JPS63100317A - Method and device for measuring road surface height - Google Patents

Abstract

PURPOSE:To measure a road surface continuously with high accuracy by relatively simple constitution by recording variation of the center position of the width of spot light detected by a linear CCD sensor as unevenness information on the road surface. CONSTITUTION:A laser light transmission and reception part 1 is equipped with a light signal transmission part 1A and a photosensor part 1B, and the transmission part 1A outputs laser light which is converged into a spot through the operation of a lens part 12 so that its optical axis TR is almost at right angles to the road surface A through the operation of a driving circuit 11, thereby irradiating a measurement point on the road surface. The photodetection axis RE of the sensor part 1B varies by an angle theta to an optical axis TR of transmission on the road surface A of reference height. The laser spot on the road A is caught on the linear sensor 18. A processing part 2 stores one-scan data of the sensor 18 in a buffer 20 and the center position of its output signal is calculated 21, so that the height of the measurement place is calculated 22 on the basis of said calculation result. The computed unevenness information on the road surface is recorded and displayed 23.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a road surface height measuring method and apparatus, and particularly to a road surface height measuring method and apparatus using laser light.

[Conventional technology]

In the conventional road surface height measuring device, as shown in FIG. The movement is converted into rotational movement via the shaft 53 and the pinion 54, thereby causing the encoder 55 to rotate. Then, the rotation amount of the encoder 55 is detected by the pulse counting circuit 56, and the height calculation circuit 57 is operated from the detected value to numerically convert it into the vertical movement amount of the measuring roller 51.
It records the unevenness of the surface.

(Problems to be Solved by the Invention) However, in such conventional examples, there is a drawback that reliability is lacking because there are many mechanically moving parts in the measurement value transmission system.In addition, when continuously measuring the road surface, Since the measurement accuracy is directly affected by the diameter of the measuring roller, for example, if the diameter of the measuring roller is small, the measuring roller will get caught on the road surface, making it impossible to perform the measuring work smoothly. Furthermore, if the measuring roller is large, there is a drawback that it is not possible to accurately measure depressions in the road surface, as shown in FIG.

On the other hand, in order to improve the drawbacks of the conventional example, a height measuring device using a laser beam has recently been published.

However, most of the conventional devices using laser light check the condition of the road surface by image processing the detection signal, which has the disadvantage that the device is large-scale and lacks versatility.

[Purpose of the invention]

An object of the present invention is to provide a road surface height measuring method and apparatus that can improve the disadvantages of the conventional example and measure the road surface continuously and with high precision with a relatively simple configuration. do.

[Means for solving problems]

Therefore, in the present invention, in a road surface height measurement method, a spot irradiation is performed on an uneven part of a road surface using a light source, and a positional change in the height direction of this spot irradiation is detected and recorded as road surface unevenness information. A one-dimensional CCD sensor is used to detect changes in the position of the light in the height direction, the center position of the width of the spot light detected by the one-dimensional CCD sensor is calculated, and the change in the center position is used as road surface unevenness information. It is intended to achieve the above objective by adopting a recording structure.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

In FIG. 1, 1 indicates a laser beam transmitting/receiving section as a signal transmitting/receiving section, and 2 indicates a signal processing section.

The laser beam transmitting/receiving section 1 includes an optical signal transmitting section IA and an optical sensor section IB. Of these, the optical signal transmitter IA includes a semiconductor laser device 10, a laser drive circuit 11 that drives the semiconductor laser device 10, a lens portion 12 that focuses the laser light output from the semiconductor laser device 10, and this lens. part 12 and semiconductor laser element 10
and a support member 13 that integrally supports the.

Therefore, when the laser drive circuit 11 operates, the laser beam focused into a spot by the action of the lens section 12 is outputted with its tip axis TR (parallel ray) substantially perpendicular to the road surface A, and It is designed to illuminate measurement points on the road surface.

Further, the optical sensor section IB of the laser beam transmitting/receiving section l is connected to the road surface A.
Interference filter 16 sequentially from the side. A condensing lens 17 and a one-dimensional CCD sensor 18 are installed in this order. Of these, the one-dimensional CCD sensor 18 is also provided with a CCD drive circuit. The signal processing section 2 is provided on the output side of the one-dimensional COD sensor 18. Further, the light receiving axis RE of the sensor part IB is on the road surface A at the reference height.
It is arranged so as to change at an angle of θ with respect to the above-mentioned transmission optical axis TR. In this case, the laser spot on the road surface A is captured on the one-dimensional CCD sensor 18 at a level as shown in FIG. 2, for example.

The signal processing section 2 includes a line buffer 20 that stores data for one scan of the one-dimensional CCD sensor 18, a first arithmetic circuit 21 that calculates the center position of the output signal of the line buffer 20, and the first and a second calculation section 22 that calculates the height of the measurement point based on the output of the calculation circuit 21. The road surface unevenness information calculated by the second calculation section 22 is recorded and displayed on the recording display section 23.

Further, the laser beam transmitting/receiving section 1 is actually installed in a road surface measurement mechanism 30 shown in FIG. 3.

