Velocity profile analyzer

• US 4,341,995 A
• Filed: 05/29/1981
• Issued: 07/27/1982
• Est. Priority Date: 05/29/1981
• Status: Expired due to Term

• Current Assignee: Sola International, Inc. (Carl-Zeiss-Stiftung)
• Original Assignee: American Optical Corporation
• Inventors: Hennick, Robert P.
• Primary Examiner(s): Krawczewicz, Stanley T.
• Application Number:
  US06/268,637
• Time in Patent Office: 424 Days
• Field of Search: 324/161, 328/134, 328/142, 364/565
• US Class Current: 324/161
• CPC Class Codes: G01P 1/127 for acceleration values

Abstract

A velocity profile analyzing device measures the change or non-linearity in the velocity of a system under test, and digitally displays the measured variation. The principle of operation is to determine any velocity differences that occur in relation to an ideal state, and to present via a digital display the difference value. The system derives from a linear encoder a velocity representative signal, which includes a grating output coupled to a first counter, and an index output for simultaneously starting the first counter and a second counter coupled to receive a reference frequency signal. The counter outputs are fed to a digital subtractor which provides a digital difference frequency signal for digital display and recording. The digital display may be scaled to directly indicate velocity difference, which can be analyzed for various cyclic or other perturbations without accommodating the whole range of deviation. This provides simple instrumentation, and both instantaneous and permanent displays of the velocity variations.

Claims

1. An apparatus for measuring the velocity change of a moving mechanical component, including means for generating an encoded electrical signal in accordance with movement of said mechanical component, said encoded electrical signal including an index signal and a velocity representative signal, comprising:

signal processing means coupled to receive said encoded electrical signal, for providing said velocity representative signal at a first output and said index signal at a second output;

first counter means coupled to said signal processing means, said first counter means having a clock input connected to said first output for receiving said velocity representative signal, and a reset input connected to said second output for receiving said index signal, said first counter means having an output;

oscillator means for generating a signal having a predetermined frequency;

second counter means having a clock input coupled to receive said oscillator signal, and a reset input connected to said second output for receiving said index signal, said second counter means having an output;

digital subtractor means having a first input connected to the output of said first counter means, and a second input connected to the output of said second counter means, said digital subtractor means having an output; and

,

digital display means connected to the output of said digital subtractor means for providing a numerical display of the velocity change of the moving mechanical component.

3. An apparatus for measuring velocity change according to either claim 1 or claim 2, further comprising:

adjustment means for setting said oscillator means at said predetermined frequency, said predetermined frequency being set as a function of the velocity of said moving mechanical component.

4. An apparatus for measuring velocity change according to claim 3, wherein said digital display means has a range in accordance with the range of output signals from said digital subtractor means, whereby said digital display is only responsive to change in velocity to numerically display incremental velocity change.

5. An apparatus for measuring velocity change according to claim 4, further comprising:

digital to analog converter means coupled to the output of said digital subtractor, said digital to analog converter means for producing a D.C. signal at an output; and

,

recorder means coupled to the output of said digital to analog converter means for making a record of said D.C. signal.

6. An apparatus for measuring velocity change according to claim 1, further comprising:

remote start means coupled to said signal processing means for gating said encoded electrical signal at the start of a measurement of velocity change.

2. An apparatus for measuring the velocity change of a moving mechanical component, comprising;

means for providing an encoded electrical signal representative of the velocity of said moving mechanical component;

remote start means for producing a start signal at the start of a measurement of velocity change;

signal processing means having first and second inputs coupled to receive said encoded electrical signal and said start signal, respectively, and having first and second outputs, said signal processing means providing said encoded electrical signal at said first output and said start signal at said second output in response to receiving said start signal at said second input;

first counter means coupled to said signal processing means, said first counter means having a clock input connected to said first output for receiving said encoded electrical signal, and a reset input connected to said second output for receiving said start signal, said first counter means having an output;

oscillator means for generating a signal having a predetermined frequency;

second counter means having a clock input coupled to receive said oscillator signal, and a reset input connected to said second output for receiving said start signal, said second counter means having an output;

digital subtractor means having a first input connected to the output of said first counter means, and a second input connected to the output of said second counter means, said digital subtractor means having an output; and

,

digital display means connected to the output of said digital subtractor means for providing a numerical display of the velocity change of the moving mechanical component.

7. An apparatus for measuring the velocity change of a moving object, comprising:

means for generating an encoded electrical signal representative of the velocity of said moving object;

first counter means coupled to receive said encoded electrical signal, and having a digital output representative of said velocity of said moving object;

oscillator means for generating a reference signal representative of a predetermined reference velocity;

second counter means coupled to receive said reference signal, and having a digital output representative of said predetermined reference velocity;

means for starting said first and second counter means simultaneously;

digital subtractor means having first and second inputs coupled to receive the digital outputs of said first and second counter means, respectively; and

,

digital display means for providing a numerical display in accordance wih the digital subtractor means output, whereby there is displayed a measurement of the velocity change of said moving object, from said predetermined reference velocity.

8. An apparatus for measuring velocity change according to claim 7, wherein said means for starting said first and second counter means further comprises means for repeatedly resetting said first and second counter means at the same time, whereby there is sequentially displayed a plurality of measurements of incremental velocity change.

9. An apparatus for measuring velocity change according to claim 8, further comprising:

digital to analog converter means coupled to receive the digital subtractor means output, said digital to analog converter means producing a D.C. output signal; and

,

recorder means for making a record of said D.C. output signal, whereby said recorder means sequentially records a plurality of measurements of incremental velocity change.