Advance Roving Device for Rescue Operation

8/20/2019 Advance Roving Device for Rescue Operation

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PROJECT

DESIGN AND FABRICATIONS OF A BOGIE FOR ARDRO

(Advanced Roving Device for Rescue Operaions!

C"APTER#$ INTROD%CTION

C"APTER#& 'ITERAT%RE REIE)

C"APTER#* PROB'E+ DEFINITION AND +OTIATION TO DO T"E )OR,

C"APTER#- DESIGN OF ARIO%S E'E+ENTS OF DEICE

A. Design Of Fron For/ 'in/ages

Grap0ica1 2e0ods of di2ensiona1 s3n0esis

+a0e2aica1 For2u1as and Ca1cu1aions

Design Of Para11e1 Side Bogie

Designing Ro4o Srucure

Se1ecion Of +oors

+ini2u2 Re5uired Tor5ue For Fron +oor

• Tor5ue Produced B3 Se1eced +oor

B. Design on AuoCAD

C"APTER#6 FABRICATION OF DEICE

C"APTER#7 SCOPE FOR F%T%RE )OR,

REFERENCES *8

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C"APTER#$ INTROD%CTION

The purpose of this project is to design and manufacturing a rescue robot bogie. In

rescue like operations, a person may encounter difficulties in seeking and assisting the

victims properly, especially in unstructured environment. Therefore using a robot to search

for injured persons as well as describing the best path to reach a victim reduces the risk in a

rescue operation. In contrast, it will increase the accuracy, safety, and the speed of a rescue

operation.

One of the challenging issues in the design of the rescue robots is their ability to

handle unstructured and unstable physical conditions of the working environment.

In order to fulfill a good rescue operation especially in uneven and unstable terrains a rescue

robot must have some features listed:

1. daptation and smooth movement on the uneven terrains.

!. "assing obstacles of different si#es.

$. Tip over stability.

%. bility to come out of holes and continue motion even when problems occur for

individual wheels.

The main structure is based on a shrimp mechanism. s a general rule, rover robots are

more adaptable and stable than walking robots. They are less complicated and more efficient

in unstructured environments. The only deficiency in shrimp rovers is that they cannot

generally climb too high.

In order to fulfill the above re&uirements the '('O will have the mechanical design as per

given below:

The '('O has si) wheels that operate separately* back and front wheels and four

side wheels that are mounted in parallel bogies system. Its special design, fle)ible elbows, a

spring fitted in the front elbow that work as a pushing force, makes it possible for robot to

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adjust rough areas and obstacles such that all si) wheels touch the ground

simultaneously+fig.1.

-ach wheel is driven by its own motor. The rear motor is fi)ed permanently to the chassis

body, and the remaining five motors are on pivoting legs.

-ach side of the chassis has a pair of wheels mounted on legs. The legs are connected by two

cross plates and pivot at two points.

ig.1 'obot fle)ibility in /onve) 0 /oncave environment.

The wheels are coupled so that the force distribution be the best possible. The spring

and dimensions of the robot are designed in a way that when it is standing on a planar

surface, forces acted on all si) wheels are the same.

This robot is somewhat similar in motion to the sea shrimp. The idea of using a

shrimp like mechanism in climbing the obstacles was first demonstrated in -" 213. This

'obot is similar to 'ocky4 2!3, 5ojourer 2$3 and 6arsokhod 2%3 in some parts but adding a

four7link mechanism in front of the robot has made it more efficient encountering the

obstacles+fig.! b.

"rocessing and optimi#ation of design parameters in order to reach the desired

behavior consist of many stages in kinematical design and dynamical analysis. irst

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kinematics of the front fork is considered* then the other parameters will be optimi#ed

according to the mentioned goals.

ig.! "arallel mechanisms a! virtual rotation a)is of a bogie 4! front fork kinematics.

8ecause the instantaneous rotation center is placed below the wheel a)is, the fork passively

folds for climbing an obstacle.

T0e Cener of Gravi39s pa0:

The robot is designed to be able to climb stairs with !9 cm in height. hile passing through

obstacles, front and side wheel;s mechanism cause the center of gravity to move gently.

