JPS63249008A - Method and apparatus for measuring road surface - Google Patents

Abstract

PURPOSE:To measure and know accurately the state of unevenness of a road surface irrespective of the length of a total road surface distance, by measuring the state of unevenness of the road surface on the basis of a change with time of a detection output of a shock-absorbing member. CONSTITUTION:Forces which suspension cylinders of shock-absorbing members of wheels receive from a road surface are detected by pressure sensors 11-14, sampled at a time interval for canceling the vibration characteristic of the suspension cylinders accompanying the running of a vehicle, and supplied in a time sharing manner to CPU 100 through a multiplexer 20 and an A/D converter 30. When a measuring mode is selected through a measuring switch 70, CPU 100 computes a differential pressure between the maximum and minimum values of detection outputs of the sensors 11-14 within a prescribed time interval determined in accordance with a vehicle speed delivered from a vehicle speed sensor 40. Based on this differential pressure, the weight of the vehicle, the vehicle speed, etc., the rank of unevenness of the road surface is determined with reference to a constant memory ROM 120, and thereby the state of unevenness of the road surface is measured and known accurately irrespective of the length of a total road surface distance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a road surface measurement capability and device for measuring the unevenness of an unpaved road at, for example, a mine or a quarry site.

[Conventional technology]

Particularly in the mines, quarry sites, etc. mentioned above, the unevenness of the road surface has a great effect on various heavy machines running on the circuit surface.

For this reason, conventionally, at each of these sites, the road surface is leveled and repaired periodically using a grader or the like.

[Problem that the invention seeks to solve]

For small mines and quarry sites where the running route is relatively short, it is easy to carry out such land leveling and repair over the entire surface of the running route, but for large mines and quarry sites where the running route has a long total surface distance. On-site, it would be a huge burden to apply this to the entire road surface.
That work is not easy either.

However, even when the total road surface distance is long like this,
Since the areas where the road surface is damaged are dispersed, in reality, it is only necessary to search for these damaged areas and repair only those areas.

However, until now, there was no device that could effectively measure the unevenness of the road surface, so even if only a part of the entire road surface is bad, it is possible to measure the unevenness of the road surface. In many cases, it was not possible to identify the problem and the entire road surface had to be repaired.

This invention has been made in view of these circumstances, and aims to provide a method and device that can accurately measure and understand the unevenness of the road surface, regardless of the length of the total road surface distance. .

[Means for solving problems]

In this invention, for example, the force received from the road surface on a cushioning member of the vehicle such as a suspension cylinder, and the unevenness of the road surface is measured based on the change in the detected value over time as the vehicle travels. I'll do what I do.

[Effect]

According to this method, it is possible to measure the unevenness of the circuit surface without using any special equipment to measure the unevenness of the road surface. Data will be collected.

Note that the detected force is a combination of the shock from the road surface and the natural vibration of the vehicle body, so the detected value is the one that cancels out the vibration characteristics of the buffer member that occurs as the vehicle travels. By using values sampled at the time intervals obtained, the maximum change (differential value) of the detected value within each time period or the difference between the maximum value and the minimum value can be made unique to that road surface. become able to.

In addition, if the data about the unevenness of the road surface collected in this way is sequentially recorded (printed out or stored in memory) on a time base according to the vehicle speed,
By analyzing this, it is also possible to identify the locations where the road surface is damaged.

〔Example〕

FIG. 1 shows an embodiment of a road surface measuring device according to the present invention.

In this embodiment, a dump truck is assumed as the traveling vehicle, and a case is taken as an example in which the dump truck is actually driven and the road surface unevenness of the traveling road is measured.

Now, the dump truck assumed here has four suspension cylinders that serve as buffer members between the vehicle and the road surface, corresponding to each of the four wheels: right front wheel, left front wheel, right rear wheel, and left rear wheel. The device of this embodiment measures the unevenness of the road surface while detecting the cylinder pressure in each of these four suspension cylinders while the vehicle is running.

