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@font-face { font-family: "TimesNewRoman"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; } Teleoperated task execution for hazardous environments is slow and requires highly skilled operators. Attempts to implement telerobotic assists to improve efficiency have been demonstrated in constrained laboratory environments but are not being used in the field because they are not appropriate for use on actual remote systems operating in complex unstructured environments using typical operators. This work describes a methodology for combining select concepts from behavior-based systems with telerobotic tool control in a way that is compatible with existing manipulator architectures used by remote systems typical to operations in hazardous environment. The purpose of the approach is to minimize the task instance modeling in favor of a priori task type models while using sensor information to register the task type model to the task instance. The concept was demonstrated for two tools useful to decontamination & dismantlement type operations—a reciprocating saw and a powered socket tool. The experimental results demonstrated that the approach works to facilitate traded control telerobotic tooling execution by enabling difficult tasks and by limiting tool damage. The role of the tools and tasks as drivers to the telerobotic implementation was better understood in the need for thorough task decomposition and the discovery and examination of the tool process signature. The contributions of this work include: (1) the exploration and evaluation of select features of behavior-based robotics to create a new methodology for integrating telerobotic tool control with positional teleoperation in the execution of complex tool-centric remote tasks, (2) the simplification of task decomposition and the implementation of sensor-based tool control in such a way that eliminates the need for the creation of a task instance model for telerobotic task execution, and (3) the discovery, demonstrated use, and documentation of characteristic tool process signatures that have general value in the investigation of other tool control, tool maintenance, and tool development strategies above and beyond the benefit sustained for the methodology described in this work.

This report describes a docking system to allow autonomous battery charging of a mobile robot, and a Web interface that allows long-term unaided use of a sophisticated mobile robot by untrained Web users around the world. The docking system and Web interface are applied to the biologically inspired RatSLAM system as a foundation for testing both its long-term stability and its practicality for real-world applications. While there are existing battery charging and Web interface systems for mobile robots, the developed solution combines the two, resulting in a self-sufficient robot that can recharge its own batteries and stay accessible from the Web. Existing mobile robots on the Internet require manual charging by a human operator, leading to significant periods when the robot is offline. Furthermore, since the robot may be operational for extended periods without powering down, it may perform learning operations that require significantly longer operation than a single battery-recharge cycle would allow. The implemented Web interface makes use of the RatSLAM navigation system. RatSLAM provides the onboard intelligence for the robot to navigate to the user-supplied goal locations (such as “go to location X”), despite long paths or obstacles in the environment. The majority of the existing robot interfaces on the Internet provide direct control of the robot (such as “drive forward”) and therefore the users suffer greatly from the inherent delays of the Internet due to the time lag between performing an action and seeing the feedback. Instead, the robot in this study uses an onboard intelligent navigation system to generate all low-level commands. Due to the minimal input required to give high-level commands to the robot, the system is robust to the long and highly unpredictable delays of Internet communication. Traditional methods of autonomous battery charging for mobile robots have had limited reliability, often due to the mechanical docking system requiring a highly precise connection. Therefore, the mechanical design of the implemented battery charging system improves reliability by allowing for a significantly larger navigation error. In addition, the robot uses a standard vision sensor for both the long-range and short-range stages of navigation to the battery charger, compared to the many systems that require an omnidirectional camera and a high-resolution Laser range finder for this process. The result of this study is a public web interface at "http://ratslam.itee.uq.edu.au/robot.html" (currently offline), where any Web user in the world can watch and control the live mobile robot that is using RatSLAM for navigation, as it drives in its laboratory environment without human assistance.

During last decades, the Internet teleobotics has been growing at an enormous ratedue to the rapid improvement of Internet technology. This paper presents theinternet-based remote control of mobile robot. To face unpredictable Internet delaysand possible connection rupture, a direct continuous control based teleoperationarchitecture with “Speed Limit Module” (SLM) and “Delay Approximator” (DA) isproposed. This direct continuous control architecture guarantees the path error of therobot motion is restricted within the path error tolerance of the application.Experiment results show the feasibility and effectiveness of this direct Internet controlarchitecture in the real Internet environment.

