Tidal level monitoring device, method and system based on trinocular lens millimeter wave radar

Abstract

The invention discloses a trinocular lens millimeter wave radar-based tide level monitoring device, method and system, belongs to the technical field of sea surface tide level monitoring, and aims to solve the problems that the existing single millimeter wave radar for monitoring the tide level cannot achieve higher precision and cannot overcome the interference of sea clutters on monitoring data. The tide level monitoring device comprises a fixing support, a trinocular lens millimeter wave radar monitoring system, a power supply system and a remote data display system. The trinocular lens millimeter wave radar monitoring system comprises a millimeter wave radar monitoring platform, an environment monitoring platform and a communication module. The millimeter-wave radar monitoring platform comprises a shell, a 77GHz millimeter-wave radar, a millimeter-wave radar lens switching device, a pitching rotating device and a data processing controller; the environment monitoring platform comprises an anemograph and an anemoscope; and the millimeter-wave radar lens switching device is controlled to switch the millimeter-wave lens below the 77GHz millimeter-wave radar according to the acquired current wind speed, so that high-precision tide level monitoring is realized.

Description

Technical Field

[0001] The patent of this invention belongs to the technical field of sea surface tide level monitoring, and specifically relates to a tide level monitoring device, method and system based on trinocular lens millimeter wave radar. Background Art

[0002] Tide monitoring has important application value in many marine-related fields. For example, tide is very critical to the timing and safety of ships entering and leaving ports. If you leave the port at low tide, you may face the risk of water shortage and stranding, and return to the port at high tide, you may face the danger of being hit by waves; by monitoring the change of tide level, you can predict the time and scale of marine natural disasters such as tsunamis and storm surges, and provide a scientific basis for disaster warning and disaster reduction; you can get long-term series of tide level change data, and provide necessary data support for fisheries, marine energy and other fields. The traditional fixed tide gauge device adopts a vertical downward measurement method, which is easily disturbed by factors such as oblique waves and reefs, as well as the influence of environmental factors such as rain, strong winds, and sea fog on the tide gauge, causing measurement errors. The float-type tide gauge is greatly affected by sea water temperature, which affects the measurement accuracy. The tidal level changes significantly under different sea surface environmental conditions. If a single millimeter-wave radar is used to monitor the tide level, it often cannot achieve high accuracy. At the same time, the monitored tide signal echo data is greatly disturbed by sea clutter. Summary of the invention

[0003] The technical problems to be solved by the present invention are:

[0004] The existing use of a single millimeter-wave radar to monitor tide levels often cannot achieve high accuracy and cannot overcome the interference of sea clutter on the monitoring data.

[0005] The present invention adopts the following technical solutions to solve the above technical problems:

[0006] The present invention provides a tide level monitoring device based on a trinocular lens millimeter wave radar, the tide level monitoring device comprises four parts: a fixed bracket, a trinocular lens millimeter wave radar monitoring system, a power supply system and a remote data display system;

[0007] The three-lens millimeter-wave radar monitoring system includes a millimeter-wave radar monitoring platform, an environmental monitoring platform and a communication module; the millimeter-wave radar monitoring platform includes a housing, a 77GHz millimeter-wave radar, a millimeter-wave radar lens switching device, a pitch rotation device and a data processing controller;

[0008] There is an area of ​​wave-transmitting material below the shell, and inside the shell are a 77GHz millimeter-wave radar and a millimeter-wave radar lens switching device; the millimeter-wave radar lens switching device is installed below the 77GHz millimeter-wave radar, and the environmental monitoring platform includes an anemometer and a wind vane;

[0009] The fixed bracket includes a base and a connecting rod assembly; the base is installed on the horizontal plane of the coast corresponding to the tide level to be monitored, the base is rotatably connected to one end of the connecting rod assembly, and the other end of the connecting rod assembly is respectively connected to the millimeter wave radar monitoring platform and the environmental monitoring platform, and the position of the trinocular lens millimeter wave radar monitoring system probing the sea level can be adjusted through the fixed bracket;

[0010] The three-lens millimeter-wave radar monitoring system is used to perform periodic pitch monitoring of sea level tide information through radar, and is also used to monitor the wind speed and wind direction of the tide. The anemometer and wind vane of the environmental monitoring platform measure the wind speed and wind direction information, and transmit the wind speed and wind direction data to the data processing controller. The millimeter-wave radar lens switching device is controlled to switch the millimeter-wave lens under the 77GHz millimeter-wave radar according to the current wind speed. When the waves and wind speed are small, narrow-beam millimeter wave monitoring is adopted, and when the waves and wind speed are large, wide-beam millimeter wave monitoring is adopted; the tide data monitored by the 77GHz millimeter-wave radar is transmitted to the data processing controller, and the data processing controller optimizes the tide data and transmits it to the remote data display system through the communication module;

[0011] The power supply system is used to power the data processing controller, data storage module, communication module, millimeter wave radar lens switching device, pitch rotation device and 77GHz millimeter wave radar;

[0012] The remote data display system is used to display the monitoring data of the trinocular lens millimeter wave radar monitoring system, and to display alarm information when the tide level is higher than a threshold.

[0013] Furthermore, the millimeter-wave radar lens switching device includes an electric servo located in the center and a short-focal-length focusing lens and a long-focal-length focusing lens located at both ends. The two lenses are respectively connected to the servo through short rods. According to the wind speed, the data processing controller controls the electric servo to rotate and switch the lens below the 77GHz millimeter-wave radar.

[0014] Furthermore, the power supply system is a solar power supply system, which uses solar energy to power the trinocular lens millimeter wave radar tide level monitoring system when there is sunlight. When the electricity generated by the solar panel exceeds the current demand, the excess electricity is stored in the battery through the power management module, and continues to supply electricity at night, on cloudy days or in other low-light conditions.

