J. Morales

J. Morales
University of Malaga | UMA · Department of Systems Engineering and Automation

About

54
Publications
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1,226
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Introduction
Skills and Expertise

Publications

Publications (54)
Article
Full-text available
This paper presents a new synthetic dataset obtained from Gazebo simulations of an Unmanned Ground Vehicle (UGV) moving on different natural environments. To this end, a Husky mobile robot equipped with a tridimensional (3D) Light Detection and Ranging (LiDAR) sensor, a stereo camera, a Global Navigation Satellite System (GNSS) receiver, an Inertia...
Conference Paper
Este artículo describe la adquisición de barridos tridimensionales (3D) nivelados en el robot móvil Andábata sin necesidad de detener su movimiento. Para ello, la computadora de Andábata debe integrar cada uno de los rangos láser, adquiridos con unos determinados ángulos de cabeceo y guiñada, con la información odométrica y las medidas de inclinaci...
Article
This paper proposes a low-cost sensor system composed of four GNSS-RTK receivers to obtain accurate position and posture estimations for a vehicle in real-time. The four antennas of the receivers are placed so that every three-antennas combination is optimal to get the most precise 3D coordinates with respect to a global reference system. The redun...
Chapter
El uso de imágenes de los espectros visible (RGB) e infrarrojo térmico (TIR) para la detección de objetos puede resultar crucial en aplicaciones donde las condiciones de visibilidad están limitadas, como la robótica para búsqueda y rescate en catástrofes. Para ello resulta beneficioso analizar cómo las técnicas de aprendizaje profundo basadas en re...
Article
Full-text available
This article presents a collection of multimodal raw data captured from a manned all-terrain vehicle in the course of two realistic outdoor search and rescue (SAR) exercises for actual emergency responders conducted in Málaga (Spain) in 2018 and 2019: the UMA-SAR dataset. The sensor suite, applicable to unmanned ground vehicles (UGVs), consisted of...
Article
Full-text available
Reactivity is a key component for autonomous vehicles navigating on natural terrains in order to safely avoid unknown obstacles. To this end, it is necessary to continuously assess traversability by processing on-board sensor data. This paper describes the case study of mobile robot Andabata that classifies traversable points from 3D laser scans ac...
Article
Full-text available
Autonomous navigation of ground vehicles on natural environments requires looking for traversable terrain continuously. This paper develops traversability classifiers for the three-dimensional (3D) point clouds acquired by the mobile robot Andabata on non-slippery solid ground. To this end, different supervised learning techniques from the Python l...
Conference Paper
Dentro de los procedimientos de respuesta a emergencias, la Primera Intervención consiste en la toma de contacto con la zona de crisis mediante la recogida de información relevante que permita decidir y organizar la entrada de los equipos de rescate. Las labores de primera intervención constituyen una aplicación significativa de la robótica de resc...
Article
Full-text available
The paper describes the case study of the mobile robot Andabata navigating on natural terrain at low speeds with fuzzy elevation maps (FEMs). To this end, leveled three-dimensional (3D) point clouds of the surroundings are obtained by synchronizing ranges obtained from a 360 ∘ field of view 3D laser scanner with odometric and inertial measurements...
Article
Full-text available
Multi-beam lidar (MBL) rangefinders are becoming increasingly compact, light, and accessible 3D sensors, but they offer limited vertical resolution and field of view. The addition of a degree-of-freedom to build a rotating multi-beam lidar (RMBL) has the potential to become a common solution for affordable rapid full-3D high resolution scans. Howev...
Chapter
The paper addresses terrain modeling for mobile robots with fuzzy elevation maps by improving computational speed and performance over previous work on fuzzy terrain identification from a three-dimensional (3D) scan. To this end, spherical sub-sampling of the raw scan is proposed to select training data that does not filter out salient obstacles. B...
Article
Navigation of many mobile robots relies on environmental information obtained from three-dimensional (3D) laser scanners. This paper presents a new 360° field-of-view 3D laser scanner for mobile robots that avoids the high cost of commercial devices. The 3D scanner is based on spinning a Hokuyo UTM-30LX-EX two-dimensional (2D) rangefinder around it...
