Error compensation method and system for linear servo actuator

Abstract

The embodiment of the invention provides an error compensation method and system for a linear servo actuator, and the method comprises the steps: obtaining the error sensing data of different error sources through a displacement feedback device, a temperature collection device, a force feedback device, a vibration collection device and other sensing devices, and carrying out the fusion processing of the error sensing data, according to the method, a dynamic error model capable of reflecting the coupling relation of different error sources along with time change is constructed, then an error compensation signal containing the superposition result of a feed-forward compensation component and a feedback compensation component is generated according to the dynamic error model, and finally the error compensation signal is loaded to a driving module of an actuator. And the displacement output of the actuating mechanism is adjusted to offset the error influence, and the control precision and stability of the linear servo actuator under the complex operation working condition are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of industrial automation, in particular to an error compensation method and system of a linear servo actuator. BACKGROUND

[0002] In the field of modern industrial automation and precision control, linear servo actuators are the core components for achieving high-precision motion control, and are widely used in applications requiring precise positioning and trajectory tracking, such as semiconductor manufacturing equipment, precision instruments and meters, and high-end numerical control machining systems. However, in actual operating environments, linear servo actuators are subject to interference from various error sources, including wear and tear of mechanical components, fluctuations in environmental temperature, sudden changes in external loads, and mechanical structure vibrations. These error sources each have an impact on the output accuracy of the actuator, and more complexly, they interact and influence each other, and this influence changes over time and with changes in operating conditions, resulting in a deviation between the actual output displacement of the linear servo actuator and the theoretical value, making it difficult to achieve high-precision control requirements.

[0003] Existing error compensation techniques often only model and compensate for a single error source, without fully considering the dynamic coupling relationship between different error sources, resulting in a lack of comprehensiveness and dynamic adaptability in the compensation strategy, which cannot effectively cope with complex and variable actual operating conditions, and is difficult to meet the control requirements of modern industry for high-precision linear servo actuators. SUMMARY

[0004] In view of this, the purpose of the embodiments of the present application is to provide an error compensation method and system for a linear servo actuator.

[0005] According to one aspect of the embodiments of the present application, an error compensation method for a linear servo actuator is provided, the method comprising: obtaining error perception data of different error sources based on a plurality of types of perception devices inside the actuator, the plurality of types of perception devices including displacement feedback devices, temperature acquisition devices, force feedback devices, and vibration acquisition devices; performing fusion processing on the error perception data to establish a dynamic error model of the actuator mechanism, the dynamic error model reflecting the coupling relationship between different error sources changing over time; generating an error compensation signal according to the dynamic error model, the error compensation signal containing the superposition result of a feedforward compensation component and a feedback compensation component; loading the error compensation signal to a driving module of the actuator to adjust the displacement output of the actuator mechanism to offset the error influence.

[0006] In a possible implementation of the first aspect, the error perception data of different error sources is acquired by the multi-type perception device inside the actuator, including: The actual displacement sequence of the actuating mechanism in different motion cycles is collected by the displacement feedback device, and the periodic deviation characteristics are determined by comparing the theoretical displacement sequence; The three-dimensional temperature distribution of the actuator shell, transmission component support seat and output end is acquired by the temperature acquisition device, and a temperature gradient change curve is established; The real-time torque fluctuation between the execution end and the load is monitored by the force feedback device, and the combined characteristics of the torque fluctuation amplitude and frequency are extracted; The vibration frequency spectrum of the actuator in the running process is captured by the vibration acquisition device, and the vibration mode corresponding to the external environmental disturbance is identified.

[0007] In a possible implementation of the first aspect, the error perception data is fused to establish a dynamic error model of the actuating mechanism, including: The periodic deviation characteristics are decomposed into a first error component related to transmission component wear and a second error component related to assembly gap; According to the temperature gradient change curve, the thermal expansion deformation of the actuating mechanism is predicted, and a spatial distribution function of thermal deformation error is generated; Combined with the combined characteristics of the torque fluctuation amplitude and frequency, the coupling effect of load change on the dynamic stiffness of the actuating mechanism is analyzed, and a load disturbance transfer function is constructed; The disturbance intensity of environmental disturbance on the stability of the actuator is identified by the energy proportion of different modes in the vibration frequency spectrum; The first error component, the second error component, the spatial distribution function of thermal deformation error, the load disturbance transfer function and the disturbance intensity are input into the time-varying coupling equation to generate a dynamic error model.

[0008] In a possible implementation of the first aspect, the periodic deviation characteristics are decomposed into a first error component related to transmission component wear and a second error component related to assembly gap, including: The difference waveform between the actual displacement sequence and the theoretical displacement sequence is extracted, the difference waveform is analyzed by harmonic analysis, and the fundamental component with the same frequency as the transmission component rotation period is separated as the first error component; The non-periodic sharp signal synchronized with the commutation action of the actuating mechanism in the difference waveform is identified, and the amplitude accumulation of the sharp signal is taken as the second error component; The wear correlation curve of the first error component and the transmission component running time is established, and the degradation correlation curve of the second error component and the cumulative number of actuating mechanism working times is established.

[0009] In a possible implementation of the first aspect, the generating a spatial distribution function of thermal deformation error by predicting thermal expansion deformation of the actuator according to the temperature gradient change curve comprises: arranging a plurality of temperature detection points on the actuator housing surface, and calculating a heat conduction path according to a temperature change rate of each detection point; establishing a thermal inertia differential equation based on a delay in heat transfer between the transmission component support seat and the output end; calculating an instantaneous temperature value of a key node of the actuator by the thermal inertia differential equation, and generating a three-dimensional deformation displacement field in combination with a material expansion coefficient; taking a projection component in the three-dimensional deformation displacement field along a movement direction of the actuator as the spatial distribution function of the thermal deformation error.

