JP4140699B2 - Slope monitoring system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a slope monitoring system for monitoring the state of a slope such as a slope based on GPS observation values, and in particular, a slope monitoring system capable of accurately dealing with an emergency such as an increase in slope displacement. It is about.
[0002]
[Prior art]
In general, slopes such as slopes, especially large-scale slopes with unstable elements, are always associated with the risk of collapsing, so it is necessary to properly maintain and manage the slopes. Work and countermeasure work are performed. However, when maintaining the slope, there are still many unclear points about how the factors such as weathering of natural ground, transition of vegetation, and aging of protective works and countermeasures are involved in the slope collapse. For this reason, the state of the slope is constantly monitored to predict the collapse of the slope in advance.
[0003]
By the way, conventionally, a method of measuring displacement of a slope using GPS (hereinafter referred to as GPS slope measurement) is known. In such GPS slope measurement, for example, a reference point arranged on the slope at a distance. The relative displacement between the observation point and the observation point is measured, and the slope displacement is measured. For example, a GPS receiver is arranged at each of the reference point and the observation point, and a reception signal (GPS signal) received by each GPS receiver is transmitted to a field office away from the slope via a wireless line. An analysis device provided in the office calculates position coordinates and relative position displacements of reference points and observation points based on GPS signals (see Patent Document 1).
[0004]
[Patent Document 1]
JP-A-5-280978 (pages 2 to 3, FIG. 2)
[0005]
As described above, when measuring the relative displacement between the reference point and the observation point using GPS or the like, and trying to know the slope state from the measurement data (observation data) Because it is necessary to detect even minute displacements, it is extremely difficult to evaluate observation data itself, and considering that observation data varies due to external factors such as weather, It is difficult to accurately obtain the displacement of the relative position between the reference point and the observation point from the observation data.
[0006]
In other words, taking into account variations in observation data, when obtaining the relative position displacement between the reference point and the observation point with high accuracy, there is almost no displacement of the slope in the normal case. (In other words, it is necessary to improve the standard deviation and calculate the displacement of the relative position every preset time (for example, about 0.5 to 1.0 hours at the shortest). Positioning (stationary positioning) is performed to determine slope displacement.
[0007]
[Problems to be solved by the invention]
By the way, in the static positioning as described above, even if the observation point moves while the positioning is interrupted, if the movement amount is within the range of ± λ / 4 (λ: wavelength of the GPS radio wave carrier), it is set in advance. If the static positioning is performed after the elapse of time, the phase bias at the time of the static positioning is the same as the previous positioning, so that the correct position can be obtained by observing the carrier phase.
[0008]
However, if the observation point moves beyond the range of ± λ / 4 during positioning interruption, the true bias value is different from that immediately before positioning interruption, and the correct position cannot be known.
[0009]
For this reason, when performing static positioning at a predetermined time interval, it is necessary to set the time interval so that the moving amount of the observation point during the positioning interruption is ± λ / 4 or less.
[0010]
However, as described above, when static positioning is performed by setting a time interval, variation in observation data can be suppressed and the displacement tendency of the slope can be accurately grasped. There is a problem that the displacement of the slope cannot be monitored in real time when there is a possibility that the displacement becomes large.
[0011]
On the other hand, if you try to measure slope displacement in real time by shortening the above-mentioned preset time, the observed data will vary greatly, and in normal conditions (other than emergency situations), the slope displacement tendency can be accurately grasped. There is a problem that it is difficult to do.
[0012]
An object of the present invention is to provide a slope monitoring system that can accurately grasp the state of a slope and can accurately cope with an emergency.
