Instantaneous angular velocity co-frequency interference error suppression method and system

Abstract

The invention discloses an instantaneous angular velocity same-frequency interference error suppression method and system, and the method comprises the following steps: carrying out error parameter identification, collecting instantaneous angular velocity signals of an encoder coded disc under different rotating speed working conditions, and building three error angular domain models, namely, an eccentric error angular domain model, an inclined error angular domain model and an intersection misalignment error angular domain model, of the encoder coded disc; calculating an instantaneous angular velocity error signal based on the error angular domain model; using a particle swarm optimization algorithm or an artificial squirrel optimization algorithm to obtain code disc error parameters, and generating a theoretical model instantaneous angular velocity error signal; decomposing the instantaneous angular velocity error signal by using empirical mode decomposition, and extracting an error component; and frequency domain coefficient correction is carried out, reconstruction of the instantaneous angular velocity signal is completed, and suppression of the same-frequency interference error is realized. By adopting the technical scheme, the instantaneous angular velocity signal is decomposed and reconstructed by adopting empirical mode decomposition, and a related frequency domain correction coefficient is provided, so that the same-frequency interference component of the instantaneous angular velocity is effectively inhibited, and the real rotating speed fluctuation signal is reserved.

Description

Technical Field

[0001] The present invention belongs to the technical field of signal processing and relates to a method and system for suppressing instantaneous angular velocity same-frequency interference errors. Background Art

[0002] In the rotating mechanical motion control system, the encoder is the core sensor for angular velocity measurement. The accuracy of its output instantaneous angular velocity signal directly determines the stability and reliability of the rotating motion system.

[0003] Research has found that eccentricity, tilt, and cross-misalignment errors in the encoder disc during manufacturing and installation can cause the true instantaneous angular velocity signal to be lost in the instantaneous angular velocity error signal. Failure to suppress these errors can reduce the stability of rotating machinery systems. Furthermore, small fluctuations in the true speed can be lost in the error signal, compromising fault diagnosis and accurate analysis of the rotating machinery's dynamic characteristics.

[0004] However, the instantaneous angular velocity error caused by manufacturing and installation errors is co-frequency with the true rotational speed. Directly performing frequency-domain filtering based on the frequency of the instantaneous angular velocity error signal would filter out the true rotational speed fluctuation signal at the same frequency, rendering traditional frequency-domain-based separation filtering methods ineffective. Therefore, the problem of how to restore the true rotational speed fluctuation signal as much as possible from the error signal while accurately suppressing the co-frequency component caused by encoder errors is an urgent issue. Summary of the Invention

[0005] The object of the present invention is to provide a method and system for suppressing instantaneous angular velocity co-frequency interference errors, which can effectively suppress the instantaneous angular velocity co-frequency interference components and achieve the retention of a true speed fluctuation signal.

[0006] In order to achieve the above object, the basic scheme of the present invention is: a method for suppressing instantaneous angular velocity co-frequency interference error, comprising the following steps:

[0007] S1, perform error parameter identification, specifically using one of the following schemes:

[0008] Option 1:

[0009] S11, collecting the instantaneous angular velocity signals of the encoder disc under different speed conditions, and building three error angular domain models of the encoder disc eccentricity, tilt and intersection misalignment;

[0010] S12, calculating an instantaneous angular velocity error signal based on the error angle domain model;

[0011] S13, using a particle swarm optimization algorithm or an artificial lemming optimization algorithm to obtain a code disc error parameter and generate an instantaneous angular velocity error signal of a theoretical model;

[0012] Option 2:

[0013] S21, collecting instantaneous angular velocity signals of the same encoder under multiple groups of different speed conditions, calculating the peak-to-peak value of each group of signals, and screening the minimum fluctuation signal;

[0014] S22, calculating the mean of the minimum fluctuation signal, initializing the error parameter, and generating a theoretical error signal;

[0015] S23, constructing an optimization objective function based on the theoretical error signal;

[0016] S24, iterating according to the artificial lemming optimization algorithm or the particle swarm optimization algorithm, and outputting the global optimal parameters if the convergence condition is met, otherwise returning to step S22;

[0017] S25, generating an instantaneous angular velocity error signal of a theoretical model based on the global optimal parameters;

[0018] S2, using empirical mode decomposition to decompose the instantaneous angular velocity error signal and extract the error components;

[0019] S3, correct the frequency domain coefficients, complete the reconstruction of the instantaneous angular velocity signal, and suppress the co-frequency interference error.

[0020] The working principle and beneficial effects of this basic solution are as follows: This technical solution, guided by physical information, builds a theoretical model of instantaneous angular velocity error and uses a particle swarm optimization algorithm to identify the encoder error parameters. Empirical mode decomposition is used to decompose and reconstruct the instantaneous angular velocity signal, and related frequency domain correction coefficients are proposed. This method effectively suppresses the instantaneous angular velocity co-frequency interference component, preserving the true speed fluctuation signal.

