Control system for improved cylinder torque balance of engine

A control method for cylinder torque balance of an internal combustion engine including multiple cylinders, comprising the steps of:

• determining individual cylinder torque having been developed by the cylinders of the engine;
• calculating, out of the determined individual cylinder torque, a multiple cylinder average;
• and
• controlling a control variable on which individual cylinder torque depends in such a manner as to decrease a deviation of the determined individual cylinder torque from the determined multiple cylinder average.

In an ignition timing control system for an internal combustion engine including a plurality of spark plugs for cylinders of the engine, respectively, the plurality of spark plugs providing sparks in response to individual spark timing commands, and control unit means for developing the individual spark timing commands, the improvement wherein:

• the control unit means inputs information of cylinder pressure within each of the engine cylinders over crank angles about top dead center (TDC) over a predetermined number of cycles;
• the control unit means determines, for each of the cylinders, a ratio, as a developed torque parameter, between integral of cylinder pressure over a predetermined angle after top dead center and integral of cylinder pressure over a predetermined crank angle before top dead center;
• the control unit means calculates integral of said determined developed torque parameter over said predetermined number of cycles and calculates an individual cylinder average for each of the cylinders;
• the control unit means calculates a multiple cylinder average out of said individual cylinder averages of the cylinders;
• the control unit means compares each of said individual cylinder averages with said multiple cylinder average;
• and
• the control unit means determines correction amounts to the ignition timing commands in response to results of comparing each of said individual cylinder averages with said multiple cylinder average, respectively.

In an ignition timing control system for an internal combustion engine including a plurality of spark plugs for cylinders of the engine, respectively, the plurality of spark plugs providing sparks in response to individual spark timing commands, and control unit means for developing the individual spark timing commands, the improvement wherein:

• the control unit means inputs information of cylinder pressure within each of the engine cylinders over crank angles about top dead center (TDC) over a predetermined number of cycles;
• the control unit means determines, for each of the cylinders, a deviation, as a developed torque parameter, between integral of cylinder pressure over a predetermined angle after top dead center and integral of cylinder pressure over a predetermined crank angle before top dead center;
• the control unit means calculates integral of said determined developed torque parameter over said predetermined number of cycles and calculates an individual cylinder average for each of the cylinders;
• the control unit means calculates a multiple cylinder average out of said individual cylinder averages of the cylinders;
• the control unit means compares each of said individual cylinder averages with said multiple cylinder average;
• and
• the control unit means determines correction amounts to the ignition timing commands in response to results of comparing each of said individual cylinder averages with said multiple cylinder average, respectively.

An ignition timing control method for an internal combustion engine including a plurality of spark plugs for cylinders of the engine, respectively, the plurality of spark plugs providing sparks in response to individual spark timing commands, and control unit means for developing the individual spark timing commands, the method comprising the steps of:

• inputting information of cylinder pressure within each of the engine cylinders over crank angles about top dead center (TDC) over a predetermined number of cycles;
• determining, for each of the cylinders, a ratio, as a developed torque parameter, between integral of cylinder pressure over a predetermined angle after top dead center and integral of cylinder pressure over a predetermined crank angle before top dead center;
• calculating integral of said determined developed torque parameter over said predetermined number of cycles and calculates an individual cylinder average for each of the cylinders;
• calculating a multiple cylinder average out of said individual cylinder averages of the cylinders;
• comparing each of said individual cylinder averages with said multiple cylinder average;
• and
• determining correction amounts to the ignition timing commands in response to results of comparing each of said individual cylinder averages with said multiple cylinder average, respectively.

An ignition timing control method for an internal combustion engine including a plurality of spark plugs for cylinders of the engine, respectively, the plurality of spark plugs providing sparks in response to individual spark timing commands, and control unit means for developing the individual spark timing commands, the method comprising the steps of:

• inputting information of cylinder pressure within each of the engine cylinders over crank angles about top dead center (TDC) over a predetermined number of cycles;
• determining, for each of the cylinders, a deviation, as a developed torque parameter, between integral of cylinder pressure over a predetermined angle after top dead center and integral of cylinder pressure over a predetermined crank angle before top dead center;
• calculating integral of said determined developed torque parameter over said predetermined number of cycles and calculates an individual cylinder average for each of the cylinders;
• calculating a multiple cylinder average out of said individual cylinder averages of the cylinders;
• comparing each of said individual cylinder averages with said multiple cylinder average;
• and
• determining correction amounts to the ignition timing commands in response to results of comparing each of said individual cylinder averages with said multiple cylinder average, respectively.