[0015] The present invention provides a tide level monitoring method based on a trinocular lens millimeter wave radar, the method comprising the following steps:

[0016] Step 1: Install the three-lens millimeter-wave radar monitoring system device on the shore of the sea area to be monitored through a fixed bracket, adjust the initial positions of the millimeter-wave radar monitoring platform and the environmental monitoring platform to a horizontal state, so that the 77GHz millimeter-wave radar should face the sea level, and measure the wind speed and wind direction information within a working cycle through an anemometer and a wind vane;

[0017] Step 2: After receiving the wind direction and wind speed information data, the data processing controller determines that the current wind speed is within a preset wind speed threshold interval, controls the electric servo according to the threshold interval where the wind speed is located, rotates the short focal length focusing lens or the long focal length focusing lens to below the 77 GHz millimeter wave radar, or uses the 77 GHz millimeter wave radar for direct measurement without using a lens;

[0018] Step 3: Monitor the tide level of the monitored sea area. The data processing controller controls the pitch rotation device to rotate. The 77GHz millimeter wave radar periodically scans the sea area to be monitored to obtain radar monitoring data. The sea clutter in the data is suppressed by the adaptive clutter suppression algorithm, and the outliers in the monitoring data are removed. Then, the data is fused by the centralized optimal weighted fusion algorithm.

[0019] Step 4: Upload tide level, wind speed, wind direction and time data to the remote data display system through the communication module, draw a tide level change curve, and display an alarm message through the display system when the tide level is higher than the threshold or the wind speed is greater than the threshold.

[0020] Furthermore, step two specifically includes: after the data processing controller receives the wind direction and wind speed information data, the data processing controller analyzes the wind speed. If the wind speed is in a small wind state of less than 3m / s, the electric servo is controlled to rotate the short-focal-length focusing lens to the bottom of the 77GHz millimeter-wave radar, and the short-focal-length focusing lens converges the beam to enable the narrow-beam millimeter-wave radar to perform high-precision monitoring of the sea surface tide level; if the wind speed is in a medium wind state between 3m / s and 6m / s, the electric servo is controlled to rotate the long-focal-length focusing lens to the bottom of the 77GHz millimeter-wave radar, and the long-focal-length focusing lens converges the beam to enable the medium-beam millimeter-wave radar to monitor the sea surface tide level; if the wind speed is in a high wind state of greater than 6m / s, the lens is not used, and the 77GHz millimeter-wave radar is used to monitor the sea surface tide level.

[0021] Furthermore, the millimeter wave radar described in step 3 uses a 77 GHz frequency modulated continuous wave millimeter wave radar, and the radar's transmission frequency is:

[0022]

[0023] Where t is the time, f 0is the operating center frequency of the transmitted signal, μ is the modulation slope, B is the modulation bandwidth, and T is the modulation period;

[0024] The receiving frequency of the radar is:

[0025] f Re (t) = f 0 +μ(t-τ)+f d (2)

[0026] Among them, f d is the Doppler frequency, τ is the propagation time of the signal in the air, assuming that the distance between the millimeter wave radar and the sea level is L, and the speed of light is c, then:

[0027]

[0028] Consider the ups and downs of the sea surface as a motion process. Since the surge of the sea waves is a reciprocating motion, they can be balanced and offset in each set of large amounts of data. The Doppler frequency f d If we ignore it, the echo signal model can be expressed as:

[0029]

[0030] Where K is the scaling factor constant, A is the signal amplitude, and φ 0 is the initial phase of the signal;

[0031] The phase of the echo signal is expressed as:

[0032]

[0033] The phase of the radar difference frequency signal is expressed as:

[0034] p m (t) = p Tr (t)-p Re (t)=2πf 0 τ+2πμτt-πμτ 2 (6)

[0035] Based on the phase p of the radar difference frequency signal m (t) Solve the radar difference frequency signal frequency:

[0036]

[0037] get:

[0038]

[0039] Furthermore, in step 3, the sea clutter in the data is suppressed by an adaptive clutter suppression algorithm, specifically:

[0040] For the echo signal model y R (t) is discretized, and the observation equation of the millimeter wave radar for the tide level at angle i is:

[0041] Y i (k) = X (k) + C i (k)+N i (k) i=1,2,…,I (9)

[0042] Among them, Y i (k) is the observed signal of the target at time k, X(k) is the target signal at time k, C i (k) is the clutter signal, N i (k) is a Gaussian white noise signal, I is the number of observation angles;

[0043] The echo signals of different distance units and their adjacent range gates are {y i,j (k)|i=1,2,…,I;j=1,2,…,J}, where J is the number of range gates, representing the echo signals at different distances measured by the radar; the echo data of different range gates satisfy independent and identical distribution, then based on all sea clutter sub-signals C i (k) is the covariance matrix R C for:

[0044]

[0045] Where p is the filter order, r C (·) is the clutter autocorrelation function, is the conjugate complex number of the clutter autocorrelation function, r C The expression of (·) is:

[0046]

[0047] Where m represents the delay of the signal when calculating the autocorrelation;

[0048] The covariance matrix R C Perform eigenvalue decomposition to obtain the eigenvalue λ i and the eigenvalue λ i The corresponding eigenvector W i :

[0049] R C W i =λ i W i (12)

[0050] Eigenvalues ​​of the sea clutter covariance matrix λ i The minimum value of λ minThe corresponding eigenvector is the optimal weighting coefficient of the adaptive clutter suppression algorithm, denoted by W o , the echo signal after suppressing sea clutter is:

[0051] Z i (k) = W 0 Y i (k) (13).

[0052] Furthermore, the removal of outliers in the monitoring data in step 3 is specifically as follows:

[0053] For the millimeter-wave radar ranging data at each angle, calculate the vertical distance d between the millimeter-wave radar monitoring platform and the sea surface:

[0054]

[0055] Among them, α is the angle between the millimeter wave radar antenna surface and the horizontal plane;

[0056] A set of tidal height data is obtained, and then the cyclic monitoring is continued; the outliers in the tidal height data are removed by the Grubbs test method, that is, the average value is first calculated for:

[0057]

[0058] Where n is the amount of data measured at each angle, and the standard deviation S is calculated as:

[0059]

[0060] The calculated G value is:

[0061]

[0062] According to the Grubbs criterion discriminant coefficient table, find the coefficient G corresponding to the sample size n and confidence q of a set of tide data. 表 , if G 表 >G 计算 , it is judged as abnormal data and removed, otherwise it is retained.

