KR101985498B1 - Location detecting device and method thereof - Google Patents

Abstract

A position detecting apparatus for detecting the position of an object according to an embodiment of the present invention includes a sensor unit including a plurality of sensors disposed adjacent to each other, And a coordinate calculation unit for calculating coordinates of the object based on the calculated flight time values.

Description

TECHNICAL FIELD [0001] The present invention relates to a position detection device and a method thereof,

Field of the Invention [0002] The present invention relates to a position detecting apparatus and a method thereof, and more particularly to a position detecting apparatus and method which can accurately detect the position of an object using a plurality of sensors.

Distance measurement is a basic method for quantifying dimensions such as length, width, and width of an object to be measured, and is widely used not only in daily life but also throughout industry. As science and technology develops, the concepts and requirements of measurement are changing and progressing. The prominent thing is the improvement of measurement accuracy and measurement speed, and the production product is miniaturized, refined, and product production speed is rapidly increasing.

Generally, ultrasonic sensors are widely used for distance measurement of objects.

The ultrasonic sensor is a sensor using characteristics of an ultrasonic wave which is a sound of a high frequency (about 20 KHz or more) that can not be heard by the human ear. Ultrasonic waves can be used regardless of gas, liquid, solid or medium. In addition, ultrasonic waves have a high frequency and a short wavelength, so that they can measure high resolution. The wavelength used for the ultrasonic sensor is determined according to the sound speed of the medium and the frequency of the sound wave, and is about 1 to 100 mm for a fish finder or sonar in the sea, 0.5 to 15 mm for a metal probe and 5 to 35 mm for a gas.

The ultrasonic sensor uses the same material as the transmitting element for transmitting the ultrasonic wave and the receiving element for receiving the ultrasonic wave. The material of the ultrasonic sensor includes a magnetostrictive material (for example, ferrite), a voltage, an electrostrictive material .

Ultrasonic sensors are mainly used to measure the distance of an object. That is, the ultrasonic sensor emits a high-frequency signal of a short wavelength with a predetermined time interval to the outside. The emitted signal propagates at the speed of sound in the atmosphere and reaches the target object. The ultrasonic sensor calculates the distance from the reference point to the target object by taking the time it takes for the radiated signal to receive the echo signal returned from colliding with the target object.

However, in the conventional position detecting device, it is difficult to detect the position of the object at any position within the range of the orientation angle of the ultrasonic sensor, and it is difficult to detect the exact position of the object from the reference point.

An object of the present invention is to provide a position detecting apparatus and method capable of detecting an accurate position and angle of an object using a plurality of sensors.

An object of the present invention is to provide a position detecting apparatus and method for detecting a precise position and an angle of an object through a flight time between a plurality of sensors, thereby enabling a user to easily avoid obstacles located in front of the object.

A position detecting apparatus for detecting the position of an object according to an embodiment of the present invention includes a sensor unit including a plurality of sensors disposed adjacent to each other, And a coordinate calculation unit for calculating coordinates of the object based on the calculated flight time values.

According to another aspect of the present invention, there is provided a position detecting method for a position detecting device including a plurality of ultrasonic sensors, the method comprising: transmitting a transmission signal to an object through the sensors; And calculating the coordinates of the object based on the calculated flight time values.

Meanwhile, the position detection method may be implemented by a computer-readable recording medium manufactured as a program to be executed by a computer.

According to the embodiment of the present invention, accurate position and angle of an object can be detected using a plurality of sensors.

In addition, according to the embodiment of the present invention, the accurate position and angle of the object are detected through the flight time between the plurality of sensors, so that the user can easily avoid obstacles located at the front.

Meanwhile, various other effects will be directly or implicitly disclosed in the detailed description according to the embodiment of the present invention to be described later.