Conference Paper
Navigability assessment is useful for planning obstacles free trajectories in autonomous navigation tasks in 3D environments. Based on Geometric-Featured Voxel (GFV) maps developed in previous works, this paper proposes a method for 2D occupancy grid generation which is efficient for local navigation in natural environments. Built from a point clou...
Article
Motion detection and tracking is a relevant problem for mobile robots during navigation to avoid collisions in dynamic environments or in applications where service robots interact with humans. This paper presents a simple method to distinguish mobile obstacles from the environment that is based on applying fuzzy threshold selection to consecutive...
Article
Full-text available
Many applications, like mobile robotics, can profit from acquiring dense, wide-ranging and accurate 3D laser data. Off-the-shelf 2D scanners are commonly customized with an extra rotation as a low-cost, lightweight and low-power-demanding solution. Moreover, aligning the extra rotation axis with the optical center allows the 3D device to maintain t...
Article
Full-text available
Surmounting terrain elevations, such as terraces, is useful to increase the reach of mobile robots operating in disaster areas, construction sites, and natural environments. This paper proposes an autonomous climbing maneuver for tracked mobile manipulators with the help of the onboard arm. The solution includes a fast 3-D scan processing method to...
Conference Paper
Full-text available
Elevation maps offer a compact 2½ dimensional model of terrain surface for navigation in field mobile robotics. However, building these maps from 3D raw point clouds containing overhangs, such as tree canopy or tunnels, can produce useless results. This paper proposes a simple processing of a ground-based point cloud that identifies and removes ove...
Article
Full-text available
The paper reports on a practical backward motion strategy for a vehicle pushing several passive trailers with any combination of on- and off-axle hitches. The last trailer is defined as a virtual tractor that can be guided along paths of varying curvature like a single non-holonomic vehicle. Then, kinematic relationships are proposed to translate t...
Conference Paper
Exploiting the huge amount of real time range data provided by new multi-beam three-dimensional (3D) laser scanners is challenging for vehicle and mobile robot applications. The Coarse Binary Cube (CBC) method was proposed to achieve fast and accurate scene registration by maximizing the number of coincident cubes between a pair of scans. The aim o...
Conference Paper
Full-text available
Mobile robot navigation through natural terrains is a challenging issue with applications such as planetary exploration or search and rescue. This paper proposes navigability assessment of natural terrains scanned from ground-based 3D laser rangefinders. A continuous model of the terrain is obtained as a fuzzy elevation map (FEM). Based on this mod...
Conference Paper
Full-text available
This paper pursues speeding up 3D point cloud matching, which is crucial for mobile robotics. In previous work, we devised the Coarse Binary Cubes (CBC) method for fast and accurate registration of 3D scenes based on an integer objective function. Instead of point distance calculations, the method optimizes the number of coincident binary cubes bet...
Article
Full-text available
This paper analyzes the effect of towing a single-axle trailer on static tip-over stability for field mobile robots on slopes. For this purpose, this study defines altered supporting polygons (ASP) for both tractor and trailer. These ASPs are based on a force-torque static equilibrium analysis that reshapes the corresponding ground contact supporti...
Article
Full-text available
Driving vehicles with one or more passive trailers has difficulties in both forward and backward motion due to inter-unit collisions, jackknife, and lack of visibility. Consequently, advanced driver assistance systems (ADAS) for multi-trailer combinations can be beneficial to accident avoidance as well as to driver comfort. The ADAS proposed in thi...
Conference Paper
Full-text available
Drivers of vehicles with one or several passive trailers, like truck-and-trailer or articulated luggage carriers, have difficulties in backward maneuvers due to jackknife and lack of visibility. Advanced driver assistance systems (ADAS) can be helpful to improve both safety and driver comfort in these complex operations. In this paper, we propose a...
Article
Full-text available
Scene registration of a pair of three-dimensional (3D) range images is a 6D optimization problem usually required in mobile robotics. This problem is different from object registration, since all scan directions and depths may contain relevant data, and because farther regions are sampled with lower densities. The paper proposes an efficient scene...
