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such as receiving voice commands
or written commands (Wi-Fi
commands), and control the flow of
information throughout the system.
to Create Robots
TigerBot was designed using
skills from three engineering majors
including mechanical engineering,
electrical engineering, and
computer engineering. Each aspect
of the robot required input from
students in each science major.
The mechanical engineering
students designed the robot’s joints
and mechanical layout. The
electrical engineers added to the
joint design through the use of
servo motors. The computer engineering students assisted
with computer board layout so there would be space for
the embedded electronics. The mechanical engineers also
designed the robot to provide enough torque for several of
the robot’s high torque positions.
The RIT TigerBot together with
the robotics team.
objects that it could come in contact with. To do this,
proximity, touch, and IMU sensors were used. To further be
able to perform the functions of a humanoid, Tigerbot also
needed to respond to voice commands. Tigerbot was
required to respond to a minimum of 16 voice commands.
The electrical engineers designed the wiring and a
power PCB to ensure the high power draw was
appropriately used. They were also in charge of the
placement of custom connectors for each component for
better connections. The electrical engineering students
designed the battery’s size and storage so it would fit and
still ensure a full hour of operation.
Human-like movements were made possible through
software libraries. These software libraries had to contain
simple algorithms such as walk and get up from a fall. The
voice commands could then be tied to some of these
Enabling Human Mimicry
The computer engineers designed the programming of
the robot, selecting the electronics that offered enough
control for the robot while staying on budget. They
interfaced the sensors with the embedded computer and
also designed the balance algorithm. It was the computer
engineers who interfaced all the communications between
the electronics. They generated the programming platform
and began the programming for the walking algorithms.
The robot has 23 DOF (degrees of freedom) of
movement, including arms that bend at the wrist, shoulder,
and elbow. The shoulders were designed to fully function
as a ball joint, according to team members. The robot can
pan and tilt at the neck, and the hips also simulate a ball
joint. Finally, the legs bend at the knee, and the feet have
vertical and horizontal rotation capabilities.
Ascending to Autonomy
In order to be autonomous, TigerBot had to be able to
act independently of user control. The robot is completely
unwired from battery power and command and control,
and can walk around freely. Numerous environmental
sensors and onboard computer intelligence instill it with
further autonomy. A gyroscope and accelerometer make
Tigerbot capable of sensing its own position and correcting
accordingly to remain stable. Two batteries are located in
the feet to enable completely wireless operation. Three USB
ports on the main controller can be used for things like
wireless network adapters, interfacing with a webcam, and
other add-on devices that may be useful in the future.
The degrees of freedom were enabled by RS-1270
revolute servomotors from RobotShop. These servos
produce a rated torque of 480 oz-in. While the robot can
make any motion a human can, it does not have a spine.
However, this was not an obstacle.
Tigerbot needed the ability to detect body position and
The intelligence architecture in one version of TigerBot
was made up of three entities: an Android HTC smart
phone with USB expansion port, an Arduino Mega2560,
and an ARC32. These controllers communicate with each
other using SPI since this is considered a fast serial protocol.
The Android phone met the requirements needed because
of its operating system, an API that makes accessing the
Wi-Fi or Bluetooth capabilities easy, and more than 2 GB of
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