[0010] In a possible implementation of the first aspect, the analyzing a coupling effect of load change on dynamic stiffness of the actuator in combination with a combined feature of the torque fluctuation amplitude and frequency, and constructing a load disturbance transfer function comprises: arranging symmetrically distributed strain detection units in the force feedback device, and calculating a real-time fluctuation amount of the load torque according to a difference value of symmetric strain signals; performing time-frequency transformation on the real-time fluctuation amount, and extracting a steady-state torque component in a low frequency band and a transient impact component in a high frequency band; establishing a stiffness attenuation relationship of the steady-state torque component and a speed of the actuator, and an inertia coupling relationship of the transient impact component and an acceleration; integrating the stiffness attenuation relationship and the inertia coupling relationship into a frequency domain transfer function to represent an influence weight of the load disturbance on positioning accuracy of the actuator.

[0011] In a possible implementation of the first aspect, the identifying disturbance intensity of the environment disturbance on stability of the actuator by the energy proportion of different modes in the vibration spectrum comprises: arranging a multi-axis vibration sensor in the vibration acquisition device, and synchronously collecting vibration acceleration signals of the actuator in three orthogonal directions in space; performing band-pass filtering on the vibration acceleration signals, and separating a main vibration mode matched with an inherent frequency of the actuator and a secondary vibration mode related to environmental excitation; calculating a ratio of an energy attenuation coefficient of the main vibration mode and an energy growth rate of the secondary vibration mode as an evaluation index of the environmental disturbance intensity; when the evaluation index exceeds a preset threshold, triggering an anti-interference compensation mode of the actuator.

[0012] In a possible implementation of the first aspect, the generating an error compensation signal according to the dynamic error model, the error compensation signal comprising a superposition of a feedforward compensation component and a feedback compensation component, comprises: extracting a predictable periodic error component from the dynamic error model, and generating the feedforward compensation component by inverse model calculation; collecting displacement deviation of the actuator in real time, and generating the feedback compensation component by a proportional-integral-derivative control algorithm; performing amplitude and phase calibration on the feedforward compensation component and the feedback compensation component, so that the superposition of the feedforward compensation component and the feedback compensation component is continuous and smooth in time domain; performing amplitude limiting processing on the superposition result according to the maximum response speed and driving capability of the actuator, to generate a final error compensation signal.

[0013] In a possible implementation of the first aspect, the generating the feedforward compensation component by inverse model calculation comprises: establishing an ideal transfer function of the actuator, the ideal transfer function representing the correspondence between an input signal and an output displacement under an error-free condition; connecting the dynamic error model and the ideal transfer function in series, and solving an inverse controller transfer function that makes the output of the series system equal to the ideal output; preprocessing a reference input signal by the inverse controller transfer function, to generate a feedforward compensation component that offsets the influence of the error; adjusting the zero-pole configuration of the inverse controller transfer function online according to the real-time updated dynamic error model parameters; In a possible implementation of the first aspect, the performing amplitude and phase calibration on the feedforward compensation component and the feedback compensation component comprises: setting a phase lead correction module in the feedforward compensation channel, to compensate for phase lag caused by mechanical delay of the actuator; setting an amplitude normalization module in the feedback compensation channel, to eliminate gain imbalance caused by different dimensions of displacement deviation; determining an optimal superposition frequency band of the feedforward compensation component and the feedback compensation component by a cross-frequency analysis method; performing coherence optimization on the two compensation signals in the optimal superposition frequency band, so that the spectral energy of the superimposed signal is concentrated in the error-sensitive frequency band.

[0014] According to another aspect of the embodiments of the present application, there is provided an error compensation system of a linear servo actuator, comprising a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other through the communication bus; the memory is configured to store a computer program; and the processor is configured to execute the computer program to implement the error compensation method of the linear servo actuator according to any one of the above aspects.

[0015] According to another aspect of the embodiments of the present application, there is provided a readable storage medium having a computer program stored thereon, wherein the computer program is executable by a processor to implement the steps of the error compensation method of the linear servo actuator according to the above aspects.

[0016] According to any one of the above aspects, by comprehensively using multiple types of sensing devices such as displacement feedback devices, temperature acquisition devices, force feedback devices and vibration acquisition devices, error sensing data of different error sources are comprehensively acquired, and various factors affecting the output accuracy of the linear servo actuator are comprehensively covered. On this basis, the acquired error sensing data is deeply fused and processed to construct a dynamic error model capable of accurately reflecting the coupling relationship between different error sources changing over time. The dynamic error model fully considers the dynamic interaction between various error sources. The error compensation signal generated according to the dynamic error model contains the superposition result of the feedforward compensation component and the feedback compensation component. This superimposed compensation method can simultaneously perform predictive compensation and real-time correction on the error, effectively improving the timeliness and accuracy of the compensation. After the error compensation signal is loaded to the driving module of the actuator, the displacement output of the actuator can be adjusted in real time, so that the actual output displacement of the actuator is closer to the theoretical value, and the control accuracy and stability of the linear servo actuator under complex operating conditions are significantly improved.

[0017] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present application more obvious and easy to understand, the following will be described in detail in conjunction with the embodiments and the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0019] Figure 1 Fig. 1 shows a component schematic diagram of an error compensation system of a linear servo actuator provided by the embodiments of the present application; Figure 2A flow chart of an error compensation method of the linear servo actuator is shown. DETAILED DESCRIPTION

[0020] In order to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. According to the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the present application.

[0021] The terms "first", "second", "third" and the like as used in the description and the claims of the present application and the above drawings, if any, are used to distinguish similar objects and are not necessarily to describe a particular sequential or chronological order. It should be understood that the data thus used can be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "comprise" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0022] Embodiment one: Figure 1An example component diagram of the error compensation system 100 of a linear servo actuator is shown. The error compensation system 100 of a linear servo actuator can include one or more processors 104, such as one or more central processing units (CPUs), each of which can implement one or more hardware threads. The error compensation system 100 of a linear servo actuator can also include any storage media 106 for storing any kind of information, such as code, settings, data, etc. Without limitation, for example, the storage media 106 can include any one or combination of the following: any type of RAM, any type of ROM, a flash memory device, a hard disk, an optical disk, etc. More generally, any storage media can store information using any technology. Further, any storage media can provide volatile or non-volatile retention of information. Further, any storage media can represent a fixed or removable component of the error compensation system 100 of a linear servo actuator. In one case, the error compensation system 100 of a linear servo actuator can perform any of the operations associated with the instructions stored in any storage media or combination of storage media when the processors 104 execute the instructions. The error compensation system 100 of a linear servo actuator also includes one or more drive units 108, such as a hard disk drive unit, an optical disk drive unit, etc., for interacting with any storage media.

