Page 117 - Robot Design Handbook ROBOCON Malaysia 2019

is at the left side and the right side. The third power window motor is used for the lifting
mechanism of the Shagai. This motor is tied with the rope which is connected the lift through
a pulley as motion converter.

For the MR1, two double acting pneumatic cylinders and two pneumatic solenoid

valves are used. Each pneumatic cylinder requires a pneumatic solenoid valve to operate.

One pneumatic cylinder is used for passing the Gerege to the MR2 and another one is used
for shooting mechanism, that is to shoot the Shagai at the Throwing Zone on game field.

The first pneumatic cylinder is attached at the top left of our the MR1 which is used to pass
the Gerege to the MR2. When the pneumatic cylinder is activated, it will lift up the Gerege
higher than the height of the MR1. The second pneumatic cylinder is attached at the centre

of the MR1. The end part of pneumatic piston (the nut) was welded to a steel plate so that
when shooting the Shagai, an even force will be distributed and it will not damage the

Shagai. When Shagai is lifted up at equal height of the second pneumatic cylinder, the
operator can trigger the shooting mechanism aiming at the Throwing Zone.

2.1.2 Electronic Design

For the MR1, Arduino UNO is used as our main board or the brain of the robot. The

Arduino UNO board is connected to USB shield as we used PS3 Controller with USB
Bluetooth dongle to control the robot. Since the MR1 is fully controlled manually, the MR1

does not have any sensor. The MR1 only receives inputs from the PS3 Controller that is
controlled by our operator. We used three DC motors with three different motor drivers.

Two of them are MD10C where we used them for both of our wheels and another motor

driver is for MD13S where we used it to lift the Shagai. For MD10C, we centralized both
of the PWM pin in Arduino to synchronize the speed of the wheels. Two relays are used to

control both of our pneumatic valves. Both of pneumatic valves are connected to Normally
Close (NC) pin of the relays, so that, the pneumatic valves always switch on until they

receive a new signal.

2.2.3 Software Design

The flow-chart shown in Figure 2 summarizes the operation of the MR1 based on
the programme in the micro-controller and the buttons of PS2 controller.

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