WO2020051785A1

WO2020051785A1 - Impeller posture information obtaining method and nacelle-type laser radar

Info

Publication number: WO2020051785A1
Application number: PCT/CN2018/105151
Authority: WO
Inventors: 肖增利; 周军; 黄晨; 李智; 朱海龙
Original assignee: 南京牧镭激光科技有限公司
Priority date: 2018-09-12
Filing date: 2018-09-12
Publication date: 2020-03-19

Abstract

Provided are an impeller posture information obtaining method and a nacelle-type laser radar (100). When it is detected that a light signal transmitted from a laser (110) is shielded by an impeller on a fan, a signal processor (140) controls a pulse generator (130) to transmit a ranging pulse signal (S110); then a frequency modulator (120) modulates the ranging pulse signal and the light signal to form a first light pulse signal and transmit same (S120); the signal processor (140) receives a reflection signal returned the impeller after the impeller reflects the first light pulse signal (S130); the signal processor (140) calculates a distance between the nacelle-type laser radar (100) and the impeller according to the preset number of sampling points of the reflection signal (S140); the signal processor (140) obtains the posture information of the impeller according to the distance (S150). The posture information of the impeller is obtained by means of the nacelle-type laser radar (100), so that the posture information of the impeller can be monitored in real time, and valid data is provided so as to maximize power generation efficiency.

Description

Impeller attitude information acquisition method and cabin-type lidar

Technical field

The disclosure relates to the technical field of wind power generation, and in particular, to a method for acquiring attitude information of an impeller and a cabin-type laser radar.

Background technique

In wind power generation, the wind field information is measured by a cabin-type lidar installed on the wind turbine. The cabin-type lidar has the advantages of long detection distance and small interference from the wake of the wind turbine, so it can detect the wind directly in front of the wind turbine. Field information to provide a basis for reducing fan load and yaw correction, so as to achieve maximum fan operation efficiency and increase power generation.

During the operation of the fan, in order to ensure the safety of the fan and improve the power generation efficiency, it is usually necessary to monitor the attitude information of the impeller. In the prior art, the cabin-type laser radar cannot measure the attitude information of the impeller, and because the pulse width of the emitted beam is large When the light beam is blocked by the impeller, the cabin lidar cannot receive a valid signal and cannot output any valid data.

Summary of the Invention

In order to overcome at least one of the above-mentioned shortcomings in the prior art, the present disclosure provides a method for acquiring attitude information of an impeller and a cabin-type laser radar.

According to a first aspect of the present disclosure, there is provided an impeller attitude information acquisition method applied to a cabin-type lidar, the cabin-type lidar being mounted on a fan, the cabin-type lidar including a laser, a frequency modulator, and a pulse generator And a signal processor; the laser is connected to the frequency modulator, the frequency modulator is connected to the pulse generator, the signal processor is connected to the pulse generator, and the method includes:

When detecting that the optical signal emitted by the laser is blocked by an impeller on the fan, the signal processor controls the pulse generator to transmit a ranging pulse signal;

The frequency modulator frequency-modulates the ranging pulse signal and the optical signal to form a first optical pulse signal for transmission;

Receiving, by the signal processor, a reflected signal returned after the first light pulse signal is reflected by the impeller;

Calculating, by the signal processor, a distance between the cabin-type lidar and the impeller according to a preset number of sampling points of the reflected signal;

The signal processor acquires attitude information of the impeller according to the distance.

Optionally, the signal processor calculating the distance between the cabin-type lidar and the impeller according to a preset number of sampling points of the reflected signal includes:

The signal processor is based on

Obtaining a distance between the cabin-type lidar and the impeller;

Wherein, R is the distance between the cabin-type lidar and the impeller, the POS ₁ -POS ₀ are preset sampling points of the reflected signal, c is the speed of light in a vacuum, and F _s is The sampling frequency at which a light pulse signal is sampled.

Optionally, the acquiring, by the signal processor, the attitude information of the impeller according to the distance includes:

The signal processor obtains a pitch angle of the impeller according to the distance, and the pitch angle of the impeller is attitude information of the impeller.

Optionally, the obtaining, by the signal processor, the pitch angle of the impeller according to the distance includes:

Obtaining, by the signal processor, a horizontally varying distance and a vertically varying distance of the impeller within a preset time interval according to the distance;

The signal processor obtains a pitch angle of the impeller according to the horizontal change distance and the vertical change distance.

Optionally, the obtaining, by the signal processor, the horizontally varying distance and the vertically varying distance of the impeller within a preset time interval according to the distance includes:

Obtaining the vertical change distance of the impeller within a preset time interval, and obtaining the horizontal change distance of the impeller within a preset time interval based on L ₂ = abs [R (t ₁ ) -R (t ₂ )], where , L ₁ is the vertical change distance, L ₂ is the horizontal change distance; ω is the rotation angle of the fan, t ₁ is the time when the optical signal is blocked by the impeller on the fan, and t ₂ is the rotation of the fan When the light signal is not blocked by the impeller on the fan when the angle is ω,

Is the average distance between the impeller and the cabin-type lidar within the preset time interval;

The obtaining of the pitch angle of the impeller by the signal processor according to the horizontal change distance and the vertical change distance includes:

Obtain the pitch angle of the impeller.

