JPH0436031A - Driving force controller for vehicle - Google Patents

Abstract

PURPOSE:To enable driving force control suitable for road conditions so as to secure proper acceleration performance even on a low road surface such as a snow road by continuously calculating an abrasion coefficient of the surface of a roads based on a rear wheel load and driving torque in a step before generation of slip of a vehicle, and decreasing the driving force of the vehicle based on the abrasion coefficient just before generation of a slip. CONSTITUTION:A torque detection means 20 which detects a driving torque of a vehicle by an engine 11 and a wheel load detection means (vehicle height sensor) 28 which detects wheel load which act on wheels 15, 16 of the vehicle are provided. In a step before slip of the vehicle is generated, an abrasion coefficient of the road surface is calculated by an abrasion coefficient calculation means 29 based on the wheel roads on the vehicle displayed by a wheel load detection means 28 and driving torque displayed by the torque detection means 20. The driving force of the vehicle is decreased by a driving force control means 27 based on this newest abrasion coefficient.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is suitable for use in, for example, preventing the drive wheels of a vehicle from slipping on the road surface and smoothly accelerating the vehicle. The present invention relates to a driving force control device for a vehicle, and particularly to a driving force control device for a vehicle equipped with an automatic transmission.

[Conventional technology]

In general, a vehicle driving force control device that calculates a vehicle slip rate based on the vehicle body speed and wheel speed and controls the engine output based on this slip rate is disclosed in, for example, Japanese Patent Application Laid-Open No. 1-178742. It is known from etc.

In this type of driving force control device, the slip rate S of the vehicle occurring between the wheels of the vehicle and the road surface is calculated based on the vehicle body speed 8 and the wheel speed vw as shown in FIG. However, when this slip ratio S exceeds a set value S0 of, for example, S = 0.3 at time t and after, a throttle actuator etc. is operated to limit the intake air amount of the engine, and the drive as rotational output is The slip ratio S is controlled to be small by reducing the force.

Here, in the middle of the intake passage of the engine, there is a throttle valve whose valve opening θ is controlled by the accelerator pedal as shown in characteristic line 1 in FIG. 8, and a sub-throttle valve whose valve opening is controlled by the throttle actuator. An intake valve is provided, and the valve opening θ of this intake valve is an eighth
As shown by a characteristic line 2 indicated by a dashed line in the figure, when the throttle actuator is operated, the opening degree θ of the throttle valve is controlled to be smaller than the valve opening θ, thereby limiting the intake air amount of the engine. When the slip rate S becomes smaller than the set value S0, the sub-throttle valve is opened by the throttle actuator, and the valve opening θ as an intake valve is controlled according to the valve opening θ of the throttle valve. .

Another conventional technique is to calculate the friction coefficient μ between the tires and the road surface when changing gears of the vehicle based on a signal from an acceleration sensor installed in the vehicle, and to calculate the slip rate S during gear changing. A driving wheel slip prevention device as a driving force control device that estimates the road surface condition based on S and the friction coefficient μ and reduces the driving torque of the vehicle according to the road surface condition is disclosed in, for example, Japanese Patent Application Laid-Open No. 1-223064. It is known from publications such as No.

[Problem to be solved by the invention]

By the way, in the above-mentioned conventional technology, the vehicle body speed (8) and the wheel speed (1) are detected, and based on these, the slip rate S of the vehicle is calculated using the equation (1) above, and this slip rate S is set to a predetermined set value S. . Since the engine output is controlled depending on whether or not the slip exceeds the limit, there is a time lag between when slip actually occurs and when control is performed, making it difficult to perform quick control appropriate to the road surface condition. There is.

In addition, in other conventional technologies, the friction coefficient μ of the road surface is calculated based on the signal from the acceleration sensor when the vehicle is shifted, so it is not possible to detect the friction coefficient μ immediately before slip (slip) occurs when the vehicle accelerates. There is a problem in that the driving force cannot be controlled in accordance with the road surface condition immediately before slipping.

