Cargo receiving facility

A cargo receiving facility includes a net and a transport mechanism. The net is suspended among supports. The net is configured to receive a cargo dropped from an unmanned aircraft in flight. The transport mechanism is configured to transport the cargo received by the net. The net has an elasticity corresponding to a mass of the cargo. The net has openings each having a size corresponding to a pressure of down-wash from the unmanned aircraft.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority from Japanese Patent Application No. 2021-159453 filed on Sep. 29, 2021, the entire contents of which are hereby incorporated by reference.

BACKGROUND

The disclosure relates to a cargo receiving facility.

A technology for delivering a cargo on an unmanned aircraft capable of taking off and landing vertically has been developed. The unmanned aircraft used to transport the cargo is caused to fly from a place of departure to a cargo delivery port along a flight route prepared in advance.

Japanese Patent No. 6778847 discloses a technology for delivering a cargo to a delivery port provided on a facility such as an apartment house or an office building on an unmanned aircraft. The unmanned aircraft lands on the delivery port to deliver the cargo or drops the cargo from above.

SUMMARY

An aspect of the disclosure provides a cargo receiving facility. The cargo receiving facility includes a net and a transport mechanism. The net is suspended among supports. The net is configured to receive a cargo dropped from an unmanned aircraft in flight. The transport mechanism is configured to transport the cargo received by the net. The net has an elasticity corresponding to a mass of the cargo. The net has openings each having a size corresponding to a pressure of down-wash from the unmanned aircraft.

DETAILED DESCRIPTION

When the unmanned aircraft lands on the delivery port to deliver the cargo as described in Japanese Patent No. 6778847, the unmanned aircraft consumes energy for landing and taking off. In addition, the efficiency of reception of the cargo is reduced because it takes time for the unmanned aircraft to land and take off.

When the cargo is dropped from the unmanned aircraft and received by the delivery port as described in Japanese Patent No. 6778847, there is a risk that the cargo will be damaged due to impact. In addition, an unmanned aircraft capable of taking off and landing vertically generally includes rotors. The unmanned aircraft may be configured to take off and land vertically. Upon hovering of the unmanned aircraft, the rotors generate an airflow below the unmanned aircraft (hereinafter the airflow is referred to as down-wash). Therefore, when the cargo dropped from the unmanned aircraft is received by the delivery port as described in Japanese Patent No. 6778847, it may be difficult to appropriately receive the cargo due to the influence of down-wash.

It is desirable to provide a cargo receiving facility capable of efficiently and appropriately receiving a cargo from an unmanned aircraft capable of taking off and landing vertically.

1. Overall Configuration of Cargo Transport System

The overall configuration of a cargo transport system100according to a first embodiment of the disclosure will be described with reference toFIG.1.FIG.1is a schematic perspective view of the cargo transport system100according to the first embodiment of the disclosure.

As illustrated inFIG.1, the cargo transport system100includes an unmanned aircraft200, a departure site (not illustrated) from which a cargo400is delivered by the unmanned aircraft200, and a cargo receiving facility300to which the cargo400is delivered. The unmanned aircraft200has an overall length of, for example, 3 m to 5 m. The cargo400is placed on the unmanned aircraft200at the departure site (not illustrated). The cargo400may be suspended from the unmanned aircraft200, removably attached to the bottom of the unmanned aircraft200, or placed in the unmanned aircraft200. The unmanned aircraft200carries the cargo400from the departure site to the cargo receiving facility300along a flight route.

In the example illustrated inFIG.1, the unmanned aircraft200includes four rotors210and a holding mechanism220. The four rotors210rotate to generate lift and thrust for the unmanned aircraft200. The unmanned aircraft200according to the present embodiment is a vertical take-off and landing (VTOL) aircraft capable of taking off and landing vertically. The unmanned aircraft200may instead be a so-called drone.

The holding mechanism220is provided on the bottom of the unmanned aircraft200. The cargo400is removably held by the holding mechanism220. The cargo400is attached to the holding mechanism220at the departure site (not illustrated) of the unmanned aircraft200. The holding mechanism220holds the cargo400while the unmanned aircraft200travels from the departure site to the cargo receiving facility300. The unmanned aircraft200hovers above the cargo receiving facility300after reaching the cargo receiving facility300. Then, the holding mechanism220drops the cargo400toward the cargo receiving facility300.

