Communication system
The communication system improves positional accuracy by using UWB wireless communication and actuator-driven device displacement to ensure reliable distance measurements, addressing communication failures and power consumption in UWB environments.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- KK TOKAI RIKA DENKI SEISAKUSHO
- Filing Date
- 2026-01-14
- Publication Date
- 2026-07-23
AI Technical Summary
Existing systems face challenges in improving the specific accuracy of a moving body's position with respect to a target position, particularly in environments where communication with UWB wireless communication devices is poor.
A communication system utilizing UWB wireless communication between a stationary body and a moving body, with an actuator displacing communication devices to alternate positions to ensure accurate distance measurements, and employing auxiliary short-range wireless communication to mitigate power consumption issues.
Enhances the accuracy of determining the moving body's position relative to the target by ensuring reliable distance information acquisition, reducing energy consumption, and minimizing errors through spatial averaging and selective device displacement.
Smart Images
Figure JP2026000933_23072026_PF_FP_ABST
Abstract
Description
Communication system
[0001] The present disclosure relates to a communication system.
[0002] Japanese Patent Application Laid-Open No. 2022-067672 discloses an aircraft as an example of a moving body equipped with a sensor for measuring its own altitude in order to land at a target position. The aircraft is configured to move toward the target position based on information regarding the altitude measured by the sensor.
[0003] It is required to improve the specific accuracy of the position of the moving body with respect to the target position.
[0004] One example of an aspect provided by the present disclosure is a communication system, including at least one first communication device mounted on a stationary body, at least one second communication device mounted on a moving body, and a control device that identifies the position of the moving body with respect to a target position associated with the stationary body based on communication conforming to the UWB wireless communication standard made between the first communication device and the second communication device, and an actuator that displaces the position of the first communication device between a first position and a second position. The control device acquires first distance information corresponding to the distance from the second communication device when the first communication device is at the first position, and second distance information corresponding to the distance from the second communication device when the first communication device is at the second position, and identifies the position of the moving body based on the first distance information and the second distance information.
[0005] According to the above configuration, the second communication device can communicate with the same first communication device at different positions, and the control device can obtain two types of distance information by communicating with the same first communication device. Even if the communication with the first communication device at the first position is poor, as long as the communication with the first communication device at the second position is good, the control device can measure the distance between the aircraft and the port. Thereby, the specific accuracy of the position of the moving body with respect to the target position can be improved.
[0006] Figure 1 illustrates a drone and landing / takeoff port included in a communication system according to one embodiment. Figure 2 illustrates a drone-side communicator and a landing / takeoff port-side communicator included in a communication system according to one embodiment. Figure 3 shows an example of the communication flow between the first port-side communicator and the first drone-side communicator in Figure 2. Figure 4 shows another example of the communication flow between the first port-side communicator and the first drone-side communicator in Figure 2. Figure 5 schematically illustrates the configuration of a landing / takeoff port according to one embodiment. Figure 6 illustrates the flow of processing executed by the drone-side control device when certain conditions are met. Figure 7 shows another example of the configuration of a landing / takeoff port.
[0007] The following describes examples of embodiments with reference to the attached drawings. In the drawings used in the following description, the scale has been appropriately changed to make each element recognizable.
[0008] Figure 1 illustrates the appearance of a drone 2 and a landing / takeoff port 3 included in a communication system 1 according to one embodiment. The communication system 1 is configured to land the drone 2 on the contact surface 3a of the landing / takeoff port 3 using communication compliant with the UWB (Ultra-Wide Band) wireless communication standard. The drone 2 is an example of an aerial body and an example of a moving body. The landing / takeoff port 3 is an example of a stationary body. The contact surface 3a is an example of a target position.
[0009] An example of a UWB wireless communication standard is channel number 9 in IEEE 802.15.4z (center frequency: 7987.2 MHz, frequency bandwidth: 499.2 MHz).
[0010] As illustrated in Figure 2, drone 2 is equipped with multiple drone-side communication devices. In this example, drone 2 is equipped with a first drone-side communication device D1, a second drone-side communication device D2, a third drone-side communication device D3, and a fourth drone-side communication device D4. The multiple drone-side communication devices are an example of a second communication device.