On the other hand, recent vehicles are equipped with drive torque detection means called a torque sensor to detect the actual drive torque T. Focusing on the behavior of the vehicle drive torque T when the vehicle is running, as shown in characteristic line 3 of the drive torque TIl shown in FIG. 8, slip occurs in the vehicle after time t1 and the slip rate S increases. When the vehicle starts to slip, the drive torque T8 suddenly decreases, and the behavior of this drive torque T responds sensitively to the slip of the vehicle.

In addition, in a vehicle equipped with an automatic transmission, the output shaft torque of the automatic transmission is calculated based on the input side rotation speed Nt, output side rotation speed NA, gear ratio GR, etc. of the torque converter, as shown in equation (6) below. Tθ can be calculated. And this output shaft torque T.

The calculated value does not change much compared to the driving torque T when the vehicle slips, as shown in the characteristic line 4 shown by the dotted line in Fig. 8, and when the slip occurs, the difference between the output shaft torque Tθ and the driving torque T3 The difference becomes larger.

The present invention has been developed in view of the problems of the prior art described above.The present invention can control the driving force based on the coefficient of friction just before the wheels slip (slip), and can effectively avoid vehicle slip. The object of the present invention is to provide a vehicle driving force control device that can improve acceleration performance, stability, etc.

[Means to solve problems]

The features of the configuration adopted by the present invention in order to solve the above problems include: a torque detection means for detecting the driving torque of the vehicle by the engine; a wheel load detection means for detecting the wheel load acting on the wheels of the vehicle; friction coefficient calculating means for calculating a friction coefficient of a road surface based on the wheel load of the vehicle determined by the wheel load detecting means and the driving torque determined by the torque detecting means at a stage before slip occurs in the vehicle; and driving force control means for reducing the driving force of the vehicle based on the latest friction coefficient calculated by the friction coefficient calculating means when the friction coefficient is generated.

Further, it is preferable that the structure is such that it is determined whether the vehicle is slipping based on the signal from the torque detecting means.

an automatic transmission connected to the output shaft of the engine and including a torque converter and a speed change gear mechanism; a speed ratio detection means for detecting a speed change ratio by the speed change gear mechanism of the automatic transmission; an input rotation speed detection means for detecting the input rotation speed; an output rotation speed detection means for detecting the output rotation speed of the torque converter; and based on detection signals from the output rotation speed detection means and the input rotation speed detection means. output torque calculation means for calculating the output torque of the torque converter; and an output for calculating the output shaft torque of the automatic transmission based on the output torque calculated by the output torque calculation means and the gear ratio from the gear ratio detection means. a shaft torque calculation means; and a torque difference calculation means for calculating the difference between the output shaft torque calculated by the output shaft torque calculation means and the drive torque detected by the torque detection means, It may be configured to determine when the vehicle is slipping by determining whether or not is larger than a predetermined set value.

[Effect]

With the above configuration, the coefficient of friction of the road surface is continuously calculated based on the wheel load and drive torque at a stage before the occurrence of slippage of the vehicle, and when slippage occurs, the driving force of the vehicle is calculated based on the friction coefficient just before the occurrence of slippage. By suppressing the driving force to the limit value, it is possible to control the driving force suitable for the road surface condition, and it is possible to prevent the driving force from decreasing more than necessary.

Furthermore, based on the signal from the torque detection means, it is possible to quickly determine when the vehicle is slipping. Then, in a vehicle equipped with an automatic transmission, by calculating the output shaft torque of the automatic transmission, a torque difference is calculated from the calculated value of the output shaft torque and the detected value of the driving torque by the torque detection means, and this torque difference is calculated. Based on this, it is possible to determine at an early stage when the vehicle is slipping, and it is possible to control the driving force more quickly than based on the calculated value of the slip ratio.

[Example] Hereinafter, examples of the present invention will be described based on FIGS. 1 to 7.
A driving force control device applied to a rear wheel drive vehicle equipped with an automatic transmission will be explained as an example.

1 to 5 show a first embodiment of the present invention.

