Electronics and Robotics Merit Badges Class 4 – Robot Subsystem Mechanics or Building Robot Bases and Drive Trains In this class, we’ll talk about that “other part of a robot” (versus the Electronics Merit Badge stuff we just covered). That is, we will now cover “Mechanical Systems” and “Mechanical Engineering” aspects required to build these complex systems - especially as to how it applies to building robot bases, their drive trains, power systems and (back to electronics!) controls. In the BSA Robotics Merit Badge Pamphlet this is called THE CHASSIS SUBSYSTEM THE MECHANICAL SUBSYSTEM THE POWER SUBSYSTEM THE CONTROLS SUBSYSTEM Our robot is the Parallax SumoBot that is based upon a simple steel base and Radio Control (R/C-type) airplane servos that have been modified to act as drive motors for locomotion of the robot. We will build these mechanicals as we discuss this aspect of robotics. 4/23/2017 Electronics and Robotics Merit Badges - Class 3

Electronics and Robotics Merit Badge Class 4 Our kit! The SumoBot Kit Our kit! Open up the zip lock bags and spread out the components. 4/23/2017 Electronics and Robotics Merit Badge Class 4

CHASSIS SUBSYSTEM 2. Robotics industry. Lets discuss the following (with your counselor): The kinds of things robots can do and how robots are best used today. 4 D’s – Dangerous, Dirty, Dull, Difficult b. The similarities and differences between remote-control vehicles, telerobots, and autonomous robots. “R/C” Models (Heli), UAV’s (semi-autonomous), Autonomous Robots (Sumobot) c. Three different methods robots can use to move themselves (other than wheels or tracks). Describe when it would be appropriate to use each method. Walk, Fly, Crawl When to use each? Muddy/Wet/Rough Terrain (Tracks – think bulldozer or tank), Smooth road/some rough – wheels, very very rough (Big Dog Video here) or humaniod (Sony)), Fly Write this stuff on your Robotics Workbook (2 a/b/c)

Electronics and Robotics Merit Badge Class 4 LET’S BUILD THE SUMOBOT Step #1 Install the Battery Box Parts Required: • Battery Box • (2) 4/40 3/8" long flat-head countersunk machine screws • (2) 4/40 nuts • SumoBot chassis Stand the SumoBot on its PCB mounting ears. Install the plastic battery pack using two 4/40 3/8” flat-head screws and nuts. The screws will be countersunk into the battery pack when tightened and should be out of the way of the batteries. This is our robot base. It is a simple steel cutout that holds all the other components of the Sumobot together. 4/23/2017 Electronics and Robotics Merit Badge Class 4

MECHANICAL SUBSYSTEM 4. Design, build, program, test. Do each of the following: a. (With your counselor's approval) Choose a task for the robotic subsystem that you plan to build. Include sensor feedback and programming in the task. Document this information in your robot engineering notebook. b. Design your robot. The robot design should use sensors and programming and have at least 2 degrees of freedom. Document the design in your robot engineering notebook using drawings and a written description. c. Build a robot or robotic subsystem of your original design to accomplish the task you chose for requirement 4a. d. Discuss with your counselor the programming options available for your robot. Then do either option 1 OR option 2. (1) Option 1. Program your robot to perform the task you chose for your robot in 4a. Include a sample of your program's source code in your robot engineering notebook. [We will not do flowcharting] (2) Option 2. Prepare a flowchart of the desired steps to program your robot for accomplishing the task in 4a. Include procedures that show activities based on sensor inputs. Place this in your robot engineering notebook. e. Test your robot and record the results in your robot engineering notebook. Include suggestions on how you could improve your robot, as well as pictures or sketches of your finished robot. Sumobot Competition Night!!!

Electronics and Robotics Merit Badge Class 4 LET’S BUILD THE SUMOBOT Step #2 Install the Servo Motors Parts Required: • (2) Parallax Continuous Rotation Servos • (8) 4/40 3/8" long pan-head machine screws • (8) 4/40 nuts • SumoBot chassis Using four 4/40 3/8” pan-head machine screws and 4/40 nuts, attach each servo motor to the chassis. The easiest way to do this is to hold the nut with one finger while turning the screwdriver with the other hand. Hacking a Servo The theory behind this hack is to make the servo think that the output shaft is always at the 90 degree mark. This is done by removing the feedback sensor, and replacing it with an equivalent circuit that creates the same readings as the sensor being at 90 degrees. Thus, giving it the signal for 0 degrees will cause the motor to turn on full speed in one direction. The signal for 180 degrees will cause the motor to go the other direction. Since the feedback from the output shaft is disconnected, the servo will continue in the appropriate direction as long as the signal remains. http://www.seattlerobotics.org/guide/servohack.html 4/23/2017 Electronics and Robotics Merit Badge Class 4 6 6

