High-altitude platform system

Abstract

It provides a high-altitude platform system that can operate at higher latitudes. [Solution] The high-altitude platform system comprises multiple solar planes equipped with a communication platform and having solar cells on at least the upper surface of the aircraft, and having a power storage device for storing the electricity converted by the solar cells. The multiple solar planes fly a circular route that includes a first area where the amount of electricity generated by the solar cells exceeds the amount of electricity consumed by the solar planes during a standard flight period, and a second area where the amount of electricity generated is less than the amount of electricity consumed during a standard flight period, so as to maintain a state in which the amount of electricity stored in the power storage device is greater than zero. During the period when one of the multiple solar planes flies in the first area, the other solar planes fly in the second area.

Description

Technical Field

[0001] The present disclosure relates to a high-altitude platform system.

Background Art

[0002] In recent years, a HAPS (High Altitude Platform Station) is known, which constructs a wireless communication network between the ground by installing a base station of a communication device such as a smartphone on an unmanned aircraft such as a solar plane and flying it in the stratosphere (about 20 km above the ground).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The above-described HAPS is required to perform continuous flight for a long period using solar energy. In the sky over an area with a high latitude, since the sunlight intensity decreases, it is necessary to increase the capacity of solar cells and storage batteries. However, increasing the capacity increases the weight of the aircraft and also increases the power consumption, so it is not always an effective countermeasure. For this reason, the maximum latitude at which the HAPS can be operated is limited. In such a HAPS, a configuration that can be operated at a higher latitude is required.

[0005] The present disclosure has been made in view of the above, and an object thereof is to provide a high-altitude platform system that can be operated at a higher latitude.

Means for Solving the Problems

[0006] The high-altitude platform system according to this disclosure comprises a plurality of solar planes equipped with a communication platform and having solar cells on at least the upper surface of the aircraft and a power storage device for storing the power converted by the solar cells, and a control device for controlling the plurality of solar planes, wherein the plurality of solar planes fly a circular route that includes a first area in a reference flight period where the amount of power generated by the solar cells exceeds the amount of power consumed by the solar planes, and a second area in the reference flight period where the amount of power generated is less than the amount of power consumed, so as to maintain a state in which the amount of power stored in the power storage device is greater than 0, and during the period in which any of the plurality of solar planes flies in the first area, the other solar planes fly in the second area.

[0007] The high-altitude platform system according to this disclosure comprises a communication platform, a solar panel provided on at least the upper surface of the aircraft, a power storage device for storing the electricity converted by the solar panel, a plurality of solar planes that fly along a predetermined orbital path, and a control device for controlling the plurality of solar planes. During the day, the plurality of solar planes fly with their noses down when heading towards the sun and with their noses up when heading away from the sun, thereby charging while flying along the orbital path, and at night or when charging is complete, they fly with their noses facing horizontally. [Effects of the Invention]

[0008] This disclosure provides a high-altitude platform system that can be operated at higher latitudes. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic diagram showing an example of a high-altitude platform system according to an embodiment. [Figure 2] Figure 2 is a schematic diagram illustrating an example of the operation of multiple solar planes in a high-altitude platform system. [Figure 3A] Figure 3A schematically shows the relationship between the amount of electricity generated, the amount of electricity consumed, and the amount of energy stored in the energy storage device of a solar-powered aircraft during the standard flight period for each area. [Figure 3B] Figure 3B schematically shows the relationship between the amount of electricity generated, the amount of electricity consumed, and the amount of energy stored in the energy storage device of a solar-powered aircraft during the standard flight period for each area. [Figure 3C] Figure 3C schematically shows the relationship between the amount of electricity generated, the amount of electricity consumed, and the amount of energy stored in the energy storage device of a solar-powered aircraft during the standard flight period for each area. [Figure 4] Figure 4 shows the case where the decrease in the amount of energy stored in the energy storage device in Area 2 during the reference flight period is equal to the increase in the amount of energy stored in the energy storage device in Area 1. [Figure 5A] Figure 5A schematically illustrates another example of the operation of multiple solar planes in a high-altitude platform system. [Figure 5B] Figure 5B schematically illustrates another example of the operation of multiple solar planes in a high-altitude platform system. [Figure 5C] Figure 5C is a schematic diagram showing how the solar plane orbits the Earth. [Figure 5D] Figure 5D is a schematic diagram showing how the solar plane orbits the Earth. [Figure 6] Figure 6 schematically illustrates another example of the operation of multiple solar planes in a high-altitude platform system. [Figure 7] Figure 7 schematically illustrates another example of the operation of multiple solar planes in a high-altitude platform system. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments of the high-altitude platform system according to this disclosure will be described with reference to the drawings. However, this embodiment does not limit the present invention. Furthermore, the components in the following embodiments include those that are easily substituted or substantially identical to those that are easily substituted by those skilled in the art.

