39results about How to "Strong ability to resist external interference" patented technology

The invention provides a human face living detection method, device and system. The method includes the steps that a first image acquired by a main camera and a second image acquired by an auxiliary camera are acquired, when the first image comprises characteristic information of a human face image, the first image is corrected, the corrected first image and the second image are subjected to three-dimension matching, a disparity map between the human face image and the main camera is obtained, a fitting plane of key points of the human face image is obtained through fitting according to three-dimensional relation matrixes between the disparity map and the main camera and between the disparity map and the auxiliary camera, and therefore the corresponding fitting deviation can be calculated; the fitting deviation is compared with a set threshold, and therefore whether the human face image comes from a living face or not can be judged. According to the technical scheme, operation is easy, the anti-outside-interference capacity is high, precision is high, and a model training part in a machine learning method is avoided.

The invention provides a blast furnace multi-element molten iron quality prediction control method and system. The method comprises the steps that the expected value of a blast furnace multi-element molten iron quality index is set; the production history data of a blast furnace are acquired; a multi-element molten iron quality prediction model is established; a sequence quadratic programming algorithm and the blast furnace multi-element molten iron quality prediction model are used to calculate the optimal input, namely the optimal control quantity, of the blast furnace multi-element molten iron quality prediction model; and the optimal control quantity is fed back to a corresponding executing mechanism, so that the blast furnace multi-element molten iron quality index tracks the set expected value of the blast furnace multi-element molten iron quality index. The system comprises an index setting unit, a model training unit, a tracking calculation unit and a feedback control unit. According to the invention, the multi-element molten iron quality index can accurately and quickly reach a given requirement; the method and the system have the advantages of good tracking performance and strong anti-interference ability; the energy consumption and the cost in a production process are reduced; and the molten iron quality is further improved.

The invention provides a small reflector ultrahigh power thermal stability supporting structure, and belongs to the technical field of the aerospace technology. The supporting structure solves the problems that in the prior art, a reflector is low in intrinsic frequency and poor in external disturbance resistance, a reflection mirror surface is large in shape change, the requirement for the assembly technique level is high, interchangeability is poor and mass production is difficult to achieve. The supporting structure comprises a mirror chamber and a flexible joint, the flexible joint and the reflector are in glue joint and fixed concentrically, the flexible joint is fixed in the mirror chamber and comprises a cylindrical barrel and multiple flexible single arms which are uniformly distributed on the outer side of the cylindrical barrel in the circumference direction and each flexible single arm is a double-layer flexible hinge. Under the action of temperature loads, in the process that thermal deformation stress deformation energy of the lens barrel is transmitted to the reflector, the thermal deformation stress deformation energy is absorbed when passing a flexible unload groove of the flexible joint, uniform deformation of the reflector is guaranteed, at the moment, surface precision slightly changes, the parts are fixedly connected, the requirement for the assembly technique is not high, and the supporting structure is good in interchangeability and high in external dynamic interference resistance.

The invention relates to a full-automatic intelligent fishing rod based on an embedded system and an implementing method of the full-automatic intelligent fishing rod. The full-automatic intelligent fishing rod based on the embedded system comprises a fishing rod body and an automated control module, wherein the fishing rod body comprises a fishing rod body, a spinning wheel and a fish wire; the automated control module comprises a signal acquiring module, a server module, a power supply module and a control module; the signal acquiring module comprises an attitude sensor and an environment detecting module; and whether fishing is suitable or not through the environment detecting module is judged, and whether fishes bite hooks or not is judged by the attitude sensor. Fish walking and alarming functions of the fishing rod are fulfilled by the control module. By the environment detecting module, a fishing position is selected intelligently, and posture change caused by external disturbance can be distinguished by the attitude sensor. Compared with a traditional automatic fishing rod, the full-automatic intelligent fishing rod based on the embedded system has the advantages that erroneous judgment caused by environment factors such as flowing water and strong wind is reduced to a great degree; and an automatic fish walking function is fulfilled, complete automatic fishing is implemented, double-ring PID control is adopted, interference resistance is high, and a system is stable.