That is, in this embodiment shown in FIG. 1, the pressure sensors 11 to 14 are arranged corresponding to the four suspension cylinders for the right front wheel, left front wheel, right rear wheel, and left rear wheel, respectively. The pressure inside each cylinder is detected, and this detected value is converted into an electrical signal and output. The signals are multiplexed and further converted into a digital signal of appropriate bits through the A/D converter 30 and taken into the CPU 100.

Further, in the same device, a vehicle speed sensor 40 is a sensor disposed in the power section of the vehicle and outputs an electric signal corresponding to the running speed (hereinafter referred to as a vehicle speed signal), and a brake sensor 50 is The parking sensor 60 is a sensor that is placed in the brake mechanism of a vehicle and outputs an electric signal (hereinafter referred to as a brake signal) indicating whether or not the brake is operated. The measurement switch 70 is a sensor that outputs a signal, and the measurement switch 70 is a switch that is placed in an appropriate part of the cockpit of the vehicle and outputs an electric signal indicating whether or not "measurement mode" is specified based on a switching operation by the operator. The calibration switch 80 is also placed at an appropriate location in the cockpit and outputs an electrical signal indicating whether or not a calibration request is required based on a switching operation by the operator. All signals are also taken into the CPU 100.

As shown in the figure, only the vehicle speed signal is taken into the rearward CPU 100 through the A/D converter 41, where it is converted into a digital signal of appropriate bits, and the contents of the other signals are converted into a logical value of "1". ” or a binary signal indicated by a logical value “0”.

The CPU 100 mainly uses the measurement switch 70 to
Provided that "Measurement Mode" is specified, it accepts the detection outputs of each of the above sensors and comprehensively executes various calculation processes to measure the unevenness of the road surface on which the vehicle is traveling. It is.

The details will be explained later with reference to FIG.

Further, in this embodiment device, the data memory 110 is a memory in which measurement data processed by the CPU 100 is stored in time series, and the constant memory 120 is a memory for storing various types of data required for the calculation processing by the CPU 100. The display device 130 is a memory in which constants are registered and stored in advance, and the display device 130 is used to visually display measurement data obtained by the arithmetic processing of the CPU 100 as appropriate in accordance with the driving of the driver 131. The printer 140 is used to display the buffer 141. The IC card 150 is used to print out the measurement data added via the CPU 100 as required, and the IC card 150 is used to print out the measurement data added through the CPU 100 when the unevenness of the road surface on which the vehicle has traveled is intensively analyzed off-line. This is a card-shaped electronic device in which measurement data calculated and processed by the IC card holder 151 is written into its built-in memory in chronological order.

Note that this IC card 50 has a structure that can be attached to and detached from the IC card holder 150, and after the recording of the measurement data is completed, it is pulled out from the IC card holder 150 by the operator, and then is placed on an IC card reader (not shown) installed at a management center or the like. This IC card reader is connected to a computer, and the measurement data recorded on the IC card 150 is taken into the computer via this card reader and analyzed as required through the computer.

Also, the purpose of the total n1 data processed by the CPU 100, that is, whether to simply store it in the data memory 110 or display it on the display 130,
Alternatively, print it on the printer 140, or print it on the IC.
Whether or not to record the information on the card 150, etc., is determined as appropriate by selecting one or more of them through a selection switch (not shown) or the like.

FIG. 2 shows, in particular, the pressure sensors 11 to 11 of the above-mentioned elements.
14. How the vehicle speed sensor 40, brake sensor 50, parking sensor 60, measurement switch 70, calibration switch 80, display 130, printer 140, IC card 150, and IC card holder 151 are arranged in the dump truck concerned. It is shown schematically.

In addition, in FIG. 2, SS indicates a suspension cylinder arranged corresponding to each wheel described above.

