JPS62199936A - Driving power controller for vehicle - Google Patents

Abstract

PURPOSE:To secure the traveling stability of a vehicle by installing a controller which calculates the slip rate from the results of the revolution speed detectors for driving wheels and driven wheels and controls the opening and closing of a throttle valve and controls the fuel feed quantity. CONSTITUTION:Each revolution speed signal is supplied into the F/V converter 6 of a controller 3 from a rear wheel revolution speed sensor 11 for the driving wheels 9 and 10 and the front wheel revolution speed sensors 14 and 15 for the driven wheels 12 and 13. The slip rate between a tire and a road surface is calculated by the controller 3. A throttle valve 18 is opening/closing-controlled by a control signal CS1 supplied from the controller 3. Further, a control signal CS2 operates a fuel feed controller 21. Therefore, the traveling stability of a vehicle can be secured.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a vehicle driving force control device.

[Conventional technology]

As a conventional vehicle driving force control device, for example, Japanese Patent Application Laid-open No. 6
There is one described in Japanese Patent No. 0-43133.

In an automobile engine output control device that controls engine output by changing the amount of fuel supplied to the engine according to the position of the accelerator pedal, it is used to detect drive wheel rotation speed, non-drive wheel rotation speed detection means, and rain detection means. A calculation means for calculating the slip ratio between the tires and the road surface from the output; a comparison means for comparing the calculated slip ratio with a set slip ratio; and a comparison means for comparing the calculated slip ratio with a set slip ratio; The system is characterized by being equipped with a slip rate control means that outputs a signal that forcibly reduces the fuel supply to the engine. By controlling the engine so that the slip ratio is below a certain value, starting performance and running stability on road surfaces with a low coefficient of friction are improved.

[Problem that the invention seeks to solve]

However, such conventional vehicle driving force control devices are configured to forcibly reduce the driving force when the slip ratio of the vehicle is greater than a set value.
If the above-mentioned setting value is set to a small value, a sudden start or sudden acceleration on a road with a low coefficient of road friction μ, such as a snowy road or an icy road, will result in a sudden decrease in driving force, resulting in an inability to start due to engine stalling or deceleration. This causes jerky vibrations due to deceleration and acceleration. On the other hand, if the front and rear setting values are set to a large value, the degree of reduction in the driving force is small, making it difficult to control slippage, resulting in a problem that the running stability of the vehicle cannot be ensured.

[Means for solving problems]

This invention was made by focusing on these conventional problems, and as shown in the basic configuration diagram in Figure 1, the invention detects the rotation speed of the drive wheel and outputs the drive wheel rotation speed signal. a driving wheel rotational speed detection means for detecting the rotational speed of a non-driving wheel and outputting a non-driving wheel rotational speed signal; a slip ratio calculation means for calculating a slip ratio between the tire and the road surface based on the signal; a first slip ratio determination means for determining whether the calculated slip ratio is larger than a first set value; a second slip ratio determination means for determining whether the calculated slip ratio is larger than a second set value that is set to be larger than the first set value; and a first driving force control means that reduces the degree of reduction in driving force when the slip ratio becomes larger than the second set value; and the first driving force control means alone or when the slip ratio becomes larger than the second set value. By configuring a vehicle driving force control device, the vehicle driving force control device is provided with a second driving force control means that reduces the driving force by a larger degree than the first driving force control means that reduces the driving force. It is characterized by solving the above problems.

[Effect]

Therefore, in the present invention, two setting values with different sizes are provided as standards for determining the magnitude of the slip ratio of the vehicle, and the values are calculated based on the driving wheel rotation speed and the non-driving wheel rotation speed. When the slip ratio becomes larger than the first setting value, the first driving force control with a relatively small degree of reduction in driving force is executed, and the second setting in which the slip ratio is set larger than the first setting value is executed. When it becomes larger than the value, the second driving force control, which has a larger degree of reduction in driving force than the first driving force control, is executed alone or together with the first driving force control to greatly reduce the driving force, The degree of reduction in driving force is changed according to the magnitude of the slip ratio to effectively suppress vehicle slip.

