H-infinity controller for an electro-mechanical actuator

Claim 2

A single-input single-output control system, comprising: (a) an H-infinity controller having an input for receiving a command input signal and an output for producing an output signal; (b) an electro-mechanical (E-M) actuator connected in series with said H-infinity controller and having an input for receiving said output signal from said H-infinity controller and an output for producing an output signal representative of an action taken by said E-M actuator; (c) a feedback loop connected in series with said E-M actuator and said H-infinity controller for transferring said output signal of said E-M actuator to said input of said H-infinity controller for combining with said command input signal and inputting an error input signal to said H-infinity controller; and (d) said H-infinity controller performing a time-related sequence of samples and continuously holding a predetermined number of most recent ones of said samples and modifying said samples by applying predetermined constants thereto to derive said error signal outputted to said E-M actuator in order to improve the stability of said E-M actuator.

Claim 3

The system of claim 1 further comprising a digital-to-analog (D/A) converter interposed in series between said H-infinity controller and said E-M actuator.

Claim 4

The system of claim 1 further comprising an analog-to-digital (A/D) converter interposed in said feedback loop in series between said E-M actuator and said H-infinity controller.

Claim 5

The system of claim 1 wherein said H-infinity controller operates in accordance with a nth order transfer function as follows: ##EQU2## where each z -1 represents a time delay of one predetermined sample period, and coefficients a and b are H-infinity coefficients for said E-M actuator, said E-M actuator having predetermined specification boundaries for robustness and performance.

Claim 6

A single-input single-output control system, comprising: (a) an H-infinity controller having an input for receiving an command input signal and an output for producing an output signal; (b) an electro-mechanical (E-M) actuator connected in series with said H-infinity controller and having an input for receiving said output signal from said H-infinity controller and an output for producing an output signal representative of an action taken by said E-M actuator; (c) a digital-to-analog (D/A) converter interposed in series between said H-infinity controller and said E-M actuator; (d) a negative unity feedback loop connected in series with said E-M actuator and said H-infinity controller for transferring said output signal of said E-M actuator to said input of said H-infinity controller for combining with said command input signal and inputting an error input signal to said H-infinity controller; (e) an analog-to-digital (A/D) converter interposed in said negative unity feedback loop in series between said E-M actuator and said H-infinity controller; and (f) said H-infinity controller performing a time-related sequence of samples and continuously holding a predetermined number of most recent ones of said samples and modifying said samples by applying predetermined constants thereto to derive said error signal outputted to said E-M actuator in order to improve the stability of said E-M actuator.

Claim 7

A single-input single-output control system, comprising: (a) an H-infinity controller having an input for receiving an command input signal and an output for producing an output signal; (b) an electro-mechanical (E-M) actuator connected in series with said H-infinity controller and having an input for receiving said output signal from said H-infinity controller and an output for producing an output signal representative of an action taken by said E-M actuator; (c) a digital-to-analog (D/A) converter interposed in series between said H-infinity controller and said E-M actuator; (d) a negative unity feedback loop connected in series with said E-M actuator and said H-infinity controller for transferring said output signal of said E-M actuator to said input of said H-infinity controller for combining with said command input signal and inputting an error input signal to said H-infinity controller; (e) an analog-to-digital (A/D) converter interposed in said negative unity feedback loop in series between said E-M actuator and said H-infinity controller; and (f) said H-infinity controller performing a time-related sequence of samples and continuously holding a predetermined number of most recent ones of said samples and modifying said samples by applying predetermined constants thereto to derive said error signal outputted to said E-M actuator in order to improve the stability of said E-M actuator.

Claim 8

The system of claim 5 wherein said H-infinity controller operates in accordance with a nth order transfer function as follows: ##EQU3## where each z -1 represents a time delay of one predetermined sample period.