Showing papers presented at "Field and Service Robotics in 2003"

Distributed Search and Rescue with Robot and Sensor Teams

Abstract: We develop a network of distributed mobile sensor systems as a solution to the emergency response problem. The mobile sensors are inside a building and they form a connected ad-hoc network. We discuss cooperative localization algorithms for these nodes. The sensors collect temperature data and run a distributed algorithm to assemble a temperature gradient. The mobile nodes are controlled to navigate using this temperature gradient. We also discuss how such networks can assist human users to find an exit. We have conducted an experiment to at a facility used to train firefighters to understand the environment and to test component technology. Results from experiments at this facility as well as simulations are presented here.

Optimal Search for a Lost Target in a Bayesian World.

Abstract: This paper presents a Bayesian approach to the problem of searching for a single lost target by a single autonomous sensor platform. The target may be static or mobile but not evading. Two candidate utility functions for the control solution are highlighted, namely the Mean Time to Detection, and the Cumulative Probability of Detection. The framework is implemented for an airborne vehicle looking for both a stationary and a drifting target at sea. Simulation results for different control solutions are investigated and compared to demonstrate the effectiveness of the method.

Real-Time Navigation, Guidance, and Control of a UAV Using Low-Cost Sensors.

Abstract: Applying low-cost sensors for the Guidance, Navigation and Control (GNC) of an autonomous Uninhibited Aerial Vehicle (UAV) is an extremely challenging area. This paper presents the real-time results of applying a low-cost Inertial Measurement Unit (IMU) and Global Positioning System (GPS) receiver for the GNC. The INS/GPS navigation loop provides continuous and reliable navigation solutions to the guidance and flight control loop for autonomous flight. With additional air data and engine thrust data, the guidance loop computes the guidance demands to follow way-point scenarios. The flight control loop generates actuator signals for the control surfaces and thrust vector. The whole GNC algorithm was implemented within an embedded flight control computer. The real-time flight test results show that the vehicle can perform the autonomous flight reliably even under high maneuvering scenarios.

Landing on a moving target using an autonomous helicopter

Abstract: We present a vision-based algorithm designed to enable an autonomous helicopter to land on a moving target. The helicopter is required to identify a target, track it, and land on it while the target is in motion. We use Hu’s moments of inertia for precise target recognition and a Kalman filter for target tracking. Based on the output of the tracker a simple trajectory controller is implemented which (within the given constraints) ensures that the helicopter is able to land on the target. We present results from data collected from manual flights which validate our tracking algorithm. Tests on actual landing with the helicopter UAV are ongoing.

An Experimental Study of Localization Using Wireless Ethernet

Abstract: This paper studies the use of wireless Ethernet (Wi-Fi) as a localization sensor for mobile robots. Wi-Fi-based localization relies on the existence of one or more Wi-Fi devices in the environment to act as beacons, and uses signal strength information from those beacons to localize the robot. Through the experiments described in this paper, we explore the general properties of Wi-Fi in indoor environments, and assess both the accuracy and utility of Wi-Fibased localization.

Scan Alignment and 3-D Surface Modeling with a Helicopter Platform

Abstract: This paper describes initial results for a laser-based aerial mapping system. Our approach applies a real-time laser scan matching algorithm to 2-D range data acquired by a remotely controlled helicopter. Results obtain for urban and natural terrain exhibit an unprecedented level of spatial detail in the resulting 3-D maps.

Decentralised SLAM with Low-Bandwidth Communication for Teams of Vehicles.

Abstract: This paper addresses the problem of simultaneous localization and mapping (SLAM) for teams of collaborating vehicles where the communication bandwidth is limited. We present a novel SLAM algorithm that enables multiple vehicles to acquire a joint map, but which can cope with arbitrary latency and bandwidth limitations such as typically found in airborne vehicle applications. The key idea is to represent maps in information form (negative log-likelihood), and to selectively communicate subsets of the information tailored to the available communication resources. We show that our communication scheme preserves the consistency, which has important ramifications for data association problems. We also provide experimental results that illustrate the effectiveness of our approach in comparison with previous

Planning under Uncertainty for Reliable Health Care Robotics

Abstract: We describe a mobile robot system, designed to assist residents of an retirement facility. This system is being developed to respond to an aging population and a predicted shortage of nursing professionals. In this paper, we discuss the task of finding and escorting people from place to place in the facility, a task containing uncertainty throughout the problem. Planning algorithms that model uncertainty well such as Partially Observable Markov Decision Processes (POMDPs) do not scale tractably to most real world problems. We demonstrate an algorithm for representing real world POMDP problems compactly, which allows us to find good policies in reasonable amounts of time. We show that our algorithm is able to find moving people in close to optimal time, where the optimal policy would start with knowledge of the person’s location.

