Force required to move a vehicle

[pawansrao]

Am designing a three wheeled cycle. The total gross weight of my vehicle including the frame + riders will be around 300Kg, which has to move at 20Kmph(5.55 m/s) speed . The basic driving force will be provided by pedaling.

Assuming the least acceleration to start from rest as 0.2m/s^2, how should i calculate the pedal force required?

I started with this approach -
Step 1: Acceleration = 0.2m/s^2
Step 2: Total force required = Rolling Frictional force + Accelerating Force
= 0.005*300*9.81 + 300*0.2 = 74.7 N
Step 3: Wheel Torque = Force X Wheel radius = 74.7*0.3 = 22Nm.
Step 4: Assuming no Gearing between wheel and pedal, Pedal Torque = Pedal force*Radius of pedal
So i get pedal force = 22 / (0.18) = 122 N

I my method/approach correct ?

Here I have used just the linear velocity and acceleration, since am dealing with pedals and wheels should I deal with the rotational velocity and acceleration?

 

[huntoon]

I think you should add:

inertia
grade (if any intended)

 

[jack action]

You can use this acceleration simulator (it is made for an engine-powered vehicle but all the basic equations apply to pedal-powered vehicle as well).

All the forces you need to know are described at the bottom of the page in the section Theory»»Longitudinal acceleration»»Accelerating