JPS62214241A - Driving force controlling device for vehicle - Google Patents

Abstract

PURPOSE:To prevent deterioration in the driving performance of a vehicle due to traveling in a hunting condition by providing a means of operating the slip ratio between a tire and a road face and a driving force controlling means for regulating the feeding quantity of fuel to an engine in accordance with said slip ratio. CONSTITUTION:A driving wheel rotating speed signal DVf from a rear wheel rotating speed detector 10 and non-driving wheel rotating speed signals DVfr, DVfl from front wheel rotating speed detectors 13, 14 are inputted into the F/V converter 6 of a controlling device 3. A microcomputer 4 operates the slip ratio between a tire and a road face and regulates the feeding quantity of fuel to an engine in accordance with the magnitude of the slip ratio. Thereby, the repetition of the reduction and recovery of driving force can be prevented, improving driving performance.

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, in such conventional vehicle driving force control devices, the slip ratio between the tires and the road surface is calculated by detecting the rotation speed of the driving wheels and the non-driving wheels, and the slip ratio is larger than the set value. The system was designed to sometimes close the throttle valve to reduce the driving force, but when the slip ratio fell below a set value, the throttle valve was opened depending on the amount of accelerator pedal depression to restore the driving force. If the amount of accelerator pedal depression is held constant, the driving force will be reduced to suppress slip, and then the original driving force will return to the original, causing slip to occur again and the driving force to decrease.
There is a problem in that recovery hunting occurs and driving performance is significantly impaired.

[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 calculating means for calculating a slip ratio between the tire and the road surface based on a signal; a slip ratio determining means for determining whether the calculated slip ratio is greater than a set value; a driving force control means that reduces the amount of fuel supplied to the engine when the slip rate is greater than a value, and a target engine output characteristic setting means that changes a target engine output characteristic with respect to an accelerator operation amount based on the slip ratio during driving force control. The above-mentioned problem is solved by configuring a vehicle driving force control device.

[Effect]

In this invention, the driving wheel rotational speed detection means detects the rotational speed of the driving wheels, and the non-driving wheel rotational speed detection means detects the rotational speed of the non-driving wheels. The slip ratio calculation means calculates the slip ratio between the tires and the road surface based on the rotational speed of By reducing the driving force by decreasing the driving force, and by changing the target engine output characteristic with respect to the accelerator operation amount using the target engine output characteristic setting means, it is possible to prevent the reduction and recovery of the driving force from being repeated and prevent the next slip. Improves driving performance by suppressing the occurrence of

〔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, which is configured to be linked to the depression of the accelerator pedal 2, and generates a voltage corresponding to the depression amount (stroke amount) of the accelerator pedal 2. The accelerator signal DA is output to the control device 3.

The control device 3 includes a microcomputer 4, an A/D converter 5, an F/V converter 6, and a motor drive circuit 7. The A/D converter 5 and motor drive circuit 7 are connected to the microcomputer 4. The microcomputer 4 includes an interface circuit 4a, an arithmetic processing unit (CPU) 4b, and a storage device 4C such as RAM and ROM.
and the accelerator potentiometer 1 and F/V
The voltage output from the converter 6 is supplied to the arithmetic processing unit 4b via the A/D converter 5 and the interface circuit 4a, and the arithmetic processing unit 4b is operated according to a program stored in advance in the storage device 4C.

In the storage device 4C, the graphs shown in Step [Phase] and Step [Phase] in FIG. 3 are stored in corresponding storage areas in the form of storage tables. The memory table corresponding to the graph shown in step [phase] is the deviation -
This is a motor speed conversion table 4d, which converts the throttle valve opening deviation Dir shown on the horizontal axis to the motor speed shown on the vertical axis.

