A sliding mode control method, device and equipment based on fixed time control theory

Abstract

The application discloses a sliding mode control method based on fixed time control theory, comprising the following steps: obtaining a strict feedback system expression of a motor servo system, designing a fixed time non-singular terminal sliding mode surface based on an auxiliary switching function, recursively deriving a sliding mode controller based on the strict feedback system expression and the fixed time non-singular terminal sliding mode surface, and finally converging the tracking error time of the motor servo system to a preset range according to the obtained sliding mode controller. The application designs a novel fixed time non-singular terminal sliding mode surface, so that the recursively derived sliding mode controller can converge the tracking error of the motor servo system to the preset range, effectively improves the convergence speed, effectively avoids the singularity phenomenon, and guarantees the convergence precision.

Description

Technical Field

[0001] This invention relates to motor servo control technology, specifically to a sliding mode control method, device, and equipment based on fixed-time control theory. Background Technology

[0002] Motor servo systems are widely used in industrial production and defense due to their outstanding characteristics such as high transmission efficiency, simple structure, and fast response speed. In recent years, with the rapid development of intelligent manufacturing, the requirements for the control performance of servo systems, such as control accuracy, motion speed, and process stability, have been continuously increasing.

[0003] The motor servo system model has many uncertainties, including inaccurate internal parameters, parameter changes due to the aging of some components, disturbances caused by external loads, interference caused by mechanical friction during transmission, defects in the motor servo system model, and other nonlinear interferences. Overcoming internal and external disturbances in the motor servo system is the focus of research.

[0004] To address the numerous problems existing in motor servo systems, some advanced control theories have been researched, and commonly used control methods include adaptive control, robust control, and optimal control. These methods can effectively handle uncertainties, interference, and noise in motor servo systems, improving system stability and tracking performance. However, they are no longer applicable to non-parameterizable uncertainties. Sliding mode control, as a simple algorithm, achieves precise control of the system by switching different controllers under different states, allowing the system state to move along the desired sliding surface. It exhibits extremely high robustness. However, due to the discontinuous sign function in the controller, chattering occurs during the switching process, exciting high-frequency oscillations, which seriously affects the control performance of sliding mode control, creating a contradiction between convergence speed and control accuracy. Therefore, improving the convergence speed while ensuring control accuracy is an urgent problem to be solved. Summary of the Invention

[0005] In order to solve the above-mentioned technical problems, or at least partially solve the above-mentioned technical problems, this disclosure provides a sliding mode control method, device and equipment based on fixed-time control theory.

[0006] According to a first aspect, embodiments of the present invention provide a sliding mode control method based on fixed-time control theory, comprising the following steps: obtaining a strict feedback system expression for a motor servo system; designing a fixed-time non-singular terminal sliding surface based on an auxiliary switching function; obtaining a sliding mode controller based on the strict feedback system expression and the fixed-time non-singular terminal sliding surface; and converging the tracking error time of the motor servo system to a preset range based on the sliding mode controller.

[0007] Optionally, obtaining the strict feedback system expression of the motor servo system includes the following steps: obtaining the dynamic equation of the motor servo system based on Newton's second law; defining state variables and transforming the dynamic equation of the motor servo system into the strict feedback system expression of the motor servo system.

[0008] Optionally, the dynamic equations of the motor servo system are: Where θ is the angular displacement. The first derivative of the angular displacement. Let be the second derivative of the angular displacement, m be the inertial load, and k be the second derivative of the angular displacement. v Where is the coefficient of viscous friction, and u is the control input. Unmodeled interference;

[0009] Define state variables The expression for a strict feedback system is:

[0010]

[0011] Where T is the transpose of the matrix; where b = g / m, λ² = -k v / m,

[0012]

[0013] Optionally, the design of a fixed-time non-singular terminal sliding surface based on an auxiliary function includes the following steps: defining a tracking error, and introducing an auxiliary function and designing a switching function based on the tracking error to obtain an auxiliary switching function; and designing a fixed-time non-singular terminal sliding surface based on the auxiliary switching function.

