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Design and Development of Control Algorithm of a Prototype Fire-Fighting Robot to
Extinguish a Candle Flame
Final Year Project Progress ReportTeoh Chieh Loon (081061128)
Mechatronic Programme
School of Mechatronic Engineering Universiti Malaysia Perlis,
E-mail: [email protected]
Abstract
Fire can be useful in human daily life but it can cause
disaster when it became big fire. Fire fighter has beendangerous job as them have to put risk of their life to save
other. So this come the role of the fire fighting robot to put
out fire and reduce the risk of any human life lost including
fire fighter. A candle used to replace the role of fire. When fire fighting robot detects the flame of candle in a mock
house, it can navigate through a mock house and avoid anyobstacle before it reach near the fire. By using the
ultrasonic, sharp analogue distance and flame sensor whichinterface with a suitable control algorithm, it will use the
programmed locomotion to navigate the obstacle and wall. Program code to control the fire fighting robot is written in
PIC18F4580 C language. When the flame of candleappeared in the sensing range of the fire fighting robot, then
it will put out the flame of candle as it supposed to do. Based on the experiment conducted, the autonomous navigation
showed satisfactory result. The developed firefighting robot
will provide a test bed for advanced path planning and navigation projects in the future.
Keywords Locomotion, control algorithm, fire fighting robot, obstacle,
1. Introduction
1.1. Background of Research
Fire is an unwanted element which often causes loss of
properties or life. Fire fighting is a dangerous core even for
the experienced fire fighters. Therefore, a fire fighting robotwill serve as a substitution to help extinguishing big fireswhich are dangerous to human beings. Instead of taking the
great leap to develop a real fire fighting robot, the proper step is to gather more knowledge and experiences from
designing a smaller scale fire fighting robot.
1.2. Motivation of Research
Robots assisting fire-fighters are not an often seen sight.However, there are robotic devices that can already be used
for such purposes. These include bots that can be throwninto the fire site to inspect the situation, as well as large
remote controlled fire extinguishers such as Anna Konnda,Hoya Firefighters' Assistance Robot, DRB Fatec ArchiBots,IZ HOLDING Firo-Series firefighting robots, Ryland
research limited Firemote, DOK-ING JELKA firefightingrobots.
1.3. Research Objectives
The objective of this project is to design a fire fighting
robot to extinguish a candle flame which is a located in a
mock house
1.4. Scope of Research
1. An efficient method to ensure robot to approach and
extinguish the candle flame.2. A well-developed algorithm for the robot navigation,
distance control and flame blow off control.3. A robot which can navigate around the field of operation
(mock house).
2. Literature review
2.1 Control Algorithm for Robot PathAlgorithm is playing an important role in determine bestway to make the fire fighting robot to be more efficient to
navigate through the mock house. Then, it searches for thefire source. If it detect fire source from candle, it will use
suited algorithm to find the candle position and move untilright in front of the candle.
2.1.1 Obstacle-Avoidance Behaviour Algorithm
The first implementation of the obstacle-avoidance
behaviour was long and complex and consisted of both proportional and integral control. Each time the behaviour
is called, it checks the front hemisphere of sonar sensors(labelled 0-8 in figure 2.1) to see if any of their ranges are
less than the minimum tolerated sonar distance. If none of these ranges are less than the minimum, the behaviour
returns the commands “full speed ahead” so the robot willcontinue to move. Otherwise, it checks to see which of the
sum of left-front ranges (sensors 0-3) or right-front ranges(sensors 5-8) is smaller, and sends commands to turn the
robot in the opposite direction.
This is illustrated in Figure 2.1. Currently, the obstacle-avoidance behaviour is keeping the robot traveling from
right to left in the centre of the hallway or at least on asinusoidal path down the centre of the hallway if it is wide.
As the robot approaches the corner, the sonar ranges will
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grow smaller on the robot’s left-front side (sensors 0-3).
