Net-displacement control of fluid device

摘要

Methods for controlling the net-displacement of a rotary fluid pressure device are disclosed. One of the net-displacement control methods (47) includes obtaining a desired input parameter (23) and a relative position (21) of a first member (43) and a second member (35) of a fluid displacement mechanism. A determination of a first and second output value is then made for each of a plurality of volume chambers (45) when the volume chambers (45) are supplied with fluid at fluid inlet and fluid outlet conditions, respectively. A total output value is then computed for each of a plurality of control valve configurations (63) and compared to the desired input parameter (23). The control valve configuration (63) with the total output value most similar to the desired input parameter (23) is then selected. A plurality of control valves (15) are then actuated in accordance with the selected control valve configuration (63).

主权项

1. A method for controlling the net-displacement of a fluid device, the method comprising:
obtaining a desired input parameter; determining a relative position of a first member and a second member of a fluid displacement assembly, wherein the first member and the second member have relative movement and define a plurality of volume chambers that expand or contract in response to the relative movement; determining a first output value for each of the plurality of volume chambers, with the first output value being based on the relative position and each of the plurality of volume chambers being supplied with fluid at a first fluid pressure; determining a second output value for each of the plurality of volume chambers, with the second output value being based on the relative position and each of the plurality of volume chambers being supplied with fluid at a second fluid pressure; calculating a total output value for each of a plurality of control valve configurations; selecting one of the control valve configurations where the total output value of the control valve configuration most closely equals the desired input parameter; and actuating a plurality of control valves in accordance with said selected control valve configuration, wherein the plurality of control valves are in fluid communication with the plurality of volume chambers.