JPH042945A - Apparatus for detecting and displaying slide resistance of road surface - 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 [Field of Industrial Application] The present invention relates to a sagging resistance detection and display device between a tire of an automobile or the like and a road surface.

[Prior Art] When the frictional resistance between the tires of a car and the road surface decreases, making the road surface more slippery, the tires may slip when the car suddenly stops, overtakes someone, or drives around a curve, which can lead to traffic accidents. There is a risk that it may cause Therefore, the analogy is
6-39946, JP-A-60-213852, JP-A-1
112131, etc., by installing various road surface friction coefficient detection devices on vehicles and using the detected road surface friction coefficients as control signals for driving performance, braking performance, etc., safety during vehicle driving can be improved. We are ensuring.

Furthermore, conventional methods for measuring the friction coefficient of road surfaces for road maintenance include the trailer method, deceleration method, braking distance method, portable tester method, and the like.

[Problems to be Solved by the Invention] However, it is not only necessary to automatically control running performance, braking performance, etc. by detecting the slip resistance coefficient between the tires and the road surface, but also to automatically control running performance, braking performance, etc. The driver is made aware of the sagging resistance coefficient of the road surface in advance, and the driver himself/herself maintains the following distance and controls the vehicle speed.
- It is more effective to encourage people to drive safely.

In addition, as part of road maintenance and management,
Measure the slip resistance coefficient of the road surface using the road surface slip resistance measuring device shown in No. 12-26150, collect measurement data,
The analysis is being carried out, but since this measuring device is trailer-type, it requires a towing vehicle.

By the way, when collecting road surface slip resistance measurement data,
With the exception of the trailer method, all of the other three methods require measurements to be taken by temporarily blocking road traffic, making them difficult to carry out at any time. On the other hand, the trailer method allows measurements to be taken while the vehicle is in motion, but the measuring device is large and expensive to manufacture, and the trailer's measuring wheels are pulled at a constant speed by applying brakes. The wear is relatively large and the service life is short.

The present invention has focused on the above-mentioned conventional problems, and is equipped with a display device that allows the driver to recognize the detected slip resistance coefficient of the road surface, and has a simplified structure and low manufacturing cost as a vehicle exclusively for measuring slip resistance. An object of the present invention is to provide a road surface skid resistance detection and display device [Means for Solving the Problems] In order to achieve the above object, a road surface skid resistance detection and display device according to the present invention provides means for forcibly causing a rotational difference between the left and right idlers, means for detecting the l-lux generated on the idler wheel shaft due to sagging resistance due to the rotational difference between the left and right idlers, and the detected idler. means for converting wheel axle torque into a coefficient of sliding resistance between the tire and the road surface;
and means for displaying the shear resistance coefficient.

[Operation] The idler wheels move on the road surface while being rotated by the traction force of the drive wheels. At this time, if a rotation difference is forcibly created between the left and right idler wheels, the rotational force of one idler wheel rotating at high speed will pull the other idler wheel rotating at low speed, so that the idler wheel rotating at low speed will not touch the road surface. This causes slippage. At this time, torsional torque is generated on the idler wheel shaft in proportion to the sliding resistance. In the present invention, the torque is converted into a road surface slip resistance coefficient and displayed to the driver, so that the road surface slip resistance coefficient can be accurately detected and displayed by normal driving.

[Example] Hereinafter, an example of the road surface slip resistance detection and display device according to the present invention will be described in detail with reference to the drawings.

The present invention is applied to a vehicle in which a driving wheel axle and an idler wheel axle are provided independently, such as a front-wheel drive vehicle. In FIG. 1, driving wheels 2a and 2b, which are the front wheels of a vehicle l, are attached to a driving wheel axle 4 driven by an engine 3 via a transmission, and idler wheels 5a and 5b, which are rear wheels, are each attached to an idler axle. It is attached to 6. A phase difference torque meter 7 is attached to the idler wheel shaft 6, and this phase difference torque meter 7 is connected to a display device 9 via a T-μ conversion calculation device 8.

The idler axle 6 and the idler wheels 5a and 5b have a structure that allows them to rotate at the same time, and during normal driving, the idler wheels 5a and '5'b
Since tires of the same diameter are mounted, no torque is generated on the idler axle 6. When trying to detect the slip resistance between the tire and the road surface, it is possible to make the outer diameters of the left and right tires different by changing the aspect ratio and rim size of one of the free-moving tires 1FA5a and 5b, or by changing the rim size or both of these. By running, the idle wheel axle 6 is caused to twist.

