JPH0435368B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a slip prevention device for a vehicle, and more particularly to a slip prevention device for a vehicle that prevents excessive slip when the vehicle starts or accelerates.

[Prior art] Conventionally, as shown in Japanese Patent Publications No. 52-198 and No. 53-30877, when the difference between the driving wheel speed and the driven wheel speed exceeds a predetermined value, the ignition timing is delayed, the engine throttle valve is opened and closed, or the fuel is cut off. A vehicle slip prevention device has been proposed that suppresses engine torque.

However, these conventional devices have a simple configuration that suppresses the engine torque when the difference between the driving wheel speed and the driven wheel speed of the vehicle exceeds a predetermined value. There is a problem in that even if a difference occurs, it is incorrectly determined to be a slip, and incorrect engine torque suppression control is executed.

For this reason, in the conventional device, there was a risk that the driving wheel speed would drop due to incorrect engine torque suppression control based on the erroneous determination.

[Object of the Invention] The present invention has been made in view of the above points, and its purpose is to prevent failures caused by incorrectly determining that the difference between the driving wheel speed and the driven wheel speed due to brake operation is the occurrence of a slip. To provide a slip prevention device for a vehicle that never fails when appropriate control is executed.

[Structure of the Invention] The structure of the present invention for achieving the above object is as shown in the basic configuration diagram in FIG.
and a driven wheel speed detection means b for detecting the driven wheel speed.
a brake operation detection means c for detecting a brake operation by the driver; a torque control means d for controlling engine torque to suppress slip of the drive wheels based on the drive wheel speed and the driven wheel speed; The gist of the slip prevention device for a vehicle is characterized in that it comprises a brake operation inhibiting means e for prohibiting control by the torque control means d when a brake operation is detected by the brake operation detecting means c. .

[Function] As configured in this manner, the slip prevention device for a vehicle of the present invention operates based on the driving wheel speed detected by the driving wheel speed detection means a and the driven wheel speed detected by the driven wheel speed detection means b. Then, it is determined whether or not there is slippage of the drive wheels, and the torque control means d controls the engine torque to suppress the slippage of the drive wheels.
However, if the brake operation detecting means c detects a brake operation, the brake operation inhibiting means e operates and engine torque control for suppressing slip is not performed. As a result, even if the difference between the driving wheel speed and the driven wheel speed due to brake operation is erroneously determined to be a slip, the engine torque will not drop unnecessarily due to erroneous control. Of course, as in the embodiments described later, it may be realized by a configuration in which the slip determination itself is not performed once a brake operation is detected.

That is, according to the slip prevention device for a vehicle of the present invention, execution of erroneous slip prevention control is appropriately prohibited.

[Example] The present invention will be described below by giving examples and referring to the drawings.

FIG. 2 is a block diagram of the slip prevention device of the first embodiment. In the figure, 1 is a driving wheel speed sensor that detects the driving wheel speed, 2 is a driven wheel speed sensor that detects the driven wheel speed, 3 is a crank angle sensor that outputs a pulse every 30°C, and 4 is when the brake pedal is depressed. a brake switch for detecting whether or not the
6 is a slip control device consisting of a microcomputer that cuts fuel when a slip occurs; 7 supplies appropriate fuel to the engine according to the operating state of the engine It is a fuel supply device. In the slip control device 6, 61 is a central processing unit (hereinafter referred to as CPU) that performs calculations such as slip determination, 62 is a counter that counts the pulse width of the speed sensors 1 and 2, and 63 is the speed sensor 1 and 2, and the crank An input device receives signals from the angle sensor 3, brake switch 4, and clutch switch 5; 64 is a random access memory (hereinafter referred to as RAM) for temporarily storing calculation results; and 65 is for storing calculation programs and control data. A read-only memory (hereinafter referred to as ROM) 66 is an output device that outputs a control signal to the fuel supply device 7.

