Improving Safety on Construction Sites Using BIM-Based Dynamic Virtual Fences and Ultra-Wideband Technology

The identification of potential accidents on construction sites has been a major concern in the construction industry and it needs a proactive safety plan to reduce the risk of accidents. There are no efficient methods for checking if safety measures are taken properly on construction sites. Consequently, workers on site are not given enough awareness about dangerous areas. In addition, construction sites are dynamic and on-site situations are changing in terms of permanent and temporary structures and facilities. This information can be represented using Building Information Modeling (BIM). The present research aims to investigate a new method for the automatic generation of Dynamic Virtual Fences (DVFs) as part of a BIM-based prevention program for construction safety following the Safety Code of Quebec Provence in Canada. First, the Safety Code is reviewed to identify the information that has spatial aspects and can be represented in BIM. Then, a method is proposed for automatic identification of falling and collision risks to generate DVFs for them. In this method, workspaces are generated in BIM based on Work Breakdown Structure (WBS) deliverables, the project schedule, the dimensions of equipment, and the geometry of the building. One set of DVFs for collision prevention is generated based on the defined workspaces. Another set of DVFs is generated where physical barriers are needed for fall prevention. The generated DVFs are used coupled with Real-time Location System (RTLS) tracking of workers and physical fences to check safety requirements and to provide safety warnings

Function Design of Mechatronic Systems for Human-Robot Collaboration

Traditionally, robots have been caged off from human activity but, recently, improvements in advance robotic technology as well as the introduction of new safety standards, have allowed the possibility of collaboration between human workers and robotic systems. The introduction of Human-Robot Collaboration has the potential to increase the quality and the flexibility of the production process while improving the working condition of the operators. However, traditional industrial robots are typically characterized by small payload and small reachable workspace that reduce the range of possible applications. These drawbacks can overcome the advantages related to a collaborative task and make the collaboration not effective. This work aims at analyzing innovative mechatronic solutions capable of increasing the workspace and the versatility of the system with the final goal of creating effective collaborations with humans. Cable driven Parallel Robots (CDPRs) are considered a promising technology able to satisfy these requirements. In fact, compared to rigid serial and parallel robots, they have several advantages such as large workspaces, high payloads per unit of weight, ease of construction, versatility and affordable costs. This work presents two innovative solutions of CDPR able to enlarge the workspace, improve the versatility and reduce the collisions risk. The first solution consists of a cable-suspended parallel robot with a reconfigurable end-effector whereas the second solution is an innovative model of cable-driven micro-macro robot. In the first part of the thesis, the kinematic and dynamic models of these innovative systems are presented and analyzed in order to characterize their capability. Trajectory planning and optimal design are addressed with the purpose of maximizing the performance of the systems. The last part of the thesis deals with the design of a novel family of Intelligent CAble-driven parallel roBOTs whose architecture and control are conceived to maximize the robot versatility to the task to be performed and the environment in which the robot is intended to operate

Legged Robots for Object Manipulation: A Review

Legged robots can have a unique role in manipulating objects in dynamic, human-centric, or otherwise inaccessible environments. Although most legged robotics research to date typically focuses on traversing these challenging environments, many legged platform demonstrations have also included "moving an object" as a way of doing tangible work. Legged robots can be designed to manipulate a particular type of object (e.g., a cardboard box, a soccer ball, or a larger piece of furniture), by themselves or collaboratively. The objective of this review is to collect and learn from these examples, to both organize the work done so far in the community and highlight interesting open avenues for future work. This review categorizes existing works into four main manipulation methods: object interactions without grasping, manipulation with walking legs, dedicated non-locomotive arms, and legged teams. Each method has different design and autonomy features, which are illustrated by available examples in the literature. Based on a few simplifying assumptions, we further provide quantitative comparisons for the range of possible relative sizes of the manipulated object with respect to the robot. Taken together, these examples suggest new directions for research in legged robot manipulation, such as multifunctional limbs, terrain modeling, or learning-based control, to support a number of new deployments in challenging indoor/outdoor scenarios in warehouses/construction sites, preserved natural areas, and especially for home robotics.Comment: Preprint of the paper submitted to Frontiers in Mechanical Engineerin

