1381 results about "Wave detection" patented technology

The present invention is an inexpensive, hand-held, and easy to operate millimeter-wave detection device that employs a non-imaging sensor which radiates a pulse of millimeter waves of a certain amplitude and frequency towards a target located at a distance from the detection device. The sensor receives pulses of millimeter waves that are reflected from the target and generates a voltage waveform that is characteristic mainly of the target material, while other parameters such as distance to the target are known. The processor of the detection device measures both the peak voltage and the rate of increase of the voltage until it reaches the maximum. Using an algorithm stored in a software module, the deviation between the rate of the voltage rise and the peak voltage is compared with values of similar parameters for a number of test targets made of different materials that were previously collected and stored in a calibration table in the memory of the device. A concealed object, e.g. a weapon, is positively identified when the measured voltage rise is found to be similar to one of the stored voltage rises. The circuitry of the detection device generates a visual and / or audio output to a display device which is indicative to the operator as to whether a concealed object is present and, if a match is found with the data in the calibration table, the nature of the concealed object is also displayed. In addition to the basic mode of operation described, various other operation modes can be employed with the detection device of the invention.

Noninvasive method for determining the liquid level and density inside of a container having arbitrary dimension and shape. By generating a flexural acoustic wave in the container shell and measuring the phase difference of the detected flexural wave from that of the originally generated wave a small distance from the generated wave, while moving the generation and detection means through the liquid / vapor interface, this interface can be detected. Both the wave generation and wave detection may be achieved by transducers on the surface of the container. A change in the phase difference over the outer surface of the vessel signifies that a liquid / vapor interface has been crossed, while the magnitude of the phase difference can be related to fluid density immediately opposite the measurement position on the surface of the vessel.

To calculate information on a relative distance or positional relationship between an interface section and an object by detecting an electromagnetic wave transmitted through the interface section, and using the electromagnetic wave from the object to detect a relative position of the object with respective to the interface section. Information on the relative spatial position of an object 101 with respect to an interface section 102 that has an arbitrary shape and deals with transmission of information or signal from one side to the other side of the interface section 102 is detected with a spatial position detection method. An electromagnetic wave 106 radiated from the object 101 and transmitted through the interface section 102 is detected by an electromagnetic wave detection section 103, and based on the detection result, information on spatial position coordinates of the object 101 is calculated by a position calculation section 104.

An apparatus and method for delivering electrical shock therapy in order to treat atrial tachyarrhythmias such as fibrillation utilizes a dynamically varying threshold to detect R-waves and synchronously deliver a defibrillation shock.

An optical inspection device 1, comprising a light generation means 2, a light irradiation means 3 irradiating an object to be inspected 4 with light generated from the light generation means 2 and a photodetection means 6 photoelectrically converting signal light obtained from the object to be inspected 4 through irradiation of light by the light irradiation means 3, and inspecting the object to be inspected 4 based on output from the photodetection means 6, wherein a light amplification means 5 amplifying signal light obtained from the object to be inspected 4 is provided. There is thus provided an optical inspection device capable of photoelectrically converting signal light from the object to be inspected with high sensitivity and promptly with its inexpensive configuration without increasing the intensity of light with which the object to be inspected is irradiated and without using an expensive low-noise and high-sensitivity photodetector.

The invention relates to pipeline defect ultrasound guided wave time reversal detection device and method. The method includes the following steps: selecting detecting frequency according to the detected pipeline corresponding free hollow column structure group velocity dispersion curve; inputting the frequency into the arbitrary function generator to generate center frequency used as single sound signal; sending the signal to each passage of exciting / receiving set to transducer unit; exciting longitudinal axis symmetry guided wave modal; sending the reflected signal to the computer and gaining reversal excitation signal by time reversal; repeatedly exciting guided signal to detect. The invention realize space and time focus for guided wave detection, greatly improve detection capability for little defect.

Disclosed is radar wave detection and DFS (dynamic frequency selection) with high efficiency while considering, for instance, the power consumption of each communication station within an autonomous distributed network. At least one communication station runs in an interference avoidance operation mode, operates a radar wave detection section, and fulfills the obligation to issue instructions for radar wave detection and DFS for an approximately predetermined period of time. After the lapse of the approximately predetermined period of time, another communication station switches to the interference avoidance operation mode and assumes the obligation to issue instructions for radar wave detection and DFS. In other words, two or more communication stations sequentially run in the interference avoidance operation mode in a time sharing manner. Therefore, the average power consumption of the communication stations decreases.

