Non-intrusive tachometer for spark ignition autos
First Claim
1. Apparatus for measuring the operational rate in revolutions per minute (RPM) of an internal combustion engine having a spark ignition system including a plurality of spark plugs, the spark ignition system radiating electromagnetic energy signals upon spark electrical discharges, the radiated electromagnetic energy signals corresponding to changing electrical current circulating in the conductive paths in the engine, said apparatus comprising:
- detection means, for sensing the electromagnetic energy signals radiating from the engine, and for providing in response thereto sensed spark signals indicative thereof;
probe signal processing means, responsive to said sensed spark signals, for providing a pulse signal having pulses indicative of said sensed spark signals;
second signal processing means, responsive to said pulse signal for determining therefrom a time between firings of the spark plugs and for providing a fundamental time signal indicative thereof, for determining actual engine RPM from said fundamental time signal and for providing a calculated engine RPM signal indicative thereof; and
display means, for displaying visually the value of said calculated actual engine RPM signal; and
keypad means for providing desired operator input signals to said second signal processing means;
said detection means, said probe signal processing means, said second signal processing means, and said display means being integrated together within a hand-held probe assembly, whereby said hand-held probe assembly comprises a complete device independent of any connections to external equipment and operable to measure and indicate the actual engine RPM.
19 Assignments
0 Petitions
Accused Products
Abstract
An non-intrusive tachometer for measuring engine RPM includes a hand-held probe having an antenna for sensing radio frequency electromagnetic signals radiated from an operative spark ignition engine. The probe includes means for providing a pulse signal indicative of plug firing events to signal processing means which executes a statistical algorithm to determine the time between spark plug firings and engine RPM. A visual display displays engine RPM. Automatic gain contol means provides the pulse signal with a relatively constant amplitude by compensating for the inherently wide variation in amplitude of the electromagnetic signals among different automobile ignition systems. The signal processing means and display are located separate from the probe in an emissions testing system, or the signal processing means and display are integrated within the probe.
27 Citations
39 Claims
-
1. Apparatus for measuring the operational rate in revolutions per minute (RPM) of an internal combustion engine having a spark ignition system including a plurality of spark plugs, the spark ignition system radiating electromagnetic energy signals upon spark electrical discharges, the radiated electromagnetic energy signals corresponding to changing electrical current circulating in the conductive paths in the engine, said apparatus comprising:
-
detection means, for sensing the electromagnetic energy signals radiating from the engine, and for providing in response thereto sensed spark signals indicative thereof; probe signal processing means, responsive to said sensed spark signals, for providing a pulse signal having pulses indicative of said sensed spark signals; second signal processing means, responsive to said pulse signal for determining therefrom a time between firings of the spark plugs and for providing a fundamental time signal indicative thereof, for determining actual engine RPM from said fundamental time signal and for providing a calculated engine RPM signal indicative thereof; and display means, for displaying visually the value of said calculated actual engine RPM signal; and
keypad means for providing desired operator input signals to said second signal processing means;said detection means, said probe signal processing means, said second signal processing means, and said display means being integrated together within a hand-held probe assembly, whereby said hand-held probe assembly comprises a complete device independent of any connections to external equipment and operable to measure and indicate the actual engine RPM.
-
-
2. Apparatus for measuring the operational rate in revolutions per minute (RPM) of an internal combustion engine having a spark ignition system including a plurality of spark plugs, the spark ignition system radiating electromagnetic energy signals upon spark electrical discharges, the radiated electromagnetic energy signals corresponding to changing electrical current circulating in the conductive paths in the engine, said apparatus comprising:
-
detection means, for sensing the electromagnetic energy signals radiating from the engine in a frequency range of from 1 MHZ to 10 MHZ, and for providing in response thereto sensed spark signals indicative thereof; probe signal processing means, responsive to said sensed spark signals, for providing a pulse signal having pulses indicative of said sensed spark signals; second signal processing means, responsive to said pulse signal for determining therefrom a time between firings of the spark plugs and for providing a fundamental time signal indicative thereof, for determining actual engine RPM from said fundamental time signal and for providing a calculated actual engine RPM signal indicative thereof; and display means, for displaying visually the value of said calculated actual engine RPM signal. - View Dependent Claims (3, 4, 5)
-
-
6. Apparatus for measuring the operational rate in revolutions per minute (RPM) of an internal combustion engine having a spark ignition system including a plurality of spark plugs, the spark ignition system radiating electromagnetic energy signals upon spark electrical discharges, the radiated electromagnetic energy signals corresponding to changing electrical current circulating in the conductive paths in the engine, said apparatus comprising:
-
detection means, for sensing the electromagnetic energy signals radiating from the engine, and for providing in response thereto sensed spark signals indicative thereof; probe signal processing means, responsive to said sensed spark signals, for providing a pulse signal having pulses indicative of said sensed spark signals; second signal processing means, responsive to said pulse signal for determining therefrom a time between firings of the spark plugs and for providing a fundamental time signal indicative thereof, for determining actual engine RPM from said fundamental time signal and for providing a calculated actual engine RPM signal indicative thereof; and display means, for displaying visually the value of said calculated actual engine RPM signal; said second signal processing means and said display means being disposed to be located apart from said detection means and said probe signal processing means, said detection means and said probe signaling processing means being integrated together within a hand-held probe assembly, said second signal processing means and said display means being integrated within a vehicle emissions testing system assembly, said vehicle emissions testing system operable for measuring the actual concentration value of each of one or more predetermined vehicle emissions gases emitted by an operative internal combustion engine. - View Dependent Claims (7)
