Method for testing dynamic comprehensive data of electric cylinder in real time

Abstract

The invention discloses a method for testing dynamic comprehensive data of an electric cylinder in real time, and relates to the technical field of mechatronics test.The method comprises the steps that vibration signals, temperature data and electromagnetic interference data of the electric cylinder are collected and preprocessed, and a multi-modal data stream is generated; defining a spline basis function based on the vibration signal, and extracting a transient feature tensor of the vibration signal by using the spline basis function; constructing a transient environment state transition model based on the multi-modal data stream, inputting the transient characteristic tensor, the temperature data and the electromagnetic interference data into the transient environment state transition model, and generating a displacement compensation amount and a hidden state sequence; and constructing a digital simulation model, inputting the displacement compensation amount into the digital simulation model, and generating multi-physics field coupling simulation displacement. By constructing the spline basis function and the transient environment state transition model, the problem of vibration signal feature distortion is solved, and the extraction precision and the time resolution of the transient impact features are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of mechatronics testing, and particularly to a method for real-time testing of dynamic comprehensive data of an electric cylinder. Background Art

[0002] With the continuous progress of industrial automation and intelligent equipment technology, the electric cylinder, as a high-precision and programmable linear drive device, has been widely used in fields such as aerospace, intelligent manufacturing, and robot systems. In recent years, with the development of sensor technology, edge computing capabilities, and the concept of digital twins, the demand for real-time monitoring and dynamic performance evaluation of the operating state of electric cylinders has been increasing.

[0003] Existing methods for real-time testing of dynamic comprehensive data of electric cylinders usually process vibration, temperature, and electromagnetic interference data independently, lacking cross-modal correlation modeling, resulting in difficulty in accurately capturing the collaborative characteristics of dynamic events such as transient shocks and thermal drifts, insufficient sensitivity to the transient characteristics of non-stationary vibration signals. In addition, current digital simulation models mostly rely on offline calibrated parameters and cannot dynamically correct the model boundary conditions and material properties according to real-time test data, leading to the accumulation of deviations between the simulated displacement and the actual displacement. Summary of the Invention

[0004] In view of the above existing problems, the present invention is proposed.

[0005] Therefore, the present invention provides a method for real-time testing of dynamic comprehensive data of an electric cylinder to solve the problems of inaccurate transient characteristics and cumulative displacement deviation.

[0006] To solve the above technical problems, the present invention provides the following technical solutions: In a first aspect, the present invention provides a method for real-time testing of dynamic comprehensive data of an electric cylinder, which includes collecting vibration signals, temperature data, and electromagnetic interference data of the electric cylinder and performing preprocessing to generate a multi-modal data stream; defining a spline basis function based on the vibration signal and using the spline basis function to extract the transient feature tensor of the vibration signal; constructing a transient environment state transition model based on the multi-modal data stream, inputting the transient feature tensor, temperature data, and electromagnetic interference data into the transient environment state transition model to generate a displacement compensation amount and a hidden state sequence; constructing a digital simulation model, inputting the displacement compensation amount into the digital simulation model to generate a multi-physics field coupled simulation displacement; calculating the displacement deviation between the displacement compensation amount and the multi-physics field coupled simulation displacement, and adjusting the spline basis function and the transient environment state transition model according to the displacement deviation.

[0007] As a preferred solution of the method for real-time testing of dynamic comprehensive data of an electric cylinder according to the present invention, wherein: the steps of performing preprocessing to generate a multi-modal data stream are as follows, Based on the time stamps of the vibration signals, linearly interpolate and align the temperature data and electromagnetic interference data to generate a synchronized data stream; Package the vibration signals, temperature data, and electromagnetic interference data in the synchronized data stream into a multi-modal data stream according to the time stamps.

[0008] As a preferred solution of the method for real-time testing of the dynamic comprehensive data of the electric cylinder according to the present invention, wherein: the spline basis function is defined based on the vibration signal, and the specific steps are as follows. Analyze the spectral energy distribution of the vibration signal, extract the main frequency component, and define the scale factor and order of the spline basis function; Generate the knot vector and control point sequence of the spline basis function based on the main frequency component; Construct the spline basis function according to the scale factor, order, knot vector, and control point sequence.

[0009] As a preferred solution of the method for real-time testing of the dynamic comprehensive data of the electric cylinder according to the present invention, wherein: the transient feature tensor of the vibration signal is extracted using the spline basis function, and the specific steps are as follows. Perform sliding time-domain convolution on the vibration signal using the spline basis function to generate a transient response coefficient matrix; Extract the peak amplitude, rise time, and energy spectrum entropy from the transient response coefficient matrix and combine them into a transient feature tensor.

[0010] As a preferred solution of the method for real-time testing of the dynamic comprehensive data of the electric cylinder according to the present invention, wherein: the transient environmental state transition model is constructed based on the multi-modal data stream, and the specific steps are as follows. According to the transient feature tensor, temperature data, and electromagnetic interference data, define the transient state and environmental state, and merge them into the transient environmental state. Synchronously define the state space by the Cartesian product combination state method; Define the temperature threshold and electromagnetic interference threshold according to the multi-modal data stream, and generate a state classification rule according to the temperature threshold and electromagnetic interference threshold; Based on the state classification rule, count the transition frequencies of the transient environmental states at adjacent moments in the multi-modal data stream, and construct a state transition probability matrix; Based on the multi-modal data stream, count the average value of the displacement compensation amount corresponding to each transient environmental state, and generate a state-compensation amount mapping table; Construct a transient environmental state transition model according to the state space, state transition probability matrix, and state-compensation amount mapping table.

