A method for real-time testing of dynamic comprehensive data of electric cylinder

Abstract

The present invention discloses a method for real-time testing of dynamic integrated data of an electric cylinder, which relates to the field of mechatronics testing technology. The method comprises collecting and preprocessing the vibration signal, temperature data, and electromagnetic interference data of the electric cylinder to generate a multimodal data stream; defining a spline basis function based on the vibration signal, and using the spline basis function to extract the transient characteristic tensor of the vibration signal; constructing a transient environmental state transition model based on the multimodal data stream, inputting the transient characteristic tensor, temperature data, and electromagnetic interference data into the transient environmental state transition model, and generating a displacement compensation amount and a latent state sequence; and constructing a digital simulation model, inputting the displacement compensation amount into the digital simulation model, and generating a multi-physics field coupled simulation displacement. By constructing a spline basis function and a transient environmental state transition model, the present invention solves the problem of vibration signal characteristic distortion and significantly improves the extraction accuracy and time resolution of transient impact characteristics.

Description

Technical Field

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

[0002] With the continuous advancement of industrial automation and intelligent equipment technologies, electric cylinders, as high-precision, programmable linear actuators, have been widely used in aerospace, intelligent manufacturing, robotic systems, and other fields. In recent years, with the development of sensor technology, edge computing capabilities, and the concept of digital twins, the demand for real-time monitoring of electric cylinder operating status and dynamic performance evaluation has been increasing.

[0003] Existing methods for real-time testing of dynamic integrated data of electric cylinders typically process vibration, temperature, and electromagnetic interference data independently, lacking cross-modal correlation modeling. This makes it difficult to accurately capture the collaborative characteristics of dynamic events such as transient impact and thermal drift, and lacks sensitivity to the transient characteristics of non-stationary vibration signals. In addition, current digital simulation models mostly rely on offline calibration parameters and are unable to dynamically correct model boundary conditions and material properties based on real-time test data, resulting in accumulated deviations between simulated and actual displacements. 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 integrated data of an electric cylinder to solve the problems of transient characteristic misalignment and displacement deviation accumulation.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a method for real-time testing of dynamic comprehensive data of an electric cylinder, comprising: collecting vibration signals, temperature data, and electromagnetic interference data of the electric cylinder and performing preprocessing to generate a multimodal data stream; defining a spline basis function based on the vibration signal, and using the spline basis function to extract a transient characteristic tensor of the vibration signal; constructing a transient environmental state transfer model based on the multimodal data stream, inputting the transient characteristic tensor, temperature data, and electromagnetic interference data into the transient environmental state transfer model, and generating a displacement compensation amount and a latent state sequence; constructing a digital simulation model, inputting the displacement compensation amount into the digital simulation model, and generating a multi-physics field coupling simulation displacement; calculating the displacement deviation of the displacement compensation amount and the multi-physics field coupling simulation displacement, and adjusting the spline basis function and the transient environmental state transfer model according to the displacement deviation.

[0008] As a preferred solution of the method for real-time testing of dynamic integrated data of electric cylinders described in the present invention, the preprocessing is performed to generate a multimodal data stream, and the specific steps are as follows:

[0009] Based on the vibration signal timestamp, linear interpolation and alignment are performed on the temperature data and electromagnetic interference data to generate a synchronized data stream.

[0010] The vibration signal, temperature data and electromagnetic interference data in the synchronous data stream are encapsulated into a multimodal data stream according to the timestamp.

[0011] As a preferred solution of the method for real-time testing of dynamic integrated data of electric cylinders described in the present invention, wherein: the spline basis function is defined based on the vibration signal, and the specific steps are as follows:

[0012] 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;

[0013] Generate knot vectors and control point sequences of spline basis functions based on the main frequency components;

[0014] Construct a spline basis function based on the scale factor, order, knot vector, and control point sequence.

[0015] As a preferred solution of the method for real-time testing of dynamic integrated data of an electric cylinder according to the present invention, the method of using a spline basis function to extract the transient characteristic tensor of the vibration signal has the following specific steps:

[0016] Perform sliding time-domain convolution on the vibration signal using spline basis functions to generate a transient response coefficient matrix;

[0017] The peak amplitude, rise time and energy spectrum entropy are extracted from the transient response coefficient matrix and combined into a transient feature tensor.

[0018] As a preferred solution of the method for real-time testing of dynamic integrated data of electric cylinders described in the present invention, wherein: the transient environment state transition model is constructed based on multimodal data stream, and the specific steps are as follows:

[0019] Based on the transient characteristic tensor, temperature data, and electromagnetic interference data, the transient state and environmental state are defined and merged into the transient environmental state. The state space is simultaneously defined by the Cartesian product combined state method.