By detecting this twist amount with the phase difference torque meter 7, the frictional force F generated between the tire and the road surface is detected. The relationship between this frictional force F and the friction coefficient μ between the tire and the road surface is as follows: F = (T:) ruq, r: tire radius) F = μW
Since the relationship (W: idle wheel load, known) holds true,
If the torque T is detected by the phase difference torque meter 7, the slip resistance coefficient μ can be determined. This calculation is performed by the T-μ conversion calculation device 8.

FIG. 2 is a diagram showing the principle of the phase difference torque meter 7.

When torque T is applied to the idler wheel shaft 6, the rotation detection means 10
A time difference t occurs between the output pulses Pa and Pb due to a and 10 b, and this corresponds to the torque T. That is, d: diameter of the idler wheel axle, G: transverse elastic modulus of the idler wheel axle, ku: rotation detection means 10a.

When the length between 10b and θ is the twist angle at both ends of the length, the torque T can be expressed as follows. Note that 0 is in a proportional relationship with the time difference t.

The vehicle speed is calculated from the rotation signal obtained by the rotation detection means of the phase difference torque meter 7, that is, the output pulses Pa and Pb of the rotation detection means 10a and 1O1 (and μ according to the vehicle speed).
If a calculation function is provided that can convert this into a braking and stopping distance, the results will be output to the display device 9, and the information for ensuring safety based on the current road surface condition and driving speed will be displayed when driving. You can inform others.

FIG. 3 is a block diagram of the T-μ conversion calculation device 8. The output pulses Pa and Pb of the phase difference torque meter 7 are input to the l·lux detection calculation unit 11 and the vehicle speed detection calculation unit 12, and
The torque is converted into a slip resistance coefficient μ by the T-)J conversion calculation unit 13, and then output to the μ correction calculation unit 14. The vehicle speed detection calculation unit 12 outputs a vehicle speed signal to the μ correction calculation unit 14 and the braking stop distance calculation unit 15. The μ correction calculation unit 14
It is output to the display device 9 and the braking/stopping distance calculating section 15. The braking stopping distance calculating section 15 calculates the braking stopping distance based on the speed-corrected shear resistance coefficient μ and the signal output from the vehicle speed detection calculating section 12. That is, braking stopping distance S(
m), V: vehicle speed (k + - r+ / b ), g:
9.81T1/sec2, J: When taken as corrected slip resistance value, it can be obtained by practical calculation. This S is output to the display device 9.

FIG. 4 shows an example of the display device 9. The zone display section 16 indicates the magnitude of the slip resistance coefficient μ, and by adding the braking/stopping distance display section 17, you can more specifically drive with regard to brake operation, accelerator operation, steering wheel operation, ensuring distance between vehicles, etc. It is possible to call people's attention.

In this way, in this example, a simplified measuring device is installed in a commonly used front-wheel drive vehicle, rather than a trailer-type or bus-type measuring vehicle, so that slip resistance can be easily detected and displayed while driving. did.

In this example, the slip resistance value of the road surface and the braking stopping distance are
Although it has been explained as a visual information transmission means displayed on a display device, it would be even safer if an auditory information transmission means was added, such as not sounding an alarm when at least one of the skid resistance value and braking stopping distance exceeds a set value. is ensured.

[Effects of the Invention] As explained above, according to the present invention, a rotation difference is forcibly generated between the left and right idler wheels, and this rotation difference is converted into a torsional torque generated on the idler wheel shaft into a slip resistance coefficient of the road surface. Since the device is designed to display the information to the driver, it is possible to accurately detect and display the sagging resistance coefficient of the actual road surface, which constantly changes depending on the driving road surface condition and weather, even though it has a simple structure. This makes it easier to ensure driving safety, and as a measurement-only vehicle, it is not necessary to tow a trailer, making it possible to reduce the manufacturing cost of the measurement device.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the schematic configuration of the road surface skid resistance detection and display device according to the embodiment, FIG. 2 is an explanatory diagram showing the operating principle of the phase difference torque meter shown in FIG. 1, and FIG. FIG. 4 is a block diagram of the -μ conversion arithmetic device, and is a schematic front view showing an example of a display device. 5a, 5b...Idle wheel 6...Idle wheel shaft 7...Phase difference torque meter 8...T-μ conversion calculation device 9...・Display device patent applicant Komatsu Ltd. 1 〇 −

Claims (1)

[Claims] means for forcibly creating a rotation difference between left and right idle wheels of a wheeled vehicle; means for detecting torque generated on the idle wheel axle due to slip resistance due to the rotation difference between the left and right idle wheels; A road surface skid resistance detection and display device comprising: means for converting the torque of an idle wheel axle into a slip resistance coefficient between the tire and the road surface; and means for displaying the slip resistance coefficient.