Some of the sonar ranges on the right-front side of robot
(sensors 5-8) will grow smaller as well, but the codecompares the sums of these two sets of sensors. When any
sonar range is less than the minimum tolerated sonar distance, the robot will turn right and proceed through the
doorway. If there was no doorway, and the sum of the leftsonar ranges matched the sum of the right sonar ranges, the
robot would turn left by default. So, this will create a dead-lock situation in which the robot gets stuck in a corner
turning back and forth. [2]
Figure 2.1 show how the sonar sensor direction and how thebehaviour will works.
2.1.3 Wall Following Algorithm
Wall following can be accomplish by using four method
which have be contact method, noncontact with active
sensor method, noncontact with passive sensor method, softcontact method. Contact method is where the robot uses a
mechanical switch, or a stiff wire connected to a switch, to
sense contact with the wall. This is the simplest method, but
the switch prone to mechanical damage over time.
Noncontact, active sensor method is the robot uses active
proximity sensors, such as infrared or ultrasonic, todetermine its distance from the wall. No physical contact
with the wall is needed for the uses of this method. In atypical noncontact system, two sensors are used to judge
when the robot is parallel to the wall. (See figure 2.2 robotB)
Noncontact, passive sensor method is the robot uses passive
sensors, such as linear Hall Effect switches, to judgedistance from a specially prepared wall by referring to
figure 2.2 robot C. In the case of Hall Effect switches, the baseboard or wall can be outfitted with an electrical wire
through which a low-voltage3 alternating current is fed.When the robot is in the proximity of the switched the
sensors will pick up the induced magnetic field provided by
the alternating current.
For soft contact method, the robot uses the mechanical
means to detect with the wall, but the contact is softened byusing pliable material. For example, the lightweight foam
wheel is used as wall roller as shown in figure 2.2 robot D.the benefit of soft contact is replace the failure of the
mechanical which may be reduced or eliminated becausethe contact with the wall is made through an elastic or
pliable medium. [3]
Figure 2.2 show four method of wall following algorithm: a,Contact switch; b, noncontact active sensor (such as
infrared); c, noncontact sensor (e.g., Hall Effect sensor and
magnetic, electromagnetic, or ferrous metal wall/baseboard); and d, “soft contact” using pliablematerial such as foam rollers.
For the uses of fire fighting robot which faces the maze of
the mock house, so the suitable method is the noncontact,active sensor method. This because the simple ultrasonic
wall follower can use single headed transmitter and receiver or two ultrasonic transmitter, receiver pair. Open doorways
that lead into other rooms or space can be sensed using alonger-range ultrasonic transducer.
2.1.3 Convergence behaviours path
In the path planning algorithm, there are two immutable
laws that must accept:a) A robot is never exactly where its position estimate says
it is. b) A robot`s position estimate is never exactly where it
wants to be.
In a straight path to a destination, the ends of path segmentsas nodes. In figure 2.2.4.1, the robot supposed to be at Node
A, and was to travel to Node B. When robot move, itrealized that its position was actually some distance from
where it should have been at Node A. The first possible
strategy is to ignore the path and move straight for thedestination Node B. the obvious problem with the strategy,is that the robot will run into an obstacle that maybe stop it
from moving to the Node A.
The second strategy is to play it safe and first move straight
to the correct starting position (node A) before heading for Node B. This strategy may be safer, but still it cause time
consuming for taking this strategy. There a problem occurs
when the robot reach Node A, it had to execute the 90-degree turn to the turn which facing Node B.
The third strategy is called by “wagon tongue” method, as it
works like a child pulling a wagon by its tongue. If thechild stays on the path, the wagon will smoothly converge
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onto the path as well. In software, the robot is given a rabbit
to chase that is on the path, the lead distance closer to the
goal than the robot. As robot chases the rabbit, the rabbitcontinues to stay the same distance ahead.
Figure 2.3 show three strategies for getting to destination
2.1.4 Closing behaviours path
There are two methods of deciding how much further todrive. The first method is to continually recalculate thedistance as the robot drive. The problem with this comes
with the fact that as robot approaches the end, and the
destination is to the side or rear, the vector distance is still positive.