In the figure, 11 is an engine mounted on the front of the vehicle;
Reference numeral 12 indicates an automatic transmission connected to the output shaft of the engine 11, and the automatic transmission 12 includes a torque converter 12A whose input shaft is connected to the output shaft of the engine 11, and a torque converter 12A connected to the output shaft of the torque converter 12A. The transmission gear mechanism 12B is generally composed of a transmission gear mechanism 12B consisting of connected planetary gears that change and reduce speed. The output shaft of the speed change gear mechanism 12B is connected to the propeller shaft 13.
The distal end side of is connected to a rear wheel 15.15, which serves as a driving wheel, via a differential gear 14 or the like. 16.16
17 and 18 indicate front wheels that are driven wheels, front wheel speed sensors that detect the rotational speed of each front wheel 16, and front wheel speed sensors 17 and 18 detect left and right front wheel speeds Vj and V, respectively. By outputting this to a control unit 29, which will be described later, the vehicle body speed V, is detected as.

Reference numeral 19 indicates a rear wheel speed sensor that detects the rotational speed of the propeller shaft 13 as the rotational speed of each rear wheel 15, and the rear wheel speed sensor 19 sends the rotational speed of each rear wheel 15 to the control unit 29 as the wheel speed ■w. It is designed to be output. Reference numeral 20 indicates a torque sensor as a torque detection means provided between the automatic transmission 12 and the propeller shaft 13, etc. 13 etc. is detected as the vehicle drive torque T8 by the engine 11, and outputted to the control unit 29.

21 is the input side rotation speed Nt of the torque converter 12A.
22 is the output side rotation speed NT of the torque converter 12A.
The rotation speed sensors 21 and 22 output respective detection signals to the control unit 29, thereby controlling the torque converter based on the respective rotation speeds NE and NT. The speed ratio e of 12A is calculated. Further, 23 indicates a speed ratio sensor as a speed ratio detection means for detecting the speed ratio by the speed change gear mechanism 12B of the automatic transmission 12, and the speed ratio sensor 23 outputs a speed ratio signal to the control unit 29. A gear ratio GR as a transmission ratio by the transmission gear mechanism 12B is set.

Next, in FIG. 2, reference numeral 24 indicates a throttle sensor that detects the valve opening degree θ of a throttle valve (not shown). When the throttle valve is opened or closed by operating an accelerator pedal (not shown), the valve opening degree θ is detected and a detection signal is output to the control unit 29.

The throttle valve controls the intake air amount of the engine 11 according to the valve opening θ, and increases or decreases the output of the engine 11 in accordance with the intake air amount. Further, a sub-throttle valve (not shown) is provided in the intake passage of the engine 11 in series with the throttle valve.

Reference numeral 25 designates a throttle actuator that opens and closes this sub-throttle valve.The throttle actuator 25 closes the sub-throttle valve to limit the intake air amount when the vehicle slips, and normally keeps the sub-throttle valve fully open. The intake air amount is controlled in accordance with the valve opening θ of the throttle valve. The throttle actuator 25 is constituted by an electric motor or the like that opens and closes a sub-throttle valve based on a control signal from a control unit 29. Reference numeral 26 denotes an ignition device that outputs an ignition signal to the engine 11. Based on the control signal from the control unit 29, the ignition device 26 changes the ignition timing of the engine 11 when the vehicle slips, etc., and changes the output of the engine 11. It is designed to be lowered together with the throttle actuator 25.

Reference numeral 27 indicates a brake control device that controls the braking force of the vehicle, and the brake control device 27 has brake cylinders (not shown) provided on each rear wheel 15 and each front wheel 16, respectively.
For example, when a vehicle slips, it supplies brake fluid pressure,
By applying braking force to each rear wheel 15 and each front wheel 16, the driving force of the vehicle by the engine 11 is forcibly reduced. Reference numeral 28 indicates a vehicle height sensor as a wheel load detection means provided between the vehicle body side and the axle side of the vehicle. Wheel 15 side or front wheel 1
By detecting the vehicle height on the 6 side and outputting the detected vehicle height signal H to the control unit 29, the control unit 29 calculates the rear wheel load W etc. as the wheel load acting on each rear wheel 15. It has become.

Furthermore, 29 indicates a control unit constituted by a microcomputer, etc., and the control unit 29 has front wheel speed sensors 17 and 18, a rear wheel speed sensor 19, a torque sensor 20, and an input rotation speed sensor 2 on its input side.
1, an output rotation speed sensor 22, a gear ratio sensor 23, a throttle sensor 24, a vehicle height sensor 28, etc. are connected, and a throttle actuator 25, an ignition device 26, a brake control device 27, etc. are connected to the output side. The control unit 29 has a third memory in its memory circuit.
The program shown in the figure is stored, and the engine 11 performs the driving force control process for the vehicle. Also,
The memory circuit of the control unit 29 stores a set value S of the slip rate S in its memory area 29A. , the characteristic map of the torque ratio ε to the speed ratio e of the torque converter 12A shown in FIG. 4, the characteristic map of the input torque capacity coefficient to the speed ratio e shown in FIG. 5, and the output shaft torque Tθ and the drive torque T1. A predetermined setting value α for the torque difference T6, a drive torque slip occurrence limit value for the friction coefficient μ of the road surface, etc. are stored, respectively.

The vehicle driving force control device according to this embodiment has the above-mentioned configuration.Next, the output control process of the engine 11 by the control unit 29 will be explained with reference to FIG.

First, when the processing operation starts, in step 1 the vehicle speed VB and the wheel speed Vw are read from the front wheel speed sensors 17, 18 and the rear wheel speed sensor 19, and in step 2 the (
1) Calculate the slip rate S using the formula. Then, the process moves to step 3, where it is determined whether or not the slip ratio S exceeds the set value S0, and when the judgment is "NO", the process moves to step 4, where the input rotation speed sensor 21 of the torque converter 12A,
From the output rotation speed sensor 22, the input side and output side rotation speed N E
, NT are read, and in step 5, the speed ratio e of the torque converter 12A is calculated using the equation (3).

Then, proceeding to step 6, the fourth
From the characteristic map shown in Fig. 5, the torque converter 12
A's torque ratio ε and input torque capacity coefficient τ are read respectively, and in step 7, the input torque Tt of the torque converter 12A is calculated as TE=τ×NE (4), and the output torque TT is , T = ε×
Calculate as τXN, (5).

Next, in step 8, the gear ratio sensor 2 of the automatic transmission 12
The gear ratio signal is read from step 3, and the process moves to step 9, where it is determined whether or not the automatic transmission 12 is in the middle of gear shifting. Pressure is transferred to the propeller shaft 13 through the automatic transmission 12. Since the driving force is transmitted to each rear wheel 15, the process moves to step 10 to read the gear ratio G8 of the speed change gear mechanism 12B based on the speed ratio signal, and in step 11, the output shaft torque Tθ of the automatic transmission 12 is From the output torque Tt and the gear ratios G and l according to equation (5), it is calculated as Tθ=ε×τXNE”XGR (6).

Then, in step 12, the driving torque Tll as the actual torque on the output shaft side of the automatic transmission 12 is read from the torque sensor 20, and the process moves to step 13, where the output shaft torque Tθ is the calculated value and the driving torque Tll is the detected value.
The torque difference T, is T,=Tθ−T,...
(7), and in step 14 it is determined whether the absolute value IT,1 of the torque difference T, is larger than the set value α.

When the determination in step 14 is "NO", the torque difference T6, that is, the difference between the drive torque T shown by the characteristic line 3.4 in FIG.
Since it is in a relatively small state as before, it can be determined that each rear wheel 15 is not slipping (idling) on the road surface, and the process moves to step 15.

Next, in step 15, the vehicle height signal H is output from the vehicle height sensor 28.
Then, the process moves to step 16 to calculate the rear wheel load W acting on each rear wheel 15 based on the vehicle height signal H. Then, proceed to step 17 and calculate the coefficient of friction μ of the road surface, μ=F/W where T8: Drive torque by torque sensor if
:Final gear ratio r by differential gear:Rear tire radius W:Rear wheel load Calculated, and the calculated friction coefficient μ of the road surface at that point in time is sequentially updated and written in the RAM etc. of the storage area 29A in step 18. Let me remember it.

