waashk/dblp huggingface dataset:
odin: team victortango's entry in the darpa urban challenge. the darpa urban challenge required robotic vehicles to travel more than 90 km through an urban environment without human intervention and included situations such as stop intersections, traffic merges, parking, and roadblocks. team victortango separated the problem into three parts: base vehicle, perception, and planning. a ford escape outfitted with a custom drive-by-wire system and computers formed the basis for odin. perception used laser scanners, global positioning system, and a priori knowledge to identify obstacles, cars, and roads. planning relied on a hybrid deliberative-reactive architecture to analyze the situation, select the appropriate behavior, and plan a safe path. all vehicle modules communicated using the jaus (joint architecture for unmanned systems) standard. the performance of these components in the urban challenge is discussed and successes noted. the result of victortango's work was successful completion of the urban challenge and a third-place finish. &copy; 2008 wiley periodicals, inc.
force cooperation in a reconfigurable field multirobot system. force cooperation between robots can enhance the mobility of robots in the field. this paper presents the multirobot system jl-1, in which the robots can dock and adjust their posture in relation to each other to execute force cooperation if necessary. to reveal how force cooperation enhances the terrain adaptability of jl-1 and to discover the limits of the current reconfiguration mechanism, this paper analyzes the forces arising between robots during force cooperation. by examining one typical, flexible force cooperation, the docking action, we deduce the self-aligning conditions of the current docking mechanism, which is useful to improve the mechanism and clarify the demands on the docking guidance sensors. the static analysis of the posture-adjusting mechanism yields the force-amplifying feature and the drivable work space of this motorized spherical joint consisting of a parallel and serial mechanism. the analysis also explains why some locomotion types of jl-1 are performed the way they are. after that, a series of on-site experiments confirm the abilities of the locomotion and the force cooperation of jl-1. as the basis of the analysis, the mechanical structure and control system architecture of jl-1 are also briefly introduced. &copy; 2008 wiley periodicals, inc.
junior: the stanford entry in the urban challenge. this article presents the architecture of junior, a robotic vehicle capable of navigating urban environments autonomously. in doing so, the vehicle is able to select its own routes, perceive and interact with other traffic, and execute various urban driving skills including lane changes, u-turns, parking, and merging into moving traffic. the vehicle successfully finished and won second place in the darpa urban challenge, a robot competition organized by the u.s. government. &copy; 2008 wiley periodicals, inc.
data-driven identification of group dynamics for motion prediction and control. a distributed model structure for representing groups of coupled dynamic agents is proposed, and the least-squares method is used for fitting model parameters based on measured position data. the difference equation model embodies a minimalist approach, incorporating only factors essential to the movement and interaction of physical bodies. the model combines effects from an agent's inertia, interactions between agents, and interactions between each agent and its environment. global positioning system tracking data were collected in field experiments from a group of 3 cows and a group of 10 cows over the course of several days using custom-designed, head-mounted sensor boxes. these data are used with the least-squares method to fit the model to the cow groups. the modeling technique is shown to capture overall characteristics of the group as well as attributes of individual group members. applications to livestock management are described, and the potential for surveillance, prediction, and control of various kinds of groups of dynamic agents are suggested. &copy; 2008 wiley periodicals, inc.
underwater slam in man-made structured environments. this paper describes a navigation system for autonomous underwater vehicles (auvs) in partially structured environments, such as dams, harbors, marinas, and marine platforms. a mechanically scanned imaging sonar is used to obtain information about the location of vertical planar structures present in such environments. a robust voting algorithm has been developed to extract line features, together with their uncertainty, from the continuous sonar data flow. the obtained information is incorporated into a feature-based simultaneous localization and mapping (slam) algorithm running an extended kalman filter. simultaneously, the auv's position estimate is provided to the feature extraction algorithm to correct the distortions that the vehicle motion produces in the acoustic images. moreover, a procedure to build and maintain a sequence of local maps and to posteriorly recover the full global map has been adapted for the application presented. experiments carried out in a marina located in the costa brava (spain) with the ictineu auv show the viability of the proposed approach. &copy; 2008 wiley periodicals, inc.
