JPH0615825B2 - Anti-slip device for vehicle - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle slip prevention device that prevents excessive slippage of drive wheels when the vehicle starts or accelerates.

[Conventional technology]

Conventionally, as this type, for example, Japanese Patent Publication No. 51-31
As shown in No. 915 and the like, when the difference between the drive wheel speed and the driven wheel speed of the vehicle becomes a predetermined value or more, it is determined that the drive wheels are in a slip state, and the opening control of the throttle valve of the engine (engine) is performed. It has been proposed to suppress the drive torque of the engine and prevent the drive wheels from slipping.

[Problems to be solved by the invention]

However, in this device, since the opening degree of the throttle valve is simply changed according to the slip state of the drive wheels,
The amount of torque fluctuation and its responsiveness vary greatly depending on the engine state at the time of the slip determination, resulting in excessive torque suppression,
Otherwise, controllability may be deteriorated due to lack thereof, and drivability may be deteriorated.

An object of the present invention is to solve the problem of steam, and to improve the controllability by appropriately controlling the throttle opening degree according to the operating state of the engine when determining the slip state of the drive wheels.

[Means for solving problems]

Therefore, in the present invention, as shown in FIG. 1, slip determining means for determining the slip state of the drive wheel from the change state of the drive wheel speed and the driven wheel speed from the drive wheel speed detecting device a and the driven wheel speed detecting means b. c, the torque change amount of the engine obtained by the torque change amount calculating means d at the time of the slip determination, the torque change amount, and the torque amount detecting means e.
The target torque amount calculating means f calculates the target torque amount from the engine torque amount obtained by the above, and the torque control means g for reducing the torque amount to the drive wheels h according to the target torque amount is provided. There is.

[Action]

According to the above configuration, when the drive wheel h slips at the time of starting and accelerating the vehicle, the torque change amount of the engine obtained by the torque change amount calculation means d, the parameter relating to the intake air amount of the engine, and the rotation speed are used. A target torque amount is calculated from the calculated torque amount of the engine, and based on this target torque amount, the torque control means g appropriately prevents the drive wheel h from slipping.

〔Example〕

 The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 2 is an overall configuration diagram showing an overall configuration of an embodiment of a vehicle slip prevention device according to the present invention. In FIG. 2, 1 is a drive wheel speed sensor for detecting the drive wheel speed, 1 is a driven wheel speed sensor for detecting the driven wheel speed, and 3 is a pulse for every 30 ° crank angle in order to detect the engine speed. An output crank angle sensor, 4 is a water temperature sensor that detects a cooling water temperature of the engine, 5 is a throttle sensor that detects the throttle opening on the engine side, 6 is an accelerator pedal sensor that detects the depression amount of the accelerator pedal,
Reference numeral 7 is a microcomputer for instructing the throttle opening according to the slip state.

Reference numeral 8 is a throttle actuator that uses a step motor or the like to directly adjust the throttle opening according to a command from the microcomputer 7. Reference numeral 9 is a throttle for adjusting the engine output. Furthermore, in the microcomputer 7,
Reference numeral 71 is a central processing unit (CPU) that performs a calculation at the time of slip determination, 72 is a counter that counts the pulse widths of the speed sensors 1 and 2, and the crank angle sensor 3, 73 is the speed sensors 1 and 2, the crank angle sensor 3, and the water temperature. Input circuits of signals of the sensor 4, the throttle sensor 5, and the accelerator pedal sensor 6, 74 is a random access memory (RAM) for temporarily storing calculation results and the like, and 75 is a lead for storing calculation programs and control data. On-memory (RO
M) and 76 are output circuits for outputting control signals to the throttle actuator 8.

Next, the operation of the above configuration will be described. Now, the microcomputer 7 determines the slip state of the driving wheels from the speed information of the speed sensors 1 and 2, and further, the crank angle sensor 3 to the engine speed, the water temperature sensor 4 to the engine cooling water temperature, and the throttle sensor 5 to the opening of the throttle 9. Degree, the accelerator pedal sensor 6 detects the amount of depression of the accelerator pedal, and sends a command to the throttle actuator 8 in accordance with these data to make the throttle 9
Adjust the opening of to prevent the drive wheels from slipping. Next, the detailed operation of the microcomputer 7 will be described with reference to the flowchart of FIG. First, in step 100,
Input each data and process it. That is, the driving wheel speed Vw, the driven wheel speed Vv, the engine speed Ne, the cooling water temperature Tw, the throttle opening θ ₁ , and the throttle opening θ ₂ (the opening command value from the driver) obtained from the accelerator pedal depression amount are input. Calculate Then, in step 101,
The driven wheel speed Vv is multiplied by K (K
= 1.1 to 2.0), and further, a predetermined speed V ₀ (V ₀ = 1 to 20 km / h) is added to prevent malfunction at low speeds and the like, and a slip determination level V _T is created. That is, V _T =
K · Vv + V ₀ .

