KR20090128827A - Vehicle weight measuring apparatus - Google Patents

Abstract

PURPOSE: A device for measuring the weight of a vehicle shaft is provided to improve the reliability of measurement response and simplify a structure by measuring the response of a beam movement. CONSTITUTION: A device for measuring the weight of a vehicle shaft comprises a bending plate(101), a transverse beam(201), a ring-shaped load cell(202), and a strain sensor. Bending is generated in the bending plate after the load of a vehicle is applied. The transverse beam is installed at the lower end of the bending plate in the vertical direction with the vehicle entry direction. The transverse beam converts the plate movement generated on the bending plate into a simple beam form for fixing both ends. The ring-shaped load cell is installed at the both lower ends of the transverse beam. The strain sensor is attached on the load cell. The strain sensor measures the strain of the load cell.

Description

Vehicle Axial Weighing Device {VEHICLE WEIGHT MEASURING APPARATUS}

The present invention relates to a vehicle shaft weighing apparatus for measuring the weight and speed of the vehicle buried in the road surface, and more specifically, compared to the conventional bending plate or load cell type shaft weighing apparatus, A vehicle axle that provides a high-sensitivity, easy-to-maintain, relatively inexpensive vehicle axle weight and speed measurement device, and provides a method for evaluating the remaining life of a bridge using weight data measured from this measurement device. Relates to weighing.

The vehicle axle weighing device is a device that collects various data related to the weight of the vehicle without being disturbed by traffic flow, which is buried on the road on which the vehicle travels, and may be particularly used to detect speeding and overloading vehicles. In particular, facilities such as bridges can cause serious damage due to the passage of heavy vehicles, and the measurement of shaft weight is considered to be a very important factor.In order to evaluate the condition and life of facilities like load capacity of bridges, Input load may also be a very important factor, but the conventional shaft weighing apparatus has the following limitations.

1 to 3 is a conventional generally used shaft weighing apparatus, Figure 1 is a shaft weighing device of the bending plate type, Figure 2 is a load cell shaft weighing device and Figure 3 is a quartz shaft weight The measuring device is shown.

Figure 1 is a conventional bending plate type, as shown in Figure 4, the bending plate is generated in the transverse direction as well as the longitudinal direction due to the passage of the vehicle due to the strain gauge response in the longitudinal direction as well as the transverse direction Since this is reflected at the same time, it is difficult to accurately characterize the input load. In addition, since the strain gauge cannot be attached to the entire plate, the measurement accuracy slightly includes an error depending on the position of the vehicle wheel. The bending plate method of FIG. 1 is a method that converts the axial weight by measuring the response caused to the plate when passing through the vehicle after attaching a sensor such as a strain gauge to the steel plate plate, and has a high accuracy range of ± 10%. There is this.

The error range of the load cell shaft weighing apparatus in which the load cell is attached to the conventional bending plate of FIG. 2 is about 6%, which is relatively higher than that of the bending plate method, but is relatively accurate when the vehicle passes near the position where the load cell is placed. Axial weight can be measured, but when the vehicle passes through a distance away from the load cell, a measurement error is gradually increased. In addition, there is a disadvantage in that the maintenance cost is high because it is necessary to constantly replace the expensive load cell.

On the other hand, the axial weight measurement apparatus using a piezoelectric sensor has the advantage that it can be installed relatively easily by inserting a piezo cable after cutting the joint, but the response is hardly measured at low speed, and the response deviation is very large depending on the speed and the road surface temperature. There are disadvantages.

The conventional shaft weighing apparatus using the quartz of Figure 3 has the advantage of a very convenient installation because the cutting width of the package is small when installed compared to the bending plate shaft weighing device, but very expensive and relatively weak durability compared to the bending plate There is this.

Therefore, in Korea, the axis weighing device of the bending plate type, which has relatively good price performance, is mainly used for medium and low speed, and the axis weighing device using quartz is applied for high speed, but high speed shaft weighing is used. There is no realistic alternative in terms of price and maintenance. In addition, although the cumulative weight of the vehicle passing through the bridge structure is an important factor to shorten the life of the bridge, so far the axial weight measuring device is used to determine only the weight calculation or the number of traffic.

