Description

Tractorbot Bobesh Mk2 is my second robot and it’s an upgrade of Tractorbot Mk1 . It helped me to win two bronze medals this year at the national championship in electronics and radio-electronics of youth and at the Czech Robotic Day in Prague on 13^th and14^th June 2015 at the Ketchup House contest .

Functions:

1. IR remote controlled
2. Programmed for Ketchup House

Home-made robotic control board with a “dual-core processor”:

PIC18F46K22 as Master MCU

• GLCD 128x64
• IR-receiver for remote control systems SFH 5110-38
• 3x IDC 10-pin connectors with 20 free I/O pins of MCU (used to connect 3 external sensor boards)
• UART communication with Slave MCU

PIC18F46K22 as Slave/MultiServo MCU

• 3x motor driver L293D with paralleled outputs for 3 bidirectional DC motors (max 1.2 A each)
• 1x Motor driver ULN2803A for 2 unipolar stepper motors (0.5 A per phase each)
• N-MOSFET IRLB8743 for speaker switching
• Voltage divider for battery control
• Digital ampermeter AD8219 for total current measurement
• 2x IDC 10-pin connectors with 16 free I/O pins of MCU (used to connect 2 mechanical limit switches)

Motors :

• 3 geared motors salvaged from truck windshield wipers, originally for 24 VDC

2 motors for differential drive

1 motor with a gear from HP DJ printer used for a gripper (finally not applied for collecting ketchup cans; fixed wide-open collector used instead)

• one unipolar stepper motor from a printer (just for fun)

External sensors boards :

• ultrasonic ranging module HC-SR04 for an opponent detection
• ultrasonic ranging module US-020 for ketchup can detection (finally not used)
• 6x reflective object sensor QRD1114 ( 5x black line detection + 1x optical encoder) + 2 mechanical limit switches

Power:

• 12 V SLA battery 7 Ah for motors and a speaker
• 7805 for MCU and sensors

Mechanical parts:

• A frame made of PC case
• Wheels from Merkur (Czech Meccano)

Posters

Robotic control board:

External sensor board:

Images

Front view:

Top view:

Bottom view on QRD1114 external board:

Bottom view on gripper gears:

Schemes

Functional scheme of the control board - Master part:

Functional scheme of the control board - Slave part:

Soldering scheme of the control board on universal PCB (e=0.1"):

Scheme of the external sensor board:

Scheme of the ultrasonic module:

What to improve in the next version of Tractorbot Mk3:

1. To double battery voltage to 24 V for increasing the robot´s speed.
2. To add an electronic compass for position control after getting lost in the playground.
3. To improve opponent detection by moving ultrasonic ranging module.

Attachment files