padvolging

Padvolging, or path following, is the control problem of guiding a mobile agent to follow a predefined geometric path in a plane or space. The objective is to minimize lateral deviation from the path while respecting the vehicle’s dynamic limits. Unlike trajectory tracking, which aims to match a time-parameterized curve, padvolging focuses on staying close to the path itself, allowing for flexible speeds along the route.

Common methods include pure pursuit, Stanley controllers, and model predictive control. Pure pursuit steers toward a look-ahead point on the path, providing simple implementation. The Stanley controller combines cross-track error with heading error to reduce lateral slip. MPC optimizes steering and speed over a horizon to minimize deviation and control effort, subject to vehicle dynamics. LQR-based approaches and other geometry-based methods are also used, especially in research and more constrained environments.

Applications of padvolging are widespread in autonomous mobility and robotics. They include road vehicles following a lane or route, warehouse and service robots navigating aisles, agricultural machines traversing fields, ships following predefined waterways, and drones maintaining a prescribed flight path.

Key challenges involve accurate localization and map alignment, disturbances such as wheel slip, wind, or uneven terrain, and handling high-curvature sections or dynamic obstacles. Balancing safety, comfort, and efficiency while complying with traffic rules or operational constraints remains an ongoing area of development.

Padvolging sits within the broader fields of path planning and autonomous control. Path planning designs the route, while padvolging executes the path by maintaining proximity and adherence, complementing trajectory tracking when time-parameterization is required.