The road surface measurement mechanism 30 in FIG.
A laser beam transmitter/receiver 1 is mounted on a moving frame 32 that reciprocates in the direction C2D along the points A' and A'' in the figure.
In order to further expand the measurement range, a configuration is adopted in which the laser beam transmitting/receiving section 1 is moved back and forth on a moving frame 32. In this case, the moving frame 32
is guided by guide rollers S+, Sz, Ss, ..., S, and reciprocated from the left side of the figure (the position indicated by the solid line) to the position indicated by the two-dot chain line on the right side of the figure. It has become. Therefore, it is possible to effectively measure a range that is more than twice the length of the main body frame 31.

In this FIG. 3, 33 indicates a drive chain, and 34
indicates the chain on the driven side. Further, 35 indicates a guide rail mounted on the moving frame 32. The laser beam transmitter/receiver 1 is guided by this guide rail 35 and follows arrows E and F.
It is designed to be able to move back and forth in the direction of. 36.37
indicates a brake means, and 38.39 indicates a position sensor. Further, 40.41 indicates a stopper for the laser advance transmitting/receiving section 1.

Next, the operation of the signal processing system in the above embodiment will be explained.

Since the road surface E (see FIG. 3) diffusely reflects the laser light, when viewed from the optical sensor section IB, the portion of the road surface E irradiated with the laser light is observed like a spot-shaped laser light source. In this case, when the reference plane A (see Figure 1) is irradiated with laser light, the light receiving axis RE of the optical sensor section IB passes through that point P, so the laser spot formed on the reference plane A is The center of the image is focused on the center point Q of the one-dimensional CCD sensor 18. On the other hand, when the laser beam is irradiated onto the road surface A' at a position h higher than the reference height, the image of the laser spot at that time has its center centered on the one-dimensional CCD sensor 18.
The image is formed at a position shifted by δ from the center (0 point) above.

The relationship between δ and h at this time is that the center of the condensing lens 17 is R
Then, h=δ・liver/(δ・cos θ+QR・si
n θ) (11) The calculation of this equation (1) is performed by the second calculation unit 22 described above.

Further, the center position of the laser spot image, that is, the center position of the image formed on the one-dimensional CCD sensor 18 mentioned above, can be simply captured as the center of the image forming line even if there is an overall shift. This calculation is performed in the first calculation section 21 described above.

Furthermore, in this embodiment, as described above, the interference filter 16 is provided on the light input side of the condenser lens 17.

The interference filter 16 is one that allows only light having a wavelength near the laser wavelength (for example, 780 nm in this embodiment) to pass therethrough in order to prevent shadows from sunlight. Therefore, there is an advantage that measurement can be continued even during the day.

In the above embodiment, the one-dimensional CCD sensor 18 is used as the optical sensor of the optical sensor section IB, but other image sensors such as a CMOS type sensor may be used.

〔Effect of the invention〕

Since the present invention is configured and functions as described above, the received signal processing system does not include any mechanically moving parts, so highly reliable measurement data can be obtained, and the spot of light can be It can be made smaller, and the unevenness can be reduced to 1n by focusing only on the misalignment of the center position of the light receiving spot.
As a result of this, the signal processing has been simplified and the processing time has been shortened, making it possible to accurately and quickly detect and analyze road surface irregularities.The structure is simple, so it can be used anywhere, regardless of the size of the road. It is possible to provide an unprecedented and excellent road surface height measuring method and device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a signal processing system in one embodiment of the present invention, FIG. 2 is an explanatory diagram showing an imaging situation in a one-dimensional CCD sensor as an optical sensor, and FIG. Explanatory diagram showing a road surface measuring mechanism equipped with a signal transmitting and receiving unit shown in Fig. 4.
5 through 5 are explanatory diagrams showing conventional examples, respectively. ■・・・Signal transmitting/receiving section, LA... Optical signal transmitting section, IB... Optical sensor section, 17...
・Condensing lens, 18... One-dimensional CCD sensor,
20・・・・・・Line buffer agent Patent attorney Isamu Takahashi Figure 1

Claims (2)

[Claims] (1) In a road surface height measurement method, in which uneven spots on the road surface are irradiated with a spot using a light source, and changes in the position of the irradiated spot in the height direction are detected and recorded as road surface unevenness information, the method comprises: Changes in position in the height direction are detected using a one-dimensional CCD sensor, the center position of the width of the spot light detected by this one-dimensional CCD sensor is calculated, and the change in the center position is recorded as road surface unevenness information. A road surface height measurement method characterized by: (2) It has an optical signal transmitter that irradiates a measurement point on the road surface with a spot, and an optical sensor that detects the measurement position on the road surface irradiated with the spot, and these optical signal transmitter and optical sensor are integrated into the road surface. In the road surface height measuring device equipped with a sensor support mechanism that moves back and forth along the optical sensor, the optical sensor is a one-dimensional CCD sensor,
It consists of a condensing lens installed on the light receiving side of the CD sensor, a line buffer that temporarily stores the received signal of a predetermined width detected by this optical sensor, and a line buffer that temporarily stores the received signal of a predetermined width detected by this optical sensor, and A first calculation unit that specifies the center position from the detected one-dimensional received signal, and a second calculation unit that calculates the height of the measurement point based on the output of the first calculation unit are connected to the first calculation unit. A road surface height measuring device characterized by being attached to a former CCD sensor.