1783 results about "Interference immunity" patented technology

A highly sensitive, high-speed dual tunnel diode detector is described for use in Ultra Wideband (UWB) object detection systems, such as a radar. The extended capability of the detector to both extremely short (sub-foot) and long distance (tens of thousands of feet) ranges is unique and permits the application of low power UWB radar to a wide variety of applications including high resolution radar altimetry at altitudes exceeding 10,000 feet and for autonomous on-deck landing operations (e.g., one-foot altitudes), the detection of extremely low radar cross section (RCS) targets for such applications as suspended wire detection for helicopters and other manned and unmanned craft, etc. High noise and interference immunity of the detector permits co-location of a UWB radar sensor with other active systems. The invention has immediate and significant application to all areas, both military and commercial, of precision distance measurement, intrusion detection, targeting, etc. over a wide range of distances.

The invention discloses a GPS/SINS (global positioning system/strapdown inertial navigation system) combined navigating system with high anti-interference performance and a realizing method thereof, which belong to the technical field of navigation. The system comprises a GPS array antenna, a radio-frequency front end, an interference inhibiting module, a GPS baseband processing link, an SINS module and a combined navigating unit. The method comprises the following steps: 1, receiving a GPS signal and treating the GPS signal by the radio-frequency front end; 2, detecting high-power electromagnetic interference; 3, regulating an antenna beam in a self-adaptive way and filtering to remove a high-power interference signal; 4, carrying out the navigation resolution and the information fusion of a GPS and an SINS; and 5, obtaining an auxiliary parameter. The system and the realizing method have favorable dynamic tracking capability and anti-interference performance; the high-power interference signal can be effectively prevented from causing the saturation and the jamming of a GSP radio-frequency front end; and the robustness performance of the navigating system for dealing with a complicated interference environment is improved.

A video processor for endoscopic camera or for videoendoscopic probe associated with a color video sensor, the video processor comprising: a signal preprocessing circuit designed to be remotely connected to the video sensor through an electrical link without any intermediate connection device, the preprocessing circuit comprising a first signal processor for generating from image signals output by the video sensor raw video signals comprising a brightness signal and a color signal, these signals being not usable directly because they are phase shifted and are noisy due to synchronization residues, and a synchronizing circuit for synchronizing the video sensor and the first signal processor; and a remote auxiliary circuit comprising a second signal processor connected to the first signal processor through a low impedance electrical link providing good immunity to interference, the second signal processor generating from said raw video brightness and color signals at least one useful video signal according to an international video standard.

The invention discloses a method and a system for orthogonal modulation of power signals. The method comprises the following steps: acquiring an initial sequence length and an initial sequence according to a frequency lower limit, a preset sampling frequency and an initially set integer signal cycle number of a power signal; acquiring a reference frequency according to the initial sequence, and further acquiring a unit cycle sequence length and a preset sequence length; acquiring first forward and reverse sequences according to a preset sequence starting point and the preset sequence length; generating first real-frequency and imaginary-frequency vector sequences and second real-frequency and imaginary-frequency vector sequences according to the first forward and reverse sequences; converting obtained first and second phases into a first forward sequence average initial phase; obtaining a new preset sequence starting point according to the average initial phase; and obtaining a cosine function modulation sequence and a sine function modulation sequence according to second forward and reverse sequences obtained from the initial sequence. By adopting the method and the system of the invention, an orthogonal modulation sequence with consistent amplitude height can be obtained, and the accuracy and anti-jamming performance of sinusoidal parameter calculation are improved.

The method includes steps: sampling AC current to be monitored; based on sampled values, looking up crossover points of the sampled waveform; calculating period T of AC current to be monitored based on crossover points; calculating frequency of AC current monitored. Crossover points are searched through software directly so as to reduce hardware spending. Averaging results of multiple times of calculation obtains final outcome in high precision. Anti-interference ability is high since questionable data including too large and too small data are thrown off. Advantages are: simple and reasonable, accurate and reliable data, and high practicability.

The invention provides a method and a system for automatically testing the anti-interference performance of a Beidou receiver. The method comprises the following steps: a satellite signal and interference signal simulation source receives setting parameters transmitted by an upper computer, simulates a motion track and state of a user and generates a Beidou satellite navigation signal and various interference intermediate frequency digital signals; the generated Beidou satellite signal and multiple interference signals are transmitted from different positions and directions through antennas through digital/analog (AD), up-conversion and power regulation; a tested receiver is arranged on a rotating platform and rotates along the rotating platform; and the receiver simultaneously receives the satellite signal and multiple interference signals, finishes anti-interference processing, signal processing and navigation calculation of the signals, outputs corresponding positioning results in different interference modes and outputs the results to the upper computer, and the upper computer finishes the anti-interference performance evaluation of the receiver and outputs the evaluation result. The anti-interference capacity of the receiver in the time domain and the frequency domain can be tested, and the anti-interference capacity of the receiver in the space domain can be tested.

