JPH0472443A - Control device for vehicle engine - Google Patents

Abstract

PURPOSE:To most suitably control the response characteristic of vehicle acceleration to the accelerator operating quantity by providing a means for estimating running resistance of a vehicle, setting a target driving shaft torque by which vehicle acceleration corresponding to the accelerator operating quantity can be obtained, based on the running resistance and the vehicle weight, and controlling an engine based on the target driving shaft torque. CONSTITUTION:An accelerator operating quantity detecting means (a) for detecting the accelerator operating quantity, a vehicle speed detecting means (b) for detecting the vehicle speed, a vehicle weight detecting means (c) for detecting the vehicle weight, a vehicle acceleration detecting means (d) for detecting the vehicle acceleration, and a driving shaft torque detecting means (e) for detecting the driving shaft torque, are provided. A target acceleration is then calculated by a target acceleration calculating means (f) based on the accelerator operating quantity and the vehicle speed, and running resistance is calculated by a means (g) based on the vehicle weight and the vehicle acceleration. Further, a target driving shaft torque is calculated by a means (h) based on the vehicle weight, the target acceleration, and the running resistance, and an engine is controlled by a control means (i) based on the torque.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a control device for a vehicle engine.

<Prior art> As a control device for a vehicle engine, it is possible to control the drive shaft torque of the vehicle according to the amount of accelerator operation, and also to select the response characteristic of the drive shaft torque according to the running condition of the vehicle. It has been proposed (Japanese Patent Application Laid-Open No. 1-313636
(See Japanese Patent Application No. 1-319026).

<Problems to be Solved by the Invention> However, in such a vehicle engine control device, the response characteristics of the drive shaft torque to the accelerator operation amount are determined based on limited conditions (steering angle, rainfall, and vehicle load weight.

Since the selection was made according to the vehicle's up/down slope condition, vehicle wheel load, etc., for conditions that are not taken into consideration in the driving condition, the acceleration according to the accelerator operation amount is The problem was that it changed under the influence of

SUMMARY OF THE INVENTION In view of these problems, an object of the present invention is to provide a vehicle engine control device that can always maintain constant acceleration according to the amount of accelerator operation in all running conditions.

<Means for Solving the Problems> Therefore, as shown in FIG. 1, the present invention provides the following (a)
A control device for a vehicle engine is configured by providing the means in (i).

(a) Accelerator operation amount detection means for detecting the accelerator operation amount (b) Vehicle speed detection means for detecting vehicle speed (C)
Vehicle weight detection means (d) for detecting vehicle weight Vehicle acceleration detection means (el) for detecting vehicle acceleration (el) Drive shaft torque detection means for detecting drive shaft torque Calculates target acceleration based on the accelerator operation amount and vehicle speed Target acceleration calculation means (g) for calculating running resistance based on the drive shaft torque, vehicle weight, and vehicle acceleration Running resistance calculation means (g) for calculating running resistance based on the vehicle weight, target acceleration, and running resistance. Target drive shaft torque calculation means (i) Engine control means for controlling the engine based on the target drive shaft torque Here, the drive shaft torque detection means (e) includes one that directly detects the drive shaft torque, The target drive shaft torque may be detected indirectly by reading the previous calculated value of the target drive shaft torque calculated by the target drive shaft torque calculation means (5).

<Operation> In the above configuration, each of the detection means (a) to (e) detects the accelerator operation amount, vehicle speed, vehicle weight, vehicle acceleration, and drive shaft torque.

The target acceleration calculation means calculates the target acceleration from the accelerator operation amount and the vehicle speed.

At the time of this setting, the target acceleration calculated based on the accelerator operation amount and the vehicle speed is defined as the vehicle acceleration.

The correction may be made based on the drive shaft torque, the slip rate of the drive wheels determined from various information, the vehicle turning state, and the like.

Further, a running resistance calculating means (the amount is calculated from the vehicle weight, vehicle acceleration, and drive shaft torque to estimate the running resistance).

At the time of this estimation, the slip rate of the drive wheels, etc. may be taken into consideration.

Then, the target drive shaft torque calculation means (Inc.) calculates the target drive shaft torque from the vehicle weight, target acceleration, and running resistance.

Then, the engine control means (i) controls the engine according to the target drive shaft torque. At this time, the detected drive shaft torque and vehicle running state may be taken into consideration.

<Example> The present invention will be explained in detail below.

In FIG. 2, 1 is an engine, 2 is a transmission, and 3 is a drive shaft.

A potentiometer-type accelerator opening sensor 4 is provided as the accelerator operation amount detection means, and generates an output voltage corresponding to the accelerator opening (accelerator operation amount) Acc operated by the driver.

As vehicle speed detection means, a vehicle speed sensor 5 is attached to the drive shaft 3 and generates a pulse signal at a period corresponding to the vehicle speed (hereinafter referred to as vehicle speed) Vsp.

As a vehicle weight detection means, a potentiometer type stroke sensor 6 is provided to detect the vehicle weight W from the stroke of the suspension when the vehicle is stopped, and generates an output voltage corresponding to the stroke of the suspension.

An acceleration sensor 7 is provided as vehicle acceleration detection means, and generates an output voltage corresponding to acceleration α in the longitudinal direction of the vehicle.

As drive shaft torque detection means, a magnetostrictive torque sensor 8 is attached to the drive shaft 3 and generates an output voltage corresponding to the drive shaft torque T.

Signals from these sensors 4 to 8 are input to the CPU 9.

By operating according to a predetermined program, the CPU 9 functions as a target acceleration calculation means, a running resistance calculation means, a target drive shaft torque calculation means, and an engine control means, and controls the engine l via various devices.

Next, the operation of the CPUI will be explained according to the program shown in the flowchart of FIG.

