Positioning method, computation device, and moving body
Patent Information
- Application Number
- PCT/JP2026/012801
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-03-27
- Filing Date
- 2026-03-27
- Publication Date
- 2026-10-01
Smart Images
Figure JP2026012801_01102026_PF_FP_ABST
Abstract
Description
Positioning method, arithmetic device, and mobile object
[0001] The present disclosure relates to a positioning method for a mobile object. The present disclosure also relates to an arithmetic device configured to execute the method, and a mobile object on which the arithmetic device is mounted.
[0002] Japanese Patent Application Publication No. 2024-124767 discloses a system that performs control to cause a drone, which is an example of a mobile object, to reach a target position using a GPS (Global Positioning System) positioning value.
[0003] There is a demand for improving the accuracy with which a mobile object reaches a target position.
[0004] A first exemplary aspect that can be provided by the present disclosure is a positioning method for a mobile object executed by at least one arithmetic device, the method comprising: starting acquisition of a first positioning value of the mobile object at a first time point using one of a first positioning method that uses short-range wireless communication conforming to the UWB wireless communication standard and a second positioning method different from the first positioning method; starting acquisition of a second positioning value of the mobile object at a second time point after the first time point using the other of the first positioning method and the second positioning method; specifying the position of the mobile object using the first positioning value until a predetermined condition is satisfied; starting specification of the position using the second positioning value when the predetermined condition is satisfied; wherein the predetermined condition is at least one of that the reliability of the first positioning value is lower than a first threshold and that the reliability of the second positioning value is higher than a second threshold.
[0005] A second exemplary aspect that can be provided by the present disclosure is an arithmetic device configured to execute the positioning method according to the first exemplary aspect.
[0006] A third exemplary aspect that can be provided by the present disclosure is a mobile object equipped with the arithmetic device according to the second exemplary aspect.
[0007] According to the configurations described in each of the above examples, the moving object can reach its target location by switching between two different positioning methods to obtain more reliable positioning values for the moving object. In particular, since one of the two positioning methods employs a communication method compliant with the UWB wireless standard, which is less susceptible to multipath reflection, the accuracy of reaching the target location can be increased.
[0008] Figure 1 illustrates the functional configuration of the drone and landing port included in a communication system according to one embodiment. Figure 2 shows an example of the communication flow between the first port-side communicator and the first drone-side communicator. Figure 2 shows another example of the communication flow between the first port-side communicator and the first drone-side communicator. Figure 2 shows an example of the processing flow executed by the arithmetic unit of the drone-side control device. Figure 5 shows an example of the drone operation realized by the processing example. Figure 2 shows another example of the processing flow executed by the arithmetic unit of the drone-side control device. Figure 7 shows an example of the drone operation realized by the processing example. Figure 5 shows another example of the drone operation realized by the processing example. Figure 7 shows another example of the drone operation realized by the processing example. Figure 5 shows another example of the drone operation realized by the processing example. Figure 7 shows another example of the drone operation realized by the processing example.
[0009] The embodiments will be described in detail below 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.
[0010] 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 control the direction of movement of the drone 2 relative to the target position 31 of the landing / takeoff port 3 using GPS and short-range wireless communication (hereinafter abbreviated as "UWB wireless 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 mobile body.
[0011] 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).
[0012] Drone 2 is equipped with multiple rotors 21. In this example, Drone 2 is equipped with four rotors 21.
[0013] As illustrated in Figure 2, the drone 2 is equipped with multiple drone-side communication devices 22. In this example, the multiple drone-side communication devices 22 include a first drone-side communication device 221, a second drone-side communication device 222, a third drone-side communication device 223, and a fourth drone-side communication device 224.
[0014] On the other hand, the arrival / departure port 3 is equipped with multiple port-side communication devices 32. In this example, the multiple port-side communication devices 32 include a first port-side communication device 321, a second port-side communication device 322, a third port-side communication device 323, and a fourth port-side communication device 324.
[0015] Each of the multiple drone-side communication devices 22 and the multiple port-side communication devices 32 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 communication devices 22 and the multiple port-side communication devices 32 is equipped with an antenna that has radio wave transmission and reception functions.
