187 results about "Square wave" patented technology

The embodiment of the invention provides a coating layer wall thickness pulse eddy current detection method and system based on multiple eddy current rings, and the method comprises the steps: applying a square wave excitation signal to an excitation coil, and carrying out the induction in a structural member with a coating layer to generate eddy current; collecting a voltage signal generated by induction of an attenuation magnetic field generated by the eddy current by using a receiving coil, wherein the attenuation process of the voltage signal comprises three stages; identifying a power function interval of the second stage to determine the starting time of the third stage; taking the starting time of the third stage as a reference, and selecting a preset thickness quantitative time interval in the third stage; calculating a first-order derivative of the voltage signal to time under a single logarithmic coordinate system in the thickness quantitative time interval to obtain a slope; according to the quantitative relation between the slope and the wall thickness of the structural part with the coating layer, the wall thickness value of the structural part with the coating layer is obtained through calculation.

The invention relates to a magnetotelluric noise suppression method based on ResAtt-CAE, and the method comprises the steps: generating a noise-free signal, adding a noise type into the noise-free signal to construct a noisy signal, and enabling the noisy signal to be matched with the corresponding noise-free signal to form a training set and a test set; designing a ResAtt-CAE model architecture, and realizing cross-level feature fusion by adopting a symmetric structure and jump connection; the ResAtt-CAE model architecture is trained and optimized through the training set and the test set, and the magnetotelluric noise is suppressed through the optimized ResAtt-CAE model architecture. The method is high in noise suppression capability: ResAtt-CAE captures cross-time scale signal features through multi-scale residual learning, enhances effective signal weights in combination with a time domain attention mechanism, and has a remarkable suppression effect on common magnetotelluric noise (square waves, harmonic waves, pulses, triangular waves and the like).

The invention discloses a thermal management system based on double-layer phase change and air cooling cooperative heat dissipation. The system comprises a battery module, a first-stage phase change layer, a second-stage phase change layer, a binding post, a supporting plate, a sleeve and an air cooling channel. The double-layer phase-change cooling device is filled with two composite phase-change materials with high heat conductivity coefficients, and the composite phase-change materials are distributed in the radial direction, so that heat generated by the battery can be quickly absorbed, and the temperature in the battery module is kept uniform. And when the power battery module operates for a preset time length, the air cooling device is automatically started, and part of heat absorbed by the phase change device is dissipated to the environment. The air cooling system adopts a square wave type air supply strategy, that is, intermittent cooling airflow is provided by periodically starting and stopping a fan. By combining the double-layer phase change cooling and air cooling technology, the problems of non-uniform internal temperature distribution and local overheating of the battery module are effectively improved, the applicable working condition range of the battery module is expanded, and the stability and reliability of the system are improved.

The invention discloses an insulation resistance measurement method, a measurement module and an anti-reverse power transmission isolation device, and relates to the field of operation and maintenance of distribution lines, and the key points of the technical scheme are as follows: a control voltage signal is generated according to the voltage demand of the insulation resistance of a test line sent by a user, and a PWM square wave signal with a duty ratio is generated according to the control voltage signal; performing high-frequency voltage transformation and voltage doubling rectification on the PWM square wave signal to obtain a direct-current voltage; calculating a current average value of the measurement loop when each resistance measurement gear is switched; presetting a current coefficient of each resistance measurement gear and weight coefficients of two adjacent resistance measurement gears; and when the current average value is greater than or equal to the product of the current coefficient and the weight coefficient, calculating the insulation resistance value of the measured circuit according to the current average value, the direct-current voltage and the resistance value corresponding to the resistance measurement gear.