[0063] Furthermore, the data fusion is performed by the centralized optimal weighted fusion algorithm described in step 3, specifically: a set of tidal level change data is measured at each angle using the millimeter wave radar, and the mean and standard deviation are calculated for each set of data; assuming that the observation equation of the tidal level of the millimeter wave radar at the i-th angle at time k after suppressing sea clutter is:

[0064] Z i (k) = X(k) + N i (k) i=1,2,…,I (18)

[0065] Radar observation noise satisfies:

[0066]

[0067] Where E represents the expectation and D represents the variance. is the variance value at each moment under the i-th angle;

[0068] The measurement noise of millimeter-wave radar at different angles is uncorrelated, that is:

[0069]

[0070] Different weights are given to the radar at each angle to obtain a virtual measurement value;

[0071]

[0072] where α i is the weighting coefficient of the millimeter-wave radar tide data measured at the i-th angle. To ensure the unbiasedness of the estimate, it satisfies:

[0073]

[0074] When hour, is an unbiased estimate of X;

[0075] Establish the estimated mean square error, the expression is:

[0076]

[0077] The weighted coefficients of radars at each angle when the estimated variance is minimized are solved using the Lagrangian conditional extreme value solution, with the help of the auxiliary function:

[0078]

[0079] Where Λ is the constraint weight in the Lagrange multiplier; thus the equation system is established:

[0080]

[0081] Solving the system of equations yields:

[0082]

[0083] At this time, the estimated variance is minimized as:

[0084]

[0085] The present invention provides a tide monitoring system based on a trinocular lens millimeter wave radar. The system has a program module corresponding to the steps of the method described in any one of the above technical solutions, and executes the steps in the above tide monitoring method based on a trinocular lens millimeter wave radar during operation.

[0086] Compared with the prior art, the present invention has the following beneficial effects:

[0087] The present invention discloses a tide monitoring device, method and system based on a three-lens millimeter wave radar, adopts a method of collaborative work of a 77GHz millimeter wave radar and a millimeter wave lens, collects wind speed and wind direction information through wind speed and wind direction sensors, controls the switching lens below the millimeter wave radar, and uses beams of different widths for tide monitoring according to different sea wave conditions, which not only reduces the influence of environmental factors on the monitoring results, but also overcomes the monitoring error of a single millimeter wave radar under different sea wave conditions, and finally comprehensively monitors the tide height through the rotation of the pitch rotation axis to obtain more accurate tide change data. The present invention suppresses sea clutter processing for each group of raw data, reduces the interference of sea clutter on the monitoring results, removes outliers, and finally obtains tide data through a centralized optimal weighted fusion algorithm, obtains more accurate tide data, uploads to a remote data display system through a communication module for display, and issues an alarm message after exceeding a set threshold.

[0088] The invention has a high intelligence level and uses solar energy for power supply, which is in line with the development concept of green environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] Figure 1 This is a schematic diagram of the structure of a millimeter wave radar tide level monitoring device based on a trinocular lens in an embodiment of the present invention;

[0090] Figure 2 is a schematic diagram of a millimeter wave radar lens switching device in an embodiment of the present invention;

[0091] Figure 3 This is a working flow chart of a tide monitoring system based on a trinocular lens millimeter wave radar in an embodiment of the present invention;

[0092] Figure 4 is a schematic diagram of millimeter wave radar monitoring in an embodiment of the present invention;

[0093] Figure 5 is a schematic diagram of a remote data center in an embodiment of the present invention;

[0094] Figure 6 This is a diagram of the remote data center host computer interface in an embodiment of the present invention.

[0095] Description of reference numerals:

[0096] 1- bracket, 2- three-eye lens millimeter wave radar monitoring system, 3- power supply system, 4- remote data display system, 11- base, 12- right-angle connecting rod, 13- support rod, 14- horizontal platform, 21- millimeter wave radar monitoring platform, 22- environmental monitoring platform, 23- communication module, 41- computer host, 42- display, 211- shell, 212- 77GHz millimeter wave radar, 213- millimeter wave radar lens switching device, 214- pitch rotation device, 215- data processing controller, 221- anemometer, 222- wind vane, 2131- electric servo, 2132- short focal length focusing lens, 2133- long focal length focusing lens. DETAILED DESCRIPTION

[0097] In order to enable those skilled in the art to better understand the scheme of the present invention, exemplary implementations or embodiments of the present invention will be described below in conjunction with the accompanying drawings. Obviously, the described implementations or embodiments are only implementations or embodiments of a part of the present invention, not all of them. Based on the implementations or embodiments of the present invention, all other implementations or embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present invention.

[0098] In the description of the present invention, it should be noted that the terminology nouns in the various embodiments, such as "up", "down", "front", "back", "left", "right", etc., which indicate directions, are only for simplifying the description of the positional relationship based on the drawings in the specification, and do not mean that the referred elements and devices must be operated according to the specific directions and defined operations and methods and structures in the specification. Such directional nouns do not constitute a limitation on the present invention.

[0099] In the description of the present invention, it should be noted that the terms "first", "second", and "third" mentioned in the embodiments of the present invention are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second", and "third" may explicitly or implicitly include one or more of the features.

