4,408 research outputs found

    OPEB: Open Physical Environment Benchmark for Artificial Intelligence

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    Artificial Intelligence methods to solve continuous- control tasks have made significant progress in recent years. However, these algorithms have important limitations and still need significant improvement to be used in industry and real- world applications. This means that this area is still in an active research phase. To involve a large number of research groups, standard benchmarks are needed to evaluate and compare proposed algorithms. In this paper, we propose a physical environment benchmark framework to facilitate collaborative research in this area by enabling different research groups to integrate their designed benchmarks in a unified cloud-based repository and also share their actual implemented benchmarks via the cloud. We demonstrate the proposed framework using an actual implementation of the classical mountain-car example and present the results obtained using a Reinforcement Learning algorithm.Comment: Accepted in 3rd IEEE International Forum on Research and Technologies for Society and Industry 201

    Bicycle and car share schemes as inclusive modes of travel? A socio-spatial analysis in Glasgow

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    Public bicycle and car sharing schemes have proliferated in recent years and are increasingly part of the urban transport landscape. Shared transport options have the potential to support social inclusion by improving accessibility: these initiatives could remove some of the barriers to car ownership or bicycle usage such as upfront costs, maintenance and storage. However, the existing evidence base indicates that, in reality, users are most likely to be white, male and middle class. This paper argues that there is a need to consider the social inclusivity of sharing schemes and to develop appropriate evaluation frameworks accordingly. We therefore open by considering ways in which shared transport schemes might be inclusive or not, using a framework developed from accessibility planning. In the second part of the paper, we use the case study of Glasgow in Scotland to undertake a spatial equity analysis of such schemes. We examine how well they serve different population groups across the city, using the locations of bicycle stations and car club parking spaces in Glasgow, comparing and contrasting bike and car. An apparent failure to deliver benefits across the demographic spectrum raises important questions about the socially inclusive nature of public investment in similar schemes

    Green-Technology Automobiles: Can modern innovations save the environment and consumers\u27 pockets

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    Cars of the past are notorious for poor fuel efficiency and high carbon emissions. With the presence of hybrid technology, along with a variety of other green innovations, many of these negative side effects can be mitigated. The purpose of this study is to answer the question: how do green technology vehicles compare with similar models that exclude such innovations in relation to efficiency and price? A total of 47 green-tech vehicles were identified and compared against their base model counterparts. Vehicle weight, horsepower, fuel efficiency and other variables were matched within pairs (green-tech vs. base) and between car types (sedans, SUVs and trucks). Regardless of vehicle type and green-tech, weight proved to be an influential factor, showing that as curb weight increased, fuel efficiency decreased. Compared to the base models, green-tech luxury vehicles also exhibited few improvements in fuel efficiency with disproportionately high growth in price. Non-luxury green-tech sedans ranging from 2500lbs to 4000lbs showed the largest improvements in efficiency while also maintaining an average MSRP of $28996±1089, producing a green-tech vehicle that is economically affordable. The impressive results from this category of vehicles suggest that consumer investment in non-luxury green sedans may not only help to save money in fuel consumption, but also save the environment

    Advanced Low-Floor Vehicle (ALFV) Specification Research

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    This report details the results of research on market comparison, operational cost efficiencies, and prototype tests conducted on a novel design for an Advanced Low Floor Vehicle (ALFV), flex-route transit bus. Section I describes how the need for such a bus arises from a combination of diminishing transit funding from the federal government and demographic and transportation factors. Section II describes the unique features of this bus design that render it suitable for rural and urban operation, including improved transit passenger and wheelchair accessibility, reduced maintenance, structural design features, safety provisions, and the technical specifications of this design. Section III details the potential differences in capital and operational costs of procuring and operating this bus in a fleet. Potential cost reductions due to the long-life vehicle concept, maneuverability, operational savings (from APTA Bus Roadeo tests), and reserve fleet savings are explored. Section IV refers to the Federal Transit Administration (FTA) new model bus tests (“Altoona Testing”). However, at the this time, the Altoona Bus Test Report for these tests is not yet released by the bus manufacturer, Ride Solution, Inc., as is its right under the Bus Testing Regulation. The report must be released to the public before this bus can be purchased by a transit agency using FTA funds. In addition to the standard Altoona Bus Test, additional research was conducted to determine the turning ability, suspension travel, ramp travel index, field of view for the driver, compliance to Americans with Disabilities Act (ADA) requirements, and timed assessment of wheelchair securement. Section IV also presents the results of these tests. Section V presents results from a market comparison that included the buses in this mid-size category that were tested at Altoona and are expected to be available for FTA grantees to purchase. The specifications and performance of the ALFV bus are compared with these buses. Section VI presents a flex-route utilization plan, and Section VII provides the results from a survey of transit professionals about their interest in the features of this bus design. Section VIII gives Ride Solution’s experience in developing the concept for ALFV. Conclusions of this report are presented in Section IX, followed by the references and appendices