[0023] The error compensation system 100 of a linear servo actuator also includes input / output 110 (I / O) for receiving various inputs (via input units 112) and for providing various outputs (via output units 114). One particular output mechanism can include a presentation device 116 and a presence-dependent graphical user interface (GUI) 118. The error compensation system 100 of a linear servo actuator can also include one or more network interfaces 120 for exchanging data with other devices via one or more communication units 122. One or more communication buses 124 couple the above-described components together.

[0024] The communication units 122 can be implemented in any way, for example, through a local area network, a wide area network such as the Internet, a point-to-point connection, etc., or any combination thereof. The communication units 122 can include any combination of hardwired links, wireless links, routers, gateway functionality, name servers, etc., governed by any protocol or combination of protocols.

[0025] Embodiment Two: Figure 2 A flowchart of a method for error compensation of a linear servo actuator is shown, which can be performed by the error compensation system 100 of a linear servo actuator shown in Figure 1 The detailed steps of the method for error compensation of a linear servo actuator are introduced as follows.

[0026] Step S110: Obtain error perception data of different error sources based on the multi-type perception devices inside the actuator, including displacement feedback devices, temperature acquisition devices, force feedback devices, and vibration acquisition devices.

[0027] In this embodiment, linear servo actuators are widely used in industrial automation production, precision instrument manufacturing, and many other fields. However, their operation is often disturbed by various error sources, leading to a decrease in execution accuracy. In order to accurately grasp these error information, it is necessary to reasonably arrange multi-type perception devices inside the actuator.

[0028] Displacement feedback devices usually use high-precision sensors such as grating rulers and encoders. Grating rulers use the optical principle of gratings to accurately measure the displacement of the actuator by detecting the movement of grating stripes; encoders calculate the linear displacement of the actuator by measuring the rotation angle and combining with the mechanical transmission ratio. These sensors can track the position changes of the actuator in real time and accurately, providing basic data for subsequent error analysis.

[0029] Temperature acquisition devices are generally composed of multiple temperature sensors arranged at key positions such as the actuator housing, transmission component support seat, and output end. These temperature sensors can be thermocouples, thermistors, etc., which can convert temperature signals into electrical signals and record the temperature values of each part through the data acquisition system. Temperature changes can cause thermal expansion or contraction of actuator components, affecting the displacement accuracy of the actuator, so temperature data is one of the important sources of error perception data.

[0030] Force feedback devices mainly work based on the strain gauge principle. Strain gauges are attached to the connection between the actuator end and the load, and when subjected to force, the resistance value of the strain gauge changes. By measuring the change in resistance value, the force can be calculated. Force feedback devices can monitor the force fluctuations between the actuator end and the load in real time. Changes in load can affect the movement of the actuator, leading to errors, so force feedback data is crucial for analyzing load-related errors.

[0031] Vibration acquisition devices usually use acceleration sensors. Acceleration sensors can measure the vibration acceleration of the actuator during operation, and through analysis of the acceleration signal, the vibration of the actuator can be understood. External environmental disturbances, unbalance of the actuator itself, and other factors can cause vibration, which can affect the stability and accuracy of the actuator. Vibration data collected by vibration acquisition devices can reflect error information in this regard.

[0032] Step S111: Collecting actual displacement sequence of the actuator in different motion cycles by the displacement feedback device, and determining periodic deviation characteristics by comparing with theoretical displacement sequence.

[0033] Then, the displacement feedback device will continuously sample the displacement of the actuator according to the pre-set sampling period. Assuming that the sampling period is T, the actual displacement values collected by the displacement feedback device in the i th motion cycle are Di1, Di2, Di3, …, Din in turn, where n is the number of sampling points in the motion cycle. These actual displacement values constitute the actual displacement sequence.

[0034] The theoretical displacement sequence is determined in advance according to the control instruction and motion planning of the actuator. For example, the motion of the actuator can be carried out according to a certain speed curve, and the theoretical displacement value at each sampling time can be calculated according to the kinematics principle. In the i th motion cycle, the corresponding theoretical displacement values are Ti1, Ti2, Ti3, …, Tin.

[0035] In order to determine the periodic deviation characteristics, the corresponding points of the actual displacement sequence and the theoretical displacement sequence need to be subtracted to obtain the deviation sequence Ei1=Di1-Ti1, Ei2=Di2-Ti2, Ei3=Di3-Ti3, …, Ein=Din-Tin. Then, the deviation sequences of multiple motion cycles are analyzed. Fourier transform and other mathematical methods can be used to convert the time domain deviation sequence to the frequency domain, and whether there is obvious periodic component in the frequency spectrum is observed. If there is a periodic component, it means that the deviation sequence presents periodic change, so it is determined that there is periodic deviation characteristics.

[0036] Step S112: Obtaining three-dimensional temperature distribution of the actuator shell, transmission component support seat and output end by the temperature collection device, and establishing temperature gradient change curve.

[0037] Then, the temperature collection device arranges multiple temperature sensors on the shell, transmission component support seat and output end of the actuator to obtain the temperature information of these parts. Assuming that m1 temperature sensors are arranged on the actuator shell, m2 temperature sensors are arranged on the transmission component support seat, and m3 temperature sensors are arranged on the output end.

[0038] At each sampling time, these temperature sensors will simultaneously measure the temperature values at their respective positions, thereby obtaining a three-dimensional temperature distribution data. Arranging these temperature data according to the spatial position, the three-dimensional temperature distribution of the actuator at that time can be constructed.

[0039] To further analyze the temperature variation law, it is necessary to establish a temperature gradient change curve. First, according to the distance between adjacent temperature sensors and the temperature difference, the temperature gradient in each direction is calculated. For example, in the x direction, the distance between adjacent temperature sensors is Δx, and the corresponding temperature difference is ΔT, then the temperature gradient in the x direction is Gx=ΔT / Δx. Similarly, the temperature gradients Gy and Gz in the y and z directions can be calculated.