[0016] Drone 2 is equipped with a drone-side control device 23. The drone-side control device 23 is configured to control the radio wave transmission operation of each of the multiple drone-side communication devices 22. The drone-side control device 23 is configured to acquire information superimposed on the radio waves received by each of the multiple drone-side communication devices 22.
[0017] The arrival / departure port 3 is equipped with a port-side control device 33. The port-side control device 33 is configured to control the radio wave transmission operation of each of the multiple port-side communication devices 32. The port-side control device 33 is configured to acquire information superimposed on the radio waves received by each of the multiple port-side communication devices 32.
[0018] Referring to Figure 3, the positioning process performed between the first drone-side communication device 221 and the first port-side communication device 321 will be explained.
[0019] The port-side control device 33 causes the first port-side communicator 321 to transmit a first start signal p1 at time t1. The first start signal p1 is received by the first drone-side communicator 221 at time t2.
[0020] The drone-side control device 23, in response to the first start signal p1, causes the first drone-side communicator 221 to transmit a first response signal r1 at time t3. The first response signal r1 is received by the first port-side communicator 321 at time t4.
[0021] The port-side control device 33, in response to the first response signal r1, causes the first port-side communicator 321 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 221 at time t6.
[0022] The drone-side control device 23 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 23 calculates the following equation to obtain the distance d11 between the first port-side communicator 321 and the first drone-side communicator 221. The symbol c is the speed of light. d11 = c[(t4 - t1) - (t3 - t2) + (t6 - t3) - (t5 - t4)] / 4
[0023] Similarly, the drone-side control device 23 obtains the distance d21 between the second port-side communication device 322 and the first drone-side communication device 221, the distance d31 between the third port-side communication device 323 and the first drone-side communication device 221, and the distance d41 between the fourth port-side communication device 324 and the first drone-side communication device 221.
[0024] Based on the distance between the first drone-side communication device 221 and each of the multiple port-side communication devices 32, the three-dimensional coordinates of the first drone-side communication device 221 can be determined by processing such as solving a system of three linear equations, which is well known in positioning technology.
[0025] The drone-side control device 23 controls the flight of the drone 2 so that the three-dimensional coordinates of the identified first drone-side communication device 221 are brought closer to the three-dimensional coordinates associated with the target position 31 of the landing port 3. Specifically, the amount of rotation of each of the multiple rotors 21 is controlled. This allows the drone 2 to land at the landing port 3.
[0026] In this embodiment, the distance between each of the second drone-side communication device 222, the third drone-side communication device 223, and the fourth drone-side communication device 224 and each of the four port-side communication devices is obtained in the same manner. Therefore, a total of 16 distance values are obtained. Based on these 16 distance values, the three-dimensional coordinates of the four drone-side communication devices 22 are obtained.
[0027] The position of the drone 2 can be determined by identifying the three-dimensional coordinates of the four drone-side communication devices 22. For example, the three-dimensional coordinates of the center of gravity, which can be calculated based on the four three-dimensional coordinates, can be used as the position of the drone 2. In the following explanation, the process of acquiring the position of the drone 2 using UWB wireless communication will be referred to as "UWB positioning." The position of the drone 2 acquired by UWB positioning will be referred to as the "UWB positioning value." UWB positioning is an example of the first positioning method.
[0028] In the above example, the start signal is transmitted from multiple port-side communicators 32 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 22 mounted on the drone 2.
[0029] In this case, since the acquired distance information is located at the departure / arrival port, the acquired distance information or information related to UWB positioning values is transmitted from the departure / arrival port 3 to the drone 2 in order for the drone 2 to determine its own position. For example, this information is transmitted using UWB wireless communication.
[0030] However, UWB wireless communication 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, the information may be transmitted using signals that do not conform to the UWB wireless communication standard.
[0031] Specifically, as illustrated in Figure 2, the drone 2 and the landing / takeoff port 3 may be equipped with auxiliary communication devices 24 and 34, respectively. The auxiliary communication devices 24 and 34 are configured to send and receive auxiliary signals AX via 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®.