Further, the memory table corresponding to the graph shown in step [phase] is a stroke amount-target opening conversion table 4e, in which the stroke IL of the accelerator pedal 2 shown on the horizontal axis is shown as the target opening of the throttle valve 17 on the vertical axis. θ. Three target engine output characteristic patterns A, B, and C are set according to the value of the maximum slip ratio Smax. The first characteristic pattern A is the maximum slip rate Sma
When x is O (Smax = O), the second characteristic pattern B is when the maximum slip rate Smax is larger than O but smaller than the preset characteristic change value Sl (0<Sm
ax<S, ), and the third characteristic pattern C is a case where the maximum slip rate Smax is larger than the characteristic change value S〃 (Smax>S+), and the target opening degree θ with respect to the stroke iL. The rate of change in is the largest for the first characteristic pattern A, followed by the second characteristic pattern B, and the third
The characteristic pattern C of is made the smallest.

Furthermore, the storage device 4C includes a set value storage area 4f that stores a preset set value SO (reference slip ratio) that is a criterion for determining the slip ratio, and a target opening degree θ of the throttle valve 17. A target opening storage area 4g where Smax is stored, a maximum slip ratio storage area 4h where the maximum slip ratio Smax is stored, and a designated value that designates forward rotation, reverse rotation, or holding of the step motor 16 is stored. A motor rotation direction storage area 41, a startup cycle storage area 4j where a startup cycle of a 001 interrupt to be described later is stored, and an up/down counter 4 where a value corresponding to the current opening (actual opening) of the throttle valve 17 is stored. The 001 interrupt is executed based on the cycle time stored in the activation cycle storage area 4j.

The amplifier down counter 4 can be incremented by a number corresponding to the number of steps required for a step motor 16, which will be described later, to drive the throttle/nottle valve 17 from a fully closed state to a fully open state. , for example, is set to O when the throttle valve 17 is fully closed.

The F/V converter 6 also receives a driving wheel rotational speed from a rear wheel rotational speed detector 10 which is a driving wheel rotational speed detection means for detecting the rotational speed of rear left and right wheels 8 and 9 which are driving wheels. Signal DVr
Right front wheel rotation speed detector 13 and left front wheel rotation speed detector 14 are non-driving wheel rotation speed detection means that individually detect the rotation speed of left and right front wheels 11 and 12, which are non-driving wheels. Wheel rotation speed signal DVfr and left non-driving wheel rotation speed signal D
Vfl are respectively supplied.

Here, the rear wheel rotation speed detector 10 detects the rotation speed of the drive wheels by detecting the rotation speed of the differential gear 15 that transmits the driving force to the rear left and right wheels 8.9, and according to the rotation speed. The drive wheel rotational speed signal DVr, which is a pulse signal having a different frequency, is output to the F/V converter 6. Further, the left and right front wheel rotational speed detectors 13.14 directly detect the rotational speed of the left and right front wheels 11.12 individually, and the left and right non-driving wheel rotational speed signals are pulse signals having a frequency corresponding to the rotational speed. D
Similarly, Vfr and D Vfl are respectively 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 D Vfr and D Vfl into voltages according to their respective frequencies, and converts these rotational speed signals D
V is converted into a digital signal by the A/D converter 5,
The signal is supplied to the microcomputer 4. As a result, the arithmetic processing unit 4b of the microcomputer 4 performs the control process described later based on the input rotational speed signals DV from the three rotational speed detectors 10, 13.14 and the accelerator signal DA from the accelerator potentiometer 1. A control signal C3 is output to the motor drive circuit 7 based on the calculated step rate S.

The motor drive circuit 7 outputs a drive current to the step motor 16 in response to a control signal C8 supplied from the microcomputer 4, and causes the step motor 16 to rotate forward or reverse, or maintains a non-rotating state. The rotation shaft 16a of the step motor 16 is integrally formed with the rotation shaft of the throttle valve 17. For example, when the step motor 16 rotates in the normal direction, the throttle valve 17 is opened, and when the step motor 16 rotates in the reverse direction, the throttle valve 17 is closed.

The arithmetic processing device 4b of the microcomputer 4 is R
For example, 1 shown in FIG.
Arithmetic processing is performed according to a timer interrupt processing program that is executed every 00m5ec, and based on the processing results, an overflow counter interwoven interrupt processing (OCI interrupt) shown in FIG. 4, for example, is executed every activation cycle.

That is, in step (2), the driving wheel rotational speed signal DVr of the rear wheel rotational speed detector 10 is read, and based on it, the rotational speed of the left and right rear wheels 8.9 which are driving wheels is calculated, and this is set as the driving wheel rotational speed Vr. It is temporarily stored in a predetermined storage area of the storage device 4C.

