A haptic base human robot interaction approach for robotic grit blasting

This paper proposes a remote operation method for a robot arm in a complex environment by using the Virtual Force (VF) based approach. A virtual robot arm is manipulated by a steering force, at the end-effecter, which is generated according to the movement of a feedback haptic. A three-dimensional force field (3D-F2) is employed in collision detection and avoidance. Repulsive forces from the 3D-F2 are produced and feedback to the haptic device that enables the operator to have a sense of touch on the encountered obstacle and then steer the arm to avoid it. As a result, collision-free poses of the virtual robot arm can then be used to command the real robot. Experiments are conducted in a mock up bridge environment where the real robot arm is steered to target points by the operator. Experiment results have shown successful collision avoidance and emulation of the actual command force and the virtual forces in remote operations

Haptics Rendering and Applications

There has been significant progress in haptic technologies but the incorporation of haptics into virtual environments is still in its infancy. A wide range of the new society's human activities including communication, education, art, entertainment, commerce and science would forever change if we learned how to capture, manipulate and reproduce haptic sensory stimuli that are nearly indistinguishable from reality. For the field to move forward, many commercial and technological barriers need to be overcome. By rendering how objects feel through haptic technology, we communicate information that might reflect a desire to speak a physically- based language that has never been explored before. Due to constant improvement in haptics technology and increasing levels of research into and development of haptics-related algorithms, protocols and devices, there is a belief that haptics technology has a promising future

Modeling and rendering for development of a virtual bone surgery system

A virtual bone surgery system is developed to provide the potential of a realistic, safe, and controllable environment for surgical education. It can be used for training in orthopedic surgery, as well as for planning and rehearsal of bone surgery procedures...Using the developed system, the user can perform virtual bone surgery by simultaneously seeing bone material removal through a graphic display device, feeling the force via a haptic deice, and hearing the sound of tool-bone interaction --Abstract, page iii

Surface Geometry and the Haptic Rendering of Rigid Point Contacts

This thesis examines the haptic rendering of rigid point contacts in virtual simulations. The haptic renderers generate force feedback so that the operator can interact with the virtual scenes in a realistic way. They must be able to recreate the physical phenomena experienced in the real world without displaying any haptic artifacts. The existing renderers are decomposed into a projection function and a regulation scheme. It is shown that the pop-through artifact, whereby the virtual tool instantaneously jumps between two distant surface points, is caused whenever the operator encounters a singularity within the renderer's projection function. This was well known for the minimum distance based renderers, but it is shown here that such singularities arise with the constraint based renderers as well. A new projection function is designed to minimize the existence of singularities within the model. When paired with an appropriate regulation scheme, this forms the proposed mapping renderer. The new projection is calculated by mapping the model onto a canonical shape where the haptic problem is trivial, e.g. a circle in the case of a 2D model of genus zero, which avoids pop-through on smooth models. The haptic problem is then recast as a virtual constraint problem, where the traditional regulation schemes, designed originally for planar surfaces, are shown to introduce a velocity dependent error on curved surfaces that can distort the model's rendering and to couple the regulation towards and dynamics along the constraint. Set stabilization control, based on feedback linearizing the haptic device with respect to a virtual output consisting of coordinates transversal and tangential to the model surface, is proposed as an alternative. It is shown to be able to decouple the system into transversal and tangential subsystems that can then be made asymptotically stable and assigned arbitrary dynamics, respectively

Does It Ping or Pong? Auditory and Tactile Classification of Materials by Bouncing Events

Two experiments studied the role of impact sounds and vibrations in classification of materials. The task consisted of feeling on an actuated surface and listening through headphones to the recorded feedback of a ping-pong ball hitting three flat objects respectively made of wood, plastic, and metal, and then identifying their material. In Experiment 1, sounds and vibrations were recorded by keeping the objects in mechanical isolation. In Experiment 2, recordings were taken while the same objects stood on a table, causing their resonances to fade faster due to mechanical coupling with the support. A control experiment, where participants listened to and touched the real objects in mechanical isolation, showed high accuracy of classification from either sounds (90% correct) or vibrations (67% correct). Classification of reproduced bounces in Experiments 1 and 2 was less precise. In both experiments, the main effect of material was statistically significant; conversely, the main effect of modality (auditory or tactile) was significant only in the control. Identification of plastic and especially metal was less accurate in Experiment 2, suggesting that participants, when possible, classified materials by longer resonance tails. Audio-tactile summation of classification accuracy was found, suggesting that multisensory integration influences the perception of materials. Such results have prospective application to the nonvisual design of virtual buttons, which is the object of our current research

Haptic Displayof Realistic Tool Contact via Dynamically Compensated Control of a Dedicated Actuator

High frequency contact accelerations convey important information that the vast majority of haptic interfaces cannot render. Building on prior work, we present an approach to haptic interface design that uses a dedicated linear voice coil actuator and a dynamic system model to allow the user to feel these signals. This approach was tested through use in a bilateral teleoperation experiment where a user explored three textured surfaces under three different acceleration control architectures: none, constant gain, and dynamic compensation. The controllers that use the dedicated actuator vastly outperform traditional position-position control at conveying realistic contact accelerations. Analysis of root mean square error, linear regression, and discrete Fourier transforms of the acceleration data also indicate a slight performance benefit for dynamic compensation over constant gain