The invention discloses a high-precision BUCK converter with variable time-constant virtual ripple compensation, and relates to the technical field of circuits, a control logic and driving module drives a high-side and low-side switch group according to a control voltage so as to convert an input voltage into a square wave voltage of a switch node, and forwards the control voltage; the LC filter is used for filtering the square wave voltage and outputting steady-state output voltage; the variable time constant ripple injection circuit generates a fixed ripple voltage by extracting an average voltage value of the square wave voltage, and adjusts the size of a time constant by controlling the voltage to generate an alternating current ripple voltage based on the square wave voltage to generate an alternating current compensation ripple voltage; the feedback resistor group divides the output voltage to generate feedback voltage; and the loop comparator compares a superposed voltage obtained by superposing the alternating current compensation ripple voltage and the feedback voltage with a reference voltage to generate a control voltage, so that the high-precision BUCK converter which is simple in structure, high in dynamic response speed and high in steady-state precision is provided.

The invention belongs to the technical field of water environment detection, and particularly relates to a heavy metal concentration and water body flow velocity synchronous detection method for a dispersed drain outlet, which is used for synchronously detecting the heavy metal cadmium concentration and the water body flow velocity. The core of the method comprises a three-electrode sensing system consisting of a working electrode coated with a tungsten oxide film, a reference electrode and a counter electrode, and is assisted by an electrochemical workstation, a peristaltic pump, a flow cell and a signal processing module. The cadmium concentration is accurately measured through the square wave anodic stripping voltammetry, the flow velocity is synchronously detected through the open circuit potentiometry, dual-function detection is achieved through integration of the square wave anodic stripping voltammetry and the open circuit potentiometry, synchronous in-situ detection of the cadmium concentration and the water body flow velocity is achieved, and errors caused by measurement position differences are effectively eliminated. The result shows that the cadmium concentration and the dissolution peak current are in a linear relationship, and the water flow velocity logarithm and the open-circuit potential are in a linear relationship. The method designed by the invention is suitable for scattered and small sewage draining exit scenes, and effectively solves the problems of time consumption and equipment redundancy of traditional step-by-step detection. In an actual water sample test, the cadmium recovery rate is 80%-120%, the flow velocity measurement RSD is smaller than or equal to 5.0%, high reproducibility, stability and anti-interference performance are achieved, technical support is provided for real-time online evaluation of the total heavy metal emission amount, and the method has remarkable environmental monitoring application potential.

This invention provides a method and system for controlling the delay time of electronic detonators, comprising: configuring delay values ​​for each electronic detonator via an initiator; sending delay time calibration commands to all electronic detonators and calculating the total duration of the reference square wave of the delay time calibration commands to obtain T0; calculating T1 based on T0; upon receiving the delay initiation command, the electronic detonator calculates and writes the value to a delay timer based on T1, and decrements the timer; after the delay timer of the electronic detonator reaches zero, writing the value of T1mod div to the delay timer and decrementing the timer; and detonating the electronic detonator after the delay timer reaches zero. This invention uses a frequency-division clock to compensate for the delay time error caused by the delay, thus solving the problem of amplified delay time error caused by using only a frequency-division clock.

The utility model provides a high-temperature-resistant sinusoidal signal source filter circuit, which comprises a high-stability oscillation source module, the high-stability oscillation source module is composed of a crystal oscillator Y1 and other elements, the frequency stability of an oscillation source is ensured, the output frequency of a sinusoidal signal source can be changed by changing the frequency of the crystal oscillator, an inverter U1B shapes and outputs oscillation source signals, and the signal quality is further ensured. The power supply filtering module effectively eliminates circuit noise and interference, the high-stability voltage source module supplies power to the oscillation source circuit through a resistor R1, a voltage stabilizing diode D1 and a capacitor C5, the temperature stability of the oscillation source circuit is good due to the characteristics of the voltage stabilizing diode D1, and it is guaranteed that the circuit works stably under different conditions. The signal amplitude adjusting module can flexibly change the output amplitude of the sinusoidal signal source, the active band-pass filtering module can accurately convert square wave signals output by the oscillation source into sine wave signals, parameter setting is reasonable, and the characteristics of quality factor Q, gain G, center frequency F and the like enable the signal processing effect to be good. And parameters of the band-pass filter are matched with parameters of the oscillating source during debugging, so that the circuit is stable and reliable in overall performance, and is suitable for high-temperature environments and other scenes with high signal quality requirements.

