JPH03115758A - Engine control device - Google Patents

Abstract

PURPOSE:To obtain engine output faithful to accelerator operation by performing simulation using the model of a driving system according to demand engine torque computed on the basis of accelerator opening so as to compute generated engine torque following the accelerator operation. CONSTITUTION:An engine control device for controlling engine torque according to accelerator opening is provided with a demand engine torque computing means 20 for computing demand engine torque on the basis of an accelerator opening signal detected by an accelerator opening sensor 13. The generated engine torque following accelerator operation is computed by performing simulation by a generated engine torque computing means 21 on the basis of the computed demand engine torque using the model of a driving system. On the basis of this generated engine torque, the actual throttle opening is set by a throttle opening setting means 22, and thus a throttle motor 9 is driven to control a throttle valve.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an engine control device that controls actual engine torque based on an accelerator opening signal.

(Prior art) Generally, an accelerator operated directly by the driver,
The throttle, which controls the amount of intake air in the engine, is directly connected with a cable etc. so that it moves as one unit, but with this structure, when the driver suddenly operates the accelerator, the throttle also rotates rapidly. , vibrations occur in the vehicle body due to sudden changes in engine torque. This vibration is called acceleration vibration 2 and has a frequency of 2 to 8 Hz, and its suppression is an issue.

Therefore, in recent years, as shown in Japanese Patent Application Laid-Open No. 59-190441, the accelerator and the throttle have been separated,
There are now systems in which the throttle opening is electronically controlled based on the accelerator opening.

[Problem to be solved by the invention]

Conventionally, in devices that electronically control the throttle opening as described above, acceleration and deceleration photography has been suppressed by limiting the throttle opening or applying a low-pass filter. However, with this type of control, the response of the throttle to accelerator operation becomes slow, resulting in an inconvenience in which linearity is impaired.

In view of these circumstances, it is an object of the present invention to provide an engine control device that can obtain engine output faithful to the actual accelerator opening while suppressing acceleration/deceleration photography of the vehicle body.

(Means for Solving the Problems) The present invention provides an engine control device that controls engine torque according to the accelerator opening, in which an accelerator opening sensor 13, etc. Based on 5, the required engine torque calculation means 20 calculates the requested engine torque, and the generated engine torque that follows the accelerator operation is calculated by performing a simulation using a drive system model based on this requested engine torque. Generated engine torque calculation means 21
and a throttle opening setting means 22 for setting the actual throttle opening based on the generated engine torque.

Further, the same effect can be obtained by a device including a setting means for setting the state of the torque changing means based on the generated engine torque.

[For production]

According to the above configuration, the required engine torque is calculated based on the accelerator opening degree, and a simulation is performed using the drive system model based on this required engine torque, so that acceleration/deceleration photography can be suppressed, and the accelerator The engine torque that is faithful to the operation is calculated, and the actual throttle opening or the state of the torque changing means is set based on the calculation result.

〔Example〕

FIG. 2 shows the overall configuration of an engine and its control device in one embodiment of the present invention.

In the figure, an air cleaner 3, an air flow meter 4, a throttle valve 5, a surge tank 6, a spark plug 7, etc. are arranged in order from the upstream side of an intake passage 2 of an engine 1. The throttle valve 5 is connected to a throttle motor 9 that is its actuator, and is also provided with a throttle sensor 10 that detects the throttle opening.

The upstream passage and the downstream passage of the throttle valve 5 are directly connected by a bypass passage 11, and the bypass passage 11 is provided with a bypass valve 12 for adjusting the bypass air flow rate.

Further, an accelerator opening sensor 13 for detecting the opening of the accelerator is provided near the accelerator of the vehicle body, and this accelerator opening sensor 13 and the throttle sensor 10. -1; Connected to tEcLJ (engine control unit) 14.

In addition to the output signals from the sensors 10 and 13, the ECU 14 receives detection signals from the idle switch 15 and engine speed sensor 16, and a signal for determining whether the automatic transmission 17 is in a lock-up state. It looks like this. This ECIJ 14 includes a required engine torque calculation means 20, a generated engine torque calculation means 21, and a throttle opening setting means 22 as shown in FIG. is now output.

Next, the contents of the throttle control performed by this ECU 14 will be explained based on the block diagram in FIG. 3 and the flowchart in FIG. 4.

