Hydraulic control apparatus

An apparatus for controlling a hydraulic circuit having a plurality of hydraulic actuators, each hydraulic actuator having first and second ends, the apparatus being connected between a source of pressurized hydraulic fluid and the hydraulic actuators, comprising:

• means for controllably providing pressurized hydraulic fluid to the hydraulic actuators, wherein said providing means includes a plurality of respective control valves, each control valve being connected to both the first and second ends of the corresponding hydraulic actuator, wherein each of said control valves includes a signal control element for controlling flow to both the first and second ends of the corresponding hydraulic actuator, wherein said plurality of control valves includes at least one open center control valve and at least one closed center pressure compensated control valve;
• means for producing a mode signal;
• controlling means for receiving said mode signal and responsively producing a plurality of command signals, each command signal corresponding to a respective hydraulic actuator, wherein said command signal corresponding to said at least one open center control valve is determined according to a set of flow characteristics responsive to said mode signal having a first value and according to a second set of flow characteristics responsive to said mode signal having a second value and wherein said command signal corresponding to said at least one closed center pressure compensated valve is determined according to a third set of flow control characteristics responsive to said mode signal having said first value and according to a fourth set of flow control characteristics responsive to said mode signal having said second value.