Article
Full-text available
Alacrane is a hydraulic mobile manipulator for search and rescue in disaster areas and natural environments, where surmounting elevations such as rubble mounds and terraces is usually required. The paper describes the autonomous terrace climbing maneuver of this mobile robot with the help of its powerful arm. During this operation, the arm is used...
Conference Paper
Full-text available
This paper reports on simplification of 3D point clouds for terrain maps. This is an important issue for mobile robot navigation and path planning in natural environments. Points cloud maps obtained from onboard 3D range-finders can provide a large amount of data which is not uniformly distributed and that can be incomplete due to occluded and out-...
Conference Paper
Full-text available
Many applications demand acquiring dense, wide ranging, accurate 3D data with low-cost, lightweight, and low power demanding sensors. This paper describes a new compact 3D laser scanner, based on pitching a commercial 2D rangefinder. The design of this mechatronic system accomplishes the following specifications: i) the optical center of the scanne...
Conference Paper
Full-text available
Autonomous mobile robots have limited energy sources. This work studies power consumption of the locomotion system of wheeled skid-steer vehicles on hard horizontal terrain at walking speeds. This issue is very important for this kind of vehicles due to relevant power losses associated to dynamic friction during turnings. The paper adopts a kinemat...
Article
Full-text available
Three-dimensional laser range-finders are increasingly being incorporated into applications, such as mobile robotics, that require real-time registration of scene data. However, the computational costs of adaptive range-dependent data selection and point cloud matching grow significantly with the number of points. Therefore, fast range-independent...
Article
Full-text available
The paper reports on mobile robot motion estimation based on matching points from successive two-dimensional (2D) laser scans. This ego-motion approach is well suited to unstructured and dynamic environments because it directly uses raw laser points rather than ex-tracted features. We have analyzed the application of two methods that are very diffe...
Conference Paper
Full-text available
This paper presents a simplification of the Lu and Milios work [1] for globally consistent Simultaneous Localization And Mapping (SLAM) with two-dimensional (2D) scan registration. The proposed method is based on global two-step (orientation-position) pose estimation. This approach reduces the computational effort since it represents a closed-form...
Conference Paper
Outdoor scene registration of two 3D range scans, as usually required by field robotics, is very different from object and indoor registration, since all scan directions and depths may contain relevant data. This is not considered by 3D matching methods devised for computer graphics and reverse engineering. In this paper, we propose a specialized r...
Conference Paper
Full-text available
The paper reports on motion control for a non-holonomic vehicle pushing several passive trailers. To avoid inter-unit collisions, tractor steering limitations were successfully applied during forward motion in our previous work. Here, this approach is extended to the case of backward motion for off-axle trailers. To this end, the last trailer is co...
Article
Full-text available
Due to its simplicity and efficiency, the pure-pursuit path tracking method has been widely employed for planned navigation of nonholonomic ground vehicles. In this paper, we investigate the application of this technique for reactive tracking of paths that are implicitly defined by perceived environmental features. Goal points are obtained through...
Article
Full-text available
Power consumption is a key element in outdoor mobile robot autonomy. This issue is very relevant in skid-steer tracked vehicles on account of their large ground contact area. In this paper, the power losses due to dynamic friction have been modeled from two different perspectives: 1) the power drawn by the rigid terrain and 2) the power supplied by...
Article
Full-text available
This paper reports on the study of the Center of Gravity (COG) for the ALACRANE mobile robot, which consists on a hydraulic tracked vehicle with a customized heavy manipulator. This analysis is necessary because the robot has to navigate on inclined terrains, where tip-over problems are present. During navigation, only three actuators are available...
Article
Full-text available
Motion control of articulated vehicles composed of a nonholonomic tractor and several passive trailers is a difficult underactuated problem. This paper proposes the application of steering limitations to the tractor to avoid inter unit collision during forward motion. This method can be used for systems that combine any type of on-axle and off-axle...
Conference Paper
Full-text available
This work aims at improving real-time motion control and dead-reckoning of wheeled skid-steer vehicles by considering the effects of slippage, but without introducing the complexity of dynamics computations in the loop. This traction scheme is found both in many off-the-shelf mobile robots due to its mechanical simplicity and in outdoor application...
