WO2018177271A1

WO2018177271A1 - Ultrasonic distance measurement device and method and related unmanned aerial vehicle

Info

Publication number: WO2018177271A1
Application number: PCT/CN2018/080604
Authority: WO
Inventors: 胡华智; 姚俊浩
Original assignee: 亿航智能设备（广州）有限公司
Priority date: 2017-03-28
Filing date: 2018-03-27
Publication date: 2018-10-04
Also published as: CN107450077A

Abstract

An ultrasonic distance measurement device and method and a related unmanned aerial vehicle. The ultrasonic distance measurement device comprises: an ultrasonic processing chip; a drive amplification circuit connected with the ultrasonic processing chip; an ultrasonic probe connected with the drive amplification circuit; and a filter circuit connected with the ultrasonic probe. The ultrasonic processing chip is used for transmitting a drive signal, recording the time and calculating the distance; the drive amplification circuit is used for carrying out amplification processing on the drive signal transmitted by the ultrasonic processing chip; the ultrasonic probe is used for converting the drive signal obtained after amplification processing into ultrasonic waves, transmitting the ultrasonic waves and receiving the reflected ultrasonic waves; and the filter circuit is used for carrying out preliminary filtration on the reflected ultrasonic waves and transmitting the filtered signal to the ultrasonic processing chip. The device can improve the distance measurement accuracy of the unmanned aerial vehicle.

Description

Ultrasonic distance measuring device and method and related aircraft

[0001] The present application relates to the field of aircraft technology, and relates to a distance measuring device and method for an aircraft, and in particular to an ultrasonic distance measuring device and method and related aircraft.

Background technique

[0002] An unmanned aerial vehicle, referred to as a drone, is a rapidly developing flying device that has the advantages of mobility, rapid response, unmanned flight, and low operational requirements. UAVs are equipped with a variety of sensors to achieve real-world image transmission and high-risk area detection. They are a powerful complement to satellite remote sensing and traditional aerial remote sensing. At present, the scope of use of drones has expanded to three major areas of military, scientific research and civil use, specifically in power, communications, meteorology, agriculture, oceanography, exploration, photography, disaster prevention and mitigation, crop yield estimation, anti-drug, border patrol, law and order. The field of anti-terrorism and other fields are widely used.

[0003] The distance measuring device is a very important device in the drone, which is used to provide the drone with information such as the flying height and the distance from the obstacle, thereby contributing to flight safety. In existing drones, flying heights are usually measured using a fixed height gauge and a barometer. However, in indoor environments or when flying altitudes are low, there are problems such as inaccurate measurement such as height gauges and barometers.

[0004] For this reason, some companies have issued some ultrasonic ranging devices. However, the existing ultrasonic distance measuring devices have problems such as poor precision, complicated equipment, and high cost.

In view of the above drawbacks of the prior art, a new type of ultrasonic distance measuring device is urgently needed.

technical problem

Problem solution

Technical solution

[0006] The purpose of the present application is to overcome the shortcomings of the prior art, and provide an ultrasonic distance measuring device and method to solve the problems of inaccurate measurement, poor precision, complicated equipment, high cost, and the like in the current fixed height of the aircraft. .

In order to achieve the above object, the present application provides the following technical solutions: [0008] An ultrasonic distance measuring device comprising an ultrasonic processing chip, further comprising: a driving amplifying circuit connected to the ultrasonic processing chip, an ultrasonic probe connected to the driving amplifying circuit, and the ultrasonic probe a connected filter circuit, wherein the ultrasonic processing chip is configured to emit a driving signal, record a turn-to-turn and calculate a distance, and the driving amplifying circuit is configured to perform amplification processing on a driving signal sent by the ultrasonic processing chip, the ultrasonic probe And a method for converting the amplified driving signal into ultrasonic waves and receiving the reflected ultrasonic waves, wherein the filtering circuit is configured to perform preliminary filtering on the reflected ultrasonic waves and send the filtered signals back to the ultrasonic processing chip.

[0009] wherein the ultrasonic distance measuring device further comprises a digital temperature sensor connected to the ultrasonic processing chip, wherein the digital temperature sensor is configured to measure temperature and transmit the measured temperature to the ultrasonic processing chip.

[0010] Further, wherein the digital temperature sensor is LM75A.

[0011] Further, wherein the ultrasonic processing chip is PGA450-Q1.

