Feed-Forward High Resolution Sensor Measurement Using Low Resolution ADC

• US 20200136634A1
• Filed: 10/29/2019
• Published: 04/30/2020
• Est. Priority Date: 10/29/2018
• Status: Active Grant

• Current Assignee: The Government Of The United States Of America, As Represented By The Secretary Of The Navy
• Original Assignee: The Government Of The United States Of America, As Represented By The Secretary Of The Navy
• Inventors: Dixon, Ray
• Granted Patent: US 10,873,340 B2
• Time in Patent Office: Days
• CPC Class Codes: H03M 1/00 Analogue/digital conversion; Digital/analogue conversion conversion of analogue values to or from differential modulation H03M3/00
• CPC Class Codes: H03M 1/06 Continuously compensating for, or preventing, undesired influence of physical parameters periodically, e.g. by using stored correction values, H03M1/10
• CPC Class Codes: H03M 1/1071 Measuring or testing
• CPC Class Codes: H03M 1/12 Analogue/digital converters H03M1/001 – H03M1/10 take precedence
• CPC Class Codes: H03M 1/48 Servo-type converters
• CPC Class Codes: H03M 1/68 with conversions of different sensitivity, i.e. one conversion relating to the more significant digital bits and another conversion to the less significant bits

Abstract

According to one aspect of the invention, a method for making relatively high resolution measurements using relatively low resolution devices includes the steps of: deriving a first anticipated measurement value; using the first anticipated measurement value as an initial feed-forward signal; comparing the initial feed forward signal to a received signal from a sensor, thereby generating a compared signal; scaling the compared signal to full scale of an analog-to-digital converter, thereby generating a scaled signal; delivering the scaled signal in binary form for computation; and iteratively performing the comparing step until the compared signal is below a predetermined threshold value.

Claims

1. A method for making relatively high resolution measurements using relatively low resolution devices, the method including the steps of:

deriving a first anticipated measurement value;

using the first anticipated measurement value as an initial feed-forward signal;

comparing the initial feed forward signal to a received signal from a sensor, thereby generating a compared signal;

scaling the compared signal to full scale of an analog-to-digital converter, thereby generating a scaled signal;

delivering the scaled signal in binary form for computation; and

iteratively performing the comparing step until the compared signal is below a predetermined threshold value.

2. The method of claim 1, wherein the step of deriving a first anticipated measurement value includes obtaining an absolute accuracy measurement and operational characteristics of the sensor.

3. The method of claim 1, wherein the step of using the first anticipated measurement value includes two digital-to-analog converters (DACs) driving a “

Coarse” and

“

Fine”

signal into a summing amplifier.

4. The method of claim 1, further comprising:

shifting the scaled signal.

5. The method of claim 1, wherein the feed-forward signal is derived in a processor

6. The method of claim 1, wherein the feed-forward signal is derived in a field-programmable gate array (FPGA).

7. The method of claim 3, wherein the “

Coarse”

signal is preferably scaled to the full range of a sensor feedback output signal.