robotics - ballrover

8/2/2019 Robotics - BallRover

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Kunal Goyal(09BEC359)

Ravi Kumar(09BEI044)


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The idea of self-balancing robots had gain

popularity among robotics and automationresearchers worldwide over last few decades. This

paper aims at development and analysis of a robot

balancing on a spherical ball which can not only

stand still but also traverse on floor and pivot

around its axis. This design conveys highmaneuverability in crowded spaces and easy

interaction with human environment. The model

discussed in this paper uses 3 Omni-directional

wheels driven by servomotors. The balancing is

achieved by the fusion of dual-axis gyroscope,triple-axis accelerometer by Kalman filter technique

and PID controller. The Robot is controlled by a 16-

bit microcontroller and runs on Ni-MH batteries..


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Multi-wheel statically-stable mobile robots tall enough to

interact meaningfully with people must have low centers of

gravity, wide bases of support, and low accelerations to

avoid tipping over. These conditions present a number of

performance limitations. Accordingly, we are developing an

inverse of this type of mobile robot that is the height, width,and weight of a person, having a high center of gravity, that

balances dynamically on a single spherical wheel. Unlike

balancing 2-wheel platforms which must turn before driving

in some direction, the single-wheel robot can move directly

in any direction.


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Minimum Turning Radius

High Maneuverability

Less Rolling Friction

High Agility


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The Spherical Wheel

Servo motors

Omni Wheels

Rotary Encoders Microcontroller

Sensors(IMU implementation)

Accelerometer

Gyroscope

Control Systems

Kalman Filter

PID Control System


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x x

y

R

P

f

z

P

1

P3

P2

Initially when the robot is switched on the control system triesto align the center of gravity to the point of contact betweenthe floor and the ball.

When an offset is given to the robot, it initially leans forwardsand moves and then slowly retreats to original straight

position. Similarly, while stopping it leans back and slowly gets back to

its initial position. The movement is agile and looks similar toroller skating.

The robot is made to pivot around it vertical axis by moving allthe motor in same direction with same speeds.


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The unique characteristics of a ballbot

open a wide range of practicalapplications.

Dynamic stability allows its uses in

crowded environments like trains, ships

etc.

Its omni-directionality makes it suitablefor quick navigation in grid-based

systems.

Its high center of gravity allows unique

perspective in human interaction.

It is most suitable in public information,daily aid or a service robot. However, so

far ballbots are still matter of research.


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The robot discussed in this paper merely

focuses on motion and design analysis but

in future certain sensors can be added for

the intelligent interaction with human

environment.

Artificial Intelligence can be employed to

widen its application in public information,

daily aid or as a service robot.

Various design parameters can be altered

such as the friction between ball and floor,

friction between wheels and ball, size of the

ball, location of center of gravity, number of

wheels can also be changed.

Machine vision and AI can make it more

suitable in human interaction.


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T.B.Lauwers, G.A.Kantor, R.L.Hollis, A Dynamically

Stable Single-Wheeled Mobile Robot with InverseMouse-Ball Drive, ,2006

Masaaki Kumaga, Takaya Ochiai, Development of

Robot balanced on ball,2009

Rezero, ETH, Zurich

A. Warnasch, and A. Killen, Low cost, high G, microelectro-mechanical systems (MEMS), inertialmeasurements unit (IMU) program, IEEE PositionLocation and Navigation Symposium, 2002

D. Simon, Kalman filtering with state constraints: A

survey of linear and nonlinear algorithms, IETProceedings in Control Theory & Applications

M. A. Johnson, and M. H. Moradi, PID Control: NewIdentification and Design Methods. Springer, 2005.

Ching-Wen Liao, Ching-Chih Tsai, Yi Yu Li, Cheng-Kai

Chan , Dynamic Modeling and Sliding-Mode Control of

a Ball Robot with Inverse Mouse-Ball Drive,2008 Umashankar Nagarajan, George Kantor and Ralph L.

Hollis, Trajectory Planning and Control of an Underactuated Dynamically Stable Single Spherical WheeledMobile Robot

H. Benjamin Brown, Jr. and Yangsheng Xu, A singlewheel, gyroscopically stabilized robot


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robotics - ballrover

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