Commercial agriculture in most industrialized countries faces a host of challenges that threaten financial viability. Farms and greenhouses around the world are under growing pressure to deliver consistent yields of high-quality crops with fewer hands-on deck. Labor is scarcer and more variable than ever; margins are tight, and operations with delicate crops like on‑the‑vine tomatoes demand rapid harvesting without damage. As vision systems, robotics, and automation systems advance, autonomous harvesting is shifting from R&D labs to the field.
Four Growers has emerged as a key player in this transition. The company’s Pittsburgh‑based team set out to turn vision‑guided, gentle picking into a fleet‑ready reality for high‑tech greenhouses with mobile robots fitted with hoses that suck tomatoes off the vine. These systems must be safe, reliable, and able to work seamlessly with existing greenhouse infrastructure. “Our main goal is to help our customers maintain reliable labor and improve their crop yields by automating the harvesting process,” says Deepak Jayaraj, Four Growers Vice President of Hardware Engineering and Manufacturing. To make that leap, they needed to outgrow early approaches to controls that had reached their limits and adopt a modern automation architecture built for performance, safety, and speed at scale. Beckhoff’s PC‑based control and EtherCAT solutions enable rapid progression from prototypes to production operating across continents.
In an emerging category like autonomous harvesting, momentum hinges on reliability, repeatability and serviceability as much as electrical engineering breakthroughs. Four Growers recognized that success would come from unifying perception, motion, and machine sequencing under a deterministic control platform that could be validated, replicated, and maintained by a globally distributed team. They also needed a control hardware footprint that was compact and rugged enough to ride onboard a mobile robot. It also had to consume less power and cabling than legacy control cabinets and evolve quickly as field realities and customer requirements changed. The company’s move to automation technology from Beckhoff centered on these priorities, aligning the control strategy with the realities of commercial deployment in commercial greenhouses.
Growing pains
The jump from proof‑of‑concept to production across continents was defined first by safety and compliance. Early prototypes, like many in R&D, deferred full safety implementation to accelerate learning. That approach does not translate to commercial fleets. To operate in Europe, North America and beyond, Four Growers had to implement robust, certifiable safety functions and documentation that map cleanly to regional standards. The safety architecture needed to be adaptable to different machine configurations without forcing a ground‑up rewire for every variant.
“One of the biggest technical demands is reliability. All the GR-200 components, movement, suction, crate shuffling, must work together smoothly, especially in hot and humid environments,” says Peter Beauregard, Four Growers Senior Electrical Engineer. Narrow greenhouse aisles and frequent obstacles demand predictable reactions to safety laser scans, emergency‑stop presses and other potential triggers. In this context, the robot still needs to coordinate suction picking, arm motion, and crate shuffling with deterministic timing to ensure high throughput with gentle handling. This requires tight integration across the harvesting and packing carts, with clean handoffs to the robot arm. Any ambiguity in timing or signal integrity quickly translates into downtime or damaged product.
Mechanical constraints on a mobile platform raised the stakes further. The controls had to fit in a compact envelope and mount directly on the robot’s backplate, without sprawling external cabinets or long runs of cabling that are vulnerable in tight aisles. Power consumption needed to come down compared with earlier iterations to extend uptime and reduce heat dissipation. And because most growers already rely on pipe rails for irrigation, the robot needed to ride on the same infrastructure without damaging it. That meant the control hardware and motion technology had to be rugged, space‑efficient, and easy to service in the field.
Finally, development and field operations demanded more speed and flexibility. As the GR-200 matured, I/O requirements shifted, and new features emerged; from integrating additional sensors to refining motion sequences. The automation software environment had to feel intuitive for engineers yet still deliver deterministic motion control and programmable safety. It also needed to streamline fleet tasks: replicate configurations across units, tune axes quickly, and diagnose issues without lengthy wiring hunts or opaque tools. In short, the team needed a platform that moved as fast as their development cycles, while hardening the system for daily agricultural production.
Today, the GR-200 delivers reliable harvesting in challenging greenhouse conditions. Vacuum suction provides gentle handling compared with traditional pick‑and‑place approaches, ensuring consistently high fruit quality. In testing, peak measurements reached 2.79 seconds per tomato, with average speeds dependent on crop density and ripeness distribution. The dual‑cart workflow mirrors established greenhouse practices but with far less manual labor: the robot harvests forward and back along the row, manages crate changes automatically and alerts staff only when unloading is required. Deterministic coordination across suction, arm motion, and crate handling translates into consistent throughput and predictable behavior in the face of obstacles or safety triggers.
Harvesting automation success
Four Growers built the GR-200 on Beckhoff’s PC‑based control platform to unify real‑time control, motion, and safety while keeping perception independent. A single Beckhoff CX5230 Embedded PC running TwinCAT—and TwinCAT/BSD for the operating system—serves as the orchestrator for all sensors, drives, machine sequencing, and safety. A separate high‑performance vision system identifies ripe fruit and sends harvesting targets to the controller.
