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Electronic Luggage Follower

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					                               Electronic Luggage Follower
     César Nuñez, Alberto García, Raimundo Onetto, Daniel Alonzo, Sabri Tosunoglu
                                         Department of Mechanical Engineering
                                            Florida International University
                                              10555 West Flagler Street
                                                 Miami, Florida 33174
                   agarc005@fiu.edu, cesar.nunez007@gmail.com, raimundo.onetto@fiu.edu

                                                                  method using an infrared light-emitting device and a
ABSTRACT                                                          receiver. In order to prevent collision with obstacles,
                                                                  ultrasonic sensors are used to detect objects that may be in
In this paper, we describe the concept of building a robot
                                                                  its path. We present the effectiveness of our approaches by
able to pursue a specific person through an airport while
                                                                  showing the experimental result using a real mobile
assisting with carrying that person’s luggage. After a
                                                                  platform.
review of the current devices available for performing these
                                                                  In this article, we describe the research carried out in the
tasks, we described our approach that aims to develop a
                                                                  attempt to develop a human-following mobile robot. It was
platform that could send and receive a signal that would
                                                                  decided to provide the followed person with a transmitter
provide a simple and practical means for the robot to
                                                                  installed on the back heel of their shoe that would broadcast
determine a path and follow it that does not require the use
                                                                  infrared signals visible to the robot’s receiver that would
of internal maps and the ability to self-localize. In
                                                                  allow it to detect the relative direction of the person. The
particular, the approach is based on a control system able to
                                                                  robot should also be able to exhibit an effective obstacle
execute obstacle avoidance and target following behavior.
                                                                  avoidance behavior and to integrate obstacle avoidance
Also, a relative location device based on a signal emitter
                                                                  with target following and exploration behaviors. Along
(placed on the target person) and a directional sensor
                                                                  with using infrared receivers and transmitters, the robot
(placed on the mobile platform).
                                                                  emit pulses of ultrasonic waves to avoid any obstacle that
                                                                  may come between itself and its owner. In the design of the
                                                                  platform that would carry the luggage, many factors must
                                                                  be taken into consideration. It must be light, but of a strong
                                                                  enough material to hold the average luggage. Compatible
                                                                  motors and microprocessors must be selected in order to
                                                                  make all the components work seamlessly.
                                                                  Through the use of modern day technology, mobile robots
                                                                  have become autonomous enough to carry out numerous
                                                                  applications. We explore this research and review the ways
                                                                  robots can provide services following commands without
                                                                  any physical contact with people. Our goal is to develop an
                                                                  autonomous robot that could follow a person with the
                                                                  purpose of assisting them in the daunting tasks of dragging
             Figure 1. Conceptual Design                          heavy luggage across long distances in airports. While
                                                                  various tasks could be applied to such a robot, i.e.
1. INTRODUCTION                                                   guidance, information supplying or escorting, in this paper,
In this research, we consider how robots can act in concert       we consider all the components and devices required to
with human behavior. Our aim is to develop a robot                complete the task of a creating follower robot with the
capable of maneuvering through busy airports behind its           capabilities of avoiding obstacles while carrying luggage.
owner while hauling his or her luggage. In this paper, we
consider the technique to be used to trail people and report      2. PROJECT CONCEPT
on the realization of a mobile robot capable of following a       The Electronic Luggage Follower (ELF) will be a luggage
person.                                                           that will follow the user throughout any flat surface without
In order to follow a human, a mobile robot needs to know          the need of the user to use force to drag it. No effort will be
the position of the person and must be able to determine its      applied by the user in order to carry different load
own path in order to follow his target. We consider a             magnitudes.




