The 20/20 on Machine Vision
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Designed collaboratively by Facteon and pallet company CHEP, a new robotic destacker uses ultrasound sensors to cope with infinite infeed variability, boosting productivity and safety on site.
Founded in Sydney over 70 years ago, CHEP is a global leader in equipment pooling and logistics, serving customers in 45 countries with hire and supply of its containers, crates and, above all, some 300 million distinctive blue pallets.
In New Zealand, the company claims 90% of the local pallet market. “You’ll see our blue pallets everywhere you go,” says Ian Palmer, Technical Manager at CHEP NZ, whose key customers include major supermarket chains and other FMCG handlers.
Keeping a huge stock of timber pallets in good shape is a full-time job. Timber parts splinter and break. Plastic wrap and food waste gets jammed in the joints.
“After a pallet is used,” explains Ian, “it goes back to our service center for conditioning: we replace broken boards, paint and stencil it, and out it goes again. In most automation systems, you see pretty boxes flying around; we don’t have that.”
On the repair station at CHEP’s plant in Penrose, Auckland, staff bring in large stacks of used pallets, feeding them into a destacker to be separated into individual pallets that can then be inspected, repaired, and put back into service.
Increasingly, CHEP automates this kind of work, to maximize efficiencies. “Over the years,” says Ian, “we’ve increased our levels of automation to increase productivity, but our destacker was more than twenty years old and kept failing. As well as causing costly downtime, this was messy and dangerous work. Pallets can weigh over 50 kg apiece.”
In their search for a new destacker, CHEP avoided going to overseas companies, owing to historic challenges and difficult communications impacted by language barriers and time differences. “We had to partner up locally,” says Ian, “and use well-known and proven automation implements such as robots, where you minimize the unknowns and have an efficient, reliable core.”
Vital for CHEP, too, was finding a local partner with whom they could interact closely and iteratively over the long lifespan of a project. “From the time we start on concepts, the final installation could easily be four years down the track. So it’s not a quick ‘pop in, offer a solution and expect the purchase order in a couple of months.’ It’s years we need, and contact, and interaction, and a high confidence level.” This made Facteon the right choice for CHEP. “We decided, let’s see what they can develop and propose.”
For Facteon’s engineers, this first project with CHEP presented interesting challenges. First, they had to work within the tight physical constraints of the Penrose site, specifically the existing infeed and outfeed of the destacking unit.
Next, there was the unpredictability of the pallets, as Project Manager Scott McKenzie explains. “Although there were only two different types of timber pallet, the pallets can break in all sorts of different ways, or can have foreign matter attached or separation sheets between them.” Adds Vision Systems Engineer Ray Russell, “A pallet is an incredibly difficult product to sense, not least because about 30% of its top surface is a set of voids. The environment is too dirty to go optical, so we used ultrasound—but ultrasonics have complex issues, too. We learnt a great deal.”
The way forward lay in a co-creation process. Ian Palmer, who himself is a highly experienced engineer, explains how Facteon’s methodology made this possible.
“Automation is easy when you have tidy boxes on a conveyor; but because we’re a ‘dirty’ business, we need unique solutions. With the skill and knowledge of Facteon’s engineers, we were able to work closely with them on the front end. At each meeting, they understood the problems, and at the next meeting they’d present a solution.”
For example, says Lawrence Owen, Facteon’s Design Lead, “This was the first project where I had to consider if the presence of a chicken carcass would impair machinery efficiency. The solution had to be as simple and robust as possible, which included removing all sensors from the end effector so that there were no vulnerable components in harm’s way.”
Also, the conveyor that brings the stacks in wasn’t designed to operate with Facteon’s machinery, so they modified the existing conveyor. And, with the destacker installed, they found that changing the outfeed from a chain conveyor to a roller conveyor delivered improvements.
The project also drew in Dalton Electrical, who handle all CHEP NZ’s day-to-day electrical, controls, automation, and maintenance tasks. They integrated the new robot cell into the existing line control system, and implemented CHEP’s in-house machine safety guarding concepts for the new robot destacker cell.
GlenSide Engineering, CHEP’s preferred mechanical team, also helped build and install the new outfeed conveyor, as well as maintaining their 24/7 callout service. Service Manager Ian Stevens says, “Involvement in this project has given us an understanding of the system, which allows us to provide crucial backup when required.”
The iterative co-creation process was key. “Thankfully,” says Scott McKenzie, “our agile methodology enabled us to co-discover issues early on and innovate along the way. We explored different technological options together and collectively came up with a solution that delivers a positive, whole-of-life customer experience and takes wider factory integration into account.”
The new destacker relies on ultrasonic sensors to locate and analyze the top pallet in the infeed stack, and to guide the robot arm to it in the appropriate configuration. The arm lifts two pallets at a time, flips them up vertically over a bin (allowing any foreign objects and broken timber to fall away), then delivers them onto the conveyor, placing them precisely, one at a time.
The new destacker is faster and more reliable than the old. It deals with the broken pallets that in the past tended to fall inside the machinery and jam it; this material is now cleared away into the bin. The infeed is more dependable, throughput is smoother, and downtime is reduced. The destacker also inverts the pallets, presenting them to the repairer in a more convenient orientation, which reduces manual handling.
With the new destacker in operation, CHEP’s Penrose operation has achieved record high productivity, made more admirable due to its relatively inexperienced team, compared to other CHEP operations. At Penrose, the average length of experience per repair station operator is one year, compared to five and greater at other sites. Therefore, Penrose can put more work through using less experienced
personnel—a bonus in this time of labor shortages and uncertainty.
For Ian, it’s a triple win. As well as boosting productivity and improving onsite safety, the destacker solution has removed a lot of nontangible frustrations felt by staff. Also, this successful project will set an example of the benefits of automation, and inspire other CHEP offices around the world. And this “win” gave Ian the collateral and confidence to seek further funding from the exec team for their next collaboration with Facteon, which is already under way.
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