Then, in step 102, the slip determination is performed by comparing the drive wheel speed Vw and the slip determination level V _T.
Vw> V _T is established at step 102, if the slip is determined to have occurred, the process proceeds to step 103, and calculates the engine torque change amount .DELTA.Te. In this case, it is necessary to reduce the torque in order to suppress the slip, and ΔTe = −T ₁ (T ₁ for example 50 kg · m / sec
Equivalent value).

Further, in step 104, the torque change amount ΔT
A target value θ ₁ ^* of the throttle opening θ is calculated from e, the throttle opening θ ₁ , the engine speed Ne, and the cooling water temperature Tw (details will be described later). Then, in step 105, the target value θ ₁ ^* is checked, and only when θ ₁ ^* becomes a negative value,
In step 106, θ ₁ ^* = 0 (fully closed) is replaced.
Then, the routine proceeds to step 107, where the throttle actuator 8 is drive-controlled so that the throttle opening θ ₁ becomes the target value θ ₁ ^*, and the routine returns to step 100. In this case, θ ₁ ^*
≦ θ ₁ , the throttle is controlled to the closing side, the engine torque is reduced, and the slip of the drive wheels is suppressed.

On the other hand, in step 102, a Vw ≦ _{V T,} Vw <
If V _T does not hold, it is determined that slip has not occurred, and the routine proceeds to step 108, where the engine torque change amount ΔTe is calculated. In this case, since the slip is suppressed or the slip does not occur, it is necessary to gradually increase the torque when the torque is reduced. ΔTe = + T ₂ (T ₂ is, for example, 40 kg
・ Value equivalent to m / sec).

Further, in step 109, as in step 104,
A target value θ ₁ ^* of the throttle opening θ ₁ is calculated from the torque change amount ΔTe, the throttle opening θ ₁ , the engine speed Ne, and the cooling water temperature Tw (details will be described later). Then, in step 110, the target value θ ₁ ^* is checked and θ ₁ ^* > θ ₂
That is, only when the target throttle value exceeds the throttle opening θ ₂ corresponding to the accelerator pedal, step 11
1 is replaced with θ ₁ ^* = θ ₂ . And step 1
Proceeding to 07, the throttle actuator 8 is driven and controlled so that the throttle opening θ ₁ becomes the target value θ ₁ ^* , and the process returns to step 100.

In this case, if θ ₂ is fixed, θ ₁ ^* ≧ θ ₁
And the throttle is controlled to the open side.

Since θ ₂ is provided as the upper limit of θ ₁ ^* ,
When the throttle 9 is not opened more than necessary and no slip occurs at all, θ ₁ ^* = θ ₂
The throttle opening θ ₁ ^* is controlled so that the throttle opening θ ₂ corresponding to the accelerator pedal is reached.

Next, the content of the calculation processing of the target throttle value θ ₁ ^* (steps 104 and 109) will be described.

FIG. 4 shows the relationship between the engine speed Ne, the throttle opening θ ₁ and the engine torque Te. As shown in the figure, even if the throttle opening θ ₁ is constant, the torque Te varies greatly depending on the engine speed, and therefore the torque Te is ΔT.
e Change amount Δ of throttle opening θ ₁ required to change Δ
θ ₁ also differs. Therefore, a method for obtaining Δθ ₁ will be described with reference to FIG. First, the current throttle opening θ
₁ = theta and engine speed Ne = _{N A} by _c, in the case of changing the ΔTe only torque, Sadamari torque _{T A} by first _{(N A} θ _c), determine the _{T B} corresponding to _T A -DerutaTe, T _B and the engine rotational speed _{N a} from θ ₁ = θ _b is obtained, and -Δθ ₁ = _{θ b} -θ _c. Further, in the relationship of FIG. 4, if the data is changed according to the engine cooling water Tw, Δθ ₁ according to the warm-up period, the warm-up period, and the like can be changed.