Florida Conference on Recent Advances in Robotics, FCRAR 2010 - Jacksonville, Florida, May 20-21, 2010                   1
3. OBJECTIVES                                                     The biggest challenge in this system is to control the
                                                                  forward and stopping motion. As the user pulls the rope a
•    A robot easy to be used and to be manageable by any          little, the sensor must be activated and the luggage must go
     person.                                                      forward.
•    A wireless system made of a transmitter part and a
     receiver part connected to the luggage.
•    An optional way to carry the luggage in case of any          6. ANALYSIS TO SET UP THE
     problem.                                                        INITIAL CONDITION
•    A sound structure and base design to resist load,
     different temperatures, and external forces.                 6.1. Velocity Analysis:
•    A luggage with an attractive and innovative exterior
                                                                  To perform gear analysis of the system, desired velocity of
     design.
                                                                  the luggage, input torque of the system is needed. The
•    A security system that the user can be free of worries       desired velocity of the luggage is 6.56 ft/s. This is the
     of his or her luggage being stolen or left behind.           measured velocity for a person walking at a fast pace. The
                                                                  input torque of the system is obtained from the design
4. FORM AND FUNCTIONALITY                                         specifications from the motor. By calculating the desired
The product comes in the same sizes as any standard               velocity, v, of the system, the angular velocity of the wheel
luggage. The system inside the bags is resistant to any load      can be obtained, using the following equation.
or external force. The luggage functions with several
different sensors, ultrasonic sensor and touch sensor. These                                        /                        (1)
sensors prevent the bag from bumping onto obstacles, such
as people, wall, and other things on the floor.                   Where ω is the angular velocity and r is the radius of the
The form of the upper part of the luggage is made round to        wheel. After performing calculations, the angular velocity
allow aerodynamics. The based form follows the upper              of the wheel is approximately, 546.7 rpm. Using this value,
part producing a sense of surface smoothness. Inside the          the gear train is analyzed. Gear 3 is attached to the same
base, all the components are arranged on the back part in a       shaft as the wheel, so the angular velocity of the gear is the
stable and practical way.                                         same as the wheel. Using the following equation, the
The functionality of the luggage as said before is to follow      angular velocity of G2, ω2, can also be found, as well as the
a person in either a manual or a wireless way. Ultrasonic         angular velocity of gear 1, ω1.
sensors are in charge of the wireless function of the
luggage. Touch sensors are used to manually drag the
luggage.                                                                                                                     (2)

5. CHALLENGES
Dragging a heavy luggage causes a strain on the person’s          Where n is the speed of the gear, and N, is the number of
body and causes discomfort. The product being developed           teeth of that gear, a is a representation of what gear speed is
will end the discomfort of having to drag luggage all             needed, and b is the gear with the known speed. So the
around any flat surface. It will also eliminate luggage being     values of the angular velocities, in rpm, for all three gears
left behind, or stolen. The original concept was developed        are as follows:
by New York architect Peter Yaedon. However, his design                                  n1 = 109.33
has not been developed and does not yet meet airline
requirements.                                                                            n 2 = 182.20
The challenges of ELF can be classified in two areas; the
wireless design and the easily drag design. For the wireless                             n3 = 546.70
system, the challenge is to achieve the physical separation       The motors used in the prototype provide a maximum
of an ultrasonic sensor. Ultrasonic sensors are sensors           speed of 100 rpm at free rotation, so the desired velocity
where the transmitter and receiver work together as a one         cannot be accomplished. With the motor loaded with the
piece. Originally the transmitter sends a signal that bounces     gears and adding small weight on the system, an input
in any surface and then is received by the receiver. The lap      velocity of 50 rpm is assumed. Using equation 2, the actual
of time in recorded and the distance is estimated. Separate       values for the system used are obtained, and they are as
this sensor is our biggest challenge. Once the physical           follows (rpm):
separation is achieved, another challenge appears. The                                    n1 = 50
sensor should estimate the distance according to the
magnitude of the feculence instead of the time that takes                                 n 2 = 83.33
the signal to leave and return to the sensor.
For the easy to drag system, the challenge is based on the                                n3 = 250
accuracy of the manual command. The user will use a rope          With these angular velocities, the output velocity of the
to “drag” the luggage. By using touch sensors, the rope will      system is approximately 5.99 ft/s. These values prove that
be an activator for motion. As the rope is moved to either        the motor used can provide enough velocity to move the
left or right, the luggage will rapidly move to the               system at about 6 ft/s. However, it is very important, when
corresponding side so that no force is required by the user.