Now, in this embodiment device, the suspension pressure and force detected by each of the pressure sensors 11 to 14 are expressed as P-f (road surface roughness, vehicle loaded weight, vehicle speed, sudden braking, sudden (acceleration, acceleration/deceleration) ... (1) It is expressed by the following functional expression. That is, the road surface roughness to be measured here is G-f (suspension pressure P1 vehicle loading weight, vehicle speed, sudden braking 1,
(sudden acceleration, acceleration/deceleration)...(2)

Incidentally, an example of actual measurement results of the suspension pressure P detected by each of the pressure sensors 11 to 14 as the dump truck runs is shown in the graph shown in FIG. 3.

In this FIG. 3, the pressure P1 shown in FIG. 3(a) is
Suspension pressure detection output of the pressure sensor 11 arranged in the suspension cylinder corresponding to the right front wheel, Fig. 3 (
The pressure P2 shown in b) is the suspension pressure detection output of the pressure sensor 12 arranged in the suspension cylinder corresponding to the front left wheel, and the pressure P3 shown in FIG. The suspension pressure detection output of the pressure sensor 13 and Fig. 3 (
The pressure P4 shown in d) indicates the suspension pressure detection output of the pressure sensor 14 disposed in the suspension cylinder corresponding to the left rear wheel.

Further, Δt shown in FIG. 3 is a time difference (time lag) corresponding to the wheelbase distance between the front and rear wheels.

As is clear from Fig. 3, although the suspension pressure P is expressed as in equation (1) above, more precisely, (a) the internal pressure of each suspension cylinder is determined by the natural vibration of the vehicle in the longitudinal direction. affected.

(d) Even if the vehicle is stationary, the suspension pressure differs for each cylinder due to cylinder sliding resistance, gas pressure variations, etc.

I understand that.

Therefore, in this embodiment device, when measuring the pressure inside the suspension cylinder, we introduce the concept of a measurement time T (this is a function of the vehicle speed) that can cancel out the vibration characteristics of each suspension cylinder.
Pay attention to each pressure signal (detection output of each pressure sensor) within this time T, and when evaluating the unevenness of the road surface, each pressure signal noted within these measurement times T should be carefully monitored. The differential pressure between the maximum value and the minimum value is determined, and the unevenness of the road surface is determined according to the magnitude of the determined differential pressure.

FIG. 4 shows the concept of the measurement time T and how to determine the differential pressure, and FIG. 5 shows a method for determining the unevenness of the road surface based on the determined differential pressure.

That is, in FIG. 4, P wax and Pa1n indicate the maximum and minimum values, respectively, for a certain suspension pressure noticed within a certain measurement time T, and ΔP
represents the differential pressure between the maximum value P wax and the minimum value Pa1n. The value of the differential pressure ΔP obtained in this way is a unique value depending on the unevenness of the road surface to be measured.

In addition, in FIG. 5, ΔP ΔP 1ΔPCD'AH
' Each curve of BC ΔPDH is an experimentally determined criterion for classifying the degree of unevenness of the road surface into five levels A-H, and ranking the water differential pressure ΔP accordingly. It is a constant curve. These constant curves are obtained as a function of the vehicle speed V and the suspension differential pressure ΔP,
For example, as shown in FIG. 5, if the value of the differential pressure ΔP determined for the suspension pressure measured at the vehicle speed Va is ΔPa, it is determined that the roughness rank of the running road is rDJ. be done.

Incidentally, in the example shown in FIG. 5, rank rA
J indicates the rank with the smallest unevenness, and rank rEJ indicates the rank with the largest unevenness.

Note that these judgment criteria differ depending on the loaded weight of the dump truck used, and in reality, each judgment standard constant curve as shown in Figure 5 varies depending on the loaded weight. More than one will be prepared. The loaded weight can be determined based on the pressure detection signals of the pressure sensors 11 to 14 disposed in each of the suspension cylinders, for example, in Japanese Patent Application No. 59-17 filed by the present applicant.
It can be measured using a method such as No. 528, entitled "Method for Measuring Loaded Weight of Vehicle". However, this measurement method is optional.

