Simulation modeling of non-linear hydraulic actuator response

A method for modeling the response of a plurality of movable components to a commanded position, the movable components being operably connected to corresponding hydraulic actuators, the hydraulic actuators being driven by a common hydraulic pump supplying pressurized fluid to the actuators through a control valve in each actuator, each control valve having a spool for controlling the flow of fluid to the actuator, the method comprising the steps of:

• (a) calculating a spool position command for each actuator based on the difference between the desired position of the movable component and the actual position of the movable component;
• (b) measuring the force on each actuator due to the force of the hydraulic fluid;
• and
• (c) using the spool position commands and the forces on the actuators as indices into tables containing data on the rate of response of each hydraulic actuator for a range of values of at least one measured variable.

An apparatus for determining the response of at least one movable component to a commanded position, the at least one movable component being operably connected to a hydraulic actuator, the apparatus comprising:

• a hydraulic pump supplying pressurized fluid to the actuator through a control valve, the control valve having a spool for controlling the flow of fluid to the actuator;
• a controller operable to calculate a spool position command based on the difference between the desired position of the movable component and the actual position of the movable component;
• means operable to measure the force on the actuator due to the force of the hydraulic fluid;
• and
• a data processor operable to execute a table look-up algorithm using the spool position command and the force on the actuator as indices into a table containing data on the rate of response of the hydraulic actuator for a range of spool position commands and actuator forces.

An apparatus for determining the response of a plurality of movable components, each movable component being operably connected to a corresponding hydraulic actuator, the apparatus comprising:

• a hydraulic pump supplying pressurized fluid to the actuators, each actuator having a control valve with a spool for controlling the flow of the pressurized fluid to the actuator;
• at least one controller operable to calculate a spool position command for each actuator based on the difference between the desired position of the movable component and the actual position of the movable component connected to the actuator;
• means operable to measure the force on each actuator due to the force of the pressurized fluid;
• and
• a data processor operable to execute a table look-up algorithm that uses the spool position commands and the forces on the actuators as indices into at least one table containing data on the rate of response of the hydraulic actuators for a range of spool position commands and actuator forces.