[0012] Further, wherein the driving signal sent by the PGA 450-Q1 is a square wave of 40 kHz.

[0013] Still further, wherein the driving amplification circuit comprises an intermediate frequency amplifying circuit and a resonant network amplifying circuit.

[0014] Further, in the present application, the ultrasonic probe is a transceiving integrated ultrasonic probe.

[0015] Further, wherein the ultrasonic probe is of the type NU40C16TR-2.

[0016] Further, wherein the filter circuit is a median filter circuit.

[0017] Further, wherein the ultrasonic processing chip is in communication with a main control unit of the flight control system

Further, wherein the ultrasonic processing chip is communicably connected to the main control unit of the flight control system through the universal asynchronous transceiver.

[0019] In the present application, there is also provided a method for performing ultrasonic ranging using the above ultrasonic ranging device, which comprises the following steps:

[0020] 1), the driving signal is sent by the ultrasonic processing chip and recording the turn-off of the driving signal; [0021] 2), the driving signal is amplified by the driving amplifying circuit;

[0022] 3) converting, by the ultrasonic probe, the amplified driving signal into ultrasonic waves and emitting; [0023] 4) receiving, by the ultrasonic probe, the reflected ultrasonic waves; [0024] 5), through the filter circuit to perform preliminary filtering on the reflected ultrasonic waves and send the preliminary filtered signal back to the ultrasonic processing chip;

[0025] 6), the ultrasonic processing chip receives the initially filtered signal and records the time;

[0026] 7) The ultrasonic processing chip calculates the distance according to the inter-turn difference and the sound speed between the two recording turns.

[0027] The method further includes: testing a temperature by the digital temperature sensor; and, the step 7

The ultrasonic processing chip determines the temperature-compensated sound velocity based on the temperature, and calculates the distance based on the inter-turn difference between the two recordings and the temperature-compensated sound velocity.

[0028] Further, wherein the ultrasonic processing chip receives the initially filtered signal and records the time interval: the ultrasonic processing chip collects the same signal as the ultrasonic frequency band emitted by the ultrasonic probe in the preliminary filtered signal. And collecting the same signal as the ultrasonic frequency band emitted by the ultrasonic probe, and recording the time.

[0029] Further, the method further includes:

[0030] 8), sending the calculated distance to the main control unit of the flight control system.

[0031] Moreover, the present application further provides another method for performing ultrasonic ranging using the above ultrasonic ranging device.

, characterized in that it comprises the following steps:

[0032] 1), sending a driving signal through the ultrasonic processing chip and recording the turn-off of the driving signal; [0033] 2), the driving signal is amplified by the driving amplifying circuit;

[0034] 3) converting, by the ultrasonic probe, the amplified driving signal into ultrasonic waves and emitting; [0035] 4) receiving, by the ultrasonic probe, the reflected ultrasonic waves;

[0036] 5), performing preliminary filtering on the reflected ultrasonic wave by the filtering circuit and sending the initially filtered signal back to the ultrasonic processing chip;

[0037] 6), the ultrasonic processing chip receives the initially filtered signal and records the time;

[0038] 7) The ultrasonic processing chip sends the two recordings to the main control unit of the flight control system and the main control unit of the flight control system calculates the distance according to the inter-turn difference and the sound speed between the two recordings.

[0039] The method further includes: testing the temperature by the digital temperature sensor; and, in the step 7), the ultrasonic processing chip also transmits the tested temperature to the main control unit of the flight control system, the flight The main control unit of the control system determines the temperature-compensated sound velocity according to the temperature, and calculates the distance according to the inter-turn difference between the two recordings and the temperature-compensated sound velocity. [0040] Further, wherein the ultrasonic processing chip receives the initially filtered signal and records the inter-times: the ultrasonic processing chip collects the same signal as the ultrasonic frequency band emitted by the ultrasonic probe in the preliminary filtered signal. And collecting the same signal as the ultrasonic frequency band emitted by the ultrasonic probe, and recording the time.

[0041] Further, wherein the ultrasonic processing chip sends a driving signal every 100 ms.

[0042] Further, wherein the filter circuit filters out frequency bands other than 40 kHz.

Furthermore, the present application also provides an aircraft characterized in that it has the above-described ultrasonic distance measuring device.

Moreover, the present application also provides another aircraft characterized in that it uses the above method for ranging.

