Transmission Delay Analysis in Heavy Delayed Digital Systems: A Prototypical Solution. C. A. Avizzano*, M. Bergamasco*, G. Casalino** *PERCRO, Scuola Superiore S .Anna, PISA Italy DIST, Univ. di Genova, Genova, Italy ** Abstract This paper presents a new control model, ideal for teleoperation, which keeps into account the problems arising with heavy delayed communicating system. This is done with the help of a general purpose neural network and a specific dedicated training structure which is able to train the network and to minimize the network errors due to convergence problems. The principal aim of this model is to give more stability to the data flux reducing the uncertainties due to a variable delay present in the communication support. Introduction New tendences in teleoperation aim to work on even more great distances using more complex data structures. In this view more powerful communicating supports are requested. On the other side communication development has concentrated its efforts to produce more flexible communicating supports. As an example, at the state of the art, the InterNet is the more widespread digital data communicating structure used. The end-user can easily access and program it to send data wherever he wants. From a technical point of view however InterNet like resources are not very good for control signal transmission. From some recent works in this field it is clear that even more projects are oriented to use such a structure as a communicating support. This tendence may be explained by considering the following facts: the low cost of this support; the great popularity; the easyness of connection between CPUs. Other recent studies are evaluating the possibility of realizing a real time communication protocol on an ethernet support. This means that probably in the future real time applications will work also on the InterNet. As stated before at the state of the art this network is still quite inadequate for such a type of communication. Feedback System System mn Environment Fig. 1 : General interconnection scheme The main reason of this is the trasmission delay which is very noised and so hard to be characterized. In a recent work presented by Kobayashi et al. [ 11 a similar problem has been kept in exame for teleoperation purposes. In this work he supposed that to reduce the noised delay effects on the Master-Slave system more inteligence has to be given to the slave replicating unit. Starting from this consideration the proposed system has a slave unit which implements and simulates a master dynamic model in order to foresee some master behaviours. b Operator E5 Environment Fig.: 2. System modification for unit insertion Proc. IROS 96 0-7803-3213-X/96/ $5.00 0 1996 IEEE 1359