A graphical user interface program was created along with shape models, which allow persons with disabilities to set up a stereovision system with off-the-shelf hardware and detect objects of interest, which can be picked up using a sensor assisted telerobotic manipulator. A Hitachi KP-D50 CCD camera and an Imaging Source CCD camera were used along with two Imaging Source DFG/LC1 frame grabbers to set up a stereovision system. In order to use the stereovision system, the two main problems of correspondence and reconstruction are solved using subroutines of the program created for this work.The user interface allows the user to easily perform the intrinsic and extrinsic camera calibration required for stereovision, by following a few basic steps incorporated into the user interface program, which are described in this thesis. A calibration table required for these tasks can also be easily created using the program. In order to detect the object of interest, shape models, created by the user interface program, are used to solve the correspondence problem of stereovision. The correspondence problem is that of locating corresponding points in the left eye and the right eye, which are necessary to perform the calculations to obtain the location of the object of interest with respect to the end-effector. The shape models created for some commonly available items such as a doorknob and a door handle are included in the program and used to test the stereovision system. As expected, the error of detection decreases as the stereo system is moved closer to the object of interest in the x-, y- and z-position.

Human-machine cooperative or co-robotics has been recognized as the next generation of robotics. In contrast to current systems that use limited-reasoning strategies or address problems in narrow contexts, new co-robot systems will be characterized by their flexibility, resourcefulness, varied modeling or reasoning approaches, and use of real-world data in real time, demonstrating a level of intelligence and adaptability seen in humans and animals. The research I focused is in the two sub-field of co-robotics: teleoperation and telepresence. We firstly explore the ways of teleoperation using mixed reality techniques. I proposed a new type of display: hybrid-reality display (HRD) system, which utilizes commodity projection device to project captured video frame onto 3D replica of the actual target surface. It provides a direct alignment between the frame of reference for the human subject and that of the displayed image. The advantage of this approach lies in the fact that no wearing device needed for the users, providing minimal intrusiveness and accommodating users eyes during focusing. The field-of-view is also significantly increased. From a user-centered design standpoint, the HRD is motivated by teleoperation accidents, incidents, and user research in military reconnaissance etc. Teleoperation in these environments is compromised by the Keyhole Effect, which results from the limited field of view of reference. The technique contribution of the proposed HRD system is the multi-system calibration which mainly involves motion sensor, projector, cameras and robotic arm. Due to the purpose of the system, the accuracy of calibration should also be restricted within millimeter level. The followed up research of HRD is focused on high accuracy 3D reconstruction of the replica via commodity devices for better alignment of video frame. Conventional 3D scanner lacks either depth resolution or be very expensive. We proposed a structured light scanning based 3D sensing system with accuracy within 1 millimeter while robust to global illumination and surface reflection. Extensive user study prove the performance of our proposed algorithm. In order to compensate the unsynchronization between the local station and remote station due to latency introduced during data sensing and communication, 1-step-ahead predictive control algorithm is presented. The latency between human control and robot movement can be formulated as a linear equation group with a smooth coefficient ranging from 0 to 1. This predictive control algorithm can be further formulated by optimizing a cost function. We then explore the aspect of telepresence. Many hardware designs have been developed to allow a camera to be placed optically directly behind the screen. The purpose of such setups is to enable two-way video teleconferencing that maintains eye-contact. However, the image from the see-through camera usually exhibits a number of imaging artifacts such as low signal to noise ratio, incorrect color balance, and lost of details. Thus we develop a novel image enhancement framework that utilizes an auxiliary color+depth camera that is mounted on the side of the screen. By fusing the information from both cameras, we are able to significantly improve the quality of the see-through image. Experimental results have demonstrated that our fusion method compares favorably against traditional image enhancement/warping methods that uses only a single image.

