11 results about "Sinusoidal excitation" patented technology

This invention discloses a method for extracting and compensating eddy current hardness features to suppress valve geometry interference, relating to the fields of nondestructive testing and signal processing. The method includes: acquiring the original impedance voltage signal and key geometric parameters of the valve under a preset multi-frequency sinusoidal excitation signal; constructing a geometry-electromagnetic coupling interference compensation model based on the key geometric parameters, excitation frequency, and electromagnetic parameters; calculating the multivariable coupled geometric interference coefficient; removing geometric interference from the original signal to obtain a pure impedance voltage signal; extracting three-dimensional features from the pure signal to obtain amplitude features, phase features, and hardness-sensitive features; introducing a dynamic temperature compensation model to nonlinearly compensate the three-dimensional feature vector according to the ambient temperature; and outputting the compensated three-dimensional hardness feature vector. This invention, by constructing a geometry-electromagnetic coupling interference compensation model, suppresses the influence of valve geometry differences on the eddy current signal, improving the accuracy and robustness of eddy current hardness detection.

The present application relates to motor manufacturing process technical field, more specifically, it relates to a kind of high torsion multi-stage series motor and structural stability detection process, including the modal response of the axial and radial of the frame of high torsion multi-stage series motor is collected, axial main frequency, axial damping ratio and the phase difference of radial two test points are calculated, and compared with preset threshold value;Continuous sweep frequency sinusoidal excitation is applied to motor frame, the nonlinear index of each frequency point is calculated and compared with preset threshold value, while detecting whether resonance peak is split;Then short-time half-sine pulse impact is applied to motor frame, free decay vibration signal is collected, and attenuation main frequency, logarithmic attenuation rate and cross-correlation peak delay are extracted from the time domain of free decay vibration signal, the pretightening force and connection stiffness index of two connecting points are back calculated, finally ensure that high torsion multi-stage series motor can meet the requirement of structural stability when leaving factory, and can be closed-loop corrected by detection Parameter of assembly process.

This application provides a phase synchronization method, system, device, and medium for a rotary transformer. It involves periodically acquiring sine and cosine signals output by the rotary transformer in response to a loop trigger counter outputting a loop trigger signal. Both the loop trigger signal and the sinusoidal excitation signal used to drive the rotary transformer are generated by converting a synchronization pulse signal output by an RPWM counter. Within each acquisition cycle, the sine and cosine signals are positively zero-crossing detected to obtain a zero-crossing detection result. Based on the zero-crossing detection result, the phase difference between the sine and cosine signals and the sinusoidal excitation signal in the current cycle is determined, and phase synchronization compensation is performed on the sinusoidal excitation signal based on the phase difference. This enhances the signal fidelity and control accuracy of the encoder under strong interference without increasing hardware costs.

This invention discloses a method and system for controlling the pressure of stacked iron cores to reduce transformer no-load losses. The method includes acquiring the excitation current signal of the stacked iron cores under constant-voltage sinusoidal excitation conditions; extracting the harmonic characteristic components of the signal and decoupling them into stress characterization indicators and air gap characterization indicators, calculating the corresponding hysteresis loss components and air gap additional loss components; gradually increasing the clamping force under a monotonically increasing pressure application path, determining the total loss gradient based on the components at each pressure step, and locating the first optimal pressure point; acquiring pre-configured compensation parameters, performing offset compensation calculations on the first optimal pressure point, obtaining the target curing pressure, and locking it. This invention, through electrical harmonic analysis, can solve the deviations caused by magnetic coupling hysteresis and process relaxation, achieving optimized control of no-load losses.

The application discloses a kind of linear feeding device and method based on piezoelectric transducer inertia drive, feeding device includes base, first to fourth spring piece, first to second connecting block, piezoelectric transducer, top disc, piezoelectric bimorph, first to third stop piece, and M+N+P adjusting bolts;When working, sine excitation signal is applied to piezoelectric transducer, the second order longitudinal vibration mode of piezoelectric transducer can be excited, to induce the reciprocating bending vibration of spring piece, drive top disc to generate horizontal and vertical direction movement.Material placed in top disc moves forward and upward with top disc in material groove.When spring piece moves to limit position, elastic potential energy stored in spring piece drives top disc to move back, at this time, material continues to move forward and falls under the action of inertia in parabolic curve.Under this periodic motion, the transportation of material in top disc is realized.The application has simple structure, and is easy to process and assemble.

This invention discloses a three-degree-of-freedom measurement method based on a planar two-dimensional time grating sensor, comprising the following steps: A moving scale base and a fixed scale base are installed parallel to each other with a certain gap; after applying sinusoidal excitation signals of the same frequency and amplitude with a phase difference of π / 2 to the four-phase excitation electrode group on the fixed scale base, the moving scale base moves relative to the fixed scale base along the X and Y directions and deflects around the Z-axis; a single sensing unit on the moving scale base can calculate the output signals along the X and Y directions and around the axis deflection; by combining the output signals of each sensing unit, the displacement values ​​of the moving scale base along the X and Y directions and the deflection angle θ can be decoupled. This method can realize displacement measurement in the X direction, Y direction, and around the Z-axis deflection angle through the combined calculation between sensing units on the moving scale base, with fast calculation speed, further elimination of interference, and improved measurement accuracy.