[0032] As illustrated in Figure 2, the drone 2 is equipped with a GPS module 25. The GPS module 25 is configured to acquire the position of the drone 2 using a well-known method using GPS. In the following description, the process of acquiring the position of the drone 2 using GPS will be referred to as "GPS positioning". The position of the drone 2 acquired by GPS positioning will be referred to as "GPS positioning value". GPS positioning is an example of a second positioning method.
[0033] The GPS module 25 is configured to output GPS data corresponding to GPS positioning values. The GPS data is received by the drone-side control device 23.
[0034] Figure 5 illustrates the processing flow executed by the computing device in the drone-side control device 23 when the drone 2 lands at the landing port 3.
[0035] First, the computing unit determines the position of the drone 2 using GPS positioning (STEP 11). Specifically, it acquires GPS positioning values corresponding to the GPS data output from the GPS module 25. The GPS positioning values are an example of first positioning values.
[0036] Next, the computing unit determines whether a predetermined condition has been met (STEP 12). The predetermined condition is that the reliability of the GPS positioning value falls below a threshold. In this case, the threshold for the reliability of the GPS positioning value is an example of the first threshold. If it is determined that the reliability of the GPS positioning value has not fallen below the threshold (NO in STEP 12), the process returns to STEP 11, and the acquisition of GPS positioning values is repeated.
[0037] As an example, the reliability of GPS positioning values can be determined based on the reception strength of GPS signals from satellites by the GPS module 25. In this case, the GPS data includes information corresponding to the reception strength of GPS signals. This information may be a measured value of the reception strength, or an index value associated with that measured value. If the measured value or index value falls below a threshold, the reliability of the GPS positioning values is determined to be below the threshold.
[0038] Alternatively, the reliability of GPS positioning values can be determined based on the magnitude of the variability of the GPS positioning values. In this case, the computing unit obtains information corresponding to the magnitude of the variability of the positioning values based on the time series of multiple acquired GPS positioning values. This information may be a calculated value of the magnitude of the variability, or an index value associated with that calculated value. This calculated value or index value may be included in the GPS data. If this calculated value or index value exceeds a threshold, the reliability of the GPS positioning values is determined to be below the threshold.
[0039] As an alternative example, the reliability of GPS positioning values may be determined based on the number of satellites that the GPS module 25 can communicate with. In this case, the GPS data includes information corresponding to the number of communicable satellites. This information may be the number of satellites itself or an index value associated with the number of satellites. If the number of satellites or the index value falls below a threshold, the reliability of the GPS positioning values is determined to be below the threshold.
[0040] As another example, the drone-side control device 23 can store a digital map in a storage not shown. The digital map includes information in which the reliability of GPS positioning is associated with positions on the map. For example, information indicating low reliability of GPS positioning is assigned to locations where the reception stability of GPS signals decreases due to terrain or the presence of a cluster of buildings. In this case, the arithmetic device determines whether the location corresponding to the obtained GPS positioning value corresponds to a location assigned with information indicating low GPS positioning reliability on the digital map. If it corresponds, it is determined that the reliability of the GPS positioning value has fallen below the threshold.
[0041] When it is determined that the reliability of the GPS positioning value is below the threshold (YES in STEP 12), the arithmetic device activates the UWB positioning process and starts acquiring a UWB positioning value (STEP 13). The arithmetic device specifies the position of the drone 2 using the UWB positioning value. The UWB positioning value is an example of a second positioning value.
[0042] An example of the operation of the drone 2 realized by the processing example of Fig. 5 will be described with reference to Fig. 6.
[0043] First, GPS positioning is started at time point t1, and the position of the drone 2 is specified using GPS positioning values. Time point t1 is an example of a first time point. Subsequently, it is determined that a predetermined condition is satisfied at time point t2, and UWB positioning is started. Time point t2 is an example of a second time point. Thereby, position specification of the drone 2 using the UWB positioning value is also started.
[0044] GPS positioning may be terminated when UWB positioning is started, or may continue to be executed in parallel with UWB positioning.
[0045] Fig. 7 illustrates the flow of processing executed by the arithmetic device provided in the drone-side control device 23 when the drone 2 takes off from the landing / takeoff port 3.