In the figure, the slip control device 6 is the speed sensor 1.
A slip is determined from the speed signals of 2 and 2, and a fuel cut signal is output to the fuel supply device 7 to cut fuel when a slip occurs.
Engine speed calculated from crank angle sensor 3
Ne is the specified engine speed N1 (N1 = 600 ~
2000 rpm), when the brake switch 4 determines that the brake is operating, or when the clutch switch 5 determines that the clutch is completely disengaged, slip control is stopped and the fuel supply is stopped. This causes the device 7 to perform normal fuel supply in the same way as when it is determined that there is no slip.

The driving wheel speed sensor 1 is a driving wheel speed detecting means a, the driven wheel speed sensor 2 is a driven wheel speed detecting means b, the brake switch 4 is a brake operation detecting means c, a slip control device 6, and a fuel supply device 7. correspond to the torque control means d, respectively.

Next, the detailed operation of the slip control device 6 using a microcomputer will be explained based on the flowchart of FIG. First, when the process starts, it is determined in step 100 whether or not the brake is depressed from the brake switch 4. If the brake is not depressed, the process proceeds to step 101 from the clutch switch 5 to determine whether or not the brake is depressed. When the clutch is not disengaged, that is, when the clutch is connected,
The program then proceeds to step 102, where the engine speed Ne is calculated from the crank angle sensor 3. Next steps
At 103, the engine speed Ne is the specified engine speed
It is determined whether or not it is greater than or equal to N1, and if it is greater than or equal to N1, slip control is performed from step 104 onwards.

That is, in step 104, the driving wheel speed Vw is calculated from the output of the driving wheel speed sensor 1, and in step 105.
The driven wheel speed is determined from the output of the driven wheel speed sensor 2 at
Calculate Vv. In the following step 106, the driven wheel speed
Vv is multiplied by K (K=1.1 to 2.0) to obtain a slip judgment level Vt, and in step 107, a slip is judged by comparing the drive wheel speed Vw and the slip judgment level Vt. If it is determined in step 107 that Vw>Vt is established and there is a slip, the process proceeds to step 108, sets a fuel cut signal, and instructs the fuel supply device 7 to perform fuel cut via the output device 66, and then proceeds to step 108. Return to 100. At step 107
If Vw>Vt does not hold and it is determined that there is no slip, the process proceeds to step 109, where the fuel cut signal is reset and the fuel supply device 7 is output via the output device 66.
A command is given to the engine to supply normal fuel, and the process returns to step 100.

On the other hand, if it is determined in step 100 that the brake is being depressed, if it is determined in step 101 that the clutch is disengaged, or if it is determined in step 103 that the engine rotation speed is less than the predetermined rotation speed N1 If any of the following is true, all steps are executed.
The program proceeds to step 109, resets the fuel cut signal, and instructs the fuel supply device 6 to supply normal fuel via the output device 66, and returns to step 100.
The same process is repeated thereafter.

As detailed above, in this embodiment, the drive wheel speed Vw
The fuel is cut when the slip exceeds the slip judgment level Vt, and the fuel cut is stopped when the brake is applied, the clutch is disengaged, or when the engine speed Ne is less than N1.

Therefore, erroneous determination (slip determination) during brake operation can be prevented, and inappropriate control based on erroneous determination will not be executed. Furthermore, this embodiment is configured to further execute the judgment processes in steps 101 and 103, so in addition to the effect of preventing inappropriate control based on these erroneous judgments, it is also possible to It is possible to suppress a drop in drive wheel speed due to fuel cut, which is performed to suppress slip when the vehicle is accelerating.

Therefore, it is possible to obtain good slip control and improve slip control performance and running reliability.

Note that the proportionality constant K may be set in two or more stages depending on the value of the driven wheel speed Vv or the engine rotation speed Ne. For example, when the driven wheel speed Vv is low, the value of K may be set relatively large, and when the driven wheel speed Vv is high, the value of K may be set relatively small. Further, during fuel cut, a warning lamp or a warning buzzer may be used to notify the driver that slip control is being performed.