[0045] Further, wherein the aircraft is a drone.

Advantageous effects of the invention

Beneficial effect

[0046] 1. It uses ultrasonic waves for distance measurement, and the measurement is accurate, especially in indoor environments or when the flying height is low, the advantages are more obvious.

[0047] 2. Since the speed of sound is affected by temperature, the digital temperature sensor is added for temperature compensation, and the sound speed is calculated according to the temperature, thereby improving the accuracy of the distance measurement.

[0048] 3. The detection result of the application adopts median filtering to filter out pulse spikes and improve the stability of ranging.

[0049] 4. The structure of the application is simple and low in cost.

Brief description of the drawing

DRAWINGS

1 is a schematic view showing the configuration of an ultrasonic distance measuring device of the present application.

2 is a flow chart of a method for performing ranging using the ultrasonic distance measuring device of the present application.

3 is a flow chart of another method for performing ranging using the ultrasonic ranging device of the present application.

Embodiments of the invention

[0053] The present application is further described below with reference to the accompanying drawings and embodiments, and the contents of the embodiments are not to be construed as limiting the scope of the application.

[0054] The distance can be measured by using ultrasonic waves, and the working principle of using ultrasonic waves for ranging is as follows: The transmitter emits ultrasonic waves and records the daytime. The ultrasonic receiver receives the ultrasonic waves and records the time between the turns, and the distance between the turns and the receiving turns is used to calculate the distance. Specifically, the ultrasonic transmitter emits ultrasonic waves in a certain direction, and the ultrasonic wave propagates in the air at the same time as the eclipse is emitted, and immediately returns to the obstacle when it hits the obstacle, and the ultrasonic receiver receives the reflected wave immediately. Stop counting. At the same time, it is known that the propagation speed of ultrasonic waves in air at normal temperature is usually 343 m/s. Thus, according to the inter-turn t recorded by the meter, the distance s from the obstacle to the obstacle can be calculated, ie: s=343t /2.

[0055] The present application is to achieve the ranging of the aircraft according to the above working principle. Specifically, Fig. 1 is a schematic view showing the configuration of an ultrasonic distance measuring device of the present application. As shown in Fig. 1, the ultrasonic distance measuring device of the present application includes an ultrasonic processing chip. The ultrasonic processing chip is used to emit a driving signal, record a turn-to-turn, and calculate a distance.

[0056] In the present application, preferably, the ultrasonic processing chip is PGA450-Q1. The PGA450-Q1 is a fully integrated programmable drive ultrasonic sensor solution that includes the following system modules: Voltage Regulator, 12-bit Successive Approximation Register (SAR), Analog to Digital Converter (ADC), 8-bit Microcontroller , digital bandpass filter, digital to analog converter (DAC), dual NMOS low side driver, low noise amplifier, oscillator, LIN 2.1 physical interface and related protocols. The PGA450-Q1 is also equipped with an 8-bit microcontroller and OTP program memory for processing echo signals and calculating the distance between the sensor and the object. The ranging function of the present application can be well achieved by the PGA450-Q1. More preferably, the drive signal from the PGA 450-Q1 is a 40 kHz square wave for subsequent processing.

[0057] The ultrasonic distance measuring device further includes a driving amplifying circuit connected to the ultrasonic processing chip, an ultrasonic probe connected to the driving amplifying circuit, and a filtering circuit connected to the ultrasonic probe.

[0058] wherein the driving amplifying circuit is configured to perform amplification processing on a driving signal sent by the ultrasonic processing chip. In the present application, preferably, the drive amplifying circuit includes an intermediate frequency amplifying circuit and a resonant network amplifying circuit. The 40 kHz method of the PGA 450-Q1 is amplified by the intermediate frequency amplifying circuit and the resonant network amplifying circuit to facilitate subsequent ultrasonic probes to convert the ultrasonic waves into ultrasonic waves.

[0059] The ultrasonic probe is configured to convert the amplified driving signal into ultrasonic waves and receive the reflected ultrasonic waves. In the present application, preferably, the ultrasonic probe is a transceiving integrated ultrasonic probe. More preferably, the ultrasonic probe is of the type NU40C16TR-2. NU40C16TR-2 is a transceiver integrated ultrasonic probe provided by Shenzhen Golden Porcelain Technology Co., Ltd., which can easily realize ultrasonic wave. Send and receive.