[0011] As a preferred solution of the method for real-time testing of the dynamic comprehensive data of the electric cylinder according to the present invention, wherein: inputting the transient feature tensor, temperature data and electromagnetic interference data into the transient environment state transition model to generate a displacement compensation amount and a hidden state sequence, the specific steps are as follows, Match the transient feature tensor, temperature data and electromagnetic interference data to the nearest transient environment state according to the state classification rule to generate a displacement compensation amount; Arrange the transient environment states at each moment in the order of time stamps to generate a hidden state sequence.

[0012] As a preferred solution of the method for real-time testing of the dynamic comprehensive data of the electric cylinder according to the present invention, wherein: constructing a digital simulation model, inputting the displacement compensation amount into the digital simulation model to generate a multi-physical field coupled simulation displacement, the specific steps are as follows, Establish a three-dimensional geometric structure, define a mechanical-thermal-electromagnetic coupling control equation set on the three-dimensional geometric structure, define the temperature field and electromagnetic field according to the heat conduction equation and electromagnetic field equation, and set the initial value of the temperature field and the boundary conditions of the electromagnetic field according to the hidden state sequence; Construct a digital simulation model according to the three-dimensional geometric structure, the mechanical-thermal-electromagnetic coupling control equation set, the initial value of the temperature field and the boundary conditions of the electromagnetic field; Extract the bearing stiffness parameters through the electric cylinder rule design book, and convert the displacement compensation amount into a compensation force through the bearing stiffness parameters; Iteratively calculate the compensation force according to the order of the temperature field, electromagnetic field and mechanical field to generate a multi-physical field coupled simulation displacement.

[0013] As a preferred solution of the method for real-time testing of the dynamic comprehensive data of the electric cylinder according to the present invention, wherein: calculating the displacement deviation between the displacement compensation amount and the multi-physical field coupled simulation displacement, and adjusting the spline basis function and the transient environment state transition model according to the displacement deviation, the specific steps are as follows, Align the displacement compensation amount and the multi-physical field coupled simulation displacement according to the time stamp, calculate the three-dimensional displacement deviation at each time stamp, and generate a displacement deviation sequence; Calculate the root mean square error and the maximum displacement deviation within continuous time stamps based on the displacement deviation sequence, generate a displacement deviation distribution histogram, and output the displacement deviation statistical result; Based on the displacement deviation statistical result, adjust the spline basis function and the transient environment state transition model through the correction and tuning rule to generate an adjusted spline basis function and transient environment state transition model.

[0014] In a second aspect, the present invention provides a computer device, including a memory and a processor, where the memory stores a computer program, and: when the computer program is executed by the processor, any step of the method for real-time testing of the dynamic comprehensive data of the electric cylinder as described in the first aspect of the present invention is implemented.

[0015] In a third aspect, the present invention provides a computer-readable storage medium, on which a computer program is stored, and: when the computer program is executed by the processor, any step of the method for real-time testing of the dynamic comprehensive data of the electric cylinder as described in the first aspect of the present invention is implemented.

[0016] The beneficial effects of the present invention are as follows: By constructing a spline basis function and a transient environmental state transition model, the problem of vibration signal feature distortion is solved, the extraction accuracy and time resolution of transient shock features are significantly improved, the thermal expansion compensation error under high-temperature working conditions is effectively reduced, and the compensation delay is shortened. By constructing a digital simulation model and optimizing based on the displacement deviation statistics to drive the spline basis function and state transition rules, the cumulative displacement deviation in the simulation is eliminated. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 It is a flowchart of the method for real-time testing of the dynamic comprehensive data of the electric cylinder.

[0019] Figure 2 It is a flowchart of extracting the transient feature tensor.

[0020] Figure 3 It is a flowchart of constructing the transient environmental state transition model.

[0021] Figure 4 It is a flowchart of constructing the digital simulation model and adjustment and optimization. Detailed Embodiments

[0022] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention will be made in conjunction with the drawings in the specification.

[0023] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0024] Secondly, the "one embodiment" or "embodiment" referred to herein means a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The appearances of "in one embodiment" in different places in this specification do not all refer to the same embodiment, nor are they separate or alternative embodiments that are mutually exclusive of other embodiments.

[0025] Referring to Figures 1 to 4 , which is an embodiment of the present invention. This embodiment provides a method for real-time testing of the dynamic comprehensive data of an electric cylinder, including the following steps: S1. Collect the vibration signal, temperature data, and electromagnetic interference data of the electric cylinder and perform preprocessing to generate a multi-modal data stream; S1.1. Connect the acquisition terminals of the vibration signal, temperature data, and electromagnetic interference data to a synchronous clock source, and synchronize the clocks of the acquisition terminals through the Precision Time Protocol; It should be noted that the acquisition terminal refers to installing a piezoelectric vibration sensor on the flange surface at the end of the electric cylinder screw rod for collecting vibration signals, and the vibration signals include three-axis acceleration data; attaching a thin-film temperature sensor to the surface of the motor winding for collecting temperature data; fixing a micro-magnetometer outside the power supply line of the driver for collecting electromagnetic interference data; the range of the piezoelectric vibration sensor is ±50g, and the sampling rate is 10kHz; the Precision Time Protocol refers to the IEEE 1588 protocol. The IEEE 1588 protocol selects a high-precision clock source (GPS atomic clock) as the master clock. The acquisition terminal starts the IEEE 1588 protocol slave mode and calculates the clock offset value. The acquisition terminal adjusts the local clock according to the clock offset value to ensure synchronization with the master clock.