The invention provides a method and device achieving far-field super-resolution imaging. According to the method, exciting light and STED light are coupled simultaneously into single mode fiber so as to achieve the beam combining effect firstly, the exciting light and the STED light after beam combination pass through a polarizer and a dual-wavelength wave plate in sequence to be modulated to two perpendicular linear polarized light in the polarization direction, a liquid crystal polarization convertor is adopted, and the exciting light and the STED light are converted into the radial direction polarized light and the angle direction polarized light. The device achieving the method comprises an exciting light source, an STED light source, a collimating lens, the polarizer, the dual-wavelength wave plate, the liquid crystal polarization convertor, a dichroscope, a high numerical aperture lens, a three-dimensional nanometer displacement platform, a focusing lens and a light intensity detector. Through the coupling effect of the ingle mode fiber and the different focusing functions of the radial direction polarized light and the angle direction polarized light under the high numerical aperture, a circular excitation facular and an annular STED facular which are focused on the surface of a sample can be overlapped automatically, and difficulty of achieving the STED super-resolution imaging is reduced.

The invention relates to an online monitoring device for grounding current of a transformer core. The online monitoring device comprises a monitoring device body and a straight-through current transformer. The monitoring device body comprises a totally closed electromagnetic interference preventing housing. The external surface of the totally closed electromagnetic interference preventing housing is provided with a liquid crystal display screen and a device state indicating lamp. The totally closed electromagnetic interference preventing housing is internally provided with a signal acquiring and processing module, a communication module and a display interface module. The signal acquiring and processing module comprises a signal conditioning module, a digital-to-analog conversion circuit and a microprocessor unit. The signal conditioning module comprises a signal conversion circuit, a filter circuit and a signal amplification circuit. According to the online monitoring device, the straight-through current transformer is utilized for acquiring a leakage current signal of a grounding line of the transformer core, and a plan that the totally closed electromagnetic interference preventing housing and the current transformer are separately arranged is utilized. The online monitoring device has advantages of accurate and reliable monitoring data, high outer interference resistance and high convenience in mounting and maintenance.

The invention provides a half-open cavity type linear polarization and ultra-narrow linewidth multi-wavelength random fiber laser. The structure of the random fiber laser comprises an overlapped fiber grating, a rare-earth doping gain fiber, a wavelength division multiplexer, a pumping laser source, a fiber on-line polarizer, a polarization-maintaining fiber ring, a polarization-maintaining fiber isolator and an overlapped fiber grating axial stress regulation device, wherein the overlapped fiber grating, the rare-earth doping gain fiber, the wavelength division multiplexer, the fiber on-line polarizer, the polarization-maintaining fiber ring and the polarization-maintaining fiber isolator are sequentially connected, a pumping light end of a dual-fiber end of the wavelength division multiplexer is connected with an output end of the pumping laser source, and an output end of the polarization-maintaining fiber isolator is used as a laser output port. By combining the overlapped fiber grating and polarization-maintaining fiber random distributed feedback, the multi-wavelength random fiber laser is achieved; and compared with a single-mode fiber random distributed feedback mechanism, the random fiber laser has the advantages that multi-wavelength random laser output with higher external interference resistant capability can be obtained, and the application of the random fiber laser in the field of a random fiber laser source requiring higher performance is achieved.

The invention discloses a spread spectrum technology-based laser radar ranging method and device, and belongs to the field of laser radar ranging. The method comprises the following steps of S1, enabling bit information of a transmission sequence to carry out phase modulation on a light source signal by utilizing a phase difference between a pair of adjacent code elements; S2, enabling the phase-modulated light signal to enter a to-be-measured space through a transmission optical antenna; S3, enabling the reflected light signal to enter a delay interferometer so as to realize the demodulationof the light signal; S4, carrying out photoelectric conversion on the demodulated light signal through a photoelectric balance detector; and S5, enabling a local sequence to realize range measurementby utilizing at least one phase comparison manner of code chip phase comparison and code clock phase comparison. Based on a spread spectrum technology, the laser radar ranging method and device are strong in external interference resistance, long in detection distance and low in cost, and are capable of carrying out rough measurement or accurate measurement according to practical requirements so as to improve the measurement speed.

