JP2000009463A - Apparatus for measuring ground surface level profile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily measure the absolute height of the height profile of the ground surface. SOLUTION: A laser lighthouse 15 for radiating a laser beam to be a height reference, based on the installation height measured by a GPS receiver 16, a light receiver 17 for receiving the laser beam to detect the vehicle height is mounted on a vehicle 11, a distance measuring means 21 measures the distance between the vehicle and ground surface while the vehicle runs, and the distance is subtracted from the vehicle height detected by the light receiver 17 to obtain the height profile of the ground surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring a height profile of a ground surface changed by subsidence or abrasion on a road, an airport, a harbor, a river, a landfill, and the like. And a device for measuring a profile.

[0002]

2. Description of the Related Art As a conventional means for measuring this kind of ground surface profile, there is, for example, an optical surveying method, and a road profile measuring apparatus proposed by the present inventors in Japanese Patent Application No. 8-325683. There is.

[0003]

In the measurement of the ground surface profile by the conventional optical survey, there is a disadvantage that the measurement takes an extremely long time. Further, the above-described road profile profile measuring device can measure only the AC component (relative height) of the ground surface profile, and cannot measure the absolute height.

An object of the present invention is to provide a profile measuring apparatus which solves these drawbacks and can easily measure the height profile of the ground surface and can measure the height to an absolute height.

[0005]

According to the first aspect of the present invention, there is provided a GPS receiver, and a laser lighthouse for emitting a laser beam serving as a height reference based on the installation height measured by the GPS receiver. Mounted on a vehicle, receiving the laser light, detecting the height of the vehicle, measuring the distance between the vehicle and the ground, and subtracting the measured distance from the detected height. Means for obtaining a height profile of the ground surface.

According to the second aspect of the present invention, a GPS receiver, a laser lighthouse that emits a laser beam serving as a height reference based on the installation height measured by the GPS receiver, and a vehicle mounted on a vehicle, Means for receiving the laser light, detecting the height of the vehicle, means for measuring the vertical acceleration of the vehicle, integrating means for integrating the measured vertical acceleration to calculate the height, and calculating the height Means for negatively feeding back the difference between the height and the detected height to the integrating means, means for measuring the distance between the vehicle and the ground, and a height profile of the ground surface by subtracting the measured distance from the calculated height. Means for determining

[0007]

Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In this example, the vehicle is driven within the range for measuring the ground surface profile, and the ground surface profile is measured while the vehicle is running. Therefore, the vehicle height (absolute height) during vehicle running and the vehicle height The distance to the ground is measured.

First, the measurement of the vehicle height will be described.
A vertical acceleration measuring means 12 for measuring a vertical acceleration of the vehicle is attached to the vehicle 11. As the vertical acceleration measuring means 12, for example, a three-axis strapdown inertia device can be used. Note that a uniaxial accelerometer may be used. The vertical acceleration measured by the vertical acceleration measuring means 12 is input to the integrating means 13, and the integrating means 13 integrates the vertical acceleration to calculate a vertical velocity. Further, the vertical speed is integrated by the integrating means 14, and the integrating means 14 calculates the height.

On the other hand, as shown in FIG.
And the GPS receiver 16 are installed on the ground. The GPS receiver 16 measures the installation height of the laser lighthouse 15,
The GPS may be a normal GPS, a differential GPS, or a real-time kinematic GPS, which is appropriately selected according to required accuracy. The laser lighthouse 15 emits a laser beam serving as a height reference into a horizontal plane based on the installation height measured by the GPS receiver 16. The laser lighthouse 15 is configured by installing a laser light emitter having a rotating structure on, for example, a tripod. Note that the GPS receiver 16 measures the installation height of the laser lighthouse 15 once and sets the height of the laser lighthouse 15, so that the GPS receiver 16 becomes unnecessary thereafter.

