83 results about "Nonlinear vibration" patented technology

The invention discloses a machine tool control method and system based on mechatronics, and the method comprises the steps: outputting an optimal cutting track sequence according to the three-dimensional model features and material attribute parameters of a machined workpiece; based on the optimal cutting track sequence, motion interference among shafts of the machine tool is eliminated through dynamic weight distribution, and an anti-interference optimization machining instruction is generated; constructing a nonlinear vibration wave propagation model according to the coupling relation between the spindle rotating speed and the feeding speed, and generating a steady speed regulation and control signal; generating an energy efficiency optimal parameter set including motor torque, cooling power and lubricating frequency based on the energy consumption efficiency constraint condition and the steady speed regulation and control signal; and outputting a closed-loop control signal and synchronously updating the three-dimensional machining precision thermodynamic diagram according to the real-time data in the machining process and the predicted deviation of the digital twin model. According to the embodiment of the invention, global optimization, dynamic adaptation and efficient operation of the machine tool can be realized, and technical support is provided for intelligent upgrading of the modern manufacturing industry.

The invention relates to a working condition following gear wear monitoring and predicting method based on a vibration signal, belongs to the technical field of gear transmission, and solves the problem that influence of different working conditions and different wear states of different positions of a gear cannot be considered in gear wear monitoring and prediction in the prior art. Comprising the following steps: S1, establishing a working condition Map graph based on dynamic working condition division of multi-source sensor fusion, and updating the working condition Map graph in real time; s2, establishing an Archard wear correction model, and calculating the wear extent of the gear; s3, establishing a gear nonlinear vibration model considering wear and clearance influence, and solving a vibration signal of a gear system; s4, a CNN-LSTM mixed wear diagnosis model is established, and training is carried out; and S5, acquiring and processing in real time to obtain a vibration signal of the gear system, and inputting the vibration signal into the CNN-LSTM mixed wear diagnosis model to obtain the current wear state probability distribution of the gear and the wear development trend prediction of the gear.

The present application provides a linear vibration motor, including a casing, a stator and a vibrator accommodated in the casing, and an elastic member for suspending the vibrator in the casing. The vibrator includes a mass block having a through-hole, and a magnetic circuit system. The magnetic circuit system includes a first magnetic steel arranged on one side of the stator and a second magnetic steel arranged on the other side of the stator. The first magnetic steel and the second magnetic steel are extended in parallel and arranged centrally symmetrically around a geometric center of the stator. The first magnetic steel includes a first magnetic steel portion, and the second magnetic steel includes a second magnetic steel portion. The asymmetric magnetic circuit structure can improve the nonlinear vibration when the stator is offset during the arrangement, which is helpful for improving the stability and yield of the test.

An ultrasonic surgical tool system with a tip capable of simultaneously vibrating in plural modes. The system includes a console capable of supplying a drive signal to the tip that includes plural components. Each component has a frequency characteristic that is based in part on the equivalent of current through the mechanical components of the tip. The frequency components are different from each other. Based on the application of drive signal the tip undergoes non-linear vibrations.

The invention discloses a low-frequency double-nonlinear quasi-zero-stiffness energy harvesting vibration isolator, and belongs to the technical field of nonlinear vibration control and energy harvesting. Comprising a supporting frame, an upper platform and a lower platform are horizontally installed on the supporting frame, and two vertical optical shafts are symmetrically installed and penetrate through the upper platform and the lower platform; the loading platform is used for bearing a vibration-isolated object and is mounted on the upper platform; the nonlinear negative stiffness structure is a bionic skeleton X-type mechanism arranged between the upper platform and the lower platform and provides negative stiffness restoring force; the non-linear positive stiffness structure is connected with the non-linear negative stiffness structure in parallel and provides restoring force which is non-linearly changed along with displacement; the energy harvesting unit comprises a copper film arranged on the inner side face of the supporting frame and a polytetrafluoroethylene film arranged on the outer side face of the upper platform, and the copper film and the polytetrafluoroethylene film form a friction nanometer generator. The problems that in the prior art, energy harvesting and ultralow-frequency vibration isolation energy harvesting cannot be carried out in a wider working frequency band are solved, and the vibration isolation energy harvesting efficiency can be effectively improved.

