BUILD AN EV3 COLOR SORTING MACHINE
So just before Christmas holidays the Greek students started working on the 1st assignment that is to design, build and program a LEGO bricks sorting machine.
Sorting would take place according to the brick colours based on the national flag of each country (ie blue and white in our case). Some spare parts of common LEGO bricks were used to represent the colored cargo and also as a basement to fix on them the final machine constructions.
We formed 3 groups of students, each group would work on its own design. The teacher was assisting the students when required and guiding them discreetly so it was mainly for the students to find their own solutions on the problem, design it, build it and program it to perform the task.
All the students were excited and started working right away!
In this process they discovered how to build things using LEGO bricks and familiarised themselves with the different block components and the roles of things like angle connectors, axles, pins, beams, gears etc. In addition they connected and programmed different types of motors and sensors. For this task several LEGO® MINDSTORMS® Education EV3 sets #45544 were used and one LEGO EV3 Expansion set #45560 that was available. Their parts inventory can be found here: #45544 #45560
For most of the students this was a completely new experience! However they managed it fine!
For programming their designs, initially they were taught to use the proprietary Lego Mindstorms (graphical block) software and then shifted to program by writing code in JAVA using the leJOS library under Eclipse software.
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Team 1
TEAM-1 short working video
Vaggelis Marios Panousos
Stefanos Papageorgiou
Aggelos Papatheofanous
Giorgos Gerontis
Eleftheria Kaliou
Emmanouil Tatouris
As a Christmas assignment we had to design and build a sorting machine that sorts Coloured Lego bricks of our country’s national flag colours (ie blue and white).
In order to cover the project’s needs we used a Large EV3 Motor and a Medium EV3 Motor used as servo motor, an EV3 Colour Sensor and definitely a Lego EV3 Smart Brick. We also use some tracks in order to make the belt as well as a sorting lever which separates the parts into the boxes.
Our robot is a colour sorting machine, it consists of a moving belt and a moving lever which separates the coloured lego blocks into 3 boxes. One box for the blue ones, one for the white ones and one for all the other colours. We have programmed its functions with Java coding language.
The belt constantly moves at a constant speed and the coloured lego bricks are moved under the Colour Sensor. This sensor then reads the colour id of each brick and according to this the EV3 Smart Brick controls the direction of the Servo Motor.
Attached to the Servo motor is a sorting lever that moves left or right to push the bricks into the appropriate boxes. We separate the blue bricks to the left side box and the white bricks to the right side. There is also a third position that the sorting lever goes far right to the end so that all the rest coloured bricks that are not blue or white fall into a small compartment under the machine.
The belt’s speed is 25 bps so the Colour Sensor can read the passing brick’s colour. The Colour Sensor is positioned 1 cm higher above the passing coloured brick that is to be read. We have programmed a specific action for each colour so that the sorting lever moves them on the appropriate boxes.
The following figure is an overview of the procedures that take place.
TEAM-1 video presentation
Pictures of the TEAM-1 project
and view from the bottom
Here is our Java code for it: NewBelt.java
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Team 2
TEAM-2 short working video
THE TEAM:
ANTONIOU ORION
KATRAKAZOS FOTIS
SPEI MARIA
HATZIKONSTANTI MARIALENA
KATSOULIS MANOLIS
MATERIALS
- A Large EV3 Motor
- A Medium (Servo) Motor
- A Colour Sensor
- LEGO technic bricks
- EV3 Smart Brick
WHAT IS IT AND HOW DOES IT WORK
There is a Large motor moving the belt at a certain speed to move the bricks through the colour sensor. The colour sensor reads the colour of each LEGO brick and returns its colour ID. According to this ID, the EV3 smart brick controls the movement of the sorting lever and sends the command to the sorting lever. That lever pushes the blocks on 2 boxes, one for the white bricks and a separate one for the blue bricks. The selector lever is moved by the servo motor.
TEAM-2 video presentation
Pictures of the TEAM-2 project
Here is our Java code for it: NewBelt.java
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Team 3
TEAM-3 short working video
Kleopatra Lymperi
Natalia Tortopidou
Eirini Mourtzi
Stefania Hatzikonstanti
Dimitra Mathiou
Eua Papagianopoulou
Anna Papagianopoulou
- Information about our project
For this project we were asked to create a LEGO EV3 sorting machine for the Erasmus+ project. Our task involved apart from building also programing a machine that sorts Lego bricks into 3 boxes depending on the color of the bricks. The machine separates the white and the blue colored bricks from the other colored bricks. We were inspired by our flag’s colors (blue & white)!
In order to cover the projects needs we used a Large Motor, a Medium Motor as a Servo Motor, a Colour Sensor, a Touch Sensor and of course a Lego EV3 Brick.
In order to build our machine we used as a basis guidance the instructions of the official Model Core Set named “Colour Sorter” as given by the LEGO MINDSTORMS EV3 set. These original building instructions can be found here.
The students then modified this design to better tackle the assignment project in terms of execution speed, reliability and process automation. More specifically they moved the position of the colour sensor so that it faces the blocks as they are passing from the stack. In the original design the user had to take by hand each lego brick and manually pass it from the colour sensor in order to read and store its colour IDs in a suitable table (array). To signify the end of this pre-reading process, the user had also to push a touch sensor at the end and after it the sorting process was starting. The sorting would start by processing all the colour IDs from this array (from memory).
We decided that it is better to place the sensor at the bottom end of the chute so that it reads one-by-one the colour of each Lego block (placed first in the sorting queue of the chute / read first), then dispense it in the appropriate collector box. This procedure then is repeated for the next block (reading its colour ID and then place it into the appropriate box). In this way the process is automated meaning that we don’t need any memory (array) for storing previous brick colours and also we avoid the manual placement of the bricks under the colour sensor or pressing any touch button. Now our process is fully automated.
Our machine has to separate in 3 small boxes different colored bricks. The top part of the construction where the bricks are placed is called the categorizer and it also includes a color sensor that “reads” the bricks. All the bricks are placed in the chute where the color sensor reads the color of each brick. Then the belt moves the categorizer depending on the position of the box where the brick is to be placed according to its color, and throws it into the box. After throwing the bricks the belt moves the categorizer back to its original position where it contacts the touch sensor and stops. This happens in order for the categorizer not to be confused, as the motor that turns the belt has to move certain degrees in order to reach each position. This due process is repeated until all the bricks are sorted.
TEAM-3 video presentation
Pictures of the TEAM-3 project
Here is our Java code for it: Group3.java
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