The second method involves calculating the distance at beginning of the run, and simply counting down the
distance remaining as a parallel process in the odometry.The problem with this approach is that we may end up
weaving about for any number of reasons, requiring a longdrive distance than calculated. But the figure 2.4 show that
an extreme case of the second law which robot do not get tothe stop at desired point because it maybe had some bad
navigation data and forced to circumnavigate an obstacle before reaching Node B. One answer is to use the parallel
distance to the node to plan the stop, not the vector distance.
As the robot approaches the end of the path, it must switch
out of the wagon tongue behaviour and attempt to close onthe end point.so it is more important that the robot end the
path at the correct heading than at the perfectly correct place. One solution is to limit the angle between the robot
and the path ever more tightly as it approaches the end.Thus, at the end of the path the robot will be consistentlyoriented parallel to the path.
Figure 2.4 shows calculating the distance remaining
2.1.5 Running on path
If the robot expected to run on from one node to the next
node without stopping, as showed figure 2.5, it will be more
complex. In this case, the robots should know ahead of timethat it is not actually running to the node B but is actually
arcing past Node B to get to Node C. The robot should plans to radius the turn and this is the distance away from
node B that it must begin to turn in this case. Once into theturn, it steers at a constant rate until the heading is that of
the B-C, similar to the wagon tongue method. When theheading matches, it can revert to convergence behaviours
and the speed in the turn must be slower as the radius ismade smaller. [4]
Figure 2.5 shows running on past a node.
3. Methodology
3.1 Basic Principle for Control System
This chapter explain the control algorithm that applied inthe fire fighting robot design and navigation process. The
subtopics for this chapter include control algorithm of sensors, servo motor and conclusions. Finally, the output
from the three types of sensors are analysed and defined for
the development of the programming codes so that therobot can make decisions based on the output from sensor.
Control systems are an integral part of modern society. Numerous applications are all around us: the rocket fire,
and the space shuttle lifts off to earth orbit; a self-guidedvehicle delivering material to workstation in an aerospace
assembly plant glided along he floor seeking its destination.These are just a few examples of the automatically
controlled systems that we can create.
A control system consists of subsystem and process (or
plants) assembled for the purpose of controlling the output
of the processes. For example, a fire fighting robot produces wind to blow off candle as a result of appearance
of the flame at the candle. In this process, subsystems,called the flame sensor detect the appearance of the flame
at the candle.
Robot designed by control system principles cancompensate for human disabilities. Control systems are
useful in remote or dangerous location. For example, amicrocontroller-controlled fire fighting robot can be useful
to blow off fire which in dangerous and hot condition.[5]
Explanation of the how does the control system works can be more understand through the figure 3.1 below, it show
the input or stimulus which is desired response will control
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by control system and give the output response which is
actual response.
Figure 3.1 of sample control system block diagram
There are two type of control system which are open loop
system and closed loop system. The open loop system hasonly input, input transducer, controller, disturbance 1, plant
disturbance 2 and output. But the closed loop system havethe input, input transducer, controller, disturbance 1, plant,
disturbance 2 and output transducer which give feedback tothe system, plant and output.
Figure 3.2 show a) open loop system, b) closed loop system[5]
3.2 Control Algorithm
The main control for this fire fighting robot is to
control its navigating system and fire detection. The certainsteps that the program must take before it can complete it's
task which is to put out a candle flame can understand byseeing flow chart below. By using sensors use by the robot,
the task can be completed. The fire fighting robot have togoing the map which will represent the mock house
according to figure 3.3
Figure 3.3 A map of the fire fighting robot routes
3.3 Process Flow Chart
3.3.1 Process flow chart how the fire fighting robot works
1. At first, robot will be place at the starting point, itwill monitoring and stay at initial position. If there
is no flame signal, it will continue monitor for anyflame signal
2. If flame detected, the robot will move andapproaching the direction of the candle.
3. If the flame is not near and no obstacles detected,it will continue repeat the step 2 and move to the
candle direction.4. If the flame not near but the robot detects obstacles
at front, left or right side, robot will turn to avoidthe obstacles and repeat back to step 2.
5. If the flame is near but there is not candle in frontof the robot, it will decide to adjust the direction
and repeat step 2 to approach until in front of thecandle.