Learning Predictions of the Load-Bearing Surface for Autonomous Rough-Terrain Navigation in Vegetation

Abstract: Current methods for off-road navigation using vehicle and terrain models to predict future vehicle response are limited by the accuracy of the models they use and can suffer if the world is unknown or if conditions change and the models become inaccurate. In this paper, an adaptive approach is presented that closes the loop around the vehicle predictions. This approach is applied to an autonomous vehicle driving through unknown terrain with varied vegetation. Features are extracted from range points from forward looking sensors. These features are used by a locally weighted learning module to predict the load-bearing surface, which is often hidden by vegetation. The true surface is then found when the vehicle drives over that area, and this feedback is used to improve the model. Results using real data show improved predictions of the load-bearing surface and successful adaptation to changing conditions.

Path Planning for Complete Coverage with Agricultural Machines.

Abstract: The problem of planning reference trajectories for agricultural machines is considered. A path planning algorithm to perform various kinds of farm-works is described. The case of convex fields is first considered. A direction of work being given, the algorithm determines the turning areas and selects a trajectory which guarantees the complete field coverage while minimizing overlapping. The method is extended to the case of fields with more complex shape including possibly obstacles. Simulations are proposed to illustrate the reasoning.

Experimental Results in Using Aerial LADAR Data for Mobile Robot Navigation

Abstract: In this paper, we investigate the use of high resolution aerial LADAR data for autonomous mobile robot navigation in natural environments. The use of prior maps from aerial LADAR (LAser Detection And Ranging) survey is considered for enhancing system performance in two areas. First, the prior maps are used for registration with the data from the robot in order to compute accurate localization in the map. Second, the prior maps are used for computing detailed traversability maps that are used for planning over long distances. Our objective is to assess the key issues in using such data and to report on a first batch of experiments in combining high-resolution aerial data and on-board sensing

Automatic 3D Underground Mine Mapping.

Abstract: For several years, our research group has been developing methods for automated modeling of 3D environments. In September, 2002, we were given the opportunity to demonstrate our mapping capability in an underground coal mine. The opportunity arose as a result of the Quecreek mine accident, in which an inaccurate map caused miners to breach an abandoned, water-lled mine, trapping them for several days. Our eld test illustrates the feasibility and potential of high resolution three-dimensional (3D) mapping of an underground coal mine using a cartmounted 3D laser scanner. This paper presents our experimental setup, the automatic 3D modeling method used, and the results of the eld test. In addition, we address issues related to laser sensing in a coal mine environment.

Development of Pneumatically Controlled Expandable Arm for Search in the Environment with Tight Access.

Abstract: A tilter mechanism for the slats of a venetian blind in which a worm and wormwheel are mounted in a housing connected to a bracket, the wormwheel has an axial extension on each axial end provided with a recess which can receive selectively the end of a tilt rod, whereby the tilt rod can extend either to the left or to the right of the wormwheel. A spring clip holds the tilt rod in engagement with the recess in one of the extensions. A rotational control disc may also be provided which has two external abutments. This disc can be mounted on the other of the extensions, the abutments being engageable with stops on the bracket to restrict rotation of the control member and thus of the wormwheel. Radially outwardly extending keys are provided on each extension, one of these engaging the spring clip to hold the tilt rod in place, and the other engaging a notch in the rotation control disc to prevent the latter rotating relative to the wormwheel.

Market-based Multirobot Coordination Using Task Abstraction

Abstract: In this paper, we introduce a novel approach to multirobot coordination that works by simultaneously distributing task allocation, mission planning, and executio n among members of a robot team. By combining traditional hierarchical task decomposition techniques with recent de velopments in market-based multirobot control, we obtain an efficient and robust distributed system capable of solving complex problems. Essentially, we have extended the TraderBots market-based architecture to include a mechanism that distributes tasks among robots at multiple levels of abstractions, represented as task trees. Results are pre sented for a simulated area reconnaissance scenario.