a perspective on emerging automotive safety applications, derived from lessons learned through participation in the darpa grand challenges. this paper reports on various aspects of the intelligent vehicle systems (ivs) team's involvement in the recent 2007 darpa urban challenge, wherein our platform, the autonomous &ldquo;xav-250,'' competed as one of the 11 finalists qualifying for the event. we provide a candid discussion of the hardware and software design process that led to our team's entry, along with lessons learned at this event and derived from participation in the two previous grand challenges. in addition, we give an overview of our vision-, radar-, and lidar-based perceptual sensing suite, its fusion with a military-grade inertial navigation package, and the map-based control and planning architectures used leading up to and during the event. the underlying theme of this article is to elucidate how the development of future automotive safety systems can potentially be accelerated by tackling the technological challenges of autonomous ground vehicle robotics. of interest, we will discuss how a production manufacturing mindset imposes a unique set of constraints upon approaching the problem and how this worked for and against us, given the very compressed timeline of the contests. &copy; 2008 wiley periodicals, inc.
co-design of fast biologically-plausible vision-based systems for controlling the reactive behaviors of mobile robots. this paper addresses the co-design of biologically-plausible vision-based algorithms applied to control the reactive behaviors of mobile robots and, especially, the control of collision avoidance in unknown and dynamic worlds. our main tools are programmable logic devices like fpga (field programmable gate arrays) to implement real-time perception&#x002f;actions schemes. &copy; 2005 wiley periodicals, inc.
evaluation of semi-autonomous convoy driving. autonomous mobility technologies may have applications to manned vehicle convoy operations&mdash;they have the ability to enhance both system performance and operator capability. this effort examines the potential impact of introducing semi-autonomous mobility [convoy active safety technologies (cast)] into manned vehicles. twelve civilians with experience driving military vehicles in convoy-type operations participated in this experiment. for the experiment, they were tasked with following a lead vehicle while completing a concurrent security task (scanning the local environment for targets). the control of the manned vehicle was varied between cast and manual control at several different speed levels. several objective speed and accuracy variables along with subjective operator assessment variables were examined for each task. the results support the potential benefits of incorporating semi-autonomous mobility technologies into manned vehicle convoy operations. the semi-autonomous mobility system was associated with significantly better performance in several aspects of operator situational awareness and convoy integrity, including enhanced target identification, improved maintenance of following distance, and improved performance for unanticipated stops. this experiment also highlighted a critical human factors issue associated with the incorporation of autonomy in real-world applications: participants felt that, overall, they outperformed the semi-autonomous system on the simulated convoy operation. the operator's perception of the system's performance could potentially affect his or her willingness to use the system in real-world applications. this experiment demonstrated that enhancements to overall system performance in real-world applications are achieved by considering both technological and human factors solutions. published 2008 wiley periodicals, inc. this article is a us government work and, as such, is in the public domain of the united states of america.
motion planning in urban environments. we present the motion planning framework for an autonomous vehicle navigating through urban environments. such environments present a number of motion planning challenges, including ultrareliability, high-speed operation, complex intervehicle interaction, parking in large unstructured lots, and constrained maneuvers. our approach combines a model-predictive trajectory generation algorithm for computing dynamically feasible actions with two higher level planners for generating long-range plans in both on-road and unstructured areas of the environment. in the first part of this article, we describe the underlying trajectory generator and the on-road planning component of this system. we then describe the unstructured planning component of this system used for navigating through parking lots and recovering from anomalous on-road scenarios. throughout, we provide examples and results from &ldquo;boss&rdquo; an autonomous sport utility vehicle that has driven itself over 3,000 km and competed in, and won, the darpa urban challenge. &copy; 2008 wiley periodicals, inc.
state space sampling of feasible motions for high-performance mobile robot navigation in complex environments. sampling in the space of controls or actions is a well-established method for ensuring feasible local motion plans. however, as mobile robots advance in performance and competence in complex environments, this classical motion-planning technique ceases to be effective. when environmental constraints severely limit the space of acceptable motions or when global motion planning expresses strong preferences, a state space sampling strategy is more effective. although this has been evident for some time, the practical question is how to achieve it while also satisfying the severe constraints of vehicle dynamic feasibility. the paper presents an effective algorithm for state space sampling utilizing a model-based trajectory generation approach. this method enables high-speed navigation in highly constrained and-or partially known environments such as trails, roadways, and dense off-road obstacle fields. &copy; 2008 wiley periodicals, inc.
