Intro
Dead reckoning is a navigation method to estimate current position by calculating speed, direction, and elapsed time from a known starting point, without relying on external references (like GPS or landmarks).
In robotics, dead reckoning estimates a robot’s position by integrating its motion over time—using wheel encoders, IMUs, or other sensors—starting from a known pose and without external localization data.
Deduced reckoning is figuring out where you are after starting from a known position, by using your speed, direction and time. (It’s effectively integration of velocity, if you want the calculus/mathematical version).
At sea you would know your direction from a compass, speed by any one of various means, and important complications like the wind speed and direction would be estimated.
Odometry is really just doing the same thing on the ground, instead of at sea. Instead you count your “footsteps” as an estimate of your walking speed. A wheeled vehicle would instead count wheel revolutions, that’s equivalent to counting footsteps.
Odometry isn’t very accurate on its own as wheel slippage, carpet “springiness” and uneven floors can affect accuracy. A separate heading sensor can help with accurate headings at least, though.