[0100] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0101] Combination Figure 1 and Figure 2 As shown, the present invention provides a tide monitoring device based on a trinocular lens millimeter wave radar, the tide monitoring device comprises a fixed bracket 1, a trinocular lens millimeter wave radar monitoring system 2, a power supply system 3 and a remote data display system 4;

[0102] The three-lens millimeter-wave radar monitoring system 2 includes a millimeter-wave radar monitoring platform 21, an environment monitoring platform 22 and a communication module 23; the millimeter-wave radar monitoring platform 21 includes a housing 211, a 77GHz millimeter-wave radar 212, a millimeter-wave radar lens switching device 213, a pitch rotation device 214 and a data processing controller 215;

[0103] There is an area of ​​wave-transmitting material below the shell 211, and inside the shell 211 are a 77 GHz millimeter wave radar 212 and a millimeter wave radar lens switching device 213; the millimeter wave radar lens switching device 213 is installed below the 77 GHz millimeter wave radar 212, and the environmental monitoring platform 22 includes an anemometer 221 and a wind vane 222;

[0104] The fixed bracket 1 includes a base 11 and a connecting rod assembly; the base 11 is installed on the horizontal plane of the coast corresponding to the tide level to be monitored, the base 11 is rotatably connected to one end of the connecting rod assembly, and the other end of the connecting rod assembly is respectively connected to the millimeter wave radar monitoring platform 21 and the environmental monitoring platform 22, and the position of the trinocular lens millimeter wave radar monitoring system 2 probing the sea level can be adjusted by the fixed bracket 1;

[0105] The three-lens millimeter-wave radar monitoring system 2 is used to perform periodic pitch monitoring of sea level tide information through radar, and is also used to monitor the wind speed and wind direction of the tide, control the anemometer 221 and the wind vane 222 of the environmental monitoring platform 22 to measure the wind speed and wind direction information, and transmit the wind speed and wind direction data to the data processing controller 215. The data processing controller 215 is integrated at the top of the millimeter-wave radar monitoring platform 21, and controls the millimeter-wave radar lens switching device 213 to switch the millimeter-wave radar lens below the 77GHz millimeter-wave radar 212 according to the current wind speed. Meter wave lens, in order to achieve narrow beam millimeter wave monitoring when the waves and wind speed are small, and wide beam millimeter wave monitoring when the waves and wind speed are large; the tide data monitored by the 77GHz millimeter wave radar 212 is transmitted to the data processing controller 215, and the data processing controller 215 optimizes the tide data, and the communication module 23 is a 4G wireless communication module, and the communication module 23 uploads the monitoring data to the cloud server, and the remote data display system 4 reads the monitoring data of the three-eye lens millimeter wave radar monitoring system in the cloud server and displays the information;

[0106] The power supply system 3 is used to supply power to the data processing controller 215, the data storage module, the communication module 23, the millimeter wave radar lens switching device 213, the pitch rotation device 214 and the 77 GHz millimeter wave radar 212;

[0107] like Figure 5As shown, the remote data display system 4 includes a computer host 41 and a display 42; the remote data display system 4 reads the monitoring data of the three-lens millimeter-wave radar monitoring system in the cloud server and displays the information, and stores the tide height, wind speed, and wind direction information in the local space; the computer host 41 accesses the cloud server through the optical fiber access network, receives real-time data information, displays the wind speed, wind direction information, the current tide height and the change curve of the tide height in the last two hours, and displays an alarm message when the tide height is higher than the threshold.

[0108] The 77 GHz millimeter wave radar 212 described in this embodiment has a beam width of ±15° and a range of 30 meters. It has a wide beam width and is not affected by light, fog, or rain. It solves the problem that ultrasonic sensors and optical sensors cannot penetrate sea fog and rain. It is suitable for monitoring tide heights when waves and winds are large, and can locate target distances more accurately, thereby enhancing the anti-interference ability of tide monitoring systems. When waves and winds are small, a millimeter wave lens is placed in front of the millimeter wave radar antenna to achieve narrow beam millimeter wave monitoring and improve measurement resolution.

[0109] Preferably, the connecting rod assembly of the fixed bracket 1 includes a right-angle connecting rod 12, a support rod 13 and a horizontal surface 14; the base 11 of the bracket is installed on the horizontal plane of the coast corresponding to the tide level to be monitored using an expansion anchor bolt; the base 11 is connected to one end of the right-angle connecting rod 12, and the other end of the right-angle connecting rod 12 protrudes out of the sea level. The support rod 13 is installed at the bend of the right-angle connecting rod 12 to form a triangular bracket to enhance the stability of the fixed bracket. The interior of the right-angle connecting rod 12 is a hollow structure for accommodating signal transmission lines and power lines; the horizontal surface 14 is installed above the end of the right-angle connecting rod 12 protruding out of the sea level, the anemometer 221, the wind vane 222 and the communication module 23 are all installed on the horizontal surface 14, the millimeter wave radar monitoring platform 21 is installed below the end of the right-angle connecting rod 12 protruding out of the sea level, and the fixed bracket 1 installs the trinocular lens millimeter wave radar monitoring system 2 on the shore of the sea area to be monitored, and adjusts the trinocular lens millimeter wave radar monitoring system 2 to protrude 2 meters above the sea level.

[0110] Preferably, if Figure 2 As shown, the millimeter-wave radar lens switching device 213 includes an electric servo 2131 located in the center and a short-focal-length focusing lens 2132 and a long-focal-length focusing lens 2133 located at both ends. The two lenses are connected to the servo through short rods, respectively. According to the wind speed, the data processing controller 215 outputs PWM signals of different frequencies to control the rotation of the electric servo 2131, switching the 77GHz millimeter-wave radar 212 to a different lens.

[0111] Preferably, the data processing controller 215 includes a data processing unit and a central control unit, which work in coordination, are connected to the anemometer and the eight-azimuth wind vane through an RS485 interface, communicate through the Modbus-RTU protocol, receive data from the anemometer 221 and the wind vane, obtain real-time wind speed and wind direction information, set a wind speed threshold, determine the wind speed threshold space in which the current wind speed is located, and control the electric servo 2131 to rotate and switch the lens below the millimeter-wave radar; control the pitch rotation device 214 to rotate through a preset program, and periodically scan the sea area to be monitored. When the pitch rotation device 214 rotates, the 77GHz millimeter-wave radar 212 antenna surface stays at 0°, 30° and 60° to the horizontal plane, and obtains a data at each angle. Each working cycle is repeated 10 times to obtain a set of data. The working interval is 20 minutes, and this periodic cycle is repeated.

