A downforce control system for an agricultural ground engaging unit provides individual control of each agricultural ground engaging row unit by providing a proportional pressure control valve connected to the retracting chamber of a double acting cylinder which varies the upward force produced by the retracting chamber of the cylinder against a constant counteracting downward force produced by an extending chamber of the cylinder, the valve control based on a comparison of a sensed resultant downward force on the agricultural ground engaging row unit and a predetermined target downward force.

A tractor includes: a three-point linkage to which a tiller is mountable a hydraulic lifting/lowering driver to lift and lower the three-point linkage, and a mechanical linkage to transmit a lifting/lowering operation amount of the three-point linkage to the lifting/lowering driver. The mechanical linkage includes a load detector to detect an amount of change in traction load via the three-point linkage, a cable to interlock according to the amount of change in the traction load detected by the load detector, and a mechanical linkage interlocked and connected to the cable and the lifting/lowering driver, the mechanical linkage being capable of transmitting the lifting/lowering operation amount according to the amount of change in the traction load to the lifting/lowering driver.

A tractor includes: a three-point linkage to which a tiller is mountable a hydraulic lifting/lowering driver to lift and lower the three-point linkage, and a mechanical linkage to transmit a lifting/lowering operation amount of the three-point linkage to the lifting/lowering driver. The mechanical linkage includes a load detector to detect an amount of change in traction load via the three-point linkage, a cable to interlock according to the amount of change in the traction load detected by the load detector, and a mechanical linkage interlocked and connected to the cable and the lifting/lowering driver, the mechanical linkage being capable of transmitting the lifting/lowering operation amount according to the amount of change in the traction load to the lifting/lowering driver.

A system measures the roughness of the ground surface over which an agricultural implement passes as measured in the direction of travel. The system includes at least one ground sensor attached to the agricultural implement that provides measurement of the distance to the ground. A controller is connected to the at least one ground sensor, and controls at least one adjustment of the agricultural implement. The at least one ground sensor provides instantaneous output based on the distance to the ground to the controller. The controller then calculates at least one statistical parameter from the instantaneous output. The at least one statistical parameter is calculated from variations in the distance to the ground in the direction of travel of the agricultural implement.

A working vehicle includes: a vehicle body; a lifting device provided on the vehicle body; a first setting member to set a reference position in a height direction of the working device coupled to the lifting device; a lifting operation member to be operated to raise and lower the lifting device; a first lifting control unit to perform reference lifting control to raise or lower the lifting device so that the working device is located at the reference position; and a second lifting control unit to stop the reference lifting control when the lifting operation member is operated during work by the working device and to raise or lower the lifting device in response to the operation of the lifting operation member. The first lifting control unit performs control to return the lifting device to a position corresponding to the reference position when the operation of the lifting operation member is released after the reference lifting control is stopped.

A working vehicle includes: a vehicle body; a lifting device provided on the vehicle body; a first setting member to set a reference position in a height direction of the working device coupled to the lifting device; a lifting operation member to be operated to raise and lower the lifting device; a first lifting control unit to perform reference lifting control to raise or lower the lifting device so that the working device is located at the reference position; and a second lifting control unit to stop the reference lifting control when the lifting operation member is operated during work by the working device and to raise or lower the lifting device in response to the operation of the lifting operation member. The first lifting control unit performs control to return the lifting device to a position corresponding to the reference position when the operation of the lifting operation member is released after the reference lifting control is stopped.

A downforce control system for an agricultural ground engaging unit provides individual control of each agricultural ground engaging row unit by providing a proportional pressure control valve connected to the retracting chamber of a double acting cylinder which varies the upward force produced by the retracting chamber of the cylinder against a constant counteracting downward force produced by an extending chamber of the cylinder, the valve control based on a comparison of a sensed resultant downward force on the agricultural ground engaging row unit and a predetermined target downward force.

A downforce control system for an agricultural ground engaging unit provides individual control of each agricultural ground engaging row unit by providing a proportional pressure control valve connected to the retracting chamber of a double acting cylinder which varies the upward force produced by the retracting chamber of the cylinder against a constant counteracting downward force produced by an extending chamber of the cylinder, the valve control based on a comparison of a sensed resultant downward force on the agricultural ground engaging row unit and a predetermined target downward force.

An agricultural machine includes a frame member; a toolbar coupled to the frame member parallel to the frame member; a row unit coupled to the toolbar; and an actuator coupled between the frame member and the toolbar, the actuator configured to rotate the toolbar based on a sensed position of the toolbar. Related methods are also disclosed.

An agricultural machine includes a frame member; a toolbar coupled to the frame member parallel to the frame member; a row unit coupled to the toolbar; and an actuator coupled between the frame member and the toolbar, the actuator configured to rotate the toolbar based on a sensed position of the toolbar. Related methods are also disclosed.