This program has a fixed time period (for example, 10m5ec)
executed every time.

In step 1 (denoted as Sl in the figure; the same applies hereinafter), the output voltage of the accelerator opening sensor 4 is read to detect the accelerator opening Acc.

In step 2, a calculation is performed based on the pulse signal from the vehicle speed sensor 5 to detect the vehicle speed Vsp.

In step 3, it is determined whether the vehicle speed Vsp=O (when the vehicle is stopped) or not, and with the vehicle speed Vsp=O as a condition, the process proceeds to step 4, where calculations are made based on the output voltage of the suspension stroke sensor 6, and the vehicle weight W Detect.

In step 5, the output voltage of the acceleration sensor 7 is read to detect the vehicle acceleration α.

In step 6, the output voltage of the torque sensor 8 is read to detect the drive shaft torque T.

However, when detecting the drive shaft torque T, the target drive shaft torque Tor is calculated in step 9, which will be described later, and the engine 1 is controlled to obtain this torque. The previously calculated value of the shaft torque Tor may be read as is.

Next, in step 7, target acceleration αr is calculated. The target acceleration αr is calculated from a map as shown in FIG. 4 based on the accelerator opening Ace and the vehicle speed Vsp.
The basic target value is searched and, if necessary, corrected based on the vehicle acceleration α, the drive shaft torque T, the slip rate of the drive wheels determined from various information, the vehicle turning state, etc. This part corresponds to the target acceleration calculation means.

In step 8, running resistance R is calculated. The running resistance R here is calculated using the following equation based on the drive shaft torque T, vehicle weight W, and vehicle acceleration α. This part corresponds to the running resistance calculation means.

R=T/r-W・α r: Driving wheel radius However, W and R should also take into consideration the inertia of the rotating part.

In step 9, the target drive shaft torque Tor is calculated.

The calculation of the target drive shaft torque Tor here is based on the vehicle weight W
, based on the target acceleration αr and running resistance R, using the following equation. This part corresponds to the target drive shaft torque calculation means.

Tor=r (W-ar +R) r: Drive wheel radius In step 10, in order to achieve the target drive shaft torque Tor, the engine l is control. This part corresponds to the engine control means.

FIG. 5 shows a more specific version of the engine control means (i) in FIG. 1, and the control method will be explained below based on this.

Transmission ratio detection means (U) for detecting the gear ratio of the gear train in the transmission, torque converter output shaft rotational speed detection means (k) for detecting the output shaft rotational speed of the torque converter in the transmission, and engine rotational speed ( Engine rotation speed detection means (1) for detecting the rotation speed of the input shaft of the torque converter is also provided.

The target engine speed setting means... is the gear ratio detection means (
j), the torque converter output shaft rotation speed detected by the torque converter output shaft rotation speed detection means (k), and the target drive shaft torque calculation means (h).
) The target engine rotation speed that the engine should generate is set in accordance with the target drive shaft torque Tor set in ).

The engine rotation speed control means (n) determines that the engine rotation speed detected by the engine rotation speed detection means (1) is determined by the target engine rotation speed setting means... in accordance with the response characteristics of the preset reference model. The engine is controlled to match the set target engine speed.

Here, when the engine rotational speed control means (n) is configured to include a target engine output shaft torque setting means (0) and an intake air amount control means fp), the target engine output shaft torque setting means (0) However, the target engine output shaft torque is set so that the engine rotation speed matches the target engine rotation speed in accordance with the response characteristics of a preset reference model, and the intake air amount control means is set as described above. The intake air amount of the engine is controlled based on the target engine output shaft torque.

In addition, when the vehicle running state detecting means (Ql) and the response characteristic model setting means (r) are provided, the vehicle running state detecting means (Q) detects the steering angle, the amount of rainfall, and the loaded weight of the vehicle.

At least one of the following: vehicle uphill/downhill condition, vehicle wheel load, etc.
The response characteristic standard model setting means (r) sets a standard model of the engine rotational speed response characteristic based on the detected vehicle driving condition.

<Effects of the Invention> As explained above, according to the present invention, the running resistance of the vehicle is estimated, and the target drive shaft is set such that the vehicle acceleration corresponding to the accelerator operation amount is obtained based on the running resistance and the vehicle weight. By setting the torque and controlling the engine based on the target drive shaft torque, the effect is that the response characteristics of vehicle acceleration to accelerator operation amount, which is the behavior of the vehicle, can always be optimally controlled regardless of the driving condition. can get.

[Brief explanation of drawings]

Fig. 1 is a functional block diagram showing the configuration of the present invention, Fig. 2 is a system diagram of an embodiment of the invention, Fig. 3 is a flowchart showing control details, and Fig. 4 is a map for calculating target acceleration. FIG. 5 is a block diagram showing a specific example of the engine control means. l...Engine 4...Accelerator opening sensor 5.
...Vehicle speed sensor 6...Stroke sensor 7.
・・Acceleration sensor 8・・Torque sensor 9・・
・CPU

Claims (1)

[Scope of Claims] Accelerator operation amount detection means for detecting an accelerator operation amount; Vehicle speed detection means for detecting vehicle speed; Vehicle weight detection means for detecting vehicle weight; Vehicle acceleration detection means for detecting vehicle acceleration. and drive shaft torque detection means for detecting drive shaft torque; target acceleration calculation means for calculating target acceleration based on the accelerator operation amount and vehicle speed;
a running resistance calculation means that calculates running resistance based on vehicle weight and vehicle acceleration; a target drive shaft torque calculation means that calculates a target drive shaft torque based on the vehicle weight, target acceleration, and running resistance; and the target drive shaft. A control device for a vehicle engine, comprising: an engine control means for controlling the engine based on torque; and a control device for a vehicle engine.