Next, proceed to step ■, and detect the right front wheel rotation speed detector 13.
reads the right non-driving wheel rotational speed signal DVfr, calculates the rotational speed of the right front wheel 11 which is a non-driving wheel based on it, and temporarily stores this in a predetermined storage area of the storage device 4c as the right non-driving wheel rotational speed Vfr. .

Next, move to step ■ and check left front wheel rotation speed detector 1.
4 reads the left non-driving wheel rotational speed signal DVfl, calculates the rotational speed of the left front wheel 12 which is a non-driving wheel based on it, and temporarily stores this as the left non-driving wheel rotational speed Vfl in a predetermined storage area of the storage device 4C. do.

Next, the process moves to step (2), and the right non-driving wheel rotational speed Vfr in step (2) and the left non-driving wheel rotational speed Vf in step (2) are determined.
Read out the left and right non-driving wheel rotation speed Vfr,
The rotational speed of the entire non-driving wheels is calculated based on Vfl, and this is temporarily stored in a predetermined storage area of the storage device 4C as the non-driving wheel rotational speed Vf. In this embodiment, the non-driven wheel rotation speed Vf is an average value of the rotation speeds of the front left and right wheels 11.12.

Next, the process moves to step (2), where the drive wheel rotation speed Vr in step (2) and the non-drive wheel rotation speed (Vf) in step (2) are read out. , 9, and the tire-road surface slip rate S that occurs between the tires and the road surface is calculated.

Next, the process moves to step (2), where the reference slip rate S0 stored in advance in the set value storage area 4f of the storage device Z4c and the slip rate S calculated in step (2) are read out, and the slip rate S is set to the set value S. Determine whether the value is greater than or not. As a result of the determination, the slip rate S is the standard slip rate S0
When it is larger (S>So), step ■ ~ step 0
While performing driving force reduction control, when the slip ratio S is less than the reference slip ratio 80 (S≦80), steps 0 to
Shift to normal driving force control in @l and steps ① to @.

In the driving force reduction control, first, in step (3), the throttle valve 1 is stored in the target opening storage area 4g of the storage device 4c.
7 target opening degree θ. Set the command value 0 to specify fully closed.

Next, the process moves to step (2), and the maximum slip ratio S max is temporarily stored in the maximum slip ratio storage area 4h of the storage device 4c.

Next, the process moves to step (2), where the current opening degree θ, which is the content of the up/down counter 4k (O when fully closed) in the storage device 4c, and the step (2) determine the intention, or the step (described later) [
The target opening degree θ is searched by [phase]. and the target opening degree θ. Subtract the current opening θ from the target opening θ. The deviation Dir of the current opening degree θ with respect to the current opening degree θ is calculated and temporarily stored in a predetermined storage area of the storage device.

In the next step [phase], the deviation Dir calculated in step (2) is read out, the deviation-motor speed conversion table 4d in the storage device 4C is referred to, and the motor speed is searched and determined from the deviation Dif.

Next, proceed to step ■, and calculate the deviation Di of step ■.
r is read out, and based on this it is determined whether to rotate the step motor 16 forward or reverse, or whether to maintain the current state, and a predetermined value representing the determination result is temporarily stored in the motor rotation direction storage area 41 of the storage device 4C. . The decision in this case is made by looking at the content of the deviation Dir; when the deviation Dir is positive, the rotation is forward, when the deviation Dif is negative, the rotation is reversed, and when the deviation Dir is O, the current rotation is maintained. It is determined that

Next, the process moves to step @, and the activation cycle of the OC1 interrupt, which will be described later, is determined based on the motor speed calculated in step [phase], and the determined time is temporarily stored in the activation cycle storage area 4j of the storage device 4C.

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

In addition, in the driving force normal control, first, in step 0,
The accelerator signal DΔ from the accelerator potentiometer 1 is read, the amount of depression of the accelerator pedal 2 is calculated based on it, and this is temporarily stored in a predetermined storage area of the storage device 4C as a pedal stroke amount.