[0040] With the passage of time, the above temperature measurement and temperature gradient calculation process is repeated, and a series of temperature gradient data at different times is obtained. Arranging these temperature gradient data in chronological order, a temperature gradient change curve can be established. By analyzing the temperature gradient change curve, the trend of the temperature distribution inside the actuator can be understood, and the influence of temperature change on the actuator can be understood.

[0041] Step S113: Monitor the real-time torque fluctuation between the execution end and the load through the force feedback device, and extract the combined features of torque fluctuation amplitude and frequency.

[0042] Subsequently, the force feedback device monitors the force change between the execution end and the load in real time, and converts the force signal into an electrical signal for processing. Since the size and direction of the load may change during the movement of the actuator, the torque between the execution end and the load will also fluctuate.

[0043] In order to extract the combined features of amplitude and frequency of torque fluctuation, first, the electrical signal collected by the force feedback device needs to be preprocessed such as amplification and filtering to remove noise interference. Then, the processed signal is sampled to obtain discrete torque data sequence Mi1, Mi2, Mi3, …, Min.

[0044] Spectrum analysis methods such as Fast Fourier Transform (FFT) are used to convert the time-domain torque data sequence to the frequency domain to obtain the frequency spectrum distribution of the torque. In the frequency spectrum, the main frequency components of the torque fluctuation and their corresponding amplitudes can be determined. For example, by searching for the peak value in the frequency spectrum, the main frequencies f1, f2, f3, … of the torque fluctuation and the corresponding amplitudes A1, A2, A3, … can be determined.

[0045] Combining these main frequencies and amplitudes, the combined features of torque fluctuation amplitude and frequency are formed. These combined features can reflect the characteristics of load change, which is of great significance for analyzing the influence of load on the dynamic stiffness of the actuator.

[0046] Step S114: Capture the vibration spectrum of the actuator during operation through the vibration acquisition device, and identify the vibration mode corresponding to the external environmental disturbance.

[0047] Then, the acceleration sensor in the vibration acquisition device measures the vibration acceleration of the actuator in real time during operation. The acceleration sensor generally uses a three-axis acceleration sensor, which can measure the vibration acceleration in x, y, and z directions simultaneously.

[0048] The collected vibration acceleration signal is a time-domain signal. In order to identify the vibration modes corresponding to external environmental disturbances, the time-domain signal needs to be converted to the frequency domain. Similarly, using the Fast Fourier Transform (FFT) method, the vibration acceleration signal in each direction is analyzed to obtain the vibration spectrum in x, y, and z directions.

[0049] In the vibration spectrum, different vibration modes correspond to different frequency components. By analyzing the peak values and frequency distribution in the spectrum, the natural vibration modes of the actuator and the secondary vibration modes corresponding to external environmental disturbances can be identified. The natural vibration modes are determined by the structure and dynamics of the actuator itself, while the secondary vibration modes are caused by external environmental disturbances.

[0050] By comparing the vibration spectrum under different working conditions and comparing with the theoretically calculated natural frequency, the vibration modes corresponding to external environmental disturbances can be accurately identified. After identifying these vibration modes, the influence of external environmental disturbances on the stability of the actuator can be further analyzed, providing a basis for subsequent error compensation.

[0051] Step S120: Fusion processing of the error perception data is performed to establish a dynamic error model of the actuator, which reflects the coupling relationship between different error sources over time.

[0052] In this embodiment, after obtaining displacement, temperature, force, and vibration, etc. multiple error perception data, fusion processing of these data is needed to establish a dynamic error model that can reflect the coupling relationship between different error sources over time. Because different error sources are not independent of each other, they may have complex interactions, for example, changes in temperature can affect the material properties of the actuator, and then affect its mechanical properties, thereby coupling with factors such as load and vibration, and jointly affecting the displacement accuracy of the actuator.

[0053] Step S121: The periodic deviation feature is decomposed into a first error component related to the wear of the transmission component and a second error component related to the assembly gap.

[0054] Then, for the periodic deviation feature, it is necessary to further decompose it into a first error component related to the wear of the transmission component and a second error component related to the assembly gap. First, the difference waveform between the actual displacement sequence and the theoretical displacement sequence is extracted. The difference waveform contains the combined effects of various error factors, and the error components related to the wear of the transmission component and the assembly gap need to be separated out through a specific method.

[0055] Harmonic analysis is performed on the difference waveform. Harmonic analysis can decompose the difference waveform into the superposition of sine and cosine waves of different frequencies. Since the wear of the transmission component is usually related to the rotation period of the transmission component, the fundamental wave component with the same frequency as the rotation period of the transmission component can be separated out as the first error component. For example, if the transmission component is a gear with a rotation period of T, then in the harmonic analysis of the difference waveform, the fundamental wave component with a frequency of 1 / T is likely to be related to the wear of the gear.

[0056] Non-periodic spike signals in the difference waveform that are synchronized with the switching action of the actuator are identified. When the actuator switches, due to the existence of the assembly gap, there will be an instantaneous change in displacement, which is manifested as non-periodic spike signals in the difference waveform. The cumulative amount of the amplitude of these spike signals is taken as the second error component.

[0057] A wear correlation curve of the first error component with the running time of the transmission component is established, and a degradation correlation curve of the second error component with the cumulative number of operations of the actuator is established. As the running time of the transmission component increases, the wear will gradually intensify, and the first error component will also increase accordingly; as the cumulative number of operations of the actuator increases, the assembly gap may gradually increase, and the second error component will also increase. Through long-term data monitoring and analysis, these two correlation curves can be obtained, which can be used to predict and compensate for errors caused by the wear of the transmission component and the assembly gap.

[0058] Step S122: predicting the thermal expansion deformation of the actuator according to the temperature gradient change curve, and generating a spatial distribution function of the thermal deformation error.

[0059] Then, according to the temperature gradient change curve established in the foregoing, the thermal expansion deformation of the actuator is predicted. A plurality of temperature detection points are arranged on the surface of the actuator housing, and the heat conduction path is calculated according to the temperature change rate of each detection point. Assuming that k temperature detection points are arranged on the surface of the actuator housing, the temperature values T1(t), T2(t), T3(t), …, Tk(t) of each detection point are recorded, where t is time. Through the calculation of the temperature difference and time interval of adjacent detection points, the temperature change rate between the detection points can be obtained. According to the principle of heat conduction, heat will conduct from a place with high temperature to a place with low temperature, so the heat conduction path can be determined according to the temperature change rate.

