A demagnetization fault tolerance synchronous control method for three electric cylinders

Abstract

The application discloses a kind of demagnetization fault tolerance synchronous control methods for three electric cylinders, comprising the following steps: constructing the mathematical model of synchronous control system under three electric cylinders demagnetization fault;Based on the synchronization control target of three-phase permanent magnet synchronous motor, the dynamic equation of the core fusion error of three-phase permanent magnet synchronous motor is calculated;Based on the linear dynamics model of electric cylinder and the dynamic equation of the core fusion error of three-phase permanent magnet synchronous motor, the final control law of three-phase permanent magnet synchronous motor system is obtained;Based on the final control law of three-phase permanent magnet synchronous motor system, the synchronization control and demagnetization fault compensation of three electric cylinders are finally realized.The three electric cylinder cooperative system aimed at by the present application transforms three-phase alternating current to d-q coordinate system, under the condition that d-axis current is zero, torque regulation of motor is realized by single control q-axis current, and linear motion of electric cylinder is converted through ball screw.

Description

Technical Field

[0001] This invention relates to the field of aero-engine drive control technology, specifically to a method for demagnetization fault compensation and displacement synchronization control of three electric cylinders based on the backstepping method, applicable to scenarios such as multi-actuator coordinated drive and multi-axis linkage high-precision synchronous control of aero-engines. Background Technology

[0002] The adjustment accuracy of the adjustable guide vanes of an aero-engine directly determines the intake efficiency and the overall stability of the engine. Its actuation system needs to achieve high-precision synchronous control of the three actuators under harsh conditions such as high temperature, airflow fluctuation, and sudden load changes. The position synchronization error of the blade adjustment needs to be controlled within the allowable range of the operating conditions. Otherwise, it will cause risks such as airflow turbulence, blade wear, and increased vibration of the entire engine, which may seriously affect the safe operation of the engine.

[0003] Currently, electric cylinders are widely used as the core drive component in the actuation system of aero-engine guide vanes. These electric cylinders provide rotational power through an internal three-phase permanent magnet synchronous motor (PMSM), which is converted into linear motion by a rigid ball screw with no transmission backlash. They have advantages such as small size, fast response speed, high control precision, excellent energy utilization efficiency, and strong resistance to external interference. They can meet the control requirements of multi-axis linkage and have become the preferred solution for scenarios such as multi-actuator collaborative drive control.

[0004] However, in the actual operating environment of aero-engines, the demagnetization problem faced by the electric cylinders has become a significant factor restricting the accuracy of synchronous control. The permanent magnets of the PMSM (Permanent Magnetic Stator) inside the electric cylinder are subjected to complex conditions of high temperature, high load, and alternating magnetic fields for extended periods, making them highly susceptible to slow demagnetization. Furthermore, due to factors such as manufacturing processes, installation errors, and actual operating conditions, the degree of demagnetization among the three electric cylinders often varies. Demagnetization directly leads to a decrease in the torque coefficient of the motor, resulting in uneven thrust output from the electric cylinders. The more severe the demagnetization of an electric cylinder, the more significant the thrust reduction. This thrust difference with other electric cylinders can cause asynchronous movement of the three actuators, not only reducing the adjustment accuracy of the guide vanes but also potentially exacerbating mechanical wear due to uneven force on the vanes, thus shortening the equipment's service life.

