KR20130032090A - Weigh-in-motion evaluation system and evaluation method - Google Patents

Abstract

PURPOSE: A weigh in motion evaluating system and an evaluating method thereof are provided to minimize data collecting time required for evaluation by making a plurality of axle load estimation formulas. CONSTITUTION: A piezo sensor part(100) comprises two piezo sensors. The two piezo sensors are laid under the ground perpendicularly to the driving direction of a road. A loop sensor part(200) comprises a loop sensor. The loop sensor is laid under the ground between the piezo sensor parts. A calculating part(300) calculates the speed of a driving vehicle, the distance between shafts, the number of shafts, the weight of the shaft, and a vehicle length. [Reference numerals] (AA) Driving direction;

Description

High-speed Axis Evaluation System and Evaluation Method {Weigh-In-Motion Evaluation System and Evaluation Method}

The present invention relates to a system and an evaluation method for evaluating a high speed shaft relay for measuring the axial weight of a vehicle traveling at a high speed, wherein the signals measured by the piezo sensor unit 100 and the roof sensor unit 200 correspond to the ground vehicle model. In this case, the estimated axial weight is calculated by substituting the measured axial weight measured for each axis into the axial weight estimation formula for each axis, and compared with the observed axial weight to calculate the error rate to determine whether the preset error rate is exceeded. The determination shall be made as to whether to recalibrate the livestock rating system.

In order to measure the axle weight running at high speed on a general road, a loop sensor for recognizing the existence of a vehicle is usually used and a piezo spaced a certain distance from each other to measure the axle weight of the vehicle and to measure the speed of the vehicle. Two Piezo sensors will be installed. These sensors are embedded in the road surface by car. That is, as the vehicle progresses by lane, the piezoelectric sensor, the loop sensor, and the piezoelectric sensor sequentially pass. At this time, the speed of the vehicle is calculated using the response time of the two piezoelectric sensors, and the inter-axle distance of the vehicle is calculated using the speed value. And the number of signals of the piezo sensor is detected equal to the number of axes of the vehicle. The vehicle classification is carried out by utilizing the number of vehicle shafts measured, the distance between the shafts, and the vehicle length, and the accuracy of such vehicle classification is usually very high, more than 95%. This is because, in the 12 kinds of vehicle classification methods of the Ministry of Land, Transport and Maritime Affairs, three or more kinds of vehicles belonging to freight vehicles are determined by the number of vehicles and the distance between the wheels, and the axial response signals of the piezoelectric sensors embedded in the road are very stable.

Piezo sensor is a kind of piezoelectric sensor. The size of the electric signal is determined in proportion to the force applied by the vehicle shaft and the speed of the vehicle. The magnitude of the electric signal is analyzed to estimate and monitor the cargo volume. High speed condensation (WIM, Weigh-In-Motion) which converts into axial weight is used.

These high speed repeaters need correction to maintain the accuracy of the measurement.A foreign case of automatic zero correction of high speed repeaters shows that the automatic steering is made by utilizing the steering shaft weight of the 3S2 (Domestic 10 Semi-Trailer) vehicles among other vehicles. There is an example of a technique for calibrating. The 3S2 vehicle adopted by this technology has a 15% variation in the axle weight ((standard deviation / average) x 100] of the axle weight on the steering shaft regardless of the vehicle load, which is smaller than that of other models. Therefore, the automatic zero compensation method of the high speed shaft relay using the 3S2 vehicle has been used continuously despite the relatively simple method.In this method, the 3S2 vehicle is found among the passing vehicles, and the difference between the existing average value and the measured value of the steering shaft is greatly generated. If you do, you will be re-run. This simple method was possible because the required accuracy of vehicle weight data collected for statistical purposes for freight volume estimation was about 20% axial weight accuracy and ± 15% gross weight accuracy. That is, the conventional method has a disadvantage in that the error has a very large value, but since the required accuracy of the vehicle weight data is not high, it can be applied without any problem.

However, there is a problem in applying the existing simple method because the demand for the accuracy of data of high speed relay is very high because of the tendency to impose a penalty on overload behavior by utilizing the measurement results of high speed relay.

In addition, since the composition ratio of the vehicle belonging to the 3S2 among the driving vehicles is not high, there is a problem that it takes a long time until a certain number of 3S2 vehicles pass to evaluate the need for zero calibration.

The present invention, which was created to solve the above problems, aims to provide a new high speed relay evaluation system and evaluation method that can minimize the data collection time required for evaluation and significantly increase the accuracy of the evaluation.

Technical composition of the present invention created to achieve the above object is as follows.

The present invention includes two piezo sensor units (100) embedded in the ground parallel to the running direction of the road; A loop sensor unit 200 embedded in the ground between the piezo sensor units 100; And a calculation unit 300 that calculates the speed, the distance between the shafts, the number of shafts, the shaft weight, and the vehicle length of the traveling vehicle according to the signals measured by the piezoelectric sensor unit 100 and the loop sensor unit 200. When the axial weight estimation formula for each axis vehicle is input in advance, and the signals measured by the piezoelectric sensor unit 100 and the loop sensor unit 200 correspond to the index vehicle type, Substituting the measured observed shaft weight into the estimated shaft weight formula for each axis calculates the estimated weight and compares it with the observed shaft weight to calculate the error rate to determine whether the preset error rate is exceeded.

