JPH0343636A - Traction controller - Google Patents

Abstract

PURPOSE:To improve responsibility of control by calculating a compensation throttle opening based on a road surface condition and on the slipping of a wheel at the time of slipping of the wheel, and by controlling opening and closing of a throttle valve according to the compensation opening. CONSTITUTION:A control unit 30 inputs various signals from sensors 20-24 that detect driving conditions of an automobile, and outputs a predetermined control signal to a motor 14 so as to control opening and closing of a throttle valve 13 of an engine 1. Difference between car acceleration and wheel acceleration calculated by means 32, 33, respectively, is compared to a set value, and the slipping of a wheel is judged by a means 34. At the time of judging the slipping of the wheel, by means of a first compensation throttle opening based on a car driving condition and on a road surface condition, as well as of a second compensation throttle opening based on the slipping of the wheel, a compensation throttle opening is calculated by a means 35. According to the compensation throttle opening, throttle driving is performed by a means 38.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a Traxilan control device that prevents slippage and optimally accelerates by controlling driving force when wheel slip occurs during rapid acceleration of a vehicle. , relates to throttle valve closing control when slipping and throttle valve opening control when gripping.

[Conventional technology]

Generally, in a vehicle, wheel slip may occur during sudden acceleration due to an increase in engine output, etc. When such wheel slip occurs, slip is prevented by closing a throttle valve and controlling engine output. So-called traction control has been proposed. In this traction control, it is important to determine whether the vehicle is slipping or gripping, how to control the closing of the throttle valve during slipping, and how to control the opening of the throttle valve during gripping.

Conventionally, regarding the above-mentioned traction control, there is a prior art disclosed in, for example, Japanese Unexamined Patent Publication No. 182434/1983. Here, a reference speed is determined based on the driven wheel speed, and slip is determined based on the relationship between this reference speed and the driving wheel speed.

Further, it is shown that a corrected speed is calculated based on the acceleration of the driving and driven wheels and the driving wheel speed, and in the event of a slip, the throttle valve is opened and closed at a speed proportional to the difference between the reference speed and the corrected speed.

[Problem to be solved by the invention]

By the way, in the prior art described above, slip is determined based on the relationship between the reference speed based on the driven wheel speed and the driving wheel speed, so it cannot be applied to four-wheel drive vehicles. Furthermore, since the reference speed is set regardless of road surface conditions, it is not possible to appropriately determine slips and the like on low-friction roads (low-μ roads) and high-friction roads (high-μ roads). Furthermore, since the throttle valve is opened and closed at a speed proportional to the difference between the reference speed and the corrected speed, the responsiveness of the throttle valve closing control during slipping deteriorates. Furthermore, since the road surface condition is not judged, slips occur repeatedly on low-μ roads, and it takes time to completely resolve them.

On the other hand, on roads other than high friction roads and low vehicle speeds, there are problems such as negative acceleration caused by sudden grip.

The present invention has been made in view of the above, and its purpose is to provide traction that can appropriately determine slippage, etc. according to road surface conditions and improve the responsiveness of slip prevention control. The purpose is to provide a control device.

[Means to solve the problem]

In order to achieve the above object, the traction control device of the present invention includes slip determination means for determining wheel slip;
corrected throttle opening calculation means for calculating a corrected throttle opening based on a first corrected throttle opening depending on the running state of the vehicle or road surface condition at the time of slip and a second corrected throttle opening depending on the amount of wheel slip; and throttle driving means for controlling the opening and closing of the throttle valve in accordance with the corrected throttle opening.

[For production]

Based on the above configuration, when the wheel acceleration becomes higher than the vehicle body acceleration by more than a set value and a slip is determined, the first correction throttle opening of the feedforward term based on the vehicle acceleration and speed and the first correction throttle opening of the feedforward term based on the amount of wheel slip are adjusted. The throttle valve is controlled to open and close to keep the amount of slip constant regardless of the road surface condition by the corrected throttle opening, which is made up of two corrected throttle openings.The throttle valve is quickly closed to avoid slipping and prevent the recurrence of slipping. The patient will be able to recover while preventing this.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, referring to the case of a four-wheel drive vehicle with a center differential, reference numeral 1 denotes an engine, and this engine L is configured to be transmitted to a center differential device 3 via a transmission 2. The front drive shaft 4 from the center differential device 3 is connected to the front differential device 5. The left and right front wheels 7L are connected via the axle 6.