[0005] Existing electric cylinder synchronization control technology still needs improvement in addressing the aforementioned demagnetization-related pain points, mainly due to the following shortcomings:

[0006] 1. Demagnetization faults have not been addressed: Existing control algorithms are mostly based on ideal motor model designs and have not designed specific compensation strategies for the time-varying torque coefficient perturbation caused by PMSM demagnetization, or only use fixed gain control, which is difficult to offset the thrust deviation caused by demagnetization, resulting in synchronization errors that significantly exceed the allowable range. 2. The handling of the difference in demagnetization amount of multiple electric cylinders has not been taken into account: Even though some existing adaptive demagnetization compensation technologies have been developed for single motor demagnetization scenarios, they have not been combined with the synchronous control constraints of three electric cylinders. The problem of uneven multi-axis thrust caused by inconsistent demagnetization degree has not been solved. On the contrary, excessive compensation of a single cylinder may aggravate the synchronous motion deviation. 3. Insufficient reliability of synchronous control: Traditional multi-electric cylinder synchronous control often adopts a master-slave control architecture, relying on the state feedback of a single reference electric cylinder for adjustment. If the reference cylinder experiences parameter perturbation or other faults, it may directly lead to the failure of synchronous tracking of the entire electric cylinder group. At the same time, the PID controllers commonly used in engineering today are difficult to balance transient response speed and overshoot, and the synchronization accuracy under disturbances is difficult to meet the requirements.

[0007] Furthermore, existing technologies do not consider the coupling relationship between demagnetization faults and synchronization control constraints—the thrust difference caused by demagnetization amplifies the synchronization error, and the accumulation of the synchronization error further exacerbates the uneven load on each cylinder, making synchronization control more difficult, thus creating a vicious cycle. Therefore, how to design a technical solution for three-cylinder engines that takes into account both demagnetization fault-tolerant compensation and high-precision synchronization control, and solve the problems of thrust balance and cooperative motion control under demagnetization differences, has become a technical challenge that urgently needs to be overcome in aero-engine actuation systems. Summary of the Invention

[0008] To address the issue that existing technologies fail to consider the coupling relationship between demagnetization faults and synchronization control constraints—where thrust differences caused by demagnetization amplify synchronization errors, and the accumulation of these errors further exacerbates uneven load distribution among cylinders, leading to increased difficulty in synchronization control and creating a vicious cycle—this invention aims to design a technical solution for three-cylinder systems that balances demagnetization fault-tolerant compensation with high-precision synchronization control, resolving the issues of thrust balancing and coordinated motion control under demagnetization differences. The technical solution adopted in this invention is: a demagnetization fault-tolerant synchronization control method for three-cylinder systems, comprising the following steps: A mathematical model of the synchronous control system under demagnetization fault of three electric cylinders is constructed; Based on the synchronization control objective of a three-phase permanent magnet synchronous motor, the dynamic equation of the core fusion error of the three-phase permanent magnet synchronous motor is calculated. Based on the linear dynamics model of the electric cylinder and the dynamic equation of the core fusion error of the three-phase permanent magnet synchronous motor, the backstepping adaptive law and control law under Lyapunov stability are designed. Based on the final control law of the three-phase permanent magnet synchronous motor system, the synchronous control and demagnetization fault-tolerant compensation of the three electric cylinders are finally realized.

[0009] Furthermore, the process of constructing the mathematical model of the synchronous control system under the demagnetization fault of the three electric cylinders is as follows: Define the relevant physical quantities of the electric cylinder, and obtain the following conversion relationship between the linear motion of the electric cylinder and the rotational motion of the three-phase permanent magnet synchronous motor; Establish a dynamic model of a fully connected synchronous system of three electric cylinders; Establish a rotary side mechanical dynamics model for a fully connected synchronous system of three electric cylinders; Substitute the following conversion relationship between the linear motion of the electric cylinder and the rotational motion of the three-phase permanent magnet synchronous motor into the rotating side mechanical dynamics model of the three-cylinder fully connected synchronous system to establish the linear side mechanical dynamics model of the electric cylinder. Based on the linear side mechanical dynamics model of the electric cylinder, a modified electric cylinder model under demagnetization fault is established. Based on the modified electric cylinder model under demagnetization fault, a dynamic model of a three-electric cylinder synchronous system is established. Based on the dynamic model of the three-cylinder synchronization system, the communication topology and mathematical model of the fully connected synchronization control system under the demagnetization fault of the three-cylinder system are established.