Optionally, the method further includes:

When it is detected that the optical signal emitted by the laser is not blocked by the impeller on the fan, the signal processor controls the pulse generator to transmit a wind measurement pulse signal;

The frequency modulator frequency-modulates the wind measurement pulse signal and the optical signal to form a second optical pulse signal for transmission;

Receiving, by the signal processor, a return light signal returned by the second light pulse signal after being scattered by aerosol in the atmosphere;

Calculating and obtaining a power spectrum of the back light signal by the signal processor;

The signal processor obtains wind field information according to the power spectrum.

Optionally, the obtaining, by the signal processor, the wind field information according to the power spectrum includes:

Obtaining, by the signal processor, a plurality of radial wind speeds in the wind field information based on v _los = λ (f _peak -f ₀ ) / 2;

Obtaining, by the signal processor, wind speed and wind direction in the wind field information based on the plurality of radial wind speeds;

Where v _los is the radial wind speed of the optical signal, los = 1,2,3 ... n, λ is the wavelength of the optical signal, f _peak is the peak point frequency in the power spectrum, and f ₀ Is the modulation frequency.

Optionally, when detecting that the optical signal emitted by the laser is blocked by an impeller on the fan, the signal processor controls the pulse generator to transmit a ranging pulse signal, including:

The signal processor calculates a signal-to-noise ratio of the return light signal received at the current moment;

When the signal-to-noise ratio of the back-to-light signal received at the current time is lower than the signal-to-noise ratio of the back-to-light signal received by the signal processor before the current time, the signal processor controls the pulse generator to The pulse signal is switched from the wind measurement pulse signal to the ranging pulse signal transmission.

According to a second aspect of the present disclosure, there is provided a cabin-type lidar, the cabin-type lidar being mounted on a fan, the cabin-type lidar including a laser, a frequency modulator, a pulse generator, and a signal processor; the A laser is connected to the frequency modulator, the frequency modulator is connected to the pulse generator, and the signal processor is connected to the pulse generator;

The signal processor is configured to control the pulse generator to transmit a ranging pulse signal when detecting that the optical signal emitted by the laser is blocked by an impeller on the fan;

The frequency modulator is configured to frequency-modulate the ranging pulse signal and the optical signal to form a first optical pulse signal for transmission;

The signal processor is further configured to receive a reflection signal returned after the first light pulse signal is reflected by the impeller;

The signal processor is further configured to calculate a distance between the cabin-type lidar and the impeller according to a preset number of sampling points of the reflected signal;

The signal processor is further configured to obtain attitude information of the impeller according to the distance.

Optionally, the signal processor is configured to be based on

Obtaining a distance between the cabin-type lidar and the impeller;

Optionally, the signal processor is configured to obtain a pitch angle of the impeller according to the distance, and the pitch angle of the impeller is attitude information of the impeller;

Optionally, the signal processor is configured to obtain a horizontally varying distance and a vertically varying distance of the impeller within a preset time interval according to the distance;

The signal processor is configured to obtain a pitch angle of the impeller according to the horizontal change distance and the vertical change distance.

Optionally, the signal processor is configured to be based on

The signal processor is configured to be based on

Obtain the pitch angle of the impeller.

Optionally, the signal processor is further configured to control the pulse generator to transmit a wind measurement pulse signal when it is detected that the optical signal emitted by the laser is not blocked by the impeller on the fan;

The frequency modulator is further configured to frequency-modulate the wind measurement pulse signal and the optical signal to form a second optical pulse signal for transmission;

The signal processor is further configured to receive a return light signal returned by the second light pulse signal after being scattered by the aerosol in the atmosphere;

The signal processor is further configured to calculate and obtain a power spectrum of the back light signal;

The signal processor is further configured to obtain wind field information according to the power spectrum.

Optionally, the signal processor is configured to obtain multiple radial wind speeds in the wind field information based on v _los = λ (f _peak -f ₀ ) / 2;

The signal processor is configured to obtain a wind speed and a wind direction in the wind field information based on the plurality of radial wind speeds;

Optionally, the signal processor is configured to calculate a signal-to-noise ratio of the return light signal received at the current moment;

The signal processor is configured to control the pulse when a signal-to-noise ratio of the light-back signal received at the current time is lower than a signal-to-noise ratio of the light-back signal received by the signal processor before the current time. The generator switches a pulse signal from the wind measurement pulse signal to the range measurement pulse signal transmission.

Compared with the prior art, the present disclosure includes the following beneficial effects:

An embodiment of the present disclosure provides a method for acquiring attitude information of an impeller and a cabin-type lidar. The method uses the signal processor to control the pulse when it is detected that an optical signal emitted by the laser is blocked by an impeller on the fan. The generator transmits a ranging pulse signal, and the frequency modulator then modulates the ranging pulse signal and the optical signal to form a first optical pulse signal for transmission, and the signal processor receives the first optical pulse signal. The reflected signal returned after the impeller reflects, the signal processor calculates a distance between the cabin-type lidar and the impeller according to a preset number of sampling points of the reflected signal, and the signal processor is based on the The attitude information of the impeller is acquired by distance. In this solution, the attitude information of the impeller can be measured by the cabin-type laser radar, so that the attitude information of the impeller can be monitored in real time, and effective data is provided for achieving the maximum power generation efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present disclosure, and therefore are not It should be regarded as a limitation on the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without paying creative work.