The invention discloses a fault positioning method for a transmission line and belongs to the technical field of power systems. The fault positioning method comprises the following steps: arranging a Rogowski coil-based broadband core-through traveling wave detection device on the high-voltage transmission line; acquiring a current traveling wave signal of a three-phase line; performing singular value detection by applying the phase mode conversion and wavelet mode maximum principle; accurately identifying the traveling wave line mode wave head, and accurately determining the wave head arrival time by using a GPS high-precision clock; and measuring the wave speed of real-time traveling wave mode on line according to different wave head time difference information to realize accurate fault positioning. The fault positioning method has the advantages of effectively avoiding two main factors influencing the traveling wave fault positioning precision, along with high positioning precision and accurate and reliable fault positioning result.

Nano-electromechanical device having an electrically conductive nano-cantilever wherein the nano-cantilever has a free end that is movable relative to an electrically conductive substrate such as an electrode of a circuit. The circuit includes a power source connected to the electrode and to the nano-cantilever for providing a pull-in or pull-out voltage therebetween to effect bending movement of the nano-cantilever relative to the electrode. Feedback control is provided for varying the voltage between the electrode and the nano-cantilever in response to the position of the cantilever relative to the electrode. The device provides two stable positions of the nano-cantilever and a hysteresis loop in the current-voltage space between the pull-in voltage and the pull-out voltage. A first stable position of the nano-cantilever is provided at sub-nanometer gap between the free end of the nano-cantilever and the electrode with a pull-in voltage applied and with a stable tunneling electrical current present in the circuit. A second stable position of the nano-cantilever is provided with a pull-out voltage between the cantilever and the electrode with little or no tunneling electrical current present in the circuit. The nano-electromechanical device can be used in a scanning probe microscope, ultrasonic wave detection sensor, NEMS switch, random access memory element, gap sensor, logic device, and a bio-sensor when the nano-cantilever is functionalized with biomolecules that interact with species present in the ambient environment be them in air or aqueous solutions. In the latest case, the NEMS needs to be integrated with a microfluidic system.

In an image projection on a screen, an image projection apparatus improves the safety of entry into a projection region by the human body and does not bring about the increase of complexity of the configuration thereof owing to the improvement of the safety. A monitoring area is regulated on the outside of the projection area (3) of the screen (2). A detection wave such as infrared rays is emitted from a detection wave source (1c) of the image projection apparatus (1). A reflection wave from the monitoring area is detected by reflection wave detection means (1d) such as a CCD sensor. Whether the human body or an obstacle enters the monitoring space, which is surrounded by a detection wave (4) between the main body unit of the image projection apparatus (1) and the screen (2), or not is detected. Once the entry is detected, the intensity of the radiation light traveling toward the projection area (3) is reduced or cut off according to the situation or the degree of the entry.

The invention discloses a comprehensive advance geological detection system carried by a tunnel boring machine. The comprehensive advance geological detection system comprises a multifunctional combination main frame, an induced polarization detection device, an earthquake wave detection device, an integrated junction device, a drilling geological radar detection device and a comprehensive interpretation decision system. The multifunctional combination main frame comprises a time division multiplexing control module, an excitation source control module and a parallel data collecting module. The excitation source control module outputs trigger signals to the three detection devices respectively, the three detection devices respectively output measurement data and feedback signals to the time division multiplexing control module through the parallel data collecting module. The comprehensive interpretation decision system supports geological interpretations and decisions through the inversion / migration imaging joint inversion of three detection methods. The detection system greatly improves the automation degree and detection speed of detection equipment on the tunnel boring machine, and multiple kinds of detection equipment can be carried by the tunnel boring machine.

There is a need for a detection device which has high photoreceptive sensitivity in a generally wide frequency region including the infrared region. Therefore, in the present invention, by utilizing a phenomenon in which electric field strength is enhanced by surface plasmon resonance in a negative dielectric constant medium, a detection device is provided which has an electromagnetic wave detection portion disposed at a position where the electric field strength is large.

The invention discloses a fingerprint identification display panel, a production method thereof, a driving method thereof, and a display device. A plurality of ultrasonic wave detection units, a plurality of identification scanning lines, and a plurality of identification output lines are disposed in the display device. Every ultrasonic wave detection unit comprises a pressure-sensing unit used for generating ultrasonic waves and sensing the changes of the ultrasonic waves caused by pressing of fingerprints, and a control switch transistor used for controlling the pressure-sensing unit to convert the changes of the ultrasonic waves into different signals for output. When fingers of users are close to the surface of the display device, because of the uneven ridges and the uneven valleys of the skins of the fingers, the intensities of the ultrasonic waves transmitted by the pressure-sensing units reflected by the positions of the ridges and the valleys of the fingers back to the pressure-sensing units are different, and then the differences of the current signals converted by the pressure-sensing units are caused, and therefore the detection of the fingerprints is realized. The pressure-sensing unit is used for the detection of the fingerprints based on piezoelectric effect, and interferences on the internal parts in the display device are not easy to generate, and therefore high-quality fingerprint detection is easily realized.

