PLEASE NOTE: this is an older version of the PID line follower, but the entire project, in its latest version, is available on the PID line follower project page.
It’s finished, at last! It’s got a project page all for itself (over here), and a new video. It hasn’t changed that much, but the PID values have been changed (see video), and the motors’ PIDs are now turned off all the time, since they only got the robot to drift off the line after turns).
More info:
PLEASE NOTE: this is an older version of the PID line follower, but the entire project, in its latest version, is available on the PID line follower project page.
Here’s the video, at last. It shows the new pausing function, which is activated whenever the magnet is removed from in front of the HiTechnic magnetic field sensor located on the back. This happens when the “tail” is lifted or the robot is tilted backwards.
PLEASE NOTE: this is an older version of the PID line follower, but the entire project, in its latest version, is available on the PID line follower project page.
The robot changed quite a lot since the last release. It’s now got a tail-like attachment with a magnet on it sticking out its back. Mounted just behind that are two HiTechnic sensors: one magnetic field reader and one IR link.
Once the program is started and the robot has read the black and white values, it sets the magnetic field sensor’s bias to zero. Since this happens with the magnet in front of the sensor, the robot can notice any big changes in its position. So, when the tail is lifted, or the robot is tilted backwards (which lifts the tail), it senses the difference in the magnetic field and pauses the entire program. This includes the motors, the line following PID stuff, and the motor’s PID. Video will be available in the follow-up post
More info:
PLEASE NOTE: this is an older version of the PID line follower, but the entire project, in its latest version, is available on the PID line follower project page.
OK, so instead of stopping the whole program when the touch sensor(s) is/ are pressed, it now pauses. When the sensor(s) is/ are released, it waits half a second and then tries to re-find the line again. It’s not fault-proof, though: when the angle is wrong, it tends to overshoot the line and drive off the table lose it for good. This didn’t change what the robot looks like, so no pictures…
PLEASE NOTE: this is an older version of the PID line follower, but the entire project, in its latest version, is available on the PID line follower project page.
Even though it’s not exactly my ideal stopping system, it works just fine. Two touch sensors are now mounted on the robot’s left and right, and are pressed when it’s upside-down. So, when the line follower is… following lines, and someone pulls its front, it rolls over, the touch sensor(s) are/ is pressed, and it stops. The new program (see below) also includes the new PID values, as seen in version 1.2-. Click the images to enlarge.
More info:
PLEASE NOTE: this is an older version of the PID line follower, but the entire project, in its latest version, is available on the PID line follower project page.
Here’s the new version of my PID line follower. The PID values changed to the following:
After being a two-by-two circular semi-rounded flat Lego piece, and a small Lego ball, the all new caster is now an ordinary, rubber-less wheel; the annoying peeping noise (paper + plastic Lego caster = AAARGH) is finally gone.
Here’s a video (music by Jarre):
More info:
PLEASE NOTE: this is an older version of the PID line follower, but the entire project, in its latest version, is available on the PID line follower project page.
Finally programmed and tuned, this PID line follower tracks the edge of a (thick) black line on a white background. The robot has partially changed since the last post on it (with pictures); the light sensor has moved to point (almost) straight down, and there’s a new caster, which works surprisingly well. The PID values for it are:
Here’s a video:
The last motor port and the top of the robot are free, to support an automatic in plug system for the Lithium battery. That’s not finished yet, though.
More info:
PLEASE NOTE: this is an older version of the PID line follower, but the entire project, in its latest version, is available on the PID line follower project page (with coding).
Here’s my newest creation: a line follower. It’s not programmed (yet), but the initial build is pretty much complete. Since there’s a lithium rechargeable battery on it, I’m going to try to make it plug itself in (using one motor – the other two ports are filled). The light sensor might be a bit problematic, since it’s at a forty-five degrees angle from the floor. This time, it’s actually got a color scheme (red and gray). Click the pictures below to enlarge them.
The front doesn’t look that impressive, since that’s where the plugging system will be installed.
