288 results about "Ground vibrations" patented technology

The invention discloses an absolute gravity measuring system and measuring method as well as a falling method of a free-falling body. The absolute gravity measuring system comprises a free-falling body device, a laser interference measuring device and a vibration isolation platform, wherein the free-falling body device is used for realizing free-falling motion of a falling object; the laser interference measuring device is used for measuring displacement generated during the free-falling motion of the falling object, and can realize accurate calibration of a measuring beam in a vertical direction by adopting a simplified structure; and the vibration isolation platform is arranged between the laser interference measuring device and the ground and is used for isolating influence of ground vibration on measurement. The absolute gravity measuring system has the beneficial effects that free-falling motion of the falling object is realized by adopting an elastic falling member suspension method, vibration influence of a motor drive system on the free-falling body device is reduced, and the accuracy of the gravity measuring result is improved; meanwhile, the zero crossing point (ZCP) feature of an interference fringe signal is computed by computer software so as to eliminate possible measurement deviation caused by a hardware circuit.

The invention relates to grounding vibration experimental method and system of a steel catenary riser. The grounding vibration experimental method of the steel catenary riser comprises the following steps of, firstly, arranging a flume, paving clay which has close physical property and mechanical property with prototype seabed soil at the bottom of the flume, arranging a wave absorbing region at the end of the flume, arranging a water outlet on the flume above the wave absorbing region, and simulating an ocean current in a riser grounding region in a mode of circulating refluxing of effluent, wherein the water level in the flume is higher than the upper surface of the clay; secondly, with the application of a method of truncation simulation, arranging a riser grounding segment model in the limited flume, applying the vertical load and the horizontal lateral load at one end of the riser grounding segment model, and simulating grounding vibration of the steel catenary riser caused by motion of a floating body and a seabed groove formed with pipe-soil interaction; and thirdly, through an acceleration sensor and a strain gauge which are arranged on the riser grounding segment model at intervals, collecting a response signal of grounding vibration of the model, thereby influences on grounding vibration of the steel catenary riser of the seabed surface soil body property and different flow rate damping conditions are acquired.

A loudspeaker system has an extended bass or low frequency response. The loudspeaker system integrates a passive radiator with a transducer. The loudspeaker system also mechanically isolates the passive radiator and the transducer. A support mechanism mechanically grounds vibrations or other forces from the transducer and passive radiator that may interfere or affect the operation of the loudspeaker.

The disclosure describes an absorption spectroscopy method for sensing hydrogen gas in a sample atmosphere and an associated hydrogen sensor. A light beam, having a wavelength corresponding to a vibrational transition of hydrogen molecules from a ground vibration state to any excited rotational vibration state via a quadrupole interaction, is introduced into an optical cavity adapted to receive a sample atmosphere to be tested for the presence of hydrogen gas. The light is introduced into the cavity in an off-axis alignment to systematically eliminate cavity resonances, while preserving the absorption signal amplifying properties of such cavities. Hydrogen absorption is measured is terms of cavity output, as in the ICOS technique.

Methods and apparatus for isolating vibrations associated induced by reaction forces and ground vibration are disclosed. According to one aspect of the present invention, a scanning stage apparatus includes a stage base, a stage, a driver, and a reaction frame. The stage moves over the stage base in a first translational direction, a second translational direction, and a first rotational direction. The driver causes the stage to move, and also causes at least one reaction force to be created when the stage moves. The reaction frame at least partially supports the driver, and along with the driver, is substantially decoupled from the stage base. The reaction force is arranged to be transmitted to the reaction frame. The electromagnetic coupling electromagnetically couples the reaction frame to a ground, and provides a stiffness and a damping between the reaction frame and the ground.

The invention relates to a vertical limit lead shear three-dimensional vibration isolation device which belongs to the structural vibration control and vibration control field. The invention designs the Belleville spring external guide part in the vertical vibration isolation device contacted with an external sealing steel plate to be a clamp plate lead shear damper; the three-dimensional vibration isolation device generates vertical vibration on the upper connecting plate under the excitation of the vertical loading; the vibration drives the lead block to have shearing deformation, so as to provide vertical damping force for the three-dimensional vibration isolation device. A vertical limiter is arranged between the external guide rod and the external sealing steel plate to control the rebound of the instantaneous Belleville spring; the vertical limiter also has the clamping plate effect, applies the horizontal pre-pressing force on the structure and avoids the extruding loss after the yield of the lead. The vertical limit lead shear three-dimensional vibration isolation device has the advantages of simple structure, stable performance, being applicable to the second vibration of the building induced by the traffic and any occasion that the three-dimensional vibration isolation device in the prior art is applicable to for isolating the ground vibration, reducing the power reaction of the structure and the device.

Methods of blasting rock are disclosed and claimed in which blast holes are arranged in group of 2 to 7 blast holes. Within each of the groups, adjacent columns of explosive material (12) are actuated within 5 ms of one another Initiation of blasting between the respective groups occurs at least 8 ms after completion of initiation of an adjacent group. Initiation devices (13, 24) may be located at the lower end, upper end or both ends of the respective blast holes, depending on the stress field that is intended to be generated within the rock. As a result, environmental stresses such as ground vibrations are reduced, and the efficiency of rock fragmentation are increased.