The application discloses an adjustable nonlinear dynamic vibration absorber and system, and has the technical scheme that a tuning mass block is slidably connected to the surface of a support plate, and first scissor structures are rotatably connected between the tuning mass block and the two ends of the support plate; the first scissor structures are provided with second scissor structures and dampers, the second scissor structures and the dampers can drive the first scissor structures to stretch and contract through elastic belts, the second scissor structures are provided with elastic elements for driving the second scissor structures to stretch and contract; the stretching direction of the elastic elements is parallel to the sliding direction of the tuning mass block, and is perpendicular to the damping direction of the dampers, so that the first scissor structures and the second scissor structures can realize vibration absorption through geometric nonlinearity when moving. The stiffness and damping characteristics of the application can be adjusted, and the linear elements can be used to realize nonlinear stiffness, damping and super-low natural frequency, and the problem of Duffing system instability that cannot be eliminated by traditional nonlinear vibration absorbers is solved.

The invention relates to the technical field of electromagnetic measurement, in particular to a method for increasing a constant-speed section in motion of a power balance coil by introducing nonlinear vibration, and the method comprises the steps: introducing an odd harmonic current component meeting a first target condition into a drive coil of a target power balance, and carrying out the initial compensation of the coil, generating an initial coil speed curve, meeting a preset flat condition, of the coil according to the initial compensation result, and introducing a second harmonic current component meeting a second target condition into the driving coil based on the initial coil speed curve to carry out at least one secondary compensation, and generating at least one coil speed curve of the coil according to the at least one secondary compensation result, and determining that the coil moves in the target constant-speed section when the fluctuation quantity and the gradient of the at least one coil speed curve meet preset standards. Therefore, the problems that in the prior art, a coil movement speed curve is prone to fluctuating and inclining, and the accuracy and repeatability of a power balance measurement result are reduced are solved.

The invention discloses a nonlinear acoustic transducer control method and system based on an Aubry-Mather set, and belongs to the technical field of acoustic transducers. The method comprises the following steps: firstly, based on an Aubry-Mather set theory, constructing a nonlinear vibration model used for describing nonlinear vibration of a transducer diaphragm; secondly, based on a nonlinear vibration model, regional piezoelectric driving and dynamic phase regulation are carried out to simulate a quasi-periodic fluctuation mode; then, on the basis of fluctuation characteristics disclosed by the nonlinear vibration model, a multi-diaphragm collaborative vibration system is constructed, and quasi-periodic superposition of sound waves is realized by optimizing diaphragm space layout; and finally, based on stiffness parameters in the nonlinear vibration model, integrating a micro electro mechanical system (MEMS) process and a nonlinear material, and realizing equivalent nonlinear stiffness on a physical device through gradient polarization design. The dynamic adaptability, the energy transfer efficiency and the high-frequency output performance of the transducer in a broadband range are effectively improved, and the transducer is particularly suitable for ultrasonic imaging and other high-frequency acoustic application scenes.

The present invention discloses a variable-section arch nonlinear vibration damping device for a rotor system, comprising a disk, a rotating shaft, a variable-section arch, a rigid ring, and a limiting pin. The rotating shaft is mounted at the center of the disk, and an annular groove coaxial with the disk is provided on the side of the disk. A plurality of variable-section arches are evenly distributed circumferentially and assembled on the inner side of the annular groove. The rigid ring is separated from the variable-section arch by a predetermined distance and is located in the annular groove and on the outer side of the variable-section arch. The rigid ring is connected to the arch top of the variable-section arch by a limiting pin to limit the relative position of the arch top of the variable-section arch and the rigid ring, thereby preventing the contact position of the variable-section arch with the rigid ring from changing when the variable-section arch is deformed too much, and ensuring that the force application point of the variable-section arch is consistent under different deformations. The present invention can effectively suppress the vibration amplitude of the rotor system within a wide speed range, occupies less space than traditional nonlinear spring vibration damping devices, and is suitable for installation in rotor systems with limited space.

The present application belongs to the technical field of bridge wind tunnel test device, and provides a kind of wind tunnel test device simulating nonlinear vibration of bridge structure, including rigid model, rigid rod, rigid circular arc suspension arm, linear tensile spring, nonlinear elastic element and light high-strength fine rope.Nonlinear elastic element can adopt cable structure, membrane structure, nonlinear tensile spring, mechanical super material or superstructure.By designing the nonlinear stiffness characteristics of nonlinear elastic element, the layout mode and the combination mode of linear tensile spring, various target nonlinear stiffness modes can be realized to carry out large amplitude vertical torsional coupled flutter test of bridge structure under nonlinear stiffness.In the process of large amplitude vibration of model, the center hanging point of nonlinear elastic element and linear tensile spring can always maintain vertical displacement and deformation, and the device can ensure stable stiffness, damping, mass and mass moment characteristics.