    Development of an autonomous mobile towing vehicle for logistic tasks

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    Frequently carrying high loads and performing repetitive tasks compromises the ergonomics of individuals, a recurrent scenario in hospital environments. In this paper, we design a logistic planner of a fleet of autonomous mobile robots for the automation of transporting trolleys around the hospital, which is independent of the space configuration, and robust to loss of network and deadlocks. Our robotic solution has an innovative gripping system capable of grasping and pulling nonmodified standard trolleys just by coupling a plate. Robots are able to navigate autonomously, to avoid obstacles assuring the safety of operators, to identify and dock a trolley, to access charging stations and elevators, and to communicate with the latter. An interface was built allowing users to command the robots through a web server. It is shown how the proposed methodology behaves in experiments conducted at the Faculty of Engineering of the University of Porta and Braga's Hospital.This work is financed by the ERDF - European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation- COMPETE 2020 Programme, and by National Funds through the Portuguese funding agency, FCT-Fundação para a CiĂȘncia e a Tecnologia, within project SAICTPAC/0034/2015 - POCI-01- 0145-FEDER-016418. Authors would like to acknowledge to Trivalor, Itau and Gertal for the support of the project RDH.info:eu-repo/semantics/publishedVersio

    Parameter tuning and cooperative control for automated guided vehicles

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    For several practical control engineering applications it is desirable that multiple systems can operate independently as well as in cooperation with each other. Especially when the transition between individual and cooperative behavior and vice versa can be carried out easily, this results in ??exible and scalable systems. A subclass is formed by systems that are physically separated during individual operation, and very tightly coupled during cooperative operation. One particular application of multiple systems that can operate independently as well as in concert with each other is the cooperative transportation of a large object by multiple Automated Guided Vehicles (AGVs). AGVs are used in industry to transport all kinds of goods, ranging from small trays of compact and video discs to pallets and 40-tonne coils of steel. Current applications typically comprise a ??eet of AGVs, and the vehicles transport products on an individual basis. Recently there has been an increasing demand to transport very large objects such as sewer pipes, rotor blades of wind turbines and pieces of scenery for theaters, which may reach lengths of over thirty meters. A realistic option is to let several AGVs operate together to handle these types of loads. This Ph.D. thesis describes the development, implementation, and testing of distributed control algorithms for transporting a load by two or more Automated Guided Vehicles in industrial environments. We focused on the situations where the load is connected to the AGVs by means of (semi-)rigid interconnections. Attention was restricted to control on the velocity level, which we regard as an intermediate step for achieving fully automatic operation. In our setup the motion setpoint is provided by an external host. The load is assumed to be already present on the vehicles. Docking and grasping procedures are not considered. The project is a collaboration between the company FROG Navigation Systems (Utrecht, The Netherlands) and the Control Systems group of the Technische Universiteit Eindhoven. FROG provided testing facilities including two omni-directional AGVs. Industrial AGVs are custom made for the transportation tasks at hand and come in a variety of forms. To reduce development times it is desirable to follow a model-based control design approach as this allows generalization to a broad class of vehicles. We have adopted rigid body modeling techniques from the ??eld of robotic manipulators to derive the equations of motion for the AGVs and load in a systematic way. These models are based on physical considerations such as Newton's second law and the positions and dimensions of the wheels, sensors, and actuators. Special emphasis is put on the modeling of the wheel-??oor interaction, for which we have adopted tire models that stem from the ??eld of vehicle dynamics. The resulting models have a clear physical interpretation and capture a large class of vehicles with arbitrary wheel con??gurations. This ensures us that the controllers, which are based on these models, are applicable to a broad class of vehicles. An important prerequisite for achieving smooth cooperative behavior is that the individual AGVs operate at the required accuracy. The performance of an individual AGV is directly related to the precision of the estimates for the odometric parameters, i.e. the effective wheel diameters and the offsets of the encoders that measure the steering angles of the wheels. Cooperative transportation applications will typically require AGVs that are highly maneuverable, which means that all the wheels of an individual AGV ahould be able to steer. Since there will be more than one steering angle encoder, the identi??cation of the odometric parameters is substantially more dif??cult for these omni-directional AGVs than for the mobile wheeled robots that are commonly seen in literature and laboratory settings. In this thesis we present a novel procedure for simultaneously estimating effective wheel diameters and steering angle encoder offsets by driving several pure circle segments. The validity of the tuning procedure is con??rmed by experiments with the two omni-directional test vehicles with varying loads. An interesting result is that the effective wheel diameters of the rubber wheels of our AGVs increase with increasing load. A crucial aspect in all control designs is the reconstruction of the to-be-controlled variables from measurement data. Our to-be-controlled variables are the planar motion of the load and the motions of the AGVs with respect to the load, which have to be reconstruct from the odometric sensor information. The odometric sensor information consists of the drive encoder and steering encoder readings. We analyzed the observability of an individual AGV and proved that it is theoretically possible to reconstruct its complete motion from the odometric measurements. Due to practical considerations, we pursued a more pragmatic least-squares based observer design. We show that the least-squares based motion estimate is independent of the coordinate system that is being used. The motion estimator was subsequently analyzed in a stochastic setting. The relation between the motion estimator and the estimated velocity of an arbitrary point on the vehicle was explored. We derived how the covariance of the velocity estimate of an arbitrary point on the vehicle is related to the covariance of the motion estimate. We proved that there is one unique point on the vehicle for which the covariance of the estimated velocity is minimal. Next, we investigated how the local motion estimates of the individual AGVs can be combined to yield one global estimate. When the load and AGVs are rigidly interconnected, it suf??ces that each AGVs broadcasts its local motion estimate and receives the estimates of the other AGVs. When the load is semi-rigidly interconnected to the AGVs, e.g. by means of revolute or prismatic joints, then generally each AGV needs to broadcasts the corresponding information matrix as well. We showed that the information matrix remains constant when the load is connected to the AGV with a revolute joint that is mounted at the aforementioned unique point with the smallest velocity estimate covariance. This means that the corresponding AGV does not have to broadcast its information matrix for this special situation. The key issue in the control design for cooperative transportation tasks is that the various AGVs must not counteract each others' actions. The decentralized controller that we derived makes the AGVs track an externally provided planar motion setpoint while minimizing the interconnection forces between the load and the vehicles. Although the control design is applicable to cooperative transportation by multiple AGVs with arbitrary semi-rigid AGV-load interconnections, it is noteworthy that a particularly elegant solution arises when all interconnections are completely rigid. Then the derived local controllers have the same structure as the controllers that are normally used for individual operation. As a result, changing a few parameter settings and providing the AGVs with identical setpoints is all that is required to achieve cooperative behavior on the velocity level for this situation. The observer and controller designs for the case that the AGVs are completely rigidly interconnected to the load were successfully implemented on the two test vehicles. Experi ments were carried out with and without a load that consisted of a pallet with 300 kg pave stones. The results were reproducible and illustrated the practical validity of the observer and controller designs. There were no substantial drawbacks when the local observers used only their local sensor information, which means that our setup can also operate satisfactory when the velocity estimates are not shared with the other vehicles

