KR101583665B1

KR101583665B1 - Magnetic center position detecting method applying for automatic driving system

Info

Publication number: KR101583665B1
Application number: KR1020140073379A
Authority: KR
Inventors: 변윤섭
Original assignee: 한국철도기술연구원
Priority date: 2014-06-17
Filing date: 2014-06-17
Publication date: 2016-01-12
Also published as: KR20150144844A

Abstract

The present invention uses a maximum value of magnetic field intensity measured and measured from a magnetic sensor using irregular magnetic distortion and a normalized distribution function modeled by a fluctuating magnetic field signal to shift the center position of the maximum value of the normal distribution function, The present invention provides a method of detecting a peak position of a magnetic signal material for a reference position applied to an automatic operation system capable of precisely determining a peak position of a magnetic signal material with a minimum value of a peak value.
Therefore, it is possible to obtain a better position accuracy performance by using a small number of magnetic sensors, and to detect the position of the apex of the magnetic signal material which is most probable even in a situation where signal distortion is present in some magnetic sensors.

Description

TECHNICAL FIELD [0001] The present invention relates to a method of detecting a peak position of a magnetic signal for a reference position applied to an automatic operation system,

More particularly, the present invention relates to a method for detecting a vertex position of a magnetic signal material by considering a random magnetic distortion, a fluctuated magnetic signal, and a time delay, To a method for detecting a peak position of a magnetic signal material for a reference position, which is applied to an automatic operation system for measuring in a stochastic manner.

As shown in FIG. 1, a magnetic signal material such as a magnetic sign 110 is installed in a moving path to detect the apex position of the magnetic signal material for reference position, and applied to moving means such as a vehicle and an unmanned conveying vehicle And a magnetic signal position detecting device 200 including a plurality of magnetic sensors 210 may be mounted on the vehicle.

As shown in FIG. 2, the magnetic signal around the magnet has an intensity distribution that increases and decreases as the magnetic mark becomes closer to the magnetic mark. The magnetic signal position detecting apparatus 200 detects magnetic signals And the area having the largest magnetic field strength is determined as the apex position of the magnet cover.

In this case, since the relative position of the moving means and the magnetic signal material is measured using the magnetic signal, the position information of the moving means is calculated, and furthermore, it is utilized as the position control and the traveling path deviation information. Do.

However, as shown in FIG. 3, the magnetic signal position detecting device 200 collects only the information of the one-dimensional magnetic field intensity in the traveling direction with a predetermined time interval, that is, the sensing period of the magnetic sensor 210, It can be seen that it has passed the apex position of the magnet cover, which is the position of the maximum value of the magnetic field strength, only after passing the point position.

Conventionally, the position of the magnet mark vertex is simply determined as the moment when the sign of the maximum value slope of the magnetic signal is changed, that is, the moment that changes from positive (+) to negative (??) However, this is not a problem because it is applied to a vehicle running at a low speed and the error due to the measurement delay of the magnet mark peak is small.

However, considering only the slope change of the magnetic signal intensity collected during traveling as in the conventional method, the recognition delay of the magnet mark vertex is not considered at the time of high-speed travel, so that a large position error is accompanied, Even when the slope of the magnetic signal is instantaneously changed due to magnetic signal distortion or the like.

For example, an error in the time between the maximum point position of the magnetic signal and the position of the maximum point results in a position error of the magnet mark vertex.

Actually, there is a problem that it is difficult to accurately measure the magnet mark in the magnetic signal position detecting device due to the use of a finite number of magnetic sensors, the spacing of the magnetic sensors, the geomagnetism characteristics, the characteristic errors of the sensors, Studies for detecting the center of the magnetic signal for the reference position have been actively conducted.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and its object is to provide a magnetic sensor that uses irregular magnetic distortion and a normal distribution function modeled with a fluctuating magnetic field signal, There is provided a method of detecting a vertex position of a magnetic signal material for a reference position applied to an automatic operation system capable of precisely determining a vertex position of a magnetic signal material with a minimum value of a summed error while moving a center position of a maximum value of a normal distribution function It has its purpose.

