KR100843699B1 - System and method for pursuiting position of trailer truck - Google Patents

Abstract

A system and a method for pursuing a position of a trailer truck are provided to allow a field engineer to easily supervise a field by detecting the position of the trailer truck. A system for pursuing a position of a trailer truck(20) includes an ultrasonic generation device(100), a distance data transmission device(200), a data processing device(300), and a monitoring device(400). The ultrasonic generation device transmits an ultrasonic signal and an RF(Radio Frequency) signal generated from at least three beacons(102,104,106,108) attached to a crane. The distance data transmission device calculates a distance between each of the beacons and the trailer truck by a traveling distance of an ultrasonic wave and then transmits each distance data wirelessly by being mounted on the trailer truck. The data processing device receives the distance data and then calculates the position of the trailer truck. The monitoring device allows a user to monitor the position of the trailer truck.

Description

System and method for pursuiting position of trailer truck}

1 is a schematic diagram showing a system according to the present invention.

Figure 2 is a block diagram showing the overall configuration for explaining a preferred embodiment of a trailer truck position tracking system according to the present invention.

3 is a wireless data transmission apparatus using Bluetooth.

4 shows that the data processing device and the monitoring device are implemented in a PC.

5 is a diagram for describing a distance measuring algorithm between a beacon and a listener.

6 is a model for calculating the position of a trailer truck by processing data received from a wireless data transmission device.

7 is a diagram illustrating a data processing procedure of a data processing apparatus used in the present invention.

8 illustrates an example of a graphical user interface (GUI) screen of the location tracking system according to the present invention.

9 shows an example of a calculation screen of the location tracking system according to the present invention.

10 is for explaining the test bed construction and test results of the position tracking system according to the present invention.

11 and 12 are diagrams for explaining obtaining a sensing range in consideration of characteristics of equipment.

13 is a flowchart for explaining a preferred embodiment of the method for tracking the location of a trailer according to the present invention.

FIG. 14 is a flowchart for explaining an example of step S104 of FIG. 13.

<Explanation of symbols for the main parts of the drawings>

100: ultrasonic generator, 200: distance data transmission device

300: data processing device, 400: monitoring device

The present invention relates to a system for shortening the loading and unloading time of a container by transmitting the exact position of a container trailer vehicle in real time using an ultrasonic wireless sensor network and Bluetooth, which are one field of ubiquitous technology.

Conventionally, a system using associative processing and infrared rays has been developed to reduce container loading and unloading time, but it has been difficult to introduce a port system because it is highly influenced by high installation cost, maintenance cost, and weather. The system using image processing is a method of transmitting a position by installing a plurality of cameras on the pole of a crane and cannot work at night, and always remove foreign substances from the camera lens. Infrared uses a laser that reflects or blocks when a container truck arrives at a fixed location and requires high installation costs.

These systems have been experimentally introduced into some of the ports, but have not been very effective. Current manpower-oriented management methods and delays in processing time lead to deterioration of port competitiveness, which requires continuous development and introduction of technology.

In order to solve the above problems, the system and method for tracking the location of a trailer truck according to the present invention is directed to a supervisor and a trailer driver through a PDA for shortening the processing time by accurately tracking a container trailer truck for loading and unloading a port. The purpose of the driver and crane operators to provide the location of the trailer in real time can be used in the work involved.

The trailer truck position tracking system according to the present invention for achieving the technical problem of the present invention is a system for tracking the position of the trailer truck when loading and unloading the container in the port, at least three beacons (beacon) attached to the crane Ultrasonic generator for transmitting the ultrasonic signal and the RF signal generated in the; A distance data transmission device attached to a trailer truck for calculating a distance between each beacon and the trailer truck by the ultrasonic flight distance and wirelessly transmitting each distance data; A data processing device for receiving the distance data and calculating a position of the trailer truck; And a monitoring device capable of monitoring a position of the trailer truck by a user.