FIG. 1 is a schematic installation diagram of a cabin-type lidar provided by an embodiment of the present disclosure; FIG.

2 is a structural block diagram of a cabin-type laser radar according to an embodiment of the present disclosure;

3 is a schematic diagram of obtaining a distance between a cabin-type lidar and an impeller according to an embodiment of the present disclosure;

4 is a schematic diagram of obtaining a pitch angle of an impeller according to an embodiment of the present disclosure;

FIG. 5 is a schematic diagram of dividing a distance gate of an echo signal according to an embodiment of the present disclosure; FIG.

FIG. 6 is a schematic diagram of performing noise cancellation on a back light signal according to an embodiment of the present disclosure; FIG.

7 is a schematic diagram of a pulse signal using two pulse widths according to an embodiment of the present disclosure;

FIG. 8 is a flowchart of a method for acquiring impeller attitude information according to an embodiment of the present disclosure.

Icons: 100-cabin-type lidar; 110-laser; 120-frequency modulator; 130-pulse generator; 140-signal processor.

detailed description

In order to make the objectives, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions in the embodiments of the present disclosure will be described clearly and completely in combination with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments These embodiments are part of, but not all of, the embodiments of the present disclosure. The components of embodiments of the present disclosure, which are generally described and illustrated in the drawings herein, may be arranged and designed in a variety of different configurations.

Accordingly, the following detailed description of embodiments of the present disclosure provided in the accompanying drawings is not intended to limit the scope of the claimed disclosure, but merely to indicate selected embodiments of the present disclosure. Based on the embodiments of the present disclosure, all other embodiments obtained by a person of ordinary skill in the art without making creative efforts fall within the protection scope of the present disclosure.

It should be noted that similar reference numerals and letters indicate similar items in the following drawings, so once an item is defined in one drawing, it need not be further defined and explained in subsequent drawings.

In the description of the present disclosure, it should be noted that the terms “first”, “second”, “third” and the like are only used to distinguish descriptions, and cannot be understood to indicate or imply relative importance.

In the description of the present disclosure, it should also be noted that the terms “setup”, “installation”, “connected”, and “connected” should be understood in a broad sense, for example, fixed connections, unless otherwise specified and limited. It can also be a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present disclosure may be understood on a case-by-case basis.

Please refer to FIG. 1 and FIG. 2. FIG. 1 is a schematic diagram of a cabin-type lidar 100 installation according to an embodiment of the present disclosure. FIG. 2 is a structural block diagram of a cabin-type lidar 100 according to an embodiment of the present disclosure. The cabin-type lidar 100 is mounted on a fan. The cabin-type lidar 100 includes a laser 110, a frequency modulator 120, a pulse generator 130, and a signal processor 140. The laser 110 is connected to the frequency modulator 120. The frequency modulator 120 is connected to the pulse generator 130, and the signal processor 140 is connected to the pulse generator 130.

The laser 110 is configured to emit an optical signal, and the optical signal is a monochromatic optical signal.

The signal processor 140 is configured to control the pulse generator 130 to transmit a ranging pulse signal when it is detected that the optical signal emitted by the laser 110 is blocked by an impeller on the fan.

The pulse generator 130 is configured to transmit a ranging pulse signal, and the ranging pulse signal and the optical signal are both input to the frequency modulator 120, and the frequency modulator 120 is configured to combine the ranging pulse signal with the After the optical signal is frequency-modulated, a first optical pulse signal is formed and transmitted.

The pulse generator 130 is configured to generate a frequency-modulated signal with a certain pulse width, that is, a ranging pulse signal. Assuming that the carrier frequency is f ₀ , that is, the frequency of the ranging pulse signal is f ₀ , if the pulse width of the ranging pulse signal is τ ₂ , The period of the ranging pulse signal is T, then the ranging pulse signal is:

In order to change certain parameters of the optical signal, such as amplitude, frequency, phase, polarization state, and duration, etc., the optical signal needs to be modulated. Therefore, the frequency modulator 120 can Frequency modulation is performed by modulating the optical signal and the ranging pulse signal to form a first optical pulse signal for transmission. Specifically, an acoustic-optical modulator (AOM) can be used to modulate the optical signal.

Because the light signal emitted by the laser 110 is blocked by the impeller on the fan, the first light pulse signal will be blocked by the impeller on the fan when the first light pulse signal is transmitted. Therefore, the first light pulse signal will be reflected by the impeller after it meets the impeller. The signal processor 140 is further configured to receive a reflection signal returned after the first light pulse signal is reflected by the impeller.

The signal processor 140 is further configured to calculate a distance between the cabin-type lidar 100 and the impeller according to a preset number of sampling points of the reflected signal, and the signal processor 140 is further configured to obtain the distance according to the distance. Posture information of the impeller.

Specifically, the signal processor 140 receives the reflected signal, samples the reflected signal to obtain a preset number of sampling points, and obtains a distance between the cabin-type lidar 100 and the impeller according to the preset number of sampling points. Known, the sampling time is known, then the speed is multiplied by the sampling time to obtain the distance between the cabin-type lidar 100 and the impeller.

In addition to the impeller on the fan rotating around the hub of the fan, the impeller can also be pitched, and because the impeller has a certain thickness, the distance between the impeller and the nacelle lidar 100 will change accordingly as the impeller is pitched. The signal processor 140 can obtain the attitude information of the impeller according to the distance, for example, what kind of pitch angle the impeller is in within a certain distance range, thereby obtaining the attitude information of the impeller, That is, the pitch angle of the impeller is the attitude information of the impeller. After obtaining the attitude information of the impeller, the main control device on the fan can control the attitude of the impeller in combination with the wind direction information, thereby improving the power generation efficiency or reducing the fan load.

Therefore, in this embodiment, the distance between the impeller and the nacelle lidar 100 can be obtained to obtain the attitude information of the impeller according to the distance, so that the attitude change of the impeller can be monitored in real time, which provides effective for the fan to achieve the maximum power generation efficiency. data.

As shown in FIG. 3, the signal processor 140 calculates a distance between the cabin-type lidar 100 and the impeller according to a preset number of sampling points of the reflected signal, including:

The distance between the cabin-type lidar 100 and the impeller is obtained.

Wherein R is the distance between the cabin-type lidar 100 and the impeller, the POS ₁ -POS ₀ are the preset sampling points of the reflected signal, c is the speed of light in a vacuum, and F _s is the A sampling frequency at which the first light pulse signal is sampled.

As an implementation manner, the signal processor 140 may obtain a pitch angle of the impeller according to the distance, and the pitch angle of the impeller is attitude information of the impeller. The manner in which the signal processor 140 obtains the pitch angle of the impeller according to the distance may be that the signal processor 140 obtains the horizontal change distance and the vertical change distance of the impeller within a preset time interval according to the distance, and then The signal processor 140 obtains a pitch angle of the impeller according to the horizontal change distance and the vertical change distance.

Specifically, as shown in FIG. 4, the signal processor 140 is based on

Is the average distance between the impeller and the cabin-type lidar 100 within the preset time interval.

The signal processor 140 is based on

Obtain the pitch angle of the impeller.

Since the cabin-type lidar 100 can also be configured to obtain wind field information, in order to enable the cabin-type lidar 100 to obtain not only the attitude information of the impeller but also the wind field information, the pulse generator 130 can send two pulse widths different The pulse signal includes the above-mentioned ranging pulse signal and wind measurement pulse signal, and the pulse generator 130 implements the switching of the pulse signal according to the signal-to-noise ratio of the signal obtained by the signal processor 140. The cabin laser radar 100 The wind field pulse signal is used to measure the wind field information.

The pulse generator 130 can generate two kinds of pulse width frequency modulation signals, namely, a ranging pulse signal and a wind measuring pulse signal. Assuming that the carrier frequency is f ₀ , the pulse width of the wind measuring pulse signal is τ ₁ , and the pulse of the ranging pulse signal is The width is τ ₂ (τ ₂ <τ ₁ ), and the period of the ranging pulse signal and the wind measuring pulse signal is T. The two types of pulse signals are:

Wherein, when the cabin-type laser radar 100 is measuring the wind field information, the signal processor 140 first controls when detecting that the optical signal emitted by the laser 110 is not blocked by the impeller on the fan. The pulse generator 130 transmits a wind measurement pulse signal. The frequency modulator 120 modulates the wind measurement pulse signal and the optical signal to form a second optical pulse signal for transmission. The signal processor 140 receives the second optical pulse signal. The light pulse signal is a return light signal after being scattered by the aerosol in the atmosphere, and then the signal processor 140 calculates and obtains a power spectrum of the return light signal, and the signal processor 140 obtains a wind field according to the power spectrum. information.

It can be understood that, in order to enable the signal processor 140 to control the pulse generator 130 to switch the transmitted pulse signal, if the signal currently received by the signal processor 140 is a return light signal returned by atmospheric aerosol scattering, the signal The processor 140 calculates a signal-to-noise ratio of the return light signal received at the current moment, and when the signal-to-noise ratio of the return light signal received at the current moment is lower than that of the return light signal received by the signal processor 140 before the current moment In the signal-to-noise ratio, the signal processor 140 controls the pulse generator 130 to switch a pulse signal from the wind measurement pulse signal to the distance measurement pulse signal for transmission. If the signal currently received by the signal processor 140 is a reflected signal reflected by the impeller, the signal processor 140 calculates the signal-to-noise ratio of the reflected signal received at the current moment, and when the signal-to-noise ratio of the reflected signal is lower than the When the signal-to-noise ratio of the reflected signal received by the signal processor 140 before the current time, the signal processor 140 controls the pulse generator 130 to switch the pulse signal from the ranging pulse signal to the wind measurement The pulse signal is transmitted.

Therefore, the two types of pulse signals are switched at the falling edge of the signal-to-noise ratio. For example, when the pulse signal currently transmitted by the pulse generator 130 is a ranging pulse signal, if the next time, that is, the current time, the first When a light pulse signal is not blocked by the impeller, since the signal processor 140 receives a reduced effective signal amplitude, the signal-to-noise ratio decreases at this time, indicating that the signal-to-noise ratio is at a falling edge at this time, and the signal processor 140 The pulse generator 130 is controlled to send a wind measurement pulse signal.

When the ranging pulse signal is transmitted by the pulse generator 130, the signal-to-noise ratio calculated by the signal processor 140 is

Wherein the value of the amplitude of the reflected signal A received signal processor 140, the noise amplitude A _n-value.

In the process of measuring the wind field information, the signal processor 140 first calculates the power spectrum of the received back light signal. The calculation process is as follows: first, the distance gate is divided for the back light signal, and then the power spectrum calculation is performed for each distance door separately. Finally, after a certain period of pulse accumulation, the background noise is removed to obtain the signal power spectrum.

As shown in FIG. 5, FIG. 5 is a schematic diagram of the range door division of the return signal. Since the cabin-type lidar 100 needs to measure the wind field information of multiple range doors at the same time, it is necessary to first calculate the starting point position based on the measured section distance, as shown in FIG. As described in 5, for the case where the section distance is R, the starting point position is:

Among them, c is the transmission rate of the optical signal, N is the number of sampling points included in each distance gate, and F _s is the sampling frequency.

In order to improve the operation efficiency, the power spectrum of the return light signal is calculated by using the periodic chart method. Before the signal processor 140 calculates the power spectrum of the return light signal, the return light signal and the light signal must pass through the cabin laser radar 100. The coupler performs beat frequency and sets the received light return signal as:

y = cos (2π (c / λ + f ₀ + f _d ) t)

Among them, c is the speed of light in vacuum, λ is the wavelength of the optical signal, f ₀ is the frequency modulated by the frequency modulator 120, and f _d is the Doppler frequency of the aerosol backscatter signal in the atmosphere.

After the return signal and the optical signal are beaten, the beat frequency signal becomes:

y _d = cos (2π (f ₀ + f _d ) t)

The cabin-type laser radar 100 further includes a balance detector configured to implement the conversion of the photoelectric signal and suppress the common mode signal.

The cabin-type lidar 100 also includes an A / D converter. The A / D converter is configured to convert analog signals to digital signals. In order to avoid spectral aliasing, the sampling rate needs to meet the Nyquist sampling law. After the signal is sampled by the A / D converter, it can be expressed as:

For the above sampled signal, calculate the Fourier transform FFT of s (n), that is:

Therefore, the power spectral density of the signal is:

In order to improve the signal-to-noise ratio, the power spectral density of multiple periodic pulse signals needs to be averaged, and the final output power spectral density is:

Among them, M is the pulse accumulation number.

Due to the presence of optical signal intensity noise and the background noise of the balanced detector, the obtained power spectrum contains relatively fixed background noise, so background noise removal is required. As shown in Figure 6, the received laser energy decreases with increasing distance, the longest distance The aerosol return light will be completely submerged in the background noise. Therefore, the farthest door power spectrum is selected as the background noise.

Let the signal power spectrum after noise cancellation be S (f) and the background noise power spectrum be N (f). When the pulse signal sent by the pulse generator 130 is a wind measurement pulse signal, the signal-to-noise ratio calculated by the signal processor 140 for:

Therefore, the signal processor 140 can control the switching of the pulse signals transmitted by the pulse generator 130 by calculating the signal-to-noise ratio under the two types of pulse signals.

Of course, as another implementation manner, in order to implement switching between two types of pulse signals, the pulse signal transmitted by the pulse generator may include two types of pulse widths. As shown in FIG. 7, after the pulse generator 130 has transmitted the pulse width τ ₁ Signal, the signal is immediately switched to a signal with a pulse width τ ₂ and processed separately after receiving the signal.

In addition, the signal processor 140 obtains multiple radial wind speeds in the wind field information based on v _los = λ (f _peak -f ₀ ) / 2; the signal processor 140 is based on the multiple radial speeds. The wind speed and wind direction are obtained in the wind field information.

Use v _los = λ (f _peak -f ₀ ) / 2 to obtain the radial wind speed of a single beam. If there are multiple beams, such as four, you can calculate the vector sum of the radial wind speeds of the four beams. The wind speed is obtained, and then the wind direction can be obtained based on the four wind speeds. For example, the wind direction can be obtained according to the formula α = arctan (v ₁ / v ₂ ), thereby obtaining wind field information, and providing a data basis for the wind turbine to achieve maximum power generation efficiency.

