JP2582638B2 - Advanced environment recognition device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an apparatus for recognizing an advanced environment for an automobile.

<Conventional technology> Conventionally, control of an engine and a driving force transmission system of an automobile is performed by
Control has been performed based on a predetermined control constant so as to approach the target value.

Therefore, control characteristic targets such as the shift timing of the electronically controlled automatic transmission have also been predetermined. That is, there is a shift pattern map that defines shift positions (gear positions; first to third and fourth speeds) so as to obtain the optimum torque required for the vehicle in accordance with the vehicle speed and the throttle valve opening. When the select lever is in the D range, the shift control is performed based on the shift (see Japanese Utility Model Laid-Open No. 62-194231), and the control characteristic target of the shift timing has been set in advance.

<Problems to be Solved by the Invention> However, if the control characteristic targets such as the shift timing of the automatic transmission are predetermined, the driving environment of the vehicle is not determined conventionally, At high altitude, the torque generated by the engine with respect to the throttle valve opening changes, and the following problems may occur. That is, since the air density decreases at high altitude, the torque generated by the engine is lower than at low altitude under the same throttle valve opening condition.
For this reason, the shift timing in the shift control that was optimal at low altitudes is shifted up earlier than the optimal value at the same throttle valve opening, and the optimal torque as described above cannot be obtained, and the engine Since vibration and shift shock are transmitted to the axle, there is a problem that noise and vibration increase.

The present invention has been made in view of the above circumstances, and provides an advanced environment recognition device that calculates an altitude from a ratio between a calculated amount of an intake air flow rate to be taken into an engine and an actually measured amount under the same engine operating conditions. With the goal.

<Means for Solving the Problems> Therefore, as shown in FIG. 1, the present invention provides a rotational speed detecting means for detecting the rotational speed of the engine, and a throttle valve opening degree detecting for detecting the opening degree of the throttle valve. Means, an intake air flow rate calculating means for calculating an intake air flow rate at a standard altitude using an engine speed and a throttle valve opening detected by these detecting means, and an intake air mass flow rate sucked into the engine. It is configured to include mass flow rate measuring means for actual measurement, and altitude calculating means for calculating altitude from the ratio between the calculated intake air flow rate calculated by the intake air flow rate calculating means and the intake air mass flow rate actually measured by the mass flow rate measuring means. .

<Operation> According to this configuration, even if the engine generated torque is lower than the standard altitude under the same throttle valve opening, the rotation speed detecting means and the throttle valve opening detecting means are used. By calculating the ratio between the calculated intake air flow rate at the standard altitude calculated by the intake air flow rate calculating means and the intake air mass flow rate actually measured by the mass flow rate measuring means according to the altitude, a correction coefficient relating to altitude is calculated. Here, at high altitudes, the air density decreases, and the intake air mass flow rate decreases. Therefore, it is possible to correct the altitude by calculating the ratio, that is, to calculate the altitude.

<Example> An example of the present invention will be described below with reference to FIG.

This embodiment is an example in which the advanced environment recognition device according to the present invention is used for a shift control device of an automatic transmission.

An automatic transmission 2 is provided on the output side of the engine 1. The automatic transmission 2 includes a torque converter 3 connected to an output shaft of the engine 1, a gear transmission 4 connected to an output shaft of the torque converter 3, and a gear transmission 4
And a hydraulic actuator 5 for performing a connection / release operation of various speed change elements therein. The operating oil pressure for the hydraulic actuator 5 is controlled via various solenoid valves, but here only the shift solenoid valves 6A and 6B for automatic shifting are shown.

The control unit 7 incorporates a microcomputer and controls the gear-type transmission 4 via the hydraulic actuator 5 by controlling the shift solenoid valves 6A, 6B and the like based on signals from various sensors. .

As the various sensors, a position sensor 8 for detecting an operation position (P, R, N, D, 2, 1) of a select lever (not shown) is provided.

Further, a vehicle speed sensor 9 for obtaining a rotation signal from an output shaft of the gear transmission 4 and detecting a vehicle speed VSP is provided.

Also, the opening TV of the throttle valve 10 of the intake system of the engine 1
A throttle sensor 11 is provided as a throttle valve opening detecting means for detecting O.

Further, in the intake passage 12 upstream of the throttle valve 10, a hot-wire flow meter 13 is disposed as a mass flow rate measuring means for measuring the intake air mass flow rate Qm drawn into the engine 1.
Here, the hot-wire flow meter 13 measures the intake air mass flow rate Qm by controlling a supply current to a bridge circuit formed by a temperature-sensitive resistor and a plurality of resistors (not shown).