[0112] Preferably, the power supply system 3 is a solar power supply system, which uses solar energy to power the trinocular lens millimeter wave radar tide level monitoring system when there is sunlight. When the electricity generated by the solar panel exceeds the current demand, the excess electricity is stored in the battery through the power management module, and continues to supply electricity at night, on cloudy days or in other low light conditions.

[0113] The present invention also provides a tide level monitoring method based on a trinocular lens millimeter wave radar, such as Figure 3 As shown, the following steps are included:

[0114] Step 1: Install the above-mentioned three-lens millimeter-wave radar monitoring system 2 device on the shore of the sea area to be monitored through the fixed bracket 1, adjust the initial positions of the millimeter-wave radar monitoring platform 21 and the environmental monitoring platform 22 to a horizontal state, so that the 77GHz millimeter-wave radar 212 should face the sea level, and measure the wind speed and wind direction information within a working cycle through the anemometer 221 and the wind vane 222;

[0115] Step 2: After the data processing controller 215 receives the wind direction and wind speed information data, the data processing controller 215 determines that the current wind speed is within a preset wind speed threshold interval, and controls the electric servo 2131 according to the threshold interval where the wind speed is located, and rotates the short focal length focusing lens 2132 or the long focal length focusing lens 2133 to below the 77 GHz millimeter wave radar 212, or uses the 77 GHz millimeter wave radar 212 for direct measurement without using a lens;

[0116] Step 3: Monitor the tide level of the monitored sea area. The data processing controller 215 controls the pitch rotation device 214 to rotate. The 77GHz millimeter wave radar 212 periodically scans the sea area to be monitored to obtain radar monitoring data. The sea clutter in the data is suppressed by the adaptive clutter suppression algorithm, and the outliers in the monitoring data are removed. Then, the data is fused by the centralized optimal weighted fusion algorithm.

[0117] Step 4: Upload tide level, wind speed, wind direction and time data to the cloud server through the communication module 23. The remote data display system 4 reads the data in the cloud server, displays the information through the display 42, draws a tide level change curve, and saves the data to the database. When the tide level is higher than the threshold or the wind speed is greater than the threshold, the display system displays an alarm message.

[0118] Preferably, in step one, before the three-eye lens millimeter-wave radar monitoring system officially starts working, the wind speed and wind direction information within a working cycle is first collected to adjust the selection of the millimeter-wave lens in the first working cycle. Each working cycle is 20 minutes. The wind speed and wind direction information collected in each subsequent working cycle will be used as reference data for lens selection in the next cycle.

[0119] Preferably, step 2 specifically includes: after the data processing controller 215 receives the wind direction and wind speed information data of the previous working cycle, the data processing controller 215 analyzes the wind speed. If the wind speed is in a small wind state of less than 3m / s, the electric servo 2131 is controlled to rotate the short-focal-length focusing lens 2132 to below the 77GHz millimeter-wave radar 212, and the short-focal-length focusing lens 2132 converges the beam to achieve high-precision monitoring of the sea surface tide level by the narrow-beam millimeter-wave radar; if the wind speed is in a medium wind state between 3m / s and 6m / s, the electric servo 2131 is controlled to rotate the long-focal-length focusing lens 2133 to below the 77GHz millimeter-wave radar 212, and the long-focal-length focusing lens 2133 converges the beam to achieve monitoring of the sea surface tide level by the medium-beam millimeter-wave radar; if the wind speed is in a high wind state of greater than 6m / s, the lens is not used, and the 77GHz millimeter-wave radar 212 is used to monitor the sea surface tide level.

[0120] Preferably, the millimeter wave radar in step 3 uses a 77 GHz frequency modulated continuous wave (FMCW) millimeter wave radar. The FMCW millimeter wave radar monitors the tide height by calculating the delay between the radar transmission signal and the echo signal. The transmission frequency of the radar is:

[0121]

[0122] Where t is the time, f 0 is the operating center frequency of the transmitted signal, μ is the modulation slope, B is the modulation bandwidth, and T is the modulation period;

[0123] The receiving frequency of the radar is:

[0124] f Re (t) = f 0 +μ(t-τ)+f d (2)

[0125] Among them, f d is the Doppler frequency, τ is the propagation time of the signal in the air, assuming that the distance between the millimeter wave radar and the sea level is L, and the speed of light is c, then:

[0126]

[0127] Consider the ups and downs of the sea surface as a motion process. Since the surge of the sea waves is a reciprocating motion, they can be balanced and offset in each set of large amounts of data. The Doppler frequency f d can be ignored, the echo signal model can be expressed as:

[0128]

[0129] Where K is the scaling factor constant, A is the signal amplitude, and φ 0 is the initial phase of the signal;

[0130] The phase of the echo signal can be expressed as:

[0131]

[0132] The phase of the radar difference frequency signal can be expressed as:

[0133] p m (t) = p Tr (t)-p Re (t)=2πf 0 τ+2πμτt-πμτ 2 (6)

[0134] The phase p of the radar difference frequency signal m (t) is derived with respect to time to obtain the instantaneous angular frequency, and then divided by 2π to obtain the instantaneous frequency. The frequency of the radar difference frequency signal can be expressed as:

[0135]

[0136] get:

[0137]

[0138] Preferably, the adaptive clutter suppression algorithm can suppress sea clutter in the data by adjusting the filter parameters according to the statistical characteristics of the clutter, which is suitable for suppressing dynamic sea clutter; R (t) Discretization processing, assuming that the observation equation of the millimeter wave radar for the tide level at angle i is:

[0139] Y i (k) = X (k) + C i (k)+N i(k) i=1,2,…,I (9)

[0140] Among them, Y i (k) is the observed signal of the target at time k, X i (k) is the target signal at time k, C i (k) is the clutter signal, N(k) is the Gaussian white noise signal, and I is the number of observation angles;

[0141] The tide monitoring radar works for a long time to obtain sample data at different tide heights and angles, and can obtain echo signals {y i,j (k)|i=1,2,…,I;j=1,2,…,J}, where J is the number of range gates; represents the echo signals at different distances measured by the radar; the echo data of different range gates satisfy independent and identical distribution, then based on all sea clutter sub-signals C i (k) is the covariance matrix R C for:

[0142]

[0143] Where p is the filter order, r C (·) is the clutter autocorrelation function, is the conjugate complex number of the clutter autocorrelation function, r C The expression of (·) is:

[0144]

[0145] Where m represents the delay of the signal when calculating the autocorrelation;

[0146] The covariance matrix R C Perform eigenvalue decomposition to obtain the eigenvalue λ i and the eigenvalue λ i The corresponding eigenvector W i :

[0147] R C W i =λ i W i (12)

[0148] Eigenvalues ​​of the sea clutter covariance matrix λ i The minimum value of λ min The corresponding eigenvector is the optimal weighting coefficient of the adaptive clutter suppression algorithm, denoted by W o , the echo signal after suppressing sea clutter is:

[0149] Z i (k) = W 0 Y i(k) (13).