[0013]
[Means for Solving the Problems]
According to the present invention, it is used when monitoring the state of a slope,
A GPS reference station that is arranged at a position outside the slope, receives radio waves from GPS satellites, and outputs the radio waves as reference GPS data;
At least one GPS station disposed at a position within the slope, receiving radio waves from the GPS satellites and outputting the radio waves as GPS data;
Monitoring the slope displacement data by obtaining the slope displacement based on the reference GPS data and the reference point position information indicating the position of the GPS reference station obtained from the GPS data and the position information indicating the position of the GPS station. A center,
The monitoring center generates the slope displacement data according to a static positioning method at each first time interval defined in advance, and when the slope displacement indicated by the slope displacement data exceeds a preset displacement threshold value. In addition, the static positioning method is used in combination with an RTK (real-time kinematic) positioning method with a second time interval shorter than the first time interval, and the slope displacement data is obtained at the first time interval. The slope displacement is monitored at the second time interval, an alarm is issued when the RTK displacement exceeds a preset regulation value for each slope, and both the static slope displacement and the RTK slope displacement are below a threshold value. , Configured to return only to the static positioning method ,
Further, the monitoring center is input with rainfall data indicating rainfall on the slope or in the vicinity of the slope, and when the slope displacement does not exceed a displacement threshold, the rainfall data has a preset rainfall threshold. When exceeding, both the positioning methods are used together, and an alarm is issued when the RTK displacement exceeds a preset regulation value for each slope, both the static slope displacement and the RTK slope displacement are below a threshold value, and the rainfall amount is the rainfall amount. A slope monitoring system characterized by being configured to return only to the static positioning method when the threshold value is not reached is obtained.
[0014]
In this way, the GPS reference station and the GPS station receive radio waves from GPS satellites at predetermined time intervals and generate reference point position information and position information according to static positioning, respectively. If the slope displacement indicated by the displacement data exceeds a preset displacement threshold value, the slope displacement data is obtained at the first time interval and the slope displacement is monitored at the second time interval. In addition to being able to grasp accurately, it is possible to deal with emergency situations such as when the displacement of the slope is large. In normal cases, the static positioning method is performed at the first time interval. The power consumption at observation points such as slopes can be reduced. Since the GPS reference station and the GPS station are connected to the monitoring center via the network, a plurality of slopes can be monitored at the same time by the monitoring center.
[0015]
Further, in the present invention, the monitoring center receives rainfall data indicating rainfall on or near the slope, and when the rainfall indicated by the rainfall data exceeds a preset rainfall threshold, The monitoring center obtains the slope displacement data at the first time interval by using the RTK positioning method in combination with the static positioning method regardless of the slope displacement indicated by the slope displacement data, that monitors the displacement of the slope in the time interval.
[0016]
Thus, when the rainfall showing rainfall amount data Ru exceeds a preset rainfall threshold, regardless of the slope displacement indicated by the slope displacement data, with determining the slope displacement data in a first time interval, the second If the displacement of the slope is monitored at this time interval, not only the state of the slope can be accurately grasped, but also an emergency such as heavy rain can be dealt with accurately.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below with reference to the drawings. In the following description, the shape, dimensions, and the like are not limited to these unless otherwise specifically described.
[0018]
Referring to FIG. 1, first, the illustrated slope monitoring system includes a plurality of slope monitoring apparatuses 11-1 to 11-N (N is an integer of 2 or more), and these slope monitoring apparatuses 11-1 to 11-11. -N is connected to the monitoring center 12 via a wired communication line 13 such as an optical cable communication line, for example. The slope monitoring devices 11-1 to 11-N are arranged on different slopes, monitor and measure the state of each slope, and send the data to the monitoring center 12 as observation data (measurement data). Here, the observation data transmitted by the slope monitoring devices 11-1 to 11-N are referred to as first to Nth observation data, respectively.
[0019]
The monitoring center 12 is provided with a computer system 12a, an output device (monitor) 12b such as a display device, an input device 12c, and a database 12d. In accordance with the first to Nth observation data obtained from the slope monitoring devices 11-1 to 11-N, slope displacement data is generated for each slope as described later. In addition, the monitoring center 12 is arrange | positioned in the point distant from the slope monitoring apparatuses 11-1 to 11-N, and collects these observation data remotely.