'obot behavior while passing stairs is shown in ig.$. In this picture, path of /.< on stairs is

very close to the behavior of a slope with the average stair slope. To soften the movement,

two parameters of si#e and location of bogies play an important role. "ath of /.< while

climbing stairs is shown in ig.% for different values of bogies si#e.

ig.$The path of /.< on stairs

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ig.% The path of center of gravity for various bogies si#e +all dimensions are in cm

APP'ICATIONS OF ARDRO:

•

6ilitary operations for underground surveillance systems vi#. bunker operations.

• /ivilian operations like 'a1 2as;id case.

• 'escue operations for natural disasters like earth &uakes, fire rescue etc.

• It is very well suitable for space operations.

• If scaled up, works as a wheelchair on structured as well as unstructured environment.

• '('O can also be used in military mine detection, combat, search operations.

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C"APTER#& 'ITERAT%RE REIE)

'ough terrain robotics is a fast evolving field of research and a lot of effort is being put

towards reali#ing fully autonomous outdoor robots. 5uch robots are applied in the scientific

e)ploration of hostile environments like deserts, volcanoes, the ntarctic or other planets.

There is also a high level of interest for such robots for search and rescuing after natural or

artificial disasters. =arious robots have already been designed with different kinematics and

dynamic respect but somewhat working on closed loop kinematics. 5ome robots using the

same principle as generally used in rescue robots and space rovers are given:

. 6'5 ->"O'TIO? 'O=-' +6-'* ig.@

ig.@ 6ars -)ploration 'over +6-' of ?5

The 6-' +5pirit 0 Opportunity are the most well known rocker bogie type rovers. Thedesign has si) wheels, whereas the front wheels are e&uipped with steering capability. It is an

asymmetric design* the distance between the wheels is not e&ual. In order to have e&ual load

on all wheels the hori#ontal position of the centre of mass +/O6 is slightly shifted forward.

Other robots like 'ocky4 2!3, I(O 2193 and 5ojourner 2113 are based on very similar

locomotion systems with small changes.

8. /'8* ig.A

ig.A /'8 +-"

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The /'8 has two parallel bogies connected at the bottom through the middle wheel

and at the top with a rotational joint to prevent hyper7statism. The vertical middle levers of

the bogies are placed at a !0$ B 10$ ratio from the middle wheel in order to distribute the

weight of chassis and payload evenly on all wheels because the /O6 is e)actly above the

middle wheel.

/. '/7-* ig.4

ig.4 /oncept - +'/7- of 'over 5cience and Technology /ompany developed for -5

The '/7- has one parallel bogie on each side in front. The back wheels are

mounted on a transversal parallel bogie that serves as a leveling mechanism in case of

asymmetric obstacles. Cowever, this mechanism has no influence on !( terrains and can be

replaced by a rigid link between chassis and back wheel without changing the kinematics of

the rover. The /O6 is situated above the middle wheel.

(. '/7/* ig.D

ig.D /oncept / +'/7/ of '/ developed for -5

The '/7/ has a bogie between back and middle wheel, whereas there is a structure

with a joint in between middle and front wheel. 8oth these elements are connected with a

joint to the chassis forming a closed kinematical loop. The /O6 is situated above the middle

wheel.

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-. /'875* ig.E

The /'875 concept is similar to the /'8, but the parallel bogies were replaced by

regular bogies and connection joints were added to the bogies to provide the re&uired degrees

of freedom. The system is symmetric with the /O6 in the middle.

ig.E /'875 +new concept

. /'87D* ig.19

ig.19 /'87D

The /'87D concept is an eight wheeled suspension system that makes use of two

parallel bogies on each side which are connected to the chassis. The system is symmetric

with the /O6 in the middle.

. (OF8- 5"'I?


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C"APTER#* PROB'E+ DEFINITION AND +OTIATION TO DO T"E )OR,

?atural disasters like earth&uakes, fire etc. lead to very large human life losses in

every year in various countries. In case of earth&uakes human bodies are found under the

destroyed building structures. The one and the most necessary step is to find out the injured person and give them a medical treatment as soon as possible. One of the major challenging

issues in rescue operations is the non7availability of rescue teams in sufficient number.

ig1!. unstructured environment created by earth&uakes.

In the same manner fire rescue operations also re&uired to search the victims inside

any fire regions, it leads to very large time if done manually. nd it is difficult for rescue

team also to survive inside fire regions.

