ROAZ AUTONOMOUS SURFACE VEHICLE DESIGN AND IMPLEMENTATION Hugo Ferreira, A. Martins, A. Dias, C. Almeida, J. M. Almeida, E. P. Silva LSA – Autonomous Systems Laboratory Instituto Superior de Engenharia do Porto R. Dr. António Bernardino de Almeida, 431 4200-072 Porto, Potugal {hf,aom,adias,c.almeida,jma,eaps}@lsa.isep.ipp.pt Abstract: The design of an Autonomous Surface Vehicle for operation in river and estuarine scenarios is presented. Multiple operations with autonomous underwater vehicles and support to AUV missions are one of the main design goals in the ROAZ system. The mechanical design issues are discussed. Hardware, software and implementation status are described along with the control and navigation system architecture. Some preliminary test results concerning a custom developed thruster are presented along with hydrodynamic drag calculations by the use of computer fluid dynamic methods. Keywords: autonomous surface vehicles, autonomous mobile robots, remote sensing robots, underwater robotics 1. INTRODUCTION Autonomous mobile systems have relevant applications in numerous fields of human activity. The areas of environmental monitoring and surveillance are an example of this. Aquatic environment scenarios provide interesting cases of application for robotic systems. These can be either autonomous underwater vehicles (AUVs) (Curtin, et al 1993), (Wernli 2001), remotely operated vehicles (usually underwater in semi autonomous operation) (Gomes, et al 2005), or autonomous surface vehicles (Caccia, et al 2005) (Pascoal, et al 2000), (Manley, et al 2000). The latter can be used in different aquatic scenarios, from full ocean, to river or even confined water spaces operation. Advantages over the use of robotic systems come from the large environment areas to be covered, repetitive tasks and the usual benefices of autonomy by reducing the human factor (both by reducing associated costs and by improving quality of results). In research and development field there are various relevant projects on autonomous surface vehicles for several oceanographic scenarios. ASV's as the ACES, ARTEMIS (Manley, et al. 1997), AUTOCAT (Manley, et al. 2000) or the SCOUT (Leonard, et al. 2005) from the MIT are used specially for shallow water operations as test beds to execute operations of bathymetry and underwater archaeology research. Other important application is the use of small catamarans as SESAMO (Caccia, et al. 2005), MUMS, for data sampling of the water surface microlayer. The FAU University and Office of Naval Research developed an ASV for collect hydrographic data and to aid the underwater vehicle navigation (Leonessa, et al. 2003), this system serve as communication link between autonomous underwater vehicles and the on-shore base. When the operation field is the sea or a place with very unstable conditions the first approach is to make more robust and larger vehicles, as an example we have LADAS a catamaran from WHOI operating on open ocean for collect water sampling data. Other major institution working in this area is the IST-ISR with their DELFIM and CARAVELA vehicles. DELFIM (Pascoal, et al. 2000) is a catamaran with several