[0011] On the other hand, the arrival / departure port 3 is equipped with multiple port-side communication devices. In this example, the arrival / departure port 3 is equipped with a first port-side communication device P1, a second port-side communication device P2, a third port-side communication device P3, and a fourth port-side communication device P4. The multiple port-side communication devices are an example of the first communication device.
[0012] Each of the multiple drone-side communicators and multiple port-side communicators has a well-known configuration that enables bidirectional communication in accordance with the aforementioned UWB wireless communication standard. In other words, each of the multiple drone-side communicators and multiple port-side communicators has radio wave transmission and reception functions.
[0013] Drone 2 is equipped with a drone-side control device 21. The drone-side control device 21 is configured to control the radio wave transmission operation of each of the multiple drone-side communication devices. The drone-side control device 21 is configured to acquire information superimposed on the radio waves received by each of the multiple drone-side communication devices.
[0014] The arrival / departure port 3 is equipped with a port-side control device 31. The port-side control device 31 is configured to control the radio wave transmission operation of each of the multiple port-side communication devices. The port-side control device 31 is configured to acquire information superimposed on the radio waves received by each of the multiple port-side communication devices.
[0015] Referring to Figure 3, the positioning process performed between the first port-side communication device P1 and the first drone-side communication device D1 will be explained.
[0016] The port-side control device 31 causes the first port-side communicator P1 to transmit a first start signal p1 at time t1. The first start signal p1 is received by the first drone-side communicator D1 at time t2.
[0017] The drone-side control device 21, in response to the first start signal p1, causes the first drone-side communicator D1 to transmit a first response signal r1 at time t3. The first response signal r1 is received by the first port-side communicator P1 at time t4.
[0018] The port-side control device 31, in response to the first response signal r1, causes the first port-side communicator P1 to transmit a first completion signal f1 at time t5. The first completion signal f1 is configured to include information that identifies times t1, t4, and t5. The first completion signal f1 is received by the first drone-side communicator D1 at time t6.
[0019] The drone-side control device 21 holds information that identifies time points t2, t3, and t6. Adding the information that identifies time points t1, t4, and t5 provided by the first completion signal f1, the drone-side control device 21 calculates the following equation to obtain the distance d11 between the first port-side communicator P1 and the first drone-side communicator D1. The symbol c is the speed of light. d11 = c[(t4 - t1) - (t3 - t2) + (t6 - t3) - (t5 - t4)] / 4
[0020] Similarly, the drone-side control device 21 obtains the distance d21 between the second port-side communicator P2 and the first drone-side communicator D1, the distance d31 between the third port-side communicator P3 and the first drone-side communicator D1, and the distance d41 between the fourth port-side communicator P4 and the first drone-side communicator D1. Based on the distances between the first drone-side communicator D1 and each of the four port-side communicators, the three-dimensional coordinates of the first drone-side communicator D1 can be determined by solving a system of three equations well known in positioning technology.
[0021] The drone-side control device 21 controls the flight of the drone 2 so that the three-dimensional coordinates of the identified first drone-side communication device D1 are brought closer to the three-dimensional coordinates corresponding to the target position of the landing port 3. This allows the drone 2 to land at the landing port 3.
[0022] In this embodiment, the distance between each of the four port-side communication devices is obtained in the same manner for each of the second drone-side communication device D2, the third drone-side communication device D3, and the fourth drone-side communication device D4. Therefore, the three-dimensional coordinates of the four drone-side communication devices are obtained based on a total of 16 pieces of distance information.
[0023] In the example above, the start signal is transmitted from multiple port-side communicators mounted on the arrival / departure port 3. However, as illustrated in Figure 4, the start signal may also be transmitted from multiple drone-side communicators mounted on the drone 2.
[0024] In this case, the acquired distance information is located at the take-off / arrival port, so in order for drone 2 to determine its own position, the acquired distance information is transmitted from take-off / arrival port 3 to drone 2. For example, the transmission of distance information is performed using communication compliant with the UWB wireless communication standard.
[0025] However, communication compliant with the UWB wireless communication standard has the characteristic that the power consumption burden is greater on the receiving side than on the transmitting side. As an alternative to avoid this problem, distance information can be transmitted using signals that do not comply with the UWB wireless communication standard.
