Programmable Robotic Painting Arm Presented by: Chincholkar Apoorv R. Joshi Sanket S. Gore Rigved B. Project Guide: Mr.M.D.Patil

Index  Project Theme  Literature Survey  Block Diagram  System Overview  Module Testing  Work Plan

Project Theme  A robotic painting arm, which can paint given object.  This robotic arm can be programmed by guiding it, by user as per his needs.  Once guided properly, it stores the coordinates in EEPROM, and work accordingly afterwards.  Advantage of this robot is repeatability, time saving, ease of operation and higher degree of accuracy with minimum initial investment.

Literature Survey  Leading car manufacturing companies use advanced robotic systems for paint job.  These robots are controlled by CNC systems.  Companies like Honda, Hitachi, FANUC, Kawasaki and Motoman build painting robotic systems.  Paint material used can be powder based, oil based or water based.

Linear paint robots

Articulated paint robots

Paint robots with carriage

Micro Controller ATMEGA AVR Position Encoders Painting Tool EEPROM Motors Solenoid Valve Motor Driver Block Diagram

System Overview  Two modes: ( I ) Training Mode ( II ) Repeat Mode ( I ) Training Mode: In this mode the robotic hand can be guided by a skilled person, only for one time. All the movement is then stored in EEPROM as coordinates. ( II ) Repeat Mode: Robotic painter simply manipulate the arm according to the data stored in EEPROM.

Module Testing  Hardware modules Stepper Motor Driver I2C EEPROM bank  Software Modules Stepper motor movement with pre-stored user data Starting position locator using limit switch LCD display in 4 bit mode I2C bus - EEPROM communication

 Relative positioning is very precise  Constant speed  Motor can be locked at any position.  Available in various size and packages  Easy to interface  Easily available Stepper Module in robotics

Stepper motor module

STEPS IN STEPPER MOTOR  Full step One coil is energized at a time.  Half step Two coils are energized to get rotor in between step.  Micro step Two coils are energized at different current levels.

A4A4 B3B3 C2C2 D1D1 comment 1000start here 1100half a step clockwise 0100complete the first full step clockwise 0110another half step 0010complete that step 0011another half step 0001complete that step 1001final half step 1000back to the starting position HALF STEP SEQUENCE

HALF STEP

 Create an instance of the stepper class, specifying the number of steps of the motor and the pins it's attached to using Stepper(steps,pin1,pin2,pin3,pin4) function.  Set the speed of the motor to required RPMs using SetSpeed(RPM).  Until the limit switch is open, keep motor rotating slowly in anti-clockwise direction using step(no. of steps) function.  On closing the limit switch start taking values from predefined array & perform the steps accordingly. Testing method : Stepper module

 EEROM is essential for storage of data files. A data file contains no. of steps to be performed for each motor as well as file name.  EEPROM used in this project is I2C bus driven EEROM IC AT24LC512 which comes in 8-pin DIP package.  Memory size available is 512Kbits which translate in to 64Kbytes of usable memory.  Up to 8 similar EEPROMs can be tied on a single 2 wire I2C bus using address arbitration. EEPROM MODULE

EEPROM AT24C512

EEPROM MODULE TEST CIRCUIT

 Assemble the circuit on breadboard.  Connect a potentiometer to the ‘analog 0’ pin of arduino.  Write a program to take the values from ADC, and store then into EEPROM at the rate of 50 samples/sec.  Hence, WRITE operation is performed here.  Next step is to READ the stored data. The data is read, and the output is given as analog output, in the form of PWM wave.  An LED can be connected to this pin, to see the output.  This program was implemented, and tested successfully. Testing method : EEPROM

Work Plan MonthProposed Work September Finalization of design, Component selection, stepper motor module testing October EEPROM with I2C bus communication, Finalization of mechanical assembly January Module interfacing, software design, painting head assembly February Software upgrading, actual testing in work environment, error analysis March Quality and reliability testing, final documentation