[0011] Figure 1 is a schematic diagram showing an example of a high-altitude platform system 100 according to this embodiment. As shown in Figure 1, the high-altitude platform system 100 comprises a plurality of solar planes 10 and a control device 20.

[0012] The solar plane 10 flies, for example, in the stratosphere. The solar plane 10 has a propulsion device 11 such as a propeller. The solar plane 10 is equipped with a communication platform 12. The communication platform 12 is a base station that can communicate with, for example, an information and communication terminal 30 such as a smartphone on the ground or a control device 20. The solar plane 10 has solar cells 13 on the upper surface 10a of the aircraft. In this embodiment, the upper surface 10a of the aircraft is given as, for example, the upper surface of the wing section 10w of the solar plane 10. In Figure 1, a solid line shows a cross-section of a part of the wing section 10w of one solar plane 10, and a dashed line shows the outer shape of the wing section 10w.

[0013] The solar cell 13 converts light energy such as sunlight into electrical energy and supplies it to the energy storage device 14. The energy storage device 14 is mounted on the solar plane 10, stores the power converted by the solar cell 13, and supplies it to the propulsion system 11, communication platform 12, and control unit 15 of the solar plane 10. The solar plane 10 has various detection units, such as a position detection unit capable of detecting altitude, latitude, longitude, etc., and a charge detection unit that detects the charge level of the energy storage device 14. The solar plane 10 has a control unit 15 that controls each of its parts. The control unit 15 controls the flight operation of the propulsion system 11 based on preset setting information or commands from the control unit 20. The control unit 15 transmits the detection results of the detection units from the communication platform 12 to the control unit 20.

[0014] The control device 20 controls the flight of each solar plane 10. The control device 20 controls the flight operation of each solar plane 10. The control device 20 includes a communication unit 21, a storage unit 22, and a processing unit 23. The communication unit 21 communicates with each solar plane 10. The storage unit 22 stores data, programs, etc. necessary for the control of the solar plane 10, such as map information and flight routes. The processing unit 23 performs processing necessary for the control of each solar plane 10.

[0015] FIG. 2 is a diagram schematically showing an example of the operation of a plurality of solar planes 10 in the high-altitude platform system 100. As shown in FIG. 2, the plurality of solar planes 10 fly along a circular route R including a first area AR1 and a second area AR2. Specifically, the plurality of solar planes 10 perform communication services while staying for a certain period of time while orbiting in the first area AR1 and the second area AR2 respectively, and move between the first area AR1 and the second area AR2 at a specified timing, thereby flying along the circular route R as a whole. In FIG. 2, the case where four solar planes 10 fly along the circular route R is taken as an example, but it is not limited to this case, and it may be three or less or five or more.

[0016] The first area AR1 is an area where the power generation amount during the reference flight period of the solar plane 10 exceeds the power consumption amount. The second area AR2 is an area where the power generation amount during the reference flight period of the solar plane 10 is less than the power consumption amount. In the present embodiment, the reference flight period is, for example, one day. Note that the reference flight period is not limited to one day.

[0017] The first area AR1 is located on the lower latitude side than the reference area AR0. The second area AR2 is located on the higher latitude side than the reference area AR0. The reference area AR0 is an area where the power stored and the power consumed during the reference flight period of the solar plane 10 are equal. The first area AR1 can be an area where the total daily sunshine amount during the flight period is larger than that of the reference area AR0 and the second area AR2. The second area AR2 can be an area where the total daily sunshine amount during the flight period is smaller than that of the reference area AR0 and the first area AR1.