[0020] Define temperature thresholds and electromagnetic interference thresholds based on multimodal data streams, and generate status classification rules based on the temperature thresholds and electromagnetic interference thresholds;

[0021] Based on the state classification rules, the transition frequency of transient environmental states at adjacent moments in the multimodal data stream is counted to construct the state transition probability matrix;

[0022] Based on the multimodal data stream, the mean displacement compensation value corresponding to each transient environmental state is calculated to generate a state-compensation mapping table;

[0023] A transient environment state transition model is constructed based on the state space, state transition probability matrix and state-compensation mapping table.

[0024] As a preferred solution of the method for real-time testing of dynamic integrated data of an electric cylinder according to the present invention, the transient characteristic tensor, temperature data and electromagnetic interference data are input into the transient environment state transition model to generate displacement compensation and hidden state sequence. The specific steps are as follows:

[0025] Match the transient characteristic tensor, temperature data and electromagnetic interference data to the nearest transient environmental state according to the state classification rules to generate displacement compensation;

[0026] Arrange the transient environment state at each moment in timestamp order to generate a hidden state sequence.

[0027] As a preferred solution of the method for real-time testing of dynamic integrated data of an electric cylinder according to the present invention, the steps of constructing a digital simulation model, inputting the displacement compensation amount into the digital simulation model, and generating a multi-physics field coupled simulation displacement are as follows:

[0028] Establish a three-dimensional geometric structure, define the mechanical-thermal-electromagnetic coupling 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 electromagnetic field boundary conditions according to the hidden state sequence;

[0029] Construct a digital simulation model based on the three-dimensional geometric structure, the mechanical-thermal-electromagnetic coupling control equations, the initial value of the temperature field, and the electromagnetic field boundary conditions;

[0030] Extract bearing stiffness parameters from the electric cylinder rule design book, and convert displacement compensation into compensation force through bearing stiffness parameters;

[0031] The compensation force is calculated according to the sequential iterative calculation of the temperature field, electromagnetic field and mechanical field to generate the multi-physics coupling simulation displacement.

[0032] As a preferred solution of the method for real-time testing of dynamic integrated data of an electric cylinder according to the present invention, wherein: the displacement compensation amount and the displacement deviation of the multi-physics field coupling simulation displacement are calculated, and the spline basis function and the transient environmental state transition model are adjusted according to the displacement deviation. The specific steps are as follows:

[0033] Align the displacement compensation amount with the multi-physics field coupling simulation displacement by timestamp, calculate the three-dimensional displacement deviation of each timestamp, and generate a displacement deviation sequence;

[0034] Based on the displacement deviation sequence, the root mean square error and maximum displacement deviation in consecutive time stamps are calculated, a displacement deviation distribution histogram is generated, and the displacement deviation statistics are output;

[0035] Based on the statistical results of displacement deviation, the spline basis function and transient environmental state transfer model are adjusted by modifying the tuning rules to generate the adjusted spline basis function and transient environmental state transfer model.

[0036] In a second aspect, the present invention provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: when the computer program is executed by the processor, any step of the method for real-time testing of dynamic comprehensive data of an electric cylinder as described in the first aspect of the present invention is implemented.

[0037] In a third aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program is executed by a processor, any step of the method for real-time testing of dynamic integrated data of an electric cylinder as described in the first aspect of the present invention is implemented.

[0038] The present invention achieves the following beneficial effects: by constructing a spline basis function and a transient environmental state transition model, it resolves the problem of vibration signal feature distortion, significantly improves the accuracy and temporal resolution of transient impact feature extraction, effectively reduces thermal expansion compensation errors and shortens compensation delays under high-temperature conditions. By constructing a digital simulation model, the spline basis function and state transition rule optimization driven by displacement deviation statistics eliminates the accumulation of simulated displacement deviations. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0040] Figure 1 The present invention is a flow chart of a method for real-time testing of dynamic integrated data of an electric cylinder.

[0041] Figure 2 Flowchart for extracting transient feature tensors.

[0042] Figure 3 Flowchart for constructing a transient environment state transition model.

[0043] Figure 4 Flowchart for building digital simulation models and adjusting optimization. DETAILED DESCRIPTION

[0044] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0045] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0046] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive of other embodiments.

