Page 231 - Robot Design Handbook ROBOCON Malaysia 2019

The MR2 walks using four legs which are connected to a shaft bracket and metal

key hub as illustrated in Figure 4. The shaft bracket is developed using 3D printer. Each leg
is controlled by a DC geared motor (12 V 248 RPM) and have two joints which are; 1)

between the DC geared motor and the shaft bracket; and 2) between the shaft bracket and
leg. Two DC geared motors will be controlled by one motor driver while Arduino MEGA

gives command to the motor driver to control the speed of motor. The motor comes with a

24:1 gear head that produces 248 RPM and 980 mN.m torque. It is suitable for general
purpose automation projects. It also comes with a five pulses per rotation encoder feed-back

to provide a real-time feed-back on the rotating position. For the MR2 walking mechanism,
the first leg will be at 45 degree and continue with the other three legs with the same degree.

The MR2 walking sequence starts with the right rear leg followed by the right front leg and
then the left rear leg and finally the left front leg. The MR2 is powered using the LiPo

rechargeable battery (11.1 V 2200 mAH). Two legs will be connected to one LiPo

rechargeable battery.

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