[0046] First, the arithmetic device specifies the position of the drone 2 using UWB positioning (STEP 21). In this case, the UWB positioning value is an example of a first positioning value.
[0047] Subsequently, the arithmetic device determines whether a predetermined condition is satisfied (STEP 22). The predetermined condition is that the reliability of the UWB positioning value falls below a threshold value. The threshold value related to the reliability of the UWB positioning value in this case is an example of a first threshold value. If it is determined that the reliability of the UWB positioning value does not fall below the threshold value (NO in STEP 22), the process returns to STEP 21, and the acquisition of the UWB positioning value is repeated.
[0048] As an example, the reliability of the UWB positioning value can be determined based on the reception intensity of the radio signal from the port-side communication device 32 by the drone-side communication device 22. In this case, the arithmetic device is configured to acquire the measured value of reception intensity or an index value associated with the measured value. When the measured value or the index value falls below the threshold value, it is determined that the reliability of the UWB positioning value has fallen below the threshold value.
[0049] As another example, the reliability of the UWB positioning value can be determined based on the magnitude of variation in the UWB positioning value. In this case, the arithmetic device acquires information corresponding to the magnitude of variation in the positioning values based on the time series of the plurality of acquired UWB positioning values. The information may be a calculated value of the magnitude of variation, or may be an index value associated with the calculated value. When the calculated value or the index value exceeds the threshold value, it is determined that the reliability of the UWB positioning value has fallen below the threshold value.
[0050] As another example, the reliability of the UWB positioning value can be determined based on the distance between the target position 31 and the position indicated by the UWB positioning value. In this case, the arithmetic device is configured to acquire the calculated value of the distance or an index value associated with the calculated value. Since the UWB positioning value is acquired by short-range wireless communication, the longer the distance, the lower the reliability. When the calculated value or the index value exceeds the threshold value, it is determined that the reliability of the UWB positioning value has fallen below the threshold value.
[0051] When it is determined that the reliability of the UWB positioning value falls below the threshold value (YES in STEP 22), the arithmetic device activates a GPS positioning process and starts acquiring a GPS positioning value (STEP 23). The arithmetic device specifies the position of the drone 2 using the GPS positioning value. In this case, the GPS positioning value is an example of a second positioning value.
[0052] Referring to Figure 8, an example of the operation of the drone 2 realized by the processing example in Figure 7 will be explained.
[0053] First, at time t1, UWB positioning is initiated, and the position of drone 2 is determined using the UWB positioning values. Time t1 is an example of the first time point. Subsequently, at time t2, it is determined that the predetermined conditions have been met, and GPS positioning is initiated. Time t2 is an example of the second time point. As a result, the position of drone 2 using the GPS positioning values is also initiated.
[0054] UWB positioning may be terminated when GPS positioning begins, or it may continue to run in parallel with GPS positioning.
[0055] Figure 9 shows another example of the operation performed when the drone 2 lands at the landing port 3. In this example, UWB positioning is started at time t2 after GPS positioning has started but before certain conditions are met. An example of time t2 is when the distance between the position of the drone 2 indicated by the GPS positioning value and the target position 31 falls below a threshold.
[0056] In this case, the "predetermined conditions" related to STEP 12 in Figure 5 may include the reliability of the UWB positioning value exceeding a threshold. The threshold for the reliability of the UWB positioning value in this case is an example of a second threshold. The computing device may determine that the "predetermined conditions" are satisfied if either the reliability of the GPS positioning value falls below the threshold or the reliability of the UWB positioning value exceeds the threshold, or if both conditions are met.
[0057] For example, if the measured value of the received strength of the wireless signal from the port-side communication device 32 by the drone-side communication device 22, or the index value associated with said measurement, exceeds a threshold, it is determined that the reliability of the UWB positioning value has exceeded the threshold.
[0058] As an alternative example, if the magnitude of variability in UWB positioning values calculated based on the time series of multiple acquired UWB positioning values, or the index value associated with said calculation, falls below a threshold, the reliability of the UWB positioning values is judged to have exceeded the threshold.