In case of gas tragedies in any industry it is very difficult to survive inside the

affected region because of the harmful gases. nd rescue members face difficulties to search

the workers in time. It is &uite possible to reduce the number of victims if they are searched

in a lesser time.

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One of the major challenging issues for army is to secure the national borders from

terrorists. In case of mountains and hilly areas at a very long height it is difficult to breath for

army persons due to lack of o)ygen and pressure.

e all are very well known about the projects from various space organi#ations like

?5 and I5'O. The robots are sent to the space and they send us the information about the

environment present there. One of the major problems for robots is to move on the surface of

planets. There may be various types of obstacles or hindrances in the paths of such robots

which is to be overcome by them.

ig1$. 5pace unstructured surface

These all respects motivate us to build a device which can work as a rescue team

member. or almost the entire above operations one of the challenging issues for rescue

members is to handle the unstructured environment.

Thus our project objective is to make a device which can handle the unstructured

surface and environment.

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C"APTER#- DESIGN OF ARIO%S E'E+ENTS OF DEICE

A. Design of fron for/ 1in/ages:

The robot;s front fork has three roles as described below:

. The spring makes it possible for wheels to touch the ground all the time.

8. hen the robot encounters an obstacle* the hori#ontal force acting on the front wheel

creates a tor&ue around the instantaneous rotating center of the front wheel. The four

bar mechanism design in the front wheel, shows that the instant center is set under the

hori#ontal line, and therefore causes the wheel to move up accordingly.

/. hen the front wheel is going up, spring is compressed and energy is stored in the

front wheel. lthough, other wheels are not in a good condition during climbing and

they donGt touch the ground completely, but this stored energy helps them to move up

easier. igure shows the performance of the front fork in passing obstacles.

'('O behavior is completely dependant on the characteristics of the front fork. (esign

criteria of front fork are:

• Inclination to move upward via obstacle climbing.

• Tendency of the robot to move forward while the front wheel is climbing. "roper

range of ascending and descending.

• 5ufficient storage of energy in the spring mounted on the mechanism to help the other

parts in climbing.

6eeting the first criterion deserves a large force component on the coupler curve in

the direction which causes the upward motion. 8elow fig.1% shows the coupler curve of a

mechanism in three different situations.

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ig.1% coupler curve of a mechanism in three different situations.

s seen in the fig.1@, the less the coupler curve angle, the more the upward

component of force will be. Cence only small angles meet our re&uirement for part1. On the

other hand, to have upward motion the instantaneous of rotation of link $ relative to the body

must be under the line which is in direction hori#ontal force. In this situation tor&ue of

hori#ontal force about instantaneous center of rotation +I/' is positive +counterclockwise

as shown in fig.%.

hen the robot encounters an obstacle* the hori#ontal force acting on the front wheel

creates a tor&ue around the instantaneous rotating center of the front wheel +fig.%. The four

bar mechanism design in the front wheel, shows that the instant center is set under the

hori#ontal line, and therefore causes the wheel to move up accordingly.

ig.1@ The front wheel

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T H h J9

ig.1A "ositive Tor&ue of orce 'elative to I/'

If we want to have hJ9 in total scaling time the main idea is keeping the dimensions

of links ! and % near each other to make the center of rotation farther away. In this approach

the coupler curve angle should be too small during the upward motion of the front wheel. or

the second criterion it is enough to have a small coupler curve angle relative to hori#ontal,

but for a good range of ascending0descending this angle shouldn;t be too small. Therefore we

have to compromise between these two goals for a good range of ascending 0descending and

minimum tor&ue in climbing. hen the front wheel falls in holes, the resultant force on the

mechanism should help it out. lso to avoid locking the front fork when getting down the

stairs we shouldn;t approach to the Kdead pointL of the mechanism.

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Grap0ica1 2e0ods of di2ensiona1 s3n0esis:


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Moin points 1, 81 and !, 8! to pole "1! .8ody rotation of link 181 about the pole "1!

can now be conceived as rotation of triangle "1!811 about imaginary pivot "1!.ith this

concept clearly,

N 81 "1! 8! H 1 "1! ! H ! P1!

gain as triangles 81 ?!"1! and 8! ?!"1! are identical,

81"1! ?!H 8!"1! ?!H P1!

lso triangles 1"1! ?1 and !"1! ?! are identical, and as such

1"1! ?1H !"1! ?1HP1!

