Patent ID: 6282891
Filing Date: 2001-09-04
Classification: F15B

Abstract:
A method for controlling fluid flow from a hydraulic fluid supply (28) via a single hydraulic pump (22) in an electrohydraulic system having multiple hydraulic cylinders (12) each connected to the hydraulic pump (22) and a corresponding work implement (14), wherein each of the cylinders (12) have at least two hydraulic circuits (16,18) for receiving the fluid supply (28) and moving the cylinders (12), the method comprising:determining a scaling factor (50) for each of the hydraulic circuits (16,18) for compensating the hydraulic circuit (16,18) for receiving less than maximum fluid flow from the pump (22) wherein the determination of the scaling factor includes averaging of fluid flows at selected input conditions for each of the hydraulic circuits (16,18) to account for hysteresis associated with the hydraulic circuit (16,18);receiving an input signal (62) representative of a desired amount of movement of at least two of the work implements (14);determining a desired percentage of fluid flow (66) to each of the hydraulic circuits (16,18) associated with each of the cylinders (12) based on the desired amount of movement of the work implements (14) and the scaling factor of the corresponding hydraulic circuits (16,18); andcontrolling the amount of fluid flow (68) from the hydraulic fluid supply (28) to each of the hydraulic circuits (16,18) based on the corresponding desired percentage of fluid flow so as to allow for maximum fluid flow to each of the hydraulic circuits (16,18).