JPH04157341A - Road surface condition detector for running vehicle - Google Patents

Abstract

PURPOSE:To detect a road surface condition for a road surface condition adapting apparatus by calculating the revolving velocity of a measuring wheel from a detected vehicle speed and a set slip ratio and calculating coefficient of friction from a detected load, a detected torque and the radius of a measuring shaft corresponding to the revolving velocity of the measuring wheel. CONSTITUTION:A measuring wheel 1 under a running vehicle 10 is brought into contact with a road surface under a pressure to be rotated by the road surface. A load surface condition detector outputs a detected vehicle speed V from a vehicle speed detector 2, a set slip ratio S from slip ratio setting means 3, the revolving velocity (v) of the measuring ring 1 of a vehicle 10, a detected load W from carrying load detection means 6 corresponding to the revolving velocity (v), a detected torque T from torque detection means 8, the radius R of the measuring ring 1 and coefficient of friction mu. In the velocity (v) and the coefficient of friction mu which constitute the points, the velocity (v) is computed by a microcomputer 4 according to an expression v=V(1+ or -S/100) in accordance with the case of driving or braking and the coefficient of friction mu is computed by the microcomputer 4 according to an expression mu=T/(WXR). The velocity (v) and the coefficient of friction mu are outputted as desired and constitute the source of input data of a road surface condition adapting apparatus.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a road surface condition detection device for a running vehicle.

[Conventional technology]

BACKGROUND ART It is important for a vehicle driver to understand the condition of the road surface in order to drive safely. For example, when it rains, snows, or freezes, any driver observes the road surface conditions before driving or after temporarily stopping driving. This means that the running wheels (hereinafter referred to as wheels)
, the driving road surface, and the design concept of the vehicle concerned. Wheels are prepared with various specifications (for example, snow tires), and wheels are prepared with various specifications (for example, snow melting devices) that adapt to the driving road conditions, and the vehicle itself is designed to suit the road conditions in terms of visibility and drivability. There are various specifications for this. In particular, when applying the brakes on the vehicle itself, the ABS system does not completely lock the wheels as in the past, but rather rotates the wheels in a rotation range that provides optimal braking.
-1ock brake 5yste+11), which is one of the measures that vehicles can take to cope with the above road surface conditions. Therefore, a conventional road surface condition detection device will be described. Conventionally,
This type of road surface condition detection device is mainly installed, and vehicle-mounted devices are hardly known. The former installed type is a fixed device that is permanently installed at a test site by, for example, a vehicle manufacturer or wheel manufacturer in order to obtain basic relationship data between the road surface and the vehicle. On the other hand, the latter vehicle-mounted type is only known, for example, as disclosed in Japanese Patent Laid-Open No. 1-257242. This technology locks the wheels during braking, detects the coefficient of friction μ between the wheels and the road surface, and visually displays this on a display. As a result, the driver can drive safely while visually checking the road surface conditions.

[The problem that the invention tries to solve! li]

As mentioned above, there are few known vehicle-mounted road surface monitoring devices. Although the above-mentioned Japanese Patent Application Laid-open No. 1-257242 is an on-vehicle type, since it obtains the friction coefficient μ when the wheels are locked, it is suitable for devices that are controlled with the background that the wheels do not lock, such as the above-mentioned ABS device. cannot serve as a basic data source for control. This will be explained with reference to FIG. This figure is a graph showing the general relationship between the friction coefficient μ and the slip rate S under various road surface conditions. As can be seen from the figure, the technology of JP-A-1-257242 is effective when the wheel is locked (i.e., slip rate 5 = 100%).
The friction coefficient μ detected is slip ratio 5 = 10 to 30%
This value is smaller than the maximum friction coefficient μ1.8 obtained by On the other hand, the ABS device described above has a maximum friction coefficient μm1aX
Since it is a technology that attempts to utilize
No. 57242 will not be able to address this issue. SUMMARY OF THE INVENTION In view of the problems of the prior art described above, it is an object of the present invention to provide a road surface condition detection device for a running vehicle that can serve as an input data source for road surface condition adaptation devices such as ABS devices. . Another object of the present invention is to provide a road surface condition detection device for a vehicle that can independently visually notify a driver of the road surface condition.