[0059] Alternatively, the reliability of the UWB positioning value can be determined based on the distance between the target position 31 and the position indicated by the GPS positioning value. In this case, the computing unit is configured to acquire a calculated value of the distance or an index value associated with the calculated value. Since the UWB positioning value is acquired by short-range wireless communication, the reliability of the UWB positioning value increases as the distance decreases. If the calculated value or index value falls below a threshold, it is determined that the reliability of the UWB positioning value has exceeded the threshold.
[0060] Alternatively, the reliability of the UWB positioning value can be determined based on the elapsed time since the start of UWB positioning. In this case, the computing unit is configured to acquire a measured value of the elapsed time from time t2 or an index value associated with that measured value. The longer the elapsed time, the closer the location is to the target position 31, thus increasing the reliability of the UWB positioning value. If the measured value or index value exceeds a threshold, it is determined that the reliability of the UWB positioning value has exceeded the threshold.
[0061] Alternatively, the reliability of UWB positioning values can be judged based on the error with GPS positioning values. Since GPS positioning and UWB positioning are performed in parallel from time t2 onward, it is possible to compare the acquired GPS positioning values with UWB positioning values. In this case, the computing unit is configured to acquire a calculated error value obtained as a result of the comparison, or an index value associated with that calculated value. If the calculated value or index value falls below a threshold, it is determined that the reliability of the UWB positioning values exceeds the threshold.
[0062] In Figure 9, it is determined that the predetermined conditions are met at time t3, and the position determination of the drone 2 using UWB positioning values is initiated.
[0063] Figure 10 shows another example of the operation that occurs when the drone 2 takes off from the landing port 3. In this example, GPS positioning is started at time t2 after UWB positioning has started but before a predetermined condition is met. An example of time t2 is when the distance between the position of the drone 2 indicated by the UWB positioning value and the target position 31 exceeds a threshold.
[0064] In this case, the "predetermined conditions" relating to STEP 22 in Figure 7 may include the reliability of the GPS positioning value exceeding a threshold. The threshold relating to the reliability of the GPS positioning value in this case is an example of a second threshold. The computing unit may determine that the "predetermined conditions" are satisfied if either the reliability of the UWB positioning value falls below the threshold or the reliability of the GPS positioning value exceeds the threshold, or if both conditions are met.
[0065] For example, if the measured value of the GPS signal reception strength from satellites by the GPS module 25, or the index value associated with said measurement, exceeds a threshold, the reliability of the GPS positioning value is judged to have exceeded the threshold.
[0066] As an alternative example, if the magnitude of variability in GPS positioning values calculated based on the time series of multiple acquired GPS positioning values, or the index value associated with said calculation, falls below a threshold, the reliability of the GPS positioning values is judged to have exceeded the threshold.
[0067] As an alternative example, if the number of satellites that the GPS module 25 can communicate with or an index value exceeds a threshold, the reliability of the GPS positioning value is judged to have exceeded the threshold.
[0068] As an alternative example, the reliability of GPS positioning values can be judged based on the error with UWB positioning values. Since UWB positioning and GPS positioning are performed in parallel from time t2 onward, it is possible to compare the acquired UWB positioning values with GPS positioning values. In this case, the computing unit is configured to acquire a calculated error value obtained as a result of the comparison, or an index value associated with said calculated value. If said calculated value or index value falls below a threshold, it is determined that the reliability of the GPS positioning values exceeds the threshold.
[0069] In Figure 10, it is determined that the predetermined conditions are met at time t3, and the position determination of the drone 2 using GPS positioning values is initiated.
[0070] According to the processing examples described above, the drone 2 can reach the target position 31 by switching between two different positioning methods to obtain more reliable positioning values for the drone 2. In particular, since one of the two positioning methods employs UWB wireless communication, which is less affected by multipath reflection, the accuracy of reaching the target position 31 can be increased.
[0071] Figure 11 shows another example of the operation that occurs when the drone 2 lands at the landing port 3. In this example as well, similar to the example shown in Figure 9, acquisition of UWB positioning values begins at time t2, after GPS positioning has started but before the predetermined conditions are met. In this example, until the predetermined conditions are met at time t3 and the position determination of the drone 2 using UWB positioning values begins, the position of the drone 2 is determined using intermediate positioning values obtained based on both GPS positioning values and UWB positioning values.
