Adaptable Web Interfaces for Networked Robots * J.-A. Fernández-Madrigal, E. Cruz-Martín, A. Cruz-Martín, J. González, and C. Galindo System Engineering and Automation Department University of Málaga, (Spain) e-mails: {jafma,anacm,jgonzalez,cipriano}@ctima.uma.es; elenacm@isa.uma.es Abstract— Most research in networked robots that use web interfaces for robot control has been focused recently on the network part, since ethernet involves poor (unpredictable) time performance. However, we believe that the problem to be addressed is more general and should not be restricted only to communication engineering: the interfaced system as a whole should adapt to get the most from the user, from the connection, and from the robot, even when no strict performance is possible. For that purpose, this paper introduces a new architecture for web remote operation of robots that exhibits a high degree of flexibility in its adaptation to each particular user (through modular, configurable JAVA Applets), to the system time-varying performance (through probability-guided, run-time adaptation of control loops), and to the robot software architecture (the standard CORBA is assumed as its middleware). Our approach constitutes an initial step for adapting comprehensively to all the mentioned issues, hence permitting to be employed in very different scenarios: real- time control, telecare, remote surveillance, etc. . Keywords- Human-Robot Interfaces, Networked Robotics, Telerobotics. I. INTRODUCTION Networked operation of robots is present in a large number of situations: telecare robotics [1], telesurgery [2], underwater operation [3], space operation [4], etc. However, although interfaces for remote human-robot interaction and control are a technology studied for a long time [5], only recently the world wide web has been considered as the support for the client side, due mainly to its pervasivity and the increase in software and network performance during the last years. Usually, the main source of difficulties in achieving correct robot control through web interfaces is considered to be the transmission delays, jitter, and lack of guarantee on the bandwidth availability over the ethernet [13]. However, this reasoning has been questioned recently since although no hard real-time is possible, a reasonable degree of dependability can be achieved, for example through specialized communication protocols [6]. These results have inspired us to take a step forward: we believe that the success of a web interfaced robot does not reside only in taking full advantage of transmissions, but in being flexible in a broad sense, that is, the interface must adapt the best to: a) each user, b) each robot operation and application, c) the robot architecture, and d) * This work has been supported by the Spanish Government under research contract DPI2002-01319. the time features (that are time-varying) of the whole system. More precisely: a) User adaptation needs an interface with flexible configuration which enables different skills for operation. In other words: the control loops of the robotic system must be reflected in the interface in different manners for different people. For example, an interface that shows a lot of information can be suitable for precision tasks, but cumbersome for home surveillance by non-expert users. b) The operations the robot is able to carry out (the application) also define the web interface configuration. For example, a robot in charge of telesurgery tasks needs high precision and smooth, small movements, which imposes different control loops from a robot for caring elderly people. c) Usually a diversity of robots can be available for implementing a given application, with architectures usually not prepared for web teleoperation. Therefore, an interfacing system capable of integrating with diverse software architectures is desirable. d) Time-varying behavior of the components of the system (user reaction, data translation algorithms, transmissions, etc.) set obvious constraints in the real-time operation of the interfaced robot. Network transmission is important, but it does not produce the only time delays in the loop. We have found that up to now the mentioned issues (a)- (d) have not been taken into account within a comprehensive framework [1,6,7]. Therefore, we propose a new architecture for web interfaces aimed to achieve maximum adaptability in all these aspects. Our interfaced system, which is defined as the composition of the client- side web-interface, the network, and the robot, is implemented following these guidelines: -User’s Environment and Application Adaptation (a)-(b). The client-side web-interface is implemented as a Java applet [8] (the portability of that technology enables maximum adaptation to the user’s computing environment) composed of a set of sensory and actuator elements that link to the system control loops (section II). The control loops linked to the interface are also associated to maximum-loop delay values for enabling further monitoring of control satisfiability. -Robot Architecture Adaptation (c). The robot architecture is assumed to be implemented upon the