[0014] Optionally, a sliding mode controller is obtained based on the strict feedback system expression and the fixed-time non-singular terminal sliding surface, specifically including the following steps: differentiating the fixed-time non-singular terminal sliding surface; and recursively obtaining the sliding mode controller based on the differentiation result and the strict feedback system expression.

[0015] Optionally, the tracking error time of the motor servo system is converged to a preset range based on the sliding mode controller, including: differentiating the first preset Lyapunov function and substituting the derivative of the fixed-time non-singular terminal sliding surface into the result to obtain a first estimated time; differentiating the second preset Lyapunov function and substituting the derivative of the fixed-time non-singular terminal sliding surface at a preset position into the result to obtain a second estimated time; obtaining the total convergence time of the motor servo system based on the first and second estimated times, and performing convergence according to the total convergence time of the motor servo system to converge the tracking error time of the motor servo system to a preset range.

[0016] According to a second aspect, embodiments of this disclosure provide a data acquisition module for acquiring a strict feedback system expression for a motor servo system; a sliding surface construction module for designing a fixed-time non-singular terminal sliding surface based on an auxiliary switching function; a controller construction module for obtaining a sliding controller based on the strict feedback system expression and the fixed-time non-singular terminal sliding surface; and a control module for converging the tracking error time of the motor servo system to a preset range based on the sliding controller.

[0017] According to a third aspect, a computer device includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to perform the method as described in the first aspect and any alternative embodiment.

[0018] According to a fourth aspect, a computer-readable storage medium stores computer instructions for causing a computer to perform the water method as described in the first aspect and any alternative embodiment.

[0019] The technical solution provided in this disclosure has the following advantages compared with the prior art:

[0020] This disclosure provides a sliding mode control method based on fixed-time control theory, comprising the following steps: obtaining the strict feedback system expression of a motor servo system; designing a fixed-time non-singular terminal sliding surface based on an auxiliary switching function; recursively obtaining a sliding mode controller based on the strict feedback system expression and the fixed-time non-singular terminal sliding surface; and finally, converging the tracking error time of the motor servo system to a preset range using the obtained sliding mode controller. This invention, by designing a novel fixed-time non-singular terminal sliding surface, enables the recursively derived sliding mode controller to converge the tracking error of the motor servo system to a preset range, effectively improving the convergence speed while effectively avoiding singular phenomena and ensuring convergence accuracy. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0022] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1This is a flowchart illustrating a specific example of a sliding mode control method based on fixed-time control theory according to an embodiment of this disclosure.

[0024] Figure 2 This is an example block diagram illustrating the control principle of a motor servo system according to an embodiment of this disclosure;

[0025] Figure 3 This is a simulation diagram of the tracking performance response curve of the motor servo system according to an embodiment of this disclosure;

[0026] Figure 4 This is a simulation diagram of the tracking error response curve of the motor servo system according to an embodiment of this disclosure;

[0027] Figure 5 This is a simulation diagram of the state variable response curve of the motor servo system according to an embodiment of this disclosure;

[0028] Figure 6 This is a connection diagram of a specific example of a sliding mode control device based on fixed-time control theory according to an embodiment of this disclosure;

[0029] Figure 7 This is a specific example structural diagram of a computer device according to an embodiment of the present disclosure. Detailed Implementation

[0030] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0031] It should be understood that the steps described in the method embodiments of this disclosure may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of this disclosure is not limited in this respect.

[0032] The term "comprising" and its variations as used herein are open-ended inclusions, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the description below.

[0033] It should be noted that the concepts of "first" and "second" mentioned in this disclosure are used only to distinguish different devices, modules or units, and are not used to limit the order of functions performed by these devices, modules or units or their interdependencies.

[0034] It should be noted that the terms "a" and "a plurality of" used in this disclosure are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0035] The names of messages or information exchanged between multiple devices in the embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of such messages or information.

[0036] In existing sliding mode control methods, the following problems still exist in the process of controlling and responding to the motor servo system:

[0037] Traditional sliding mode control methods suffer from chattering. Traditional sliding mode controllers use discontinuous sign functions, which generate chattering, excite high-frequency oscillations, degrade the system's tracking performance, and severely affect the convergence speed and control accuracy of sliding mode control.