Provided is a cyclic shift sequence generation method which can prevent coming of an interference wave into a desired wave detection window even if a cyclic shift sequence has a high mutual correlation in different bandwidths, thereby improving a channel estimation accuracy in a base station. In this method, a cyclic shift sequence number to be allocated to a cell is decided in advance. Moreover, when the cyclic shift amount between cyclic shift sequences allocated in cells is Δ1 and the cyclic shift amount of the cyclic shift sequences allocated between the cells is Δ2, Δ1 and Δ2 are made different when generating a cyclic shift sequence.

The invention discloses a vital sign parameter evaluation device on the basis of volume pulse wave detection, comprising an input module, a volume pulse wave collecting module, a main control module and a display; the input module is used for inputting the basis information of the user such as height HT, weight WT, systolic pressure Ps, and diastolic pressure pd; the input module, the volume pulse wave collecting module and the display are connected with the main control module; the main control module comprises a volume pulse wave characteristic point extractor and a vital sign parameter calculator; the vital sign parameter calculator comprises a pulse blood-ejection prophase PEP calculator; the blood-ejection prophase can be gained directly by the calculation of the volume pulse; one signal of the volume pulse wave can realize the innovative detection of main vital sign parameter; the volume pulse wave is generally measured at the finger end and the requirement on the position of the sensor is not high; furthermore, the detection and analysis speed is quick, the cost is low, the repeatability is good, and the stability is high.

The invention discloses a distributed fault location method for an overhead line-cable hybrid circuit. The method comprises the following steps: S1, arranging fault traveling wave detection devices at the joint of the hybrid circuit and a bus and the joints of different circuits in the hybrid circuit, judging a failed circuit according to the polarity of a first fault travelling wave head detected by each fault traveling wave detection device, wherein when fault current travelling wave heads detected by two adjacent fault travelling wave detecting devices are of opposite polarities, a circuit between the two adjacent fault travelling wave detection device is the failed circuit; and S2, judging the source of a second travelling wave head according to the arriving time of the fault travelling wave heads detected by the fault travelling wave detection devices at the two ends of the failed circuit, and selecting a proper fault location method for positioning. According to the distributed fault location method, online calculation of the travelling wave transmission speed of a power transmission line is realized, and the source of a second fault travelling wave of a detection point is judged according to the analysis of a travelling wave sequence; and the method has a good application prospect.

The invention relates to the technical field of terahertz spectrums, in particular to a graphene-based all-optically controlled ultra-high speed terahertz intensity modulator. The technical problems of low modulation speed and narrow spectrum range of the conventional terahertz intensity modulator are solved, and the application range of a system is widened. According to the graphene-based all-optically controlled ultra-high speed terahertz intensity modulator, gold nanoparticles are adopted, so that the photon absorption efficiency of graphene is enhanced, the concentration of photon-generated carriers is improved, the absorption of terahertz waves is further enhanced, and the modulation effect of the modulator is enhanced. The graphene-based all-optically controlled ultra-high speed terahertz intensity modulator comprises a terahertz wave generation device, a pumping light wave generation device, a terahertz intensity modulator and a terahertz wave detection device, which are connected to finish the design of the graphene-based all-optically controlled ultra-high speed terahertz intensity modulator. The graphene-based all-optically controlled ultra-high speed terahertz intensity modulator is mainly applied to the fields of terahertz communication systems and terahertz researches.

The invention discloses a feeding control system and method for fish culture. The system comprises a split beam transducer, a feeding unit and a signal collecting, processing and control unit, wherein the split beam transducer is used for converting acoustic waves and electric signals and transmitting and receiving the acoustic waves in water, the feeding unit is used for receiving a control instruction to feed the cultured fishes, the signal collecting, processing and control unit is used for receiving an echo signal which is collected by the split beam transducer, and converting the echo signal into echo images through phase difference detection and wave detection, and the weight of single fish and the total weight of a fish school in the feeding water area are respectively calculated after target identification and acoustic wave image processing, so the feeding amount is adjusted. The system and the method have the advantage that the growth change of the fishes in the feeding water area can be monitored, and the feeding amount is adjusted in real time, so the waste on culture baits is reduced.

