WIP for calculating the required torque, and modelling the 6-wheeled rocker bogie system.

Variable	Known (assumed) /Unknown	Symbol	Value	Unit	Notes
Gross Weight	Known	W_g	TBD	Kg
Wheel Diameters	Known	D	TBD	m	Assumed all wheel diameters are the same
Rolling Resistance Coefficient	Known	c	TBD	unitless	Assumed rubber tire on concrete
Time to accelerate	Known	t_a	TBD	s	Assuming linear acceleration, how long do we want it to take to accelerate?
Maximum speed	Known	V_max	TBD	m/s	At the end of acceleration, how fast do we want our robot to be moving?
Slope Angle	Known	θ	TBD	degrees (or radians)	Angle of the slope that the robot is currently on

Calculating Force to Accelerate

F_accel = W_g * V_max / t_a

Calculating Force due to Slope

F_slope = W_g*sinθ

Calculating Force due to Rolling Resistance

F_roll = cW_g

Total Tractive Force Required

F_tract= F_accel + F_slope + F_roll

Since we have 6 wheels. We device F_tract by 6 to get the tractive force required per wheel, which is the required wheel torque.

21/08/27 Motor Torque Calculations

Loading Condition

Notes

Minimum Torque, no SF (Nm)

Safety factor for torque

Minimum Torque, 1.25 SF (Nm)

Minimum Speed (RPM)

Hill climb

constant velocity

8.67

1.4

12.1

87

flat ground

constant velocity

3.68

1.25

4.6

223

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