Control system for integrating a work attachment to a work vehicle

An apparatus for controlling a fluid system of a work vehicle having an engine, at least one fluid circuit having a pump driven by the engine, a plurality of control valves for controllably passing fluid from the pump to a plurality of respective work elements, said control valves having movable valve stems, and a plurality of operator control elements, the apparatus comprising:

• a work attachment having a respective control valve, said work attachment control valve being connected to said fluid system, said work attachment being removably attached to said work vehicle and adapted to perform a specific work function;
• means for providing demand signals in response to selected settings of each respective operator control elements, each demand signal being indicative of a requested fluid flow to one of a respective work element and a respective work attachment;
• memory means for storing select parameters of said fluid system, one of the select parameters being a predetermined priority value representing the order in which fluid is delivered from the pump to the control valve of said work attachment;
• means for providing a plurality of work mode signals, each work mode signal representing a predetermined electrohydraulic circuit arrangement associated with the control valves of the work elements;
• means for receiving the work mode signal, determining the sequence in which fluid is distributed from the pump to the control valves associated with the predetermined electrohydraulic circuit arrangement in response to receiving the work mode signal, and responsively assigning a priority value to each control valve associated with the predetermined electrohydraulic circuit arrangement;
• means for receiving the predetermined priority value of said work attachment, responsively redetermining the sequence in which fluid is distributed from the pump to the control valves associated with the predetermined electrohydraulic circuit arrangement, and reassigning the priority values of the control valves associated with the predetermined electrohydraulic circuit arrangement in response to the redetermined sequence;
• and
• means for receiving the demand signals, determining the total requested flow rates of the respective control valves in response to the demand signals, comparing the total requested flow rates of the respective control valves to the maximum flow capacity of the fluid system, calculating the valve stem displacements of the respective control valves in response to the demand signals, modifying the calculated valve stem displacements to limit the requested fluid flow to the lower priority control valves when the calculated valve stem displacement of the highest priority control valve yields less than the required fluid flow, delivering control signals to the respective control valves in response to the modified calculated valve stem displacements, and selectively positioning the stems of the respective control valves.