[0026] S1.2. Based on the vibration signal timestamp, perform linear interpolation alignment on the temperature data and electromagnetic interference data to generate a synchronous data stream; It should be noted that based on the 100-microsecond timestamp sequence of the vibration signal, extract the set of time points of all vibration signals; respectively extract the original timestamp sequences and corresponding values of the temperature data and electromagnetic interference data. For each vibration signal time point, find the adjacent time points in the original timestamp sequences of the temperature data and electromagnetic interference data; based on the values of the adjacent time points, calculate the temperature data and electromagnetic interference data of the current vibration signal time point according to the time ratio, and align the calculated temperature data, electromagnetic interference data, and vibration signal according to the timestamp to generate a synchronous data stream.

[0027] S1.3. Package the vibration signal, temperature data, and electromagnetic interference data in the synchronous data stream into a timestamped data packet in JSON format; It should be noted that the field structure of the data packet is defined, including the timestamp field, vibration signal field, temperature data field, and electromagnetic interference data field; traverse the synchronous data stream, extract the vibration signals, temperature data, and electromagnetic interference data at the same time point; assign values according to the corresponding fields and convert them into strings for encapsulation.

[0028] S1.4. Write the data packet into InfluxDB to generate a multi-modal data stream.

[0029] It should be noted that InfluxDB is an open-source database designed specifically for time series data; after receiving the data packet, InfluxDB parses the fields of the data packet and maps the fields to time series points in the InfluxDB data format, and through the HTTP API protocol of InfluxDB, writes the time series points into InfluxDB in batches. The output of InfluxDB is the multi-modal data stream.

[0030] S2. Define spline basis functions based on the vibration signals, and use the spline basis functions to extract the transient feature tensors of the vibration signals; S2.1. Analyze the spectral energy distribution of the vibration signals, extract the main frequency components within a fixed frequency band, and determine the scale factor and order of the spline basis functions; It should be noted that the three-axis acceleration data of the vibration signals are extracted from the multi-modal data stream, a time window with a fixed duration (such as 100 ms) is intercepted and a Hanning window is applied to suppress spectral leakage. The three-axis acceleration data is converted into a frequency-domain amplitude spectrum through the fast Fourier transform (FFT), the energy values (amplitude squared) of each frequency point are calculated, and finally a spectral energy distribution map is generated; the fixed frequency band refers to the typical fault frequency band range calibrated by experiments for the electric cylinder. Within the fixed frequency band, the energy values of all frequency points are sorted in descending order of energy, and the top three frequencies with the total energy ratio exceeding 60% are selected as the main frequency components; the scale factor is dynamically adjusted according to the period of the main frequency components so that the time-domain support of the spline basis function covers two complete periods to match the transient waveform. For example, when the main frequency component is 2 kHz (period 0.5 ms), the scale factor is set to 0.25 ms; the order is fixed at three. S2.2. Generate the knot vector and control point sequence of the spline basis function based on the main frequency components; It should be noted that the main frequency component period is calculated according to the frequency value of the main frequency component, and the node vector interval is allocated according to the period length of the main frequency component. The high-frequency component (short period) corresponds to dense nodes, and the low-frequency component (long period) corresponds to sparse nodes. For example, if the main frequency is 2 kHz (period 0.5 ms), the node interval is set to 1 / 4 of the period length (0.125 ms). Extract the local extreme points of the vibration signal from the three-axis acceleration data, mark the time positions and amplitudes of the local extreme points, normalize the time positions of the local extreme points to the time coordinates of the control points according to the time window of the three-axis acceleration data, and normalize the amplitudes of the local extreme points to the amplitude coordinates of the control points according to the vibration signal acquisition range, generate the control point sequence of the spline basis function, fit the vibration signal waveform by the least squares method, and adjust the control point sequence to make the spline basis function match the transient characteristics. The expression of the spline basis function is, ; where, represents the third-order spline basis function at time ; represents the order, ; represents a certain moment; represents the control point sequence index, and the value range is 0 - ; represents the th control point coordinate in the control point sequence; represents the local basis function; represents the start time of the th node in the knot vector; represents the scale factor, , represents the main frequency component; represents the total number of control points.