In this embodiment device, for the measurement time T, CP Ul 00 is determined each time based on the vehicle speed signal from the vehicle speed sensor 40, and the constant ΔP 1Δ
AB BCOD' for P , ΔP ΔP
DO is pre-registered in the constant memory 120 in the form of a table, and the CPU 100 selects the corresponding value based on the loading amount and vehicle speed signal each time.

In addition, this embodiment device also detects whether there has been a brake operation or a change in vehicle speed within the measurement time T, and whether there has been a turn to the right or left. And even if these contents are detected,
It is assumed that the CPU 100 forms an identification code indicating each item and stores it in the data memory 110.

In this embodiment, the pressure signals P3 of the pressure sensors 13 and 14 corresponding to the right rear wheel and the left rear wheel, respectively, are
The unevenness of the road surface described above is measured and evaluated based on P4, and the presence or absence of the turning is detected based on the pressure signals P1 and P2 of the pressure sensors 11 and 12 corresponding to the front right wheel and the front left wheel, respectively. Let's do it.

In particular, when detecting the presence or absence of this turning, as a preliminary calibration, the average value ( This is hereinafter referred to as a calibration value) and stored in the data memory 110, for example.
The same pressure signals P1 and P within the subsequent measurement time T
2, subtract the above calibration value from each average value of the collected signals P1 and P2,
The stable average values of the signals P1 and P2 (these are referred to as Play and P2av, respectively) are first obtained, and the average pressure values Play and P2av for the right and left sides are compared, and the difference is calculated as described above. The road surface rank determined based on the output pressure signals P3 and P4 of the pressure sensors 13 and 14 regarding the rear wheels (more precisely, the differential pressure ΔP3 and ΔP4 for each of them) is on the larger side (i.e., the side with the larger differential pressure). )about,
If the pressure is greater than a certain specified pressure value (this is referred to as Δq) depending on the vehicle speed and loaded weight, it indicates that the vehicle is turning.In other words, the currently evaluated road surface rank is not valid. It is stated that the error is incorrect and is influenced by the turning of the vehicle.

Note that the specified pressure value Δq used for this detection is also determined by the CPU 100 at any time according to the detected and measured vehicle speed and loaded weight of the vehicle. This value Δq can also be determined through preliminary experiments, etc.
In the same embodiment device, this value Δq is also the same as the constant ΔP
1ΔPBC'B ΔP 1ΔP etc., the chamber CD is arranged in a table shape.
It is assumed that the data is pre-registered in the DB number memory 120.

FIG. 6 is a flowchart that collectively shows the operation mode of the CPU 100 including the various processes described above.Finally, an example of the operation of the apparatus of this embodiment as a whole will be described in detail with reference to the flowchart.

First, through the calibration switch 80,
"Calibration" is requested, CPU1
00 is determined to that effect (step 501), and the output pressure signals P1 and P2 of the pressure sensors 11 and 12 at this time are
multiplexer 20 and A/D converter 30, respectively.
At the same time, the calibration value is obtained by taking the average thereof (step 5O2), and is stored in the data memory 110 or a built-in register or the like (step 803).

As described above, such calibration is required and performed when the vehicle is stopped or running on a flat road surface.

Thereafter, when the vehicle actually runs on the measurement target running road, if the "measurement mode" is instructed through the measurement switch 70, the CPU 100 determines that (step 5IO) and selects the vehicle speed sensor 40 and the pressure. Based on the detection outputs of the sensors 11 to 14, the current speed and loaded weight of the vehicle (dump truck) are detected (step 511), and the measurement time T is determined based on the detected vehicle speed and loaded weight. and determine constants ΔP 1ΔP 1ΔP ΔP and A according to the detected vehicle speed and loaded weight, respectively, from the constant memory 120.
BBCCD'DEΔq is selected and temporarily stored in a built-in register or the like (step 512).