Conference Paper
Full-text available
The paper presents ALACRANE, a new mobile robot assistant for exploration and rescue missions with dexterous load manipulation capability. ALACRANE consists of a tracked vehicle with a 4-DOF articulated arm, whose end-effector is an independent pair of 3-DOF manipulators (LR-Arms) plus a common rotation on the main arm wrist. All actuators are hydr...
Conference Paper
Power consumption is a key element in mobile robot autonomy. This issue is more critical in tracked vehicles than in wheeled vehicles on account of relevant energy losses due to soil-track friction. This paper analyzes power efficiency in tracked mobile robots both from theoretical and experimental points of view. In particular, we have analysed po...
Article
Full-text available
The paper reports on mobile robot motion estimation based on matching points from successive two-dimensional (2D) laser scans. This ego-motion approach is well suited to unstructured and dynamic environments because it directly uses raw laser points rather than extracted features. We have analyzed the application of two methods that are very differ...
Article
Full-text available
In this paper we propose a kinematic approach for tracked mobile robots in order to improve motion control and pose estimation. Complex dynamics due to slippage and track–soil interactions make it difficult to predict the exact motion of the vehicle on the basis of track velocities. Nevertheless, real-time computations for autonomous navigation req...
Article
This paper presents a compliant motion control method for the robotic assistant ERM (Endoscopic Robotic Manipulator), designed and developed by the authors for handling the camera in laparoscopic surgery. Since the robot has a passive wrist and it is not fixed to the operating table, the relative position between the robot camera holder and the ins...
Article
In this paper, kinematics of train-like vehicles consisting of an au- tonomous tractor and several passive trailers with on/o-axle hitching is employed to avoid collisions between the dierent bodies during forward path tracking. This is achieved by limiting the tractor's curvature according to the propagation of the relative constraints between con...
Conference Paper
Full-text available
This paper presents an adaptive trajectory planning method concerning to the robotic assistant ERM (endoscopic robotic manipulator), designed and developed by the authors for handling the camera in laparoscopic surgery. In order to emulate the human assistant, camera movements must be defined relative to the fulcrum point, where the optic passes th...
Conference Paper
Full-text available
The paper proposes a kinematic approach for tracked vehicles in order to improve motion control and pose estimation. Complex dynamics due to slippage and soil shearing make it difficult to predict the exact motion of the vehicle from the velocity of the two tracks. Nevertheless, reliable geometric approximations are necessary to perform onboard rea...
Article
Full-text available
Resumen Este artículo presenta el diseño de un sistema robótico modular para la asistencia a la cirugía laparoscópica. Su propósito es proporcionar una asistencia rápida en un quirófano sin necesidad de ninguna modificación, y tiene como componente principal un robot manipulador para el manejo de la cámara laparoscópica de funcionamiento totalmente...

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Project (1)
Project
The aim of the present proposal is to develop a robotic system for HALS procedures by using the concept of co-worker robot, where the manipulator works side by side with the surgeon, collaborating during the surgical maneuvers and learning from practice. Thus, experience is expected to improve robot’s assistance and to make the system able to detect emergency situations. To that goal, the system will be composed of a manipulator able to handle both an articulated laparoscopic tool and an endoscope, and another arm specialized in the control motion of miniature robots inside the abdominal cavity. On the other hand, the system will include a human-machine interface based on a smart surgical glove, and it will also emulate the concept of “transparent abdomen” by combining real images with augmented reality. Thus, the system will be supposed to recognize the present stage of the surgical workflow by means of the surgeon’s hand gestures, the motions of the surgical instrument or through the outputs of the physiological signals combined with a patient-procedure model. Thanks to this information, the robotic arms will be able to collaborate with the surgeon and to assist him/her with the articulated tool and placing the endoscope and the miniature robots in the suitable location to provide a complete and appropriate view of the surgical field. Additionally, the “transparent abdomen” system will provide the surgeon information of interest to him/her. Overall elements will be integrated in a cognitive architecture, which will include a supervisor system to watch over the system integrity, the performance of the surgical intervention and the safety of the patient.