The invention discloses a sub-aperture splicing interferometer system, which comprises a ground vibration insulating unit, a filler, an insulating layer, a first active vibration insulating unit, a platform, an air floatation guide rail, a first platform, a second active vibration insulating unit, a second platform, a moving mechanism, a revolving table, an optical lens to be tested, an air floatation guide rail, a truss and a transparent cover. According to the sub-aperture splicing interferometer mechanism with a vibration insulating effect, provided by the invention, the influence of ground vibration on measurement can be isolated through multilayer vibration insulating treatment; the glass cover is arranged, and nitrogen gas is charged into a measuring space, so that air current and temperature fluctuations are reduced; and the active vibration insulating unit is arranged above the air floatation guide rail, so that the influence of air film fluctuation on phase shift is reduced. Meanwhile, the mechanism can perform two-dimensional translation and rotation motions, so that absolute measurement can be realized in a splicing process. The invention further provides a method for measuring the surface shape of an optical lens by using the sub-aperture splicing interferometer system.

Disclosed is a satellite momentum wheel vibration disturbance test and a data interpretation method. The method comprises the steps of firstly building a harmonic wave superposition mathematical model through actual measurement of disturbing force generated by a momentum wheel; then building satellite finite element models of satellites in an orbit state and multiple kinds of ground vibration disturbance test states respectively, adopting a frequency response analysis method to calculate vibration disturbance overall response of each harmonic wave to sensitive equipment in all kinds of satellite states, choosing a ground test state with minimum analysis result difference of the satellites in the orbit state to carry out the momentum wheel vibration disturbance test and conduct actual measurement of a vibration disturbance of a momentum wheel to the sensitive equipment; finally amending the analysis result of the orbit sate through postprocessing of the measurement result so as to assess and verify the accuracy and validity of the design of the satellite momentum anti-wheel vibration disturbance. According to the satellite momentum wheel vibration disturbance test and the data interpretation method, simulated analysis is adopted to guide test program design and result interpretation, the influences of each harmonic wave component of momentum wheel disturbing force to the sensitive equipment respectively can be assessed, the calculated amount is small, and convenience is brought to project implementation.

The invention relates to the field of low-frequency or ultralow-frequency vibration isolators, in particular to a disc spring quasi-zero stiffness vibration isolator which is applied to ground vibration tests of spacecrafts. In order to overcome the defects that an existing quasi-zero stiffness vibration isolator is low in bearing capacity, complex in structure, and relatively short in effective stroke nearly zero-stiffness, the invention provides the quasi-zero stiffness vibration isolator. The quasi-zero stiffness vibration isolator comprises a disc spring, a pressing piece, a rigid casing, a linear spring and a linear spring length regulator, wherein the outer edge of the disc spring is connected with the rigid casing through the pressing piece; the center of the disc spring is fixedly connected with the top of the linear spring; the bottom of the linear spring is fixedly connected with the linear spring length regulator; and the linear spring length regulator is in threaded connection with the rigid casing. Compared with the existing low-frequency vibration isolator, the quasi-zero stiffness vibration isolator disclosed by the invention has the advantages of being small in added mass, high in bearing capacity, adjustable in bearing capacity, small in size, simple in structure, easy to maintain, high in reliability and the like.

The invention discloses an optical fiber intelligent sensor used in a security system. An optical cable is used as a sensing and detecting unit for outside accurate invasion point positioning, outside invasive object analysis and the like; when an invader tries to go across or damage a guardrail, an optical sensor array can receive ground vibration information, an optical fiber vibration signal mode and recognition system performs signal analytic processing of collected information, a specific invaded ground vibration type is generated according to the processing result, the numerical result is input into an alarming control master computer, the vibration information processing result is converted by the software system of the alarming control master computer into an alarming signal automatically, the alarming position is displayed in form of three-dimensional electronic map on a cable head, and at the same time, the alarming control master computer automatically extract security area videos, a linked matrix, a hardware video recorder and equipment to be linked such as on-site lighting and sound and light alarming equipment. Thus, video of the alarming site can be viewed as soon as possible so as to make a security policy quickly.

The invention discloses a seismic magnitude rapid estimation method based on deep learning feature fusion. The method comprises the following steps: (1) collecting a large number of seismic monitoringstation ground vibration waveform records and corresponding seismic catalogues; (2) calculating traditional parameter characteristics and statistical characteristics of a data sample; (3) training adepth model, and extracting image features and time sequence features in the data sample; and (4) fusing the features extracted from the data sample to form vector representation, training an XGBoostmodel to obtain a seismic magnitude rapid estimation model, and further utilizing the model to obtain a corresponding seismic magnitude according to seismic waveform record estimation. Research results of traditional seismology are utilized, and are combined with deep learning, a seismic magnitude rapid estimation model is learned by utilizing a large amount of seismic data, and the accuracy of seismic magnitude rapid estimation is improved.

