Tolerance dataset: mating process of plug-in cable connectors for wire harness assembly tasks

In this research, we studied the mating tolerance of various plug-in cable connectors and provide a mating tolerance dataset of 70 different connectors. This dataset will be highly advantageous to industries for wire harness assembly tasks using robots. Understanding the mating tolerance is crucial for automating the mating process because it is closely related to the control specifications of a robotic manipulator. Our system uses a 2-finger Robotiq adaptive gripper attached to a 6 degree-of-freedom industrial robot (ABB Robotics) to test the mating process of wire harness assembly tasks. In addition, we use 70 types of wire harness connectors with different numbers of pins widths, lengths, and thicknesses, and various shapes, to test the mating tolerance. The results indicate that the connector mating tolerance of our dataset is more generous than the repeatability of conventional industrial manipulators, and further demonstrate the suitability of the position control methods to wire harness assembly tasks.

     

RUR53: an unmanned ground vehicle for navigation,recognition, and manipulation

ABSTRACT

This paper proposes RUR53: an Unmanned Ground Vehicle able to navigate through, identify, and reach areas of interest. There, it can recognize, localize, and manipulate work tools to perform both indoor and outdoor complex tasks. Indeed, a wide range of sensors composes the robot and enables it to perceive vast workspaces, reach distant targets, and face the uncertainties of the real world. Precise object detection is also guaranteed, essential to manipulate objects of different shapes and materials. Moreover, a customized 3-finger gripper makes the gripping mode suitable for any lightweight object. Two modalities are proposed: autonomous and teleoperated, letting both unskilled and skilled human operators easily adapt the system to complete personalized tasks. The paper exhaustively describes RUR53 architecture and demonstrates its good performance while executing both indoor and outdoor navigation and manipulation tasks. A specific case study is described where the proposed modular architecture allows to easily switch to a semi-teleoperated mode: the 2017 Mohamed Bin Zayed International Robotics Challenge, where our team ranked third in the Grand Challenge in collaboration with the Czech Technical University in Prague, the University of Pennsylvania, and the University of Lincoln (UK).     

Diminishing returns of engineering effort in telerobotic systems

Robotic systems range from teleoperated to fully autonomous (where no human intervention takes place). The word “telerobotic” describes robotic systems which, although guided by a human, have a degree of autonomous behavior. This paper examines the tradeoff between the increasing design and implementation effort necessary as the system moves through the continuum from teleoperated to autonomous and the amount of human interaction required. A case study of a human “shepherd” interacting with a robotic “sheepdog” which directs a robotic “sheep” is used     

Intelligent robotic gripper with adaptive grasping force

The on-off control robot gripper is widely employed in pick-and-place operations in Cartesian space for handling hard objects between two positions. Without contact force monitoring, it can not be applied in fragile or soft objects handling. Although, an appropriate grasping force or gripper opening for each target could be searched by trial-and-error process, it needs expensive force/torque sensor or an accurate gripper position controller. It has too expensive and complex control strategy disadvantages for most of industrial applications. In addition, it can not overcome the target slip problem due to mass uncertainty and dynamic factor. Here, an intelligent gripper is designed with embedded distributed control structure for overcoming the uncertainty of object’s mass and soft/hard features. A communication signal is specified to integrate both robot arm and gripper control kernels for executing the robotic position control and gripper force control functions in sequence. An efficient model-free intelligent fuzzy sliding mode control strategy is employed to design the position and force controllers of gripper, respectively. Experimental results of pick-and-place soft and hard objects with grasping force auto-tuning and anti-slip control strategy are shown by pictures to verify the dynamic performance of this distributed control system. The position and force tracking errors are less than 1 mm and 0.1 N, respectively.

     

Teleoperated equipment for emergency response applications at the savannah river site

The Robotics Development Group (RDG) of the Westinghouse Savannah River Company (WSRC) is developing an array of teleoperated vehicles and support equipment to be used in emergency response applications. Teleoperators have been used to monitor and map radiation areas, perform decontamination tasks, and handle radioactive material. Other possible scenarios include video surveillance, remote sensing, and fire fighting. The primary justification for developing teleoperated vehicles and support hardware is to eliminate or significantly reduce personnel exposure to radioactive or other hazardous activities. This article discusses past, present, and future applications that use teleoperated equipment and current development work on several mobile teleoperators at the U.S. Department of Energy's (DoE) Savannah River Site (SRS).     