[0072] As an example, the intermediate positioning value can be calculated as the average of the GPS positioning value and the UWB positioning value. The average calculation may also be performed after applying weighting coefficients according to the reliability of each positioning value as described above. The intermediate positioning value obtained in this way is an example of a third positioning value.
[0073] Figure 12 shows another example of the operation that occurs when the drone 2 takes off from the landing port 3. In this example as well as in the example shown in Figure 10, the acquisition of GPS positioning values begins at time t2, after UWB positioning has started but before the predetermined conditions are met. In this example as well as in the example shown in Figure 11, the position of the drone 2 is determined using intermediate positioning values obtained based on both GPS positioning values and UWB positioning values until the predetermined conditions are met at time t3 and the position determination of the drone 2 using GPS positioning values begins.
[0074] With this configuration, by utilizing the period during which GPS positioning and UWB positioning are performed in parallel, an intermediate positioning value can be provided that can buffer the switching between GPS positioning and UWB positioning used to determine the drone 2's location. Therefore, the switching between the two positioning methods can be made smoother.
[0075] In the operational examples illustrated in Figures 6, 9, and 11, UWB positioning is initiated after GPS positioning has started. However, UWB positioning may be initiated simultaneously with GPS positioning.
[0076] In the operational examples illustrated in Figures 8, 10, and 12, GPS positioning is initiated after UWB positioning has started. However, GPS positioning may be initiated simultaneously with UWB positioning.
[0077] As illustrated in Figure 2, the drone 2 is equipped with a sensor 26. The sensor 26 includes at least one sensor that acquires information related to the flight environment of the drone 2 and outputs sensor data corresponding to that information. Examples of such sensors include a barometric pressure sensor and a camera.
[0078] In this case, the computing device of the drone-side control device 23 may be configured to evaluate the reliability of at least one of the GPS positioning values and UWB positioning values by referring to sensor data.
[0079] For example, sensor data may include information corresponding to atmospheric pressure detected by a barometric pressure sensor. In this case, the computing device may be configured to calculate the flight altitude of the drone 2 based on the information corresponding to atmospheric pressure. The computing device compares the calculated altitude value with the z-axis value corresponding to the height direction in the three-dimensional coordinate system corresponding to the GPS positioning value, and determines that the reliability of the GPS positioning value has fallen below the threshold if the difference value or the index value associated with the difference value exceeds the threshold. Similarly, the computing device compares the calculated altitude value with the z-axis value corresponding to the height direction in the three-dimensional coordinate system corresponding to the UWB positioning value, and determines that the reliability of the UWB positioning value has fallen below the threshold if the difference value or the index value associated with the difference value exceeds the threshold.
[0080] As an alternative example, sensor data may include image information acquired by a camera. In this case, the computing unit may be configured to determine the flight environment of the drone 2 based on this image information. For example, if it is determined that the drone 2 is flying in an area surrounded by buildings, the computing unit will determine that the reliability of the GPS positioning values has fallen below a threshold.
[0081] With this configuration, it is possible to add criteria for determining the reliability of positioning values, which can only be defined within each positioning method, based on information acquired by the sensor 26. This increases the diversity of criteria related to determining the reliability of positioning.
[0082] A computing device capable of performing the various processes described above can be realized by at least one dedicated integrated circuit equipped with memory elements on which a computer program for realizing the said process is pre-installed. Examples of dedicated integrated circuits include microcontrollers, ASICs, and FPGAs.
[0083] Alternatively, the arithmetic unit may be implemented by at least one general-purpose microprocessor operating in cooperation with at least one general-purpose memory. Examples of general-purpose microprocessors include CPUs, MPUs, and GPUs. Examples of general-purpose memory include ROMs and RAMs. In this case, the ROM may store a computer program for implementing the function. The general-purpose microprocessor selects at least a portion of the program stored in the ROM and loads it into the RAM, and then works with the RAM to execute the above-described process. The arithmetic unit may also be implemented by a combination of a general-purpose microprocessor and a dedicated integrated circuit.