[0047] Reference Figures 1 to 4 , is an embodiment of the present invention, which provides a method for real-time testing of dynamic integrated data of an electric cylinder, comprising the following steps:

[0048] S1. Collect vibration signals, temperature data, and electromagnetic interference data of the electric cylinder and perform preprocessing to generate a multimodal data stream;

[0049] S1.1. Connect the vibration signal, temperature data, and electromagnetic interference data collection terminals to a synchronous clock source and synchronize the clocks of the collection terminals using the Precision Time Protocol.

[0050] It should be noted that the acquisition terminal refers to a piezoelectric vibration sensor installed on the flange surface at the end of the electric cylinder screw, which is used to collect vibration signals. The vibration signals include three-axis acceleration data; a thin-film temperature sensor is attached to the surface of the motor winding to collect temperature data; a miniature magnetometer is fixed outside the drive power cord to collect electromagnetic interference data; the piezoelectric vibration sensor has a range of ±50g and a sampling rate of 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.

[0051] S1.2. Based on the vibration signal timestamp, perform linear interpolation alignment on the temperature data and electromagnetic interference data to generate a synchronized data stream.

[0052] It should be noted that, based on the 100 microsecond timestamp sequence of the vibration signal, the time point set of all vibration signals is extracted; the original timestamp sequence and corresponding values ​​of the temperature data and electromagnetic interference data are extracted respectively, and for each vibration signal time point, the adjacent time points are searched in the original timestamp sequence of the temperature data and electromagnetic interference data; based on the values ​​of the adjacent time points, the temperature data and electromagnetic interference data of the current vibration signal time point are calculated according to the time ratio, and the calculated temperature data, electromagnetic interference data and vibration signal are aligned according to the timestamp to generate a synchronous data stream.

[0053] S1.3. Encapsulate the vibration signal, temperature data, and electromagnetic interference data in the synchronous data stream into a data packet with a timestamp in JSON format;

[0054] 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; the synchronous data stream is traversed to extract the vibration signal, temperature data and electromagnetic interference data at the same time point; values ​​are assigned according to the corresponding fields and converted into strings for encapsulation.

[0055] S1.4. Write the data packet into InfluxDB to generate a multimodal data stream.

[0056] It should be noted that InfluxDB is an open source database designed specifically for time series data. After receiving a data packet, InfluxDB parses the fields in the data packet and maps the fields to time series points according to the InfluxDB data format. The time series points are written to InfluxDB in batches through the InfluxDB HTTP API protocol. The output of InfluxDB is a multimodal data stream.

[0057] S2. defining a spline basis function based on the vibration signal, and extracting a transient feature tensor of the vibration signal using the spline basis function;

[0058] S2.1. Analyze the spectral energy distribution of the vibration signal, extract the main frequency component within a fixed frequency band, and determine the scale factor and order of the spline basis function;

[0059] It should be noted that the three-axis acceleration data of the vibration signal is extracted from the multimodal data stream, a time window of fixed length (such as 100ms) is intercepted and a Hanning window is applied to suppress spectrum leakage, and the three-axis acceleration data is converted into a frequency domain amplitude spectrum through fast Fourier transform (FFT), and the energy value (amplitude square) of each frequency point is calculated to finally generate a spectrum energy distribution diagram; the fixed frequency band refers to the typical fault frequency band range of the electric cylinder through experimental calibration. Within the fixed frequency band, the energy values ​​of all frequency points are sorted in descending order of energy, and the first three frequencies with a total energy share of more than 60% are selected as the main frequency components; the scale factor is dynamically adjusted according to the period of the main frequency component 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 2kHz (period 0.5ms), the scale factor is set to 0.25ms; the order is fixed to third order.

[0060] S2.2. Generate the knot vector and control point sequence of the spline basis function based on the main frequency component;

[0061] It should be noted that the period of the main frequency component 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 2kHz (period 0.5ms), the node interval is set to 1 / 4 of the period length (0.125ms). The local extreme points of the vibration signal are extracted from the three-axis acceleration data, and the time position and amplitude of the local extreme points are marked. The time position of the local extreme points is normalized to the time coordinates of the control points according to the time window of the three-axis acceleration data, and the amplitude of the local extreme points is normalized to the amplitude coordinates of the control points according to the vibration signal acquisition range. The control point sequence of the spline basis function is generated, and the vibration signal waveform is fitted by the least squares method. The control point sequence is adjusted to match the spline basis function with the transient characteristics. The expression of the spline basis function is:

[0062] ;

[0063] in, Indicates time is The third-order spline basis function when ; represents the order, ; Indicates a moment; Indicates the control point sequence index, the value range is 0- ; Indicates the control point sequence coordinates of control points; represents the local basis function; Indicates the node vector The start time of each node; represents the scale factor, , Indicates the main frequency component; Indicates the total number of control points.