A low-cost internet-based telerobotic system for access to remote laboratories

This paper presents an account of the design of a low-cost Internet-based teleoperation system implemented on China's Internet. Using a multimedia-rich human-computer interface, combining predictive displays and graphical overlays, a series of simple tasks were performed within a simulated space environment scenario. Internet clients anywhere can monitor the robotic workspace, talk with technicians, and control the Arm/Hand integrated system with 15 DOF located in lab to perform tasks (such as grasping a vessel, pouring a liquid, and peg-in-hole assembling, etc.). Our main contributions are to establish a foundation for teleoperated science and engineering research, and we have addressed some issues involving the time-delay associated with the Internet. We also developed several key software adaptation technologies and products used for Internet-Based teleoperation, compatible with the BH-III dexterous hand, BH1 6-DOF mechanical arm and five-finger 11-DOF data glove, constructed in our laboratory. This system has been successfully tested and applied in remote robotic education (Virtual Laboratories) system via China's Internet using our Master/Slave architecture, which combines mixed modes of remote monitor/manipulate and local autonomous control.     

Iterative design of a semi-autonomous social telepresence robot research platform: a chronology

Our research focuses on how a telepresence robot operator, the people with the robot, and the robot itself collaborate so that the operator reaches his/her intended destination. Our research requires higher levels of autonomous navigation so that the robot can, for example, go to a specified destination and follow a person. However, commercial telepresence robots are primarily teleoperated, and only a few provide assisted navigation around obstacles. Our system must include sensors and processing to enable these capabilities. We present the chronology of our iterative design for augmenting two VGo Communications’ VGo robots, Hugo and Margo, over a period of 3 years. We detail the requirements and design constraints encountered while developing our telepresence robot platforms.     

自动钻机的自诊断体系

针对钻机的特点，首先提出钻机故障诊断的概念体系，结合遥控系统，建立了机器人化自动钻机全方位故障检测与故障定位体系，并由软硬件系统实现．该自动钻机已由“８６３”专家委正式验收．     

Design and kinetostatic modeling of a compliant gripper for grasp and autonomous release of objects

A gripper with an embedded compliant bistable mechanism (BM) for gripping and autonomous release of objects is developed. Due to adhesion forces, objects might stick to the end effector of a gripper upon release, where a shaking operation may be employed to release the objects. Vibration of the end effector induced by an impact pestle adjacent to the shuttle mass of the BM may achieve autonomous release of objects adhered to the end effector. Gripping and autonomous release of objects are accomplished when the BM moves between its two stable equilibrium positions. An analytical model is developed to predict the kinetostatic behavior of the BM and to assist in the design of the gripper.     

Guidance and nonlinear control system for autonomous flight of minirotorcraft unmanned aerial vehicles

Small unmanned aerial vehicles (UAVs) are becoming popular among researchers and vital platforms for several autonomous mission systems. In this paper, we present the design and development of a miniature autonomous rotorcraft weighing less than 700 g and capable of waypoint navigation, trajectory tracking, visual navigation, precise hovering, and automatic takeoff and landing. In an effort to make advanced autonomous behaviors available to mini‐ and microrotorcraft, an embedded and inexpensive autopilot was developed. To compensate for the weaknesses of the low‐cost equipment, we put our efforts into designing a reliable model‐based nonlinear controller that uses an inner‐loop outer‐loop control scheme. The developed flight controller considers the system's nonlinearities, guarantees the stability of the closed‐loop system, and results in a practical controller that is easy to implement and to tune. In addition to controller design and stability analysis, the paper provides information about the overall control architecture and the UAV system integration, including guidance laws, navigation algorithms, control system implementation, and autopilot hardware. The guidance, navigation, and control (GN&C) algorithms were implemented on a miniature quadrotor UAV that has undergone an extensive program of flight tests, resulting in various flight behaviors under autonomous control from takeoff to landing. Experimental results that demonstrate the operation of the GN&C algorithms and the capabilities of our autonomous micro air vehicle are presented. © 2009 Wiley Periodicals, Inc.     

Portable compact suction pad unit for parallel grippers

This paper proposes a portable compact suction pad unit for the parallel grippers of a mobile manipulation robot to place items for product display. In addition, this paper includes verification of the unit’s mechanism. Given that robots have to hold various items, we propose an operation method by which the parallel gripper holding the compact suction pad unit switches between a pinching mode and a vacuum suction mode depending on the item being placed. The compact suction pad unit is self-contained, with all the devices necessary for the suction operation inside the unit. The suction operation is switched on and off wirelessly by an external host system controller. The compact suction pad unit produced a suction force of about 5.6?N at an allowable inclination angle of 15°. We demonstrated in a competition that our proposed operation method of the compact suction pad unit is useful by having it place a beverage in a cup with lid and a boxed lunch.     