The invention discloses a method for detecting fire disaster smog by video on the basis of color saturation and motion mode, which comprises the following steps: firstly, extracting a foreground motion block from a video image acquired by a monitoring camera through a difference method; secondly, detecting the color saturation of the foreground motion block, estimating the direction of the motion block, and calculating the cumulant and the main moving direction of the motion block; and thirdly, calculating the color saturation detection percentage of each region, the average cumulant and the main moving direction ratio to form a characteristic vector, and adopting a Bayesian classifier to judge whether the smog is the fire disaster smog. The detection of the color saturation reflects a rough color distribution of the smog and eliminates a large amount of foreground interfering objects with glowing colors. The color detection in a blocking mode further improves the anti-interference performance of a system. The cumulant shows the characteristic of continuous movement nearby a smoldering point of the smog, and has very good anti-interference performance for a non-reciprocating object. The comprehensive utilization of the color saturation detection percentage, the average cumulant and the main movement ratio can greatly reduce the rate of false alarm for the system.

The invention provides a sliding-mode control method of a permanent magnet synchronous motor based on reaching law and disturbance observation compensation. A new reaching law algorithm is designed, and applicable in design of a speed controller in a sliding-mode variable structure; simultaneously, a saturation function is used in a disturbance observer control law, and used for improving a disturbance observer; a value observed by the disturbance observer is compensated in the speed controller; and therefore, a new control strategy is formed. The new control method is applicable in a vector control system of the permanent magnet synchronous motor; a current-speed double-closed-ring control structure is adopted; for buffeting and anti-interference problems in the sliding-mode control, an integral sliding-mode surface and a new reaching law are added based on the conventional sliding-mode speed controller; simultaneously, the disturbance observer is added; disturbance due to load changeis effectively inhibited; the responsiveness of the system is improved; buffeting of the system is reduced; and the anti-interference performance and the robustness of the system in a complex environment are obviously improved.

The invention discloses a biological characteristic identifying system. By adopting a double-mode identifying method, complementarity and pertinency laws between characteristics of multiple living things such as face of human being, voice, fingerprint and the like, limitation of single mode biological characteristic identifying can be avoided effectively, and the system based on a client/server network structure model for biological characteristic identifying reduces the network transmission data amount effectively and reduces the heavy burden of server operation by utilizing a limited bandwidth, and the system has advantages of fault tolerance, extendibility, interference immunity, robustness and environment adaptability.

The invention relates to a digital electronic detonator chip based on a double-wire bus and a control method. The chip adopts the non-polar and one-leader-multiple-follower half-duplex type double-wire bus with communication and power supply functions, and communication of an amplitude and pulse width modulation modes is supported; during pulse width modulation communication, a downlink communication standard pulse width value can be configured according to needs, and a uplink communication standard pulse width value is fixed; the chip comprises all the function modules for completing the detonation operation and a communication instruction set, a charging voltage value can be externally configured; the chip control method is composed of 'detonator chip information injection and detonatorchip on-site detonation'; and through the mode, the digital electronic detonator chip and the control method can meet requirements and practical application demands of the latest Chinese public security industry standard, namely the 'Industrial Electronic Detonator Information Management General Rule(GA1531-2018) ', the anti-interference performance and the communication safety reliability are improved, the application scene is expanded, the configurability and the detonation safety of the chip are improved, the control process is standardized, improper operation is avoided, and the comprehensive cost is reduced.

This array antenna with anti-jamming in reception for radioelectrical or ultrasound waves is provided with radiating elements fitted out individually or in groups with amplitude-controlled and phase-controlled passive or active modules enabling aiming at transmission as well as at reception by analog beam-forming. It possesses a reception anti-jamming circuit carrying out successively two reduced, adaptive computational beam-forming operations, one in elevation which is performed on a grouping, in horizontal alignments, of the reception signals of the radiating elements and working on the reception signals by modifying the settings of the controlled modules and the other in relative bearing, performed on a grouping, in vertical alignments, of the signals of the radiating elements that which it phase-shifts and adds up to form a reception channel for the total antenna. The reception anti-jamming thus obtained has performance characteristics comparable to those that would result from a full adaptive beam-forming operation. At the same time, it requires a far smaller volume of processing.

