PROCESS

 10.1 ROBO MOVEMENT
            The movements of the pick and place robot is rectangular movement in a fixed path. The picking and placing of the object and the rectangular movement are controlled by the electro pneumatic circuit, which ca be programmed with help of the microprocessor. The pick and place action and the rectangular movement are achived by the three pneumatic cylinders (i.e.) CY1, CY2, CY3.(Ref. to fig. PIC/001/001 and PICCIR/001/03).

            The cylinder CY2 and CY3 are gives the movement in vertical direction and cylinder CY1 gives movement in horizontal direction.
            The vertical movement of the cylinder CY3 controls the axial movement of the jaws. The whole process has to be controlled with the help of microprocessor.
   
10.2 PICK AND PLACE OPERATIONS
        In the pick and place operations two places are selected. Let 'A and B' be the two places. 'A' be the place where object have to be picked and 'B' be the place where the object have to be placed. The pneumatic circuit controls the movement between the 'A' and 'B'.(Ref. to fig. PIC/001/001).

 

WORKING PROCESS
            To process the pick and place work, and to the reset the robot five kinds of operations have to be performed and these operations are carried out by ten pneumatic actions.

    The operations are as follows:
    OPERATION 1:
  • The arm has to be made very close to the object (i.e. in the place A).
    OPERATION 2:
  • The object has to be picked up.       
    OPERATION 3:
  • The arm has to be moved to the place where the object has to be placed (i.e at place B).
    OPERATION 4:
  • The object must be placed.
    OPERATION 5:
  • This operation is to set the robot to original position. These cycles will be performed at regular time interval.
   
    10.3 PNEUMATIC ACTIONS:
            To perform above operations the following pneumatic actions are performed. to perform the operation 1 two pneumatic actions (PNA) are performed simultaneously.

PNA 1:
  • The piston P2 of cylinder CY2 is extended out.
PNA 2:
  • The piston P3 of the cylinder CY3 is retracted in.
    These two pneumatic action will make the arm near to the object.
To perform the operation 2 , following two pneumatic actions are performed consequently.
PNA 3:
  • The piston P3 of the cylinder CY3 is extended out.
PNA 4:
  • The piston P2 of the cylinder CY2 is retracted in.
    These actions pick up the object.
To perform the operation 3, following two pneumatic actions are performed. 
PNA 5:
  • The piston P1 of the cylinder CY1 is extended out.
PNA 6:
  • The piston P2 of the cylinder CY2 is extended out.
    These two actions will move the arm to where the object is to be placed.
 To perform the operation 4, the following pneumatic actions is performed.
PNA 7:
  • The piston P3 of the cylinder CY3 is retracted in.
    This operation will make the object to be placed.
To perform the operation 5 , following three pneumatic action is performed.
PNA 8:
  • The piston P2 of the cylinder CY2 is retracted in.
PNA 9:
  • The piston P1 of the cylinder CY1 is retracted in.
PNA 10:
  • The piston P3 of the cylinder CY3 is extended out.
    This operations makes the robot to the original position.
The retraction and extension of the piston is controlled by either giving current (or) shutting off the current to the respective valves. The valves V1, V2, V3 are controlled through the control unit of the microprocessor.

10.4 CONTROL UNIT:
        The control unit consist of three transistors T1, T2, and T3., which are coupled with the valves through the relays RL1, RL2, and RL3 respectively (Ref. to fig. PICCIR/001/03). This circuit works as per told in the working of the electronic circuit. When the voltage is given to the bases of the transistor. So the circuit can be programmed.
    The input from port-A of 8255 is in the form of binary. The binary input for above pneumatic actions are given in the following table.
PNEUMATIC ACTIONS
BINARY CODE
HEXCODE
A2
A1
A0
PNA1
PNA2
1
1
0
06
PNA3
0
1
0
02
PNA4
0
0
0
00
PNA5
0
0
1
01
PNA6
0
1
1
03
PNA7
1
1
1
07
PNA8
1
0
1
05
PNA9
1
0
0
04
PNA10
0
0
0
00

10.5 MICROPROCESSOR PROGRAMMING:
        The microprocessor is programmed in such a way that all actins are performed step by step at regular intervals.
        The hex code is the data send out by the microprocessor to the control unit. These data are stored in consecutive memory location.
        The microprocessor is programmed to send the data one by one to the control circuit with some time delay of 2 seconds.