Society of Robots - Robot Forum

General Misc => Robot Videos => Topic started by: growler on July 12, 2011, 11:31:17 AM

Title: My new line follower
Post by: growler on July 12, 2011, 11:31:17 AM
Well, I got this little guy up and running fairly smoothly. I'm aware its not breaking any speed records, other than my personal best but I think I can get it going faster as I have not done much to tune the line following PID constants.

Approximately 25 cm/s according to homemade encoders and I can push the motors up to about 75 cm/s with this amount of weight while maintaining some power headroom for speed regulation so I'm thinking I can get this significantly faster.

I think the biggest limitations at this point is the number of sensors I put in the array (5) limiting my range of error values and the fact I am using LDRs which don't respond that fast to light changes.  At least I think my control loop is running faster than the sensor's resistance changes in response to light changes.

Suggestions and comments welcome!

Robot doing another lap. (http://www.youtube.com/watch?v=Fq-_63V0RZs#)

That is odd, the video works in the preview.

Now it works here to.
Title: Re: My new line follower
Post by: GosuSheep on July 20, 2011, 05:29:41 PM
Awww, it is quite adorable (is it bad that I find robots cute?-.-)

I would love to make a similar beast in the future. Would you be open for questions later on?
Title: Re: My new line follower
Post by: BigKLaxer on July 21, 2011, 07:15:02 AM
Awww, it is quite adorable (is it bad that I find robots cute?-.-)

One more step closer to the robot apocalypse.  If the lolCats don't take over first.
Title: Re: My new line follower
Post by: GosuSheep on July 21, 2011, 11:31:21 AM
Yis. Once robots start playing with string and balls of yarn, we are screwed.

@Growler, have you seen competitions for line-following robots? Do you believe that yours would have a chance at becoming victorious? Are your algorithms and hardware easily modifiable to account for different lighting and different color lines?
Title: Re: My new line follower
Post by: growler on July 26, 2011, 11:26:06 PM
GosuSheep,

I know they exist but have never been to one and therefore have no idea as to victory odds.

As to changing lighting conditions, it can calibrate itself and the sensors are fairly well blocked from ambient light anyway. The far curve in that video is in direct sunlight if the window shade is up and it can make it through there fine.

I think converting to a light on dark line would only require changing a > to a < somewhere. I've never tried to detect anything other than light dark contrast so am unsure about any other color detection.

I can certainly answer any questions you have about the design or software.