One of the most pressing needs in greenhouse operations is ensuring worker safety while maintaining efficiency. Dennis Marchand, a designer and machine builder at Innomation Technologies in Canada with over 40 years of experience, shares more about their machine prototype designed to address these issues.
A new approach to an old method
Dennis is currently working on his prototype string-tying machine to eliminate one of the most difficult and dangerous tasks in greenhouses. He explains, "This job is performed 15 feet in the air, in very hot conditions, and traditionally, workers use scissor lifts to tie strings for crops manually. It's not a comfortable or safe working environment."
"Tying strings at height is a risky job, and workers often have to endure extreme heat inside different types of greenhouses," he says. "I've been in several greenhouses and have seen workers come down from stringing, completely soaked in sweat. It's a tough job that only a few people can or want to do. But it's essential for vertical farming, as it provides the structure for plants to grow efficiently."
He adds that the introduction of automation will refine and streamline the process. "Right now, we're using products designed for manual labor—like twine made to be tied by hand. With a machine, everything changes, including greenhouse designs, which will need to adapt to accommodate automation in stringing and other growing environments."
The machine automates string tying, reducing the need for human intervention at dangerous heights. It can tie 1,500 strings in a row and is designed to work along the heat pipes commonly found in greenhouses. "The machine is placed on a scissor lift to reach the required height, and it moves along heat pipes, which serve as rails for the carts," he says.
Challenges in development
Building a fully functional, autonomous machine has not been without its challenges. "We've gone through 17 designs to get to a prototype that works consistently," Dennis shares. The difficulty lies in controlling the string, which is a polyester twine measuring up to eight kilometers per spool. "String is very hard to manage because you don't always know where it is," he notes.
The machine also ties a specific knot that simplifies the cleanup process. "When the crop cycle ends, a worker can simply pull the string to release the plants and string, which then falls to the ground for composting," Dennis emphasizes the environmental considerations of using biodegradable strings, which ensure sustainability and efficiency.
Addressing power requirements
Powering the machine has been another hurdle. Currently, it relies on electricity from the greenhouse, but this setup is not viable for autonomous operation. "We've considered propane-powered generators, but greenhouses are hesitant to allow propane due to safety concerns," he says.
Instead, the team is exploring the use of battery packs. These replaceable batteries will allow the machine to operate continuously without needing to be connected to a power source. "The batteries would be briefcase-sized, and the system would need a schedule for charging and replacement. When one battery is removed, the machine continues running on the other, ensuring no downtime," he explains.
Refining the design
One of the key principles guiding the development of the string-tying machine is simplifying the design. "When you start, designs are often complicated. As you refine them, they get simpler," he remarks. "For instance, we found that using air pumps was the most effective way to feed the string through the machine."
Despite the progress, there is still room for improvement. "We need to ensure the machine can automatically lift itself to the right height in the greenhouse and precisely identify the cables to which it ties the strings," Dennis says.
Prototype A
Expanding to other solutions
Innomation Technologies have also developed other automation solutions for the agricultural sector, including a machine for packaging tomatoes. "This specific device uses robots with specialized grippers to weigh and sort tomatoes into packages with perfect accuracy," Dennis shares.
"The machine knows the weight and position of each tomato. It ensures that packages meet the required weight without being over or under, which is critical for compliance with grocery store standards," he explains.
Additionally, the company has explored solutions for handling vine crops like peppers, tomatoes, and cucumbers after harvest, wanting to address the diverse crops of greenhouse operators.
Prototype B
Collaboration with greenhouses
"We're looking for input from greenhouses to understand their specific needs and challenges," Dennis says. This feedback will help refine the machines and ensure they are practical and effective in real-world settings.
Dennis is optimistic about the potential of automation to transform greenhouse operations. "We've put thousands of hours into this machine, and the components are not the cheapest, but they work," he states. "We want to build equipment that has the potential to make greenhouses safer and more efficient places to work."
For more information:
Innomation Technologies Inc.
Dennis Marchand
[email protected]
innomationtech.com