Arduino Robot 2 - Part 1 - Forward Scanner

-
Work has been coming along well on the development of the second version of Arduino Robot. There have been multiple set backs; the biggest of which is my purchase of a continuous rotation servo instead of a normal one. Otherwise the bot is constructed and mostly works in tests.

The goals for Robot 2 were a step up from Robot 1:
  • Ability to continually scan in front of itself.
  • Ability to back and turn to avoid obstacles.
  • Smoother movement.
Basically Robot 2 is a wandering avoidance robot; called Arduino Robot 2 - Wandering Tank. For this to work, I needed some type of affordable sensor to place at the front of the robot; and from there the ability to look around with it. My solution was to mount a sensor on a servo. The servo would be used to sweep across a selected field of vision looking for possible collisions. So Wandering Tank has to do the following:
  • Move Forward
  • Scan left to right
  • Move backwards while object detected
  • Turn after object no longer detected 
  • Repeat 
Because only a continuous rotation servo was available without spending more money; the design was changed so that instead of targeting a degree; the servo would have some way to trigger moving back and forth. The eventual solution was to mount a light sensor just behind the servo. A disk was then cut with a slot cut out defining the open degrees of movement. The scanner would scan back and forth, reversing direction each time the light sensor met darkness. It didn't work out this simple, and I'm still perfecting the code. It does perfectly scan back and forth in normal light conditions however.

To fix the problem, a led will be added with the purpose of providing a continually known light source. The problem being that when moved from the work bench to any other area, the relative light/dark changes and the servo starts to just spin and rip wires asunder.

Until part 2, where the complete Wandering Tank project will be shared, here is the scanning servo. Any ideas on doing this better are welcome!

Comments

Post a Comment

Popular posts from this blog

Resuming My Robot Work With Bonus 3D Printer Project

-
Image
Well after a long break of working on the house; this blog will be returning to a primarily robot programming focus. My work on the house is shared elsewhere... So; I've resumed work on my robot and added a second Arduino to my arsenal; this way I can prototype ideas without disassembling the robot. I have used it to go through the tutorial for the TFT screen: The new Arduino is an UNO; they come in much more sophisticated packaging than their predecessor: That is a sticker sheet on the right and a EULA in the middle. The first nice thing to notice about the UNO is it auto switches the power source. You can see this difference and other slight changes in the comparison here: So; I will post about the robot again when line following can be demonstrated and the code is ready to share. I hope to share two versions (with and without TFT info printing). With that; the other exciting news is that I am building a 3D printer; which I will document here and share my proble...
Read more

Arduino Robot 2 - Wandering Tank

-
Image
My second robot was a bit more complex and ended up taking twice as long to build as originally intended. The budget changed, the designed changed, and my understanding of Robotics in general changed. The second robot is an attempt to make an obstacle avoidance robot that isn't overly simple. I will be outlining the goals, budget, build and code for Wandering Tank. The goals for Wandering Tank were simple: Should be able to scan an area in front of itself. Should be able to avoid not only walls, but obstacles. Avoid random decision making; the robot should use information when avoiding. Wandering tank meets these goals, and also looks pretty cool doing it. The code for the robot will show how the third goal is met and the other two will be obvious in the video. The budget for Wandering Tank was quite cheap. Since I started with Robot 1, the only additional cost for Wandering was the sensor and the servo. Robot 1 ($98.00) Sensor - Digital Distance Sensor 10cm $6.95 + $2.00...
Read more

Quick Post About Hexy

-
Image
Hello, just a quick post about Hexy the robot. I was recalibrating the printer after finishing up the rebuild and wanted to do some printing. Since I was curious about the sizing of Hexy and also my ability to print parts for it; I decided to grab the STL files and get printing. There was trouble; not all of the stl files were ready, some of them needed to be run through http://cloud.netfabb.com/ first. It took me a while to figure this out; but once I found it everything went smoothly. You may be curious; so here are some leg pieces for Hexy; printed in blue PLA. That's all for now. I'm prepping a full post on the rebuild reprap; my robot progress, and another project that is coming along very nicely.
Read more