Method for determining octane ratings of fuels under road conditions

Claim 1

A device for producing a substantially constant knock condition in the presence of engine background noise in an automotive engine over a range of engine speeds which comprises: a. generating means coupled to said automotive engine for producing an electrical signal proportional to engine noise and knock noise; b. frequency selection means for passing a preselected portion of said electrical signal; c. amplification means to increase the amPlitude of said preselected portion of said electrical signal; d. means for separating out from a portion of the electrical signal resulting from step (c) a second electrical signal which is substantially proportional to the engine noise component present in said electrical signal resulting from step (c); e. comparator means for obtaining continuously a difference electrical signal between said electrical signal coming from step (c) and said second electrical signal, said electrical signal coming from step (c) being porportional to engine noise and knock noise and said second electrical signal being substantially proportional to engine noise; and f. turning means operated by said continuously obtained difference signal for changing the spark timing of said internal combustion engine so as to maintain continually over said range of engine speeds said substantially constant knock condition.

Claim 2

A device for producing a substantially constant knock condition in the presence of engine background noise in an automotive engine over a range of engine speeds which comprises: a. generating means coupled to said automotive engine for producing an electrical signal proportional to engine noise and knock noise; b. frequency selection means for passing a preselected portion of said electrical signal; c. amplification means to increase the amPlitude of said preselected portion of said electrical signal; d. means for separating out from a portion of the electrical signal resulting from step (c) a second electrical signal which is substantially proportional to the engine noise component present in said electrical signal resulting from step (c); e. comparator means for obtaining continuously a difference electrical signal between said electrical signal coming from step (c) and said second electrical signal, said electrical signal coming from step (c) being porportional to engine noise and knock noise and said second electrical signal being substantially proportional to engine noise; and f. turning means operated by said continuously obtained difference signal for changing the spark timing of said internal combustion engine so as to maintain continually over said range of engine speeds said substantially constant knock condition.

Claim 5

The method of producing a knock condition of substantially constant intensity in the presence of engine background noise in an automotive engine over a range of engine speeds which comprises: a. using the electrical output of at least one transducer contacting said engine to produce a ramp voltage substantially proportional to said electrical output over said range of engine speeds in the absence of engine knock, and b. continuously comparing over said range of engine speeds said ramp voltage with the output of said transducer when engine knock is present, and c. continuously using the difference between said ramp voltage and said output of said transducer when engine knock is present to generate an electrical signal substantially proportional to said difference, and d. using said electrical signal to continuously adjust the position of the engine timing such that said difference is substantially constant.

Claim 6

The method of producing a knock condition of substantially constant intensity in the presence of engine background noise in an automotive engine over a range of engine speeds which comprises: a. using the electrical output of at least one transducer contacting said engine to produce a ramp voltage substantially proportional to said electrical output over said range of engine speeds in the absence of engine knock, and b. continuously comparing over said range of engine speeds said ramp voltage with the output of said transducer when engine knock is present, and c. continuously using the difference between said ramp voltage and said output of said transducer when engine knock is present to generate an electrical signal substantially proportional to said difference, and d. using said electrical signal to continuously adjust the position of the engine timing such that said difference is substantially constant.

Claim 9

A method of producing a knock level in an automotive engine during a controlled engine acceleration of said engine wherein said knock level is substantially the same as a predetermined knock level comprising: a. using the electrical output of at least one transducer in contact with said engine undergoing a controlled acceleration to produce an electrical signal which is substantially proportional to engine knock alone, and b. storing said electrical signal in a peak memory unit as said predetermined knock level, and c. using the electrical output of at least one transducer in contact with said engine undergoing a controlled acceleration to produce a suitable time-averaged electrical signal substantially proportional to knock alone, and d. comparing the knock level of step (c) with said predetermined knock level stored in step (b), and e. recording the spark advance position of said engine if the knock level produced in step (c) and step (a) are substantially the same, and f. changing the spark advance position of said engine using a staircase generator actuating a servo drive operationg said spark advance if said knock level produced in step (c) is not substantially the same as that produced in step (a), and g. carrying out step (c) a plurality of times until the knock level produced in substantially the same as the predetermined knock level stored in step (b).

Claim 10

A method of producing a knock level in an automotive engine during a controlled engine acceleration of said engine wherein said knock level is substantially the same as a predetermined knock level comprising: a. using the electrical output of at least one transducer in contact with said engine undergoing a controlled acceleration to produce an electrical signal which is substantially proportional to engine knock alone, and b. storing said electrical signal in a peak memory unit as said predetermined knock level, and c. using the electrical output of at least one transducer in contact with said engine undergoing a controlled acceleration to produce a suitable time-averaged electrical signal substantially proportional to knock alone, and d. comparing the knock level of step (c) with said predetermined knock level stored in step (b), and e. recording the spark advance position of said engine if the knock level produced in step (c) and step (a) are substantially the same, and f. changing the spark advance position of said engine using a staircase generator actuating a servo drive operationg said spark advance if said knock level produced in step (c) is not substantially the same as that produced in step (a), and g. carrying out step (c) a plurality of times until the knock level produced in substantially the same as the predetermined knock level stored in step (b).

Claim 13

A method for collecting engine test data for an automotive engine at a preset knock level in said engine which comprises: a. using the electrical output of at least one transducer in contact with said engine to proDuce a suitably time-averaged electrical signal which is substantially proportional to engine knock alone, and b. adjusting the bias of a voltage comparator to be substantially equal to said signal, and c. accelerating said engine through a range of engine speeds such that a suitably time-averaged electrical signal substantially proportional to engine knock alone from said transducer which exceeds the bias of said comparator is produced, and d. feeding said signal of step (c) in said comparator such that a phase change occurs, and e. using said phase change of said comparator to actuate the readout of an engine characteristic at the time said phase change occurs.

Claim 14

A method for collecting engine test data for an automotive engine at a preset knock level in said engine which comprises: a. using the electrical output of at least one transducer in contact with said engine to proDuce a suitably time-averaged electrical signal which is substantially proportional to engine knock alone, and b. adjusting the bias of a voltage comparator to be substantially equal to said signal, and c. accelerating said engine through a range of engine speeds such that a suitably time-averaged electrical signal substantially proportional to engine knock alone from said transducer which exceeds the bias of said comparator is produced, and d. feeding said signal of step (c) in said comparator such that a phase change occurs, and e. using said phase change of said comparator to actuate the readout of an engine characteristic at the time said phase change occurs.