| 摘要 |
In a work vehicle that has several hydraulic actuators a system and method for controlling and scaling flow between the actuators includes an electronic controller that is connected to several hand controls that provide a proportional signal indicating how far the operator has moved the hand controls. The controller reads the hand controls and proportionally scales the total available flow to make sure the operator does not demand too much fluid from the hydraulic pump. The controller generates its own flow rate for another actuator, usually, although not necessarily based on one or two of the hand control positions. The hydraulic actuators do not all need to be scaled, however. Some devices may take priority, such as a supply of fluid to a hydraulic motor that drives a tool and need to operate at a constant speed. The controller first insures that the priority devices, if any, get their required amount of flow, then it divides up the remaining flow between the non-priority hydraulic actuators. If the signals from the hand controls and the signal generated by the controller are together greater than the remaining available capacity, the controller divides the remaining flow between the non-priority hydraulic actuators. Especially when the controller is coordinating the motion of the non-priority actuators, such as when they control multibar linkages such as a backhoe, front loader, fork lift, high lift device or similar devices, it is important that each actuator receive it "share" of the remaining flow. For this reason, the controller preferably proportionately scales the flow that has been requested by the operator and that has been generated internally by the controller to preserve the coordinated motion of the linkage, albeit operating at a slower speed than the operator requested. In addition, for actuators that must move more precisely, sensors that better indicate the flow rate to that actuator can be monitored by the controller to trim or fine tune the scaled flow rate for that actuator. This entire process is repeated many times each second.
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