The position of pole "1! therefore, depends only on the initial and final position of the

rigid body, representing by the line 8 further discussions above refer to finite displacement

as distinct from the concept of infinitesimally small displacement. /learly when angle !P 1! of

rotation infinitesimally small, the pole "1! becomes the instantaneous centre of rotation.

n important rule follows from above discussions considering to finitely separated

positions 181 and !8! of line 8, let O and O8 be arbitrarily selected position of pivots

along midnormals of lines 1! and 818! respectively. et O8?! and O?1 be the

midnormals of lines 818! and 1!, intersecting at point "1! to give pole of rotation from

discussions above,

81"1! ?! H1"1! ?1H P1!0! join 1 to "1!.

dding common angles 1"1! ?! to e&ual angles 81"1! ?! and 1"1! ?! +each e&ual to P1!0!

we conclude that Oa"1!1 H 1"1! O b.

T0is 1eads o fo11o>ing genera1i?ed ru1e:

The coupler and the frame link subtend angles at the pole " 1! which are either e&ual

or differ from each other by an angle of 1D9Q.

If the pole "1! happens to fall too away from frame as in fig.A, the link 8 can be

guided as a coupler of %7bar mechanism with pivots located suitably at Oa and Ob on the

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mid7normals of lines joining 1, ! and 81, 8!. The point is called circle point because an

arc of circle can be passes through the corresponding positions 1 and !./orresponding

centre7 point in the form of fi)ed pivot Oa, can in fact be located anywhere along the mid7

normal of line 1! and will be known as center point7 conjugate to the circle point . link

joining center point to the circle point can guide point from 1 to !. 5imilar discussion is

valid for circle point 8 and its conjugate center point +fi)ed pivot Ob .

In rigid body guidance +i.e. motion generation a designer has the choice of selecting

position of line 8 anywhere in the body or its e)tension. Thus in guiding a rigid body

through two positions three free choices e)ists for selecting a pair of circle point and

corresponding center point: two choices in respect of independent variables ) and y for point

a in the coordinate frame and one in respect of location of fi)ed pivot Oa anywhere along

mid7normal of line joining two positions 1 and ! of point . Therefore three infinites of

solution are possible for fi)ing a pair of circle point and center point in constructing a %7bar

linkage for rigid body guidance. -ven if it is not possible to locate fi)ed pivot O 8 on the mid7

normal of 818!, it does not matter.

e have applied this synthesis for four bar front fork mechanism for a vertical

displacement of 1@ cm and get the lengths of linkages as shown in figure 14.

+a0e2aica1 For2u1as and Ca1cu1aions:

Freudensein9s e5uaion (e5uaion for disp1ace2en!:


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It is used to find the length of links R also calculate the displacements of links. /onsider a

four bar mechanism of 8/( as shown in fig.4 in which O!H!, 8H$, 8O%H%, O!O%H1.

The link O!O% is fi)ed R lies along >7a)is .et the links O!, 8, 8O%, O!O% makes angles

P!, P$ and P% respectively along the >7a)is or link O!O%.

ig.1D reudenstein;s e&uation +e&uation for displacement

The relation between the angles R the lengths may be developed by considering the links as

vectors.

(isplacement nalysis: 7 or e&uilibrium of the mechanism, the sum of the components

along >7a)is R along S7a)is must be e&ual to #ero.

irst of all taking the sum of the components along >7a)is as shown in fig1D.

e have

! cosP! $ cosP$ B % cosP% 7 1H9 +1

! cosP$ H % cosP% 1 B ! cosP! +!

5&uaring both sides

+!cos P$UH +% cosP% 1 B ! cosP!U +$

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?ow taking the sum of the components along S7a)is, we have

! sinP!$ sinP$ B sinP%H9 +%

$sin P$H%sin P% 7 ! sinP! +@

5&uaring both sides

+$sin P$UH +%sin P% 7 ! sinP!U +A

dding e&u.$ R A

e get

cos P% cosP!sinP% sinP! H !U 7 $U %U 1U0! !% +1cos P% 0 ! B +1cosP! 0 % +4

et

1 0 ! H k 1, 1 0 $Hk !, !U7$U%U1U0!!% H k $ +D

/osP%cosP! sinP% sinP! H k 1cos P% 7 k ! cosP! k $

/os+P! 7 P% H k 1 cosP% 7 k ! cosP! k $ +E

This e&u.E is known as reudenstein e&uation.

