Development and testing of haptic interfaces using electro-rheological fluids

Research has been performed to develop haptic interface devices, utilizing advanced actuators, to transmit information and receive control signals through interaction with a user's sense of touch. Haptic systems convey tactile and force information through the sense of touch by applying forces to a user's hands and other similar methods. The ability to generate force information allows systems to be designed where operators can see, hear and feel virtual or remote environments. In addition, using the sense of touch allows for new pathways to present information to a user, along with the standard visual and auditory interfaces. Interface devices have been developed to improve and simplify the manner in which a person interacts with computers and other technological systems. The focus has been to develop force-feedback interface systems to be used to control various devices such as the climate control and audio systems within an automobile. These advanced computer controlled systems can be used to consolidate various controls into fewer feedback control devices to create a simpler, more efficient interface. In addition, the use of force cues allows information to be transmitted to the user and control settings to be changed by the user without requiring the user's visual attention. Electrorheological Fluid (ERF) based actuators have been developed to provide the required feedback sensations. ERFs are fluids that change their viscosity in response to an electric field. Using the electrically controlled rheological properties of ERFs, devices have been developed that can resist operator forces in a controlled and tunable fashion. Three ERF-based actuators have been designed and prototypes have been built. Analytical models have been developed to describe the performance of these systems, and experimental analyses performed to verify the operation of the actuators. The actuators have been incorporated into various prototype Haptic Knob and Haptic Joystick devices. The addition of force cues allows these familiar devices to be used as advanced interface systems to provide information to and sense commands from a user. Force information from these devices has been maximized by performing Human Factors experiments to assess whether different designvariations can increase the systems' effectiveness. Factors such as hand position and handle texture have been assessed, statistical analyses performed on the results and the most effective versions have been identified. Methods for the application to the automotive haptic devices have been developed. Demonstrations have been created to prove the ability of the systems to provide information through the use of advanced haptic interfaces. In addition, concepts for future avenues of research have been developed to allow for continued research.Ph. D.Includes bibliographical references (p. 201-206)