What is a nano quadrotor?

The Rise of the Machines. It's not only the title of the disappointing third installment of the "Terminator" franchise; it's also an apt description of the recent wave of technological innovations that have robots taking on a wide range of complex tasks—from trading stocks to harvesting crops to performing surgeries. While this incredible technological progress is exciting, it often leads to justified fears. The idea of robots and rogue technology seizing control of the world has long been a common theme in literature, TV, and film. Back in 1968, Stanley Kubrick introduced us to HAL, the highly sensitive supercomputer who could control a spacecraft while keeping anyone who threatened his power at bay [source: Ebert].

Today, one of the most chilling representations of the power of robot technology is a YouTube video featuring a swarm of 20 small drones flying in perfect unison, weaving through windows, shifting formations, and even executing synchronized figure-eight patterns—all without any human intervention.

Engineers at the University of Pennsylvania's General Robotics, Automation, Sensing, and Perception (GRASP) lab have developed a nano quadrotor, a compact robot capable of performing impressive feats in the sky. These autonomous drones feature four tiny propellers at each corner and are designed for agile flight, moving in formations similar to a flock of pelicans, or perhaps a group of droid starfighters from Star Wars. Not only can they fly in intricate formations, but they can also shift seamlessly between patterns mid-flight, from a rectangular shape to an 'x' formation, for instance, while navigating around obstacles. Videos have showcased the robots carrying out various tasks, such as constructing basic structures and playing the James Bond theme song. [sources: Davies, Owano, Saenz]

So, how exactly do these machines operate? While developers of the nano quadrotors are keeping many details secret, some clues have emerged.

How a Nano Quadrotor Works

A nano quadrotor is essentially a miniature version of a larger quadrotor, a machine that utilizes four rotors to achieve flight. With a diameter of about 8 inches (20 centimeters), the nano model weighs just 2 ounces (57 grams) and consumes 15 watts of power. The device stays aloft by spinning all four rotors at equal speeds, and it can move and change direction by adjusting the speed of one or more rotors. [source: Kumar]

The quadrotor's ability to spin through the air like a whirling dervish, avoiding obstacles and maneuvering through tight spaces, relies on both the speed of the rotors and the rapid processing of information. Motion capture cameras track the quadrotor's position and detect nearby obstacles 100 times per second, while an onboard processor sends commands to each motor 600 times a second. [source: Kumar]

One of the most impressive aspects of nano quadrotor technology is its ability to sense its environment and collaborate with other aerial robots, working together without colliding. These drones can fly within mere inches of each other, maintaining their balance. This capability allows them to pool their strength to lift heavy objects collectively. For example, developers employed an algorithm to coordinate several robots, telling them which object to pick up, when to do it, and where, resulting in the creation of a quadrotor-built tower. [source: Kumar]

In environments outside the lab, a quadrotor uses a motion capture camera and laser scanner to create a real-time map of its surroundings, identifying features like doorways, people, and furniture. It then positions itself accordingly, continuously tracking its movements in relation to these landmarks with a personal coordinate system. [source: Kumar]

You don't need a degree in physics or engineering to recognize the power of nano quadrotor technology. And you certainly don't have to be a conspiracy theorist to have genuine concerns about its potential applications. While developers, law enforcement, and policymakers praise the possibilities of similar drone technologies to revolutionize our daily lives, some critics express valid worries about how it could impact personal privacy. [source: Kumar]

Nano Quadrotor Uses and Concerns

The possibilities for nano quadrotors seem endless. In the future, tiny flying robots could become the first to arrive at crime scenes or disaster zones, sending vital information back to authorities from a safe distance. They could also be used for high-risk military operations. Additionally, large swarms of these quadrotors may be employed for large-scale construction tasks that go beyond what has been done at the GRASP lab. [sources: Searles, Owano]

Dr. Vijay Kumar, a professor at the University of Pennsylvania who worked on this technology alongside former students Daniel Mellinger and Alex Kushleyev, has shared that the aim of this project and others like it is to assess whether 'large numbers of autonomously functioning vehicles' can be 'reliably deployed to carry out a prescribed mission,' especially in hostile environments, where their roles may change based on the situation. [source: SWARMS] Essentially, nano quadrotor missions could be anything imaginable. However, this kind of power also raises serious privacy concerns.

Quadrotors are a more advanced form of drones. With their autonomous swarm behavior, these flying robots don’t require individual programming. Much like the larger, often covert, and sometimes lethal machines that are increasingly dominating the skies, quadrotors bring with them potential for privacy violations. This concern has led several U.S. states to impose restrictions on their domestic use. [sources: Searles, Owano]

In February 2012, a law was passed that set the stage for the Federal Aviation Administration (FAA) to authorize unmanned aircraft for civilian use starting in 2015. Drones are expected to be used for various tasks such as crop monitoring, tracking animal migration, and safeguarding international borders. As drone technology improves, it's expected to become more affordable. For example, China’s DJI is already selling commercially available, video-capable flying drones, and another company is reportedly working on a nano quadrotor with an onboard photo camera. [sources: Kuruvilla, Ackerman, Svensson]

The concern is that cheap surveillance technology will inevitably lead to corruption. If nano quadrotors and other drones become as widely available as iPads, they could be used for spying by law enforcement, paparazzi, corporations, or even ordinary people who want to monitor their neighbors. Additionally, the risk of personal injury and property damage from drone crashes cannot be ignored. Consequently, U.S. federal and state officials are working on developing policy standards to protect privacy and safety while still allowing users to take advantage of the significant potential of drone technology. Like the nano quadrotors themselves, the regulatory landscape in which they will eventually operate is still evolving. [sources: Kuruvilla, Svensson]