DEWBOT VI Bridgewater Battle

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Team 1640 with (BR)2 Engineering Excellence Award - L->R: Andrew, Carly, Douglas, Faith McKown, John Stumpo, Heather McKown, Matt, Kenneth, Paul, Ben - Missing: Jen, Mike Rizzo & Clem McKown (taking photo)
DEWBOT VI participated in the 2nd Bridgewater Raritan Battle Royale (BR)2 at Bridgewater-Raritan High School in Bridgewater, NJ on 29-May-2010. Team 1640 received the competition's Engineering Excellence Award for DEWBOT's unique, multi-mode pivot drive-train and the mirror mounted to find balls hidden behind the bumps.

1640 placed 12th out of 21 teams in the qualifying matches and was selected by the 2nd Alliance (2753 Overdrive & 1279 Cold Fusion). There were 4 alliances. We were eliminated in the semifinals.

Check out the event website.

There was also a large VEX event--the first VEX Round-Up Qualifier in the world--held concurrently at this location. 18 teams participated and Team 81 brought home the Build Award.


Qualifying Matches

There were (7) qualifying matches for each robot. Unfortunately, I'm not sure how many of these we won or lost, or by what score.

Q4: Tie 2-2 with 714 Panthra & 75 RoboRaiders against 2753 Overdrive, 1989 Viking Robotics & 3314 The Nobles
Q7: ? with 263 Sachem Aftershock & 2753 against 369 High Voltage & 896 Central Blue Steel & 136 Killer Kardinals
Q10: Win 5-3 with 369 & 224 The Tribe against 2753, 1340 Adams Robotics & 1071 Team MAX
Q13: ? with 1071 & 1989 against 303 Panther Robotics, 263 & 1340
Q15: Win with 1923 The Midknight Inventors and 25 Raider Robotix against 75, 369 & 1071
Q18 ? with 2590 Nemesis & 2016 Mighty Monkey Wrenches against 3314, 263 & 714
Q23 Loss with 752 & 3314 against 303, 1367 Barringer Blue Bears & 224

Seeding Score: 95 (highest was 170)
Coopertition Bonus: 32 (highest 70)
Hanging Bonus: 0

Play-off Matches

With Alliance 2 Captian 2753 Overdrive & 1279 Cold Fusion against Alliance 3 1923 The Midknight Inventors, 714 Panthra & 75 RoboRaiders

SF 2-1 Win
SF 2-2 Loss
SF 2-3 Loss 4-11 - one robot absent due to 2753 mechanical problems

Who was there

Students: Paul, Ben R, Carly, Matt, Douglas, Jen, Andrew, Kenneth
Mentors: Mike Rizzo, Heather McKown, John Stumpo, Faith & Clem McKown
Parents: Alex Klufas

Drivers: Carly & Paul
Operators: Paul & Jen
Coach: Clem McKown
Human Player: Andrew
Administrator: Faith McKown
Pit Captain: Douglas
Pit Mentors: John Stumpo & Heather McKown
Scouts: Ben R.,Ken & Carly
Referee: Mike Rizzo

What was new

The (BR)2 Organizers spiced up the competition with the following changes:

  • An additional ball is added in each zone for each alliance at the start of the game (4 in far-field; 3 in mid-field; and 2 near-field). So, there are 6 additional balls in play (18 rather than 12).
  • Balls scored during autonomous period are worth 2 points each.
  • In the final 20 seconds, two orange bonus balls are put into play, one in each end zone. Scoring the bonus ball earns two points.
  • Hanging bonus

DEWBOT VI also sported some new features:

  • Most visibly, a 12" high x 24" wide aluminized polycarbonate mirror was mounted on the top front of the robot, tilted forward at an angle of about 12°. This mirror enables the driver to see balls hiding behind bumps while the robot "strafes" sideways behind the bump. The mirror is hinged and held up with an elastic spring, allowing tunnel passage. The mirror may be set either up or down at the start of a match.
  • Autonomous changes. Because of the increased scoring opportunity in autonomous (both more balls & double points), we modified the autonomous sequence as follows:
  • No wheel calibration at the start of autonomous. Wheels need to be calibrated & pre-set by tether before the match.
  • The 3-position switch is used to se the wheel angles to: 1) straight ahead; 2) 22° CW; or 3) 50° CW. The angles are selected for scoring using the middle column of ball positions from either the mid-field or near-field, respectively. By targeting the middle column ball positions, we avoid interfering with alliance partner autonomous scoring.
  • The kicker was pre-armed before the match.
  • Steering Motor Locking Pins were removed on the hypothesis that these were the cause of intermittent steering lock-up.

