Systems, methods, and apparatus for controlling a position of one or more float arms in an unlocked configuration may include a first valve movable between a first position configured to cause the float arm to move to a locked configuration and a second position configured to cause the float arm to move to the unlocked configuration; a first source of pressurized fluid in communication with the first valve; and a second source of pressurized fluid in communication with the first valve. In the first position, the first valve may be configured to transmit the first fluid from the first source and, in response, to cause the float arm to move to the locked configuration. In the second position, the first valve may be configured to transmit the second fluid from the second fluid source and, in response, cause the float arm to move to the unlocked configuration.

Systems, methods, and apparatus for controlling a position of one or more float arms in response to operation of a gauge wheel or in response to an input are described. In some instances, a float arm is moved to a selected position automatically in response to extension or retraction of a gauge wheel. In some instances, a position of a float arm in an unlocked configuration is altered in response to an input, such as a user input. In some instances, a position of the float arm is controlled in response to application of fluid pressures, such as hydraulic pressure. Fluidic pressure may be altered in response to changing a position of one or more valves.

A method for dynamically operating a header float system of an agricultural vehicle having a header movably mounted to a frame by an actuator and a flotation adjustment system that relies on ground-contact force measurement. The method includes: determining an initial zero value load sensor output signal representative of an initial position of the header raised out of contact with the ground surface, calibrating the sensor with the initial zero value, operating the header to process a crop material, detecting a subsequent position of the header out of contact with the ground surface, determining a subsequent zero value representative of the subsequent position of the header, and re-calibrating the sensor with the subsequent zero value. Also, an agricultural vehicle having a header operated as described above.