Florida Conference on Recent Advances in Robotics, FCRAR 2010 - Jacksonville, Florida, May 20-21, 2010                   2
working with rational mov                   eck           s
                            ving parts to che that there is       lugga             day use, a hig
                                                                      age, and everyd                         otor is
                                                                                                 gher torque mo
            que              m,             rge
enough torq on the system to carry a lar load and still   l           ed.
                                                                  neede
travel at the desired speed.
                                                                     RECEIVER AND TRA
                                                                  7. R      R              R
                                                                                    ANSMITER
        que/Force An
6.2. Torq          nalysis:
                                                                     S
                                                                     SET UP
            get
In order to g the luggage to start moving, a great amount     t
                                                                        der
                                                                  In ord to use a wir                 s
                                                                                       reless system as desired, two seeparate
of torque neeeds to be provided. To start off the coefficient
                                            ff,               t
                                                                       its
                                                                  circui must be dev   veloped. One ci                 ide
                                                                                                      ircuit will provi the
            between the flo and the whe
of friction b               oor              eels needs to be e
                                                                       sonic sensor tra
                                                                  ultras                                              d
                                                                                       ansmitter with the power and input
determined. For the calc                     is
                            culations of thi luggage, the     e
                                                                                       Figure 2). The o
                                                                  signal required (see F                              ll
                                                                                                      other circuit wil adapt
                             n              ber
coefficient of static friction between rubb and concrete      e
                                                                  the siignal received s that it can b used by the Micro-
                                                                                       so             be
                                            n
was found. The coefficient of static friction is used because e
                                                                  Contrroller.
            is               alue
the system i at rest. The va of the coeff                     n
                                            ficient of friction
                                             he
is 1.0. Once this value is chosen, then th friction force     e
            e                e               e
between the wheels and the ground can be found with the       e
following eqquation:

                           Ff = μFn                          )
                                                           (3)

            is                              e
Where Ff i the friction force, µ is the coefficient of       f
            d               al              ction force is the
friction, and Fn is the norma force. The fric                e
force needed to get the lugg               oving. This force
                            gage to start mo                 e
can be plu                                  on.
            ugged into the Power equatio The power           r
                            ork
equation is a function of wo and time.

                         W
                     P = Work / Time                         )
                                                           (4)

            he             d                         t
However, th work required by the wheel is unknown, but                               2.
                                                                              Figure 2 Transmitter Circuit
            termined by usin equation 5.
it can be det              ng
                                                                  In Fiigure 2, the 9V battery that p
                                                                                      V               provides energy to the
                                                                  frequency generator and the ultraso onic transmitter at the
                         ce
                  W = Forc x Distance                        )
                                                           (5)                        zed. A power co
                                                                  same time is visualiz                               aced so
                                                                                                      onditioner is pla
                                                                  that t voltage can be reduced to 5 before enteri the
                                                                       the                            5V               ing
           g               o               e              n
Substituting equation 5 into equation 4, the power equation                           r                               d
                                                                  frequency transmitter (the frequency transmitter used works
becomes                                                           at 5v) The frequency transmitter wil create a sine w
                                                                       ).             y               ll              wave of
                                                                       Hz             sent
                                                                  40 KH that will be s by the ultras                  r.
                                                                                                      sonic transmitter
 P = (Forc x Distance)/
         ce                       e              )
                      /Time = Force x Velocity (6)

             he
Now, all th values needed to calculate the power are         e
            d
known, and the power requ    uired by the wh                 -
                                            heels is 229.6 ft-
             g               oad
lbs, carrying a maximum lo of 70 lbs. U     Using this power,
or the correesponding torque along with th gear analysis,
                             e,             he
the torque r required by the motor is determ mined. The gear r
             the
attached to t wheel, G3, re                                  -
                             equires a torque of about 230 ft-
lbs. This torrque is transmitt to G2 throug force Ft32 and
                             ted             gh             d
                             g               equation:
this force is calculated using the following e