2. Configuration of Cargo Receiving Facility

The cargo receiving facility300receives the cargo400transported by the unmanned aircraft200. According to the present embodiment, the cargo receiving facility300is installed on, for example, the roof of a building to which the cargo400is delivered. Examples of the building include commercial facilities, such as a distribution center, a supermarket, and a department store; industrial facilities, such as a factory and a warehouse; and public facilities, such as a school and an office facility.

The cargo receiving facility300includes a plurality of supports, a net310, and a transport mechanism320. The supports are columns supporting the net310. For example, according to the present embodiment, the supports include a first slide rail322a, a second slide rail322b, a third slide rail322c, and a fourth slide rail322d(hereinafter sometimes collectively referred to as slide rails322) illustrated inFIG.1. The net310is suspended between the supports and disposed to spread substantially horizontally. The transport mechanism320transports the cargo400received by the net310.

The net310is obtained by combining flexible linear members, such as strings and fibers, into the form of a mesh. The net310is made of, for example, an elastic material. The net310is strong enough to receive the cargo400dropped from the unmanned aircraft200. The net310has an elasticity and a strength that corresponds to the mass of the cargo400.

FIG.2is an enlarged partial view of the net310according to the first embodiment of the disclosure.FIG.2is an enlarged view of a part II of the net310circled by the dashed line inFIG.1. As illustrated inFIG.2, the net310includes linear members310aand openings310b. The linear members310aare composed of highly flexible strings or steel wires. The net310has a grid-shaped structure in which the linear members310aare tied in the form of a grid.

In the present embodiment, the linear members310amay be made of an elastic material, such as rubber. However, the linear members310aare not limited to this, and may instead be woven into the net310in such a way that the net310has an elasticity.

The linear members310ahave a spring constant corresponding to the mass of the cargo400and the drop height. For example, the spring constant of the linear members310ais in the range of 10 N/m to 300 N/m. In one example, when the mass of the cargo400is 30 kg and the drop height is 4 m, the spring constant of the linear members310ais 73.5 N/m. When the mass of the cargo400is 40 kg and the drop height is 6 m, the spring constant of the linear members310ais 147 N/m. Thus, the ratio of expansion and contraction of the linear members310aincreases as the mass of the cargo400increases and as the drop height increases. The spring constant and the strength of the linear members310aare adjusted in accordance with the expected type and mass of the cargo400.

The net310has the openings310bsurrounded by the linear members310a. The openings310bhave a size corresponding to a wind load caused by the down-wash from the unmanned aircraft200, that is, the mass of the unmanned aircraft200, and the mass of the cargo400. The openings310bare large enough to allow the down-wash from the unmanned aircraft200to pass therethrough. Each of the openings310bhas, for example, a square shape with a side length of 5 to 10 cm. The shape of the openings310bis not limited to this, and may instead be, for example, rectangular, circular, elliptical, rhomboidal, or polygonal.

For example, when the mass of the unmanned aircraft200is 300 kg and the mass of the cargo400is 30 kg, the ratio of the projection area of the openings310bin the projection area of the net310is 10%. When the mass of the unmanned aircraft200is 300 kg and the mass of the cargo400is 15 kg, the ratio of the projection area of the openings310bin the projection area of the net310is 5%. Thus, as the ratio of the mass of the unmanned aircraft200to the mass of the cargo400increases, the ratio of the projection area of the openings310bin the projection area of the net310is increased. The size of the openings310bis adjusted in accordance with the expected type of the unmanned aircraft200and the intensity of the down-wash. Thus, the elasticity of the linear members310aand the size of the openings310bare appropriately set in accordance with the cargo400. Accordingly, the influence of the down-wash can be reduced, and the impact of the dropped cargo400is absorbed so that the cargo400can be appropriately received.

Referring again toFIG.1, the transport mechanism320includes the slide rails (supports)322provided with dampers, a first wire324a, and a second wire324b.

The slide rails322provided with the dampers include the first slide rail322a, the second slide rail322b, the third slide rail322c, and the fourth slide rail322d(hereinafter sometimes collectively referred to as the slide rails322). Each slide rail322is installed to extend upward from the roof surface of the building by using a holding member. The slide rails322support the net310at a position spaced above the roof surface of the building. The net310is suspended between the slide rails322and spreads substantially horizontally. The tension of the net310may be adjusted so that the net310appropriately receives the cargo400while absorbing the impact of the dropped cargo400.

The slide rails322a,322b,322c, and322dhave grooves326that extend in a longitudinal direction. Sliders328are attached to the grooves326so that the sliders328are movable back and forth along the grooves326.

The grooves326are provided with coil springs (not illustrated) and dampers (not illustrated). The coil springs press the sliders328toward the top ends of the slide rails322a,322b,322c, and322d. The dampers are composed of, for example, cylinders in which oil and air are enclosed, and reduce vibrations of the coil springs. The dampers also function as impact absorbers that absorb an impact of the cargo400that is received. The grooves326are also provided with ratchet mechanisms that restrain the sliders328from returning upward until the ratchet mechanisms are released.

One end of the first wire324ais coupled to the slider328on the first slide rail322a, and the other end of the first wire324ais coupled to the slider328on the second slide rail322b. As a result, the first wire324aextends between the first slide rail322aand the second slide rail322b.

One end of the second wire324bis coupled to the slider328on the third slide rail322c, and the other end of the second wire324bis coupled to the slider328on the fourth slide rail322d. As a result, the second wire324bextends between the third slide rail322cand the fourth slide rail322d.

The net310is attached between the first wire324and the second wires324b. The first and second slide rails322aand322bare spaced from each other in the direction in which the first wire324aextends. The third and fourth slide rails322cand322dare spaced from each other in the direction in which the second wire324bextends. The first and second slide rails322aand322brespectively face the third and fourth slide rails322cand322dwith the net310disposed therebetween.

The interval between the bottom ends of the first and second slide rails322aand322bis less than the interval between the top ends of the first and second slide rails322aand322b. The interval between the first and second slide rails322aand322bgradually decreases from top to bottom.

The interval between the bottom ends of the third and fourth slide rails322cand322dis less than the interval between the top ends of the third and fourth slide rails322cand322d. The interval between the third and fourth slide rails322cand322dgradually decreases from top to bottom.

The bottom ends of the third and fourth slide rails322cand322dare positioned higher than the bottom ends of the first and second slide rails322aand322b. The height of the bottom ends of the third and fourth slide rails322cand322ddiffers from the height of the bottom ends of the first and second slide rails322aand322b.

Thus, the four slide rails322according to the present embodiment serve as a height-difference generating mechanism that generates a height difference between parts of the net310. To generate a height difference between parts of the net310means to place the net310at an angle with respect to a horizontal plane in a certain direction (for example, in a direction toward a take-out position312described below).

FIG.3is a schematic perspective view of the cargo receiving facility300according to the first embodiment of the disclosure. As illustrated inFIG.3, an external transport mechanism350includes a conveyor line352and sorting mechanisms354. The conveyor line352is composed of, for example, a roller conveyor, and transports cargoes400disposed on rollers by rotating the rollers with a motor (not illustrated). The conveyor line352is divided into a plurality of sorting lines356. The number of sorting lines356is three in the present embodiment, but is not limited to this. The number of sorting lines356may instead be two or four or more.

Each sorting mechanism354includes, for example, a triangular sorting member that is rotatable in directions a and b by a motor (not illustrated). The sorting mechanisms354come into contact with the cargoes400on the conveyor line352to thereby change the conveying directions of the cargoes400. Referring toFIG.3, the sorting mechanisms354each rotate in direction a or b to sort the cargoes400conveyed along the conveyor line352between the sorting lines356. In the present embodiment, the cargoes400on the conveyor line352can be sorted between three lines and stored on the respective lines.

In the present embodiment, the external transport mechanism350transports the cargoes400received by the net310to a position separated from the unmanned aircraft200by a predetermined distance or more. As described in detail below, the cargo400on the net310is guided to the external transport mechanism350through the take-out position312. The cargo400guided to the external transport mechanism350moves along the conveyor line352, is fed to one of the three sorting lines356by the sorting mechanisms354, and is stored on that sorting line356.

The external transport mechanism350transports the cargoes400received by the net310to the position separated from the unmanned aircraft200by the predetermined distance or more. Therefore, a worker can safely unpack the cargoes400without being affected by the down-wash from the unmanned aircraft200or being hit by another cargo400that has been dropped. The sorting mechanisms354may sort the cargoes400in accordance with, for example, the type, size, mass, or shape of the cargoes40. Therefore, workload of a worker that sorts the cargoes400received by the net310can be reduced.

3. Operation of Cargo Receiving Facility

The operation of the cargo receiving facility300according to present embodiment will now be described with reference toFIGS.1to3.

First, as illustrated inFIG.1, the unmanned aircraft200carries the cargo400to the cargo receiving facility300and hovers above the cargo receiving facility300.

Next, the holding mechanism220of the unmanned aircraft200drops the cargo400toward the cargo receiving facility300. Accordingly, as illustrated inFIG.3, the cargo400dropped from the holding mechanism220of the unmanned aircraft200falls onto the net310.

When the cargo400falls onto the net310, load is transmitted to the coil springs and the dampers through the first wire324a, the second wire324b, and the sliders328, so that the coil springs and the dampers contract. When the coil springs and the dampers contract, the sliders328move from the top ends toward the bottom ends of the slide rails322a,322b,322c, and322d.

As described above, the interval between the first and second slide rails322aand322bdecreases toward the bottom. Similarly, the interval between the third and fourth slide rails322cand322dalso decreases toward the bottom.

Therefore, when the sliders328move downward along the slide rails322upon reception of the cargo400as illustrated inFIG.3, the first and second wires324aand324bsag downward. Accordingly, the net310also sags downward. As the first and second wires324aand324bsag downward, the amount of sag of the net310increases. As the amount of sag of the net310increases, the cargo400is guided toward the center of the net310due to its own weight. As described above, the net310is elastic, and the sliders328move downward along the slide rails322while the dampers exert an impact absorbing function. Therefore, the net310is capable of reliably receiving the cargo400that has been dropped.

After that, the cargo400received by the net310automatically moves to the take-out position312at one end of the net310due to the height-difference generating mechanism. In one example, the bottom ends of the third and fourth slide rails322cand322dare positioned higher than the bottom ends of the first and second slide rails322aand322b. As illustrated inFIG.3, when the net310reaches the bottom ends and sags, an end of the net310at a side adjacent to the third and fourth slide rails322cand322dis positioned higher than an end of the net310at a side adjacent to the first and second slide rails322aand322b. As a result, the sagging net310is inclined downward in a direction from the third and fourth slide rails322cand322dtoward the first and second slide rails322aand322b.

Accordingly, the cargo400on the net310may be caused to slide in the direction from the third and fourth slide rails322cand322dtoward the first and second slide rails322aand322b. In other words, the cargo400on the net310may be caused to slide toward the take-out position312. As a result, the cargo400is guided along the net310to the take-out position312at one end of the net310.

The external transport mechanism350is disposed adjacent to the take-out position312on the net310. The cargo400that has moved to the take-out position312is guided to the external transport mechanism350.

After the cargo400is moved from the net310to the external transport mechanism350, the ratchet mechanisms on the grooves326are released. Accordingly, load applied to the coil springs on the slide rails322is eliminated, and the coil springs expand. When the coil springs expand, the sliders328move from the bottom ends of the slide rails322toward the top ends.

According to the present embodiment, the cargo receiving facility300is capable of appropriately receiving the cargo400dropped form the unmanned aircraft200in flight. Therefore, the building provided with the cargo receiving facility300may include no take-off and landing area for the unmanned aircraft200. Since the unmanned aircraft200may not land on or take off from the cargo receiving facility300on the building, energy consumed when the unmanned aircraft200lands and takes off may be reduced.

Since the unmanned aircraft200takes no time to land and take off, multiple cargoes400can be successively received by a single cargo receiving facility300. Accordingly, the time efficiency of the process of receiving the cargoes400can be increased. In addition, each cargo400can be received without human intervention, and therefore the number of workers can be reduced.

The cargo receiving facility300includes the net310that is suspended between the supports (for example, the slide rails322a,322b,322c, and322d). The net310has an elasticity that corresponds to the mass of the cargo400. Therefore, the impact of the cargo400dropped onto the net310can be reduced.

The net310has the openings having a size corresponding to the pressure of the down-wash from the unmanned aircraft200. Accordingly, when the cargo400is dropped onto the net310and down-wash is generated by the rotors210of the unmanned aircraft200, irregular and unsteady movement of the cargo400on the net310due to the down-wash can be suppressed. As a result, the cargo receiving facility300is capable of appropriately receiving the cargo400dropped from the unmanned aircraft200.

The slide rails322a,322b,322c, and322dare provided with the sliders328coupled to the ends of the net310. The sliders328move along the slide rails322a,322b,322c, and322dto reduce the impact of the cargo400dropped onto the net310from the unmanned aircraft200.

The slide rails322a,322b,322c, and322dare also provided with the dampers that absorb an impact of the sliders328that move downward along the slide rails322a,322b,322c, and322d. Accordingly, the impact of the sliders328that move downward along the slide rails322a,322b,322c, and322dcan be reduced.

