In the November/December 2011 issue of Robot Magazine, Terry Jackson and Salvador Garcia of the Chibots robot group authored an article titled “2011 Midwest SRS RoboMagellan Competition.” The subtitle was “There can be only one!”
This exclusive online bonus content is a supplement to the main story and consists of five sidebars detailing some of the robots that participated in the RoboMagellan competition.
|Robot name: Wheel-E
Builder: CIRC (Central Illinois Robotics Club)
Cost & hours to build: not given
|Robot name:Robo-RabbitBuilder:Tyler WulfCost & hours to build:$1,000/250 hoursOutstanding features:
|Robot name:No NameBuilder:Rick BrooksCost & hours to build:$1,000/1,000 hoursOutstanding features:
The twin motors of the Traxxas E-Maxx chassis were replaced with the single Titan motor with its transmission locked in low gear. Rear Steer was added to increase maneuverability. Since the robot now weighs 13.75 pounds, heavy duty springs and shocks were adjusted to produce a very stable sensor platform at higher speeds over a typical RoboMagellan course. Stability control is provided in the software so that the robot will not flip over or roll on its own. The original motor control was replaced with the RoboteQ AX1500 for ease of use and reliability.
The main control board is very simple. It has a Parallax Propeller Prop Stick USB for all of the processing power needed. A four line LCD is included that displays six different user selectable screens to keep track of all of the sensor inputs and control outputs. A rolling code receiver acts as the remote kill switch. A micro SD card holder records GPS position in KML file format.
There is an I2C IO expander (PCF8574AN) because as Rick puts it “I just because I wanted to play with one”. Finally, five voltage regulators (two switched and three analog) provide the power for all of the electronics. The only protection on the Propeller pins is a group of serial resistors (2.2K for outputs and 10K for inputs).
A Lynxmotion encoder is located where the second E-Maxx motor would normally be mounted. Its primary function is to provide speed input for stability control. It also provides the total distance traveled on the RoboMagellan course. Directional feedback is simply provided by the Honeywell compass. The GPS unit furnishes very reliable location information for updating distance and direction to the next waypoint. Finally, the five sonar units both avoid objects in the robots path and provide the exact location of the destination cones.
All software is from either the Parallax Propeller Forum or the Parallax Propeller object exchange. No additional software needed to be developed, although the various Objects and Methods were modified to produce the exact characteristics desired for this application. All of the basic functions of the robot operate on five of the Propeller cogs. The sixth cog provides simplified user input of waypoint commands for the RoboMagellan course and other manual functions. The seventh cog is needed to write GPS data to the uSD card. Finally, the eighth cog is used for the R/C receiver when it is plugged in for testing.
|Title:Team ConeheadRobot name:Â SDRBuilder:Team ConeheadCost & hours to build:$700 (so far)/125 hoursOutstanding features:
It can climb over 5” barriers and go through rough and rocky terrain. The prototype chassis is made of various materials â€“ acetyl and styrene plastic, plywood and aluminum angle. The final chassis will be welded 6061 aluminum. The wide treads and weight allows the tank to navigate through the heavy grass, over uneven terrain and across the multitude of surfaces that are encountered on the competition course.
Team Conehead was formed in 2009 by Eddy Wright and John “KJohn” Kjellman.Â Our first Robomagellan entry was a large scale toy tank with an onboard PC. Unfortunately, the toy tank was not durable and did not last to see a second contest.Â In 2011, Team Conehead expanded to include Stuart Hecht and Glen Aidukas, both avid designers and robot builders.
Eddy Wright â€“ long-time electronics enthusiast that began working with robots in the late 1990s. Eddy joined Chibots in 2001 and is still an active member. In 2002, Eddy formed Wright Hobbies LLC, a web-based electronics and robotics design, manufacture and sales company (http://www.wrighthobbies.net). Eddy lives in Bolingbrook, IL.