[0026] Specifically, as illustrated in Figure 2, the drone 2 and the landing / takeoff port 3 may be equipped with auxiliary communication devices 22 and 32, respectively. The auxiliary communication devices 22 and 32 are configured to send and receive auxiliary signals ax using short-range wireless communication that does not conform to the UWB wireless communication standard. Examples of such short-range wireless communication include Bluetooth®, Bluetooth Low Energy®, ZigBee®, and Wi-Fi®.
[0027] Figure 5 schematically illustrates the configuration of a departure / arrival port 3 according to one embodiment. The departure / arrival port 3 is equipped with a support base 33. A first port-side communication device P1, a second port-side communication device P2, a third port-side communication device P3, and a fourth port-side communication device P4 are fixed to the support base 33.
[0028] The first port-side communicator P1, the second port-side communicator P2, the third port-side communicator P3, the fourth port-side communicator P4, and the support base 33 are displaceable between a first position and a second position. The first port-side communicator P1, the second port-side communicator P2, the third port-side communicator P3, the fourth port-side communicator P4, and the support base 33 located in the first position are illustrated by solid lines in Figure 5. The first port-side communicator P1, the second port-side communicator P2, the third port-side communicator P3, the fourth port-side communicator P4, and the support base 33 located in the second position are illustrated by dashed lines in Figure 5.
[0029] The arrival / departure port 3 is equipped with an actuator 34. The actuator 34 has a well-known configuration that can displace the support base 33. When the actuator 34 displaces the support base 33, the positions of the first port-side communicator P1, the second port-side communicator P2, the third port-side communicator P3, and the fourth port-side communicator P4 are displaced between the first position and the second position.
[0030] Therefore, by performing the aforementioned two-way wireless communication between the drone 2 and the landing / takeoff port 3, the drone-side control device 21 can acquire multiple different distance information corresponding to the positions of the multiple port-side communicators. This allows, for example, if distance information cannot be properly acquired when the multiple port-side communicators are in the first position, the drone can attempt to acquire distance information by displacing the multiple port-side communicators to the second position. This improves the accuracy of determining the position of the drone 2 relative to the target position.
[0031] The port-side control device 31 according to this embodiment may be configured to displace the positions of multiple port-side communication devices using an actuator 34 when certain conditions are met. Figure 6 illustrates the flow of processing performed by the drone-side control device 21 in this case.
[0032] When the drone-side control device 21 starts communication to determine the position of the drone 2, the drone-side control device 21 instructs multiple drone-side communicators to communicate with multiple port-side communicators located at the first position to acquire first distance information (STEP 11).
[0033] Next, the drone-side control device 21 determines, as an example of the above-mentioned specific conditions, whether a communication failure occurred in step S11 between at least one of the multiple drone-side communication devices and the multiple port-side communication devices at the first position (step 12). A communication failure may include the failure to obtain distance information in each communication, and the detection of a value that is clearly out of sync with the distance information obtained in other communications.
[0034] If it is determined that a communication failure has occurred between at least one of the multiple drone-side communicators and the multiple port-side communicators located in the first position (YES in STEP 12), the drone-side control device 21 transmits a signal to the port-side control device 31 to cause the actuator 34 to move the port-side communicator from the first position to the second position (STEP 13). Upon receiving the signal, the port-side control device 31 causes the actuator 34 to move the first port-side communicator P1, the second port-side communicator P2, the third port-side communicator P3, and the fourth port-side communicator P4 from the first position to the second position.
[0035] Once the displacement of the first port-side communicator P1, the second port-side communicator P2, the third port-side communicator P3, and the fourth port-side communicator P4 is complete, the drone-side control device 21 instructs the multiple drone-side communicators to communicate with the multiple port-side communicators located at the second position to acquire second distance information (STEP 14).
[0036] Next, the drone-side control device 21 determines the position of the drone 2 based solely on the second distance information (STEP 15).
[0037] If it is determined that no communication failure occurred between the multiple drone-side communicators and at least one of the multiple port-side communicators located at the first position (NO in STEP 12), the drone-side control device 21 determines the position of the drone 2 based solely on the first distance information (STEP 16).
[0038] With this configuration, the displacement of the port-side communication device by the actuator 34 does not need to occur each time the position of the drone 2 is determined. In other words, unless certain conditions are met, the displacement of the port-side communication device from the first position to the second position by the actuator 34 does not occur, thus reducing the amount of energy consumed at the landing / takeoff port 3.