According to another aspect of the present invention, there is provided a method for detecting a peak position of a reference position magnetic signal material applied to an automatic operation system of the present invention, A method of detecting a vertex position of a magnetic signal material using a position detecting device including a magnetic sensor, the method comprising: detecting a magnetic field intensity, a maximum value and a maximum value of a magnetic field intensity measured every sensing period of the magnetic sensor, Modeling a normal distribution function using a maximum value of the stored magnetic field intensity; Obtaining a summed measurement value of the magnetic field signal measured by the magnetic sensor; And comparing the summed measurement value with a preset value to determine the summed value; Storing a magnetic field intensity, a gradient of a maximum value and a maximum value of a magnetic field intensity, and a movement distance of a sensing period, measured every sensing period of the magnetic sensor during operation of the mobile vehicle; Determining whether a vertex position of the magnet mark passes through a sign of a slope of a maximum value of the stored magnetic field strength; Determining whether the magnitude of the maximum value of the magnetic field strength is equal to or greater than a predetermined magnitude; A maximum value of the stored magnetic field intensity is arranged, and a maximum value of the stored maximum value is set as a starting point of the normal distribution function to determine the center of the maximum value of the modeled normal distribution function Positioning a position; An error between a maximum value of each stored magnetic field intensity and a magnitude value f (x) of a normal distribution function corresponding to a position of a maximum value of the magnetic field intensity is obtained, an absolute value is obtained from the error, Obtaining and storing a sum; Moving the normal distribution function; Determining whether a center position (b) of a maximum value of the normal distribution function has reached an end point with the other end of a stored maximum value as an end point; Determining a minimum value of the sum of the absolute values of the stored errors if the center position (b) of the maximum value of the normal distribution function reaches the end point; Determining a vertex position of the magnetic signal material to a position corresponding to the minimum value; And a control unit.

Also, the modeling of the normal distribution function is characterized by being modeled by Equation (1) below. The maximum value (a) and the magnitude (c) of the normal distribution function are the maximum value and the width Is set corresponding to the size.

According to the magnetic signal center detection method for an automatic operation reference position of the present invention, a better position accuracy performance can be obtained by using a small number of magnetic sensors, and even when there are signal distortions in some magnetic sensors, The peak position of the magnetic signal material can be detected.

In addition, it is possible to improve the accuracy of position measurement on a moving means using an actual magnetic signal, and to improve the accuracy of the center position measurement, the performance of an automatic driving means or a driving support system using the same can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing a magnetic signal position detecting device and a movable vehicle according to the present invention. FIG.
2 is a schematic view showing a magnetic signal position detecting device, a magnetic signal material and a magnetic field signal applied to the present invention.
3 is a schematic view showing the magnetic field intensity around the magnetic signal material three-dimensionally in the traveling direction.
4 is a table showing a maximum value distribution and a normal distribution function of a magnetic field signal measured by a magnetic sensor;
5 is a table showing a maximum value distribution and a normal distribution function of a magnetic field signal measured by a magnetic sensor.
6 is a table showing the sum of the maximum value distribution of the magnetic field signals measured by the magnetic sensor and the absolute value of the error accumulated by the normal distribution function.
7 is a flowchart showing a method of detecting a magnetic signal center position for a reference position according to the present invention.

For a better understanding of the present invention, a preferred embodiment of the present invention will be described with reference to the accompanying drawings. The embodiments of the present invention may be modified into various forms, and the scope of the present invention should not be construed as being limited to the embodiments described in detail below. The present embodiments are provided to enable those skilled in the art to more fully understand the present invention. Therefore, the shapes and the like of the elements in the drawings can be exaggeratedly expressed to emphasize a clearer description. It should be noted that in the drawings, the same members are denoted by the same reference numerals. Further, detailed descriptions of well-known functions and configurations that may be unnecessarily obscured by the gist of the present invention are omitted.

As shown in FIG. 1, a magnetic signal position detecting apparatus 200 to which a method for detecting a peak position of a reference position magnetic signal material according to the present invention is applied is provided with a magnet cover 110 A signal processor 220 for collecting the magnetic field intensity measured by the magnetic sensor 210 and transmitting the measured magnetic field intensity to the controller 230, And a controller 230 for measuring apexes of the cover.

First, when the movable vehicle passes through the magnet cover 110, the controller 230 controls the speed and movement distance of the movable vehicle, the magnetic field strength measured every sensing period of the magnetic sensor 210, The slope of the maximum value and the travel distance of the sensing period are stored.

Also, the controller 230 takes an absolute value of the measured values of the plurality of magnetic sensors 210 measured for a given sample time to unify the +, - operation codes according to the polarity (S pole, N pole) of the magnetic signal The total sum is obtained. In order to simplify the calculation relation according to the magnet polarity, the absolute value is taken and changed to a positive value, and the total sum is obtained.