[0038] To address the aforementioned problems, this disclosure provides a sliding mode control method, apparatus, and device based on fixed-time control theory. The sliding mode control method based on fixed-time control theory provided by this disclosure will be described below with reference to the accompanying drawings.

[0039] Figure 1 A schematic flowchart of a sliding mode control method based on fixed-time control theory provided in an embodiment of this disclosure is shown.

[0040] like Figure 1 As shown, the sliding mode control method based on fixed-time control theory includes the following steps:

[0041] S100: Obtain the strict feedback system expression of the motor servo system.

[0042] Optionally, the dynamic equations of the motor servo system are obtained based on Newton's second law; state variables are defined, and the dynamic equations of the motor servo system are transformed into a strict feedback system expression for the motor servo system.

[0043] In this embodiment of the disclosure, the motor servo system is as follows: Figure 2 As shown, it mainly consists of a control algorithm module, a controller, a servo driver, a DC motor, and an inertial load. The control algorithm module receives the reference position signal and the position feedback data sent by the inertial load, and sends the control information to the controller based on the reference position signal and the position feedback data. The controller controls the servo driver to drive the DC motor to rotate, thereby causing the inertial load to perform corresponding motion actions.

[0044] In this embodiment of the disclosure, according to Newton's second law, the dynamic equation of the motor servo system is: Where m is the inertial load and θ is the angular displacement. Let be the first derivative of the angular displacement, and represent the angular displacement velocity. Let be the second derivative of the angular displacement, represent the angular displacement acceleration, g be the torque constant, u be the control input, and k be the second derivative of the angular displacement. v The coefficient of viscous friction, This indicates unmodeled interference.

[0045] In this embodiment of the disclosure, the state variable is T is the transpose of the matrix, which transforms into the expression for a strict feedback system as follows: Where b = g / m, λ² = -k v / m,

[0046] S200, Design of fixed-time non-singular terminal sliding surface based on auxiliary switching function.

[0047] Optionally, a tracking error is defined, and an auxiliary function and a switching function are introduced based on the tracking error to obtain an auxiliary switching function; a fixed-time non-singular terminal sliding surface is designed based on the auxiliary switching function.

[0048] In this embodiment of the disclosure, the expression for the tracking error is: Where x1 is the system output, Let x1 be the first derivative, and y be the first derivative. d Given a tracking signal, For y d The first derivative of t, e(t) is the tracking error.

[0049] In this embodiment of the disclosure, the auxiliary function is: Where δ is a preset positive constant.

[0050] In this embodiment of the disclosure, the switching function is:

[0051] In this embodiment of the disclosure, the auxiliary switching function is:

[0052] In this embodiment of the disclosure, the properties of the auxiliary switching function are obtained by calculating the switching function: Where γ is a pre-defined positive number. Based on this property, we can obtain...

[0053]

[0054] In this embodiment of the disclosure, the fixed-time non-singular terminal sliding surface is: Where σ>1, ε1>0, ε2>0 are the design parameters of the fixed-time non-singular terminal sliding surface.

[0055] S300. A sliding mode controller is obtained based on the strict feedback system expression and the fixed-time non-singular terminal sliding surface.

[0056] Optionally, the sliding mode surface of the fixed-time non-singular terminal is differentiated; the sliding mode controller is obtained recursively based on the differentiation result and the strict feedback system expression.

[0057] In this embodiment of the disclosure, the differential of the fixed-time non-singular terminal sliding surface is calculated, and the parameters in the strict feedback system expression are substituted into it to obtain the following expression: in, For y d The second derivative, for The first derivative, This is an auxiliary function.

[0058] In this embodiment of the disclosure, the sliding mode controller is: u = (u eq +u rl ) / b, where,

[0059] u rl =-(Lsign(s)+n1s) 2μ-1 sign(s)+n2s 2v-1 sign(s)),

[0060] in, 0 < μ < 1, υ > 1, n1 > 0, n2 > 0 are preset parameters. for Upper bound of a function.