7R, and the rear drive shaft 8 is connected to a rear differential device 10 via a propeller shaft 9 and the like, and further connected to left and right rear wheels 12L and 12R via an axle 11. Further, a motor 14 is connected to the throttle valve i3 of the engine 1, and the throttle valve 18 is electrically opened and closed in response to operation of an accelerator pedal (not shown).

Next, regarding the electric control system, the throttle valve 1
Throttle opening sensor 20° attached to 3. Accelerator opening sensor 21 attached to the accelerator pedal. Each wheel speed sensor 22L, 22R, 23L is attached to the left and right front wheels 7L, 7R and the left and right rear wheels 12L, 12R.
and acceleration sensor 24 installed on the 23R1 vehicle body side
These sensor signals are input to the control unit 30.

The control unit 30 has drive wheel speed calculation means 31 and vehicle body speed calculation means 32. The driving wheel speed calculation means 31 includes four wheel speed sensors 22L, 22R, and 23L.
, 23R each wheel speed'l) FLI U PRI
U RLI U RR is operated manually, and the wheel speed U
is calculated as follows.

11-r(Lj PL, U FR, 2/IIL,
U RR) Here, in order to make it easier to detect a slip, the function r takes the larger value of the left and right front wheel speeds Upt+LjpR, and the left and right rear wheel speeds Uvu1. Take the larger value of URR and find the average value of both. That is, UPL
> U PRIU RL > U RR, then U
-(U pt+ U RL) /2, thus determining the thickness.

The vehicle speed calculating means 32 manually inputs the above-mentioned left front transport speed UpLr right front wheel speed UP Rl left rear wheel speed URt+ right rear wheel speed URR and the vehicle body acceleration G of the vehicle body acceleration sensor 24, and calculates the vehicle body speed V as follows. Calculate as follows.

V-g (G・UpL・UFR・IJRt, uqR
) Here, in order to make it easier to detect slips, it is necessary to set the wheel speed U to be large as described above, and to set the vehicle body speed V to be small. Therefore, the function g is determined by selecting the smallest value among the integral value fGdt of the acceleration G and each wheel speed of the four wheels. That is, U.

> Upt (-UpR) > Up, L > fGdt
In this case, it is set as V-fGdt.

The wheel speed U is manually input to the wheel acceleration calculation means 33, and the wheel acceleration dUldt is calculated by differentiating the wheel speed υ.

Then, the vehicle body acceleration G and the wheel acceleration dU/dt are input to the slip determination means r5j, 34, and the difference dp/d between the two is input.
Compare t-G and set value GA, dlJ/dt-GAG
In case A, it is determined that there is a slip, and a slip signal is input to the corrected throttle opening calculation means 35.

The corrected throttle opening calculation means 35 controls the throttle valve t3 to close immediately at the time of slip, and then gradually controls the throttle valve 13 to open and return to its original state, and calculates the wheel speed U, the vehicle speed V, and the vehicle acceleration G. is input, and the corrected throttle opening degree θ5 is calculated using the following equation.

θs −Ko + 1 −G+ 2 ・V+ 3 (
4 ・V for U-) (I (4 for 0- is a constant) In addition, in the above formula, the first corrected throttle opening θs1 is θ5.-K. 2 correction throttle opening θs2, 3 to θ52 (4 to U-)
・V).

Then, the first correction throttle opening degree θs1 is a feedforward ring that is set according to the running condition of the vehicle and the road surface condition at the time of slipping. Here, if the corrected throttle opening θS is uniformly set to a predetermined value, negative acceleration will occur on roads other than relatively high μ roads and low vehicle speeds, and on low μ roads, acceleration will be small and the amount of slip will be large, so this can be avoided. There is a need to. Therefore, as described above, the first corrected throttle opening degree θ,1 is calculated proportionally to the vehicle body acceleration G and the vehicle body speed V. Therefore, from the two-dimensional map for vehicle acceleration G and vehicle speed V as shown in Figure 2, the first
The corrected throttle opening degree θS can be determined.

