JP2008298550A - Road surface height measuring apparatus and road surface height measuring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a road surface height at a fine pitch so as to obtain an accurate vertical cross section along a river in a river levee. <P>SOLUTION: A road surface height measuring apparatus for measuring locations and altitudes of the road surface comprises: a wheel 10 rotated while it contacts the road surface; a pole 40 for rotatably supporting the wheel, and having a known length; a receiving apparatus 41 provided at a top of the pole, receiving GPS radio waves, and obtaining information on the locations of a moving point; and a storage apparatus 50 for storing GPS data obtained by the GPS receiving apparatus along with a clock time. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an apparatus and a method for measuring a road surface height along a road surface, such as obtaining a longitudinal sectional view of a river bank.

  Conventionally, maintenance of river embankments has been performed in order to prevent the river embankments from breaking down. To that end, it was necessary to obtain an accurate longitudinal cross-sectional view along the river of the river bank to know which position of the bank was insufficient. For this purpose, there is an aerial survey using a laser. In this method, a GPS and a laser are mounted on a helicopter, and the position of the helicopter is measured by GPS. The direction and distance from the helicopter to the road surface of the embankment, the laser beam is irradiated onto the road surface of the embankment, the reflected wave is received, the direction is measured from the irradiation angle, and the time from the laser irradiation to the reception of the reflected wave Measure distance. Then, XYZ coordinates at the laser irradiation point of the bank are obtained from the position of the helicopter and the direction and distance from the helicopter to the road surface of the bank. As another method, there is a method of actually going to the embankment, walking, measuring the position and height of the embankment by horizontal and triangulation. As surveying and positioning using GPS, methods described in Patent Documents 1 and 2 below are known.

JP-A-6-75034 2005-62083

  However, aerial survey using a laser has a problem that when the weeds grow on the road surface, the height of the road surface cannot be measured accurately because the laser beam is reflected at the tip of the weeds. In addition, there is a problem that it is expensive because the survey is performed using an aircraft. On the other hand, in the conventional horizontal and triangulation surveys by walking at distance markers at every 200 m, there is a problem of overlooking the collapse of the dike road surface in a section within 200 m. For this reason, even if the road surface height of the embankment exceeds the standard value at the distance marker point, the road surface height may actually be lower than the standard value between the distance marker points. Further, if triangulation is performed on foot at intervals shorter than 200 m, it takes much time and there is a limit to the increase in the number of measurement points. For this reason, it has been virtually impossible to accurately obtain a longitudinal sectional view of a dike.

  On the other hand, the methods of Patent Documents 1 and 2 are merely methods for accumulating GPS data at each point to perform surveying and positioning, and a method for obtaining an accurate longitudinal sectional view of a river bank has been suggested. Absent.

  The present invention has been made to solve the above-described problems, and the object of the present invention is to increase the road surface height at such a fine pitch that an accurate longitudinal sectional view along the river of the river bank is obtained. Is to be able to get.

  1st invention for solving the said subject is the road surface height measuring apparatus which measures the position and altitude of a road surface, supports the wheel which can rotate in contact with a road surface, a wheel rotatably, and length is known. , A receiving device that receives GPS radio waves provided at the top of the pole to acquire movement point position information, and a storage device that stores GPS data acquired by the GPS receiving device together with time Is a road surface height measuring device.

  Further, the second invention is a road surface height measuring method for measuring the position and altitude of the road surface while moving the road surface height measuring device of the first invention on the road surface, at the time of measuring the position and altitude of the road surface, A first base station and a second base station are respectively set at two points separated by a predetermined distance on the road surface to be measured. At the time of measurement, the first base station, the second base station, and the road surface height measuring device The GPS radio waves are received at the time, and the GPS data is stored together with the time. From the GPS data, the relative position of the road surface height measuring device at the time with respect to the first base station and the second base station is obtained. From the GPS data at each time received at the electronic reference point existing near the station and the second base station, and the GPS data at the time at the first base station and the second base station, the first base station and The absolute position of the two base stations at that time is obtained, and the absolute position of the road height measuring device at that time is obtained from the absolute positions of the first base station and the second base station at that time and the relative position of the road height measuring device. This is a road surface height measuring method characterized by obtaining.

  In a third aspect based on the third aspect, the absolute position of the road surface height measuring device is obtained from the first absolute position obtained from the relative position with respect to the first base station and the relative position with respect to the second base station. The second absolute position according to the ratio of the distance from the second base station to the distance between the first base station and the distance from the first base station to the distance between the first base station and the second base station. It is characterized in that it is obtained by a value obtained by weighted addition.

