Help with line follower build please!
Kayduh
Posts: 9
Hey guys, so I made a huge detailed post here last night took almost an hour or so... after posting it, it said it needed to be approved or something like that before it could be posted (Dont remember exactly what it said it was 4 am and I was tired so i'm going to try to post again) So pretty much, I am trying to build a line follower robot (as a robotic hobbyist) and would like some feed back on my hardware and also the basis of how i plan on programming the robot before I actually purchase the parts and get started.
Hardware:
I have a few questions / concerns with the hardware:
Let me start off by describing the track I was thinking of building. Imagine a straight path through the hall way of your house, now add an additional path going in to each bedroom / room along said hall way. So pretty much the track is one start point with end points in various rooms. I understand the logic behind using a continuous looping path that has no set start or end point, the robot will just follow the line and turn depending on the state of the sensors. However with my path, since there are various end points seems a little trickier I have been trying to figure out how to make the robot to ignore certain turns in the path because it wants to turn at the last room in the hall way rather than the first room.
The idea i had so far was to create a T - intersection at each bedroom door, the T - intersection will trigger all 4 sensors at once and in the program I will add a special case for when ever all 4 sensors are triggered simultaneously it will create a counter and increment after each intersection it passes. Now, with a "normal" line follower robot, said robot would turn right when the sensors on the right are triggered and left when the left are triggered. With the idea I had, the robot would turn either left or right (depending on which i tell it to) only when it comes to an intersection AND the counter is incremented to a certain value.
So a little example, lets say I wanted the robot to go into the third bedroom (i.e. third intersection and turn left):
Hardware:
to be used as the base of the entire robot (chassis, motors, micro controller, etc)
to be used as the ir sensors
bluetooth to send commands wirelessly from my PC to the boe bot
I have a few questions / concerns with the hardware:
- I was reading in forum posts (i dont remember which post exactly but it was an old post) and stumbled across one that was saying that the boe bot kit is excellent for "simple" applications but once you start to make it more advanced it starts to be come a pain. Would building the boe bot with the QTI kit, and controlling it with blue tooth be "pushing the limits" of the boe bot's boe / micro controller?
- I noticed the torque of the servos is 38 oz-in, I dont exactly understand how to figure out torque in regards to how much the robot can pull / carry. But I would like to be able to pull maybe 5 lbs with the boe bot if possible, it would be across a surface with no incline and would be on wheels as well. Could anyone recommend different servos? or even dc motors?
Let me start off by describing the track I was thinking of building. Imagine a straight path through the hall way of your house, now add an additional path going in to each bedroom / room along said hall way. So pretty much the track is one start point with end points in various rooms. I understand the logic behind using a continuous looping path that has no set start or end point, the robot will just follow the line and turn depending on the state of the sensors. However with my path, since there are various end points seems a little trickier I have been trying to figure out how to make the robot to ignore certain turns in the path because it wants to turn at the last room in the hall way rather than the first room.
The idea i had so far was to create a T - intersection at each bedroom door, the T - intersection will trigger all 4 sensors at once and in the program I will add a special case for when ever all 4 sensors are triggered simultaneously it will create a counter and increment after each intersection it passes. Now, with a "normal" line follower robot, said robot would turn right when the sensors on the right are triggered and left when the left are triggered. With the idea I had, the robot would turn either left or right (depending on which i tell it to) only when it comes to an intersection AND the counter is incremented to a certain value.
So a little example, lets say I wanted the robot to go into the third bedroom (i.e. third intersection and turn left):
- robot senses line and moves forward
- robot comes to first intersection, counter = 1. since counter ≠ 3, the robot does not turn and continues forward along the path
- robot comes to second intersection, counter = 2. since counter ≠ 3, the robot does not turn and continues forward along the path
- robot comes to third intersection, counter = 3. since counter = 3, the robot turns left and continues down the path
Comments
I don't think pbasic will have a problem with what you want to do but the BS2 has only so much code space. If that becomes a problem then you might want to consider a more powerful Stamp module, such as a BS2P.
Edit:
Also would I need to purchase a motor controller such as the HB-25 to use with the motors? (I have never used DC motors before)
With DC motors, you need some sort of motor controller. The HB-25 has the advantage that it looks like a servo motor to the microcontroller. Pololu makes a variety of similar motor controllers. Look at their website. If you were using a Propeller, you would need an H-Bridge to handle the power switching for the motor, but the Propeller itself can do the other motor control functions.