[Means to solve the problem]

In order to achieve the above object, the road surface condition detection device for a traveling vehicle according to the present invention will be described with reference to FIG. A rotating measuring wheel 1 and a vehicle speed detecting means 2
, a slip rate setting means 3, a microcomputer 4 that stores the measuring wheel radius R in advance, a loading means 5 that brings the measuring wheel 1 into pressure contact with the road surface 20, and a means for detecting the load applied to the measuring wheel 1 by the loading means 5. 6, a motor 7 for rotating the measuring wheel 1, and a torque detecting means 8 for the measuring wheel 1. Input S and calculate the rotational speed υ of the measuring wheel 1, which is V (1-3/l OO) - 〇 during braking and V /' (1 + 3 / 100) = u when driving, and adapt to this speed υ. The motor 7 is rotated so that the measuring wheel radius R and
Using the detected load W input from the applied load detection means 6 and the detected torque T input from the torque detection means 8 at the rotational speed υ, a friction coefficient μ of T/ (W×R)=μ is calculated, and this friction coefficient μ and desired data among the various data V, S, υ, R, W, . Furthermore, in the above configuration, a configuration may be adopted in which a road surface temperature detection means 2I is provided and the detected temperature t is also output. Furthermore, in each of the above two configurations, a display 91 is provided, and in the configuration of claim 1,
In a configuration in which the friction coefficient μ and desired data among various data V, S, υ, R, W, and T are input and displayed in a desired format, and in the configuration of claim 2, the friction coefficient It may be configured to input μ and desired data among various data V, S, υ, R, W, and TS t, and display these in a desired format.

[For use]

The road surface condition detection device for a traveling vehicle according to the first aspect outputs the friction coefficient μ and desired data among various data V1S, υ, R, W, and T. Among these data, the measured wheel rotational speed υ and the friction coefficient μ calculated by the microcomputer 4 are particularly important in the above configuration. First, the former measurement wheel rotational speed O is based on the following general formulas (1) and (2). The slip rate (S) during braking is: S = + (V-υ) / VIX100 (%), ゛, v =
V (+-5/ 100)...----111 Also, the slip rate (S) during driving is: S=+(V-υ)/υl X100 (%),..., υ=
V/ (1+S/100)・・・・・・・・・(2)
In addition, ■ is the vehicle speed, and υ is the measurement wheel rotation speed. Next, the latter friction coefficient μ is based on the following general formula (3). μ=F/W or T=F−R 1゛, μ=T/ (W×R)・・・・・・・・・・・・
(3) In addition, F is the tangential force of the measuring wheel, T is the torque, and R is the radius of the measuring wheel stored in the microcomputer 4 in advance. The slip ratio S is set to an arbitrary value by the slip ratio setting means 3, and is sequentially input to the microcomputer 4. The vehicle speed V is
The vehicle speed is detected by the vehicle speed detection means 2 and sequentially inputted to the microcomputer 4. The measuring shaft rotational speed υ is calculated by the microcomputer 4 sequentially using the slip rate S, the vehicle speed ■, and equations (1) and (2), and the measuring wheel ■ is rotated through the motor 7 to adjust the measuring wheel rotational speed υ.
Rotate it with . On the other hand, as described above, a load W is applied by the loading means 5 to the measuring wheel 1 which is rotating at the rotational speed υ, and this load W is detected by the applied load detection means 6 and inputted to the microcomputer 4. At the same time, the rotation torque T of the measuring wheel 1 is also detected by the torque detection means 8, and the microcomputer 4
is input. The friction coefficient μ is the result of the microcomputer 4 calculating these data V and T×R using the above equation (3). In addition, in practice, some values are selected between -100% and 100% between 0% and 100% during braking (wheel lock) and 0% and -100% during driving (wheel spinning). Typical slip rate S or continuous slip rate S
At various vehicle speeds V, the respective friction coefficients μ are sequentially output. Furthermore, as mentioned above, this friction coefficient μ and its conditional data V, S, υ, R, W, ,T
is output as desired. Next, the road surface condition detection device for a traveling vehicle according to the second aspect is as follows:
The present invention includes a road surface temperature detection means 21, which adds the detected temperature t to various data V, S1υ, R, W, T, and μ, and outputs desired data among these. Although the road surface temperature has a great influence on the road surface, the causal relationship between them can be clarified by the output of the present invention. Note that this claim 2 is one mode of utilization of the above claim 1, and is merely cited as an example. That is, the causal relationship with other factors that affect the road surface condition, such as wheel temperature, wind force, wind direction, climbing, descending, meandering of the running road, skidding of the vehicle, etc., is determined by the temperature detection means and wind force detection means that detect these factors. By adding wind direction detection means, slope detection means, steering angle detection means, sideslip angle detection means, etc. to claim 1, these data and the data of claim 1 can be organically combined and output. This is because it becomes like this. Next, the road surface condition detection device for a traveling vehicle according to the third aspect of the invention includes:
The configuration of claim 1 or 2 includes a display 91, and displays the friction coefficient μ, various data V, Ssu, R, W, T, or desired data among various data v, , S1υ, RlW, T, t. It is a system that manually displays data in a desired format visually. As a result, the driver can drive safely while visually checking the road surface conditions.