1 is a block diagram of a position detection apparatus 100 according to an embodiment of the present invention.
2 is a flowchart of a position detecting method of the position detecting apparatus 100 according to an embodiment of the present invention.
3 is a view for explaining the arrangement of six ultrasonic sensors included in the position detecting device 100 according to an embodiment of the present invention.
4 is a diagram for explaining a transmission signal transmitted from each ultrasonic sensor and a received reflection signal.
FIG. 5 is a diagram for explaining a table in which flight times calculated using six ultrasonic sensors are summarized.
6 is a diagram for explaining a process for detecting the position of an object using the flight time.
7 is a diagram for explaining a process of transmitting and receiving signals between ultrasonic sensors.
8 is a diagram for explaining a process of converting local coordinates into global coordinates.
9 is a diagram for explaining simulation results for detecting the position of an object using the position detecting apparatus 100 according to an embodiment of the present invention.
10 is a view showing an application example of the position detecting device 100 according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be easily understood by those skilled in the art.

1 is a block diagram of a position detection apparatus 100 according to an embodiment of the present invention.

Referring to FIG. 1, the position detecting apparatus 100 may include a sensor unit 110, a flight time calculating unit 120, a coordinate calculating unit 130, and a display unit 140.

The sensor unit 110 may transmit a transmission signal to the outside and receive a reflection signal that is reflected by the transmitted transmission signal.

The sensor unit 110 may include a plurality of sensors, and each sensor may be an ultrasonic sensor. Hereinafter, it is assumed that a plurality of sensors are ultrasonic sensors.

The flight time calculator 120 may calculate the flight time using the reflection signal.

The flight time calculation unit 120 may include a flight time calculation unit 121 and a flight time correction unit 123.

The flight time calculation unit 121 can calculate the flight time through the reflection signal received by each ultrasonic sensor. The flight time may be half the time it takes for the transmission signal transmitted from the ultrasonic sensor to be received by the reflection signal reflected by the object.

The flight time correction unit 123 can check whether there is an unrecognized flight time among the calculated flight times. When there is an unrecognized flight time among the flight times calculated through the reflection signals received by the ultrasonic sensors and other ultrasonic sensors based on one ultrasonic sensor for transmitting a transmission signal, Can be corrected.

The coordinate calculation unit 130 can calculate the coordinates of the object based on the flight time values calculated by the flight time calculation unit 120. [

The coordinate calculation unit 130 may include a coordinate calculation unit 131, a coordinate correction unit 133, and a coordinate conversion unit 135.

The coordinate calculation unit 131 can calculate the temporary local coordinates using the corrected flight time.

The coordinate correcting unit 133 can confirm whether a discontinuous intersection occurs through the calculated temporary local coordinates, and can perform an averaging overlapping process to correct the calculated temporary local coordinates when a discontinuous intersection occurs.

The coordinate conversion unit 135 can convert the corrected temporary local coordinates into global coordinates.

The display unit 140 may display the converted global coordinates.

The display unit 140 may be a PDP, an LCD, an OLED, a flexible display, a 3D display, or a touch screen, and may be used as an input device in addition to an output device.

A more detailed description of each component of the position detecting device 100 will be described below.

Next, a position detecting method for detecting the position of an object will be described in detail with reference to Figs. 2 to 8. Fig. A position detecting method of the position detecting apparatus 100 according to an embodiment of the present invention will be described in connection with the contents described in FIG.

FIG. 2 is a flowchart illustrating a method of detecting the position of the position detecting apparatus 100 according to an embodiment of the present invention. FIG. 3 is a flow chart illustrating a method of detecting the position of the position detecting apparatus 100 according to an embodiment of the present invention. 4 is a view for explaining a transmission signal transmitted from each ultrasonic sensor and a received reflection signal, and FIG. 5 is a table for summarizing the flight times calculated using the six ultrasonic sensors FIG. 6 is a view for explaining a procedure for detecting the position of an object using flight time, FIG. 7 is a view for explaining a process of transmitting and receiving a signal between ultrasonic sensors, and FIG. 8 is a diagram for explaining a process of converting local coordinates into global coordinates.

Referring to FIG. 2, the sensor unit 110 transmits a transmission signal (S101). The sensor unit 110 may include a plurality of sensors, and the plurality of sensors may be an ultrasonic sensor. The plurality of ultrasonic sensors may be disposed adjacent to each other with a predetermined gap therebetween. The sensor unit 110 may include six ultrasonic sensors, but is not limited thereto.

Each ultrasonic sensor may include an oscillator that generates a frequency signal of 38 to 42 KHz and may drive the oscillator with an external trigger pulse.

Referring to FIG. 3, the six ultrasonic sensors may be spaced apart by the same distance as the reference point around the reference point, and may be arranged at regular intervals.