In addition, the present invention relates to a method for evaluating a high-speed livestock relay evaluation system using the axial weight estimation formula for each of the ground vehicle model, the first step of selecting the ground vehicle model to input the specifications of the ground vehicle model; A second step of calculating an axis-by-axis correlation coefficient by measuring the axis weight of each indicator vehicle for each axis and generating an axis-by-axis estimation equation based on the axis; A third that calculates the weight estimation axial weight of the driving vehicle by substituting the observed axial weight of the traveling vehicle measured for each axis into the axial weight estimation formula when the specification of the traveling vehicle measured by the high speed shaft evaluation system corresponds to the indicator vehicle type; step; And calculating the error rate by comparing the estimated weight weight of the driving vehicle with the observed shaft weight of the driving vehicle to determine whether the preset error rate exceeds the preset error rate, and when the calculated error rate exceeds the preset error rate The fourth step of determining that the recalibration of the need; comprises a.

According to the configuration of the present invention, by making and using the axial weight estimation formula for each axial vehicle for estimating axial weight for each index vehicle type, it is possible to minimize the data collection time required for the evaluation and to significantly increase the accuracy of the evaluation.

1 schematically illustrates the components of the present invention.
2 illustrates a vehicle model having a high correlation coefficient between the axis among the 12 vehicle model classifications.
Figure 3 shows the calculation result of the axis-specific correlation coefficient for each indicator vehicle.
4 shows an axial weight estimation formula for each vehicle model.
5 shows a high speed relay (WIM) evaluation algorithm.
6 shows a security algorithm when missing measurement data.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

1 schematically illustrates the components of the present invention.

Piezo sensor unit 100 is composed of two piezo sensors embedded in the ground parallel to the running direction of the road at right angles.

The loop sensor unit 200 is composed of a loop sensor embedded in the ground between the piezoelectric sensor unit 100.

The calculation unit 300 calculates the speed, the distance between the shafts, the number of shafts, the shaft weight, and the vehicle length of the traveling vehicle according to the signals measured by the piezoelectric sensor unit 100 and the loop sensor unit 200.

The axial weight estimation formula for each axis vehicle is input to the calculator 300 in advance.

When the signal measured by the piezoelectric sensor unit 100 and the loop sensor unit 200 corresponds to the indicator vehicle type, the calculating unit 300 substitutes the observed axial weight measured for each axis into the axial weight estimation formula for each axis to calculate the weight estimation axial weight. The error rate is calculated by comparing the weight with the observed shaft weight to determine whether the preset error rate is exceeded.

Here, the surface vehicle model refers to 6, 8, 10, 11, and 12 vehicle models with high correlation coefficients between the axis and the axis among the vehicle models based on the 12 kinds of vehicle classification methods of the Ministry of Land, Transport and Maritime Affairs. And the axle arrangement, the average interaxial distance (wheelbase) between each axis is shown, Figure 3 shows the results of calculating the axis-specific correlation coefficient for each vehicle model.

The correlation coefficients by axis calculated by the surface vehicle models show that the correlation coefficients between the 1st and 2nd axis, and the 1st and 3rd axis of the six types of vehicles are as high as 0.86 and 0.85, respectively. In this way, it can be seen that there is a high correlation coefficient between three and four axes of eight vehicles and two and three axes, two and four axes, and two and five axes of ten vehicles. In addition, 11 and 12 vehicles show high correlation coefficient between 4 and 5 axes in 2 and 3 axes.

Figure 4 shows the axial weight estimation formula for each vehicle model, the axial weight estimation formula for each axis is generated in a direction of reducing the estimation error for a specific axis for each vehicle model with reference to the axis-specific correlation coefficient calculated for each indicator vehicle.

The coefficient estimation of the axial weight calculation formula for each vehicle model shown in FIG. 4 is estimated through a Least Squares Estimation, a Maximum Likehood Estimation, and the like, which are widely used in conventional statistics.

A method of evaluating the high speed shaft repeating evaluation system using the axial weight estimation formula for each vehicle model is as shown in FIG. 5.

(1) Step 1

The step of inputting the specifications of the indicator vehicle by selecting the indicator vehicle model. These specifications are stored in a separate database. In addition to the surface model, the specifications of the general model are also entered.

(2) Step 2

It is a step of calculating the correlation coefficient for each axis by measuring the axial weight of each index vehicle model and generating an axial weight estimation formula for each axis. In order to generate the correlation coefficient for each axis and the axial weight estimation formula for each axis, more than a certain amount of information must be obtained for each indicator vehicle.

According to the generated estimation equation, the calculation unit performs a calculation required in a subsequent procedure.

The first stage and the second stage may be regarded as a preliminary stage for starting the evaluation procedure unless otherwise illustrated in FIG. 5.

(3) Step 3

Measure and collect the specifications of the vehicle (vehicle speed, the number of vehicles, the distance between the wheels, the weight of each vehicle length) through the high speed shaft evaluation system installed in the field, and determine the model using the measured specifications of the vehicle. The vehicle model is determined by comparing the measured vehicle axis number, the inter-axle distance, and the vehicle length with the previously stored specifications of the vehicle.

Once the vehicle model has been determined, check whether it is a ground vehicle model.

In the case of the ground vehicle type, the estimated axial weight P of the driving vehicle is calculated by substituting the observed axial weight K of the traveling vehicle measured for each axis into the axial weight estimation formula for each axis.

In this third step, if the weight of each axle collected after the vehicle model is determined is smaller than the minimum value (Min value) of the vehicle, it is determined that recalibration is necessary, and the weight of each axis is equal to or greater than the minimum value (Min value) of the vehicle model. Only in this case, the process of checking whether or not it corresponds to the indicator vehicle may be further included.

In addition, as shown in FIG. 6, in the third step, when the weight measurement of any axis of the driving vehicle is missed after the vehicle model of the driving vehicle is determined, the observed axle weight of the remaining driving vehicle for each axis of the corresponding vehicle model is determined. Substituting the missing axial weight with a value calculated by substituting the axial weight estimation formula may be further included.

For example, if there are five models of the driving vehicle, the number of axes is three, but the weight of one axle is 1.8 tons, and the weight of two axles is missing due to sensor errors and failures during the operation of the equipment. Assuming that the weight is measured at 6.5 tons, the values for shaft weight 1 and 3 measured in the shaft weight estimation formula (axial weight 2 = 0.58 + 0.59 * shaft weight 3 + 0.40 * shaft weight 1) for the missing two axes Substituting for, obtain the shaft weight 2 and use it as the measured value for the two axes.

(4) Step 4

Compute the error rate by comparing the estimated weight of the driving vehicle (P) and the observed vehicle weight (K) of the driving vehicle, respectively (error rate = (| P-K | / K) * 100) to see if it exceeds the preset error rate. If it is determined whether or not the calculated error rate exceeds the preset error rate, it is determined that recalibration of the high speed relay evaluation system is required and a report is requested.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, Addition or deletion of a technique, and limitation of a numerical value are included in the protection scope of the present invention.

100: piezo sensor unit
200: loop sensor
300: calculation part

Claims (4)

Piezo sensor unit 100 consisting of two piezo sensors embedded in the ground parallel to the running direction of the road;
A loop sensor unit 200 formed of a loop sensor embedded in the ground between the piezo sensor units 100; And
A calculation unit (300) for calculating the speed, the distance between the wheels, the number of shafts, the shaft weight, and the vehicle length of the traveling vehicle according to the signals measured by the piezo sensor unit (100) and the loop sensor unit (200);
And,
The calculation unit 300,
The axial weight estimation formula for each index vehicle is input in advance, and when the signals measured by the piezoelectric sensor unit 100 and the loop sensor unit 200 correspond to the ground vehicle model, the measured axial weight of each axial axis is measured. A high-speed shaft repeating evaluation system, characterized in that it calculates an error rate by calculating the estimated weight by substituting the estimated equation and calculating the error rate by comparing it with the observed weight. The present invention relates to a method for evaluating a high-speed shaft repeating evaluation system using an axial weight estimation formula for each ground vehicle.
A first step of selecting an indicator vehicle model and inputting a specification of the indicator vehicle model;
A second step of calculating an axis-by-axis correlation coefficient by measuring the axis weight of each indicator vehicle for each axis and generating an axis-by-axis estimation equation based on the axis;
A third that calculates the weight estimation axial weight of the driving vehicle by substituting the observed axial weight of the traveling vehicle measured for each axis into the axial weight estimation formula when the specification of the traveling vehicle measured by the high speed shaft evaluation system corresponds to the indicator vehicle type; step; And
Compute the error rate by comparing the estimated weight of the running vehicle with the observed axle weight of the running vehicle to determine whether the preset error rate exceeds the preset error rate, and if the calculated error rate exceeds the preset error rate, A fourth step of determining that correction is necessary;
High speed axis repeat evaluation system evaluation method comprising a. In claim 2,
The third step is
After the vehicle model is determined, if the weight of each vehicle in the high-speed axle relay evaluation system is smaller than the minimum value of the vehicle, recalibration is necessary, and the weight of each shaft is more than the minimum value (Min value) of the vehicle. The method of evaluating a high speed relay system, characterized in that it further includes a process of checking whether or not it corresponds to the surface vehicle model only. In claim 2,
The third step is
When the measurement of any axis of the driving vehicle is missed, the observed axis weight of the remaining measured vehicle is substituted into the estimated axis weight equation for each axis and replaced with the missing measured axis weight. Evaluation method of high speed relay evaluation system.

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