【Example】

DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the road surface condition detection device for a traveling vehicle according to the present invention will be described in detail below with reference to FIGS. 1 to 3. FIG. 1 is a diagram showing a traveling vehicle 10 equipped with an embodiment and a schematic configuration of the embodiment. In the embodiment of claim 1, as shown in the upper right corner of the figure, in a running vehicle 10, a measuring wheel 1, a vehicle speed detecting means 2, and a loading means 5 for pressing the measuring wheel 1 against the road surface 20 are provided at the lower part thereof. , a motor 7 for rotating the measuring wheel 1, and a slip rate setting means 3 and a microcomputer 4 inside the vehicle. For details, please refer to the measurement wheel 1 for constant velocity di-day India 81
．． It is connected to the output shaft of the motor 7 via the torque shaft 81 and the torque shaft 82, and is rotated by the motor 7, and the traveling road surface 2 is
0. A magnetostrictive torque sensor, which is torque detection means 8, is attached to the output shaft of the motor 7, which detects the rotational torque T of the measuring wheel 1 and transmits it to the microcomputer 4.
It is output to. A load sensor, which is a loaded load detection means 6, is attached to the rond of the hydraulic cylinder 5, and detects the vertical load W of the measuring wheel I with respect to the traveling road surface, and outputs this to the microcomputer 4. Note that it is also possible to move the measuring wheel 1 away from the road surface 20 by contracting the hydraulic cylinder 5. The vehicle speed detection means 2, which is a speed sensor such as a laser type or an ultrasonic type, sequentially detects the traveling speed of the vehicle with high precision and outputs it to the microcomputer 4. Slip rate setting means 3
is a dial type or the like, and is used to freely set the slip ratio S between the wheel and the road surface during braking and driving, and this setting signal (set slip ratio S) is sent to the microcomputer 4. Output. The microcomputer 4 stores the measuring wheel radius R in advance, inputs the detected values T, W, ■ and the set value S, performs the following calculation, and outputs the results to the motor 7 and output device 9. do. First, regarding the output to the motor 7 and its calculation, the calculation is based on the vehicle speed V and the slip rate S. When braking, the formula is 2V (I S/100) = υ, and when driving, the formula is v/ (] + S/100) = υ. The output υ to the secondary motor 7 is the result of the above calculation and is given as the rotational speed υ of the measuring wheel 1. The output υ to the motor 7 is a control signal that maintains this rotational speed υ. Therefore, the motor 7 receives this control signal and rotates the measuring wheel 1 at a rotational speed υ. Next is the output to the output device 9, which is calculated using the measurement shaft radius R, load W, torque T, and these RSW and T as the formula T/ (W・R)=μ. Ifl coefficient μ and the other detected value S
SV, o. Note that this output device 9 may be a road surface condition adapting device such as a BS device or the display device 91 of claim 3 of 1a.
Pointing to 1. These can be selected as appropriate. Next, the effects of this embodiment will be described. If the output device 9 is an ABS device, according to this embodiment, data sufficient to drive the device is output to the ABS device. That is, AB
The S device inputs each friction coefficient μ and rotational speed υ of the measurement wheel at various set slip rates S from the embodiment device. Then, the ABS device selects the maximum friction coefficient μsa from among these friction coefficients μ, and selects the maximum friction coefficient μsa from among these friction coefficients μ, and
Measuring wheel rotation speed υ at slip rate S, which is the basis of K
The ABS device can achieve its purpose by controlling the braking so that the rotational speed of the running wheels of the vehicle is the same as the rotational speed of the running wheels of the vehicle during braking. That is, according to this embodiment, since basic data regarding the relationship between the vehicle and the road surface can be output, it is basically possible to perform multiple operations on other road surface condition adaptation devices. Finally, the embodiment of the U & condition detection device for a traveling vehicle according to claim 2 will be explained based on FIG. This detected temperature t is the output V in the configuration of claim ri41, SSo
, R, W, T, /J C'hi E L Yo. In addition, it is explained in the action column! , the ms of claim 2 is the configuration of claim 1 - usage deaf-like 5
,Therefore, wheel temperature, wind force, wind direction, climbing, descending, meandering of the running road, vehicle surface (" + wheel temperature for detecting skidding, etc. @ exit step, force detection means, wind direction detection means, gradient detection means, speed)・Appropriately add one steering angle detection means, one sideslip angle detection f, etc. 1.: From 1) to 1) each can output 1-no data. Next! The implementation of the road surface condition detection device i?l' lj, - also the explanation given in Figure 1 vh
B-on top! In the imperial edict + clause l or claim 2,
A display device 91 (or embodiment 1' of claim 1 above) is provided.
-, the output device 719 is the main display 91), the friction coefficient lI, and various data t/, S, υ, R,, W, °1゛ or V, S. Input the desired data of υ, R, W, , T, and format them in the desired format: Table 1i. The display by the display 91 may be, for example, a road surface condition graph of Suiri・1;S (horizontal axis) and 9 friction coefficient tt (R@) (as shown in FIG. 2), or a third
As shown in the figure, the predetermined road surface temperature + (t in this example)
-20'') and slip rate S (5-30% in this example), a road surface condition graph of vehicle speed (horizontal axis) and friction coefficient μ (vertical axis).However, this indicator I is optional. Since the data υ, RlW, T, are also input, the data S, μ, and
), input ζ, po, L, Jc
In addition, in other aspects of item 2, there is a temperature detection stage, wind force detection means, wind direction detection means L2, slope?, [detection, 1 stage, steering/ring angle detection means, +z, i:l”
If I add 1.2 detection f-fiξ, knead...)? -Participate in the above day 4' with Kaku!・Can you also use a wide range of fingers 6 t')? , it becomes like that.