Electronics and Robotics Merit Badge Class 4 LET’S BUILD THE SUMOBOT Step #3 Install the Rear SumoBot PCB Stand-offs Parts Required: • (2) 5/8" round standoffs • (2) 4/40 3/8" long panhead machine screws • SumoBot chassis Using a 4/40 3/8" pan-head machine screw, attach each stand-off to the rear of the SumoBot chassis. Back to work! 4/23/2017 Electronics and Robotics Merit Badge Class 4 7 7

Electronics and Robotics Merit Badge Class 4 LET’S BUILD THE SUMOBOT Install the Front SumoBot PCB Stand-offs Parts Required: • (2) 5/8" round standoffs • (2) 4/40 1" long panhead machine screws • SumoBot PCB Using a 4/40 1" pan-head machine screw, attach each standoff to the front mounting holes of the SumoBot PCB. 4/23/2017 Electronics and Robotics Merit Badge Class 4 8 8

CONTROLS SUBSYSTEM 5. Demonstrate. Do the following: a. Demonstrate for your counselor the robot you built in requirement 4. b. Share your robot engineering notebook with your counselor. (NEXT TIME!!) Talk about how well your robot accomplished the task, the improvements you would make in your next design, and what you learned about the design process.

Electronics and Robotics Merit Badge Class 4 LET’S BUILD THE SUMOBOT Step #5 Mounting the PCB Parts Required: • SumoBot PCB • (2) 4/40 3/8" long pan-head machine screws • (2) 1-1/4" round stand-offs • (2) Nylon washers • SumoBot chassis Feed the ends of the 1" long pan-head machine screws through the front mounting holes on the SumoBot chassis. Secure the rear side of the SumoBot PCB to the 5/8“ standoffs with two 3/8" pan-head machine screws. Holding the chassis upside-down, place a nylon washer onto the end of each 1" long pan-head machine screw, then secure by threading on the 1-1/4" round standoff. Now its beginning to look like something… 4/23/2017 Electronics and Robotics Merit Badge Class 4 10 10

Electronics and Robotics Merit Badge Class 4 LET’S BUILD THE SUMOBOT Step #6 Prepare the Wheels Parts Required: • (2) SumoBot wheels • (2) SumoBot rubber tires Stretch a "tire" of each wheel and adjust so that the"tire" is centered across the wheel. What where those other modes of movement again? FLY CRAWL WALK? 4/23/2017 Electronics and Robotics Merit Badge Class 4 11 11

Electronics and Robotics Merit Badge Class 4 LET’S BUILD THE SUMOBOT Step #7 Mount the Wheels Parts Required: • (2) Prepared wheels/tires • (2) Black servo-horn screws • SumoBot chassis Carefully press each prepared wheel onto the servo splines. Secure each wheel with the small black Phillips head screw. Almost there! 4/23/2017 Electronics and Robotics Merit Badge Class 4 12 12

Electronics and Robotics Merit Badge Class 4 LET’S BUILD THE SUMOBOT Step #8 Mount the Scoop Parts Required: • SumoBot scoop • (2) 4/40 1/4" long panhead machine screws • (2) 4/40 nuts • SumoBot chassis Using two 4/40 1/4” pan-head machine screws and 4/40 nuts, attach the scoop to the SumoBot chassis. Carefully center the scoop before tightening the screws and nuts. Review sumo rules here? 4/23/2017 Electronics and Robotics Merit Badge Class 4 13 13

SumoBot Rules The Match: 1) Flip a coin to determine who positions their robot first in the ring 2) Place the ‘bot in the ring as directed by the referee 3) Press the start button on the bot when directed by the referee. After 5 seconds the bot may begin moving (sound/light indicates robot working). 4) Move back at least 3 feet from the edge of the ring 5) Catch any bot that is out of the ring and turn it off 6) Place the bot back in a holding area between matches. A contestant may make adjustments between matches, but may not leave the holding area. Basic Rules: One match will consist of three rounds, within a total of 3 minutes each. The team who wins two rounds out of three wins the match. 2) The match will be stopped and a rematch will ensue when it is apparent that neither bot is making any progress for duration of about 4 seconds (as determined by the referee). 3) If a part on the bot comes off that is less than 5 grams, the round will continue. 4) A player has 30 seconds to correct a problem between rounds. 5) The referee has the final decision in a match. Electronics and Robotics Merit Badge Class 3

Electronics and Robotics Merit Badge Class 4 LET’S BUILD THE SUMOBOT Step #9 Install Line Sensor Wires Parts Required: • (2) 10" 3-pin extension cables • SumoBot chassis Carefully feed each 10" 3-pin extension cable through the center chassis slot. Sensors? Which members of the Patrols (KIAH-1 and JACOB-2) will program the sensors? 4/23/2017 Electronics and Robotics Merit Badge Class 4 15 15

Electronics and Robotics Merit Badge Class 4 LET’S BUILD THE SUMOBOT Step #10 Install the QTI Line Sensors Parts Required: • (2) QTI line sensors • (2) 4/40 1/4" long pan-head machine screws • SumoBot chassis Using two 4/40 1/4” pan-head machine screws, attach the QTI line sensors to the 1-1/4" round stand-offs. Connect the ends of the 10" 3-pin extension cables to the QTI line sensors, noting the polarity markings B[lack]-R[ed]-W[hite] on the QTI sensors. And how will they design the sensors? (Have to have these for the edge, but placement of the opponent sensors is varied). 4/23/2017 Electronics and Robotics Merit Badge Class 4 16 16

POWER SUBSYSTEM We use standard AA batteries to run our SumoBot. Usually made of Zinc–carbon or Alkaline (Capacity under 500mA constant drain - 400-1700 mAh/1800-2600 mAh/1.5 V). We may also experiment with newer high-power Lithium (Li-Ion) batteries used in Electric Cars (or “EV’s” as we call them at Eaton – Electric Vehicles).