[0061] S400. Based on the sliding mode controller, the tracking error time of the motor servo system is converged to a preset range.

[0062] Optionally, the derivative of the first preset Lyapunov function is calculated, and the derivative result of the fixed-time non-singular terminal sliding surface is substituted to obtain the first estimated time; the derivative of the second preset Lyapunov function is calculated, and the derivative result of the fixed-time non-singular terminal sliding surface at the preset position is substituted to obtain the second estimated time; the total convergence time of the motor servo system is obtained based on the first estimated time and the second estimated time, and convergence is performed according to the total convergence time of the motor servo system to bring the tracking error of the motor servo system to a preset range.

[0063] In this embodiment of the disclosure, the first preset Lyapunov function is: The second presupposed Lyapunov function is:

[0064] In this embodiment of the disclosure, the derivative of the first preset Lyapunov function is calculated, and the derivative of the fixed-time non-singular terminal sliding surface is substituted into the expression, which is: According to the fixed-time control theory, the first estimated time T1 can be obtained as:

[0065] In this embodiment of the disclosure, when the non-singular terminal sliding surface is at a preset position at a fixed time, i.e., when s = 0, the expression for its tracking error e2 is:

[0066] In this embodiment, the second preset Lyapunov function is differentiated, and the derivative of the function at a preset position with a fixed-time non-singular terminal sliding surface is substituted into the expression, which is: From this equation, we can deduce that the tracking error e1 converges to any small interval δ, i.e., |e1| < δ. According to the fixed-time control theory, the second estimated time T2 is:

[0067] In this embodiment of the disclosure, based on the sliding surface s=0 and |e1|<δ, it can be deduced that: e2≤ε1(2δ) σ +ε2.

[0068] In this embodiment of the disclosure, the total convergence time of the motor servo system is estimated as follows: The motor servo system converges based on the total convergence time, bringing the tracking error of the motor servo system to a preset range.

[0069] This invention discloses an embodiment that obtains the strict feedback system expression of a motor servo system, designs a fixed-time non-singular terminal sliding surface based on an auxiliary switching function, and then recursively derives a sliding mode controller based on the strict feedback system expression and the fixed-time non-singular terminal sliding surface. Finally, the tracking error time of the motor servo system is converged to a preset range using the obtained sliding mode controller. This invention, by designing a novel fixed-time non-singular terminal sliding surface, enables the derived sliding mode controller to converge the tracking error of the motor servo system to a preset range, effectively improving the convergence speed while effectively avoiding singular phenomena and ensuring convergence accuracy.

[0070] under, Figures 3-5 This paper uses the parameters of a real motor servo system as an example for simulation analysis.

[0071] The specific parameters for the motor servo system are: inertial load m = 0.3kGm 2 Voltage torque gain g = 4 Ngm / V; viscous friction coefficient k v =0.1Ngm; Uncertain disturbance term d = -0.5sin(2t); Given reference position signal y d=sin(t); Controller design parameters: n1=n2=1; ε1=ε2=1; μ=2 / 3; v=5 / 3; σ=3; Preset accuracy error δ=0.01; Robust term adjustment gain L=1.

[0072] According to the calculation formula provided in the embodiments of this disclosure, we can obtain: T1 = 0.88s, T2 = 1.92s.

[0073] Depend on Figure 3 It can be seen that the motor servo system can track the given reference signal well under external disturbances, indicating that the sliding mode control method based on fixed-time control theory provided in this embodiment has strong robustness.

[0074] Depend on Figure 4 It can be seen that the sliding mode control method based on fixed-time control theory provided in this embodiment can ensure that the tracking error of the motor servo system converges within a preset accuracy range within a fixed time by adjusting the controller parameters, thus solving the contradiction between convergence speed and control accuracy.

[0075] Depend on Figure 5 It can be seen that the non-singular fixed-time terminal sliding surface and tracking error convergence designed in the embodiments of this disclosure indicate that it can effectively avoid the occurrence of singular phenomena.