In this case, if the total sum is larger than the predetermined reference set value, it is determined that the magnetic signal is measured.

The slope of the maximum value of the magnetic field intensity measured by the magnetic sensor 210 increases when approaching the vertex position which is the center of the magnet cover 110 and decreases when it has the peak at the vertex position and moves away from the vertex position.

That is, the slope of the maximum value can be obtained by dividing the error of the maximum value previously stored in the current maximum value of the magnetic field signal stored in the sensing period of the magnetic sensor 210 by the moving distance of the sensing period, It can be determined that it has passed the apex position of the magnet cover 110 when it has the sign.

In this case, the spatial distribution characteristic of the peripheral magnetic field intensity around the vertex of the magnet cover can be modeled as a normal distribution function using the maximum value information of the stored magnetic field intensity. Can be defined as shown in Equation 1 below.

[Equation 1]

a: the maximum value of the normal distribution function

b: the center of the maximum value of the normal distribution function

c: Size of the width at half the maximum value of the normal distribution function

x: position value of normal distribution function

f (x): Size value according to position value of normal distribution function

The maximum value (a) of the normal distribution function, the center position (b) of the maximum value, and the magnitude (c) of the width are appropriately selected as a variable corresponding to the maximum value of the magnetic field strength measured and stored in the magnetic sensor 210 The shape of the function can also be determined according to the distribution characteristic of the maximum point of the stored magnetic field intensity.

4, the maximum value (a) and the width (c) of the normal distribution function correspond to the maximum value and the magnitude of the magnetic field intensity stored in the controller 230 .

As shown in FIG. 5, the maximum value of the stored magnetic field intensity is measured from the time when the slope of the stored maximum value is changed from positive (+) to negative (-) every sensing period according to the measured one-dimensional distance .

Then, the value of the center position (b) of the maximum value of the modeled normal distribution function is changed to set the storage point of the first stored maximum value as the starting point of the normal distribution function, Move to the end point which is the save point.

(B) of the normal distribution function is located at a starting point, and the magnitude value f (x) of the normal distribution function corresponding to the maximum value of each stored magnetic field intensity and the position of the maximum value And the absolute value is obtained from the error.

Thereafter, the sum of the absolute values is obtained and stored, and the value of the center position (b) is changed to move to the next position. In this case, the movement interval according to the changed value of the center position (b) of the maximum value of the normal distribution function can be set according to the desired position precision resolution.

In this case, as shown in FIG. 6, when the normal distribution function is moved, the position of the smallest minimum value among the sum of the absolute values of the stored errors and the moving distance by the stored sensing period are utilized, The position closest to the position can be calculated.

Also, the same result can be obtained by moving the center position (b) of the normal distribution function to the starting point after locating the center position (b) on the end point.

In addition, even when signal distortion and noise signals of some magnetic sensors are generated, it is possible to determine the peak position of the magnet cover that most probably matches.

Therefore, as shown in FIG. 7, in the method of detecting the vertex position of the reference position magnetic signal material applied to the automatic operation system according to the present invention, The slope of the maximum value and the maximum value of the magnetic field intensity, and the moving distance of the sensing period, and model the normal distribution function using the stored maximum value (S10).

The normal distribution function is modeled by Equation (1) as described above. The maximum value (a) of the normal distribution function and the magnitude (c) of the width are set corresponding to the maximum value of the stored magnetic field intensity and the magnitude of the width .

(S20) of obtaining a summed measurement value of the magnetic field signal measured by the magnetic sensor (210) while the mobile vehicle is traveling (S21).

If it is determined that the measured value is larger than the set value, the magnetic field intensity, the gradient of the maximum value and the maximum value of the magnetic field intensity measured at every sensing period of the magnetic sensor 210, and the moving distance of the sensing period are stored (S30 ).

After that, it is determined that the slope of the stored maximum value has not yet passed the peak position of the positive water magnetic pole cover 110, and the process returns to step S30. If the slope of the maximum value passes through the peak position of the negative water magnetic pole cover 110 And proceeds to the next step (S31).

In this case, even if the slope of the maximum value of the stored magnetic field strength is determined to be negative, if there is distortion or loss of the measured magnetic field signal, it can be determined that the magnetic field signal has passed though the peak position of the magnet cover 110, It is possible to determine whether the magnitude of the magnetic field intensity when the slope of the maximum value of the magnetic field strength is negative is equal to or greater than a predetermined magnitude.

