Calculate needed traction for a pushing wheeled robot

Community General Discussions
1

Hi all,

I want to make a wheeled robot that is able to exert 6kg of pushing force (so this is not the weight of the object).

I want to reduce the weight of the robot as much as possible to not negatively impact the torque requierements. I therefore would like to calculate the minimal necessary weight of the robot to provide enough traction to push the object. I found the calculator to determine torque (https://www.robotshop.com/blog/en/drive-motor-sizing-tool-9698), but I cannot find a formula to determine the necessary weight of my robot first.

Can anyone help me with that?

I suppose that the type of wheels also influence the equation. The first version will run inside a house on a marmol floor, so I guess that small 3cm rubber wheels with low profile would be preferable to have as much touching surface as posible.

Any help is greately appreciated.

 

2

Calculations

The drive motor sizing tool won’t be of much use. You would need to factor in static and kinetic friction, the weight of the robot acting on each wheel, the acceleration (and then RPM). You need to do a torque balance on one wheel using all this data to determine the torque required (per wheel). Start with a free body diagram (you can upload here if you’d like confirmation) showing all the forces (as vectors).