US 5,207,239 A · Variable gain servo assist

Abstract

A variable gain control apparatus for a servo assist system includes a position sensor, a valve, a controller and an actuator. The valve has an actuated member and a variable flow orifice to communicate hydraulic fluid between the high pressure supply line and a reservoir of hydraulic fluid. The position of the actuated member determines the cross sectional area of the variable flow orifice. The position sensor determines the present position of the actuated member. The controller determines a position error between the present position of the actuated member and a varying predetermined position of the actuated member. The actuator in response to the position error actuates the actuated member to eliminate the position error so that assist pressure to the servo assist system is varied as a function of the varying predetermined position.

Claims17

Dependent claims

A variable assist gain control apparatus for a servo assist system comprising:

a valve having an actuated member and a variable flow orifice wherein the position of said actuated member determines the cross sectional area of said orifice, said orifice to communicate hydraulic fluid between a high pressure side of said servo assist system an a low pressure side of said servo assist system, said high pressure side having an operating pressure determined as a function of said area;
and
an actuator responsive to a present state of variable conditions in the environment of said servo assist system to actuate said movable member to a position at which said area of said variable orifice has a dimension to establish said operating pressure substantially at a value preselected to exist upon the occurrence of said present state of said variable conditions.

A variable assist gain control apparatus for a servo assist system comprising:

a valve having an actuated member and a variable flow orifice wherein the position of said actuated member determines the cross sectional area of said orifice, said orifice to communicate hydraulic fluid between a high pressure side of said servo assist system and a low pressure side of said servo assist system, said high pressure side having an operating pressure determined as a function of said area;
an actuator responsive to a position command signal to actuate said movable member;
and
a position controller responsive to an assist gain signal developed as a function of the present state of variable conditions in the environment of said servo assist system and a sensed actuator position electrical signal to develop said position command signal as a function of each of said assist gain signal and said sensed actuator position signal, said position command signal being applied to said actuator to actuate said movable member to a position at which said area of said variable orifice has a dimension to establish said operating pressure substantially at a value preselected to exist upon the occurrence of said present state of said variable conditions.

1 more element

Dependencies are inferred from the claim text.

Variable gain servo assist

Life of this patent

Variable gain servo assist

Life of this patent

Abstract

Claims17