[0020]
The slope monitoring device (GPS measuring device) 11-n (where n is any number from 1 to N) includes at least two GPS (Global Positioning System) receivers (measuring devices). Then, it has the three GPS receivers 11a-11c. One of these, for example, the GPS receiver 11a, is arranged at a point other than the slope as a reference point receiver (GPS reference station). That is, the reference point receiver 11a is disposed on the stable ground away from the slope.
[0021]
On the other hand, the other GPS receivers 11b and 11c are arranged on the slope (at least one GPS receiver may be arranged on the slope). The GPS receivers 11a to 11c receive radio waves (GPS radio waves) from at least four GPS satellites at a preset time interval (first time interval), and receive GPS data at each time interval described above. Output as observation data. The time interval is set by an observation time setting command from the computer system 12a, for example.
[0022]
These GPS receivers 11 a to 11 c are connected to a communication aggregator 11 d or a wireless aggregator 11 e used as a communication device, and the communication aggregator 11 d is connected to a wired communication line 13. Then, the communication concentrator 11 d sends each observation data to the monitoring center 12 via the wired communication line 13.
[0023]
In addition, the wireless aggregation device 11e sends each observation data to the wireless relay device 16 via a wireless line. FIG. 1 shows one radio repeater 16, but actually, a plurality of radio repeaters 16 are arranged, and a communication area is defined for each radio repeater 16. Observation data is received from the wireless aggregator 11e located in the communication area. The wireless repeater 16 is connected to the wired communication line 13 described above, and observation data for each slope is sent from the wireless repeater 16 to the monitoring center 12. Each observation data is added with information for identifying the GPS receiver (GPS receiver identification information).
[0024]
Further, as shown in the drawing, for example, a rain gauge 21 is installed on each slope, and the rainfall measured by the rain gauge 21 is transmitted as rain data via the communication aggregator 11d or the wireless aggregator 11e. (It is also possible to receive the distribution of meteorological data without installing a rain gauge on each slope. In other words, meteorological data indicating rainfall on the slope or in the vicinity of the slope (rainfall) (Quantity data) may be received).
[0025]
The observation data (GPS data) obtained as described above represents the position information of each GPS receiver three-dimensionally over time, and now the position information of the reference point receiver (GPS reference station) 11a. Is the reference point position information, and based on this reference point position information and position information obtained from other GPS receivers (hereinafter referred to as other position information), the displacement of the slope is time-series and three-dimensional. Can get to.
[0026]
Referring also to FIG. 2, in the monitoring center 12 (that is, the computer system 12a), on the basis of the reference point position information and other position information obtained as described above, the displacement data of the slope is as follows. (Slope displacement data) is obtained. As described above, the reference point position information and other position information are given to the computer system 11a from each of the GPS receivers 11a to 11c (step S1). In the computer system 12a, slope displacement data is obtained at predetermined time intervals using the reference point position information and other position information (step S2). The slope displacement data is displayed with time on the horizontal axis and displacement on the vertical axis, and is displayed on the monitor 12b and stored in the database 12d for each slope. For example, as shown in FIGS. 3A to 3C, the slope displacement data is represented as a displacement point sequence in the north-south direction, the east-west direction, and the vertical direction (FIG. 3 (b) shows the east-west direction, and FIG. 3 (c) shows the vertical displacement point sequence).
[0027]
By the way, the above-mentioned slope displacement data includes variations (varies in a band shape) due to various external factors (for example, the state of the GPS satellite, the influence of the ionosphere and the troposphere, the multipath, and the baseline length). It is difficult to accurately grasp and evaluate the state of the slope from the slope displacement data. Therefore, the monitoring center 12 (that is, the computer system 12a) performs filtering and smoothing processing on the slope displacement data to generate processed displacement data (filter data) (step S3).
[0028]
Here, the filtering process and the smoothing process will be described. Here, the system noise variance τ ^{2, the} observation noise variance σ ² , and the order k are calculated by estimating the state vector x _n using the Kalman filter algorithm. Then, _xn is obtained discretely, and the optimal _xn is estimated using the log likelihood and AIC.
