A Mechanistic Force Model for Simulating Haptics of Hand-Held Bone Burring Operations

The research presented in the thesis is concentrated on developing a mechanistic model to predict the forces experienced during bone burring with application to haptic feedback for virtual reality surgical simulations. This model can be used in haptic devices to provide haptic feedback for virtual reality (VR) surgical simulations. The model is developed based on the understanding of the force profile recorded in the experiments. To determine the force produced under various cutting orientations, experiments are conducted using a surgical burr on a synthetic bone. The total force experienced in bone burring can be understood as a combination of resistive force and vibrational force. The resistive force is calculated using the concept of the specific cutting energy of the bone material. The specific cutting energy (Us) is a concept adopted from the mechanics of grinding. Data from the experiments is used to calibrate the specific cutting energy of the material. The vibrational force is developed as an empirical component of the coupled model. Comparisons between the experimentally measured force data and the force profile predicted by the model show a similar trend. Results confirm that the proposed model is capable of effectively predicting the haptics in bone burring, specifically with the abrasive type of burr

Advanced teleoperation and control system for industrial robots based on augmented virtuality and haptic feedback

There are some industrial tasks that are still mainly performed manually by human workers due to their complexity, which is the case of surface treatment operations (such as sanding, deburring, finishing, grinding, polishing, etc.) used to repair defects. This work develops an advanced teleoperation and control system for industrial robots in order to assist the human operator to perform the mentioned tasks. On the one hand, the controlled robotic system provides strength and accuracy, holding the tool, keeping the right tool orientation and guaranteeing a smooth approach to the workpiece. On the other hand, the advanced teleoperation provides security and comfort to the user when performing the task. In particular, the proposed teleoperation uses augmented virtuality (i.e., a virtual world that includes non-modeled real-world data) and haptic feedback to provide the user an immersive virtual experience when remotely teleoperating the tool of the robot system to treat arbitrary regions of the workpiece surface. The method is illustrated with a car body surface treatment operation, although it can be easily extended to other surface treatment applications or even to other industrial tasks where the human operator may benefit from robotic assistance. The effectiveness of the proposed approach is shown with several experiments using a 6R robotic arm. Moreover, a comparison of the performance obtained manually by an expert and that obtained with the proposed method has also been conducted in order to show the suitability of the proposed approach

Framing the past: How virtual experience affects bodily description of artefacts

This study uses a novel, interdisciplinary approach to investigate how people describe ancient artefacts. Here, we focus on gestures. Researchers have shown that gestures are important in communication, and those researchers often make a distinction between beat and iconic gestures. Iconic gestures convey meaning, specifically, visual-spatial information. Beat gestures do not convey meaning; they facilitate lexical access. In our study, we videotaped participants while they described artefacts presented through varied media: visual examination, physical interaction, and three-dimensional virtual and material replica (i.e., 3D prints) interaction. Video analysis revealed that media type affected gesture production. Participants who viewed actual objects displayed in a museum-style case produced few gestures in their descriptions. This finding suggests that traditional museum displays may diminish or limit museum users degree of engagement with ancient artefacts. This interdisciplinary work advances our knowledge of material culture by providing new insights into how people use and experience ancient artefacts in varied presentations. Implications for virtual reproduction in research, education, and communication in archaeology are discussed.This paper is part of a larger study on how people perceive ancient artefacts, which was partially funded by the University of California Humanities Network and the Center for the Humanities at the University of California, Merced.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.culher.2015.04.00

