Data Bus



This is an overview of the 2014 version of Data Bus, 3rd place winner of the 2012 Sparkfun AVC.

Data Bus Specs

Total Cost$650
Chassis1/10th 2wd ECX Circuit RC vehicle with suspension tuned for improved cornering
BodyParma “Skool Bus” custom painted by author
MotorTacon 3000Kv 2848-540XL brushless
Battery Gens Ace 2S, 5000mAH 40C LiPo
WeightApproximately 5 lbs
MCUmbed 96MHz ARM Cortex M3
Language C/C++
Power Supply Pololu 3.5A, 5V Step Up Regulator
GPS 3DR uBlox LEA-6H set a 4Hz update rate
Gyro Pololu MinIMU-9 with an STM L3G4200D 3-axis gyro
Wheel Encoders 32 ticks per revolution; QRE1113 IR sensor from Sparkfun,  custom Schmitt trigger interface
EstimationHeading via gyro in near real time unbiased using 2-state Kalman filter using GPS heading and time-lagged gyro heading inputs. Distance via wheel encoders.
GCSCustom Ground Control Station written in Java Swing

Changes Since 2012

  • Converted to offline compile for mbed SDK. [source]
  • Improved user configuration
  • Attempted to implement FreeRTOS. Fail.
  • Replaced previous GPS with 3DR uBlox LEA6-H.
  • Converted path following to Pure Pursuit algorithm.
  • Custom Ground Control Station (GCS) [source]
  • Telemetry broadcast to GCS via Xbee Pro.
  • Converted to XT60 connectors and new 2S LiPo.
  • New RoverBaseboard to support mbed and LPCXpresso.
  • New RoverMux multiplexer board.

Still To Do

  • Robot does not stop upon reaching last waypoint;
  • Unclear whether robot is accurately navigating to final waypoint;
  • Test runs to verify precision, accuracy;
  • Attempt to improve performance in speed, precision, and accuracy.

More Technical Details

For additional technical detail about the robot, click here.

Resources

diyrovers discussion group
http://is.gd/diyrovers

ArduRover user's group at
http://diydrones.com/group/ardurover-user-group

WheelEncoderGenerator program:
http://code.google.com/p/wheel-encoder-generator/

Fundamentals of Kalman Filtering: A Practical Approach, Paul Zarchan,
ISBN: 1563474557

Vendors

ECX, www.ecxrc.com, (800) 338-4639
Sparkfun Electronics, www.sparkfun.com, (303) 284-0979 (No phone orders)
Pololu, www.pololu.com, (877) 776-5658
HobbyPartz, hobbypartz.com, (626) 968-9860
A Main Hobbies, www.amainhobbies.com, (800) 705-2215
Acroname Robotics, www.acroname.com, (720) 564-0373

2012 AVC Results

Air:

1st Place: Team Overhead, 36.62 seconds
2nd Place: Team Robota, 44.50 seconds
3rd Place: Lost in Air-Space, 54 seconds

Ground:

1st Place: Team 0x27, 2.08 seconds (32.08 raw)
2nd Place: Team Minuteman, 9.46 seconds (39.46 raw)
3rd Place: Team Databus, 37.16 seconds (37.16 raw)

Other:

Crowd pleaser: Die!Wheel!
Rookie Award: Short Circuit
Best Dressed: Kegbot
Water Hazard: Viator
Engineer's choice: Namniart
Kill Switch: Snobbotics
Purple Heart: Snobbotics, Team Databus

Sparkfun AVC


2 comments:

  1. Eagerly awaiting to see more good things from DataBus and your other creations!

    ReplyDelete
    Replies
    1. Thanks! Sad to say that Data Bus had to sit out the AVC again this year. I just didn't have time to figure out the heading estimate "improvements" I made. :)

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