Experimental results obtained with the Autonomous Underwater Vehicles developed in the “Thesaurus... more Experimental results obtained with the Autonomous Underwater Vehicles developed in the “Thesaurus” project are reported. The Thesaurus AUVs, “Typhoon”, are low-cost torpedo-shaped 300 m depth-rated vehicles implementing a distributed communication and localization scheme based on acoustic modems, one of them with Ultra Short Base Line (USBL) capabilities. Communication and localization results obtained in the experimentation of the Thesaurus project and the CMRE (NATO Ctr. Maritime Res. Exp.) cruise CommsNet13 show that the modem-based acoustic localization has the capacity of correcting the navigation drift of low-cost inertial units even at the very low and time-varying communication rates encountered in experimental conditions.
22nd Mediterranean Conference on Control and Automation, 2014
The Thesaurus project, funded by the Tuscany Region, had among its goals the development of techn... more The Thesaurus project, funded by the Tuscany Region, had among its goals the development of technologies and methodologies for archaeological search with Autonomous Underwater Vehicles working as a team in exploration missions. This has led to the design and realization of a new AUV class, the Typhoon, on the basis of the archaeological requirements, and of an appropriate acoustic simultaneous communication and localization scheme. The paper describes the project background, the technical characteristics of the Typhoon AUVs, and the field results in acoustic localization as obtained in the CommsNet13 cruise, led by the NATO CMRE (Centre for Maritime Research and Experimentation), to which the Thesaurus project teams of the University of Pisa and Florence took part. In particular, the fields result reports the performance of acoustic localization through on-board USBL communicating with fixed modems placed in initially unknown locations.
A mixed USBL / LBL acoustic navigation system has been experimentally tested in the framework of ... more A mixed USBL / LBL acoustic navigation system has been experimentally tested in the framework of the CommsNet 13 sea trial, organized and led by CMRE in September 2013. The system set-up included a "Typhoon" AUV, equipped with a USBL/acoustic modem transducer, and a set of acoustic modems anchored at the bottom. The navigation procedure tested consisted in first geolocalizing the seabottom modems through the AUV USBL, with the AUV at the sea surface in GPS contact. Subsequently, the AUV navigates underwater using the USBL to track its relative position with respect to the moored modems and, exploiting the knowledge about their location, eventually determining its absolute position. The procedure has been tested with the AUV using the USBL communication within a network transmission protocol, i.e., at a slower transmission rate with respect to the fastest achievable with the given equipment. The AUV is equipped with a low-cost inertial measurement unit for dead reckoning navigation between two subsequent acoustic fixes. The experimental results obtained show that this navigation modality allows to bound the navigation error even in presence of low rate acoustic updates of the position.
The stability of industrial vehicles, such as forklifts and lifters, is very important from a saf... more The stability of industrial vehicles, such as forklifts and lifters, is very important from a safety point of view: these vehicles are subjected to variable loading conditions and their design is often optimized to privilege handling in narrow spaces instead of stability. In order to study in deep the problem of vehicle capsize prevention and to have the possibility to perform the necessary related experiments, the authors developed a scaled AGV (Automated Guided Vehicle). It is, in particular, a three wheeled differential drive mobile robot (built with low cost commercial components and fast prototyping techniques). The position of the wheels and the loads can be easily modified in order to simulate different vehicle configurations and operating scenarios . The vehicle is controlled through a Texas Instrument C2000 controller, programmable by using Matlab-Simulink Embedded Coder™. In addition, the forces exchanged between the wheels and the ground are monitored using low cost load ...
The stability of industrial vehicles, such as forklift and lifters, is very important from a safe... more The stability of industrial vehicles, such as forklift and lifters, is very important from a safety point of view: these vehicles are subjected to variable loading conditions and their design is often optimized to privilege handling in narrow spaces, instead of stability. To study in deep the problem of vehicle capsize prevention, the authors developed a scaled AGV (Automated Guided Vehicle). It is a three wheeled differential drive mobile robot, with front motorized wheels, driven by speed-controlled drivers. The position of the wheels and the loads can be easily modified to simulate different vehicle configurations and operating scenarios. The vehicle is controlled with a Texas Instrument C2000 controller, programmable through Matlab-Simulink Embedded Coder™. In addition, the forces exchanged among the wheels and the ground are monitored using low cost load cells, with miniaturized amplification stages. MEMS three-axial accelerometers and gyros are installed in order to detect ine...
Mechatronics is a multidisciplinary and application oriented science. Fast prototyping of a compl... more Mechatronics is a multidisciplinary and application oriented science. Fast prototyping of a complete, scaled mechatronic system is very useful both for research and teaching activities. This work describes the development of a scaled AGV, using fast prototyping techniques, both for the design of the mechanical components and the development of the vehicle control system. The scaled AGV is used as a scaled demonstrator to verify the feasibility of an anti-capsize controller. Capsize is a typical problem that have to be avoided on industrial vehicles, forklifts and moving lifter where heavy and partially unknown loads have to be moved using vehicles with a design that privilege manoeuvrability and small costs against stability. The AGV is a three wheeled differential drive mobile robot, with front motorized wheels, driven by speed-controlled drivers. The vehicle is controlled through a Texas Instrument C2000 controller, programmable by using Matlab-Simulink Embedded Coder™. Forces exc...
Within the framework of the Thesaurus project (Italian acronym for "TecnicHe per l'Esplorazione S... more Within the framework of the Thesaurus project (Italian acronym for "TecnicHe per l'Esplorazione Sottomarina Archeologica mediante l'Utilizzo di Robot aUtonomi in Sciami"), the authors have developed a low cost, multirole Autonomous Underwater Vehicle, briefly called Tifone, whose design is the main topic of this paper. According to the expected performances and specifications, the vehicle has to maintain a good autonomy and efficiency, typical features of an AUV (Autonomous Underwater Vehicle), also maintaining high manoeuvrability and hovering capabilities, which are instead more common on ROVs (Remotely Operated Vehicles).Cooperative exploration and surveillance tasks involve the use of swarms of vehicles; the control, the mutual localization and communications among vehicles are fundamental tasks to be optimized. In particular, the optimization of costs with respect to benefits plays a critical role, considering that within the Thesaurus project a first fleet of three vehicles has to be developed. This work mainly deals with the different design phases of the vehicle and with the results of preliminary simulations and tests performed in the MDM laboratories, before the next lake (Roffia basin, between Pisa and Florence, Italy) and sea testing activities (Elba Island, Italy) that will be performed in spring and summer 2013.
The CommsNet 2013 experiment took place in September 2013 in the La Spezia Gulf, North Tyrrhenian... more The CommsNet 2013 experiment took place in September 2013 in the La Spezia Gulf, North Tyrrhenian Sea. Organized and scientifically led by the NATO S&T Org. Ctr. for Maritime Research and Experimentation (CMRE, formerly NURC), with the participation of several research institutions, the experiment included among its objectives the evaluation of on-board acoustic Ultra-Short Base Line (USBL) systems for navigation and localization of Autonomous Underwater Vehicles (AUVs). The ISME groups of the Universities of Florence and Pisa jointly participated to the experiment with one Typhoon class vehicle. This is a 300 m depth rated AUV with acoustic communication capabilities originally developed by the two groups for archaeological search. The CommsNet 2013 Typhoon, equipped with an acoustic modem/USBL head, navigated within the fixed nodes acoustic network deployed by CMRE. This allows the comparison between inertial navigation, acoustic self-localization and ground truth represented by GPS signals (when the vehicle was at the surface). The preliminary results of the experiment show that the acoustic USBL self-localization is effective, and it has the potential to improve the overall vehicle navigation capabilities.
An algorithmic framework and experimental results on acoustic self-localization and mapping for a... more An algorithmic framework and experimental results on acoustic self-localization and mapping for an AUV equipped with an USBL modem are reported. The methodology proposed is quite general and applicable to a wide range of AUV and of navigation needs; however, the results presented refer to the Typhoon AUV and to the experimental configuration as available in the CommsNet13 cruise, led by the NATO S&T Ctr. for Maritime Research and Experimentation. The obtained results show that, even with a low cost, inertial motion units, and in presence of hostile acoustic channel conditions, the approach is able to keep the navigation error bounded and within 3 -4 times GPS accuracy.