Electronics and Robotics Merit Badge Class 4 LET’S BUILD THE SUMOBOT Step #11 Make the Connections Plug the servo motors and QTI sensors into the SumoBot PCB connectors as indicated below. Note that the "B" pin on each connector is for the black wire. X7 = Left Servo Motor X6 = Right Servo Motor X5 = Left QTI Line Sensor X4 = Right QTI Line Sensor Connect the battery pack wires to SumoBot PCB connector X1. The battery pack's white-striped lead connects to the + terminal. Hook up the power (don’t forget to load the batteries). 4/23/2017 Electronics and Robotics Merit Badge Class 4 18 18

Electronics and Robotics Merit Badge Class 4 LET’S BUILD THE SUMOBOT Step #12 Powering the SumoBot The SumoBot PCB has a three-position power switch. The state of each position is shown below. The three-position switch has a middle position that powers the entire circuit except the servos. A complete schematic of the SumoBot PCB follows. Also note the new Li-ion Boe-Bot Power Pack-Charger. Position 0 – No Power Position 1 – Power PCB Position 2 – Power PCB & Servos TURN IT ON – does the LED light? Success!!! Ready to install sensors and program the robot base/drive train… 4/23/2017 Electronics and Robotics Merit Badge Class 4 19 19

Electronics and Robotics Merit Badge Class 4 COMPLETE SUMOBOT CIRCUIT DIAGRAM APPENDIX A – Circuit Diagram 4/23/2017 Electronics and Robotics Merit Badge Class 4 20 20

Electronics and Robotics Merit Badge Class 4 Robotics merit badge requirements         Safety. Do each of the following: a. Explain to your counselor the most likely hazards you may encounter while working with robots and what you should do to anticipate, mitigate and prevent, and respond to these hazards. Describe the appropriate safety gear and clothing that should be used when working with robotics. b. Discuss first aid and prevention for the types of injuries that could occur while participating in robotics activities and competitions, including cuts, eye injuries, and burns (chemical or heat). Robotics industry. Discuss the following with your counselor: a. The kinds of things robots can do and how robots are best used today. b. The similarities and differences between remote-control vehicles, telerobots, and autonomous robots. c. Three different methods robots can use to move themselves other than wheels or tracks. Describe when it would be appropriate to use each method. General knowledge. Discuss with your counselor three of the five major fields of robotics (human-robot interface, mobility, manipulation, programming, sensors) and their importance to robotics development. Discuss either the three fields as they relate to a single robot system OR talk about each field in general. Find pictures or at least one video to aid in your discussion. Design, build, program, test. Do each of the following: a. With your counselor's approval, choose a task for the robot or robotic subsystem that you plan to build. Include sensor feedback and programming in the task. Document this information in your robot engineering notebook. b. Design your robot. The robot design should use sensors and programming and have at least 2 degrees of freedom. Document the design in your robot engineering notebook using drawings and a written description. c. Build a robot or robotic subsystem of your original design to accomplish the task you chose for requirement 4a. d. Discuss with your counselor the programming options available for your robot. Then do either option 1 OR option 2. (1) Option 1. Program your robot to perform the task you chose for your robot in 4a. Include a sample of your program's source code in your robot engineering notebook. (2) Option 2. Prepare a flowchart of the desired steps to program your robot for accomplishing the task in 4a. Include procedures that show activities based on sensor inputs. Place this in your robot engineering notebook. e. Test your robot and record the results in your robot engineering notebook. Include suggestions on how you could improve your robot, as well as pictures or sketches of your finished robot. Demonstrate. Do the following: a. Demonstrate for your counselor the robot you built in requirement 4. b. Share your robot engineering notebook with your counselor. Talk about how well your robot accomplished the task, the improvements you would make in your next design, and what you learned about the design process. Competitions. Do ONE of the following. a. Attend a robotics competition and report to your counselor what you saw and learned about the competition and how teams are organized and managed. b. Learn about three youth robotics competitions. Tell your counselor about these, including the type of competition, time commitment, age of the participants, and how many teams are involved. Careers. Name three career opportunities in robotics. Pick one and find out the education, training, and experience required for this profession. Discuss this with your counselor, and explain why this profession might interest you. APPENDIX B – Merit Badge Requirements 4/23/2017 Electronics and Robotics Merit Badge Class 4 21 21