Variable float and variable blade impact

A control system operable to control movement of a work implement of a work vehicle, the control system comprising:

• a reservoir configured to retain fluid;
• a pump in fluid communication with the reservoir;
• an actuator in fluid communication with the pump, the actuator having a first side and a second side;
• a control valve fluidly positioned between the pump and the actuator;
• a first proportional relief valve fluidly positioned between the pump and the first side of the actuator;
• a second proportional relief valve fluidly positioned between the pump and the second side of the actuator;
• and
• a position sensor configured to sense a position of a piston in the actuator, and to compare the sensed position to a set position,
• wherein the first proportional relief valve is configured to permit flow of fluid from the first side of the actuator to the reservoir when a pressure at the first side of the actuator exceeds a pressure set point,
• wherein the set position is configured to be set by the operator from the cab of the work vehicle, and
• wherein the controller is configured to send a signal to the first proportional relief valve to increase the pressure set point, to thereby permit flow of fluid from the first side of the actuator to the reservoir when the controller determines that the sensed position differs from the set position.

A method of moving a work implement of a work vehicle in response to an impact force, the method comprising:

• setting a first set point pressure at which a first proportional relief valve is configured to open via an operator positioned in the work vehicle;
• setting a second set point pressure at which a second proportional relief valve is configured to open via the operator positioned in the work vehicle;
• monitoring an actuator to detect movement thereof from a first position;
• permitting fluid flow between a first side of the actuator, a reservoir and a pump while the first proportional relief valve is open;
• permitting fluid flow between a second side of the actuator, the reservoir and the pump while the second proportional relief valve is open;
• upon movement of the actuator from the first position, determining if an operator commanded the actuator to move;
• if an operator commanded the actuator to move, detecting a second position of the actuator;
• if an operator did not command the actuator to move, permitting fluid flow to the first side of the actuator from the pump to thereby inhibit movement of the actuator away from the first position;
• monitoring a first side working pressure at the first side of the actuator;
• comparing the first side working pressure to the first set point pressure;
• and
• while the first side working pressure is less than the first set point pressure, opening the first proportional pressure relief valve to permit fluid to flow from the reservoir into the first side of the actuator.

A method of moving a work implement of a work vehicle, the method comprising:

• setting a downward force on the work implement;
• determining a set position of the work implement;
• permitting fluid flow between a first side of an actuator, a reservoir and a pump while a first valve is open;
• permitting fluid flow between a second side of the actuator, the reservoir and the pump while a second valve is open;
• upon movement of the work implement from the set position, determining if the work implement moved upward or downward from the set position;
• if the work implement moved upward from the set position, the controller configured to send a first signal to the first valve and to the second valve to increase the downward force on the work implement to thereby inhibit further upward movement of the work implement;
• and
• if the work implement moved downward from the set position, the controller configured to send a second signal to the first valve and to the second valve to decrease the downward force on the work implement to inhibit further downward movement of the work implement.