[0018] Figs. 3A to 3C are diagrams schematically showing the relationships among the stored power amount, the power consumption amount, and the stored power amount of the power storage device 14 in the solar plane 10 during the reference flight period (one day) for each area. The horizontal axes of Figs. 3A to 3C indicate the time of day, and the vertical axes indicate the magnitude of the power or the power amount. Note that the stored power amount is shown as a positive value, and the power consumption amount is shown as a negative value. As shown in Figs. 3A to 3C, in the solar plane 10, power is stored during the period when the generated power amount exceeds the power consumption amount during the day. Also, in the solar plane 10, power is consumed throughout the day, that is, during the entire period of the daytime when the sun is up and the nighttime when the sun is down).

[0019] Fig. 3A shows the reference area AR0. As shown in Fig. 3A, in the reference area AR0, the stored power amounts in the power storage device 14 are equal at the first and last points of the reference flight period. That is, in the reference area AR0, the generated power amount generated by the solar cell 13 during the daytime is equal to the power consumption amount consumed during the entire reference flight period. Therefore, in the reference area AR0, if the stored power amount of the power storage device 14 exceeds 0 at the first point of the reference flight period, the state where the stored power amount of the power storage device 14 exceeds 0 can be maintained over a plurality of reference flight periods.

[0020] Figure 3B shows the first area AR1. As shown in Figure 3B, in the first area AR1, the amount of energy stored in the energy storage device 14 is greater at the end of the reference flight period than at the beginning. In other words, in the first area AR1, the amount of electricity generated by the solar cells 13 during the daytime is greater than the amount of electricity consumed over the entire reference flight period. Therefore, in the first area AR1, if the flight spans multiple reference flight periods, the amount of energy stored in the energy storage device 14 will gradually increase up to the maximum capacity of the energy storage device 14.

[0021] Figure 3C shows the second area, AR2. As shown in Figure 3C, in the second area, AR2, the amount of energy stored in the energy storage device 14 is less at the end of the reference flight period than at the beginning. In other words, in the second area, AR2, the amount of electricity consumed over the entire reference flight period is greater than the amount of electricity generated by the solar cells 13 during the daytime. Therefore, in the second area, AR2, if the flight spans multiple reference flight periods, the amount of energy stored in the energy storage device 14 will gradually decrease. Note that the daytime sunlight intensity is weaker in winter than in summer, and is weakest around the winter solstice. In other words, the amount of electricity generated by the solar cells 13 during the reference flight period during the daytime is lowest around the winter solstice. Therefore, it is preferable to use the value for the amount of electricity generated by the solar cells 13 during the daytime in the second area, AR2, which is under the most severe conditions, around the winter solstice.

[0022] For example, if the solar plane 10 continues to fly in the second area AR2, the amount of charge stored in the power storage device 14 will gradually decrease to zero. When the amount of charge stored in the power storage device 14 reaches zero, the solar plane 10 will be unable to fly. Therefore, in this embodiment, the solar plane 10 flies along a circular path R that includes the first area AR1 and the second area AR2, such that the amount of charge stored in the power storage device 14 exceeds zero.

[0023] Figure 4 schematically shows the relationship between the amount of power generated by the solar plane 10, the amount of power consumed, and the amount of power stored in the energy storage device 14 when the solar plane 10 flies through the second area AR2, then through the reference area AR0 to the first area AR1. The example shown in Figure 4 is when the solar plane stays and flies in the second area AR2 during the daytime on a certain day (day 1), moves to the first area AR1 via the reference area AR0 at night, and then stays and flies in the first area AR1 during the daytime on the following day (day 2).

