Control apparatus

Claim 2

A control apparatus comprising: (a) means for detecting an output value related to an operating state of a controlled object; (b) an actuator adjusting the operating state of the controlled object; and (c) means for determining a target control quantity of the actuator and controlling the actuator in accordance with the determined target control quantity; wherein the determining/controlling means comprises: means for storing the detected output value and the determined target control quantity; and means for calculating a new target control quantity of the actuator on the basis of a vector of feedback gains and a vector of state variables, wherein the feedback gains are determined on the basis of a dynamic model which is an approximation to the operating state of the controlled object, and wherein the state variables are composed directly of the output value stored in the storing means and the control quantity stored in the storing means.

Claim 3

The control apparatus of claim 1 wherein the determining/controlling means further comprises means for accumulating a difference between a predetermined target output value and the detected output value and thereby calculating an accumulation value representing the accumulated difference, and wherein the state variables are composed directly of the output value stored in the storing means, the control quantity stored in the storing means, and the accumulation value.

Claim 4

The control apparatus of claim 1 wherein the dynamic model of the controlled object is determined, through approximation, on the basis of an auto-regressive moving average model having a dead time p (p=0,l,2,...) and an order [n,m] (n=1,2,3,..., m=1,2,3,...), the average model being expressed by the following equation: y(k) a₁·y(k-1) + a₂·y(k-2) + ... ... + a n · y(k-n) + b₁·u(k-1-P) + b₂·u(k-2-p) + ... ... + b m ·u(k-m-p) where the characters "y" denote the output values, the characters "u" denotes the control quantities, the characters a₁,...,a n and b₁,...,b m denote predetermined constants, and the character "k" denotes the number of times of sampling; and wherein the new target control quantity u(k) is given by the following equation: u(k) F₁·y(k) + F₂·y(k-1) + ... + F n ·y(k-n+l) + F n+1 ·u(k-1) + F n+2 ·u(k-2) + ... + F p+n+m-1 ·u(k-m-p+1)

Claim 5

An air-to-fuel ratio control apparatus for an engine comprising: (a) means for detecting an air-to-fuel ratio of an air-fuel mixture supplied to the engine; (b) an actuator adjusting the air-to-fuel ratio; and (c) means for determining a target control quantity of the actuator on the basis of the detected air-to-fuel ratio and controlling the actuator in accordance with the determined target control quantity; wherein the determining/controlling means comprises: means for storing the detected air-to-fuel ratio and the determined target control quantity; and means for calculating a new target control quantity of the actuator on the basis of a vector of predetermined optimal feedback gains and a vector of state variables, wherein the optimal feedback gains depend on model constants in a dynamic model which is an approximation to the operating state of the engine, and wherein the state variables are composed directly of the air-to-fuel ratio stored in the storing means and the control quantity stored in the storing means.

Claim 6

An air-to-fuel ratio control apparatus for an engine comprising: (a) means for detecting an air-to-fuel ratio of an air-fuel mixture supplied to the engine; (b) an actuator adjusting the air-to-fuel ratio; and (c) means for determining a target control quantity of the actuator on the basis of the detected air-to-fuel ratio and controlling the actuator in accordance with the determined target control quantity; wherein the determining/controlling means comprises: means for storing the detected air-to-fuel ratio and the determined target control quantity; and means for calculating a new target control quantity of the actuator on the basis of a vector of predetermined optimal feedback gains and a vector of state variables, wherein the optimal feedback gains depend on model constants in a dynamic model which is an approximation to the operating state of the engine, and wherein the state variables are composed directly of the air-to-fuel ratio stored in the storing means and the control quantity stored in the storing means.

Claim 7

The control apparatus of claim 4 wherein the determining/controlling means further comprises means for accumulating a difference between a predetermined target air-to-fuel ratio and the detected air-to-fuel ratio and thereby calculating an accumulation value representing the accumulated difference, and wherein the state variables are composed directly of the air-to-fuel ratio stored in the storing means, the control quantity stored in the storing means, and the accumulation value.

Claim 8

A control apparatus comprising: (a) means for periodically sampling a value of a controlled parameter; (b) means for accumulating a difference between the sampled value of the controlled parameter and a target value of the controlled parameter and thereby deriving an accumulation value representing the accumulated difference; (c) means for adjusting the controlled parameter in accordance with a variable control quantity; (d) means for periodically determining a value of the control quantity in synchronism with the sampling of the controlled parameter, wherein the value of the control quantity equals a product of a preset optimal feedback gain vector and a state variable vector; and (e) means for periodically determining the state variable vector in synchronism with the sampling of the controlled parameter, wherein the state variable vector determined during a present period includes three components consisting of the accumulation value, the value of the controlled parameter sampled during the present period, and the value of the contol quantity determined during a period preceding the present period, respectively.

Claim 9

A control apparatus comprising: (a) means for periodically sampling a value of a controlled parameter; (b) means for accumulating a difference between the sampled value of the controlled parameter and a target value of the controlled parameter and thereby deriving an accumulation value representing the accumulated difference; (c) means for adjusting the controlled parameter in accordance with a variable control quantity; (d) means for periodically determining a value of the control quantity in synchronism with the sampling of the controlled parameter, wherein the value of the control quantity equals a product of a preset optimal feedback gain vector and a state variable vector; and (e) means for periodically determining the state variable vector in synchronism with the sampling of the controlled parameter, wherein the state variable vector determined during a present period includes three components consisting of the accumulation value, the value of the controlled parameter sampled during the present period, and the value of the contol quantity determined during a period preceding the present period, respectively.

Claim 10

The control apparatus of claim 6 wherein the controlled parameter consists of an air-to-fuel ratio of an air-fuel mixture supplied to an engine.