US 4,961,441 A · Method and system for controlling a pressure regulator

Abstract

A method and system are provided for controlling a pressure regulator and an electric actuator mechanism for operating the pressure regulator by modifying a generated error signal as a function of at least one correction factor so that the actuator mechanism is controlled as a function of the actual level of regulated control fluid pressure to compensate for varying system operating conditions. A first correction factor is generated as a function of the difference between an actual pressure differential signal and an expected pressure differential signal. A second correction factor is based on the level of a feedback signal which is a function of the actual pressure of the regulated control fluid. An error signal generated by the method and system defines a ramp signal, wherein the shape of the ramp signal is defined by a data matrix of actual pressure differentials. The ramp signal may have a linear, exponential or a constant accelerationdeceleration shape. Preferably, the pressure regulator is a pilot operated pressure regulator and the actuator mechanism includes an up solenoid and a down solenoid.

Claims19

Dependent claims

A method for controlling a pressure regulator and an electric actuator means for operating the pressure regulator to control the pressure of control fluid regulated by the pressure regulator in response to a reference signal, the method comprising the steps of:

generating feedback signals including a first feedback signal as a function of the actual pressure of the regulated control fluid;
generating an error signal based on the difference between the reference signal and the feedback signals, the error signal being representative of a desired amount of control fluid pressure change;
and generating a first control signal as a function of the error signal to control the actuator means, wherein the improvement comprises:
generating an expected pressure differential signal based on the difference between the reference signal and the first feedback signal;
generating a second feedback signal as a function of the pressure of the regulated control fluid in response to the first control signal;
generating an actual pressure differential signal as a function of the difference between the first and second feedback signals;
generating a correction factor based on the difference between the actual pressure differential signal and the expected pressure differential signal;
modifying the error signal as a function of the correction factor;
storing the correction factor;
and
generating a second control signal as a function of the modified error signal to control the actuator means as a function of the actual level of regulated control fluid pressure to compensate for varying system operating conditions.

8 more elements

A control system for controlling a pressure regulator to control the pressure of control fluid regulated by the pressure regulator in response to a reference signal, the control system including electric actuator means adapted to be coupled to the pressure regulator for operating the pressure regulator as a function of control signals, feedback means for generating feedback signals including a first feedback signal as a function of the actual pressure of the regulated control fluid;

means for generating an error signal as a function of the difference between the reference signal and the feedback signals, and control means for generating a control signal as a function of the error signal to control the actuator means, the feedback means generating a second feedback signal as a function of the pressure of the regulated control fluid in response to the control signal;
the error signal being representative of a desired amount of control fluid pressure change, wherein the improvement comprises:
means for generating an expected pressure differential signal based on the difference between the reference signal and the first feedback signal;
means for generating an actual pressure differential signal as a function of the difference between the first and second feedback signals;
means for generating a correction factor based on the difference between the actual pressure differential signal and the expected pressure differential signal;
means for storing the correction factor;
and
error signal modifying means for modifying the error signal as a function of the correction factor, the control means generating a second control signal as a function of the modified error signal to control the actuator means as a function of the actual level of control fluid pressure to compensate for varying system operating conditions.

5 more elements

Dependencies are inferred from the claim text.

Method and system for controlling a pressure regulator

Life of this patent

Method and system for controlling a pressure regulator

Life of this patent

Abstract

Claims19