The Intelligent Ground Vehicle Competition (IGVC) is the precursor to the DARPA Grand Challenge, and in many ways it is just as difficult. We have the pleasure of being at the competition this year with the Tennessee Technological University Autonomous Robotics Team. The teams at the competition pull off some amazing home-brew robotics, so we’ve decided to do a short section on some exemplary robotic hacking each day of the competition.
Today’s robot comes from the York College of Pennsylvania. The robot, dubbed “Green Lightning”, features an impressive set of custom made hardware.
We ask, who wouldn’t want a rotating motion and distance tracking radar? Sure in today’s day and age anyone could purchase a wide-angle sonar or IR solution that achieves the same goal, but [LuckyLarry] took it old school and made his own rotating radar. He used an Arduino, servo, and ultrasonic sensor as a base to gather data, and the open source programming language Processing to draw the data on the screen. He says it’s a little inaccurate currently, but will try out some other sensors in the future.
Reader [Joshua] sent in his latest project. using a sonar rangefinder, an Arduino, and some clever programming, he’s made is computer react to his distance from it. As you can see in the video after the jump, he has programmed it to change text size and background color depending on his distance from the screen. While he admits that his implementation doesn’t seem immediately useful, there’s lots of potential there. We can actually think of several uses. What would you use it for?
[Lynne] had this crazy idea to build a piece of clothing that would give you feedback about your surroundings using sonar. She started with a carefully selected thrift store jacket. She wanted something that looked good and also provided plenty of places to hide electronics. She used the LilyPad system, with a vibration pad and a sonar range finder. When the system detects an object within a certain distance directly in front of the wearer, it warns them with some vibration. Not only is it practical, it looks pretty cool too. Did we mention she designs clothing?
She notes, in the comments section, that while it can detect an obstacle, it cannot detect a void. How could she detect a drop in the floor or a step down?
[Tony Messina] had been fascinated with bat’s echolocation since he was a kid. After he retired, he decided to act on this fascination and built a simple bat detector.
The simple bat detector uses frequency division to lower the bat’s chirping to a frequency we can hear. For example, if a bat is calling at 91kHz the system will divide it by 16 and put out 5.7kHz. The system is digital, so all amplitude is lost. You’ll just hear clicks like a Geiger counter. Being digital has its advantages though. Unlike similar analog devices that have to be tuned to a small frequency range, the simple bat detector can detect a much wider window.