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Indoor Navigation System based on Multi-Pixel Time-of-Flight Imaging for Nano-Drone Applications
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• About the Project
• Hardware
  • Components
  • PCB
• Getting Started
  • Software
  • Installation

Unmanned aerial vehicles (UAVs) have recently attracted the industry's attention due to their numerous civilian and potential commercial applications. A promising UAV sub-class includes nano and micro UAVs, characterized by centimeter size, few grams of payload and extremely limited on-board computational resources. Those features pose major challenges to enable autonomous navigation or even more basic relevant sub-tasks, such as reliable obstacle avoidance. This project exploits a multi-zone Time of Flight (ToF) sensor to enable autonomous navigation and obstacle avoidance with a low lower computational load than most common visual-based solutions.

The matrix ToF sensor, and thus this project aims to characterize and in-field evaluate the sensors VL53L5CX from STMicroelectronics using a nano-drone platform. This project exploits a commercial nano-UAV platform, the Crazyflie 2.1 from bitcraze, together with a custom PCB designed to support two 8x8 ToF sensors. The following sections describe in detail the overall framework and the hardware setup.

The VL53L5CX is a ToF multizone ranging sensor produced by STMicroelectronics. It integrates a single-photon avalanche diode (SPAD) array, physical infrared filters, and diffractive optical elements (DOE) to achieve a millimeter accuracy in various ambient lighting conditions with a wide range of cover glass materials. The working range spans between 2 cm and 4 meters, but above 2 m the overall ranging precision degrades to 11% of the absolute distance. The most important feature of the VL53L5CX is the multizone capability, which can be configured as an 8x8 or 4x4 matrix. Listed below the list of key components for our integrated deck targetted for the Crazyflie 2.1 platform:

• VL53L5CX, ToF multizone ranging sensor
• TPS62233, 3-MHz Ultra Small Step-Down Converter
• TCA6408A, Low-Voltage 8-Bit I2C and SMBus I/O Expander

The H-Watchs printed circuit board (PCB) is built of 4 Layers with a total board thichness of only 0.83mm. Further informations about the PCB can be found here:

The preview of the assembly, with details of logical connections can be found here:

• One fully mounted Deck_schematics.pdf and two Sensor_Board_schematics.pdf assembled as shown here: Final_Assembly_3D.pdf
• The Crazyflie 2.1
• The Flow Deck v2. The VL53L1x ToF sensor measures the distance to the ground with high precision and the PMW3901 optical flow sensor measures movements of the ground.

• STM32CubeIDE
• Firmware Package FW_WB V1.8.0
• Altium

If you use Matrix ToF Drone in an academic or industrial context, please cite the following publications:

@INPROCEEDINGS{20.500.11850/476189,
	copyright = {Creative Commons Attribution 4.0 International},
	year = {2022},
	author = {Niculescu Vlad, Müller Hanna, Ostovar Iman, Polonelli Tommaso, Magno Michele, Benini Luca},
	keywords = {UAV, nano-drone, autonomous navigation, obstacle avoidance, Time of Flight},
	language = {en},
	title = {Towards a Multi-Pixel Time-of-Flight Indoor Navigation System for Nano-Drone Applications.},
}