Next, the process moves to step (2), where the stroke measurement of step [phase] is read out, and it is determined whether the stroke measurement is 0 or not. The determination in this case is to check whether the accelerator pedal 2 is depressed or not, and as a result of the determination, if the stroke IL is O, the process moves to step [phase] and the slip rate of the storage device 4C is maximized. Value storage area 4
The contents of h are cleared to 0 and the process moves to step [phase]. On the other hand, when L≠0, the process moves directly to step [phase].

In this step [phase], the maximum slip rate S max stored in step ■ or ■ and the stroke weight read in step ■ are read out, and the maximum slip rate S max stored in the slip rate maximum value storage area 4h of the storage device 4c is Two target engine output characteristic patterns A.

The target opening degree θ according to the stroke iL with reference to the characteristic pattern corresponding to the maximum slip rate S max of B or C. Search and decide. Then, the process moves to step (2) described above.

Next, the OCI interrupt processing shown in FIG. 4 will be explained. As described above, this OC■ interrupt processing is executed according to the activation cycle of the time set in step 0.

That is, first, in step [phase], the step motor 16
It is determined whether or not to maintain the current rotational position and set it to non-rotation. The determination in this case is executed by looking at the contents of the motor rotation direction storage area 41 in step 0. As a result of the determination, if it is determined that the current rotational position of the step motor 16 is to be maintained, the current OCI interrupt processing is finished and the OCI interrupt processing is performed again according to the startup cycle of the OCT interrupt processing. Execute the embedded processing or start the main program
, and executes 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 16 is not to be maintained, the process moves to step (2) and it is determined whether or not to rotate the step motor 16 in the normal direction. In this case, the determination is also made in step [
phase], the motor rotation direction storage area 4 of step
This is done by looking at the contents of 1. As a result of the determination, the step motor 16 is rotated in the normal direction (direction to open the throttle valve 17).
When the step motor 16 is reversed (in the direction of closing the throttle valve 17), the step moves to step [phase], where 1 is added to the current value θ of the up/down counter 4, and then the step proceeds to step ■. , moves to step [phase], subtracts 1 from the current value θ in the up/down counter 4, and then moves to step 0.

In this step [phase], the drive current that is the control signal C3 for forwardly rotating the step motor 16 by one step, or the same drive current for rotating the step motor 16 by one step in the reverse direction, is output. The OCI interrupt processing ends.

The processing of steps ■ to step ■ above constitutes a slip ratio calculation means, the processing of step ■ constitutes a slip/slump rate determination means, and steps
The processing of step motor 16 and the step motor 16 constitute a driving force control means, and further, the processing of steps ①, ② and steps 0 to [phase] constitute a target engine output characteristic setting means.

Next, the effect will be explained.

Assume that the vehicle is currently traveling on a road with a low coefficient of road friction, such as a snowy road or an icy road, and if the timer interrupt process shown in FIG. 3 is executed at predetermined intervals in this state, first,
In step ■, the drive wheel rotation speed Vr is read, in the next step ■, the right non-drive rotation speed Vfr is read, and in step ■, the left non-drive rotation speed Vfl is read. Non-driving wheel rotation speed V fr, V
The non-driving wheel rotation speed vr of the entire non-driving wheels is calculated from fl.

In the next step (2), based on the driving wheel rotation speed Vr and the non-drive wheel rotation speed Vf, the slip ratio S between the tires and the road surface, which represents the slip state of the vehicle on the road surface, is calculated. , it is determined whether the calculated slip ratio S is larger than the reference slip ratio S0.

At this time, if the slip rate S of the vehicle is greater than the reference slip rate S0, that is, if the vehicle is in a slip state because the throttle valve 17 is opened too much and excessive driving force is applied, then the determination in step Shifting to the driving force reduction control in step (2) and subsequent steps, first, in step (2), the target opening degree θ is set regardless of the current depression amount (stroke tL) of the accelerator pedal 2. The specified value O that specifies fully closed is stored in the target opening storage area 4g, and in the next step ■, the slip rate S at the current vehicle slip is
The maximum value Smax (maximum slip ratio) is stored in the slip ratio maximum value storage area 4h.