〔Example〕

The present invention will be explained below based on illustrated embodiments.

FIGS. 2 to 4 show an embodiment of the present invention, which is applied to a rear wheel drive vehicle.

First, to explain the configuration, 1 shown in FIG. 2 is an accelerator potentiometer that detects the depression amount (stroke amount) L of the accelerator pedal 2, and an accelerator signal DA having a voltage corresponding to the stroke amount is sent to the control device 3. Output to.

The control device 3 includes a microcomputer 4, an A/D converter 5, an F/V converter 6, a drive circuit 7, and an output circuit 8.
and an A/D connected to the F/V converter 6.
A converter 5, a drive circuit 7 and an output circuit 8 are connected to the microcomputer 4. The microcomputer 4 includes an interface circuit 4a and a processing unit (CPU).
4b, and a storage device 4C such as RAM or ROM, and the accelerator signal DA and the rotation speed signal DV, which will be described later, from the F/V converter 6 are transmitted via the A/D converter 5 and the interface circuit 4a. The signal is supplied to the arithmetic processing unit 4b, and the arithmetic processing unit 4b is operated according to a program stored in advance in the t9 device 4C.

The F/V converter 6 also receives a driving wheel rotational speed from a rear wheel rotational speed detector 11 which is a driving wheel rotational speed detection means for detecting the rotational speed of left and right rear wheels 9, 10 which are driving wheels. Signal DV
r, and the right front wheel rotation speed detector 14 and left front wheel rotation speed detector 15, which are non-driving wheel rotation speed detection means that individually detect the rotation speeds of the left and right front wheels 12 and 13, which are non-driving wheels. Driving wheel rotation speed signal DVfr and left non-driving wheel rotation speed signal D
Vf+ is supplied respectively.

Here, the rear wheel rotation speed detector 11 detects the rotation speed of the driving wheels by detecting the rotation speed of the differential gear 16 that transmits the driving force to the left and right rear wheels 9. The driving wheel rotation speed signal DVr, which is a frequency pulse signal, is output to the F/V converter 6. Further, the left and right front wheel rotational speed detectors 14.15 individually detect the rotational speed of the left and right front wheels 12.13, and the left and right non-driving wheel rotational speed signal DVfr is a pulse signal having a frequency corresponding to the rotational speed.
, DVfl are similarly output to the F/V converter 6.

The F/V converter 6 converts the driving wheel rotational speed signal DVr and the left and right non-driving wheel rotational speed signals DVfr and DVfl into voltages according to their respective frequencies, and converts the driving wheel rotational speed signal DVr and the left and right non-driving wheel rotational speed signals DVfr and DVfl into voltages according to their frequencies, and converts the driving wheel rotational speed signal DVIJ
<The signal is converted into a digital signal by the A/D converter 5 and supplied to the microcomputer 4. The arithmetic processing unit 4b of the microcomputer 4 executes arithmetic processing based on the rotational speed signal DV and the accelerator signal DA, and outputs two types of control signals CSI and CS2 according to the processing results.
Output.

The one control signal CSt is output to the drive circuit 7, which outputs a drive current as a motor drive signal CAl to the step motor 17 to rotate the step motor 17 in the forward or reverse direction or in the non-clockwise direction. Hold in rotation. The rotation shaft 17a of the step motor 17 is configured integrally with the rotation shaft of the throttle valve 18. For example, when the step motor 17 rotates in the normal direction, the throttle valve 18 is opened, and when the step motor 17 rotates in the reverse direction, the throttle valve 18 is closed. In this manner, the opening and closing of the throttle valve 18 is controlled through the operation of the step motor 17 driven by the control signal C3I.

