Dead reckoning is a process used in navigation to determine one's current position based on a previously known position, or fix, and advancing that position based upon known or estimated speeds over a period of time, and the direction in which the person or vehicle is known or estimated to have moved. The name "dead reckoning" comes from "deduced reckoning," sometimes abbreviated as 'ded' reckoning, which has been further abbreviated to "dead" reckoning.
In the context of robotics and autonomous vehicles, including rescue robots, dead reckoning is a method used to estimate the robot's current position based on a known starting point, the robot's estimated speed, the direction it's known to have moved, and the amount of time it's been moving.
For example, if a rescue robot knows it started at a particular spot, and it knows that it's been moving straight ahead at 1 meter per second for 10 seconds, then by dead reckoning, it would estimate that it is now 10 meters from its starting point.
One critical piece of dead reckoning data is the estimation of the direction of movement. This can be achieved by using a device called an Inertial Measurement Unit (IMU), which can measure things like acceleration and turn rate.
However, it's important to note that dead reckoning is prone to cumulative errors over time. Small errors in the estimation of speed or direction can result in increasingly larger errors in position estimation over longer periods of time. Therefore, dead reckoning is often used in conjunction with other forms of navigation, like GPS or computer vision, to correct for these errors and provide more accurate navigation data.