Decision in motion
In the context of the EU project Decisions in Motion, we have recently built an innovative robotic head to study the neural mechanisms used to guide behaviour in complex visual scenes, in which the observer is in motion and navigates to avoid moving objects. The robot is capable of using optical flow information to navigate through obstacles in order to reach a target.
See the video of our robot features on the on NewScientist webpage
Research on Rehabilitation Robotics
We are currently evaluating the usage of robotic and virtual reality technologies in the context of upper limb rehabilitation with chronic post-stroke patients, with a particular focus on exoskeleton technologies.
Interaction in Virtual Environments
The Integrated Project Presenccia is undertaking a research programme that has as its major goal the understanding and exploitation of brain mechanisms for the enhancement of presence and interaction in mixed and virtual reality. The project is highly interdisciplinary, combining neuroscience, computer science, psychiatry, psychology, psychophysics, mechanical engineering, philosophy and drama.
The main contribution of PERCRO has been the development of two innovative devices: a fingertip haptic interface for the display of local contact geometry; a vibro-tactile dataglove for virtual social environment.
A light dataglove for human-to-human or human-to-object mediated interaction, fulfilling the requirements of portability and integration with high immersive systems for their application in simulated virtual persistent communities and states of correlational presence. The use of vibrotactile pads applied on different parts of the hand, such as palm and fingerpads, allows testing the role of sensorial substitution or haptic illusions in the social use of haptics and virtual manipulation of objects.
Innovative haptic interfaces: can local cutaneous cues improve haptic perception?
A novel device capable of providing simultaneously both kinesthetic and local haptic cues at the level of the fingerpad has been designed. It is composed of a supporting haptic interface and a fingertip haptic display. The augmentation of locally displayed haptic information improves the performance in tasks such as shape recognition by haptic exploration. Experimental investigation has been carried out on the role of kinesthetic and tactile modalities in virtual experiences mediated by touch, such as interpersonal interaction and active manipulation of objects.
"A Fingertip Haptic Display for Improving Curvature Discrimination A. Frisoli, M. Solazzi, F. Salsedo, M. Bergamasco Presence: Teleoperators & Virtual Environments December 2008, Vol. 17, No. 6: 550–561.
Download the free available [PDF] from here.
Research on Haptic Interfaces
Haptic Interfaces are electro-mechanical devices that are used to return force feedback to an operator, immersed in a VE. HI allow the feeling of objects, during the computer interaction. With respect to GUI, the man-computer interaction is enhanced and a more realistic feeling is achieved during simulations.
The PureForm Haptic Interface system
Here it is a picture of the Haptic Interface system that we are currently using in the PureForm system (see link at www.pureform.org). The system in a force-feedback arm exoskeleton for the arm. It is made of carbon fiber and can achieve the value of weight/payload ration ~ 1:1. The arm-exoskeleton is integrated with an haptic interface for the fingertips which can apply two independent forces on the two fingertips. The mobility off the all system can cover 80% of arm workspace together will full mobility of wrist and index/thumb fingers.
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The 6 DOF Haptic Interface
This is the CAD model of a 6 dof joystick, based on an innovative tendon drive system. The HI has been designed for simulation in VE of tasks of dextrous manipulation.
More information related to the joystick system is available following the link 6DOFJOY.
The 2 DOF Highly Isotropic Haptic Interface
This is the CAD model of a 2 dof HI, based on an closed-loop tendon drive system, which enhances the quality of force feedback. The system is based on a closed-loop 5-bar linkage and allows the user to perceive 2D force inside a planar rectangular workspace.
More information related to 5-bar system is available following the link 2DOFJOY.
The 3 DOF Haptic Interface
The 3 DOF system is a parallel mechanism system that allows only a three dimensional translational motion of the upper platform. The kinematics has been selected among all the possible symmetric parallel arrangements of legs which constraint the possible rotational motions of the platform. The kinematic optimazion and the mechanical design has been performed by Damaso Checcacci, in his degree thesis in mechanical engineering.
Some Available documentation
There is growing interest on Low DOFs parallel manipulator, for their potentiality of being employed in manufacturing, assemblying and CNC centers. In the paper below there is a systematic synthesis of parallel manipulators which can allow only translational motions of the coupler.
A.Frisoli, D. Checcaci, F.Salsedo, M.Bergamasco,Synthesis by screw algebra of translating in-parallel actuated mechanisms in Advances in Robot Kinematics ed. by J. Lenarcic and M.M. Stanisic, 2000 Kluwer Academics Publ.
The first PERCRO arm-exoskeleton for force-feedback in VEs
Here there is an image of the 5 DOF arm exoskeleton developed at PERCRO in 1993. The system was realized under the GLAD-in-ART project.
I and Luc Mo Costabella of EPFL (Lausanne, Switzerland) developed an application for a virtual interaction with deformable objects. This is the scheme of the exoskeleton control system that we used for this application.
The exoskeleton control system is based on a transputer control network, which computes the kinematics and gravity compensation forces with a maximum frequency of 1000 Hz. The control system has been implemented by the control engineer Carlo Albero Avizzano, leader of the PERCRO control group. We used the force feedback library, developed by him, to test an algorithm for the collision detection with deformable objects. All the work was supervised by eng. Avizzano, whose help was indispensable and greatly appreciated.
Here you can see the wrist-exos interface, designed by eng. Fabio Salsedo, head of unit of the PERCRO group of mechanics. The device allows the force feedback on the flexion-extension and abduction-adduction movements of the wrist.
The wrist and the 5 dof exo-skeleton can be assembled together for implementing a whole arm interaction. Recently we have changed the motors of the 5dof exo-skeleton to improve the back-drivability of the system. We are going to develop new applications on the exo-wrist system.