The other control signal C32 is output to the output circuit 8, and via this output circuit 8, a drive current as the coil drive signal CA2 is output to the drive relay 9 having a normally closed contact. Open and close. The drive relay 19 is provided in an electric circuit 22 of a fuel supply control device 21 that controls the amount of fuel supplied to an engine having six cylinders 20a to 20f, and receives a control signal C32 output from the microcomputer 4, for example. When is the “Hi” signal, the drive relay 19 is opened, and as a result, the fuel injection pulse signal CB output from the fuel supply control bag W21 is “Hi”.
The signal becomes "Lo-", and the fuel supply is cut off.On the other hand, when the control signal C32 output from the microcomputer 4 is "Lo-", the drive relay 19 remains closed, thereby cutting off the fuel supply. The control device 21
Since the fuel injection pulse signal CB consisting of the i'' signal is output, fuel supply is continued.

Next, the effect will be explained.

2 and 3 explain the operation of the microcomputer 4 according to the present invention.
3 is a timer interrupt processing program that is executed every 00m5ec, and FIG. This is clubbed interrupt processing (OCl interrupt).

In FIG. 2, first, in step (2), the rear wheel rotation speed signal DVr of the rear wheel rotation speed detector 11 is read, and based on this, the rotation speed of the differential gear 16 indicating the rotation speed of the rear wheel 9.10 is calculated. .

Next, move to step ■ and check the right front wheel rotation speed detector 1.
The right non-driving wheel rotational speed signal DVfr of No. 4 is read, the rotational speed of the right front wheel 12 is calculated based on this, and the process proceeds to step (3), where the left non-driving wheel rotational speed signal of the left front wheel rotational speed detector 15 is read. Read the DVfl and adjust the left front wheel 13 based on this.
Calculate the number of rotations.

Then, proceeding to step (2), the rotation speed Vf of the non-driving wheels is calculated from the left and right front wheel rotation speeds obtained in steps (2) and (2). In this embodiment, the average value of the rotation speeds of the left and right front wheels 12.13 is used as the non-driven wheel rotation speed vr.

Next, the process moves to Ste/Knob (2), and the slip rate S of the vehicle is calculated based on the front wheel rotational speed Vf calculated in step (2) and the rear wheel rotational speed Vr read in step (2).

Then, the process proceeds to step (2), where it is determined whether or not the slip rate S calculated in step (2) is greater than a preset first set value S.
When the slip ratio S is larger than 1 (S>Sl), the process moves to step ■, and the driving force reduction control of steps ■ to step ■ is executed, while when the slip ratio S is smaller than the first set value Sl (S In Sl), the process moves to step [phase], and proceeds to step [phase], (2), and driving force reduction control of steps (2) to (2).

In the driving force reduction control, first, in step (3), it is determined whether the slip ratio S is larger than a second set value S2 that is set larger than the first set value S1, and the slip ratio S is When it is larger than the second set value S2 (S>32), the process moves to step (3), and the control signal C32, which is an "H4" signal, is output to the output circuit 8. As a result, the output circuit 8 outputs a coil drive signal CA2 that excites the coil of the drive relay 19, and as a result, the drive relay 19 is opened and the fuel injection pulse signal CB becomes a "Low" signal, and the six cylinders 20a Fuel supply to ~20f is cut off.

On the other hand, as a result of the determination in step ■, when the slip ratio S is less than or equal to the second set value 82 (S≦32), step
Then, the control signal C32 consisting of the "Loiv" signal is output. As a result, the output circuit 8 outputs the coil drive signal CA2 that maintains the demagnetized state of the coil of the drive relay 19, and as a result, the fuel injection pulse signal CB changes to the "H4" signal in order to maintain the drive relay 19 in the closed state. Then,
Fuel is supplied to the six cylinders 20a-20f as usual.

In the next step [phase], a command value specifying the target opening degree θ0 of the throttle valve 18 to be fully closed is set in a predetermined storage area M of the storage device. Next, the process moves to step (2), where the current opening degree θ of the throttle valve 18 is subtracted from the target opening degree θ0 set in step [phase] or determined in step O, which will be described later, and thereby the target opening degree θ0 is Current opening degree θ
Calculate the deviation Dir. Next, proceed to step @, and based on the deviation Dir calculated in step [phase],
For example, the motor speed is searched and determined by referring to a deviation-motor speed conversion table stored in advance in the storage device 4C.

Next, the process moves to step 0, and it is determined based on the deviation Dir whether to rotate the step motor 17 in the forward or reverse direction, or to maintain the current state. In this case, the deviation Dir
When the deviation Dir is positive, it is determined that the rotation is normal, when the deviation Dir is negative, the rotation is reversed, and when the deviation Dir is 0, the current state is maintained. Next, the program moves to step @, and determines the activation cycle of an OCI interrupt, which will be described later, based on the motor speed determined in step @.

This completes the timer interrupt processing, returns to the main program, and then shifts to the OCI interrupt processing shown in FIG.

In the driving force normal control, first, in step (2), a control signal C32 consisting of a "Low" signal is output.

As a result, the drive relay 19 is held in the closed state and the fuel injection pulse signal CB
becomes a “Hi” signal, and the six cylinders 20a to 20f
Fuel supply continues as usual.

Subsequently, the process moves to step [phase], where the accelerator signal DA of the accelerator potentiometer 1 is read, and the stroke fiL of the accelerator pedal 2 is calculated based on it. Then, the process moves to step O, and based on the stroke ff1L calculated in step [phase], for example, the memory device W4
The target opening degree θ0 is searched and determined by referring to the stroke amount-target opening degree conversion table stored in advance in c. Thereafter, the process moves to the step [phase] described above.

Next, the oct interrupt process shown in FIG. 4 will be explained. In this OC1 interrupt processing, first, in step [phase],
It is determined whether the rotational position of the step motor 17 is to be maintained as it is and not rotated. As a result of the determination, if it is determined that the current rotational position of the step motor 17 is to be maintained, the current Oct interrupt processing is now terminated, and the OCI interrupt processing is executed again according to the activation cycle. , or return to the main program and execute the timer interrupt process shown in FIG. 3 after a predetermined time.

On the other hand, if it is determined in step [phase] that the current rotational position of the step motor 17 is not to be maintained, the process moves to step (2) and it is determined whether or not to rotate the step motor 17 in the normal direction. As a result of the determination, the step motor 17
If it is determined that the motor is to be rotated in the normal direction, the process moves to step @, where 1 is added to the current opening degree θ stored in the storage device 4C, and then the process moves to step [phase], while the step motor 17 is rotated. If it is determined that it should be reversed, step 0
After subtracting 1 from the current opening degree θ, the process moves to step [phase].

In this step (2), a control signal C81 consisting of an "Hl" signal (or "Lo-" signal) for causing the step motor 17 to rotate forward (or reverse) by one step is output to the drive circuit 7. This causes the drive circuit 7 to drive the step motor 1.
In order to output a drive current which is a motor drive signal CAI that rotates the motor 7 in the normal direction (or in the reverse direction), the step motor 17 rotates by one step in the normal direction (or in the reverse direction). As a result, the throttle valve 18, which rotates integrally with the rotating shaft 17a of the step motor 17, is controlled to open and close depending on the direction and amount of rotation of the step motor 17.

A slip rate determination means is configured by the processing of steps ■ to step ■ above, a first slip rate determination unit is configured by step ■, a second slip rate determination unit is configured by step ■, and a slip rate determination unit is configured by steps ■ to step [ phase], the drive circuit 7, and the step motor 17 constitute a first driving force control means, and further, step (2).

Step [phase] to step [phase], the output circuit 8, the drive relay 19, and the fuel supply control device 21 constitute a second driving force control means.

In the above embodiment, the rear wheel rotation speed detector 11 detects the driving wheel rotation speed Vr, and the left and right front wheel rotation speed detectors 14.15 detect the non-driving wheel rotation speeds Vfr, Vf.
l is detected to calculate the non-driving wheel rotational speed vr, and based on the driving wheel rotational speed Vr and the non-driving wheel rotational speed Vf, the slip rate S is calculated.
The slip ratio S is compared with a set value S1 and a second set value S2 which is larger than this to determine its magnitude, and the slip ratio S is determined to be the first and second set value 31. When the slip becomes larger than S2, that is, when the slip of the driving wheels 9 and 10 is large, such as when suddenly starting or accelerating on a road surface with a low friction coefficient, the fuel supply amount is reduced to throttle valve control that reduces the degree of reduction in driving force. The degree of reduction in driving force is increased by adding fuel supply control that increases the degree of reduction in driving force.

