HEAD MOUNTED INPUT DEVICE
USING MEMS SENSORS
Anbarasu V
Research scholar, Sathyabama University, Chennai-600119, Tamilnadu, India E-mail: [email protected]
Tel: +91-948-6805566
Dr.T.Ravi
Professor & Head, Dept of CSE, KCG College of Technology, Chennai-600097, Tamilnadu, India E-mail: [email protected]
Tel: +91-988-4435101 Abstract
A person who has limited control over their limbs cannot do much for themselves. If this person stay at home, they need others assistance to do a task. Task also implies those concerned with the PC. Hence, to make them handle and control a PC easily, in our paper we design economical wireless mouse and keyboard that emulates it functions. So users will not have any physical connection while interacting with their computer system. Our model uses MEMS accelerometer to detect the user’s head movement in order to direct mouse position on the monitor. Also clicking events are generated by detecting complete eye blinking as a selection mechanism. The system has been demonstrated to perform mouse movements and clicking events successfully. The demonstration results are presented in this paper.
Keywords: tilt sensor, wireless mouse, MEMS accelerometer, eye blinking.
1. Introduction
In the evolution of computer user interfaces, the mouse and the keyboard have withstood challenges from other input devices such as joystick, light pen, track ball and many more devices. But still in most of the computer application we are using mouse and keyboard as standard devices. This is not same for the people who with severe disabilities. However as computers become more compact and powerful, e.g., PDAs, notebooks, wearable computers…etc., traditional designs for the mouse and keyboard may not be suitable for interfacing with the small computing systems. But all these devices need physical connection with computer system. We believe that by combining the advent in sensors and wireless technologies, it is possible to develop a novel computer input system that could enable multi-functional input tasks and allow the overall shrinkage in size of the graphical and text interface devices. Our experimental results could be performed using MEMS based motion detection sensors.
From our literature analysis, although there are many computer input devices available are not wearable multifunctional devices. Prince has developed finger mounted device [1] using pressure sensors, but no hardware has been realized so far. B Thomas [2] has done analysis on virtual keyboard, but it needs mouse as an alternative to give an input an individual character. Again users need physical kind of interaction with computer system. J. K. Perng has developed a model that uses sensors for input text through gestures [3]. Mascaro [4] [5] has investigated a fingernail sensor to measure the finger posture and forces, which could be used to develop a virtual mouse, but its limited in sensing the pressure between finger and table surface and hence cannot be used in mid-air for 3D emulation. Samsung [6] and Senseboard [7] have introduced a novel virtual keyboard, which allows mini computer users to type efficiently without physical connection. But both has disadvantage of sensing the speed and velocity of fingertip and latter one may not be used as a mouse or a light pen. Our proposed model could perform mouse and keyboard like functions.
2. System Description
modality for pointing and scrolling on mobile devices. We evaluate the effectiveness of using tilting in the two tasks then a model for predicting their execution time is developed.
Fig.1. Human Interface section
Our paper describes the implementation of head operated mouse that uses tilt sensors placed on headset to determine head position. Also, it uses 3 axis MEMS accelerometers to detect head tilt in order to direct mouse movement on the monitor. Accelerometer sends the information to the microcontroller. Microcontroller then passes the actual information to encoder. Information encoded is then sent using Transmission to Zigbee receiver. Zigbee receiver will decode the received information. Microcontroller sends to PC through RS232 cable. It will perform the operation. Same operation for selecting any documents with the help of eye blink. We constructed an interface system that would allow a similarly paralyzed user to interact with a computer with almost full functional capability. That is, the system operates as a mouse initially, but the user has the ability to toggle in and out of a keyboard mode allowing the entry of text. This is achieved by using the control from a single eye, tracking the position of the pupil for direction, and using blinking as an input. Our proposed paper describes the design of a system that is compatible for all operating systems.
VCC VCC_BAR VCC_BAR Ey eBlink TX RX MCLR 9V AC 1 2 1 2 C6 100uF /16 V R3 330E C5 470uF/25V - + D1 DB106 1 2 3 4 D3 SSF-LXH101 C5 470 uF /25V R3 330E PIC16F877A 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 MCLR/VPP RA0/ANO RA1/AN1 RA2/AN2/VREF-/CVREF RA3/AN3/VREF+ RA4/TOCKI/C1OUT RA5/AN4/SS/C2OUT REO/RD/AN5 RE1/WR/AN6 RE2/CS/AN7 VD D VSS OSC1/CLKI OSC2/CLKO RCO/T1OSO/T1CKI RC1/T1OSI/CCP2 RC2/CCP1 RC3/SCK/SCL RD0/PSP0 RD1/PSP1 RB7/PGD RB6/PGC RB5 RB4 RB3/PGM RB2 RB1 RB0/INT VD D VSS RD7/PSP7 RD6/PSP6 RD5/PSP5 RD4/PSP4 RC7/RX/DT RC6/TX/CK RC5/SDO RC4/SDI/SDA RD3/PSP3 RD2/PSP2 C7 CAP SW0 RST Y 1 4 Mhz C5 4 70uF /25V R3 560E IN OUT GND 7805 MEMS TE A8 AD11 A7 A0 AD8 A1 DOUT AD10 AD9 A4 A6 A2 OSC1 A5 A3 HT12E OSC2 RF Transmitter Antenna 1 2 4 3
Fig.2. Computer Interface section
3. Spectacle Prototype
Cursor can be moved with the help of head movements. 3-Axis Accelerometer will send the movement direction to Microcontroller. Microcontroller then passes the actual information to encoder. Zigbee receives encoded information and sends to PC through RS232. Also sensor is activated when the user blinks their eye. It allows individuals to operate electronic equipment like communication aids and environmental controls hands-free. Each blink of the eye is detected by an infrared sensor, which is mounted on dummy spectacle frames. The eye blink switch can be set up to operate on either eye and may be worn over normal glasses. The sensitivity of the switch can be adjusted to the users needs and involuntary blinks are ignored. The sensor is connected to a hand-held control unit with a rechargeable battery.