[0060] the filter circuit is configured to perform preliminary filtering on the reflected ultrasonic waves and send the filtered signals back to the ultrasonic processing chip, and the ultrasonic processing chip performs processing, for example, performing distance according to the inter-turn difference Calculation, etc. In the present application, preferably, the filter circuit is a median filter circuit. The median filtering is used to filter out the pulse spikes, which improves the stability of the ranging. In the present application, the filter circuit mainly performs filtering according to the frequency band used by the probe. As described above, a square wave of 40 kHz is used in the present application, and therefore, the filter circuit filters out a frequency band other than 40 kHz.

[0061] The present application uses ultrasonic waves for ranging, and the measurement is accurate, especially in indoor environments or when the flying height is low, and the advantages are more obvious.

[0062] In the same way, it is known that the propagation speed of ultrasonic waves in air is affected by temperature, that is, c = (331.45 + 0.

61t/°C) m/s, where 331.45 is the velocity of the ultrasonic wave in air at 0 degrees, t is the temperature, and c is the propagation velocity of the ultrasonic wave in the air at a temperature of t吋.

[0063] Since the propagation speed of ultrasonic waves in the air is affected by temperature, if the distance is calculated at a fixed speed of 340 m/s, there is naturally an error. Accordingly, in the present application, the ultrasonic distance measuring device further includes a digital temperature sensor coupled to the ultrasonic processing chip. The digital temperature sensor is for measuring temperature and transmitting the measured temperature to the ultrasonic processing chip. Thus, the ultrasonic processing chip can determine the accurate ultrasonic wave propagation speed by using the above formula according to the temperature, thereby improving the accuracy of the ranging.

[0064] In the present application, preferably, the digital temperature sensor is LM75A. The LM75A is a high-speed I2C interface temperature sensor that converts temperature directly to digital signals from -55°C to +125°C and achieves an accuracy of 0.125°C. The ultrasonic processing chip can directly read data in its internal register through the I2C bus. This makes it easy to obtain digital temperature data directly, making it easy to determine the temperature compensated sound velocity.

[0065] Since the ultrasonic ranging device is used for ranging of an aircraft, in the present application, the ultrasonic processing chip is communicably connected with a main control unit of the flight control system, so as to directly output a distance value to the calculated distance. The main control unit of the flight control system, or directly output the detected data (such as temperature and time) to the main control unit of the flight control system, and the distance is calculated by the main control unit of the flight control system.

[0066] In the present application, preferably, the ultrasonic processing chip passes through a universal asynchronous transceiver (Universal Asynchronous Receiver/Transmitter (abbreviated as UART) is connected to the main control unit of the flight control system. The Universal Asynchronous Receiver is a general purpose serial data bus for asynchronous communication. The bus bidirectional communication enables full duplex transmission and reception. Therefore, the universal asynchronous transceiver is used to facilitate information interaction between the main control unit of the flight control system and the ultrasonic processing chip.

2 shows a flow chart of a method of performing ranging using the ultrasonic ranging device of the present application. As shown in Figure 2, the method includes the following steps:

[0068] 1. The driving signal is sent by the ultrasonic processing chip and the time when the driving signal is sent is recorded.

[0069] 2. The driving signal is amplified by the driving amplifier circuit.

[0070] 3. The amplified driving signal is converted into ultrasonic waves by the ultrasonic probe and emitted.

[0071] 4. The reflected ultrasonic wave is received by the ultrasonic probe.

[0072] 5. Performing preliminary filtering on the reflected ultrasonic waves by the filtering circuit and sending the initially filtered signals back to the ultrasonic processing chip.

[0073] 6. The ultrasonic processing chip receives the initially filtered signal and records the daytime.

[0074] 7. The ultrasonic processing chip calculates the distance according to the inter-turn difference and the sound speed between the two recording turns.

[0075] Of course, the method can further include testing the temperature by the digital temperature sensor. Moreover, in the seventh step, the ultrasonic processing chip determines the temperature-compensated sound velocity according to the temperature, and calculates the distance according to the inter-turn difference between the two recording turns and the temperature-compensated sound velocity.