[0076] Based on the simulation analysis results of this disclosure, it can be concluded that the sliding mode control method based on fixed-time control theory provided in the embodiments of this disclosure has a convergence time that can be obtained according to fixed-time control theory. Its performance is only related to the design parameters and is independent of the initial state conditions. At the same time, the novel fixed-time non-singular terminal sliding surface designed can effectively avoid the occurrence of singular phenomena, making the system more stable.

[0077] Figure 6 This disclosure provides a sliding mode control device based on fixed-time control theory, comprising: a data acquisition module for acquiring a strict feedback system expression of a motor servo system; a sliding mode surface construction module for designing a fixed-time non-singular terminal sliding mode surface based on an auxiliary switching function; a controller construction module for obtaining a sliding mode controller based on the strict feedback system expression and the fixed-time non-singular terminal sliding mode surface; and a control module for converging the tracking error time of the motor servo system to a preset range based on the sliding mode controller.

[0078] For specific limitations and beneficial effects of the sliding mode control device based on fixed-time control theory, please refer to the limitations of the sliding mode control method based on fixed-time control theory mentioned above, which will not be repeated here. Each module of the aforementioned sliding mode control device based on fixed-time control theory can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of the electronic device in hardware form or independently of the processor, or stored in the memory of the electronic device in software form, so that the processor can call and execute the corresponding operations of each module.

[0079] This invention also provides a computer device, such as... Figure 7 As shown, Figure 7 This is a schematic diagram of a computer device provided in an optional embodiment of the present invention. The computer device may include at least one processor 41, at least one communication interface 42, at least one communication bus 43, and at least one memory 44. The communication interface 42 may include a display screen and a keyboard; optionally, the communication interface 42 may also include a standard wired interface or a wireless interface. The memory 44 may be high-speed RAM (Random Access Memory) or non-volatile memory, such as at least one disk storage device. Optionally, the memory 44 may also be at least one storage device located remotely from the aforementioned processor 41. The processor 41 may be combined with... Figure 6 The described apparatus has an application program stored in memory 44, and the processor 41 calls the program code stored in memory 44 to perform the steps of any of the above method embodiments.

[0080] The communication bus 43 can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The communication bus 43 can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 7 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0081] The memory 44 may include volatile memory, such as random-access memory (RAM); the memory may also include non-volatile memory, such as flash memory, hard disk drive (HDD) or solid-state drive (SSD); the memory 44 may also include a combination of the above types of memory.

[0082] The processor 41 can be a central processing unit (CPU), a network processor (NP), or a combination of CPU and NP.

[0083] The processor 41 may further include a hardware chip. This hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof.

[0084] Optionally, memory 44 is also used to store program instructions. Processor 41 can invoke program instructions to implement the present invention. Figure 1 The sliding mode control method based on fixed-time control theory is shown in the embodiment.

[0085] This invention also provides a non-transitory computer storage medium storing computer-executable instructions that can execute the methods described in any of the above-described method embodiments. The storage medium may be a magnetic disk, optical disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk drive (HDD), or solid-state drive (SSD), etc.; the storage medium may also include combinations of the above types of memory.

