Odometria

Odometria is a process used in robotics and navigation to estimate the position and orientation of a vehicle or robot by integrating sensor measurements over time. The term "odometry" itself is derived from the Greek words "hodos" (way) and "metron" (measure). The most common type of odometry relies on wheel encoders, which measure the rotation of wheels. By knowing the radius of the wheels and the number of rotations, the distance traveled can be calculated.

In wheeled robots, odometry typically involves tracking the movement of each wheel. For a differential drive robot with two independently driven wheels, the change in position and orientation can be calculated based on the relative speeds and distances traveled by each wheel. More complex systems might use more wheels or different types of sensors. Odometry provides a continuous estimate of the robot's pose, updating it with each new sensor reading.

However, odometric estimates are prone to accumulating errors due to various factors. Wheel slippage, uneven surfaces, sensor inaccuracies, and calibration errors can all lead to drift in the estimated position. This means that over time, the odometric estimate can diverge from the robot's true position. To mitigate these errors, odometry is often combined with other localization techniques, such as simultaneous localization and mapping (SLAM) or landmark-based localization, which can correct drift and provide a more accurate global position estimate. Despite its limitations, odometry remains a fundamental and widely used technique for dead reckoning in many robotic applications.