Accelerating Mixed Discrete-Continuous Motion Planning via Neural Graphs of Convex Sets

Ananya Trivedi1,(✉︎), Sarvesh Prajapati1, Mohamed Khalid M Jaffar2, Zhexin Xu1, David Rosen1, Taşkın Padır1

1 Northeastern University, Boston, MA 02115, USA

2 University of Maryland, College Park, MD 20742, USA

Abstract

Motion planning problems such as collision-free navigation and contact-rich manipulation can be naturally formulated as optimization problems that couple discrete decisions with continuous trajectories. The Graphs of Convex Sets (GCS) framework offers a practical solution to these problems. It represents discrete decisions as nodes of a graph and encodes continuous trajectories in the edges connecting them. However, the resulting optimization subproblems can become computationally prohibitive for online replanning.

In this work, we propose a learning-based strategy to mitigate this limitation. Specifically, we replace the costly convex relaxation step required by nominal GCS with a single forward pass through a Graph Attention Network that predicts a set of highly probable candidate paths through the graph. A lightweight ranking network then orders these candidates by their estimated trajectory cost. Evaluating them in this order, we terminate our search early while still recovering a near-optimal motion plan. We validate the resulting pipeline across diverse robotic tasks, including collision-free motion planning for a 3D quadrotor and a 7-DoF manipulator, and planning through contact for planar pushing. Across both convex and non-convex cost and constraint settings, our approach yields up to two orders of magnitude speedup over nominal GCS while maintaining a 100% success rate, at the cost of some suboptimality in the recovered solutions.

Results

Obstacle-Free Motion Planning

3D Quadrotor Navigating a 25m X 25m Building
Planning in Configuration Space using 7-DOF KUKA IIWA

Long-Horizon Planning Through Contact

Pushing a Box Into a Goal Configuration
Pushing a Tee Into a Goal Configuration