Method and system for operating a power-producing machine at maximum torque under varying operating conditions

A method of operating an internal combustion engine at maximum output torque under varying operating conditions, said engine having an output shaft and an adjustable input engine variable the setting of which controls the output torque, the method comprising:

• oscillating the setting of the input variable by a predetermined amount with respect to a variable reference setting;
• sensing an output variable representative of said output torque during at least three successive phases of the oscillation;
• sensing whether the detected output variables establish one of first and second sequential relationships of a plurality of possible sequential relationships indicating that said variable reference is on one of a first and second sides, respectively, of an optimum position;
• and
• adjusting said variable reference setting toward said optimum position exclusively in response to one of the sensed first and second sequential relationships.

A method of operating an internal combustion engine at maximum output torque under varying operating conditions, said engine having an output shaft and an adjustable spark ignition variable the setting of which controls the output torque, said method comprising the steps of:

• (a) reading a reference spark ignition datum from a memory;
• (b) repeatedly causing ignitions to occur a predetermined number of times at a reference timing based on the datum read from said memory;
• (c) storing a datum representative of the speed of revolution of said output shaft during an interval in which said ignitions occurred;
• (d) generating an advance spark ignition datum representing an ignition timing which is advanced with respect to said reference timing by a predetermined amount;
• (e) repeatedly causing ignitions to occur at advanced timing said predetermined number of times in accordance with said advance ignition datum generated in the step (d);
• (f) storing a datum representative of the speed of revolution of said output shaft during an interval in which said ignitions occurred at said advanced ignition timing;
• (g) generating a retard spark ignition datum representing an ignition timing which is retarded with respect to said reference timing by a predetermined amount;
• (h) repeatedly causing ignitions to occur at retarded timing said predetermined number of times in accordance with said retard spark ignition datum generated in the step (g);
• (i) storing a datum representative of the speed of revolution of said output shaft during an interval in which the ignitions occurred at said retarded timing;
• (j) comparing the data stored in the steps (c), (f) and (i) with each other to detect whether said compared data establish one of first and second sequential relationships of a plurality of possible sequential relationships indicating that said reference timing is on one of the advance and retard sides, respectively, of an optimum position;
• (k) varying said reference spark ignition datum of the step (a) in a first direction only when said first sequential relationship is detected and in a second direction only when said second sequential relationship is detected;
• and
• (l) repeating the steps (a) to (k).

A control system for operating a power-producing machine at maximum output torque under varying operating conditions, said machine having an adjustable input machine variable means the setting of which controls the output torque, comprising:

• processing means for oscillating the setting of the adjustable input machine variable means by a predetermined amount with respect to a variable reference setting;
• and
• means for sensing an output machine variable representative of said output torque during at least three successive phases of the oscillation;
• said processing means detecting whether the detected output variables establish one of first and second sequential relationships of a plurality of possible sequential relationships indicating that said variable reference setting is on one of a first and second sides, respectively, of an optimum position;
• and
• said processing means adjusting said variable reference setting toward said optimum position exclusively in response to one of the detected first and second sequential relationships.

A control system for operating an internal combustion engine at maximum output torque under varying operating conditions, said engine having an output shaft and an adjustable input engine variable means the setting of which controls the output torque, comprising:

• processing means for oscillating the setting of the adjustable input engine variable means by a predetermined amount with respect to a variable reference setting;
• and
• means for sensing an output engine variable representative of said output torque during at least three successive phases of said oscillation;
• said processing means detecting whether said sensed output engine variables establish one of first and second sequential relationships of a plurality of possible sequential relationships indicating that said variable reference setting is on one of a first and second sides, respectively, of an optimum position;
• and
• said processing means adjusting said variable reference setting toward said optimum position exclusively in response to one of the detected first and second sequential relationships.

A control system for operating an internal combustion engine at maximum output torque under varying operating conditions, said engine having an output shaft and an adjustable spark ignition advance timing means the setting of which controls the output torque, comprising:

• a random access memory;
• means for generating a speed signal related to the speed of revolution of said output shaft;
• means for sensing the intake air pressure of said engine;
• and
• a microcomputer programmed to perform the following steps:
• (a) storing in said random access memory a set of reference ignition setting data as a function of said speed signal and as a function of the sensed intake air pressure;
• (b) selectively reading a datum from said random access memory at periodic intervals in response to said speed signal and intake air pressure;
• (c) oscillating the setting of said spark ignition timing means by a predetermined amount with respect to the setting of said datum read out of said memory;
• (d) successively storing data representative of said speed signal during at least three successive phases of the oscillation in said memory;
• (e) detecting when said stored speed representative data establish one of first and second sequential relationships of a plurality of possible sequential relationships indicating that the setting of said ignition timing means is on one of the advance and retard sides, respectively, of an optimum position;
• and
• (f) correcting said stored reference ignition setting data by a predetermined amount in one of a first and second directions exclusively in response to one of said detected first and second relationships.