Reachability-Aware Time Scaling for Path Tracking

TL;DR

This paper introduces a reachability-aware time scaling method for path tracking in systems with acceleration limits, improving the ability to follow collision-free paths with sharp turns.

Contribution

It develops a reachability-guided quadratic-program tracker with offline and online components to adapt speed profiles ensuring acceleration constraints are met.

Findings

The method effectively handles high-curvature paths with bounded acceleration.

Offline evaluation of acceleration margins improves real-time tracking.

The approach maintains collision-free, feasible trajectories during path following.

Abstract

This paper studies tracking of collision-free waypoint paths produced by an offline planner for a planar double-integrator system with bounded speed and acceleration. Because sampling-based planners must route around obstacles, the resulting waypoint paths can contain sharp turns and high-curvature regions, so one-step reachability under acceleration limits becomes critical even when the path geometry is collision-free. We build on a pure-pursuit-style, reachability-guided quadratic-program (QP) tracker with a one-step acceleration margin. Offline, we evaluate this margin along a spline fitted to the waypoint path and update a scalar speed-scaling profile so that the required one-step acceleration remains below the available bound. Online, the same look-ahead tracking structure is used to track the scaled reference.