ollowing results are obtained from above e)ercise:

5U H !U 1U 7! V1V!VcosP! +by cosine rule

P$ H arccos2+$U5U7%U0+!V$V53 B W

W H arctan 2+!sinP!0 +1 B!cosP!3

/o7ordinates of point "*

>p H !cosP! @ cos +X P$ +19

Sp H !sinP! @ sin +X P$ +11

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Fro2 0is 2e0od of di2ensiona1 s3n0esis fo11o>ing design is o4ained for fron for/:

ig.1E

ithin the front fork design section appropriate setting for the front fork was

discussed and now its implementation and mechanical detail design will be considered. These

conditions ensure effective operation of the mechanism:

Y ppropriate strength especially against lateral loads and impact forces caused by front

obstacles while designing with minimum clearance.

Y "roviding enough space for a highly adjustable spring.

B. Design of para11e1 side 4ogies:

s mentioned earlier, two parallel four7link mechanisms have been mounted on each

side of the robot main body. 8ecause of the essential role of these parts for adapting to

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A

AB=21cms

AD=6cms

CD=13.5cm

s

BC=15cms

BE=15cms

B

D

E

C


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rugged routes and obstacles, it is imperative to have a good rotational capability in addition

to high stiffness. To overcome the rotation difficulties, two pairs of angular contact ball

bearing have been used for installation of each bogie. /learance between linkages has been

reduced by proper mounting method.

?ow similarly we applied the graphical method of synthesis for parallel side bogies

and get following results+fig.!9, which are checked by reudenstein;s e&uation +e&uation for

displacement.

ig.!9

5ince parallel bogies pass the obstacles easier than classical bogies +although both have

similarities in kinematics and in kinetics, they are used in this design +igure.

20

A B

CD E

F

G H

AB=CD=20cms

AD=EF=BC=6cms

AG=BH=12cms


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ig.!1 the bogies.

C. Designing Ro4o Srucure

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"arts of the robot structure are the fork and parallel bogies that were considered

earlier. The other part connects back wheel with those three parts and is e)plained in this

section. 'obot structure is similar to a bo) that connects the wheels, as its nodes, together

and transfers loads from them to ground. 5election from the various forms available was

based on these notes:

Cigh strength and low weight that have lead to a holed structure.

The structure is made from plates, similar to a house structure. The batteries +one of the

densest and most sensitive parts of the robot, electrical wires, and other parts of robot are

located within these plates.

inally, the KbackboneL or structure of the middle of the robot is in complete

accordance with available operational space while considering motion of large wheels and

motors.

(espite the e)pense and large amount of machining time, re&uired for reducing

structure weight, it is very effective in its purpose as robot structure and does its best in

increasing robot beautifully due to its harmony with other parts.

D. Se1ecion Of +oors

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)0ee1 Forces:

ig.!! ree body diagrams of towed +a and driven +b wheels

rigid wheel sinks on the soft terrain as in figure !!. sh distance is called sinkage height.


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ig!$. heel passing over same wheel diameter +a and more than half wheel diameter +b

height obstacle

In figure !$ +a, height of the obstacle is same or less than the half diameter of the wheel.

or this condition, the wheel;s instant center of rotation +I/1 is located at the contact point

of the obstacle and wheel. Trajectory of the wheel centers; during motion generates a soft

curve, thus, hori#ontal motion of the wheel center does not break. 5ince in figure !$ +b,

height of the obstacle is more than the half diameter of wheel, this condition can be classified

as climbing. /limbing motion consist of two sub motions. irst one is a vertical motion,

which causes a hori#ontal reaction force on wheel center. This vertical motion;s instant center

+I/! is at infinity. 5econd one is a soft rotation similar to figure !$ +a with instant center of

rotation +I/$ at the corner.

)0ee1 S1ip and Ro11ing Resisance:

The intent is to formulate a holistic model of a robot to optimi#e the control of the

wheel motor tor&ues to minimi#e wheel slip. Therefore it is helpful to review the governinge&uations on wheel slip and rolling resistance. These e&uations are later incorporated into a

&uasi7static model of a robot. igure !% shows the common forces acting on the wheel of a

mobile robot.

