Beam Robotics and Nervous Networks (EMERGING TREND IN ROBOTICS)

AUTHORS: K.Ramya A.V.D.Sai Priyaka B.Tech 3rdyear(E.C.E), B.Tech 3rdyear(E.C.E), ramya85115k@gmail.com priyanka .agolu@gmail.com

S.R.K .INSTITUTE OF TECHNOLOGY

ABSTRACT: The field of ROBOTICS has been a

fascination since the advent of

computational technologies. To induce life

into the robos, complex and powerful

electronic components are required. Hence

advance knowledge and great funds are

required to build even small robots. These

create hurdles to the beginners in this field.

These hurdles can be overcome by

adopting a new philosophy called BEAM

ROBOTICS formulated by Mark. W.

Tilden. Here minimal electronics are used

and using solar power, miniature creatures

are created first from which new

prototypes can be evolved. Unlike

conventional robos, which use costly

microprocessor controlled architecture,

these have interconnection of elementary

circuits called NERVOUS NETWORKS.

Here a reconfigurable central network

oscillator is utilized for autonomous and

independent operation of components.

Further it favors development of legged

robos. The nervous technology provides

(1) pulse delay circuits (neurons),

interconnected in closed loops, which

generate square waves and (2) pulse

neutralization circuits. The central

sequencing network and limb circuits

control the direction of the motor thereby

the motion of their legs. The advantage is

that the use of microprocessors and costly

components is eliminated and the

processes are localized and self-sustaining.

Thus beginners and students can

implement the innovative ideas without

having high knowledge, skill and fund.

We are very happy to place this paper

before the academic fraternity. Now it will

be our pleasure to receive the reader’s

feedback. We feel such a feedback is vital

to improving the knowledge of an efficient

engineer, thereby achieving its purpose.

BEAM ROBOTICS

Intr

oduction:

From time immemorial humans are in

search of something that has qualities and

behaviors like themselves. They tried to

train animals to attain the level of

perfection they were having. They went to

look beyond the stars to know whether

there are any civilizations that can

dominate this universe better than they do.

Finally when computers started to evolve,

they made their mind to build some

mechanical creatures stimulated using

clever electronics ……….the ROBOTS.

Today the field of ROBTICS is a

fascination for the men of science and a

factor of enjoyment for the children. The

field has attracted thousands of scientists

who just can’t wait to put what they have

in them to build some extraordinarily

intelligent creatures that can senses similar

to them. The final zeal of any robo

scientist- to create robos those have

ability to think and act accordingly by

themselves (that is survive by themselves).

To achieve this they use mechanical

components that are stimulated by

powerful electronic circuits and bundle of

computer chips that store the programs, the

complete intelligent systems that control

anything and everything in the robo. They

invented algorithms that form concepts

and response rules, entirely on which these

robots depend for interpretation of external

events and the choice of actions are based

on the response rules, sometimes called

‘productions’. At times, just like we

imagine the outcome of our action, they

determine the situation that might arise

from their action, which results in best

probable action.

The other blocks in the path for these

people are:

* A deep knowledge of the subject is

required.

* Many times even simple circuits

require costly and rarely available

components.

* Success can be achieved only after a

great research, that is, even simple robos

can be built by only after some failures.

* As programming is a must for every

action of these robos, it is extremely a

complex process that only a team of hi

intellect and brilliant guys can achieve

success.

* And for all these heavy fund is

required which sets the big block to the

interest of the beginners in this field.

Some 20 years ago, one man wanted to

overcome all these hurdles. He is Mark W.

Tilden who is presently working as a

Biophysicist in LOS ALAMOS

NATIONAL LAB, USA. He formulated a

new philosophy that enables even small

children to enter into the fascinating arena

of ROBOTICS.

BEAM Robotics is a brainchild of this

man. It is a new field in robotics.

BEAM is an acronym standing for...

BIOLOGY Many aspects of the

design and function of BEAM

robots parallel nature. We look to

Mother Nature for inspiration;

keeping in mind that she didn't

have some of the techniques we

have available, like wheels,

bearings.

