Analog signal preprocessor

• US 5,249,138 A
• Filed: 01/07/1991
• Issued: 09/28/1993
• Est. Priority Date: 01/07/1991
• Status: Expired due to Fees

• Current Assignee: CSI Technology Incorporated (Emerson Electric Company)
• Original Assignee: Computational Systems Incorporated (Emerson Electric Company)
• Inventors: Piety, Kenneth R. Jr., Craven, Timothy A., Bowers, Stewart V. III
• Primary Examiner(s): Smith, Jerry
• Assistant Examiner(s): Garland, Steven R.
• Application Number:
  US07/638,747
• Time in Patent Office: 995 Days
• Field of Search: 364/508, 364/807, 364/160, 364/180, 364/132, 364/571.01, 364/497, 364/572, 364/574, 340/679, 340/682, 340/683, 324/77 B, 324/78 F
• US Class Current: 702/57
• CPC Class Codes: G05B 19/4065 Monitoring tool breakage, life or condition
• CPC Class Codes: G05B 2219/37493 Use of different frequency band pass filters to separate different signals
• CPC Class Codes: G05B 2219/37498 Variable amplification, gain for detected signal, select correct level range
• CPC Class Codes: G08C 19/02 in which the signal transmitted is magnitude of current or voltage G08C19/36, G08C19/38 take precedence

Abstract

The specification describes a system for analyzing and processing an input analog signal. This invention provides an analog signal preprocessor which is operated in conjunction with a main instrument for measuring any defects or wear of machinery parts. The analog signal preprocessor operates to preprocess an analog signal by filtering and amplifying a signal from the analog signal to allow a more accurate reading by the main instrument. The preprocessor will adjust itself for optimum operation and communicate the operation modes to the main instrument. Also, the preprocessor can be addressed by the main instrument to setup the operation of the preprocessor according to a program or input entered into the main instrument.

Claims

1. A system for processing and analyzing an input signal comprising:

an analog signal preprocessor for receiving and processing the input signal comprising;

a) at least one processing stage for receiving the input signal and processing the input signal, said processing stage having at least first and second operating modes determinative of the manner in which the input signal is to be processed by said processing stage, said processing stage for producing a first preprocessed signal when operating in said first operating mode and for producing a second preprocessed signal when operating in said second operating mode, said first preprocessed signal being different from said second preprocessed signal; and

b) preprocessor control means connected to said processing stage for monitoring and controlling said processing stage and selecting one of said operating modes of said processing stage to determine the manner in which the input signal is to be processed;

a main instrument for receiving and analyzing an output of said analog signal preprocessor to determine at least one characteristic of said preprocessed signal and for controlling said analog signal preprocessor comprising;

a) input means connected to said analog signal preprocessor for receiving at least one of said first and second preprocessed signals; and

b) master control means for producing at least processing stage control signals;

communication means for providing a communication link between said analog signal preprocessor and said main instrument and for transmitting at least said processing stage control signals from said master control means to said preprocessor control means; and

said preprocessor control means being responsive to said processing stage control signals to select at least one of said first and second operating modes for said processing stage.

2. The system of claim 1 further comprising:

said master control means having means for producing an autorange processing stage control signal; and

said preprocessor control means further responds to said autorange processing stage control signal to independently select at least one of said first and second operating modes.

3. The system of claim 1 further comprising:

monitoring means for monitoring said preprocessed signals, comparing said preprocessed signals to a predetermined limit, and producing predetermined limit signals when the predetermined limit is exceeded by said preprocessed signals; and

said preprocessor control means receiving said predetermined limit signals and being responsive to said predetermined limit signals to select at least one of said first and second operating modes.

4. The system of claim 1 further comprising:

said master control means further producing an autorange processor stage control signal and a manual processor stage control signal, said master controller generating at least one of said autorange or manual processor stage control signals depending upon input provided to said master controller and further providing said signal to said preprocessor control means;

monitoring means for monitoring said preprocessed signals, comparing said preprocessed signals to predetermined limits, and producing a limit signal when said preprocessed signals exceed a predetermined limit;

said preprocessor control means for further responding to the limit signal to independently select at least one of said operating modes to adjust said preprocessed signals to remain within said predetermined limits when the autorange processor stage control signal is received from said master control means; and

said preprocessor control means being responsive to said limit signal to generate a limit exceed signal and provide said limit exceed signal to said master control means when said manual processor stage control signal is received from said master control means while remaining in the selected operating mode.