[0150] The weighting coefficient of the filter can be adjusted according to the statistical characteristics of sea clutter, and the echo signal can be processed to suppress sea clutter to obtain an ideal output signal.

[0151] Preferably, the removal of abnormal values ​​in the monitoring data in step 3 is specifically as follows: the control system controls the pitch rotation device 214 to rotate, and the stepper motor converts the pulse signal into a control element of angular displacement or linear displacement. The specific method of controlling the rotation of the pitch rotation device 214 is as follows: after determining the lens used by the monitoring platform in the current measurement cycle, the pitch rotation device 214 is controlled to rotate through a preset program so that the antenna surface of the 77GHz millimeter wave radar 212 stays at 0°, 30° and 60° with the horizontal plane, and a radar ranging data is obtained at each angle, such as Figure 4 As shown in the figure, the vertical distance d between the millimeter wave radar monitoring platform and the sea surface is calculated by the Pythagorean theorem of triangles:

[0152]

[0153] Among them, α is the angle between the millimeter wave radar antenna surface and the horizontal plane;

[0154] A set of tide height data is obtained, and then the cycle continues to rotate, with a cycle period of 20 minutes;

[0155] Outliers can have a significant impact on real data. There are three main factors that cause outliers: the first is that the reefs on the sea surface are within the radar detection range, causing long-term detection errors; the second is that ships or other objects pass through the radar detection range, causing short-term fluctuations in detection errors; the third is that the echo received by the millimeter-wave radar is inaccurate due to electromagnetic signal interference, causing detection errors. The Grubbs test method is used to remove outliers from a set of tide data. The specific method is to first calculate the average value of a set of tide data.

[0156]

[0157] Where n is the amount of data measured at each angle, and the standard deviation S is calculated as:

[0158]

[0159] Calculate the G value:

[0160]

[0161] According to the Grubbs criterion discriminant coefficient table, find the coefficient G corresponding to the sample size n and confidence q of a set of tide data. 表 , if G 表 >G计算 , it is judged as abnormal data and removed, otherwise it is retained.

[0162] Preferably, the data fusion is performed by a centralized optimal weighted fusion algorithm as described in step 3, specifically: the change in the sea surface tidal height is regarded as a dynamic motion process, and factors such as oblique waves will affect the measurement results, so a centralized optimal weighted fusion algorithm is introduced; a set of tidal change data is measured at each angle using a millimeter wave radar, and the mean and standard deviation are calculated for each set of data; at this time, it is assumed that the observation equation of the tidal level by the millimeter wave radar at the i-th angle at time k after suppressing sea clutter is:

[0163] Z i (k) = X(k) + N i (k) i=1,2,…,I (18)

[0164] Among them, Z i (k) is the data of the millimeter wave radar observing the tide level at time k and filtering out the sea clutter, X(k) represents the target state, N i (k) represents the observation noise of the radar at angle i at time k, which is mainly Gaussian white noise;

[0165] Then the radar observation noise can simultaneously satisfy:

[0166]

[0167] Where E represents the expectation and D represents the variance. is the variance value at each moment under the i-th angle;

[0168] The measurement noise of millimeter-wave radar at different angles is uncorrelated, that is:

[0169]

[0170] The centralized optimal weighted fusion algorithm assigns different weights to the radar at each angle, performs weighted operations based on these weights, and obtains a virtual measurement value;

[0171]

[0172] where α i is the weighting coefficient of the millimeter-wave radar tide data measured at the i-th angle. To ensure the unbiasedness of the estimate, it satisfies:

[0173]

[0174] When hour, is an unbiased estimate of X;

[0175] Establish the estimated mean square error, the expression is:

[0176]

[0177] The weighted coefficients of radars at each angle when the estimated variance is minimized are solved using the Lagrangian conditional extreme value solution, with the help of the auxiliary function:

[0178]

[0179] Where Λ is the constraint weight in the Lagrange multiplier; thus the equation system is established:

[0180]

[0181] Solving the system of equations yields:

[0182]

[0183] At this time, the estimated variance is minimized as:

[0184]

[0185] By analyzing the expression, it can be found that the weighting coefficient of the data measured by the millimeter-wave radar in each direction is inversely proportional to its corresponding variance; specifically, the smaller the variance of the measured data in a certain direction, the larger the weighting coefficient of the data in that direction, and vice versa; through such weighted calculation, the weight of the tidal data in the direction with low measurement accuracy and large deviation can be reduced, and the weight of the tidal data in the direction with high measurement accuracy and small deviation can be increased, and finally the variance of the tidal data is smaller than the variance of the measured data in each direction.

[0186] like Figure 6 As shown, in step 4 of this embodiment, the computer host 41 of the remote data display system 4 parses the received data, including time, tide height, wind speed, wind direction and time, and displays the parsed data on the display 42. At the same time, the data is stored in the database of the computer host 41, and the long-term tide level change data can be analyzed to study its change law, and applied in the fields of fishery, meteorology, etc. In this embodiment, the tide level height threshold is set to 2 meters, and the wind speed threshold is set to 10.8m / s, that is, the wind strength threshold is level 6 wind. When the tide level is greater than the tide level threshold, or the wind speed is greater than the set wind speed strength threshold, an alarm is triggered, and the display 42 displays the alarm information.