The application provides a stress detection system and method based on active and passive dual modes, and relates to the technical field of stress detection.The system comprises a stress sensor and a data processing module in communication connection.The stress sensor comprises a first coil assembly, a second coil assembly and a three-axis magnetic sensor.The first coil assembly is configured to apply a square wave current to the first coil assembly by an excitation source to generate an ACSM effect.The data processing module is configured to collect a voltage signal and a phase signal of the second coil assembly under the ACSM effect, collect a magnetic field signal of the three-axis magnetic sensor, perform feature extraction on the voltage signal, the phase signal and the magnetic field signal to obtain feature data, and input the feature data into a joint feature decoupling mathematical model to determine a pipeline stress value of a to-be-detected pipeline, so as to solve the problems that the current stress sensor has a large error when detecting in a low stress area, and the detection result has low accuracy due to environmental magnetic field interference.

The invention provides a repair circuit, a display panel and a display device. The repairing circuit is used for repairing abnormal scanning signals in the display panel. The repair circuit comprises a shaping module and an inverting module. The shaping module comprises a pull-up unit which comprises a first control end and a second control end; and the pull-down unit comprises a third control end and a fourth control end. The first control end and the third control end are coupled to a signal to be repaired, the second control end and the fourth control end are coupled to a corresponding clock signal, and the output ends of the pull-up unit and the pull-down unit are coupled to a first output node and used for performing NAND logical operation on the signal to be repaired and the corresponding clock signal and outputting a shaping signal in a square wave form. The inverting module is coupled to the first output node and is used for performing inverting processing on the shaping signal and outputting a repairing signal at a second output node. The repairing circuit can effectively repair abnormal grid signals in the display panel, and the product yield is improved.

The application discloses a control device for a lamp, the lamp, a control method of the lamp and a lamp system. The control device comprises a first voltage comparison module, a command input module and a first control module. The first voltage comparison module is used for comparing an alternating current input voltage with a preset voltage and outputting a corresponding first digital signal. The command input module is used for inputting a light control command. The first control module is used for receiving a square wave signal and the light control command, and controlling whether a switch of an alternating current input into the lamp is turned on or not according to the square wave signal and the light control command. The first end and the second end of the first control module are connected with the first voltage comparison module and the command input module respectively, and the third end of the first control module is connected with an input end of a switch module.

The embodiment of the invention provides a method and system for detecting the position of a weld joint of a pipeline with a coating layer based on the attenuation characteristic of a magnetic field, and the method comprises the steps: applying pulsed eddy current excitation to the pipeline with the coating layer, and employing a square wave or step wave signal; a plurality of magnetic field sensors are arranged along the circumference of the pipeline and receive voltage signals which are inducted by the pulsed eddy current in the pipeline and contain secondary magnetic field decay signals, and the magnetic field sensors are coils or magnetic sensors; measuring the magnetic field decay rate of the voltage signal received by each magnetic field sensor, wherein the magnetic field decay rate is represented by the attenuation slope of the secondary magnetic field decay signal; superimposing the decay rate slope values of the plurality of magnetic field sensors in the later stage of magnetic field decay to obtain a superimposed decay rate slope value; and based on comparison of the superimposed decay rate slope value and a preset threshold value, the existence and the position of the welding seam are judged, and the preset threshold value is set based on the decay rate slope value of the welding-seam-free area.

This invention discloses a magnetotelluric denoising method and system based on a physics-driven and conditional diffusion model, belonging to the field of electromagnetic signal processing technology. This method integrates the advantages of neural networks and the physical characteristics of magnetotelluric signals, and proposes a physics-driven synthesis strategy based on statistical priors of measured source data and a curriculum-based dynamic physics-driven noise addition strategy based on training progress factors. Addressing the scarcity of high-quality, clean samples, a clean background field that highly approximates real physical characteristics is synthesized using a parametric mathematical model. The introduction of curriculum-based dynamic physics-driven noise addition (such as noise floor annealing, square wave incrementing, and morphological clustering pulses) accurately simulates natural background degradation and complex human interference, enabling the model to adapt to extremely complex time-frequency characteristics under different geological structural backgrounds. This completely overcomes the domain shift problem caused by static Gaussian white noise training, constructs a richer sample library, and lays the foundation for accurate denoising of conditional diffusion models.