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Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Telerobotics is a field of robotics interested in controlling robots from a distance. Incorporating visual and haptic (touch) feedback allows the operator greater accuracy in manipulating objects in a remote environment. This project endeavours to develop a telerobotic system by using two similar industrial robotic manipulators, one acting as a haptic input device (known as the Master), the other as the telerobot (known as the Slave). This project makes use of a diverse range of technologies to achieve a telerobotic system. As such it makes use of Systems Engineering and Technology Management principles to guide the development process of converting standard industrial robots into a telerobotic system that allows the operator to “see” and “feel” in the remote environment. The ability of the robot to perceive touch is accomplished by incorporating a multi-axis force and torque sensor to both industrial robots to measure any applied force or torque acting on each robot’s end-effector. A communication system is developed that receives the force and torque readings from each sensor as well as transmit the robot instructions to both Master and Slave. Haptic feedback is achieved by combining the force and torque readings from both sensors within a control system before manipulating the data into a robot instruction that is used to control both Master and Slave. Testing of the developed telerobotic system indicates that a functional system has been developed. However, several issues were identified that limit the control capabilities the operator has over the Slave and as such could lead to safety concerns. / AFRIKAANSE OPSOMMING: Telerobotika is ’n veld van robotika wat belangstel in die beheer van robotte oor ’n afstand. Die insluiting van visuele en hapties (voel) terugvoer stel die operateur instaat om voorwerpe in ’n afgeleë omgewing met hoër akkuraatheid te manipuleer. Hierdie projek streef daarna om ’n telerobotiese stelsel te ontwikkel deur gebruik te maak van twee soortgelyke industriële robot manipuleerders, een wat optree as ’n meganiese invoer toestelle (bekend as die Meester), die ander as die telerobot (bekend as die Slaaf). Hierdie projek maak gebruik van ’n verskeidenheid van tegnologieë om ’n telerobotiese stelsel te ontwikkel. Sodanig word tegnologie bestuur en stelsels ingenieurswese beginsels deur die loop van die projek geïmplementeer om die ontwikkelings proses te lei - van standaard industriële robotte tot ’n telerobotiese stelsel wat dit moontlik maak vir die operateur om te “sien” en “voel” in ’n afgeleë omgewing. Die robot se vermoë om fisiese kontak te ervaar word bereik deur middel van ’n multi-as krag en torsie sensor wat aan beide industriële robotte toegepas word. ’n Kommunikasie stelsel is ontwikkel wat die krag en torsie lesings van beide sensors kan ontvang sowel as die robot instruksies na elke robot (Meester en Slaaf) kan stuur. Haptiese terugvoer word bereik deur die krag en torsie lesings van beide sensors te kombineer in ’n beheer stelsel voordat dit verder gemanipuleer word in die form van ’n robot instruksie wat gebruik word vir die beheer van beide Meester en Slaaf. Toetsing van die ontwikkelde telerobotiese stelsel dui aan dat ’n funksionele stelsel ontwikkel is. Daar is egter verskeie kwessies geïdentifiseer wat die operateur se beheer vermoeëns oor die Slaaf beperk wat sodoende na veiligheids kwessies kan lei.

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<p>Have a nice day :)</p> / <p>This thesis presents a unified framework for coordination and control of human-in-the-loop asymmetric semi-autonomous robotic systems. It introduces a highly general teleoperation system configuration involving any number of operators, haptic interfaces, and robots with possibly different degrees of mobility. The proposed framework allows for mixed teleoperation/autonomous control of user-defined subtasks by establishing position/force tracking as well as kinematic constraints among relevant <em>teleoperation control frames</em>. Three layers of velocity-based autonomous subtasks at different priority levels with respect to human teleoperation are integrated into the control system design. The control strategy is hierarchical comprising of a high-level teleoperation coordinating controller and low-level joint velocity controllers. A Lyapunov-based adaptive joint-space velocity controller is presented as one candidate for the low-level control. The approach utilizes idempotent, generalized pseudoinverse and weighting matrices, as well as a soft-switching rank changing algorithm in order to achieve new performance objectives that are defined for such asymmetric semi-autonomous teleoperation systems. A detailed analysis of system performance and stability is presented. The proposed framework constitutes the most general formulation and solution for the teleoperation control problem to date. It yields many interesting and useful system configurations never studied before, in addition to those already considered in the literature. In particular, seven system configurations arising from the proposed teleoperation architecture are analyzed and studied in detail. Experimental results are provided to demonstrate the desired system response in these configurations. Moreover, human factors experiments are carried out to assess operator(s) performance in maneuverability and grasping under various teleoperation system configurations. The results show statistically significant performance improvement in teleoperation of a nonholonomic mobile robot and telegrasping using a twin-armed manipulator.</p> / Doctor of Philosophy (PhD)