[0086] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0087] The above description is merely a specific embodiment of this disclosure, enabling those skilled in the art to understand or implement it. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A sliding mode control method based on fixed-time control theory, characterized in that, Includes the following steps: Obtain the strict feedback system expression for the motor servo system; The process of obtaining the strict feedback system expression of the motor servo system includes the following steps: The dynamic equations of the motor servo system are obtained based on Newton's second law; The dynamic equations of the motor servo system are: in, For angular displacement, The first derivative of the angular displacement. The second derivative of the angular displacement. For inertial load, The coefficient of viscous friction, To control the input, Unmodeled interference, It is the torque constant; Define state variables and transform the dynamic equations of the motor servo system into a strict feedback system expression for the motor servo system; Define state variables The expression for the strict feedback system is: Design of a fixed-time non-singular terminal sliding surface based on an auxiliary switching function; The design of a fixed-time non-singular terminal sliding surface based on an auxiliary function includes the following steps: Define the tracking error, and based on the tracking error, introduce an auxiliary function and design a switching function to obtain the auxiliary switching function; The auxiliary function for: in, Preset positive numbers; Indicates tracking error; Design a fixed-time non-singular terminal sliding surface based on the aforementioned auxiliary switching function; A sliding mode controller is obtained based on the strict feedback system expression and the fixed-time non-singular terminal sliding surface; Based on the sliding mode controller, the tracking error time of the motor servo system is converged to a preset range; The tracking error time of the motor servo system is converged to a preset range based on the sliding mode controller, including: The first preset Lyapunov function is differentiated, and the result of the differentiation of the fixed-time non-singular terminal sliding surface is substituted to obtain the first estimated time; The first preset Lyapunov function is: In the formula, Represents a fixed-time non-singular terminal sliding surface; The derivative of the second preset Lyapunov function is calculated, and the derivative of the preset position of the fixed-time non-singular terminal sliding surface is substituted into the derivative to obtain the second estimated time. The second preset Lyapunov function is: In the formula, Indicates tracking error; Preset positive numbers; Indicates the switching function, ; The total convergence time of the motor servo system is obtained based on the first estimated time and the second estimated time, and convergence is performed according to the total convergence time of the motor servo system to bring the tracking error of the motor servo system to a preset range.

2. The sliding mode control method based on fixed-time control theory according to claim 1, characterized in that, The process of obtaining a sliding mode controller based on the strict feedback system expression and the fixed-time non-singular terminal sliding surface specifically includes the following steps: Differentiate the fixed-time non-singular terminal sliding surface; The sliding mode controller is obtained recursively based on the derivative and the strict feedback system expression.

3. A sliding mode control device based on fixed-time control theory, characterized in that, include: The data acquisition module is used to obtain the strict feedback system expression of the motor servo system; The process of obtaining the strict feedback system expression of the motor servo system includes the following steps: The dynamic equations of the motor servo system are obtained based on Newton's second law; The dynamic equations of the motor servo system are: in, For angular displacement, The first derivative of the angular displacement. The second derivative of the angular displacement. For inertial load, The coefficient of viscous friction, To control the input, Unmodeled interference, It is the torque constant; Define state variables and transform the dynamic equations of the motor servo system into a strict feedback system expression for the motor servo system; Define state variables The expression for the strict feedback system is: The sliding surface construction module is used to design fixed-time non-singular terminal sliding surfaces based on auxiliary switching functions; The design of a fixed-time non-singular terminal sliding surface based on an auxiliary function includes the following steps: Define the tracking error, and based on the tracking error, introduce an auxiliary function and design a switching function to obtain the auxiliary switching function; The auxiliary function for: in, Preset positive numbers; Indicates tracking error; Design a fixed-time non-singular terminal sliding surface based on the aforementioned auxiliary switching function; The controller construction module is used to obtain a sliding mode controller based on the strict feedback system expression and the fixed-time non-singular terminal sliding surface; The control module is used to converge the tracking error time of the motor servo system to a preset range based on the sliding mode controller; The tracking error time of the motor servo system is converged to a preset range based on the sliding mode controller, including: The first preset Lyapunov function is differentiated, and the result of the differentiation of the fixed-time non-singular terminal sliding surface is substituted to obtain the first estimated time; The first preset Lyapunov function is: In the formula, Represents a fixed-time non-singular terminal sliding surface; The derivative of the second preset Lyapunov function is calculated, and the derivative of the preset position of the fixed-time non-singular terminal sliding surface is substituted into the derivative to obtain the second estimated time. The second preset Lyapunov function is: In the formula, Indicates tracking error; Preset positive numbers; Indicates the switching function, ; The total convergence time of the motor servo system is obtained based on the first estimated time and the second estimated time, and convergence is performed according to the total convergence time of the motor servo system to bring the tracking error of the motor servo system to a preset range.

4. A computer device, characterized in that, include: At least one processor; And a memory at least communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to perform the method as described in any one of claims 1 and 2.

5. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to perform the method as described in any one of claims 1 and 2.

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