The robot we are going to design should have a differential drive configuration, and from the preceding specification, we can first determine the motor torque values. From the payload value and robot body weight, we can easily compute the motor torque.
Let's calculate the torque required to move this robot.
The number of wheels is four, including two caster wheels. The number of wheels undergoing actuation is only two. We can assume the coefficient of friction is 0.6 and of wheel radius is 4.5 cm. We can use the following formula:
Total weight of robot = Weight of robot + Payload
Weight of the robot: 3 x 9.8 ≈ 30 N (W = mg)
Payload: 2 x 9.8 ≈ 20 N
Total weight: 30 + 20 = 50 N
This total weight should be split among the four wheels of the robot, so we can write it as W = 2 x N1 + 2 x N2, where N1 is the weight acting on each robot wheel and N2 is the weight acting on each caster wheels. The configuration of wheels...