                        F32t = (2T)/d                        )
                                                           (7)
                                                                                    3.          r
                                                                             Figure 3 Transmitter Circuit 2
                             iameter of the gear, and T is the
In this case d is the pitch di                               e
torque trans                                his
            smitted by this gear. Using th equation, the     e
torque trans
           smitted through each gear can be obtained.
                             e              e                     Once the signal is recorded by the ultrasonic sensor
                                                                  receiv a signal amp
                                                                        ver,           plifier, based on 741 Op Amps, is used
          able 1. Calcula
         Ta             ated Torque V
                                    Values                        in ord to increase the signal freq
                                                                        der                                            hat,
                                                                                                       quency. After th the
                                                                                       e
                                                                  signal is used by the PIC16F690. H    Here the analog signal
                      T1    5
                            51.58 ft-lbs                          comin in is transfor
                                                                        ng             rmed to digital in order to quantify it
                      T2    1
                            139.9 ft-lbs                                              ng
                                                                  later. A programmin code is used to convert the digital
                      T3    2
                            229.6 ft-lbs                          frequency of the inpu signal into a r
                                                                                      ut                range number between
                                                                       d              quency increases the number be
                                                                  0 and 99 (as the freq                 s,              ecomes
          of              ue            move the luggage
The value o T1 is the torqu required to m                e             er).            se
                                                                  bigge Then, a puls with modula       ation is created so that
           red            .56
at the desir speed of 6. ft/s. The m    motors purchased d        this n                                nto
                                                                        number can be transformed in the percent       tage of
cannot prov               e
           vide such torque so for comme                 e
                                         ercial use of the        elapse time for a du cycle that w be created at 50Hz.
                                                                        ed            uty              will            t



           ference on Rece Advances in R
Florida Conf             ent           Robotics, FCRAR 2010 - Jackso
                                                     R                               May         0
                                                                   onville, Florida, M 20-21, 2010                      3
This duty cycle is totally compatible with the micro-             voltage range of about 2.0 V - 5.5 V, and an internal (4
controller, so from there on the conditions of the program        MHz) or external clock select. Finally, the chip has a cpu
can be written without further problems.                          speed of 5 MIPs.
                                                                  A main component of the PIC16F877A that will be used
                                                                  toward the performance testing of the microcontroller is the
8. HUMAN DECTECTION USING                                         universal synchronous/asynchronous receiver/transmitter
   ULTRASOUND SENSORS                                             (USART). This component is what gives the
First, we equip the person with a sensor-emitting device          microcontroller the ability to translate and send data to the
and make the robot detect this device using an ultrasound         computer. This device changes internal information to
sensor. In order to determine the distance to the human, we       serial data so that it can be sent on a communication line.
use the sending and receiving time of the signal between          Finally, this chip is very inexpensive ($4.75) and can be
the sensors. The person carries this device perpendicular to      easily programmed using MikroC.
the ground. By receiving the signal of this device, the robot
is able to determine the distance to the human due to the
time interval between the two signals. It can also determine
the direction taken by the device by gathering information
based on the ultrasound sensors time interval of the signal
sent by the human carried device.
If we consider how a mobile robot could estimate the
position of a specific object by using ultrasonic sensors, it
is also possible to find the distance to the object by using
the pulse echo method. The use of a sensor consisting of
several receivers enables us to determine where the
obstacles are and avoid them.
However, it is not possible with this method to recognize a
specific object among several others. We considered that it
would be possible to differentiate a specific object if the
ultrasonic wave emitted by the robot performing
measurements can be separated from the ones emitted by a                 Figure 4. Microcontroller PIC16F877A
transponder carried by the object whose position is to be
detected. The robot transmits an ultrasonic pulse A and the       9.2. 25AA640
object which has an transponder transmits another
                                                                  The 25AA640 is a small 64kbit Serial Electronically
ultrasonic pulse B after detecting pulse A while the pulse A
                                                                  Erasable PROM (EEPROM). EEPROM is a chip that can
is returned by the reflection at an obstacle.
                                                                  be programmed multiple times, and it does not need to be
                                                                  taken out of the computer to program it again. A major
                                                                  advantage of this chip is that the information that is saved
9. MICROCONTROLLER                                                on it does not erase when the chip is turn off. This chip can
   SELECTION                                                      be bought for a dollar, and can be programmed also using
                                                                  mikroC.
It is important to properly select the correct microcontroller    Contrary to the PIC16F877A, this chip only has 6 pins.
based on the objectives set out. Based on the design goals,       Two of the 6 pins are programmable, one as the input and
the major components that will influence the performance          one as the output. For the electronic luggage follower, only
of the electronic luggage follower are identified as follows:     two programmable pins is a major disadvantage since more
       •   Million of Intructions per Second (MIS)                than one sensor will be installed as input and more than one
       •   Number of Programming Pins                             sensor will be installed as output. Additionally, this chip
       •   Power Consumption                                      has a maximum clock frequency of 1 MHz, which
       •   Programming Language                                   compared to other PICs is very slow. Finally, a major
                                                                  disadvantage towards the study of the performance of this
9.1. PIC16F877A                                                   chip is that it does not contains UART, and the information
                                                                  cannot be sent back to the computer to read it.
The PIC16F877A is an 8-bit programmable integrated
circuit made by Microchip. This PIC has forty pins, with
various different purposes. For example, there are PORTB
and PORTC which are bidirectional I/O port and can be
software programmed. A major advantage of this chip is
the versatility of all the 40 pins, since the peripherals are
spread out over the pins. Furthermore, it maximizes the
number of external devices to attach when compared to
other microcontrollers. Another feature of this chip that is
favorable for the user is each pin has only two to three
functions, making it easier for the user to decide the
purpose of each pin. Additionally, it has a wide operating                 Figure 5. Microcontroller 25AA640