Development of an integrated robotic polishing system

This thesis presents research carried out as part of a project undertaken in fulfilment of the requirements of Loughborough University for the award of Philosophical Doctorate. The main focus of this research is to investigate and develop an appropriate level of automation to the existing manual finishing operations of small metallic components to achieve required surface quality and to remove superficial defects. In the manufacturing industries, polishing processes play a vital role in the development of high precision products, to give a desired surface finish, remove defects, break sharp edges, extend the working life cycle, and meet mechanical specification. The polishing operation is generally done at the final stage of the manufacturing process and can represent up to a third of the production time. Despite the growth automated technology in industry, polishing processes are still mainly carried out manually, due to the complexity and constraints of the process. Manual polishing involves a highly qualified worker polishing the workpiece by hand. These processes are very labour intensive, highly skill dependent, costly, error-prone, environmentally hazardous due to abrasive dust, and - in some cases - inefficient with long process times. In addition, the quality of the finishing is dependent on the training, experience, fatigue, physical ability, and expertise of the operator. Therefore, industries are seeking alternative solutions to be implemented within their current processes. These solutions are mainly aimed at replacing the human operator to improve the health and safety of their workforce and improve their competitiveness. Some automated solutions have already been proposed to assist or replace manual polishing processes. These solutions provide limited capabilities for specific processes or components, and a lack of flexibility and dexterity. One of the reasons for their lack of success is identified as neglecting the study and implementing the manual operations. This research initially hypothesised that for an effective development, an automated polishing system should be designed based on the manual polishing operations. Therefore, a successful implementation of an automated polishing system requires a thorough understanding of the polishing process and their operational parameters. This study began by collaborating with an industrial polishing company. The research was focused on polishing complex small components, similar to the parts typically used in the aerospace industry. The high level business processes of the polishing company were capture through several visits to the site. The low level operational parameters and the understanding of the manual operations were also captured through development of a devices that was used by the expert operators. A number of sensors were embedded to the device to facilitate recording the manual operations. For instance, the device captured the force applied by the operator (avg. 10 N) and the cycle time (e.g. 1 pass every 5 sec.). The capture data was then interpreted to manual techniques and polishing approaches that were used in developing a proof-of-concept Integrated Robotic Polishing System (IRPS). The IRPS was tested successfully through several laboratory based experiments by expert operators. The experiment results proved the capability of the proposed system in polishing a variety of part profiles, without pre-existing geometrical information about the parts. One of the main contributions made by this research is to propose a novel approach for automated polishing operations. The development of an integrated robotic polishing system, based on the research findings, uses a set of smart sensors and a force-position-by-increment control algorithm, and transpose the way that skilled workers carry out polishing processes

Robotic assistance for industrial sanding with a smooth approach to the surface and boundary constraints

Surface treatment operations, such as sanding, deburring, finishing, grinding, polishing, etc. are progressively becoming more automated using robotic systems. However, previous research in this field used a completely automatic operation of the robot system or considered a low degree of human-robot interaction. Therefore, to overcome this issue, this work develops a truly synergistic cooperation between the human operator and the robot system to get the best from both. In particular, in the application developed in this work the human operator provides flexibility, guiding the tool of the robot system to treat arbitrary regions of the workpiece surface; while the robot system provides strength, accuracy and security, not only holding the tool and keeping the right tool orientation, but also guaranteeing a smooth approach to the workpiece and confining the tool within the allowed area close to the workpiece. Moreover, to add more flexibility to the proposed method, when the user is not guiding the robot tool, a robot automatic operation is activated to perform the treatment in prior established regions. Furthermore, a camera network is used to get a global view of the robot workspace in order to obtain the workpiece location accurately and in real-time. The effectiveness of the proposed approach is shown with several experiments using a 6R robotic arm

Haptic communication for remote mobile and manipulator robot operations in hazardous environments

Nuclear decommissioning involves the use of remotely deployed mobile vehicles and manipulators controlled via teleoperation systems. Manipulators are used for tooling and sorting tasks, and mobile vehicles are used to locate a manipulator near to the area that it is to be operated upon and also to carry a camera into a remote area for monitoring and assessment purposes. Teleoperations in hazardous environments are often hampered by a lack of visual information. Direct line of sight is often only available through small, thick windows, which often become discoloured and less transparent over time. Ideal camera locations are generally not possible, which can lead to areas of the cell not being visible, or at least difficult to see. Damage to the mobile, manipulator, tool or environment can be very expensive and dangerous. Despite the advances in the recent years of autonomous systems, the nuclear industry prefers generally to ensure that there is a human in the loop. This is due to the safety critical nature of the industry. Haptic interfaces provide a means of allowing an operator to control aspects of a task that would be difficult or impossible to control with impoverished visual feedback alone. Manipulator endeffector force control and mobile vehicle collision avoidance are examples of such tasks. Haptic communication has been integrated with both a Schilling Titan II manipulator teleoperation system and Cybermotion K2A mobile vehicle teleoperation system. The manipulator research was carried out using a real manipulator whereas the mobile research was carried out in simulation. Novel haptic communication generation algorithms have been developed. Experiments have been conducted using both the mobile and the manipulator to assess the performance gains offered by haptic communication. The results of the mobile vehicle experiments show that haptic feedback offered performance improvements in systems where the operator is solely responsible for control of the vehicle. However in systems where the operator is assisted by semi autonomous behaviour that can perform obstacle avoidance, the advantages of haptic feedback were more subtle. The results from the manipulator experiments served to support the results from the mobile vehicle experiments since they also show that haptic feedback does not always improve operator performance. Instead, performance gains rely heavily on the nature of the task, other system feedback channels and operator assistance features. The tasks performed with the manipulator were peg insertion, grinding and drilling.EThOS - Electronic Theses Online ServiceGBUnited Kingdo