[0024] As shown in Figure 4, by flying through Area 2 AR2 during the daytime on the first day and moving through Reference Area AR0 at night, the amount of charge stored in the power storage device 14 at 24:00 on the first day decreases compared to the amount of charge stored at 0:00 on the first day. Subsequently, by flying through Reference Area AR0 and then through Area 1 AR1 for the standard flight period during the daytime on the second day, the amount of charge stored in the power storage device 14 at 24:00 on the second day increases compared to the amount of charge stored at 0:00 on the second day (24:00 on the first day). Figure 4 shows the case where the amount of charge stored in the power storage device 14 at 0:00 on the first day is equal to the amount of charge stored in the power storage device 14 at 24:00 on the second day. In this case, the decrease in the amount of charge stored in the power storage device 14 in Area 2 AR2 during the standard flight period is equal to the increase in the amount of charge stored in the power storage device 14 in Area 1 AR1. As shown in this example, the first area AR1 and the second area AR2 may be set so that the increase and decrease in the amount of charge stored in the energy storage device 14 are equal during the reference flight period. By flying in this manner, the solar plane 10 can continuously and stably fly for a long period of time along the circular path R that includes the first area AR1 and the second area AR2, so that the amount of charge stored in the energy storage device 14 is greater than zero.

[0025] Furthermore, as shown in Figure 2, in this embodiment, while one of the solar planes 10 flies in the first area AR1, another solar plane 10 flies in the second area AR2. By simultaneously positioning the solar planes 10 in both the first area AR1 and the second area AR2, communication becomes possible between the communication platform 12 and the ground area corresponding to the first area AR1 and the ground area corresponding to the second area AR2. Therefore, the communication platform 12 of the high-altitude platform system 100 according to this embodiment can be operated even in areas with high latitude, i.e., areas with low sunlight intensity.

[0026] For example, by using a solar plane 10 with a reference area AR0 at approximately 40 degrees north latitude (e.g., Akita), and using multiple solar planes 10 to orbit a second area AR2 at 43 degrees north latitude (e.g., Sapporo), which is higher than the reference area AR0, and a first area AR1 at 36 degrees north latitude (e.g., Tokyo), it becomes possible to operate on the higher latitude side of 43 degrees north latitude.

[0027] Figures 5A and 5B schematically illustrate other examples of the operation of multiple solar planes 10 in the high-altitude platform system 100. As shown in Figures 5A and 5B, during the daytime, the solar planes 10 charge while flying by lowering their noses 10c when heading towards the sun and raising their noses 10c when heading away from the sun.

[0028] When heading towards higher latitudes, as shown in Figure 5A, by pointing the nose 10c of the solar plane 10 downwards, the angle of incidence α1 of sunlight on the solar cell 13 can be made smaller compared to when the nose 10c is pointed horizontally, allowing the solar cell 13 to receive sunlight more efficiently. Similarly, when heading towards lower latitudes, as shown in Figure 5B, by pointing the nose 10c of the solar plane 10 upwards, the angle of incidence α2 of sunlight on the solar cell 13 can be made smaller compared to when the nose 10c is pointed horizontally, allowing the solar cell 13 to receive sunlight more efficiently.

[0029] Figures 5C and 5D schematically illustrate the orbit of a solar plane. Figure 5C shows a conventional example, and Figure 5D shows an example of this embodiment. In Figure 5D, the contour line LH is shown corresponding to the orbit of the solar plane 10.

[0030] As shown in Figure 5C, conventionally, when the solar plane 10R stays in the air, it is common to orbit equial points in a circular pattern.

[0031] In contrast, as shown in Figure 5D, in this embodiment, when the solar plane 10 is in the upper atmosphere, during the period when the sun is at a lower latitude, if it is moving from a high latitude to a low latitude, it moves by pointing its nose 10c downwards, thereby decreasing its altitude. Conversely, if it is moving from a low latitude to a high latitude, it moves by pointing its nose 10c upwards, thereby increasing its altitude. As shown in Figure 5D, the trajectory of the solar plane 10 is a circular orbit extending in a straight line between the high latitude and the low latitude.

[0032] Furthermore, during nighttime hours when charging is not performed, or when the energy storage device 14 is fully charged, the solar plane 10 can fly with its nose pointed horizontally. The tilt angle of the nose 10c of the solar plane 10 may also be changed according to the time of day, season, etc.

[0033] Figures 6 and 7 schematically illustrate other examples of the operation of multiple solar planes 10 in the high-altitude platform system 100.

