Source : Mouser Electronics

Swarm Robotics Provides New Opportunities for Industry, Agriculture, and More

From precision agriculture to disaster response, aerial drones, also known as uncrewed aerial vehicles (UAVs), are getting smarter, faster, and more coordinated. Their next evolution: synchronized flight.

Recent advances in edge computing, wireless communication, and sensor fusion have significantly boosted the capabilities of autonomous robotics. At the same time, drone systems have become more complex, creating new design challenges like managing distributed processing, maintaining low-latency connectivity, and meeting strict power constraints.

As these systems evolve, attention is shifting toward multi-robot coordination, where groups of autonomous drones work together to perform tasks more efficiently than a single unit could manage alone. This article explores the expanding use of coordinated drones and robotics, known as swarm robotics.

Inspired by Nature

Swarm robotics entails the use of large numbers of drones working in concert to accomplish a common task. Perhaps the highest-profile example of swarm robotics is the familiar alternative to fireworks, where drones perform dazzling displays at sporting events and celebrations (Figure 1).

Figure 1: The 2022 Platinum Jubilee in London included a drone show, with coordinated swarms of drones forming the shape of a corgi. (Source: New Zealand Government, Office of the Governor-General, public domain)

There are many examples of swarms in the natural world, too. Many species of insects, including ants and bees, work together as a cohesive unit without centralized control. Despite this lack of overall control, they coordinate their activities to achieve complex tasks. Inspired by this behavior, designers are creating swarms of robots for new operational applications across an array of use cases.[1]

Swarm Robotics in Industry

The manufacturing world was one of the earliest adopters of robots, but these were simple machines designed to perform limited tasks, albeit more quickly and consistently than human workers. The modern smart factory requires robots to be far more flexible and able to respond to rapidly changing demands. Such facilities are already using autonomous mobile robots (AMRs) for many tasks, including material transport and order picking. However, these robots often follow predefined paths and are optimized for the structured environment of the factory floor.

Swarm-capable robots allow far more flexibility. These swarms are designed to make local decisions and eliminate the need for centralized or structured control. The many units involved allow the swarm to complete tasks based on availability and conditions. If we consider the swarm as a single entity, it is fault-tolerant, as failures can be bypassed by allocating alternative units to ensure a successful outcome.

A swarm of autonomous robots allows materials to be transported around the facility with greater flexibility. High-traffic areas can be avoided, and idle units can receive new tasks and respond quickly to unusual situations.

Farming Robots

Modern-day agriculture spans vast, unpredictable environments that are very different from the controlled environment of a factory. Smart farming technology is starting to replace manual labor with sensors and data-driven decisions, but the scale and variability of tasks across a farm remain a challenge.[2]

Robot swarms provide a solution to this challenge. Different from highly sophisticated agricultural machinery, robotic swarms are formed from large numbers of relatively simple machines. They are useful because they can deploy over wide areas and work cooperatively to complete repetitive and time-consuming tasks.

Agricultural robots combine the advantages of ground-based and airborne drones. Ground-based systems can interact directly with plants and soil, while aerial drones can survey large areas and conduct spraying operations. This combination creates a multi-layered, adaptive system customized to the unique farming environment. Since the robots are mobile, they are not dependent on fixed infrastructure, making them ideal for use in remote locations.

Robot swarms are also scalable, as additional units can be added or removed quickly to respond to seasonal requirements. Therefore, the swarm is a large robotic workforce that can perform many repetitive activities around the farm without requiring central control, allowing the farmer to take on a more supervisory role.

Infrastructure Maintenance

Farms aren’t the only environments where autonomous robots provide value. Critical infrastructure, like pipelines, power grids, and wind turbines, encounters similar challenges. Such infrastructure spans vast geography, can be in remote locations, and requires regular inspections. Helicopter flyovers help, but they don’t provide the necessary details. Ground inspections provide finer details, but are slow, expensive, and sometimes dangerous.

