DEWBOT V

DEWBot V Team and Robot after winning the Rockwell Automation Innovation in Control Award

The 2009 game Lunacy (Game Animation) was a departure from the prior games and created some challenges for DEWBOT V. The salient challenge was the severe reduction in wheel-to-playing surface friction coefficient; by about an order of magnitude. We thought we had a good drive-train & chassis design before kick-off. Well, we thought wrong! Back to the drawing board!

A 6-Wheel Drive (6wd) wide chassis is employed with left and right drives. Each drive is powered by (1) CIM motor via a custom gearbox. A novel 7th Wheel provides the Pilot/Driver with dual driving modes. 6wd is the default mode. When selected by the Pilot, however, the 7th Wheel is engaged, allowing the robot to pivot rapidly on 3 wheels. This drive-train provided excellent agility and control on the low-friction Lunacy playing surface. It turned out to be an awesome drive-train. At the Chesapeake Regional, Team 1640 was awarded Rockwell Automation's Innovation in Control Award, principally for its novel and highly effective drive-train design.

DEWBOT V picks up Moon Rocks using a beater bar with curved back-plate and delivers these into a spiral Hopper for storage. Up to 14 Moon Rocks may be stored.

The beater bar can also be used to transfer Empty Cells to the Airlocks.

A pneumatic Shooter is installed at the top of the Hopper. A Camera on the Hopper top provides target recognition and tracking. The entire Hopper/Shooter/Camera system is able to traverse 270° to shoot Moon Rocks into opposing trailers. The traverse may either be controlled by the Pilot/Operator or by the Vision System.

A very large portion of DEWBOT V was designed using CAD (Autodesk Inventor) before being built. This and a real-time Bill-of Materials meant that mass management was a continuous process thereby preventing surprises.

This robot provided Team 1640 with a number of firsts:

first student-welded robot
first custom gearbox
first 6wd drivetrain
first measurement of friction coefficients; static & dynamic; in-line & transverse
first analytically-designed drive-train
use of a number of new materials
use of adhesives for critical, load-bearing joints
employed (10) jigs, forms and mandrels to facilitate construction
first engineering award (Rockwell Automation)
first championship (at PARC XII)

PARC XII Winning Alliance - L>R Teams 1640, 222 & 2753

DEWBOT V Build

season is detailed here.

Design Details

The links below will take you to details about the robot components.

Drive Train

DEWBOT V incomplete chassis with turntable set up for driving tests

DEWBOT V possesses an awesome drive-train. Both agile and powerful. It's hard to score on us. We can push most opponents around. We play great defense. This is a true driver's robot. More agile than suited to straight runs.

A 6 Wheel Drive (6wd) drive-train with the chassis oriented wide was selected for this year’s robot on the basis of providing superior maneuverability on a low-friction surface.

Wheelbase is 20.25” (long) x 33.25” (wide). Center of Mass (for the Robot) is about 9” above the Playing Surface and about 2” aft of chassis center.

Drive-train is Tank, with independent Left and Right drives. For each side, Middle wheels are direct-driven by custom gearboxes. Front and Rear wheels are slave-driven from the middle wheels via independent chains, minimizing the impact should the robot lose a chain.

Direct-drive gearboxes are based on AndyMark Super Shifters modified to: 1) add an additional axle and reduction for direct drive; and 2) disable the shift mechanism (unnecessary for Lunacy). (1) CIM motor is used per drive. Overall reduction ratio (CIM to Wheel) is 24:1, providing a maximum speed of 5.9 ft/s and more than adequate torque for turning.

A novel 7th Wheel is provided at the center-rear of the chassis, driven independently via a direct Globe Motor. The 7th Wheel is beneficial for 1) rotating (spinning) the robot in-place; and 2) braking. The 7th Wheel is oriented perpendicular to the 6wd and may be engaged or disengaged by the Pilot/Driver. When disengaged (default), the 7th Wheel is raised off the playing surface and the robot drives in 6wd Tank mode using dual joysticks. When the Pilot/Driver holds down the trigger on either drive joystick, the 7th Wheel is lowered via a pneumatic cylinder to contact the playing surface. This also takes weight off the (4) wheel 6wd wheels so that the robot is able to pivot rapidly on (3) wheels, Front Left, Front Right and 7th. When engaged, the (3) drives are controlled in Arcade mode using the triggered joystick. Releasing the trigger returns the 7th Wheel to its default raised and inactive position (and the driver joysticks to 2-joystick Tank mode).