Florida Conference on Recent Advances in Robotics, FCRAR 2010 - Jacksonville, Florida, May 20-21, 2010                  4
9.3. DSPIC30F4011                                                 send a signal for 5 µs to the ultrasonic sensor. After the
The DSPIC30F4011A is a 16-bit digital signal                      signal has been sent, the microcontroller then waits for 1 µs
programmable integrated circuit made by Microchip. The            to change from output to the input mode. When the pin is
advantage of this DSPIC is that it is a combination 16-bit        set to input, a while loop is initialized to wait at input until
microcontroller and a DSP. The 16-bit microcontroller will        the signal is received. Finally when the chip obtains the
enhance the performance while the DSP will implement a            signal, it will send 5 Volts to the speaker. The speaker
high computation speed. Similar to the PIC16F877A, it has         provides an indication that the sonar sensor is detecting an
40 pins that can be used for programming external devices,        object.
analog-to-digital converter, interrupts, EEPROM memory,
UART, etc.
A major advantage over the other two options is the
internal speed of the microcontroller. This chip has a 7.37
MHz internal clock and other components that will enhance
the cpu speed to 30 MIPs. Also, if the user is trying to
obtain information about the external devices connected to
it, this microcontroller has two different UARTs, and can
be an advantage when trying to test any devices.
Furthermore, this chip can be found in the market for about
$5.00 and it can be easily programmed just as any other                        Figure 7. Signal Propagation
microchip product using mikroC.
                                                                  After analyzing the specifications of the chips, the
                                                                  microcontroller that will be best suitable for the electronic
                                                                  luggage follower was chosen. The decision was made over
                                                                  several factors, such as price, number of pins, CPU speed,
                                                                  and programming language. Based on the datasheet of all
                                                                  options, the PIC16F690 was chosen as the optimal
                                                                  microcontroller for the design. Although it was the
                                                                  smallest, it proved to have the sufficient amount of pins for
                                                                  the platform. Even though the DSPIC30F4011 was the
                                                                  fastest, it uses a different programming language that is
                                                                  more complicated, and it will lead to an over-designed
                                                                  platform, as the speed exceeds the requirement. While the
                                                                  PIC16F690 had a cost of $1.91, the others cost nearly 5
     Figure 6. Microcontroller DSPIC30F4011                       times more.

