Planning and control of robotic manipulation actions for extreme environments

A large societal and economic need arises for advanced robotic capabilities, where we need to perform complex human-like tasks such as tool-use, in environments that are hazardous for human workers. This thesis addresses a collection of problems, which arise when robotic manipulators must perform complex tasks in cluttered and constrained environments. The work is illustrated by example scenarios of robotic tool use, grasping and manipulating, motivated by the challenges of dismantling operations in the extreme environments of nuclear decommissioning Contrary to popular assumptions, legacy nuclear facilities (which can date back three-quarters of a century in the UK) can be highly unstructured and uncertain environments, with insufficient a-priori information available for e.g. conventional pre-programming of robot tasks. Meanwhile, situational awareness and direct teleoperation can be extremely difficult for human operators working in a safe zone that is physically remote from the robot. This engenders a need for significant autonomous capabilities. Robots must use vision and sensory systems to perceive their environment, plan and execute complex actions on complex objects in cluttered and constrained environments. Significant radiation, of different types and intensities, provides further challenges in terms of sensor noise. Perception uncertainty can also result from e.g. vision systems observing shiny featureless metal structures. Robotic actions therefore need to be: i) planned in ways that are robust to uncertainties; and ii) controlled in ways which enable the robust reaction to disturbances. In particular, we investigate motion planning and control in tasks where the robot must: maintain contact while moving over arbitrarily shaped surfaces with end-effector tools; exert forces and withstand perturbations during forceful contact actions; while also avoiding collisions with obstacles; avoiding singularity configurations; and increasing robustness by maximising manipulability during task execution. Furthermore, we consider the issues of robust planning and control with respect to uncertain information, derived from noisy sensors in challenging environments. We explore the Riemannian geometry and robot's manipulability to yield path planners that produce paths for both fixed-based and floating-based robots, whose tools always stay in contact with the object's surface. Our planners overcome disturbances in the perception and account for robot/environment interactions that may demand unexpected forces. The task execution is entrusted to a hybrid force/motion controller whose motion space behaves with compliance to accommodate unexpected stiffness changes throughout the contact. We examine the problem of grasping a tool for performing a task. Firstly, we introduce a method for selecting the grasp candidate onto an object yielding collision-free motion for the robot in the post-grasp movements. Furthermore, we study the case of a dual-arm robot performing full-force tasks on an object and slippage on the grasping is allowed. We account for the slippage throughout the task execution using a novel controller based on the sliding mode controllers

Research on a semiautonomous mobile robot for loosely structured environments focused on transporting mail trolleys

In this thesis is presented a novel approach to model, control, and planning the motion of a nonholonomic wheeled mobile robot that applies stable pushes and pulls to a nonholonomic cart (York mail trolley) in a loosely structured environment. The method is based on grasping and ungrasping the nonholonomic cart, as a result, the robot changes its kinematics properties. In consequence, two robot configurations are produced by the task of grasping and ungrasping the load, they are: the single-robot configuration and the robot-trolley configuration. Furthermore, in order to comply with the general planar motion law of rigid bodies and the kinematic constraints imposed by the robot wheels for each configuration, the robot has been provided with two motorized steerable wheels in order to have a flexible platform able to adapt to these restrictions. [Continues.

Theory and Synthesis of the Imbalance Organism

The long term goal of this initiative is to establish a technology that will enable the development of practical and useful nonbiological entities for the real world. The reasoning behind the specific word choice used here (e.g., practical, useful, nonbiological) will be outlined in this document. Specific word choice is extremely important within this document and, as such, the terminology used is chosen to convey a specific meaning and done so for the sake of clarity. Clarity is of the utmost importance when it comes to Robotics. As what is common knowledge in engineering, it is difficult to achieve success if one is not clear about what one is aiming at, what the objectives are, what the problem is that needs to be solved. As well, it is imperative to compare apples with apples. When diving into a world as complex as the biological, clarity is a prerequisite before we can start to argue and compare. Hence, the reader will find below that much time is spent on defining as clearly as possible the terminology used. This project brings to a conclusion the first phase of the long term goal. In other words, this document presents the work that has been done from when the first concepts took shape until the present day (a period of roughly two years). With respect to time scales and effort, it is predicted that the majority of the work still lies ahead

The Development of a Multi-arm Mobile Robot System for Nuclear Decommissioning Applications.

