Luciano Cantelli

UAV/UGV cooperation for surveying operations in humanitarian demining

Unmanned Ground Vehicles can be a useful tool to help operators in humanitarian demining. However in many difficult environments autonomous operations are impossible and moreover it can be really difficult to teleoperate the robot from an onboard camera. This work presents an architecture to allow cooperation between a ground robot and a quadrotor UAV. The UAV can autonomously follow the ground robot, by using an image processing algorithm. In this way aerial images are provided that can help trajectory planning in rough environments, via a developed webGIS platform.

Volcanic Environments: Robots for Exploration and Measurement

The study of volcanic activity is important from a scientific point of view as it allows for a better understanding of one of the most spectacular geological phenomena and of the working principles that are at the basis of geophysics. Furthermore, there are numerous events that directly result from volcanic eruptions and that affect many populations. Therefore, improving the prediction methods of eruptive phenomena would be of great benefit. There are more than 1,500 potentially active volcanoes in the world, and roughly 10% of the worlds population live in areas directly threatened by volcanoes. In all of these areas, volcanoes have a strong influence on many day-to-day activities. The eruption of Eyjafjallajökull in Iceland in April 2010 caused the cancellation of more than 100,000 European flights and, consequently, left more than 10 million passengers stranded. Each year, on a graver note, many regions in the world are destroyed or heavily damaged by lava or pyroclastic flows, in some cases, resulting in numbers of casualties that could have been avoided with the improvement of early warning systems.

An Arc Welding Robot Control for a Shaped Metal Deposition Plant: Modular Software Interface and Sensors

This paper is focused on the study and the control of a process of robotic arc welding. The system developed has been used to study the whole process and to develop an automatic controller for the arc process of deposition. The process consists of a shaped metal deposition (SMD) system that is an innovative method for the manufacturing of metal objects, which uses a layer-by-layer deposition technique. A useful software interface has been implemented in a Labview environment to study the system and to develop and tune the parameters of an automatic controller.

A Joint-Angle Estimation Method for Industrial Manipulators Using Inertial Sensors

This paper focuses on the use of low-cost inertial sensors in industrial manipulators. In particular, an easy-to-install joint-angle estimation method is proposed. This scheme can work independently from the primary encoder-based sensor, for the creation of a fault-detection system. It can also be the primary joint-angle sensor in low-cost robotic manipulators. A robot with six degrees of freedom has been used, with three inertial measurement units set on its arms; one for each pair of joints. Three cascaded extended Kalman filters have been used to estimate the joint angles by the fusion of the outputs of triaxial gyroscopes and accelerometers. The results of three experimental tests are reported in order to show the performance and limitations of this approach, in comparison with the simple gyroscope measurements integration.

A closed loop welding controller for a rapid manufacturing process

The aim of this paper is to investigate on the closed loop welding controller of a rapid manufacturing shaped metal deposition (SMD) process. SMD was developed and patented by Rolls-Royce in order to produce mechanical parts directly from a CAD model. The paper describes a deep investigation upon the welding dynamics and parameters in order to develop an SMD automatic controller. An SMD plant has been set up as described in the paper, and some experimental work pieces have been produced. On the basis of the experiences acquired, some basic control laws have been carried out, and a closed loop controller has been implemented, using image processing and a video feedback control. The experimental results reported confirm the validity of the proposed strategy.

Intelligent Prodder: Implementation of Measurement Methodologies for Material Recognition and Classification With Humanitarian Demining Applications

In this paper, a novel sensing technique for material recognition is presented. This issue is actually particularly addressed due to its large application fields, such as, for example, humanitarian demining, recycling industry, or material processing. The proposed approach is based on the contact between the sensing unit and the surface of the unknown material: an intelligent prodder has been developed that stimulates the material surface and reads the response. The measurement procedure identifies a set of suitable parameters from the viscoelastic response and uses these parameters for material recognition and classifications. Both the stimulation and the sensing functions have been implemented using piezoelectric transducers. An experimental prototype of the system has been realized and characterized against a large set of materials of interest in the area of humanitarian demining, and the false positive rate has been determined for the set of considered materials. Experimental, in field, validations have also been performed.

A modular software interface for the control system of an arc welding robot

In this paper an interface designed for developing and studying a process of robotic arc welding, is described. The interface has been implemented in Labview™ environment. The process consists in the control of a SMD (Shaped Metal Deposition) system that is an innovative method for rapid manufacturing of metal objects. The system developed can also be used just to control arc process of deposition.

A System for Autonomous Landing of a UAV on a Moving Vehicle

This paper describes the approach employed to implement the autonomous landing of an Unmanned Aerial Vehicle (UAV) upon a moving ground vehicle. We consider an application scenario in which a target, made of a visual pattern, is mounted on the top of a ground vehicle which roams in an arena using a certain path and velocity; the UAV is asked to find the ground vehicle, by detecting the visual pattern, and then to track it in order to perform the approach and finalize the landing. To this aim, Computer Vision is adopted to perform both detection and tracking of the visual target; the algorithm used is based on the TLD (Tracking-Learning-Detection) approach, suitably integrated with an Hough Transform able to improve the precision of the identification of the 3D coordinates of the pattern. The output of the Computer Vision algorithm is then exploited by a Kalman filter which performs the estimation of the trajectory of the ground vehicle in order to let the UAV track, follow and approach it. The paper describes the software and hardware architecture of the overall application running on the UAV. The application described has been practically used with success in the context of the “Mohamed Bin Zayed” International Robotic Challenge (MBZIRC) which took place in March 2017 in Abu Dhabi.

Auto-Calibration Methods of Kinematic Parameters and Magnetometer Offset for the Localization of a Tracked Mobile Robot

This paper describes an automatic calibration procedure adopted to improve the localization of an outdoor mobile robot. The proposed algorithm estimates, by using an extended Kalman filter, the main kinematic parameters of the vehicles, such as the wheel radii and the wheelbase as well as the magnetometer offset. Several trials have been performed to validate the proposed strategy on a tracked electrical mobile robot. The mobile robot is aimed to be adopted as a tool to help humanitarian demining operations.

Arc welding Control for Shaped Metal Deposition Process

Abstract This paper is focused on the study and the control of a deposition process of robotic arc welding. The process consists of a SMD (Shaped Metal Deposition) system, that is a novel rapid prototyping tungsten inert gas (TIG) welding technique leading to near-net-shape, using a layer by layer deposition technique. An experimental setup has been properly implemented in order to study the system and to develop and tune the parameters of an automatic controller.