The invention provides an attitude control method for a propeller unmanned drone aircraft based on adaptive control, and the method comprises the steps: 1, determining an unmanned plane linear mathematic model; 2, determining an unmanned plane linear mathematic reference model; 3, employing an adaptive control algorithm to calculate a control law upsilon of an unmanned plane linear control system. The method is used for designing an attitude controller of an unmanned plane, thereby enabling the actual control output of the system to quickly and accurately track the reference adaptive control of models. The method is high in resistance to external interference.

The invention relates to a Gauss quadrature algorithm-based optical voltage transformer. The Gauss quadrature algorithm-based optical voltage transformer includes a grading ring, a high-voltage side electrode, a low-voltage grounding side electrode, a shielding tube, a base, a transmission unit, a high-voltage binding post, a hollow insulator, electric field sensors, an SLD light source and a signal acquisition and processing unit. The grading ring is located at the exterior of the top of the hollow insulator; the high-voltage binding post is located at the topmost end of the hollow insulator and is connected with the high-voltage side electrode; the high-voltage side electrode and the low-voltage grounding side electrode are arranged in the hollow insulator; the high-voltage side electrode and the low-voltage grounding side electrode are respectively located at the top and the bottom of the hollow insulator; the electric field sensors are connected with the SLD light source and the signal acquisition and processing unit through the transmission unit; and polarized light with phase difference transmitted from the electric field sensors is transferred to the signal acquisition and processing unit for performing signal acquisition and data processing. According to the Gauss quadrature algorithm-based optical voltage transformer of the invention, the five electric field sensors are adopted; Gauss-Legendre quadrature is performed on electric field values measured by the five electric field sensors, so that a high-voltage side voltage value can be calculated out; and therefore, influence of temperature and external magnetic fields on the optical voltage transformer can be decreased, and measurement accuracy and operation stability of the optical voltage transformer can be improved.

The invention, which belongs to the technical field of the reeling type irrigation sprinkler, provides a detection apparatus of the number of layers of a PE tube of a reeling type irrigation sprinkler. The detection apparatus comprises a moving plate, a static plate, a signal transmitting device, a signal receiving device, and a signal detection system. The moving plate is installed at one end of an irrigation sprinkler press lever shaft; and a press lever is installed on the press lever shaft. The position of the press lever is changed when the number of layers of a PE tube is changed; and then the moving plate position is changed because of the change of the position of the press lever. The static plate is installed on a rack of the irrigation sprinkler. The signal transmitting device and the signal receiving device are installed on the moving plate or the static plate. The signal receiving device receives different signals to output different codes; and the signal detection system determines the number of layers of the PE tube based on the codes of the signal receiving device. According to the invention, the reliability is high; real-time monitoring and displaying can be realized; and the influence by the historical parameters during the irrigation sprinkler operation process can be avoided.

The invention provides a micro-wind vibration energy consumption suppression device for a service steel pipe tower rod part, and the device is suitable for vortex-induced wind vibration control of animportant lattice type steel pipe tower framework part such as a power transmission tower. The micro-wind vibration energy consumption suppression device is composed of a steel sleeve sheet, a first viscoelastic material, a second viscoelastic material, SMA springs, a flow guide sheet, connecting bolts and connecting plates. The device has a two-stage micro-wind vibration control effect, can destroy the Karman vortex to inhibit or reduce the generation of micro-wind vibration, and can completely achieve the purpose of controlling the micro-wind vibration of a steel pipe component through the deformation consumption of the viscoelastic materials. Meanwhile, the SMA springs with the super-elastic effect are connected between the steel pipe and the steel sleeve, so that the device has a remarkable self-resetting capability. The device is simple in structure, light in structure, flexible in arrangement, low in manufacturing cost and convenient to replace. The device has the self-resettingcapability, is strong in resistance to external interference and is good in robustness; and the two-stage micro-wind vibration control principle is achieved, the vibration control effect is remarkable, good social and economic benefits are achieved, and the application prospect is wide.