The application discloses a method for testing response time of a mini / micro LED direct display screen, which can avoid the influence of subjective evaluation of human visual perception on the response time, and provides a means for high-precision testing of the response time of the direct display screen through quantitative evaluation method. The method comprises the following steps: (1) a power supply inputs a stable voltage to the direct display screen, the direct display screen is lighted when a square wave driving voltage is input, light enters a microscope lens and converges on a target surface of a high-speed photoelectric detector, a response voltage signal is generated after the target surface is irradiated by the light, the voltage signal is filtered by a high-frequency filter to suppress high-frequency noise, and the voltage signal is connected to an oscilloscope through a BNC line; (2) the power supply is driven and controlled to realize different refresh rates; and step (1) is repeated to realize the response time test of the direct display screen under different refresh rates; and (3) different colors are realized by controlling a signal of the driving power supply; and step (1) is repeated to realize the response time test of the direct display screen under different colors.

The invention discloses a non-Newtonian fluid-based particle and biomolecule stepping separation method and device. Through microstructure arrangement of the non-Newtonian fluid, particles and biomolecules which cause different shear rates have blocking and passing characteristics, molecules with different volumes and different charge quantities are separated under the action of a square wave electric field, or molecules with different volumes and different charge quantities are separated under the action of a uniform gradient square wave magnetic field. The invention relates to a method for separating particles with different ferromagnetism or biomolecules combined with magnetic microbeads. Comprising a non-Newtonian fluid and a carrier thereof, a square wave electric field for providing power and a corresponding electrode or a magnetic field generator, and a support carrier for accommodating particles and biomolecules. After the particles and the biomolecules are separated in the square wave electric field for a period of time, the electric field intensity is changed, the second type of particles or biomolecules are separated, and the electric field intensity is sequentially switched according to the number of components to be separated, so that the separation purpose is achieved.

The invention discloses a permanent magnet synchronous motor starting control method based on high-frequency square wave injection. A bus voltage threshold value is set; during initial starting, high-frequency square waves are injected into the d axis, and the rotor position and the angular speed are obtained; performing reverse braking and forward starting control on the rotor according to the rotor position and the angular speed; during braking, reverse torque is applied to the rotor through rotating speed and current double-closed-loop control; circularly acquiring real-time bus voltage and comparing the real-time bus voltage with the bus voltage threshold value; and if the real-time bus voltage exceeds the bus voltage threshold, increasing the voltage amplitude of the high-frequency square wave injected by the d axis. The rotor position and the angular speed are obtained by injecting the high-frequency square waves, and the problem that the rotor observer is large in error at the low speed is solved; when the reverse rotation is started, the current of the stator coil is increased by increasing the voltage amplitude of the high-frequency square wave, so that the stator coil is used as an energy-consuming circuit to consume the counter electromotive force, the real-time bus voltage is reduced, and the cost is reduced.

The invention provides a detection circuit, wireless transmission equipment and an object detection method. The detection circuit comprises a frequency generator, a driving circuit, a resonance circuit and a controller. The frequency generator is used for generating square wave signals. The driving circuit is connected with the output end of the frequency generator and used for amplifying the square wave signal. The resonance circuit is connected with the output end and the input end of the drive circuit and used for converting the square wave signal into an oscillation signal. And the controller is connected with the resonance circuit and is used for determining the quality factor of the resonance circuit according to the voltage of the oscillation signal so as to determine whether an object is detected. Whether the foreign matter exists near the wireless transmission equipment or not can be simply and quickly detected, and meanwhile, the power consumption is low and the reliability is high.