If there are multiple optical signals emitted by the cabin-type lidar 100, the cabin-type lidar 100 may further include a circulator, an optical switch, and multiple optical antennas. The circulator is connected to the frequency modulator 120 and the optical switch, respectively. Multiple optical antennas are connected. If there are four optical signals, the optical switch can be a 1 * 4 optical switch, which can be switched between 1, 2, 3, and 4 at a fixed frequency to realize the transmission and reception of lasers at four positions in the space. The circulator is configured to isolate the transmitting and receiving signals. When the pulse signal is transmitted outward, only the output port can pass the optical signal with almost no loss, thereby suppressing the intensity of the reflected signal from the optical antenna of the receiving branch.

The optical antenna, which is a telescope, is configured to improve the efficiency of receiving and emitting signals. When the signal is transmitted, the transmission distance of the optical signal can be maximized by adjusting the telescope's focal length. When the signal is received, the telescope can collect scattered light in different directions and converge into parallel light. Thereby improving reception efficiency.

Please refer to FIG. 8. FIG. 8 is a flowchart of a method for acquiring an impeller attitude information according to an embodiment of the present disclosure. The method is applied to the above-mentioned cabin-type laser radar 100. The method includes the following steps:

Step S110: When it is detected that the optical signal emitted by the laser 110 is blocked by the impeller on the fan, the signal processor 140 controls the pulse generator 130 to transmit a ranging pulse signal.

Step S120: The frequency modulator 120 modulates the ranging pulse signal and the optical signal to form a first optical pulse signal for transmission.

Step S130: The signal processor 140 receives a reflection signal that is returned after the first light pulse signal is reflected by the impeller.

Step S140: The signal processor 140 calculates a distance between the cabin-type lidar 100 and the impeller according to a preset number of sampling points of the reflected signal.

Step S150: The signal processor 140 acquires attitude information of the impeller according to the distance.

Optionally, the signal processor 140 calculates a distance between the cabin-type lidar 100 and the impeller according to a preset number of sampling points of the reflected signal, including:

The signal processor 140 is based on

Obtaining the distance between the cabin-type lidar 100 and the impeller;

Optionally, the acquiring, by the signal processor 140, attitude information of the impeller according to the distance includes:

The signal processor 140 obtains a pitch angle of the impeller according to the distance, and the pitch angle of the impeller is attitude information of the impeller.

Optionally, the signal processor 140 obtaining the pitch angle of the impeller according to the distance includes:

Obtaining, by the signal processor 140, a horizontally varying distance and a vertically varying distance of the impeller within a preset time interval according to the distance;

The signal processor 140 obtains a pitch angle of the impeller according to the horizontal change distance and the vertical change distance.

Optionally, the signal processor 140 obtains the horizontally varying distance and the vertically varying distance of the impeller within a preset time interval according to the distance, including: the signal processor 140 is based on

Obtaining the vertical change distance of the impeller within a preset time interval, and obtaining the horizontal change distance of the impeller within a preset time interval based on L ₂ = abs [R (t ₁ ) -R (t ₂ )], where , L ₁ is the vertical change distance, L ₂ is the horizontal change distance; ω is the rotation angle of the fan, t ₁ is the moment when the optical signal is blocked by the impeller on the fan, and t ₂ is the rotation of the fan When the light signal is not blocked by the impeller on the fan when the angle is ω,

Is the average distance between the impeller and the cabin-type lidar 100 within the preset time interval;

The signal processor 140 obtains the pitch angle of the impeller according to the horizontal change distance and the vertical change distance. The signal processor 140 includes:

Obtain the pitch angle of the impeller.

Optionally, the method further includes:

When it is detected that the optical signal emitted by the laser 110 is not blocked by the impeller on the fan, the signal processor 140 controls the pulse generator 130 to transmit a wind measurement pulse signal;

The frequency modulator 120 frequency-modulates the wind measurement pulse signal and the optical signal to form a second optical pulse signal for transmission;

The signal processor 140 receives a return light signal returned by the second light pulse signal after being scattered by aerosol in the atmosphere;

The signal processor 140 calculates and obtains a power spectrum of the back light signal;

The signal processor 140 obtains wind field information according to the power spectrum.

Optionally, the obtaining, by the signal processor 140 according to the power spectrum, wind field information includes:

The signal processor 140 obtains multiple radial wind speeds in the wind field information based on v _los = λ (f _peak -f ₀ ) / 2;

The signal processor 140 obtains a wind speed and a wind direction in the wind field information based on the multiple radial wind speeds;

Optionally, when detecting that the optical signal emitted by the laser 110 is blocked by an impeller on the fan, the signal processor 140 controls the pulse generator 130 to transmit a ranging pulse signal, including:

The signal processor 140 calculates a signal-to-noise ratio of the return light signal received at the current moment;

When the signal-to-noise ratio of the back-to-light signal received at the current time is lower than the signal-to-noise ratio of the back-to-light signal received by the signal processor 140 before the current time, the signal processor 140 controls the pulse generation The transmitter 130 switches a pulse signal from the wind measurement pulse signal to the distance measurement pulse signal for transmission.

Those skilled in the art can clearly understand that, for the convenience and brevity of the description, the specific working process of the method described above can refer to the corresponding process in the aforementioned device, and will not be repeated here.