Then, in step 19, a release signal for canceling the driving force control is continued to be output, and the output of the engine 11 is controlled according to, for example, the valve opening θ of the throttle valve.Then, by moving to step 20 and returning, the process is performed after step 1. Continue processing.

Furthermore, when it is determined that rYEsJ is present in step 14,
For example, as shown in characteristic lines 3 and 4 shown in FIG. 8 (after time t1, the torque difference T becomes larger than the predetermined set value α, and each rear wheel 15 begins to slip with respect to the road surface. , the process moves to step 21 to read out the latest friction coefficient μ stored in the storage area 29A, and in step 22, based on this friction coefficient μ, the driving force of the vehicle by the engine 11 is reduced to, for example, a limit value at which slipping occurs. In order to let
The control signal is sent to the throttle actuator 25 and the ignition device 2.
For example, when the sub-throttle valve is closed by the throttle actuator 25, the intake air amount of the engine 11 is limited, and the friction coefficient μ of the road surface is
The so-called traction control is performed by reducing the driving torque Ts etc. to the βR limit value for occurrence of slip.

And even if it is determined to be rYEsJ in step 3,
Since the slip rate S has become larger than the set value S0 and the vehicle is slipping, step 21.
Moving on to step 22, the driving force of the vehicle is controlled based on the latest friction coefficient μ. Further, when it is determined that rYESJ is determined in step 9, the automatic transmission 12 is in the middle of shifting, and the drive torque T8 may vary greatly, so step 1
9 to output a hold or release signal, hold this during the drive force control, and continue to release the drive force control at other times to prevent the drive force control from being performed erroneously. , and return at step 20. Then, by repeating the processes of steps 1 to 22, traction control is performed so that the vehicle can be smoothly accelerated by the output of the engine 11 while avoiding slippage of the vehicle as quickly as possible.

Therefore, according to the present embodiment, in a vehicle equipped with the automatic transmission 12, the output shaft torque To of the automatic transmission 12 is calculated, and the torque difference T6 between the output shaft torque Tθ and the driving torque T8 detected by the torque sensor 20 is calculated. A configuration in which the driving force control is determined based on whether or not this torque difference T is larger than the set value α, and the driving force control is performed based on the friction coefficient μ of the road surface calculated and stored before the slip occurs. Therefore, the slip rate S is the set value S. It is possible to quickly and highly responsively determine when a vehicle slips occur based on the torque difference T6 before the torque difference T6 is reached, and not only can vehicle slip be effectively avoided, but also the maximum torque (limit value) that can be applied can be It becomes possible to transmit information from the engine 11 to each rear wheel 15, and various effects can be achieved, such as ensuring good acceleration even on low μ road surfaces such as snowy roads, and improving safety when starting and driving.

In the first embodiment, of the program shown in FIG. 3, step 7 shows a specific example of the output torque calculation means, which is a component of the present invention, and step 11 shows a specific example of the output shaft torque calculation means. , step 13 is a specific example of the torque difference calculation means, step 17 is a specific example of the friction coefficient calculation means, and step 22 is a specific example of the driving force control means.

Next, FIG. 6 and FIG. 7 show a second embodiment of the present invention, and the feature of this embodiment is that the fluctuation rate of the drive torque is calculated based on the signal from the torque detection means, and the calculated fluctuation rate is The present invention is configured to determine when the vehicle is slipping by determining whether or not is larger than a predetermined rate of variation.

In this embodiment, the same components as in the first embodiment are denoted by the same reference numerals, and their explanations will be omitted.

In the figure, reference numeral 31 indicates a control unit constituted by a microcomputer, etc., and the control unit 31 has front wheel speed sensors 17, 18, a rear wheel speed sensor 19, a torque sensor 20, and a throttle sensor 24 on its input side.
A vehicle height sensor 28 and the like are connected, and a throttle actuator 251, an ignition device 26, a brake control device 27, etc. are connected to the output side. The control unit 31 stores a program shown in FIG. 7 in its memory circuit, and is configured to control the driving force of the vehicle by the engine 11.