  In the invention of the road surface height measuring device, the wheel of this device is brought into contact with the road surface, the person holds the pole, and the GPS wave is received only by moving on the road surface while rotating the wheel. It can be memorized. As a result, since the pole is moved while the wheel is in contact with the road surface of the bank, the measurement becomes extremely simple. Further, in the road surface height measuring method using this measuring device, the first base station and the second base station are determined, the road surface height measuring device is moved between the base stations, and the GPS data in the first and second base stations is determined. At the same time, GPS data is measured by a moving road surface height measuring device. Therefore, the relative position of the road surface height measuring device with respect to the first base station and the second base station is obtained together with the time from the GPS data of the three parties at the same time. Therefore, as a result of specifying the position of the moving road surface height measuring device as the relative position with respect to the two base stations at the common time, a more accurate position can be determined. Further, since the GPS data of the base station is further corrected by the GPS data at the electronic reference point at the time when the GPS data is acquired, the road surface height between the first base station and the second base station is continuously increased. Thus, accurate measurement can be performed.

  In addition, the relative position of the road surface height measuring device with respect to the two base stations is measured. As the relative position is shorter, the base station and the road surface height measuring device receive GPS radio waves on the same route. Therefore, the error becomes small. Therefore, as in the third invention, the position of the road surface height measuring device obtained from the GPS data of the first base station and the position of the road surface height measuring device obtained from the GPS data of the second base station are It is possible to obtain an accurate absolute position of the road surface height measuring device by performing weighted addition with the ratio of the distance to the base station to the distance between the base stations.

  Hereinafter, the present invention will be described based on specific examples. However, the present invention is not limited to the following examples.

  1A and 1B are diagrams showing a configuration of a road surface height measuring apparatus 1, in which FIG. 1A is a front view and FIG. 1B is a side view. The wheel 10 having the rubber tire 11 contacts the road surface 20 and is supported by a support member 30 so as to be rotatable on the road surface 20. The wheel 10 has an axle 12 at the center of rotation, and the axle 12 is rotatably supported by a ball bearing 31 provided on a support member 30. The support member 30 has a triangular front shape and a U-shaped side surface that is a folded flat plate. A rod 40 having a predetermined length is erected on the U-shaped flat top 32. An antenna 41 that receives GPS radio waves is provided at the top end of the rod 40. The GPS data received by the antenna 41 is stored in the recording device 50 together with the measurement time. In a state where the wheel 10 is brought into contact with the road surface 20 and the rod 40 is held perpendicular to the road surface 20, the diameter of the wheel 10 is set so that the radio wave receiving surface of the antenna 41 is exactly 2 m from the road surface 20. The length of the rod 40 and the thickness of the antenna 41 are designed.

Next, a method for measuring a longitudinal sectional view along the river of the river embankment using the road surface height measuring device 1 will be described.
FIG. 2A is a plan view of a river bank. River embankments 60 and 62 exist on both sides of the river 61, and this method is a method for obtaining a longitudinal cross-sectional view shown in (b) along the river of the river embankment 60. First, the first base station 71 and the second base station 72 are provided at both ends of the measurement section. The distance between these base stations is set to 2 km. The first and second base stations 71 and 72 are devices that can accurately receive GPS data together with time, and perform precise stationary observation. Each base station receives GPS data from at least four GPS satellites. The GPS data is data including (transmission time, satellite position) and the like. The first and second base stations 71 and 72 continuously store the reception time, the phase of the received radio wave, and the GPS data from the satellite.

  Next, the road surface height measuring device 1 is moved along the road surface 20 of the embankment 60 from the first base station 71 toward the second base station 72 to receive GPS data at intervals of 1 second, and the recording device 50 Record the reception time, the phase data of the radio wave at that time, and the GPS data. Further, every 200 m, the road surface height measuring device 1 is stopped, and data for 10 seconds is accumulated to perform stationary observation. During this time, the road surface height measuring apparatus 1 and the first and second base stations 71 and 72 store the GPS data transmitted from these satellites and the phase of the received radio wave together with the reception time.

  On the other hand, in the electronic reference station, latitude, longitude, and altitude are accurately specified as known values. GPS data from each satellite in this electronic reference station is recorded together with the reception time.

