Obstacle detection algorithm of low computational cost for Guanay II AUV

Obstacle detection is one of the most important stages in the obstacle avoidance system. This work is focused to explain the operation of a designed and implemented for the overall detection of objects with low computational cost strategy. This strategy of low computational cost is based on performing a spatial segmentation of the information obtained by the SONAR and determine the minimum distance between the SONAR (AUV) and the obstacle.Postprint (published version

Design of obstacle detection and avoidance system for GUANAY II AUV

Postprint (published version

pH sensor calibration procedure

This paper describes the calibration of pH sensor located at the OBSEA marine Observatory. This instrument is based on an industrial pH electrode that is connected to a CTD instrument (Conductivity, Temperature, and Depth ). The calibration of the pH sensor has been done using a high precision spectrophotometer pH meter from Institute of Marine Sciences (ICM), and in this way it has been obtained a numerical function for the p H sensor proportional to real pH.Peer ReviewedPostprint (published version

Design a vectorial propulsion system for Guanay II AUV

The autonomous underwater vehicle(AUV) Guanay II was designed to navigate on the surface of the sea, and to realize a vertical immersion in specific points. This vehicle has three thrusters located on stern, oriented to provide propulsion and yaw control on the horizontal plane. On the other hand, the immersion system used in the Guanay II is based in the change of the buoyancy of the vehicle, by using a piston system. Therefore, the vehicle does not have the ability to navigate in immersion, due to its design, which the inclination of the vehicle (pitch angle) cannot be controlled. In this work, we show the design a vector propulsion system for the vehicle Guanay II, which will allow to control the pitch of the AUV in immersion. For this purpose, we have provided to the two laterals thruster the possibility of varying their propulsion angle on the vertical plane, using two servomotors. Next, we will show the design and the results obtained.Postprint (published version

Design of the obstacle detection system with the SONAR MK3 on Guanay II AUV

Autonomous underwater vehicles (AUV) perform inspection missions and intervention in known and unknown environments, where it is necessary to ensure their safety. The AUV must have the ability to detect and avoid obstacles in the path of navigation. This article, an obstacle detection system for experimental Guanay II AUV is proposed, using a mechanical scanning SONAR Tritech Micron MK3. Since Guanay II operates autonomously, we have designed software that allows adjustment and control of the parameters of SONAR, and the acquisition and processing of the signals obtained. Experimental tests at sea have allowed to verify the correct operation of software designed, as well as, experimental tests in a controlled environment have allowed to determine the optimal values of the basic parameters of SONAR.Postprint (published version

Vilanova sea trials of Guanay II AUV

This work presents the last trials of Guanay II AUV in the Mediterranean Sea. Guanay II is an AUV designed to navigate on the surface of the sea following a path and at some points it carries out a vertical dive to take measurements of a water column. During the last year we have focused on the design of an automatic control and its algorithms. For the control system, we split the controller into two loops: an inner loop and an outer loop. The first loop is responsible for setting the yaw ¿ and the forward velocity u, given a reference (¿ref, uref). At this level we develop a fuzzy controller which integrates the different linear controllers adjusted for different forward velocities. The second loop is responsible for setting the reference for yaw and forward velocity for a given path. The mission consisted of following 13 waypoints along a total journey of 3600m with three vertical dives up to 5m of deep. Through this test the operability of the vehicle was validated and different designed controllers were also tested. During this mission, a set of measurements of salinity and temperature were obtained.Peer ReviewedPostprint (published version