To sum up, the embodiments of the present disclosure provide a method for acquiring attitude information of an impeller and a cabin-type laser radar 100. When detecting that an optical signal emitted by the laser 110 is blocked by an impeller on the fan, the method The signal processor 140 controls the pulse generator 130 to transmit a ranging pulse signal, and then the frequency modulator 120 modulates the ranging pulse signal and the optical signal to form a first optical pulse signal for transmission. The processor 140 receives a reflected signal returned after the first light pulse signal is reflected by the impeller, and the signal processor 140 calculates the cabin-type lidar 100 and the impeller according to a preset number of sampling points of the reflected signal Distance between the signal processor 140 and the attitude information of the impeller according to the distance. In this solution, the attitude information of the impeller can be measured by the cabin-type laser radar 100, so that the attitude information of the impeller can be monitored in real time, and effective data is provided for maximizing the power generation efficiency.

The above descriptions are merely preferred embodiments of the present disclosure, and are not configured to limit the present disclosure. For those skilled in the art, the present disclosure may have various modifications and changes. Any modification, equivalent replacement, or improvement made within the spirit and principle of this disclosure shall be included in the protection scope of this disclosure.

Industrial applicability

The disclosure can monitor the attitude information of the impeller in real time, and provide effective data for achieving maximum power generation efficiency and fan load control.

Claims

An impeller attitude information acquisition method, which is characterized in that it can be applied to a cabin-type lidar, which is mounted on a fan. The cabin-type lidar includes a laser, a frequency modulator, a pulse generator, and signal processing. The laser is connected to the frequency modulator, the frequency modulator is connected to the pulse generator, the signal processor is connected to the pulse generator, and the method includes:

When detecting that the optical signal emitted by the laser is blocked by an impeller on the fan, the signal processor controls the pulse generator to transmit a ranging pulse signal;

The frequency modulator frequency-modulates the ranging pulse signal and the optical signal to form a first optical pulse signal for transmission;

Receiving, by the signal processor, a reflected signal returned after the first light pulse signal is reflected by the impeller;

Calculating, by the signal processor, a distance between the cabin-type lidar and the impeller according to a preset number of sampling points of the reflected signal;

The signal processor acquires attitude information of the impeller according to the distance.
The method for acquiring impeller attitude information according to claim 1, wherein the signal processor calculates a distance between the cabin-type lidar and the impeller according to a preset number of sampling points of the reflected signal, comprising:

The signal processor is based on
Obtaining a distance between the cabin-type lidar and the impeller;

Wherein, R is the distance between the cabin-type lidar and the impeller, the POS 1 -POS 0 are preset sampling points of the reflected signal, c is the speed of light in a vacuum, and F s is The sampling frequency at which a light pulse signal is sampled.
The method for acquiring impeller attitude information according to claim 2, wherein the acquiring, by the signal processor, the attitude information of the impeller according to the distance comprises:

The signal processor obtains a pitch angle of the impeller according to the distance, and the pitch angle of the impeller is attitude information of the impeller.
The method for acquiring attitude information of an impeller according to claim 3, wherein the obtaining, by the signal processor, the pitch angle of the impeller according to the distance comprises:

Obtaining, by the signal processor, a horizontally varying distance and a vertically varying distance of the impeller within a preset time interval according to the distance;

The signal processor obtains a pitch angle of the impeller according to the horizontal change distance and the vertical change distance.
The method for acquiring impeller attitude information according to claim 4, wherein the signal processor acquires the horizontal change distance and vertical change distance of the impeller within a preset time interval according to the distance, comprising: Processor based
Obtaining the vertical change distance of the impeller within a preset time interval, and obtaining the horizontal change distance of the impeller within a preset time interval based on L 2 = abs [R (t 1 ) -R (t 2 )], where , L 1 is the vertical change distance, L 2 is the horizontal change distance; ω is the rotation angle of the fan, t 1 is the time when the optical signal is blocked by the impeller on the fan, and t 2 is the rotation of the fan When the light signal is not blocked by the impeller on the fan when the angle is ω,
Is the average distance between the impeller and the cabin-type lidar within the preset time interval;

The obtaining of the pitch angle of the impeller by the signal processor according to the horizontal change distance and the vertical change distance includes: the signal processor is based on
Obtain the pitch angle of the impeller.
The method for acquiring impeller attitude information according to any one of claims 1-5, wherein the method further comprises:

When it is detected that the optical signal emitted by the laser is not blocked by the impeller on the fan, the signal processor controls the pulse generator to transmit a wind measurement pulse signal;

The frequency modulator frequency-modulates the wind measurement pulse signal and the optical signal to form a second optical pulse signal for transmission;

Receiving, by the signal processor, a return light signal returned by the second light pulse signal after being scattered by aerosol in the atmosphere;

Calculating and obtaining a power spectrum of the back light signal by the signal processor;

The signal processor obtains wind field information according to the power spectrum.
The method for acquiring impeller attitude information according to claim 6, wherein the obtaining, by the signal processor, the wind field information according to the power spectrum comprises:

Obtaining, by the signal processor, a plurality of radial wind speeds in the wind field information based on v los = λ (f peak -f 0 ) / 2;

Obtaining, by the signal processor, wind speed and wind direction in the wind field information based on the plurality of radial wind speeds;

Where v los is the radial wind speed of the optical signal, los = 1,2,3 ... n, λ is the wavelength of the optical signal, f peak is the peak point frequency in the power spectrum, and f 0 Is the modulation frequency.
The method for acquiring attitude information of an impeller according to claim 6, characterized in that, when detecting that the optical signal emitted by the laser is blocked by the impeller on the fan, the signal processor controls the pulse generator to transmit and detect Pitch signals, including:

The signal processor calculates a signal-to-noise ratio of the return light signal received at the current moment;

When the signal-to-noise ratio of the light-back signal received at the current time is lower than the signal-to-noise ratio of the light-back signal received by the signal processor before the current time, the signal processor controls the pulse generator to The pulse signal is switched from the wind measurement pulse signal to the ranging pulse signal transmission.
A cabin-type lidar, characterized in that the cabin-type lidar is mounted on a fan, the cabin-type lidar includes a laser, a frequency modulator, a pulse generator, and a signal processor; the laser and the frequency A modulator connection, the frequency modulator is connected to the pulse generator, and the signal processor is connected to the pulse generator;

The signal processor is configured to control the pulse generator to transmit a ranging pulse signal when detecting that the optical signal emitted by the laser is blocked by an impeller on the fan;

The frequency modulator is configured to frequency-modulate the ranging pulse signal and the optical signal to form a first optical pulse signal for transmission;

The signal processor is further configured to receive a reflection signal returned after the first light pulse signal is reflected by the impeller;

The signal processor is further configured to calculate a distance between the cabin-type lidar and the impeller according to a preset number of sampling points of the reflected signal;

The signal processor is further configured to obtain attitude information of the impeller according to the distance.
The cabin-type lidar according to claim 9, wherein the signal processor is configured to be based on
Obtaining a distance between the cabin-type lidar and the impeller;

Wherein, R is the distance between the cabin-type lidar and the impeller, the POS 1 -POS 0 are preset sampling points of the reflected signal, c is the speed of light in a vacuum, and F s is The sampling frequency at which a light pulse signal is sampled.
The cabin-type lidar according to claim 10, wherein:

The signal processor is configured to obtain a pitch angle of the impeller according to the distance, and the pitch angle of the impeller is attitude information of the impeller.
The cabin-type lidar according to claim 11, wherein:

The signal processor is configured to obtain a horizontally varying distance and a vertically varying distance of the impeller within a preset time interval according to the distance;

The signal processor is configured to obtain a pitch angle of the impeller according to the horizontal change distance and the vertical change distance.
The cabin-type lidar according to claim 12, wherein:

The signal processor is configured to be based on
Obtaining the vertical change distance of the impeller within a preset time interval, and obtaining the horizontal change distance of the impeller within a preset time interval based on L 2 = abs [R (t 1 ) -R (t 2 )], where , L 1 is the vertical change distance, L 2 is the horizontal change distance; ω is the rotation angle of the fan, t 1 is the moment when the optical signal is blocked by the impeller on the fan, and t 2 is the rotation of the fan When the light signal is not blocked by the impeller on the fan when the angle is ω,
Is the average distance between the impeller and the cabin-type lidar within the preset time interval;

The signal processor is configured to be based on
Obtain the pitch angle of the impeller.
The cabin-type lidar according to any one of claims 9 to 13, wherein:

The signal processor is further configured to control the pulse generator to transmit a wind measurement pulse signal when it is detected that the optical signal emitted by the laser is not blocked by the impeller on the fan;

The frequency modulator is further configured to frequency-modulate the wind measurement pulse signal and the optical signal to form a second optical pulse signal for transmission;

The signal processor is further configured to receive a return light signal returned by the second light pulse signal after being scattered by the aerosol in the atmosphere;

The signal processor is further configured to calculate and obtain a power spectrum of the back light signal;

The signal processor is further configured to obtain wind field information according to the power spectrum.
The cabin-type lidar according to claim 14, wherein:

The signal processor is configured to obtain a plurality of radial wind speeds in the wind field information based on v los = λ (f peak -f 0 ) / 2;

The signal processor is configured to obtain a wind speed and a wind direction in the wind field information based on the plurality of radial wind speeds;

Where v los is the radial wind speed of the optical signal, los = 1,2,3 ... n, λ is the wavelength of the optical signal, f peak is the peak point frequency in the power spectrum, and f 0 Is the modulation frequency.
The cabin-type lidar according to claim 14, wherein:

The signal processor is configured to calculate a signal-to-noise ratio of the return light signal received at the current moment;

The signal processor is configured to control the pulse when a signal-to-noise ratio of the light-back signal received at the current time is lower than a signal-to-noise ratio of the light-back signal received by the signal processor before the current time. The generator switches a pulse signal from the wind measurement pulse signal to the range measurement pulse signal transmission.