[0039] Figure 7 shows another example of the configuration of the arrival / departure port 3. The arrival / departure port 3 in this example is equipped with multiple support bases. Specifically, the multiple support bases include a first support base 33A, a second support base 33B, a third support base 33C, and a fourth support base 33D. The first port side communication device P1 is fixed to the first support base 33A. The second port side communication device P2 is fixed to the second support base 33B. The third port side communication device P3 is fixed to the third support base 33C. The fourth port side communication device P4 is fixed to the fourth support base 33D.
[0040] The first support base 33A, second support base 33B, third support base 33C, and fourth support base 33D in this example can be displaced independently between the first and second positions. Therefore, the first port-side communication device P1, second port-side communication device P2, third port-side communication device P3, and fourth port-side communication device P4 can also be displaced independently between the first and second positions. The first port-side communication device P1, second port-side communication device P2, third port-side communication device P3, fourth port-side communication device P4, first support base 33A, second support base 33B, third support base 33C, and fourth support base 33D, all located in the first position, are illustrated by solid lines in Figure 7. The first port-side communication device P1, the second port-side communication device P2, the third port-side communication device P3, the fourth port-side communication device P4, the first support base 33A, the second support base 33B, the third support base 33C, and the fourth support base 33D, all located in the second position, are illustrated by dashed lines in Figure 7.
[0041] The arrival / departure port 3 in this example is equipped with multiple actuators. These multiple actuators include a first actuator 34A, a second actuator 34B, a third actuator 34C, and a fourth actuator 34D.
[0042] The first actuator 34A, the second actuator 34B, the third actuator 34C, and the fourth actuator 34D each have a well-known configuration for displacing the first support base 33A, the second support base 33B, the third support base 33C, and the fourth support base 33D. When the first actuator 34A displaces the first support base 33A, the position of the first port-side communicator P1 is displaced between the first position and the second position. When the second actuator 34B displaces the second support base 33B, the position of the second port-side communicator P2 is displaced between the first position and the second position. When the third actuator 34C displaces the third support base 33C, the position of the third port-side communicator P3 is displaced between the first position and the second position. When the fourth actuator 34D displaces the fourth support base 33D, the position of the fourth port-side communicator P4 is displaced between the first position and the second position.
[0043] According to the configuration according to this example, among the communications between the plurality of port-side communicators and the plurality of drone-side communicators, when a communication failure occurs between even one port-side communicator and the drone-side communicator, the port-side control device 31 is configured to individually displace the port-side communicator from the first position to the second position.
[0044] In this case, for example, when a communication failure occurs only between the drone-side communicator and the first port-side communicator P1, only the first actuator 34A that displaces the first port-side communicator P1 is activated. Since only the port-side communicator that requires remeasurement is displaced, the amount of energy consumed at the departure / arrival port 3 for obtaining the second distance information is reduced.
[0045] On the other hand, as illustrated in FIG. 5, when all the port-side communicators are supported by one support base 33, it becomes possible to displace all the port-side communicators collectively with one actuator 34. Thereby, the number of actuators mounted on the departure / arrival port 3 can be reduced, and the mechanism for displacing the port-side communicator for obtaining the second distance information is simplified.
[0046] When both the first distance information and the second distance information are acquired, the drone-side control device 21 can obtain a spatial average distance by spatially averaging the distance corresponding to the first distance information and the distance corresponding to the second distance information. In this case, the position of the drone 2 can be specified using the spatial average distance.
[0047] According to such a configuration, compared with the case where the position of the drone 2 is specified by referring to only one of the distance information, the influence of the error included in at least one of the two distance information can be mitigated.
[0048] In any of the examples illustrated in FIGS. 5 and 7, the port-side communicator is displaced relative to the contact surface 3a. Specifically, the support base to which the port-side communicator is fixed is displaced by the operation of the actuator, but the contact surface 3a including the target position is not displaced. According to such a configuration, compared with the case where the actuator also displaces the contact surface 3a, the weight of the object to be displaced by the actuator can be reduced. Thereby, the amount of energy consumed at the docking port 3 for acquiring the second distance information is reduced.
