JP7767973B2 - Position detection device for cranes - Google Patents

Description

The present invention relates to a position detection device for a crane.

During crane operations, load monitoring cameras are sometimes used to check the position of the load.

For example, Patent Document 1 discloses a load monitoring device that includes a load monitoring camera that captures an image of a suspended load, a controller that generates a composite image by combining the image captured by the load monitoring camera with a mesh-like guide line that indicates the height of the hook, and a display that displays the composite image. This load monitoring device displays the composite image on the display, allowing the crane operator to intuitively recognize the height of the hook from the guide line in the composite image. As a result, this load monitoring device makes it easier to operate the crane.

Japanese Patent Application Laid-Open No. 2016-153335

Some load monitoring cameras do not have a wide enough field of view. As a result, the load monitoring camera may not be able to confirm the location of people or objects around the boom.

Furthermore, even if the field of view of a suspended load monitoring camera is wide, the wide field of view can result in people or objects appearing small. As a result, it is difficult to accurately measure the position of people or objects.

The present invention has been made to solve the above problems, and aims to provide a position detection device for a crane that can accurately detect the position of a person or object around the boom.

In order to achieve the above object, a position detection device for a crane according to a first aspect of the present invention comprises:
A position detection device that is equipped on a crane with a boom and receives radio waves emitted from a transmitter attached to a person or an object to detect the position of the transmitter,
a plurality of first antenna elements provided on a right side surface of the boom and arranged in an extending direction of the boom to receive the radio waves;
a plurality of second antenna elements provided on a left side surface of the boom and arranged in an extending direction of the boom to receive the radio waves;
a position calculator that determines the respective positions of the plurality of first antenna elements and the plurality of second antenna elements relative to a reference point of the crane based on the boom hoisting angle and the length of the boom, and calculates the position of the transmitter relative to the reference point from the reception strength of the radio waves received by each of the plurality of first antenna elements and the plurality of second antenna elements and the determined positions of the plurality of first antenna elements and the plurality of second antenna elements relative to the reference point;
The present invention is characterized by comprising:

a plurality of third antenna elements disposed on either a vehicle body of the crane or an outrigger of the vehicle body, the third antenna elements receiving the radio waves;
The position calculator may calculate the position of the transmitter relative to the reference location from the reception strength of the radio waves received by each of the plurality of third antenna elements and the position of each of the plurality of third antenna elements relative to the reference location.
The crane also includes a plurality of third antenna elements that are disposed at the tip of an outrigger that the crane body has and that receive the radio waves,
The position calculator may determine the position of each of the plurality of third antenna elements relative to the reference location based on the extension length of the outrigger, and calculate the position of the transmitter relative to the reference location from the reception strength of the radio waves received by each of the plurality of third antenna elements and the determined positions of each of the plurality of third antenna elements relative to the reference location.
Furthermore, the position calculator may determine that the accuracy of the calculated position of the transmitter is low when the position of the transmitter relative to the reference location calculated using the reception strength of the radio waves received by each of the plurality of first antenna elements and the plurality of second antenna elements is greater than a predetermined distance from the position of the transmitter relative to the reference location calculated using the reception strength of the radio waves received by each of the plurality of third antenna elements.

A position detection device for a crane according to a second aspect of the present invention comprises:
A position detection device for a crane that is equipped on a crane having a boom and receives radio waves emitted from a transmitter attached to a person or an object to detect the position of the transmitter,
a plurality of first antenna elements provided on a right side surface of the boom and arranged in an extending direction of the boom to receive the radio waves;
a plurality of second antenna elements provided on a left side surface of the boom and arranged in an extending direction of the boom to receive the radio waves;
a position calculator that calculates a position of the transmitter relative to a reference point from reception intensities of the radio waves received by each of the plurality of first antenna elements and the plurality of second antenna elements and respective positions of the plurality of first antenna elements and the plurality of second antenna elements relative to a reference point of the crane;
a fourth antenna element provided on a lower surface of the boom or on a boom head of the boom, the fourth antenna element receiving the radio waves ;
Equipped with
The position calculator is characterized in that, when the fourth antenna element receives the radio waves and the plurality of first antenna elements and the plurality of second antenna elements receive the radio waves, it determines that the plurality of first antenna elements and the plurality of second antenna elements are operating normally, and calculates the position of the transmitter relative to the reference location.

The system may further include an alarm device that notifies the crane operator of the position of the transmitter relative to the reference point calculated by the position calculator.

A position detection device for a crane according to a third aspect of the present invention comprises:
A position detection device for a crane that is equipped on a crane having a boom and receives radio waves emitted from a transmitter attached to a person or an object to detect the position of the transmitter,
a plurality of first antenna elements provided on a right side surface of the boom and arranged in an extending direction of the boom to receive the radio waves;
a plurality of second antenna elements provided on a left side surface of the boom and arranged in an extending direction of the boom to receive the radio waves;
a position calculator that calculates a position of the transmitter relative to a reference point from reception intensities of the radio waves received by each of the plurality of first antenna elements and the plurality of second antenna elements and respective positions of the plurality of first antenna elements and the plurality of second antenna elements relative to a reference point of the crane;
a first receiver having the plurality of first antenna elements;
a second receiver having the plurality of second antenna elements;
Equipped with
The radio waves carry an identification signal for identifying the person or object to which the transmitter is attached,
the first receiver receives the radio waves via the plurality of first antenna elements, thereby receiving the identification signal carried on the radio waves;
the second receiver receives the radio waves by the plurality of second antenna elements, thereby receiving the identification signal carried on the radio waves;
The position calculator identifies the person or the object to which the transmitter is attached based on the identification signal received by the first receiver or the second receiver.

the reference point is a tip of a boom head provided on the boom,
The position calculator may calculate the position of the transmitter relative to the tip of the boom head.

According to the configuration of the present invention, multiple first antenna elements are provided on the right side of the boom, and multiple second antenna elements are provided on the left side of the boom. Therefore, even if a transmitter is located on the right or left of the boom, the crane position detection device can receive radio waves from the transmitter and detect the transmitter's position without the radio waves being blocked by the boom.

In addition, multiple first antenna elements and multiple second antenna elements are arranged in the extension direction of the boom. Therefore, if a transmitter is located in the extension direction of the boom, the crane position detection device can receive radio waves from the transmitter and detect the transmitter's position.

As a result, the position detection device for the crane can accurately detect the position of a person or object around the boom when the transmitter is attached to the person or object.

1 is a side view of a rough terrain crane to which a crane position detection device according to an embodiment of the present invention is attached. 1 is a block diagram of a position detection device for a crane according to an embodiment. FIG. 2 is a block diagram of a transmitter and a right receiver, a left receiver, a bottom receiver, a tip receiver, and a reference receiver provided in the position detection device. FIG. 2 is a top view of a rough terrain crane showing the mounting positions of the right receiver, left receiver, lower receiver, tip receiver, and reference receiver provided in the position detection device. FIG. 1 is a top view of a loaded truck crane equipped with a position detection device.

A position detection device for a crane according to an embodiment of the present invention will be described in detail below with reference to the drawings. Note that hereafter, a position detection device for a crane will be referred to simply as a position detection device. In addition, the same or equivalent parts in the drawings will be designated by the same reference numerals.

The position detection device according to this embodiment is a device that detects the position of an object relative to a crane in order to facilitate crane operation. Below, the configuration of this position detection device will be explained using the example of a device attached to a rough terrain crane. First, the configuration of the rough terrain crane to which it is attached will be explained.

Figure 1 is a side view of a rough terrain crane 100 equipped with a position detection device 1 according to an embodiment of the present invention. Note that, for ease of understanding, Figure 1 shows only a portion of the components of the position detection device 1.

As shown in Figure 1, the rough terrain crane 100 comprises a rotating body 120 mounted on a vehicle 110 with a traveling function, a boom 130 mounted on the rotating body 120, and a hook 150 for suspending a load 200 connected to a wire rope 140 hanging down from the tip of the boom 130.

The vehicle 110 has outriggers 111F and 111R at the front and rear, which extend out to the left and right using jack cylinders (not shown). During crane operations, the vehicle 110 extends these outriggers 111F and 111R, causing the floats at the tips of the outriggers 111F and 111R to touch the ground. This increases the stability of the vehicle 110 during crane operations and prevents it from tipping over.

In addition, a rotating body 120 is provided on top of the vehicle 110 to enable crane operations with the outriggers 111F and 111R extended.

The rotating unit 120 is mounted on the upper portion of the vehicle 110 with its central axis A of rotation oriented in the vertical direction. The rotating unit 120 rotates around the central axis A when driven by a rotation motor 121. A boom 130 is also mounted on the rotating unit 120. The rotating unit 120 rotates due to the rotation of the rotation motor 121, thereby rotating the boom 130.

The boom 130 is attached to the rotating unit 120 by fastening the boom foot at its base with a foot pin. The boom 130's middle section, which is closer to the tip than the base, is supported by a boom-raising cylinder 131 attached to the rotating unit 120. The boom 130 is raised and lowered by the extension and contraction of the boom-raising cylinder 131.

The boom 130 is also telescopic. A telescopic cylinder 132 is provided inside the boom 130. The boom 130 extends and retracts as the telescopic cylinder 132 extends and retracts.

Furthermore, a boom head 134 incorporating a sheave 133 is provided at the tip of the boom 130. At the boom head 134, a wire rope 140 is looped around the sheave 133. One end of the wire rope 140 hangs down from the sheave 133. A hook 150 is mechanically connected to one end of the wire rope 140. With this configuration, the boom head 134 suspends the hook 150.

The other end of the wire rope 140, opposite the one end described above, is wound around a winch drum 141 mounted on the rotating body 120. The wire rope 140 is wound up or lowered by rotating the winch drum 141 forward or backward. As described above, a hook 150 is connected to one end of the wire rope 140. As a result, the hook 150 rises or falls as the wire rope 140 is wound up or lowered.

To transport a nearby load 200 suspended by the hook 150, the rough terrain crane 100 operates the rotating body 120 and boom 130, described above, to move the boom head 134 above the load 200. In this state, the operator also operates the winch drum 141 to lower the hook 150.

At this time, in order to accurately move the boom head 134 directly above the load 200, the operator needs to know the exact position of the load 200. Therefore, for example, the operator views an image captured by a suspended load monitoring camera, and thereby determines the position of the load 200.

However, suspended load monitoring cameras have a narrow viewing angle, and may not be able to capture an image of load 200 if the load 200 is located at a distance. Also, if the load 200 is located at a distance, the captured image of load 200 may be small, making it difficult to determine the position of the load 200.

Due to these problems, it is desirable that the operator be provided with positional information such as the direction of the load 200 relative to the boom head 134 and the distance from the boom head 134 to the load 200. Furthermore, in order to prevent contact or interference with objects around the rough terrain crane 100, such as buildings and construction machinery, it is desirable that the operator be provided with positional information about these objects. Furthermore, to further ensure safety, it is desirable that the operator be provided with positional information about people around the rough terrain crane 100.

The rough terrain crane 100 is therefore equipped with a position detection device 1 that detects the position of a transmitter 10 attached to a person or object relative to the vehicle 110, in order to provide the operator with position information about nearby people or objects. Next, the configuration of the position detection device 1 will be explained with reference to Figures 2-4.

Figure 2 is a block diagram of the position detection device 1. Figure 3 is a block diagram of the transmitter 10 and the right receivers 21R-23R, left receivers 21L-23L, lower receiver 24, tip receiver 25, and reference receivers 31-34 provided in the position detection device 1. Figure 4 is a top view of the rough terrain crane 100 showing the mounting positions of the right receivers 21R-23R, left receivers 21L-23L, lower receiver 24, tip receiver 25, and reference receivers 31-34 provided in the position detection device 1.

For ease of understanding, Figure 2 shows not only the configuration of the position detection device 1, but also part of the configuration of the rough terrain crane 100.

As shown in FIG. 2, the position detection device 1 includes: (1) right receivers 21R-23R, left receivers 21L-23L, lower receiver 24, front receiver 25, and reference receivers 31-34 that receive radio waves emitted by the transmitter 10; (2) a position calculator 40 that calculates the position of the transmitter 10 from the data received by the right receivers 21R-23R, left receivers 21L-23L, lower receiver 24, front receiver 25, and reference receivers 31-34; and (3) a display device 45 that displays the position data of the transmitter 10 calculated by the position calculator 40.

Transmitter 10 is a device that is attached to a person or object whose location the operator needs to know during crane operations using rough terrain crane 100, and communicates that location. Transmitter 10 is also known as a beacon, radio beacon, etc.

In detail, the transmitter 10 is attached to a person or object with which the boom head 134 is to be prevented from coming into contact or colliding, such as a worker at a construction site, construction machinery such as an excavator, bulldozer, or truck at the construction site, or a building at the construction site. The transmitter 10 then transmits radio waves to notify the position detection device 1 of its location.

To transmit the radio waves, the transmitter 10 includes a communication module 11 and an antenna element 12, as shown in Figure 3.

The communication module 11 includes a baseband circuit, a radio frequency (RF) circuit, a modulation circuit, and other components (not shown). In the communication module 11, the baseband circuit generates a baseband signal from a transmitter signal that includes an identification signal. Here, the identification signal is a signal that identifies which transmitter 10 sent the signal when there are multiple transmitters 10. Meanwhile, the radio frequency circuit generates a carrier wave. The modulation circuit then superimposes the baseband signal generated by the baseband circuit onto the carrier wave generated by the radio frequency circuit. The communication module 11 sends the carrier wave on which the baseband signal is superimposed to the antenna element 12.

Antenna element 12 converts the carrier wave superimposed with the baseband signal into radio waves and radiates the converted radio waves into space. As a result, antenna element 12 transmits the converted radio waves to the right receivers 21R-23R, left receivers 21L-23L, lower receiver 24, tip receiver 25, and reference receivers 31-34.

In contrast, the right receivers 21R-23R, left receivers 21L-23L, lower receiver 24, tip receiver 25, and reference receivers 31-34 are devices attached to the rough terrain crane 100 and receive radio waves transmitted by the transmitter 10.

In detail, the right receivers 21R-23R and the left receivers 21L-23L are provided on the right and left sides of the boom 130, as shown in Figure 4. As a result, the right receivers 21R-23R and the left receivers 21L-23L receive radio waves transmitted by the transmitter 10 from the right and left sides of the boom 130.

The right receivers 21R-23R and left receivers 21L-23L are located in these positions because if the right receivers 21R-23R and left receivers 21L-23L were located on only one of the right and left sides of the boom 130, the metal boom 130 would block the radio waves from the other side of the boom 130, making it difficult to receive the radio waves. Furthermore, by locating the right receivers 21R-23R and left receivers 21L-23L at a distance from each other in the left-right direction, when the transmitter 10 is located to the right or left of the boom 130, the radio waves emitted by the transmitter 10 are received at a stronger intensity by either the right receivers 21R-23R or the left receivers 21L-23L. As a result, the difference in reception strength makes it easier to detect the left-right position of the transmitter 10.

The right receivers 21R-23R and left receivers 21L-23L are arranged along the extension direction of the boom 130. Specifically, the right receivers 21R-23R are arranged from the tip to the end of the boom 130 in the order of right receiver 21R, right receiver 22R, and right receiver 23R. They are also arranged apart from one another in the extension direction of the boom 130. Furthermore, the left receivers 21L-23L are each arranged to the left of the right receivers 21R-23R. As a result, the left receivers 21L-23L are arranged in a similar positional relationship to the right receivers 21R-23R in the extension direction of the boom 130. The right receivers 21R-23R and left receivers 21L-23L each include an antenna element 210, as described below, and by being arranged as described above, they form a so-called antenna array. As a result, the right receivers 21R-23R and left receivers 21L-23L receive the radio waves emitted by the transmitter 10 at an intensity that corresponds to the position in the extension direction of the boom 130. As a result, the difference in reception intensity makes it easier to detect the position of the transmitter 10 in the extension direction of the boom 130.

In this way, the right receivers 21R-23R and left receivers 21L-23L receive radio waves from the transmitter 10 from the right and left sides of the boom 130 and from the tip and tail of the boom 130, respectively. The right receivers 21R-23R and left receivers 21L-23L then measure the strength of the radio waves from the transmitter 10 and transmit that strength to the position calculator 40. As a result, the right receivers 21R-23R and left receivers 21L-23L provide the position calculator 40 with data for calculating the position of the transmitter 10. The right receivers 21R-23R and left receivers 21L-23L also receive radio waves from the transmitter 10. They then extract signals contained in the radio waves and transmit the resulting signals to the position calculator 40.

On the other hand, the lower receiver 24 and the front receiver 25 are provided to obtain information to determine whether or not the reception is correct when the right receivers 21R-23R and left receivers 21L-23L receive radio waves.

More specifically, the lower receiver 24 and the tip receiver 25 are located on the underside of the boom 130 and the tip of the boom head 134, where radio waves from the transmitter 10 can be easily received. The lower receiver 24 and the tip receiver 25 receive radio waves from the transmitter 10, extract signals contained in the received radio waves, and transmit the extracted signals to the position calculator 40. When the position calculator 40 receives signals from the right receivers 21R-23R and left receivers 21L-23L and receives the same signals from the lower receiver 24 or the tip receiver 25, it determines that the right receivers 21R-23R and left receivers 21L-23L are receiving the signals correctly. In this way, the lower receiver 24 and the tip receiver 25 provide the position calculator 40 with information for determining whether the reception by the right receivers 21R-23R and left receivers 21L-23L is correct.

The reference receivers 31-34 are also provided to assist in detecting the position of the transmitter 10 using the right receivers 21R-23R and left receivers 21L-23L. Therefore, like the right receivers 21R-23R and left receivers 21L-23L, the reference receivers 31-34 provide the position calculator 40 with data for calculating the position of the transmitter 10.

Specifically, reference receivers 31 and 32 are provided at the right and left ends of outrigger 111F, respectively. Reference receivers 33 and 34 are provided at the right and left ends of outrigger 111R, respectively. In other words, reference receivers 31-34 are provided at the four corners of vehicle 110 when viewed from above. Reference receivers 31-34 measure the radio wave intensity of transmitter 10 at their respective positions and transmit that intensity to position calculator 40. In this way, reference receivers 31-34 provide data for calculating the position of transmitter 10 to position calculator 40.

Returning to Figure 3, the right receivers 21R-23R, left receivers 21L-23L, bottom receiver 24, tip receiver 25, and reference receivers 31-34 each have an antenna element 210 and a communication module 220 to receive radio waves from the transmitter 10.

The antenna element 210 receives radio waves emitted by the transmitter 10 and converts the radio waves into electrical signals. The antenna element 210 then transmits the converted electrical signals to the communication module 220.

The communication module 220 includes a demodulation circuit, a voltage rectification circuit, etc., which are not shown. The demodulation circuit, which is not shown, removes the carrier wave component from the electrical signal transmitted from the antenna element 210 to extract a baseband signal. The communication module 220 transmits the extracted baseband signal to the position calculator 40.

In addition, a voltage rectifier circuit (not shown) included in the communication module 220 measures the amplitude of the electrical signal transmitted from the antenna element 210. The communication module 220 then transmits the measured amplitude as the strength of the received radio wave to the position calculator 40 shown in Figure 2.

The position calculator 40 includes a CPU (Central Processing Unit) 41 for processing signals transmitted from the communication modules 220 included in the right receivers 21R-23R, left receivers 21L-23L, lower receiver 24, tip receiver 25, and reference receivers 31-34, a RAM (Random Access Memory) 42, a ROM (Read-Only Memory) 43, and a storage device 44 for storing various data.

The CPU 41 is electrically connected to the swing angle detection sensor 161, boom angle detection sensor 162, boom length detection sensor 163, and outrigger extension detection sensor 164 provided on the rough terrain crane 100 via a bus (communication line) not shown.

Here, the swing angle detection sensor 161 is a sensor that detects the angle at which the swing unit 120 is swung by the swing motor 122 shown in FIG. 1. The boom angle detection sensor 162 is a sensor that detects the angle at which the boom 130 is raised or lowered due to the extension or contraction of the hoisting cylinder 131. The boom length detection sensor 163 is a sensor that detects the length of the boom 130 when the boom 130 is extended or lowered due to the extension or contraction of the telescopic cylinder 132. The outrigger extension detection sensor 164 is a sensor that detects the extension length of the outriggers 111F, 111R. These sensors transmit the detected data of the swing angle of the swing unit 120, the boom hoisting angle of the boom 130, the length of the boom 130, and the extension length of the outriggers 111F, 111R to the CPU 41.

Returning to Figure 2, the CPU 41 reads the position calculation program stored in the ROM 43 into the RAM 42 and executes it. As a result, the position calculator 40 performs position calculation processing.

In this position calculation process, the position calculator 40 receives data on the strength of the received radio waves from each of the right receivers 21R-23R, left receivers 21L-23L, and reference receivers 31-34. The position calculator 40 also receives, from each of the right receivers 21R-23R, left receivers 21L-23L, and reference receivers 31-34, the baseband signals that they extract from the radio waves of the transmitter 10.

When the position calculator 40 receives radio wave intensity data and baseband signals from each of the right receivers 21R-23R, left receivers 21L-23L, and reference receivers 31-34, it receives baseband signals extracted from the radio waves of the transmitter 10 by the lower receiver 24 and the front-end receiver 25 from the lower receiver 24 and the front-end receiver 25 to determine whether the reception by the right receivers 21R-23R, left receivers 21L-23L, and reference receivers 31-34 is correct. The position calculator 40 then compares the baseband signals received from each of the right receivers 21R-23R, left receivers 21L-23L, and reference receivers 31-34 with the baseband signals received from the lower receiver 24 and the front-end receiver 25.

If the baseband signals do not match, the position calculator 40 determines that the reception by the right receivers 21R-23R, left receivers 21L-23L, and reference receivers 31-34 is incorrect and does not calculate the position of the transmitter 10. On the other hand, if the baseband signals match, the position calculator 40 determines that the reception by the reference receivers 31-34 is correct. The position calculator 40 then calculates the position of the transmitter 10 based on the radio wave intensity data received from the right receivers 21R-23R, left receivers 21L-23L, and reference receivers 31-34.

Explaining in detail how the transmitter 10's position is calculated, the position calculator 40 first reads various data required for calculation from the storage device 44. Specifically, the storage device 44 stores coordinate data indicating the positions of the right receivers 21R-23R and left receivers 21L-23L within the boom 130, for example, coordinate data with the boom foot of the right receivers 21R-23R and left receivers 21L-23L as the origin. The storage device 44 also stores coordinate data indicating the positions of the reference receivers 31-34, which are associated with the extension lengths of the outriggers 111F, 111R, relative to the reference location of the vehicle 110. The storage device 44 also stores coordinate data indicating the position of the boom foot relative to the reference location of the vehicle 110. The position calculator 40 reads this coordinate data.

Here, the reference point of the vehicle 110 refers to the reference point that serves as the origin of the coordinate system indicating the position of each part of the rough terrain crane 100. For example, it is the center of rotation of the rotating body 120.

The position calculator 40 also receives data on the rotation angle of the rotating unit 120, the boom angle detection sensor 162, the boom length detection sensor 163, and the outrigger extension detection sensor 164, including the rotation angle of the rotating unit 120, the boom hoisting angle of the boom 130, the length of the boom 130, and the extension length of the outriggers 111F and 111R. The position calculator 40 uses the data from these sensors and the coordinate data read from the storage device 44 to calculate the respective positions of the right receivers 21R-23R, left receivers 21L-23L, and reference receivers 31-34, for example, their positions when the center of rotation of the rotating unit 120 is set as the origin.

The position calculator 40 calculates the position of the transmitter 10 relative to the reference location of the vehicle 110 from the calculated positions of the right receivers 21R-23R, left receivers 21L-23L, and reference receivers 31-34, and the strength of the radio waves received by the right receivers 21R-23R, left receivers 21L-23L, and reference receivers 31-34 in the initial stage of the position calculation process described above.

At this time, the position calculator 40 calculates the distance from each of the right receivers 21R-23R, left receivers 21L-23L, and reference receivers 31-34 to the transmitter 10 using the Friis propagation formula. The position calculator 40 also applies triangulation to the calculated distances from each of the right receivers 21R-23R and left receivers 21L-23L to the transmitter 10 and the respective positions of the right receivers 21R-23R and left receivers 21L-23L to calculate the position of the transmitter 10 relative to a reference location on the vehicle 110.

Note that, hereafter, this calculated position of the transmitter 10 will be referred to as the position of the transmitter 10 calculated from the data of the right receivers 21R-23R and the left receivers 21L-23L.

As described above, the baseband signals received by the position calculator 40 from the right receivers 21R-23R, left receivers 21L-23L, and reference receivers 31-34 each contain an identification signal that indicates which transmitter 10 it is. The position calculator 40 outputs the transmitter 10 position data calculated from the data from the right receivers 21R-23R and left receivers 21L-23L, along with the identification number data, to the display device 45.

Furthermore, the position calculator 40 applies triangulation to the distances from each of the reference receivers 31-34 to the transmitter 10 calculated above and the positions of each of the reference receivers 31-34 to calculate the position of the transmitter 10 relative to the reference location of the vehicle 110.

Note that, hereafter, this calculated position of the transmitter 10 will be referred to as the position of the transmitter 10 calculated from the data of the reference receivers 31-34.

The position calculator 40 compares the position of the transmitter 10 calculated from the data of the right receivers 21R-23R and left receivers 21L-23L with the position of the transmitter 10 calculated from the data of the reference receivers 31-34, and if the distance is greater than a predetermined distance, it determines that the accuracy of the calculated position of the transmitter 10 is low. If the position calculator 40 determines that the accuracy of the position of the transmitter 10 is low, it outputs a signal to the display device 45 indicating that the accuracy of the calculated position data may be low.

The display device 45 is composed of a liquid crystal display or an organic EL (Electro-Luminescence) display. The display device 45 is installed in the cabin of the rough terrain crane 100. When the transmitter 10 position data and identification number data are output from the position calculator 40, the display device 45 displays this data on its screen. This notifies the operator of the rough terrain crane 100 of the position of the person or object to which the transmitter 10 is attached.

For this notification, it is desirable that data associating the identification signal with object information identifying the person or object to which the identification signal is attached, such as the name of the person or object, be stored in advance in the storage device 44, and that the position calculator 40 reads out this data and outputs the object information corresponding to the identification signal to the display device 45. As a result, it is desirable that the display device 45 display the position of the transmitter 10 and the object information. In other words, it is desirable that the display device 45 display the object information identifying the person or object to which the transmitter 10 is attached, along with the position of the transmitter 10.

In addition, if the display device 45 outputs a signal indicating that the accuracy of the position data calculated by the position calculator 40 may be low, it will display on the screen that the accuracy of the position data from the transmitter 10 is low. This alerts the operator of the rough terrain crane 100.

As described above, the position detection device 1 according to embodiment 1 of the present invention is provided on the boom 130 and includes right receivers 21R-23R and left receivers 21L-23L that receive radio waves from the transmitter 10, and a position calculator 40 that calculates the position of the transmitter 10 from the strength of the radio waves received by the right receivers 21R-23R and left receivers 21L-23L. As a result, when the transmitter 10 is attached to a person or object, the position detection device 1 can accurately detect the position of the person or object in the vicinity of the boom 130.

The right receivers 21R-23R are mounted on the right side of the boom 130, and the left receivers 21L-23L are mounted on the left side of the boom 130. Therefore, even if the transmitter 10 is located to the right or left of the boom 130, the position detection device 1 does not have its radio waves blocked by the boom 130. As a result, the position detection device 1 can receive radio waves from the transmitter 10 and detect the position of the transmitter 10.

Furthermore, the right receivers 21R-23R and left receivers 21L-23L are arranged in the extension direction of the boom 130. In other words, the right receivers 21R-23R and left receivers 21L-23L form an antenna array arranged in the extension direction of the boom 130. Therefore, when the transmitter 10 is located in the extension direction of the boom 130, the position detection device 1 can receive radio waves from the transmitter 10 and detect the position of the transmitter 10.

When the transmitter 10 is attached to a person or object, the position detection device 1 accurately detects the position of the person or object around the boom 130 and notifies the operator of the rough terrain crane 100 of that position. This allows the operator to operate the rough terrain crane 100 more accurately.

The right receivers 21R-23R and left receivers 21L-23L receive a baseband signal containing the identification number of the transmitter 10, and the position calculator 40 displays the identification number and the transmitter 10's position data on the display device 45. This allows the operator to identify the detected transmitter 10.

In the above embodiment, the right receivers 21R-23R correspond to the first receiver in the claims, and the antenna element 210 provided by the right receivers 21R-23R corresponds to the first antenna element in the claims. Furthermore, the left receivers 21L-23L correspond to the second receiver in the claims, and the antenna element 210 provided by the left receivers 21L-23L corresponds to the second antenna element in the claims. Furthermore, the antenna element 210 provided by the reference receivers 31-34 corresponds to the third antenna element in the claims. The antenna element 210 provided by each of the lower receiver 24 and the front receiver 25 corresponds to the fourth antenna element in the claims. Furthermore, the vehicle 110 corresponds to the vehicle body in the claims.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, in the above embodiments, the position detection device 1 is attached to the rough terrain crane 100, but the present invention is not limited to this. In the present invention, the position detection device 1 may be attached to a crane that has a boom 130. Therefore, the position detection device 1 may be attached to a crane that has a boom 130 other than the rough terrain crane 100.

Figure 5 is a top view of a loaded truck crane 101 equipped with a position detection device 1.

As shown in FIG. 5, the position detection device 1 may be attached to a loaded truck crane 101 (also called a cargo crane). In this case, the reference receivers 31-34 may be placed in the cabin 112 provided on the loaded truck crane 101. For example, the reference receivers 31-34 may be placed in the front right, front left, rear right, and rear left parts of the cabin 112, respectively.

Furthermore, in the above embodiment, the transmitter 10 transmits radio waves, and the right receivers 21R-23R, left receivers 21L-23L, lower receiver 24, front receiver 25, and reference receivers 31-34 each receive the radio waves. However, the present invention is not limited to this. In the present invention, the transmitter 10 may further include the same components as the communication module 220, such as a demodulation circuit and a voltage rectification circuit, and may not only transmit radio waves but also receive them. Furthermore, the right receivers 21R-23R, left receivers 21L-23L, lower receiver 24, front receiver 25, and reference receivers 31-34 may further include the same components as the communication module 11, such as a baseband circuit, a radio frequency circuit, and a modulation circuit, and may not only receive radio waves but also transmit them. As a result, the right receivers 21R-23R, left receivers 21L-23L, lower receiver 24, tip receiver 25, and reference receivers 31-34 may each transmit radio waves, and the transmitter 10 may receive the radio waves from the right receivers 21R-23R, left receivers 21L-23L, lower receiver 24, tip receiver 25, and reference receivers 31-34. This allows communication to occur between the right receivers 21R-23R, left receivers 21L-23L, lower receiver 24, tip receiver 25, and reference receivers 31-34 and the transmitter 10.

Furthermore, in the above embodiment, the right receivers 21R-23R, left receivers 21L-23L, lower receiver 24, tip receiver 25, and reference receivers 31-34 each include an antenna element 210 and a communication module 220. However, the present invention is not limited to this. In the present invention, the position calculator 40 includes a communication module 220, and as a result, the right receivers 21R-23R, left receivers 21L-23L, lower receiver 24, tip receiver 25, and reference receivers 31-34 do not each include a communication module 220. In other words, the right receivers 21R-23R, left receivers 21L-23L, lower receiver 24, tip receiver 25, and reference receivers 31-34 may each include only an antenna element 210. In this case, they may simply be referred to as antenna elements or antennas.

In the above embodiment, each of the right receivers 21R-23R and left receivers 21L-23L is composed of three receivers. However, the present invention is not limited to this. The number of right receivers 21R-23R and the number of left receivers 21L-23L may be plural. This is because, with such a number, the position of the transmitter 10 can be calculated by applying triangulation to the strength of the radio waves from the transmitter 10. If the above-mentioned right receivers 21R-23R and left receivers 21L-23L do not have a communication module 220 and only have antenna elements 210, each of the right receivers 21R-23R and left receivers 21L-23L may have multiple antenna elements 210.

In the above embodiment, an example was shown in which one transmitter 10 was present, but in the present invention, it is sufficient that at least one transmitter 10 is present. There may also be multiple transmitters 10.

In the above embodiment, the position calculator 40 calculates the position of the transmitter 10 relative to a reference point on the vehicle 110. The center of rotation of the rotating unit 120 is exemplified as the reference point. However, the present invention is not limited to this. In the present invention, the reference point on the vehicle 110 may be any reference point on the crane. For example, the reference point may be the tip of the boom head 134 or the sheave 133 on the boom head 134. This is because such a point serves as the reference for the hook 150 that suspends the load 200, and knowing the position of the transmitter 10 from such a point facilitates operation of the rough terrain crane 100 or the loaded truck crane 101. The reference point may also be the cabin.

In the above embodiment, the location of the transmitter 10 is displayed on the display device 45, thereby informing the operator of the location of the transmitter 10. However, the present invention is not limited to this. In the present invention, the display device 45 may be any notification device that notifies the operator of the location of the transmitter 10. Therefore, the display device 45 may be, for example, a speaker. In this case, the location of the transmitter 10 may be announced audibly from the speaker.

1...position detection device, 10...transmitter, 11...communication module, 12...antenna element, 21R-23R...right receiver, 21L-23L...left receiver, 24...lower receiver, 25...tip receiver, 31-34...reference receiver, 40...position calculator, 41...CPU, 42...RAM, 43...ROM, 44...storage device, 45...display device, 100...rough terrain crane, 101...loading truck crane, 110...vehicle, 111F, 111R...outrigger, 112...cabinet 120...swivel unit, 121...swivel motor, 130...boom, 131...hoisting cylinder, 132...telescopic cylinder, 133...sheave, 134...boom head, 140...wire rope, 141...winch drum, 150...hook, 161...swivel angle detection sensor, 162...boom angle detection sensor, 163...boom length detection sensor, 164...outrigger extension detection sensor, 200...load, 210...antenna element, 220...communication module, A...center axis

Claims (8)

A position detection device for a crane that is equipped on a crane having a boom and receives radio waves emitted from a transmitter attached to a person or an object to detect the position of the transmitter,
a plurality of first antenna elements provided on a right side surface of the boom and arranged in an extending direction of the boom to receive the radio waves;
a plurality of second antenna elements provided on a left side surface of the boom and arranged in an extending direction of the boom to receive the radio waves;
a position calculator that determines the respective positions of the plurality of first antenna elements and the plurality of second antenna elements relative to a reference point of the crane based on the boom hoisting angle and the length of the boom, and calculates the position of the transmitter relative to the reference point from the reception strength of the radio waves received by each of the plurality of first antenna elements and the plurality of second antenna elements and the determined positions of the plurality of first antenna elements and the plurality of second antenna elements relative to the reference point;
A position detection device for a crane comprising: a plurality of third antenna elements disposed on either a vehicle body of the crane or an outrigger of the vehicle body, the third antenna elements receiving the radio waves;
the position calculator calculates the position of the transmitter relative to the reference location from the reception strength of the radio wave received by each of the plurality of third antenna elements and the positions of each of the plurality of third antenna elements relative to the reference location.
2. The position detection device for a crane according to claim 1. a plurality of third antenna elements disposed at the tip of an outrigger provided on the vehicle body of the crane and configured to receive the radio waves;
the position calculator determines the position of each of the plurality of third antenna elements relative to the reference location based on the extension length of the outrigger, and calculates the position of the transmitter relative to the reference location from the reception strength of the radio wave received by each of the plurality of third antenna elements and the determined positions of each of the plurality of third antenna elements relative to the reference location.
3. A position detection device for a crane according to claim 1 or 2. the position calculator determines that the accuracy of the calculated position of the transmitter is low when the position of the transmitter relative to the reference location calculated using the reception strength of the radio waves received by each of the plurality of first antenna elements and the plurality of second antenna elements is greater than a predetermined distance from the position of the transmitter relative to the reference location calculated using the reception strength of the radio waves received by each of the plurality of third antenna elements;
4. The position detection device for a crane according to claim 2 or 3. A position detection device for a crane that is equipped on a crane having a boom and receives radio waves emitted from a transmitter attached to a person or an object to detect the position of the transmitter,
a plurality of first antenna elements provided on a right side surface of the boom and arranged in an extending direction of the boom to receive the radio waves;
a plurality of second antenna elements provided on a left side surface of the boom and arranged in an extending direction of the boom to receive the radio waves;
a position calculator that calculates a position of the transmitter relative to a reference point from reception intensities of the radio waves received by each of the plurality of first antenna elements and the plurality of second antenna elements and respective positions of the plurality of first antenna elements and the plurality of second antenna elements relative to a reference point of the crane;
a fourth antenna element provided on a lower surface of the boom or on a boom head of the boom, the fourth antenna element receiving the radio waves ;
Equipped with
the position calculator determines that the plurality of first antenna elements and the plurality of second antenna elements are operating normally when the fourth antenna element receives the radio waves and the plurality of first antenna elements and the plurality of second antenna elements receive the radio waves, and calculates the position of the transmitter relative to the reference location;
Position detection device for cranes . The crane further includes an alarm device that notifies an operator of the position of the transmitter relative to the reference point calculated by the position calculator.
The position detection device for a crane according to any one of claims 1 to 5 . A position detection device for a crane that is equipped on a crane having a boom and receives radio waves emitted from a transmitter attached to a person or an object to detect the position of the transmitter,
a plurality of first antenna elements provided on a right side surface of the boom and arranged in an extending direction of the boom to receive the radio waves;
a plurality of second antenna elements provided on a left side surface of the boom and arranged in an extending direction of the boom to receive the radio waves;
a position calculator that calculates a position of the transmitter relative to a reference point from reception intensities of the radio waves received by each of the plurality of first antenna elements and the plurality of second antenna elements and respective positions of the plurality of first antenna elements and the plurality of second antenna elements relative to a reference point of the crane;
a first receiver having the plurality of first antenna elements;
a second receiver having the plurality of second antenna elements;
Equipped with
The radio waves carry an identification signal for identifying the person or object to which the transmitter is attached,
the first receiver receives the radio waves via the plurality of first antenna elements, thereby receiving the identification signal carried on the radio waves;
the second receiver receives the radio waves by the plurality of second antenna elements, thereby receiving the identification signal carried on the radio waves;
the position calculator identifies the person or the object to which the transmitter is attached based on the identification signal received by the first receiver or the second receiver.
Position detection device for cranes . the reference point is a tip of a boom head provided on the boom,
the position calculator calculates the position of the transmitter relative to the tip of the boom head;
A position detection device for a crane according to any one of claims 1 to 7 .