CoRL 2023 • Atlanta, USA 🇺🇸

Context-Aware Deep Reinforcement Learning for Autonomous Robotic Navigation in Unknown Area

Jingsong Liang, Zhichen Wang, Yuhong Cao, Jimmy Chiun, Mengqi Zhang, Guillaume Adrien Sartoretti

Deep RLGraph AttentionMapless NavigationReal-Time Planning
0.18–0.22 s to plan one step, at every complexity tier 83–88% less than D* lite
15–32% faster end to end than D* lite planning time is where the gap opens
34% shorter route than FAR across seven goals 1,367 m against 2,060 m in Gazebo
150 randomised dungeon scenarios tested 50 each at simple, medium and complex

Abstract

Mapless navigation refers to a challenging task where a mobile robot must rapidly navigate to a predefined destination using its partial knowledge of the environment, which is updated online along the way, instead of a prior map of the environment. Inspired by the recent developments in deep reinforcement learning (DRL), we propose a learning-based framework for mapless navigation, which employs a context-aware policy network to achieve efficient decision-making (ie, maximize the likelihood of finding the shortest route towards the target destination), especially in complex and large-scale environments. Specifically, our robot learns to form a context of its belief over the entire known area, which it uses to reason about long-term efficiency and sequence show-term movements. Additionally, we propose a graph rarefaction algorithm to enable more efficient decision-making in large-scale applications. We empirically demonstrate that our approach reduces average travel time by up to 61.4% and average planning time by up to 88.2% compared to benchmark planners (D* lite and BIT) on hundreds of test scenarios. We also validate our approach both in high-fidelity Gazebo simulations as well as on hardware, highlighting its promising applicability in the real world without further training/tuning.

How It Works

The robot knows where it is going but not what stands between it and the goal. Every step is a bet about the shape of the space it has not seen yet.

LiDAR point cloud of a partially observed indoor environment around the robot.
What the planner has to work with — a partial point cloud, and a destination somewhere beyond it.
  1. 01

    Mapless, but not blind

    No prior map, no pre-built roadmap: the planner samples viewpoints in the space it has observed so far and connects them into a graph it can reason over, extending that graph as the LiDAR reveals more.

  2. 02

    Attention over context, not just distance

    A deep reinforcement learning policy with graph attention weighs the environment’s structure against the pull of the destination, which keeps the robot curious about unknown space without wandering — the failure mode that lengthens the sampling-based baselines’ routes.

  3. 03

    Graph rarefaction keeps it real-time

    Sparsifying the graph is what makes a step cost roughly 0.2 s. Removing it costs 136% more planning time per step and 8% more distance travelled in the large Gazebo world.

  4. 04

    Neighbourhood size is a dial, not a retrain

    The model was trained with each node connected to its 20 nearest neighbours, then run unchanged at k = 10 and k = 5. At k = 10 it still beats FAR on every criterion; at k = 5 the graph gets too sparse and routes degrade by 254 m.

  5. 05

    Onto a real vehicle

    A ground vehicle carrying a Leishen C16 LiDAR ran the policy through a 60 m Ă— 15 m laboratory strewn with chairs, boxes and tripods, with a local planner turning each published waypoint into motion commands.

Results

Randomised dungeon maps first, then one large Gazebo world with seven successive goals, then the lab.

Trajectories through a large indoor Gazebo world, coloured per goal.
The route through the 130 m Ă— 100 m Gazebo world, where each goal starts from a fully unknown map.

A full run, with the graph growing as the robot uncovers the space.

Hardware Validation

A 60 m Ă— 15 m laboratory with randomly placed obstacles, traversed through a series of predefined points on partially observed point-cloud data.

Point-cloud map of a long laboratory with the ground vehicle's trajectory overlaid in colour.
The vehicle’s real trajectory through the lab, coloured by leg, over the point cloud it built on the way.

Paper Video

BibTeX

@inproceedings{liang2023context,
  title={Context-aware deep reinforcement learning for autonomous robotic navigation in unknown area},
  author={Liang, Jingsong and Wang, Zhichen and Cao, Yuhong and Chiun, Jimmy and Zhang, Mengqi and Sartoretti, Guillaume Adrien},
  booktitle={Conference on Robot Learning},
  pages={1425--1436},
  year={2023},
  organization={PMLR}
}

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