Roboat II: A Novel Autonomous Surface Vessel for Urban Environments

TL;DR

Roboat II is an innovative autonomous surface vessel designed for urban waterway transportation, featuring advanced SLAM, control, and path planning capabilities, with experimental validation demonstrating its effective mapping, localization, and navigation.

Contribution

This paper introduces Roboat II, a novel ASV with integrated multi-sensor SLAM, nonlinear control, and path planning tailored for complex urban water environments.

Findings

Successful online mapping and localization in waterway environments

Robust trajectory tracking demonstrated in experiments

Enhanced payload capacity and holonomic motion capabilities

Abstract

This paper presents a novel autonomous surface vessel (ASV), called Roboat II for urban transportation. Roboat II is capable of accurate simultaneous localization and mapping (SLAM), receding horizon tracking control and estimation, and path planning. Roboat II is designed to maximize the internal space for transport and can carry payloads several times of its own weight. Moreover, it is capable of holonomic motions to facilitate transporting, docking, and inter-connectivity between boats. The proposed SLAM system receives sensor data from a 3D LiDAR, an IMU, and a GPS, and utilizes a factor graph to tackle the multi-sensor fusion problem. To cope with the complex dynamics in the water, Roboat II employs an online nonlinear model predictive controller (NMPC), where we experimentally estimated the dynamical model of the vessel in order to achieve superior performance for tracking control. The states of Roboat II are simultaneously estimated using a nonlinear moving horizon estimation (NMHE) algorithm. Experiments demonstrate that Roboat II is able to successfully perform online mapping and localization, plan its path and robustly track the planned trajectory in the confined river, implying that this autonomous vessel holds the promise on potential applications in transporting humans and goods in many of the waterways nowadays.