7 results about "Inverse transfer function" patented technology

The invention discloses a voltage frequency converter with a transfer function in inverse proportion. Comprising the following steps: an integrator buffers an input voltage and generates a ramp voltage which linearly rises or falls along with time; the voltage comparator compares the ramp voltage output by the integrator with zero voltage to generate a trigger pulse; the monostable trigger generates a rectangular pulse signal with a fixed pulse width, and the output pulse is used for controlling a post-stage switched capacitor charge pump; the charge control and reset unit is used for resetting the integrator to realize charge balance; the switched capacitor charge pump samples an input voltage, performs voltage-charge conversion, injects a charge packet in direct proportion to the input voltage into a summation point of the integrator, and outputs the frequency of the whole converter at the same time. According to the invention, the output pulse frequency is accurately inversely proportional to the input voltage value and does not need to depend on complex digital calculation or a low-precision analog multiplier / divider.

The application discloses a DPD implementation method and system in a hybrid beamforming system, wherein a PA inverse transfer function parameter is estimated according to a PA baseband input signal and an output signal through a generalized memory polynomial (GMP) model, and digital pre-distortion DPD is implemented through a cascade digital pre-distortion architecture comprising a phase shifter parameter matrix module, a PA inverse transfer function module and a phase compensation module. The application significantly simplifies the hardware configuration of a feedback link, and can maintain excellent linearization performance without recalibration when the beam direction changes, and has strong robustness.

The present application relates to the technical field of material performance testing, and discloses a kind of test methods for evaluating the chemical solvent penetration resistance of reinforced plastic, comprising the following steps: constructing inverse transfer function to compensate platform lag, using historical strain data to predict the starting time of microcrack opening in the next cycle, combining platform inherent delay to calculate instruction sending time, based on stiffness attenuation rate calculated in real time to adaptively adjust the best disturbance frequency, using inverse transfer function to generate modified disturbance instruction and superimposed injection, deducting fluid viscous damping work previously calibrated from single cycle data to obtain effective dissipation density, determining failure end point based on the second derivative change of effective dissipation density sequence.The present application realizes the time synchronization of pressure wave and crack opening through prediction feedforward strategy, maintains deep penetration driving force using adaptive disturbance, and eliminates fluid damping interference through energy decoupling mechanism, improving the authenticity and result accuracy of stress-assisted solvent penetration test.

The invention relates to the technical field of material performance testing, and discloses a testing method for evaluating the chemical solvent permeation resistance of reinforced plastics, which comprises the following steps: constructing an inverse transfer function to compensate platform lag, and predicting the starting time of microcrack opening in the next period by using historical strain data, the method comprises the following steps: calculating an instruction sending moment by combining inherent delay of a platform, adaptively adjusting an optimal disturbance frequency based on a stiffness attenuation rate calculated in real time, generating a correction disturbance instruction by using an inverse transfer function, performing superposition injection, and deducting pre-calibrated fluid viscous damping work from single-cycle data to obtain effective dissipation density. And determining a failure end point based on the second derivative change of the effective dissipation density sequence. According to the method, the time synchronization of pressure waves and crack opening is realized through a prediction feedforward strategy, the deep penetration driving force is maintained by utilizing self-adaptive disturbance, the fluid damping interference is eliminated through an energy decoupling mechanism, and the authenticity and the result accuracy of the stress-assisted solvent penetration test are improved.

A test system is provided which includes an actuator that actuates a test piece, a virtual model that operates in association with the test piece, a controller that controls the actuator, a computing device that computes the virtual model, and an inverse transfer function correcting unit that corrects a signal from the virtual model with a proper inverse transfer function that is determined based on a transfer function of a system including communication units between the test piece and the actuator and between the actuator and the controller and a communication unit between the computing device and the controller. The controller controls the actuator based on the signal corrected by the inverse transfer function correcting unit.

The invention discloses a multi-plane spread spectrum iteration phase recovery method based on an angular spectrum diffraction theory. The method comprises the following steps: acquiring light intensity distribution of a to-be-recovered plane and a plurality of propagation distance planes; preprocessing the phase distribution of the plane to be recovered, and combining the preprocessed phase distribution of the plane to be recovered with the light intensity distribution of the plane to be recovered to obtain the initial complex amplitude of the plane to be recovered; iterating the initial complex amplitude with the light intensity distribution on the plurality of propagation distance planes by adopting a spread spectrum iteration phase recovery algorithm based on an angular spectrum to obtain initial recovery phase distribution of the plurality of planes to be recovered; fusing the preliminary recovery phases of the plurality of planes to be recovered according to a multi-plane phase space frequency domain fusion algorithm to obtain a fused phase spectrum; and obtaining a fused phase recovery result according to the fused phase spectrum. High-frequency noise is suppressed and high-frequency information is released through an angular spectrum inverse transfer function fused with a dynamic regulation factor; and the anti-noise capability of phase recovery is improved by dynamically distributing the frequency domain weight.

The invention relates to a direct-current switching device in which, on the assumption that the fault current increases linearly, the actually flowing current is extrapolated from the measured current corrected with an inverse transfer function, the slope thereof and the stored time offset (tv) between the measured value (33) and the actual current (31), and when the extrapolated current reaches a switching-off threshold value, the actual current (31) is switched off from the measured value (33) and the actual current (31). And cutting off.