6. But when it detect the flame is near and the candle
in front of the robot, the fire fighting robot willtrigger on the fan to blow off the flame.
7. If the flame not blown off, the robot will continue
blow off the candle.
Figure 3.4 show how the flow charts of fire fighting robot
work toward its objective.
3.3 Control System with Servo motor
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This robot is programmed for known environment that is
not expected to change. So this helps us to give a
programming technique to navigate the robot to its possibledestinations for searching for the objective of blow off the
candle. The basic of the control system with servo motor can be tabulated from the figure 3.4.
Figure 3.5 show the feedback from ultrasonic, analogue
distance sensor and flame sensor to servo motor control system.
4. Project Progress
Based on the Gantt Chart proposed, the project are wellmanage to carry out all the progress within the desired date
and time. As for now, progression is assembly andfabrication of fire fighting robot stage. But starting with the
project proposal preparation and submission, basic idea wasgenerated on how the project will be done. The literature
review based on the related field was studied and study of fire fighting robot also carried out including journal
presentation with the supervisor. Testing and analysis of thefire fighting now commencing as robot are been tested for
programming and control algorithm for how does it chooseits locomotion to find the flame of the candle and
extinguish it by blowing the fan toward the flame of thecandle.
Figure 4.1 Grant Chart
4.1 Result and Discussion
From the assembly and fabrication of the fire fightingrobot, the result of design of the fire fighting robot can be
seen in the picture below:
Figure 4.2 Front view of the fire fighting robot
Figure 4.3 Side view of fire fighting robot
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Figure 4.4 Top view of fire fighting robot
Figure 4.5 Bottom view of fire fighting robot
As for voltage regulator circuit for the fire fighting robot,
the list of component in the circuit component consists:1 unit voltage regulator LM7805,
1 unit voltage regulator LM7806,
2 unit of capacitor 0.33 µF,2 unit of capacitor 0.1 µF,1 unit diode 1N4001,
1 unit LED ,1 unit transistor 2N2222A,
2 unit of resistor 1kΩ1 unit relay
Figure 4.6 Donut board mounted with Circuit of fire fighting robot
5. ConclusionBy reading and review the journal, innovative ideas andtheories about the application of fire fighting robot, the
method of previous and past project of the fire fighting
robot have inspired and implemented to this project. Thus,
this robot going to better in term of its function and
application compared with others.
In the nut shell, this project has meet up to its progressaccording planned in the Grant Chart which proposed in
previous report.
For future work, this project planned to accomplish
objective and scope of the fire fighting robot according to
the Grant Chart. More effort on analysis will given
in order to ease troubleshooting of the
locomotion of the fire fighting robot.
ReferencesBibliography[1]Tom Duckett and Ulrich Nehmzowb.(2001) Mobile
robot self-localisation using occupancy histograms anda mixture of Gaussian location hypotheses
a)Centre for Applied Autonomous Sensor Systems,Department of Technology, University of Orebo, S-
70182 Orebo, Sweden b) Department of Computer Science, University of
Manchester, Manchester M13 9PL, UK
Data retrieved December 4 2011 fromhttp://citeseerx.ist.psu.edu/viewdoc/summary?
doi=10.1.1.26.9985
[2]Adam A. Ray “Cooperative Robotics UsingWireless Communication” A Thesis Submitted to the
Graduate Faculty of Auburn University in Partial
Fulfilment of the Requirements for the Degree of Master of Science Data retrieved December 4 2011from http://citeseerx.ist.psu.edu/viewdoc/summary?
doi=10.1.1.26.9985[3]Gordon McComb, Myke Predko “Robot Builder`s
Bonanza” McGraw-Hill, Third Edition 2006.References obtained from Chapter 33 page 599.
[4] John M. Holland “Designing Autonomous MobileRobots”Newnes 2004 Reference from chapter 9 page
127.[5]Norman S.Nise “Control System Engineering”
Fourth Edition, Wiley Publication
Evaluated by:
_________________________________ Supervisor Name: Dr. IR. Marwan Affandi
Date: 13 January 2012Official stamp:
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