【Effect of the invention】

As explained above, according to the road surface condition detection device for a traveling vehicle according to claim 10 of the present invention, it can serve as a source for detecting road surface conditions such as a 11A B S device. Further, according to the road surface condition detection device for a traveling vehicle in Claim 291, Cth: Soot; Claim 10 Road surface condition detection for a traveling vehicle 'J': Fl+? ) - Use q! , and the road surface temperature is ABSP: l! Human IH with road surface condition adaptation equipment such as
It becomes possible to use it as data. Further, according to the road surface condition detection device for a traveling vehicle according to claim 3 of the present invention, the display device is provided in place of or in conjunction with a road surface condition adapting device such as an ABS device, so that the driver can easily inform the driver of the road surface condition. It becomes 91 that can do something.

[Brief explanation of drawings]

Figure 1 is a schematic configuration diagram of a traveling heavy vehicle equipped with claims 1 to 3 embodiments, and Figures 2 and 3 are examples of display on the display of claim 2. Fig. 2 is a road surface condition graph of slip name S and 12 coefficient μ, and Fig. 3 is a graph of vehicle speed ■ and I9 at a predetermined road surface temperature and slip rate S.
Figure 4 shows the general relationship between the friction coefficient μ and the slip ratio S in each of the 41 road conditions. Vehicle speed detection means, 21...
・・Road surface temperature detection means, 3.
... Applied load detection means, 7... Motor, 8. - Torque detection means, 9...Torque detection means, 91...
・, Shikiki, R.

Claims (3)

[Claims] (1) In the traveling vehicle 10, the measuring wheel 1, which is provided at the lower part of the vehicle 10 and rotates in pressure contact with the traveling road surface 20, the vehicle speed detecting means 2, the slip rate setting means 3, and the measuring wheel radius R are stored in advance. a microcomputer 4 that presses the measuring wheel 1 against the road surface 20; a load detecting means 6 applied to the measuring wheel 1 by the loading means 5; a motor 7 that rotates the measuring wheel 1; The microcomputer 4 inputs the detected vehicle speed V from the vehicle speed detecting means 2 and the set slip rate S from the slip rate setting means 3, and calculates V(1-S/100) during braking. = υ During driving, the rotational speed υ of the measuring wheel 1 is calculated as V/(1+S/100)=υ, and the motor 7 is rotated to match this speed υ, and the measuring wheel radius R and the rotational speed are From the detected load W input from the applied load detection means 6 at υ and the detected torque T input from the torque detection means 8, a friction coefficient μ of T/(W×R)=μ is calculated, and this friction coefficient μ and the above A road surface condition detection device for a running vehicle, characterized by a configuration that outputs desired data among various data V, S, υ, R, W, and T. (2) In the configuration of claim 1, the road surface temperature detection means 21
A road surface condition detection device for a running vehicle, characterized by a configuration that outputs the detected temperature. (3) In the configuration of claim 1 or claim 2, the display device 9
1, friction coefficient μ, and various data V, S, υ, R, W
, T or desired data of V, S, υ, R, W, T, and t, and displays the data in a desired format.