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" : e)ternal wheel joint force T : friction force

? : normal force ' : wheelGs radius

Zo : static friction coefficient 6 : motor tor&ue

Z : dynamic friction coefficient

igure !%. cting forces on a wheel

The wheel is balanced if the friction force fulfils the e&uation:

staticH Z9 V ? +1!

This case represents static friction.

If the static friction force canGt balance the system, the wheel slips and the friction force

becomes:

dynamicH Z V ? +1$

In order to avoid wheel slip, the friction force which depends directly from the motor tor&ue,

6, should satisfy the e&uation +1!

TH6 @ ' H f H Z9 V ? +1%

The above e&uations suggest that there are two ways to reduce wheel slip. irst, assume that

Zo is known and set:

T H Z9 V ? +1@

In fact, it is difficult to know Zo precisely because it depends on the kind of wheel7soil

interaction. (uring e)ploration, the kind of soil interacting with the wheels isnGt known

which makes Zo impossible to pre7determine. ntilock break systems in automobiles sense

slip and then compensate T until slip is not sensed anymore. 8ut in this case slip has already

occurred. nother way to avoid wheel slip is to first assume that the wheel does not slip. It is

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then possible to calculate the forces T and ? as a function of the tor&ue and the result is

optimi#ed in order to minimi#e the ratio T 0 ?. ccounting for the previous assumption:

T 0 ? H Zn V? 0 ?H Zn +1A

Zn is similar to a friction coefficient. In minimi#ing this ratio, then minimi#ing Zn weoptimi#e our chances that this coefficient is smaller than the real friction coefficient Z9. If this

is the truth, there is no slip. Therefore, it is possible to minimi#e the ratio T 0 ? without

knowing the real static friction coefficient. The second method is used here, because it is

more robust. Cowever, determination of parameters T and ? re&uire a model of the mobile

robot. 'olling resistance is another important aspect to the &uasi7static model, and is

therefore reviewed here. static model balances the forces and moments on a system to

remain at rest or maintain a constant speed. 5uch a system is an ideal case and does not

include resistance to movement. The rolling resistance is introduced in order to complete the

model. This results in a &uasi7static model. or a motori#ed wheel +fig.!@,we have:

T, ? : tangential0normal force s : movement of the wheel

T;, ?; : ground reaction forces e0r : rolling resistance parameter

' : wheelGs radius 6r : friction tor&ue

ig.!@ 'olling resistance on a motori#ed wheel

The friction tor&ue, or rolling resistance tor&ue, is opposed to the movement +Cert#7oppl

model 2D3:

6r H ' VT H 9.1@ +' 0 l V -+10! V ? +$0! +14

where l is the length of the rectangular contact patch and - is the reduced elasticity module

described by :

- H !V-1V-! 0 +-1-! +1D

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where -1 and -! are the elasticity of the wheel and the ground. This representation e)presses

the friction tor&ue as dependant on the normal force applied on the wheel. greater normal

force results in a greater resistance tor&ue which follows intuition.

-&uation 14 is not linear which can be difficult for analytical solutions. It is therefore

simplified as:

6r H X V 9.1@ +' 0 l V -+10! V ? +1E

where X is a coefficient for reducing the simplification error. X is identified after an iterative

process that estimates the simplification error.

+ini2u2 Re5uired Tor5ue for Fron +oor:

s discussed earlier in the design of the front fork, a hori#ontal force on the front

wheel will produce a positive tor&ue that pulls up the mechanism on the first step

independent from the tor&ue of the motor. 8ut we have to use this tor&ue to overcome the

spring resistance.

ssuming the weight of the bogie, its components such as batteries, switches, motors

and wheels etc e&uals to Akg.

'eaction at each wheelH?H1kgHE.D?

riction force at the wheelHZV?HE.DZ

?ow from above formula it is very well known that friction force depends upon Z,

which depends on the wheel7soil interaction.

In such case we assume Z as 1, which is ma)imum possible value. Thus,

F friction H E.D ?

Tor&ue re&uired for overcoming this friction force,

T f H F f V r +!9

r H radius of the wheelHAcm.

T f H E.D V 9.9A ?7m H 9.@DD ?7m [ 9.A9

Tor5ue produced 43 se1eced 2oor:

If we are using motors having ?H@9 rpm, = H 1!=, IH9.@amp.

"ower produced by motor H V I H A watts.