The apparatus for transmitting distance data includes: a reception-only ultrasonic receiver (listener) attached to an upper end of the trailer truck to receive the ultrasonic signals and the RF signals; A distance calculation device attached to an upper end of the trailer truck and calculating a distance between the beacons and the trailer truck by calculating a flight distance of the ultrasonic waves; And a data transmission node attached to an upper end of the trailer truck to remotely transmit each distance data calculated by the distance calculator by a Bluetooth transmission device.

The ultrasonic flight distance may be a distance between the beacon and the ultrasonic radio receiver.

The beacons are displayed in coordinates based on an arbitrary fixed coordinate system, and the position of the trailer truck is calculated by using a distance equation between coordinates of each beacon and coordinates of the ultrasonic radio receiving node. Can be.

The monitoring device may be characterized in that the site manager, the crane driver, the driver of the trailer truck and the client can monitor the position of the trailer truck individually.

The data processing device and the monitoring device may be provided in a wireless communication terminal.

The monitoring device may be connected to the internet network through a web server to remotely monitor the location of the trailer truck.

The monitoring device may display the trailer truck to the user when the trailer truck is located at a predetermined target point.

In the distance calculation device, the distance between the beacon and the trailer truck may be calculated using a time difference of arrival (TDoA) algorithm.

When at least four beacons are included, the data processing apparatus may be configured to calculate a location of a trailer truck based on three distance data received first among distance data received from non-identical beacons.

When the beacons are four, the beacons may have the same height from the ground and may be installed at each vertex of a square shape.

According to an aspect of the present invention, there is provided a method for tracking a trailer truck according to the present invention, the method including: (a) transmitting an ultrasonic signal and an RF signal generated from at least three beacons installed in a crane; (b) receiving the ultrasound and RF signals, calculating the distance between the beacon and the trailer truck based on the flight distance of the ultrasound and transmitting distance data to a data processing device; And (c) calculating and displaying the position of the trailer truck by using the distance data received by the data processing device.

Step (c) may include determining whether the trailer truck is located at a target point; And if it is determined that the trailer truck is located at a target point, displaying the same on the monitoring device.

The beacons are displayed in coordinates based on a fixed coordinate system, and the step (c) is based on the equation of the distance between the coordinates of each beacon and the coordinates of the ultrasonic radio receiving node to determine the location of the trailer truck. It may be characterized by calculating.

In step (b), the distance between the beacon and the trailer truck may be calculated using a TDoA (Time Difference of Arrival) algorithm.

If at least four beacons are present, the step (c) is further characterized in that the data processing device calculates the location of the trailer truck based on the three distance data received first of the distance data received from non-identical beacons. It can be characterized.

Hereinafter, with reference to the accompanying drawings, the configuration and operation of the present invention will be described in detail. Like reference numerals in the drawings denote components that perform the same function.

1 shows a system for tracking the position of a trailer truck during loading and unloading at a port, schematically showing a system according to the present invention, and FIG. 2 shows a preferred embodiment of a position tracking system for a trailer truck according to the present invention. It is a block diagram which shows the whole structure for demonstrating.

According to the present invention, an RF signal and an ultrasonic signal are simultaneously emitted from a sensor node attached to a specific position. Each node has a node-by-node system time, and the sensor node attached to the vehicle receives and calculates the emitted signal.

In this case, the distance of each node is calculated by analyzing the flight distance of the ultrasonic wave and the RF signal of each node, and data is transmitted to a data processing device such as a PC by using a wireless communication system such as Bluetooth.

The received data is filtered to display the correct position value on the screen, and the driver of the trailer truck moves the vehicle to the desired position based on this.

1 and 2, the position tracking system of the trailer truck according to the present invention includes a transmission-only ultrasonic wave generator 100, a distance data transmission device 200, a data processing device 300, and a monitoring device 400. Equipped.