  As described above, GPS data is accumulated with time while the road surface height measuring device 1 is moved on the road surface 20 of the bank 60. First, let D1 (t) -D4 (t) be the data accumulated in the road surface height measuring device 1. That is, the road height measuring device 1 uses transmission data at time t (included in GPS data) by a clock mounted on the satellite, and D1 (t) to D4 (t) are reception data received from each satellite. . This data includes reception times T1 to T4 by the clock of the road surface height measuring device 1 that has received transmission data from each satellite at the transmission time t. At times T1 to T4, the resolution of the time, that is, the distance between each satellite and the road surface height measuring device 1, is improved by detecting the phase of the radio wave transmitted from each satellite. The clock of the road surface height measuring device 1 is not as accurate as the satellite clock. Therefore, it is assumed that the clock of the road surface height measuring device 1 is advanced by an unknown time Δ with respect to the satellite clock. This Δ gives the same time difference to the four satellites. Accordingly, the distance L1 (t) between each satellite and the road surface height measuring device 1 at time t is expressed as L1 (t) = (T1−t−Δ) × v1 (t). Where v1 (t) is the propagation speed of the radio wave transmitted from the satellite 1 at time t. This varies depending on the ionosphere and weather conditions, but it can be considered constant in the section where the levee 60 is measured in consideration of the position and height of the satellite.

  For four satellites, the expression at time t is L1 (t) = (T1−t−Δ) × v1 (t),..., L4 (t) = (T4−t−Δ) × v4 (t) The following four equations can be established. The unknown variables are three coordinates of the latitude, longitude, and altitude of the road surface height measuring device 1, Δ, and v1 (t) to v4 (t) 8 variables. The known variables are the position of each satellite and the time t. Such an equation can be established for the first base station 71 and the second base station 72. However, it is assumed that the latitude, longitude, and altitude of the first base station 71 and the second base station 72 are first measured accurately and the values are known. Eventually, the first base station 71 or the second base station 72 and the road surface height measuring device 1 can establish 8 simultaneous statistic formulas for 8 unknown variables, and the time of the road surface height measuring device 1 The latitude, longitude and altitude at t can be measured. Even if the latitude, longitude, and altitude of the first base station 71 and the second base station 72 are not accurately obtained, it is considered that the radio wave path common to the road surface height measuring device 1 is configured for each satellite. Since it is thin, the relative latitude, longitude, and altitude with respect to the 1st base station 71 or the 2nd base station 72 of the road surface height measuring apparatus 1 can be calculated | required correctly.

  Next, the first base station 71 and the second base station 72 perform precise multiple measurements, and receive data S1 (t) to S4 (t) from the satellite at the electronic reference point closest to the measurement section. Is used to determine the exact latitude, longitude, and altitude of the first base station 71 and the second base station 72. There are 1200 electronic reference points nationwide, and the latitude, longitude, and altitude are required very accurately. And the reception data S1 (t) to S4 (t) from each satellite at this electronic reference point are made public. t is a satellite clock and is therefore also the exact time of year, month, day, hour, minute, second ... on the earth. At a common time t, the electronic reference point and the first base station 71 and the second base station 72 determine the latitude, longitude, and altitude at the time t of the first base station 71 and the second base station 72 by the method described above. Obtainable. Next, the relative latitude, longitude, and altitude of the road surface height measuring device 1 relative to the first base station 71 or the second base station 72 at the time t determined as described above are set as the first base station 71, or The latitude, longitude, and altitude at the time t of the second base station 72 are added. This value gives an accurate latitude, longitude, and altitude at the time t of the road surface height measuring device 1. This value corresponds to first-class GPS fixed point observation.

  The latitude, longitude, and altitude of the road surface height measuring device 1 are values (x1, y1, z1) obtained from information of the first base station 71 and values (x2, y2) obtained from information of the second base station 72. , Z2). If the road surface height measuring apparatus 1 is closer to the first base station 71 than the second base station 72, the value obtained from the first base station 71 is the second value. It can be said that the error is smaller than the value obtained for the base station 72. That is, when the base station and the road surface height measuring device 1 look at four satellites, it can be said that the error is smaller when the information is obtained using the information of the base station closer to the radio wave path.

Therefore, the true latitude, longitude, and altitude (x, y, z) of the road surface height measuring device 1 are obtained by the following equations.
x = (1−α) · x1 + α · x2 (1)
y = (1−α) · y1 + α · y2 (2)
z = (1−α) · z1 + α · z2 (3)
However, α is the distance from the first base station 71 of the road surface height measuring device 1 / (the distance between the second base station 72 and the first base station 71), that is, with respect to the measurement section of the road surface height measuring device 1. The internal ratio.