As a result, vehicle slippage can be stopped quickly, and the running stability of the vehicle can therefore be ensured.

Further, when the slip rate is larger than the first set value S1 but smaller than the second set value S2, that is, when the slip is relatively small, only the throttle valve control that reduces the degree of reduction in driving force is performed to control the throttle valve 18. By closing, the degree of reduction in driving force is reduced. This makes it possible to keep the deceleration and acceleration applied to the vehicle to a small level, thereby preventing the occurrence of jerky vibrations that occur in the vehicle body due to large deceleration and acceleration, and speeding up the recovery of the vehicle from slipping. can.

In the above embodiment, the step motor 17 that operates the throttle valve 18 is used as the first driving force control means, but the step motor 17 is not limited to this. It can be configured with a rotary encoder. Also, the first and second
As the driving force control means, in addition to the above-mentioned throttle valve or means for controlling the fuel supply amount, means for adjusting the ignition timing or means for applying brakes to the wheels can be used. , combining these, the first
By configuring the degree of reduction of the driving force of the second driving force control means to be larger than that of the second driving force control means, the same effects as in the above-mentioned embodiment can be obtained.

Furthermore, the control device is not limited to the configuration described above (it can also be configured with electronic circuits such as a subtraction circuit, a comparison circuit, a logic circuit, etc.). Although an example has been described, it goes without saying that the present invention can also be applied to front-wheel drive vehicles.

〔Effect of the invention〕

As described above, according to the present invention, the driving wheel rotation speed detection means, the non-driving wheel rotation speed detection means, and the tire rotation speed detection means are provided.
a slip ratio calculation means for calculating a slip ratio between road surfaces;
A first step that compares and determines the magnitude of the slip ratio and the first set value.
a second slip rate determining means that compares and determines the magnitude of the slip rate and a second set value; a first driving force control means that reduces the degree of force reduction; and a first driving force control means that reduces the driving force either alone or together with the driving force reduction control by the first driving force control means when the slip ratio is larger than the second set value. Since the vehicle driving force control device includes the second driving force control means which has a larger degree of reduction in driving force than the driving force control means, when the slip of the vehicle is relatively small, the second driving force control means has a smaller degree of reduction in driving force than the second driving force control means. By controlling the driving force of It can speed up recovery. In addition, when the slip of the drive wheels is large, such as when suddenly starting or accelerating on a road surface with a low coefficient of friction, the second drive force control, which reduces the drive force to a large degree, is executed alone or together with the first drive force control. By increasing the degree of reduction of the driving force, vehicle slip can be stopped quickly, thereby achieving the effect that running stability of the vehicle can be ensured.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the basic configuration of the invention, FIG. 2 is a schematic explanatory diagram showing an embodiment of the invention, and FIGS. 3 and 4 show an example of the processing procedure of the control device according to the invention. 3 is a flowchart showing each of the steps.

Claims (1)

[Claims] Drive wheel rotation speed detection means that detects the rotation speed of a drive wheel and outputs a drive wheel rotation speed signal, and non-drive wheel rotation that detects the rotation speed of a non-drive wheel and outputs a non-drive wheel rotation speed signal. a slip ratio calculating means for calculating a slip ratio between the tire and the road surface based on the driving wheel rotation speed signal and the non-driving wheel rotation speed signal; a first slip ratio determination means for determining whether the calculated slip ratio is greater than a second set value that is set larger than the first set value; a first driving force control means that reduces the degree of driving force reduction for reducing the driving force when the slip ratio becomes larger than the first set value;
The first driving force control means reduces the driving force by itself or together with the driving force reduction control by the first driving force control means when the slip ratio becomes larger than the second set value. a large second driving force control means;
A vehicle driving force control device comprising: