# Design and Implementation of a Low-Cost Perception System for Aerial Robots in Confined Spaces

## TL;DR

This paper presents a low-cost perception system for drones flying in tight spaces like ship tanks, using time-of-flight sensors to avoid collisions and enable safe navigation.

## Contribution

A novel perception system using 12 ToF sensors is proposed as a lightweight, low-cost alternative to bulky LiDAR for aerial robots in confined spaces.

## Key findings

- The system provides a 360° radial view within 4 meters using strategically placed sensors.
- Experiments confirmed the system's reliability, repeatability, and synchronization in real-world and simulated confined spaces.
- The design enables safe navigation for small drones in featureless and cluttered environments.

## Abstract

Operating an aerial vehicle in a confined space, such as a vessel ballast tank, is a major challenge in terms of localization, perception, and control due to limited visibility, constrained maneuvering space, and the absence of reliable (if any) GNSS signals. This paper addresses the design considerations for a quadcopter in confined spaces, focusing on a novel perception system using 12 VL53L8CX time-of-flight (ToF) sensors from STMicroelectronics. These sensors are used for enhanced perception and collision avoidance while flying in confined spaces, making them a suitable alternative to bulky LiDAR systems, reducing weight, cost, and required computational power. These sensors are placed strategically around the quadcopter to cover 360° radial view within a 4 m range. Experiments are conducted to test the reliability and repeatability of the integrated system, along with its synchronization feature. Furthermore, the applicability is verified by flying in confined and cluttered spaces, both in simulation and the real world. This design and study aims to establish a baseline for lightweight, compact, and safe navigation for small drones in confined and featureless environments.