  In this way, since the latitude, longitude, and altitude at the antenna 41 of the road surface height measuring device 1 can be accurately measured, if the height of 2.000 m of the antenna 41 is uniformly subtracted from the value, the latitude, Longitude and altitude can be obtained. In this way, a longitudinal sectional view of the river bank can be obtained as shown in FIG.

  The longitudinal section of the river dike was actually measured by the above method. The position through which the wheel 10 of the road surface height measuring device 1 on the road surface 20 of the river bank passes is defined as a white line indicating the boundary with the river surface side bank embankment, 1 m from the front shoulder, and the center line of the management road. The first base station 71 and the second base station 72 were installed at intervals of 2 km, and the road surface between them was measured by reciprocating the road surface height measuring device 1 once. The measurement interval was 1 second, the moving speed was approximately 1 m / sec, and stationary observations were performed for 10 seconds at fixed points every 200 m. Moreover, the measured value in each position was calculated | required by said (1)-(3) Formula. Moreover, the longitudinal section of the river dike was measured over a total length of 50 km.

The difference between the measured values was determined. The reference value was a value obtained by first-class fixed point observation.
The results are shown in Tables 1 and 2.

  Table 1 shows a case where fixed points are observed at intervals of 200 m and fixed points are observed for 10 seconds. Taking the height as an example, the average difference is 0.000 m, the standard deviation is 0.010 m, the maximum value of the difference is 0.040 m, and the minimum value of the difference is -0.042 m.

  Table 2 shows the difference in measured values of altitude when measured at 1 m intervals while moving the road surface height measuring device 1 at 1 m / sec. The maximum value of the average difference is 0.009 m, and the maximum value of the standard deviation is 0.030 m. Although the maximum difference is as high as 0.192 m, the average difference in the section including the value is smaller by 0.009, so that it is understood that a reliable value is obtained as a whole.

  Moreover, as a result of measuring the longitudinal section of other dikes with this method, a maximum of 8 cm of road surface subsidence was observed in the part where the embankment reinforcement work was carried out by the concrete block tensioning on the embankment river front side. In addition, there was a place where earth and sand were temporarily placed on one side of the dike for 300 m. In this section, subsidence of up to 5 cm was observed over 300 m. In addition, there are sections where the earth retaining method by embankment is different, but it was observed by this method that the amount of ground subsidence differs due to this difference in construction method.

  As described above, by using the present invention, the longitudinal dike can be measured in cm order.

  The present invention can be used to obtain a longitudinal section of a river bank.

The block diagram which shows the road surface height measuring apparatus which concerns on the specific Example of this invention. Explanatory drawing which shows the measuring method which obtains the longitudinal cross-section of an embankment using the road surface height measuring apparatus of an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Road surface height measuring device 10 ... Wheel 12 ... Axle 30 ... Supporting member 31 ... Bearing 32 ... Top 40 ... Rod 41 ... Antenna 50 ... Recording device

Claims (3)

In the road surface height measuring device that measures the position and altitude of the road surface,
Wheels capable of rotating in contact with the road surface;
The wheel is rotatably supported, and a pole with a known length;
A receiving device that receives GPS radio waves provided at the top of the pole and obtains moving point position information;
A road surface height measuring device comprising: a storage device that stores GPS data acquired by the GPS receiver together with time. In the road surface height measuring method for measuring the position and altitude of the road surface while moving the road surface height measuring device according to claim 1 on the road surface,
At the time of measuring the position and altitude of the road surface, the first base station and the second base station are respectively set at two points separated by a predetermined distance on the road surface to be measured.
At the time of the measurement, the first base station, the second base station and the road surface height measuring device receive GPS radio waves, store the GPS data along with the time,
From those GPS data, obtain the relative position of the road surface height measuring device at the time with respect to the first base station and the second base station,
GPS data at each time received at an electronic reference point located near the first base station and the second base station, and GPS data at the time at the first base station and the second base station, From the absolute position at the time of the first base station and the second base station,
A road surface height characterized in that an absolute position at the time of the road surface height measuring device is obtained from the absolute positions of the first base station and the second base station at the time and the relative position of the road surface height measuring device. Measuring method.   The absolute position of the road surface height measuring device is obtained by calculating a first absolute position obtained from a relative position with respect to the first base station and a second absolute position obtained from a relative position with respect to the second base station. A ratio of the distance from the second base station of the road surface height measuring device to the distance between the base station and the second base station, and a value obtained by weighted addition according to the ratio of the distance from the first base station. The road surface height measuring method according to claim 2, wherein the road surface height measuring method is obtained.

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