The invention discloses a rotating speed measuring device and method, and the method comprises the steps: enabling a PI input square wave signal to sequentially pass through a square wave shaping unit, a sampling and counting unit, a sliding window processing unit and a rotating speed calculation unit in an MCU microcontroller for processing, and obtaining a rotating speed measurement result; the square wave shaping unit is used for processing complementation shaping of PI input square wave signals and sending complementation shaping square waves to the sampling counting unit; the sampling counting unit judges a square wave counting value input into the sliding window processing unit according to comparison between an absolute value of a counting difference value of two adjacent square waves and an allowable error threshold value; the sliding window processing unit automatically adjusts the depth of the sliding window according to the input square wave count value; the sliding window processing unit sends the adjusted window depth to the rotating speed calculation unit, the rotating speed calculation unit calculates the rotating speed according to the adjusted window depth, the self-adaptive sliding window depth is adopted, different depth windows are adopted for different frequency signals for frequency calculation, and the operation complexity is reduced.

The application relates to a fast edge generating device and an implementation method thereof, and the device comprises a signal generator, a fast edge generator module and an amplifier module; the signal generator is used for generating a nanosecond-level square wave or pulse signal; an input end of the fast edge generator module is connected with the signal generator, is used for receiving the nanosecond-level square wave or pulse signal sent by the signal generator, and converts the nanosecond-level square wave or pulse signal into a lower edge signal; the lower edge signal is sent to the amplifier module; an input end of the amplifier module is connected with the fast edge generator module, is used for receiving the edge signal sent by the fast edge generator module, and amplifies the edge signal to a target high-voltage specification and then outputs. An input signal with extremely fast edge characteristics is generated by an external high-performance signal source, a general signal source is used to generate a signal, and the economy, flexibility and expandability of the system are significantly improved.

The utility model relates to a goaf site fan foundation horizontal force loading model test device, which comprises a goaf foundation model frame, a fixing device, a loading device, a goaf foundation model and a wind turbine generator model, the front end of an electric cylinder is connected with a loading rod through a spring, and the loading rod is connected with the top of a tower drum in a bolt manner. An adjustable loading system is adopted in the aspect of a wind load loading system, stable output of waveforms such as sine waves, square waves and sawtooth waves can be achieved, and control software can track and correct peak and valley values of controlled variables (such as loads) in the test loading process. The typical value of the dynamic error of each peak value in the whole test process is + / -1% FS, and the adjusting capability is strong; wind loads can be applied to different positions of a goaf site under different engineering geological conditions according to test requirements, and the utilization rate of the test fixing device is improved.

The application relates to the technical field of circuit design, and discloses a soft-start voltage circuit and a control method and a direct-current conversion circuit. The soft-start voltage circuit comprises a capacitor charging circuit and a clamping circuit. The capacitor charging circuit comprises a current source, a first switch tube, a second switch tube and a charging capacitor. The current source, the first end of the first switch tube and the charging capacitor are sequentially connected. The other end of the current source is used for connecting a power supply voltage. The second switch tube is connected between the charging capacitor and a series connection node between the first end of the first switch tube. The control end of the first switch tube is used for inputting a square wave signal. The second switch tube is used for inputting an enable signal. The clamping circuit is connected between the current source and the series connection node between the first end of the first switch tube. The clamping circuit is used for voltage clamping of the first end of the first switch tube when the capacitor charging circuit charges the charging capacitor. The application makes the soft-start time more accurate.

The invention discloses a method for removing anions in soil and underground water through electrokinetic remediation-in-situ electrochemical green rust production adsorption coupling. An electrokinetic remediation unit and an electric flocculation unit located on a device are included. According to the electrokinetic remediation-electric flocculation coupling, a periodic square wave power supply is adopted to control two units to work alternately, and a square wave periodic power supply mode with different duty ratios of EC and EK is adopted, so that the removal efficiency of anions is improved, and the energy consumption of working units is reduced; the anode of the electric flocculation unit is doped with magnesium and zinc, Fe < 2 + > electrolysis is promoted, the green rust yield and stability are improved, and the efficiency of capturing and removing anions is further promoted; the cathode of the electric flocculation unit has a high local pH value, precipitates or micro-precipitates are generated with cations generated by electrolysis to pre-capture anions, and the anions are deposited to the bottom of the electric flocculation unit to further promote the removal efficiency of the anions and provide a smooth path for subsequent migration and capture of the anions at the same time.