Robotic swarms offer an alternative that combines mobility and precision for quick and safe data collection. Equipped with high-resolution cameras and other sensor systems, large groups of drones can provide rapid inspection from multiple viewpoints. They can hover to closely inspect critical structures and then move rapidly to the next site, unaffected by the surrounding terrain.

Airborne Rescuers

In any large-scale emergency, from earthquakes to wildfires, early intervention can significantly improve the chances of human and wildlife survival. Speed is also critical in search-and-rescue operations, where rapid response can mean the difference between life and death.

Conventional ground-based search-and-rescue teams must contend with highly hazardous conditions. Other dangers, including unstable buildings and localized hotspots, can force rescuers to move slowly.

Swarms of search-and-rescue drones can be deployed quickly in the aftermath of almost any emergency. Equipped with advanced detection systems, including infrared and atmospheric sensors, these drones (Figure 2) can quickly create an accurate model of ground conditions.

Figure 2: Aerial robots can work together to automate tasks over large areas and buildings. (Source: Free-styler/stock.adobe.com)

These search-and-rescue drones’ decentralized control enables operators to conduct parallel searches over large areas, identifying potential survivors for follow-up teams. Their swarm intelligence allows them to dynamically reorganize routes, and their small size allows them to safely inspect locations that would be dangerous for humans to enter.

Enabling Technology

Inter-drone communication is the main requirement for getting a swarm to function. Sharing information with minimal delay is necessary for the swarm to operate as a cohesive unit. Each drone needs to share data about its position, the status of its assigned task, and observations about its surroundings.

The volume of information generated by an array of robots or drones can challenge the capabilities of common protocols, such as Wi-Fi, Zigbee, and LTE. Dense swarms require both low-latency communications and scalability. Emerging mesh network protocols and dedicated swarm communication standards, such as mobile ad-hoc networks (MANETs), could be a solution. MANETs are decentralized wireless networks that do not require pre-existing infrastructure, such as routers or wireless access points.

Each drone that forms part of a MANET is independent but changes its links to other members of the swarm as it moves around. Each drone, therefore, forms part of a network, passing not only its own data but also relaying information from its neighbors.

Accurate positioning information is an important element of the data that must be shared. Global positioning systems (GPS) are an established means of providing accurate locations, but are of limited use in enclosed or underground situations. The drones must also be able to function in GPS-denied areas. Other technologies, including ultra-wideband (UWB) communication and vision-based simultaneous localization and mapping (SLAM) techniques, ensure continued accuracy.

SLAM is a technique used by robots and autonomous vehicles to create a map of their surroundings and pinpoint their position within it.[3] Using the information generated by vision-based sensors and lidar, SLAM technology requires low-latency communication between positional sensors and processors. However, it can provide centimeter-level accuracy, even when other technologies are unavailable.

Alongside sensors, communications, and positioning systems, drones require energy storage and propulsion. Designers must balance weight and performance with battery life and durability. Batteries using lithium-ion or lithium-polymer technologies offer an ideal combination of energy density and weight for small aerial robots. Designers must also be aware of the conditions in which drone swarms must operate. When deployed into industrial or agricultural environments or to aid in natural disasters, drones must be able to withstand wind, rain, and extreme temperatures.

Future Directions

The future of robotic swarms encompasses advanced features, including autonomous mission planning and integration with enterprise systems. In the industrial world, swarms will work directly with automated enterprise resource planning (ERP) and Internet of Things (IoT) networks to allow fully autonomous operations. Other applications will see an increased level of collaboration with human operators, including the use of high-level commands such as gestures and direct speech.

These additional capabilities will require new policies and regulations. At the operational level, airspace must be shared with conventional crewed aircraft. With the growth of artificial intelligence (AI) and increased autonomy, ethical and privacy considerations arise, and maintaining public confidence is crucial to ensure their widespread acceptance in everyday use.

Robotic swarms are providing a new approach to industry, agriculture, infrastructure, and emergency response. With advancements in autonomy, communication, and positioning systems, decentralized swarms offer scalable and efficient solutions. As policies and regulations mature, robotic swarms will evolve from innovation to integration.