Motor Candidates

Ballpark torque required. Will require simulation of the loading on each wheel at different positions of the drivetrain to determine the exact torque we should spec for/validate our rough calculations. 

Parameters

• Max rover weight: 50 kg
• Max object weight for Extreme Retrieval and Delivery mission: 5 kg
  • Assuming we carry at max 2 rocks at a time
• Assuming we operate under 48 V
• Assuming the drivetrain will use 6 motors (each design we're considering is a 6wd and requires a motor per wheel)
• Assuming a wheel diameter of 9", or 0.229 m
• Ideally, with any variety of rocker-bogie design, the load is spread equally across the 6 wheels in any position
• Setting a safety factor of 2
• Assume a 10% efficiency loss per gearbox stage

Rough Calculations

1. Under our above assumptions, determine the weight acting upon a single wheel/motor

Estimate load per motor = [(50 kg + (2 rocks * 5 kg)) / 6 motors] * safety factor = ~10 kg per motor * 2 = ~20 kg per motor

2. Determine the force acting upon a single motor

F_motor = 20 kg * 9.81 m/s² = 196.20 N

Is this over-overestimate intended? This is the force required to lift the load vertically ie 90° slope incline

3. Determine the torque we need each motor and gearbox to produce in order to operate the drivetrain

T_dt = F_motor x R_wheel = 196.20 N * 0.1145 m = ~22.465 Nm

Motor Vendors

Brushless Motor Suggestions