In order to solve the problems described above, the present invention utilizes the advantages of the bending plate method and the load cell method to switch the measurement of the response using the strain gauge of the bending plate method to the beam behavior instead of measuring the plate behavior. By measuring the response of the beam behavior by the load cell, the structure is very simple and aims to greatly improve the reliability of the measurement response. In addition, it is possible to measure the speed of the vehicle at the same time, so that the speed compensation is possible to provide a vehicle axle weighing apparatus that can further improve the precision. In addition, there is an additional object to provide a method for evaluating the bridge remaining life using the measurement results by the axial weight measuring apparatus provided in the present invention.

The object of the present invention is to remove a portion of the package to form a groove, and installed in the formed groove in the vehicle axle weighing apparatus for measuring the axle weight of the moving vehicle, plate bending is generated when the vehicle load is applied A bending plate having a shape and a plate beam generated in the bending plate are converted into a fixed simple beam type at both ends, and transverse beams are installed at the bottom of the bending plate in a direction perpendicular to the vehicle entry direction, and both ends of the transverse beams. And a load cell installed at a lower end, the load cell supporting the lateral beam and receiving the deflection of the lateral beam due to a vehicle load, and a strain sensing sensor attached to the load cell to measure the strain of the load cell. Can be achieved by a vehicle shaft weighing apparatus.

By providing a shaft weighing device capable of simultaneously measuring the vehicle load and passing speed through the bending plate supported by the simple beam, the load cell, and the sensor installed in the V-shaped groove, the shaft weight of the conventional bending plate type In the measuring device, the plate behavior measuring method is guided to the beam behavior and the load cell measuring method, or in the case of an expensive load cell measuring method, an inexpensive and accurate axis is replaced by a ring or rhombic load cell with a strain sensor which is inexpensive. The weight can be measured. In addition, high-speed weighing can be performed, and by using FBG fiber optic sensor or OTDR sensor selectively, the reliability of measured value can be improved without being affected by the external environment.

Hereinafter, the advantages, features and preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

5 is a system configuration diagram of (a) the strain gauge attached to the conventional bending plate and (b) the axial weight measuring apparatus of the present invention, Figure 6 is a configuration diagram for explaining the measurement principle of (a) the conventional bending plate, (b) is a block diagram for explaining the measuring principle of the axial weight measuring apparatus of the present invention, Figure 7 is a conceptual diagram for explaining the principle of the reaction force against the load of a simple beam (simple beam).

In order to overcome the disadvantages of the prior art as described above, as shown in Figure 5 (b) and Figure 6 (b), the axial weight measuring apparatus of the present invention is a plate 101, the vehicle under the plate 101 The horizontal beam 201 which is placed in a direction perpendicular to the traveling direction of the horizontal beam 201, and the load cell 202 is provided on both lower ends of the horizontal beam 201.

The axial weight measuring apparatus according to the present invention allows the load acting on the plate 101 when the vehicle passes by to the load cells 202 installed on both sides by the transverse beam 201. As described in FIG. 7, the reaction force is measured by load cells 202 installed at both ends of the transverse beam 201 regardless of the load placed on the bending plate plate 101 according to the principle of the action load and the reaction force of the simple beam. By summing this, the input load can be accurately estimated without error.

In general, the load cell 202 used herein attaches an FBG fiber strain sensor or an OTDR sensor 301 to a ring-shaped pedestal, as shown in FIG. 8 (a), and fixes both ends of the optical fiber sensor to both ends of the ring-type by applying prestrain. In this case, the ring shape is compressed and deformed in the vertical direction due to the load acting on the upper part, and thus the tensile shape is deformed in the horizontal direction. Can be. In addition, the load cell of the present invention may be configured by attaching an FBG optical fiber strain sensor or an OTDR sensor to which a prestrain is applied to a diamond as shown in FIG.

The shape of the load cell is not limited to the shape in FIG. 8, and various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention to those skilled in the art. It will be obvious.

In addition, the load cell to be used in the present invention can be configured by installing at least one FBG optical fiber strain sensor or OTDR sensor 301 on the ring-shaped side as shown in Figure 9 (a). As shown in FIG. 9 (b), the FBG optical fiber strain sensor or the OTDR sensor is attached to one outer side and one inner side, respectively, so that the variation occurs with respect to the temperature change, and only the strain against the load is measured by compression-tension. Since it can be configured a load cell capable of temperature compensation in the long term.

In addition, the load cell to be used in the present invention is characterized in that it can be configured by attaching the electrical resistance strain gauge 302 in the form of a full bridge on both inside and outside sides as shown in FIG.

Accordingly, as shown in FIGS. 11 and 12, the configuration of the shaft weighing apparatus according to the present invention includes a bending plate 101 in which bending occurs when a vehicle load is applied, and a displacement generated in the bending plate to the load cell 202. The transverse beam 201 and the load of the bending plate 101 are converted into the reaction force of the simple beam fixed at both ends, which converts the plate behavior due to the transfer and the plate behavior by the load into the fixed beam type at both ends, and A load cell 202 which serves to measure and supports the upper bending plate 101 and the transverse beam 201, and is attached to the pedestal of the ring 202 or rhombus 203 in the form of prestrain applied thereto. And the FBG optical fiber sensor, the OTDR sensor 301 or the electric resistance strain gauge 302, which performs the function of calculating the upper vehicle load by measuring that the ring-shaped or rhombic pedestal is deformed by the load. One or more points at each entrance and exit are installed at the entrance and exit to measure the transit time from a sensor placed at a predetermined distance to measure the moving speed of the vehicle. The magnetic groove 207 and the sensor 301 installed therein, the shaft weighing device fixing frame 205 which is installed inside the package 204 and serves to fix the shaft weighing system including the bending plate, and the bending plate. It is basically composed of a fixing bolt 206 for connecting and fixing the 101 and the fixing frame 205.

In addition, the error of the conventional vehicle axle weighing device has an error generated according to the vehicle entry speed, the axial weight measuring device of the present invention is the response by the load of Figs. In addition, the speed can be further measured by measuring the passing time by installing the sensor in the V-shape and the sensors installed in both V-shape 207 at the known distance, thereby compensating for the speed with one system. It can be carried out by itself. At this time, the V-shaped groove 207 should be continuous in the direction perpendicular to the vehicle driving, and the more sensors for measuring the warp in the vehicle driving direction, the more accurate weight and vehicle speed can be measured.

The most effective speed correction method is to derive a correlation between speed and weight by measuring the weight according to the actual vehicle traveling speed, and then use this value as a correction factor. Examples are shown in Table 1.

Example of measurement city type Actual weight calculation example

The minimum sampling value per second for measuring the speed of a high-speed driving vehicle is about 200 Hz considering the width of the weighing device's banding plate and the maximum speed of the driving vehicle, and only about 100 Hz when the width of the bending plate is 60 cm or more. It was enough. Table 2 shows sampling values per second considering the time required for each speed when the WIM device passes.

    Speed (km / hr) WIM device width (m) 100 110 120 130 140 150 160 170 180 190 200 0.3 93 102 111 120 130 139 148 157 167 176 185 0.4 69 76 83 90 97 104 111 118 125 132 139 0.5 56 61 67 72 78 83 89 94 100 106 111 0.6 46 51 56 60 65 69 74 79 83 88 93 0.7 40 44 48 52 56 60 63 67 71 75 79 0.8 35 38 42 45 49 52 56 59 63 66 69 0.9 31 34 37 40 43 46 49 52 56 59 62 One 28 31 33 36 39 42 44 47 50 53 56

In addition, it is possible to classify the axial weight measured by the vehicle shaft weighing apparatus provided by the present invention in each weight step, to give an influence coefficient to the bridge structure in each axial load step, and the weight accumulated by the number of traffic vehicles Evaluating the remaining life of the bridge by using is a more effective and realistic method than the existing bridge life evaluation method, which is shown in FIG.

