Mechanical Design and Control of a High-Bandwidth Shape Memory Alloy Tactile Display

: We have constructed a tactile shape display which can be used to convey small-scale shapes in teleoperation and virtual environments. A line of 10 pins spaced 2 mm on center are each actuated with a shape memory alloy wire. A combination of careful mechanical design and liquid cooling allows a simple proportional controller with constant current feed-forward to achieve 40 Hz bandwidth. To quantify the value of increased bandwidth, an experiment involving a prototypical search task has been conducted using the display. A digital filter limited the frequency response of the display to three cutoff frequencies: 1, 5 and 30 Hz. Subjects were able to complete the search more than six times as quickly with 30 Hz bandwidth than with 1 Hz.

• Type: Conference
• Year: 1997
• Where: ISER
• Authors: Parris S. Wellman, William J. Peine, Gregg Favalora, Robert D. Howe
• Keywords: Hz Bandwidth, ISER 1997, Robotics, Shape Memory Alloy, Tactile Shape Display