Print PDF
Favorite
Email
Step 8Motivation and Improvement
Motivation:
This robot was designed to fill the obvious gap between the capable but expensive guide dog and the inexpensive but limited white cane. In the development of a marketable and more capable Robotic White Cane, the Roomba Create was the perfect vehicle for designing a quick prototype to see if the concept worked. In addition, the prizes would provide economic backing for the considerable expense of building a more capable robot.
Improvement:
The amount I learned building this robot was substantial and here I will attempt to lay out what I have learned as I move on to attempt to build a second generation robot:
1) Obstacle Avoidance - I have learned a lot about real time obstacle avoidance. In the process of building this robot I have gone through two completely different obstacle avoidance codes, starting with the original object force idea, then moving to the principle of finding and seeking the most open vector, and then moving back to the object force idea with the key realization that the object response should be non-linear. In the future I will correct my mistake of not doing any online research of previously used methods before embarking on my project, as I'm now learning a quick Google search would have yielded numerous great papers on the subject.
2) Design of the stick sensors - Beginning this project I thought my only option for a linear sensor was to use a slide pot and some sort of linear bearing. I now realize that a much simpler option would have been to simply attach the top of the rod to a joystick, such that pushing the stick forward would also push the joystick forwards. In addition a simple universal joint would allow the twist of the stick to be translated into the twist axis of many modern joysticks. This implementation would have been much simpler then the one I currently use.
3) Free turning wheels - Although this would have been impossible with the Roomba, it now seems obvious that a robot with free turning wheels would be ideal for this task. A robot that rolls passively would require no motors and a smaller battery and thus be lighter. In addition, this system requires no linear sensor to detect the users push, the robot would simply roll at the users speed. The robot could be turned by steering the wheels like a car, and if the user needed to be stopped brakes could be added. For the next generation eyeRobot I will certainly use this very different approach.
4) Two spaced sensors for wall following - As discussed earlier problems arose when trying to wall follow with only one side facing sensor, thus it was necessary to move the robot between readings to achieve different points of reference. Two sensors with a distance between them would simplify wall following greatly.
5) More sensors - Although this would have cost more money it was difficult trying to code this robot with so few windows on the world outside the processor. It would have made the navigation code much more powerful with a more complete sonar array (but of course sensors cost money, which I didn't have at the time).
This robot was designed to fill the obvious gap between the capable but expensive guide dog and the inexpensive but limited white cane. In the development of a marketable and more capable Robotic White Cane, the Roomba Create was the perfect vehicle for designing a quick prototype to see if the concept worked. In addition, the prizes would provide economic backing for the considerable expense of building a more capable robot.
Improvement:
The amount I learned building this robot was substantial and here I will attempt to lay out what I have learned as I move on to attempt to build a second generation robot:
1) Obstacle Avoidance - I have learned a lot about real time obstacle avoidance. In the process of building this robot I have gone through two completely different obstacle avoidance codes, starting with the original object force idea, then moving to the principle of finding and seeking the most open vector, and then moving back to the object force idea with the key realization that the object response should be non-linear. In the future I will correct my mistake of not doing any online research of previously used methods before embarking on my project, as I'm now learning a quick Google search would have yielded numerous great papers on the subject.
2) Design of the stick sensors - Beginning this project I thought my only option for a linear sensor was to use a slide pot and some sort of linear bearing. I now realize that a much simpler option would have been to simply attach the top of the rod to a joystick, such that pushing the stick forward would also push the joystick forwards. In addition a simple universal joint would allow the twist of the stick to be translated into the twist axis of many modern joysticks. This implementation would have been much simpler then the one I currently use.
3) Free turning wheels - Although this would have been impossible with the Roomba, it now seems obvious that a robot with free turning wheels would be ideal for this task. A robot that rolls passively would require no motors and a smaller battery and thus be lighter. In addition, this system requires no linear sensor to detect the users push, the robot would simply roll at the users speed. The robot could be turned by steering the wheels like a car, and if the user needed to be stopped brakes could be added. For the next generation eyeRobot I will certainly use this very different approach.
4) Two spaced sensors for wall following - As discussed earlier problems arose when trying to wall follow with only one side facing sensor, thus it was necessary to move the robot between readings to achieve different points of reference. Two sensors with a distance between them would simplify wall following greatly.
5) More sensors - Although this would have cost more money it was difficult trying to code this robot with so few windows on the world outside the processor. It would have made the navigation code much more powerful with a more complete sonar array (but of course sensors cost money, which I didn't have at the time).
| « Previous Step | Download PDFView All Steps | Next Step » |
 |
Add Comment
|