Further, a crank angle sensor 14 is provided on the output shaft of the engine 1 or on a shaft that rotates in synchronization with the output shaft. The signal from the crank angle sensor 14 is, for example, a pulse signal for each reference crank angle, and the engine speed N is calculated from the cycle thereof.

Here, the control unit 7 performs shift control suitable for the operation position of the select lever and the driving conditions of the vehicle based on various input signals, and particularly, when the select lever is in the D range, the shift position of the first to fourth speeds. Is automatically set, and the combination of ON / OFF of the shift solenoid valves 6A and 6B is controlled to shift the gear type transmission 4 to its shift position.

Next, the shift control based on the recognition of the altitude environment in the D range by the control unit 7 will be described with reference to the flowchart of FIG.

In step 1, the vehicle speed VSP, the throttle valve opening TVO, and the engine speed N are read.

In step 2, the mass flow rate Qm of the intake air is read by the hot wire flow meter 13.

In step 3, the intake air flow rate Q at the standard altitude (low altitude) is calculated based on the engine speed N and the throttle valve opening TVO.
Using a three-dimensional map to which c is assigned in advance, Qc is searched from the engine speed N and the throttle valve opening TVO. That is, the function of step 3 corresponds to intake air flow rate calculation means.

In step 4, the ratio γ (= Qc / Qm) of the calculated intake air flow rate Qc determined in step 3 to the intake air mass flow rate Qm read in step 2 is calculated. Here, at high altitudes, the air density ρ decreases and the intake air mass flow rate increases.
Qm is smaller than intake air mass flow Qc at standard altitude (low altitude). Thus, the higher the altitude, the higher the ratio γ becomes. Therefore, by obtaining the ratio γ, it is possible to make a correction relating to altitude.

The intake air mass flow rate Qm is an average Qm
It is desirable to use (for example, an average value of a predetermined time).

 That is, the function of step 4 corresponds to the altitude calculation means.

In step 5, the actual TVO = TVO ₁ , with reference to a shift pattern map in which shift positions (gear positions; 1st to 3rd and 4th speeds) are determined corresponding to the vehicle speed VSP and the throttle valve opening TVO. VSP
= Set the shift position from VSP ₁ by searching. However, the search is not the actual TVO, but the actual TVO is performed using the ratio γ multiplied by a constant K as a correction parameter for calculating the altitude.
TVO '= TVO ₁ × γ × K with O corrected is used. That is, the fourth
As shown in the figure, throttle valve opening TVO ₁ × γ × K and vehicle speed
Since the shift position is determined corresponding to VSP ₁ , the point A where the throttle valve opening TVO is actually TVO ₁ is set to the point B where the throttle valve opening TVO is TVO ₁ × γ × K. It is assumed to be and will be controlled. Therefore, point A
Is in the third speed state, but the shift position at the point B is still in the second speed state, so that the upshift can be delayed.

As a correction method based on the altitude, a map of a plurality of shift patterns may be prepared in advance according to the altitude (ratio γ), and the shift position may be set after selecting the map based on the altitude (ratio γ). .

As described above, the shift timing in the shift control that was optimal at the standard altitude (low altitude) is changed to the ratio γ
Upshifting at high altitudes at a high altitude using the correction parameters including the above allows an optimal torque to be obtained at the same throttle valve opening, and has the effect of preventing the generation of noise and vibration. is there.

<Effects of the Invention> As described above, according to the present invention, even if the engine-generated torque is lower than the standard altitude, the calculated intake air flow rate determined by the rotation speed and the throttle valve opening is:
By calculating the ratio with the intake air mass flow rate actually measured according to the altitude, the altitude can be calculated, so that various control characteristic targets can be optimally set according to the altitude.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing the configuration of the present invention, FIG. 2 is a system diagram when the advanced environment recognition device according to the present invention is used in a shift control device of an automatic transmission as one embodiment,
Fig. 4 is a flowchart of the embodiment, and Fig. 4 is a view showing shift positions for explaining the operation of the embodiment. DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Automatic transmission, 7 ... Control unit, 10 ... Throttle valve, 11 ... Throttle sensor, 13 ... Hot wire flow meter, 14 ... Crank angle sensor

Claims (1)

(57) [Claims] 1. An engine speed detecting means for detecting an engine speed, a throttle valve opening detecting means for detecting an opening of a throttle valve, an engine speed and a throttle valve opening detected by these detecting means. Intake air flow rate calculating means for calculating the intake air flow rate at a standard altitude using the degrees,
An altitude is calculated from a ratio of a calculated mass flow rate of the intake air calculated by the calculated mass flow rate of the intake air to a mass flow rate measured by the measured mass flow rate of the mass flow rate. And an altitude calculation means.