ELECTRONICS Simple control

circuitry, which allows for

emergent behavior

AESTHETICS Aesthetics means

looks cool. Sure, something crappy

may work, but it's worth the extra

effort to get it as nice as can be.

Make robots pretty and they work

better.

The aim is

Use minimalist electronics

Recycle & Reuse components out

of techno scrap

Solar power it if possible

BEAM robotics is a new field of robotics.

It uses minimalist electronics to create

elegant mechanical creatures that parallel

their natural counterparts in many ways.

The simplicity of BEAM construction

allows people from all walks of life and

levels of education to create very capable

autonomous robots without learning to

program or a government research grant.

If you have the mechanical skill to

straighten out a paperclip until it can roll

down an incline plane you can build a

beambot. The potential for progressive

learning makes BEAM an excellent hobby

for young children who can learn basic

construction techniques and mechanics,

with parental aid of course, and move up

to the electronics portion when they are

ready

BEAM devices come in infinite shapes

and sizes. Some have wheels, some have

legs, some even have wings and there are

some, which use completely different

modes of transportation. The brains used

to control BEAM "life forms" are very

simple compared to the rats-nets of wiring

and circuitry in conventional robots. These

brains, also called nervous networks,

contain no microprocessors with many

BEAM critters having fewer transistors

than a common radio. By wiring in basic

sensors to influence the nervous network,

we can control how the robot behaves

much like putting blinkers on a racehorse

to make it run straight. These sensors

include light detectors, touch feelers, heat

sensors and just about anything you can

think of. Your imagination is the limit.

One of the simple beam bots (with legs) is

shown below:

Some of the great children of this

philosophy are…

Photovore-likes light.

The Walker – can walk or run using 2

legs.

The SPIDER- can walk thro

any obstacle, climb mini staircase etc.

Another photovore

The Moby

Mo

Legs

Solar

The Twalky (Side Fig.)

These ROBOTS are designed in unique

but simple manner that they think

themselves in various situations; no

programming is required for every

simulation as in conventional robots. Just

new innovative ideas molded into an

artificial life induced boy. They have the

new nervous networks (NN) - the boon

given by Mark. W. Tilden to the field of

ROBOTICS. Let us see what this NN is.

NERVOUS NETWORKS

The Nervous Network is an

interconnection of basic elemental circuits

called the ‘Pulse Delay Circuits’, the pulse

delay circuit acting like a neuron,

generating a square wave and hence

functioning as an oscillator.

The most significant characteristic of

nervous network is the absence of

microprocessors and other complicated

circuitry to enable locomotion. The

nervous network in robotic limb control is

simple and autonomous, and any

incorporated complex circuitry in the robot

can be fully dedicated to the actual

purpose of the robot rather than its

locomotion.

The nervous technology promises to

change significantly the design of robots,

by replacing wheeled robots with limbed

ones, making them capable of movement

in virtually any terrain. Moreover the

whole system can be designed at a very

low cost due to use of commonly available

electronic components.

PROBLEMS IN CONVENTIONAL

ROBOTS

Robots have innumerable potential

applications on both industrial and

domestic levels.

To date the most successful designs have

involved wheeled devices. However,

wheeled devices have very limited utility

in many environments. More than half of

earth's landmass is impassable by wheeled

vehicles of today's conventional size.

Wheels are simply unsuitable in many

environments, for example in rough or soft

terrain. Moreover, any wheeled device is

restricted to largely horizontal travel, since

traction relies entirely on the force of

gravity.

On the other hand, legged devices are

capable of traveling on virtually any type

of terrain. Such devices, although slower

than wheeled devices, are far more

versatile and adaptive to their

environment, are capable of traversing

obstacles that are impassable to wheeled

devices, and if properly equipped are able

to climb vertically. Once the difficulties of

mechanical power requirements,

interconnection complexity and excessive

weight are overcome, there remains the

problem of control.

Autonomous legged creatures, to move

and react effectively within their

environment, require precise

synchronizing control circuitry and the

ability to adapt to new conditions as

they arise.

