32 results about "Velocity response" patented technology

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 relates to an impulse vibrating method for testing the bridge substructure natural frequency of vibration which uses avoirdupois weight to stroke the pier and tests the vibrating response of the pier to analyze and compute the natural frequency of vibration. It uses avoirdupois weight to stroke the pier top part and tests the speed and hastens response of the bridge. It usually dose multi-stroke and uses the recording wave mode superposition to dispel the noise to obtain the accurate response wave mode. It reads the response wave mode to do Fourier analysis to ascertain Fourier frequency spectrum and combines with the peak spectrum to ascertain the natural frequency of vibration of bridge.

The invention discloses a method for detecting the quality of a large-diameter tubular pile at a low strain. A plurality of acceleration sensors are arranged on the top of the tubular pile; a central angle corresponding to two adjacent acceleration sensors is 90 DEG; central angles between exciting points and all the acceleration sensors are 45 DEG or 135 DEG; acceleration responses are obtained through the measurement of the acceleration sensors, and speed responses are obtained through acceleration response integrals; an average value is obtained by superposing the speed responses obtained through the measurement at all measuring points to obtain an average speed response curve; and the integrity of a pile body is determined according to the obtained average speed response curve. By the method, a plurality of sensors are use for multipoint measurement, so that the propagation law of stress waves along the circumferential direction of a pile wall can be obtained, and the influence of a three-dimensional effect is eliminated; and due to the adoption of the average speed response curve, the problem of high-frequency interference waves can be completely solved, and the excitation of the points which form an angle of 45 DEG or 135 DEG with the acceleration sensors is better than the conventional excitation of the points which form an angle of 90 DEG with the sensors. The method for detecting the quality of the large-diameter tubular pile is easy to operate, convenient to implement, low in measurement cost, high in measurement accuracy and high in efficiency.

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.

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 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 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 provides a tunnel structure damage identification device based on a vibration response test. A vibration pulse signal is excited by a pulse excitation device, structural vibration response is collected by a high-precision acceleration sensor, and an extraction structure transmits function information to identify the tunnel structure damage (namely, change of structural dynamic properties); the damage identification device mainly comprises acceleration sensors, the pulse excitation device, a central control computer, a signal collector, a horizontal telescopic arm and a matched circuit; an operator controls the development length of the horizontal telescopic arm through an operation instruction to determine a detection range. The acceleration sensors on both ends of the horizontal telescopic arm are fixed on the surface of the structure, the pulse excitation device is controlled to apply pulse excitation on the structure to collect the acceleration response of the structure, and the central control computer is used for carrying out the structure damage identification through tunnel structure damage identification system software.

Methods, systems, and computer-readable media generate acceleration time histories. An initial acceleration history is applied to a response model with natural frequencies across a spectrum of interest to develop a displacement response. Low-frequency enhancement signals are determined by comparing the displacement response to a standard displacement response. The enhancement signals are combined with the initial acceleration history to develop a second acceleration history, which is applied to the response model to develop an acceleration response. High-frequency enhancement signals are determined by comparing the acceleration response to a standard acceleration response. The enhancement signals are combined with the second acceleration history to develop a desired acceleration history. Acceleration histories also may be created by adding random phase angles at various frequencies to an initial acceleration history in the frequency domain, which is then converted to the time domain and scaled to generate a low-correlation history.

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 steel framework structure mutational damage recognition method and system. The method includes the following steps that vibration situations of a steel framework structure are monitored, and an acceleration response signal is obtained; the wavelet coefficient of the acceleration response signal at each moment is calculated, the damage index of each node of the structure is calculated through the change rate of the wavelet coefficients, and the damage indexes and the damage degree of the steel framework structure are in a linear relation; the moment when the steel framework structure is damaged is determined according to changes of the damage indexes along with time, and the position where damage occurs is determined by comparing the damage indexes at different portions of the steel framework structure; the damage degree of the structure is determined according to the damage indexes corresponding to the damage occurrence moment. The method and device are suitable for mutational damage recognition of the steel framework structure at different types of excitation, mutational damage of a small degree can be accurately recognized, high noise reduction capacity is achieved, the problem that a traditional damage recognition method can not be used for recognizing the damage degree of the structure is solved, and high application value is achieved.

The invention relates to a control method for increasing the operation performance of a plurality of ultrasonic motors running in equipment. The method belongs to the automatic control field. When a plurality of ultrasonic motors are needed to drive and control at the same time in a set of equipment, the position feedback control can obtain better position accuracy, and the speed of the ultrasonic motors changes more tempestuously because the response speed of the ultrasonic motors is very fast, so the running stability of the whole equipment cannot be ensured; and the speed feedback control can obtain well moving stability, but the position accuracy is worse. In order to resolve the contradiction, a novel speed-position double close loop control mode is designed, the speed close loop control voltage increment and the position close loop control voltage increment are added up, and the sum is taken as the total control voltage increment and acts on drivers of the ultrasonic motors so as to increase the integral operation performance of the ultrasonic motors and driving equipment thereof. The control method is applied to the equipment driven by the ultrasonic motors, and is especially suitable for occasions requiring a plurality of the ultrasonic motors to drive and control at the same time.

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.

