Tactile Interface for the VisuallyImpaired and Blind Assistive

Tactile Interface for the Visually-Impaired and Blind Assistive Devices Track – P 11017 Team Members (Left to Right) Faculty Guide: Dr. Elizabeth Debartolo Customers: Franklin Le. Gree Carry Joanis Stephanie Ulman Project Description The P 11017 Tactile Navigation Device will be a hands-free device that can be used to navigate visually-impaired (VI) and blind people through high traffic areas where directions cannot be conveyed by voice commands, therefore making tactile directions necessary to guide the user. The end goal of this device is to effectively integrate with other navigation aids being developed in parallel: An intra-building navigation system and bus identification system. Tim Giguere Tim De. Bellis Christian Seemayer Robert Proietti William Kelly Mechanical Engineer - Team Leader Electrical Engineer - Interface Engineer Electrical Engineer Mechanical Engineer Device Customer Requirements • Markets as low cost alternative to current technology. Currently $484. • A portable and simple to use device for VI/Blind people. • Accepts user input of destinations. • Consumes low power and supports a rechargeable battery. • Navigates with correct directions via tactile means. • Relays proximity warning with respect to upcoming direction changes. • Works as a hands-free device. • Utilizes input buttons that are clearly distinguishable. Electrical Systems Mechanical Systems • Electrical system built around an 8 -bit PIC C-based microcontroller. • All motors are controlled by PIC and driven by BJT network. • User communicates with device via a keypad which is continuously polled in software. • Keypad inputs stored in a string of variable length. • Low power mode activated by interrupt provided by user. • Device powered by 6 V Ni. MH rechargeable battery. • ~6 hour battery life. • 0. 53 W power consumption. • Size 5. 5” x 4. 375” x 2. 25” Weight 18. 8 oz • Utilizes blunt edged HDPE tactile pegs for directionality. • Proximity guidance from vibration motor • Indicator bumps placed on a 16 key number pad • Servo driven tactile pegs. • Servo arms made from Aluminum with plastic gear insert • Bottom Housing was Rapid Prototyped Future Developments Structural Issues Testing • Switch from Garolite to HDPE for housing wall material. • Correction of battery gap structural flaw. • Obtained human comfort level of 4 out of 5 from device size Possible Design Improvements and weight effects after wearing for one week. • Allows 25 minutes of constant use before surpassing vibration • Research of tubular solenoids instead of servos. • Customized battery and vibration motor to reduce size. daily exposure limit. • Expanding drawings tolerances to avoid extra machining. • Keypad Entry – Storing information into an array. 100% • Switch from rapid-prototyped to injection molded bottom success. housing. • Directional Output of Pegs – PWM commands initiate servo • Adjustable curvature to provide better fit for user. movements to relay proper directionality. 100% success. • Programmed direction output to convey to VI/Blind population. • Addition of power, button lock, and cancel buttons. • Indicator for acceptable inputs. • Users found correct button inputs blindfolded with 98. 6% • Increase microcontroller oscillator speed. accuracy. Future Optimization Ideas • Users exhibited a 94% success rate for correct direction • Creation of two part device to reduce overall bulk on arm. identification from the device. • Wirelessly connected devices. • Users averaged a device training time of 3. 04 minutes. • Integration with P 11016 Intra-Building Navigation Team project. Acknowledgements: Dr. Elizabeth Debartolo – Faculty Guide ME Department Association of the Blind and Visually Impaired Dr. Marca Lam-Anderson – ME Professor Dr. Roy Melton – CE Professor Dr. Dorin Patru – EE Professor P 11016 Navigation Map Team Mr. John Bonzo Mr. Jeff Lonneville – CEMA Lab Technician This material is based upon work supported by the National Science Foundation under Award No. BES-0527358. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author and do not necessarily reflect the views of the National Science Foundation.