Shearer Guidance: A Major Advance in Longwall Mining.

Abstract: A packer assembly for a cable-suspended well pumping system comprises a cylindrical housing carrying an external sealing sleeve of resilient material and a series of axially movable radially expandable slips for gripping a well casing. The slips are operated by liquid pressure developed upon initiation of a downwell pumping operation, by movement of a tubular piston within the housing which is connected to the slips through openings in the housing wall. Further, the slips abut a collar attached to one end of the sealing sleeve so that axial movement of the slips also causes the sealing sleeve to be axially compressed and radially expanded into engagement with the well casing. After pumping is terminated, the slips and seal can be disengaged from the well casing simply by raising the assembly.

A Terrain-Aided Tracking Algorithm for Marine Systems.

Abstract: This paper presents a novel method for incorporating unstructured, natural terrain information into the process of tracking of underwater vehicles. Terrainaided navigation promises to revolutionise the ability of marine systems to track underwater bodies in deepwater applications. This work represents a crucial step in the development of underwater technologies capable of long-term, reliable deployment. A particle based estimator is used to incorporate observations of altitude into the estimation process. Results of the application of this technique to the tracking of a towed body are shown.

Development of a Personal Service Robot with User-Friendly Interfaces

Abstract: This paper describes a personal service robot developed for assisting a user in his/her daily life. One of the important aspects of such robots is the user-friendliness in communication; especially, the easiness of user’s assistance to a robot is important in making the robot perform various kinds of tasks. Our robot has the following three features: (1) interactive object recognition, (2) robust speech recognition, and (3) easy teaching of mobile manipulation. The robot is applied to the task of fetching a can from a distant refrigerator.

An Enhanced Robotic Library System for an Off-Site Shelving Facility

Abstract: This paper describes our continued work of a unique robotics project, Comprehensive Access to Printed Materials (CAPM), within the context of libraries. As libraries provide a growing array of digital library services and resources, they continue to acquire large quantities of printed material. This combined pressure of providing electronic and print-based resources and services has led to severe space constraints for many libraries, especially academic research libraries. Consequently, many libraries have built or plan to build off-site shelving facilities to accommodate printed materials. An autonomous mobile robotic library system has been developed to retrieve items from bookshelves and carry them to scanning stations located in the off-site shelving facility. This paper reviews the overall design of the robot system and control systems, and reports the new improvement in the accuracy of the robot performance; in particular, the pick-up process.

Case Studies of a Borehole Deployable Robot for Limestone Mine Profiling and Mapping.

Abstract: Inherent dangers in mining operations motivate the use of robotic technology for addressing hazardous situations that prevent human access. In the context of this case study, we examine the application of a robotic tool for map verification and void profiling in abandoned limestone mines for analysis of cavity extent. To achieve this end, our device enables remote, highly accurate measurements of the subterranean voids to be acquired. In this paper we discuss the design of the robotic tool, demonstrate its application in void assessment for prevention and response to subsidence, and present results from a case study performed in the limestone mines of Kansas City, Kansas.

Spraying Robot for Grape Production

Abstract: A robot whichcould spraychemicals under grapevine trellis was developed and experimented .From the experimental results ,it was observed that the robot system made precise sprayin go peration and its preciseo peration recordp ossible. Based on the precise operationsand records,a no ptimumm anagement of chemicals could bee xpected, that is, necessary amount of chemicals would be sprayed only at necessary places for protection of environment and ecosystem. Inaddition,it was considered that this robot would beab le t o contribute the minimu mi nput-maximu mo utput production system b yestablishment of traceability system in grape production.

Dragline automation: Experimental evaluation through productivity trial

Abstract: Since 1993 we have been working on the automation of dragline excavators, the largest earthmoving machines that exist. Recently we completed a large-scale experimental program where the automation system was used for production purposes over a two week period and moved over 200,000 tonnes of overburden. This is a landmark achievement in the history of automated excavation. In this paper we briefly describe the robotic system and how it works cooperatively with the machine operator. We then describe our methodology for gauging machine performance, analyze results from the production trial and comment on the effectiveness of the system that we have created. © Springer-Verlag Berlin Heidelberg 2006.

Bayesian Programming Multi-Target Tracking: an Automotive Application

Abstract: SA prerequisite to the design of future AdvancedDriver Assistance Systems for cars is a sensing systemproviding all the information required for high-level driv-ing assistance tasks. In particular, target tracking is stillchallenging in urban trafc situations, because of the largenumber of rapidly maneuvering targets. The goal of thispaper is to present an original way to perform target positionand velocity, based on the occupancy grid framework. Themain interest of this method is to avoid the decision prob-lem of classical multi-target tracking algorithms. Obtainedoccupancy grids are combined with danger estimation toperform an elementary task of obstacle avoidance with anelectric car. I. I NTRODUCTION Unlike regular cruise control systems, Adaptive CruiseControl (ACC) systems use a range sensor to regulate thespeed of the car while ensuring collision avoidance withthe vehicle in front. ACC systems were introduced onthe automotive market in 1999. Since then, surveys andexperimental assessments have demonstrated the interestfor this kind of systems. They are the rst step towardsthe design of future Advanced Driver Assistance Sys-tems (ADAS) that should help the driver in increasinglycomplex driving tasks. The use of today’s commerciallyavailable ACC systems is pretty much limited to motor-ways or urban expressways without crossings. The trafcsituations encountered are rather simple and attention canbe focused on a few, well dened detected objects (carsand trucks). Nonetheless, even in these relatively simplesituations, these systems show a number of limitations:they are not very good at handling x ed obstacles andmay generate false alarms; moreover, in some ’cut-in’situations,

Wall following with constrained active contours

Abstract: A motor-nozzle coupling member for coupling a motor to a nozzle in an electro-hydraulic control structure wherein a linear electric motor having an armature is located at a fixed distance relative to the nozzle by a coupler which engages the motor and nozzle and extends therebetween to establish the spacing between the motor and nozzle and with the coupler being deformable after initial assembly to set the desired spacing.

Development of a Terrain Adaptive Stability Prediction System for Mass Articulating Mobile Robots.

Abstract: Dynamic stability is an important issue for vehicles which move heavy loads, turn at speed, or operate on sloped terrain. In many cases, vehicles face more than one of these challenges simultaneously. This paper presents a methodology for deriving proximity to tipover for autonomous field robots which must be productive, effective, and self reliant under such challenging circumstances. The technique is based on explicit modelling of mass articulations and determining the motion of the center of gravity, as well as the attitude, in an optimal estimation framework. Inertial sensing, articulation sensing, and terrain relative motion sensing are employed. The implementation of the approach on a commercial industrial lift truck is presented.

ROBHAZ-DT2: Passive Double-Tracked Mobile Manipulator for Explosive Ordnance Disposal.

Abstract: In this paper ,d esign and integration of ROBHAZ-DT2 is presented which is a newly developed mobile manipulator system. It is designed to carry out military and civilian missions in various hazardous environments. In developing the integrated ROBHAZ-DT2 system, we have focused on tw oi ssues :1 )n ove lm echanism design for mobility and manip- ulation and 2) intuitive user interface for teleoperation. In mechanism design, ad ouble tracks connected by ap assive joint has been designed to achieve high speed and rugged mobility on uneve nt errain. In addition, as ix-dof foldable manipulator suitable for the mobile manip- ulation has been designed. Secondly ,an ew compact 6-dof haptic device has been developed for teleoperation of the ROBHAZ-DT2. This haptic device is specially designed for simulta- neous control both of the mobile base and the manipulator of ROBHAZ-DT2. As ar esult of integration of RobhAZ-DT2 and the user interface unit including the haptic device, we could successfully demonstrate at ypical EOD task requiring abilities of mobility and manipulation in outdoor environment.

Performing skilled work with an interactively operated service robot

Abstract: In the paper we are considering skilled tasks that are performed by a human-like robot in outdoor unstructured environment when working interactively with a human operator. As skill tasks we understand tasks, which - like when humans perform them - are non-trivial and demand learning or training. Typically such tasks may also fail and require several trials to be successfully executed. Performing requires use of senses and development of a unique mini-plan, which takes into account the present situation. The mini-plan, which may also be called "skill", produces a sequence of unit operations needed for successful performing of the task. The paper discusses preliminary experiences on implementing and experimenting such skilled tasks with a mobile centaur-like service robot.