Now, in the microcomputer 7, Δθ ₁ is calculated using the map as shown in FIG. That is, from the data of FIG. 4, the engine cooling water temperature Tw and the engine speed N
When the throttle opening θ ₁ is determined, the change amount Δθ ₁ of the throttle opening θ ₁ required to change the engine torque Te by ΔTe in that case is determined. If ΔTe is small, Δθ ₁ / ΔTe is Since it is a nearly constant value, ∂θ ₁ /
∂Te is required. Therefore, each (Ne, θ ₁ , Tw)
∂θ ₁ / ∂Te for each combination of
If mapped as shown in FIG. 5 and stored in the ROM 75, if Ne, θ ₁ , Tw, and ΔTe are given, Δθ ₁ = ∂
Δθ ₁ is obtained from the relationship of θ ₁ / ∂Te (Ne, θ ₁ , Tw) × ΔTe, and the target throttle value θ ₁ ^* is also obtained from θ ₁ ^* = θ ₁ + Δθ ₁ . The above processing will be described again with reference to the flowchart of FIG. This is a subprogram portion for calculating the throttle target value θ ₁ ^* , and corresponds to steps 104 and 109 in FIG. First, in steps 200 to 204, the map is switched according to the engine cooling water temperature Tw. That is, the predetermined value T that becomes the cooling water temperature Tw in step 200.
Compared with w ₁ (for example, Tw ₁ = 60 ° C.), Tw ≧ Tw ₁
In the case of, the process proceeds to step 202, the map I is selected, and the process proceeds to step 205. On the other hand, in step 200, Tw <
If it is Tw ₁ , the process proceeds to step 201, the cooling water temperature Tw is compared with a predetermined value Tw ₂ (for example, Tw ₂ = 0 ° C.), and if Tw ≧ Tw ₂ and Tw <Tw ₂ is not established,
Go to step 203, select map II and step 20
Go to 5. On the other hand, if Tw <Tw ₂ in step 201, the process proceeds to step 204, the map III is selected, and the process proceeds to step 205. After selecting the map, in step 205, ∂θ ₁ / ∂Te corresponding to the engine speed Ne and the throttle opening θ ₁ is obtained with reference to the map. This is ∂θ ₁ on the intersection of Ne and θ ₁ as shown in FIG.
Although / ∂Te is imported, in reality (Ne,
Interpolated from map values in the vicinity of θ ₁ ). Then, the routine proceeds to step 206, where the throttle opening change amount Δθ ₁ is obtained from the product of ∂θ ₁ / ∂Te and the torque change amount ΔTe, and at step 207, Δθ ₁ is added to the current throttle opening θ ₁ to change the throttle opening. Calculate the target opening value θ ₁ ^* ,
At step 208, the process returns to the main program. That is, steps 104 and 109 in the flowchart of FIG.
Return to each.

Although the predetermined values −T ₁ and T ₂ are used as the change amount ΔTe of the engine torque Te in the above-described first embodiment, these predetermined values are set according to the engine speed Ne and the cooling water temperature Tw. The correction may be changed. That is, the dynamic characteristics of the engine torque differ depending on the engine speed Ne (the lower Ne is, the poorer the response) and also depending on the cooling water temperature Tw (the lower the Tw, the poorer the response).
This is because there are -T ₁ and T ₂ suitable for each Ne and Tw.

Further, in the first embodiment, the slip state is divided into only two states, with / without slip, and ΔTe is switched to −T ₁ and T _2. However, ΔTe may be determined by further dividing the slip state. . That is, ΔTe is determined according to the driving wheel speed Vw and the driving wheel acceleration w which is a differential value thereof. This embodiment will be described with reference to FIGS. FIG. 8 is a flow chart of the present embodiment, and FIG. 7 is an explanatory diagram of step 303 in FIG.
A method of determining Te will be described. That is, in FIG. 7, the horizontal axis represents the drive wheel speed Vw, the vertical axis represents the drive acceleration V, and V
_T1 and V _T2 are slip determination speeds, respectively, and V _T1 = K ₁ × Vv + V _O1 and V depending on the driven wheel speed Vv.
It is given the _{T2 = K 2 × Vv + V} O2. (Here, for example, K ₁ = 1.1, K ₂ = 1.25, V _O1 =
3 km / h, V _O2 = 5 km / h). Also, G ₁ , G ₂
Are acceleration values for determination, for example G ₁ = 10 m
/ Sec ² , G ₂ = -8 m / sec ² . And
It is divided into nine regions as shown in FIG. 7 by Vw, w and V _T1 , V _T2 , G ₁ , G ₂ , and T _{1 to} T ₉ and ΔTe are given respectively.

Here, for example, T ₁ = T ₅ = T ₉ = 0 kg · m / se
c equivalent, T ₂ = T ₆ = −20 kg · m / sec equivalent, T
₃ = -60 kg · m / sec equivalent, T ₄ = T ₈ = + 20
Equivalent to kg · m / sec, T ₇ = + 50 kg · m / sec
It is considerable. As a result, the larger the slip is, the larger the torque reduction amount is. On the other hand, the torque change amount is given according to the change of the driving wheel speed, that is, the acceleration, so that the very good slip control is performed.

