“Hello Everyone, thank you for showing interest in our project. In this project, we are showing a fully automated robot that sorts fruits and vegetables based on their color.
The project happened in the context of the Bruface program and more precisely in the mechatronics 1 course. The Brussels Faculty of Engineering (in short, Bruface) is a joint initiative between Vrije Universiteit Brussel (VUB) and Université Libre de Bruxelles (ULB), offering a broad spectrum of fully English-taught Master Programmes in the field of Engineering.
The team is composed of 3 members
Ankit Pandey
Tigran Pletser
Julien van Delft
The main purpose of the Mechatronics course is to teach both mechanical structure and electronics. This is the reason why we chose a robot with a mechanical solid structure and a moving flexible gripper able to detect the fruit in a certain zone and sort them by color.
Initially, we started with a silicone molded soft gripper for sorting vegetables/fruit based on its matureness but as the laboratory was closed for November due to coronavirus and very little time was available to create the soft gripper we switched to a flexible gripper instead of a soft gripper.
The project took 3 months to complete but do not worry this project will regroup all the files needed for the building of the vegetable/fruit sorter robot.
The project is about the fabrication of a vegetable/fruit gripper sorter. The gripper is made in a flexible way to be able to pick fragile fruits of various sizes. The total budget you should consider to make this project is around 100-150€ (120-180$) and it will take you 15 to 20h of work to build the entire prototype. We advise you to have someone to help you at some point when you will build the global structure to hold the plate while you screw them together.
he design looks like this with two laser-cut feet with small supports to ensure stability.
The motion is driven by a belt and a stepper motor fixed to the right feet and a lead screw and a stepper motor fixed on the top.
Two linear rods of 70cm are attached between the two feet on which the gripper will slide thanks to linear bearings.
To ensure a good motion in Z, two linear rods of 22cm are also fixed with the motor and sliding in linear bearings in the fixation.
The gripper in itself is driven by a 3D-printed rack and pinion and a servo motor controlling the opening and the closing of the gripper. It is a flexible gripper allowing it to take various sizes of objects.
Needed Material
All the needed material is in the list below.
tons of screws and bolts M3 (for the laser cut assembly mainly) and M5
2 Linear rods 8mm diameter 70cm long
2 Linear rods 8mm diameter 22cm long
1 Lead screw and trapezoidal nut 8mm diameter 15 cm long
1 Trapezoidal belt 5mm width, 1.4m long
1 Arduino Uno
2 Stepper motor NEMA 17 (needed torque around 20Ncm at least)
1 Shaft coupler 5x8mm
1 pulley 5mm inside diameter
2 Stepper motor drivers DRV8825
1 Servomotor MG996R
1 Ball bearing 5mm inside diameter, 13mm outside diameter
5 Linear bearings 8mm inside diameter,15mm outside diameter
1 color sensor TCS3200
1 Laser range sensor GP2Y0A21
2 end switches SS-5GL
1 Potentiometer
1 Button
1 Voltage source 12V (we chose a 12V PDC004 to power the robot through usb-c)
1 DC-DC Voltage step down power module LM2596
Cables
Needed Prerequisite
To finish this project, you will need some basic electronic knowledge in order to connect everything and most importantly, not burn a component or even worst your laptop. Also, you will need to solder cables and components so either you will need to be good at soldering or good in electronic debugging to find the problem after some soldering errors (trust me it happens very often). Same for the coding, we will give you every codes and files to build the project but bugs may occur, knowing the basics about Arduino coding is good to have.
Tools
Lots of pieces are laser cut or 3D printed so you will need access to both a 3D printer and a laser cutter. If like us, you cannot directly obtain the right size of linear rods and lead screw, a metal handsaw or even better a metal cutting rotating saw will save you some hard physical effort to cut your pieces. For the rest, you will need some basic tools as screwdrivers, measuring tools such as caliper, hammer, and so on. To solder components and the wires, a soldering iron is needed as well as tin. Finally, for the 3D printer and the laser cutter, we use regular PLA and birch plate of 3mm and 6mm thickness.”