little ben: the ben franklin racing team's entry in the 2007 darpa urban challenge. this paper describes "little ben," an autonomous ground vehicle constructed by the ben franklin racing team for the 2007 darpa urban challenge in under a year and for less than $250,000. the sensing, planning, navigation, and actuation systems for little ben were carefully designed to meet the performance demands required of an autonomous vehicle traveling in an uncertain urban environment. we incorporated an array of a global positioning system (gps)-inertial navigation system, lidars, and stereo cameras to provide timely information about the surrounding environment at the appropriate ranges. this sensor information was integrated into a dynamic map that could robustly handle gps dropouts and errors. our planning algorithms consisted of a high-level mission planner that used information from the provided route network definition and mission data files to select routes, whereas the lower level planner used the latest dynamic map information to optimize a feasible trajectory to the next waypoint. the vehicle was actuated by a cost-based controller that efficiently handled steering, throttle, and braking maneuvers in both forward and reverse directions. our software modules were integrated within a hierarchical architecture that allowed rapid development and testing of the system performance. the resulting vehicle was one of six to successfully finish the urban challenge. &copy; 2008 wiley periodicals, inc.
vision-based terrain following for an unmanned rotorcraft. experiments from biology suggest that the sensing of image motion or optic flow in insects provides a means of determining the range to obstacles and terrain. when combined with a measure of ground speed from another sensor such as global positioning system, optic flow can be used to provide a measure of an aircraft's height above terrain. we apply this principle to the control of height in a helicopter, leading to the first optic flow&ndash;based terrain-following system for an unmanned helicopter. using feedback of the height estimated from optic flow ranging to the collective pitch control of the helicopter, it has been possible to maintain terrain clearance in flights of up to 2 km. in this paper, we present flight test data demonstrating the successful application of this to an 80-kg yamaha rmax unmanned helicopter and an 8-kg electric helicopter. to complete this work, we have extended the optic flow image interpolation algorithm (i2a) to include an adaptive capability providing a greater dynamic range. the new algorithm, called the iterative image interpolation algorithm (i2a), exhibits excellent robustness in an outdoor environment and makes it suitable for flight control in a real-world environment. &copy; 2008 wiley periodicals, inc.
a perception-driven autonomous urban vehicle. this paper describes the architecture and implementation of an autonomous passenger vehicle designed to navigate using locally perceived information in preference to potentially inaccurate or incomplete map data. the vehicle architecture was designed to handle the original darpa urban challenge requirements of perceiving and navigating a road network with segments defined by sparse waypoints. the vehicle implementation includes many heterogeneous sensors with significant communications and computation bandwidth to capture and process high-resolution, high-rate sensor data. the output of the comprehensive environmental sensing subsystem is fed into a kinodynamic motion planning algorithm to generate all vehicle motion. the requirements of driving in lanes, three-point turns, parking, and maneuvering through obstacle fields are all generated with a unified planner. a key aspect of the planner is its use of closed-loop simulation in a rapidly exploring randomized trees algorithm, which can randomly explore the space while efficiently generating smooth trajectories in a dynamic and uncertain environment. the overall system was realized through the creation of a powerful new suite of software tools for message passing, logging, and visualization. these innovations provide a strong platform for future research in autonomous driving in global positioning system&ndash;denied and highly dynamic environments with poor a priori information. &copy; 2008 wiley periodicals, inc.
vision-based operations of a large industrial vehicle: autonomous hot metal carrier. hot metal carriers (hmcs) are large forklift-type vehicles used to move molten metal in aluminum smelters. this paper reports on field experiments that demonstrate that hmcs can operate autonomously and in particular can use vision as a primary sensor to locate the load of aluminum. we present our complete system but focus on the vision system elements and also detail experiments demonstrating reliable operation of the materials handling task. two key experiments are described, lasting 2 and 5 h, in which the hmc traveled 15 km in total and handled the load 80 times. &copy; 2008 wiley periodicals, inc.
caroline: an autonomously driving vehicle for urban environments. the 2007 darpa urban challenge afforded the golden opportunity for the technische universit&auml;t braunschweig to demonstrate its abilities to develop an autonomously driving vehicle to compete with the world's best. after several stages of qualification, our team carolo qualified early for the darpa urban challenge final event and was among only 11 teams from initially 89 competitors to compete in the final. we had the ability to work together in a large group of experts, each contributing his expertise in his discipline, and significant organizational, financial, and technical support by local sponsors, who helped us to become the best non-u.s. team. in this report, we describe the 2007 darpa urban challenge, our contribution, &ldquo;caroline,&rdquo; the technology, and algorithms, along with her performance in the darpa urban challenge final event on november 3, 2007. &copy; 2008 wiley periodicals, inc.
