1 - Advanced methods of analysis and synthesis of open and
closed chain spatial mechanisms. In particular: determination of
efficient algorithms for real-time control; singularity avoidance;
synthesis of new isotropic architectures; definition of kinemati
and dynamic performance indeces.
2 - Development of new architectures of compliant mechanisms and
of original methods for the modelling and the
mechanism real-time control.
3 - Algorithms for the evaluation of the influence of the
manipulator joint clearance (open and closed chains).
4 - New equivalent mechanisms for the passive motion
simulation of human articulations (specifically knee and ankle),
taking into consideration the influence of ligament and
bone interactions.
5 - Synthesis and design of advanced prosthetic arms for
shoulder and knee amputees (based on patents of the responsible of
the research and his collaborators).
6 - Synthesis and design of robotic rehabilitation systems and biomedical devices.
1. Advanced methods of synthesis and analysis of spatial
mechanisms.
Special families of parallel manipulators may be conceived that
may overcome the typical drawbacks of closed-chain mechanisms
(limited dexterity, involved kinematic relations, critical
singularities), though preserving their favorable characteristics
(large payload to robot weight ratio, stiffness, high dynamic
performances). In this perspective, innovative parallel robots for
translational motion have been designed. In many instances, they
exhibit outstanding performances, such as full decoupling of motion
and input-output homokinetic transmission.
2. Compliant mechanisms.
An iterative technique to perform the non-linear position
analysis of planar compliant mechanisms has been developed. The
technique makes it possible to find the position and orientation
(pose) of each link of a mechanism whose input link deflection is
assigned. The innovative part is that, instead of relying on the
finite-element method, large deflections are considered, and the
position analysis is solved without resorting to the linear
approximation of small deflections. The technique is highly
suitable for rigid-link mechanisms with compliant kinematic pairs.
Different types of compliant kinematic pairs have been developed
and other types are under investigation in order to define their
performances.
3. Joint clearance modelling.
The presence of clearance in a mechanism's kinematic pairs
causes additional degrees of freedom and then errors in the pose
(position and orientation) of a mechanism's reference link. The aim
of this activity is the modelling of planar and spatial
clearance-affected kinematic pairs and the development of
algorithms which determines the pose error induced by clearance on
a mechanism's links.
4. Equivalent spatial mechanisms for the human joint motion
simulation.
The objective of this activity is the definition of kinematic
and dynamic models of the human knee that can have both theoretical
and practical applications. The aim is pursued by a careful
analysis of the knee structures which drive and constrain the
natural motion of the joint. Starting from studies carried out in
collaboration with the Oxford Orthopaedic Institute of the
University of Oxford (Great Britain), new results have been
obtained in collaboration with the Rizzoli Orthopaedic Institute
(Bologna, Italy). These results, presented in several papers in the
last few years, proved to be useful for the prosthetic design. New
mechanisms are also investigated to reproduce the relative motion
of the main bones of the ankle joint during passive motion
(equivalent mechanisms). The mathematical models of these new
mechanisms represent a powerful tool both for pre-operation
planning and for the prosthesis design. The collaboration with the
Rizzoli Orthopaedic Institute (Bologna, Italy) makes it possible to
collect experimental data in order to define and test the
models.
5. Prosthesis design.
Based on the theoretical achievements, internal knee and ankle
prosthesis have been designed, also in collaboration with Rizzoli
Orthopaedic Institute. Moreover, a further activity, carried
out with the INAIL Prosthesis Center (Bologna, Italy), has
been focused on the development of a new electrically-powered
prosthesis for upper limb amputees with a high level amputation.
Both innovative mechanical architectures and control strategies are
studied.
6. Synthesis and design of robotic rehabilitation systems and biomedical devices.
The activity focuses on the synthesis of exoskeletons for the rehabilitation of patients suffering from motor disabilities derived from various causes such as stroke. In particular, the synthesis and design of hand and upper limb exoskeletons are addressed. Regarding the design of biomedical devices, the synthesis and design of tools for minimally invasive surgery, such as laparoscopic interventions, are at an advanced stage.