The ultrasonic generator 100 is installed in a crane. The ultrasonic generator 100 generates ultrasonic waves and RF signals through the beacons 100-1, 100-2, 100-3, and 100-4 attached to the crane and transmits them to the trailer truck 20. In this case, it is preferable that at least 3 beacons are provided.

The distance data transmission device 200 is attached to the trailer truck 20 to receive ultrasound and RF signals. The distance data transmission device 200 transmits the calculated distance data to the data processing device 300 by calculating the flight distance of the ultrasonic waves. The ultrasonic flight distance is the distance that ultrasonic waves fly between beacons 100-1, 100-2, 100-3, 100-4 and listeners installed in the trailer truck.

The distance data transmission device 200 may include a reception-only ultrasonic reception node 211, a distance calculation device 212, and a data transmission node 213.

The reception-only ultrasonic reception node 211 is attached to the top of the trailer truck 20 to receive the ultrasonic signal and the RF signal.

The distance calculation device 212 is attached to the top of the trailer truck 20 to calculate the flight distance of the ultrasonic waves.

In addition, the data transmission node 213 is attached to the top of the trailer truck 20 to remotely transmit each distance data calculated by the distance calculating device 200 via a Bluetooth transmission device.

The data processing apparatus 300 receives the distance data value and analyzes the location information and the moving direction of the trailer truck 20 so that the user can monitor it. That is, only distance data, which is a distance value between the beacon and the listener, is provided from the distance calculating device 212 and an algorithm for using the same is performed to accurately calculate the position of the trailer truck.

Monitoring device 400 refers to a means for displaying the location of the trailer truck 20 so that the user 500 can know. For example, the user may be the site manager 510, the crane driver 520, the driver 530 of the trailer truck, and the client 540.

The existing system was to manually move the vehicle position between the driver and the crane operator through a message from the crane operator and the person in charge of the received signal through wireless communication. However, by implementing the position tracking system of the trailer truck according to the present invention can avoid wasting time and manpower required for loading and unloading operations.

The data processing device 300 and the monitoring device 400 may be implemented in a wireless communication system such as a personal digital assistant (PDA) as well as a personal computer. In this case, the PC and the PDA receive the distance data from the distance data transmission device 200 to calculate the position of the trailer truck 20 and display it to the user through the display device.

2 shows a process of receiving data and monitoring the location information of the trailer truck by the field manager 510, the crane driver 520, the driver 530 of the trailer truck, and the client 540.

For example, the site manager 510, the crane driver 520, or the driver 530 of the trailer truck provided with the PDA receives the distance data from the distance data transmission device 200 and receives the data reception devices 311, 331, and 341. Receive through.

The data processing devices 312, 332, and 342 embedded in the respective PDAs process the data to calculate the position of the trailer truck, and then the user 510, 520, and 530 through the monitoring devices 313, 333, and 342. The location of the trailer truck 20 will be sprayed on the screen.

The site manager 510 may easily supervise the site by identifying the location of the trailer truck 20, and the crane driver 520 and the trailer driver 530 may easily operate their equipment.

The client 540 may be connected to the internet network 50 through the web server 40 so that the client 540 may monitor the internet network 50. That is, the data processed by the data processing device 323 is uploaded to the web server 40, and the client 540 connected through the internet network 50 is connected to the trailer truck 20 by the monitoring device 323 thereof. The location can be monitored.

For the efficiency of loading or unloading the container, when the trailer truck 20 is located at a predetermined target point, the status can be displayed to the user through the monitoring device to inform that the scheduled work can be performed. Accordingly, inconvenience of work due to a mismatch in communication between the site manager 510, the crane driver 520, and the trailer driver 530 may be eliminated.

3 is a distance data transmission apparatus using Bluetooth, and FIG. 4 shows a data processing apparatus and a monitoring apparatus implemented in a PC. The distance calculation device may be implemented as an external device.

Receives ultrasonic signals and RF signals from beacons through listeners. The distance data transmission device 200 of FIG. 3 calculates the distance and transmits the distance to the Bluetooth device mounted in the PC of FIG. 4 through a Bluetooth dongle. At this time, the PC becomes a master and the distance data transmission device becomes a slave to communicate.

As described above, up to seven communication can be performed using the distance data transmission apparatus as a base station. In other words, by implementing Bluetooth communication, the speed and distance limitations of the base station for data collection and processing can be overcome.

Referring to FIG. 4, the data processing apparatus 300 calculates the position of the trainer truck 20 based on the distance data received by the extension antenna 310 and sprinkles it on the monitor 400. As described above, when receiving the distance data from the data transmission apparatus by mounting the expansion antenna, the data can be processed by its own power even at a distance of 100M or more in the indoor environment and 200M or more in the outdoor environment.

FIG. 5 is a diagram for describing an algorithm for measuring a distance between a beacon and a listener, and illustrates calculating an ultrasonic flight distance between four beacons and a listener.

Referring to FIG. 5, the beacon node is attached to a crane at fixed coordinates to transmit ultrasonic waves and RF signals to a listener node attached to a trailer truck. The algorithm used to measure the distance between the beacon and the listener is the TDoA (Time Difference of Arrival). The distance between the beacon and the listener is obtained by the following equation.

In order to obtain the coordinates of the listener using the TDoA algorithm, only three beacons can be obtained enough. However, in the study for the present invention, if four beacons were used, four random beacons were used to calculate the coordinates. .

6 is a model for calculating the position of a trailer truck by processing data received from a wireless data transmission device.

Referring to FIG. 6, beacons B1, B2, B3, and B4 are known coordinates as fixed coordinates. This is because the beacon is mounted at the same height. Through the ultrasonic flight distance, the distance value is stored in the buffer to obtain (X, Y, Z) coordinates of the listener. The screen display calculates and displays the stored value once every 400 to 1500 ms.

To find the coordinates of the listener, we apply the Pythagorean theorem and then use

(XA ₁ ) ² + (YB ₁ ) ² + (ZC ₁ ) ² = (Distance ₁ ) ²

(XA ₂ ) ² + (YB ₂ ) ² + (ZC ₂ ) ² = (Distance ₂ ) ²

(XA ₃ ) ² + (YB ₃ ) ² + (ZC ₃ ) ² = (Distance ₃ ) ²

Since the four beacons are installed at the same height, the Z coordinate values C ₁ = C ₂ = C ₃ of the _three beacons for obtaining the coordinates. Since the beacons are all fixed points, each coordinate is identified by grasping the reference coordinate system.

7 is a diagram illustrating a data processing procedure of a data processing apparatus used in the present invention.

The distance obtained from the distance calculator is stored in the buffer 260 except for the distance value having a large error through the filter 250. The distance data stored in the buffer 260 has respective IDs and distance values.

If only three values enter randomly in the buffer 260, they are calculated and put in the queue 270. The error varies depending on the distance and angle due to the nature of ultrasonic waves, but considering the environmental factors, it is efficient to receive only three values as random values first.

8 illustrates an example of a graphical user interface (GUI) screen of the location tracking system according to the present invention. I chose the JAVA language so that it was not implemented in the operating system.

The "Connection Setting" section can detect and select the active port automatically, and can freely connect and close. "

"Setting etc" is a part that sets the position where the trailer should be placed so that it can be set by software. It is displayed until the displayed time.

"Position Calculation Test" is the part that tests basestation and software through arbitrary coordinates before installing the hardware. "

Positioning Information "part refers to the error between the reference point and the reference point set in the" Setting etc "part and the setting value of the error range. This allows the vehicle to recognize the error and move to the reference point. ”

Position Mapping Test "section is used to measure the error from the reference point by setting (x, y, z) coordinates before actual installation.

The “Location Tracking” screen is used to calculate and scatter the truck's position in real time. Beacon Setting ”is a menu that sets the first coordinate (x, y, z) of Beacon, which is a fixed coordinate. In the performance measurements, we set (150, 150, 150) and built a testbed.

9 is a screen illustrating a calculation screen of a location tracking system according to the present invention, and is a screen showing information calculated internally by a monitoring system. Shows the calculated value as well as the calculated distance to each beacon, and rounds off the decimal places.

Figure 10 is shown to explain the construction and test results of the test bed of the position tracking system according to the present invention, reference numeral 70 is an ultrasonic generator, reference numeral 80 is a model of a crane to which the ultrasonic generator is attached.

Fig. 10A shows the transmission angle of the ultrasonic waves. Depending on the type and characteristics of the ultrasonic sensor, the ultrasonic sensor used in this project should be adjusted to less than 45 degrees at close range.

Due to the nature of ultrasonic waves, it is important to consider the effects of reflected waves. Because it is influenced by walls, obstacles and even the position of people, detailed settings such as adjusting the angle according to the distance, the life cycle of the ultrasonic wave and the transmission time per beacon must be followed. In fact, it was learned from experiments, but it was also influenced by the wavelength from the ballast of fluorescent lamps installed in the ceiling of the laboratory.

10 (b) is a scene in which the angle is measured in consideration of the relationship of the figure on the left when constructing the test bed. Through this experiment, it was possible to calculate the sensing possible minimum, maximum distance, and sensing angle of the beacon and the listener (see FIG. 11 (a)).

     If you measure the maximum distance with the listener and beacon in a straight line, you can theoretically measure up to 10.5m, but as the distance approaches the limit distance, only the RF-free RF signal is often detected. After several tests, we found the optimal distance that the RF signal and the ultrasonic wave always come together.

Since the ultrasonic waves are generated in the form of pulse waves from the transmitter of the cricket, the sensing range of the ultrasonic waves is circular.

The cricket manual states that the cricket's sensing angle is approximately 80 ° (40 ° left + 40 ° right of center). Sensing is possible even at an angle of more than 80 degrees, but often only RF signals are received and ultrasonic waves are not detected or reflected ultrasonic waves are often detected. Since the study should consider only 100% sensing, it does not consider the large data obtained through the reflected wave at an angle of more than 80 °.

11 and 12 are diagrams for describing obtaining a sensing range in consideration of characteristics of equipment. In this case, the place where the listener can be placed is defined as the optimal space for a cuboid whose base is a square of length x.

Referring to FIG. 11 (a), the minimum distance is the distance from the theoretical beacon and listener's theoretical sensing range to which the height has been set in the test environment until it has descended by the height of the height set vertically from a and the distance shorter than this distance is ignored. .

The maximum distance is set to the longest distance of the sensing range at the point where C meets the shortest distance g in the vertical direction and a to g.

As shown in FIG. 11A, if the distance between the center of one side of the bottom side and the vertex of the opposite height is set to 600 m, the maximum sensing distance, at least three beacon signals may be received at any point on the bottom. In the third figure, one beacon exceeds a maximum distance of 600m, but since the coordinates of the listener can be calculated using only three pieces of distance data, the coordinate calculation is not unreasonable. When the distance between the center of one side of the base and the vertex of the opposite height is set to 600 m, the maximum sensing distance, the length and height of the side of the bottom can be calculated.

의 결과가 나온다. 도 11(d)를 참조하여 선분 AB(=H)를 Y값으로 나타내면, H=YTan50˚이다. As shown in FIG. 11 (b), when the point C is a listener, the angle 40 ° of ∠C′CA is achieved if the angle C is considered to be 40 °. Considering the point C and the side AB, the height of the cuboid, are triangular, ∠ACB is 50 ° and ∠BAC is a right triangle with an angle of 40 °. Referring to Fig. 11 (c), if line segment BC is y and is calculated using Pythagorean theorem, then X ² = 2Y ^2. From

Results. Referring to Fig. 11 (d), the line segment AB (= H) is represented by a Y value, where H = Y Tan 50 °.

On the other hand, ΔBDE and ΔABE are used to find the value of x (see Fig. 11 (e)). If we define hypotenuse BE for x in ΔBDE, we know the value of x because we have defined an hypotenuse for 600cm, height AB and base BE for x.

12 (a) and 12 (b), the line segment BE (= Z) is obtained from ΔBDE.

이다. From Z ² = X ² + (1 / 2X) ² ,

to be.

Since we know the values of all the line segments of △ BDE, we can find the value of X.

Referring to FIG. 12 (c), the values obtained above are obtained by applying the Pythagorean theorem.

Solving the above equation, X = 428.556307717 and H = 361.143134913.

Therefore, when the maximum sensing distance of the ultrasonic waves by the listener is 600m, at least three beacons are all within the optimum distance at any point on the floor within the range of the above rectangular parallelepiped (Fig. 12 (d)). Receiving rate can be guaranteed.

13 is a flowchart for explaining a preferred embodiment of the method for tracking the location of a trailer according to the present invention. Since the overlapping information regarding the location tracking method of the trailer according to the present invention has been described with reference to FIGS. 1 to 12, description thereof will be omitted.

First, at least three beacons (beacon) installed in the crane to transmit the ultrasonic wave and the RF signal (S100).

Next, an ultrasonic wave and an RF signal are received, the distance between the beacon and the trailer truck is calculated by the ultrasonic flight distance, and the distance data is transmitted to the data processing device (S102). In this step, the distance between the beacon and the trailer truck is calculated using the Time Differential of Arrival (TDoA) algorithm.

Next, the data processing apparatus calculates and displays the position of the trailer truck using the received distance data (S104). In addition, when at least four beacons (beacon), the data processing device may be characterized by calculating the position of the trailer truck based on the three distance data received first of the distance data received from the non-identical beacons.

The beacons are displayed in coordinates based on a fixed coordinate system, and in this step, the position of the trailer truck can be calculated using each equation of the distance between the beacon coordinates and the coordinates of the ultrasonic radio receiving node.

FIG. 14 is a flowchart for explaining an example of step S104 of FIG. 13.

The method may further include a step S202 of determining whether the trailer truck is located at the target point (S200), and displaying it if it is determined that the trailer truck is located at the target point (S202). That is, the location of the trailer is displayed in real time, and when the trailer is located at a predetermined target point, it is displayed separately.

The best embodiments have been disclosed in the drawings and specification. Although specific terms have been used herein, they are used only for the purpose of describing the present invention and are not used to limit the scope of the present invention as defined in the meaning or claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

The present invention is a trailer truck positioning system and method, the supervisor, trailer driver, crane driver through the PDA in real time to reduce the processing time through accurate location tracking of container trailer truck for loading and unloading port It is effective to provide a system and method for providing a trailer location that can be utilized in the work involved by providing the location of the.

Claims (16)

delete A system for tracking the location of trailer trucks during loading and unloading of containers in ports, An ultrasonic generator for transmitting ultrasonic signals and RF signals generated from at least three beacons attached to the crane; A distance data transmission device attached to a trailer truck for calculating a distance between each beacon and the trailer truck by the ultrasonic flight distance and wirelessly transmitting each distance data; A data processing device for receiving the distance data and calculating a position of the trailer truck; And It is provided with a monitoring device for the user to monitor the location of the trailer truck, The distance data transmission device, A reception-only ultrasound receiver attached to an upper end of the trailer truck to receive the ultrasound signal and the RF signal; A distance calculation device attached to an upper end of the trailer truck and calculating a distance between the beacons and the trailer truck by calculating a flight distance of the ultrasonic waves; And And a data transmission node attached to an upper end of the trailer truck and configured to remotely transmit each distance data calculated by the distance calculator by a Bluetooth transmission device. The method according to claim 2, And the ultrasonic flight distance is a distance between the beacon and the ultrasonic radio receiver. The method according to claim 3, The beacons are displayed in coordinates based on an arbitrary fixed coordinate system, and the position of the trailer truck is calculated using a distance equation between coordinates of each beacon and coordinates of the ultrasonic radio receiving node. Trailer truck location tracking system. A system for tracking the location of trailer trucks during loading and unloading of containers in ports, An ultrasonic generator for transmitting ultrasonic signals and RF signals generated from at least three beacons attached to the crane; A distance data transmission device attached to a trailer truck for calculating a distance between each beacon and the trailer truck by the ultrasonic flight distance and wirelessly transmitting each distance data; A data processing device for receiving the distance data and calculating a position of the trailer truck; And It is provided with a monitoring device for the user to monitor the location of the trailer truck, Wherein the monitoring device is a site manager, crane driver, trailer truck driver and client of the trailer truck location tracking system, characterized in that to monitor the location of the trailer truck individually. The method according to claim 5, And said data processing device and said monitoring device are provided in a wireless communication terminal. The method according to claim 5, Wherein the monitoring device is a trailer truck location tracking system, characterized in that connected to the Internet network via a web server to remotely monitor the location of the trailer truck. The method according to claim 5, And the monitoring device displays to the user when the trailer truck is located at a predetermined target point. The method according to any one of claims 2 to 4, And a distance between the beacon and the trailer truck in the distance calculator using a time difference of arrival algorithm. A system for tracking the location of trailer trucks during loading and unloading of containers in ports, An ultrasonic generator for transmitting ultrasonic signals and RF signals generated from at least three beacons attached to the crane; A distance data transmission device attached to a trailer truck for calculating a distance between each beacon and the trailer truck by the ultrasonic flight distance and wirelessly transmitting each distance data; A data processing device for receiving the distance data and calculating a position of the trailer truck; And It is provided with a monitoring device for the user to monitor the location of the trailer truck, If the beacon is at least four, the data processing apparatus calculates the position of the trailer truck based on the first three distance data received among the distance data received from the unequal beacons. Tracking system. The method according to claim 10, If the beacon is four, the beacon is a trailer truck position tracking system, characterized in that installed at each vertex of the square shape having the same height from the ground. delete (a) transmitting an ultrasonic signal and an RF signal generated from at least three beacons installed in the crane; (b) receiving the ultrasound and RF signals, calculating the distance between the beacon and the trailer truck based on the flight distance of the ultrasound and transmitting distance data to a data processing device; And (c) calculating and displaying the location of the trailer truck using the distance data received by the data processing apparatus; In step (c), (c1) determining whether the trailer truck is located at a target point; And and (c2) if it is determined that the trailer truck is located at the target point, displaying the same on the monitoring device. (a) transmitting an ultrasonic signal and an RF signal generated from at least three beacons installed in the crane; (b) receiving the ultrasound and RF signals, calculating the distance between the beacon and the trailer truck based on the flight distance of the ultrasound and transmitting distance data to a data processing device; And (c) calculating and displaying the location of the trailer truck using the distance data received by the data processing apparatus; The beacons are displayed in coordinates based on a fixed coordinate system, and the step (c) is based on the calculation of the distance between the coordinates of each beacon and the coordinates of the ultrasonic radio receiving node to determine the location of the trailer truck. Position tracking method of the trailer truck, characterized in that the calculation. The method according to claim 13 or 14, In step (b), the distance between the beacon and the trailer truck is calculated using a TDoA (Time Difference of Arrival) algorithm. The method according to claim 13 or 14, If the beacon is at least four, In the step (c), the data processing apparatus calculates the position of the trailer truck based on the three distance data received first among the distance data received from non-identical beacons.

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