The invention provides a current source resonance type inter-line direct current power flow controller topology and a frequency conversion control method. The current source resonance type inter-line direct current power flow controller topology comprises a first current source type H bridge, a second current source type H bridge, an isolation transformer and a resonance capacitor, each H bridge serves as a port and is composed of four bidirectional switches, and each bidirectional switch comprises two power MOSFETs with common source electrodes connected in series; the turn ratio of the primary side to the secondary side of the isolation transformer is 1: 1; the two resonant capacitors and the leakage inductor of the isolation transformer form a CLC resonant circuit; wherein the direct current side of the first current source type H bridge is connected with a first direct current line, and the alternating current side is connected with the primary side of the isolation transformer through the CLC resonance circuit; the direct-current side of the second current source type H bridge is connected with a second direct-current line, and the alternating-current side is connected with the secondary side of the isolation transformer through the CLC resonance circuit; during operation, the first current source type H bridge and the second current source type H bridge invert direct current of a direct current line into alternating current in a square wave form and inject the alternating current into the CLC resonance circuit.

The invention discloses a sampling method, system and device. The method comprises the following steps: converting an AC voltage / current signal of an active power distribution network in a current period into a square wave signal with the same frequency in the current period; according to the square wave signal of the current period, a high-frequency stable pulse of a local clock and a square wave signal frequency of a previous period, generating a sampling pulse which has the same frequency as the square wave signal of the current period and is at equal phase intervals; according to the sampling pulse, performing equal-phase-interval sampling on the square wave signal of the current period to obtain a sampling signal; and performing phase angle correction on the sampling signal according to the time information of the equal-time-interval time mark pulse and the sampling pulse of the local clock. According to the method, the frequency of the sampled signal can be tracked, phase angle correction is carried out on the sampled signal, high-precision synchronous sampling is realized on the premise of not increasing a large amount of extra calculated amount, and the monitoring and control performance of the feeder terminal of the active power distribution network can be improved.

The utility model discloses a kind of low-power single lithium battery boost circuit, including single lithium ion battery V1, resistance R1, capacitor C1, capacitor C2, capacitor C3, capacitor C4, capacitor C5, diode D1, diode D2, diode D3, diode D4, 555 chip U1, the utility model has adopted low-power 555 chip and constitutes minimalistic oscillation circuit, realize the square wave output of 50% duty cycle of micro-power consumption, output square wave is boosted to 9-10V by multistage charge pump, there is no inductive element in circuit, and work in low-frequency state, will not produce electromagnetic interference, it is adopted 555 chip of micro-power consumption, oscillation circuit and charge pump boost circuit are also micro-power consumption, overall power consumption is very small, less than 0.1mA, ensure that battery power consumption is also very small when long time storage, the cost of entire boost circuit is very low, only a few cents, with high cost performance.

A vehicle on-board power conversion device includes a power converter, a conversion device-side connector that is configured to be connected to an external connector, and a check circuit that is configured to check a connection state of the conversion device-side connector and the external connector. The power converter includes a microcontroller. The vehicle on-board power conversion device includes an isolator located between the check circuit and the microcontroller. The check circuit includes an inverting circuit that is configured to invert the signal including the square wave and generate an inverted wave. The microcontroller includes an output terminal configured to output a square wave, and a detection terminal configured to detect the square wave. The microcontroller determines whether there is an inter-terminal short-circuit anomaly based on a detection result of the detection terminal.

