M-BLOCKS

A NEW INVENTION IN

MODULAR ROBOTS

NIRMAL THOMAS

M.TECH ROBOTICS

SRM UNIVERSITY

BATCH : 2013 – 2015

INTRODUCTION

• What if robots could reassemble themselves at will? (The liquid metal cyborg

in Terminator was terrifyingly useful. It could look like anyone, repair shotgun

blasts, even turn its hand into a murderous icepick )

• And then of course, you’ve got Transformers, wherein alien robots morph from

cars and trucks into giant humanoid fighting machines.

• We are going to explore such type of robots….

• The are Called as Modular Robots or Self assembling robots

DIFFERENCE BETWEEN SWARM AND MODULAR ROBOTS

• In modular robots, physically independent entities or modules collaborate to perform

common tasks. Modularity is a concept well exploited by natural systems where relatively

simple modules form highly complex structures.

• In swarm systems, physically independent entities or modules collaborate to perform

common tasks.

• The fields of modular and swarm robotics have shown to be an ideal playground to

study, for instance, self-organization, self-assembly, self-repair, adaptation,

collaboration, social interaction, distributed intelligence, smart materials in robotic and

natural systems

MODULAR ROBOTS

• Started in 1988 (CEBOT).

• It is different from a fixed morphology robot.

• It is made of small units which consist of common or different hardware parts and shape

• These units can be connected by any means of locking or connecting mechanism to

perform a specified task.

• They change its shape by rearranging each units.

MODULAR ROBOTS TYPES

• Based on Architecture

1. Lattice architecture

2. Chain architecture

3. Hybrid architecture

• Based on design of the modules

1. Homogeneous

2. Heterogeneous

M - Blocks

• Small cubes that can independently roll across the ground, leap

through the air, and snap together to form different shapes have

been developed by scientists at the Massachusetts Institute of

Technology (MIT).

M-Block

• The main difference between M-blocks and other existing modular robots is

that others are SLIDING CUBE MODEL and the M-Block is the PIVOTING CUBE

MODEL robotic blocks

• They are controlled by a single actuator, even-though they can exhibit several

motions including rolling, Spinning in plane and jumping over the obstacles up

to twice its height.

M-BLOCK FEATURES

• Weight – 143g

• Constructed from 50mm cubic frame using

7075 Aluminium

• Have 24 cylindrical bonding magnet

• Each face has 8 outward facing magnet that assist in alignment between neighboring

models

• Manufacturing cost of one piece - $260 + $100 = $360

STRUCTURE AND DESIGN

• On each edge of a cube are two cylindrical magnets, mounted like rolling pins. When two

cubes approach each other, the magnets naturally rotate, so that north poles align with

south, and vice versa. Any face of any cube can thus attach to any face of any other.

• The cubes’ edges are also beveled, so when two cubes are face to face, there’s a slight

gap between their magnets. When one cube begins to flip on top of another, the bevels,

and thus the magnets, touch. The connection between the cubes becomes much stronger,

anchoring the pivot.

• On each face of a cube are four more pairs of smaller magnets, arranged symmetrically,

which help snap a moving cube into place when it lands on top of another.

FLYWHEEL SECTION

The flywheel can reach speeds of 20,000rpm

and when the robot cube puts the brakes on, it

gives itself angular momentum.

A flywheel is a rotating mechanical device that is used to store rotational

energy. Flywheels have a significant moment of inertia and thus resist

changes in rotational speed.

• Fly wheel is made from steel and

brass

• Moment of Inertia = 5.5E-6 kgcm2

BRAKING THE FLYWHEEL

• To detach from the magnetic bond ,it need to provide a torque for a relative

short period of time. The actuator is a unidirectional reaction wheel(flywheel)

need to release energy in a short period of time.

• Less than 15ms.

• This will create an impulsive

torque which detach the cube

from magnetic bond

• For this a BELT Type braking

system is used, It is actuated by

a Hobby style servo motor.

ELECTRONICS

• Custom built PCB board

• Microcontroller - 32bit ARM processor

• Communication – Xbee (802.11.4)

• Battery – 3.7V 125 mAh LiPo

• IR LED and Photodiode are used for

neighbour Communication.

• An encoder is attached to the flywheel to measure the speed of the

motor

How do the cubes somersault?

"Inside each M-Block is a flywheel that can reach speeds of 20,000

revolutions per minute; when the flywheel is suddenly / gradually braked, it

imparts its angular momentum to the cube. On each edge of an M-Block,

and on every face, are cleverly arranged permanent magnets that allow

any two cubes to attach to each other,

• They are currently controlled by computer instructions sent over wireless radio,

but in future the researchers hope algorithms can be loaded directly into the

blocks, making them entirely autonomous and capable of adapting to

different environments.

• This ability to potentially “think” independently leads to philosophical

questions about how the advance could impact on the development of

artificial intelligence.

PREDICTING MODULAR ROBOT MOVEMENT

• In predicting the movement and analyzing the movement of the Robots two

models are used

1. Sliding Cube Model

2. Pivoting Cube Model

Pivoting Cube model is developed

based on the m-block physical

model to predict and analyze the

movement of robot in 3d Space

PIVOTING CUBE MODEL

•FUTURE PLANS

• We want hundreds of cubes, scattered randomly across the floor, to be able to identify each

other, coalesce, and autonomously transform into a chair, or a ladder, or a desk, on demand,"

says John Romanishin, a research scientist working on the project.

• Reactions so far...

• - "A search and rescue plane could carry a few hundred thousand of these blocks to be drop

into the ocean upon which they self assemble into a small boat.

- Drop them into a desert where they self assemble into a hut for shelter.

- Drop them into a broken dam where they self assemble to plug the dam.

- Make the outside casing conductive so they can self assemble into a long power line in the

event of a downed power line out in the middle of ... "nowhere".Until the crew arrives," says

YouTube user Pullman WA.

• "Imagine what this technology is going to look like once its been shrunk down to the smallest

size possible? Imagine a billion grains of sand, each one a tiny modular robot, all linking

together to have any form it sees fit. It would be something like the T-1000 from Terminator

2," says YouTube user CoronaMage.

REFERENCE

• John W. Romanishin, Kyle Gilpin and Daniela Rus “M-Blocks: Momentum-

driven, Magnetic Modular Robots” 2013 IEEE/RSJ International Conference on

Intelligent Robots and Systems (IROS) November 3-7, 2013. Tokyo, Japan

• “Roombots: A hardware perspective on 3D self-reconfiguration and

locomotion with a homogeneous modular robot “A. Spröwitz *,R. Moeckel,M.

Vespignani,S. Bonardi,A.J.

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