JPH0577869B2 - - Google Patents

Abstract

PURPOSE:To enable an actual car speed to be rapidly and smoothly adjusted to a desired car speed, by a method wherein desired acceleration having a change rate differing with a range in which deviation is high or low is set according to a deviation between a desired car speed and an actual car speed, and control is effected so that actual acceleration is coincided with desired acceleration. CONSTITUTION:A device is provided a desired car speed setting means 3 which sets a desired car speed responding to an accel control amount detected by a control amount detecting means 1, and a desired acceleration setting means 5 which sets a desired acceleration responding to an output from a car speed deviation detecting means 4, which determines a deviation between the desired car speed and an actual car speed, detected by an actual car speed detecting means 2, and an accel control amount. The desired acceleration is set such that the more a deviation DELTAV is increase, the more the desired acceleration is increase, and in a range within which the deviation DELTAV is low, a change rate is high, and in a range within the deviation DELTAV is high, a change rate is decreased. A deviation DELTAalpha between the desired acceleration and actual acceleration, detected by an actual acceleration detecting means 6, is determined by an acceleration deviation detecting means 7, and the output of an engine is controlled by a control means 8 according to the deviation DELTAalpha and the desired acceleration.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a device for controlling the speed of a vehicle such as an automobile.

[Prior art]

As a conventional device of this kind, for example, as described in Published Patent Publication No. 43626 of 1975,
2. Description of the Related Art A device is known that sets a target vehicle speed according to the amount of operation of an accelerator pedal and controls the throttle valve opening so that the actual vehicle speed matches the target vehicle speed.

[Problem that the invention seeks to solve]

However, in the conventional device as described above, the throttle valve opening degree when accelerating to reach the target vehicle speed is uniquely determined according to the amount of operation of the accelerator pedal. There was a problem in that even if the same amount of operation was performed, the same acceleration could not be obtained if the load and engine speed at that time were different.

In other words, the acceleration of a vehicle is determined by the load (number of passengers, up/down road, wind direction, etc.) and the engine's output torque, but the load constantly changes depending on the driving situation, and the engine's output torque depends on the rotation. Since the acceleration changes depending on the number of driving conditions, there is a problem in that even if the accelerator pedal is operated by the same amount, the acceleration will differ each time depending on the driving situation, which does not match the driving sensation.

The present invention aims to solve the above problems.

[Means for solving the problem] In order to achieve the above object, in the present invention,
The deviation between the target vehicle speed and the actual vehicle speed increases as the deviation ΔV increases, and the rate of change is large in a small range of ΔV, and the rate of change is small in a large range of ΔV.The target acceleration is set so that the actual acceleration becomes the target acceleration. The engine output is controlled to match the engine output.

FIG. 1 is a block diagram illustrating the functionality of the present invention.

In FIG. 1, the operation amount detection means 1 detects the operation amount of an accelerator means (an accelerator pedal operated by the foot, an accelerator lever operated by the hand, etc.), and for example, detects the operation amount according to the amount of depression of the accelerator pedal. This is a potentiometer that outputs an analog signal.

Further, the actual vehicle speed detection means 2 is for detecting the actual vehicle speed of the vehicle, and can use a normal vehicle speed sensor or the like.

Next, the target vehicle speed setting means 3 sets a target vehicle speed corresponding to the amount of operation of the accelerator means.

Further, the vehicle element deviation detection means 4 detects the deviation ΔV between the target vehicle speed and the actual vehicle speed.

Next, the target acceleration setting means 5 sets a target acceleration corresponding to the above-mentioned deviation ΔV. At this time, the target acceleration increases as the deviation ΔV increases, and the rate of change increases in a small range of ΔV. is large, and the rate of change is small in a large range of ΔV.

Next, the actual acceleration detection means 6 detects the actual acceleration of the vehicle, which can be detected, for example, from the rate of change in the actual vehicle speed, or by using a device such as an acceleration sensor. It can also be detected.

Next, the acceleration deviation detection means 7 detects the deviation Δα between the target acceleration and the actual acceleration.