[0084] The configurations described herein are merely examples to facilitate understanding of this disclosure. Each configuration example may be modified and combined with other configuration examples as appropriate, without departing from the spirit of this disclosure.
[0085] In the above embodiment example, the computing unit of the drone-side control device 23 switches between GPS positioning values and UWB positioning values for determining the position of the drone 2. However, if the sensor 26 includes a stereo camera, the sensor data may include image information in which the target position 31 acquired by the stereo camera is captured. The computing unit can acquire the positioning value of the drone 2 relative to the target position 31 based on this image information. The process of acquiring the positioning value of the drone 2 using a stereo camera is referred to as "camera positioning". The positioning value of the drone 2 acquired by camera positioning is referred to as "camera positioning value". Camera positioning is an example of a second positioning method.
[0086] When drone 2 lands at takeoff / landing port 3, the camera positioning value can be an example of the first positioning value. When drone 2 takes off from takeoff / landing port 3, the camera positioning value can be an example of the second positioning value.
[0087] For example, the reliability of camera positioning values can be determined based on whether or not an object exists within a predetermined range from the target position 31. Examples of objects include unexpected people, animals, or other objects. If the presence of such an object is confirmed as a result of processing the above image information, the computing unit determines that the reliability of the camera positioning values has fallen below a threshold.
[0088] As an alternative, the reliability of camera positioning values can be determined based on the visibility of the target location 31. Under adverse weather conditions such as rain, snow, or fog, the visibility of the target location 31 in the image acquired by the sensor 26 decreases. If, as a result of processing the above image information, the index value corresponding to the visibility of the target location 31 is determined to be below a threshold, the computing unit determines that the reliability of the camera positioning values has fallen below the threshold.
[0089] The "UWB wireless communication standard" used in the above embodiment example originates from a standardization standard compliant with IEEE 802.15. However, this expression is not intended to limit the scope to that standard. Any short-range wireless communication standard that can determine the relative positions of communication devices with high accuracy and has advantages such as low power consumption and low interference with other communications may be adopted. For example, distance values may be obtained by short-range wireless communication compliant with the Bluetooth Low Energy (registered trademark) standard.
[0090] In the above embodiment, the drone-side control device 23 is equipped with a computing device that performs processing to estimate the position and attitude of the drone 2. However, this computing device may also be equipped in the port-side control device 33. In this case, the data indicating the estimated position and attitude of the drone 2 can be transmitted to the drone 2 using, for example, the auxiliary communication device 34 described above.
[0091] 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.
[0092] The contents of Japanese Patent Application No. 2025-053796, filed on 27 March 2025, are incorporated herein by reference as forming part of this disclosure.
Claims
1. A positioning method for a moving object, performed by at least one computing device, comprising: at a first time point, starting to acquire a first position value of the moving object using either a first positioning method that uses short-range wireless communication compliant with the UWB wireless communication standard or a second positioning method different from the first positioning method; at a second time point following the first time point, starting to acquire a second position value of the moving object using the other of the first positioning method and the second positioning method; identifying the position of the moving object using the first position value until a predetermined condition is satisfied; and, once the predetermined condition is satisfied, starting to identify the position using the second position value, wherein the predetermined condition is at least one of the following: the reliability of the first position value is below a first threshold and the reliability of the second position value is above a second threshold.
2. The positioning method according to claim 1, wherein, from the time the acquisition of the second positioning value is started until the predetermined conditions are satisfied, the position is determined using a third positioning value obtained based on both the first positioning value and the second positioning value.
3. The positioning method according to claim 1 or 2, wherein the reliability of at least one of the first positioning value and the second positioning value is determined using a sensor that acquires information relating to the moving environment of a moving object.
4. The positioning method according to any one of claims 1 to 3, wherein the second positioning method uses GPS.
5. The positioning method according to any one of claims 1 to 4, wherein the moving body is an aerial vehicle.
6. A computing device configured to perform the positioning method described in any one of claims 1 to 5.
7. A mobile body equipped with the computing device described in claim 6.