Agricultural toolbar apparatus, systems and methods

An agricultural toolbar, comprising:

• a left wing section comprising a left wing bar member supporting a first plurality of row units;
• a center section coupled to the left wing section and comprising a center bar member supporting a second plurality of row units;
• a right wing section coupled to the center section and comprising a right wing bar member supporting a third plurality of row units;
• at least a first height sensor disposed on at least one row unit of the first plurality of row units:
• at least a second height sensor disposed on at least one row unit of the second plurality of row units;
• and
• at least a third height sensor disposed on at least one row unit of the third plurality of row units;
• wherein the first, second, and third height sensors are disposed to measure heights with respect to a soil surface.

An agricultural toolbar, comprising:

• a plurality of toolbar sections each having a respective bar member supporting at least one row unit;
• wherein the at least one row unit comprises:
• a row unit frame;
• a parallel linkage connecting the row unit frame to the respective bar member;
• and
• a downforce actuator having an extendable rod applying a force between the respective bar member and the parallel linkage;
• wherein each of the plurality of toolbar sections has at least one height sensor comprising an LVDT displacement transducer configured to measure a length of the extendable rod and determine a height with respect to a soil surface.

A method of adjusting a height of toolbar sections comprising a left wing section, a center section, and a right wing section of an agricultural toolbar, wherein the left wing section pivots on a first vertical axis and a first horizontal axis relative to the center section, wherein the right wing section pivots on a second vertical axis and a second horizontal axis relative to the center section, wherein each of the toolbar sections supports at least one row unit, wherein each of the respective toolbar sections has a height sensor, and wherein each of the toolbar sections has a height control actuator configured to adjust a height of that toolbar section with respect to a soil surface, the method comprising:

• (a) for a first section of the toolbar sections, measuring a height with respect to the soil surface of the first section using the first section's height sensor;
• (b) comparing the measured height to a desired height range;
• and
• (c) repeating acts (a) and (b) for each toolbar section.

A method of adjusting a height of respective toolbar sections comprising an agricultural toolbar, each of the respective toolbar sections supporting at least one row unit, each of the respective toolbar sections having a plurality of height sensors and each of the respective toolbar sections having a respective height control actuator configured to adjust a height of that respective toolbar section with respect to a soil surface, the method comprising:

• calculating an average section height with respect to the soil surface of each of the respective toolbar sections based on heights measured by the plurality of height sensors of that respective toolbar section;
• comparing each calculated average section height to a desired height range;
• consulting a lookup table that specifies actions to be performed by the respective height control actuators of each of the respective toolbar sections depending on whether the calculated average section height is higher than the desired height range, lower than the desired height range, or within the desired height range;
• adjusting at least one of the respective height control actuators as specified by the lookup table.