Features Handling Systems Structures & Equipment
Greenhouse robotics a win-win situation

The biggest cost line item in practically any industry these days is labour.

The biggest cost line item in practically any industry these days is labour. In the greenhouse business, it typically represents 30 to 35 per cent of overall input costs. It’s also probably the only cost that a grower has immediate and direct control over, since all the others are set by a supplier.

Many of the manual labour tasks are rightly or wrongly seen by potential new recruits to our industry as being boring, repetitive, strenuous or dirty. Or all of the above. Understandably, many people are put off entering what is a fabulous industry. Mechanization, however, offers growers two significant benefits: increased efficiency with reduced costs and a potentially more attractive workplace for bringing in new recruits.

There are a number of work areas that have been investigated for increased mechanization for some years. These include planting (e.g., tulips and seed sowing), transplanting (bedding plants from plug trays into flats or multi-packs), pruning (e.g., potted plants such as mini roses on container benches), spacing/moving and pot handling with spacing forks, mobile benches and conveyors, harvesting (search for news on the Wageningen UR Greenhouse Horticulture cucumber harvesting robot), and spraying (there are a number of suppliers who provide automatic spray machines that operate on greenhouse pipe-heating rails).

Not surprisingly, a number of researchers have been developing robots that can do this and other tasks independently of human operators.

GREENHOUSE ROBOTICS
Unfortunately, this is not as easy as it might seem at first, since designing robots for use in horticulture involves a number of unique challenges not faced in other industries.

For a start, a greenhouse is a pretty aggressive environment – humidity and temperatures are often quite high, and the light levels may be constantly changing. Secondly, horticultural products are not all the same – designing a robot to harvest greenhouse vegetables means developing a machine capable of differentiating colour (ripeness), shape and size (e.g., tomato, cucumber and pepper fruit grades).

And unlike auto parts or factory-produced “widgets,” the delicate nature of fresh produce also makes fruit and flowers prone to being easily damaged or bruised when handled mechanically.

But such difficulties do not stop engineers from trying to figure out ways to handle greenhouse challenges. Canadian researchers leading the way include professors Medhat and Hussein at the University of Guelph School of Engineering and their “Guelph Intelligent Greenhouse Automation System” (GIGAS), along with the robotic systems being developed by Vineland’s project manager for robotics, John Van de Vegte.

Of course, some of these machines will likely come with a hefty price tag.

While this will ultimately save those who can afford the equipment lots of money, smaller businesses that cannot afford these items will no doubt find the cost squeeze even more painful.

LOW-COST AUTOMATION SYSTEMS
One institution working to engineer affordable robotic systems is Argentina’s National Institute of Agricultural Technology. There, they are developing robots that are able to move, produce 3D maps, fertilize and prune greenhouse crops1. The essence of their systems is to make them fully autonomous and offer great adaptability to any greenhouse design allowing for efficient management of the resources. Further, they are using free software for control and cheap (or free!) hardware to reduce manufacturing costs.1

The engineering department of the same institution is also developing an automatic greenhouse spraying machine (the “Trakür agricultural robot”2) using the same principles of utilizing already available components and software to keep costs down. They claim to be able to produce a machine for less than half the cost of similar machines made in Europe.

So, while there are unique challenges to setting robots loose in a greenhouse, there are also significant advantages to be had. Perhaps the secret is to focus on low-cost, robust yet readily available components that will make such systems affordable and more accessible.

As an extra spinoff, designing and building these systems offers new career pathways for engineers wanting to use their skills in a “plant-focused” environment and to be involved in horticulture in less traditional ways.

1. National Institute of Agricultural Technology (INTA), Argentina, reported in HortiDaily.com, Nov 2013.
2. Ian Mount, “Argentine greenhouse robot brings automation to the masses.” Smart Planet, 2012.      

Gary Jones is a faculty member in the School of Horticulture at Kwantlen University, Langley, B.C. He serves on several industry committees and would welcome comments at Gary.Jones@Kwantlen.ca.