Internal combustion engine operating control system and method

Internal combustion engine (10) operating control system comprising

• combustion sensor means (11) for sensing knocking combustion conditions;
• signal processing means (12,13) receiving signals from the knock sensing means representative of knocking combustion conditions and other engine combustion operating conditions, and providing a knock condition signal;
• engine control means (18,19) having parameter adjusting elements for controlling a plurality of operating conditions of the engine, and capable of changing the operating conditions thereof in the manner to reduce the tendency to knock, or to inhibit knocking;
• means for generating a permissible knock signal (S.sub.K);
• a comparator stage (14) receiving the knock condition signal (I.sub.K) as an actual operating condition signal and the permissible knock signal (S.sub.K) for comparison, and providing a control output signal to the engine in the direction of non-knocking operation if the comparison by said comparator stage (14) exceeds a permissible value;
• means (15, 16, 17) responsive to said control output signal for simultaneously actuating a second parameter adjusting element (19) having a rapid but temporary effect on engine operation and a first parameter adjusting element (18) having a more slowly effective but persistent effect on engine operation;
• a control circuit (15,16,17) connected to receive the control output signal from the comparator stage (14) and controlling the engine control means (18,19), said circuit including
• a first controller (15) connected to the comparator stage (14), and providing an output signal which is a function of an input signal received from said comparator stage (14);
• a second controller (16) connected to said first controller (15) and providing an output signal which is a predetermined function of an input signal applied thereto by said first controller (15);
• and
• a second comparator (17) receiving the output signal from the second controller (16) and a comparison input signal (S.sub.a) representative of a desired operating condition of said first parameter adjusting element (18), the second comparator (17) controlling the operation of said first parameter adjusting element (18) in dependence on said desired input signal (S.sub.a) and the output from the second controller (16).

Method of controlling operation of an internal combustion engine (10), said engine having

• knock sensing means (11) for sensing knocking combustion conditions;
• signal processing means (12,13) receiving signals from the knock sensing means representative of knocking combustion conditions and providing a knock-condition signal (I.sub.K);
• and
• engine control means (18,19) controlling a plurality of operating conditions of the engine and capable of changing the operating condition thereof in a manner which reduces the tendency of, or inhibits, knocking,
• said method comprising the steps of
• generating a permissible knocking signal (S.sub.K);
• comparing the permissible knocking signal with the knock-condition signal (I.sub.K) and deriving a control output signal;
• and
• simultaneously initiating, in response to said output signal, a rapidly effective modification according to a signal having a first value effective for only a few combustion cycles and a slowly effective but persistent modification according to a signal having a second value which is determined in response to said first value of engine operating parameters, in the direction of non-knocking operation if the comparison step results in an output which deviates from a predetermined level.

Internal combustion engine (10) operating control system having combustion sensor means (11) for sensing knocking combustion conditions;

• signal processing means (12,13) receiving signals from the knock sensing means representative of knocking combustion conditions and other engine combustion operating conditions, and providing a knock condition signal;
• engine control means (18,19) having first (18) and second (19) parameter adjusting elements for controlling a plurality of operating conditions of the engine, and capable of changing the operating conditions thereof in the manner to reduce the tendency to knock, or to inhibit knocking once it starts,
• and comprising, in accordance with the invention,
• means for generating a permissible knock signal (S.sub.K);
• a comparator stage (14) receiving the knock condition signal (I.sub.K ) as an actual operating condition signal and the permissible knock signal (S.sub.K) for comparison, and to provide a control output signal to the engine in the direction of non-knocking operation if the comparison by said comparator stage (14) exceeds a permissible value;
• and
• a control circuit (15,16,17) connected to receive the control output signal from the comparator stage (14) and controlling the engine control means (18,19), said circuit including
• a first controller (15) connected to the comparator stage (14), and providing an output signal having a first adjustment value which is a function of an input signal received from said comparator stage (14) and which is applied to one of said parameter adjusting elements;
• a second controller (16) connected to said first controller (15) and providing an output signal having a second adjustment value which is a predetermined function of said first adjustment value which is applied thereto by said first controller (15);
• and
• a second comparator (17) receiving the output signal from the second controller (16) and a comparison input signal (S.sub.a) representative of a desired operating condition of the other parameter adjusting element (18), the second comparator (17) controlling the operation of the other parameter adjusting element (18) in dependence on said desired input signal (S.sub.a) and the output from the second controller (16).

Method of controlling operation of an internal combustion engine (10), said engine having

• knock sensing means (11) for sensing knocking combustion conditions;
• signal processing means (12,13) receiving signals from the knock sensing means representative of knocking combustion conditions and providing a knock-condition signal (I.sub.K);
• control signal means (15,16,17) receiving and evaluating said knock-condition signal and producing signals for controlling said engine;
• and
• engine control means (18,19) having parameter adjustment elements responsive to said control signals for controlling a plurality of operating conditions of the engine and capable of changing the operating condition thereof in a manner which reduces the tendency of, or inhibits, knocking,
• said method comprising the steps of
• generating a permissible knocking signal (S.sub.K);
• comparing (14) the permissible knocking signal with the knock-condition signal (I.sub.K) and deriving a first control output signal;
• deriving (15) an second control output signal which is a predetermined function of said first control signal;
• deriving (16) a third control output signal which is a predetermined function of said second control signal;
• combining (17) said third control signal (I.sub.a) with a signal (S.sub.a) representative of an optimum engine working point to determine the timing and degree of a particular knock-suppression step;
• and
• controlling one parameter adjustment element (19) by said second control output signal and another parameter adjustment element (18) by said combined signal in a direction to change the engine operating conditions of the engine in the direction of non-knocking operation, if the comparison step results in an output which deviates from a predetermined level.