OUT3 RXD VT OUT1 TXD OUT4 TE OUT2 TXD RXD DATAIN VT VCC VCC VCC VCCr VCC VCCr U1 AT89S51 9 18 19 20 29 30 31 40 1 2 3 4 5 6 7 8 21 22 23 24 25 26 27 28 10 11 12 13 14 15 16 17 39 38 37 36 35 34 33 32 RST XTAL2 XTAL1 GN D PSEN ALE/PROG EA/VPP VC C P1.0 P1.1 P1.2 P1.3 P1.4 P1.5 P1.6 P1.7 P2.0/A8 P2.1/A9 P2.2/A10 P2.3/A11 P2.4/A12 P2.5/A13 P2.6/A14 P2.7/A15 P3.0/RXD P3.1/TXD P3.2/INTO P3.3/INT1 P3.4/TO P3.5/T1 P3.6/WR P3.7/RD P0.0/AD0 P0.1/AD1 P0.2/AD2 P0.3/AD3 P0.4/AD4 P0.5/AD5 P0.6/AD6 P0.7/AD7 C3 33PF C R3 SIP 9 10k 1 2 3 4 5 6 7 8 9 C1 10uF C2 10u F C4 10uF X1 11.0592MHz R3 33K C5 10uF P1 SE R IAL PO R T 5 9 4 8 3 7 2 6 1 C1 0.1uF C3 10uF - + D1 DB106 1 2 3 4 9V AC 1 2 1 2 R3 330E C6 100 uF /1 6V C4 33PF U1 HT-12D 1 2 3 4 5 6 7 8 9 10 11 12 13 14 18 17 16 15 A0 A1 A2 A3 A4 A5 A6 A7 Vss D8 D9 D10 D11 DIN Vdd VT Osc1 Osc2 8K 2 C5 470uF/25V D3 SSF-LXH101 U1 MAX232 13 8 11 10 1 3 4 5 2 6 12 9 14 7 16 15 R1IN R2IN T1IN T2IN C+ C1-C2+ C2-V+ V-R1OUT R2OUT T1OUT T2OUT VC C GN D SW 0 RS T GN D DA TA GN D RF 433.92MHz 7805 Recognition Kit Out VC C GN D Voice GND VC C AN T OUT IN DA TA
4. Experimental Results
Thus our demonstration shows how VB interface was created with menus and our prototype allows the disabled people to operate the system and utilize the resources stored in it. Fig 1. Shows Visual Basic forms with basic menus that can be operated through clicking events. Fig 2 and Fig 3 shows how menus are operated and its working.
Fig.1. VB Interface with menus
Fig.3. Through a complete eye blink user can able to open IE.
5. Conclusion
Thus our prototype helps the disabled people to operate the system and utilize the resources stored in it. Hence when the user moves his head in a tri-axis, the microcontroller reads the motion based on the readings the mouse cursor will move over the PC screen. Also voice recognition kit helps to emulates keyboard functions that help especially abled people. But still we face difficulty in cursor movements.
References
[1] A.R. Prince, “Finger mounted computer input device”, United States Patent, patent number 5,581,484, Dec 3, 1996.
[2] B. Thomas, S. Tyerman, and K. Grimmer, “Evaluation of three input mechanisms for wearable computers”, Wearable Computers, 1997. Digest of Papers., 1997, pp. 2–9.
[3] B. Fisher, J.K. Perng, S. Hollar, and K.S.J. Pister, “Acceleration sensing glove (ASG)”, Digest of Papers. The Third International Symposium on Wearable Computers, 1999, pp. 178 –180.
[4] S. Mascaro, and H.H. Asada, “Photoplethysmograph fingernail sensors for measuring finger forces without haptic obstruction”, IEEE Transactions on Robotics and Automation, Volume: 17 Issue: 5, Oct. 2001, pp. 698 – 708.
[5] S. Mascaro, and H.H. Asada, “Finger posture and shear force measurement using fingernail sensors: initial experimentation”, Proceedings of the 2001 IEEE International Conference on Robotics and Automation, Volume: 2, 2001, pp. 1857 -1862. [6] www.cnn.com/2001/TECH/ ptech/11/17/comdex.gadgets/index.html
[7] www.senseboard.com
[8] Wen J. Li and Alan H. F. Lam, “MIDS: GUI and TUI in Mid-Air Using MEMS Sensors”, Proceedings of the International
Conference
on Control and Automation, June 2002, pp. 1218-1222. Author’s Profile
Anbarasu V received the B.E degree in Computer Engineering from Sardar Vallabhbhai
National Institute of Technology, Deemed University, India in 2003, and the M.Tech degree in Information Technology from Sathyabama University, in 2006. Currently, he is a Associate Professor in Jeppiaar Engineering College, Anna University, Chennai, he is also a Research Scholer in Sathyabama University, Chennai. His research interests are the Human Computer Interface, Operating Systems and Problem solving and programming methodology.
Dr.T.Ravi graduated from Madurai Kamaraj University in April 1991 and received his post