Fig. 14 shows a bridge life evaluation system incorporating a shaft weight measuring device on a bridge. The overall life of the bridge should be calculated by considering the impact factor of 1.3k and the maximum number of fatigue-related repeated loads of 2 million times in 96kN celebrating the 1st bridge design load. The method of calculating the life reduction level using the cumulative weight is not limited to this method, and may be changed within a range without departing from the technical spirit of the present invention.

The present invention described above is not limited to the above-described embodiments and drawings, and various substitutions, modifications, and changes are possible within the scope without departing from the technical spirit of the present invention. It will be apparent to those who have

1 is a shaft weighing apparatus of the conventional bending plate type.

Figure 2 is a conventional load cell axial weight measuring apparatus.

3 is a shaft weight measurement apparatus of a conventional quartz method.

4 is a strain gauge attached to a conventional bending plate.

5 is a system configuration diagram of (a) the strain gauge attached to the conventional bending plate and (b) the axial weight measuring apparatus of the present invention.

6 is a configuration diagram for explaining the measurement principle of a conventional bending plate, (b) is a configuration diagram for explaining the measurement principle of the axial weight measurement apparatus of the present invention.

7 is a conceptual diagram for explaining the principle of reaction force against load of a simple beam;

8 is a load cell comprising an FBG optical fiber strain sensor or an OTDR sensor prestrained and installed in a ring or rhombus according to the present invention.

9 is a load cell configured by surface-attaching an FBG optical fiber strain sensor or OTDR sensor on the side of the ring-shaped pedestal.

10 is a load cell configured by attaching an electrical resistance strain gauge in a full bridge form on the side of a ring-shaped pedestal.

11 is a configuration diagram for explaining the main elements of the axial weight measurement apparatus of the present invention.

12 is a configuration diagram for explaining the entire system of the present invention.

13 is a bridge life evaluation method using the present invention.

14 is a configuration diagram applying a bridge life evaluation method using the present invention to the bridge.

***** Brief description of the main symbols on the drawing ******

101: bending plate 102: strain gauge

103: load cell 104: Quartz sensing element

201: (lateral direction) beam 202: ring-shaped load cell

203: rhombus load cell 204: pavement surface

205: Axial Weighing Device Fixing Frame

206: fixing bolt 207: V-shaped groove

301: FBG fiber optic sensor or OTDR sensor

302: electric resistance strain gauge

Claims (6)

In the vehicle shaft weight measuring apparatus for removing a portion of the package to form a groove, and installed in the formed groove to measure the shaft weight of the moving vehicle, A plate-shaped bending plate in which bending occurs when a vehicle load is applied; A transverse beam that converts the plate behavior generated in the bending plate into a fixed simple beam type at both ends, and installed in a direction perpendicular to the vehicle entry direction at the bottom of the bending plate; Load cells which are installed at both lower ends of the lateral beams to support the lateral beams and receive deflection of the lateral beams due to a vehicle load; And a strain sensing sensor attached to the load cell to measure a strain of the load cell. The method of claim 1, And a fixing frame installed inside the groove to fix the bending plate, and a fixing bolt for connecting and fixing the bending plate and the fixing frame. The method according to claim 1 or 2, And the transverse view is installed at the center of the bending plate. The method of claim 3, wherein Vehicle axial weight measurement, characterized in that the v-shaped grooves are formed in the lower surface of the bending plate in the front and rear with respect to the direction of the vehicle relative to the transverse beam, and the v-shaped groove further comprises an axis sensor. Device. The method according to claim 1 or 2, The strain detection sensor is a vehicle axle weighing apparatus, characterized in that using one selected from the FBG optical fiber sensor, OTDR sensor and electrical resistance strain gauge. The method according to claim 1 or 2, The load cell is a vehicle axle weighing apparatus, characterized in that consisting of a ring or rhombus.

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