New depth controls help stay the course

Active Depth Control Might the depth control system from a beet harvester show up on your next air drill?

FARGO, N.D. — A new automatic depth control system keeps extra mud from going through the processor during sugar beet harvesting while ensuring the high-value beet tips get into the truck.

While other automatic depth control systems function only on the hitch cylinders at the front of the harvester, the new Active Depth Control (ADC) from Amity Technology in Fargo also controls the two rear axle hydraulic cylinders to equalize the digging depth across the machine.

Boom depth is critically important to the beet grower. If the rotating discs run too deep in the soil, they bring up extra soil that the harvester must handle. Not only does that consume more fuel and put extra stress on the machine, but it also puts dirt into the truck, exporting it from the field.

If the boom is running too shallow, it slices off the bottom tip of the beet, which contains the highest concentration of sugar.

Booms on sugar beet harvesters now reach 12 rows for an operating width of 31 feet. If the left side of that boom starts to dig too deep into the mud, the right side goes up.

As well, the weight dynamics of a beet harvester are continually changing as field conditions or tank or boom loads change. It all happens in fractions of a second and is too fast for a human to keep up with.

With the ADC, the operator still has to decide what depth he wants to run the discs. That adjustment can change throughout the field: a spot with bigger beets requires the boom to go deeper while a spot with smaller beets requires the boom to run shallower.

Once the operator has made that initial determination and manually set the depth, the ADC does the rest and maintains the boom at that depth. Further depth changes are manually made by the operator as harvest conditions change, and the ADC follows its new instructions.

The challenge is to control the depth of a tool that’s working below the surface where it can’t be seen, said Joe Heilman, OEM product manager for Appareo Systems in Fargo, which builds the ADC for Amity.

Heilman said it’s not possible to measure the depth of a subterranean working tool with radar or sonar.

“But if we can use a sensor or a wand of some sort that skims along the surface at a known distance above the rotating disc, we have all the information we need to control the hydraulics,” Heilman said.

“If the wand drops below surface level, then we know the rotating discs are running too deep. They’re hauling up lots of soil, using too much fuel and slowing us down.

“If the wand floats along above the surface, we know the disc is too close to the surface and it’s cutting tips. We’re losing money. ”

Heilman said the wands look like steel skis with a significant curve at the front so that they skim the soil without digging themselves in. Each boom has a wand at the left side and right side.

The two sensors are mounted to the harvester frame. They are programmed to determine disc depth according to the angle of the wands. If one side or both sides of the boom need adjustment, that information is sent to the monitor.

The monitor then instructs the hydraulic valve block to make adjustments to the hitch cylinders and the rear axle cylinders, thus bringing the boom and rotating discs back to the desired depth.

Chris Giese of Appareo said Amity engineers did the initial design work on the ADC and then turned the project over to Appareo for production.

“The smarts of the whole system are in this control box. It sends instant information from the sensors to the box, then to the hydraulic valve block, then to the hydraulic cylinders,” he said.

“The system accounts for any type of depth control issues you’d ever find in a field: drainage ditches, rough ground, soft soil, hill tops. It’s designed so the operator can put depth control to the back of his mind and focus his attention on the truck running beside him, along with all the other tasks.”

Giese said the ADC sends all information to the screen in the cab so that the operator is always aware of what the boom is doing and what the ADC is up to.

“There are multiple applications for this technology. Potato harvest is the obvious one,” Heilman said. “But it could give very precise control on your air drills and fertilizer application equipment. On those really big 100 foot drills, you could control each section independently. On the precision drills, you could easily put a sensor on each seeding tool.”

Heilman said sugar beet growers are trading in their current harvesters for the new ADC machines. The inventory of used non-ADC Amity machines is bad for dealers, he added, because Amity has 80 percent of the North American market for sugar beet harvesters.

“This creates somewhat of a problem. The dealers are getting so many trades, and nobody wants a harvester that doesn’t have ADC.”

To address the problem, Amity is working on a retrofit kit for older Amity harvesters. Heilman said the kit will likely involve major changes to the older hydraulics.

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