[0034] As shown in Figure 6, each solar plane 10 may have additional solar cells 13 arranged on the underside 10b of the aircraft. In this embodiment, the upper surface 10a of the aircraft is, for example, the underside of the wing portion 10w of the solar plane 10. In other words, the wing portion 10w of the solar plane 10 has a configuration in which solar cells 13 are arranged on both the upper and lower surfaces.

[0035] In this configuration, the solar plane 10 can be charged by reflected sunlight arriving from below. Such reflected light includes, for example, at least one of the following: reflected sunlight L1 from the ground surface 51, reflected sunlight L2 from snow 52 on the ground surface, and reflected sunlight L3 from clouds 53. These reflected lights L1, L2, and L3 from the ground surface 51, snow 52, ​​and clouds 53 can be used when flying in the above-mentioned reference area AR0, first area AR1, and second area AR2. In this way, power generation can be carried out by appropriately utilizing reflected light according to the ground surface conditions and cloud conditions. Furthermore, even in areas with low sunlight intensity (for example, second area AR2) and during seasons with low sunlight intensity (such as winter), charging can be carried out appropriately using reflected light.

[0036] Furthermore, as shown in Figure 7, the solar plane 10 may fly in a circular path between the area where the ground surface 51, snow 52, ​​and clouds 53 are located below, as shown in Figure 6, and the area where urban areas 54, farmlands 55, etc., are located. By flying in such a way, the electricity stored by the reflected light L1, L2, and L3 from the ground surface 51, snow 52, ​​and clouds 53 in areas with relatively high levels of reflected light can be used as power when flying over urban areas 54, farmlands 55, etc., where reflected light is relatively low.

[0037] As described above, the high-altitude platform system 100 according to this disclosure comprises a plurality of solar planes 10 equipped with a communication platform 12, each having solar cells 13 on at least the upper surface 10a of the aircraft, and a power storage device 14 for storing the power converted by the solar cells 13, and a control device 20 for controlling the plurality of solar planes 10. The plurality of solar planes 10 fly a circular route R that includes a first area AR1 where the amount of power generated by the solar cells 13 exceeds the amount of power consumed by the solar planes 10 during a standard flight period, and a second area AR2 where the amount of power generated is less than the amount of power consumed during a standard flight period, so as to maintain a state in which the amount of power stored in the power storage device 14 is greater than 0. During the period when one of the plurality of solar planes 10 flies in the first area AR1, the other solar planes 10 fly in the second area AR2.

[0038] With this configuration, the solar plane 10 can continuously fly along a circular path R that includes the first area AR1 and the second area AR2 for a long period of time, such that the amount of charge stored in the energy storage device 14 exceeds zero. In this way, by simultaneously positioning the solar plane 10 in both the first area AR1 and the second area AR2, communication with the communication platform 12 becomes possible in the ground area corresponding to the first area AR1 and the ground area corresponding to the second area AR2.

[0039] In the high-altitude platform system 100 relating to this disclosure, the first area AR1 is located at a lower latitude than the reference area AR0, where the amount of power generated and the amount of power consumed are equal during the reference flight period, and the second area AR2 is located at a higher latitude than the reference area AR0.

[0040] This configuration makes it possible to provide a high-altitude platform system 100 that can be operated even in areas with high latitude, i.e., areas with low sunlight intensity.

[0041] In the high-altitude platform system 100 described herein, multiple solar planes 10 fly with their noses 10c lowered when heading towards the sun during the day, and with their noses 10c raised when heading away from the sun, thereby charging while flying along a circular path R. At night or when charging is complete, they fly with their noses 10c facing horizontally.

[0042] With this configuration, the angle of incidence of sunlight on the solar cell 13 can be made smaller compared to when the nose 10c is pointed horizontally, so that sunlight can be efficiently received by the solar cell 13.

[0043] The high-altitude platform system 100 according to this disclosure is equipped with a communication platform 12, has solar cells 13 on at least the upper surface 10a of the aircraft, and has a power storage device 14 for storing the power converted by the solar cells 13, and comprises a plurality of solar planes 10 that fly along a predetermined orbital path R, and a control device 20 that controls the plurality of solar planes 10. The plurality of solar planes 10 charge while flying along the orbital path R by flying with their noses 10c pointed downwards when heading towards the low latitudes during the daytime when the sun is at a low latitude, and with their noses 10c pointed upwards when heading towards the high latitudes, and at night or when charging is complete, they fly with their noses 10c pointed horizontally.

