How to view npc's movement speed in Fallout 4?

To get the speed of a robot as it is moving, open the console, click on the robot, and type:

getgraphvariablefloat speed

If it doesn't work, make sure you have a clear path to the robot. Even if you do have a clear path, often you will find that you have not actually clicked on the robot but rather a nearly invisible field of mist placed in the cell, or whatever. You may have to walk right up to one to click on it depending on the area.

Most biological NPCs have fspeedwalk and fspeedrun that you could use to get the supposed speeds of their walk and run for their current movement type (the type will differ if they have weapons sighted/equipped/etc.) but that probably wouldn't help anyway as the robots most likely all have the same default movement speeds which are then adjusted by speedmult. To get the speedmult, select a robot with the console open and type:

getav speedmult

This may give you the difference without having to lead them along typing the first line. 1 is 100% of normal speed, 1.05 is a 5% increase, etc.

Note that getgraphvariablefloat speed will give you net speed going forward or backward, etc., and may change depending on a decrease or increase in acceleration, so check it a few times while a robot is moving, ideally when the robot is moving fast.