The application discloses a double-coil structure electromagnetic damping nonlinear vibration isolator, which comprises a rigid structure and a damping structure matched with each other; the damping structure comprises a top cover, a first left limiting part, a first right limiting part, a first magnetic material, a first coil, a second right limiting part, a base, a second coil, a second left limiting part, a second magnetic material, a base connecting shaft and a part connecting shaft; the first left limiting part, the second left limiting part, the first right limiting part and the second right limiting part are arranged on the base. The nonlinear electromagnetic vibration isolator has the characteristics of damping nonlinearity, adjustable damping and function conversion, and the reliability problem of the ordinary nonlinear vibration isolator under the working condition of low-frequency large amplitude vibration is solved through the damping end, so that the vibration isolator has a better vibration isolation effect under the low-frequency working condition.

The utility model provides a chimney damping device, which belongs to the technical field of chimney damping, and comprises a mounting assembly and an adjusting assembly, the mounting assembly comprises a mounting track annularly arranged on the periphery of a chimney and a mounting seat slidably connected to the mounting track, and the mounting track is connected to the chimney; the adjusting assembly comprises a fixing rod connected to the mounting base and a balance weight mechanism connected to the fixing rod, the fixing rod extends in the radial direction of the mounting rail, and the balance weight mechanism is located at the end, away from the mounting base, of the fixing rod. The balance weight mechanism comprises a balance weight block connected to the fixing rod in a sliding mode and two elastic pieces connected to the balance weight block, and the two elastic pieces are arranged on the two sides of the balance weight block respectively along the extending path of the fixing rod. The utility model provides a chimney damping device which aims at solving the problem that when an existing tuned mass damper faces nonlinear vibration, the damping effect of the damper is poor.

The invention discloses a motor bearing performance degradation state evaluation method and system, and relates to the technical field of bearing performance evaluation, and the method comprises the following steps: building a time-frequency response mapping model of a rolling body fatigue micro-crack region, and calculating the performance degradation state of a motor bearing according to a vibration signal, rotation speed fluctuation and load change of the motor bearing in the operation process; extracting an energy distribution curve of the micro-lag region, and constructing a multi-scale phase delay matrix according to the energy distribution curve; and constructing a local energy coupling identification network based on a phase delay matrix output by the time-frequency response mapping model. Accurate identification and early degradation prediction of motor bearing microcrack energy behaviors are realized through time-frequency mapping and a phase delay matrix, and self-healing adjustment and closed-loop control of an energy field are realized through a self-adaptive phase inversion and anti-lag compensation mechanism, so that nonlinear vibration instability is effectively inhibited; the running stability and the service life of the bearing are obviously improved.

The nonlinear vibration isolator containing electromagnetic damping and crank rocker mechanism of the present application comprises a crank rocker, a base, a base rear cover, a first magnetic material and a second magnetic material; the first magnetic material and the second magnetic material are fixedly arranged on the base, are sleeved with the base and are embedded in a cavity of the base containing a rotor, and the base is screwed with the base rear cover. The vibration isolator can select the nonlinear form of stiffness and damping according to the working load, and the electromagnetic damping has no friction resistance, so that the vibration isolator has superior reliability and applicability.

The invention discloses a parameter regulation and control method for a nonlinear vibration absorber of a thin-wall component, which comprises the following steps of: acquiring signal data of a piezoelectric module under the control of an external acting force of a piezoelectric plate for driving a thin-wall component plate module and the piezoelectric module; based on the bias input voltage, the signal data sequentially passes through the circuit module and the control module to obtain the control input voltage and the control output voltage of the control module and the bias output voltage of the circuit module; based on the signal data and the external acting force, parameters of an equivalent circuit are obtained through the thin-wall structure dynamic model and the control model, and the parameters of the equivalent circuit are used for regulating and controlling parameters of the nonlinear vibration absorber; and based on the signal data, the control input voltage, the control output voltage, the bias input voltage and the bias output voltage, linear parameters and nonlinear parameters of the control module are obtained, so that the nonlinear parameters are matched with capacitance parameters in the parameters of the equivalent circuit, and the linear parameters are matched with inductance parameters and resistance parameters in the parameters of the equivalent circuit.

The present application belongs to the technical field of structure vibration isolation and reduction, and particularly relates to a vertical quasi-zero stiffness limiting vibration isolation device with adjustable load. The device comprises a bearing plate, an upper limiting plate, a lower limiting plate, a positive stiffness mechanism, a negative stiffness mechanism, a connecting rod and an adjusting support part. The positive stiffness mechanism is arranged between the bearing plate and the upper limiting plate, and the negative stiffness mechanism and the adjusting support part are arranged between the upper limiting plate and the lower limiting plate. The adjusting support part comprises four supporting cylinders and eight round-hole sliders. The connecting rod connects the positive stiffness mechanism and the negative stiffness mechanism, and a central connecting block is arranged on the connecting rod. One end of the negative stiffness mechanism is connected with the central connecting block, and the other end is connected with a round-hole slider. By adjusting the pre-compression coefficient of the inclined elastic element of the negative stiffness mechanism, the stroke of the round-hole slider and the position of the central connecting block on the connecting rod, the quasi-zero stiffness characteristic is maintained at the initial static force balance position, and the nonlinear vibration isolation effect of high static stiffness and low dynamic stiffness is realized.

The application provides a risk domain control method and system based on train formation operation risk cause analysis, belongs to the technical field of train operation control, and realizes real-time perception of formation state information, realizes adjacent train state information interaction based on vehicle-vehicle communication technology, takes low brake anti-skid system efficiency and communication link establishment failure between formation trains as a risk source, takes train formation collision as an accident result, constructs a risk situation propagation model by using a dynamic Bayesian network, and performs sensitivity analysis and sorting on each risk node, uses nonlinear vibration theory and Rayleigh equation to describe vibration characteristics and a micro evolution process in the change of the risk situation, takes the sensitivity weight value of the node most influencing the collision accident occurrence probability as a damping coefficient of the Rayleigh equation, and explores the relationship between the control variable and the damping coefficient based on damping control, so that the risk domain converges to an initial safe state. The application can realize risk domain control for train formation operation from a system level.

The application discloses a multi-stable electromagnetic energy capturing vibration absorber, and belongs to the field of vibration suppression and energy capturing. The multi-stable electromagnetic energy capturing vibration absorber comprises a nonlinear vibration suppression device and an electromagnetic multi-stable energy capturing oscillator installed thereon. The nonlinear vibration suppression device is designed based on the technical principle of a quasi-zero stiffness vibration isolator, multi-stable motion is realized through the structural design of the electromagnetic multi-stable energy capturing oscillator, and the vibration energy capturing performance is further improved. The problems that the existing vibration isolation-energy capturing integrated device can only realize single-stable small-amplitude oscillation, vibration energy cannot be fully converted, the potential well width is limited, and large-amplitude motion cannot be realized under low-frequency conditions are solved.

The invention belongs to the technical field of bridge wind tunnel test devices, and provides a wind tunnel test device for simulating nonlinear vibration of a bridge structure, which comprises a rigid model, a rigid rod, a rigid arc suspension arm, a linear extension spring, a nonlinear elastic element and a light high-strength string. The nonlinear elastic element can adopt a cable structure, a membrane structure, a nonlinear extension spring, a mechanical metamaterial or a superstructure. Various target nonlinear rigidity modes can be realized by designing the nonlinear rigidity characteristics and the arrangement mode of the nonlinear elastic elements and the combination mode of the nonlinear elastic elements and the linear extension springs, so that a large-amplitude vertical torsion coupling flutter test under the nonlinear rigidity of a bridge structure can be carried out. In the large-amplitude vibration process of the model, the central lifting point of the nonlinear elastic element and the linear extension spring can always keep vertical displacement and deformation, and the device can ensure stable rigidity, damping, mass and mass moment characteristics.

The invention discloses an HB-AFT-based shell-rotor system model rapid solving method, which comprises the following steps of: establishing a kinetic model of a complex shell-rotating shaft-motor coupling system, firstly performing primary model order reduction based on an intrinsic orthogonal decomposition (POD) method, and then performing model rapid solving based on the HB-AFT method. According to the method, the rotor system has higher calculation efficiency, the complex nonlinear vibration problem can be rapidly solved, and the dynamic behavior mechanism of the core cabin of the complex underwater vehicle can be clarified. Compared with a traditional numerical method, the method has the advantages that an unstable solution can be obtained through the semi-analysis and semi-numerical method, so that researchers are helped to better analyze the vibration phenomenon of the underwater vehicle core cabin system, and then optimization design is conducted on the underwater vehicle core cabin system.

This invention provides a method and system for analyzing the vibration response of an SFD rotor system during acceleration and deceleration. The method includes constructing an SFD rotor system; the SFD rotor system includes an SFD dynamic model, in which stiffness varies with rotational speed; calculating the vibration response of the SFD rotor system sequentially according to the rotational speed changes during acceleration and deceleration; and calculating the vibration response in a nonlinear manner during nonlinear changes. The nonlinear vibration response calculation includes: determining an initial displacement response value; wherein the initial displacement response value is determined based on the displacement responses corresponding to preset rotational speeds before the current speed; obtaining the stiffness and damping values ​​at the current rotational speed based on the SFD dynamic model and the initial displacement response value; and calculating the displacement response value based on the stiffness and damping values ​​at the current rotational speed, thereby obtaining the vibration response analysis results under nonlinear conditions.

In the field of medical wearable devices, the present invention provides a wearable device for suppressing arm tremors, comprising a flexible wristband and a nonlinear vibration suppression component. Four nonlinear vibration suppression components are evenly distributed around the outer wall of the flexible wristband. The nonlinear vibration suppression components are detachably mounted on the flexible wristband. The nonlinear vibration suppression components capture and consume vibration energy through a targeted energy transfer mechanism. The nonlinear vibration suppression components utilize their own strong nonlinear stiffness to form a resonant capture behavior with the natural frequency of the main vibration system, transferring the energy of the main vibration system to the NES through targeted energy transfer and dissipating it through damping. Most of the energy does not return from the NES to the main vibration system, achieving one-way energy transfer, thereby preventing arm tremors.

The invention belongs to the technical field of vibration reduction and noise reduction, and particularly relates to a vibration reduction fastener for rail transit, which comprises a lower base plate, an inter-plate buffer base plate, an upper base plate and at least two limiting components, the lower base plate is provided with at least two positioning bosses; the inter-plate buffering base plate is provided with at least two first positioning holes used for being arranged on the corresponding positioning bosses in a sleeved mode respectively. The upper base plate is arranged above the inter-plate buffer base plate, and the upper base plate is provided with at least two second positioning holes which are respectively sleeved on the corresponding positioning bosses; the at least two limiting assemblies are arranged above the upper base plate and arranged on the corresponding positioning bosses in a sleeving mode, and the limiting assemblies and the positioning bosses are mutually locked in a concave-convex fit mode. Through the integrated pre-assembly design, the concave-convex locking structure, the double-layer nonlinear vibration reduction mechanism and the limiting part function, the problems that in the prior art, the construction efficiency is low, the pre-pressure is not stable, and the vibration reduction effect is poor are solved.

The application discloses a variable center distance split type gear test bench and a nonlinear vibration testing method. The test bench uses a split open gear box design, and the driving gear shaft and the driven gear shaft are respectively arranged on two parallel driving gear boxes and driven gear boxes. The driving gear box shaft system is fixed on the workbench surface and cannot be moved. The driven gear box, the sensor on the coaxial system and the load motor are placed on the movable platform supported by the linear sliding guide rail, so that the center distance between the driving gear shaft and the driven gear shaft can be adjusted. After the center distance is determined, the center distance is locked through the locking mechanism between the box bodies. The application solves the problem that the traditional integrated gear box cannot change the theoretical gear side clearance. The application can be used for observing the meshing impact phenomenon caused by the gear side clearance, the meshing impact occurs in the gear meshing line direction, and can be used for verifying the nonlinear characteristics in the gear box meshing process, such as periodic state, quasi-periodic state and chaotic state.

This invention discloses a variable cross-section arched nonlinear vibration damping device for multi-split conductors, comprising a clamp-type rotary spacer, a variable cross-section arch, a hollow cylindrical pin, and a rigid mass ring. Multiple arc-shaped notches are evenly distributed circumferentially on the inner side of the clamp-type rotary spacer. A variable cross-section arch is rigidly connected to the inner side of each arc-shaped notch, and the outward direction of the arch apex of the variable cross-section arch is opposite to the inward direction of the arc-shaped notch. The rigid mass ring located inside the variable cross-section arch is rigidly connected to the center of the arch apex. This invention obtains different stiffness ranges by changing the structural parameters of the variable cross-section arch, exhibiting strong adaptability, simple structure, and easy installation. All connections are rigid, forming a complete energy dissipation chain: conductor → arch structure → hollow cylindrical pin → rigid mass ring. This broadens the effective vibration damping frequency band and improves vibration energy dissipation efficiency compared to previous methods.