[0064] S2.3. Perform sliding time-domain convolution on the vibration signal using the spline basis function to generate a transient response coefficient matrix;

[0065] It should be noted that the vibration signal is divided into segment windows through a dynamic sliding window, and each segment window is arranged from left to right in time axis order; 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 size is consistent with the scale factor to achieve overlap between segment windows and avoid truncation of transient events; each segment window covers the complete support interval of the spline basis function, and the convolution matching degree of each segment window and the spline basis function is calculated by 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 dimensional fluctuations in the convolution results of the same spline basis function, the segment windows need to be normalized by the L2 norm to eliminate the dimensional differences caused by the strength of the transient event energy in different segment windows. The convolution matching degrees are arranged according to the spline basis function sequence in time order to generate a transient response coefficient matrix with rows representing time series and columns representing spline basis function numbers.

[0066] 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.

[0067] It should be noted that the local maximum value in each column is extracted from left to right in the time sequence of each segment window as the peak amplitude, and the time position of each peak in the corresponding segment window is recorded to generate the peak time index; the sampling interval is calculated according to the sampling rate of the piezoelectric vibration sensor; the starting moment of each corresponding segment window where the peak appears on the entire vibration signal time axis is recorded to generate the window start time; at the same time, the energy distribution is calculated for the convolution matching degree in each segment window and the energy spectrum entropy is obtained based on the Shannon entropy formula, and 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 time series and columns containing peak amplitude, rise time and energy spectrum entropy.

[0068] S3. Construct a transient environmental state transfer model based on the multimodal data stream, input the transient characteristic tensor, temperature data, and electromagnetic interference data into the transient environmental state transfer model, and generate a displacement compensation amount and a hidden state sequence;

[0069] S3.1. Define a transient state based on a transient characteristic tensor; define a temperature threshold and an electromagnetic interference threshold based on temperature data and electromagnetic interference data and generate a state classification rule; define an environmental state based on the state classification rule, combine the transient state and the environmental state into a transient environmental state, and define the state space using a Cartesian product combined state method;

[0070] It should be noted that the statistical quantiles of the peak amplitude and energy spectrum entropy of the transient characteristic 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 the peak amplitude and energy spectrum entropy in the transient characteristic tensor are both lower than the peak amplitude threshold and the energy spectrum entropy threshold, it is a normal transient; otherwise, if either one exceeds the threshold, it is an abnormal transient. The statistical quantiles of the temperature data and the 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 5V / m. Then the temperature threshold is 42°C. Above 42°C is high temperature, and not exceeding 42°C is low temperature. The electromagnetic interference threshold is 5V / m. Above 5V / m is high interference, and not exceeding 5V / m is low interference. State classification rules are generated based on temperature thresholds and electromagnetic interference thresholds: temperature > 42°C and electromagnetic interference > 5V / m indicates high temperature and high interference; temperature > 42°C and electromagnetic interference < 5V / m indicates high temperature and low interference; temperature < 42°C and electromagnetic interference > 5V / m indicates low temperature and high interference; and temperature < 42°C and electromagnetic interference < 5V / m indicates low temperature and low interference. Based on the four environmental states of low temperature and low interference, low temperature and high interference, high temperature and low interference, and high temperature and high interference, transient state categories and environmental state categories are combined into transient environmental states (e.g., abnormal transient + high temperature and high interference). The Cartesian product combined state method is used to exhaustively enumerate all transient environmental states to generate a set of state pairs of all possible combinations, and a unique code is assigned to each state pair to generate a transient environmental state code, forming a state space composed of all transient environmental state codes.

[0071] S3.2. Based on the state classification rules, count the transition frequencies of transient environmental states at adjacent moments in the multimodal data stream and construct a state transition probability matrix;

[0072] It should be noted that based on the generated transient environmental state code, the time window sequence of the multimodal data stream is traversed, the number of transitions between the transient environmental state codes at adjacent moments is counted, and an 8×8 transition number matrix that records the number of transitions is generated. The transition probability matrix is ​​calculated based on the transition number matrix, and an extremely small probability is given to the state pairs where no transition occurs to avoid the zero probability problem, thereby completing the construction of the state transition probability matrix.

[0073] S3.3. Based on the multimodal data stream, calculate the mean value of the displacement compensation corresponding to each transient environmental state and generate a state-compensation mapping table;

[0074] It should be noted that the displacement compensation data corresponding to each transient environmental state code is extracted, and the arithmetic mean of all displacement compensation values ​​under the same transient environmental state is counted; for 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 other matched transient environmental codes is assigned to the transient environmental state code that has not appeared as the default displacement compensation value, and finally a state-compensation mapping table is generated with the transient environmental state code as the index and the displacement compensation value mean as the value.

[0075] S3.4. Construct a transient environment state transition model based on the state space, the state transition probability matrix, and the state-compensation mapping table;

[0076] It should be noted that the hidden state set of the transient environment state transfer model is defined based on the state space, the state transfer probability matrix is ​​used as the state transfer probability distribution to describe the temporal transfer relationship between hidden states, and the state-compensation mapping table is used to construct the output mapping function from state to compensation. The state space, state transfer probability matrix and state-compensation mapping table are integrated into the transient environment state transfer model framework; the state transfer rules are defined according to the multimodal data stream. For example, when the temperature data is greater than 80℃, it is forced to transfer to the high temperature state; by initializing the state transfer probability distribution, associating the state transfer rules with the compensation generation logic, the transient environment state transfer model of the displacement compensation and hidden state sequence is output. The expression is,

[0077] ;

[0078] in, Indicates the next moment The hidden state of Indicates the current time The hidden state of represents the state space; Represents the state transition probability distribution; Indicates the current time The displacement compensation amount; represents the state-compensation mapping function; Indicates a moment.

[0079] S3.5. Match the transient characteristic tensor, temperature data, and electromagnetic interference data to the most recent transient environmental state according to the state classification rules to generate a displacement compensation amount;

[0080] 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 one exceeds the threshold, it is an abnormal transient. The temperature data and electromagnetic interference data are compared with the temperature threshold and 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.

[0081] S3.6. Arrange the transient environment state codes at each moment in timestamp order to generate a hidden state sequence.

[0082] 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. The transient environmental state code of each timestamp is read in turn, and 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 of timestamps to generate a hidden state sequence that is strictly aligned with the time axis of the multimodal data stream and output.

[0083] 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;

[0084] S4.1. Based on the mechanical parameters of the electric cylinder, establish a three-dimensional geometric structure including a screw, nut, and bearing. Define the mechanical motion equations, heat conduction equations, and electromagnetic field equations on the three-dimensional geometric structure to generate a set of mechanical-thermal-electromagnetic coupling control equations.

[0085] It should be noted that the electric cylinder's screw lead parameters, screw diameter parameters and bearing stiffness parameters 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. In the electromagnetic field equation, the current density distribution is constructed 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 mechanical-thermal-electromagnetic coupling control equation group.

[0086] It should also be noted that the spatial position relationship refers to the relative position, contact method and assembly relationship of the components (screw, nut, bearing) in the electric cylinder in the three-dimensional geometric structure; the temperature field refers to the distribution state of temperature data in space, and the temperature distribution result calculated by the heat conduction equation; the superposition rule refers to the correction logic of the mechanical motion equation by different physical field effects (temperature field, electromagnetic force field) in multi-physical field coupling.

[0087] 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 electromagnetic field boundary conditions;

[0088] It should be noted that the transient environmental state code at the current moment (such as abnormal transient + high temperature and high interference) is extracted from the hidden state sequence, the corresponding temperature threshold and electromagnetic interference threshold are queried in the state classification rule, the temperature threshold is used as the initial value of the temperature field of the digital simulation model, and the electromagnetic interference threshold is converted into the electromagnetic field boundary condition.

[0089] S4.3. Construct a digital simulation model based on the three-dimensional geometric structure, the mechanical-thermal-electromagnetic coupling control equations, the initial value of the temperature field, and the electromagnetic field boundary conditions;

[0090] It should be noted that hexahedral mesh units are selected in the ANSYS finite element tool, and the screw thread and bearing contact surface are locally encrypted (mesh size ≤ 0.1 mm) for mesh division to generate a mesh data file containing the node coordinates and unit topology relationship; the mechanical-thermal-electromagnetic coupling control equations are discretized into node equilibrium equations (the mechanical motion equations are converted into weak form, and the node displacement equilibrium equations are generated by shape function and Galerkin weighted residual method; the finite volume method is used for the heat conduction equation to generate the node temperature equilibrium equation; the edge unit method is used for the Maxwell equations to generate the node magnetic field equilibrium equation); the initial value of the temperature field and the electromagnetic field boundary conditions are mapped to the corresponding mesh nodes, and a digital simulation model in the form of a sparse matrix is ​​constructed by merging the node equilibrium equations and the electromagnetic field boundary conditions. The expression is,

[0091] ;

[0092] in, Represents the displacement of multi-physics coupling simulation; is the mechanical response coefficient, which represents the displacement response of the electric cylinder load. Represents the amplification effect, Indicates inhibitory effect; Indicates the displacement compensation amount; Indicates the coefficient of thermal expansion displacement, in m / °C, which indicates the equivalent displacement generated by each 1°C increase in temperature; Indicates the initial value of the temperature field, unit: °C; is the electromagnetic-displacement conversion coefficient, in m / T, which represents the equivalent displacement produced by the magnetic field strength per unit Tesla. ; Indicates the conversion coefficient between electromagnetic interference threshold and current density, the unit is 1 / T m, represents the displacement conversion efficiency of the coil per unit area under unit magnetic field strength; Represents the geometric area of ​​the driver coil; Indicates the electromagnetic interference threshold, the unit is Tesla (T);

[0093] It should also be noted that the formula unifies the mechanical, thermal and electromagnetic field effects into multi-physics field coupling simulation displacement through linear superposition, which not only retains the independent contribution of each physical field, but also Dynamically correct the overall response of the electric cylinder, ultimately achieving fast and robust simulation of the electric cylinder displacement under complex working conditions.

[0094] S4.4. Convert the displacement compensation amount into compensation force through the bearing stiffness parameter and add it to the external load term of the mechanical equation. Generate the multi-physics field coupling simulation displacement by sequential iterative calculation based on the temperature field, electromagnetic field and mechanical field.

[0095] 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), the temperature threshold and the electromagnetic interference threshold are matched according to the current encoding of the hidden state sequence, the temperature threshold is set as the global initial value of the temperature field of the digital simulation model, the electromagnetic interference threshold is converted into a current density boundary condition and loaded into the electromagnetic field equation, the compensation force is superimposed on the external load term of the mechanical motion equation, and the displacement solution change is iteratively calculated in the order of temperature field, electromagnetic field, and mechanical field until the displacement solution change is less than the convergence threshold, and finally the axial displacement value of the screw end is extracted from the mechanical displacement field, and the multi-physics field coupling simulation displacement is generated according to the timestamp.

[0096] It should also be noted that the change in displacement solution is a measure of the difference in the mechanical displacement field between two adjacent iterations, which is used to determine whether the multi-field coupling solution has converged. The convergence threshold is set according to the ISO 10791-5 CNC machine tool accuracy standard and is used to determine whether the change in displacement solution between two adjacent iterations is small enough during the iterative solution process. The value is 0.001 mm.

[0097] S5. Calculate the displacement compensation amount and the displacement deviation of the multi-physics field coupling simulation displacement, and adjust the spline basis function and the transient environmental state transfer model according to the displacement deviation.

[0098] S5.1. Align the displacement compensation amount with the multi-physics field coupling simulation displacement according to the timestamp, calculate the three-dimensional displacement deviation of each timestamp, and generate a displacement deviation sequence;

[0099] It should be noted that the timestamp and displacement data are read line by line, and the timestamp (e.g., 100ms) and the corresponding displacement value (e.g., displacement compensation 0.5mm, multi-physics coupling simulation displacement 0.48mm) are extracted by string segmentation. The timestamp is converted to an integer value (e.g., 100→100ms), and the displacement value is converted to a floating-point value (e.g., 0.5→0.5mm). 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. The keys of the displacement compensation dictionary and the multi-physics coupling simulation displacement dictionary are matched by traversing the timestamp intersection to generate an aligned data pair list. The aligned displacement compensation and multi-physics coupling simulation displacement data pair list is loaded, and the displacement compensation and multi-physics coupling simulation displacement data points with the same timestamp are aligned using a timestamp matching algorithm. The three-dimensional displacement deviation (Euclidean distance between the displacement compensation and the multi-physics coupling simulation displacement in the x, y, and z directions) is calculated for each matching timestamp to generate a displacement deviation sequence with a timestamp.

[0100] S5.2. Calculate the root mean square error and maximum displacement deviation in the continuous time window based on the displacement deviation sequence, generate a displacement deviation distribution histogram, and output the displacement deviation statistics;

[0101] It should be noted that the displacement deviation sequence is loaded and stored as an ordered list in ascending order of timestamps, and then the ordered list is divided into continuous time windows according to a fixed time length. The root mean square error and maximum displacement deviation are calculated for the displacement deviation value in each time window. After the displacement deviation values ​​of all windows are merged, the frequency is counted according to the preset interval to generate a displacement deviation distribution histogram. Finally, the root mean square error, maximum displacement deviation and displacement deviation histogram of each time window are integrated to generate the displacement deviation statistical results.

