Agricultural planting system with automatic depth control

1. A control system for controlling the depth of an opener device in an agricultural planter, said control system comprising:

a gauge wheel on a pivotably mounted support arm,

a rocker arm coupled to said support arm to move in response to changes in the angle of said support arm,

a sensor adapted to measure changes in the relative elevations of said opener device and said gauge wheel to produce a first output signal representing the current relative elevations of said opener device and said gauge wheel, and

an electronic controller receiving said first output signal from said sensor and producing a second output signal for maintaining said opener device at a selected elevation relative to said gauge wheel.

2. The control system of claim 1 , further comprising a moisture sensor producing a signal representing the moisture content of the soil being planted, said electronic controller being responsive to said moisture-representing signal for producing a third output signal representing the desired depth of said opening opener device.

3. The control system of claim 1 , wherein said sensor translates the upward force from the support arm into a fluid pressure in a fluid chamber.

4. The control system of claim 3 , wherein said fluid pressure is proportional to the gauge wheel load.

5. The control system of claim 3 , further comprising a pressure transducer coupled to said fluid chamber, the pressure transducer producing a pressure signal that changes in proportion to changes in said fluid pressure in said fluid chamber, said electronic controller receiving said pressure signal and using that pressure signal to produce said second output signal.

6. The control system of claim 1 , further comprising a remote sensor producing a chemistry signal representing the changes in the chemistry of the soil being planted, said electronic controller being responsive to said chemistry signal for producing a third output signal representing the desired depth of said opener device.

7. The control system of claim 6 , wherein the remote sensor is a satellite system or a drone system.

8. A method of controlling the depth of an opener device in an agricultural planter having a gauge wheel on a pivotably mounted support arm, said method comprising:

in response to changes in the angle of said support arm, moving a rocker arm coupled to said support arm,

producing a first output signal representing the current relative elevations of said opener device and said gauge wheel, in response to changes in the relative elevations of said opener device and said gauge wheel, and

in response to said first output signal, producing a second output signal for maintaining said opener device at a selected elevation relative to said gauge wheel.

9. The method of claim 8 , further comprising producing a signal representing the moisture content of the soil being planted, and in response to said moisture-representing signal, producing a third output signal representing the desired depth of said opening opener device.

10. The method of claim 8 , wherein the upward force from the support arm is translated into a fluid pressure in a fluid chamber.

11. The method of claim 10 , wherein said fluid pressure is proportional to the gauge wheel load.

12. The method of claim 10 , further comprising producing a pressure signal that changes in proportion to changes in said fluid pressure in said fluid chamber, and using that output pressure signal to produce said second output signal.