The present application provides a current breaking apparatus and a control method therefor, and a direct-current power transmission and distribution system. The current breaking apparatus comprises a first through-flow branch, a second through-flow branch, a first transfer branch, a second transfer branch, an energy consumption branch, a reactor and a self-excitation module, wherein the first through-flow branch comprises a first mechanical switch; the second through-flow branch comprises a second mechanical switch; the second transfer branch comprises a capacitor; the energy consumption branch comprises an energy absorption device; the reactor is provided in the first through-flow branch and / or the first transfer branch and / or the second transfer branch; the self-excitation module is provided in the first through-flow branch or the first transfer branch or the second transfer branch; when a short-circuit fault occurs in a power line, the self-excitation module outputs a pulse square-wave voltage, and excites the capacitor and the reactor to oscillate to generate an oscillation current having the same amplitude as a fault current and having a direction opposite to that of the fault current, so as to turn off the first mechanical switch and the second mechanical switch; and the energy absorption device is used for consuming energy.

The invention discloses a magnetic integrated inductor direct-current converter which comprises an input module, a magnetic integrated inductor, an output module, a control circuit and a main power part, the main power part works in a staggered mode through two Boost circuits, and each Boost circuit comprises a switching tube which is driven to be switched on and off through a common ground. The control circuit is composed of a phase control chip and two sets of PWM control chips. The phase control chip outputs two paths of 180-degree complementary square waves, converts the square waves into pulse signals and then transmits the pulse signals to the two sets of PWM control chips. The two switching tubes are switched on and switched off in a 180-degree staggered manner, so that input and output ripples of a direct-current power supply can be effectively reduced, the conversion efficiency and the power density are improved, the peak value of current ripples is reduced, the valley value of the current ripples is increased, the ripple current is remarkably reduced, and the output ripple current is lower than that of a single switching tube; the problems of large volume and heavy weight of the aviation high-voltage power supply system power supply conversion are effectively solved.

The invention discloses pressure wave and shock wave dual-mode ultrasonic nerve stimulation equipment which comprises a power panel, an upper computer board, a lower computer board and an ultrasonic transducer. The power supply board comprises a DAC module and a phase-shifted full-bridge circuit; the lower computer board comprises a lower computer control unit and an ultrasonic driving circuit unit; the upper computer board controls the driving square wave phase difference of the phase-shifted full-bridge circuit by adjusting the voltage of the DAC module so as to control the output voltage; the output voltage of the phase-shifted full-bridge circuit is used as the direct-current power supply voltage of the ultrasonic driving circuit unit and is used for calculating the focus sound pressure of the ultrasonic transducer; the upper computer board sends a pulse parameter instruction to the lower computer board, and the lower computer control unit emits a square wave to excite the ultrasonic driving circuit unit based on the pulse parameter instruction; the surface sound pressure of the ultrasonic transducer is adjusted by adjusting the voltage of the DAC module, and the forming distance of shock waves is adjusted by changing the sound pressure. According to the invention, the same set of drive circuit and the same transducer can generate shock waves and pressure waves at the same time.

This invention proposes a maximum torque-to-current ratio control method and system considering the inductor nonlinearity of a permanent magnet synchronous motor (PMSM), belonging to the field of motor technology. The method includes alternating injection of a voltage square wave at a frequency one-quarter of the control frequency, extracting the difference current between two control cycles, and identifying the fully incremental inductance containing cross-coupled inductance under various operating conditions. The cross-coupled inductance is divided into relative position mutual inductance and flux linkage saturation mutual inductance. Under unsaturated conditions, the relative position mutual inductance is used to calculate the actual position coordinate system angle. Under saturated conditions, the flux linkage saturation mutual inductance is obtained through a mutual inductance iteration method to calculate the decoupling coordinate system angle. A high-order sliding mode observer is used to fit the back electromotive force to observe the permanent magnet flux linkage and phase resistance parameters. The optimal current angle is calculated in the decoupling coordinate system to achieve maximum torque-to-current ratio control. This invention considers the influence of PMSM inductor nonlinearity on maximum torque-to-current ratio control, improving control accuracy and robustness, and achieving higher system efficiency.