[0076] In the present application, in the present application, the receiving, by the ultrasonic processing chip, the preliminary filtered signal and recording the inter-time may include: the ultrasonic processing chip collecting the ultrasonically-derived frequency band emitted by the ultrasonic probe from the preliminary filtered signal The same signal, and the same signal as the ultrasonic frequency band emitted by the ultrasonic probe is collected and recorded.

[0077] Finally, the calculated distance can be sent to the main control unit of the flight control system.

3 shows a flow chart of another method of performing ranging using the ultrasonic ranging device of the present application. As shown in FIG. ₃ , similar to the previous method, the method also includes the following steps:

[0079] 1. The driving signal is sent by the ultrasonic processing chip and the time when the driving signal is sent is recorded.

[0080] 2. The driving signal is amplified by the driving amplification circuit.

[0081] 3. The amplified driving signal is converted into ultrasonic waves by the ultrasonic probe and emitted.

[0082] 4. The reflected ultrasonic wave is received by the ultrasonic probe. [0083] 5. Performing preliminary filtering on the reflected ultrasonic waves by the filtering circuit and sending the initially filtered signals back to the ultrasonic processing chip.

[0084] 6. The ultrasonic processing chip receives the initially filtered signal and records the daytime.

[0085] Different from the previous method, in the method, the ultrasonic processing chip does not directly calculate the distance, but sends the two recordings to the main control unit of the flight control system and is controlled by the flight control system. The master unit calculates the distance based on the inter-turn difference and the speed of sound between the two recordings.

[0086] Preferably, the method further comprises testing the temperature by the digital temperature sensor; and the ultrasonic processing chip also transmits the tested temperature to the main control unit of the flight control system, the main control unit of the flight control system The temperature-compensated sound velocity is determined according to the temperature, and the distance is calculated according to the inter-turn difference between the two recording turns and the temperature-compensated sound velocity.

[0087] In the present application, the ultrasonic processing chip receives the initially filtered signal and records the inter-times: the ultrasonic processing chip collects the same signal as the ultrasonic frequency band emitted by the ultrasonic probe in the preliminary filtered signal. And collecting the same signal as the ultrasonic frequency band emitted by the ultrasonic probe, and recording the time.

[0088] In the present application, the ultrasonic processing chip may send a driving signal every 100 ms and receive echo data to calculate a distance, that is, a data output frequency of 10 Hz.

[0089] Of course, in the present application, an aircraft having the above-described ultrasonic distance measuring device is also required to be protected. As long as the aircraft employs the above ultrasonic ranging device, it falls within the scope of protection of the present application.

[0090] Also, in the present application, an aircraft employing the above ultrasonic waves, in particular, a drone, is also claimed. As long as the aircraft adopts the above ultrasonic ranging method, it falls within the scope of protection of the present application.

[0091] Finally, preferably, the aircraft is a drone.

The above-described embodiments of the present application are merely illustrative of the present invention and are not intended to limit the embodiments of the present application. Other variations or modifications of the various forms may be made by those skilled in the art in light of the above description. It is not possible to exhaust all implementations here. Obvious changes or variations that extend to the technical solution of the present application are still within the scope of this application.

Claims

Claim

[Answer 1] An ultrasonic distance measuring device comprising an ultrasonic processing chip, further comprising: a driving amplifying circuit connected to the ultrasonic processing chip, an ultrasonic probe connected to the driving amplifying circuit, and the a filter circuit connected to the ultrasonic probe, wherein the ultrasonic processing chip is configured to emit a driving signal, record the inter-turn and calculate the distance, and the driving amplifying circuit is configured to perform amplification processing on the driving signal sent by the ultrasonic processing chip, The ultrasonic probe is configured to convert the amplified driving signal into ultrasonic waves and receive the reflected ultrasonic waves, and the filtering circuit is configured to perform preliminary filtering on the reflected ultrasonic waves and send the filtered signals back to the ultrasonic processing chip. .

[Claim 2] The ultrasonic distance measuring device according to claim 1, further comprising a digital temperature sensor connected to the ultrasonic processing chip, wherein the digital temperature sensor is configured to measure temperature and transmit the measured temperature The ultrasonic processing chip is given.

[Claim 3] The ultrasonic distance measuring device according to claim 2, wherein the digital temperature sensor is an LM75A.

[Attachment 4] The ultrasonic distance measuring device according to claim 3, wherein the ultrasonic processing chip is PGA450-Q1.