A port on-site data acquiring, transmitting, sending and issuring system based on zigbee technology in the remote monitoring and controlling field of electromechanical equipment, comprises a wireless sensing network and a remote data server, wherein the wireless sensing network is distributed in a port working field, and can acquire working state data of the port field, collect the intra-network acquired data in a zigbee wireless manner, pack the collected data, and transmit to the remote data server via wired enterprise in-house network based on a transmission control protocol and an internetwork protocol. The remote data server can receive the data based on the transmission control protocol and the internetwork protocol, resolve the data according to the packed data transmission format, store the data in a database, and issue the data in a web service mode. The invention provides data support for monitoring application program development, failure pre-warning and equipment maintenance. In addition, the low-cost zigbee technology can reduce system complexity, and has good anti-interference performance, expandability and practicability.

The invention provides a heartbeat frequency detection algorithm of a non-contact vital sign detection system; the steps are: respectively doing bandpass filtering for I and Q two way signals outputted by a continuous wave doppler radar; using a center estimate algorithm to carry out useful dc component recovery; using a complete cluster experience modal decomposition algorithm to separate a heartbeat signal from a human body jitter signal, a breathing signal and environment interference noises; resolving a Hilbert marginal spectrum of each decomposition signal and doing peak value detection; finding out the Hilbert marginal spectrum corresponding to the heartbeat signal according to a marginal spectrum peak position and energy concentration degree close to the spectrum peak; obtaining heartbeat frequency information according to the spectrum peak position. The heartbeat frequency detection algorithm can effectively extract the heartbeat signal under unstable human body and large environment interference noises, thus obtaining accurate heartbeat frequency information, improving anti-interference property of the non-contact vital sign detection system, and satisfying heartbeat frequency detection accuracy demands of medical affairs personnel.

The invention provides a high potential direct current (DC) voltage energy-taking power supply which is good in electrical isolation performance, and is capable of meeting the requirement of power supply of a high potential electronic circuit and stably working under the condition of wider DC input voltage range; and the DC voltage energy-taking power supply is rapid in starting speed so as to maintain stable rated output under the condition of lower DC voltage input, is good in anti-interference performance so as to be capable of normally working in the severe electromagnetic environment and is small in volume so as to meet the compact design of a device.

The invention discloses an integrated desk-type signal simulation platform for a satellite navigation anti-interference test, and the platform comprises a control module which is used for setting scene parameters according to different performance test requirements, generating a navigation message and observation data according to a navigation algorithm, and transmitting the generated data and interference signal parameters to an FPGA; and a signal generation module which is used for generating a navigation signal and an interference signal. The platform is characterized in that, compared with the prior art, the platform achieves the simple and effective testing and evaluation of anti-interference performances of navigation receiving equipment; the platform controls a signal simulation source to generate the satellite navigation signal and the interference signal; the receiving equipment decodes the received mixed signal, and transmits the positioning speed measurement information to the control module for the evaluation of anti-interference performances.

The invention provides a control device of a digital electric steering engine and a control method. The control method comprises the steps that a steering surface deflection angle given signal is subjected to voltage transformation, filtering and amplitude limiting processing by a signal conditioning circuit, and sent to a controller DSP (Digital Signal Processor) by AD (Analogue-to-Digital) conversion; the DSP outputs a digital control signal; the digital control signal is subjected to digital isolation and then sent to a driving circuit to be converted into a power control signal; a brushless DC (Direct Current) motor is controlled to operate by controlling a main power circuit, and drives a steering surface to deflect through a transmission gear set to follow the steering surface deflection angle given signal; the bus current of the brushless DC motor is sampled by a current sensor and fed back to the DSP; an angle sensor connected with the transmission gear set feeds back a current deflection angle of the steering surface in real time and sends the current deflection angle to the DPS. The control device and the control method effectively accelerate frequency response of a brushless DC electric steering engine, and improve the interference immunity of a system.

Through designing a radial basis function neural network compensator to estimate coupling between channels, a model uncertainty part and external interference, a pole-placement method is used to determine a gain initial value of a fractional order proportional differential controller, the control performance is further improved by the fine adjustment of a fractional order differential order number, the flexibility of a system is enhanced, finally a feedback linearization controller is designed to obtain a control amount, and the stable attitude control with strong anti-interference for a four-rotor unmanned aerial vehicle is realized. The invention has the advantages that an unmodeled part of the system, the coupling effect between the channels and the external interference are considered, and the universality of an attitude control method is improved. Through designing a radial basis function neural network estimator to estimate the unmodeled part of the system, the coupling effect between the channels and the external interference for compensation, the system has good anti-interference ability. On the basis of traditional proportional differential control, fractional order differential is introduced to improve the control performance and flexibility of the system.