How are indoor drones proving themselves useful in a new, uncharted market?

Drones, a type of Unmanned Autonomous Vehicle (UAV), is basically a flying version of a robot. While they have made quite a reputation of how resourceful they are outdoors, now, drones are set to expand their usability in the indoors too. For, e.g., Corvus Robotics, a St. Louis startup is providing drone solutions for warehouse inventory and facilities inspection to logistics and manufacturing facilities. Another Swiss startup Flyability too, offers aerial inspection indoor drones to inspect confined spaces. Indoor Drones are generally smaller in size as compared to their outdoor version. Further, they provide better accessibility and can scale varied heights, which is not always possible with crawlers and ground bots (robots that move on ground surfaces). Because of their autonomous flying feature, they have more versatility and bigger tolerance to unknowns in the environments. Further, apart from inspection and monitoring purposes, indoor drones can be immensely helpful in vlogging, practice tool for larger drones, and for entertainment purposes too.

Market Scope and Uses

In a 2019 report, it was mentioned that the drone market would grow by $29 billion by 2027, with a CAGR of almost 20 percent. The report also suggests that indoor drones offer some primary advantages like less inclusion of hazardous tasks like climbing (crawler), fast return on investment due to manageable acquisition costs of hardware. It is also easier to get approval for indoor drones when compared with outdoor ones. The main industry for these gadgets is the warehouse and logistics industry, where they can help in inventory management, indoor intra-logistics, and inspection & surveillance. Earlier this year, Digital Aerolus, developed the world's first indoor drone (Aertos 120-UVC) with C-band ultraviolet (UVC) lights. This drone was created specifically to combat the spread of the COVID-19 (SARS-CoV-2) virus with a 99% disinfection rate. Aertos 120-UVC can fly stably inside buildings and sterilize areas, thus reducing exposure of frontline workers to infections. Research studies indicate that UVC light can damage the RNA of viruses when centered around 265 nm wavelength.

Technology behind it

Since GPS does not work inside most buildings, most of these indoor drones use image recognition technologies for autonomous flight. For instance, last month, researchers in Japan have developed a single-camera machine vision algorithm that allows lightweight hovering robots to guide themselves by identifying and interpreting reference points on a tiled floor. The project head, Chinthaka Premachandra, an associate professor in the Department of Electronic Engineering at Shibaura Institute of Technology in Tokyo, says that, as GPS signals are too weak to penetrate most structures, indoor drones typically depend on visual environmental cues. His research team aimed to design the guidance algorithm to be as simple as possible, allowing for a small, inexpensive microprocessor. The team used the Raspberry pi3, an open-source computing platform that weighs approximately 45 grams. Their prototype had a single downward-facing camera with intentionally low resolution – only 80 by 80 pixels. "Our robot only needed to distinguish its direction of motion and identify corners. From there, our algorithm allows it to extrapolate its position in the room, helping it avoid contacting the walls," Premachandra added.

Another method that is used by indoor drones is Structure from Motion algorithm (SfM). SfM computes the relative relationship between cameras based on images to be acquired from various locations and obtains disparity to enable restoration of 3D space. Even the Flyability's  Elios 2 drone uses collision tolerance and onboard lighting to allow the drone pilot to maneuver the drone safely and efficiently without any external light source. Elios 2 also has seven vision stability sensors that help it in achieving GPS-free stabilization. One of the Flyability clients, Bureau Veritas France, uses Elios 2 to carry ballast tank inspection on one of its cargo ships, in three ten-minute flights. This is an incredible feat as the same inspection would require three to four inspectors utilizing ropes, oxygen monitoring devices, and extensive safety equipment without the drone.

Wrapping up

Though indoor drones present colossal potential, there are certain challenges that need to be addressed first. The indoor drone has to be self-aware and avoid moving objects by itself. It needs to upgrade itself to better stabilization systems that can enhance its stability performance in spaces having fans or the presence of an indoor draft. By improving these aspects, indoor drones will be a step closer to reach a fully autonomous and functional status.