Next, a second embodiment will be explained. As shown in the block diagram of FIG. 4, this embodiment has almost the same configuration as the first embodiment, except that the neutral switch 5
a second crank angle sensor 3a that outputs a pulse every 720°C A, and a third crank angle sensor that outputs a pulse every 720°C A that is out of phase by 360°C with respect to the output of the second crank angle sensor 3a. 3b and the control program has been changed.

FIG. 5 shows a flowchart of the control program of this embodiment. The processing of this embodiment will be explained below along with this flowchart.

First, when the process starts, the driving wheel speed Vw is calculated from the output of the driving wheel speed sensor 1 in step 200, the driven wheel speed Vv is calculated from the output of the driven wheel speed sensor 2 in step 201, and the driving wheel speed Vv is calculated from the output of the driven wheel speed sensor 2 in step 201. At 202, the driven wheel acceleration Vv is calculated from the change in the driven wheel speed Vv per unit time based on the driven wheel speed Vv. In the following step 203, it is determined whether the driven wheel acceleration V〓v is less than a predetermined value α (for example, α=0 m/s ² ). If it is determined that V〓v≧α, that is, the driving wheel speed Vv is not in a deceleration state, the process proceeds to step 204.
At step 204, the neutral switch 5a
It is determined whether the neutral switch 5a is ON or not, and if it is determined that the neutral switch 5a is OFF, the step
At 205, the engine rotation speed Ne is calculated based on the pulse interval of the 30°C A signal from the crank angle sensor 3.
At step 206, the magnitude of the engine speed Ne is determined based on a predetermined engine speed value N2 (N2=600 to 2000 rpm).

Then, if it is determined in step 206 that Ne≧N2, that is, the engine speed is high, the step
In step 207, the driven wheel speed Vv is multiplied by K (K=1.1 to 2.0) to obtain a slip determination level Vt, and in step 208, the drive wheel speed Vw is compared with the slip determination level Vt to determine a slip. Vw at step 208
> If Vt is established and it is determined that there is a slip,
In step 209, the magnitude of the engine speed Ne is set to a predetermined engine speed value N3 (N3 = 1000 to 3000 rpm).
If it is determined that Ne≧N3, that is, the engine speed is high, a fuel cut signal is set in step 210, and the fuel cut signal is sent to the fuel supply device 7 via the output device 66 to supply power to all cylinders. Command to perform fuel cut and return to step 200.

On the other hand, if it is determined in step 209 that Ne<N3, that is, the engine speed is low, the step
211, the current state is G1 mode (period from the pulse generation of the second crank angle sensor 3a to the pulse generation of the third crank angle sensor 3b) or G2 mode (period from the pulse generation of the third crank angle sensor 3b to the second crank angle sensor 3b). If the current mode is G1 mode, go to step 210 and cut fuel, and if the current mode is not G1 mode but G2 mode, go to step 212 and start normal fuel supply. Each command is given to the fuel supply device 7 via the output device 66, and the process returns to step 200. As a result, when Ne<N3, the G1 mode and the G2 mode are switched every engine revolution, so that fuel cut is performed every other revolution, that is, fuel cut for half of the cylinders.

On the other hand, if it is determined in step 203 that the driven wheel acceleration V〓v is less than α, for example, if it is determined that the brake is activated and the vehicle is decelerating, it is determined in step 204 that the transmission gear is in the neutral switch position. If the engine speed Ne is less than the predetermined engine speed N2 in step 206, all steps are executed.
The program proceeds to step 212, resets the fuel cut signal, and instructs the fuel supply device 7 to supply normal fuel through the output device 66, and returns to step 200.
The same process is repeated thereafter.

The operation of the second embodiment is almost the same as that of the first embodiment, but the clutch switch 5 corresponds to the neutral switch 5a, the brake switch 4 corresponds to "V〓<α" judgment, and the fuel cut signal corresponds to Ne If ≧N3, it is executed in both G1 and G2 modes (hereinafter referred to as M1 mode), that is, all cylinder fuel is cut.
If Ne<N3, it is executed in G1 mode (below
It's called M2 mode. ), which means that half of the cylinders have fuel cut.