Improving crane safety by agent-based dynamic motion planning using UWB real-time location system

The safe operation of cranes requires not only the experience of the operator, but also sufficient and appropriate support in real time. Due to the dynamic nature of construction sites, unexpected changes in the site layout may create new obstacles for the crane that can result in collisions and accidents. Limited research has been done on efficient re-planning for cranes with near real-time environment updating while considering communications between construction crews. To improve the safety of mobile crane operations and to provide more awareness on site, the present research proposes a near real-time monitoring and motion planning approach to improve crane safety on construction sites using an ultra wideband (UWB) real-time location system (RTLS) technology. In addition, an agent system framework is proposed to guide crane operators for safe crane operations by enhancing environment awareness and by providing intelligent re-planning. Location data are collected from tags attached to cranes and are processed by the agent system to identify the poses of dynamic objects, which is used to generate a new motion plan to guide the crane movement and thus to avoid potential collision. A motion planning algorithm, RRT-Con-Con-Mod, is proposed to efficiently generate safe and smooth paths for crane motions, mainly for the boom movement, while taking into account the engineering constraints and the path quality. A dynamic motion planning algorithm, DRRT-Con-Con-Mod, is proposed to ensure safety during the execution phase by quickly re-planning and avoiding collisions. In addition, an anytime algorithm is proposed to search for better solutions during a given time period by improving the path smoothness and by reducing the path execution time. The proposed algorithms are compared with other motion planning and re-planning algorithms. The results show that the proposed algorithms can quickly find a safe and smooth motion plan. Several tests of a UWB system have been applied in the laboratory and in indoor and outdoor environments to investigate the requirements of applying UWB on construction sites, that is, requirements including accuracy, visibility, scalability, and real-time. To satisfy these requirements, the configuration of the UWB system has been analyzed in detail to decide the sensors’ and tags’ locations and numbers based on heuristic rules. These tests show a good potential for using UWB tracking technology in construction sites by processing and organizing location data into useful information for near real-time environment updating. Furthermore, the framework of an agent system is proposed to integrate the proposed methodologies of motion planning and near real-time tracking. Different agents are created to represent the equipment, to coordinate tasks, and to update the site information. The functions of these agents include exchanging information, deciding priorities, etc. The current research will benefit the construction industry by providing more awareness of dynamic construction site conditions, a safer and more efficient work site, and more reliable decision support based on good communications

A hardware-in-the-loop testing facility for unmanned aerial vehicle sensor suites and control algorithms

In the past decade Unmanned Aerial Vehicles (UAVs) have rapidly grown into a major field of robotics in both industry and academia. Many well established platforms have been developed, and the demand continues to grow. However, the UAVs utilized in industry are predominately remotely piloted aircraft offering very limited levels of autonomy. In contrast, fully autonomous flight has been achieved in research, and the degree of autonomy continues to grow, with research now focusing on advanced tasks such as navigating cluttered terrain and formation ying.The gap between academia and industry is the robustness of control algorithms. Academic research often focuses on proof of concept demonstrations with little or no consideration to real world concerns such as adverse weather or sensor integration.One of the goals of this thesis is to integrate real world issues into the design process. A testing environment was designed and built that allows sensors and control algorithms to be tested against real obstacles and environmental conditions in a controlled, repeatable fashion. The use of this facility is demonstrated in the implementation of a safe landing zone algorithm for a robotic helicopter equipped with a laser scanner. Results from tests conducted in the testing facility are used to analyze results from ights in the field.Controlling the testing environment also provides a baseline to evaluate different control solutions. In the current research paradigm, it is difficult to determine which research questions have been solved because the testing conditions vary from researcher to researcher. A common testing environment eliminates ambiguities and allows solutions to be characterized based on their performance in different terrains and environmental conditions.This thesis explores how flight tests can be conducted in the lab using the actual hardware and control algorithms. The sensor package is attached to a 6 DOF gantry whose motion is governed by the dynamic model of the aircraft. To provide an expansive terrain over which the flight can be conducted, a scaled model of the environment was created.The the feasibility of using a scaled environment is demonstrated with a common sensor package and control task: using computer vision to guide an autonomous helicopter. The effcts of scaling are investigated, and the approach validated by comparing results in the scaled model to actual flights. Finally, it is demonstrated how the facility can be used to investigate the effect of adverse conditions on control algorithm performance. The overarching philosophy of this work is that incorporating real world concerns into the design process leads to more fully developed and robust solutions.Ph.D., Mechanical Engineering -- Drexel University, 201