Scoring at Monty Madness into 303's trailer

Ball Handling, Shooter

This is how we score. DEWBOT V picks up Moon Rocks using a Beater Bar, transfers these to a helical Hopper. A central Spindle drives the Moon Rocks up the Hopper to the Shooter. The whole Hopper assembly traverses to aim the Shooter.

Payload Specialists

Lunacy provides an huge opportunity for Human Players (a.k.a. Payload Specialists) to score directly...and to score big!

Programming

Use of the vision system allows for computer assisted shooting. A HeadsUP LED display allows the operator to understand the current state and take action without taking their attention away from the field. The “7th” wheel control is incorporated into the robot drive controls to allow the driver to effectively use it for turning. Computer assistance in traction and hopper positioning allow the drive / operator team to focus on game play.

Electrical

The low profile of the base and the open helix hopper design did not leave a lot of room for the cRio, Jaguar motor drivers, the battery, air compressor, power distribution board, etc.

Pneumatics

DEWBOT V posesses a complete pneumatic system with on-board compressor and (4) Clippard storage cylinders. There are (2) pneumatics users:

The 7th Wheel actuator uses (1) Bimba 170.5 DP Cylinder (1½" diam x ½" stroke)
The Shooter actuator uses (1) Bimba 042 DP Cylinder (3/4" diam x 2" stroke)

Open the Microsoft PowerPoint Pneumatic Lesson.

Autonomous Mode

Autonomous mode was designed to make DEWBOT V a difficult target for Payload Specialists during the autonomous period. To allow us some flexibility in autonomous mode, and also to prevent us from being too predictable, any one of (6) autonomous programs may be selected prior to the start of a match. The autonomous program is set via two switches on the robot:

Finished DEWBOT V weight

switch 1

straight
wide turn
sharp turn

switch 2

left
right

This is an effective Autonomous mode.

Weight

Robot weight was managed very carefully this year. A detailed Bill-of-Materials was maintained in real-time as part of the design effort. This BoM included weights and costs of all parts on the robot. We finished with pounds to spare. No features were sacrificed for weight savings. No last minute holes were drilled.

Bumpers

Following our DEWBOT IV bumper removal experience, this was a priority. Bumpers were designed for fast installation and removal. These operations take a minute or less with this robot. Bumper bolts are permanently attached to the bumper boards this year, with wing nuts used to secure these (so no tools required). There is good access to the wing nuts.

Post-Mortem

Open pdf-format post-mortem analysis.

Events

DEWBOT V attended a number of events in 2009. The links below will take you to the details of each event.

Chesapeake Regional: was the only official event we went to. We did fairly well in the preliminary matches. We received the Rockwell Automation's Innovation in Control Award for our 6+1=3 drive system and the corresponding control and heads up display system.

PARC XII: was our first off season event. There were fifteen teams present. We got picked by the number one alliance and went on to win the event.

Monty Madness: was the week after PARC XII.

Bridgewater Battle: on 6-June. Team 1640 placed 3rd out of 18 teams in the qualifying matches.

Pool Party: 12-July at the McKown's. We ate. We drank. We swam. DEWBOT didn't. We shot paint balls (but not at each other). Awards were presented for conspicuous excellence among graduating seniors.

Duel on the Delaware: October 10th. FRC Team Sab-BOT-age and DEWBOT V gave a good performance at Duel on the Delaware. We won 3 of 5 qualifying matches, placing 14th of 24. Selected for the 1st Alliance (1218 - alliance captain, 433 Firebirds and 1640), we won the won the quarterfinals, moving up to the semi's. Lost the first semi-final, won the second, but lost the third. Kenneth (Operator) and Praveen (Payload Specialist) joined the New Field Team. Thanks goes to Corey for an excellent scouting job.

Ramp Riot: November 14th and DEWBOT V's last competition. Our robot scoring performance (hitherto not a strong point for us) was significantly improved over earlier competitions. Carly drove very aggressively, and has become adept at pinning between the robot and trailer, so that we can score. Ken and Paul took turns as Operator. Cole, Matt & Vamshi were our Payload Specialists and did a great job. Ken and Ben R took the lead on scouting. We won 3 of 5 qualifying matches, placing 17th of 36, but were not selected for an alliance.

Second Bay at DEC: Downingtown Area Robotics expanded into a 2nd bay at DEC. The new bay will be used for FRC and VEX storage. The original (larger) bay will house our power tools and will remain a work area.