■Each pressure sensor 11 at the total time T determined above
~14 detected pressure signals P1 to P4, respectively, the maximum value (P1max - P4+++ax) and the minimum value (P
1m1n -P4iin), and these calculated values are also temporarily stored in a built-in register or the like (step 513).

■However, at this time, if a brake operation (detected based on the brake signal) or a gear shift operation (detected based on the vehicle speed signal) is detected within the measurement time T determined above (step S14 or 515), aborts the measurement process corresponding to the measurement time T, forms an identification code indicating that these operations have been performed, and stores this in the data memory 110 (step 5141 or 5).
151).

■If such an operation is not detected, calculate the average value of Pl and P2 of the pressure signals, and subtract the calculated and memorized calibration values from each of them to calculate the values for the right and left rear wheels. The stable average values Play and P2av described above are determined, and the determined average values Play and P2Hv are temporarily stored in a built-in register or the like (step 516).

■ Regarding P3 and P4 of the above pressure signals, the corresponding road surface rank is searched based on the differential pressures ΔP3 and ΔP4 in the manner described above with reference to FIG. 517). Of course, in this search, the judgment constant Δ selected in the previous step S12
PAB'ΔP ΔP ΔPDE is used.

BC' CDゝ■ However, at this time, the differential pressures ΔP3 and ΔP4 are compared (step 818), and if, for example, ΔP3 is larger, that is, if a larger suspension differential pressure is recognized on the right side of the vehicle, , when the average values Play and P2av obtained and stored above satisfy the relationship P lay −P 2av>Δq, that is, the suspension pressure applied to the right side of the vehicle is lower than the specified value Δq than the suspension pressure applied to the left side of the vehicle. If it is larger than that, it is determined that the vehicle is turning to the right, and an identification hood indicating that the vehicle is turning is formed and this is stored in the data memory 110 in steps 5181 and 5181.
2) Only when such a relationship is not satisfied, data indicating the road surface rank searched and determined in step S17 is stored in the data memory 110 (step 518).
1 and 51811).

Conversely, if ΔP4 increases among the above differential pressures,
That is, when a larger suspension differential pressure is recognized on the left side of the vehicle, the average values Play and P2av determined and stored above are P2av - P1av
> Δq, that is, if the suspension pressure on the left side of the vehicle is greater than the suspension pressure on the right side of the vehicle by more than the specified value Δq, the vehicle is turning left. Steps 5182 and 5 similarly form an identification code indicating that the vehicle is turning and store it in the data memory 110.
1812), and only if such a relationship is not satisfied, the data indicating the road surface rank searched and determined in step 817 is stored in the data memory 110 (steps 5182 and 51821).

A series of processes such as these are executed repeatedly.

As a result, as the vehicle travels, data indicating the road surface condition and data indicating the operation status of the operator are written in the data memory 110 in chronological order. Note that when writing these data to the data memory 110, by writing them together with the vehicle speed data at a predetermined time base, it is possible to easily identify each desired location on the driving road surface during subsequent analysis. be able to identify.

As described above, the data thus collected is displayed on the display 130 as necessary, printed out through the printer 140, and recorded on the IC card 150.

In the above embodiment, in order to detect whether or not the vehicle is turning, the calibration in steps 801 to 803 and the suspension pressure comparison in steps S16 and S18.8181°5182 are performed. However, in addition to this, for example, an angle sensor may be provided in the turning mechanism of the vehicle, and the presence or absence of the same turning may be detected based on the detection of a predetermined turning angle by such a sensor. You can also do that.

However, as in the above embodiment, if the suspension pressure detection signal (pressure signal) from the pressure sensor is used and compared and processed as required as described above, the sensor configuration can be kept to a minimum in terms of the device configuration. It happens.

Furthermore, when the pressure signal is used in this way, in the above embodiment, the pressure signal related to the rear wheels is used to evaluate the unevenness of the road surface, and the presence or absence of this turning is detected using the pressure signal related to the front wheels. Of course, the manner in which the pressure signals for the front and rear wheels are used may be reversed.