The invention relates to a tandem vector thrust full-driving aircraft and a design method thereof, and relates to the technical field of aerospace. A front vector actuating mechanism is connected with a front connecting mechanism and a front electric thrust system together to form a front thrust vector actuating mechanism; a front connecting mechanism is connected with the front end of an aircraft body; two front steering engines are connected with the front vector actuating mechanism; a rear vector actuating mechanism is connected with a rear connecting mechanism and a rear electric thrust system together to form a rear thrust vector actuating mechanism; a rear connecting mechanism is connected with the rear end of the aircraft body; and two rear steering engines are connected with the rear vector actuating mechanism to form a tandem manner. Through the adoption of the tandem vector thrust full-driving aircraft disclosed by the invention, vertical takeoff, landing and hanging of the aircraft can be realized; the applying flexibility is high; and except a vertical flight mode, the aircraft can load fixed wings for level flight, so that requirements of speed and efficiency for long-distance flight are met; a full-driving system is arranged close to a working point, so that under the premise that attitude deflection is not performed, lateral guiding force can be directly generated, and position translation is directly performed; the external disturbance resistance is high; and the mobility is high.

The invention discloses a vehicle liquid level warning and protection device which belongs to the field of the electrics of the automobile body of an automobile. The device comprises a signal collection module, a voltage conversion module, a signal comparison module, a warning module, a protection control module and the like, wherein the signal collection module takes a pressure sensor as a measurement element and is installed at the bottom of a liquid container to be measured; a voltage signal output by the sensor is input into two voltage comparators which work independently, and the output ends of the two voltage comparators are respectively connected with the warning module and the protection control module; and the voltage conversion module converts an external power supply into voltage which is suitable for the device to work. Compared with a traditional liquid level protection device, the device provided by the invention uses the sensor to carry out measurement and has stable output and reliable measurement; and the device has a regulation function and can carry out regulation according to different liquid properties. When the measured liquid level exceeds a critical value, the device has two functions of warning and protection. Furthermore, the device can also be used for detecting liquid with poor insulativity and electric conductivity.

The invention provides a magnetism holding contactor which comprises a transmission rod. A movable contact is arranged at the top end of the transmission rod. A static contact is correspondingly arranged above the movable contact. A first magnetic force part is arranged at the bottom end of the transmission rod. A second magnetic force part is arranged corresponding to the first magnetic force part. An electromagnetic device is arranged on the outer side of the first magnetic force part and the moving track of the first magnetic force part. Under the action of the electromagnetic device, the first magnetic force part is matched with the second magnetic force part to drive the transmission rod to move upward so as to enable the movable contact to be in touch with the static contact. A reset spring is further arranged outside the transmission rod. The electromagnetic device is connected with a polar conversion circuit. The polar conversion circuit comprises a conversion circuit and a time delay circuit and is mainly composed of a relay and an electronic chip. The magnetism holding contactor is high in stability and reliability, and strong in ability to resist external interference, and can achieve the purpose of control without changing a control circuit due to the fact that the polar conversion circuit is further arranged at the front end of a coil of the electromagnetic device.

The present invention discloses a defect warning device of an insulating member in a switch cabinet. The device comprises four paths of gas sensors, a signal processing unit, an A / D conversion circuit, a microprocessor control unit and a host computer. The four paths of gas sensors, the signal processing unit, the A / D conversion circuit, the microprocessor control unit and the host computer are connected in order. The four paths of gas sensors are arranged in the switch cabinet and are hydrogen cyanide, carbon dioxide, ammonia and ozone sensors. The device has the advantages of simple structure, convenient operation, strong external anti-interference ability and high defect relevance, and the defect early warning can be realized. A low-pass filter and four paths of AD sampling are employed, the measuring range is expanded, the circuit structure is simplified, the volume of the device is reduced, and the reliability of the device is enhanced.