The invention discloses electromagnetic drive underground high-power resonant wave displacement device and method. The displacement device comprises a ground vibration source, an artificial well bottom and an underground vibrator, wherein the ground vibration source is distributed at the right upper part of a well opening of a vibration source well; the artificial well bottom is distributed at the well bottom of the vibration source well; the underground vibrator is vertically inserted into the vibration source well from top to bottom; the ground vibration source is an electromagnetic vibrator which drives the underground vibrator to vibrate up and down; and a front rope end of a steel rope is fixed to the upper end part of the underground vibrator after penetrating through a central through hole of the ground vibration source from top to bottom, and the steel rope is tightly connected with the ground vibration source. The displacement method comprises the following steps of: 1. selecting the vibration source well; 2. positioning equipment; 3. adjusting a working parameter of the ground vibration source; and 4. carrying out underground vibration displacement by adopting a resonantwave. The invention has the advantages of reasonable design and good construction effect, is convenient for installation and distribution and simple and convenient for use and operation, directly converts electric energy into vibration mechanical energy with stable frequency and stable energy by utilizing an electromagnetic device and greatly improves crude oil yield when reducing the saturation of residual oil.

The embodiment of the invention discloses a gravitational acceleration measurement device and method. The device comprises a rubidium clock, a laser interferometer, a vibration meter, an interference fringe acquisition unit, a vibration acquisition unit, a compensation processing unit and a fitting processing unit, wherein the rubidium clock is used for measuring the fall time t of a measured falling body; the laser interferometer is used for generating interference fringes in the falling process of the measured falling body; the vibration meter is used for measuring ground vibration displacement; the interference fringe acquisition unit is used for acquiring the number of the interference fringes, and the number of the interference fringes is used for calculating the fall displacement X of the measured falling body; the vibration acquisition unit is used for acquiring the ground vibration displacement of the vibration meter, and the ground vibration displacement is used for indicating displacement Y of a reference prism; the compensation processing unit is used for obtaining the actual falling displacement S of the measured falling body within the fall time t according to the formula S=X-Y; the fitting processing unit is used for conducting least squares fitting on three or more data sets (S, t) of falling time t and corresponding actual falling displacement S to obtain the numerical value of gravitational acceleration g. A more accurate numerical value of gravitational acceleration g can be obtained through the gravitational acceleration measurement device and method.

The invention provides a spacecraft ultra-quiet environment simulating and testing system, which includes a crane, a sound absorbing structure, a sound insulation wall, a mass block, an air spring isolator, a vibration isolation track, a laboratory ground base, a sound insulation door, a maintenance channel, a vibration isolation channel, and a fine sand cushion. The sound insulation wall and the laboratory ground base are connected through the vibration isolation track; the mass block and the laboratory ground base are connected through the air spring isolator; the sound absorbing structure and the sound insulation wall are fixedly connected; the crane is located above the mass block; the internal part of the laboratory ground base is provided with the maintenance channel; the sound insulation wall and the sound absorbing structure are connected; the vibration isolation channel is connected with the fine sand cushion. The system of the invention is capable of increasing isolation effect of ground vibration and transverse vibration, increasing the sound insulation effect of the wall, enhancing the isolation effect of air and sound, effectively reducing the background noise in a testing area, meeting the background noise requirement in micro-vibration test and the environmental interference suppression requirement, increasing the isolation effect of the testing area to sounds of solid objects and providing advanced micro-vibration testing means to a high precision large scale spacecraft.

Disclosed is an earthquake sensing alarm system installed to a ceiling finish panel or inner wall of a building. The system includes a sensor unit measuring ground vibration data, a measurement controller controlling the sensor unit, a signal amplifier amplifying the ground vibration data, a high frequency filtering unit removing a high frequency component from the amplified data, an A/D converter converting the filtered ground vibration data into digital data, a microprocessor classifying the digital data according to earthquake stages and controlling an external speaker to issue auditory alarms for behavior and evacuation guidelines, a response correction switch setting measurement sensitivity in each earthquake stage by adjusting sensitivity for the ground vibration data to reflect building characteristics and an installation location, an LED display lighting LEDs according to the stages, an I/O port connected to a central disaster monitoring device in the building, a power supply, and an electric charger.

The invention discloses an Internet of things based mine geological disaster monitoring system, which is characterized in that a ground vibration monitoring subsystem, a support column displacement monitoring subsystem, a support column internal pressure monitoring subsystem and a mine roadway air component monitoring subsystem are connected with a plurality of distributed sensor nodes and realize communication with a multi-type data fusion system, all distributed nodes are connected in the same network through the Internet of things, and transmission and aggregation of data are realized; the multi-type data fusion system transmits the data to a mine geological disaster analysis system, the mine geological disaster analysis system performs comprehensive analysis and risk evaluation according to the collected information and provides the geological disaster occurrence possibility of a mine at present. According to the invention, a lot of sensor nodes are deployed in the underground mine, all of the sensor nodes are organized together by applying a multi-information collection and fusion algorithm and Internet of things technologies, and real-time monitoring for geological change conditions in all regions in the underground mine is realized.