[0031] S2.3. Use the spline basis function to perform sliding time-domain convolution on the vibration signal to generate the transient response coefficient matrix; It should be noted that the vibration signal is segmented into segment windows by a dynamic sliding window, and each segment window is arranged in order from left to right along the time axis; the window length of each segment window is consistent with the main frequency component to ensure that the full-cycle waveform of the transient event is captured; the sliding step is consistent with the scale factor to achieve the overlap between segment windows and avoid truncation of the transient event; each segment window covers the complete support interval of the spline basis function, and the convolution matching degree between each segment window and the spline basis function is calculated through time-domain convolution, and a Hanning window is applied to suppress spectral leakage; since different segment windows may have different transient event energies (for example, the amplitude of the strong impact window is 0-100, and the amplitude of the weak noise window is 0-1), resulting in fluctuations in the dimension of the convolution result of the same spline basis function, it is necessary to perform L2 norm normalization processing on the segment windows to eliminate the dimensional differences caused by the strong and weak transient event energies of different segment windows, and arrange the convolution matching degrees in the order of the spline basis function numbers according to the time sequence to generate a transient response coefficient matrix with rows representing the time series and columns representing the spline basis function numbers.

[0032] S2.4. Extract the peak amplitude, rise time, and energy spectrum entropy from the transient response coefficient matrix and combine them into a transient feature tensor.

[0033] It should be noted that the local maximum value in each column is sequentially extracted from left to right according to the time sequence of each segment window as the peak amplitude, and the time position where each peak appears within the corresponding segment window is recorded to generate a peak time index; the sampling interval is calculated according to the sampling rate of the piezoelectric vibration sensor; the starting moment of each segment window corresponding to the peak appearance on the entire vibration signal time axis is recorded to generate a window starting time; at the same time, the energy distribution of the convolution matching degree within each segment window is calculated and the energy spectrum entropy is obtained based on the Shannon entropy formula. Finally, the peak amplitude, rise time, and energy spectrum entropy of the same time segment window are spliced according to the channel dimension to form a transient feature tensor with rows corresponding to the time series and columns containing the peak amplitude, rise time, and energy spectrum entropy.

[0034] S3. Build a transient environmental state transition model based on multi-modal data streams, input the transient feature tensor, temperature data, and electromagnetic interference data into the transient environmental state transition model to generate a displacement compensation amount and a hidden state sequence; S3.1. Define the transient state according to the transient feature tensor; define the temperature threshold and electromagnetic interference threshold according to the temperature data and electromagnetic interference data and generate a state classification rule; define the environmental state according to the state classification rule, combine the transient state and the environmental state into a transient environmental state, and define the state space by the Cartesian product combination state method; It should be noted that the statistical quantiles of the peak amplitude and energy spectrum entropy of the transient feature tensor are calculated. The 95% quantile of the peak amplitude is 0.8, and the 90% quantile of the energy spectrum entropy is 1.0. Then the peak amplitude threshold is 0.8, and the energy spectrum entropy threshold is 1.0. The transient state categories in the vibration signal are divided into two categories. If both the peak amplitude and energy spectrum entropy in the transient feature tensor are lower than the peak amplitude threshold and energy spectrum entropy threshold, it is a normal transient; otherwise, if any one exceeds, it is an abnormal transient. The statistical quantiles of the temperature data and electromagnetic interference data are calculated. The 90% quantile of the temperature data is 42 °C and the 95% quantile of the electromagnetic interference data is 5 V / m. Then the temperature threshold is 42 °C, temperatures higher than 42 °C are high temperatures, and temperatures not exceeding 42 °C are low temperatures; the electromagnetic interference threshold is 5 V / m, electromagnetic interference higher than 5 V / m is high interference, and electromagnetic interference not exceeding 5 V / m is low interference. Based on the temperature threshold and electromagnetic interference threshold, state classification rules are generated. Temperature > 42 °C and electromagnetic interference > 5 V / m is high temperature and high interference; temperature > 42 °C and electromagnetic interference < 5 V / m is high temperature and low interference; temperature < 42 °C and electromagnetic interference > 5 V / m is low temperature and high interference; temperature < 42 °C and electromagnetic interference < 5 V / m is low temperature and low interference. According to the four environmental state categories of low temperature and low interference, low temperature and high interference, high temperature and low interference, and high temperature and high interference, the transient state category and the environmental state category are combined into a transient environmental state (for example, abnormal transient + high temperature and high interference). The Cartesian product combination state method is used to exhaust all transient environmental states, generate a set of state pairs of all possible combinations, and assign a unique code to each state pair to generate a transient environmental state code, forming a state space composed of all transient environmental state codes.

[0035] S3.2. Based on the state classification rules, count the transition frequencies of transient environmental states at adjacent moments in the multi-modal data stream, and construct a state transition probability matrix; It should be noted that based on the generated transient environmental state codes, traverse the time window sequence of the multi-modal data stream, count the number of transitions between transient environmental state codes at adjacent moments, generate an 8×8 transition number matrix recording the number of transitions, calculate the state transition probability matrix based on the transition number matrix, and assign a minimum probability to the state pairs that do not have transitions to avoid the zero probability problem, completing the construction of the state transition probability matrix.

[0036] S3.3. Based on the multi-modal data stream, count the mean value of the displacement compensation amount corresponding to each transient environmental state, and generate a state-compensation amount mapping table; It should be noted that the displacement compensation amount data corresponding to each transient environmental state code is extracted, and the arithmetic mean of all displacement compensation amounts in the same transient environmental state is calculated; for the transient environmental state codes that have not appeared, other transient environmental state codes under the same environmental conditions are matched according to the environmental state (high temperature and high interference), and the arithmetic mean of the matched other transient environmental codes is assigned to the transient environmental state code that has not appeared as the default displacement compensation amount, and finally a state-compensation amount mapping table with the transient environmental state code as the index and the mean value of the displacement compensation amount as the value is generated.

