Robotics 101

FRC Kick-off WorkshopsKen Stafford

2011

Caveats!

• One size does NOT fit all!– Only “secret sauce” is to do what’s right for

YOUR students• It is not about the robot…• It IS about the team

20 year’s of doing this

And us?• FRC 190 (WPI/Mass Academy)

– 1 of 28 that competed in 1992 competition– 1 of 7 teams that are starting our 20th

continuous year in FRC– “Wow over win” philosophy

• My 13th year as team leader– Normally give Motors, Pneumatics,

Transmission, Mechanism workshops…– Adj Associate Prof, Robotics Engineering

How tough can this be???• Just build a robot!

– Oh yeah—design it first– Test, improve, etc

• Someone’s got to drive, prepare, repair, coach, etc

• What about getting it to/from the venue?– And to/from the field/pits

• Other bits to compete?

Step-by-step…

• The “six-weeks” (actually 45 days!)– The robot– The team– Shipment– Event preparation– Nits and bits

All you need to know

Week 1, The Big Ideas

• The preface (day 1)…– Establish Team Vision

• Will guide season decisions

– Attend Kick Off (virtually if nothing else)– Inventory KoP

• Important for getting feel • Weigh each major piece

– Consider building field elements• Useful for Brainstorming

Week 1…

• Brainstorming Phase 1 (day 2)– Review game rules en masse– Form B/S teams: optimal 6-8 per– NO DESIGNS, just strategies

• Based up on expected game results

– Establish prioritized list of strategic obj• EG: lift partners, score balls, defend goals, etc

– As complete team, develop consensus!

Week 1…

• Brainstorming Phase 2– Optimal size: 6-8 per mixed team

• Do NOT allow crosstalk between teams

– Develop concepts/design sketches to meet team strategic priorities

– After 3 days, meet for “Team Reveal”• Critique only for clarification/rule breaks

– After 5 days, develop consensus!• B/S teams give their efforts away to the team

Week 1 (meanwhile)

• Consider any extra parts from FIRST Choice– Free, but first come/first serve on Day 3

• Order any parts missing from KoP– Must be in by Day 5

• Consider building kit-bot

Week 2, Subsystem Design

• Organize team functionally, IE:– Mechanical

• Driveline/Chassis• Subsystem 1 (eg Ball Holder)• Subsystem 2 (eg Kicker)

– Controls• Operator Interface• Driveline programming• Sensor programming

190 Team StructureTeam Leader

Team Director

Mech

Driveline

Subsystem1

Subsystem2

Controls

Op Interface

Sensors

Programming

Tactics

Scouting

Coaching

Team Co-Captains

Awards

Public Relations

Website

Week 2, …• Each sub team build prototypes to

prove/explore concepts– Wood, cardboard, plastic…fast and easy– Virtual (CAD models)– Do not forget to work on programming/code

• VEX or kit-bot useful to test codes

• Do not forget to do analysis!• As concepts start to jell, allocate critical

resources to subsystems (motors, etc)

Week 2 (meanwhile)• Last chance to order extra parts (free)

from FIRST Choice• Do not let your team members miss

important FIRST scholarship deadlines!– A bunch are due by 15 Jan!

Week 3, Subsystem Power-up• By week’s end you should have all major

subsystems powered up in bench tests • Schedule a Preliminary Design Review

– Formal presentation in front of all stake-holders and advisors that you can find

– Detail your process and progress to-date– Demo subsystems– Seek critiques and comments

Week 4, Manufacturing!• By week’s end you should have all major

subsystems powered up in bench tests– A drivable chassis*!

• Especially important for rookie teams without a vintage robot to practice with!

• Be sure to ballast it with your expected full-up weight so that drivers get reasonable feel

Week 4 (meanwhile)• All registration payments must be in• More scholarships applications are due

– Bunch on 1 Feb!• Administer Rule book–based knowledge

test to all students and mentors– Make it hard!

• NO ONE has ever passed Team 190’s test on the first go! We require 100% correct.