The invention discloses a time synchronization control system of an off-grid photovoltaic power system, which comprises a time receiving circuit, a clock correction computation control circuit and an off-grid system drive control circuit, wherein the time receiving circuit has a receiving antenna, receives a radio standard time signal transmitted by a radio time launcher and sends the received signal to the clock correction computation control circuit; the clock correction computation control circuit is used for filtering and analyzing the standard time signal, comparing the standard time signal with an actual clock signal of the photovoltaic power system, correcting the actual clock signal and sending the corrected clock signal to the off-grid system drive control circuit; and the off-grid system drive control circuit is connected with at least two off-grid photovoltaic power systems and drives all the off-grid photovoltaic power systems according to the received corrected clock signal, so that all the off-grid photovoltaic power systems are kept synchronous. When the embodiment of the invention is used, the precise control over the time synchronization of the off-grid photovoltaic power systems is realized, and the construction cost of a project can be reduced.

The invention provides a detection device for the number of PE pipe layers of a reel type sprinkler irrigation machine, which belongs to the technical field of reel type sprinkler irrigation machines. , a signal receiving device and a signal detection system; the moving piece is installed on one end of the pressure rod shaft of the sprinkler irrigation machine, and a pressure rod is installed on the pressure rod shaft, and the change in the number of layers of the PE pipe causes the position of the pressure rod to change, so The change of the position of the pressure bar causes the position of the moving piece to change, the static piece is installed on the sprinkler frame, the signal transmitting device and the signal receiving device are installed on the moving piece or the static piece, the The signal receiving device outputs different codes upon receiving different signals, and the signal detection system determines the number of layers of the PE pipe according to the codes of the signal receiving device. The invention has high reliability, can realize real-time monitoring and display, and is not affected by historical parameters in the operation process of the sprinkler irrigation machine.

The invention relates to an industrial network cable, in particular to a special communication double-layer shielding cable for the industrial network. The special communication double-layer shielding cable comprises an outer sheath, in which an insulating core quad is arranged; the insulating core quad consists of a red insulating core wire, a black insulating core wire, a yellow insulating core wire and a blue insulating core wire; the red insulating core wire is stranded with the black insulating core wire to form a red-black core quad; the yellow insulating core wire is stranded with the blue insulating core wire to form a yellow-blue core quad; the red-black core quad is stranded with the yellow-blue core quad; and a shielding layer is arranged between the inner side of the outer sheath and the insulating core quad. The special communication double-layer shielding cable is characterized by high transmission performance and strong external interference resisting capability, which meets the high requirement on the cable signal transmission in the industrial network, and ensures that the signal can be transmitted successfully even if the inner interference of the cable per se is reduced to the lowest value; and meanwhile, the special communication double-layer shielding cable removes the shielding of the external interference signal so that the signal transmission does not distort.

The invention discloses a preparation method of a doped sensitive material for improving the performance of a hydrogen sensor. The preparation method comprises the following steps: S1, adding a precipitant into deionized water, and fully and uniformly mixing to obtain a colorless and transparent mixed solution A; S2, adding ferric trichloride and transition metal salt into the mixed solution A obtained in the step S1, and fully and uniformly mixing to obtain a clear and transparent precursor solution B; S3, putting the precursor solution B obtained in the step S2 into a high-temperature stirring reaction kettle with a polytetrafluoroethylene lining, and performing stirring and heat preservation at 120 DEG C for 12-24 hours; and S4, centrifuging, washing and drying the material obtained in the step S3 to obtain the doped alpha-Fe2O3-based sensitive material. The preparation method is simple in synthesis process, high in repeatability and low in cost, and high-temperature calcination and use of a surfactant are not needed. The sensitivity, the stability and the selectivity of the hydrogen sensor made of the sensitive material are remarkably improved.