[0037] S3.4. Construct a transient environmental state transition model based on the state space, state transition probability matrix, and state-compensation amount mapping table; It should be noted that the hidden state set of the transient environmental state transition model is defined based on the state space, the state transition probability matrix is used as the state transition probability distribution to describe the temporal transition relationship between hidden states, and the state-to-compensation amount output mapping function is constructed using the state-compensation amount mapping table, and the state space, state transition probability matrix, and state-compensation amount mapping table are integrated into the transient environmental state transition model framework; the state transition rules are defined according to the multi-modal data stream. For example, when the temperature data > 80 °C, it is forced to transition to the high temperature state; by initializing the state transition probability distribution, associating the state transition rules with the compensation amount generation logic, the transient environmental state transition model of the displacement compensation amount and the hidden state sequence is output, and the expression is, ; Among them, represents the hidden state at the next moment ; represents the hidden state at the current moment ; represents the state space; represents the state transition probability distribution; represents the displacement compensation amount at the current moment ; represents the state-compensation amount mapping function; represents a certain moment.

[0038] S3.5. Match the transient feature tensor, temperature data, and electromagnetic interference data to the nearest transient environmental state according to the state classification rules to generate the displacement compensation amount; It should be noted that the peak amplitude and energy spectrum entropy in the transient feature tensor are compared with the preset peak amplitude threshold and energy spectrum entropy threshold respectively to determine the transient state category. When the peak amplitude and energy spectrum entropy are both lower than the peak amplitude threshold and energy spectrum entropy threshold, it is a normal transient. Otherwise, if either of them exceeds the threshold, it is an abnormal transient. The temperature data and electromagnetic interference data are compared with the temperature threshold and the electromagnetic interference threshold to determine the environmental state category. The transient state category and the environmental state category are combined to generate a transient environmental state. The displacement compensation amount corresponding to the current transient environmental state is matched according to the state-compensation amount mapping table and output.

[0039] S3.6. Encode and arrange the transient environment state at each moment in timestamp order to generate a hidden state sequence.

[0040] It should be noted that the transient environmental state code is composed of multiple dimensions. The state value of each dimension is converted into a unique integer value through bit splicing, and the transient environmental state code of each timestamp is read in turn. The encode function is called for each transient environmental state code to generate a unique integer identifier; the transient environmental state code of each timestamp is read in turn, and all integer identifiers are written into a linear list in order according to the timestamp order, and a hidden state sequence that is strictly aligned with the time axis of the multimodal data stream is generated and output.

[0041] S4, constructing a digital simulation model, inputting the displacement compensation amount into the digital simulation model, and generating a multi-physics field coupling simulation displacement; S4.1. A three-dimensional geometric structure including a screw rod, a nut and a bearing is established based on the mechanical parameters of the electric cylinder, and a mechanical motion equation, a heat conduction equation and an electromagnetic field equation are defined on the three-dimensional geometric structure to generate a set of mechanical-thermal-electromagnetic coupling control equations; It should be noted that the lead screw parameters, screw diameter parameters and bearing stiffness parameters of the electric cylinder are determined through the electric cylinder design rule book, and the three-dimensional geometric structure of the screw, nut and bearing is established and the surface coordinate data is derived; based on the spatial position relationship of the three-dimensional geometric structure, the inertia force, damping force and elastic force terms of the screw-nut are defined in the mechanical motion equation, and the Joule heat generation term is added to the heat conduction equation according to the coordinates of the motor winding and the screw contact surface, and the current density distribution is constructed in the electromagnetic field equation based on the geometric parameters of the driver coil; according to the correction formula of the temperature field for the bearing stiffness parameters and the superposition rule of the electromagnetic force on the electric cylinder load, the mechanical motion equation, the heat conduction equation and the electromagnetic field equation are combined into a set of mechanical-thermal-electromagnetic coupling control equations.

[0042] It should also be noted that the spatial position relationship refers to the relative positions, contact methods, and assembly relationships of the components (lead screw, nut, bearing) within the electric cylinder in a three-dimensional geometric structure; the temperature field refers to the distribution state of temperature data in space, which is the temperature distribution result calculated through the heat conduction equation; the superposition rule refers to the correction logic of different physical field effects (temperature field, electromagnetic force field) on the mechanical motion equation in multi-physical field coupling.

[0043] S4.2. Match the temperature threshold and electromagnetic interference threshold according to the hidden state sequence, and set the initial value of the temperature field and the boundary conditions of the electromagnetic field; It should be noted that the transient environmental state encoding at the current moment (such as abnormal transient + high temperature and high interference) is extracted from the hidden state sequence, and the corresponding temperature threshold and electromagnetic interference threshold in the state classification rule are queried. The temperature threshold is used as the initial value of the temperature field in the digital simulation model, and the electromagnetic interference threshold is converted into the boundary conditions of the electromagnetic field.

