2007 Santa’s Little Messenger Race

This year, like last, I decided to hold the Santa’s Little Messenger Bicycle Race benefiting Atlanta’s Toys For Tots program. The concept behind the race is that individuals and businesses around town, who were going to donate a toy to Toys For Tots, register the toy with me via a web form instead of finding a local drop off point. Then, on the day of the race, riders picked up the toys and returned them to the “base”. Two categories of racers (solo and two-person teams) competed to earn the most “toy miles”.

The race began almost immediately with a terrible rain storm but all the riders really toughed it out and did a great job. This year, seventeen racers (six teams and five solo racers) collected 96 toys. The complete results are available on Faster Mustache.org.

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Performance Testing NXT’s Ultrasonic Range Finder

I have plans to utilize the Lego NXT system for several upcoming robotics projects. The success of these projects depends on the capabilities of the kit’s ultrasonic (US) range finder. I created a test rig with the US sensor and NXT brick and conducted several experiments in order to characterize the sensor.

Test rig: wood block, measuring tape, protractor, US sensor, NXT brick (from left to right).
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SLAM-5 Bot part 1: The Hardware

I recently purchased Lego’s new NXT hobbyist robotics kit. After familiarizing myself with the basic layout of the command module, available hardware and sensors, and third-party programing languages by building several single-task robots, I decided to use the NXT as a forum for my studies in SLAM robotics. As I have previously quoted, Dr. John Leonard of MIT says,

The problem of SLAM is stated as follows: starting from an initial position, a mobile robot travels through a sequence of positions and obtains a set of sensor measurements at each position. The goal is for the mobile robot to process the sensor data to produce an estimate of its position while concurrently building a map of the environment.

My goal and new perspective on the problem is to design a system which is as simple as possible. I immediately realize that much of the complication in SLAM systems lays in the timeliness with which the system processes information in real time. I know that some compromise between speed and simplicity had to be established, and in pursuing the most simple system, I am willing to sacrifice a lot in speed. So I have created what I am calling the “slam five robot”. The real acronym is S.S.S.S.S.L.A.M. which stands for “super-simple, super-slow, simultaneous localization and mapping robot”.

The system consists of three components: the physical hardware of the robot, the control algorithm which guides the hardware and sensors, and the post processing algorithm which interprets the sensor data. I begin here by describing the hardware and sensor setup.

Front view of the SLAM-5 bot, showing ultrasonic range finder and wiring for the drive motors.

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Meerkats Slay Muddy Buddy

This weekend, I was part of Team Meerkat in the Atlanta Muddy Buddy with my friend Katie Davis. The race was held at the Georgia International Horse Park in Conyers, GA. We won our division (Coed 45 and Under) and placed 21st overall out of 740 teams which finished. The race is one in which a 6-7 mile course is divided into five stages. For each stage one teammate mountain bikes and the other runs. Then at the stage intervals, the teammates switch positions and carry on for the next stage. Teammates are not required to stick together. In fact Katie and I only saw each other twice through out the race.

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NYC: Bike Punks and Coffee Geeks

Back in February, I traveled to New York City to participate in Monstertrack and investigate the 3rd wave coffee shop scene. I drove up with my friends Seth, Gregg, and Chris. We left Atlanta at 4pm on Thursday and drove throughout the night, arriving in Manhattan about 10 am Friday morning. As soon as we pulled into the parking garage, we assembled our bikes and took off to explore the city. We had plans to stay with NY messengers Pablo and Victor, who were organizing the race, so first we dropped off most of our gear at Pablo’s house in the Lower East Side.

The race, which wouldn’t be until the next day, consisted of eleven checkpoints. Five of them were released on the internet several weeks prior, so the four of us decided to pinpoint their exact locations. Furthermore, I knew that I would need a bike helmet for the race so our next stop was one of the checkpoints: a track bike-only shop called Trackstar.
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