JPH0617684A - Method for controlling acceleration of automobile - Google Patents

Abstract

PURPOSE:To provide a method for controlling driving force, which can achieve the acceleration proportional to a step-on angle of an accelerator pedal and also the same acceleration as usual even if load resistance and altitude of the place are changed, and can perform stable running. CONSTITUTION:In this method, it is intended that acceleration of an automobile can be controlled according to target torque of a drive shaft corresponding to desired acceleration, even if a gear ratio and an engine speed are changed, by compensating a torque change due to variation of drive shaft torque before and after speed change and engine speed, through adding an electronically controlled throttle valve 26 and a driving force control device 1 in addition to an engine control device and a transmission control device equipped with microcomputers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control method for controlling an engine by outputting an engine output operation amount to an engine output operation means such as an electronically controlled throttle valve, and a transmission means such as a stepped automatic transmission. The present invention relates to a transmission control method for outputting a gear ratio command to control a gear ratio, and a driving force control device for implementing these.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Application Laid-Open No. 2-201061 discloses one that positively controls the drive shaft torque of an automobile.

In this control method, first, one kind of target drive shaft torque curve corresponding to the vehicle speed and the accelerator pedal operation amount is stored in advance in a memory or the like, and the current vehicle speed and accelerator pedal operation amount are calculated. The target drive shaft torque is obtained from the target drive shaft torque, the target engine torque is obtained from the target drive shaft torque and the transmission gear ratio, and the throttle valve opening is controlled so that the target engine torque is obtained.

By using the target drive shaft torque curve in this way, this control method can meet the driver's preference.
Alternatively, it is to obtain acceleration that is easy to drive.

[0005]

However, in such a conventional technique, when the vehicle speed and the accelerator pedal operation amount are the same, the throttle valve opening is always the same, so that, for example, when moving from a lowland to a highland. If the vehicle environment changes, such as when a large amount of load is loaded, the same acceleration cannot be obtained even if the vehicle speed and the accelerator pedal operation amount are the same, and the driver's preference is met. Or, there is a problem that acceleration that is easy to drive cannot be obtained.

The present invention has been made by paying attention to such a conventional problem, and engine control capable of obtaining an acceleration according to a driver's preference or easy to drive even if the vehicle environment changes. An object of the present invention is to provide a method, a transmission control method, and these control devices.

[0007]

A driving force control device for achieving the above object is an accelerator opening detecting means for detecting an operation amount of an accelerator pedal, a vehicle speed detecting means for detecting a vehicle speed, and an accelerator pedal operation. A means for generating a target acceleration according to the amount, a target drive axis torque calculating means for obtaining a target drive axis torque from the target acceleration and the detected vehicle speed, and a drive axis of the vehicle emits the target drive axis torque. An engine operation amount calculating means for obtaining an engine output operation amount and a gear ratio command and outputting the engine output operation amount to the engine output operating means; and a gear ratio calculating means for outputting the gear ratio command to the gear changing means. It is characterized by having.

[0008]

In the means for generating the target acceleration, the actual acceleration obtained by differentiating the vehicle speed detected by the vehicle speed detecting means to the reference target acceleration corresponding to the operation amount of the accelerator pedal detected by the accelerator opening detecting means. The target acceleration is obtained by compensating for the deviation between and.

The target drive shaft torque calculating means calculates the target drive shaft torque by multiplying the target acceleration by the vehicle body weight and further limiting the maximum torque.

The engine operation amount calculation means obtains the engine output operation amount so that the drive shaft of the vehicle emits the target drive shaft torque, and outputs this to the engine output operation means.

The gear ratio calculating means selects an optimum gear ratio in relation to the engine output manipulated variable so that the drive shaft of the vehicle emits the target drive shaft torque, and this is output to the gear changing means.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments according to the present invention will be described below with reference to the drawings. In the description of various embodiments, the same parts are designated by the same reference numerals, and the duplicated description will be omitted.

First, a first embodiment according to the present invention will be described with reference to FIGS.

As shown in FIG. 1, the driving force control apparatus 1 of the present embodiment inputs signals from the accelerator opening sensor 2, the vehicle speed sensor 3 and the turbine sensor 4 to the automatic transmission control apparatus 5 to change gears. A command is output to the electronic throttle control device 6 as an engine output operation amount. That is, in this case, the engine output operating means is the electronic throttle 26.