[0060] Based on the heat transfer delay between the transmission component support seat and the output end, a thermal inertia differential equation is established. Thermal inertia refers to the inertial characteristics of temperature change when an object absorbs or releases heat. Due to the different material properties and structures of the transmission component support seat and the output end, there will be a certain delay in the heat transfer between them. The thermal inertia differential equation can describe the relationship between the heat transfer process and the temperature change.

[0061] The instantaneous temperature values of the key nodes of the actuator are calculated through the thermal inertia differential equation. The key nodes include the key parts of the transmission component, specific positions of the output end, etc. The temperature data of each detection point is taken as the boundary condition and substituted into the thermal inertia differential equation for solving to obtain the instantaneous temperature values of the key nodes.

[0062] A three-dimensional deformation displacement field is generated by combining the material expansion coefficient. Different materials will expand or contract to different degrees when the temperature changes, and the material expansion coefficient reflects this characteristic. According to the instantaneous temperature values of the key nodes and the material expansion coefficient, the thermal expansion amounts of each key node can be calculated. These thermal expansion amounts are interpolated and fitted in three-dimensional space to generate a three-dimensional deformation displacement field.

[0063] The projection component along the motion direction of the actuator in the three-dimensional deformation displacement field is taken as the spatial distribution function of the thermal deformation error. The motion direction of the actuator is usually predetermined, and the projection of the three-dimensional deformation displacement field onto this direction can obtain the distribution of the thermal deformation error in this direction, thereby generating the spatial distribution function of the thermal deformation error.

[0064] Step S123: Based on the combined characteristics of the torque fluctuation amplitude and frequency, the coupling effect of load change on the dynamic stiffness of the actuator is analyzed, and a load disturbance transfer function is constructed.

[0065] Subsequently, the coupling effect of load change on the dynamic stiffness of the actuator is analyzed based on the combined characteristics of the torque fluctuation amplitude and frequency. Symmetrically distributed strain detection units are arranged in the force feedback device, and the real-time fluctuation amount of the load torque is calculated according to the difference between the symmetric strain signals. The symmetrically distributed strain detection units can effectively eliminate some common mode interference and improve the accuracy of measurement. Assuming that two sets of symmetric strain detection units are arranged in the force feedback device, strain signals ε1 and ε2 are measured, and the real-time fluctuation amount of the load torque can be calculated according to ε1-ε2 through the conventional algorithm in the related technology.

[0066] The real-time fluctuation amount is subjected to time-frequency transformation, such as wavelet transformation or short-time Fourier transformation, to extract the steady-state torque component in the low frequency band and the transient impact component in the high frequency band. The steady-state torque component in the low frequency band usually reflects the average change of the load, while the transient impact component in the high frequency band reflects the instantaneous change of the load.

[0067] The stiffness attenuation relationship between the steady-state torque component and the actuator velocity and the inertia coupling relationship between the transient impact component and the acceleration are established. When the velocity of the actuator changes, the steady-state torque component will affect the dynamic stiffness of the actuator, resulting in stiffness attenuation; when the acceleration of the actuator changes, the transient impact component will be coupled with the inertia of the actuator. Through analysis and fitting of experimental data, the specific expressions of the two relationships can be obtained.

[0068] The stiffness attenuation relationship and the inertia coupling relationship are integrated into a frequency domain transfer function to represent the influence weight of the load disturbance on the positioning accuracy of the actuator. The frequency domain transfer function can quantify the influence of the load disturbance on the positioning accuracy of the actuator at different frequencies, providing an important basis for subsequent error compensation.

[0069] Step S124: The disturbance intensity of the environmental disturbance on the stability of the actuator is identified through the energy proportion of different modes in the vibration spectrum.

[0070] Then, the disturbance intensity of the environmental disturbance on the stability of the actuator is identified through the energy proportion of different modes in the vibration spectrum. A multi-axis vibration sensor is arranged in the vibration acquisition device to synchronously acquire vibration acceleration signals of the actuator in three orthogonal directions in space. The multi-axis vibration sensor can simultaneously measure vibration accelerations in x, y, and z directions, comprehensively reflecting the vibration condition of the actuator.

[0071] The vibration acceleration signals are band-pass filtered to separate the primary vibration mode matching the natural frequency of the actuator and the secondary vibration mode related to environmental excitation. Band-pass filtering can effectively remove unwanted frequency components and only retain the frequency range of interest. According to the design parameters and theoretical calculations of the actuator, its natural frequency can be determined, and the primary vibration mode matching the natural frequency can be separated through band-pass filtering; at the same time, the secondary vibration mode related to environmental excitation also appears in a specific frequency range, which is separated through filtering.

[0072] The ratio of the energy attenuation coefficient of the primary vibration mode to the energy growth rate of the secondary vibration mode is calculated as an evaluation index of the environmental disturbance intensity. The energy attenuation coefficient of the primary vibration mode reflects the damping characteristics and stability of the actuator itself, and the energy growth rate of the secondary vibration mode reflects the influence degree of environmental excitation on the actuator. The ratio of these two parameters as an evaluation index can comprehensively reflect the disturbance intensity of the environmental disturbance on the stability of the actuator.

[0073] When the evaluation index exceeds the preset threshold, the anti-interference compensation mode of the actuator is triggered. The preset threshold is determined according to the performance requirements of the actuator and the actual application scenario. When the evaluation index exceeds the threshold, it indicates that the environmental disturbance has a greater impact on the stability of the actuator, and the anti-interference compensation mode needs to be started to take corresponding measures to reduce the error.

[0074] Step S125: input the first error component, the second error component, the spatial distribution function of the thermal deformation error, the load disturbance transfer function and the interference intensity into the time-varying coupling equation to generate a dynamic error model.

[0075] Finally, the first error component, the second error component, the spatial distribution function of the thermal deformation error, the load disturbance transfer function and the interference intensity obtained in the foregoing are input into the time-varying coupling equation. The time-varying coupling equation considers the coupling relationship between different error sources changing over time, which can describe how these error factors interact with each other and jointly affect the displacement error of the actuator.