[0187] The tide level monitoring method (algorithm) based on the trinocular lens millimeter wave radar proposed in the present invention is the underlying technical core of the present invention, and various products can be derived based on the algorithm.

[0188] Based on the method proposed in the present invention, a tide monitoring system based on trinocular lens millimeter wave radar is developed using a programming language. The system has a program module corresponding to the steps of the above technical solution, and executes the steps in the above tide monitoring method based on trinocular lens millimeter wave radar during operation.

[0189] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A tide level monitoring device based on trinocular lens millimeter wave radar, characterized in that: The tide level monitoring device comprises four parts: a fixed bracket (1), a three-eye lens millimeter wave radar monitoring system (2), a power supply system (3) and a remote data display system (4); The three-lens millimeter-wave radar monitoring system (2) comprises a millimeter-wave radar monitoring platform (21), an environmental monitoring platform (22) and a communication module (23); the millimeter-wave radar monitoring platform (21) comprises a housing (211), a 77 GHz millimeter-wave radar (212), a millimeter-wave radar lens switching device (213), a pitch rotation device (214) and a data processing controller (215); There is an area below the shell (211) made of wave-transmitting material, and inside the shell (211) are a 77 GHz millimeter wave radar (212) and a millimeter wave radar lens switching device (213); the millimeter wave radar lens switching device (213) is installed below the 77 GHz millimeter wave radar (212), and the environmental monitoring platform (22) includes an anemometer (221) and a wind vane (222); The fixed support (1) comprises a base (11) and a connecting rod assembly; the base (11) is installed on a coast horizontal plane corresponding to the tide level to be monitored, the base (11) is rotatably connected to one end of the connecting rod assembly, and the other end of the connecting rod assembly is respectively connected to a millimeter wave radar monitoring platform (21) and an environmental monitoring platform (22), and the position of the trinocular lens millimeter wave radar monitoring system (2) probing the sea level can be adjusted by the fixed support (1); The three-lens millimeter wave radar monitoring system (2) is used to perform periodic elevation monitoring of sea level tide information through radar, and is also used to monitor the wind speed and wind direction of the tide. The anemometer (221) and the wind vane (222) of the environmental monitoring platform (22) measure the wind speed and wind direction information, and transmit the wind speed and wind direction data to the data processing controller (215). The millimeter wave radar lens switching device (213) is controlled to switch the millimeter wave lens below the 77 GHz millimeter wave radar (212) according to the current wind speed. When the sea waves and wind speed are small, narrow beam millimeter wave monitoring is adopted. When the sea waves and wind speed are large, wide beam millimeter wave monitoring is adopted. The tide data monitored by the 77 GHz millimeter wave radar (212) is transmitted to the data processing controller (215), and the data processing controller (215) optimizes the tide data and transmits it to the remote data display system (4) through the communication module (23); The power supply system (3) is used to supply power to a data processing controller (215), a data storage module, a communication module (23), a millimeter wave radar lens switching device (213), a pitch rotation device (214) and a 77 GHz millimeter wave radar (212); The remote data display system (4) is used to display monitoring data of the trinocular lens millimeter wave radar monitoring system, and to display warning information when the tide level is higher than a threshold.

2. The tide level monitoring device based on trinocular lens millimeter wave radar according to claim 1 is characterized in that: The millimeter wave radar lens switching device (213) comprises an electric steering gear (2131) located in the center and a short focal length focusing lens (2132) and a long focal length focusing lens (2133) located at two ends, the two lenses being connected to the steering gear via short rods respectively, and according to the wind speed, the data processing controller (215) controls the electric steering gear (2131) to rotate, thereby switching the lens below the 77 GHz millimeter wave radar (212).

3. The tide level monitoring device based on trinocular lens millimeter wave radar according to claim 1 is characterized in that: The power supply system (3) is a solar power supply system, which uses solar energy to power the trinocular lens millimeter wave radar tide level monitoring system when there is sunlight. When the power generated by the solar panel exceeds the current demand, the excess power is stored in the battery through the power management module, and continues to supply power at night, on cloudy days or in other low light conditions.

4. A tide level monitoring method based on trinocular lens millimeter wave radar, characterized in that: The method comprises the following steps: Step 1, installing the three-lens millimeter-wave radar monitoring system (2) of claim 1 on the shore of the sea area to be monitored through a fixed bracket (1), adjusting the initial positions of the millimeter-wave radar monitoring platform (21) and the environmental monitoring platform (22) to a horizontal state, so that the 77 GHz millimeter-wave radar (212) should face the sea level, and measuring the wind speed and wind direction information within a working cycle through the anemometer (221) and the wind vane (222); Step 2: After the data processing controller (215) receives the wind direction and wind speed information data, the data processing controller (215) determines that the current wind speed is within a preset wind speed threshold interval, and controls the electric steering gear (2131) according to the threshold interval where the wind speed is located, and rotates the short focal length focusing lens (2132) or the long focal length focusing lens (2133) to below the 77 GHz millimeter wave radar (212), or uses the 77 GHz millimeter wave radar (212) to directly measure without using a lens; Step 3: monitoring the tide level of the monitored sea area, the data processing controller (215) controls the pitch rotation device (214) to rotate, the 77 GHz millimeter wave radar (212) periodically scans the sea area to be monitored, obtains radar monitoring data, suppresses sea clutter in the data through an adaptive clutter suppression algorithm, removes abnormal values ​​in the monitoring data, and then performs data fusion through a centralized optimal weighted fusion algorithm; Step 4: Upload the tide level, wind speed, wind direction and time data to the remote data display system (4) through the communication module (23), draw a tide level change curve, and display an alarm message through the display system when the tide level is higher than the threshold or the wind speed is greater than the threshold.

