EXPERIMENTAL BILATERAL CONTROL TELEMANIPULATION USING A VIRTUAL EXOSKELETON Josep Amat 1 , Alícia Casals 2 , Manel Frigola 2 , Enric Martín 2 1 Robotics Institute. (IRI) UPC / CSIC Llorens Artigas 4-6, 2a pt. 08028 Barcelona, SPAIN 2 Dep. Automatic Control and Computer Engineering Pau Gargallo n. 5, 08028 Barcelona Universitat Politècnica de Catalunya (UPC) Abstract. The introduction of less invasive interfaces in control usually carry with them new drawbacks such as less perception, less dexterity, etc. This work tackles the experimentation of new means of perceptual feedback in teleoperation, when the operator guides the task by means of a visual exoskeleton, and consequently without any mechanical device that can be provided with haptic devices. The work describes the evaluation of augmented images and sound feedback as alternative means for the bilateral control. 1. Introduction When working on teleoperated tasks, the control of the slave arms can be performed by means of different elements. Such elements can be control devices, such as joysticks, or gesture based systems using an adequate exoskeleton. The advantage of using a mechanical exoskeleton is that it can incorporate sensorial feedback, forces and torques, in a more natural or immersive way [1], compared to the use of other devices, such as joystick type [2]. Nevertheless, such mechanical structures become heavy and burden. With the aim of making the teleoperation tasks easier through the use of exoskeletons, avoiding at the same time the drawbacks of wearing mechanical elements, which are highly invasive, the possibility of using a virtual exoskeleton has been studied. This new interface is based on a stereoscopic vision system that detects the operator arms and computes their spatial position [3, 4]. The first results obtained [5] were positive in what refers to the operator’s mobility and easy of movements. But, the system introduces as main drawbacks; first, movement delays, when the operator moves excessively quickly; second, a lower precision in the slave arms positioning, and third, and more important, the lack of force feedback. This kind of feedback helps significantly, in many cases, in the development of a task, providing more safety and efficiency. Limitations of the system dynamics, when the operator moves too quickly for the control, do not appear when the operator is “covered” by a mechanical exoskeleton, due to the physical or ergonomic constraints, that restrict the operator’s movements. Nevertheless, these control limitations, produced by this more comfortable and agile system, do not annoy the user after a short training period. Poor precision of the controlled movements, due to the measurement errors produced by the 3D vision system that detects and tracks the operator’s movements, can be easily corrected by the operator, by closing the loop through the visual feedback during the execution of the teleoperated task. The lack of force feedback during the teleoperation process has motivated the study of alternative sensorial feedback. We have experimented different systems based on the acoustic perception of the efforts carried out, as well as on the visualisation, over the screen, of the synthetic images, from which the effort exerted over the environment can be interpreted. This superposition does not reduce the visual capabilities. This work focuses on the evaluation of the improvement in efficiency through the use of these new means of sensorial feedback. The visual or acoustic feedback perception is evaluated in relation to the different kind of teleoperated tasks.