In addition, the memory circuit of the control unit 31 stores a set value So of the slip ratio S and a predetermined set value Δθ for the rate of change of the valve opening θ of the throttle valve in its memory area 31A. , a set value ΔT as a predetermined variation rate with respect to the variation rate of the drive torque Tll.

Also, the slip occurrence limit value of the drive torque with respect to the friction coefficient μ of the road surface, etc. are stored in advance.

Then, the control unit 31 performs the vehicle driving force control process in steps 31 to 33 as shown in FIG.
The same processing as steps 1 to 3 shown in the figure is performed, and when it is determined that rNOJ is determined in step 33, the process proceeds to step 34, where the valve opening θ of the throttle valve is read from the throttle sensor 24, and in step 35, this valve opening θ is determined to be rNOJ. rate of change Δ
θ is calculated as d θ △θ=□ (9) t, and the process moves to step 36, where the rate of change is changed to the set value. When it is determined that it is rNOJ, the valve opening θ of the throttle valve changes rapidly and the driver is trying to increase or decrease the output of the engine 11 by operating the accelerator pedal. Therefore, the process moves to step 44 and continues to output the release signal, for example, the sub-throttle valve is kept fully open by the throttle actuator 25, and the intake air amount of the engine 11 is controlled according to the valve opening θ of the throttle valve.
Return is made in step 45.

On the other hand, if rYESJ is determined in step 36, the process moves to step 37, and the torque sensor 20 detects the engine 11.
The driving torque Ts of the vehicle is read in, and in step 38, the fluctuation rate T of the driving torque Ts is calculated as dTyoΔTs''−...(10) t, and in step 39, this fluctuation rate ΔT,
It is determined whether or not is larger than the set value ΔT. If rNOJ is determined in step 39, steps 40 to 45 perform the same processing as steps 15 to 20 shown in FIG. let

Furthermore, when it is determined that rYESJ is determined in step 39,
Even though the valve opening θ of the throttle valve does not change much, for example, as shown in characteristic line 3 shown in FIG.
Since this is the case where the drive torque Tll suddenly decreases (varies) in step 1, it is possible to immediately determine when the vehicle slips, and in steps 46 and 47, the same process as steps 21 and 22 shown in FIG. 3 is performed. Then, the driving torque T8 and the like are reduced to the limit value for slip occurrence with respect to the friction coefficient μ of the road surface, and so-called traction control is performed.

(Thus, in this embodiment configured in this way, it is possible to obtain substantially the same effects as in the first embodiment, but in particular, in this embodiment, slippage is controlled based on the behavior of the drive torque T8. It is possible to immediately determine when (idling) has occurred, and the overall configuration of the control process can be simplified.

In the second embodiment, in the program shown in FIG. 7, step 42 shows a specific example of the friction coefficient calculating means, which is a component of the present invention, and step 47 shows a specific example of the driving force control means. be.

Further, in the second embodiment, when controlling the driving force based on the behavior of the driving torque T8, steps 34 to 36
In this process, it is possible to eliminate the case where the drive torque T fluctuates due to a change in the valve opening θ of the throttle valve. A determination process may be added, and in this case, it is possible to eliminate the case where the drive torque T8 fluctuates during the shift timing of the automatic transmission 12, and the reliability of the drive force control can be further improved.

Further, in each of the above embodiments, the output of the engine 11 is reduced by, for example, the throttle actuator 25, but instead of this, the output may be reduced by, for example, limiting the amount of fuel injected from the injection valve when slip occurs. You may also do so.

Furthermore, in each of the above embodiments, a rear-wheel drive vehicle equipped with an automatic transmission was used as an example of the vehicle.
It can also be used as a driving force control device for various vehicles.