In the subsequent slip ■, the target opening degree θ set in step ■. The deviation Dir is calculated by subtracting the current opening degree θ, which is the content of the up/down counter 4, from the up/down counter 4. In this case, the throttle valve 17 of the vehicle in the running state is connected to the accelerator pedal 2.
is opened according to the stroke IL of the target opening θ set in step ■. is 0, so the deviation Di
r becomes a negative value.

In the next step [phase], the motor speed corresponding to the absolute value of the deviation Dir is searched from the deviation-motor speed conversion table 4d, and in the following step
is a negative value, the rotational direction of the step motor 16 is determined to be the reverse direction, that is, the direction in which the throttle valve 17 is closed, and in the next step 0, the activation cycle corresponding to the motor speed retrieved in step [phase] is determined. is determined.

When the OCT interrupt process shown in FIG. 4 is executed following this timer interrupt process, first, it is determined in step [phase] that the step motor 16 is not held at the current position, and in the following step ■, the step motor 16 is It is determined that 16 is reversed. Therefore, the process moves to step 0, 1 is subtracted from the current value θ in the up/down counter 4, and the next step [
phase], the motor drive circuit 7 sends a control signal CS to rotate the step motor 16 by one step in the reverse direction.
Output to. As a result, the motor drive circuit 7 outputs a motor drive signal to the step motor 16, so the step motor 16 rotates one step, and the throttle valve 17 is closed by the rotation angle.

Subsequently, when the next OCI interrupt is started according to the activation cycle set in step @, the current value θ of the up/down counter 4 is changed in step [phase] through step [phase] and step ■, in the same way as above. 1 is subtracted from , and in the next step [phase], a motor drive signal is output to the step motor 16 via the motor drive circuit 7 to further rotate the step motor 16 by one step in the reverse direction. As a result, the step motor 16 rotates one step, the throttle valve 17 is further closed by the rotation angle, and the predetermined time required for one cycle of the timer interrupt processing shown in FIG. 3 elapses. is repeated until

Therefore, when the slip ratio S becomes larger than the standard slip ratio So, such as when the driving force is suddenly increased on a road surface with a low friction coefficient, the throttle valve 17 closes at a relatively high speed due to the activation period determined in step @. As a result, the driving force can be reduced quickly and slips can be stopped quickly, thereby ensuring running stability of the vehicle on a road surface with a low coefficient of friction.

After that, when the slip state of the vehicle subsides due to the driving force reduction control described above, the process shifts to normal driving force control below step 0 based on the determination in step (2). First, in step 0, the stroke IL of the accelerator pedal 2 is read, and In step O, Axel's work amount expressed as stroke amount is O
, that is, whether the accelerator pedal 2 is being depressed.

At this time, if the accelerator pedal 2 is not depressed, the process shifts from step ■ to normal driving force control for steps below step 0. First, the stroke amount L=O is read in step 0, and then in the next step 0. Since it is determined that the stroke ff1L=0, the process moves to step ■, where the maximum slip rate S max is rewritten to 0, and in the next step [phase], it corresponds to the stroke 1L=o based on the first characteristic pattern A. Target opening θ. −〇 is searched. As a result, the deviation Djf calculated in step ■ becomes 0, and it is determined in step 0 that the current rotational position of the step motor 16 will be maintained, so the next 001 interrupt will be completed only by processing step [phase]. Become. Therefore, in this case, the throttle valve 17 remains closed.

On the other hand, assuming that the driving force reduction control is performed with the accelerator pedal 2 depressed, if the slip ratio S decreases to the reference slip ratio 80 or less due to the closing control of the throttle valve 17, the determination in step (2) is made. Then, in step 0, the stroke IL is detected by the accelerator potentiometer 1, so in the next step @, it is determined that the stroke amount L≠0. Therefore, in the next step [phase], the target opening degree θ is determined according to the stroke iL based on the maximum slip rate S max stored in the step (2). is searched from the second characteristic pattern B or the third characteristic pattern C in which the rate of change of the target opening degree θ0 with respect to the stroke IL is smaller than the first characteristic pattern A.

