Engine deficiency indicator

• US 4,627,275 A
• Filed: 05/07/1984
• Issued: 12/09/1986
• Est. Priority Date: 05/07/1984
• Status: Expired due to Fees

• Current Assignee: Wayne State University
• Original Assignee: Wayne State University
• Inventors: Henein, Naeim A., Sood, Arun K.
• Primary Examiner(s): MYRACLE, JERRY
• Application Number:
  US06/607,570
• Time in Patent Office: 946 Days
• Field of Search: 73/117.3, 73/112, 73/116, 364/551
• US Class Current: 73/114.26
• CPC Class Codes: F02D 2041/288 for performing a transformation into the frequency domain, e.g. Fourier transformation
• CPC Class Codes: F02D 41/0097 using means for generating speed signals
• CPC Class Codes: G01P 3/489 Digital circuits therefor

Abstract

An engine deficiency indicator includes a detector for detecting a pre-determined amount of angular rotation of an engine. The detector generates a first signal upon the start of one period of rotation of the engine which enables a counter for counting clock pulses. A second signal from the sensor, indicative of the completion of the pre-determined amount of angular rotation of the engine, disables the counter. A processing unit reads and stores the counter data in a memory. The counter data corresponds to the time required for the engine to rotate through a pre-determined amount of angular rotation. At the completion of a pre-determined number of engine rotational cycles, the processing unit analyzes the stored time sequence signals using a discrete Fourier transform analysis and/or an autocorrelation analysis to generate a manifestation of deficient engine operation. A display connected to the processing unit provides a visual or audible indication of efficient or deficient engine operation.

Claims

1. An apparatus for indicating deficient engine operation comprising:

means for continuously detecting a pre-determined amount of angular rotation of a rotatable component of an engine;

means, responsive to the detecting means, for continuously determining the time period of each pre-determined amount of engine rotation;

processing means, responsive to the determining means, for continuously generating a manifestation of engine efficiency and deficiency based on each time period; and

display means, responsive to the processing means, for continuously indicating the efficiency or deficiency of engine operation.

2. The apparatus of claim 1 wherein the detecting means comprises:

means for detecting a pre-determined amount of angular rotation of a rotatable component of the engine.

3. The apparatus of claim 2 wherein:

the rotatable engine component is the engine flywheel having a plurality of circumferentially spaced gear teeth; and

the detecting means detects the passage of each flywheel gear tooth past the detecting means.

4. The apparatus of claim 1 wherein the determining means comprises:

a counter having an input; and

a clock, the clock connected to the input of the counter;

the output of the detecting means enables the counter once for each pre-determined amount of engine rotation, the counter storing a count equivalent to the time period of each pre-determined amount of engine rotation.

5. The apparatus of claim 4 wherein the processing means includes;

first stored program means for computing the time period of each pre-determined amount of engine rotation.

6. The apparatus of claim 5 wherein the processing means includes;

second stored program means for computing a manifestation of efficient or deficient engine operation, the processing means activating the display means upon computing a manifestation of efficient or deficient engine operation.

7. An apparatus

for indicating deficient engine operation comprising:

means for continuously detecting a predetermined amount of angular rotation of an engine;

means responsive to the detecting means, for continuously determining the time period of each pre-determined amount of engine rotation, the determining means including;

a counter having an input; and

a clock, the clock connected to the input of the counter;

the output of the detecting means enables the counter once for each pre-determined amount of engine rotation, the counter storing a count equivalent to the time period of each pre-determined amount of engine rotation;

processing means, responsive to the determining means, for continuously generating a manifestation of engine efficiency and deficiency, the processing means including first stored program means for computing the time period of each pre-determined amount of engine rotation and second stored program means for computing a manifestation of efficient or deficient engine operation, the processing means activating the display means upon computing a manifestation of efficient or deficient engine operation; and

the second stored program computing the discrete Fourier transform of the time periods, display means reponsive to the processing means, for continuously indicating the efficiency or deficiency of engine operation.

8. An apparatus

for indicating deficient engine operation comprising:

means for continuously detecting a predetermined amount of angular rotation of an engine;

means responsive to the detecting means, for continuously determining the time period of each pre-determined amount of engine rotation, the determining means including;

a counter having an input; and

a clock, the clock connected to the input of the counter;

the output of the detecting means enables the counter once for each pre-determined amount of engine rotation, the counter storing a count equivalent to the time period of each pre-determined amount of engine rotation;

processing means, responsive to the determining means, for continuously generating a manifestation of engine efficiency and deficiency, the processing means including first stored program means for computing the time period of each pre-determined amount of engine rotation and second stored program means of computing a manifestation of efficient or deficient engine operation, the processing means activating the display means upon computing a manifestation of efficient or deficient engine operation; and

the second stored program computing the auto-correlation of the time periods, display means responsive to the processing means, for continuously indicating the efficiency or deficiency of engine operation.

9. An apparatus for indicating deficient engine operation comprising:

means for continuously detecting a predetermined amount of angular rotation of an engine;

means responsive to the detecting means, for continuously determining the time period of each pre-determined amount of engine rotation, the determining means including;

a counter having an input; and

a clock, the clock connected to the input of the counter;

the output of the detecting means enables the counter once for each pre-determined amount of engine rotation, the counter storing a count equivalent to the time period of each pre-determined amount of engine rotation;

processing means, responsive to the determining means, for continuously generating a manifestation of engine efficiency and deficiency, the processing means including first stored program means for computing the time period of each pre-determined amount of engine rotation and second stored program means for computing a manifestation of efficient or deficient engine operation, the processing means activating the display means upon computing a manifestation of efficient or deficient engine operation; and

the second stored program computing the discrete Fourier transform and the auto-correlation of the time periods, display means responsive to the processing means, for continuously indicating the efficiency or deficiency of engine operation.

10. A method for determining and indicating deficient engine operation comprising the steps of:

continuously detecting a pre-determined amount of angular rotation of an engine;

continuously determining the time period of each pre-determined amount of engine rotation;

mathematically processing the time period of each pre-determined amount of engine rotation based on each time period;

continuously generating a manifestation of efficiency and deficiency of the engine; and

continuously indicating the efficiency and deficiency caused by the occurrence of a fault in the engine operation.

11. A method for determining and indicating deficient engine operation comprising the steps of:

continuously detecting a pre-determined amount of angular rotation of an engine;

continuously determining the time period of each pre-determined amount of engine rotation;

mathematically processing the time period of each pre-determined amount of engine rotation including

calculating the discrete Fourier transform of the time periods for each pre-determined amount of engine rotation according to;

##EQU3## continuously generating a manifestation of efficiency and deficiency of the engine; and

continuously indicating the efficiency and deficiency caused by the occurrence of a fault in the engine operation.

12. The method claim 11 further including the steps of performing a ratio test according to R=x(l)/x(n) on the discrete Fourier transform values.

13. The mehtod of claim 11 further including the step of calculating a difference test according to D=X(l)-X(n) on the discrete Fourier transform values.

14. A method for determining and indicating deficient engine operation comprising the steps of:

continuously detecting a pre-determined amount of angular rotation of an engine;

continuously determining the time period of each pre-determined amount of engine rotation;

mathematically processing the time period of each pre-determined amount of engine rotation, including the step of calculating an auto-correlation according to;

##EQU4## where N is the number of samples in an engine cycle and MEAN and VAR are the mean and variance of samples equal to, respectively;

##EQU5## continuously generating a manifestation of engine efficiency and deficiency; and

continuously indicating the efficiency and deficiency caused by the occurrence of a fault in the engine operation.