John Kjellman â€“ (aka KJohn) Been creating robots since the late 1990s, first using Lego Mindstorms and later Vex, Tamiya and various kit parts. An active Chibots member since 2003.Â A systems architect and software engineer by trade, also an instructor at Moraine Valley Community College teaching courses in operating systems and .NET development. John lives in Orland Park, IL.
Glen Aidukas â€“ IT Manager at a small software company with experience in hardware design. Glen has been involved in electronics since 1990 and robotics since 2003. In collaboration with Wright Hobbies, Glen developed the Bahbots controller, an advanced microcontroller board for robotics and electronics projects. Glen is a very active member of the robotics club in Philadelphia called Philly Robotics (phillyrobotics.org). Glen lives one hour outside of Philadelphia, PA.
SDR images by Eddy Wright
|Title:Blast From the Past: The First CompetitionThe first Midwest SRS RoboMagellan competition was held in 2008 at Moraine Valley Community College. Chibots organizers liked the campus due to its center quad, an area lush with vegetation, grass, uneven terrain, trees and cement sidewalks. This environment posed a number of challenges to the robot, including unseen “dangers” such as metal rebar or conduits under the sidewalk that affected the compass’ functionality.Team Hassenplug was a major part of this event. They brought 4 different competition entries, all made using LEGOs Mindstorms. Other competitors included Team Conehead, represented by Eddy Wright and John Kjellman, Eric Gregori and Rick Brooks. While the Team Hassenplug robots all ran, the Team Conehead and Eric’s robots had problems and were unable to run the course.The winner of our very first competition in 2008 was Steve Hassenplug, using a 100% Lego robot he called the Green Monster.Â Steve is known to many in the robotics community for his leadership in creating Monster Chess, a Lego-based robotic chess game.Â The game is played on a laptop and radio-controlled robotic chess pieces move about an eight-foot square playing area.Â (See www.teamhassenplug.orgor type in monster chess in your favorite search engine)Aside from the 4 competitors, others brought their robots to show them to the eager crowd. Among the people showcasing their robots were Jeff Sampson and Kenneth. The weather was hot and humid as it usually is during this time of the year, although I don’t remember anyone bathed in sweat at the end of the competition as it happened this year (2011).
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BP images by Jeff Sampson
BP2 images by Steve HassenplugGreen Monster
by Steve HassenplugGreen Monster competed in the first three Chibots RoboMagellen events, finishing the course all three times.Â It is an all-LEGO robot that uses the LEGO MINDSTORMS NXT as its main controller and was programmed using RobotC.
The primary navigation source was an external GPS connected through the MINDSTORMS’ built-in bluetooth to receive the GPS coordinates from which it could calculate the direction and distance to each waypoint.Â Waypoints were entered by simply walking through the course with the GPS and NXT.
Green Monster has two parts to the driving base.Â The main section has two drive motors for differential-drive (tank-style) along with the NXT and most of the sensors.Â The tail section has the mounting for the GPS, and a single drive motor connected via a single axle to both back wheels.
The robot’s main section contains a sensor array that includes a HiTechnic compass sensor for directional navigation, a single ultra-sonic sensor for object detection, a camera sensor that is programmed to identify an orange blob within it’s field of vision (for cone detection), and a touch sensor to detect when the robot actually contacts the cone.
To avoid getting stuck, the software will scan the ultra-sonic sensor for objects, watch the wheel encoders (built into the motors) to ensure the wheels are moving, and monitor the speed value returned from the GPS.Â If any of these fail their test, the robot will stop, turn the front wheels, and back-up for a couple seconds.Â Then, it will check the compass, and follow the new heading for several seconds (again scanning to ensure movement) before recalculating a new heading, based on the new GPS coordinates.
The Green Monster software will also generate a KML file which contains a log of GPS coordinates and robot-state information (what the robot was doing during the run) that can be used with Google maps to generate a complete record of the run.
More information and video can be found on the web site: http://www.teamhassenplug.org/robots/GreenMonster