Next, the control means 8 outputs a control signal for controlling the engine output so that the actual acceleration of the vehicle matches the target acceleration according to the target acceleration and the deviation Δα.

This control means 8 outputs, for example, a signal for feedback control so that the deviation Δα becomes zero.

Next, the driving means 9 controls the engine output according to the above control signal, and is, for example, an actuator that adjusts the throttle valve opening.

As described above, in the present invention, the target acceleration is set according to the vehicle speed deviation ΔV, and the actual acceleration is controlled to match the target acceleration.
Regardless of the load or the engine speed at that time, if the amount of operation of the accelerator means is constant, a constant acceleration can always be obtained, and the driving characteristics can be made to match the driving sensation.

In addition, the target acceleration is set to be kept at a large value in a range where the deviation ΔV between the target vehicle speed and the actual vehicle speed is large, and the acceleration is set to be reduced in a range where ΔV is small, that is, when the actual vehicle speed approaches the target vehicle speed. Therefore, the target vehicle speed is reached at an early stage with a large acceleration, and there is no discontinuous sudden drop in acceleration when the target vehicle speed is reached, so excellent drivability that adapts to the senses of the driver can be obtained.

[Embodiments of the invention]

FIG. 2 is a block diagram of one embodiment of the present invention.

In FIG. 2, a potentiometer 11 detects the amount of operation of the accelerator pedal, and corresponds to 1 in FIG. 1.

The vehicle speed sensor 12 detects the actual speed of the vehicle, and corresponds to 2 in FIG. 1 above.

Further, the acceleration sensor 13 detects the actual acceleration of the vehicle, but as described above, the sensor 13 is not necessary when detecting the acceleration from the rate of change in the actual vehicle speed.

Next, 14 is a calculation device, for example, AD
It consists of a converter, microprocessor, DA converter, etc.

This arithmetic unit 14 corresponds to portions 3 to 8 in FIG.

Next, the drive circuit 15 drives the servo motor 16 in accordance with the control signal given from the arithmetic unit 14, thereby controlling the opening degree of the throttle valve 18 and controlling the engine output.

Further, the potentiometer 17 generates an analog signal corresponding to the throttle valve opening and feeds it back to the drive circuit 15 for control so as to match the target throttle valve opening.

15 to 17 above correspond to 9 in FIG. 1 above.

Next, calculations within the calculation device 14 will be explained.

FIG. 3 is a flowchart showing an example of the calculation in the calculation device 14.

The calculation shown in FIG. 3 is repeatedly performed at predetermined timing.

First, at P1, the accelerator operation amount L is read.

Next, at P2, the target vehicle speed Vt corresponding to L
Calculate.

This target vehicle speed Vt is read out from a value stored in advance in a data table as a value corresponding to the accelerator operation amount L, for example, as shown in FIG. 4A.

Next, in P3, the actual vehicle speed Va is read.

Next, in P4, the deviation ΔV between the target vehicle speed Vt and the actual vehicle speed Va is calculated.

Next, in P5, the actual acceleration αa is calculated. This actual acceleration αa may be obtained by reading the value detected by an acceleration sensor, or by calculating the rate of change of the actual vehicle speed Va.
That is, it can also be calculated from the difference between Va in the previous calculation and the value in the current calculation.

Next, in P6, target acceleration αt according to ΔV is calculated.

This target acceleration αt is also read from a value previously stored in the data table as a value corresponding to the deviation ΔV.

As a characteristic of the deviation ΔV and the target acceleration αt, for example, as shown in Figure 4B, it is possible that αt changes linearly with respect to ΔV, but according to such characteristics, the actual vehicle speed approaches the target vehicle speed. As the vehicle speed increases, the acceleration always decreases, and when ΔV is small, the acceleration is small, so it takes time to reach the target vehicle speed. Therefore, the characteristics shown in C are more desirable.

In other words, the deviation ΔV is a predetermined value x (for example, 10 Km/h)
In the above range, a large acceleration is maintained and the deviation is x
It is preferable to have a characteristic that reduces the acceleration when the acceleration becomes smaller.

Note that if a polygonal characteristic is used as shown in C, there is a risk that the acceleration will change discontinuously, so it is actually preferable to use a curved characteristic as shown in D.