[0029]
In other words, a state space _model, and _{x n = F n x n-} 1 + G n ν n, y n = H n x n + w n. Here, x _n : state vector that cannot be observed directly (stochastic system model), ν _n : system noise (mean 0, variance-covariance matrix Q _n ), y _n : observation data (observation model), w _n : observation noise ( The mean is 0 and the variance-covariance matrix R _n ), and F _n , G _n , and H _n are transition matrices defined by Gauss-Markov processes, respectively. And let this state space model be a probability difference equation. Assuming that H _{n xn} = t _n , y _n = t _n + w _n (observation model), Δkt _n = ν _n (when k = 1, Δt _n = t _n −t _n−1 = ν _n , Δkt _n Is the k-th order difference equation).
[0030]
Then, the Kalman filter is used to calculate the first-term prediction (first step), filter (second step), and smoothing (third step) as a series of flows, and the observed value y _n = {y ₁ , y _2, ..., a state under given are _{y n} x n = {x} 1, x 2, ..., seek _{x n}.}
[0031]
After performing the filtering process and the smoothing process in this way, the processed displacement data is stored in the database 12d together with the above-described displacement data and displayed on the monitor 12b. This processed displacement data is represented as a line segment indicated by a solid line in FIGS.
[0032]
Then, after obtaining the processed displacement data, if the processed displacement data exceeds a preset displacement threshold value, for example, the slope displacement (referred to as static slope displacement) indicated by the processed displacement data is changed to the displacement threshold value. (Step S4), the computer system 12a issues a real-time kinematic (RTK) positioning command to the slope monitoring device where the displacement is measured (step S5).
[0033]
In the slope monitoring device that has received the RTK positioning command, the built-in CPU receives GPS radio waves in real time (second time interval) in response to the RTK positioning command, regardless of the predetermined time interval described above. The observation data is sent to the monitoring center 12 (step S6). Hereinafter, this observation data will be referred to as RTK observation data.
[0034]
In the monitoring center 12, the computer system 12a extracts the RTK observation data at predetermined time intervals (first time intervals), and performs the filtering process and the smoothing process as described above to process the processed displacement data. In addition, displacements in the north-south direction, the east-west direction, and the vertical direction are detected from time to time in real time according to the RTK observation data (step S7: hereinafter, this displacement is referred to as RTK displacement). In the computer system 12a, when the RTK displacement exceeds a change amount (RTK change amount) defined in advance for each slope (step S8), an alarm is issued to notify an emergency (step S9).
[0035]
On the other hand, if the static slope displacement is equal to or less than the displacement threshold value in step S4 described above, the computer system 12a has a rainfall threshold value (this rainfall value per hour) indicated by the rainfall data (for example, rainfall per hour) set in advance. It is determined whether or not the rainfall threshold exceeds a slope for each slope (step S10). When the rainfall indicated by the rainfall data exceeds the rainfall threshold, the computer system 12a performs the above-described step S5.
[0036]
If the rainfall indicated by the rainfall data is equal to or less than the rainfall threshold value, static positioning is performed at a preset time interval as described above.
[0037]
In this way, when the static slope displacement exceeds the displacement threshold or the rainfall exceeds the rainfall threshold, the static positioning (first positioning technique) and the RTK positioning (second positioning technique) are substantially used in combination. The situation of the slope will be monitored and prepared for an emergency.
[0038]
When both the static slope displacement and the RTK slope displacement are settled (that is, when the static slope displacement is not more than the slope threshold, the RTK slope displacement is not more than the RTK change amount, and the rainfall is not more than the rainfall threshold (step S11). ) The computer system 12a sends a static positioning command to the above-described slope monitoring device (step S12). Thus, the slope monitoring apparatus performs static positioning at a preset time interval (that is, returns to step S1). Although not shown, upon receiving information that a natural disaster such as an earthquake has occurred near the slope (natural disaster occurrence information), the computer system 12a changes from static positioning to RTK positioning as described above. Then, the state of the slope may be monitored.
