[ SYSTEM DESCRIPTION] EIRELESS CONTROLLED ROBOTIC ARM

[REPORT]WIRELESS CONTROLLED ROBOTIC ARM

3.  SYSTEM DESCRIPTION

3.1            BLOCK DIAGRAM

The functional block diagram of our system is as follow:

FIGURE 3.1: BLOCK DIAGRAM OF THE SYSTEM


3.2            BLOCK DIAGRAM DESCRIPTION

            Overall block diagram is divided into two main parts. One is User side or Control panel and robot side. The robot is either controlled using joystick or via Control software at PC. The control signal is sent to robot from PC via the receiver microcontroller at Arduino board. The receiver microcontroller receives control signals from PC and forwards signal to the robot. The control signal refers to the mode selection signals, position signals for arm and base motors. Software sends signal serially via USB to microcontroller, microcontroller then forwards the signals via XBee RF module to next RF Module at robot side. Microcontroller to XBee communication is also serial communication.

            In Joystick mode, the position of joystick determines the position of arm. On the movement of joystick, TX microcontroller sends the angular position of joystick to the robot so that robot-side microcontroller could receive the angular position and command the servomotors to have desired position.


3.3         SYSTEM ALGORITHM

The system algorithm for our project is as below

Transmitter side

Step1: Start

Step2: XBee Initialization.

Step3: Check if it is in Arm Mode

            If yes: Goto step 4

            If No: Goto step 8

            Step4: Read analog value from POT.

Step 5: Convert analog integer into angular value.

Step 6: Create packet and send it via Radio Frequency Module

Step7: Goto Step 3 [Loop]

Step 8: Read which button s pressed

Step 9: Send control signal to control motion of dc motor according to button pressed

Step 10: Goto Step 3 [Loop]

         

Receiver Side

            Step 1: Start

            Step2:  Initialize XBee

            Step3: Read Serial Data and Analyze.

                        Check the Start Bytes of Packets [*@]

            Step 4: Found Start bits?

                        If Yes: Goto Step 5

Step 5:  Read six characters serially and assign each char corresponding to servo motor.

            Step 6: Goto Step 3

            Step 7: Read Start byte of packet [‘8’,’4’,’2’,’6’]

            Step 8: Correct sequence detected?

                        If yes: Goto Step 9

                        If No:  Goto Step 3

            Step 9: Control the corresponding movement of respective DC Motor.

            Step 10: Goto Step 3

                                 

            Note: char ‘8’ is followed by integer 8 to indicate that button UP is pressed.

            Two different bytes are used to indicate that DC motor control button is pressed.














3.4            SYSTEM OPERATION FLOWCHART



Transmitter side functional flow chart:

          
   
      

FIGURE 3.4 (a): FLOW DIAGRAM FOR TRANSMITTER




Oval: StartReceiver side functional flow chart:

          
   
       

FIGURE 3.4 (b): FLOW DIAGRAM FOR RECEIVER