Each ultrasonic sensor can transmit an ultrasonic signal at regular intervals. Each ultrasonic sensor can transmit an ultrasonic signal simultaneously or sequentially.

4, a waveform is shown when the ultrasonic sensor transmits the ultrasonic signal to the outside at intervals of 50 ms, and the lower left graph shows the case where the ultrasonic sensor receives the reflection signal to the transmission signal And the graph on the right below shows a waveform that shows the frequency band of the transmission signal.

Referring again to FIG. 2, the sensor unit 110 receives reflected ultrasound signals reflected from an object positioned ahead of the ultrasound signals (S103). Each of the ultrasonic sensors of the sensor unit 110 can receive a reflected signal that is reflected by the transmission signal transmitted by the sensor unit 110 striking an object positioned ahead.

In addition, each of the ultrasonic sensors can receive a reflected signal in which an ultrasonic signal transmitted by another ultrasonic sensor hits an object positioned ahead and is reflected.

The time of flight (TOF) calculation unit receives the reflected signal and calculates the flight time (S105). The flight time may be half the time it takes for the transmission signal transmitted from the ultrasonic sensor to be received by the reflection signal reflected by the object.

The flight time may vary depending on the number of ultrasonic sensors included in the sensor unit 110. For example, when the sensor unit 110 includes six ultrasonic sensors from No. 1 to No. 6, a total of 36 flight times can be calculated. That is, since the No. 1 ultrasonic sensor can receive the reflection signal for its own transmission signal and the reflection signal for the transmission signal of the 5th ultrasonic sensor from the remaining No. 2, 6 flight times related to the No. 1 ultrasonic sensor are calculated . Likewise, the remaining five ultrasonic sensors can calculate six flight times in total by calculating the total of 36 flight times.

Referring to FIG. 5, the first row of the horizontal axis and the first column of the vertical axis represent the numbers of the six ultrasonic sensors. In addition, the first column of the vertical axis indicates that each ultrasonic sensor is transmitting, and the first row of the horizontal axis indicates that each ultrasonic wave is receiving. For example, when the second ultrasonic sensor transmits the transmission signal and the third ultrasonic sensor receives the reflection signal corresponding to the transmission signal of the second ultrasonic sensor, it is found that the time taken until that time is 25.

Referring again to FIG. 2, the flight time correction unit 123 determines whether there is an unrecognized flight time in the calculated flight time (S107). The unrecognized flight time may be a time that may occur when the ultrasonic sensor is distant from another ultrasonic sensor, or if it can not receive a reflected signal from another ultrasonic sensor due to other factors.

Referring to FIG. 5, the flight time indicated by 255 represents the unrecognized flight time.

Referring again to FIG. 2, when there is an unrecognized flight time, the flight time correction unit 123 performs a correction for averaging the flight time (S109). That is, the flight time correction unit 123 calculates an average value of the flight times excluding the unrecognized flight time to compensate for errors that may occur due to the unrecognized flight time, and replaces the unrecognized flight time with the calculated average value can do.

Referring to FIG. 5, there is an unrecognized flight time of 255 based on the 5th ultrasonic sensor transmitting an ultrasonic signal. That is, the first to third ultrasonic sensors can not receive the reflection signals corresponding to the transmission signals transmitted from the fifth ultrasonic sensor, and can not recognize the flight time. At this time, the flight time correction unit 123 may calculate 23, which is an average of the flight times for the reflection signals received by the ultrasonic sensors # 4 to # 6, and replace the unrecognized flight time by 23.

2, the coordinate calculation unit 131 calculates the temporary local coordinates of the object using the flight time received from the flight time calculation unit 121 or the flight time correction unit 123 (S111) . The coordinate calculation unit 131 can calculate the temporary local coordinates using the intersection of the circle and the circle on the local coordinate plane through the flight time.

Referring to FIG. 6, the ultrasonic sensors 1 to 6 are arranged on the ellipse in the local coordinate plane. A half of the time taken for the reflection signal reflected from the first ultrasonic sensor through the object to be received by the first ultrasonic sensor is denoted by t1 and the transmission signal transmitted from the second ultrasonic sensor is reflected through the object Let t2 be the time obtained by subtracting t1 from half of the time taken for the reflected signal to be received by the first ultrasonic sensor.