The invention discloses an open trench vibration isolation design method based on quantitative analysis. The method includes the steps that 1, a finite element calculation model related to the foundation is established; 2, foundation soil dynamic material parameters and a dynamic load time travel curve are determined; 3, a dynamic finite element basic equation is established, vibration isolation trenches with different depths are set on the finite element calculation model, the finite element calculation model is analyzed, and the dynamic finite element basic equation is solved by utilizing the dynamic material parameters and dynamic load of foundation soil to obtain mass matrixes, damping matrixes, stiffness matrixes and nodal load vectors of all node units of the finite element calculation model; 4, transient analysis is conducted to acquire a post-trenching surface vertical velocity response value; 5, according to the post-trenching surface vertical velocity response value, a post-trenching vibration velocity maximum value and distance relation curve of the vibration isolation trenches with different depths is obtained by fitting, and the range of a velocity response enhancementzone and a building and vibration isolation trench distance corresponding to an expected vibration isolation effect of the vibration isolation trenches in later engineering construction of the reinforcement zone are obtained through the curve.

The invention provides a step-by-step diagnosis method for a node weld seam damage of a welded spatial grid structure. The method is characterized by comprising the following steps: firstly, dividingthe structure into a plurality of sub-areas according to wavelet analysis or power spectrum density sensitivity analysis of structure acceleration response, and identifying a sub-area having the nodeweld seam damage; and then determining a damaged location of a node in the sub-area having the node weld seam damage, and assessing the damage level. The objective of the invention is to provide the step-by-step diagnosis method for the node weld seam damage of the welded spatial grid structure in view of the defects in the prior art, so that damage positioning and damage level assessment are simple and easy.

The invention relates to the field of historic building structure protection, and particularly relates to a method for determining integral inclination of a historic building structure under the effect of industrial vibration. The method comprises steps of measuring on site the horizontal velocity response V[0] of the highest point of the historic building structure and the horizontal velocity response V[01] of the highest point of the bearing structure; selecting the equivalent shearing elastic wave velocity V[S] according to the type of the historic building; measuring on site the shearing elastic wave velocity V[S1] of the bearing structure; calculating the integral horizontal dynamic strain [epsilon][S] of the historic building structure according to horizontal velocity response V[0] of the highest point of the historic building structure and the equivalent shearing elastic wave velocity V[S]; and calculating the horizontal dynamic strain [epsilon][S1] of the bearing structure of the historic building according to horizontal velocity response V[01] of the highest point of the bearing structure and the shearing elastic wave velocity V[S1] of the bearing structure.

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.

The velocity of a wireless communications device (WCD) (106) is estimated. In response to this estimate a power control command rate is determined. The WCD 106 transmits power control signals to a base station (102) according to the power control command rate. The power control command rate may be determined by mapping the estimated velocity to a velocity range, and selecting a rate that corresponds to the velocity range as the power control command rate. Velocity is estimated by measuring a level crossing rate of a multipath signal.

A driving force control apparatus includes a first torque calculator configured to calculate turning radius correspondence torques indicating the magnitudes of the driving forces to be transmitted to a right rear wheel and a left rear wheel based on a turning radius, a second torque calculator configured to calculate steering velocity response torques based on a steering velocity of a steering wheel and a vehicle speed, a corrector configured to calculate a corrected torque by correcting a turning radius correspondence torque of at least one of wheels on an inner side of turning and on an outer side of turning in accordance with the steering velocity response torque, and a current controller configured to supply currents to torque couplings so that driving forces based on the corrected torque are transmitted.

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 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 discloses an alternating current servo drive major loop based on three electrical levels of an MOSEFT. According to the major loop, on the basis of the increased level number of a three-electrical-level MOSFET main circuit topological structure, the voltage waveform input by a motor is improved, the deformation of the motor voltage waveform is reduced, the harmonic wave of motor current is decreased, and temperature rise in the motor is reduced; meanwhile, the stress of a diode Du / a diode Dt, which is performed on switch devices, is greatly decreased, an insulated part of a motor rotor winding can be effectively prevented form being penetrated, and the EMI characters of an overall servo drive can be improved; the switching frequency reaches 50 KHZ, and the integral propertyof servo control is significantly improved, particularly the dynamic property and the velocity response bandwidth.

The embodiment of the invention provides a method and device for determining the equivalent acceleration of a rail transit vehicle. The method comprises the steps: obtaining the target speed and the target average acceleration of the vehicle, obtaining the response time from a handle traction instruction to brake release, and the idle running time generated by impact rate limitation, and calculating the equivalent acceleration of the vehicle according to the target speed, the target average acceleration, the response time and the idle running time. According to the method and the device, the response time and the idle running time which influence the equivalent acceleration are considered according to the actual starting process of the vehicle, so that the accuracy of the equivalent acceleration is improved.

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 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.

The invention discloses a novel 3D scanning data automatic collecting device. The device employs a precision ball screw transmission mode, so the device is high in transmission precision and quick inresponse, can improve the data collection efficiency and the collection data accuracy for providing convenience for the subsequent point cloud data processing of a three-dimensional model, and improves the object printing precision of a 3D printer. The device solves problems that a conventional hand-held or support fixing scanning mode is low in efficiency, is not accurate in collected data, and is difficult in the subsequent point cloud data processing of the three-dimensional model.