[0021] Furthermore, in step S11, the three error angle domain models of encoder code disc eccentricity, tilt and intersection misalignment are:

[0022]

[0023] Among them, ω er is the instantaneous angular velocity error of the code disk when the probe is arranged radially in the eccentric state, ρ r is the radial eccentricity, α′ represents the position angle information read by the probe, ω(t) is the instantaneous angular velocity of the code disk when it rotates, ω t Indicates the instantaneous angular velocity error of the code disk in the tilted state; α is the actual rotation angle; β is the tilt angle of the code disk, ω misr is the instantaneous angular velocity error when the probe is arranged radially.

[0024] Constructing three error angle domain models of encoder code disc eccentricity, tilt and intersection misalignment is beneficial for data analysis.

[0025] Furthermore, in step S12, the instantaneous angular velocity error signal is calculated based on the error angle domain model, specifically:

[0026] The instantaneous angular velocity signal IAS obtained under different speed conditions or multiple measurements on the same encoder m In the example, the instantaneous angular velocity signal IAS with the smallest speed fluctuation is selected. min And calculate its mean IAS mim_m As a theoretical model speed benchmark;

[0027] Based on the theoretical model speed benchmark, the particle swarm search parameters are initialized. If the code disk is known to be a single error type, then based on ω er and ω t , generating an instantaneous angular velocity error signal;

[0028] Otherwise, based on ω misr Generate the instantaneous angular velocity error signal and replace ω(t) in the formula with IAS mim_m , calculate and generate a set of theoretical error signals under different error parameters, recorded as IAS e :

[0029] IAS e =[IAS e1 (ρ1,β1),IAS e2 (ρ2,β2),…,IAS en (ρ n ,β n )]

[0030] Among them, IAS en is the theoretical error signal calculated under different error parameters, ρ n Indicates the eccentricity error of the code disk, β n represents the code disk tilt angle error, and n represents a sequence of different error parameters.

[0031] Based on the error angle domain model, the instantaneous angular velocity error signal is calculated with simple operation.

[0032] Furthermore, in step S13, the particle swarm optimization algorithm is used to obtain the error parameters of the code disk as follows:

[0033] The eccentricity ρ and tilt angle β parameters are optimized synchronously by particle swarm optimization algorithm to make the experimental signal IAS m and the theoretical error signal IAS er The root mean square logarithmic function f(ρ,β) of the frequency domain difference is minimized, and the final output is the inherent error parameter ρ which is independent of the speed. gBest and β gBest Complete identification; generate the theoretical model instantaneous angular velocity error signal IAS at the stable speed of this working condition [ρ,β]best :

[0034] f(ρ,β)=min(log(rms(F[IAS m -IAS er ])))

[0035] Wherein, rms represents the root mean square function, and F represents Fourier transform.

[0036] The particle swarm optimization algorithm is used to identify the error parameters of the code disk.

[0037] Furthermore, in step S21, the peak-to-peak value V of each group of signals is calculated. pp , screening minimum fluctuation signal IAS k for:

[0038] V pp =V max -V min

[0039] IAS k =arg min[V pp (IAS1,IAS2,…,IAS n )]

[0040] Among them, V max , V min Indicates the maximum and minimum values of each group of signals; IAS n is the nth fluctuation signal.

[0041] The calculation is simple, the corresponding parameters are obtained, and the influence of the rotational speed fluctuation on the instantaneous angular velocity error signal generated by the theoretical model is reduced.

[0042] Furthermore, in step S22, the mean of the minimum fluctuation signal is calculated, the error parameter is initialized, and the method for generating the theoretical error signal is as follows:

[0043] Calculate the mean of the minimum instantaneous angular velocity fluctuation signal, recorded as IAS k_m , which is the speed reference in the theoretical error model:

[0044] IAS k_m =mean(IAS k )

[0045] Among them, IAS k is the minimum fluctuation signal;

[0046] If the code disc is known to have a single error type, generate the instantaneous angular velocity error signal:

[0047]

[0048] Among them, ω eris the instantaneous angular velocity error of the encoder when the probe is arranged radially in the eccentric state, ω ar is the instantaneous angular velocity error of the code disk when the probe is arranged axially in an eccentric state; ρ r is the radial eccentricity, ρ a is the axial eccentricity; α′ represents the position angle information read by the probe, α is the actual rotation angle; Δr is the eccentricity distance, r is the radius of the code disk, ω(t) is the instantaneous angular velocity of the code disk when it rotates, ω t Indicates the instantaneous angular velocity error of the code disk in the tilted state;

[0049] Otherwise, the instantaneous angular velocity error signal is generated as:

[0050]

[0051] Among them, ω(t) is replaced by IAS k_m , generate a set of theoretical error signals under different error parameters, denoted as IAS e ;

[0052] IAS e =[IAS e1 (ρ1,β1),IAS e2 (ρ2,β2),…,IAS en (ρ n ,β n )]

[0053] Where β is the tilt angle of the code disk, ω misr is the instantaneous angular velocity error when the probe is arranged radially, ω misa Instantaneous angular velocity error when the probe is arranged axially, IAS en is the theoretical error signal calculated under different error parameters, ρ n Indicates the eccentricity error of the code disk, β n Indicates the code disk tilt angle error.

[0054] Generate error parameters and initialize the artificial lemming's search position.

[0055] Further, in step S23, the instantaneous angular velocity IAS with error is selected for measurement. m and the theoretical error signal IAS e The minimum value f(ρ,β) of the logarithm of the root mean square value rms of the spectrum of the difference between the two is the optimization objective function, which is:

[0056] f(ρ,β)=min(log(rms(F[IAS m -IAS e ])))

[0057] Here, F represents Fourier transform.

[0058] Due to the phase misalignment between the experimental signal and the theoretical simulation signal, direct subtraction of the two signals in the time domain results in amplitude variations or abnormal energy distribution. However, in the frequency domain amplitude spectrum, the impact of phase variations does not need to be considered, so this optimization objective function is selected.

[0059] Furthermore, in step S24, the global optimal parameters are calculated according to the principle of artificial lemming optimization algorithm, specifically:

[0060]

[0061] E(t)=4×arctan(1-t / T max )×ln(1 / rand)

[0062] in, is the current optimal solution; F is the sign of changing the search direction; A vector representing random Brownian motion; It is a random number in 1 row and Dim column between [-1,1], which is used to control the movement of the current optimal individual and random individuals in the lemming population; is a randomly selected individual in the population; L is a random number related to this iteration; is a random search individual in the population; G represents the escape coefficient of lemmings, which decreases with the increase of the number of iterations; Levy is Levy flight, which is used to simulate the deceptive behavior of lemmings; E(t) represents the energy coefficient.

[0063] Since the error parameters of the same code disk do not change with the change of the speed condition, the error parameters remain unchanged under other subsequent speed conditions, completing the identification of the error parameters of an error code disk.

[0064] Furthermore, in step S2, the instantaneous angular velocity error signal is decomposed using empirical mode decomposition to extract the error component, which is:

[0065]

[0066] Among them, IAS i It is the speed signal under a certain working condition measured experimentally; IMF i For IAS i Several eigenmode components are obtained after EMD decomposition; r is the residual component.

[0067] Empirical mode decomposition is used to decompose the error signal and extract the error components.

[0068] Furthermore, in step S3, the frequency domain coefficients are corrected to complete the reconstruction of the instantaneous angular velocity signal. The specific steps are as follows:

[0069] The instantaneous angular velocity error signal IAS of the theoretical model [ρ,β]best Perform Fourier transform and calculate the maximum amplitude of its spectrum, which is recorded as the error signal proportional reconstruction coefficient k1;

[0070] k1=max(F[IAS [ρ,β]best ])

[0071] Where F represents Fourier transform;

[0072] If the error signal proportional reconstruction coefficient is positive, the IMF component and IAS m If the value is negative, the correlation is negative:

[0073]

[0074] Where N represents the length of the signal, and Respectively represent the measured instantaneous angular velocity IAS i and the average value of the kth eigenmode component; pcc k represents the Pearson correlation coefficient, x i Indicates the measured instantaneous angular velocity IAS i The data of a certain point in the ik Represents the data of a certain point in the kth eigenmode component;

[0075] Find the IMF corresponding to the maximum error signal proportional reconstruction coefficient j , this component contains both error and true speed fluctuation components, and calculates the maximum value k2 of the spectrum;

[0076] k2=max(F[IMF j ])

[0077] Among them, the IMF j Indicates the calculated PCC k The corresponding eigenmode component is too large when it is at its maximum;

[0078] Calculate the instantaneous angular velocity IAS containing measurement error after empirical mode decomposition EMD transition decomposition i and the frequency domain correction coefficient k under co-channel interference after ALA optimization error parameter identification;

[0079] k=(k2-k1) / k2;

[0080] The IMF corresponding to the frequency domain correction coefficient k and the maximum error signal proportional reconstruction coefficient j Multiply it with other components IMF i And the residual component r is used to reconstruct the signal, then the instantaneous angular velocity IAS after the reconstruction of the same frequency interference component is suppressed rec-r for;

[0081] IAS rec-r =IMF1+IMF2+…+k*IMF j +r.

[0082] Based on the relevant frequency domain correction coefficient, the instantaneous angular velocity co-frequency interference component is effectively suppressed, and the true speed fluctuation signal is retained.

[0083] The present invention also provides an instantaneous angular velocity co-frequency interference error suppression system, comprising a data acquisition unit and a processing unit, wherein the data acquisition unit is used to collect instantaneous angular velocity signals of an encoder code disc under different speed conditions and transmit the signals to the processing unit;

[0084] The processing unit executes the method of the present invention to suppress co-channel interference errors.

[0085] This system is guided by physical information to suppress the same-frequency interference error and retain the real speed fluctuation signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] Figure 1 1 is a flow chart of a method for suppressing instantaneous angular velocity co-frequency interference errors according to the present invention;

[0087] Figure 2 This is a diagram of an eccentricity error model of the instantaneous angular velocity same-frequency interference error suppression method of the present invention;

[0088] Figure 3 1 is a coordinate diagram of the eccentricity error of the instantaneous angular velocity same-frequency interference error suppression method of the present invention;

[0089] Figure 4 is a diagram of a tilt error model of the instantaneous angular velocity co-frequency interference error suppression method of the present invention;

[0090] Figure 5 1 is a side view of the tilt error of the instantaneous angular velocity co-frequency interference error suppression method of the present invention;

[0091] Figure 6 is an n' direction view of the tilt error of the instantaneous angular velocity co-frequency interference error suppression method of the present invention;

[0092] Figure 7 This is a diagram of the intersecting misalignment error model of the instantaneous angular velocity same-frequency interference error suppression method of the present invention. DETAILED DESCRIPTION

[0093] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0094] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0095] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal communication between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0096] The present invention discloses a method for suppressing instantaneous angular velocity co-frequency interference errors. Based on physical information guidance, a theoretical model of instantaneous angular velocity error is built, and the particle swarm optimization algorithm is used to complete the identification of the code disk error parameters. Finally, the empirical mode decomposition is used to decompose and reconstruct the instantaneous angular velocity signal, and the relevant frequency domain correction coefficient is proposed. This method can effectively suppress the instantaneous angular velocity co-frequency interference component and realize the retention of the true speed fluctuation signal. Figure 1 As shown, the instantaneous angular velocity co-frequency interference error suppression method includes the following steps:

[0097] S1, perform error parameter identification, specifically using one of the following schemes:

[0098] Option 1:

[0099] S11, collecting the instantaneous angular velocity signals of the encoder disc under different speed conditions, and building three error angular domain models of the encoder disc eccentricity, tilt and intersection misalignment;

[0100] S12, calculating an instantaneous angular velocity error signal based on the error angle domain model;

[0101] S13, using a particle swarm optimization algorithm or an artificial lemming optimization algorithm to obtain a code disc error parameter and generate an instantaneous angular velocity error signal of a theoretical model;

[0102] Option 2:

[0103] S21, collecting instantaneous angular velocity signals of the same encoder under multiple groups of different speed conditions, calculating the peak-to-peak value of each group of signals, and screening the minimum fluctuation signal;

[0104] S22, calculating the mean of the minimum fluctuation signal, initializing the error parameter, and generating a theoretical error signal;

[0105] S23, constructing an optimization objective function based on the theoretical error signal;

[0106] S24, iterating according to the artificial lemming optimization algorithm or the particle swarm optimization algorithm, and outputting the global optimal parameters if the convergence condition is met, otherwise returning to step S22;

[0107] S25, generating an instantaneous angular velocity error signal of a theoretical model based on the global optimal parameters;

[0108] S2, using empirical mode decomposition to decompose the instantaneous angular velocity error signal and extract the error components;

[0109] S3, correct the frequency domain coefficients, complete the reconstruction of the instantaneous angular velocity signal, and suppress the co-frequency interference error.

[0110] In a preferred embodiment of the present invention, Figure 2-Figure 7 As shown, in step S11, the three error angle domain models of encoder code disc eccentricity, tilt and intersection misalignment are:

[0111]

[0112] Among them, ω er is the instantaneous angular velocity error of the code disk when the probe is arranged radially in the eccentric state, ρ r is the radial eccentricity, α′ represents the position angle information read by the probe, ω(t) is the instantaneous angular velocity of the code disk when it rotates, ω t Indicates the instantaneous angular velocity error of the code disk in the tilted state; α is the actual rotation angle; β is the tilt angle of the code disk, ω misr is the instantaneous angular velocity error when the probe is arranged radially.