First, as shown in step S1 in FIG. 4, it is determined whether the automatic transmission 17 is in a lock-up state (
Step S1). If it is not in a lock-up state (NO in step S1), vibration is suppressed by the action of the torque converter and no special throttle control is required, so simple control is performed to keep the throttle opening equal to the accelerator opening. (Step S2).

On the other hand, if the automatic transmission 17 is in a lock-up state (YES in step S1), the currently requested acceleration is calculated based on the accelerator opening (step 83). Specifically, the target acceleration force Gt is calculated from a map prepared in advance based on the accelerator opening degree and vehicle speed.

Furthermore, the engine torque to be generated is calculated from this requested acceleration (step 84).

Specifically, first, the required engine torque TQeQ is determined from the required acceleration. This required engine torque T qea can be determined, for example, from the following equation.

TQe(J −Gt −W−R−Dd+Jwhere, Gt
is the target acceleration force, W is the weight, R is the tire radius, [) (l
ef indicates the final reduction ratio. Then, by applying negative state feedback as shown in FIG. 3 to this required engine torque Tqeg, the accelerator 111
The engine torque (generated engine torque) TQet that should be generated in order to follow the engine speed and suppress acceleration/deceleration vibration is calculated.

Here, the state variables are engine-side propeller shaft rotation angle θe <-θ1), vehicle-side propeller shaft θb (-02), engine-side propeller shaft rotation speed +e (-θ3), and vehicle-side propeller shaft Using four variables of rotational speed 7b (-θ4), these four variables θ1. θ2. θ3. θ4 is set to a preset state feedback coefficient of 1. kz, 3. Multiply by 4 and add them together, and let the sum be the state feedback recitation T q + Jb.

The state feedback coefficients 1 to 4 are values determined in advance through simulation to suppress acceleration/deceleration photography. In this example, it is assumed that the engine side and the vehicle body side are approximately symmetrical, and kl -- to 2. The calculation is performed by setting kz - 4 to 4.

That is, in this embodiment, the required engine torque T q
Based on eg, the generated engine torque T Qet is the following 2
Calculated by the formula.

TQet-TQeg-TQefb Tqetb-kl '2 to θe+ - 3 to θb+
e + 4-4b - 1 (θe-θb) + 3 (4e-shab) The above state variables θ1 to θ4, that is, the variable θe.

θb, 4e, and S are determined by a simulation operation based on a drive system model and required engine torque Tqeo as shown in FIG.

That is, in the above model, if the given engine torque is T (-Tqeg), then the following two state equations are created for the engine side and the vehicle body side: where D is the gear ratio and is is the moment of inertia of the engine. ,
ib is the equivalent moment of inertia of the vehicle body, C is the damping coefficient between the vehicle body and the engine, and K is the spring constant between the vehicle body and the engine.

By solving the above state equation, that is, the simultaneous differential equations, the state variables θ1 to θ4 corresponding to the required engine torque T qeQ can be instantaneously calculated, and finally the generated engine torque T qet can be calculated.

After calculating the generated engine torque Tqet in this manner, the target throttle opening corresponding to the generated engine torque T(l13t) is set by calculation in step S5.
), the throttle valve 5 is adjusted based on this target throttle opening.
Controls the opening degree. As a result, the engine is operated at an acceleration that follows the accelerator opening and causes almost no acceleration or deceleration vibrations.

As described above, this device calculates the state variables by performing a simulation using a preset drive system model based on the currently required engine torque, and then calculates the generated engine torque by applying state feedback. Since it is calculated every moment, it is possible to obtain acceleration/deceleration that is faithful to the accelerator opening and that is less likely to generate vibrations.

Figure 6 shows a device of the present invention, a device that performs control such that the engine torque completely rises in 100 m5ec (hereinafter referred to as the first conventional device), and a control device that performs control such that the engine torque completely rises in 500 isec. A device that does this! (hereinafter referred to as the second conventional device) shows the relationship between time, vehicle body acceleration, and engine torque. In the figure, a solid line 60 indicates the present invention II! The solid line 61 shows the time change of the engine torque in the device of the present invention, the broken line 62 shows the time change in the engine torque in the first conventional device, and the dashed line 63 shows the time change in the throttle opening area in the second conventional device. The solid line 64 shows the time change of the vehicle body acceleration in the device of the present invention, the broken line 65 shows the time change in the engine torque in the first conventional device, and the dashed line 66 shows the engine torque in the second conventional device. Each figure shows the change in torque over time.