A light receiver 17 is attached to the vehicle 11 as means for receiving the laser light emitted from the laser lighthouse 15, and the light receiver 17 can detect the height of the vehicle from the position (height) at which the light was received. It has become something. Receiver 1
The difference between the height detected by step 7 and the height calculated by the above-mentioned integrating means 14 is obtained by the subtracting means 18, and this difference is calculated by the integrating means 13 or 14 or 13,.
14 is negatively fed back. Thus, when there is a bias error in the vertical acceleration output, the divergence of the error in the integrating means 13 and 14 due to the bias error is suppressed, and the output of the integrating means 14 indicates the absolute height. In this way, real-time absolute height data during the running of the vehicle 11 is obtained from the integrating means 14.

The distance between the vehicle 11 and the ground is measured by distance measuring means 21 attached to the vehicle 11. As the distance measuring means 21, for example, a laser distance meter is used. It is desirable that the distance measuring means 21 is attached at the same position as the vertical acceleration measuring means 12 in order to avoid a change in height relative to the vertical acceleration measuring means 12 due to the inclination of the vehicle 11.

The data of the distance between the vehicle and the ground measured by the distance measuring means 21 and the height data of the vehicle calculated by the integrating means 14 are inputted to the profile calculating means 22. The profile calculation means 22 subtracts the distance data between the vehicle and the ground from the height data of the vehicle for each unit time or unit distance, thereby obtaining and outputting a height profile of the ground surface.

For example, the laser lighthouse 15 is omitted and G
It is conceivable that the PS receiver 16 is mounted on the vehicle 11, but in this case, the GPS receiver 1
It is not a good idea because a situation may occur in which 6 cannot be used. In addition, since the GPS altitude data generally fluctuates during the measurement, the fluctuation error becomes an error in the low profile of the ground surface, and this is not a good idea.

FIG. 3 shows a simple configuration of a ground level low profile measuring apparatus using a laser lighthouse 15 whose height is set by a GPS receiver 16. In this example, the height detected by the light receiver 17 is used for the height data of the vehicle, that is, the distance data between the vehicle and the ground measured by the distance measuring means 21 and the height of the vehicle detected by the light receiver 17. Data and the profile calculation means 22
, And a height profile of the ground surface is required.

The configuration shown in FIG. 3 is similar to that of FIG.
Compared to the configuration using acceleration, there are the following disadvantages, but they can be used properly depending on the use conditions. (1) In the configuration of FIG. 3, if there is an obstacle that blocks laser light in the range of the laser lighthouse 15, it is impossible to measure only that portion. The configuration shown in FIG. 1 can be used for a short time even if the laser beam is blocked by an obstacle.

(2) Vehicle height data must be obtained at the frequency required for profile measurement. However, since the laser lighthouse 15 generally rotates a laser emitter,
In the case of the configuration in FIG. 3, height data cannot be obtained at a required frequency, and profile measurement may be insufficient. FIG.
This configuration does not have this disadvantage.

[0017]

As described above, according to the present invention, it is possible to easily measure the height profile of the ground surface while traveling with a vehicle, and also to measure an absolute height.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the invention of claim 2;

FIG. 2 is a diagram illustrating a state in which measurement is performed while traveling in a vehicle.

FIG. 3 is a block diagram showing an embodiment of the invention of claim 1;

Claims (2)

[Claims] 1. A GPS receiver, a laser lighthouse that emits a laser beam serving as a height reference based on an installation height measured by the GPS receiver, a laser lighthouse mounted on a vehicle, and receiving the laser beam Means for detecting the height of the vehicle, means for measuring the distance between the vehicle and the ground, and means for obtaining the height profile of the ground surface by subtracting the measured distance from the detected height. A surface height low profile measuring device characterized by the following. 2. A GPS receiver, a laser lighthouse that emits a laser beam serving as a height reference based on an installation height measured by the GPS receiver, and a laser lighthouse mounted on a vehicle and receiving the laser beam. Means for detecting the height of the vehicle; means for measuring the vertical acceleration of the vehicle; integrating means for calculating the height by integrating the measured vertical acceleration; Means for negatively feeding back the difference from the height to the integrating means, means for measuring the distance between the vehicle and the ground, means for subtracting the measured distance from the calculated height to obtain a height profile on the ground, An apparatus for measuring the height of a ground surface profile, comprising: