76 results about "Transient vibration" patented technology

A system for balancing an aircraft propeller system receives a vibration signal from the aircraft propeller system and determines whether the vibration signal indicates a transient vibration condition. If it is determined that the vibration signal does not indicate a transient condition, the system enables a balance correction controller. The controller generates a balance correction signal based on the vibration signal, and balances the aircraft propeller system in response to the balance correction signal if the balance correction controller is enabled.

A method of using a torque converter bypass clutch to launch a vehicle, mitigate transient vibration, and mitigate vehicle natural frequency harshness. The method uses the torque converter when the bypass clutch power capacity is approaching its limit, when the vehicle load is high, or the vehicle is on a grade, where normally the bypass clutch would launch the vehicle.

The invention discloses a novel transient oscillation signal angular domain order tracking sampling and analytical method. The method comprises the following steps that fixed sample frequency is utilized, rotating mechanical vibration signals and key phase pulse signals are synchronously collected, rotating speed key phase pulses are identified, an angular domain sampling sample time sequence is calculated, original signals are sampled, digital signals are sampled again, and the angular signals are processed. The novel transient oscillation signal angular domain order tracking sampling and analytical method has the advantages of being high in accuracy and real-time performance, clear in spectral lines, and high in self-adaptability and robustness.

The invention discloses a transient vibration detection method for ballastless track soundness, which comprises the following steps that: sleepers generate vibration signals; the vibration signals are converted into electric signals by a vibration pickup, the electric signals are input to the multi-channel A/D conversion module of a computer to convert the vibration signals, and the converted signals are uploaded to the data processing module of the computer; the computer conducts operational processing to the vibration signals; the vibration signals are filtered by adopting a fuzzy wavelet method to eliminate noises; Fourier transform is conducted to response signals to obtain frequency spectrum and phases; soundness indicators are calculated; and a sleeper soundness basic database is inquired for to obtain sleeper crack degree evaluation. The invention has the advantages that the transient vibration detection method for ballastless track sleeper cracks is convenient, rapid, simple and reliable, the rapid detection of the sleepers can be realized and the safety of railway lines can be ensured; and the labor strength of construction personnel for the railway lines is greatly reduced and the automatic measurement level is improved.

The invention relates a transient speckle measurement optical system based on a double-pulse laser, and belongs to the field of dynamic mechanical quantity laser measurement. The system comprises a light source, a light path transmission system and a photoelectric receiving system; the light source emits double-pulse laser, the energy of the laser is adjusted by an attenuation piece, and the space filtering is carried out for speckles of the laser by a space filtering mirror group which consists of a first long focal length lens, a metal pinhole and a second long focal length lens; the light beam passes through a second reflector after the space filtering is expanded and collimated by a first reflector, an expanded beam lens and a collimating lens, and is divided into a path of measurement light and a path of reference light through a beam splitter prism to be incident on a measured surface and a reference surface respectively; the two paths of scattered light are gathered after passing through the beam splitter prism, and are interfered mutually; and the interfered light beam is imaged on the receiving surface of a CCD (Charge-Coupled Device) camera by an eyepiece. The system obtains speckle images of transient vibration of an object structure surface in an adjustable time interval; and the signal to noise ratio of the obtained speckle images is high.

The invention discloses a helicopter rotor blade movement parameter measurement method based on vibration correction and belongs to the technical field of vision measurement. The helicopter rotor blade movement parameter measurement method based on vibration correction comprises the following steps of placing a certain number of coded mark points on a hub and blades of a helicopter rotor; constructing a binocular stereo vision system to obtain helicopter rotor image data; calculating three-dimensional coordinates of the coded mark points and constructing a rotor coordinate system; calculatinga transient vibration displacement vector of the rotor in a high speed rotation state to correct the three-dimensional coordinates of the coded mark points; and on the basis of the corrected three-dimensional information of the coded mark points, calculating movement parameters of the rotor blades in the current transient state according to definitions of the movement parameters of the rotor blades. The helicopter rotor blade movement parameter measurement method based on vibration correction, disclosed by the invention, has the advantages that the movement parameters of the rotor blades can be accurately measured by correcting vibration displacement errors caused by rotor high speed rotation, the operation is simple, the method is in the non-contact form, the accuracy is high, and the safety is good.