The second corrected throttle opening θs2 is determined by the wheel speed U and the vehicle body speed V.
This is a feedback ring determined by the amount of wheel slip that is the difference between the
Controls the opening and closing of 3.

On the other hand, the throttle opening degree θ of the throttle opening degree sensor 20 is manually detected by the actual throttle opening degree detection means 39 . Further, the accelerator opening degree φ of the accelerator opening degree sensor 21 is manually determined by the target throttle opening setting means 37 to set the target throttle opening degree θ according to the accelerator opening degree φ.
. Establish. Then, the above-mentioned corrected throttle opening θ and target throttle opening θ. The actual throttle opening θ is input to the throttle drive means 38, and according to the determination result of the control mode determining means 39 (described later), the corrected throttle opening θS is set during traction control, and the target throttle opening θ0 is set when traction control is not performed. , the actual throttle opening θ
, the throttle control signal is sent to the motor 14 so as to follow the motor 14.
It is designed to output to .

Furthermore, the above-mentioned slip signal, actual throttle opening θ1. Target throttle opening θ. control mode determination means 3 inputted by
9, determines each mode of slip and normal running, and inputs this mode signal to the drive means 3B. Then, a throttle control signal is output according to each mode, especially θ, ≧θ during traction control. When it does, it switches to normal mode.

Next, the action of the groove bottom traction control device is as follows:
This will be described using the flowchart in FIG. 3 and the timing chart in FIG.

First, by depressing the accelerator pedal at the time of starting, etc., power from the engine 1 is transmitted to the front wheels 7L, 7R and the rear wheels 12L, L2R via the transmission 2° center differential device 3, etc. So the front wheel 7I4
．． The vehicle travels by the rotation of 7R and rear wheels 12L and 12R.

At this time, the flowchart in FIG. 3 is executed, and in step 5lot each wheel speed U FLI U PRI U
RLI U IIIR is read, and in step 5102 wheel speed U is calculated from the larger average value of the front and rear wheel speeds. Further, in step 5103, the vehicle body acceleration G detected by the acceleration sensor 24 is read, and in step 8104, the vehicle body speed V is calculated by combining the integral value of the vehicle body acceleration G and each wheel speed U described above.
It is calculated using the minimum value among pLtU PRI U RLI U RR. Further, in step 5105, the wheel acceleration dLj/dt is calculated, and in step 8106, the actual throttle opening θ1. detected by the throttle opening sensor 20 is calculated. Target throttle opening θ according to accelerator opening φ. is set.

Therefore, in step 3107, the presence or absence of slip is determined based on the difference between the wheel acceleration d7#dL and the vehicle body acceleration G and the set value GA, and in the case of non-slip, step 8108
Check the traction control flag F, and if it is cleared, it is determined that it is normal mode.

and step 5109. Through step 5IIO, the actual throttle opening θ becomes the target throttle opening θ. Control the throttle to follow. Therefore, the motor 14 is driven forward and backward until the target throttle opening θ0 corresponds to the accelerator opening φ, and the throttle valve 13 is electrically opened and closed.

On the other hand, when starting suddenly on a low μ road as shown in Fig. 4, if the wheel acceleration d27/di suddenly increases relative to the vehicle body acceleration G and becomes d27/dt-G≧GA at time t1, it is determined that a slip has occurred. The process advances from step 5107 to step 5ill. Therefore, corrected throttle opening θ.

is set, but in this case, first the first corrected throttle opening θ5. is set by searching the map in FIG. 2 based on the vehicle speed V and vehicle acceleration G at this time, and the second corrected throttle opening θs2 is set based on the wheel speed U and vehicle speed ■. A corrected throttle opening degree θ5 is calculated, and the throttle is controlled in accordance with this corrected throttle opening degree θS in step 5L15 via step 5l12° and step 8113.

Note that the traction control flag F is set in step 5113, and traction control is started. For this reason,
Immediately after time t1, as shown in FIG. 4, the throttle valve 3 is immediately controlled to close to the corrected throttle opening θ5, and accordingly, the wheel speed U and wheel acceleration d'lJ/dt rapidly decrease to prevent slipping. do.

Due to the closing control of the throttle valve 13, the wheel acceleration dL
When R, dt decreases and becomes d2/'/dt -G < GA, from step 5108 to step S I
Proceed to -1 and 4, and the actual throttle opening θ is checked.
Initial θ1×θ. At the stage of , step 5ill again,
The process proceeds to step 5l15 via 3112°5ti3.

Therefore, in such a case as well, the opening and closing of the throttle valve 13 is controlled by the corrected throttle opening degree θ5.

That is, after time t2 in FIG. 4, as the vehicle speed V increases, the opening degree of the throttle valve 13 increases by an amount corresponding to the first corrected throttle opening degree θs1 and gradually returns.
Second corrected throttle opening θs2 which is a feedback term
As a result, the wheel speed U recovers upward along with the vehicle speed V while keeping the amount of slip equal to the vehicle speed V, and recurrence of slip due to rapid recovery is suppressed.

Then, the actual throttle opening θ, recovers to the target throttle opening according to the accelerator opening φ, and θ, ≧θ. When the relationship is reached, the process proceeds from step Sl14 to step 5109, where the traction control is ended and the process returns to the normal mode.

Here, as shown by the broken line in FIG.
, if the difference in vehicle speed V is large, the corrected throttle opening θ
The value of , becomes smaller, and the opening degree of the throttle valve t3 also recovers more slowly.

On the other hand, when the value of the road surface friction coefficient μ is large as shown by the dashed line, on the other hand, the value of the corrected throttle opening θ5 becomes large together with the vehicle speed V and the vehicle acceleration G, and the opening of the throttle valve 13 quickly recovers. It turns out.

Note that the corrected throttle opening degree θ is the first. Second corrected throttle opening θ51. The parameter of θ52 may be other values. That is, the first corrected throttle opening degree θ5. may be determined from a map of the vehicle body acceleration G and the engine speed Ne as shown in FIG. 5, and in this case, the engine output can be directly controlled in relation to the engine speed Ne.

Although the embodiments of the present invention have been described above, the present invention can be similarly applied to two-wheel drive vehicles.

〔Effect of the invention〕

As described above, according to the present invention, in vehicle traction control, the opening and closing of the throttle valve is controlled according to the vehicle running condition and the road surface condition when the vehicle slips, thereby improving the responsiveness of slip prevention.

It is highly reliable and can reliably prevent slip recurrence.

Furthermore, in the event of a slip, the feedforward term of the first corrected throttle opening based on the vehicle speed or engine rotational speed and the vehicle body acceleration can ensure slip prevention depending on the conditions of driving and road surface friction coefficient.

Furthermore, the feedback ring of the second corrected throttle opening, which is determined by the slip amount of the difference between the wheel speed and the vehicle body speed, allows the throttle valve to be opened in accordance with the road surface condition, thereby achieving optimal acceleration. Furthermore, since the amount of slip is controlled to be constant, recurrence of slip is extremely reduced.

Furthermore, slippage can be quickly determined by comparing wheel acceleration and vehicle body acceleration, and can be applied to four-wheel drive vehicles.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram showing an embodiment of the traction control device of the present invention, Fig. 2 is a diagram showing a map of the first corrected throttle opening, Fig. 3 is a flowchart showing the action of traction control, Fig. 4 is the throttle opening and acceleration when slipping. Characteristic diagram showing the state of traction control depending on speed, 5th
The figure shows another map of the first corrected throttle opening. t...engine, 13...throttle valve, 14...
- Motor, 30... Control unit, 34... Slip determination means, 35... Correction throttle opening calculation means,
38... Throttle drive means

Claims (3)

[Claims] (1) Slip determination means for determining wheel slip;
A corrected throttle opening calculation means for calculating a corrected throttle opening based on a first corrected throttle opening depending on the running condition of the vehicle or the road surface condition at the time of slip, and a second corrected throttle opening depending on the amount of wheel slip; A traction control device comprising a throttle drive means for controlling the opening and closing of the throttle valve depending on the corrected throttle opening. (2) The first corrected throttle opening is set based on the relationship between vehicle acceleration and vehicle speed or engine rotation speed (
1) The traction control device described above. (3) The traction control device according to claim 1, wherein the second corrected throttle opening degree is calculated based on a difference between wheel speed and vehicle body speed.