[0113] In a preferred embodiment of the present invention, in step S12, the instantaneous angular velocity error signal is calculated based on the error angle domain model, specifically:

[0114] The instantaneous angular velocity signal IAS obtained under different speed conditions or multiple measurements on the same encoder m In the example, the instantaneous angular velocity signal IAS with the smallest speed fluctuation is selected. min And calculate its mean IAS mim_m(The average value of the instantaneous angular velocity signal with the smallest speed fluctuation over all time) is used as the speed reference of the theoretical model;

[0115] Based on the theoretical model speed benchmark, the particle swarm search parameters are initialized. If the code disk is known to be a single error type, then based on ω er and ω t , generating an instantaneous angular velocity error signal;

[0116] Otherwise, based on ω misr Generate the instantaneous angular velocity error signal and replace ω(t) in the formula with IAS mim_m , calculate and generate a set of theoretical error signals under different error parameters, recorded as IAS e :

[0117] IAS e =[IAS e1 (ρ1,β1),IAS e2 (ρ2,β2),…,IAS en (ρ n ,β n )]

[0118] Among them, IAS en is the theoretical error signal calculated under different error parameters, ρ n Indicates the eccentricity error of the code disk, β n Represents the tilt angle error of the code disk, and n represents a sequence of different error parameters (the particle swarm search parameters have been initialized before. There is more than one parameter here, but a range, so a set of theoretical error signals under different error parameters will be generated accordingly).

[0119] In a preferred embodiment of the present invention, in step S13, the method for obtaining the error parameters of the code disk using the particle swarm optimization algorithm is as follows:

[0120] The eccentricity ρ and tilt angle β parameters are optimized synchronously by particle swarm optimization algorithm to make the experimental signal IAS m and the theoretical error signal IAS er The root mean square logarithmic function f(ρ,β) of the frequency domain difference is minimized, and the final output is the inherent error parameter ρ which is independent of the speed. gBest and β gBest Complete identification; generate the theoretical model instantaneous angular velocity error signal IAS at the stable speed of this working condition [ρ,β]best :

[0121] f(ρ,β)=min(log(rms(F[IAS m -IAS er ])))

[0122] Wherein, rms represents the root mean square function, and F represents Fourier transform.

[0123] In a preferred embodiment of the present invention, in step S21, the peak-to-peak value V of each group of signals is calculated. pp , screening minimum fluctuation signal IAS k for:

[0124] V pp =V max -V min

[0125] IAS k =arg min[V pp (IAS1,IAS2,…,IAS n )]

[0126] Among them, V max , V min Indicates the maximum and minimum values of each group of signals; IAS n is the nth fluctuation signal.

[0127] In a preferred embodiment of the present invention, in step S22, the method for calculating the mean of the minimum fluctuation signal, initializing the error parameter, and generating the theoretical error signal is:

[0128] Calculate the mean of the minimum instantaneous angular velocity fluctuation signal, recorded as IAS k_m , which is the speed reference in the theoretical error model:

[0129] IAS k_m =mean(IAS k )

[0130] Among them, IAS k is the minimum fluctuation signal;

[0131] If the code disc is known to have a single error type, generate the instantaneous angular velocity error signal:

[0132]

[0133] Among them, ω er is the instantaneous angular velocity error of the encoder when the probe is arranged radially in the eccentric state, ω ar is the instantaneous angular velocity error of the code disk when the probe is arranged axially in an eccentric state; ρ r is the radial eccentricity, ρ a is the axial eccentricity; α′ represents the position angle information read by the probe, α is the actual rotation angle; Δr is the eccentricity distance, r is the radius of the code disk, ω(t) is the instantaneous angular velocity of the code disk when it rotates, ω t Indicates the instantaneous angular velocity error of the code disk in the tilted state;

[0134] Otherwise, the instantaneous angular velocity error signal is generated as:

[0135]

[0136] Among them, ω(t) is replaced by IAS k_m , generate a set of theoretical error signals under different error parameters, denoted as IAS e ;

[0137] IAS e =[IAS e1 (ρ1,β1),IAS e2 (ρ2,β2),…,IAS en (ρ n ,β n )]

[0138] Where β is the tilt angle of the code disk, ω misr is the instantaneous angular velocity error when the probe is arranged radially, ω misa Instantaneous angular velocity error when the probe is arranged axially, IAS en is the theoretical error signal calculated under different error parameters, ρ n Indicates the eccentricity error of the code disk, β n Indicates the code disk tilt angle error.

[0139] The radial arrangement of the probe means that the installation direction of the probe is perpendicular to the rotation direction of the shaft, and the axial arrangement means that the probe is arranged along the axis of the shaft to monitor axial displacement or vibration.