EtherCAT provides all-purpose, deterministic networking and the modular I/O needed for a system that continues to evolve. Fast, real‑time EtherCAT communication synchronizes tomato suction timing, robotic arm motion, imaging triggers, and crate handling with high precision. Modular I/O terminals make it straightforward for the Four Growers team to add signals as the design evolves. This currently includes digital and analog I/O, safety inputs and outputs, encoder feedback, brake choppers, and RTD temperature sensors for thermal monitoring. “As a standard EtherCAT I/O terminal, an EL6224 IO‑Link master connects smart field devices as needed, opening the door to plug‑and‑play sensors and actuators.” says Ola Roberts, Four Growers Electrical Engineer. “Built‑in EtherCAT diagnostics streamline commissioning and troubleshooting, allowing us to scan the network, discover devices and pinpoint cabling issues quickly.” Safety technology moved to the center of the design through TwinSAFE and Functional Safety over EtherCAT (FSoE). Pre‑certified function blocks and the TwinCAT Safety Editor helped the team implement and validate safety logic efficiently, with clear mapping to required performance levels. “The pre-certified safety blocks were very helpful in designing our safety logic as we had to comply with different safety standards,” says Beauregard. FSoE carries e‑stop and other safety states between the harvesting and packing carts without additional hardwiring, simplifying the dual‑cart architecture and reducing points of failure. Safety laser scanners, physical e‑stop devices and other protective inputs connect through TwinSAFE I/O, and safe‑state handoffs to the robot arm occur via a standard EtherCAT network along with all other GR-200 communications. The result is a unified automation and safety system that’s both robust and adaptable, with the documentation and diagnostics needed for certification.
Motion control is also consolidated onto the CX5230 Embedded PC to drive six axes, replacing multi‑controller setups from earlier iterations. Compact, DIN‑rail mounted ELM7231-9018 servo terminals connect with AM8000 series servomotors with One Cable Technology (OCT) to reduce wiring and fit neatly inside the robot. This eliminates bulky external cabinets while improving serviceability. The tight integration between the machine controller and drives improves synchronization across axes and reduces latency in speed and torque commands. TwinCAT Drive Manager simplifies parameter setup, duplication across units and on‑site tuning, so new systems can be commissioned quickly and consistently.
Across the software toolchain, Beckhoff’s ecosystem accelerates configuration and quality assurance for greenhouse fleet deployments. Automatic hardware scanning with TwinCAT and EtherCAT reduces the chance of misconfiguration as machines ship and evolve quickly. Engineers can code in familiar, modern PLC programming languages within TwinCAT, including structured text. TwinCAT also integrates Microsoft Visual Studio® in its engineering environment, which further eases development work for team members with C++ and Python backgrounds. “TwinCAT is extremely intuitive for someone with a computer science background. This made starting motion control projects a straightforward process,” says Meara Murphy, Four Growers Robotics Engineer. Project comparison tools support code reviews and controlled changes across the fleet, helping maintain consistency while enabling rapid software iteration.
Rooted in results
With the Beckhoff automation and control platform in place, Four Growers achieved safety compliance and validation across regions, unlocking market access while reducing wiring complexity through EtherCAT, FSoE, and modular TwinSAFE logic. The safety design is now a core, fully integrated asset rather than a bolt-on system: it maps cleanly to standards, documents easily for audits and scales across configurations without redesigning the machine. That, in turn, shortens the path from prototype to production for new variants.
The control architecture is simpler and more resilient. A single embedded PC now handles all motion axes that previously required multiple controllers, cutting complexity and reducing points of failure. “The greenhouse operator can put the system in the row, enter a few configurations, and hit start, and the robot will begin its harvest and notify when done. They can just push the button and walk away,” says Murphy. Compact ELM series servo drive terminals with One Cable Technology (OCT) bring the motion stack inside the robot’s footprint, improving robustness in tight aisles and reducing power consumption compared with earlier iterations. For a mobile platform riding existing water pipe rails, the smaller, cooler, and easier‑to‑service control package is a tangible advantage.
Perhaps most importantly, the GR-200 system automated by Beckhoff scales. TwinCAT’s unified environment, Drive Manager and project comparison tools make it faster to configure, replicate and maintain robots across the fleet. The modular I/O enables Four Growers to add features and devices without redesigning the control platform and EtherCAT’s built‑in diagnostics reduce time spent chasing wiring faults in the field.
With the success already seen in numerous GR-200 systems deployed worldwide, the company has moved decisively from prototypes to commercial fleets harvesting daily. “We launched our first robotic fleet in the Netherlands at one of the country’s largest greenhouse operations. We have five robots, operating and harvesting daily. Last year we also added a new continent to our market size,” says Four Growers Chief of Staff, Christine Morgan. On the same automation backbone from Beckhoff, they continue to refine diagnostics, energy usage and feature exposure, while developing next‑generation capabilities that build on a proven control foundation.
As autonomous agriculture is finding its footing, Four Growers illustrates how the right control platform can turn an emerging idea into a running operation. By developing on PC‑based control, EtherCAT-enabled motion, and integrated functional safety from Beckhoff, the team has aligned advanced robotic perception with industrial‑grade automation. The payoff is a fleet‑ready system that fits existing greenhouses and gives engineers and growers the flexibility to move fast—bringing autonomous tomato harvesting from concept to reality.