9.4. PIC16F690
The PIC16F690 was the last programming chip that was
analyzed made by Microchip. This is an easy-to-use chip
that has 20 pins, with various different purposes. The
microcontroller is small in size which acts as a major
advantage towards the purpose of the project. Furthermore,
it is an 8 bit chip with nano-Watt technology for low power
battery consumption. Finally, the PIC16F690 was
purchased with a kit which facilitated the development of
computer programming.
The PIC16F690 also has an 8MHz internal clock and has a
CPU speed of 5 MIPs. A disadvantage of the                                  Figure 8. Programming Algorithm
microcontroller is that it does not contain the UART
feature. Without this component, transforming information
                                                                  After the selection of the microcontroller, a test was
from the chip to the computer was not possible. Finally,
                                                                  conducted in order to ensure the performance was
this chip is very inexpensive ($2.00) and can be easily
                                                                  accpetable. A circuit board was set-up in a way that the
programmed using MikroBasic.
                                                                  chip was connected to both an ultrasound sensor and a
                                                                  speaker. Afterwards, the set-up was completed by
                                                                  developing a test program. This program instructs the
10. TESTING AND RESULTS                                           microcontroller to send a signal to the ultrasonic sensor and
                                                                  then when it receives the signal, it activates the speaker.
                                                                  This program proved the high-performance and the
The algorithm in Figure 8 is a representation of the
                                                                  simplicity of the microcontroller’s features.
programming of the sensor. The program performs in such
a way that a pin is first initialized as output and used to




Florida Conference on Recent Advances in Robotics, FCRAR 2010 - Jacksonville, Florida, May 20-21, 2010                    5
                                                                    Figure 11. Thermal Analysis on the Base of the
                                                                             ELF (Aluminum Alloy 2014)
                                                                  The second material used was the Plastic ABS and this
               Figure 9. Testing Sensors                          plastic by applying the heat was deformed in some little
                                                                  zones. As it can be seen in the next figure, the maximum
11. HUMAN FOLLOWING BEHAVIOR                                      deformation is produced where the motors are; in other
                                                                  words, the deformation is maximum where heat is situated.
In order to prevent collision with obstacles, the robot           The plastic ABS has passed the thermal test, yielding a
should track the route followed by its target. The robot          very similar result comparing to the Aluminum Alloys
calculates the distance between the actual position of the        2014. The plastic ABS passed the thermal test.
human and the previous location of the human. If the
distance the human moved is greater than a value decided
in advance, the mobile platform will increase its speed until
it reach the right time interval between the sensors signals.
In order to estimate its position, the vehicle uses odometer
and computes the location of the human relatively to the
position of the vehicle. The location of the human is
recorded by the robot in a global referential. The robot can
adjust its speed according to the number of points recorded
in the list that exist between the actual pose of the robot and
the location of the human. By doing so, the robot can track
the path followed by its target.

12. STUDY CASES
                                                                    Figure 10. Thermal Analysis on the Base of the
12.1. Thermal Analysis:                                                           ELF (Plastic ABS)
The thermal analysis was performed on the base. The
reason is that the base is the part most exposed to heat. For     12.2. Force Analysis:
this analysis, 25°C is used as room temperature and a heat
                                                                  The force analysis is made on the base and the shelves
power of 50W is also used. The team performed this
                                                                  since these are the parts that will receive or resist the higher
thermal test with different types of materials, some failing
                                                                  loads. The base will support the entire weight of luggage
while others passed the benchmark. The materials that
                                                                  which, we estimate to be approximately 50 lb. The shelves
passed the thermal test were selected as viable option to be
                                                                  will contain clothes, shoes, etc. so they should be able to
used as the final material for the electronic luggage
                                                                  support more than 5 lb each.
follower platform. This was important because a priority
                                                                  For the force analysis on the base, 70 lb force is applied.
was luggage being safe enough to be in any regular
                                                                  The load was exaggerated in order to have a stronger
temperature. The materials used to do this test were
                                                                  luggage that can sometimes carry extra weight. The force
aluminums and plastics.
                                                                  analysis is divided in three parts: deformation,
The following figure shows how the aluminum alloy 2014
                                                                  displacement, and stress. The force analysis will be
past the thermal test. The part covered by the blue color is
                                                                  expressed in three different figures.
the part that was not affected by the heat produced by the
                                                                  Aluminum alloy 2014 is the first material to be evaluated
motors, and as hotter the piece as redness the color. This
                                                                  for the force test on the base of the ELF. The following
indicates on the figure that the base is safe as far as heat
                                                                  figures show that the aluminum alloy 2014 force test failed
concerns. The most heated parts are where the wheels will
                                                                  by deformation in the middle part of the luggage. This
be connected and the rest of the structure is maintained in a
                                                                  deformation is produced basically because of the lack of
low temperature. That problem can be fixed by changing
                                                                  support in the middle region. The solution that the team
the piece affected and by adding some more material in the
                                                                  suggests for this deformation is to add to our design an all
critical zone.
                                                                  axis movement wheel that will not affect the movement of
                                                                  the luggage and provide the support needed to prevent