[0049] Each of the configurations described so far is merely an example for facilitating the understanding of the present disclosure. Each configuration example can be appropriately modified or combined with other configurations without departing from the spirit of the present disclosure.
[0050] The "UWB wireless communication standard" used in the above embodiment example originates from a standardized standard compliant with IEEE 802.15. However, the expression is not intended to be limited to the standard. As long as it is a short-range wireless communication standard having the advantages of being able to specify the positional relationship between communicators with high accuracy and having low power consumption and interference with other communications, appropriate derivative standards or alternative standards can be adopted.
[0051] In the above embodiment, the position of the drone 2 relative to the target location is determined based on bidirectional communication between multiple drone-side communicators and multiple port-side communicators. However, the number of communicators mounted on the drone 2 and the number of communicators mounted on the landing / takeoff port 3 can each be at least one. Furthermore, the number of communicators mounted on the drone 2 and the number of communicators mounted on the landing / takeoff port 3 do not necessarily have to be the same.
[0052] In the above embodiment, the drone-side control device 21 is configured to acquire first distance information and second distance information using the drone-side communication device. However, the port-side control device 31 may be configured to acquire first distance information and second distance information using the port-side communication device. When the port-side control device 31 starts communication to determine the position of the drone 2, the port-side control device 31 may cause the multiple port-side communication devices at the first position to communicate with the multiple drone-side communication devices to acquire first distance information. If the port-side control device 31 determines that a communication failure has occurred between the multiple drone-side communication devices and at least one of the multiple port-side communication devices at the first position, the port-side control device 31 may cause the actuator 34 to move the port-side communication device from the first position to the second position.
[0053] In this case, if a communication failure occurs between the port-side communication device and the drone-side communication device, the port-side control device 31 may transmit information about the communication failure to the drone-side control device 21 by sending an auxiliary signal ax from the port-side auxiliary communication device 32 to the drone-side auxiliary communication device 22.
[0054] In the above embodiment, the communication system 1 is used to determine the position of the drone 2 relative to the target position. However, the communication system 1 may also be used to determine the position of an aircraft capable of carrying a person. Alternatively, the communication system 1 may be used to determine the position of a mobile body other than the drone 2. Examples of such mobile bodies include vehicles, trains, and ships. Such mobile bodies do not necessarily require a driver.
[0055] In the above embodiment, the landing port 3 has a contact surface 3a on which the drone 2 can land, and the contact surface 3a is the target position. However, the drone 2 may be configured to reach the target position by hovering near the landing port 3 rather than landing directly on the landing port 3. In this case, the target position is the position where the drone 2 hovers.
[0056] In part with respect to this disclosure, the contents of Japanese Patent Application No. 2025-005336, filed on January 15, 2025, are incorporated herein by reference.
Claims
At least one first communication device mounted on the stationary body, At least one second communications device mounted on the mobile unit, A control device that determines the position of the moving body relative to the target position associated with the stationary body based on communication in accordance with the UWB wireless communication standard between the first communication device and the second communication device, An actuator that displaces the position of the first communication device between a first position and a second position, It includes, The control device is First distance information corresponding to the distance between the first communication device and the second communication device when the first communication device is in the first position is acquired, and second distance information corresponding to the distance between the first communication device and the second communication device when the first communication device is in the second position. Based on the first distance information and the second distance information, the position of the moving body is determined. Communication system. The actuator displaces the first communication device when certain conditions related to the communication are met. The communication system according to claim 1. The aforementioned at least one first communication device includes a plurality of first communication devices, The aforementioned at least one second communication device includes a plurality of second communication devices, The communication is made between each of the plurality of first communication devices and the plurality of second communication devices. The aforementioned specific condition is that a communication failure occurs between at least one of the plurality of first communication devices and the plurality of second communication devices. The communication system according to claim 2. The actuator displaces at least one of the plurality of first communication devices that satisfy the specific conditions. The communication system according to claim 3. The control device determines the position of the moving object by processing the first distance information and the second distance information so as to obtain a spatial average of the first distance, which is the distance between the first communication device and the second communication device when the first communication device is in the first position, and the second distance, which is the distance between the first communication device and the second communication device when the first communication device is in the second position. A communication system according to any one of claims 1 to 4. The first communication device is designed to be displaceable relative to the target position. A communication system according to any one of claims 1 to 5.