[0102] It should also be noted that the preset interval refers to the pre-defined numerical range for statistically analyzing the distribution of displacement deviation values ​​when generating a displacement deviation distribution histogram. The maximum and minimum displacement deviation values ​​are extracted based on the displacement deviation sequence, which is the preset interval; the frequency refers to the number of data points of the displacement deviation value falling within each preset interval, which is used to describe the density of the displacement deviation distribution.

[0103] S5.3. Based on the statistical results of the displacement deviation, the spline basis function and the transient environmental state transfer model are adjusted by modifying the tuning rules to generate adjusted spline basis function and transient environmental state transfer model.

[0104] It should be noted that based on the statistical results of displacement deviation, the root mean square error and maximum displacement deviation of each time window are traversed; based on the factory accuracy parameters of the electric cylinder and the ISO 10791-5 CNC machine tool accuracy standard, a preset threshold is set; if the root mean square error exceeds the preset threshold, the correction tuning rule is triggered, the weight coefficient of the spline basis function corresponding to the time window is reduced and a new node is inserted at the time point corresponding to the maximum displacement deviation. At the same time, the correction tuning rule is triggered according to the high-frequency interval in the displacement deviation distribution histogram, the transition probability of the high-deviation hidden state is reduced and the displacement compensation amount generation amplitude is increased, and finally the adjusted spline basis function and transient environmental state transition model are generated;

[0105] It should also be noted that the core starting point of calculating the displacement deviation between the input data (displacement compensation) and the output data (multi-physics field coupling simulation displacement) of the digital simulation model is to improve control accuracy and safety through physical coupling verification and dynamic optimization; the displacement compensation is a theoretical prediction value, and the multi-physics field coupling simulation displacement reflects the actual deformation through the digital simulation model calculation. The displacement deviation can be used to identify whether the displacement compensation exceeds the material strength or environmental bearing limit, avoiding equipment damage due to over-compensation; the displacement deviation directly reflects the prediction error of the transient environmental state transfer model, drives the spline basis function weight adjustment and the hidden state sequence transition probability optimization, so that the transient environmental state transfer model can adapt to dynamic changes such as temperature and electromagnetic interference in real time.

[0106] This embodiment also provides a computer device suitable for the method of real-time testing of dynamic comprehensive data of an electric cylinder, comprising: 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 of real-time testing of dynamic comprehensive data of an electric cylinder proposed in the above embodiment.

[0107] The computer device may be a terminal, comprising a processor, memory, a communication interface, a display, and an input device connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores an operating system and computer programs. The internal memory provides an environment for the operating system and computer programs stored in the non-volatile storage media. The communication interface of the computer device is used to communicate with external terminals via wired or wireless communication. Wireless communication may be achieved via Wi-Fi, a carrier network, NFC (near-field communication), or other technologies. The display of the computer device may be a liquid crystal display or an electronic ink display. The input device may be a touchscreen overlay on the display, buttons, a trackball, or a touchpad on the computer device housing, or an external keyboard, touchpad, or mouse.

[0108] This embodiment further provides a storage medium having a computer program stored thereon. When the program is executed by a processor, the program implements the method for real-time testing of dynamic integrated data of an 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 (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0109] In summary, this invention addresses the problem of nonstationary vibration signal feature distortion by constructing a spline basis function and a transient environmental state transition model. This significantly improves the accuracy and temporal resolution of transient impact feature extraction, effectively reduces thermal expansion compensation errors and shortens compensation delays under high-temperature conditions. Furthermore, by constructing a digital simulation model, the spline basis function and state transition rule optimization driven by displacement deviation statistics eliminates the accumulation of simulated displacement deviations.

