32 results about "Velocity response" patented technology

A contact thermometer for determining-temperature of an inner wall of a cavity, where accuracy and speed response is assured by use of a probe having a variable geometry where the first shape of the probe exists before and during placing the probe into a cavity and the second shape is formed during the measurement process. The temperature measuring tip of the probe makes an intimate thermal contact with an inner wall of a cavity after the second geometrical shape is assumed. The accuracy is assured by use of at least two temperature sensors while the speed response is improved by taking at least two readings, from one temperature sensor.

The velocity of a wireless communications device (106) is estimated. In response to this estimate, a filter bandwidth, such as a pilot filter (310) bandwidth, is adjusted so that the introduction of noise and distortion to a signal received by the device is mitigated. The filter bandwidth is adjusted by increasing it as the estimated velocity increases; and decreasing it as the estimated velocity decreases. Such adjustments may be accomplished through providing a number of predetermined bandwidths that each correspond to a particular velocity range, and setting the filter bandwidth to the predetermined bandwidth that corresponds to the estimated velocity.

The invention relates to a desity measuring device which is used to measure a density, rho, of a flowable medium and comprises measuring device electronics (ME) and a measuring transducer (MW) electrically connected to the measuring device electronics. The measuring transducer comprises a measuring tube (10), a vibration exciter (41) for exciting and maintaining vibrations, and a vibration sensor (51) for sensing vibrations of the at least one measuring tube. The measuring device electronics are designed to adjust, by means of a vibration measurement signal (s1) and an exciter signal (e1), a driving force that causes useful vibrations, namely vibrations having a specified useful frequency, fN, of the measuring tube, in such a way that a phase shaft angle, phi N, by which a velocity response, VN, of the measuring tube is phase shafted with respect to a useful force component, FN, of the driving force is less than -20 and greater than -80 degrees during a specified phase control interval, and / or the useful frequency has a frequency value that is more than 1.00001 times but less than 1.001 times a frequency value of an instantaneous resonance frequency of the measuring tube. Furthermore, the measuring device electronics are designed both to determine at least one frequency measured value, xf, representing the useful frequency for said phase control interval on the basis of the vibration measurement signal (s1) present during the phase control interval and to generate a density measured value, x rho, representing the density, rho, by using the frequency measured value, xf.

A voltage-mode VCM controller is provided comprising an Infinite Impulse Response (IIR) filter that modifies a servo control voltage signal to a voltage driver in response to an adaptive compensator that configures the IIR filter in relation to an observed VCM velocity and an actual VCM velocity. An associated method is provided comprising modeling a velocity response of a VCM to a voltage input; inputting the observed velocity and an actual VCM velocity to an adaptive compensator that computes a gain and a VCM response pole frequency in relation to the VCM resistance and inductance; configuring an IIR filter in relation to the computed gain and pole frequency values; and using the IIR filter to modify a voltage command from a servo controller to a power driver.

The invention discloses a building structure seismic damage assessment system and a method based on a wireless sensor network. The system mainly comprises a plurality of wireless sensor nodes and a control computer center which are wirelessly connected. With the help of the characteristics of low cost and self-organization of the wireless sensor network technique, the building structure seismic damage assessment system based on the wireless sensor network is constructed, and the goals of zero line arrangement and long-term all-weather working are really realized from the aspect of functions. By using detected acceleration and angular velocity responses for conducting numerical analysis and calculation to obtain the velocity response and the inter-story displacement response of a structure, seismic damage assessment cannot only be conducted to the overall structure and structural members through inter-story displacement, but also can be conducted to nonstructural members such as velocity-sensitive or acceleration-sensitive members through the velocity and acceleration responses of the structure, and the performance-based seismic damage assessment requirement of the building structure is really met.

The invention provides a bridge structure damage positioning method based on indicated frequency space-time evolution, wherein the method includes following steps: (a) collecting data at various spatial position test points in a bridge structure, wherein the test points form a spatial lattice; (b) collecting vibration frequency data of various spatial position test points in the bridge structure; c) performing damage positioning to the bridge structure according to the change rules of the vibration frequency of different spatial position test points within a time domain. According to the bridge structure damage positioning method based on the indicated frequency space-time evolution, travelling vehicles, which runs on the bridge structure, are employed as a power excitation source, so that the method is free of manual excitation and is free of interference on normal traffic, thereby saving economic and time cost. The hardware in the method can be changed at any time and is suitable for bridges in different types. By means of bridge structure acceleration response, the method is high in data quality, is stable and reliable, is low in test cost and is suitable for being popularized in large area.

The present invention discloses a method and system for monitoring rigidity damage of a structure. The method comprises the steps of: monitoring vibration responses of the structure and obtaining acceleration response signals of the structure; performing EMD decomposition for the acceleration response signals, determining first IMF component gradients at any time, and calculating monitoring factors at different positions of the structure; rejecting false monitoring factors by using a constrained condition, wherein the monitoring factors and rigidity damage degrees of the structure have a linear relation; determining the time when the rigidity damage of the structure occurs according to features of the monitoring factors changing over time, and determining the position where the damage occurs by comparing distribution of the monitoring factors at different positions of the structure; and determining the rigidity damage degree of the structure according to an amplitude of the monitoring factor corresponding to the time when the rigidity damage occurs. The method of the present invention is especially suitable for monitoring and determining tiny rigidity damage of the structure under the effect of impact loading, can accurately identify the tiny rigidity damage, has a good anti-noise capability, can determine the damage degree by calculating the amplitude of the monitoring factor, and has a high application value.

The invention relates to a maneuverability improving and controlling method based on a distributively driven electric vehicle. The method includes steps: acquisition of an ideal differential power-assisted steering curve, namely acquiring the differential power-assisted steering curve according to a longitudinal vehicle speed and a steering wheel torque; calculation of a reference yaw velocity, namely calculating an ideal yaw velocity target value according to a steering wheel turn angle and vehicular running parameters, and taking the calculated ideal yaw velocity target value as the reference yaw velocity; calculation of an additional yaw torque, namely tracking the calculated reference yaw velocity in real time, calculating the additional yaw torque through feedforward control and feedback control; longitudinal force distribution, namely distributing driving torques of front-axle left and right wheels and rear-axle left and right wheels according to the ideal differential power-assisted steering curve and the additional yaw torque. Compared with the prior art, the method has the advantages that overall yaw velocity response is improved while operating burden is relieved for a driver, and accordingly maneuverability of the whole vehicle is effectively improved.

The invention discloses a blasting seismic wave model construction method based on building seismic response equivalence. The blasting seismic wave model construction method comprises the steps of: selecting an actually measured blasting seismic wave velocity signal as a signal to be simulated; converting the blasting seismic wave velocity signal into an acceleration signal; calculating a structural response of a building structural analysis object under the action of an acceleration load, and recording an amplitude value of a top layer velocity response; subjecting the blasting seismic wave velocity signal to multiresolution wavelet decomposition and reconstruction, and determining main frequencies and amplitude values of reconstructed subsignals with an energy ratio reaching 10% or more;constructing a blasting seismic wave model of the signal to be simulated; adopting the same time-history analysis method to calculate a specific value of a when the value equals the top layer velocity response amplitude value; and substituting the calculated specific a value into the constructed model to obtain a specific expression of a blasting seismic wave analog signal based on building seismic response equivalence. The obtained blasting seismic wave model has property parameters of the actually measured waveform, and can be applied to the study of a blasting seismic effect mechanism.

The invention provides a sensitivity numerical calculation method based on a response signal, which comprises the steps of constructing a velocity frequency response function matrix, obtaining a firstm-order modal frequency, and adding a stiffness perturbation term from the first node of the structure; obtaining the perturbed velocity frequency response function by substituting the velocity frequency response function information into the matrix correction formula; obtaining the sensitivity of structural modal frequency to stiffness by extracting the frequency information of the structure;changing the position of the stiffness perturbation point according to the node order, obtaining the sensitivity of the whole structural modal frequency to stiffness and drawing the sensitivity curve. The method is characterized by firstly obtaining the velocity frequency response function information of the structure through the finite element calculation, when the structural stiffness changes, using the matrix transformation formula to obtain the velocity response information after perturbation only by numerical calculation of the initial velocity frequency response function without the finiteelement recalculation, so that the method simplifies the calculation efficiency and is more convenient. The fast calculation method of frequency sensitivity to stiffness is realized based on the velocity frequency response function, so that the method has practical engineering significance.