CHRONOS-CONTROL COMPUTER CONTROL USING TI CHRONOS Cihat Keser Yeditepe University - 2011.
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Transcript of CHRONOS-CONTROL COMPUTER CONTROL USING TI CHRONOS Cihat Keser Yeditepe University - 2011.
CHRONOS-CONTROLCOMPUTER CONTROL USİNG TI
CHRONOS
Cihat Keser
Yeditepe University - 2011
Presentation Plan
Introduction & Problem Definition Proposed Solution Concept Overall Software Design System Calibration Mouse Control Keyboard Control Evaluation Results
Section 1 of 7
«For me being online is everything. It’s my hi-fi, my source of income, my supermarket, my telephone. It’s my way in.» Lynn Holdsworth, screen reader user, Web Developer and Programmer
Introduction & Problem Definition
Introduction & Problem Definition (1)
Computers are already part of our daily life
All modern services are being
«computerized»
Human computer interface alternatives are
limited
Some people cannot use traditional
interfaces (mouse and keyboard)
Introduction & Problem Definition (2)
This project aims to provide an
alternative interface
Target user base is disabled people who
can still move (tilt) their head
Section 2 of 7
Proposed Solution Concept
Proposed Solution Concept (1)
Head acceleration data acquired using wireless head mounted accelerometer
TI Chronos is wireless and includes an accelerometer
Data analyzed by Java application and translated to keyboard or mouse input
Proposed Solution Concept (2)
Acceleration data converted to pitch & roll degrees
Not possible to calculate yaw using single accelerometer
Analysis works on pitch & roll degrees
Section 3 of 7
Overall Software Design
Overall Software Design
Data Layer• Manages connection between Chronos
and computer• Polls Chronos For acceleration data• Keeps a collection of previously received
dataLogic Layer• Chooses the appropriate analyse logic
depending on operation mode (keyboard, mouse or calibration)
• Passes any detected input events (output of analyzer) to the Operating System (OS)
User Interface Layer• Manages and updates the user
interface
Section 4 of 7
System Calibration
System Calibration
Analyzer needs to know the limits of the user
Calibration carried out by a wizard like
interface
Four steps are involved:
Neutral area detection
Usable area detection
Left click characteristics detection
Right click characteristics detection
Section 5 of 7
Mouse Control
Mouse Control (1)
Tilting head in any direction moves the
cursor
Simple speed adaptable relative mapping
used
New cursor location calculated relative to
old location
Cursor speed directly proportional to tilt
degree
Mouse Control (2)
Clicking only possible in «click mode»
Cursor movement disabled in click mode
Staying in neutral position enables click mode
Making a click movement, simulates mouse click
A successful click or timeout disables click mode
Mode switcher interface shows click mode status
Mouse Control (3)
Click movement detection done by analyzing past data collection
Peak and two closest neutral points found
Height and duration calculated
Compared to characteristic values obtained in calibration
Tilt angle versus time plots for (a) left (b) right clicks
Section 6 of 7
Keyboard Control
Keyboard Control (1)
Clicking the button on «mode switcher» while in mouse mode, switches
operation mode to keyboard
An on screen keyboard (OSK) is shown
OSK has special layout to compensate for head’s circular motion limitation
Keyboard Control (2)
Tilting head changes the selected key
Key navigation uses absolute mapping method
Usable tilt range divided to number of keys
Waiting on a key, simulates a key press event
To avoid navigation jitter, key stickiness parameter
proposed
Selected key changes only if multiple contionous data is
received to select it
Section 7 of 7
Evaluation Results
Evaluation Results (Keyboard) Test subjects typed
«the quick brown fox jumps over the lazy dog» three times
Changed waiting time to press a key (W) and repeated
Changed stickiness and repeated W = 700ms W = 800ms
210
231
240
216
Average time spent typing (seconds)
Stickiness ONStickiness OFF
Evaluation Results (Mouse)
Test subjects clicked on eight circles randomly drawn on screen, three times
Changed maximum mouse speed and repeated Average of all subjects
149156
178
Average time spent to click all circles (seconds)
Vmax=10pixelsVmax=14pixelsVmax=18pixels
Evaluation Results
Test subjects had difficulty using click mode
Simple speed adaption method for cursor
movement was partially effective
Special keyboard layout successfully solved
circuilar motion limitation problem
Keyboard jitter was not solved by stickiness
parameter
Thank You!