Until now, all attempts to create such a

device have involved elaborate

arrangements of feedback systems

utilizing complex sensor inputs and

extensive control and sequencing

circuitry hard-wired to one or more

central processors.

Such a robot is extremely complex and

expensive to build, even to accomplish

very simple tasks. Moreover, due to

the complexity of such a device and its

heavy reliance on a central processing

system power requirements are

enormous, and a relatively minor

problem, such as injury to a limb, is

likely to cause total system failure.

Such walking devices are accordingly

impractical for other than experimental

or educational uses.

SOLUTION

The nervous technology overcomes the

given problems and other disadvantages by

providing a completely different control

system approach. Rather than utilizing a

central processor to process sensor

information and responsively drive all

mechanical processes, the device of the

robot utilizes a reconfigurable central

network oscillator to sequence the

processes of the devices limbs, each of

which is it autonomous. Once activated,

each limb sequentially executes its

processes independent of the central

sequencer.

The nervous technology further provides a

pulse delay circuit, with a delay of

variable duration, which connected to a

second pulse delay circuit acts as an

artificial "neuron".

The nervous network is made of basic

elemental circuit called the pulse delay

circuit (neuron). The neuron diagram is

given below.

It is made of simple electronic components

like the resistor, capacitor and inverter.

The capacitor forms a "differentiating

element" in a circuit and responds to

changes in input voltage. The resistor and

the capacitor induce a time delay between

the input and the output, and the delay is

determined by the time constant RC.

Hence the delay can be controlled by

varying the value of the resistance and the

capacitance.

ny neurons are

connected in

series with one

another, the

output of the

last neuron

connected to

the input of the first, it forms a closed loop

oscillator in which the alternate neurons

have similar states. The Pulse Delay

Circuit (PDC) is shown beside.Certain

additions to the basic neuron have been

made. Depending on the network's

initialization circuitry, we can have one or

more active processes running around in it.

The native state for a "raw" Nervous Net

at power up is saturation -- here, there are

half as many active processes as there are

Nervous (alternate Nervous are active at

any given time).

Another elemental component of the

nervous network is the pulse

neutralization

circuit. The

diagram of the

Pulse

Neutralization Circuit (PNC) is shown.

It is different from the pulse delay circuit

in that the position of the resistor and the

capacitor has been interchanged. This is

actually a neural neuron and it is here that

the nervous network incorporates features

from the neural network. The circuit is a

modified low pass filter permitting signals

of only low frequency i.e. signals of longer

duration to pass through. The PNC can

take any of the three configurations shown

in the diagram. It is an effective circuit for

controlling the introduction of pulses to

the central sequencing loop.

These are the two principal circuits used in

a legged robot built on nervous

technology. Explained below is the

implementation of the nervous

technology in a four-legged robot.

The robot has two main nervous networks

the first one being a central sequencing

loop and the second a limb control circuit.

The diagram of the central sequencing

loop is shown below.

The biasing resistor is connected to the

second neuron C2. Between the third

neuron C3 and the fourth neuron C4 is

connected the pulse neutralization circuit.

As mentioned earlier the signal goes high

and low at the output of every neuron. This

signal output can be given as the input to

every limb control circuit connected

between the neurons.

The limb control circuit is given below.

The limb circuit has four neurons N1-N4

connected in series. The input from the

central sequencing loop is given to the first

neuron. The four-neuron limb can run two

motors, one for horizontal movement and

the other for vertical movement. Which

input is high determines the direction of

rotation. The motor is connected as shown.

Hence the driver turns the motor 1 in the

forward direction. When the signal reaches

the output of neuron N2 after a time delay,

the junction J2 is high and junction J4 is

low. Hence the driver turns the motor 2 in

the forward direction. When the signal

reaches the output of neuron N3 after a

time delay, the junction J3 is high and

junction J1 is low. Hence the driver turns

the motor 1 in the reverse direction. When

the signal reaches the output of neuron N4

after a time delay, the junction J4 is high

and junction J2 is low. Hence the driver

turns the motor 2 in the reverse direction.