Although the functions of the driving force control device have been described above, the actual hardware configuration is, as shown in FIG. 2, an input interface circuit 7, a CPU 8 for executing various calculations, various data, and the like. It is configured to have a ROM 9 and a RAM 10 that store programs and the like, and an output interface circuit 11. Mapped data such as engine characteristic curve and calculation program ROM
9 are stored. The CPU 8 uses the data from the input interface 7 and the data from the ROM 9 to
While transferring data in and out of the RAM 10 as appropriate during calculation,
The above function is achieved by executing the calculation according to the calculation program of the ROM 9 and outputting the result to the output interface circuit 11.

In this system, the depression angle of the accelerator pedal is regarded as the driver's willingness to accelerate, and the accelerator opening detecting means 12 causes the target reference acceleration α depending on the output of the accelerator opening sensor 2 and the changing speed thereof. Outputs ₀ . on the other hand,
The signal of the vehicle speed sensor 3 is converted into the actual acceleration α by the differential calculation unit 13, and the deviation from the target reference acceleration α ₀ is integrated and compensated by the integration compensation unit 14.
And is added to the target reference acceleration α ₀ . The required torque is calculated by multiplying this by the vehicle body weight m in the torque calculation unit 15, but the target drive shaft torque is obtained through the torque limiter 16 in order to prevent the generation of excessive torque.

The gear ratio calculator 17 converts the target drive shaft torque into the transmission input shaft torque. This part is a simple proportional calculation for both torque and rotation speed. The engine torque calculation unit 18 stores characteristics of the torque converter 19 for converting the transmission input shaft torque into engine torque.
As is well known, the torque converter has a function of amplifying torque by causing slip between the pump blade and the turbine blade. Therefore, at the same time as obtaining the target engine torque from the torque amplification factor, the slip is corrected to correct the target engine rotation speed. The number also needs to be calculated.

Generally, as shown in FIG. 3, the characteristics of the torque converter are as follows: the horizontal axis is the rotational speed ratio e = n ₂ / n ₁ between the input and the output, the torque ratio between the input and the output t = T ₂ / T ₁ Coefficient C
It is represented by p = T ₁ / n ₁ ² .

Here, n _{1 is the} input speed, n _{2 is the} output speed, T _{1 is the} input torque, and T ₂ is the output torque.

The capacity coefficient Cp represents the individuality of the torque converter and is a characteristic determined by its size and structure.
The above Cp is expressed by the torque T ₁ on the input side and the rotation speed n ₁ , but if expressed by using the torque T ₂ and the rotation speed n ₂ on the output side as Cp ′, then Cp ′ = T ₂ / n It can be determined as a characteristic curve peculiar to the torque converter from the relationship of ₂ ² = tCp / e ² .

Therefore, when Cp 'is obtained by setting the transmission input torque target value obtained by the gear ratio conversion unit 4 and the rotational speeds at that time as T ₂ and n ₂ , respectively, the rotational speed ratio e is obtained from the graph of FIG. Since the torque ratio t is determined, the target engine torque and the target engine speed are obtained.

The throttle opening calculation unit 20 stores the torque characteristic of the engine, and calculates the throttle opening from the target engine torque and the target engine speed. A typical engine torque characteristic is shown in FIG. This characteristic is mapped and stored, and the throttle opening at the intersection of the required rotation speed and torque is read.

This series of calculations is repeated for the number of shift stages of the transmission, and the condition determining section 21 determines the optimum combination of the gear ratio and the throttle opening for achieving the required torque.

The throttle opening signal thus obtained is applied to the electronically controlled throttle valve 7 via the electronic throttle control device 6 to obtain the target drive shaft torque. In addition,
The engine control device 22 controls the optimum fuel injection amount and ignition timing according to the throttle opening.

According to the method of the present embodiment, the acceleration command is controlled so as to satisfy the acceleration command. Therefore, the acceleration does not change before and after the shift, and the same acceleration is obtained even if the slope gradient, the load weight, the altitude, etc. change. Is obtained and the driver's feeling is not changed. In addition, since the system is a combination of feedforward control and feedback control, it has a characteristic that the response is fast and stable.

Of course, in actual control, for example, a combination of fine control methods such as correction corresponding to a change in torque converter characteristics due to a change in temperature of the torque converter oil is required, but only the essence of the invention is described here.

Next, a second embodiment of the present invention will be described with reference to FIG.

The parts from the vehicle speed and accelerator opening to the part for generating the target drive shaft torque are the same as in the case of FIG. The gear ratio calculation unit 17 converts the target drive shaft torque into the transmission input shaft torque, and the engine torque calculation unit 18 obtains the target engine torque from the torque amplification factor, and at the same time, corrects the slip to obtain the target engine speed. The calculation is the same as in the case of FIG. The condition determination unit 21 determines only the optimum gear ratio that achieves the required torque.