[0039]
【The invention's effect】
As described above, in the present invention, in the monitoring center, when the slope displacement indicated by the slope displacement data observed according to the static positioning method exceeds a preset displacement threshold, RTK (Real Time Kinematic) is used as the static positioning method. By using the positioning method together, the slope displacement data is obtained at the first predetermined time interval, and the slope displacement is monitored at the second time interval shorter than the first time interval. In addition to being able to accurately grasp the state of the above, there is an effect that it is possible to appropriately cope with an emergency such as a case where the displacement of the slope is large.
[0040]
In addition, in normal cases, positioning (static positioning) is performed at a preset first time interval, so that not only the load at the monitoring center can be reduced, but also the power consumption at observation points such as slopes. There is also an effect that can be reduced.
[0041]
Further, since the GPS reference station and the GPS station are connected to the monitoring center via a network, there is an effect that a plurality of slopes can be monitored at the same time by the monitoring center.
[0042]
In the present invention, when the rainfall showing rainfall amount data Ru exceeds a preset rainfall threshold, regardless of the slope displacement indicated by the slope displacement data, in combination with RTK positioning method statically positioning techniques, predefined In addition to obtaining slope displacement data at the first time interval and monitoring the displacement of the slope at the second time interval (real time), not only can the slope condition be accurately grasped, but also emergency such as heavy rain There is an effect that the situation can be dealt with accurately.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an example of a slope monitoring system according to the present invention.
FIG. 2 is a flowchart for explaining processing in the slope monitoring system shown in FIG. 1;
3 is a diagram showing observation data and processed displacement data obtained by the slope monitoring system shown in FIG. 1, wherein (a) is a diagram showing the north-south direction, (b) is a diagram showing the east-west direction, and (c). Is a diagram showing a vertical direction.
[Explanation of symbols]
11-1 to 11-N Slope monitoring device 11a to 11c GPS receiver 11d Communication aggregator 11e Wireless aggregator 12 Monitoring center 12a Computer system 13 Wired communication line 16 Wireless repeater 21 Rain gauge

Claims (2)

Used to monitor slope conditions,
A GPS reference station that is arranged at a position outside the slope, receives radio waves from GPS satellites, and outputs the radio waves as reference GPS data;
At least one GPS station disposed at a position within the slope, receiving radio waves from the GPS satellites and outputting the radio waves as GPS data;
Monitoring the slope displacement data by obtaining the slope displacement based on the reference GPS data and the reference point position information indicating the position of the GPS reference station obtained from the GPS data and the position information indicating the position of the GPS station. A center,
The monitoring center generates the slope displacement data according to a static positioning method at each first time interval defined in advance, and when the slope displacement indicated by the slope displacement data exceeds a preset displacement threshold value. In addition, the static positioning method is used in combination with an RTK (real-time kinematic) positioning method with a second time interval shorter than the first time interval, and the slope displacement data is obtained at the first time interval. The slope displacement is monitored at the second time interval, an alarm is issued when the RTK displacement exceeds a preset regulation value for each slope, and both the static slope displacement and the RTK slope displacement are below a threshold value. , Configured to return only to the static positioning method ,
Further, the monitoring center is input with rainfall data indicating rainfall on the slope or in the vicinity of the slope, and when the slope displacement does not exceed a displacement threshold, the rainfall data has a preset rainfall threshold. When exceeding, both the positioning methods are used together, and an alarm is issued when the RTK displacement exceeds a preset regulation value for each slope, both the static slope displacement and the RTK slope displacement are below a threshold value, and the rainfall amount is the rainfall amount. A slope monitoring system configured to return only to the static positioning method when a threshold value or less is reached .   The slope monitoring system according to claim 1, wherein the GPS reference station and the GPS station are connected to the monitoring center by a network.

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