shared environment representation for a human-robot team performing information fusion. this paper addresses the problem of building a shared environment representation by a human-robot team. rich environment models are required in real applications for both autonomous operation of robots and to support human decision-making. two probabilistic models are used to describe outdoor environment features such as trees: geometric (position in the world) and visual. the visual representation is used to improve data association and to classify features. both models are able to incorporate observations from robotic platforms and human operators. physically, humans and robots form a heterogeneous sensor network. in our experiments, the human-robot team consists of an unmanned air vehicle, a ground vehicle, and two human operators. they are deployed for an information gathering task and perform information fusion cooperatively. all aspects of the system including the fusion algorithms are fully decentralized. experimental results are presented in form of the acquired multi-attribute feature map, information exchange patterns demonstrating human-robot information fusion, and quantitative model evaluation. learned lessons from deploying the system in the field are also presented. &copy; 2007 wiley periodicals, inc.
design and control of a planar haptic device with passive actuators based on passive force manipulability ellipsoid (fme) analysis. in this paper, we propose an optimal design for a passive haptic device with brakes and its control method. the inability of a brake to generate torque significantly affects the performance of a multi-dof haptic device, in that a desired force can be generated only approximately in some workspace and, in some cases, the device may become stuck contrary to the user's intention. in this research, these limitations are analyzed by means of the so-called passive force manipulability ellipsoid. through the analysis, performance indices are developed for evaluating the limitations associated with passive haptic devices. optimization is conducted for a 5-bar mechanism with redundant actuation, and a coercive force approximation scheme is developed to avoid unsmooth motion during the wall-following task along the virtual wall. it is experimentally shown that the performance in relation to the limitations is greatly improved for the optimized mechanism. &copy; 2005 wiley periodicals, inc.
development and implementation of a team of robotic tractors for autonomous peat moss harvesting. this paper describes the key system components of a team of three tractors in a peat moss harvesting operation. the behavior and actions of the tractors were designed to mimic manual harvest operations while maintaining a safe operating environment. to accomplish this objective, each of the three tractors was equipped with a bolt-on automation package, and a human operator (team leader) was given a remote user interface to command and monitor the mission. the automation package included positioning, planning, and control, as well as coordination and perception systems to preserve field harvesting order, detect obstacles, and report physical changes in the operating environment. the system performed more than 100 test field harvesting missions during one season in a working peat bog, including three complete system tests with the end users. &copy; 2009 wiley periodicals, inc.
path planning in image space for autonomous robot navigation in unstructured environments. path planning systems using graph-search algorithms such as a* usually operate in uniform plan-view occupancy grids. however, the sensors used to construct these grids observe the environment in their own sample space based on sensor type and viewpoint. in this paper we present an image space technique for path planning in unknown unstructured outdoor environments. our method differs from previous techniques in that we perform path search directly in image space&mdash;the native sensor space of the imaging sensor. after an image space path has been found, it is used for navigation in the real world. by operating at the resolution of the image sensor, image space planning facilitates accurate robot vs. obstacle localization and enables a high degree of movement precision. our image space planning techniques can potentially be used with many different kinds of sensor data, and we experimentally evaluate the use of stereo disparity and color information. we present an extension to the basic image space planning system called the cylindrical planner that simulates a 2&pi; field of view with a cylindrically shaped occupancy grid. we believe that image space planning is well suited for use in the local subsystem of a hierarchical planner and implement a hybrid hierarchical planner that utilizes the cylindrical planner as a local planning subsystem and a two-dimensional cartesian planner as the global planning subsystem. all three systems are implemented and experimentally tested on a real robot. we evaluate the failure modes of image space planning and discuss how to avoid them. we find that image space enables precise real-time, near-field planning. &copy; 2009 wiley periodicals, inc.
learning long-range vision for autonomous off-road driving. most vision-based approaches to mobile robotics suffer from the limitations imposed by stereo obstacle detection, which is short range and prone to failure. we present a self-supervised learning process for long-range vision that is able to accurately classify complex terrain at distances up to the horizon, thus allowing superior strategic planning. the success of the learning process is due to the self-supervised training data that are generated on every frame: robust, visually consistent labels from a stereo module; normalized wide-context input windows; and a discriminative and concise feature representation. a deep hierarchical network is trained to extract informative and meaningful features from an input image, and the features are used to train a real-time classifier to predict traversability. the trained classifier sees obstacles and paths from 5 to more than 100 m, far beyond the maximum stereo range of 12 m, and adapts very quickly to new environments. the process was developed and tested on the lagr (learning applied to ground robots) mobile robot. results from a ground truth data set, as well as field test results, are given. &copy; 2009 wiley periodicals, inc.