[Attachment 5] The ultrasonic distance measuring device according to claim 4, wherein the PGA450-Q

The driving signal sent by 1 is a square wave of 40 kHz.

[Claim 6] The ultrasonic distance measuring device according to claim 5, wherein the drive amplifying circuit includes an intermediate frequency amplifying circuit and a resonant network amplifying circuit.

The ultrasonic distance measuring device according to claim 6, wherein the ultrasonic probe is a transceiving integrated ultrasonic probe.

The ultrasonic distance measuring device according to claim 7, wherein the ultrasonic probe is of the type NU40C16TR-2.

The ultrasonic distance measuring device according to claim 8, wherein the filter circuit is a median filter circuit.

The ultrasonic distance measuring device according to any one of claims 1 to 9, wherein the ultrasonic processing chip is communicably connected to a main control unit of the flight control system.

[Ansm. 11] The ultrasonic distance measuring device according to claim 10, wherein the ultrasonic processing chip is communicably connected to a main control unit of the flight control system through a universal asynchronous transceiver.

[Claim 12] A method for ultrasonic ranging using the ultrasonic distance measuring device according to any one of claims 1 to 11, characterized in that it comprises the following steps:

1) transmitting a driving signal through the ultrasonic processing chip and recording a time when the driving signal is sent;

2), performing amplification processing on the driving signal by using the driving amplification circuit;

3) converting the amplified driving signal into ultrasonic waves by using the ultrasonic probe;

4) receiving, by the ultrasonic probe, the reflected ultrasonic wave;

5), performing preliminary filtering on the reflected ultrasonic waves by using the filtering circuit, and sending the preliminary filtered signals back to the ultrasonic processing chip;

6), the ultrasonic processing chip receives the initially filtered signal and records the daytime;

7) The ultrasonic processing chip calculates the distance according to the inter-turn difference and the sound velocity between the two recording turns.

[Claim 13] The method according to claim 12, further comprising: testing a temperature by the digital temperature sensor; and, in the step 7), the ultrasonic processing chip determines the passing according to the temperature The speed of sound after temperature compensation, and the distance is calculated based on the inter-turn difference between the two recording turns and the speed of sound after the temperature compensation.

[Claim 14] The method according to claim 13, wherein the ultrasonic processing chip receives the preliminary filtered signal and records the inter-times: the ultrasonic processing chip collects the preliminary filtered signal and the The ultrasonic probe emits the same signal in the ultrasonic frequency band, and collects the same signal as the ultrasonic frequency band emitted by the ultrasonic probe.

[Claim 15] The method according to claim 14, further comprising:

8) Send the calculated distance to the main control unit of the flight control system.

[Claim 16] A method for performing ultrasonic ranging using the ultrasonic distance measuring device according to any one of claims 1 to 11, comprising the steps of:

1), sending a driving signal through the ultrasonic processing chip and recording a driving signal Daytime

4) receiving, by the ultrasonic probe, the reflected ultrasonic wave;

7) The ultrasonic processing chip transmits the two recordings to the main control unit of the flight control system and the main control unit of the flight control system calculates the distance according to the inter-turn difference and the sound speed between the two recordings.

[Claim 17] The method according to claim 16, further comprising: testing a temperature by the digital temperature sensor; and, in the step 7), the ultrasonic processing chip also sends the tested temperature Providing to the main control unit of the flight control system, the main control unit of the flight control system determines the temperature-compensated sound velocity according to the temperature, and calculates the distance according to the inter-turn difference between the two recording turns and the temperature-compensated sound speed .

[Claim 18] The method according to claim 17, wherein the ultrasonic processing chip receives the preliminary filtered signal and records the inter-times: the ultrasonic processing chip collects the preliminary filtered signal and the The ultrasonic probe emits the same signal in the ultrasonic frequency band, and collects the same signal as the ultrasonic frequency band emitted by the ultrasonic probe.

The method according to any one of claims 12 to 18, wherein the ultrasonic processing chip emits a driving signal every 100 ms.

[Claim 20] The method according to claim 19, wherein the filter circuit filters out 40k

A frequency band other than Hz.

[Claim 21] An aircraft having the ultrasonic distance measuring device according to any one of claims 1-11.

[Claim 22] An aircraft, characterized in that it is subjected to ranging using the method of any one of claims 12-20. [Aspect 23] The aircraft according to claim 21 or 22, wherein the aircraft is a drone.