[0140] In a preferred embodiment of the present invention, in step S23, the instantaneous angular velocity IAS containing an error is selected to be measured. m and the theoretical error signal IAS e The minimum value f(ρ,β) of the logarithm of the root mean square value rms of the spectrum of the difference between the two is the optimization objective function, which is:

[0141] f(ρ,β)=min(log(rms(F[IAS m -IAS e ])))

[0142] Here, F represents Fourier transform.

[0143] In a preferred embodiment of the present invention, in step S24, the global optimal parameters are calculated according to the principle of artificial lemming optimization algorithm, specifically:

[0144]

[0145] E(t)=4×arctan(1-t / T max)×ln(1 / rand)

[0146] in, is the current optimal solution; F is the sign of changing the search direction; A vector representing random Brownian motion; It is a random number in 1 row and Dim column between [-1,1], which is used to control the movement of the current optimal individual and random individuals in the lemming population; is a randomly selected individual in the population; L is a random number related to this iteration; is a random search individual in the population; G represents the escape coefficient of lemmings, which decreases with the increase of the number of iterations; Levy is Levy flight, which is used to simulate the deceptive behavior of lemmings; E(t) represents the energy coefficient.

[0147] In a preferred embodiment of the present invention, in step S2, the instantaneous angular velocity error signal is decomposed using empirical mode decomposition to extract the error component, which is:

[0148]

[0149] Among them, IAS i It is the speed signal under a certain working condition measured experimentally; IMF i For IAS i Several eigenmode components are obtained after EMD decomposition; r is the residual component.

[0150] In a preferred embodiment of the present invention, in step S3, the frequency domain coefficients are corrected to complete the reconstruction of the instantaneous angular velocity signal. The specific steps are as follows:

[0151] The instantaneous angular velocity error signal IAS of the theoretical model [ρ,β]best Perform Fourier transform and calculate the maximum amplitude of its spectrum, which is recorded as the error signal proportional reconstruction coefficient k1;

[0152] k1=max(F[IAS [ρ,β]best ])

[0153] Where F represents Fourier transform;

[0154] If the error signal proportional reconstruction coefficient is positive, the IMF component and IAS m If the value is negative, the correlation is negative:

[0155]

[0156] Where N represents the length of the signal, and Respectively represent the measured instantaneous angular velocity IAS i and the average value of the kth eigenmode component; pcck represents the Pearson correlation coefficient, x i Indicates the measured instantaneous angular velocity IAS i The data of a certain point in the ik Represents the data of a certain point in the kth eigenmode component;

[0157] Find the IMF corresponding to the maximum error signal proportional reconstruction coefficient j , this component contains both error and true speed fluctuation components, and calculates the maximum value k2 of the spectrum;

[0158] k2=max(F[IMF j ])

[0159] Among them, the IMF j Indicates the calculated PCC k The corresponding eigenmode component is too large when it is at its maximum;

[0160] Calculate the instantaneous angular velocity IAS containing measurement error after EMD (Empirical Mode Decomposition (EMD Empirical Mode Decomposition) was proposed by NEHuang et al. It is suitable for analyzing and processing non-stationary and nonlinear signal data. It can decompose complex signals into the sum of a finite number of intrinsic mode functions (IMF Intrinsic Mode Function)) transition decomposition i and the frequency domain correction coefficient k under co-channel interference after ALA optimization error parameter identification;

[0161] k=(k2-k1) / k2;

[0162] The IMF corresponding to the frequency domain correction coefficient k and the maximum error signal proportional reconstruction coefficient j Multiply it with other components IMF i And the residual component r is used to reconstruct the signal, then the instantaneous angular velocity IAS after the reconstruction of the same frequency interference component is suppressed rec-r for;

[0163] IAS rec-r =IMF1+IMF2+…+k*IMF j +r.

[0164] The present invention also provides an instantaneous angular velocity co-frequency interference error suppression system, which includes a data acquisition unit and a processing unit. The data acquisition unit is used to collect instantaneous angular velocity signals of the encoder code disk under different speed conditions and transmit them to the processing unit.

[0165] The processing unit executes the method of the present invention to suppress co-channel interference errors.