The embodiment of the invention discloses an icing power transmission line galloping determination method and a related device. The method comprises the following steps: acquiring n first working conditions; determining a galloping coefficient of each first working condition; solving a nonlinear vibration equation according to the galloping coefficient corresponding to each first working condition, and determining a first moving distance and a first moving speed of the ice-coated power transmission line corresponding to each first working condition; taking each first working condition and the first moving distance and the first moving speed corresponding to each first working condition as training samples, and training the KAN network through the training samples to obtain a galloping model; obtaining a target working condition; inputting the target working condition into a galloping model, and determining a target moving distance and a target moving speed; and determining the galloping probability of the ice-coated power transmission line according to the target moving distance and the target moving speed. By adopting the embodiment of the invention, when whether the icing power transmission line gallops is determined, the galloping determination efficiency can be improved on the premise of ensuring the galloping determination precision.

Embodiments of the present application relate to the technical field of structural dynamics characteristic analysis, and particularly relate to a method suitable for determining nonlinear response of a plate-shell structure to external excitation of multi-physical field coupling, comprising: determining a relationship between stress and strain of the plate-shell structure; determining a relationship between strain energy, kinetic energy and work done by external force of the plate-shell structure according to the determined relationship; determining the external excitation according to multi-physical fields applied to the plate-shell structure; updating the relationship between the strain energy, kinetic energy and work done by external force of the plate-shell structure according to the external excitation; transforming the updated relationship by using Hamilton's variational principle, and determining the response of the plate-shell structure to the external excitation. The method provided by the embodiments of the present application is beneficial to the study of strong nonlinear vibration characteristics of the plate-shell structure, so as to obtain a nonlinear dynamic response result of the plate-shell structure under multi-physical field coupling with high precision and strong universality, which has great significance for aerospace structural dynamics modeling analysis, vibration reduction and buffering, etc.

The present invention discloses a planar diaphragm for suppressing nonlinear vibrations, comprising an upper washer and a lower washer, a diaphragm assembly being disposed between the upper and lower washers, a groove being provided on the side of the upper and lower washers close to the diaphragm assembly, and a frequency modulation assembly being disposed inside the two grooves to increase the tension of the diaphragm assembly while ensuring the flatness of the diaphragm assembly; the diaphragm assembly comprising a planar diaphragm, the planar diaphragm comprising an A surface and a B surface disposed opposite each other, and the A surface of the planar diaphragm being disposed correspondingly to the upper washer. By providing the diaphragm assembly, the present invention can reduce the mechanical strength difference of the planar diaphragm in the direction intersecting with the conductor coil through a plurality of uniformly distributed reinforcing ribs of uniform length during use of the planar diaphragm, thereby more evenly dividing the vibration, reducing the nonlinear distortion caused by the nonlinear division of the vibration, and improving the use effect of the planar diaphragm.

The invention discloses a quadratic Manhattan entropy calculation method and a nonlinear vibration system complexity measurement method, and belongs to the technical field of rotating machinery fault detection and diagnosis. According to the method, phase-space reconstruction is carried out on an original time sequence, the distance between subsequences is measured by using a quadratic Manhattan distance, the difference between elements is represented by measuring the distance, the similarity of obtained distance values is further represented by introducing a perception function, and finally the quadratic Manhattan entropy is defined through an information entropy theorem. The quadratic Manhattan entropy has good consistency, complexity estimation capability and noise immunity for nonlinear vibration system signals of the rotating machine, and can accurately represent characteristic parameters reflecting fault essence in the vibration signals.

The invention provides a nonlinear vibration coupling analysis method for an aerostatic spindle under sliding mode control, and relates to the technical field of machine tool precision machining. A multi-degree-of-freedom system dynamics model is constructed by performing nonlinear coupling calculation on gas film force, unbalanced magnetic pulling force and mass eccentric excitation. Time-varying nonlinearity of bearing rigidity is accurately described through calculation of dynamic air film force, the two-way coupling effect between an electromagnetic field and mechanical motion is revealed through introduction of unbalanced magnetic pulling force, and complex combined frequency vibration can be generated through interaction of mass eccentricity serving as classical external synchronous excitation and the two kinds of internal excitation. According to the method, the controller design can consider and compensate the nonlinear time variation of the gas film force, the state dependence disturbance of the magnetic pulling force and the eccentric force excitation in advance, the reverse influence of the control action on the gas film stability and the electromagnetic field can be evaluated, and the real mechanical-electric-gas-control collaborative optimization is realized.