By this sequence of turns the motors

would have moved the limb back, lifted it,

moved the limb forward and then dropped

it. This is basically how the limb moves. If

every limb makes this pattern with a time

delay the robot basically walks or even

runs if the time delay is less. The above

two circuits are built into the robot whose

basic top view is given below.

The central sequencing loop along with the

limb circuit and the PNC forms the overall

control circuit of the robot, which is given

above.

The central sequencing loop has the four

neurons C1-C4. Between every two

neurons of the central sequencing loop is

the limb circuit with four neurons and

motors with their drivers. The PNC is

connected to the central loop. A sensor-

stimulated pulse of any duration less than

the time constant of the PNC will have no

effect, while a sustained stimulation will

introduce a single pulse to the loop. A

pulse may then be injected into the central

sequencing loop through a sensor-

controlled PNC or directly from the source

potential, at the input of any PDC in the

loop, initiating all processes.

By biasing the PDC's in the central

sequencing loop to fire at predetermined

intervals, movement of each limb is

initiated at the appropriate time. In the

central sequencing loop, these pulses can

be neutralized to stop all motion by

applying the source potential directly to

the output of any inverter in the loop; this

prevents the capacitor from discharging

and effectively breaks the firing chain to

the next PDC. Once a pulse is propagating

around the central sequencing loop, the

limb control circuits are initiated

automatically in the manner described

above. Through remote or local control,

source applied to any inverter input will

start the device, and source applied to any

inverter output will stop it.

It is easy to realize that for every limb just

2 neurons are needed and hence many

limbs can be added easily using the

74xx240 or the 72xx14 inverter IC’s.

handling. Internal feedback exists between

the motors depending on the load. This is

also called impex feedback.This is the

incorporation of nervous networks into

robotics.

(NERVOUS NETWORK is a patent of Mark. W. Tilden)

RESULTS

The application of nervous networks in

robotics to nullify complex circuitry in the

control of the locomotion of the robot has

been achieved.

A judicious distribution of the various

types of PNC's throughout the central

sequencing circuit and the limb control

circuits will integrate the various limb

processes for smoother performance, and

will facilitate the use and effects of many

different types of sensors to render the

device fully autonomous.

It will be apparent that a walking device

embodying the nervous network will have

applications in many industries.

Such a walking device could patrol

secured premises with a video camera

transmitting signals to a remote recorder;

could carry out cleaning and maintenance

functions in inaccessible areas such as

ipes, or in hazardous areas such as

nuclear reactors.

Equipped with a brush it could perform

simple household chores such as dusting

and cleaning floors. Because of its

versatility and low cost, the potential

applications are unlimited.

The number of combinations and

permutations of the circuits described

herein are believed to be infinite, but the

principles involved will remain the same.

The advantages of this technology

are numerous.

* The pulse delay circuit is very

inexpensive and all components are

presently available "off the shelf". Power

requirements are very small.

* The control circuits simplify

mechanical process controls to mere pulse

trains, requiring no microprocessor, so

that if a microprocessor is utilized it can be

virtually entirely dedicated to task

planning and information retrieval.

* The process controllers are self-

stabilizing, and since each limb is

essentially autonomous it is unnecessary to

hardwire all actuators and sensors to the

central torso; moreover, if a limb is

damaged or malfunctions it can be

removed from the sequence automatically,

without affecting the central sequencing

processes or the operation of any other

limb.

FUTURE OF BEAM ROBOTICS

(CONCLUSION)

The future of BEAM is brighter as a clear sky sun. From a state of hobby it will emerge as a branch of study. New walking mechanisms touch and vision systems, and encrusted robots with photodiode scales are some recent innovations. Eventually, the B.E.A.M. robot cists hope to see all sorts of tiny robotic creatures lurking in the shadows of our lives, performing menial and repetitive tasketles wrangling dust bunnies), scrub out toxic chemical tanks, hunt down insect pests, re-seed the rain forest, and terrify the cats, dogs, and kids in your neighborhood. The possibilities are endless.