[0166] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0167] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A method for suppressing instantaneous angular velocity co-frequency interference error, characterized in that: The steps include: S1, perform error parameter identification, specifically using one of the following schemes: Option 1: S11, collecting the instantaneous angular velocity signals of the encoder disc under different speed conditions, and building three error angular domain models of the encoder disc eccentricity, tilt and intersection misalignment; S12, calculating an instantaneous angular velocity error signal based on the error angle domain model; S13, using a particle swarm optimization algorithm or an artificial lemming optimization algorithm to obtain a code disc error parameter and generate an instantaneous angular velocity error signal of a theoretical model; Option 2: S21, collecting instantaneous angular velocity signals of the same encoder under multiple groups of different speed conditions, calculating the peak-to-peak value of each group of signals, and screening the minimum fluctuation signal; S22, calculating the mean of the minimum fluctuation signal, initializing the error parameter, and generating a theoretical error signal; S23, constructing the optimization objective function based on the theoretical error signal; S24, iterating according to the artificial lemming optimization algorithm or the particle swarm optimization algorithm, and outputting the global optimal parameters if the convergence condition is met, otherwise returning to step S22; S25, generating an instantaneous angular velocity error signal of a theoretical model based on the global optimal parameters; S2, using empirical mode decomposition to decompose the instantaneous angular velocity error signal and extract the error components; S3, correct the frequency domain coefficients, complete the reconstruction of the instantaneous angular velocity signal, and suppress the co-frequency interference error.

2. The method for suppressing instantaneous angular velocity co-frequency interference error according to claim 1, wherein: In step S11, the three error angle domain models of encoder code disc eccentricity, tilt and intersection misalignment are: Among them, ω er is the instantaneous angular velocity error of the code disk when the probe is arranged radially in the eccentric state, ρ r is the radial eccentricity, α′ represents the position angle information read by the probe, ω(t) is the instantaneous angular velocity of the code disk when it rotates, ω t Indicates the instantaneous angular velocity error of the code disk in the tilted state; α is the actual rotation angle; β is the tilt angle of the code disk, ω misr is the instantaneous angular velocity error when the probe is arranged radially.

3. The method for suppressing instantaneous angular velocity co-frequency interference error according to claim 2, wherein: In step S12, the instantaneous angular velocity error signal is calculated based on the error angle domain model, specifically: The instantaneous angular velocity signal IAS obtained under different speed conditions or multiple measurements on the same encoder m In the example, the instantaneous angular velocity signal IAS with the smallest speed fluctuation is selected. min And calculate its mean IAS mim_m As a theoretical model speed benchmark; Based on the theoretical model speed benchmark, the particle swarm search parameters are initialized. If the code disk is known to be a single error type, then based on ω er and ω t , generating an instantaneous angular velocity error signal; Otherwise, based on ω misr Generate the instantaneous angular velocity error signal and replace ω(t) in the formula with IAS mim_m , calculate and generate a set of theoretical error signals under different error parameters, recorded as IAS e : IAS e =[IAS e1 (ρ1,β1),IAS e2 (ρ2,β2),…,IAS en (r n ,b n )] Among them, IAS en is the theoretical error signal calculated under different error parameters, ρ n Indicates the eccentricity error of the code disk, β n represents the code disk tilt angle error, and n represents a sequence of different error parameters.

4. The method for suppressing instantaneous angular velocity co-frequency interference error according to claim 1, wherein: In step S13, the particle swarm optimization algorithm is used to obtain the error parameters of the code disk as follows: The eccentricity ρ and tilt angle β parameters are optimized synchronously by particle swarm optimization algorithm to make the experimental signal IAS m and the theoretical error signal IAS er The root mean square logarithmic function f(ρ,β) of the frequency domain difference is minimized, and the final output is the inherent error parameter ρ that is independent of the speed. gBest and β gBest Complete identification; generate the theoretical model instantaneous angular velocity error signal IAS at the stable speed of this working condition [ρ,β]best : f(ρ,β)=min(log(rms(F[IAS m -IAS er ]))) Wherein, rms represents the root mean square function, and F represents Fourier transform.

5. The method for suppressing instantaneous angular velocity co-frequency interference error according to claim 1, wherein: In step S21, the peak-to-peak value V of each signal group is calculated. pp , screening minimum fluctuation signal IAS k for: V pp =V max -V min IAS k =arg min[V pp (IAS1,IAS2,…,IAS n )] Among them, V max , V min Indicates the maximum and minimum values of each group of signals; IAS n is the nth fluctuation signal.

