JPH0811503B2 - Automotive slip status display - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slip state display device for an automobile, which displays a grip state of a drive wheel according to a slip state of the drive wheel.

(Prior Art and Problems Thereof) The magnitude of the slip of the drive wheel with respect to the road surface has a great influence on the grip force of the drive wheel. That is, the grip force gradually increases as the slip value increases, and the maximum grip force is obtained. After that, the grip force gradually decreases as the slip value increases. Further, the lateral force (sand force) of the driving wheels tends to gradually decrease as the slip value increases. The magnitude of the slip value when the maximum grip force is generated depends on the slipperiness of the drive wheels with respect to the road surface, that is, the asphalt road, the snow road, or the ice burn.

Therefore, if the driver can know the current grip state of the drive wheels, it is very preferable because the driver can drive according to the slipperiness of the road surface. In particular, recently, various slip control devices have been proposed which prevent the slip of the driving wheels from becoming excessive by controlling the torque applied to the driving wheels (for example, JP-A-58-58).
Even in the case of performing this slip control, if the driver can know the current grip state, it becomes possible to avoid unnecessary slip control as much as possible.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a slip state display device for a vehicle that allows a driver to know the current grip state of the drive wheels.

(Means and Actions for Solving Problems) In order to achieve the above-mentioned object, the present invention provides a seventh aspect.
The configuration is as shown in the figure. That is, the slip detection means for detecting the slip state of the drive wheel, the display means for displaying the grip state of the drive wheel, and the plurality of characteristics each showing the grip state for the slip state of the drive wheel Characteristic selecting means for selecting a characteristic corresponding to the state, and determine the grip state of the driving wheel from the slip state of the driving wheel based on the characteristic selected by the selecting means,
Display control means for displaying the grip state on the display means.

As described above, in the present invention, even if the slip state is the same, the grip state is displayed while responding to the change in the grip state depending on the slipperiness of the drive wheels with respect to the road surface. Therefore, the driver can drive appropriately while confirming the displayed grip state.

Embodiments Embodiments of the present invention will be described below with reference to the accompanying drawings.

1. Overview of Overall Configuration In FIG. 1, an automobile 1 includes four wheels, that is, left and right front wheels 2 and 3 serving as driving wheels and left and right rear wheels 4 and 5 serving as driven wheels. An engine 6 as a power source is mounted on a front portion of the automobile 1. The torque generated by the engine 6 passes through a clutch 7, a transmission 8, and a differential gear 9, and then passes through left and right drive shafts 10 and 11. And transmitted to the left and right front wheels 2 and 3 as drive wheels. Thus, the vehicle 1 is of the FF type (front engine / front drive).

In FIG. 1, U is a control unit,
It is constituted by an analog or digital computer, preferably a microcomputer. Signals from the sensors (or switches) 21 to 24 are input to the control unit U.
The sensors 21 and 22 detect the number of rotations of the left and right front wheels 2 and 3 as driving wheels. The sensor 23 detects the rotational speed of the left rear wheel 4 as a driven wheel, that is, the vehicle speed. The sensor (switch) 24 inputs (selects) a road surface condition described later by a manual operation by the driver. The sensors 21, 22, and 23 are each configured by using a pickup, for example. Further, the control unit U outputs to display means 25 described later.

The control unit U is basically a CPU, RO
Equipped with M, RAM, CLOCK, and other input / output interfaces, and A / D according to input and output signals.
It also has a D or D / A converter, but since these points are the same as those in the case of using a microcomputer, detailed description thereof will be omitted. The maps and the like in the following description are stored in the ROM of the control unit U.

Next, the control contents of the control unit U will be sequentially described, and the slip ratio S as a slip value (slip size) used in the following description is defined by the following equation.

WD: Number of rotations of driving wheels (2, 3) WL: Number of rotations of driven wheel (4) (vehicle speed) Here, in the present embodiment, the state of slipperiness of the driving wheels with respect to the road surface is defined as "asphalt road" There are at least three types of μ-S characteristics A as shown in FIG. 2, which are roughly classified into three types, “snow road” and “iceburn”,
It has a storage means for storing B and C. In FIG. 2, μ represents the grip force as the magnitude of the friction coefficient, and S represents the slip value as the slip ratio. Of the above three characteristics A, B and C, the characteristic A for "for asphalt"
Generates maximum grip force when the slip ratio S is S1,
Similarly, the maximum grip force is generated in the characteristic B at S2 and in the characteristic C at S3. In the embodiment, the characteristics A, B, C are created on the assumption that a normal tire is used.

On the other hand, as shown in FIG. 3, the manual mode switch for inputting the slipperiness of the driving wheels with respect to the road surface, as shown in FIG. Equipped with 24. This mode switch 24 is a slide type lever 24a.
, And two push-push type buttons 24b and 24c, respectively. The lever 24a is for manually inputting (selecting) the current road surface condition by its sliding operation. Also, the button
24b automatically selects the road surface condition prior to the lever 24a. Furthermore, the button 24c is for stopping the display of the grip state.