This application provides a method and system for constructing a leakage inductance calculation model for a high-frequency transformer with Litz wire windings. The method obtains the core window parameters and Litz wire winding parameters of the high-frequency transformer, and maps the three-dimensional core window region onto a two-dimensional plane according to the actual cross-sectional structure to establish a two-dimensional geometric model for high-frequency electromagnetic field analysis. The electromagnetic excitation conditions of the high-frequency transformer are set, along with the sinusoidal excitation frequency and corresponding boundary conditions. A current density distribution constraint varying with frequency is introduced into the winding cross-section to construct a finite element model of the core window. The finite element model is used to calculate the magnetic field strength distribution and magnetic field energy distribution within the core window region, and a high-frequency effect correction coefficient is introduced to construct a leakage inductance calculation model considering high-frequency effects, thereby predicting the leakage inductance within the core window region. This application achieves accurate prediction of leakage inductance in high-frequency transformer design, optimizes winding structure, and improves overall energy utilization.

This invention belongs to the field of flight control and fault diagnosis technology for flying-wing unmanned aerial vehicles (UAVs), and relates to an active identification method for the performance loss of multiple control surfaces in flying-wing UAVs. The method superimposes a single, mutually exclusive set of orthogonal multi-sine excitation signals with distinct frequencies onto the closed-loop control commands of the six trailing-edge control surfaces of the flying-wing UAV; it collects three-axis angular velocities, obtains the three-axis torque coefficients through numerical differentiation and inverse kinematics of rigid body rotation; constructs three-channel regression models for roll, pitch, and yaw; and uses a recursive least squares equation error method with a forgetting factor to identify the control derivatives of each control surface online; normalizes the identified control derivative values ​​of each control surface in the three torque channels to obtain channel-by-channel performance coefficients; pre-determines the set of torque channels participating in the voting according to the physical main control action of each control surface; weights the selected channels within a sliding window using the reciprocal of the coefficient of variation as the weight; and uses a dual criterion of coefficient of variation and drift criterion for convergence determination, outputting the final performance coefficients.

This invention discloses an online mode identification method and system for a magnetic levitation motor rotor. The method includes: obtaining the rotor simulation mode frequency based on rotor simulation results; setting an excitation frequency range centered on the rotor simulation mode frequency while the rotor is in a levitation state, and applying an adjustable sinusoidal excitation signal at the controller output position; during the excitation process, acquiring displacement signals in the X and Y directions and power amplifier current signals along the rotor radial direction; calculating the phase difference between the displacement and the power amplifier current signal in each direction; within the excitation frequency range, the excitation frequency corresponding to the sudden change in phase difference is the rotor's current order mode frequency; obtaining the higher-order mode frequencies of the rotor by frequency sweeping to complete the identification; this invention does not require additional dedicated excitation equipment and can identify mode frequencies and vibration modes online under different operating states such as rotor levitation, low-speed rotation, and high-speed rotation, and has the advantages of simple implementation, high identification accuracy, and no impact on the normal operation of the system.

The application discloses a self-calibration method based on a planar two-dimensional time grating sensor, which comprises an upper dynamic scale base and a lower fixed scale base, the fixed scale base is uniformly provided with exciting electrodes, and the dynamic scale base is provided with two sensing electrode groups along diagonal directions, each sensing electrode group is composed of a plurality of sensing electrode arrays arranged along X and Y directions. Equal-amplitude and same-frequency sinusoidal exciting voltages with a phase difference of pi / 2 are respectively applied to different categories of exciting electrodes, combination operation is conducted between the sensing electrodes of the sensing electrode groups, displacement signals of a single sensing electrode group along X and Y directions can be decoupled and output, combination operation is conducted between the output signals of the sensing electrode groups arranged along the moving direction, output signals containing measurement error information can be obtained, discrete Fourier transform is conducted on the processed data of the output signals, amplitude and phase parameters are calculated to construct an error function, and measurement errors of the sensor along X and Y directions are self-calibrated and corrected.

A kind of ultra-high efficiency accelerometer sensitivity dynamic calibration method based on multi-frequency sine excitation.It includes constructing wideband accelerometer sensitivity calibration system;Based on logarithmic interval frequency distribution method and enhanced hippo optimization algorithm, the multi-frequency sine excitation signal is optimized;Collecting the voltage signal of charge amplifier and the accelerometer to be calibrated;Based on five-parameter sine approximation method, the frequency, amplitude and phase of each frequency point are solved;Using comparison method to calculate the amplitude and phase sensitivity of the accelerometer to be calibrated at each frequency point and other steps.The method is efficient, stable and has high calibration precision, and can be used for one-time sensitivity calibration of accelerometer under wideband calibration conditions.The logarithmic interval frequency distribution method is used to obtain low harmonic distortion multi-frequency sine excitation signal to improve the calibration precision.The improved hippo optimization algorithm is used to improve the convergence speed and global search ability, and increase the measurement range.