The invention provides a micro-wind vibration energy consumption suppression device for a service steel pipe tower rod part, and the device is suitable for vortex-induced wind vibration control of animportant lattice type steel pipe tower framework part such as a power transmission tower. The micro-wind vibration energy consumption suppression device is composed of a steel sleeve sheet, a first viscoelastic material, a second viscoelastic material, SMA springs, a flow guide sheet, connecting bolts and connecting plates. The device has a two-stage micro-wind vibration control effect, can destroy the Karman vortex to inhibit or reduce the generation of micro-wind vibration, and can completely achieve the purpose of controlling the micro-wind vibration of a steel pipe component through the deformation consumption of the viscoelastic materials. Meanwhile, the SMA springs with the super-elastic effect are connected between the steel pipe and the steel sleeve, so that the device has a remarkable self-resetting capability. The device is simple in structure, light in structure, flexible in arrangement, low in manufacturing cost and convenient to replace. The device has the self-resettingcapability, is strong in resistance to external interference and is good in robustness; and the two-stage micro-wind vibration control principle is achieved, the vibration control effect is remarkable, good social and economic benefits are achieved, and the application prospect is wide.

The invention discloses an orthogonal rhombus dual-mode precise piezoelectric stick-slip rotating platform and a driving method thereof, and aims to solve the technical problems of low external interference resistance caused by poor static retention of a current micro-nano stick-slip rotating platform, motion oscillation caused by displacement rollback, weak output performance and the like. The motor is composed of a pre-tightening assembly, a stator, a rotor, a base and an end cover. The single-step displacement amount of the platform is increased through the rhombic displacement amplification mechanism, high-precision feeding and accurate positioning are achieved through a single-stacking driving mode, the operation speed and the load capacity of the rotating platform are improved through a coupling driving mode, displacement rollback is restrained, and motion oscillation is reduced; meanwhile, due to the fact that the stick-slip driver has a coupling driving mode, the stick-slip driver can have larger holding force in a static state and is high in external interference resistance in a non-working state; the rotor shell is in interference fit with the outer ring of the bearing, the vertical bearing force of the rotating table is transmitted to the bearing, the driving effect of the stator is not affected, and the load capacity of the rotating table is improved. The invention has the characteristics of simple structure, good output performance, high positioning precision, large static retentivity and the like, and has good development potential and application value in the field of precision driving and positioning.

The invention relates to a full-automatic intelligent fishing rod based on an embedded system and an implementing method of the full-automatic intelligent fishing rod. The full-automatic intelligent fishing rod based on the embedded system comprises a fishing rod body and an automated control module, wherein the fishing rod body comprises a fishing rod body, a spinning wheel and a fish wire; the automated control module comprises a signal acquiring module, a server module, a power supply module and a control module; the signal acquiring module comprises an attitude sensor and an environment detecting module; and whether fishing is suitable or not through the environment detecting module is judged, and whether fishes bite hooks or not is judged by the attitude sensor. Fish walking and alarming functions of the fishing rod are fulfilled by the control module. By the environment detecting module, a fishing position is selected intelligently, and posture change caused by external disturbance can be distinguished by the attitude sensor. Compared with a traditional automatic fishing rod, the full-automatic intelligent fishing rod based on the embedded system has the advantages that erroneous judgment caused by environment factors such as flowing water and strong wind is reduced to a great degree; and an automatic fish walking function is fulfilled, complete automatic fishing is implemented, double-ring PID control is adopted, interference resistance is high, and a system is stable.