The invention discloses a harmonic wave detection method based on Fourier transformation, comprising the following steps: (1) carrying out oversampling and analog-to-digital conversion on a measured signal, and ensuring that data of two signal periods can be sampled from each group of data according to the maximum periodic value estimated by the measured signal; (2) filtering harmonic wave components outside fundamental waves by a digital low pass filter; (3) calculating a fundamental wave period by a periodic method; (4) extracting 2*N numbered data points within one period, wherein, N-1 is the highest harmonic order number; and (5) calculating the parameter of each harmonic wave component by utilizing a synchronous sample FFT. The method of the invention belongs to the signal processingtechnical field, and also can be used for spectrum analysis of other signals. Very high harmonic wave detection accuracy can be obtained by the method; the instantaneity can be doubled compared with three to five signal periods of a quasi-synchronizing method; and the time of two signal periods are only needed, and the fundamental wave frequency also can be accurately measured.

The invention discloses a fundamental wave based on Kaiser Window bispectrum line interpolation FFT (Fast Fourier Transform) and a harmonic wave detection method. The method comprises the following steps: analog-to-digital conversion and low-pass filtration treatment is conducted on the signal to be detected; the Kaiser Window with free proportion selection between the attenuation of a main lobe and side lobes, flexible design realization, low side lobe level and quick attenuation speed is adopted to conduct windowing FFT operation on the signal; and bispectrum line interpolation algorithm is used for detecting base wave and harmonic quantities of the detected signal. The following aspects are included: (1) analog-to-digital conversion and low-pass filtration; (2) the FFT operation based on the Kaiser Window; (3) base wave and harmonic wave parameters derived by bispectrum line interpolation and polynomial fitting.

A ultrasonic wave detection device of petroleum pipeline is prepared as setting ultrasonic probe at front end of robot body, arranging a rubber disc at tail end of robot, forming robot body by front unit and back unit as the two being connected by universal couple, applying driven wheels as traveling mechanism of robot and setting these wheels on front unit and back unit separately. Its dynamic-detecting method is also disclosed.

The invention discloses a metamaterial-based terahertz adjustable polarized wave insensitive electromagnetically-induced transparency device, and belongs to the fields of electromagnetic wave detection and sensor. The electromagnetically-induced transparency device comprises multiple basic units periodically arranged in the same direction; each basic unit comprises an upper layer graphene layer and a lower layer dielectric layer, and the dielectric layer is fixed on a substrate device; graphene is cut to form graphene square rings with openings in the adjacent edges; after the graphene layer is completely cut in one time, the middle part of the substrate device is hollow out; and finally, electroplating of a layer of conductive adhesive is carried out. The electromagnetically-induced transparency device has the same electromagnetically-induced transparency phenomenon on line polarized light in the x and y directions; when the polarized mode of incident wave is changed, device replacement is not needed; and in addition, an adjustable electromagnetically-induced transparency phenomenon can be realized by regulating the externally applied voltage without changing the device structure,thereby achieving important guidance significance and reference value on the development of an adjustable terahertz functional device.

The invention provides an electrocardio signal QRS complex wave detection method based on morphology and wavelet transform. The method comprises a first step of inputting an electrocardiograph (ECG) signal which restrains base line drift and after high-frequency noise is removed and carrying out segmentation, a second step of using a db6 wavelet to carry out four-layer wavelet decomposition to the segmented ECG signal obtained in the first step, a third step of using a multiresolution morphology decomposition method to decompose the segmented ECG signal obtained in the first step and searching a common model maximum value point on a third layer detail component and a fourth layer detail component and regarding the common model maximum value point as an R peak location, a fourth step of carrying out the OR operation to the R peak locations obtained in the second step and the third step and preserving a result as a new R peak location if the result is 1, a fifth step of recalling an R peak, a sixth step of confirming a starting point and a terminal point of an QRS complex wave, and a seventh step of confirming whether total ECG signal detection is finished or not, finishing the operation if the detection is finished, and updating a threshold value and repeating the second step to the seventh step until an algorithm is finished, if the detection is not finished. The method can reach detection accuracy rate of more than 99%.