Next, the flow of processing in the present embodiment will be described with reference to the flowchart of FIG. 8 focusing on the points different from the first embodiment. First, each data is input in step 300, the driving wheel acceleration w is calculated from the driving wheel speed Vw in step 301, and the slip determination levels V _T1 and V _T2 are created in step 302 as described above. Step 303
As described with reference to FIG. 7, the torque change amount ΔTe is obtained from the drive wheel speed Vw and the same acceleration w, and the target value θ ₁ ^* of the throttle opening is set in step 304 as in the first embodiment. Calculate and θ _{1 in} steps 305 to 308
^* Is adjusted so as to satisfy 0 ≦ θ ₁ ^* ≦ θ ₂ and the throttle actuator 8 is drive-controlled in step 309 to set the throttle opening θ ₁ to θ ₁ ^* , and step 30
Return to 0.

Further, the slip determination level and the determination acceleration in the present embodiment may be set in multiple stages instead of two stages respectively.
Further, ΔTe may be given as a continuous function as a function of Vw, w.

Further, in addition to Ne and Tw, the gear shift position of the vehicle transmission may be detected by a clutch, a transmission, a shift lever, etc., and the substitution value of ΔTe may be changed so as to be optimum for each shift position. That is, since the moment of inertia of the drive wheels and the driving force are greatly different depending on the shift position, the optimum ΔTe is different, so that the switching of the control parameter depending on the shift position is very effective.

Further, the road surface friction coefficient μ may be estimated from the vehicle acceleration or the driven wheel acceleration v when the slip occurs, and the substitution value of ΔTe may be changed according to μ. Note that μ is μ≈ (W
/ W _R ). (Vv / g). (W:
Vehicle weight, W _R : drive wheel load, g: gravity acceleration).

Further, in the first embodiment, the throttle actuator 8
Drives the throttle 9 directly, but a throttle may be provided separately from the original throttle to control the drive of another throttle, and the throttle opening is driven to the return side between the original throttle and the accelerator pedal. A device may be provided to control.

Further, for slip control, in addition to throttle control, suppression of engine torque by fuel cut, lean A / F, ignition timing delay, etc., change of gear ratio, braking of drive wheels, etc. may be used in combination.

〔The invention's effect〕

As described above, in the present invention, the slip of the drive wheels is automatically determined when the vehicle starts and accelerates, and the torque applied to the drive wheels by the engine is reduced to prevent the slip. While being able to
The target torque amount is calculated from the torque amount and the torque change amount based on the parameters related to the intake air amount of the engine at the time of slip determination and the rotation speed, and the engine torque is constantly suppressed based on this target torque amount. There is an excellent effect that appropriate correction can be performed according to the state, and excessive fluctuation of the engine torque can be suppressed and stable control can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing the outline of the present invention, FIG. 2 is an overall configuration diagram showing the first embodiment of the present invention, FIG. 3 is a flow chart showing the arithmetic processing of the microcomputer of FIG. FIG. 4 is a characteristic diagram showing an engine operating state-torque characteristic, FIG. 5 is an explanatory diagram showing a map of the throttle target value of FIG. 3, FIG. 6 is a detailed flowchart showing the third throttle target value calculation, and FIG. FIG. 8 is an explanatory diagram for distinguishing the area selection of the second embodiment of the present invention, and FIG. 8 is a flow chart showing the arithmetic processing in the second embodiment of the present invention. a ... driving wheel speed detecting means, b ... driven wheel speed detecting means, c ... slip determining means, d ... torque change amount calculating means, e ... torque amount calculating means, f ... target torque amount calculating means , G ... Torque control means, h ... Drive wheel, 1 ...
Drive wheel speed sensor, 2 ... driven wheel speed sensor, 3 ... crank angle sensor, 4 ... water temperature sensor, 5 ... throttle sensor, 6 ... accelerator pedal sensor, 7 ... microcomputer, 8 ... throttle actuator , 9 ...
…throttle.

Claims (2)

[Claims] 1. A driving wheel speed detecting means for detecting a driving wheel speed of a vehicle, a driven wheel speed detecting means for detecting a driven wheel speed of the vehicle, and a level determination of a relative change state of the driven wheel speed. Slip determining means for determining a slip state of the driving wheels based on the above; torque amount calculating means for determining a torque amount of the engine by a parameter relating to an intake air amount to the engine and the number of revolutions of the engine at the time of the slip determination; Calculation means for obtaining a torque change amount of the engine at the time of slip determination of the drive wheels by the slip determination means, and a target for suppressing the torque based on the torque amount of the engine at the time of the slip determination and the torque change amount. Target torque amount calculation means for calculating the torque amount, and for suppressing the torque of the engine at the time of the slip determination based on the target torque amount. The vehicle slip control system, characterized in that it comprises a torque control means for outputting a torque control signal. 2. The apparatus according to claim 1, further comprising an engine temperature detecting means for detecting the engine temperature, wherein the target torque amount calculating means further includes the engine temperature as a parameter. A characteristic vehicle slip control device.