The invention provides a model-free adaptive control system and method for multi-element molten iron quality in a blast furnace. Set the expected value of the multi-element molten iron quality index of the blast furnace; obtain the blast furnace body production condition parameter variables at several historical moments required for parameter correction of the model-free adaptive controller and the measured values ​​of the multi-element molten iron quality index at the corresponding time. For the sensitive model-free adaptive controller Parameters and initial values ​​of pseudo-partial derivatives are corrected offline; a model-free adaptive controller is used to online control the molten iron quality index to track the set expected value of the multi-element molten iron quality index of the blast furnace. Combining the model-free adaptive control technology to establish an online recursive controller for the multi-element molten iron quality of the blast furnace; and establish a recursive subspace prediction model between the multi-element molten iron quality of the blast furnace and the two control quantities as an auxiliary model for parameter correction, using multi-parameter sensitivity analysis, The genetic algorithm offline corrects the controller parameters and the initial value of the pseudo-partial derivative to adapt it to the current dynamic characteristics of the blast furnace and achieve effective control of the quality of multi-element molten iron.

The tandem vector thrust full-drive aircraft and its design method relate to the technical field of aerospace. The front vector actuating mechanism is respectively connected with the front connecting mechanism and the front electric thrust system to form a front thrust vector actuating mechanism. The moving mechanism is respectively connected with the rear connecting mechanism and the rear electric thrust system to form a rear thrust vector actuating mechanism. The rear connecting mechanism is connected with the rear end of the body. The invention can realize the vertical take-off, landing and hovering of the aircraft, and has strong application flexibility. In addition to the vertical flight mode, it can be mounted on a fixed wing for horizontal flight, taking into account the requirements of speed and efficiency for long-distance flight. Near the working point is a full-drive system, which can directly generate lateral control force without attitude deflection, and directly perform position translation, with strong anti-interference ability and high maneuverability.

The invention discloses a method and a device for estimating sea surface wind speed based on line spectrum intensity in radar echoes. The method comprises the steps of establishing an experiential model in which intensities of a first-order peak and a secondary harmonic peak are changed along air speed, firstly estimating model parameters by fitting by taking air speed data measured in real time by virtue of a site buoy and air speed estimated on a radar close range unit by virtue of a conventional second-order spectrum method as standards, then estimating air speed by virtue of the intensities of the first-order peak and the secondary harmonic peak in an echo Doppler spectrum, weighting and combining the estimating model parameters with the air speed, so as to obtain a final air speed estimation value. According to the method and the device, the problem of high-frequency ground wave radar that an existing air speed estimation method based on an echo second-order spectrum is not accurate enough is solved; the intensities of a first-order Bragg peak and the secondary harmonic peak in the echo Doppler spectrum are related with the air speed value, so that the air speed can be directly extracted from line spectrums including the first-order peak, the secondary harmonic peak and the like, and the estimation precision of the sea surface wind speed by the high-frequency ground wave radar is substantially improved.

The invention discloses a device for monitoring a pressure. The device for monitoring the pressure comprises a control module, a sensing module, a shell and a protrusion; the control module and the sensing module are positioned in the shell; both ends of the control module are fixed to the shell; the sensing module is positioned on the lower side of the control module and fixed with the control module; and the protrusion passes through the lower end of the shell and is provided with an outside screw thread. The device for monitoring the pressure has dampproof and waterproof functions and stronger capability of resisting external interferences, and can better protect internal elements from being damaged, guarantee good working performance and accuracy of data transmission, and prolong the service life of the device.

The invention discloses a method and device for laser radar distance measurement based on spread spectrum technology, which belongs to the field of laser radar distance measurement, and includes the following steps: S1: the bit information of the transmission sequence is compared with the phase difference of a pair of adjacent symbols The light source signal is phase-modulated, S2: the phase-modulated optical signal is transmitted through the transmitting optical antenna into the space to be measured, S3: the reflected optical signal enters the delay interferometer, thereby realizing the demodulation of the optical signal, S4: the demodulated The optical signal is photoelectrically converted by the photoelectric balance detector. S5: The local sequence uses at least one phase comparison method of chip phase comparison and code clock phase comparison to realize distance measurement. The method and device for laser radar ranging of the present invention are based on spread spectrum technology, have strong anti-interference ability, have a longer distance for detection, and are cheap. At the same time, rough measurement or fine measurement can be performed according to actual needs, and the measurement speed can be improved.