Then, a circle having a radius of r0 is formed around the first ultrasonic sensor, and r0 can be obtained by multiplying the speed of the sound wave (v = 330 m / s) by the flight time (t1). Further, a circle having a radius of r1 is formed around the second ultrasonic sensor, and r1 can be obtained as the product of the speed of the sound wave (v = 330 m / s) and the t2.

Two intersection points may occur due to the two circles formed around the coordinates of the first ultrasonic sensor and the second ultrasonic sensor. The two intersection points represent the local coordinates of the object.

The coordinates of the first ultrasonic sensor and the coordinates of the second ultrasonic sensor are predetermined, and the radius of each circle can be known through the flight time of each ultrasonic sensor, so that the original equation can be obtained. The coordinate calculation unit 131 can obtain the two intersections using the original equation. Specifically, the coordinate calculation unit 131 can obtain the above two intersections using the intersection equations of circles and circles.

Hereinafter, a process of obtaining two intersections will be described.

Using the intersection equation of circles and circles, three equations can be obtained as shown in [Equation 1] below.

[Equation 1]

a = 4 * (x1 ² + y1 ² );

b = -4 * (x1 * (x1 ² + y1 ² + r0 ² + r1 ² ));

c = (x1 ² + y1 ² + r0 ² -r1 ² ) -4 * y1 * r0 ²

Solving the quadratic equation for x1 in Equation (1), two roots (root1, root2) can be obtained as in Equation (2) below.

&Quot; (2) "

root1 =

root2 =

Using Equation (2), the local coordinates for the two intersections can be obtained as shown in Equation (3) below.

&Quot; (3) "

idx1 < idx2 &quot; may be a case where the second ultrasonic sensor is located on the right side of the first ultrasonic sensor, and idx1 &gt; idx2 may be a case where the second ultrasonic sensor is located on the left side of the first ultrasonic sensor.

As described above, the coordinate calculation unit 131 can calculate the temporary local coordinates of the object using the intersection equation of the circle and the circle.

In the above example, only the example in which the temporary local coordinates are calculated using the first ultrasonic sensor and the second ultrasonic sensor is described. However, the coordinate calculation unit 131 uses the two ultrasonic sensors of the six ultrasonic sensors to perform the above- The temporary local coordinates of the object can be calculated.

Referring to FIG. 7, the second ultrasonic sensor 112 of the three ultrasonic sensors can receive a reflection signal for the transmission signal transmitted by the second ultrasonic sensor 112, and the reflection signal for the transmission signal is transmitted to the first ultrasonic wave The sensor 111 and the third ultrasonic sensor 113, respectively. Accordingly, when a circle is formed around the coordinates of each ultrasonic sensor, a plurality of intersection points can occur. In one embodiment, the number of intersections may be two times the number of ultrasonic sensors.

Referring again to FIG. 2, the coordinate correcting unit 133 thereafter confirms whether a discontinuous intersection phenomenon has occurred through the calculated temporary local coordinates (S113). The discontinuous intersection phenomenon can mean a phenomenon that no intersection occurs between two circles formed around two ultrasonic sensors.

If a discontinuous intersection phenomenon occurs, the coordinate correcting unit 133 may correct the local coordinates calculated through the averaging overlapping process (S115). The averaging overlapping process may be a process of replacing a case where a discontinuous intersection occurs when the discontinuous intersection phenomenon occurs and the average of the remaining local coordinates except the discontinuous intersection phenomenon occurs.

Thereafter, the coordinate correcting unit 133 calculates final local coordinates (S117).

The coordinate conversion unit 135 converts the calculated final local coordinates into global coordinates (S119). The coordinate transforming unit 135 may input the calculated final local coordinates as the vector value of the final local coordinates calculated. The coordinate transformation unit 135 may transform the final local coordinates input as vector values into global coordinates using a transformation matrix and a rotation matrix.

Referring to FIG. 8, a process of converting final local coordinates into global coordinates using a transformation matrix and a rotation matrix is shown.

The display unit 140 displays the converted global coordinates (S121). The user can see the converted global coordinates displayed through the display unit 140, and can precisely confirm where the object is located in front.