5. The tide level monitoring method based on trinocular lens millimeter wave radar according to claim 4 is characterized in that: Step 2 specifically includes: after the data processing controller (215) receives the wind direction and wind speed information data, the data processing controller (215) analyzes the wind speed, and if the wind speed is in a low wind state of less than 3m / s, controls the electric steering gear (2131) to rotate the short focal length focusing lens (2132) to below the 77GHz millimeter wave radar (212), and the short focal length focusing lens (2132) converges the beam, so that the narrow beam millimeter wave radar can perform high-precision monitoring of the sea surface tide height; if When the wind speed is in a medium wind state between 3m / s and 6m / s, the electric steering gear (2131) is controlled to rotate the long focal length focusing lens (2133) to the bottom of the 77GHz millimeter wave radar (212), and the long focal length focusing lens (2133) converges the beam, so that the medium beam millimeter wave radar can monitor the sea surface tide level; if the wind speed is in a high wind state greater than 6m / s, the lens is not used, and the 77GHz millimeter wave radar (212) is used to monitor the sea surface tide level.

6. The tide level monitoring method based on trinocular lens millimeter wave radar according to claim 4 is characterized in that: The millimeter wave radar described in step 3 uses a 77GHz frequency modulated continuous wave millimeter wave radar, and the radar's transmission frequency is: Where t is time, f0 is the operating center frequency of the transmitted signal, μ is the modulation slope, B is the modulation bandwidth, and T is the modulation period; The receiving frequency of the radar is: f Re (t)=f0+μ(t-τ)+f d (2) Among them, f d is the Doppler frequency, τ is the propagation time of the signal in the air, assuming that the distance between the millimeter wave radar and the sea level is L, and the speed of light is c, then: Consider the ups and downs of the sea surface as a motion process. Since the surge of the sea waves is a reciprocating motion, they can be balanced and offset in each set of large amounts of data. The Doppler frequency f d If we ignore it, the echo signal model can be expressed as: Where K is the scaling factor constant, A is the signal amplitude, and φ0 is the initial phase of the signal; The phase of the echo signal is expressed as: The phase of the radar difference frequency signal is expressed as: p m (t)=p Tr (t)-p Re (t)=2πf0τ+2πμτt-πμτ 2 (6) Based on the phase p of the radar difference frequency signal m (t) Solve the radar difference frequency signal frequency: get:

7. The tide level monitoring method based on trinocular lens millimeter wave radar according to claim 4 is characterized in that: Step 3 describes suppressing sea clutter in the data through an adaptive clutter suppression algorithm, specifically: For the echo signal model y R (t) is discretized, and the observation equation of the millimeter wave radar for the tide level at angle i is: Y i (k)=X(k)+C i (k)+N i (k)i=1,2,…,I (9) Among them, Y i (k) is the observed signal of the target at time k, X(k) is the target signal at time k, C i (k) is the clutter signal, N i (k) is a Gaussian white noise signal, I is the number of observation angles; The echo signals of different distance units and their adjacent range gates are {y i,j (k)|i=1,2,…,I;j=1,2,…,J}, where J is the number of range gates, representing the echo signals at different distances measured by the radar; the echo data of different range gates satisfy independent and identical distribution, then based on all sea clutter sub-signals C i (k) is the covariance matrix R C for: Where p is the filter order, r C (·) is the clutter autocorrelation function, is the complex conjugate of the clutter autocorrelation function, r C The expression of (·) is: Where m represents the delay of the signal when calculating the autocorrelation; The covariance matrix R C Perform eigenvalue decomposition to obtain the eigenvalue λ i and the eigenvalue λ i The corresponding eigenvector W i : R C W i =λ i W i (12) Eigenvalues ​​of the sea clutter covariance matrix λ i The minimum value of λ min The corresponding eigenvector is the optimal weighting coefficient of the adaptive clutter suppression algorithm, denoted by W o , the echo signal after suppressing sea clutter is: WITH i (k)=W0Y i (k) (13)。 8. The tide level monitoring method based on trinocular lens millimeter wave radar according to claim 4 is characterized in that: The removal of outliers in the monitoring data described in step 3 is specifically as follows: For the millimeter-wave radar ranging data at each angle, calculate the vertical distance d between the millimeter-wave radar monitoring platform and the sea surface: Among them, α is the angle between the millimeter wave radar antenna surface and the horizontal plane; A set of tidal height data is obtained, and then the cyclic monitoring is continued; the outliers in the tidal height data are removed by the Grubbs test method, that is, the average value is first calculated for: Where n is the amount of data measured at each angle, and the standard deviation S is calculated as: The calculated G value is: According to the Grubbs criterion discriminant coefficient table, find the coefficient G corresponding to the sample size n and confidence q of a set of tide data. 表 , if G 表 >G 计算 , it is judged as abnormal data and removed, otherwise it is retained.

9. The tide level monitoring method based on trinocular lens millimeter wave radar according to claim 4 is characterized in that: The data fusion described in step 3 is performed by a centralized optimal weighted fusion algorithm, specifically: a set of tidal level change data is measured at each angle using the millimeter-wave radar, and the mean and standard deviation are calculated for each set of data; assuming that the observation equation of the tidal level at the i-th angle of the millimeter-wave radar at time k after suppressing sea clutter is: Z i (k)=X(k)+N i (k) i=1,2,…,I (18) Radar observation noise satisfies: Where E represents expectation and D represents variance. is the variance value at each moment under the i-th angle; The measurement noise of millimeter-wave radar at different angles is uncorrelated, that is: Different weights are given to the radar at each angle to obtain a virtual measurement value; where α i is the weighting coefficient of the millimeter-wave radar tide data measured at the i-th angle. To ensure the unbiasedness of the estimate, it satisfies: When hour, is an unbiased estimate of X; Establish the estimated mean square error, the expression is: The weighted coefficients of radars at each angle when the estimated variance is minimized are solved using the Lagrangian conditional extreme value solution, with the help of the auxiliary function: Where Λ is the constraint weight in the Lagrange multiplier; thus the equation system is established: Solving the system of equations yields: At this time, the estimated variance is minimized as:

10. A tide monitoring system based on trinocular lens millimeter wave radar, characterized in that: The system has a program module corresponding to the steps of the method described in any one of claims 4 to 9, and executes the steps of the tide level monitoring method based on trinocular lens millimeter wave radar when running.

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