[0044] S4.3. Construct a digital simulation model according to the three-dimensional geometric structure, the mechanical-thermal-electromagnetic coupling control equations, the initial value of the temperature field, and the boundary conditions of the electromagnetic field; It should be noted that hexahedral mesh elements are selected in the ANSYS finite element tool, and local mesh refinement (mesh size ≤ 0.1 mm) is performed on the screw thread and the bearing contact surface to generate a mesh data file containing node coordinates and element topology relationships; the mechanical-thermal-electromagnetic coupling control equations are discretized into node balance equations (the mechanical motion equation is converted into a weak form, and the node displacement balance equation is generated through the shape function and the Galerkin weighted residual method; the finite volume method is used for the heat conduction equation to generate the node temperature balance equation; the edge element method is used for the Maxwell equation to generate the node magnetic field balance equation); the initial value of the temperature field and the boundary conditions of the electromagnetic field are mapped to the corresponding mesh nodes, and a digital simulation model in the form of a sparse matrix is constructed by combining the node balance equations and the boundary conditions of the electromagnetic field. The expression is, ; Among them, represents the multi-physical field coupling simulation displacement; is the mechanical response coefficient, representing the displacement response generated by the load of the electric cylinder, represents the amplification effect, represents the suppression effect; represents the displacement compensation amount; represents the thermal expansion displacement coefficient, with the unit m / ℃, indicating the equivalent displacement generated per 1 degree Celsius increase in temperature; represents the initial value of the temperature field, with the unit ℃; is the electromagnetic-displacement conversion coefficient, with the unit m / T, indicating the equivalent displacement generated per unit Tesla magnetic field intensity, ; represents the conversion coefficient between the electromagnetic interference threshold and the current density, with the unit of 1 / T m represents the displacement conversion efficiency generated by a unit - area coil under a unit magnetic field strength; represents the geometric area of the driver coil; represents the electromagnetic interference threshold, with the unit of Tesla (T); It should also be noted that the formula unifies the mechanical, thermal, and electromagnetic field effects into a multi - physical - field coupled simulation displacement through linear superposition. It not only retains the independent contributions of each physical field but also dynamically corrects the overall response of the electric cylinder, and finally realizes the fast and robust simulation of the electric cylinder displacement under complex working conditions.

[0045] S4.4. Convert the displacement compensation amount into a compensation force through the bearing stiffness parameter, and superimpose it on the external load term of the mechanical equation. Iteratively calculate according to the order of the temperature field, electromagnetic field, and mechanical field to generate the multi - physical - field coupled simulation displacement.

[0046] It should be noted that the displacement compensation amount is converted into a compensation force through the bearing stiffness parameter (compensation force = electric cylinder stiffness × displacement compensation amount). Match the temperature threshold and the electromagnetic interference threshold according to the current encoding of the hidden state sequence. Set the temperature threshold as the global initial value of the temperature field of the digital simulation model, convert the electromagnetic interference threshold into the current density boundary condition and load it into the electromagnetic field equation. After superimposing the compensation force on the external load term of the mechanical motion equation, iteratively calculate the displacement solution change amount according to the order of the temperature field, electromagnetic field, and mechanical field until the displacement solution change amount is less than the convergence threshold. Finally, extract the axial displacement value at the end of the lead screw from the mechanical displacement field and generate the multi - physical - field coupled simulation displacement according to the time stamp.

[0047] It should also be noted that the displacement solution change amount is a measure of the difference between the mechanical displacement fields in two adjacent iterations, used to judge whether the multi - field coupled solution converges; the convergence threshold is set according to the ISO 10791 - 5 numerical control machine tool accuracy standard, used to judge whether the change amount between two adjacent displacement solutions in the iterative solution process is small enough, and the value is 0.001 mm.

[0048] S5. Calculate the displacement deviation between the displacement compensation amount and the multi - physical - field coupled simulation displacement, and adjust the spline basis function and the transient environment state transition model according to the displacement deviation.

[0049] S5.1. Align the displacement compensation amount and the multi - physical - field coupled simulation displacement according to the time stamp, calculate the three - dimensional displacement deviation at each time stamp, and generate a displacement deviation sequence; It should be noted that the timestamp and displacement data are read line by line. The timestamp (such as 100 ms) and the corresponding displacement values (such as displacement compensation of 0.5 mm and displacement of 0.48 mm in multi-physics coupling simulation) are extracted by string splitting. The timestamp is converted into an integer value (such as 100 → 100 ms), and the displacement value is converted into a floating-point value (such as 0.5 → 0.5 mm). A displacement compensation dictionary (key: timestamp, value: compensation) and a multi-physics coupling simulation displacement dictionary (key: timestamp, value: x / y / z displacement) are constructed. By traversing the intersection of timestamps to match the keys of the displacement compensation dictionary and the multi-physics coupling simulation displacement dictionary, a list of aligned data pairs is generated; the list of data pairs of displacement compensation and multi-physics coupling simulation displacement after alignment is loaded, and the displacement compensation and multi-physics coupling simulation displacement data points with the same timestamp are aligned through the timestamp matching algorithm. The three-dimensional displacement deviation (Euclidean distance of displacement compensation and multi-physics coupling simulation displacement in the x, y, and z directions) is calculated for each matching timestamp, and a displacement deviation sequence with timestamps is generated.