Experimental results obtained with the Autonomous Underwater Vehicles developed in the “Thesaurus... more Experimental results obtained with the Autonomous Underwater Vehicles developed in the “Thesaurus” project are reported. The Thesaurus AUVs, “Typhoon”, are low-cost torpedo-shaped 300 m depth-rated vehicles implementing a distributed communication and localization scheme based on acoustic modems, one of them with Ultra Short Base Line (USBL) capabilities. Communication and localization results obtained in the experimentation of the Thesaurus project and the CMRE (NATO Ctr. Maritime Res. Exp.) cruise CommsNet13 show that the modem-based acoustic localization has the capacity of correcting the navigation drift of low-cost inertial units even at the very low and time-varying communication rates encountered in experimental conditions.
22nd Mediterranean Conference on Control and Automation, 2014
The Thesaurus project, funded by the Tuscany Region, had among its goals the development of techn... more The Thesaurus project, funded by the Tuscany Region, had among its goals the development of technologies and methodologies for archaeological search with Autonomous Underwater Vehicles working as a team in exploration missions. This has led to the design and realization of a new AUV class, the Typhoon, on the basis of the archaeological requirements, and of an appropriate acoustic simultaneous communication and localization scheme. The paper describes the project background, the technical characteristics of the Typhoon AUVs, and the field results in acoustic localization as obtained in the CommsNet13 cruise, led by the NATO CMRE (Centre for Maritime Research and Experimentation), to which the Thesaurus project teams of the University of Pisa and Florence took part. In particular, the fields result reports the performance of acoustic localization through on-board USBL communicating with fixed modems placed in initially unknown locations.
A mixed USBL / LBL acoustic navigation system has been experimentally tested in the framework of ... more A mixed USBL / LBL acoustic navigation system has been experimentally tested in the framework of the CommsNet 13 sea trial, organized and led by CMRE in September 2013. The system set-up included a "Typhoon" AUV, equipped with a USBL/acoustic modem transducer, and a set of acoustic modems anchored at the bottom. The navigation procedure tested consisted in first geolocalizing the seabottom modems through the AUV USBL, with the AUV at the sea surface in GPS contact. Subsequently, the AUV navigates underwater using the USBL to track its relative position with respect to the moored modems and, exploiting the knowledge about their location, eventually determining its absolute position. The procedure has been tested with the AUV using the USBL communication within a network transmission protocol, i.e., at a slower transmission rate with respect to the fastest achievable with the given equipment. The AUV is equipped with a low-cost inertial measurement unit for dead reckoning navigation between two subsequent acoustic fixes. The experimental results obtained show that this navigation modality allows to bound the navigation error even in presence of low rate acoustic updates of the position.
The stability of industrial vehicles, such as forklifts and lifters, is very important from a saf... more The stability of industrial vehicles, such as forklifts and lifters, is very important from a safety point of view: these vehicles are subjected to variable loading conditions and their design is often optimized to privilege handling in narrow spaces instead of stability. In order to study in deep the problem of vehicle capsize prevention and to have the possibility to perform the necessary related experiments, the authors developed a scaled AGV (Automated Guided Vehicle). It is, in particular, a three wheeled differential drive mobile robot (built with low cost commercial components and fast prototyping techniques). The position of the wheels and the loads can be easily modified in order to simulate different vehicle configurations and operating scenarios . The vehicle is controlled through a Texas Instrument C2000 controller, programmable by using Matlab-Simulink Embedded Coder™. In addition, the forces exchanged between the wheels and the ground are monitored using low cost load ...
The stability of industrial vehicles, such as forklift and lifters, is very important from a safe... more The stability of industrial vehicles, such as forklift and lifters, is very important from a safety point of view: these vehicles are subjected to variable loading conditions and their design is often optimized to privilege handling in narrow spaces, instead of stability. To study in deep the problem of vehicle capsize prevention, the authors developed a scaled AGV (Automated Guided Vehicle). It is a three wheeled differential drive mobile robot, with front motorized wheels, driven by speed-controlled drivers. The position of the wheels and the loads can be easily modified to simulate different vehicle configurations and operating scenarios. The vehicle is controlled with a Texas Instrument C2000 controller, programmable through Matlab-Simulink Embedded Coder™. In addition, the forces exchanged among the wheels and the ground are monitored using low cost load cells, with miniaturized amplification stages. MEMS three-axial accelerometers and gyros are installed in order to detect ine...