• *Schedule driver practice as possible

Sample Rules Test1. How long is the Autonomous period of the Match? The Teleoperated? The

finale?

2. How many teams are on each alliance?

3. When can the human player re-enter the balls to the field?

4. When do game pieces count as scored?

5. When are the match scores calculated?

6. What safety equipment must be worn all times when in the pit or on stage?

7. What is the robot's starting size, in inches?

8. What size and weight can the robot expand to when in the finale configuration?

9. A robot is allowed to possess how many balls at one time? How many balls can it carry?

10. How far can the ball protrude inside the robot's frame perimeter?

11. How many points is a ball scored in autonomous worth? In teleoperation? In the endgame?

12. How much is a suspended robot worth? An elevated robot?

Sample Rules Test13. How many coopertition bonus points does the winning alliance receive?

The losing alliance?

14. Where can the balls be placed before autonomous? How many balls, total, begin in each zone? How many robots may be in each zone, per alliance?

15. How many robots may be in their opponent's zone, maximum?

16. Who is allowed to talk to the Head Referee after a match to dispute or clarify a call?

17. How many balls may a robot possess at a time?

18. How many balls may a robot carry at a time?

19. How long can you pin a robot before being penalized?

20. A blue robot scores a ball into a red goal. How many penalties does the blue alliance receive? How many points? Does the red alliance gain a point?

21. What two criteria can be met to allow the robot to expand to its finale configuration?

22. How far can the ball protrude into the robot's frame perimeter?

23. How long does each alliance have to return a ball to the field after it is scored? A second ball?

Sample Rules Test• Scenario 1:• The red alliance has 1 robot hanging on the tower, and another

robot attached to the hanging robot, 24" above the carpeted surface. The blue alliance has 1 robot hanging on the tower, 1 robot parked on the platform, and 1 robot parked on top of the robot on the platform, touching the tower. The red alliance scored 2 balls in autonomous and 9 balls in teleoperation. The blue alliance scored 1 ball in autonomous and 14 balls in teleoperation, and was called once for carrying a ball.

 • Blue Alliance Match Seeding Points:• Blue Alliance Coopertition Bonus:• Red Alliance Match Seeding Points:• Red Alliance Coopertition Bonus:

Sample Rules Test 

• What is the primary strategic objective of the robot this year?

• What is the team vision we decided on for this year?

• How does the 2010 robot fulfill the strategic objective and the team vision?

• Describe, to the best of your ability, the main strategy of our robot.

• Why do you want to be a part of the travel team?

Week 5, System Integration• Firm up battery, control hardware,

compressor locations• Start assembling subsystems onto

chassis, subroutines into master program– Resolve glitches!– Optimize wiring, tubing, and chain paths

Week 5 (meanwhile)• Select Travel Team/Stage Crew

– Administer Technical Test• Shows composure and breadth of knowledge

– Administer Practical evaluation• Do it “blind” if at all possible• Simulate game conditions as much as possible

– Hold selection board• Establish objective and subjective criteria

Sample Tech Test1. In general, what are the functions of the cRIO and the Driver

Station?  How do they communicate with each other?

2. There are several sensors in front of me (point to pile) and more on 2K5.  Select three and describe what they are used for and why.

3. What are the two types of speed controllers found on 2k9?  What are the two types and how did we decide where to use each type?

4. There are multiple types of over-current protection devices on our robot.  Point out two different kinds (on 2k5 or the Gears Bot), describe what they do, how they work, and what is different about them.

5. Describe what happens when voltage is applied to a motor and, due to the load imposed, it does not turn.

6. Choose one motor from each of these two piles, name them, explain what they are being used for on this year's robot, and why we chose them.

Sample Tech Test7. Relative to the robot driveline, answer the following: How is it

powered? What driving modes exist? What is its maximum speed?

 8. What are the independently powered systems that take the moon rocks from the ground to scoring?  What are the parameters necessary to be in a scoring position?  How many moon rocks can we hold?

9. How does our robot contend with the limited traction available with the Lunacy field?  Describe the motor control and sensor suite that enables this capability.

