Subject:
|
Automated brick sorter
|
Newsgroups:
|
lugnet.robotics
|
Date:
|
Thu, 8 Oct 1998 21:39:20 GMT
|
Viewed:
|
1467 times
|
| |
|
|
Automated LEGO brick sorter
I have built a Mindstorms version of the 8094 mechanical arm that lifts 2x4
bricks and puts them in bins. Of course with Mindstorms, it can actually see
what color the brick is and take it to the appropriate bin.
It uses 2 touch switches: one to tell when the arm has rotated to the 'brick
loading bay', and one to tell when the arm has lowered into position ready
to grip the brick. The light sensor sits below the brick to be picked up to
determine its color.
Here's how it works:
The arm positions itself around the brick. The brick is picked up and the
arm rotated an amount dependent on the color until it is over the appropiate
bin whereupon it is dropped. The arm returns to position and picks up
another. This continues until all bricks have been picked up.
There are 3 bins: One for light colour bricks, one for dark, and one for
imbetween. The ambient lighting conditions tend to determine which colour
goes where. White and black always go in the right bins, though. The
numbers in the source below tend to vary by +/- 3 so it is difficult to tell
exactly what color brick it is with 100% accuracy. Perhaps a future version
will have another light sensor to measure ambient light and make the
appropriate adjustment.
I'll have images on my web page tommorrow as soon as I have borrowed a
digital camera!
Many thanks to David Baum for NQCC - an excellent tool that make Mindstorms
development so much easier, quicker and fun.
Has anyone else made one of these?
// arm.nqc by Huw Millington
// Written in NQCC 0.5b1
#define EYE IN_1
#define ANGLE IN_2
#define HEIGHT IN_3
#define JAWS OUT_A
#define ARM OUT_B
#define ROTATE OUT_C
// Colors of bricks measured in my dimmed computer room
#define WHITE 54
#define YELLOW 54
#define RED 51
#define GREY 49
#define BLUE 40
#define BLACK 38
#define AMBIENT 32
#define RaiseArm Fwd(ARM,4)
#define LowerArm Rev(ARM,4)
#define StopArm Off(ARM)
#define OpenJaws Fwd(JAWS,OUT_FULL); Sleep(150); Off(JAWS)
#define CloseJaws Rev(JAWS,OUT_FULL); Sleep(400); Off(JAWS)
#define ArmClockwise Fwd(ROTATE,OUT_FULL)
#define ArmAntiClockwise Rev(ROTATE,OUT_FULL)
#define StopRotate Off(ROTATE)
int Color;
task main
{
// Set up ports
Sensor(EYE,IN_LIGHT);
Sensor(ANGLE, IN_SWITCH);
Sensor(HEIGHT, IN_SWITCH);
while (1 == 1) {
// Rotate to position if not already there
ArmAntiClockwise;
wait((ANGLE == 1));
StopRotate;
//Lower arm ready to lift brick if not already there
LowerArm;
wait(HEIGHT == 1);
StopArm;
// Get color of brick
Color = EYE;
// If there's no brick there, exit
if (Color <= AMBIENT+1)
break;
// Grip brick
CloseJaws;
// Raise the arm a bit
RaiseArm;
Sleep(50);
StopArm;
// Rotate arm towards bins
ArmClockwise;
// Rotation angle dependent on color of brick
if (Color >= RED-1)
Sleep(300);
else if (Color >= GREY-1)
Sleep(650);
else
Sleep(850);
// Stop rotating, lower arm, drop brick
StopRotate;
LowerArm;
Sleep(50);
StopArm;
OpenJaws;
// Raise arm ready for next time
RaiseArm;
Sleep(50);
StopArm;
}
}
|
|
Message has 2 Replies:
 | | Re: Automated brick sorter
|
| (...) <snip> (...) I built a different type of sorter that separated red and blue 2x2 bricks. It is not as elaborate as yours, but it was a nice, quick Mindstorms project. Pictures are at: (URL) reply to: dbaum at enteract dot com (26 years ago, 9-Oct-98, to lugnet.robotics)
|
9 Messages in This Thread:
  
- Entire Thread on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
|
|
|
|