Mechatronics is a multidisciplinary and application oriented science. Fast prototyping of a compl... more Mechatronics is a multidisciplinary and application oriented science. Fast prototyping of a complete, scaled mechatronic system is very useful both for research and teaching activities. This work describes the development of a scaled AGV, using fast prototyping techniques, both for the design of the mechanical components and the development of the vehicle control system. The scaled AGV is used as a scaled demonstrator to verify the feasibility of an anti-capsize controller. Capsize is a typical problem that have to be avoided on industrial vehicles, forklifts and moving lifter where heavy and partially unknown loads have to be moved using vehicles with a design that privilege manoeuvrability and small costs against stability. The AGV is a three wheeled differential drive mobile robot, with front motorized wheels, driven by speed-controlled drivers. The vehicle is controlled through a Texas Instrument C2000 controller, programmable by using Matlab-Simulink Embedded Coder™. Forces exc...
Within the framework of the Thesaurus project (Italian acronym for "TecnicHe per l'Esplorazione S... more Within the framework of the Thesaurus project (Italian acronym for "TecnicHe per l'Esplorazione Sottomarina Archeologica mediante l'Utilizzo di Robot aUtonomi in Sciami"), the authors have developed a low cost, multirole Autonomous Underwater Vehicle, briefly called Tifone, whose design is the main topic of this paper. According to the expected performances and specifications, the vehicle has to maintain a good autonomy and efficiency, typical features of an AUV (Autonomous Underwater Vehicle), also maintaining high manoeuvrability and hovering capabilities, which are instead more common on ROVs (Remotely Operated Vehicles).Cooperative exploration and surveillance tasks involve the use of swarms of vehicles; the control, the mutual localization and communications among vehicles are fundamental tasks to be optimized. In particular, the optimization of costs with respect to benefits plays a critical role, considering that within the Thesaurus project a first fleet of three vehicles has to be developed. This work mainly deals with the different design phases of the vehicle and with the results of preliminary simulations and tests performed in the MDM laboratories, before the next lake (Roffia basin, between Pisa and Florence, Italy) and sea testing activities (Elba Island, Italy) that will be performed in spring and summer 2013.
The CommsNet 2013 experiment took place in September 2013 in the La Spezia Gulf, North Tyrrhenian... more The CommsNet 2013 experiment took place in September 2013 in the La Spezia Gulf, North Tyrrhenian Sea. Organized and scientifically led by the NATO S&T Org. Ctr. for Maritime Research and Experimentation (CMRE, formerly NURC), with the participation of several research institutions, the experiment included among its objectives the evaluation of on-board acoustic Ultra-Short Base Line (USBL) systems for navigation and localization of Autonomous Underwater Vehicles (AUVs). The ISME groups of the Universities of Florence and Pisa jointly participated to the experiment with one Typhoon class vehicle. This is a 300 m depth rated AUV with acoustic communication capabilities originally developed by the two groups for archaeological search. The CommsNet 2013 Typhoon, equipped with an acoustic modem/USBL head, navigated within the fixed nodes acoustic network deployed by CMRE. This allows the comparison between inertial navigation, acoustic self-localization and ground truth represented by GPS signals (when the vehicle was at the surface). The preliminary results of the experiment show that the acoustic USBL self-localization is effective, and it has the potential to improve the overall vehicle navigation capabilities.
An algorithmic framework and experimental results on acoustic self-localization and mapping for a... more An algorithmic framework and experimental results on acoustic self-localization and mapping for an AUV equipped with an USBL modem are reported. The methodology proposed is quite general and applicable to a wide range of AUV and of navigation needs; however, the results presented refer to the Typhoon AUV and to the experimental configuration as available in the CommsNet13 cruise, led by the NATO S&T Ctr. for Maritime Research and Experimentation. The obtained results show that, even with a low cost, inertial motion units, and in presence of hostile acoustic channel conditions, the approach is able to keep the navigation error bounded and within 3 -4 times GPS accuracy.
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Papers by Niccolò Monni