The invention discloses a radial pulse wave detection device, comprising a base, a sliding seat, a tooth holder, a rocker arm, a sensor connector and a sensor; the sliding seat is arranged on the sliding rail at the bottom part of the base, the sliding seat and the base are both provided with a supporting face for supporting and fixing a wrist; the tooth holder is fixed on the upper part of the base; the rocker arm is installed on the tooth holder through a revolving shaft; the joint surface of the rocker arm and the tooth holder is meshed by a tooth face; the sensor connector is installed on the rocker arm in a slip manner; the sensor is installed on the sensor connector; and the output end of the sensor is connected with a signal collecting device; and the output signal is successively processed by a computer. The radial pulse wave detection device of invention fully exposes radial pulse, maintains the detected person to be at a natural state, and simultaneously realizes rapid and accurate noninvasive detection of radial pulse, thereby solving the problems that the detection point position and external applying force are difficult to be determined, and the position of the detection point is easily to be changed in radial pulse wave detection process,.

In an image projection on a screen, an image projection apparatus improves the safety of entry into a projection region by the human body and does not bring about the increase of complexity of the configuration thereof owing to the improvement of the safety. A monitoring area is regulated on the outside of the projection area (3) of the screen (2). A detection wave such as infrared rays is emitted from a detection wave source (1c) of the image projection apparatus (1). A reflection wave from the monitoring area is detected by reflection wave detection means (1d) such as a CCD sensor. Whether the human body or an obstacle enters the monitoring space, which is surrounded by a detection wave (4) between the main body unit of the image projection apparatus (1) and the screen (2), or not is detected. Once the entry is detected, the intensity of the radiation light traveling toward the projection area (3) is reduced or cut off according to the situation or the degree of the entry.

An approach is provided for detecting EM waves using a photodetector coupled to an amplifier stage. The amplifier stage uses capacitive feedback to reduce or cancel intrinsic capacitance of the photodetector. A variety of capacitance structures may be used to provide the capacitive feedback such as shielded capacitors and capacitor arrays. The amplifier stage may be either single-ended or fully differential, depending upon the requirements of a particular application. Noise cancellation circuitry may also be included to reduce noise and offset sources present in the amplifier stage. The approach is applicable to a variety of contexts and applications. Example applications include, without limitation, detection of both brightness and Time of Flight (TOF) in 3D sensing applications. The approach may also be used to detect EM wave intensity in 2D sensing systems and, in general, for any application requiring simultaneously high speed and high sensitivity EM detection.

The invention relates to an earth fault distance measurement method based on traveling wave modulus time difference, belonging to the field of power electronic technology. The invention utilizes traveling wave detection devices installed at detections points along the line to ensures an effective detection point closer to a fault point to accurately distinguish a zero mode and a line mode initial wave head, and uploads the time difference between the zero mode and the line mode initial wave head into a monitor station. The monitor station is used for sequencing all the collected modulus time difference from big to small, firstly judges the detection point which is closed to the fault point for a first step, and then completing accurate fault distance measurement according to the primary locating result. The invention does not need a time synchronous system, has low communication traffic, is not influenced by line tap points, is easy for project implementation, and has higher reliability and distance measurement accuracy.

The invention discloses a frequency self-adaptive real-time fractional harmonic wave detection method. Phase locking is conducted on power grid voltages through a phase locked loop, the power grid voltage frequency fg is obtained, the system control frequency fs is adjusted according to the power grid voltage frequency fg, when the power grid voltage frequency fluctuates, the number of sampling points of a system within the power grid fundamental wave period is kept unchangeable, the function of frequency self-adaptation of an n-harmonic-wave band-pass filter is achieved, and then subtraction is carried out on the input quantity of the n-harmonic-wave band-pass filter to remove mutual interference among all times of harmonic waves. Finally, n harmonic waves of a detected signal are extracted through the n-harmonic-wave band-pass filter, and then the harmonic waves of the detected signal can be accurately detected in a real-time and fractional mode.

The invention discloses a method and a device for selecting the small unit average constant false alarm rate for the real-time detection of a moving target of a synthetic aperture radar (SAR); the device comprises: a linear wave detector, a first reference unit, a first protection unit, a second protection unit, a detection unit, a comparator unit, a first average processing unit, a second average processing unit, a small-selecting comparator unit and a multiplier unit; the method comprises that: the image data of the synthetic aperture radar is carried out the linear wave detection and then is sequentially input into the detection unit; the both ends of the detection unit are respectively provided with one protection unit and the reference unit, the small value of the two values after averaging each reference unit is taken, and the threshold is obtained by multiplying the small value with the detection threshold; the detection unit and the threshold are compared to obtain the detection result; then, the image edge is carried out the detection to obtain the whole frame of the detected target image. The method solves the problems such as lower detection probability, high false alarm rate and vulnerability of the interference of the prior art; and the invention provides the system which has small calculation amount, simple operation, improved detection effect and is applicable to the real-time detection of the moving target.