[0110] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for real-time testing of dynamic integrated data of an electric cylinder, characterized by: include, Collect vibration signals, temperature data, and electromagnetic interference data from the electric cylinder and perform preprocessing to generate multimodal data streams; A spline basis function is defined based on the vibration signal, and the transient feature tensor of the vibration signal is extracted using the spline basis function; A transient environmental state transfer model is constructed based on a multimodal data stream, and the transient characteristic tensor, temperature data, and electromagnetic interference data are input into the transient environmental state transfer model to generate a displacement compensation amount and a hidden state sequence. The specific steps of constructing a transient environmental state transfer model based on a multimodal data stream are as follows: Based on the transient characteristic tensor, temperature data, and electromagnetic interference data, the transient state and environmental state are defined and merged into the transient environmental state, and the state space is simultaneously defined through the Cartesian product combined state method; the temperature threshold and electromagnetic interference threshold are defined according to the multimodal data stream, and the state classification rules are generated based on the temperature threshold and electromagnetic interference threshold; based on the state classification rules, the transition frequency of the transient environmental state at adjacent moments in the multimodal data stream is counted to construct a state transition probability matrix; based on the multimodal data stream, the mean value of the displacement compensation corresponding to each transient environmental state is counted to generate a state-compensation mapping table; Construct a transient environment state transition model based on the state space, state transition probability matrix and state-compensation mapping table; Constructing a digital simulation model, inputting the displacement compensation amount into the digital simulation model, and generating a multi-physics field coupling simulation displacement; Constructing a digital simulation model, inputting the displacement compensation amount into the digital simulation model, and generating a multi-physics field coupling simulation displacement, the specific steps are as follows: A three-dimensional geometric structure is established, and a set of mechanical-thermal-electromagnetic coupling control equations is defined on the three-dimensional geometric structure. The temperature field and electromagnetic field are defined based on the heat conduction equation and the electromagnetic field equation. The initial value of the temperature field and the electromagnetic field boundary conditions are set according to the hidden state sequence. A digital simulation model is constructed based on the three-dimensional geometric structure, the set of mechanical-thermal-electromagnetic coupling control equations, the initial value of the temperature field, and the electromagnetic field boundary conditions. The bearing stiffness parameters are extracted from the electric cylinder rule design document, and the displacement compensation amount is converted into compensation force through the bearing stiffness parameters. The compensation force is calculated sequentially and iteratively according to the temperature field, electromagnetic field and mechanical field to generate the multi-physics field coupling simulation displacement; Calculate the displacement compensation amount and the displacement deviation of the multi-physics field coupling simulation displacement, and adjust the spline basis function and transient environmental state transfer model according to the displacement deviation.

2. The method for real-time testing of dynamic integrated data of an electric cylinder according to claim 1, characterized in that: The preprocessing is performed to generate a multimodal data stream. The specific steps are as follows: Based on the vibration signal timestamp, linear interpolation and alignment are performed on the temperature data and electromagnetic interference data to generate a synchronized data stream. The vibration signal, temperature data and electromagnetic interference data in the synchronous data stream are encapsulated into a multimodal data stream according to the timestamp.

3. The method for real-time testing of dynamic integrated data of an electric cylinder according to claim 2, characterized in that: The specific steps of defining the spline basis function based on the vibration signal 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; Calculate the period of the main frequency component based on the main frequency component to generate the knot vector and control point sequence of the spline basis function; Construct spline basis functions based on scale factor, order, knot vector, and control point sequence.

4. The method for real-time testing of dynamic integrated data of an electric cylinder according to claim 3, wherein: The specific steps of using spline basis function to extract the transient feature tensor of the vibration signal are as follows: Perform sliding time-domain convolution on the vibration signal using spline basis functions to generate a transient response coefficient matrix; The peak amplitude, rise time and energy spectrum entropy are extracted from the transient response coefficient matrix and combined into a transient feature tensor.

5. The method for real-time testing of dynamic integrated data of an electric cylinder according to claim 4, characterized in that: The transient characteristic tensor, temperature data and electromagnetic interference data are input into the transient environment state transfer model to generate the displacement compensation and hidden state sequence. The specific steps are as follows: Match the transient characteristic tensor, temperature data and electromagnetic interference data to the nearest transient environmental state according to the state classification rules to generate displacement compensation; Arrange the transient environment state at each moment in timestamp order to generate a hidden state sequence.

6. The method for real-time testing of dynamic integrated data of an electric cylinder according to claim 5, characterized in that: The calculation of the displacement compensation amount and the displacement deviation of the multi-physics field coupling simulation displacement, and the adjustment of the spline basis function and the transient environment state transfer model according to the displacement deviation are specifically performed as follows: Align the displacement compensation amount with the multi-physics field coupling simulation displacement by timestamp, calculate the three-dimensional displacement deviation of each timestamp, and generate a displacement deviation sequence; Calculate the root mean square error and maximum displacement deviation within consecutive time stamps based on the displacement deviation sequence, and output the displacement deviation statistics; Based on the statistical results of displacement deviation, the spline basis function and transient environmental state transfer model are adjusted by modifying the tuning rules to generate the adjusted spline basis function and transient environmental state transfer model.

7. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method for real-time testing of dynamic comprehensive data of the electric cylinder according to any one of claims 1 to 6 are implemented.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for real-time testing of dynamic integrated data of an electric cylinder according to any one of claims 1 to 6 are implemented.

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