Tor&ue produced by the motor H +P V A9 @ !VVN H 1.1%@ ?7m, +!1

This is greater than re&uired tor&ue.

5o, selected motor is suitable according to re&uirements.

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Design on AuoCAD

(esign of device is made on uto/( according to dimensions obtained from analytical and

graphical method. ew images of robot design are given in following pages:

ig.!A 5- Isometric =iew

ig.!4 5- Isometric =iew of front fork

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ig.!D Top =iew+dimensions in mm

ig.!E ? Isometric =iew Of "arallel 5ide 8ogies

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C"APTER#6 FABRICATION OF DEICE

• %#Cross Secion Bars And C31indrica1 Rods e have joined ! F cross section7

!cmV!cm having depth and thickness !cm and !mm respectively*1.!cmV1.!cm

having depth and thickness 1.! cm and ! mm respectively and cylindrical rods

having diameter @mm.+fig.$9

.

ig.$9

• Roar3 Joins igure shows the rotary joint mechanism used in the device.+fig.$1

ig. $1

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• Seering +ec0anis2#e made an assembly for steering purpose as shown in figure

motor a)le is fi)ed to a block having wheel and motor assembly. ith such a steering

mechanism device can steered our device by an angle of E9\ right hand side.+fig$!

.

ig.$!

• Side Bogie To Rigid Srucure Joins# side bogies are pivoted to main frame or rigid

structure.+fig $$

ig.$$

• +oor To )0ee1 And Bogie7 +fig.$%

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ig.$%

• Baeries and adoper used7 +fig.$@

NiCad (Nic/e1 Cad2iu2! batteries are good for small to medium si#e range

robots. They have the highest current output, are more affordable than ?i6CGs, and

can be recharged within one or two hours. ?i/ad, over many charges, can only

store less and less energy after each recharge.

dopter used have ac input 1997!@9= ,@9 0 A9 C#,9.$ amp,1@ watt.

nd output generated is 1!v dc,! amp.

ig.$@

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C"APTER#7 SCOPE FOR F%T%RE )OR,

'obotics is the very fast evolving field of research and development. In today

scenario robots are used in various type of machining, assembling, painting and many other

processes in industries. ccuracy and degree of reliability on robots can be seen by knowing

that typical surgeries, operations etc have been doing successfully. =arious countries are

sending there satellite to planets to know about the whether and surface conditions. These all

things have a very large contribution by robots. 'obots developed for space missions are

using various sensors and data communication techni&ues. e are suggesting some

techni&ues and devices by which improvement is possible in working of '('O. These can

be listed as:

1. (esign Improvement:

ll the joints used in '('O are rotary. 8y using bearing at those joints we can

reduce the friction and finally transmission losses.

8y using hub motors we can reduce the si#e of assembly comparatively. e have a

design concept for wheel assembly also +fig.$A . ig shows a concept of designing the

wheel in such a manner that motor can be easily fitted inside the inner periphery of it.

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ig $A.

!. 5ensor based navigation:

The objective of the sensor based navigation of a mobile robot is to reach the target in

any unknown workspace, cluttered with obstacles of any shape, si#e and orientation. Thedecision for the proper turn angle of the mobile robot is taken based on the sensory

information and the target location with respect to the current location of the mobile

robot.

$. 5olar energy powering system:

5olar energy is a renewable energy resource. nd we can use solar cells on '('O body

by which the powering system can be more efficient and independent form electric charging

and it will be able to work continuously.

%. 6ine detection:

/urrently, more than 199 million anti7personnel mines are under the ground all over the

world. These mines not only disturb the economic development of mine7buried nations, but

also injure or kill more than !999 people a month. s a result, the removal of landmines has

become a global emergency. Fnder this ultimate environment, a roving robot may be an

effective and efficient means of detecting and removing mines while ensuring the safety of

local residents and people engaged in the removal work.

The mine detection sensor has a mi)ed sensor which means a metal detector and a radar

sensor. nd, anti7personnel mines and anti7tank mines could be detected by the mi)ed sensor.

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6otor

heel having larger width

and less thickness


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REFERENCES:

1. Kn Innovative 5pace 'over with -)tended /limbing bilitiesL Institute of 'obotic

5ystems, -".

!. ]'ocky 4: ?e)t

Advance Roving Device for Rescue Operation

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Transcript of Advance Roving Device for Rescue Operation