[0076] By solving the time-varying coupling equation, the displacement error prediction values of the actuator at different times are obtained. These prediction values are sorted and analyzed to generate a dynamic error model. The dynamic error model can reflect the coupling relationship between different error sources and the change over time, providing an accurate basis for subsequent error compensation.

[0077] Step S130: generating an error compensation signal according to the dynamic error model, the error compensation signal comprising the superposition result of a feedforward compensation component and a feedback compensation component.

[0078] In this embodiment, after the dynamic error model is established, an error compensation signal needs to be generated according to the model to offset the error influence in the running process of the actuator. The error compensation signal is composed of a feedforward compensation component and a feedback compensation component, the feedforward compensation component is used to compensate the predictable error in advance, and the feedback compensation component is used to correct the error in actual operation in real time.

[0079] Step S131: extracting a predictable periodic error component from the dynamic error model to generate a feedforward compensation component through inverse model calculation.

[0080] Next, the predictable periodic error component is extracted from the dynamic error model. Since the dynamic error model reflects the coupling relationship between different error sources and the change over time, some of the error components have obvious periodic characteristics, such as errors caused by transmission component wear and assembly clearance. By analyzing and processing the dynamic error model, these predictable periodic error components can be extracted.

[0081] An ideal transfer function of the actuator is established, which represents the relationship between the input signal and the output displacement under the condition of no error. According to the dynamic characteristics and control principle of the actuator, the expression of the ideal transfer function can be derived.

[0082] The dynamic error model is connected in series with the ideal transfer function, and the inverse controller transfer function that makes the output of the series system equal to the ideal output is solved. The inverse controller transfer function has the effect of pre-processing the input signal to offset the error caused by the dynamic error model. Through mathematical derivation and calculation, the specific form of the inverse controller transfer function can be obtained.

[0083] The reference input signal is pre-processed by the inverse controller transfer function to generate a feedforward compensation component that offsets the error. The reference input signal is an input signal preset according to the motion requirements of the actuator. After processing by the inverse controller transfer function, the signal obtained is the feedforward compensation component, which can compensate before the error occurs.

[0084] According to the real-time updated dynamic error model parameters, the zero-pole configuration of the inverse controller transfer function is adjusted online. As the actuator operates, the parameters of the dynamic error model may change. In order to ensure the accuracy of the feedforward compensation, the parameters of the dynamic error model need to be monitored in real time, and the zero-pole configuration of the inverse controller transfer function needs to be adjusted according to the change of the parameters.

[0085] Step S132: Real-time acquisition of displacement deviation of the actuator, generation of feedback compensation component by proportional-integral-derivative control algorithm.

[0086] Then, the displacement deviation of the actuator is collected in real time. The displacement feedback device will continuously monitor the actual displacement of the actuator and compare it with the theoretical displacement to obtain the displacement deviation. Assuming that at a certain time t, the actual displacement is D(t) and the theoretical displacement is T(t), then the displacement deviation e(t)=D(t)-T(t).

[0087] The proportional-integral-derivative (PID) control algorithm is a commonly used feedback control algorithm, which is used to generate a feedback compensation component according to the displacement deviation. The output u(t) of the PID controller is composed of three parts: the proportional term, the integral term and the derivative term.

[0088] The calculation of the proportional term is to multiply the displacement deviation by the proportional coefficient Kp, that is, the proportional term P(t)=Kp×e(t). The proportional coefficient Kp determines the response speed of the controller to the displacement deviation. The larger Kp is, the more quickly the controller responds to the deviation, but it may lead to a decrease in the stability of the system.

[0089] The calculation of the integral term is to integrate the displacement deviation and multiply the integral coefficient Ki, that is, the integral term I(t) = Ki x ∫e(τ)dτ, the integral is from the starting time to the current time t. The role of the integral term is to eliminate the steady-state error of the system, and by continuously accumulating the displacement deviation, the controller can compensate for the long-term deviation.

[0090] The calculation of the differential term is to calculate the rate of change of the displacement deviation, and multiply the differential coefficient Kd, that is, the differential term D(t) = Kd x de(t) / dt. The role of the differential term is to predict the trend of the displacement deviation and compensate in advance to improve the dynamic response performance of the system.

[0091] The proportional term, integral term and differential term are added to obtain the output u(t) = P(t) + I(t) + D(t) of the PID controller, which is the feedback compensation component. The feedback compensation component will be dynamically adjusted according to the real-time collected displacement deviation to correct the displacement error of the actuator in real time.

[0092] Step S133: Amplitude and phase calibration is performed on the feedforward compensation component and the feedback compensation component to make the superposition result of the feedforward compensation component and the feedback compensation component continuous and smooth in time domain.

[0093] Then, in order to effectively superimpose the feedforward compensation component and the feedback compensation component, amplitude and phase calibration is needed.

[0094] A phase lead correction module is arranged in the feedforward compensation channel to compensate for the phase lag caused by the mechanical delay of the actuator. In actual operation, due to the inertia of the mechanical structure and the transmission delay and other factors, there will be a phase lag between the input signal and the output signal. The phase lead correction module can adjust the phase of the feedforward compensation component by introducing a phase lead element, so that it is more matched with the phase of the actual error signal.

[0095] An amplitude normalization module is arranged in the feedback compensation channel to eliminate the gain misadjustment caused by the different dimensions of the displacement deviation. Since the dimension of the displacement deviation may differ due to different measurement systems or changes in actual working conditions, this may cause the amplitude of the feedback compensation component to be misadjusted. The amplitude normalization module can normalize the amplitude of the feedback compensation component to be within a suitable range, thereby avoiding the influence of gain misadjustment on the system performance.

[0096] The best superimposition frequency band of the feedforward compensation component and the feedback compensation component is determined by the cross frequency analysis method. The cross frequency analysis method is a frequency domain analysis method, which finds a suitable frequency range by analyzing the characteristics of the feedforward compensation component and the feedback compensation component at different frequencies, and the superimposition of the two compensation components in this range can achieve the best compensation effect.