Florida Conference on Recent Advances in Robotics, FCRAR 2010 - Jacksonville, Florida, May 20-21, 2010                    6
failure in the critical zone. Figures 12 displays the force
analysis results for the aluminum alloy 2014.




                                                                                Figure 14. ELF Prototype
                                                                  We presented a method to achieve human following
                                                                  behavior as a first step toward the development of an
                                                                  intelligent escort robot moving along with a person. We
                                                                  showed two methods to realize the human following
Figure 12. Force Analysis Stress on the Base of the ELF
                                                                  behavior using ultrasonic sensors. As future work, further
                (Aluminum Alloy 2014)
                                                                  investigation is needed to assess the robustness of these
The second material evaluated is the plastic ABS. The             methods and develop new approaches to cope with
plastic ABS performed quite well compared to the                  situations when the robot cannot detect humans. The team
aluminum alloy 21014. The deformation showed in the               is also planning to make experiments using sound
next figure is very little and because the force applied is       generation to inform the status of the robot to the human in
greater than the regular force used by the luggage users, the     order to realize a smoother interaction. Furthermore, the
material can be considered as one of the final options. The       team is developing an accompanying behavior model for
base using the plastic ABS presents some critical                 the human. Once the stage of building a clever robot
deformation in the front part of the luggage. Figure 13           capable of moving along with the humans is achieved, we
shows FEA results for plastic ABS.                                will then model the relation between human and intelligent
                                                                  robot interaction.

                                                                  14. References
                                                                  [1] Bianco R., Caretti M. Nolfi S. Developing a robot able
                                                                      to follow a human target in a domestic environment.
                                                                      In A. Cesta (Ed.), Proceeding of the First Robocare
                                                                      Workshop. Institute of Cognitive Sciences and
                                                                      Technologies, CNR. Roma: Italy, 2002.
                                                                  [2] Krohn A., Beigl M., Hazas M., Gellersen H., Schmidt
                                                                      A. (2005). Using Fine-Grained Infrared Positioning to
                                                                      Support the Surface-Based Activities of Mobile Users.
                                                                      Proceedings of the 5th International Workshop on
                                                                      Smart Appliances and Wearable Computing
                                                                      (IWSAWC), Columbus, USA, 2005.
Figure 13. Force Analysis Stress on the Base of the
                                                                  [3] R. Bischoff, .Advances in the Development of the
                ELF (Plastic ABS)                                     Humanoid Service Robot HERMES,.Field and
                                                                      Service Robotics Conference , pp.156-161, 1999.
13. CONCLUSION                                                    [4] Y. Hayashibara, Y. Sonoda, T. Takubo, H. Arai and
In this paper, we addressed various design stages of a                K. Tanie, .Localization and Obstacle Detection for a
follower robot that is envisioned to carry the owner’s                Robot for Carrying Food Trays, IEEE/RSJ
luggage through crowded air terminals and follow the                  International Conference on Intelligent Robots and
owner. The machine is developed to be affordable for a                Systems, pp.695-700, 1999.
new invention that can lead to new applications to aid
humans further.




Florida Conference on Recent Advances in Robotics, FCRAR 2010 - Jacksonville, Florida, May 20-21, 2010                 7

				
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