Electrohydraulic implement control system and method

A method of moving a work implement coupled to the boom of a work machine comprising:

• receiving, with a controller, an indication of a direction of upward or downward movement for the boom relative to a mainframe of the work machine to which the boom is coupled;
• detecting, with a sensor coupled to the boom, a velocity and a position of the boom;
• determining a desired work implement velocity based on ratio data that includes boom velocities and corresponding work implement velocities required to maintain the work implement at a constant angle relative to the mainframe during movement of the boom;
• wherein the ratio data includes, for an upward direction of movement of the boom and a downward direction of movement of the boom, boom velocities and corresponding work implement velocities required to maintain the work implement at a constant angle relative to the mainframe during movement of the boom;
• and
• wherein the ratio data for the upward direction of movement of the boom is different than the ratio data for the downward direction of movement of the boom;
• transmitting, from a controller in communication with the sensor, one or more signals causing movement of the work-implement relative to the boom at the desired work implement velocity, which is based on the detected velocity of the boom, the detected position of the boom, and the direction of upward or downward movement for the boom relative to the mainframe.

An open loop control system for a work machine including a mainframe, a boom moveable relative to the mainframe, and a work implement moveable relative to the boom, the open loop control system comprising:

• a boom operator control configured to transmit one or more signals indicative of a boom movement command including a direction of upward or downward movement of the boom relative to the mainframe;
• a boom sensor configured to (i) detect a velocity of the boom and (ii) transmit one or more signals indicative of the detected velocity of the boom;
• a work-implement actuator coupled to the work implement and configured to move the work implement relative to the boom;
• and
• a controller configured to (i) receive one or more signals from the boom sensor, and (ii) transmit one or more signals to the work-implement actuator causing the work-implement actuator to extend or retract at a velocity that maintains the work implement at a constant angle relative to the mainframe during movement of the boom, wherein the one or more signals that the controller is configured to transmit are based on the detected velocity of the boom and the direction of upward or downward movement of the boom relative to the mainframe;
• wherein the controller includes a memory configured to store ratio data that includes boom velocities and corresponding work implement velocities required to maintain the work implement at a constant angle relative to the mainframe during movement of the boom;
• wherein the ratio data includes, for an upward direction of movement of the boom and a downward direction of movement of the boom, boom velocities and corresponding work implement velocities required to maintain the work implement at a constant angle relative to the mainframe during movement of the boom;
• and
• wherein the ratio data for the upward direction of movement of the boom is different than the ratio data for the downward direction of movement of the boom.