[0097] The coherence of the two compensation signals in the optimal superimposed frequency band is optimized so that the spectral energy of the superimposed signal is concentrated in the error-sensitive frequency band. The coherence optimization can be achieved by adjusting the phase and amplitude of the feedforward compensation component and the feedback compensation component so that they can produce the maximum compensation effect in the error-sensitive frequency band after superimposition, while reducing interference in other frequency bands.

[0098] Step S134: According to the maximum response speed and driving ability of the actuator, the superposition result is amplitude-limited to generate the final error compensation signal.

[0099] Then, the feedforward compensation component and the feedback compensation component after amplitude and phase calibration are superimposed to obtain a superposition result. However, the response speed and driving ability of the actuator are limited. If the superposition result exceeds the maximum response speed or driving ability of the actuator, it may cause the actuator to malfunction or damage.

[0100] Therefore, the superposition result needs to be amplitude-limited according to the maximum response speed and driving ability of the actuator. Assuming that the maximum positive response speed of the actuator is Vmax+, and the maximum negative response speed is Vmax-, when the speed component of the superposition result exceeds Vmax+, it is limited to Vmax+; when the speed component of the superposition result is less than Vmax-, it is limited to Vmax-. Similarly, similar amplitude limiting is performed on the driving ability to ensure that the superposition result is within the range that the actuator can withstand.

[0101] After amplitude limiting, the obtained signal is the final error compensation signal, which can maximize the cancellation of error effects within the range of the actuator's ability.

[0102] Step S140: Load the error compensation signal to the driving module of the actuator to adjust the displacement output of the actuator to offset the error effect.

[0103] In this embodiment, after generating the final error compensation signal, the signal needs to be loaded to the driving module of the actuator to adjust the displacement output of the actuator to offset the error effect.

[0104] The driving module of the actuator is usually composed of power amplifiers, motor drivers, etc. The error compensation signal is processed and input into the driving module. The driving module adjusts the driving signal provided to the actuator according to the size and direction of the error compensation signal, such as adjusting the voltage or current of the motor.

[0105] When the error compensation signal is positive, the driving module will increase the driving power to the actuator, so that the displacement of the actuator increases; when the error compensation signal is negative, the driving module will reduce the driving power to the actuator, so that the displacement of the actuator decreases. In this way, the displacement output of the actuator will be adjusted in real time according to the error compensation signal, so as to offset the displacement error caused by various error sources and improve the positioning accuracy and running stability of the actuator.

[0106] In practical applications, it is also necessary to monitor the displacement output of the actuator in real time to verify the effect of error compensation. If it is found that the error still exists or the effect of error compensation is not ideal, the error compensation signal can be further adjusted and optimized according to the monitoring results, such as re-adjusting the parameters of the PID controller, updating the dynamic error model, etc., to continuously improve the accuracy and reliability of error compensation.

[0107] In summary, by obtaining error perception data based on multiple types of perception devices inside the actuator, performing fusion processing on these data to establish a dynamic error model, generating an error compensation signal containing a feedforward compensation component and a feedback compensation component, and loading it to the driving module of the actuator, the displacement output of the actuator can be effectively adjusted to offset the error and improve the performance and accuracy of the linear servo actuator.

[0108] Embodiment three: the embodiment of the present application provides an error compensation method for a linear servo actuator, which comprises: obtaining error perception data of different error sources based on multiple types of perception devices inside the actuator, wherein the multiple types of perception devices include external displacement feedback devices, internal encoder devices, temperature acquisition devices, force feedback devices and vibration acquisition devices; performing fusion processing on the error perception data to establish a dynamic error model of the actuator, wherein the dynamic error model reflects the coupling relationship between different error sources changing over time; generating an error compensation signal according to the dynamic error model, wherein the error compensation signal contains the superposition result of a feedforward compensation component and a feedback compensation component; loading the error compensation signal to the driving module of the actuator to adjust the displacement output of the actuator to offset the error.

[0109] Further, the error perception data of different error sources obtained based on the multiple types of perception devices inside the actuator comprises: acquiring the actual displacement sequence of the external actuator at different motion cycles through the external displacement and speed feedback device, and comparing the linear displacement and speed sequence with the determined periodicity deviation characteristics of the rotational displacement and speed; The temperature acquisition device acquires the three-dimensional temperature distribution of the actuator shell, the transmission component support seat and the output end, and establishes a temperature gradient change curve; The force feedback device monitors the real-time torque fluctuation between the execution end and the load, and extracts the combination characteristics of the torque fluctuation amplitude and frequency. The built-in encoder device monitors the actual deviation of the speed, displacement and theoretical value of the internal rotary actuator in actual operation.

[0110] The vibration acquisition device captures the vibration spectrum of the actuator during operation, and identifies the vibration mode corresponding to the external environmental disturbance.

[0111] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system, device and unit described above can refer to the corresponding process in the foregoing method embodiments, which will not be repeated here.

[0112] It is obvious to those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application.

Claims

1. A method for compensating an error of a linear servo actuator, characterized in that: The method comprises: Acquiring error sensing data of different error sources based on multiple sensing devices inside the actuator, wherein the multiple sensing devices include a displacement feedback device, a temperature acquisition device, a force feedback device, and a vibration acquisition device; Performing fusion processing on the error perception data to establish a dynamic error model of the actuator, wherein the dynamic error model reflects the coupling relationship between different error sources that changes over time; generating an error compensation signal according to the dynamic error model, wherein the error compensation signal includes a superposition result of a feedforward compensation component and a feedback compensation component; The error compensation signal is loaded into the drive module of the actuator to adjust the displacement output of the actuator to offset the error effect.

2. The error compensation method for a linear servo actuator according to claim 1, wherein: The error sensing data of different error sources obtained based on the multi-type sensing devices inside the actuator include: The displacement feedback device is used to collect the actual displacement sequence of the actuator in different motion cycles, and the periodic deviation characteristics are determined by comparing the actual displacement sequence with the theoretical displacement sequence; The three-dimensional temperature distribution of the actuator housing, the transmission component support seat and the output end is obtained by the temperature acquisition device, and a temperature gradient change curve is established; The force feedback device is used to monitor the real-time torque fluctuation between the actuator and the load, and extract the combined characteristics of the torque fluctuation amplitude and frequency; The vibration acquisition device captures the vibration spectrum of the actuator during operation and identifies the vibration mode corresponding to the external environmental disturbance.