It is a feature of this embodiment that the calculation of the throttle opening is performed again after selecting the gear ratio to improve the accuracy of the calculation. That is, in turbine torque calculation unit 23, is divided by the target drive shaft torque T _o gear ratio n which is determined, torque T _t to produce the turbine of the torque converter
To calculate. The engine torque T _e necessary for producing this turbine torque T _t is calculated by the target engine torque calculation unit 2
In step 4, correction is performed using the characteristics of the torque converter.
Since the measured values are used for the engine rotation N _e and the turbine rotation N _{t at} this time, the obtained target engine torque T _e is more accurate than in the case of FIG. Throttle opening calculation unit 25
Since it is calculated by giving the actual engine speed, more accurate calculation is possible.

After determining the gear ratio n and the throttle opening as described above, a shift command is sent to the electronic throttle control device 6 to the automatic transmission control device 5 just as in the case of FIG. The engine output manipulated variable is output.

According to the present embodiment, in addition to the features described in the first embodiment, the throttle opening is calculated using the actual engine rotation and the actual turbine rotation, so that more accurate acceleration control can be achieved. There is a feature that you can do it.

[0032]

According to the method of the present invention, the same acceleration can be obtained even when the gear is changed, the slope gradient or the loaded weight is changed, and a stable driving feeling can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a control device of the present invention.

FIG. 3 is a characteristic diagram of a torque converter.

FIG. 4 is a torque characteristic diagram of the engine.

FIG. 5 is a block diagram showing a second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Driving force control device, 2 ... Accelerator opening sensor, 3 ... Vehicle speed sensor, 4 ... Turbine sensor, 5 ... Automatic transmission control device, 6 ... Electronic throttle control device, 12 ... Accelerator opening detection means, 17 ... Gear Ratio calculation unit, 18 ... Engine torque calculation unit, 19 ... Torque converter, 20, 25 ... Throttle opening calculation unit, 21 ... Condition determination unit, 23 ... Turbine torque calculation unit, 24 ... Target engine torque calculation unit, 26 ...
Electronically controlled throttle valve.

Claims (4)

[Claims] 1. An engine of an automobile, a transmission connected to an output shaft of the engine, an output operating means for controlling an output of the engine, a gear ratio operating means for switching a gear ratio of the transmission, an accelerator pedal, the accelerator. An accelerator sensor that outputs a signal proportional to a pedaling angle, a vehicle speed sensor that detects a vehicle speed, and a gear ratio signal to the gear ratio operating means and the output by inputting the accelerator sensor output and the vehicle speed sensor output. In the driving force control device for generating an engine output signal to the operating means, the driving force control device sets a reference target acceleration according to the output of the accelerator sensor and differentiates the vehicle speed sensor output. The measured acceleration value is calculated, and the deviation from the reference target acceleration is added to the target reference acceleration via a compensation element to obtain the target acceleration, and the target acceleration is calculated. Body weight over the target drive shaft torque, acceleration control method of a motor vehicle and calculates the optimum gear ratio signal and the engine output signal to achieve the target drive shaft torque. 2. An acceleration control system for an automobile according to claim 1, wherein the output operation means is an electronically controlled throttle valve and its control circuit. 3. The method according to claim 1, wherein the means for calculating the optimum gear ratio signal for achieving the target drive shaft torque and the means for calculating the engine output signal are values obtained by dividing the target drive shaft torque by each gear ratio. In addition, the target engine torque and the target engine speed corresponding to each gear ratio are calculated by correcting the torque ratio characteristics of the torque converter incorporated in the transmission, and these values are used to correspond to each gear ratio. An acceleration control method for an automobile, characterized in that a target throttle opening is calculated, the most fuel efficient throttle opening is used as an engine output signal, and a gear ratio corresponding to the throttle opening is used as a gear ratio signal. 4. The means for calculating an optimum gear ratio signal for achieving the target drive shaft torque according to claim 1, which is built in the transmission to a value obtained by dividing the target drive shaft torque by each gear ratio. The target engine torque and the target engine speed corresponding to each gear ratio are calculated by correcting the torque ratio characteristics of the torque converter, and the target throttle opening corresponding to each gear ratio is calculated from these values. The means for calculating the engine output signal by using the gear ratio that belongs to the most fuel-efficient value among them as the gear ratio signal, calculates the target turbine torque by dividing the target drive shaft torque by the gear ratio signal, and The target engine torque is obtained from the engine speed and the turbine speed that are detected at the engine speed, and the throttle opening obtained from the target engine torque and the actually detected engine speed is used as the engine opening. Acceleration control method of a motor vehicle, characterized in that the force signal.