[0044] With this configuration, the angle of incidence of sunlight on the solar cell 13 can be made smaller compared to when the nose 10c is pointed horizontally, so that sunlight can be efficiently received by the solar cell 13.

[0045] In the high-altitude platform system 100 described herein, multiple solar planes 10 have solar cells 13 further arranged on the underside 10b of the aircraft, and are charged by reflected sunlight that arrives from below.

[0046] With this configuration, charging can be performed using reflected sunlight arriving from below, allowing for power generation by appropriately utilizing reflected light depending on the conditions below the solar plane 10.

[0047] In the high-altitude platform system 100 relating to this disclosure, the reflected light includes at least one of the following: reflected light from sunlight by the ground surface 51, reflected light from sunlight by snow 52 on the ground surface, and reflected light from sunlight by clouds 53.

[0048] This configuration allows for power generation by appropriately utilizing reflected light depending on the ground conditions and cloud conditions.

[0049] The technical scope of the present invention is not limited to the embodiments described above, and modifications can be made as appropriate without departing from the spirit of the invention. [Explanation of Symbols]

[0050] 10 Solar Planes 10a Top of the aircraft 10b Underside of the fuselage 10c Nose 10w wing 11 Propulsion device 12 Communication Platforms 13 Solar Cells 14. Energy storage device 15 Control Unit 20 Control equipment 21 Communications Department 22 Memory section 23 Processing Unit 30 Information and communication terminals 51 Ground surface 52 Snow 53 Clouds 54 Urban area 55 Fields and farms 100 High-Altitude Platform Systems AR0 Reference Area AR1 Area 1 AR2 Area 2 L1,L2,L3 Reflected light R Loop Route

Claims

1. The system comprises a plurality of solar planes equipped with a communication platform, having solar cells on at least the upper surface of the aircraft, and having a power storage device for storing the electricity converted by the solar cells, and a control device for controlling the plurality of solar planes, Multiple solar planes fly a circular route that includes a first area where the amount of electricity generated by the solar cells exceeds the amount of electricity consumed by the solar planes during a standard flight period, and a second area where the amount of electricity generated is less than the amount of electricity consumed during the standard flight period, so as to maintain a state in which the amount of electricity stored in the energy storage device is greater than zero. During the period in which one of the multiple solar planes flies in the first area, the other solar planes fly in the second area. High-altitude platform system.

2. The first area is located at a lower latitude than the reference area where the amount of power generated and the amount of power consumed are equal during the reference flight period. The second area is located at a higher latitude than the reference area. The high-altitude platform system according to claim 1.

3. Multiple solar planes, during the daytime, fly with their noses pointed downwards when heading towards low latitudes and with their noses pointed upwards when heading towards high latitudes, thereby charging while flying along the aforementioned circular path. At night or when fully charged, the aircraft will fly with its nose pointed horizontally. The high-altitude platform system according to claim 1.

4. A communication platform is installed, solar cells are provided on at least the upper surface of the aircraft, and a power storage device is provided for storing the power converted by the solar cells, and the system comprises a plurality of solar planes that fly along a predetermined circular path, and a control system that controls the plurality of solar planes, Multiple solar-powered planes, during the daytime, fly with their noses down when heading towards the sun and with their noses up when heading away from the sun, thereby charging while flying along the aforementioned circular path. At night or when fully charged, the aircraft will fly with its nose pointed horizontally. High-altitude platform system.

5. Multiple of the aforementioned solar-powered aircraft have additional solar panels positioned on their undersides, which charge using reflected sunlight that reaches them from below. The high-altitude platform system according to claim 1 or claim 4.

6. The reflected light includes at least one of the following: reflected sunlight from the ground surface, reflected sunlight from snow on the ground surface, and reflected sunlight from clouds located below the circular path. The high-altitude platform system according to claim 5.

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