Apparatus for controlling operating state of an internal combustion engine

• US 4,653,449 A
• Filed: 12/19/1985
• Issued: 03/31/1987
• Est. Priority Date: 12/19/1984
• Status: Expired due to Term

• Current Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Original Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Inventors: Kamei, Eiichi, Namba, Hideaki, Ohba, Masahiro, Kiyono, Masashi, Yonekawa, Masao, Takao, Mitsunori
• Primary Examiner(s): Nelli, Raymond A.
• Application Number:
  US06/810,566
• Time in Patent Office: 467 Days
• Field of Search: 123/478, 123/492, 123/493, 123/325, 123/326, 123/340, 123/341, 123/349, 123/352
• US Class Current: 123/478
• CPC Class Codes: F02B 1/04 with fuel-air mixture admission into cylinder
• CPC Class Codes: F02D 2041/1415 using a state feedback or a state space representation
• CPC Class Codes: F02D 2041/1416 Observer
• CPC Class Codes: F02D 2041/1426 taking into account control stability
• CPC Class Codes: F02D 2041/1433 using a model or simulation of the system
• CPC Class Codes: F02D 41/1401 characterised by the control or regulation method F02D41/1473, F02D41/1477 take precedence
• CPC Class Codes: F02D 43/00 Conjoint electrical control of two or more functions, e.g. ignition, fuel-air mixture, recirculation, supercharging or exhaust-gas treatment

Abstract

Apparatus for controlling the operating state of an internal combustion engine (M1), has a demand amount detecting an unit (M2) for detecting amount of demand to the engine, an operating condition varying unit (M3) for varying a condition of operation of the engine, an operating state detecting an unit (M4) for detecting operating state of the engine, a target value setting unit (M5) for determining target values of variables of the operating condition, a control unit (M6) for controlling the operating condition varying unit (M3) by determining feedback amount of the operating condition variables so that detected values equal to the target values. In such apparatus, the target value setting unit (M5) is constructed to determine a target intake air quantity as a value with which fuel supply amount becomes minimum on the basis of the correlation between intake air quantity and fuel supply amount when output torque is made constant, and the control unit (M6) is constructed as an integral-added optimal regulator which determines the feedback amount on the basis of an optimal feedback gain predetermined in accordance with dynamic model of a system relating to the operation of the internal combustion engine.

Claims

1. An apparatus for controlling an operating state of an internal combustion engine, comprising:

demand amount detecting means for detecting a demand amount, including detecting at least the manipulation amount of an accelerator, as an amount of demand for the operation of said internal combustion engine;

operating condition varying means for varying variable of operating condition, which include at least fuel supply amount and throttle valve opening degree;

operating state detecting means for detecting variables of operating state which include at least intake air quantity, rotational speed and output torque;

target value setting means for determining respective target values for operating state variables which include at least target output torque and target intake air quantity, using said demand amount detected by said demand amount detecting means;

control means for controlling said operating condition varying means by determining feedback amounts of said operating condition variables in order to cause variables of the detected operating state of said internal combustion engine to approach said determined target value;

wherein said target value setting means determines said target intake air quantity as an intake air quantity with which said fuel supply amount becomes minimum on the basis of a correlation between intake air quantity and fuel supply amount when output torque is made constant; and

wherein said control means is an integral-added optimal regulator which determines said feedback amount on the basis of an optimal feedback gain predetermined in accordance with a dynamic model of a system relating to the operation of said internal combustion engine, said integral-added optimal regulator of said control means having;

(a) state evaluating means for estimating state variables of an appropriate order indicative of a dynamic internal state of the system based on operating state and operating condition of said internal combustion engine using parameters determined on the basis of the dynamic model of the system relating to the operation of said internal combustion engine;

(b) accumulating means for accmulating respective differences between the target values of the operating state variables determined by said target value setting means and said detected operating state variables, for at least output torque and intake air quantity; and

(c) feedback amount determining means for determining respective controlled variables of operating condition including at least fuel supply amount and throttle opening degree which are controlled by said operating condition varying means using said optimal feedback gain determined on the basis of the dynamic model of said system, said estimated state variables, and said accumulated value.

2. Apparatus for controlling an operating state of an internal combustion engine as claimed in claim 1, wherein at least one of:

a) the parameters of said state evaluating means and b) the optimal feedback gain of said feedback amount determining means can be switched in response to the change in the dynamic model of the system of said internal combustion engine.

3. Apparatus for controlling an operating state of an internal combustion engine as claimed in claim 2, wherein the switching of said at least one of said parameters and said feedback gain is performed depending on temperature of coolant of the internal combustion engine.

4. Apparatus for controlling an operating state of an internal combustion engine as claimed in claim 3, wherein the switching of said at least one of parameters and feedback gain is performed within a given hysteresis width of the temperature of coolant.

5. Apparatus for controlling an operating state of an internal combustion engine as claimed in claim 1, wherein said target value setting means is also for determining intake air quantity from output torque and rotational speed of said internal combustion engine using a map prepared in advance when determining target intake air quantity, and for determining a target intake air quantity which causes fuel supply amount to be minimum using said intake air quantity as a base.

6. Apparatus for controlling operating state of an internal combustion engine as claimed in claim 5, wherein values of said map are renewed to predetermined target intake air quantities when a predetermined target intake air quantity is different from the value of intake air quantity of said map.

7. Apparatus for controlling an operating state of an internal combustion engine, comprising:

(a) means for detecting an intake air quantity, an output torque, a rotational speed, and a fuel injection amount injected into the internal combustion engine;

(b) target output torque setting means for setting a target output torque using an accelerator opening degree;

(c) target intake air quantity setting means for setting a target intake air quantity as a value which causes a minimum fuel consumption amount using said target output torque from said target output torque setting means, and said intake air quantity, output torque, rotational speed, and fuel injection amount detected by said detecting means;

(d) first and second integrator means for obtaining a first accumulated value by accumulating deviations of said actual output torque from said target output torque, and a second accumulated value by accumulating deviations of said actual intake air quantity from target intake air quantity;

(e) perturbation component extracting means for extracting a perturbation component from various values during a steady operating state of output torque, intake air quantity and rotational speed;

(f) state evaluating means means for obtaining state estimated variables by estimating state variables which represent the internal state of the internal combustion engine using the perturbation component of the condition of operation and the perturbation components of the operating state;

(g) feedback amount determining means for obtaining controlled variables by multiplying the state estimated variables and the above-mentioned accumulated value by the optimal feedback gain; and

(h) reference setting value adding means for determining the variables of the operating condition of the internal combustion engine by adding reference setting values corresponding to the steady operating condition to the perturbation components.