This PhD thesis is based in the field of robotics and introduces a case study of the design and development of a multi-arm mobile robot system for nuclear decommissioning (MARS-ND). A key premise underlying the research was to develop intelligence in the robot that is similar to the cooperation and communication between the human brain and its two arms; hence the human body was adopted as the starting point to establish the size and functionality of the proposed system. The approach adopted for this research demonstrates the development, integration and configuration of a multi-arm robot system which consists of two human armlike off-the-shelf manipulators whose joints are controlled using potentiometer sensors and hydraulic actuators. Using the manipulators' sensor feedback, a wide variety of complex tasks found in the rapidly expanding field of nuclear decommissioning can be undertaken. The thesis also considers the issue of collaboration, collision detection and collision avoidance between the two arms of MARS-ND. As part of the final stage of this research the author participated in a collaborative research project with the Sugano Laboratory at Waseda University, Tokyo, Japan. The three major research issues addressed in this thesis are: 1. The selection and integration of off-the-shelf hardware in the development of MARS-ND using the latest technology available for robotic systems 2. The creation of a suitable control system for the robot arms; and the building of an advanced, user-friendly interface between the robot system and the host computer 3. The investigation and implementation of collaboration, coordinated motion control and collision detection & avoidance techniques for the robot arms The hardware and software integration for the whole robotic system is explained with the proposed software architecture and the use of National Instruments (NI) functions and tools to control the movement of the arm joints and the performance of a selected decommissioning task. This thesis also examines the operational software applied within the research through its discussion of four interlinked areas: 1. The control software and hardware interface for the MARS-ND and the controller architecture 2. The application of an NI Compact FieldPoint controller and FieldPoint I/O modules to facilitate wireless communication between the Multi-Arm Mobile Robot system and the user interface in the host PC 3. The use of Measurement and Automation Explorer (MAX) and LabVIEW software tools for calibration and the building of user interfaces required for sending and receiving the signals needed to control the robot arm joints accurately 4. The application of a PID toolkit in LabVIEW for the design of a simple PID controller for the individual arm joints with a potentiometer sensor fitted inside each joint in order to provide a feedback signal to the controller The thesis concludes that MARS-ND is a good example of a robotic system specifically designed for hazardous nuclear decommissioning applications. It demonstrates the complexity of such a system from a number of aspects such as the need for mobility, control, sensor and system design, and integration using modem tools that are available off-the-shelf. In addition the use of these modern tools allows a single mechatronics engineer to design, integrate, interface and build a motion control system for MARS-ND as compared to the traditional way of building a similar robot by a team of specialised engineers. The contribution this research makes to the design and building of multi-arm robot system for nuclear decommissioning industry concerns its size and mobility using a mobile platform to transport the multi-arm robot system. In addition links have been made between Lancaster University and Waseda University in the context of the development of multi-arm robot systems

Special oils for halal and safe cosmetics

Three types of non conventional oils were extracted, analyzed and tested for toxicity. Date palm kernel oil (DPKO), mango kernel oil (MKO) and Ramputan seed oil (RSO). Oil content for tow cultivars of dates Deglect Noor and Moshkan was 9.67% and 7.30%, respectively. The three varieties of mango were found to contain about 10% oil in average. The red yellow types of Ramputan were found to have 11 and 14% oil, respectively. The phenolic compounds in DPKO, MKO and RSO were 0.98, 0.88 and 0.78 mg/ml Gallic acid equivalent, respectively. Oils were analyzed for their fatty acid composition and they are rich in oleic acid C18:1 and showed the presence of (dodecanoic acid) lauric acid C12:0, which reported to appear some antimicrobial activities. All extracted oils, DPKO, MKO and RSO showed no toxic effect using prime shrimp bioassay. Since these oils are stable, melt at skin temperature, have good lubricity and are great source of essential fatty acids; they could be used as highly moisturizing, cleansing and nourishing oils because of high oleic acid content. They are ideal for use in such halal cosmetics such as Science, Engineering and Technology 75 skin care and massage, hair-care, soap and shampoo products

Development of an assisted-teleoperation system for a dual-manipulator nuclear decommissioning robot

This thesis concerns a robotic platform that is being used for research into assisted tele–operation for common nuclear decommissioning tasks, such as remote handling and pipe cutting. The machine consists of dual, seven–function, hydraulically actuated HYDROLEK manipulators mounted (in prior research) on a mobile BROKK base unit. Whilst the original system was operated by remote control, the present thesis focusses on the development of a visual servoing system, in which the user selects the object of interest from an on–screen image, whilst the computer control system determines and implements via feedback control the required position and orientation of the manipulators. Novel research contributions are made in three main areas: (i) the development of a detailed mechanistic model of the system; (ii) the development and preliminary testing in the laboratory of the new assisted–teleoperation user interface; and (iii) the development of improved control systems for joint angle set point tracking, and their systematic, quantitative comparison via simulation and experiment. The mechanistic model builds on previous work, while the main novelty in this thesis relates to the hydraulic component of the model, and the development and evaluation of a multi–objective genetic algorithm framework to identify the unknown parameter values. To improve on the joystick direct teleoperation currently used as standard in the nuclear industry, which is slow and requires extensive operator training, the proposed assisted–teleoperation makes use of a camera mounted on the robot. Focussing on pipe cutting as an example, the new system ensures that one manipulator automatically grasps the user–selected pipe, and appropriately positions the second for a cutting operation. Initial laboratory testing (using a plastic pipe) shows the efficacy of the approach for positioning the manipulators, and suggests that for both experienced and inexperienced users, the task is completed significantly faster than via tele-operation. Finally, classical industrial, fuzzy logic, and novel state dependent parameter approaches to control are developed and compared, with the aim being to determine a relatively simple controller that yields good performance for the hydraulic manipulators. An improved, more structured method of dealing with the dead–zone characteristics is developed and implemented, replacing the rather ad hoc approach that had been utilised in previous research for the same machine