As a result, the target opening degree θ is reached in step [phase]. A value smaller than that when the door is closed and there is no slipping is searched for, and its target opening degree θ is found. Since this value is larger than the current opening degree θ, in the next step (2), a positive deviation Dir having a smaller value than when the accelerator is not operated is calculated. Then, the motor speed is determined in step [phase] based on this deviation Dir, and in the next step 0, the rotation direction of the step motor 16 is designated as the forward rotation direction, and in the next step @, based on the motor speed. CO[The activation cycle of interrupt processing is determined.

As a result, a control signal C8 for rotating the step motor 16 by one step in the forward rotation direction is output to the motor drive circuit 7 at step [phase] after the processing of the next step [phase] to step ■. . As a result, a motor drive signal is output to the step motor 16, and the step motor 16 rotates one step in the normal rotation direction at a slower speed than when the accelerator is not operated. As a result, the step motor 16
Throttle valve 1 is rotated by the rotation angle corresponding to one step of
7 is opened at a relatively low speed, and this driving force recovery control is continued until the deviation DiflJ<O.

As a result, the driving force is gradually increased, making it possible to recover the driving force while suppressing the occurrence of subsequent vehicle slips, and preventing hunting of vehicle slips due to repeated reduction and recovery of the driving force. can.

Therefore, in the above embodiment, when the vehicle is in a slipping state (S>SO), the target opening degree θ. is set to 0 to reduce the driving force early, and at this time the maximum slip ratio Sm
ax is memorized, and when the driving force is restored after the slip condition subsides, the maximum slip rate S max during the driving force reduction control is
By reducing the opening characteristic of the throttle valve 17 with respect to the depression iL of the accelerator pedal 2, that is, the target engine output characteristic with respect to the accelerator operation amount,
It is possible to prevent the next occurrence of vehicle slippage, prevent hunting driving due to repeated reduction and recovery of driving force, and ensure running stability of the vehicle.

In the above embodiment, the driving force is reduced by closing the throttle valve 17 and adjusting the amount of intake air, but the present invention is not limited to this. For example, the amount of fuel supplied may be adjusted, By adjusting the ignition timing, and also by combining these with the throttle valve control described above, the driving force reducing means can be configured. Further, in the above embodiment, the step motor 16 is used as the driving force control means, but it is not limited to this. For example, it may be configured with a digital servo motor and a rotary encoder attached to its rotating shaft. I can do it.

Further, the control device 3 is not limited to the above-mentioned configuration, and may be configured with electronic circuits such as a subtraction circuit, a comparison circuit, and a logic circuit. Further, in the above embodiments, an example of a rear wheel drive vehicle has been described, but the present invention can of course be applied to a front wheel drive vehicle.

〔Effect of the invention〕

As described above, according to the present invention, the drive wheel rotation speed detection means, the non-drive wheel rotation speed detection means, and the slip ratio between the tire and the road surface are calculated from the rotation speeds of the drive wheels and the non-drive wheels. a slip ratio calculation means; a slip ratio determination means for comparing and determining the magnitude of the slip ratio with respect to a set value; a driving force control means for adjusting the amount of fuel supplied to the engine according to the magnitude of the slip ratio; Since the vehicle driving force control device is configured with a target engine output characteristic setting means for changing the target engine output characteristic with respect to the accelerator operation amount according to the slip ratio, the vehicle is in a slip state due to generation of excessive driving force. Sometimes, the driving force is quickly reduced to suppress slip early, and after the slip subsides, when increasing the driving force again, the target engine output is reduced relative to the accelerator operation amount based on the slip rate during the driving force reduction control. By restoring the driving force, the next occurrence of slip can be effectively suppressed. Therefore, it is possible to prevent hunting in the control due to repeated reduction and recovery of the driving force, and it is possible to prevent deterioration of the driving performance of the vehicle due to hunting running.

[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, and determining whether the calculated slip ratio is larger than a set value. a slip ratio determining means for determining whether the slip ratio is higher than the set value; a driving force control means for reducing the amount of fuel supplied to the engine when the slip ratio is larger than the set value; and an accelerator operation amount based on the slip ratio during driving force control. A vehicle driving force control device comprising: target engine output characteristic setting means for changing a target engine output characteristic.