Improving Maritime Prepositioning Force (MPF) offloads using modeling and simulation

The Marine Corps' Maritime Prepositioning Force (MPF) marries fly-in troops to their gear in an expeditionary environment. The arrival and assembly operation underneath this larger umbrella of MPF Operations proves itself a somewhat chaotic, definitively complex and dynamic logistics operation. From the moment the offload of the ship or ships begins when equipment and rolling stock exit the ships, until it ends as using units sign for their intended equipment, all personnel involved in this process--drivers, assistant drivers, heavy equipment handlers, crane operators, equipment managers--and all equipment involved present a flurry of activity that must be effectively managed, tracked, and optimized. Modeling, Virtual Environments, and Simulation, or MOVES, tools, aid in providing such capability. The creation of a Discrete Event Simulation (DES) using the open-source tool Viskit enables MPF planning, training, and analysis in its ability to portray the effects that size, amount of personnel support, and time have on the operation. Scenario Authoring and Visualization for Advanced Graphical Environments (Savage) comprises an archive of extensible three dimensional (3D) models that, when tied to the DES in an Extensible 3D (X3D) Graphics environment, enable the animation of the simulation, and when connected to real-world tracking data of the offload, allow for real-time visual tracking of this logistics process, creating a Common Operating Picture (COP) for the Arrival and Assembly Operations Group (AAOG).http://archive.org/details/improvingmaritim109453731US Marina Corps (USMC) author.Approved for public release; distribution is unlimited

Robot Manipulators

Robot manipulators are developing more in the direction of industrial robots than of human workers. Recently, the applications of robot manipulators are spreading their focus, for example Da Vinci as a medical robot, ASIMO as a humanoid robot and so on. There are many research topics within the field of robot manipulators, e.g. motion planning, cooperation with a human, and fusion with external sensors like vision, haptic and force, etc. Moreover, these include both technical problems in the industry and theoretical problems in the academic fields. This book is a collection of papers presenting the latest research issues from around the world

Design and Experimental Evaluation of a Hybrid Wheeled-Leg Exploration Rover in the Context of Multi-Robot Systems

With this dissertation, the electromechanic design, implementation, locomotion control, and experimental evaluation of a novel type of hybrid wheeled-leg exploration rover are presented. The actively articulated suspension system of the rover is the basis for advanced locomotive capabilities of a mobile exploration robot. The developed locomotion control system abstracts the complex kinematics of the suspension system and provides platform control inputs usable by autonomous behaviors or human remote control. Design and control of the suspension system as well as experimentation with the resulting rover are in the focus of this thesis. The rover is part of a heterogeneous modular multi-robot exploration system with an aspired sample return mission to the lunar south pole or currently hard-to-access regions on Mars. The multi-robot system pursues a modular and reconfigurable design methodology. It combines heterogeneous robots with different locomotion capabilities for enhanced overall performance. Consequently, the design of the multi-robot system is presented as the frame of the rover developments. The requirements for the rover design originating from the deployment in a modular multi-robot system are accentuated and summarized in this thesis