According to the present embodiment, the cargo receiving facility300may simply have a space for receiving a single cargo400on the roof of the building and a space for storing the received cargo400. Thus, the infrastructure cost of the building can be reduced.

The bottom ends of the third and fourth slide rails322cand322dare positioned higher than the bottom ends of the first and second slide rails322aand322b. Accordingly, when the cargo400is dropped onto the net310, a bottom end of the net310at a side adjacent to the third and fourth slide rails322cand322dis positioned higher than the bottom end of the net310at a side adjacent to the first and second slide rails322aand322b.

Thus, according to the present embodiment, the first slide rail322a, the second slide rail322b, the third slide rail322c, and the fourth slide rail322dfunction as a height-difference generating mechanism that generates a height difference between parts of the net310. Since a height difference is generated between parts of the net310, the cargo400received by the net310can be automatically slid to the take-out position312, and be moved from the take-out position312to the external transport mechanism350. Thus, the cargo400received by the net310may be moved to the external transport mechanism350without using any driving device.

The external transport mechanism350transports the cargo400received by the net310to a position outside the net310and separated from the unmanned aircraft200. Therefore, the cargo400can be opened and closed at a position separated from the unmanned aircraft200. As a result, the cargo400can be easily unpacked by an ordinary worker other than a dedicated operator.

When the cargo400is dropped onto the net310, the weight on the unmanned aircraft200is reduced by the weight of the cargo400. Therefore, when the unmanned aircraft200returns to the departure site from the cargo receiving facility300and lands on the departure site, the unmanned aircraft200takes a uniform landing position and can be easily controlled.

5. Second Embodiment

A cargo receiving facility according to a second embodiment of the disclosure will now be described with reference toFIG.4.FIG.4is a schematic perspective view of a cargo receiving facility500according to the second embodiment of the disclosure.

Components of the cargo receiving facility500according to the second embodiment that are substantially the same as those of the cargo receiving facility300according to the first embodiment will be denoted by the same reference signs, and description thereof will be omitted.

As illustrated inFIG.4, the cargo receiving facility500according to the second embodiment includes a plurality of supports (a first column510a, a second column510b, a third column510c, and a fourth column510d), a net310, and a transport mechanism520.

The supports are columns that support the net310. The supports according to the present embodiment include the first column510a, the second column510b, the third column510c, and the fourth column510d(hereinafter sometimes collectively referred to as columns510). The columns510have the same height. The four columns510support the net310at a position spaced above the roof surface of the building.

The transport mechanism520includes a height-difference generating mechanism530and an external transport mechanism350. The height-difference generating mechanism530applies a downward tension to the net310at a take-out position312at one end of the net310to generate a height difference between parts of the net310.

According to the height-difference generating mechanism530, an end of the net310at a side adjacent to the third and fourth columns510cand510dis positioned higher than an end of the net310adjacent to the first and second columns510aand510bat the take-out position312. According to the height-difference generating mechanism530, at least a part of the net310is inclined downward toward the take-out position312. Accordingly, the cargo400on the net310can be automatically slid toward the take-out position312in a direction from the third and fourth columns510cand510dtoward the first and second columns510aand510b.

As described above, according to the second embodiment, the cargo receiving facility500includes the columns510a,510b,510c, and510das the supports for supporting the net310in place of the slide rails322provided with dampers according to the first embodiment. Accordingly, the structure of the supports is simpler than that in the cargo receiving facility300according to the first embodiment. In addition, the above-described operation and effects of the first embodiment can be provided.

Although embodiments of the disclosure have been described with reference to the accompanying drawings, the disclosure is, of course, not limited to the above-described embodiments. It is obvious that various alterations and modifications are conceivable by those skilled in the art within the scope defined by the claims, and such alterations and modifications are to be understood as being included in the technical scope of the disclosure.

In the above-described embodiments, the cargo receiving facilities300and500each include the height-difference generating mechanism530that applies a height difference between parts of the net310. However, the height-difference generating mechanism530may be omitted. Thus, the cargo receiving facility may include no height-difference generating mechanism.

In the above-described embodiments, the cargo receiving facilities300and500each include the external transport mechanism350that transports the cargo400to the outside of the net310. However, the external transport mechanism350may be omitted. Thus, the cargo receiving facility may include no external transport mechanism350.

The disclosure provides a cargo receiving facility capable of efficiently and appropriately receiving a cargo from an unmanned aircraft capable of taking off and landing vertically.