The invention discloses an early warning method and system for abnormal vibration of a wind driven generator. The early warning method comprises the following steps of: A, data acquisition of acquiring real-time transient vibration data of a machine set; B, data pre-treatment of performing pre-treatment on the acquired data to obtain a calculation sample; C, vibration characteristic extraction of performing ellipse fitting on the calculation sample and extracting a characteristic value of a fitted ellipse; D, vibration state assessment of assessing the vibration state of the machine set based on comparing the characteristic value with the set warning threshold value. The early warning method and system for abnormal vibration of the wind driven generator are used for analyzing the vibration state of the machine set, detecting the vibration characteristics and establishing an early warning mechanism, are good for finding hazard of the machine set as early as possible, reduce the running time of the machine set in fault, accordingly provide judgment basis for repair or replacement of key parts, decrease part damage risk and reduces machine set downtime and spare part consumption cost.

The invention discloses a precise detection device and a detection method for stress of an invitro prestressed steel beam. The method comprises the following steps that magnetic induction sensors are subjected to tensioning testing machine calibration; the magnetic induction sensors and a vibration sensor are mounted; a transient loss coefficient is determined by tensioning testing; an initial prestressed steel beam stress prediction model is acquired; after steel beam tensioning is accomplished, data of the vibration sensor is tested; transient vibration data after the tensioning is obtained; the transient invitro steel beam vibration frequency after the tensioning is calculated; measured values x of the magnetic induction sensors and the data of the vibration sensor are measured according to a predetermined target and the testing time after the tensioning; and a stress value is calculated. By combining a magnetic induction effect testing method and a vibration testing method, the method overcomes the disadvantage that a stress relaxation influence of an invitro prestressed steel beam stranded wire cannot be eliminated by separately using the magnetic induction sensors and a magnetic induction acquisition device for testing analysis, and the testing precision is improved effectively.

A class of bearings, each of them can be used as a connecter to connect two parts in a structural system and as a supporter to transfer loads from one part to another, for examples, gravity of a superstructure to a substructure in a bridge or a building, or that of a machine to its foundation. While performing load transmission, it is able to reduce the transmission of transient vibrations between connected two structural parts and preserve the integrity of entire structural system; for examples, to protect a bridge's structural integrity when either an earthquake strikes its pier and foundation or a tsunami hits its superstructure or both occur simultaneously.

The invention discloses a helicopter rotor vibration displacement measuring method in a low-speed wind tunnel test, and belongs to the technical field of low-speed wind tunnel test measurement. The method comprises the following steps: arranging a certain number of coded marking points on a helicopter rotor hub; acquiring image data of the helicopter rotor in a stationary state; calculating the three-dimensional coordinates of the coded marker points in the image data, and constructing a rotor coordinate system; acquiring the transient image data of the helicopter rotor in a high-speed rotation state; calculating the three-dimensional coordinates of the hub central coded marker point in the rotor coordinate system; and calculating the transient vibration displacement vector of the helicopter rotor in the high-speed rotation state. The method provided by the invention can effectively measure the vibration displacement deviation caused by the high-speed rotation of the helicopter rotor,is easy to operate, achieves noncontact measurement, and is high in precision and good in safety.

An object of the present invention is to provide an active vibration isolating support apparatus to effectively reduce a transient vibration which occurs at the time of engine starting. In order to achieve the above object, an active vibration isolating support apparatus for suppressing a vibration transmitted to a vehicle body including: active mounts to elastically support a load of an engine in the vehicle body each of which includes an actuator; and a control unit to drive the actuator to extend and contract periodically in response to a waveform of the vibration of the engine; in which the control unit supplies a predetermined current to the actuator based on a starting control condition, and starts a control of the actuator based on a control instruction value of a current in response to the vibration of the engine is provided.

Embodiments of the present invention provide a method and a system for generating optimal feedforward signal for the seek control to suppress the RTV (Random Transient Vibrations) and the seek acoustic noise. One aspect is directed to a method of providing a revised feedforward signal using an adaptive filter in a feedforward control system for controlling an actuator to move a head to seek a track and settle on the track of a disk in a disk drive apparatus. The method comprises performing a seek operation of the head using an initial feedforward signal; obtaining an error signal at settling after performing the seek operation; determining filter characteristics of the adaptive filter to minimize the error signal; and implementing the adaptive filter having the determined filter characteristics in the feedforward control system to produce a revised feedforward signal for controlling the actuator for moving the head in the disk drive apparatus.

The invention relates to a blast vibration safety judgment method considering crustal stress transient unloading. The blast vibration safety judgment method includes the steps that 1, a vibration meter is used for carrying out vibration monitoring on an excavated tunnel body and surrounding buildings to obtain actual measurement surrounding rock vibration signals; 2, the actual measurement vibration peak value PPV1 is obtained; 3, blast load (BL) and crustal stress transient unloading (IS) are recognized; 4, vibration amplitudes caused by two excitation source coupling action, crustal stress transient unloading and blast load, corresponding main vibration frequency and frequency demarcation point of blast high-frequency waves and transient low-frequency waves are obtained respectively; 5, the transient vibration peak value PPV2 and the blast vibration peak value PPV3 are obtained; 6, blast vibration safety allowable values [PPV1], [PPV2] and [PPV3] corresponding to the coupling vibration main frequency f1, the transient main frequency f2 and the blast main frequency f3 are selected; 7, the coupling vibration peak value PPV1 and the coupling safety allowable value [PPV1], the crustal stress transient vibration peak value PPV2 and the transient safety allowable value [PPV2] as well as the blast vibration peak value PPV3 and the blast safety allowable value [PPV3] are compared. The blast vibration safety judgment method is capable of accurately and reliably evaluating blast vibration safety.

A class of bearings, each of them can be used as a connector to connect two parts in a structural system and as a supporter to transfer loads from one part to another, for examples, gravity of a superstructure to a substructure in a bridge or a building, or that of a machine to its foundation. While performing load transmission, it is able to reduce the transmission of transient vibrations between connected two structural parts and preserve the integrity of entire structural system; for examples, to protect a bridge's structural integrity when either an earthquake strikes its pier and foundation or a tsunami hits its superstructure or both occur simultaneously.

The invention discloses a method for analyzing in-orbit vibration of a cable-mesh reflector space-borne antenna. The method comprises the following steps: inducing and resolving the cable-mesh reflector space-borne antenna into basic parts with certain functions; describing the geometrical features of each part and extracting the geometrical information of each part to complete finite element modeling of heat and structure; calculating the antenna in-orbit temperature field distribution and the time history of temperature field distribution of antenna entering and exiting a shadow region by utilizing orbit parameters; performing transient dynamic analysis and static analysis of the space-borne antenna, and calculating thermotropic transient vibration; establishing the linear approximate relation of electrical performance and vibration features; and determining the electrical performance variation when the antenna enters and exits the shadow region. The method realizes quick modeling to improve the analysis efficiency of in-orbit vibration of the cable-mesh reflector space-borne antenna; main geometrical information of the antenna can be described by simple lines and areas, so that the geometrical description of the antenna structure is simplified, and partition of finite element meshes in multi-field analysis can be benefited.

The invention discloses a double-pulse digital speckle transient measuring device and method, belonging to the field of digital speckle interference measurement. The measuring device comprises a double-pulse laser, an optical system, a synchronous controller, an image acquisition system and a transient speckle data processor and is characterized in that the double-pulse laser and a double-exposure camera are used as a light source and a photoelectric receiving system respectively, the accurate timing of the synchronous controller controls the synchronous work of the laser and the camera, and the transient speckle data processor is used to realize the measurement of the transient vibration shape of the structure surface within the adjustable time interval. The measuring device has the advantages of non contract, high resolution, overall simultaneous measurement and accurate acquisition of the transient vibration shape of the object. In addition, the measuring device has indispensable application value in the dynamic characteristic analysis and transient measurement of the complicated structure, micro structure and thin-wall structure in the military hardware.

The invention relates to a simulation method for a water turbine generator set shafting vibration transient state and belongs to the water turbine generator set stability analysis and control field. The simulation method for the water turbine generator set shafting vibration transient state comprises enabling the external force which acts on a shifting to be served as an additional input control item to increase universality and obtaining an angular acceleration item which is reserved in a model and can reflect angular velocity variation during the transient process; introducing other subsystem models into a shifting vibration model through water turbine torque and electric generator torque items in a set motion equation and achieving connection between the shafting vibration model and other subsystem models in the set; converting the shifting model into a first order differential equation sets to be combined with the set motion equation, forming into a shafting transient vibration calculation equation set and achieving the simulation. The simulation method for the water turbine generator set shafting vibration transient state aims at researching the vibration performance of the set under various transient state disturbances, particularly under a large disturbance and providing research methods and means for designing and controlling of safety and stability of the set shafting.

A flex cable assembly for a head stack assembly of a hard disk drive comprises a flex cable for conducting data signals from the head stack assembly to a connector. The flex cable has a dynamic loop section between a termination for the head stack assembly and the connector. The flex cable has a constrained layer damper for attenuating random transient vibration. The constrained layer damper has a symmetrically tapered shape for reducing stress concentration and is coupled with the dynamic loop section of the flex cable adjacent to an area of the flex cable configured for receiving a coupler for coupling the flex cable assembly with the head stack assembly.

A method and computer program product for sending a data request from a host bus adapter logic processor to a hard disk drive, setting a standard time out period for receiving a reply from the hard disk drive, sensing vibration in the hard disk drive, sending a vibration alert signal from the hard disk drive to the host bus adapter logic processor in response to the sensed vibration exceeding a predetermined amount of vibration, and, in response to receiving the vibration alert signal from the hard disk drive, the host bus adapter logic processor establishing an extended time out period for receiving the reply. The rotational vibration sensor used by the hard disk drive for repositioning the read/write head may also be used to sense the vibration and form the basis for the vibration alert signal, such as a vibration error code. By extending the time out period during high vibration events, the hard disk drive can ride out the event without being tagged as having failed. Accordingly, the hard disk drive can then be available for use following the high vibration event.

A method and apparatus identifies a region of interest of transient vibration data needing analysis and provides context and construction for analytical plots. The method comprises providing transient data and determining a region of interest of the transient data, specifying a construction mode corresponding to a derived graphical display of the transient data and specifying a construction parameter corresponding to the specified construction mode. The method also comprises processing the transient data to produce at least one derived plot based on the transient data, the region of interest, the specified construction mode, and the specified construction parameters. This method may be performed by a graphical tool having a hardware module and a software module. The hardware module including a processor, a memory, a display, and a communicator, and the software module including a plotting module and a plotcontrol module.

The invention provides a gearbox fault diagnosis method based on resonance base bandwidth Fourier decomposition, and the method comprises the steps: firstly building a transient vibration response model of a gearbox based on a single-degree-of-freedom mass rigidity damping system through resonance base bandwidth Fourier decomposition; then, estimating the natural vibration frequency of a gearbox vibration system through Fourier spectrum maximum value point search, extracting a resonance band in an original signal through bandwidth optimization, finally, selecting out effective components containing more fault information in a decomposition result according to the characteristic frequency ratio, and realizing accurate identification of gearbox faults through Hilbert demodulation. The methodhas the characteristics of high calculation speed, strong anti-noise capability and high fault identification precision, and can be effectively applied to gearbox fault diagnosis in a complex noise environment.

Featured is an accurate and inexpensive system to detect and report engine idling in a vehicle including a detection portion and a reporting portion. The detection portion detects or senses the presence of voltage from the vehicle's ignition switch and vehicle's mechanical vibration from the running engine. The detection portion also can filter out transient vibrations which are not related to engine running. The detection portion forwards signal or information relating to engine running and vehicle movement to a reporting portion of the system. The reporting portion (e.g., a software application being executed on a computer or microprocessor) determines from the forwarded information if the vehicle engine is idling and if there is excessive idling. The fleet operator can define recommended maximum idling parameters to determine such excessive idling. Also featured are apparatuses, devices and methods related thereto.