Master of Science, Miami University, 2019, Mechanical and Manufacturing Engineering

Realistic haptic feedback is necessary to provide meaningful touch information to users of numerous technologies, such as virtual reality, mobile devices and robotics. For a device to convey realistic haptic feedback, two touch sensations must be present: tactile feedback and kinesthetic feedback. Tactile feedback is felt at the surface of one's skin and displays textures and vibrations, whereas kinesthetic feedback is felt in one's joints and muscles and transmits position and movement information. While many devices today display tactile feedback through vibrations, most neglect to incorporate kinesthetic feedback due to size constraints. To provide comprehensive feedback, this study investigates a new haptic device based on an unconventional actuation method: electrorheological (ER) fluid, a smart fluid with tunable yield stress under the application of electric field. The device's control electronics and structural components are integrated into a compact printed circuit board, resulting in a slim device suitable for mobile applications. By controlling the ER fluid flow via applied electric fields, the device can generate a wide and distinct range of both tactile and kinesthetic sensations. These sensations were derived analytically from ER fluid's governing equations as well as experimentally. The device may be used as a haptic interface between a user and virtual environment.

Committee: Jeong-Hoi Koo Ph.D. (Advisor); Tae-Heon Yang Ph.D. (Committee Member); Michael Bailey Van Kuren Ph.D. (Committee Member) Subjects: Computer Engineering; Materials Science; Mechanical Engineering

Master of Science (MS), Ohio University, 2007, Computer Science (Engineering)

This thesis presents implementation and evaluation of a multiple-points haptic rendering algorithm using the PHANToM haptic interface, in the context of our Virtual Haptic Back Project at Ohio University. This algorithm will increase realism in palpation with the Virtual Haptic Back and other virtual haptic palpation tasks when compared to the single point haptic rendering. The single-point haptic rendering cannot provide tool-object interactions in which more than one object is in contact simultaneously at different locations of the tool or finger. Since a single point does not represent the finger haptically well, this thesis uses a multiple-points probe. The multiple-points collision detection is computationally expensive and complicated than the single-point haptic rendering. This thesis constructs the volume object using a sphere. The center of this sphere is the original PHANToM position and the end-points consist of points on the sphere. The collision detection between these line segments and objects in the virtual scene is completed and a resultant force is displayed to the user. The multiple-points haptic rendering algorithm was integrated with simple haptic objects and with the complex Virtual Haptic Back. The multiple-points algorithm is made efficient using concepts such as rasterisation, hashing and spatial decomposition. Experiments have determined that multiple-points haptic rendering can improve the user's experience with virtual reality applications based on this first step in implementation and evaluation.

Committee: Robert Williams II (Advisor) Subjects: Computer Science