JPH05502924A - Drive slip control device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Drive slip control device! Conventional technology A drive slip control device having the features according to the preamble of claim 1 is disclosed in German Patent Publication No. It is known from No. 374347.

Advantages and description of the invention For medium and high speeds, the wheel speed profiles shown in Figures 1a and 1b are possible. . Here, the speed VIle, (reference speed) of the non-driving wheels and the reference speed V Re a slip threshold SS that exists above r by a predetermined value or a predetermined %; The constant wheel speed VR is shown graphically.

Figure 1a shows that the drive wheel rotates for a relatively long time with a very small slip requirement. is characteristic of the speed course of , and in this case reduces the slip threshold to improve stability. can do.

In the case of Figure 1b, the amount of slip required is quite large even if the wheels are stable.

In order to reduce the responsiveness sensitivity to road surface disturbances, the previous slip threshold was must be held and thus suffer a loss of traction. the worst For the case (Fig. 1b) the previous slip threshold is used.

In the proposed solution, the throttle valve opens DKZ below the slip threshold SS. is started and the slip threshold is adapted to the wheel signals. Throttle valve opening star The output is shown in Figure 2.

At various points in the course of the opening of the throttle valve, for example at each point of increasing opening or The ratio a/b or b/a is calculated at predetermined time intervals. a and b are wheels This is the distance from the speed slip threshold SS or the distance from the reference speed. Figure 3 is a diagram Figure 2 shows a partial enlarged view of Figure 2. In Figure 3, the values of a and b at various times are read. I can take it. The value of the ratio is a measure of the slip requirement. Although this value is small in Figure 1a, Large in Figure 1b. It is also possible to integrate the value of a / b over a specific time It is also possible. In this case, sample values as many as 1 are added, and in this case, the calculation is The resulting ratio is used to modify the slip threshold (see Figure 3a).

The slip threshold is modified depending on the ratio a, bo.

If a/b≦1, the slip threshold is not modified; if a/b is >1 If the slip threshold is reduced by e.g. O, lkm/h/focus (however, For example, the maximum speed is only 0.5 km/h); if b/a > 1, there is a risk of slipping. The value is, for example, 0.1 km/h/bit, but the maximum is, for example, 0.5 km/h. is increased to the initially calculated slip threshold.

The minimum value of the slip threshold is a certain percentage difference between the initial slip threshold and the reference speed. It is present in 60% of cases. This value depends on various factors (e.g. vehicle acceleration, friction coefficient, etc.).

speed, etc.).

In case of instability, match the new slip threshold to the initial slip threshold. Good too. For example, this matching is performed in steps of O, lkm/h/10m5. For example, this is done after the Looms filter time. An advantage of the invention is that the slip threshold The wheel moment whose value is required by e.g. tire tolerances or road surface friction coefficient. The reason is that it can be adjusted to the required amount of slippage. Therefore, the instability that occurs gradually gender can be detected early.

An embodiment of the hardware designed according to the present invention will be described using FIGS. 4 and 5. . In Figure 4, the wheel speed sensor of the non-driving wheel is 1, and the speed sensor of the driving wheel is 2. is shown. Block 3 slips from the signals of these sensors 1 and 2 5=V R,, -V, are formed. This value is set to a predetermined threshold value SS in threshold stage 4. be compared. When the threshold is exceeded, this activates the pulse generator 5, which The pulse generator 5 provides pulses to the motor 6, which in turn controls the throttle valve 7. Adjust stepwise in the closing direction (left side of t in Figure 2). Slip is below set slip (or the reference value of VR at tl) the pulse generator 8 is activated and the pulse The generator 8 then adjusts the motor stepwise in the throttle valve opening direction (as shown in Figure 2). (right side of tl).

In the calculator 9, the ratio a/b (Fig. 3) is formed for each throttle valve opening point. be done. As shown in Figure 5, when this ratio is greater than 1, the The slip threshold in block 4 is reduced in steps and the new slip threshold is A new excessive SS occurs. In the embodiment of FIG. 5, the new slip threshold value −AS When Sneu and wheel speed VR match, the new slip threshold is completed and the wheel speed is correct. Activate the normal course of events. However, even if we first allow a/b<1 to occur, That would be good. In this case, the slip threshold value is set via the conductor 11. It will cause a step-like rise. Block 4 includes a restriction, the restriction allows only the maximum sum value when the slip threshold decreases and then the slip value becomes positive. This prevents the slip value from being exceeded at all times.

Fig coα abstract After a certain drive slip occurs, the engine torque is reduced in steps and the slip threshold is reached. ASR where the engine torque is increased again in steps when the value falls below the specified value again. is listed.

According to the invention, in this case, in each case when increasing the ASR, the wheel speed is set to the reference speed. It is checked if it is closer or closer to the slip threshold. According to the reference speed If they are close to each other, the slip threshold is respectively lowered by a predetermined value.

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Claims (11)

[Claims] 1. The torque of the drive engine when the speed of the drive wheels exceeds a predetermined slip threshold where the slip threshold is raised with a small slope after it has been reduced and fallen below. In the drive slip control system for vehicles; after the slip threshold is lowered, the drive wheel It is checked whether the speed of is closer to the reference speed than the slip threshold. and the slip threshold is set to a predetermined value when it is determined that it is closer to the reference speed. to be lowered by; A drive slip control device featuring: 2. Drive slide according to claim 1, characterized in that the checks are carried out at predetermined time intervals. Control device. 3. that the check is done at the time of the step; and that it is closer to the reference speed. the slip threshold is reduced by a predetermined value each time the determination is made; 3. The method of claim 2, wherein the small gradient is obtained by a stepped rise. Drive slip control device. 4. 4. The drive slip control system of claim 3, wherein the total reduction is limited. 5. To check, the distance a of the wheel speed from the slip threshold and the basis of the wheel speed are Claims 1 to 4, characterized in that a ratio of the distance b to the quasi-velocity is determined. Drive slip control device. 6. The slip threshold is reset again when the wheel speed exceeds the reduced slip threshold. The drive slip control according to any one of claims 1 to 5, characterized in that it is set to a default value. control device. 7. 7. Drive slip control device according to claim 6, characterized in that the adjustment takes place in steps. . 8. Drive slip control according to claim 6, characterized in that the adjustment takes place after the filter time. Device. 9. After the ratio a/b≧1, the slip threshold is lowered stepwise and then When the ratio a/b < 1 occurs after , the slip threshold is increased stepwise; If a/b is given as a constant or at least one parameter (car The driving slide according to claim 5, characterized in that the variable is dependent on both vehicle speed and vehicle acceleration. control device. 10. the minimum slip threshold is given in advance; and this and/or depending on the coefficient of friction and/or vehicle acceleration; A drive slip control device according to any one of claims 1 to 9, characterized in that: 11. Claim 1, characterized in that the value of a/b is integrated over a specific time. The drive slip control device according to any one of Ishi 10.