If it is determined that the peak position of the magnetic marker 110 has passed, the maximum value of the stored magnetic field intensity is arranged, and the maximum value of the stored maximum value is set as the starting point of the normal distribution function The center position b of the value is positioned (S40).

An error between a maximum value of each stored magnetic field intensity and a magnitude value f (x) of a normal distribution function corresponding to a position of a maximum value of the magnetic field intensity is obtained, an absolute value is obtained from the error, The total sum is obtained and stored (S41).

(S42) of shifting the normal distribution function, and determining whether the center position (b) of the maximum value of the normal distribution function has reached the end point with the storage point of the latest stored maximum value as an end point, If not, the process returns to step S41. If the end point is reached, the process proceeds to step S43.

(S50) of determining the smallest smallest sum of the absolute values of the stored errors, and determining a peak position of the magnet cover at a position corresponding to the minimum value (S60).

With this center position detection method, even though the signal distortion and the noise signal of some magnetic sensors 210 are included, it is possible to stably and efficiently determine the apex position of the magnetic signal material that most probabilistically matches.

The embodiments of the method of detecting the peak position of the magnetic signal material for reference position applied to the automatic operation system of the present invention described above are merely illustrative and those skilled in the art will understand from the description thereof It will be appreciated that various modifications and equivalent embodiments are possible. Therefore, it is to be understood that the present invention is not limited to the above-described embodiments. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims. It is also to be understood that the invention includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

111: Magnet cover 200: Position detecting device
210: magnetic sensor 220: signal processor
230:

Claims

A magnetic sensor (200) comprising a position detecting device (200) including a plurality of magnetic sensors (210) installed in a mobile vehicle and measuring magnetic field strength from a magnetic marker (110) In the vertex position detection method,
A step S30 of storing the magnetic field intensity, the gradient of the maximum value and the maximum value of the magnetic field intensity and the movement distance of the sensing period measured every sensing period of the magnetic sensor 210 during the operation of the mobile vehicle;
Determining whether a peak position of the magnetic marker 110 has passed through a sign of a slope of a maximum value of the stored magnetic field intensity (S31);
If the maximum value of the stored magnetic field intensity is determined, the maximum value of the normalized distribution function modeled as the starting point of the normal distribution function (B);
An error between a maximum value of each stored magnetic field intensity and a magnitude value f (x) of a normal distribution function corresponding to a position of a maximum value of the magnetic field intensity is obtained, an absolute value is obtained from the error, Obtaining and storing the total sum (S41);
Moving the normal distribution function (S42);
Determining whether the center position (b) of the maximum value of the normal distribution function has reached the end point with the end of the stored maximum value as the end point (S43);
If the center position (b) of the maximum value of the normal distribution function has reached the end point (S50), determining a minimum value of the sum of the absolute values of the stored errors; And
Determining a vertex position of the magnetic signal material at a position corresponding to the minimum value (S60);
Wherein the magnetic field signal is generated by the magnetic field sensor.

The method according to claim 1,
In step S30,
The magnetic field strength, the slope of the maximum value and the maximum value of the magnetic field intensity, and the movement distance of the sensing period, which are measured every sensing period of the magnetic sensor 210, are stored in the portable vehicle. Modeling a normal distribution function (SlO);
The method comprising the steps of: detecting a position of a reference position magnetic signal material;

The method of claim 2,
In step S40,
Determining whether the magnitude of the maximum value of the magnetic field strength is equal to or greater than a predetermined magnitude;
The method comprising the steps of: detecting a position of a reference position magnetic signal material;

The method according to claim 1,
In step S30,
Acquiring a summed measurement value of the magnetic field signal measured by the magnetic sensor (210); And
Comparing the summed value with a predetermined value to determine (S21);
The method comprising the steps of: detecting a position of a reference position magnetic signal material;

The method of claim 2,
The modeling of the normal distribution function (S10)
Wherein a maximum value a of the normal distribution function and a magnitude c of the width are set corresponding to a maximum value and a magnitude of the width of the stored magnetic field intensity, A method for detecting a peak position of a magnetic signal material for a reference position applied to an automatic operation system.
[Equation 1]

a: the maximum value of the normal distribution function
b: the center of the maximum value of the normal distribution function
c: Size of the width at half the maximum value of the normal distribution function
x: position value of normal distribution function
f (x): Size value according to position value of normal distribution function