896 results about "Vibration amplitude" patented technology

The invention provides a feed mixing process uniformity dynamic evaluation and parameter adjustment method, and relates to the technical field of data processing, and the method comprises the steps: building a material characteristic matrix according to raw material characteristic data; correspondingly storing the material characteristic matrix and initial operation parameters of the mixing equipment to generate first mixing control data; in the mixing process, collecting local vibration amplitudes and temperature rise rates at different spatial positions, and combining the local vibration amplitudes and the temperature rise rates with the first mixing control data; calculating the vibration amplitude distribution difference in adjacent sampling periods in the feed mixing treatment process to obtain a spatial fluctuation index; when the spatial fluctuation index is continuously reduced and the temperature rise rate is periodically and suddenly increased, generating local accumulation indication data, and triggering short-time acceleration and inversion operation; executing feed mixing treatment, and generating a mixing termination signal when the spatial fluctuation index change rate of three continuous sampling periods is lower than a preset fluctuation threshold value; according to the invention, autonomy and accuracy of feed mixing uniformity adjustment are improved.

The invention provides a vibration test bench, and relates to a vibration test device, and the vibration test bench comprises a pedestal, and a plurality of vibration frames which are arranged on the pedestal in parallel at intervals and are sequentially arranged on the pedestal from top to bottom; each sliding guide rail is arranged between every two adjacent vibration frames and between the vibration frame on the lowermost layer and the base, and the guide directions of the sliding guide rails are different from one another; each driving mechanism is fixedly connected to the vibration frame located on the lower layer or the base and drives the vibration frame located on the upper layer to do reciprocating rectilinear motion along the corresponding sliding guide rail. Each locking mechanism is arranged between every two adjacent vibrating frames and between the vibrating frames and the base, and each locking mechanism can selectively lock the reciprocating motion of the vibrating frame located on the upper layer; the control unit is in communication connection with all the driving mechanisms and independently controls operation of all the driving mechanisms. The vibration test bench can realize multi-degree-of-freedom movement, and has a broadband vibration frequency / amplitude adjusting function.

The invention provides a vibration measurement device for motor equipment, and relates to the field of vibration measurement, and the device comprises a main body support frame, and the left and right sides of the top of the main body support frame are provided with self-locking worm gears A; a mounting angle adjusting shaft is rotationally mounted on the inner side of the main body supporting frame; self-locking worms A are arranged on the left side and the right side of the mounting angle adjusting shaft; the self-locking worm A is matched and connected with the self-locking worm gear A; guide pieces are arranged on the left side and the right side of the main body supporting frame. A mounting angle adjusting part is arranged in the middle of the mounting angle adjusting shaft; the vibration testing device can test vibration of motor equipment at different installation angles and output angles, the universality and accuracy of the vibration testing result of the device are improved, and the problem that the vibration amplitude of the motor equipment is affected to a certain extent due to installation modes at different angles is solved. And a vibration measurement result obtained by only testing plane installation does not have universality.

The invention discloses a distributed optical fiber acoustic sensing highway abnormal vibration real-time early warning system, and relates to the technical field of highway monitoring. A vibration analysis and mechanism triggering module calculates the speed of vibration amplitude changing along with time, if the change speed exceeds a set threshold value, abnormal fluctuation is marked, the maximum deviation and the minimum deviation of a vibration signal are calculated, and the maximum deviation and the minimum deviation of the vibration signal are calculated; if the deviation values exceed a preset range, an early warning program is started, an early warning strategy output module constructs a material flow state stability index based on the speed of the vibration amplitude changing along with time, creates a construction area uniformity index in combination with a vibration propagation track, analyzes the coordination degree between the vibration behavior and the road construction state according to a regulation and control coordination coefficient, and outputs early warning information. And a corresponding vibration early warning strategy is generated based on the analysis result. The early warning system realizes accurate and operable abnormal vibration real-time early warning through distributed optical fiber sensing, dynamic feature extraction, multi-dimensional index construction and intelligent model analysis.

The invention discloses a dynamic calibration device and method for a visual vibration measurement system, the device comprises a dynamic standard vibration source, a calibration target, a laser Doppler interferometer, a data processing unit and a control unit, the dynamic standard vibration source outputs steady state, transient state and random vibration signals, the calibration target is fixed at the vibration output end of the dynamic standard vibration source, and the laser Doppler interferometer is fixed at the vibration output end of the dynamic standard vibration source. An acquisition target is provided for a calibration process; the calibrated visual vibration measurement system collects a dynamic image to obtain a vibration measurement parameter, and the laser Doppler interferometer synchronously obtains a standard vibration dynamic parameter; the data processing unit receives the dynamic vibration measurement parameters and the dynamic standard vibration parameters, and quantifies dynamic amplitude deviation, frequency tracking delay and phase difference; and the control unit generates calibration parameters of the calibrated visual vibration measurement system according to the type of the dynamic error under the condition that the dynamic error exceeds an error threshold value. According to the invention, quantitative evaluation and automatic calibration of the dynamic error can be realized, and the calibration precision and efficiency are improved.

The invention relates to a cylindrical shell structure vibration measuring point optimizing and monitoring method, device, equipment and medium, and relates to the technical field of cylindrical shell structure monitoring. The method comprises the steps that a simulation model of a cylindrical shell structure is established, and a plurality of response points are arranged on the surface of a shell; then constructing a modal shape matrix; calculating a contribution matrix based on the modal shape matrix, and calculating an acceleration response matrix; the vibration amplitude of each response point under the fault correlation frequency is extracted, and a fault acceleration response matrix is obtained through normalization processing; constructing a comprehensive vibration energy index based on the acceleration response matrix and the fault acceleration response matrix; carrying out weighted fusion on the contribution matrix and the comprehensive vibration energy index, and constructing a multi-target game model; solving based on a modal observability index and a vibration characterization capability index to obtain an optimal weight; and determining an optimal sensor arrangement scheme of the cylindrical shell structure based on the optimal weight. According to the invention, multiple monitoring targets can be met cooperatively.

The invention discloses an acoustic excitation digital modulation noise reduction method and system for laser acoustic vibration detection and application. Comprising the following steps: step 1, acquiring single-point measurement time sequence parameters of laser vibration measurement equipment, step 2, measuring response characteristics of an audio excitation device, and determining pre-stabilization time required by an audio excitation signal from starting to reaching a stable amplitude; step 3, constructing an on-off keying modulation function, generating a digital gating function according to the time sequence parameter and the pre-stabilization time, and performing time domain multiplication on the audio excitation signal and the digital gating function to generate a modulated intermittent audio excitation signal; and 4, controlling the audio excitation device to play intermittent audio excitation signals, and synchronously triggering the laser vibration measurement equipment to scan and collect the measurement points on the surface of the object to be measured according to the time sequence parameters. Through the on-off keying digital modulation technology, audio excitation can be started only in the effective detection time period of laser vibration measurement, and therefore the average noise level and equipment power consumption are remarkably reduced.

The invention relates to the technical field of fiber laser cutting, in particular to a high-precision fiber laser metal plate cutting method and system, and the method comprises the following steps: obtaining an original capacitance value of a capacitive induction ring; the original capacitance value of the capacitive induction ring is separated into an average capacitance value and a high-frequency vibration signal; extracting a vibration amplitude from the high-frequency vibration signal; according to the non-linear relation between the capacitance value and the distance of the capacitive induction ring, the vibration amplitude and the average capacitance value, direct current deviation caused by high-frequency vibration is calculated; subtracting the direct current deviation from the average capacitance value to obtain a corrected average capacitance value; and controlling the distance between the nozzle and the metal plate according to the corrected average capacitance value. And the cutting quality and the size precision can be improved.

The invention relates to the technical field of rock mass mechanical property detection and stability evaluation, and discloses a rock mass stability quantitative evaluation method based on disturbance stress and fracture evolution, and the method comprises the steps: collecting the amplitude spectrum of a target rock mass; monitoring and separating internal fracture sound of the target rock mass to obtain fracture frequency; performing amplitude interference analysis on the target rock mass based on the amplitude spectrum and the fracture frequency to obtain a vibration interference factor of the target rock mass; and performing humidity compensation on the vibration interference factor based on the humidity degree in the target rock mass to obtain an environment compensation factor of the target rock mass, predicting the fracture state of the target rock mass based on the environment compensation factor and the inherent strength parameter of the target rock mass, and generating a stability evaluation report of the target rock mass based on the fracture state. According to the method, the problems that in existing rock mass stability evaluation, disturbance stress and fracture evolution dynamic association is not effectively combined, environmental interference is neglected, strength verification is lacked, and evaluation accuracy and reliability are insufficient can be solved.

The invention discloses a drill rod signal transmission monitoring control method, which comprises the following steps: capturing drill rod axial vibration waveform and peripheral magnetic field vector change data in real time, analyzing and marking potential resonance frequency points, calculating magnetic field intensity break variable, and judging a geomagnetic anomaly region; determining the relevance between a resonance frequency point and geomagnetic mutation through time alignment processing, and separating and coupling interference signals; generating an anti-phase damping wave according to the resonance frequency point, dynamically adjusting the amplitude, and injecting a pre-compensation phase to counteract carrier offset; the signal-to-noise ratio and the phase error after suppression are calculated in real time, and a parameter readjustment process is triggered to ensure the suppression effect; when the rock drilling vehicle enters a new rock stratum, parameters are automatically recorded and updated to adapt to different rock stratum interference characteristics; the drilling stability and the signal quality are obviously improved, and the equipment loss and the maintenance cost are reduced.

The invention discloses a non-linear aerodynamic damping identification method and system for self-excitation hysteresis vibration and a storage medium. The method comprises the steps that structure wind-induced vibration response data is acquired; aerodynamic damping is modeled as a non-monotonic high-order function about the amplitude, and an expansion state vector and state space model containing damping parameters and load items is constructed; performing recursive estimation on the state vector by using a filtering algorithm, and synchronously identifying a damping parameter; calculating a damping-amplitude curve according to the parameters; a full-amplitude domain splicing strategy is adopted, a small-amplitude interval high-precision recognition result is fused to correct the large-amplitude interval recognition curve, and a high-precision target damping curve is obtained; by analyzing the intersection point and slope of the curve and the structural damping line, stable and unstable balance points are identified. The method solves the problems that a traditional method cannot accurately describe the multistable hysteretic phenomenon and the recognition precision of a small amplitude interval is insufficient, and high-precision recognition of nonlinear aerodynamic damping and quantitative analysis of a hysteretic mechanism are achieved.

The utility model relates to the field of vibration discs, and discloses a vibration disc capable of discharging stably, which comprises a vibration base I and a classifier base, the vibration base I is provided with a buffer mechanism and a vibration mechanism, and the classifier base is provided with a roller feeding classifier. Vibration energy is effectively absorbed and noise and vibration are reduced through rotating connection, the vibration mechanism is linked through a belt wheel, a belt, a motor and a rotating shaft and is matched with a limiting column, a spring and a roller to form a vibration system, the periodic contact of a rotating shaft protruding block and the roller is combined with the reset function of the spring, the vibration amplitude and frequency are flexibly adjusted, and energy consumption is reduced. According to the integrated roller feeding sorter, automatic sorting and conveying are achieved through the sliding rail, the separating structure and the sorting track, the sorter is flush with the vibration base to ensure smooth transition of materials, deviation and collision are prevented through the limiting plate and the rubber pad, and the conveying stability, the automation degree and the yield are remarkably improved.

The invention belongs to the technical field of shock absorption of building structure engineering, and provides an adjustable resonance suppression method for a floorboard, and the method comprises the steps: deploying a vibration sensor on the floorboard, obtaining a vibration signal in real time, and carrying out the analysis, so as to precisely recognize a dominant excitation frequency, a transmission path of vibration energy, and the contribution degree of the transmission path; the contribution degree of a transmission path and the vibration amplitude of a floor plate are taken as optimization targets, meanwhile, the parameter constraint space of the adjustable steel support is taken into consideration, and it is ensured that the generated tuning parameter combination meets the suppression requirement and meanwhile adapts to the structural bearing capacity of the adjustable steel support; driving the adjustable steel support to perform grading adjustment, obtaining feedback data after grading adjustment, and recalculating the contribution variation of the transmission path and the amplitude attenuation rate of the floor plate; and when the regulation and control effect does not reach the standard, the solution parameter of the optimization function and the analysis parameter of the vibration signal are correspondingly adjusted, so that the suppression method is ensured to have good dynamic adaptability, and the stable resonance suppression effect can be continuously maintained.

The invention discloses a method for analyzing the internal dynamic response of a rock-filled foundation with an ultra-large particle size in the rolling process of a road roller. The method comprises the following steps: step 1, evaluating the uniformity of a time sampling interval; step 2, filtering the collected vibration signals under the two working modes of weak vibration and strong vibration of the road roller respectively; step 3, outputting the filtered time domain signal data according to an Excel file format; 4, calculating a time interval standard deviation of the data, and evaluating the uniformity of a time sampling interval; 5, signal preprocessing is carried out; 6, arranging the data and storing the data to a specified path; and 7, analyzing the influence of the filling thickness and the number of rolling times on the vibration energy in the foundation and the change rule. The method has the advantages that spatial distribution and change rules of vibration acceleration, vibration amplitude and vibration energy in the high-fill roadbed can be truly reflected, and the method can be effectively used for prediction and analysis of dynamic response change rules in high-fill roadbed filling.

The invention discloses a linear friction welding machine vibration compensation control method based on iterative learning, and the method comprises the steps: collecting a vibration signal of an electro-hydraulic servo vibration system of a linear friction welding machine in a welding process, determining a vibration amplitude, frequency and vibration center deviation, and when the vibration amplitude or the center deviation exceeds a preset threshold value, starting the linear friction welding machine; the controller starts vibration compensation control; an electro-hydraulic servo vibration system model is established, the rigidity characteristic and the dynamic load change of the system are comprehensively considered, an iterative learning control law of a controller is designed, and control convergence conditions are analyzed to ensure the stability and the high efficiency of control; based on the output of the controller, the error trend of the vibration signal is predicted in real time in combination with historical iteration data, and a feed-forward control signal is generated through a feed-forward compensation mechanism to adjust the vibration signal error in advance. According to the method, the iterative learning is applied to the vibration compensation control of the linear friction welding machine, so that the precise compensation of the vibration signal is realized.

Vibration sensors are provided. The vibration sensor may include: a vibration assembly, the vibration assembly including a mass element and an elastic element, and the mass element being connected to the elastic element; a first acoustic cavity, the elastic element constituting one of sidewalls of the first acoustic cavity, and the vibration assembly vibrating to make a volume of the first acoustic cavity change in response to an external vibration signal; an acoustic transducer, the acoustic transducer being in communication with the first acoustic cavity and the acoustic transducer generating an electrical signal in response to a volume change of the first acoustic cavity; and a buffer, the buffer limiting a vibration amplitude of the vibration assembly, wherein the acoustic transducer has a first resonance frequency, the vibration assembly has a second resonance frequency, and the second resonance frequency of the vibration assembly is smaller than the first resonance frequency.

The invention relates to the technical field of steam feed pump monitoring, and discloses a steam feed pump running state monitoring method and system based on multi-parameter fusion. The method comprises the steps that multi-dimensional real-time parameters such as vibration amplitude, bearing temperature, inlet and outlet pressure difference, rotating speed fluctuation quantity and medium flow change rate in a continuous operation period are collected; according to the vibration amplitude time domain distribution and frequency domain energy ratio vibration anomaly grade, the temperature anomaly grade is determined by combining the bearing temperature rising slope, a pressure-rotating speed coupling coefficient is generated based on the coupling relation of the inlet and outlet pressure difference and the rotating speed fluctuation quantity, and the flow stability index is calculated through the deviation degree of the medium flow change rate and the historical reference flow. Integrating to generate a comprehensive degradation degree index; identifying steady state, transition state and critical state operation switching nodes according to the dynamic trend of the index; clustering grouping parameters, extracting state characterization parameters, and inputting a degradation prediction model to output a residual service life prediction value.

The invention relates to the technical field of ultrasonic bonding, in particular to an ultrasonic adjusting method of a bonding system, which comprises the following steps of: acquiring voltage and displacement waveforms, analyzing a power trend, shielding a main window if a rising proportion is high and displacement exceeds a limit, extracting a maximum displacement point frequency to divide a standby window, and generating standby configuration by combining an impedance library. And monitoring peak time difference fluctuation and offset, calling configuration and matching a displacement time sequence generation instruction, monitoring displacement stability to be matched with pressure, setting a standby window as a main window if the condition is met, and generating a reconstruction mark. According to the method, the driving voltage and the transducer displacement waveform are continuously monitored, the power trend and the displacement fluctuation are analyzed in real time, the peak time difference fluctuation is synchronously monitored, the abnormal working conditions are screened to trigger the driving strategy switching, and the main frequency band is reconstructed according to the steady-state displacement characteristics. Pseudo soldering and material damage are avoided, the vibration energy utilization rate is improved, and the bonding pressure control precision and the connection strength are guaranteed.

A classifying apparatus performs: acquiring a waterfall data that indicates amplitude of vibration for each point in time and for each sensing point in a vibration sensor that is placed along a target object; performing semantic segmentation on the waterfall data to generate a class data that indicates a normal class or an abnormal class for each element of the waterfall data; and classifying the sensing points into a monitoring point and a non-monitoring point. The normal class is assigned to the element whose sensing point is predicted to be the monitoring point. The abnormal class is assigned to the element whose sensing point is predicted to be the non-monitoring point. The monitoring point is the sensing point that is placed along the target object. The non-monitoring point is the sensing point that is not placed along the target object.

The invention discloses a dynamic evaluation method for physical constitutive and reliability of bridge vibration along a time axis, and relates to the technical field of dynamic evaluation of bridge reliability along the time axis, and the method comprises the steps: building a loss function of a physical information driving model through a vibration equation of a bridge and initial conditions and boundary conditions of the vibration equation of the bridge; a feasible region of a sample point is divided into a plurality of feasible region units to obtain a training sample of a physical information driving model, after the physical information driving model is trained, the amplitude on a bridge is predicted, and a system performance function is established to obtain the dynamic failure probability of the bridge along a time axis. According to the method, the amplitude of the bridge is predicted by using a physical information driving model, the problem that the traditional reliability dynamic evaluation along the time axis needs to depend on a large amount of simulation calculation to obtain samples is solved, and the calculation cost is effectively reduced. By adopting a dynamic resampling method, higher training speed and higher performance response calculation precision can be obtained.

The invention discloses an ultrasonic vibration auxiliary milling method for a Ti2AlNb material, and belongs to the technical field of alloy material machining. The method comprises the following steps: removing a surface oxide layer from a Ti2AlNb material piece; the Ti2AlNb material piece is subjected to longitudinal-torsional composite ultrasonic vibration auxiliary milling machining; wherein the longitudinal-torsional composite ultrasonic vibration is used for assisting milling, and the vibration parameters of the longitudinal-torsional composite ultrasonic vibration are as follows: the torsional vibration tangential line amplitude is 4-8 microns, the ultrasonic frequency is 20-30 kHz, the longitudinal vibration amplitude is 3-6 microns, and the phase difference is 90 degrees. According to the method, the Ti2AlNb material piece with the machining surface small in roughness value and large in residual compressive stress value is finally obtained, harmful tensile stress of the machining surface obtained through pure milling machining is converted into compressive stress, generation of microcracks can be effectively restrained, and the service life of the material is prolonged.

The invention relates to a system for determining the compaction of a flowable, solidifiable building material, in particular concrete, during the production of a structural element with the building material, wherein the flowable building material is introduced into a formwork system (10), comprising: at least three sensors (S1, S2, S3) to determine an amplitude (A S1 , A S2 , A S3 ) a vibration introduced into the flowable building material by a vibration unit (VE), wherein the sensors (S1, S2, S3) are arranged on the formwork system (10), at least one computing unit that is set up to perform calculations based on the amplitudes (A) determined by the at least three sensors (S1, S2, S3). S1 , A S2 , A S3) to calculate possible positions (D1, D2, D3) of the vibration unit (VE) relative to the respective sensors (S1, S2, S3) and, based on this, to triangulate the current position of the vibration unit (VE) relative to the formwork system (10), a documentation unit for documenting the dwell time of the vibration unit (VE) in the respective current positions of the vibration unit (VE) relative to the formwork system (10), the computing unit determines a calculated compaction value in the respective current positions based on the respective current positions of the vibration unit (VE) and the documented dwell time in the respective current positions.

The invention relates to the technical field of power monitoring and early warning, in particular to an intelligent external damage prevention warning method and device for a cable path, and the method comprises the steps: deploying sensing nodes along the cable path, cooperatively sensing a vibration signal through multiple sensors, such as an MEMS acceleration sensor and a positioning module; and through combination of vibration wave propagation direction verification, amplitude attenuation mode verification and multi-feature fusion intelligent verification, accurate risk discrimination is realized. According to the method, the AI recognition model can be dynamically optimized through an incremental learning mechanism, and the adaptive capacity of the system is improved; the service life of equipment is prolonged by adopting an event-driven low-power-consumption strategy, and the monitoring coverage precision is improved through node layout optimization. The method significantly reduces the false alarm rate, enhances the accuracy and real-time performance of cable path external damage risk monitoring, and is suitable for an intelligent external damage prevention scene of an urban power distribution network.

The invention discloses a rotor vibration adjustment prediction method and system based on deep learning, and belongs to the technical field of rotor vibration control. The method comprises the following steps: receiving a vibration amplitude, a phase, a blade number and geometric parameters; analyzing the phase into sine and cosine components, interacting with a vibration value, converting geometric parameters into physical characteristics such as a span-chord ratio and rotational inertia, and constructing a 31-dimensional characteristic vector; a multi-layer perceptron model is trained for 2-8 blades, the input of the multi-layer perceptron model is the 31-dimensional feature vector, and the output of the multi-layer perceptron model is the balance weight adjustment amount of each non-reference blade; and performing feature processing on real-time data, inputting the processed data into a corresponding model, obtaining a prediction scheme, and estimating the vibration reduction amount. According to the method, high-precision, rapid and self-adaptive rotor vibration prediction and adjustment are realized by fusing a physical mechanism and deep learning, and the maintenance efficiency and the flight safety are remarkably improved.

Systems and methods for monitoring underwater structures are provided. First and second sets of point cloud data that are obtained at different times are compared to determine whether the location of the underwater structure has changed. For detecting vibration, a series of range measurements taken along a line intersecting the underwater structure are compared to one another to determine an amplitude and frequency of any vibration present in the underwater structure. For detecting temperature, the ratio of different components of return signals obtained from a point in the water surrounding the underwater structure is measured to derive the temperature of the water. Leak detection can be performed by scanning areas around the underwater structure. Monitoring systems can include a primary receiver for range measurements, and first and second temperature channel receivers for temperature measurements.

The invention discloses an active vibration reduction damper for oil field drilling, and belongs to the technical field of oil field drilling equipment, the active vibration reduction damper comprises an upper damping shell and a lower damping shell, the upper damping shell and the lower damping shell are mutually sleeved, and a grouting conveying pipe is arranged in the upper damping shell and the lower damping shell; a driving rod frame is installed on the grouting conveying pipe, a primary vibration reduction assembly and a multi-stage vibration reduction assembly are arranged in the lower damping shock absorption shell, a fixing disc is arranged above the primary vibration reduction assembly and the multi-stage vibration reduction assembly, and the fixing disc is fixedly connected into the upper damping shock absorption shell. By means of the primary vibration reduction assembly, the vibration reduction requirement can be met when the vibration amplitude is small, when the vibration amplitude exceeds a preset threshold value, the multi-stage vibration reduction assembly is started to achieve stepped step-by-step vibration reduction, the overall vibration reduction capacity is improved, the problem of vibration reduction failure caused by dynamic changes of the vibration amplitude in the well drilling process is effectively solved, and stable operation of well drilling equipment is guaranteed.

The present invention discloses a high-frequency, small-amplitude vibration-assisted laser cladding apparatus and method for large workpieces. In the apparatus, parallel wavy cams are installed coaxially and with equal phase difference and mounted on the main shaft of an upper stationary box. The wavy cams are short-amplitude outer linear cams. The parallel wavy cams and corresponding cantilever beams form a vibration source. The corresponding cantilever beam assemblies are mounted inside a lower movable box. The upper stationary box assembly and the lower movable box assembly form a closely spaced movable pair. The lower movable box is mounted on a vibration receiving plate. The right end of the high-natural frequency spring is fixedly supported by a pair of high-natural frequency springs, the lower end of which is fixedly supported by a frame. The wavy cams are driven by a motor via a pulley. The amplitude of the processed workpiece can be adjusted according to needs, and the vibration frequency of the processed workpiece can be changed by changing the number of wavy cams and the corresponding cantilever beams. This method is particularly applicable to grain refinement, stress relief, homogeneous phases, and forged structure formation through vibration-assisted laser cladding.

The invention provides a method for a wind turbine, having rotor assembly including a rotor hub and rotor blades, to be performed when the rotor assembly is in a partially installed state in which one or more of the rotor blades is finally installed in the rotor hub and one or more of the rotor blades is in a pre-installed state relative to the rotor hub. The method includes receiving sensor data indicative of vibrations of the rotor blade(s) finally installed in the rotor hub, and determining, based on the received sensor data, whether an amplitude of the vibrations of the rotor blade(s) finally installed in the rotor hub exceeds a defined threshold amplitude. If the vibrations amplitude exceeds the threshold amplitude, then the method includes outputting a signal for adjusting pitch of at least one of the finally installed rotor blades to reduce the vibrations amplitude.

A vibratory compaction machine includes a chassis, at least one drum, and a control system. The at least one drum is rotatable about an axis that faces in a Y-axial direction and is mounted to the chassis to allow rotation of the drum over a work surface. The at least one vibration mechanism is configured to generate vibrations that are transmitted as impacts directed in a Z-axial direction by the at least one drum to the work surface. The at least one vibration mechanism is provided with a plurality of different amplitude settings. The control system is configured to measure acceleration forces of the at least one drum in a direction that substantially corresponds to an X-axial direction, wherein the acceleration forces are generated by the vibration mechanism and the X-axial direction extends in a direction that is substantially orthogonal to the Y-axial direction and the Z-axial direction.

A system for vehicle exterior noise reduction, comprising: a measuring component for measuring an amplitude and a phase of an exterior noise, the exterior noise propagating at least partially in a first direction from at least one exterior noise source of a vehicle and having an acoustic transmission path, wherein the exterior noise propagates at least partially below a bottom of the vehicle; a computing component for computing an out-of-phase signal based at least in part on the measured amplitude and phase of the exterior noise; and a generating component for generating an out-of-phase sound based at least in part on the computed out-of-phase signal, the out-of-phase sound configured to cancel the exterior noise, wherein the generated out-of-phase sound propagates at least partially in the first direction of the acoustic transmission path.