As shown in FIG. 4, the display means 25 for displaying the grip state of the drive wheels according to the type of road surface condition in relation to the slip ratio S is further provided at a position easily visible to the driver. There is. This display means 25 corresponds to the above-mentioned three characteristics A, B, C, and is displayed on the display unit shown in FIG. 4 (a).
26 is characteristic A, and display unit 27 shown in FIG. 4 (b) is characteristic B.
Further, the display unit 28 shown in FIG. 4 (c) corresponds to the characteristic C. Each of the display portions 26 to 28 is configured in a bar graph type extending in the lateral direction, and a plurality of areas “a ₁ , a ₂ , ...
-, "," b _1, b _2, · · ·, "," c _1, c _2, · · ·, and has a "position where the maximum grip force is generated is displayed (by symbol X Shown). Each area is individually light-emitted by, for example, a liquid crystal or a light emitting diode, and only the area corresponding to the current grip state is illuminated. That is, if the characteristic A is selected, for example, the display unit 26 corresponding to the characteristic A is displayed.
Of these, only the area (area a _{4 in} FIG. 4) corresponding to the current grip state (slip ratio S) is lit (indicated by the broken line in the figure). Although FIG. 4 shows a state in which one area is lit on each of the display units 26, 27, and 28 (broken line portion in the figure), even if the slip rate is the same, the road surface condition This is for reference to show that the grip state is different depending on the difference.

FIG. 5 shows another modification of the display unit 25,
The parts corresponding to those in FIG. 4 are designated by the same reference numerals. In FIG. 5, a shape imitating the characteristics A, B and C as shown in FIG. 2 is shown so that the driver can easily recognize the grip state.

The control as described above will be described with reference to the flowchart shown in FIG. 6. In the following description, P represents a step. First, after the slip value (slip ratio) of the driving wheels is measured in P100, it is determined in P101 whether or not the display stop is requested by the button 24c. this
If NO in P101, it is determined in P102 whether or not the auto mode is selected by the button 24b. P1
If NO in 02, in P103, one of the three characteristics A, B, and C described above is selected according to the operating state of the lever 24a. After that, in P104, the current grip state is determined in accordance with the characteristic selected in P103 according to the magnitude of the slip ratio S in P100. And P1
In 05, only the area (for example, a ₁ ) at the position corresponding to the current grip state of the display section (one of 26 to 27) corresponding to the characteristic selected in P103 is lit (P104). Display of grip state determined by.

If YES in P102, the process shifts to P106, where 3 is determined based on the slip rate S estimated from the maximum acceleration GMAX of the vehicle body (driven wheels) (eg, sampling is performed at predetermined time intervals).
Any one of the two characteristics A, B and C is selected. After this, the processing after P104 is performed. In addition, GMAX
It is possible to determine the magnitude of the slip ratio at the time when the maximum grip force is generated, and as a result, the characteristic corresponding to the current road surface condition can be known from GMAX.

 If NO in P101, the control ends as it is.

Although the embodiment has been described above, the present invention is not limited to this, and includes the following cases, for example.

In order to display the grip state on the display unit 25, it is not always necessary to show it together with the slip value (slip rate). In short,
It is sufficient to be able to recognize whether or not the current grip state has a sufficient grip force.

As the display means 25, a cathode ray tube or the like may be used to display only the selected characteristics, and the other characteristics not selected may be completely invisible to the driver.

The slip states of the left and right drive wheels may be individually and independently displayed, or, for example, the grip state of only the drive wheel having the larger slip state may be displayed.

When used in combination with the slip control device, for example, a lamp or the like may be provided near the portion for displaying the grip state to notify whether or not the slip control is currently being performed.

In order to make the condition of the slipperiness of the drive wheels on the road surface more accurate, in addition to the road surface information such as asphalt, snow road, etc., the type of tire such as normal tire and spike tire, the grip state against the slip state It may be added as information for selecting the characteristic of.

(Effects of the Invention) As is apparent from the above description, the present invention allows the driver to know the current grip state of the drive wheels in accordance with the slipperiness of the road surface. It becomes possible to carry out appropriate and appropriate operation.

[Brief description of drawings]

FIG. 1 is an overall system diagram showing an embodiment of the present invention. FIG. 2 is a graph showing an example of a characteristic diagram showing the correspondence between the slip state and the grip state. FIG. 3 is a diagram showing an example of a mode switch for manually inputting the slippery condition of the road surface. 4 and 5 are views showing an example of display means for displaying the grip state. FIG. 6 is a graph showing a control example of the present invention. FIG. 7 is an overall configuration diagram of the present invention. 1: Automotive 2.3: Drive wheels 4.5: Driven wheels 6: Engine 22/23: Sensor (rotation speed) 24: Mode switch 25: Display unit U: Control unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoji Imai 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (56) References: 57-177153 (JP, U) Actual: 61- 114146 (JP, U)

Claims (1)

[Claims] 1. A slip detection means for detecting a slip state of a drive wheel, a display means for displaying a grip state of the drive wheel, and a plurality of characteristics each showing a grip state for the slip state of the drive wheel. Characteristic selection means for selecting a characteristic corresponding to the current traveling state, and a grip state of the drive wheel is determined from a slip state of the drive wheel based on the characteristic selected by the selection means, and the grip state is displayed by the display means. A slip state display device for an automobile, comprising: