Patent Description:
Conventionally, a crane composed of a vehicle and a crane apparatus is known. The vehicle is equipped with a plurality of wheels and outriggers, and can move to an unspecified place, thereby expanding a workable range at the destination. In addition to a boom, the crane apparatus is composed of wire ropes, hooks, and so on, so that a load can be moved.

A technique for displaying a movable range of a distal end of a boom on a display apparatus in such a crane has been known (see Patent Literature (hereinafter referred to as "PLT") <NUM>). According to this, since the operator can grasp the movable range of the distal end of the boom by looking at the display apparatus, he/she can easily perform manipulations such as luffing-up/down, extension/retraction, and swivel of the boom. <CIT>, <CIT> and <CIT> disclose a crane, respectively. In particular, the crane disclosed in <CIT> includes a vehicle, a boom, a wire rope, a hook, a camera, a control apparatus, and a display apparatus according to the preamble of claim <NUM>, respectively of claim <NUM>. The control apparatus disclosed in <CIT> calculates a performance line of the crane. Then, the display apparatus disclosed in <CIT> displays an image in which an image indicating the performance line is superimposed on the image taken by the camera.

However, although the movable range described in PTL <NUM> shows the boundary in a direction in which the distal end of the boom is away from the vehicle, the movable range does not show the boundary in a direction in which the distal end of the boom approaches the vehicle. In other words, the direction in which the distal end of the boom approaches the vehicle all falls within the movable range. Accordingly, the operator can refer to the displayed movable range when moving the load suspended on the hook in a direction away from the vehicle, but cannot refer to the displayed movable range when moving the load suspended on the hook in a direction approaching the vehicle.

It is an object of the present invention to provide a crane capable of easily performing manipulations such as luffing-up/down, extension/retraction and swivel of the boom by displaying a non-movable or movable range in a direction in which a hook approaches a vehicle. It is another object of the present invention to provide an information display method capable of easily performing manipulations such as luffing-up/down, extension/retraction and swivel of a boom by displaying a non-movable or movable range in a direction in which a hook approaches a vehicle.

According to a first aspect, the present invention provides a crane according to independent claim <NUM>. According to a second aspect, the present invention provides a crane according to independent claim <NUM>. According to a third aspect, the present invention provides a method according to independent claim <NUM>. Further aspects of the present invention are set forth in the dependent claims, the drawings and the following description.

A crane according to an aspect of the present invention comprises: a vehicle; a boom disposed on the vehicle; a wire rope spanning from a base end side to a distal end side of the boom; a hook hanging from the distal end side of the boom and ascending and descending by feeding in and feeding out the wire rope; a camera that takes an image including the hook a display apparatus for displaying the image; and a control apparatus connected to the camera and the display apparatus and configured to process information, wherein the control apparatus calculates an inner boundary based on a length of the boom or a height of the hook, the inner boundary being a boundary between a movable range and a non-movable range in a direction in which the hook approaches the vehicle, and the display apparatus preferably displays an image in which an image indicating the inner boundary is superimposed on the image taken by the camera.

In the crane of the present invention, the movable range is a range in which the boom is movable after being luffed up with the length of the boom maintained.

In the crane of the present invention, the movable range is a range in which the boom is movable after being luffed up and/or swiveled with the height of the hook maintained.

In the crane of the present invention, when the vehicle is positioned outside the image taken by the camera, the display apparatus may display an image in which an image indicating a direction in which the vehicle is positioned is superimposed on the image taken by the camera.

In the crane of the present invention, the control apparatus may calculate a swivel boundary which is a boundary between a swivelable range and a non-swivelable range of the boom, and the display apparatus may display an image in which an image indicating the swivel boundary is superimposed on the image taken by the camera.

The information display method of the present invention is an information display method in a crane, the crane comprising: a vehicle; a boom disposed on the vehicle; a wire rope spanning from a base end side to a distal end side of the boom; a hook hanging from the distal end side of the boom and ascending and descending by feeding in and feeding out the wire rope; a camera that takes an image including the hook; a display apparatus that displays the image; and a control apparatus connected to the camera and configured to process information, the method comprising: calculating by the control apparatus an inner boundary based on a length of the boom or a height of the hook, the inner boundary being a boundary between a movable range and a non-movable range in a direction in which the hook approaches the vehicle; and displaying by the display apparatus, an image in which an image indicating the inner boundary is superimposed on the image taken by the camera.

According to the crane and the information display method of the present invention, by displaying an image in which an image indicating the inner boundary is superimposed on an image taken by the camera on the display apparatus, the operator can visually grasp the movable range in a direction in which the hook approaches the vehicle by viewing the display apparatus, so that it is possible to easily perform manipulations such as luffing-up/down, extension/retraction, and swivel of the boom.

Crane <NUM> will be described with reference to <FIG>.

Crane <NUM> is mainly composed of vehicle <NUM> and crane apparatus <NUM>.

Vehicle <NUM> includes a left-right pair of wheels <NUM> and a left-right pair of rear wheels <NUM>. In addition, vehicle <NUM> is provided with outrigger <NUM> which is grounded for stabilization when carrying out the transporting work of load W. Further, vehicle <NUM> is provided with an engine, a transmission, or the like for driving them.

Crane apparatus <NUM> is provided with boom <NUM> such that boom <NUM> protrudes forward from the rear portion. Therefore, boom <NUM> is swivelable by an actuator (see arrow A). Further, boom <NUM> is extendable and retractable by an actuator (see arrow B). Furthermore, boom <NUM> is capable of being luffed up and down by an actuator (see arrow C). In addition, wire rope <NUM> is stretched over boom <NUM>. On the base end side of boom <NUM>, winch <NUM> wrapped around wire rope <NUM> is disposed, on the distal end side of boom <NUM>, hook <NUM> is suspended by wire rope <NUM>. Winch <NUM> is integrally configured with the actuator to allow winding and unwinding of wire rope <NUM>. Therefore, hook <NUM> is movable up and down by an actuator (see arrow D). Further, crane apparatus <NUM> includes cabin <NUM> on the side of boom <NUM>. Inside cabin <NUM>, as described later, swivel manipulation tool <NUM>, telescopic manipulation tool <NUM>, luffing manipulation tool <NUM>, winding manipulation tool <NUM>, manipulation tool <NUM>, display apparatus <NUM> is provided.

Next, information display system <NUM> will be described with reference to <FIG>.

Information display system <NUM> is mainly composed of control apparatus <NUM>. Various manipulation tools <NUM> to <NUM> are connected to control apparatus <NUM>. Further, various valves <NUM> to <NUM> are connected to control apparatus <NUM>. In addition, various sensors <NUM> to <NUM> are connected to control apparatus <NUM>.

As described above, boom <NUM> is swivelable by an actuator (see arrow A in <FIG>). In the present embodiment, such an actuator is defined as swivel hydraulic motor <NUM> (see <FIG>). Swivel hydraulic motor <NUM> is appropriately operated by swivel valve <NUM>, which is an electromagnetic proportional switching valve. In other words, swivel hydraulic motor <NUM> is appropriately operated by swivel valve <NUM> switching the flow direction of the hydraulic oil or adjusting the flow rate of the hydraulic oil. Further, the swivel angle of boom <NUM> (not shown) is detected by swivel sensor <NUM>. Therefore, control apparatus <NUM> can recognize the swivel angle of boom <NUM>.

As described above, boom <NUM> is capable of being extended and retracted by the actuator (see arrow B in <FIG>). In the present embodiment, such an actuator is defined as hydraulic cylinder <NUM> for extension and retraction (see <FIG>). Extension and retraction hydraulic cylinder <NUM> is appropriately operated by extension and retraction valve <NUM>, which is an electromagnetic proportional switching valve. In other words, extension and retraction hydraulic cylinder <NUM> is appropriately operated by extension and retraction valve <NUM> switching the flow direction of the hydraulic oil or adjusting the flow rate of the hydraulic oil. Extension/retraction length E of boom <NUM> (see <FIG>) is detected by extension and retraction sensor <NUM>. Therefore, control apparatus <NUM> can recognize extension/retraction length E of boom <NUM>.

Further, as described above, boom <NUM> is capable of being luffed up/down by an actuator (see arrow C in <FIG>). In the present embodiment, such an actuator is defined as luffing hydraulic cylinder <NUM> (see <FIG>). Luffing hydraulic cylinder <NUM> is appropriately operated by luffing valve <NUM>, which is an electromagnetic proportional switching valve. In other words, luffing hydraulic cylinder <NUM> is appropriately operated by luffing valve <NUM> switching the flow direction of the hydraulic oil or adjusting the flow rate of the hydraulic oil. Further, luffing angle F of boom <NUM> (see <FIG>) is detected by luffing sensor <NUM>. Therefore, control apparatus <NUM> can recognize luffing angle F of boom <NUM>.

In addition, as described above, hook <NUM> is movable up and down by an actuator (see arrow D in <FIG>). In the present embodiment, such an actuator is defined as winding hydraulic motor <NUM> (see <FIG>). Winding hydraulic motor <NUM> is appropriately operated by winding valve <NUM>, which is an electromagnetic proportional switching valve. That is, winding hydraulic motor <NUM>, is appropriately operated by winding valve <NUM> switching the flow direction of the hydraulic oil or adjusting the flow rate of hydraulic oil. Hanging length L of hook <NUM> (see <FIG>) is detected by winding sensor <NUM>. Therefore, control apparatus <NUM> can recognize hanging length L of hook <NUM>.

In addition, manipulation tool <NUM>, camera <NUM>, and display apparatus <NUM> are connected to control apparatus <NUM>.

Manipulation tool <NUM> selectively switches the display mode of display apparatus <NUM>, or switches the photographing magnification and the photographing direction of camera <NUM>. The display mode includes a display of an image taken by camera <NUM>, a display of an image indicating the boundary between the movable range and the non-movable range of hook <NUM> superimposed on the image, a display of an image indicating the boundary between the swivelable range and the non-swivelable range of boom <NUM> superimposed on the image or the like.

Camera <NUM> is for taking an image. Camera <NUM> is attached to a distal end portion of boom <NUM>. Control apparatus <NUM> may be controlled so that camera <NUM> takes an image that includes hook <NUM>. Camera <NUM> is capable of taking images in nearly real time.

As described above, display apparatus <NUM> displays an image taken by camera <NUM>, an image of superimposing an image representing the boundary between the movable range and the non-movable range of hook <NUM> on the image, an image of superimposing an image representing the boundary between the swivelable range and the non-swivelable range of boom <NUM> on the image, and the like.

Next, a display mode of display apparatus <NUM> will be described with reference to <FIG>. Here, as shown in <FIG>, a state in which hook <NUM> is in a state in which load W is suspended, and a state in which the height from the ground to the bottom surface of load W is lower than the height of vehicle <NUM> will be described.

The inner boundary, which is the boundary between the movable range and the non-movable range of load W in the direction in which hook <NUM> approaches vehicle <NUM>, and the swivel boundary, which is the boundary between the swivelable range and the non-swivelable range of boom <NUM> are displayed after inner boundary calculation step K101, swivel boundary calculation step K102, and display step K103.

In inner boundary calculation step K101, control apparatus <NUM> computes the first inner boundary that is the boundary between the movable range and the non-movable range of load W in the direction in which hook <NUM> approaches vehicle <NUM> based on the length of boom <NUM>. Specifically, control apparatus <NUM> recognizes the current length of boom <NUM> and calculates the inner boundary (first inner boundary) of the range in which hook <NUM> is movable when boom <NUM> is luffed up with its length maintained. Since the maximum value of luffing angle F is determined by the specification of crane <NUM>, the first inner boundary is determined by determining the length of boom <NUM>.

Further, in inner boundary calculation step K101, control apparatus <NUM> computes the second inner boundary that is the boundary between the movable range and the non-movable range of load W in the direction in which hook <NUM> approaches vehicle <NUM> based on the height of hook <NUM>. Specifically, control apparatus <NUM> recognizes the height from the ground to the bottom surface of load W, and calculates an inner boundary (second inner boundary) within a range in which when boom <NUM> is luffed up and/or swiveled with the height of hook <NUM> maintained can be moved without load W `s collision with vehicle <NUM>.

Since the height of vehicle <NUM> is determined by the specification of crane <NUM>, by determining the height from the ground to the bottom surface of load W, it can be determined whether or not load W collides with vehicle <NUM> when hook <NUM> is moved in a direction approaching vehicle <NUM> with the current height of hook <NUM> maintained. As a result, the second inner boundary along the outer periphery of vehicle <NUM> is determined in the case of collision. On the other hand, the second inner boundary is not calculated in the case of no collision.

The height from the ground to the bottom surface of load W can be calculated, for example, by obtaining the length from hook <NUM> to the bottom surface of load W in advance. Specifically, from the detection result of winding sensor <NUM> at the time of lifting offload W, the time when wire rope <NUM> is in a tension state is recognized. Then, the value obtained by subtracting hanging length L of hook <NUM> from the height of the distal end of boom <NUM> at that time becomes the length from hook <NUM> to the bottom surface of load W. Therefore, subsequently in order to determine the height from the ground to the bottom surface of load W in a state in which load W is lifted, a value obtained by adding the length from hook <NUM> obtained in advance to hanging length L of hook <NUM> to the bottom surface of load W may be subtracted from the height of the distal end of boom <NUM>.

In swivel boundary calculation step K102, control apparatus <NUM> calculates a swivel boundary which is a boundary between the swivel range and the non-swivel range of boom <NUM>. The swivelable range of boom <NUM> is a range in which crane <NUM> can be swiveled without falling down, and the swivel boundary is calculated based on the length of boom <NUM>, luffing angle F of boom <NUM>, and the load detected by winding sensor <NUM>.

In display step K103, display apparatus <NUM> displays the image, which an image showing the inner boundaries (the first inner boundary and the second inner boundary) and an image showing the swivelable boundary superimposed to the image taken by camera <NUM> (see <FIG>). Specifically, control apparatus <NUM> superimposes image <NUM> indicating the first inner boundary, image <NUM> indicating the second inner boundary, and image <NUM> indicating the swivel boundary on image <NUM> taken by camera <NUM> to generate output image <NUM>. Then, control apparatus <NUM> outputs output image <NUM> to display apparatus <NUM>, display apparatus <NUM> displays output image <NUM>.

In <FIG>, image <NUM> showing the first inner boundary, image <NUM> showing the second inner boundary, and an image <NUM> showing the swivel boundary display the boundary lines. Therefore, the range from the position of load W displayed on output image <NUM> to each boundary line is a range in which load W can move. Instead of the boundary lines, a movable range or a non-movable range may be displayed in a color different from the surrounding. For example, the movable range may be displayed in color, and the non-movable range may be displayed in black and white.

In addition to the calculation result of swivel boundary calculation step K102, the swivel boundary may be arbitrarily inputted by the operator. It may be contemplated that the operator enters for example, the swivel range of a building wall or a nearby crane as a swivel boundary. In this case, the swivel boundary input by the operator is similarly superimposed on output image <NUM>.

Thus, by displaying output image <NUM> in which images <NUM>, <NUM> indicating the inner boundary and image <NUM> indicating the swivel boundary are superimposed on image <NUM> taken by camera <NUM> to display apparatus <NUM>, the operator by viewing display apparatus <NUM> can visually grasp the movable range of the direction and the swivel direction in which load W approaches vehicle <NUM>, can perform manipulations such as luffing-up/down, extension/retraction, and swivel of the boom.

Furthermore, between inner boundary calculation step K101 and swivel boundary calculation step K102, an outer boundary calculation step may be added, and in display step K103, display apparatus <NUM> may display an image in which an image indicating the outer boundary superimposed on the image taken by camera <NUM> (see <FIG>). Specifically, control apparatus <NUM> recognizes the current length of boom <NUM> and the load detected by winding sensor <NUM>, and calculates the outer boundary of the range in which hook <NUM> is movable when boom <NUM> is luffed down with its length maintained. The range in which hook <NUM> can be moved is a range in which crane <NUM> can be luffed down without collapsing, and the outer boundary is calculated based on the current length of boom <NUM> and the load detected by winding sensor <NUM>.

Subsequently, control apparatus <NUM> superimposes image <NUM> indicating the first inner boundary, image <NUM> indicating the second inner boundary, image <NUM> indicating the swivel boundary, and image <NUM> indicating the outer boundary on image <NUM> taken by camera <NUM> to generate output image <NUM>. Then, control apparatus <NUM> outputs output image <NUM> to display apparatus <NUM>, and display apparatus <NUM> displays output image <NUM>.

Thus, by displaying output image <NUM> in which image <NUM> indicating the outer boundary superimposed on image <NUM> taken by camera <NUM> on display apparatus <NUM>, since the operator can visually grasp the movable range in the direction in which load W is away from vehicle <NUM> by viewing display apparatus <NUM>, he/she can easily perform manipulations such as luffing up/down, extension/retraction, and swivel of the boom.

Furthermore, when vehicle <NUM> is positioned outside the image taken by camera <NUM>, display apparatus <NUM> may display the image, in which the image indicating the direction in which vehicle <NUM> is positioned superimposed on the image taken by camera <NUM> (see <FIG>). Specifically, control apparatus <NUM> recognizes the position of vehicle <NUM> outside the image taken by camera <NUM>, and superimposes an arrow image <NUM> indicating the direction in which vehicle <NUM> is positioned and images <NUM> and <NUM> indicating each boundary to image <NUM> taken by camera <NUM> to generate output image <NUM>. Then, control apparatus <NUM> outputs output image <NUM> to display apparatus <NUM>, and display apparatus <NUM> displays output image <NUM>.

Thus, when the vehicle is positioned outside the image taken by the camera, by displaying output image <NUM>, in which arrow image <NUM> indicating the direction in which vehicle <NUM> is superimposed on image <NUM> taken by camera <NUM> on display apparatus <NUM>, the operator by viewing display apparatus <NUM> can visually grasp the direction in which vehicle <NUM> is positioned, therefore he/she can easily perform manipulations such as luffing-up/down, extension/retraction, and swivel of the boom.

In the above-described embodiment, the case has been described in which load W is suspended by hook <NUM> as an example, but even when the load is not suspended by hook <NUM>, the boundary between the movable range and the non-movable range of hook <NUM> can be calculated and displayed similarly. In this case, the second inner boundary is the boundary of the range in which hook <NUM> does not interfere with vehicle <NUM>.

Further, image <NUM> showing the first inner boundary, image <NUM> showing the second inner boundary, image <NUM> showing the swivel boundary, image <NUM> showing the outer boundary may be superimposed alone on the image taken by camera <NUM>, or a combination of them may be displayed as appropriate. These display modes may be switched by manipulating tool <NUM>.

Further, crane <NUM> may be provided with a jib for enlarging the lifting range and the working radius of crane apparatus <NUM>. In this case, similarly for the hook of the jib, it is possible to display an image showing the inner boundary, the swivel boundary, the outer boundary.

Output images <NUM>, <NUM>, and <NUM> shown in <FIG> may be displayed three-dimensionally using 3D mappings or the like.

Claim 1:
A crane (<NUM>) comprising:
a vehicle (<NUM>);
a boom (<NUM>) disposed on the vehicle (<NUM>);
a wire rope (<NUM>) spanning from a base end side to a distal end side of the boom (<NUM>);
a hook (<NUM>) hanging from the distal end side of the boom (<NUM>) and ascending and descending by feeding in and feeding out the wire rope (<NUM>); and
a camera (<NUM>) that takes an image including the hook (<NUM>),
a control apparatus (<NUM>) configured to be connected to the camera (<NUM>) and to process information,
a display apparatus (<NUM>) that is connected to the control apparatus (<NUM>),
characterized in that
the control apparatus (<NUM>) calculates, based on a length of the boom (<NUM>) or a height of the hook (<NUM>), an inner boundary (<NUM>, <NUM>), wherein the inner boundary (<NUM>, <NUM>) being between a movable range of the hook (<NUM>) and a non-movable range of the hook (<NUM>) when the hook (<NUM>) moves in the direction approaching the vehicle (<NUM>); and
the display apparatus (<NUM>) displays an image in which an image indicating the inner boundary (<NUM>) is superimposed on the image taken by the camera (<NUM>)
wherein
the inner boundary (<NUM>) is a first inner boundary in which the boom (<NUM>) is movable after being luffed up with the length of the boom (<NUM>) maintained, the first inner boundary is computed based on the length of the boom (<NUM>) by the control apparatus (<NUM>).