Powering the future of Farming: DC motors in Agriculture 4.0

Agricultural production is where the food processing chain begins, but with challenges to traditional agricultural approaches continuing, such as a reduced workforce, the sector will have to increasingly rely on robotics and automation. This shift is raising the dependence on motion systems powering technology in the field. 

Agriculture is the essential first step in food production, yet the industry faces continued pressure to increase productivity, efficiency, and meet the challenges of evolving government policy. To respond to these demands, Agriculture 4.0 represents the integration of modern technologies, where the use of robotics and automated techniques, managed and monitored via cloud computing with real-time data, is starting to emerge .

Central to these technology advances, and a fundamental cog in Agriculture 4.0, is the DC motor, enabling precise motion, alongside compact dimensions and low maintenance. DC motors achieve the most efficient form of rotary motion for battery-powered devices, and crucially, they enable easy integration with IoT technologies, allowing for real time adjustments and data-driven decision making. 

Motion in Agri 4.0 applications

The Autonomous Mobile Robot (AMR), or agribot, is a prime example of the advantages of Agriculture 4.0 technology and is transforming farming as these systems become increasingly deployed and economically feasible compared to traditional farming methods. Agribots are gaining traction in the market due to drivers such as the high cost of herbicides and labour, as well as increased scrutiny on environmental practices. These robots are designed to perform tasks including mechanical weeding, fruit picking, precision seeding, and even manure scraping and feeding in the livestock sector. 
Though many AMRs integrate sophisticated opti/geo guidance systems, they must still be safe and relatively easy to operate. Agribots rely on DC motors for driving their wheels as well as manipulating tools or equipment. These motors and their controls need to provide precision, and as they are required to operate seasonally in dynamic environmental conditions, they’ve got to be highly durable.

Agribots are driven by precise and reliable DC motors.

Meanwhile, advancements in Unmanned Aerial Vehicles (UAVs) have led to the growth in the agri-drone sector for tasks such as spraying, seeding, mapping, and inspection of crops and livestock. Drones are not constrained by difficult terrain and can help reduce costs and lower water consumption by enabling targeted and precise application of sprays and fertilisers based on real time data. Drones do not cause soil compaction and can have environmental benefits by minimising chemical and water usage through selective spraying techniques. 

DC motors provide the drone with propulsion through the propellers as well as powering auxiliary equipment such as pumps for spraying, or gimbles for cameras. This means that safety and reliability, along with energy efficiency, are key factors in motor choice.

Another developing sector enabled by the advantages of Agri 4.0 is vertical farming. Though this approach is currently confined to high value cropping systems such as leafy greens, herbs, strawberries, and tomatoes, it offers year-round production regardless of weather and can be set up in urban areas, minimising the distance from farm to fork. Here, adjustable lighting and ventilation systems are required to ensure optimal light and climate. Across these applications, DC motors are typically required to drive ventilation and climate control systems, as well as smart irrigation, delta planting, and harvesting robots.

The demand on motion systems 

The requirements of these applications are placing new demands on the motion systems responsible for powering and controlling them. To optimise the kind of robotic coordination necessary for a gripper to pick a strawberry without damaging it, the motion system must have highly precise control. From a motor standpoint, fruit-picking robots often share some interesting similarities with prosthetics despite their apparent differences. Both systems require high dexterity and precision using sensors and feedback systems. Compact, coreless DC motor technology is increasingly relied on instead of traditional motor designs with iron rotors. A coreless design should combine features that provide very low cogging, giving smooth control that supports precision and careful product management.

Robots are increasingly used in swarms of more compact, lightweight designs rather than fewer numbers of very large machines. This approach increases efficiency and redundancy over any downtime. Taking drones, for example, motion systems increasingly need to offer a high torque-to-mass ratio. This enables the robot to carry a greater payload and reduces demand on its battery power source. As a result, compact power, dense and efficient DC motors, which are smaller and lighter than their AC counterparts, will continue to have a key role to play, and technology like coreless designs, which further reduce weight, will be relied on. 

Drones can be used in agriculture tasks ranging from inspection to spraying.

Energy efficiency is also crucial for the same reasons, so brushless DC (BLDC) motor technology, which uses electronic commutation, will be important. This motor design, such as maxon’s EC motor range, uses electronic commutation, which minimises energy losses compared to brushed commutation. 
Importantly, robots might need to operate at all times of the year, in various weather conditions, and in various locations worldwide. Motion systems must ensure repeatable performance and long-term durability, preventing downtime.

Automation in the real world of agriculture 

In the real world, introducing robots in farming is still relatively limited. A combination of high capital costs and inexperience has led to farmers considering the Robotics-as-a-Service business model. The concept involves an operating and service contract with the machine manufacturer instead of purchasing the whole system outright. Where the work is seasonal and often provides just a short window of time, Robotics-as-a-Service also minimises the challenges and costs of downtime in the middle of a harvest, as the manufacturer can provide a replacement or rapid service for most stoppages. 

While the use of robotics in agricultural food production isn’t common to every farm across the UK and Europe, the advantages it could provide in productivity and efficiency mean that we can continue to expect its introduction to a more diverse range of farms over the next two to five years. This is especially true given the reduced agricultural labour force. As this happens, the reliance on DC motor technology will become increasingly important.