In addition, in a large range of deviation ΔV, the rate of change is set to 0,
In other words, the characteristic may be flat as shown by the broken line D.

Next, in P7, the throttle valve opening θi for obtaining the target acceleration αt described above is calculated.

This throttle valve opening degree θi may be obtained by storing a value that is thought to produce the target acceleration αt in a standard operating state in advance in a data table, etc., and reading it out.

Next, in P8, the deviation Δα between the target acceleration αt and the actual acceleration αa is calculated.

Next, in P9, the throttle valve opening degree Δθ is calculated according to Δα.

Note that Δθ may have a negative value depending on Δα.

Next, at P10, target throttle valve opening θ=θi
+Δθ is calculated.

In this way, by setting the value obtained by adding the throttle valve opening Δθ corresponding to the deviation Δα to the throttle valve opening θi corresponding to the standard state as the target throttle valve opening, the actual acceleration can be made to match the target acceleration. can be controlled.

Next, in P11, the target throttle valve opening θ is output, and the throttle valve opening is adjusted accordingly to control the engine output.

In a normal fuel control system, the amount of intake air,
In other words, if the throttle valve opening changes, the fuel supply amount is calculated accordingly.
Engine output can be controlled by controlling the throttle valve opening.

Note that it is of course possible to provide a device in which the fuel supply amount is controlled according to the target acceleration αt and the deviation Δα, and the intake air amount is controlled accordingly.

〔Effect of the invention〕

As explained above, in the present invention, the target acceleration is set according to the deviation ΔV between the target vehicle speed and the actual vehicle speed, and the actual acceleration is controlled to match the target acceleration. Regardless of the rotation speed, if the amount of operation of the accelerator means is the same, the same acceleration can be obtained.

Also, the target acceleration is set to be kept at a large value in a range where the deviation ΔV between the target vehicle speed and the actual vehicle speed is large, and the acceleration is set to be reduced in a range where ΔV is small, that is, when the actual vehicle speed approaches the target vehicle speed. Therefore, the target vehicle speed is reached at an early stage with a large acceleration, and there is no discontinuous sudden drop in acceleration when the target vehicle speed is reached, resulting in excellent drivability that adapts to the driver's senses. There is an effect.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing the functions of the present invention, Figure 2 is a block diagram showing the functions of the present invention.
FIG. 3 is a block diagram of an embodiment of the present invention, FIG. 3 is a flowchart showing an embodiment of the calculation in the present invention, and FIG. 4 is a diagram showing an example of the operating characteristics of the present invention. Explanation of symbols, 1... Operation amount detection means, 2... Actual vehicle speed detection means, 3... Target vehicle speed setting means, 4...
Vehicle speed deviation detection means, 5...Target acceleration setting means, 6
... Actual acceleration detection means, 7 ... Acceleration deviation detection means, 8 ... Control means, 9 ... Driving means, 11 ...
Potentiometer, 12...Vehicle speed sensor, 13...
... Acceleration sensor, 14 ... Arithmetic device, 15 ... Drive circuit, 16 ... Servo motor, 17 ... Potentiometer, 18 ... Throttle valve.

Claims (1)

[Claims] 1 operation amount detection means for detecting the operation amount of the accelerator means; target vehicle speed setting means for setting a target vehicle speed corresponding to the operation amount; actual vehicle speed detection means for detecting the actual vehicle speed of the vehicle; A vehicle speed deviation detection means for detecting the deviation ΔV from the actual vehicle speed, and a target acceleration which increases as the deviation ΔV increases, and has a characteristic that the rate of change is large in a small range of ΔV and small in the range of a large ΔV. a target acceleration setting means for setting the actual acceleration of the vehicle; an acceleration deviation detection means for detecting a deviation Δα between the target acceleration and the actual acceleration; and a target acceleration and the deviation Δα. A vehicle speed control device comprising: a control means for outputting a control signal for controlling the engine output so that the actual acceleration of the vehicle matches the target acceleration according to the target acceleration; and a drive means for adjusting the engine output according to the control signal. .