3. The error compensation method for a linear servo actuator according to claim 2, wherein: The fusing and processing the error perception data to establish a dynamic error model of the actuator includes: Decomposing the periodic deviation feature into a first error component related to transmission component wear and a second error component related to assembly clearance; Predicting the thermal expansion deformation of the actuator according to the temperature gradient change curve, and generating a spatial distribution function of the thermal deformation error; Combining the combined characteristics of the torque fluctuation amplitude and frequency, the coupling effect of load change on the dynamic stiffness of the actuator is analyzed, and a load disturbance transfer function is constructed; Identifying the interference intensity of environmental disturbances on actuator stability through the energy proportion of different modes in the vibration spectrum; The first error component, the second error component, the spatial distribution function of the thermal deformation error, the load disturbance transfer function and the disturbance intensity are input into a time-varying coupling equation to generate a dynamic error model.

4. The error compensation method for a linear servo actuator according to claim 3, wherein: Decomposing the periodic deviation feature into a first error component related to transmission component wear and a second error component related to assembly clearance includes: Extracting a difference waveform between the actual displacement sequence and the theoretical displacement sequence, performing harmonic analysis on the difference waveform, and separating a fundamental wave component having the same frequency as the rotation period of the transmission component as a first error component; Identifying a non-periodic peak signal in the difference waveform that is synchronized with the commutation action of the actuator, and taking the amplitude accumulation of the peak signal as a second error component; A wear correlation curve between the first error component and the running time of the transmission component and a degradation correlation curve between the second error component and the cumulative working times of the actuator are established.

5. The error compensation method for a linear servo actuator according to claim 3, wherein: The step of predicting the thermal expansion deformation of the actuator according to the temperature gradient change curve and generating a spatial distribution function of the thermal deformation error includes: Arranging a plurality of temperature detection points on the surface of the actuator housing, and calculating the heat conduction path according to the temperature change rate of each detection point; Based on the heat transfer delay between the transmission component support and the output end, a thermal inertia differential equation is established; The instantaneous temperature value of the key node of the actuator is calculated by the thermal inertia differential equation, and a three-dimensional deformation displacement field is generated in combination with the material expansion coefficient; The projection component of the three-dimensional deformation displacement field along the movement direction of the actuator is used as the spatial distribution function of the thermal deformation error.

6. The error compensation method for a linear servo actuator according to claim 3, wherein: The method combines the combined characteristics of the torque fluctuation amplitude and frequency, analyzes the coupling effect of load change on the dynamic stiffness of the actuator, and constructs a load disturbance transfer function, including: Symmetrically distributed strain detection units are provided in the force feedback device, and the real-time fluctuation of the load torque is calculated according to the difference of the symmetrical strain signals; Performing time-frequency transformation on the real-time fluctuation quantity to extract the steady-state torque component in the low-frequency band and the transient impact component in the high-frequency band; Establishing a stiffness attenuation relationship between the steady-state torque component and the actuator velocity, and an inertial coupling relationship between the transient impact component and the acceleration; The stiffness attenuation relationship and the inertial coupling relationship are integrated into a frequency domain transfer function to characterize the influence weight of the load disturbance on the positioning accuracy of the actuator.

7. The error compensation method for a linear servo actuator according to claim 3, wherein: The identifying the interference intensity of the environmental disturbance on the actuator stability by the energy proportion of different modes in the vibration spectrum includes: A multi-axis vibration sensor is provided in the vibration collection device to synchronously collect vibration acceleration signals of the actuator in three orthogonal directions in space; performing band-pass filtering on the vibration acceleration signal to separate a primary vibration mode that matches the natural frequency of the actuator and a secondary vibration mode related to environmental excitation; Calculating the ratio of the energy attenuation coefficient of the primary vibration mode to the energy growth rate of the secondary vibration mode as an evaluation index of the environmental interference intensity; When the evaluation index exceeds a preset threshold, the anti-interference compensation mode of the actuator is triggered.

8. The error compensation method for a linear servo actuator according to claim 1, wherein: Generating an error compensation signal according to the dynamic error model, wherein the error compensation signal includes a superposition result of a feedforward compensation component and a feedback compensation component, includes: Extracting a predictable periodic error component from the dynamic error model and generating a feedforward compensation component through inverse model calculation; The displacement deviation of the actuator is collected in real time, and the feedback compensation component is generated through the proportional-integral-differential control algorithm; Performing amplitude and phase calibration on the feedforward compensation component and the feedback compensation component so that a superposition result of the feedforward compensation component and the feedback compensation component is continuous and smooth in the time domain; According to the maximum response speed and driving capability of the actuator, the superposition result is limited to generate a final error compensation signal.

9. The error compensation method for a linear servo actuator according to claim 8, wherein: The generating of the feedforward compensation component by inverse model calculation includes: Establishing an ideal transfer function of the actuator, wherein the ideal transfer function represents the corresponding relationship between the input signal and the output displacement under error-free conditions; Connecting the dynamic error model to the ideal transfer function in series, and solving the inverse controller transfer function that makes the series system output equal to the ideal output; Preprocessing the reference input signal by the inverse controller transfer function to generate a feedforward compensation component that offsets the effect of the error; Adjusting the zero-pole configuration of the inverse controller transfer function online according to the dynamic error model parameters updated in real time; The performing amplitude and phase calibration on the feedforward compensation component and the feedback compensation component includes: A phase advance correction module is set in the feedforward compensation channel to compensate for the phase lag caused by the mechanical delay of the actuator; An amplitude normalization module is set in the feedback compensation channel to eliminate gain imbalance caused by different displacement deviation dimensions; The optimal superposition frequency band of the feedforward compensation component and the feedback compensation component is determined by the cross-frequency analysis method; The coherence of the two compensation signals is optimized within the optimal superposition frequency band, so that the spectrum energy of the superposed signal is concentrated in the error-sensitive frequency band.

10. An error compensation system for a linear servo actuator, characterized in that: include: A processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other via the communication bus; The memory is used to store a computer program; the processor is used to implement the error compensation method steps of the linear servo actuator according to any one of claims 1 to 9 when executing the computer program.

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