-
-
8. Apparatus for measuring the operational rate in revolutions per minute (RPM) of an internal combustion engine having a spark ignition system including a plurality of spark plugs, the spark ignition system radiating electromagnetic energy signals upon spark electrical discharges, the radiated electromagnetic energy signals corresponding to changing electrical current circulating in the conductive paths in the engine, said apparatus comprising:
-
detection means, for sensing the electromagnetic energy signals radiating from the engine, and for providing in response thereto sensed spark signals indicative thereof; probe signal processing means, responsive to said sensed spark signals, for providing a pulse signal having pulses indicative of said sensed spark signals; second signal processing means, responsive to said pulse signal for determining therefrom a time between firings of the spark plugs and for providing a fundamental time signal indicative thereof, for determining actual engine RPM from said fundamental time signal and for providing a calculated actual engine RPM signal indicative thereof, and for providing an amplitude signal indicative of the ability of said sensed spark signals to accurately indicated valid firings of the spark plugs; and display means, for displaying visually the value of said calculated actual engine RPM signal. - View Dependent Claims (9, 10, 11, 12)
-
-
13. Apparatus for measuring the operational rate in revolutions per minute (RPM) of an internal combustion engine having a spark ignition system including a plurality of spark plugs, the spark ignition system radiating electromagnetic energy signals upon spark electrical discharges, the radiated electromagnetic energy signals corresponding to changing electrical current circulating in the conductive paths in the engine, said apparatus comprising:
-
detection means, for sensing the electromagnetic energy signals radiating from the engine in a frequency range of from 1 MHZ to 10 MHZ, and for providing in response thereto sensed spark signals indicative thereof; probe signal processing means, responsive to said sensed spark signals, for providing a pulse signal having pulses indicative of said sensed spark signals; second signal processing means, responsive to said pulse signal for determining therefrom a time between firings of the spark plugs and for providing a fundamental time signal indicative thereof, for determining actual engine RPM from said fundamental time signal and for providing a calculated actual engine RPM signal indicative thereof, for determining said time between firings as the time between successive pulses of said pulse signal, for developing a time signal having a magnitude indicative of said determined time between plug firings, for collecting a plurality of successive ones of said time signals as developed over time, for ordering said plurality of time signals in magnitude from smallest to largest, for sorting said ordered time samples into one or more bins, each bin having upper and lower boundary criteria based on a range of magnitude of time that any one of said time samples may lie within, for averaging the time value of the resulting one or more of said bins, whereby, if a single bin results as a result of said sorting of said ordered time samples, said fundamental time signal equals the average time value of said single bin, and for determining said fundamental time signal if a plurality of bins result from said sorting of said ordered time samples; and display means, for displaying visually the value of said calculated actual engine RPM signal. - View Dependent Claims (14, 15, 16, 17, 18)
-
-
19. A non-intrusive hand-held tachometer for measuring the operational rate in revolutions per minute (RPM) of an internal combustion engine having a spark ignition system including a plurality of spark plugs, the spark ignition system radiating electromagnetic energy signals upon spark electrical discharges, the radiated electromagnetic energy signals corresponding to changing electrical current circulating in the conductive paths in the engine, said tachometer comprising:
-
detection means, for sensing the electromagnetic energy signals radiating from the engine, and for providing sensed spark signals indicative thereof; signal processing means, responsive to said sensed spark signals, for providing a pulse signal in response to each of said sensed spark signals having an amplitude in excess of a predetermined threshold, for determining from said pulse signal the time between firings of the spark plugs and for providing time signals indicative thereof;
determining actual engine RPM from said time signals and for providing a calculated engine RPM signal indicative thereof, for providing an amplitude signal responsive to said pulse signal indicative of the ability of said sensed spark signals to accurately indicate valid firings of the spark plugs; anddisplay means, for displaying visually the value of said calculated engine RPM signal. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
-
-
31. A method for measuring the operational rate in revolutions per minute (RPM) of an internal combustion engine having a spark ignition system including a plurality of spark plugs, the spark ignition system radiating electromagnetic energy upon spark electrical discharges, the electromagnetic energy signals being radiated corresponding to changing electrical current circulating in the conductive paths in the engine, said method comprising:
-
sensing the electromagnetic energy signals radiating from the engine; generating sensed spark signals indicative of the sensed electromagnetic energy signals radiating from the engine; developing, in response to each of said sensed spark signals, a pulse signal having pulses indicative of said sensed spark signals; developing from said pulse signal a fundamental time signal indicative of a time between firings of the spark plugs; and determining actual engine RPM from said fundamental time signal; said fundamental time signal step comprising the steps of; determining from said pulse signal the time between firings of the spark plugs as the time between successive pulses of said pulse signal; developing a time signal having a magnitude indicative of said determined time between firings of the spark plugs; collecting a plurality of successive ones of said time signals as developed over time; ordering said plurality of time signals in magnitude from smallest to largest; sorting said ordered time samples into one or more bins, each bin having upper and lower boundary criteria based on a range of magnitude of time that any one of said time samples may lie within; averaging the time value of each resulting one of said one or more of said bins; equating said fundamental time signal to said averaged time value of a resulting single bin if, as a result of said sorting of said ordered time samples, a single bin results; and determining the value of said fundamental time signal when a plurality of bins result form said sorting of said ordered time samples. - View Dependent Claims (32, 33, 34, 35, 36, 37, 38, 39)
-
Specification