    ASME Design Competition - Group H

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    This document presents our solution for the ASME pick-and-place design competition. In brief, the challenge is to collect balls from an arena and return them to a ‘home base’. The specifics of the competition are elaborated on within. The document walks through the design decisions that went into the prototype; the Goalkeeper concept that we ultimately landed on best solved the problems presented by the challenge statement as interpreted by our customer, Dr. James Jackson Potter. Several of the design choices were made by applying mathematical relationships, with the math and results included to illuminate our methods. We include a computer-aided design model that was used to plan construction, and an analysis of the device taking into account certain user impairments. We determine that the device is safe, and largely risk-free for even highly impaired users. The final prototype is built out of plywood and PVC to minimize device weight. It has two drive motors and two servo actuators to enable the collection and deposition of the balls, powered by an Arduino Uno microcontroller. The operator uses a PlayStation 4 controller to remotely control the device, with a button assignment chosen to be intuitive to a firsttime user. Photographs of the prototype are included

    Using a 2-D Simulation Program to Support Interactive Learning of 3-D Vehicle Dynamics

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    The author has developed an undergraduate course to introduce students to the basic principles of land vehicle dynamics. Many students, though they are intrinsically interested in the subject, have difficulty grasping the physical principles needed to enable a sufficient understanding of the subject to support their aspirations of making informed vehicle design decisions. An intriguing potentially useful fact is that the computer gaming world has developed widely available very sophisticated vehicle computer models with realistic human driver interfaces. However, while very entertaining, these computer games are not suitable for helping undergraduate engineering students understand the basic principles needed for land vehicle design. Therefore, as part of this course, the students develop their own dynamic models of vehicles (using Working Model 2D) starting with simplified quarter-vehicle suspension systems and working up to a steerable four-wheel drive vehicle traveling over a rough road. The innovation from an instructional standpoint is that students can get a good understanding of some three-dimensional effects, and thus the design principles derivable from this understanding, through employing a fairly simple to program and use widely available 2-D dynamic simulator software. The paper outlines the methodology for incorporating 3-D effects for land vehicle problems, and this methodology is illustrated with some specific examples

    Cooperative Object Transport in Multi-robot Systems:A Review of the State-of-the-Art

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    In recent years, there has been a growing interest in designing multi-robot systems (hereafter MRSs) to provide cost effective, fault-tolerant and reliable solutions to a variety of automated applications. Here, we review recent advancements in MRSs specifically designed for cooperative object transport, which requires the members of MRSs to coordinate their actions to transport objects from a starting position to a final destination. To achieve cooperative object transport, a wide range of transport, coordination and control strategies have been proposed. Our goal is to provide a comprehensive summary for this relatively heterogeneous and fast-growing body of scientific literature. While distilling the information, we purposefully avoid using hierarchical dichotomies, which have been traditionally used in the field of MRSs. Instead, we employ a coarse-grain approach by classifying each study based on the transport strategy used; pushing-only, grasping and caging. We identify key design constraints that may be shared among these studies despite considerable differences in their design methods. In the end, we discuss several open challenges and possible directions for future work to improve the performance of the current MRSs. Overall, we hope to increase the visibility and accessibility of the excellent studies in the field and provide a framework that helps the reader to navigate through them more effectivelypublishersversionPeer reviewe
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