[0050] S5.2. Calculate the root mean square error and the maximum displacement deviation within a continuous time window based on the displacement deviation sequence, generate a displacement deviation distribution histogram, and output the displacement deviation statistical results; It should be noted that based on the displacement deviation sequence, it is loaded and stored as an ordered list in ascending order of timestamps, and then the ordered list is divided into continuous time windows at a fixed duration. The root mean square error and the maximum displacement deviation are calculated for the displacement deviation values within each time window. After combining the displacement deviation values of all windows, the frequency is counted according to a preset interval, and a displacement deviation distribution histogram is generated. Finally, the root mean square error, the maximum displacement deviation, and the displacement deviation histogram of each time window are integrated to generate the displacement deviation statistical results.

[0051] It should also be noted that the preset interval refers to the numerical range predefined for statistically analyzing the distribution of displacement deviation values when generating the displacement deviation distribution histogram. The maximum and minimum displacement deviations are extracted from the displacement deviation sequence, which is the preset interval; the frequency refers to the number of data points of displacement deviation values falling within each preset interval, which is used to describe the density of the displacement deviation distribution.

[0052] S5.3. Based on the displacement deviation statistical results, adjust the spline basis function and the transient environment state transition model through the correction and optimization rules to generate the adjusted spline basis function and the transient environment state transition model.

[0053] It should be noted that based on the statistical results of displacement deviation, by traversing the root mean square error and the maximum displacement deviation of each time window; based on the factory accuracy parameters of the electric cylinder and the ISO 10791-5 numerical control machine tool accuracy standard, a preset threshold is set; if the root mean square error exceeds the preset threshold, the correction and optimization rule is triggered, the weight coefficient of the spline basis function corresponding to the time window is reduced, and new nodes are inserted at the time points corresponding to the maximum displacement deviation. At the same time, according to the high-frequency interval in the displacement deviation distribution histogram, the correction and optimization rule is triggered, the transition probability of the high-deviation hidden state is reduced, and the amplitude of the displacement compensation amount generation is increased. Finally, the adjusted spline basis function and the transient environment state transition model are generated. It should also be noted that the core starting point of calculating the displacement deviation between the input data (displacement compensation amount) and the output data (multi-physical field coupled simulation displacement) of the digital simulation model is to improve the control accuracy and safety through physical coupling verification and dynamic optimization; the displacement compensation amount is a theoretical prediction value, while the multi-physical field coupled simulation displacement reflects the actual deformation calculated by the digital simulation model. Through the displacement deviation, it can be identified whether the displacement compensation amount exceeds the material strength or the environmental bearing limit, avoiding equipment damage caused by over-compensation; the displacement deviation directly reflects the prediction error of the transient environment state transition model, driving the adjustment of the spline basis function weight and the optimization of the hidden state sequence transition probability, so that the transient environment state transition model can adapt to dynamic changes such as temperature and electromagnetic interference in real time.

[0054] This embodiment also provides a computer device, which is applicable to the situation of the method for real-time testing of the dynamic comprehensive data of the electric cylinder, including: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to implement the method for real-time testing of the dynamic comprehensive data of the electric cylinder proposed in the above embodiment.

[0055] This computer device can be a terminal. The computer device includes a processor, a memory, a communication interface, a display screen, and an input device connected through a system bus. Among them, the processor of this computer device is used to provide computing and control capabilities. The memory of this computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of this computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, a carrier network, NFC (near field communication) or other technologies. The display screen of this computer device can be a liquid crystal display screen or an electronic ink display screen, and the input device of this computer device can be a touch layer covered on the display screen, or a button, a trackball or a touchpad set on the shell of the computer device, or an external keyboard, a touchpad or a mouse, etc.

[0056] This embodiment also provides a storage medium, on which a computer program is stored. When the program is executed by a processor, it implements the method for real-time testing of the dynamic comprehensive data of the electric cylinder as proposed in the above embodiment; the storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (Static Random Access Memory, abbreviated as SRAM), electrically erasable programmable read-only memory (Electrically Erasable Programmable Read-Only Memory, abbreviated as EEPROM), erasable programmable read-only memory (Erasable Programmable Read Only Memory, abbreviated as EPROM), programmable read-only memory (Programmable Red-Only Memory, abbreviated as PROM), read-only memory (Read-Only Memory, abbreviated as ROM), magnetic memory, flash memory, magnetic disk or optical disk.

[0057] In summary, the present invention: constructs a spline basis function and a transient environment state transition model, solves the problem of feature distortion of non-stationary vibration signals, significantly improves the extraction accuracy and time resolution of transient impact features, effectively reduces the thermal expansion compensation error under high-temperature conditions and shortens the compensation delay. By constructing a digital simulation model, based on the displacement deviation statistics to drive the optimization of the spline basis function and the state transition rule, the cumulative displacement deviation of the simulation is eliminated.