5. A system for processing and analyzing an input signal comprising:

an analog signal preprocessor having a plurality of operating modes comprising;

a) a preamplifier for receiving and preamplifying the analog signal in accordance with a selected gain determined by the operating mode and producing a preamplified analog signal;

b) a filtering stage for receiving the preamplified analog signal, filtering a selected frequency range from the preamplified signal selected in accordance with a frequency range determined by the operating mode and producing a filtered analog signal;

c) an envelope demodulator for receiving the filtered analog signal, rectifying the filtered analog signal, filtering the filtered analog signal and producing a preprocessed signal, said envelope demodulator either selected or de-selected in accordance with the operating mode; and

d) preprocessor control means for controlling said operating modes of said analog signal preprocessor;

a main instrument for receiving the preprocessed signal and analyzing the preprocessed signal to determine at least one characteristic of said signal, said main instrument having a master control means for controlling the analysis of the preprocessed signal and producing operating control signals;

communication means for providing a communication link between said analog signal preprocessor and said main instrument and for transmitting at least said operating control signals to said preprocessor control means; and

said preprocessor control means receiving the operating control signals and being responsive to the operating control signals to select at least one of said operating modes.

6. The system of claim 5 further comprising monitoring means for monitoring at least one of the operating modes and producing a monitored signal.

7. The system of claim 5 further comprising:

monitoring means for monitoring the preprocessed signal and producing a monitor signal;

said preprocessor control means receiving the monitor signal and being responsive to the monitor signal and the operating control signals to select one of said plurality of operating modes.

8. The system of claim 5 further comprising an amplifier for receiving and amplifying the filtered analog signal and producing an amplified analog signal to be received by said envelope demodulator.

9. The system of claim 8 further comprising:

monitoring means for monitoring the preprocessed signal and at least one of the preamplified analog signal, the filtered analog signal and the amplified analog signal and for producing monitor signals;

said preprocessor control means receiving said monitor signals and being responsive to said monitor signals and the operating control signals to select at least one of said plurality of operating modes.

10. The system of claim 8 further comprising:

monitoring means for monitoring the preamplified analog signal, the filtered analog signal, the amplified analog signal and the preprocessed signal, said monitoring means producing monitor signals; and

said preprocessor control means receiving the monitor signals and being responsive to the monitor signals and the operating control signals to select one of said operating modes said preprocessor control means responsive to said selected operating mode to generate control signals for selecting at least one of the following parameters;

the gain of the preamplifier, the selected frequency range of the filtering stage, the gain of the amplifier, and the selection or de-selection of the envelope demodulator.

11. The system of claim 8 further comprising:

monitoring means for monitoring the preamplified analog signal, the filtered analog signal, the amplified analog signal and the preprocessed signal, and producing predetermined limit signals when a predetermined limit is exceeded by the preamplified analog signal, the filtered analog signal, the amplified analog signal or the preprocessed signal;

said preprocessor control means receiving the predetermined limit signals and being responsive to the predetermined limit signals and the operating control signals to select at least one of said operating modes.

12. The system of claim 8 further comprising:

negative limit detection means for detecting exceeded predetermined negative limit by the preamplified analog signal, the filtered analog signal, the filtered analog signal, the amplified analog signal and the preprocessed signal and the preprocessed signal, said negative limit detection means for producing negative limit signals;

positive limit detection means for detecting an exceeded predetermined positive limit by the preamplified analog signal, the filtered analog signal, the amplified analog signal and the preprocessed signal, said positive limit detection means producing positive limit signals;

said preprocessor control means receiving the negative and positive limit signals and being responsive to the negative and positive limit signals and the operating control signals to select one of said operating modes.

13. The system of claim 8 wherein said preamplifier comprises a selective gain amplifier being controlled by said preprocessor control means.

14. The system of claim 8 wherein said amplifier comprises selective gain amplifier being controlled by said preprocessor control means.