Managing cultivators’ depth guidance

The depth guidance of semi-mounted cultivators has so far generally been managed with guidance wheels mounted on the vehicle frame and the following roller.
Managing cultivators’ depth guidance

This system works relatively well on level ground, where adherence to the set working depth and the load on the support wheels is relatively constant.

On uneven and rough land, and in particular for long cultivators, they often work too deep when crossing over a hump, and too shallow when passing over a hollow or dip.

Traction reinforcement systems that act exclusively on the cultivator drawbar, and not via the three-point linkage, allow ground adjustment in these conditions, but the load transmission to the tractor is uneven.

A new control system from Lemken won a silver medal for innovation at Agritechnica. In this system, the load acting on the support wheels is constantly measured, and allows hydraulic control of the roller position.

If the support load drops, the roller is raised. The cultivator works into the ground until a pre-set support wheel load is reached. This novel system relieves the work load on the operator and improves the quality of work.

Spraying rates differ when negotiating bends, with the application rate lower than the set value at the outer edge of the bends, and higher at the inner edges.

This poses problems in the many non-rectangular fields of arable crops, and where there are obstacles that the operator has to drive around.

In such situations there can be deviations of 40% to 160% from the set value of the spray application quantity, for a 36-metre boom.

The Agritechnica’s curves control application from Herbert Dammann Gmbh regulates the spray quantity in such a way that the average values per section match the set value. This is made possible by calculating the data generated by a sensor that measures the curve radius, the measured speed of the wheel sensor, data from the machine, and the set value of the spray application rate per hectare.

To reduce the calculated deviation from the set value in each sprayer section, the calculator controls the volume sprayed by switching nozzles on and off, changing the spray pressure in the section, or combining both controls.

Horsch have developed the Horsch Leeb boom control for exact and safe sprayer boom guidance over the crop.

This active boom guidance includes precise adaptation of the boom to the field conditions, made possible by decoupling the boom absolutely from the chassis. Used for spray application at a very short distance from the target surface, this minimises the effects of wind on spray drift.

The boom control includes two hydraulic cylinders, an extremely fast proportional hydraulic valve, and new control software with gryroscopic sensors. The equipment won a silver medal for innovation at Agritechnica.

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