depending on their nature, singularities give rise to dexterity or controllability losses and thus are to be avoided during the normal operation of a robot. They may, however, give rise to mechanical advantage too - i.e., to the transformation of small joint torques into large end-effector forces - which may be beneficial on specific applications. Also, output singularities provide the boundary of the workspace, which is a useful information for the robot designer. As a consequence, the group is developing new geometric tools that allow characterizing and computing the various singularity loci of a manipulator, either for classes of parallel mechanisms, or for general multi-body systems.
These are the latest research projects of the Kinematics and Robot Design research line:
CUIK++: An Extension of Branch-and-Prune Techniques for Motion Analysis and Synthesis of Complex Robotic Systems
Start Date: 01/01/2011
Start Date: 20/12/2011
Start Date: 01/01/2012
Technology Transfer Contract
Start Date: 20/06/2014
Start Date: 30/10/2008
These are the most recent publications (2016 - 2015) of the Kinematics and Robot Design
J.M. Porta and S. Hernández. Path planning for active tensegrity structures. International Journal of Solids and Structures, 78: 47-56, 2016.
O. Bohigas, M. Manubens and L. Ros. Planning wrench-feasible motions for cable-driven hexapods. IEEE Transactions on Robotics, 32(2): 442-451, 2016.
E. Celaya and A. Agostini. Online EM with weight-based forgetting. Neural Computation, 27(5): 1142–1157, 2015.
F. Thomas. A distance geometry approach to the singularity analysis of 3R robots. Journal of Mechanisms and Robotics, 8(1): 1-11, 2015.
O. Bohigas, M. Manubens and L. Ros. Computing wrench-feasible paths for cable-driven hexapods. Technical Report IRI-TR-15-04, Institut de Robòtica i Informàtica Industrial, CSIC-UPC, 2015.
N. Rojas, A. Dollar and F. Thomas. A unified position analysis of the Dixon and the generalized Peaucellier linkages. Mechanism and Machine Theory, 94: 28-40, 2015.
G. Alexandre, J. Cristophe, V. Ruiz de Angulo and C. Torras. Variable symmetry breaking in numerical constraint problems. Artificial Intelligence, 229: 105-125, 2015.
A. Rull, J.M. Porta and F. Thomas. Distance bound smoothing under orientation constraints, 2015 IEEE International Conference on Robotics and Automation, 2015, Seattle, pp. 1431-1436.
Kinematic and Robot Design Laboratory
The Kinematics and Robot Design Laboratory was created thanks to the financial support of the VALTEC program, co-financed with FEDER funds, of the Autonomous Goverment of Catalonia. It was initially created to validate the practical interest of our parallel robot designs, but it has rapidly derived into an active lab where the prototypes designed by the researchers of the Group of Kinematics and Robot Design are implemented as proofs of concept.