6. The method for suppressing instantaneous angular velocity co-frequency interference error according to claim 1, wherein: In step S22, the mean of the minimum fluctuation signal is calculated, the error parameter is initialized, and the method for generating the theoretical error signal is as follows: Calculate the mean of the minimum instantaneous angular velocity fluctuation signal, recorded as IAS k_m , which is the speed reference in the theoretical error model: IAS k_m =mean(IAS k ) Among them, IAS k is the minimum fluctuation signal; If the code disc is known to have a single error type, generate the instantaneous angular velocity error signal: Among them, ω er is the instantaneous angular velocity error of the encoder when the probe is arranged radially in the eccentric state, ω ar is the instantaneous angular velocity error of the code disk when the probe is arranged axially in an eccentric state; ρ r is the radial eccentricity, ρ a is the axial eccentricity; α′ represents the position angle information read by the probe, α is the actual rotation angle; Δr is the eccentricity distance, r is the radius of the code disk, ω(t) is the instantaneous angular velocity of the code disk when it rotates, ω t Indicates the instantaneous angular velocity error of the code disk in the tilted state; Otherwise, the instantaneous angular velocity error signal is generated as: Among them, ω(t) is replaced by IAS k_m , generate a set of theoretical error signals under different error parameters, denoted as IAS e ; IAS e =[IAS e1 (ρ1,β1),IAS e2 (ρ2,β2),…,IAS en (r n ,b n )] Where β is the tilt angle of the code disk, ω misr is the instantaneous angular velocity error when the probe is arranged radially, ω misa Instantaneous angular velocity error when the probe is arranged axially, IAS en is the theoretical error signal calculated under different error parameters, ρ n Indicates the eccentricity error of the code disk, β n Indicates the code disk tilt angle error.

7. The method for suppressing instantaneous angular velocity co-frequency interference error according to claim 1, wherein: In step S23, the instantaneous angular velocity IAS with error is selected for measurement. m and the theoretical error signal IAS e The minimum value f(ρ,β) of the logarithm of the root mean square value rms of the spectrum of the difference between the two is the optimization objective function, which is: f(ρ,β)=min(log(rms(F[IAS m -IAS e ]))) Here, F represents Fourier transform.

8. The method for suppressing instantaneous angular velocity co-frequency interference error according to claim 1, wherein: In step S24, the global optimal parameters are calculated according to the principle of artificial lemming optimization algorithm, specifically: E(t)=4×arctan(1-t / T max )×ln(1 / rand) in, is the current optimal solution; F is the sign of changing the search direction; A vector representing random Brownian motion; It is a random number in 1 row and Dim column between [-1,1], which is used to control the movement of the current optimal individual and random individuals in the lemming population; is a randomly selected individual in the population; L is a random number related to this iteration; is a random search individual in the population; G represents the escape coefficient of lemmings, which decreases with the increase of the number of iterations; Levy is Levy flight, which is used to simulate the deceptive behavior of lemmings; E(t) represents the energy coefficient.

9. The method for suppressing instantaneous angular velocity co-frequency interference error according to claim 1, wherein: In step S2, the instantaneous angular velocity error signal is decomposed using empirical mode decomposition to extract the error component, which is: Among them, IAS i It is the speed signal under a certain working condition measured experimentally; IMF i For IAS i Several eigenmode components obtained after EMD decomposition; r is the residual component.

10. The method for suppressing instantaneous angular velocity co-frequency interference error according to claim 1, wherein: In step S3, the frequency domain coefficients are corrected to complete the reconstruction of the instantaneous angular velocity signal. The specific steps are as follows: The instantaneous angular velocity error signal IAS of the theoretical model [ρ,β]best Perform Fourier transform and calculate the maximum amplitude of its spectrum, which is recorded as the error signal proportional reconstruction coefficient k1; k1=max(F[IAS [ρ,β]best ]) Where F represents Fourier transform; If the error signal proportional reconstruction coefficient is positive, the IMF component and IAS m If the value is negative, the correlation is negative: Where N represents the length of the signal, and Respectively represent the measured instantaneous angular velocity IAS i and the average value of the kth eigenmode component; pcc k represents the Pearson correlation coefficient, x i Indicates the measured instantaneous angular velocity IAS i The data of a certain point in the ik Represents the data of a certain point in the kth eigenmode component; Find the IMF corresponding to the maximum error signal proportional reconstruction coefficient j , this component contains both error and true speed fluctuation components, and calculates the maximum value k2 of the spectrum; k2=max(F[IMF j ]) Among them, the IMF j Indicates the calculated PCC k The corresponding eigenmode component is the maximum; Calculate the instantaneous angular velocity IAS containing measurement error after empirical mode decomposition EMD transition decomposition i and the frequency domain correction coefficient k under co-channel interference after ALA optimization error parameter identification; k=(k2-k1) / k2; The frequency domain correction coefficient k is proportional to the maximum error signal reconstruction coefficient corresponding to the IMF j Multiply it with other components IMF i And the residual component r is used to reconstruct the signal, then the instantaneous angular velocity IAS after the reconstruction of the same frequency interference component is suppressed rec-r for; IAS rec-r =IMF1+IMF2+…+k*IMF j +r。 11. A system for suppressing instantaneous angular velocity co-frequency interference errors, characterized in that: It includes a data acquisition unit and a processing unit, wherein the data acquisition unit is used to collect the instantaneous angular velocity signal of the encoder code disc under different speed conditions and transmit it to the processing unit; The processing unit executes the method according to any one of claims 1 to 10 to suppress co-channel interference errors.

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