Controller for internal combustion engine

Abstract

A driving force control system comprises an internal combustion engine model (1000) represented by a model linearized while containing a primary delay element, an operating unit (2000) for calculating deviation of an estimated engine torque from a target engine torque, a delay compensator (3000) for compensating response delay of deviation, and an adder (4000) for calculating an engine torque control amount by adding a delay-compensated deviation to the target engine torque.

Description

technical field

[0001] The present invention relates to a vehicle control device including a power train having an engine and a transmission, and more particularly to a driving force control device (control device for an internal combustion engine) capable of achieving good control It outputs the driving force corresponding to the driving force required by the driver while maintaining the response characteristics and control stability. Background technique

[0002] In the case of a vehicle including an engine and an automatic transmission capable of controlling the engine output torque independently of the driver's accelerator pedal operation, there is a concept of "driving force control" in which positive and negative The target driving torque, the vehicle behavior, etc. are obtained as the engine torque and the gear ratio of the automatic transmission. Control schemes called "driving force request type" and "driving force demand type" also belong to this concept. [0003...

Examples

no. 1 approach

[0042] The driving force control system according to the present embodiment aims at improving response characteristics. When calculating the engine torque control amount for realizing the target engine torque, the drive force control system compensates for the control response delay based on the difference between the estimated engine torque estimated from the target engine torque control amount and the target engine torque. Calculate target engine torque. Therefore, it is possible to calculate the control amount that has correctly compensated for the control response delay. Here, the internal combustion engine model used to calculate the estimated engine torque is assumed to be a linear model, excluding dead time, thereby facilitating execution on an ECU (Electronic Control Unit).

[0043] A control block diagram of the driving force control system according to the present embodiment will be described below with reference to FIG. 1 . It should be noted that the transfer fun...

no. 2 approach

[0065]A driving force control system according to a second embodiment of the present invention will be described below. The driving force control system according to the present embodiment is intended to avoid overshoot due to the dead time of the internal combustion engine. In the driving force control system according to the first embodiment described above, since the transfer function of the internal combustion engine includes a dead time component, the transfer function of the internal combustion engine at the time of calculating the engine torque control amount is different from the transfer function at the time of executing the torque control amount. Different, so overshoots such as overshoot and undershoot occur. Thus, the behavior of the vehicle is disturbed.

[0066] Therefore, in the driving force control system according to the present embodiment, in consideration of the dead time of the internal combustion engine, the engine torque control amount based on the esti...

no. 3 approach

[0100]Delay compensation or dead time compensation in addition to delay compensation is performed in the above-described embodiments. That is, this compensation is performed (compensation is performed by multiplying the deviation between the estimated actual output value and the target value by a gain to obtain a control amount, thereby compensating for delay and dead time). If such compensation is performed without exception for a small change in the target value, an actuator such as an electronic throttle valve that adjusts an intake air amount will oscillate to reduce durability. In particular, even when feedback control is being performed and a steady state is reached (basically, when there is no change in driving force required by the driver or a vehicle control system such as cruise control), the calculated target value is constantly changing. Usually, this variation is small and the response characteristics of this variation are not problematic. Therefore, in this embo...

technical field

[0001] The present invention relates to a vehicle control device including a power train having an engine and a transmission, and more particularly to a driving force control device (control device for an internal combustion engine) capable of achieving good control It outputs the driving force corresponding to the driving force required by the driver while maintaining the response characteristics and control stability. Background technique

[0002] In the case of a vehicle including an engine and an automatic transmission capable of controlling the engine output torque independently of the driver's accelerator pedal operation, there is a concept of "driving force control" in which positive and negative The target driving torque, the vehicle behavior, etc. are obtained as the engine torque and the gear ratio of the automatic transmission. Control schemes called "driving force request type" and "driving force demand type" also belong to this concept. [0003...

Examples

no. 1 approach

[0042] The driving force control system according to the present embodiment aims at improving response characteristics. When calculating the engine torque control amount for realizing the target engine torque, the drive force control system compensates for the control response delay based on the difference between the estimated engine torque estimated from the target engine torque control amount and the target engine torque. Calculate target engine torque. Therefore, it is possible to calculate the control amount that has correctly compensated for the control response delay. Here, the internal combustion engine model used to calculate the estimated engine torque is assumed to be a linear model, excluding dead time, thereby facilitating execution on an ECU (Electronic Control Unit).

[0043] A control block diagram of the driving force control system according to the present embodiment will be described below with reference to FIG. 1 . It should be noted that the transfer fun...

no. 2 approach

[0065]A driving force control system according to a second embodiment of the present invention will be described below. The driving force control system according to the present embodiment is intended to avoid overshoot due to the dead time of the internal combustion engine. In the driving force control system according to the first embodiment described above, since the transfer function of the internal combustion engine includes a dead time component, the transfer function of the internal combustion engine at the time of calculating the engine torque control amount is different from the transfer function at the time of executing the torque control amount. Different, so overshoots such as overshoot and undershoot occur. Thus, the behavior of the vehicle is disturbed.

[0066] Therefore, in the driving force control system according to the present embodiment, in consideration of the dead time of the internal combustion engine, the engine torque control amount based on the esti...

no. 3 approach

[0100]Delay compensation or dead time compensation in addition to delay compensation is performed in the above-described embodiments. That is, this compensation is performed (compensation is performed by multiplying the deviation between the estimated actual output value and the target value by a gain to obtain a control amount, thereby compensating for delay and dead time). If such compensation is performed without exception for a small change in the target value, an actuator such as an electronic throttle valve that adjusts an intake air amount will oscillate to reduce durability. In particular, even when feedback control is being performed and a steady state is reached (basically, when there is no change in driving force required by the driver or a vehicle control system such as cruise control), the calculated target value is constantly changing. Usually, this variation is small and the response characteristics of this variation are not problematic. Therefore, in this embo...

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