As shown in this figure, the first conventional device that rapidly increases engine torque has excellent acceleration responsiveness to accelerator operation, but has the disadvantage of generating large vibrations, and conversely, it gradually increases engine torque. The second conventional @ position, in which the vehicle is raised to a higher position, does not generate large vibrations, but has the disadvantage that the acceleration response to the accelerator operation is slow. On the other hand, according to the device of the present invention, it is possible to obtain an acceleration faithful to the accelerator operation while avoiding the occurrence of vibration.

Next, a second embodiment will be described based on the flowchart of FIG.

Here, instead of changing the engine torque using the throttle valve, the engine torque during deceleration is controlled by changing the amount of bypass air when the throttle valve is fully open.

First, when the idle switch 15 is off (step S
s), that is, when the throttle valve 5 is not fully closed, the amount of bypass air is not adjusted and j is kept at a constant value (step Sto>).

On the other hand, if the idle switch 15 is on (YES in step S6), the process moves to step S7. Here, even if fuel cut is performed (YES in step S7), since engine torque is not generated, the amount of bypass air is fixed constant (step Si).

If the fuel cut has not been performed (NO in step S7), the process moves to step $8. Here, if the engine speed NO is less than the preset 11Neth (step Sg), it is assumed that the engine is in an idling state and feedback control is performed to keep the idling speed constant (step 89).

On the other hand, if the engine speed Ne exceeds the set value Neth, then YES in step S8>, it is assumed that deceleration is occurring and the process moves to step S1, and the generated engine torque is then Calculate Tqet (steps 33, 84). Then, a target amount of bypass air corresponding to the generated engine torque T qet is set based on the calculation (step 511), and the opening degree of the bypass valve 12 is controlled based on this amount of bypass air.

With such a device, the vehicle body can be decelerated at a deceleration that is faithful to the accelerator operation while suppressing vibrations when the vehicle decelerates.

Although the vibrations during acceleration and deceleration are significantly suppressed by the above-described embodiment, if some vibration still remains, use other well-known photographic suppression means, such as changes in engine speed. If the control of the ignition timing based on the above-described method is performed together with the control of the device of the present invention, even better effects can be expected.

Furthermore, although each of the above embodiments shows the case where the present invention is applied to an AT vehicle, the present invention can also be applied to an MTI.

〔Effect of the invention〕

As described above, the present invention calculates the required engine torque based on the accelerator opening signal, and calculates the generated engine torque that follows the accelerator operation by performing a simulation using a drive system model based on this required engine torque. This has the effect of suppressing acceleration/deceleration vibration while obtaining engine output that is faithful to accelerator operation.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the engine W control device of the present invention, FIG. 2 is an overall configuration diagram showing the engine and its υIIO device in the first embodiment of the invention, and FIG. 3 is the same control 11 device. Fig. 4 is a flowchart showing the control contents of the control device, Fig. 5 is a schematic diagram showing a model of the drive system used in the control device, and Fig. 6 is a block diagram showing the control contents of the control device. FIG. 7 is a graph showing temporal changes in the throttle opening area, engine torque, and acceleration when the engine is operated, and is a flowchart showing the control contents of the engine control device in the second embodiment. DESCRIPTION OF SYMBOLS 1... Engine, 5... Throttle valve, 9... Throttle motor, 10... Throttle sensor, 12...
...Bypass valve, 13...Accelerator opening sensor, 14
... ECU, 20... Requested engine torque calculation means, 21... Generated engine torque calculation means, 22...
Throttle opening setting means.

Claims (1)

[Claims] 1. In an engine control device that controls engine torque according to an accelerator opening degree, based on an accelerator opening degree signal,
A required engine torque calculation means that calculates the requested engine torque, and a generated engine torque calculation that calculates the generated engine torque that follows the accelerator operation by performing a simulation using a drive system model based on the requested engine torque. and throttle opening setting means for setting an actual throttle opening based on the generated engine torque. 2. In an engine control device that controls engine torque according to the accelerator opening degree, based on the accelerator opening signal,
A required engine torque calculation means that calculates the requested engine torque, and a generated engine torque calculation that calculates the generated engine torque that follows the accelerator operation by performing a simulation using a drive system model based on the requested engine torque. 1. A control device for an engine, comprising: a means for controlling a torque; and a setting means for setting a state of a torque changing means based on the generated engine torque.