Multi-Query Shortest-Path Problem in Graphs of Convex Sets
Savva Morozov, Tobia Marcucci, Alexandre Amice, Bernhard Paus Graesdal, Rohan Bosworth, Pablo A. Parrilo, Russ Tedrake
TL;DR
This work generalizes the classical all-pairs shortest-path problem to graphs of convex sets to enable multi-query precomputation for robotics problems that combine discrete routing with continuous state trajectories. It introduces a two-stage solution: offline synthesis of cost-to-go lower bounds via semidefinite programming, and online rollout with a greedy, short-horizon lookahead policy that uses these bounds to build paths incrementally. To handle the no-vertex-revisit constraint, the authors incorporate revisit penalties and relaxations that yield tractable SDPs with quadratic lower bounds, achieving near-optimal paths with fast online solves; experiments on a 7-DoF robotic arm show substantial speedups (offline ~6s, online ~2–11 ms per query) and competitive path quality. The approach scales to large graphs and high-dimensional configuration spaces, offering practical deployment potential in robotics through offline precomputation and fast online planning.
Abstract
The Shortest-Path Problem in Graph of Convex Sets (SPP in GCS) is a recently developed optimization framework that blends discrete and continuous decision making. Many relevant problems in robotics, such as collision-free motion planning, can be cast and solved as an SPP in GCS, yielding lower-cost solutions and faster runtimes than state-of-the-art algorithms. In this paper, we are motivated by motion planning of robot arms that must operate swiftly in static environments. We consider a multi-query extension of the SPP in GCS, where the goal is to efficiently precompute optimal paths between given sets of initial and target conditions. Our solution consists of two stages. Offline, we use semidefinite programming to compute a coarse lower bound on the problem's cost-to-go function. Then, online, this lower bound is used to incrementally generate feasible paths by solving short-horizon convex programs. For a robot arm with seven joints, our method designs higher quality trajectories up to two orders of magnitude faster than existing motion planners.
