Plenary Talks
PLENARY A - March 18, 2005 - 19.15
TITLE: Tactile afferent information in planning and control of dexterous object manipulations in humans
Roland S Johansson, Physiology Section, Department of Integrative Medical Biology, Umeå University, SE-901 87 Umeå, Sweden
ABSTRACT: Any purposeful action reflects a desire to turn from the current sensory state to a more advantageous sensory state, which thus represents the goal of the action. Natural object manipulations involve action plans composed of sequences of action phases whose goals are organized around contact events involving the hands and manipulated objects. The prediction of useful motor commands for each action phase uses different types of sensorimotor 'initial state' information. In conjunction with memory mechanisms, visual and tactile modalities identify important hand-object relations and physical properties of objects involved, such as shape, surface friction, mass, and distribution of mass. Furthermore, learning and maintenance of sensorimotor correlations that underlie predictions of suitable motor commands requires that the brain monitors and evaluates the sensory consequences of executed motor commands. To this end, current evidence suggest that the brain establishes checkpoints that correspond to predicted alignments in space and time between haptic and gaze events that correspond to goal completion of task phases. This multimodal sensory information, when put in register with corresponding efferent copy, proprioceptive and sometimes auditory signals, presumably supports learning and upholding of the mappings required between 'initial state' information and suitable motor commands. In the framework of this general control scheme, tactile afferents provide information about a variety of important fingertip events. Besides various transient mechanical events, tactile afferents encode direction and magnitude of fingertip forces, shape of contacted surfaces, object position relative to the hand and friction between the fingertips and contacted surfaces. The encoding of such fingertip parameters by human tactile afferents and the use of the tactile signals in planning and control of manipulations is discussed in some detail.
PLENARY B - March 19, 2005 - 9.00
TITLE: Haptics Technologies for Virtual Reality
Tsuneo Yoshikawa, Department of Mechanical Engineering, Kyoto University, Japan
ABSTRACT: Haptics technologies in the field of virtual reality will be reviewed in this talk. Some results obtained in our laboratory will be introduced using video clips, including a haptic display system for two-finger manipulation of dynamic virtual objects, haptic interfaces that can display both touch and force sensation, human skill observation using peg-insertion tasks in virtual environment, and an encountered-type haptic interface for multiple fingers.
Biography of Tsuneo Yoshikawa: Dr. Yoshikawa received the Ph.D. degree in 1969 from Kyoto University, Kyoto, Japan. Since 1969 he has been with Kyoto University and currently he is a Professor in the Department of Mechanical Engineering. His research interests include robotics (analysis and control of robot manipulators, force control of robotic systems, modeling and control of flexible manipulators, master-slave systems, etc.), haptic virtual reality (control of force display interfaces, multiple-finger manipulation of dynamic virtual objects, observation of human skill, etc.), and mechatronics. He is the author of "Foundations of Robotics" (MIT Press, 1990). He received various awards including the 1995 JDSMC Best Paper Award from the ASME Dynamic Systems and Control Division, and the 1997 ICRA Best Conference Paper Award from the IEEE Robotics and Automation Society. Also he is a Fellow of IEEE and Japan Society of Mechanical Engineers. He is currently the President of the Robotics Society of Japan.