9 is a diagram for explaining simulation results for detecting the position of an object using the position detecting apparatus 100 according to an embodiment of the present invention.

Referring to FIG. 9, a simulation result for detecting an accurate position of an actual object using the position detecting device 100 according to the embodiment of the present invention is shown. The simulation result of FIG. 9 uses six ultrasonic sensors and the simulation is performed using the Hokuyo Laser Scanner.

10 is a view showing an application example of the position detecting device 100 according to an embodiment of the present invention.

10, a position detecting apparatus 100 according to an embodiment of the present invention includes a walker as shown in FIG. 10 (a), a shopping cart as shown in FIG. 10 (b), and a walker as shown in FIG. So that the position of the obstacle located at the front can be accurately detected. Thus, the user using the position detecting apparatus 100 can accurately ascertain the position of the obstacle ahead, and can easily avoid the obstacle.

The location detection method according to an embodiment of the present invention may be implemented as a program for execution on a computer and stored in a computer readable recording medium. Examples of the computer readable recording medium include a ROM, a RAM, CD-ROMs, magnetic tapes, floppy disks, optical data storage devices, and the like, as well as carrier waves (e.g., transmission over the Internet).

The computer readable recording medium may be distributed over a networked computer system so that computer readable code can be stored and executed in a distributed manner. And, functional programs, codes and code segments for implementing the above method can be easily inferred by programmers of the technical field to which the present invention belongs.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It should be understood that various modifications may be made by those skilled in the art without departing from the spirit and scope of the present invention.

100: Position detecting device
110:
120: flight time calculation unit
130: flight time correction unit
140: Coordinate calculation unit
150:
160: Coordinate transformation unit
170:

Claims (16)

A position detecting apparatus for detecting a position of an object,
A sensor unit including a plurality of sensors disposed adjacent to each other at a predetermined position;
A flight time calculating unit for obtaining flight time values and unrecognized flight time values using reflection signals of the transmission signals of the sensors; And
And calculating a coordinate of the object on the basis of the calculated flight time values,
The flight time calculation unit calculates,
A flight time calculation unit for calculating the flight time values using the reflection signal; And
And an aviation time correction unit that performs an averaging process for replacing an average value of the flight time values excluding the unrecognized flight time with the unrecognized flight time value,
The coordinate calculation unit
Calculating two intersections of two circles formed around the coordinates of two sensors among the plurality of sensors as temporary local coordinates of the object,
The radius of each of the two circles is obtained by multiplying the speed of the transmission signal and the corresponding flight time value
Position detecting device. delete delete delete delete The apparatus according to claim 1,
Further comprising a coordinate correcting unit for confirming whether a discontinuous intersection occurs through the calculated temporary local coordinates and performing averaging overlap correction when the discontinuous intersection occurs. The apparatus according to claim 6,
And a coordinate conversion unit for converting the final local coordinates of the state in which the averaging overlay correction has been performed to global coordinates. 8. The apparatus according to claim 7,
And applying vector values of the final local coordinates to the transformation matrix and the rotation matrix to transform the global coordinates into the global coordinates. The method according to claim 1,
And a display unit for displaying coordinates of the object. The method according to claim 1,
Wherein the sensor is an ultrasonic sensor. A position detecting method of a position detecting device including a plurality of ultrasonic sensors,
Transmitting a transmission signal to an object through the sensors;
Obtaining a flight time value and an unrecognized flight time value using a reflection signal for the transmission signal; And
And calculating coordinates of the object based on the calculated flight time values,
The obtaining step
Calculating the flight time values using the reflected signal;
Performing the averaging correction to replace the average value of the flight time values except the unrecognized flight time with the unrecognized flight time value,
The calculating step
Calculating two intersections of two circles formed around the coordinates of two sensors among the plurality of sensors as temporary local coordinates of the object,
The radius of each of the two circles is obtained by multiplying the speed of the transmission signal and the corresponding flight time value
Position detection method. delete delete 12. The method of claim 11,
Confirming whether a discontinuous intersection occurs through the calculated temporary local coordinates, and performing averaging overlap correction when the discontinuous intersection occurs. 15. The method of claim 14,
And converting the final local coordinates of the state in which the averaging overlay correction has been performed to global coordinates.

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