In addition, the method and number of standards for ranking the road surface unevenness conditions are not limited to the form shown in Figure 5 above, and are arbitrary, depending on the road surface to be measured and the equipment installed. It can be determined freely depending on the actual situation of the vehicle being used.

Further, in the same embodiment, the rank determination reference constants determined in this manner are registered in advance in the memory in the form of a table, but it is of course possible to calculate these constants each time.

Furthermore, in the above embodiment, in order to make the value of each pressure signal to be extracted unique to the measured road surface, the difference between the maximum value and the minimum value of the pressure signal sampled at the measurement time T, which is a function of the vehicle speed, That is, although the differential pressure ΔP is used, the maximum variation (differential value) of the pressure signal sampled during the same measurement time T may also be used.

In addition, in the above embodiment, as a practically preferable form, a configuration was adopted in which the operator's brake operation, gear change operation, and even the presence or absence of turning are detected. Any device that can detect changes in suspension pressure over time is sufficient, and it is possible to measure the unevenness of the road surface to the bare minimum.

Moreover, the vehicle in which the device of this embodiment is installed is not limited to the above-mentioned dump truck, and the pressure to be detected may even be the force that the buffer member of the vehicle receives from the road surface. do it.

[Effects of the Invention] As described above, according to the present invention, it becomes possible to accurately measure and understand the unevenness of the circuit surface, regardless of the length of the total road surface distance of the traveling route.

Therefore, road surface maintenance etc. can be carried out rationally and efficiently.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the road surface measurement device according to the present invention, Fig. 2 is a schematic diagram showing how the embodiment device is mounted on a dump truck, and Fig. 3 is a block diagram showing an embodiment of the road surface measuring device according to the present invention. FIG. 4 is a diagram showing an example of actually measured values of changes in each suspension pressure as the vehicle travels, and FIG.
FIG. 5 is a diagram showing a road surface rank determination method based on the device of the embodiment, and FIG. 6 is a flowchart showing an example of the operation of the device of the embodiment. 11-14... Pressure sensor, 20... Multiplexer, 30.41... A/D converter, 40... Vehicle speed sensor, 50... Brake sensor, 60... Parking sensor, 70...・・Measurement switch, 80・Calipre silane switch, 100・CPU, 110・
・・Data memory, 120 ・Constant memory, 130・
...Display device, 140...Printer, 150...IC
card. (”−＼

Claims (6)

[Claims] (1) A road surface measurement method that detects the force that a buffer member of a vehicle receives from the road surface, and measures the unevenness of the road surface based on changes in the detected value over time as the vehicle travels. (2) The road surface measuring method according to claim (1), wherein the detected value is a value sampled at a time interval that can cancel out the vibration characteristics of the buffer member caused by the running of the vehicle. (3) A pressure sensor that is arranged on a buffer member between the vehicle and the road surface and detects the force that the member receives from the road surface, a vehicle speed sensor that detects the vehicle speed of the vehicle, and a predetermined value that is determined as a function of the detected vehicle speed. a calculating means for calculating a pressure difference between the maximum value and the minimum value of the detected value of the pressure sensor during the time period; and a determining means for determining the unevenness of the road surface based on the calculated pressure difference. Equipped with a road surface measuring device. (4) The buffer member on which the pressure sensor is disposed is a suspension cylinder disposed corresponding to each wheel of the vehicle, and the pressure sensor is a suspension cylinder disposed corresponding to each wheel of the vehicle. A road surface measuring device according to claim (3), which detects pressure. (5) The determining means has a memory in which multiple ranks of unevenness of the road surface are registered in advance in correspondence with the differential pressure, and the determined differential pressure is registered in advance with the pre-registered ranks. The road surface measurement device according to claim 4, which determines the unevenness of the road surface by comparison. (6) The road surface measurement method according to claim (5), wherein the ranks of the plurality of levels to be compared are determined as a function of the weight and speed of the vehicle.