A technology transfer journey to a model-driven access control system

In the model-driven security domain, access control systems provide an application for handling access of persons through controlled gates. A gate, such as a door, can have a lock mechanism for securing the area from unauthorized access. Most commercial solutions for access control management offer pre-packaged software systems where customization of the authorization logic is either not allowed or subject to payment. Moreover, cross-platform development is a barrier for solution providers due to the high cost of development and maintenance that it implies. To overcome these limitations and further optimize the entire access control systems development process, we propose a model-driven approach that supports automatic code generation to enable communication between an IoT infrastructure and platforms for Facility Access Management. Specifically, the approach combines the benefits of Near-Field Communication (NFC) and Tinkerforge (i.e., an open-source hardware platform) with model-driven techniques. This allows the approach to exploit both behavioral and structural models for the modeling and the consequent code generation of part of the authorization mechanism, thus providing complete coverage of the code generated for the whole system. We implemented and evaluated our approach in a real-world case study within the premises of a fitness center with an IoT infrastructure consisting of several heterogeneous sensors by showing its practical applicability. Experimental results demonstrate the effectiveness of our approach in supporting abstraction and automation concerning traditional code-centric development through code generation features. Consequently, our approach makes the whole development process less time-consuming and error-prone, thus reducing the system’s time to market.

     

Static grip selection for robot-based automated assembly systems

In this article we present an algorithmic approach to determine the suitable grasp of an object in an automated assembly environment. The algorithm is based on the available object surfaces and the initial and final task constraints and gripper characteristics. If the imposed task and gripper constraints do not allow a possible grasp, intermediate motions may need to be made to reorient the part. Once a set of possible grasps which statisfy task and gripper constraints are found, the stability of each grasp is analyzed using screw theory. An optimal grasp is one which minimizes the grasping forces over the possible set of grasps. Results utilizing our methodology are presented. Our method can be interfaced with CAD database such as a solid modelling system based on boundary representation for automatic selection of grasping configurations.     

Real-time behavior-based robot control

Behavior-based systems form the basis of autonomous control for many robots, but there is a need to ensure these systems respond in a timely manner. Unexpected latency can adversely affect the quality of an autonomous system’s operations, which in turn can affect lives and property in the real-world. A robots ability to detect and handle external events is paramount to providing safe and dependable operation. This paper presents a concurrent version of a behavior-based system called the Real-Time Unified Behavior Framework, which establishes a responsive basis of behavior-based control that does not bind the system developer to any single behavior hierarchy. The concurrent design of the framework is based on modern software engineering principles and only specifies a functional interface for components, leaving the implementation details to the developers. In addition, the individual behaviors are executed by a real-time scheduler, guaranteeing the responsiveness of routines that are critical to the autonomous system’s safe operation. Experimental results demonstrate the ability of this approach to provide predictable temporal operation, independent of fluctuations in high-level computational loads.     

Active object tracking using context estimation: handling occlusions and detecting missing targets

When performing visual servoing or object tracking tasks, active sensor planning is essential to keep targets in sight or to relocate them when missing. In particular, when dealing with a known target missing from the sensor’s field of view, we propose using prior knowledge related to contextual information to estimate its possible location. To this end, this study proposes a Dynamic Bayesian Network that uses contextual information to effectively search for targets. Monte Carlo particle filtering is employed to approximate the posterior probability of the target’s state, from which uncertainty is defined. We define the robot’s utility function via information theoretic formalism as seeking the optimal action which reduces uncertainty of a task, prompting robot agents to investigate the location where the target most likely might exist. Using a context state model, we design the agent’s high-level decision framework using a Partially-Observable Markov Decision Process. Based on the estimated belief state of the context via sequential observations, the robot’s navigation actions are determined to conduct exploratory and detection tasks. By using this multi-modal context model, our agent can effectively handle basic dynamic events, such as obstruction of targets or their absence from the field of view. We implement and demonstrate these capabilities on a mobile robot in real-time.

     

A User-Configurable Hypermedia-Based Interface Via the Functional Model of the Link

Hypermedia management systems often make use of database management systems for the persistent storage of links and of the linked information components. In this paper, we argue that a hypermedia management system with its support for reader-directed navigation provides an attractive type of database system interface in that it facilitates ease of database access or more specifically, of locating (‘discovering’) relevant information.

Furthermore, our approach to hypermedia management, based on the Functional Model of the link, provides for extensive user-configurability of that interface. This configurability particularly applies to fully dynamic links, which free the user from much of the link creation and maintenance duties.

A prototype system incorporating this approach is overviewed in this paper.     

可视化移动抓取设备的研究与实现

在诸如污染物泄露、排爆现场、狭小作业空间等不宜人员出现的危险场景中,可远程控制并且能将现场图像传输回操作人员眼前的设备尤为重要。现有的此类设备中,其特点多为履带式底盘,越障能力强;附带可控机械抓手、视频采集与传输单元;各个单元之间的依赖性较高,需要运行在一个稳定的操作系统上。机器人操作系统ROS对现有传感器数据类型进行了分类封装、定义了各个功能节点程序之间的通讯方式,能有效组织机器人运动、控制、传感器数据采集等各个功能之间的协调稳定运行。在ROS的基础上设计了一台具有图像传输、可控抓手、运送物体功能的可视化移动抓取设备,并构造了一台具有完整功能的设备样车。