Abstract:
An optimum control parameter in control of an internal combustion engine and the like is searched. In a plurality of search cycles, a control parameter that maximizes an output of an object to be controlled which shows an output realized by a given control parameter is searched using control parameters. The control parameters are provided at each search cycle by a predetermined algorithm. A periodic function of a predetermined period and a correction value obtained in a previous search cycle are added to the control parameters to obtain an input parameters to the object. An output obtained from the object with the input parameters is multiplied by the periodic function to obtain a correction value for correcting the control parameters such that the search converges.
Abstract:
Nonlinear functions (table and map) of a temperature estimation model are corrected based on outputs from a temperature sensor. An electronic control system calculates, for a plant model constructed to calculate an estimated temperature value of the plant, an estimated temperature value using a correlation model between a first parameter regarding the plant and a second parameter regarding the plant model. This control system controls the temperature of the plant based on the calculated estimated temperature value of the plant. The control system also defines a plurality of functions (Wi) in a range of a plurality of the first parameters for the correlation model, calculates correction coefficients (Kli, Kci) that adjust the height of the plurality of functions based on the output of the temperature sensor and the calculated estimated temperature value of the plant, and corrects the correlation model by the plurality of functions (Wi) and correction coefficients (Kli, Kci).
Abstract:
A method of controlling ignition timing of an engine. In the control method, final ignition timing for performing ignition is calculated by adding a variation component to a set ignition timing. According to the final ignition timing, an indicated average effective pressure of an in-cylinder pressure detected when ignition is performed is calculated. An ignition timing characteristic curve indicating the correlation between the indicated average effective pressure and the variation component is estimated and optimal ignition timing is calculated from the characteristic curve. Feedback control for converging the set ignition timing to the optimal ignition timing is then performed. Consequently, the ignition timing is controlled to an optimal ignition timing corresponding to a current operational state of the engine.
Abstract:
A device and a method for determining the trouble of a cylinder pressure sensor. The device accurately detecting the trouble of the cylinder sensor without increasing cost calculates the cylinder pressure of an internal combustion engine based on an output from the cylinder sensor installed in the internal combustion engine and calculates a drift parameter indicating the drift amount of the cylinder pressure based on the cylinder pressure. When the drift parameter is not within a specified range, the device determines that the cylinder pressure sensor is defective. According to one embodiment, the specified range can be set based on the behavior of the cylinder pressure. According to the other embodiment, a correction factor is obtained according to the operating state of the internal combustion engine, and the drift parameter is corrected with the correction factor. Also, according to the third embodiment, the cylinder pressure sensor is operated so that a specified search signal is superimposed on the output from the cylinder pressure sensor. The cylinder pressure is calculated based on the output from the cylinder pressure sensor on which the search signal was superimposed.
Abstract:
There is provided a control system for a plant and an internal combustion engine, which is capable of enhancing controllability and control accuracy in controlling a plurality of control amounts while eliminating a mutual interaction existing between a plurality of control inputs and the control amounts. The control system 1 for the plant 90 in which a mutual interaction exists between TH_cmd and Liftin_cmd as control inputs and PB and Gcyl as control amounts calculates the two control inputs TH_cmd and Liftin_cmd as two non-interacting inputs for causing PB and Gcyl to follow target values PB_cmd and Gcyl_cmd, respectively, the two control inputs TH_cmd and Liftin_cmd eliminating the mutual interaction, with a predetermined algorithm in which a predetermined response-specifying control algorithm (equations (2) to (8)) and a predetermined non-interacting control algorithm (equation (9)) are combined based on a plant model (equation (20)) formed by modeling the plant 90 into a discrete-time system model.
Abstract:
A control for a modeled plant is provided. The modeled plant is represented by a model expression that is based on an input into the plant, an output from the plant, model parameters, and an estimated value for disturbance that is applied to the plant. The model expression includes a term in which the estimated disturbance value is multiplied by at least one of the model parameters. The model parameters are identified. The estimated disturbance value is calculated so that an error between a model output that is calculated based on the model expression and an actual output of the plant is minimized. The input into the plant is calculated based on the model expression so as to control the plant. Thus, the estimated disturbance value is directly reflected in the input into the plant without being calculated by any of the model parameters.
Abstract:
A plant control includes determining a control input into the plant to cause a control output of the plant to converge to a desired value. A value of at least one parameter for adjusting a speed of change of the control output relative to change of the desired value is determined in accordance with a plant condition. The control input is determined based on the parameter having the value thus determined. The parameter includes a first parameter for changing a speed of change of the control input relative to change of the desired value. The parameter can also include a second parameter for changing the relative speed via a corrected desired value that is determined by correcting the desired value. The second parameter can further include a gradient parameter and a gradually-approaching characteristic parameter.
Abstract:
A control apparatus which is capable of compensating for a control error properly and quickly even under a condition where the control error is temporarily increased e.g. by degradation of reliability of the detection results of reference parameters other than controlled variables, thereby making it possible to ensure a high accuracy of control. An air-fuel ratio controller of the control apparatus calculates modified errors by multiplying e.g. an air-fuel ratio error estimated value by link weight functions, calculates basic local correction values such that the modified errors become equal to 0; calculates local correction values by multiplying the basic local correction values and the like by the link weight functions; calculates corrected valve lift by adding a lift correction value, which is the total sum of the local correction values, to a value of valve lift; calculates a first estimated intake air amount for feedforward control of an air-fuel ratio, based on the corrected valve lift; calculates an air-fuel ratio correction coefficient for feedback control of the air-fuel ratio; and calculates a fuel injection amount based on these.
Abstract:
A plant control system using response specifying control that makes it possible to independently set a follow-up behavior for an output value of a plant when a target output value of the plant changes and a convergent behavior for a difference between a target output value and an output value when the output value of the plant changes. The control system has a controller for determining a clutch stroke on the basis of a model equation of a clutch device such that a target rotational speed and an actual rotational speed of the clutch device coincide with each other. The controller includes a target value filter for carrying out filtering computation on a target rotational speed to calculate a filtering target value that converges to the target rotational speed with a response delay, and a response specifying control unit that determines the clutch stroke by response specifying control such that the filtering target value and the clutch rotational speed coincide with each other.
Abstract:
A device, a method, and a program for estimating an intake air amount. The device for estimating the intake air amount used for providing the intake air amount of an internal combustion engine having a variable valve mechanism comprises a reference value acquisition means for providing an intake air amount reference value from a specified map based on the rotational speed, valve lift, and valve phase angle of the internal combustion engine, a measurement value acquisition means for providing a measurement value according to the output of an air flow meter installed in the intake pipe of the internal combustion engine, a calculation means for providing a correction factor to minimize a deviation between a value obtained by multiplying the intake air amount reference value by the correction factor and the measurement value, and an estimated value calculating means for calculating an estimated intake air amount value by multiplying the provided correction factor by the intake air amount reference value.