In addition, Paul was qualified as a DEWBOT VI driver and drove the robot during four of the qualifying matches.

Problems Encountered

  • During Q13, we lost the steering chain for wheel 3. Cause was due to the driven steering sprocket, which had slipped downwards until the chain face contacted the robot frame (wear on frame is evident). This contact removed the master link locking clip and ultimately, the chain failed when the master link came out. Since we were up again in Q15, we ended up playing two matches with wheel 3 spinning uncontrollably. Good pit organization allowed us to replace the chain (old one reused) before Q18.
  • During Q7, the encoder connector for wheel 4 became disconnected when going over the bump. This also makes the wheel spin endlessly. During SF 2-2, a particularly violent impact from 75 (which left us in the goal - see photo below) caused both wheels 2 & 3 (left side) encoder connectors to disconnect. Carly wire-tied the encoder connectors following this incident.
  • The removal of the Steering Motor Locking Pins did not resolve the problem with intermittent steering lock-up. In particular, at the end of Q18, wheel 4 was almost 90° out from the other three wheels. Carly indicates that she can correct via calibration, but this wastes valuable game time.
  • During Q7, we were unable to arm the kicker.
  • During Q23, our kicking was weak and unreliable. We had replaced kicker elastics prior to this match.
  • We scored no autonomous points. Problem was with the kicking. Initially, with the possessor on, we did not kick until we had already over-ridden the ball, at which point kicking is ineffective (kicker fires, but ball remains trapped under the robot - the kicker then continues to try to arm & fire). Later, with the possessor turned off, we generally failed to kick at all. We managed one effective kick (first of the day - it went out of the field). Once, we managed a weak (poorly-timed) kick, which just managed to knock the other balls lined in front of us out of the way.
  • Autonomous wheel angles seem to be off. Need to recheck geometry and test.
  • The IR sensor was broken in the semi-finals (SF 2-1).


DEWBOT VI took a real hammering at (BR)2. Especially during the semifinals. The only things which broke due to the hammering were the encoder connectors, which became disconnected rather than breaking, and the kicker IR sensor (in an exposed position). This is robust robot. Can we rotate the encoder connectors inboard to leave them less exposed to damage (I guess so)? Carly's wire ties were good thinking.

The steering chain failure is more of a design/maintenance failure (which makes it really a design failure, when you come down to it). We must pull Pivot 3 to put the driven steering sprocket in the right position (we pried the sprocket up enough to avoid interference between chain and frame, but it is not fixed). Suggest we pull all Pivots and add a PVC spacer between the bottom 1" bearing and the driven sprocket. This would prevent a reoccurrence should a sprocket loosen again. Since the driven sprocket is already close to the top 1" bearing, a top spacer is not necessary, but adding a spring washer here would be good practice.

Hat's off to Douglas, who spoke with the judges. The Engineering Excellence Award is a very nice one. 1279 Cold Fusion won this last year. Not bad company to keep.

Overall, the pit performance was excellent. The steering chain repair with a 2-match break required excellent planning and preparation.

There were 7 qualifying matches. Very fast pace. In spite of the fact that we purchased 2 new batteries, the battery situation was marginal.

Autonomous needs more work. I believe a sensor change is needed. Angled autonomous seems a good concept, but we have to consider this an basically untested at this point. Wheel angles need to be refined.

The mirror works. We can see hidden balls behind bumps. But with 18-20 balls on the field, finding balls is not such a high priority. We can get through the tunnel without trouble and even went through backwards (with the mirror already down). Mirror stays down when pushed down (so maybe having a servo to raise it would be a good idea). Need to verify that the mirror never breaks the (front of the) frame perimeter. When the mirror was mounted, I considered the latex spring a cheesy, temporary expedience. In retrospect, it is a highly-effective, simple, elegant, minimalist mechanism.

The Steering Motor problem is not fixed. Need to.

Bridgewater Raritan Battle Royale Photo Gallery