As detailed above, in this embodiment, the drive wheel speed Vw
exceeds the slip judgment level Vt, fuel cut (fuel cut for all cylinders when Ne≧N3, Ne<
In addition to cutting half the cylinder fuel at N3,
When the neutral switch is turned on, fuel cut is stopped when the driven wheel acceleration V〓v is less than a predetermined value α or when the engine speed Ne is less than N2.

This prevents erroneous judgments that occur when V〓v<α, and suppresses the drop in driving wheel speed Vw due to fuel cut to suppress slip when the vehicle is in neutral or accelerating at low engine speed. obtain. In addition, the above fuel cut is N3>Ne≧
When N2 is established, fuel cut for half of the cylinders is executed, and the reduction in engine torque is approximately half, and as a result, the driving wheel speed Vw can be precisely controlled.

Therefore, it is possible to obtain good slip control and improve slip control performance and running reliability.

Note that the proportionality constant K may be changed as appropriate depending on the values of the driven wheel speed Vv and the engine rotation speed Ne.

Note that, regardless of this embodiment, an analog circuit may be used instead of the microcomputer, and instead of switching the number of cylinders to which fuel is cut according to the engine speed, it is possible to cut fuel to each cylinder according to the engine speed. It is also possible to switch the fuel supply amount. That is,
The engine torque may be reduced by cutting fuel when the engine speed is high and increasing the air-fuel ratio when the engine speed is low. In addition, in step 210, the cylinder to which fuel is cut is further selected depending on the engine speed. For example, the number of cylinders from which fuel is cut may be determined in proportion to the engine speed, and engine torque may be controlled more precisely, such as lean air-fuel ratio, suppression of intake air amount, opening/closing of throttle valve, etc. The engine torque may be controlled by controlling the engine torque, and the torque transmitted to the driving wheels may be suppressed by controlling the gear position of the transmission and the amount of clutch slippage. The examples are not limited.

[Effects of the Invention] The present invention provides a configuration in which, when controlling engine torque to suppress drive wheel slip based on drive wheel speed and driven wheel speed, such engine torque control is prohibited during brake operation. It was adopted. As a result, there is no possibility that engine torque control is performed based on a mistaken determination that a slip has occurred due to brake operation, and it is possible to accurately prevent inappropriate control from being executed.

[Brief explanation of drawings]

Figure 1 is a basic configuration diagram of the present invention, and Figure 2 is the basic configuration diagram of the present invention.
3 shows a flowchart of the control program of the first embodiment, FIG. 4 shows a block diagram of the second embodiment, and FIG. 5 shows a flowchart of the control program of the second embodiment. . 1... Drive wheel speed sensor, 2... Driven wheel speed sensor, 3... Crank angle sensor, 6... Slip control device, 7... Fuel supply device, 61... CPU,
62...Counter, 64...RAM, 65...
ROM.

Claims (1)

[Scope of Claims] 1. A driving wheel speed detecting means for detecting the driving wheel speed; a driven wheel speed detecting means for detecting the driven wheel speed; a brake operation detecting means for detecting a brake operation by the driver; torque control means for controlling engine torque to suppress slip of the driving wheels based on the speed and the driven wheel speed; and when a brake operation is detected by the brake operation detection means, the torque control means 1. A slip prevention device for a vehicle, comprising: means for inhibiting brake operation for inhibiting control. 2. The slip prevention device for a vehicle according to claim 1, wherein the torque control means includes a prohibition means for prohibiting control of the engine torque when the engine speed is below a predetermined speed. . 3. The slip prevention device for a vehicle according to claim 1 or 2, wherein the torque control means includes prohibition means for stopping control of the engine torque when the clutch is disengaged. 4. The slip prevention device for a vehicle according to any one of claims 1 to 3, wherein the torque control means includes a prohibition means for stopping control of the engine torque when the gear is in neutral. 5. The slip prevention device for a vehicle according to any one of claims 1 to 4, wherein the torque control means includes a circuit for controlling engine torque by cutting off fuel.