 10. What is the minimum operating voltage we should ever use for a match, and what voltage should you see in a fully charged battery?

 11. Situation: During our first attempted moon rock delivery, the upper section of the cobra becomes disabled, what do we do for the remainder of the match?

 12. Compared to other teams, what do you feel makes us different?

Coach Test

Why do you think you would be a good coach for Team 190?

We expect to see the following characteristics in effective coaches, please choose two of the following and provide evidence that supports your ability.

Situational Awareness

 

Assertive Diplomacy

 

Expert Rules Knowledge

 

Excellent Communications

 

Composure

Coach TestIf selected as coach, what would you do between now and the

competitions? What would you do between each of our competitions?

How/when would you use the scouting information available to you at the competitions?

The match is going well when suddenly the robot stops dead and the driver tells you that it’s not responding. How do you go about solving the problem? Explain your decisions. (10 secs)

Scenario: Team 190 is going into the semifinal rubber match (Match #3), as the alliance captain. The shooter is currently broken, but the steering and collection still works. The replacement robot is more maneuverable than team 190’s, but has no scoring or collection mechanisms. Your opponents have one good long range shooter and two decent dumpers, and your partners are decent ranged shooters. The turret cannot be fixed before you must choose to play the match or go for a replacement. Do you choose to play the replacement? Explain your decision. (30 secs)

Travel Team Selection

Travel Team Selection

Travel Team Selection

Travel Team Selection• Final Score

– 40% Skill (objective)• Driver/Operator/Human Player/Coach tryouts

– 20% Technical Test (objective)• Depth of knowledge

– 15% Commitment (objective)• Meetings/events attended• Support/Ops hours logged

– 25% Attitude (subjective)• Subjective through reviewers “Team 190 Image”

Week 6, Integration/Test• Test each robot system as it is installed

on chassis– Tweak as necessary

• Seek full or major portion in game field for near full scale testing

• Do not be surprised if you need to go “back to the drawing board” on a system

Week 6 (meanwhile)• Consider how to transport robot at event

– Design/build a “wagon”– Generally good idea if robot can be operated

while on the wagon: driveline clear, height• Chairman’s and other award submissions• Schedule your Critical Design Review

– Same folks as PDR– Unveiling of 95% robot

Week 6½, Break/Fix/Ship• Get yourself into a local scrimmage

– Even if robot is not quite ready– Drive the robot hard!– Find the weak points

• Mechanically, programmatically, tactically

• Fix what broke– Make necessary design modifications

• Ship it or seal it!

Week 6½ (meanwhile)• If you are shipping, you need to build a

shipping crate– Specs are in rule book– Make it as light as possible! Over 400lbs

combined weight will cost you!• Take photos of completed robot

– Judge’s material, photos and team essays due two days after shipping

Specific Recommendations• Develop order schedule to avoid excess

shipping charges– McMasterCarr, Yarde Metals, Online Metals,

AndyMark, DigiKey, etc • Consider spares when building/ordering• Maintain hard midseason milestones

(Decision, PDR, CDR, Scrimmage)– “Pull all-nighters early”

Resources• Other teams—seek mentorship!

– Invite to design reviews• Online assets

– Think Tank (http://thinktank.wpi.edu/Portal)– FIRST Robotics Resource Center (

http://first.wpi.edu/index.html) – FRC Resources (

http://www.usfirst.org/roboticsprograms/frc/content.aspx?id=478)

Other Resources(buyer beware)

• ChiefDelphi (http://www.chiefdelphi.com/) – Rumors/social/useful

• YouTube (http://www.youtube.com/user/FIRSTWorldTube) – Frequent team updates– Be cautious about innovation…

Successful Robots…• Good Design

– Can meet your strategic/tactical objectives– Don’t let “better” be enemy of “good

enough”

• Robust Manufacturing- Built as designed- Wiring, fasteners, chains; can take hits

• Human/Robot Interface- Operator Practice- Excellent Coaching/scouting

Questions?