ECE 001 Lego Robot Project

1
ECE 001Lego Robot Project

• Group 6
• Taylor Gould, Olivia Graffis, Taylor Guidon and
  Bdho Gdeh

2
Purpose

• Build a robot out of Legos that would enable
  movement along a flat surface
• Design code (C interactive) that would be
  implemented within the handyboard to instruct the
  robot to
• Move along a path from a start point to a finish
  line being guided by a thick black line of tape
• Perform a U-turn and then follow the black line
  back to the starting point

3
Resources

• Handyboard
• (2) Motors
• (2) Top-hat sensors
• Lego Kit including wheels and corresponding
  rubber tires
• C Interactive computer program with connecting
  wires to attach to computer

2 The Handyboard
4
Method

• Constructed a chassis and a base for the robot
• It had to be large enough to place the handyboard
  on along with the two motors
• We built walls around the base to enclose the
  handyboard in
•  The 2 motors were placed on the back end of the
  machine
• Wheels were attached to rods with gears
  (increasing torque) running through to the base
  of the motors
• Lastly, the light sensors were added to the front
  of the robot, being placed approximately 5 mm
  from the ground.
• Paper formed into cones were wrapped around the
  base of the sensors in order to prevent outside
  interference and coordinate anchorage to the
  machine.

5
Assembled Robot
6
Code

• void main ()
• int Flag1, Flag2
• int sensor1, sensor2
• while (!start_button())
• Flag11
• Flag21
• while (Flag11)
• sensor1 analog(4) /right/
• sensor2 analog(5) /left/
• if ((sensor1lt150 sensor2lt150))
• motor (1, 50) /motor1/
• motor (2, -50) /motor 2/
• if ((sensor1lt150) (sensor2gt150))
• motor (1, 75)

• This is the final code used in the program to
  direct the robot down the path, along the black
  line, make a U-turn at the end, and then return
  in the same manner to the other end.
• Commands such as int defined the variables
  (Flag1, Flag2) as integers, whereas, if and
  while statements were utilized to form the
  loops necessary to complete the program.
• Since the robot completed a U-turn, the while
  loop was broken up in order to form another loop
  so that the robot would stop the second time its
  sensors encountered darkness on both sides of the
  robot.

7
Robot in Action
8
Challenges

• Design of the robot
• Tested periodically throughout the project to
  ensure that the best combination of Lego design
  and the necessary technological features
  interacted symbiotically
• Light sensors failed to work.
• Taped small paper cones around the sensors so the
  light would be absorbed in a specific area
• The robot would occasionally make its U-turn
  early
• Tests completed on various tracks outside light
  (mostly unevenly distributed shadows) was
  disrupting the sensors readings

9
Centrifuge Experiment

• A centrifuge is a piece of equipment that is
  driven by a motor which rotates an object around
  a fixed axis at very fast speeds. This
  acceleration and centrifugal force separates one
  fluid from another fluid based on greater and
  less density. There are numerous different types
  of centrifuges and they can be used to accomplish
  a variety of different tasks. Examples of these
  include isotope separation, separation of
  macromolecules, separation of oil components as
  used in the petroleum industry, oil-water
  separation as we completed in our experiment as
  well as other commercial applications.
  Centrifuges have an especially important role in
  biomedical studies.

10
Experimental Set-up

• Lego pieces, gears and motors were used for
  assembly
• Created a sturdy base that would support the fast
  rotation
• Positioned the gears, motors and cuvette holder
• Added counterweight on opposite side
• Note Many modifications to the design were made
  to achieve our final model of the centrifuge

11
Code

• The source code that we used to carry out the
  centrifuge experiment was separated into two
  parts. This first part spun the suspension
  around an axis
• void main()
• int i /We define the different variables
  that we are going to use in the experiment/
• int j
• int s
• while(start_button()0)
• for(i10 ilt100 ii10)
• motor(1,i)
• sleep(0.2)
• sleep(5.0)
• for(j0 jlt100 jj10)
• s100-j
• motor(1,s)
• sleep(0.2)

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Raw Data

• The table below demonstrates the results from the
  readings from our centrifuge experiment.

13
Processed Data Centrifuge Performance
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Conclusions

• The combination of both code-writing and
  structural design forced the group to adapt to
  the challenges that were presented, and work
  together to solve problems by testing and
  reformatting the experimental design
• Improvements
• The sensors could have been more exact in
  evaluating the amount of lightness or darkness
• As a result, it reduced the robot to a jerky
  motion in response to radical changes in darkness
  and is likely to have relayed the robot to a
  slower performance when turning to avoid the
  black tape line.
• This produced inconsistent values for the
  centrifuge and is likely to have prevented
  constructive data values for assessment
• For better stability along the track and maximum
  velocity attainment, the combination of wheels
  and weight would be altered

15
Works Cited

1. "HandyBoard Layout." Chart. The Handyboard How to
   Guide. 29 Sept. 2006. Council Rock South
   Technology Club. 12 Nov. 2008 lthttp//www.southtec
   h.org/handyboard/images/handyboard_layout.gifgt.
2. The Handyboard. Digital image. Digital Sketchbook
   Computer Graphics 530 Continued Development of
   Human-Art Interaction. 22 Jan. 2004. Syracruse
   University. 12 Nov. 2008 lthttp//web.syr.edu/dfmo
   ore/log/530.htmlgt.
3. Rumley, Regina, John Whichard, Rachel Rosenberg,
   and Katie Knupp. The Forces Acting in a
   Centrifuge. Digital image. The Physics of a
   Centrifuge. 2008. The University of North
   Carolina at Chapel Hill. 6 Nov. 2008
   lthttp//www.unc.edu/reginara/gt.
4. Generalic, Eni. Centrifuge. Digital image.
   Ilustrated Croatian-English Chemistry Dictionary
   Glossary. 2005. Croatian Ministry of Science,
   Education and Sports. 12 Nov. 2008
   lthttp//www.ktf-split.hr/glossary/en_o.php?defcen
   trifugegt.