Agricultural trench depth sensing systems, methods, and apparatus
Systems, methods and apparatus are provided for determining the depth of a trench opened by an agricultural planter. Sensors are provided for detecting the position of a ground-engaging element of the planter such as a gauge wheel or seed firmer of a row unit of the planter. Apparatus and methods are provided for installing such sensors onto a row unit of the planter. Systems, methods and apparatus are provided for controlling downpressure on a row unit based on the trench depth. Methods are provided for mapping trench depth measured by the depth sensors.
1. A method of measuring actual depth of a trench opened in a soil surface of a field by an opening disc of agricultural row unit, the agricultural row unit including a gauge wheel, the gauge wheel supported by a gauge wheel arm pivotally mounted to a frame of the agricultural row unit, a depth adjustment assembly having a plurality of selectable positions, each of the selectable positions establishing a selected trench depth by limiting an amount of upward travel of the gauge wheel relative to the opening disc, the method of measuring the actual trench depth comprising:
as the agricultural row unit traverses the field with the depth adjustment assembly in one of the selectable trench depth positions, generating a trench depth signal related to an actual trench depth opened in the soil surface by the opening disc;
determining a measured trench depth value based on said trench depth signal;
determining a location of the agricultural row unit in the field based on a GPS signal;
associating said measured trench depth value with said location; and
generating a trench depth map spatially relating a plurality of locations in the field with the measured trench depth at each of said plurality of locations.
2. The method of claim 1 , further comprising:
comparing said measured trench depth to the selected trench depth; and
modifying a position of a depth actuator to bring said measured trench depth closer to the selected trench depth.
3. The method of claim 1 , further comprising:
comparing said measured trench depth to the selected trench depth; and
modifying a configuration of a downpressure valve to bring said measured trench depth closer to the selected trench depth.
4. The method of claim 1 , further comprising:
comparing said measured trench depth to a full depth; and
if said measured trench depth is not equal to a full depth, adjusting the pressure of a downpressure actuator, said downpressure actuator disposed to modify a downpressure applied to the agricultural row unit.
5. The method of claim 4 , further comprising:
determining whether said measured depth is less than a zero depth;
if said measured depth is less than the zero depth, adjusting downpressure by a first increment; and
if said measured depth is not less than the zero depth, adjusting downpressure by a second increment, wherein said first increment is different in value from said second increment.
6. The method of claim 1 , further comprising:
displaying on a display viewable to a user, said trench depth map.
7. The method of claim 6 , wherein said step of determining a measured trench depth value comprises looking up said first depth signal in a calibration dataset.
8. The method of claim 7 , wherein said calibration dataset is updated by a calibration process, said calibration process comprising:
recording a first calibration signal while the first gauge wheel arm is in a first known position; and
modifying said calibration dataset based on said first calibration signal.
9. The method of claim 8 , wherein said calibration process further comprises:
recording a second calibration signal while said first gauge wheel arm is in a second known position; and
selecting a subset of said calibration dataset based on said second calibration signal.
10. The method of claim 8 , wherein said first gauge wheel arm is placed in said first known position by lowering the agricultural row unit onto a surface, wherein said surface is not penetrated by the opening disc of the agricultural row unit.