〔Effect of the invention〕

As described in detail above, according to the present invention, the friction coefficient of the road surface is continuously calculated based on the rear wheel load and drive torque at a stage before the vehicle slips, and when the slip occurs, the friction coefficient of the road surface is continuously calculated based on the friction coefficient just before the vehicle slips. Since the driving force is reduced, driving force control suitable for the road surface condition becomes possible, and good acceleration performance can be ensured even on low μ road surfaces such as snowy roads.

In addition, since the occurrence of slip is determined based on the signal etc. from the torque detection means, the occurrence of slip can be determined early before the slip ratio reaches a predetermined set value, and the driving force can be quickly reduced. This not only effectively avoids vehicle slippage, but also improves acceleration performance, increases safety when starting and driving the vehicle, and reliably improves the responsiveness of driving force control. It has various effects such as:

[Brief explanation of drawings]

Figures 1 to 5 show a first embodiment of the present invention, Figure 1 is a configuration diagram of a rear wheel drive vehicle equipped with an automatic transmission, Figure 2 is a control block diagram, and Figure 3 is a driving force diagram. Flowchart showing control processing, FIG. 4 is an explanatory diagram showing a characteristic map of torque ratio stored in the storage area, FIG. 5 is an explanatory diagram showing a characteristic map of input torque capacity coefficient stored in the storage area, 6 and 7 show the second embodiment, FIG. 6 is a control block diagram, FIG. 7 is a flowchart showing the driving force control process, and FIG. 8 is a conventional technique showing vehicle body speed, wheel speed, FIG. 3 is a characteristic diagram of valve opening degree, drive torque, etc. 11...Engine, 12...Automatic transmission, 12A・
...Torque converter, 12B...Speed gear mechanism, 1
3... Propeller shaft, 15... Rear wheel, 16...
・Front wheel, 17.18... Front wheel speed sensor, 19... Rear wheel speed sensor, 20... Torque sensor, 25... Throttle actuator, 29.31... Control unit, VB...Vehicle speed, Vw...Wheel speed, S...Slip ratio, Ta...Output torque, Tθ
...output shaft torque, T, ...driving torque, T6...
・Torque difference, △T. ···Rate of change. Patent Applicant Japan Electronics Co., Ltd. Agent Patent Attorney Kazuhiko Hirose Diagram Speed Ratio (e) Diagram Speed Ratio (e) Diagram Sakima (1)

Claims (3)

[Claims] (1) In a vehicle driving force control device that determines whether or not slip has occurred between the wheels of the vehicle and the road surface, and controls the driving force of the vehicle by the engine when the slip occurs, torque detection means for detecting the driving torque of the vehicle; wheel load detection means for detecting the wheel load acting on the wheels of the vehicle; a friction coefficient calculating means for calculating a friction coefficient of a road surface based on a load and a driving torque obtained by the torque detecting means; and when a slip occurs in the vehicle, reducing the driving force of the vehicle based on the latest friction coefficient obtained by the friction coefficient calculating means. 1. A vehicle driving force control device comprising a driving force control means for controlling the vehicle. (2) The vehicle driving force control device according to claim (1), wherein the vehicle driving force control device determines when a slip occurs in the vehicle based on the signal from the torque detection means. (3) an automatic transmission connected to the output shaft of the engine and including a torque converter and a speed change gear mechanism; a speed ratio detection means for detecting a speed change ratio by the speed change gear mechanism of the automatic transmission; and the torque converter. an input rotation speed detection means for detecting the input rotation speed of the torque converter, an output rotation speed detection means for detecting the output rotation speed of the torque converter, and a detection signal from the output rotation speed detection means and the input rotation speed detection means. output torque calculation means for calculating the output torque of the torque converter based on the output torque calculation means, and calculating the output shaft torque of the automatic transmission based on the output torque calculated by the output torque calculation means and the gear ratio from the gear ratio detection means. output shaft torque calculation means; and torque difference calculation means for calculating the difference between the output shaft torque calculated by the output shaft torque calculation means and the driving torque detected by the torque detection means, The vehicle driving force control device according to claim 1 or 2, wherein the vehicle driving force control device determines when the vehicle slips by determining whether the difference is larger than a predetermined set value.