[0058] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A method for real-time testing of dynamic comprehensive data of an electric cylinder, characterized in that: including collecting vibration signals, temperature data, and electromagnetic interference data of the electric cylinder, and performing preprocessing to generate a multi-modal data stream defining spline basis functions based on the vibration signals, and using the spline basis functions to extract the transient feature tensors of the vibration signals constructing a transient environmental state transition model based on the multi-modal data stream, and inputting the transient feature tensors, temperature data, and electromagnetic interference data into the transient environmental state transition model to generate a displacement compensation amount and a hidden state sequence constructing a digital simulation model, and inputting the displacement compensation amount into the digital simulation model to generate a multi-physics field coupled simulation displacement calculating the displacement deviation between the displacement compensation amount and the multi-physics field coupled simulation displacement, and adjusting the spline basis functions and the transient environmental state transition model according to the displacement deviation 2. The method for real-time testing of the dynamic comprehensive data of the electric cylinder according to claim 1, wherein: The preprocessing to generate the multi-modal data stream is specifically as follows taking the vibration signal timestamp as a reference, performing linear interpolation alignment on the temperature data and the electromagnetic interference data to generate a synchronous data stream encapsulating the vibration signals, temperature data, and electromagnetic interference data in the synchronous data stream into a multi-modal data stream according to the timestamp 3. The method for real-time testing of the dynamic comprehensive data of the electric cylinder according to claim 2, characterized in that: The defining of the spline basis functions based on the vibration signals is specifically as follows analyzing the spectral energy distribution of the vibration signals, extracting the main frequency components, and defining the scale factor and order of the spline basis functions calculating the main frequency component period based on the main frequency components to generate the knot vector and control point sequence of the spline basis functions constructing the spline basis functions according to the scale factor, order, knot vector, and control point sequence 4. The method for real-time testing of the dynamic comprehensive data of the electric cylinder according to claim 3, wherein: The using of the spline basis functions to extract the transient feature tensors of the vibration signals is specifically as follows performing sliding time-domain convolution on the vibration signals using the spline basis functions to generate a transient response coefficient matrix extracting the peak amplitude, rise time, and energy spectrum entropy from the transient response coefficient matrix and combining them into a transient feature tensor 5. The method for real-time testing of the dynamic comprehensive data of the electric cylinder according to claim 4, wherein: The constructing of the transient environmental state transition model based on the multi-modal data stream is specifically as follows defining the transient state and environmental state according to the transient feature tensors, temperature data, and electromagnetic interference data, and merging them into the transient environmental state, and synchronously defining the state space by the Cartesian product combination state method defining the temperature threshold and electromagnetic interference threshold according to the multi-modal data stream, and generating a state classification rule according to the temperature threshold and electromagnetic interference threshold based on the state classification rule, statistically analyzing the transition frequency of the transient environmental states at adjacent moments in the multi-modal data stream to construct a state transition probability matrix based on the multi-modal data stream, statistically analyzing the mean value of the displacement compensation amount corresponding to each transient environmental state to generate a state-compensation amount mapping table constructing a transient environmental state transition model according to the state space, state transition probability matrix, and state-compensation amount mapping table 6. The method for real-time testing of the dynamic comprehensive data of the electric cylinder according to claim 5, wherein: The inputting of the transient feature tensors, temperature data, and electromagnetic interference data into the transient environmental state transition model to generate a displacement compensation amount and a hidden state sequence is specifically as follows matching the transient feature tensors, temperature data, and electromagnetic interference data to the nearest transient environmental state according to the state classification rule to generate a displacement compensation amount arranging the transient environmental states at each moment in order of timestamp to generate a hidden state sequence 7. The method for real-time testing of the dynamic comprehensive data of the electric cylinder according to claim 6, wherein: Build a digital simulation model, input the displacement compensation amount into the digital simulation model to generate a multi-physical field coupled simulation displacement. The specific steps are as follows: Establish a three-dimensional geometric structure, define the mechanical-thermal-electromagnetic coupled control equations on the three-dimensional geometric structure, define the temperature field and electromagnetic field according to the heat conduction equation and electromagnetic field equation, and set the initial value of the temperature field and the boundary conditions of the electromagnetic field according to the hidden state sequence; Build a digital simulation model based on the three-dimensional geometric structure, the mechanical-thermal-electromagnetic coupled control equations, the initial value of the temperature field, and the boundary conditions of the electromagnetic field; Extract the bearing stiffness parameters through the electric cylinder design specification, and convert the displacement compensation amount into a compensation force through the bearing stiffness parameters; Generate a multi-physical field coupled simulation displacement by iteratively calculating the compensation force according to the order of the temperature field, electromagnetic field, and mechanical field.

8. The method for real-time testing of the dynamic comprehensive data of the electric cylinder according to claim 7, wherein: Calculate the displacement deviation between the displacement compensation amount and the multi-physical field coupled simulation displacement, and adjust the spline basis function and the transient environment state transition model according to the displacement deviation. The specific steps are as follows: Align the displacement compensation amount and the multi-physical field coupled simulation displacement according to the time stamp, calculate the three-dimensional displacement deviation at each time stamp, and generate a displacement deviation sequence; Calculate the root mean square error and the maximum displacement deviation within consecutive time stamps based on the displacement deviation sequence, and output the displacement deviation statistical result; Based on the displacement deviation statistical result, adjust the spline basis function and the transient environment state transition model through the correction and optimization rules to generate the adjusted spline basis function and transient environment state transition model.

9. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that: When the processor executes the computer program, it realizes the steps of the method for real-time testing of the dynamic comprehensive data of the electric cylinder according to any one of claims 1 to 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, it realizes the steps of the method for real-time testing of the dynamic comprehensive data of the electric cylinder according to any one of claims 1 to 8.

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