[0010] Furthermore, the linear-side dynamic model of the three-cylinder synchronous system is as follows:

[0011] in, Represents the linear displacement and velocity of the i-th electric cylinder; This represents the q-axis current of the PMSM inside the i-th electric cylinder; Let represent the total disturbance on the linear side of the i-th electric cylinder; For the equivalent quality after conversion, This is the equivalent damping coefficient. This is the equivalent thrust coefficient. This represents the total disturbance on the straight side.

[0012] Furthermore: Based on the synchronization control objective of the three-phase permanent magnet synchronous motor, the process of calculating the dynamic equation of the core fusion error of the three-phase permanent magnet synchronous motor is as follows: Based on the synchronization control objective of a three-phase permanent magnet synchronous motor, position tracking error, speed tracking error, and synchronization error are defined. Calculate the second-order dynamic equation for the position tracking error; Based on the second-order dynamic equation of the tracking error, the dynamic equation of the error reconstructed signal is calculated. Based on the dynamic equation of the error reconstruction signal, the dynamic equation of the core fusion error of the three-phase permanent magnet synchronous motor is calculated.

[0013] Furthermore, the process of designing the Lyapunov stability-based backstepping adaptive law and control law based on the linear dynamics model of the electric cylinder and the dynamic equation of the core fusion error of the three-phase permanent magnet synchronous motor is as follows: Based on the linear dynamics model of the electric cylinder and the dynamic equation of the core fusion error of the three-phase permanent magnet synchronous motor, the dynamic equation of the fusion error is obtained. Based on the fusion error dynamic equation, the backstepping control law is designed; To simultaneously ensure the synchronous tracking stability of the three-phase permanent magnet synchronous motor system and the convergence of the demagnetization estimate, a composite Lyapunov function is constructed. By differentiating the composite Lyapunov function, the adaptive law of demagnetization perturbation is derived. Based on the demagnetization perturbation adaptive law, the derivative of the Lyapunov function is simplified, and then based on the backstepping control law, the final control law of the three-phase permanent magnet synchronous motor system is obtained.

[0014] Furthermore, the expression for the final control law is as follows:

[0015] in: This is an estimate of the demagnetization perturbation. To let Error decay gain for fast convergence; This is the first derivative of the synchronization error.

[0016] A fault-tolerant synchronization control device for demagnetization faults in three electric cylinders includes: Building Module: Used to construct the mathematical model of the synchronous control system under the demagnetization fault of the three electric cylinders; Calculation module: Used to calculate the dynamic equation of the core fusion error of a three-phase permanent magnet synchronous motor based on the synchronization control target of the motor. Design module: Used to design the inverse step adaptive law and control law under Lyapunov stability based on the linear dynamics model of the electric cylinder and the dynamic equation of the core fusion error of the three-phase permanent magnet synchronous motor. Implementation module: Used for the final control law of the three-phase permanent magnet synchronous motor system, ultimately realizing the synchronous control and demagnetization fault-tolerant compensation of the three electric cylinders.

[0017] This invention provides a fault-tolerant synchronous control method for three electric cylinders to address demagnetization faults. The control problem of the electric cylinders is equivalent to the control problem of their internal three-phase PMSM (Motor-Motor System). Through motion conversion via the ball screw, the linear position of the electric cylinder corresponds one-to-one with the rotational position of the PMSM. Therefore, the synchronous control of the three electric cylinders is essentially the position synchronous control of the three motors. This invention targets a three-electric cylinder cooperative system where each internal motor is rigidly connected to the ball screw. Essentially, this rigid connection makes the linear motion control of the electric cylinder equivalent to the rotational control of the motor—the motor control uses traditional vector control methods, transforming the three-phase AC quantities to the dq coordinate system. Under the condition that the d-axis current is zero, the torque regulation of the motor is achieved by controlling the q-axis current alone, and then converted into the linear motion of the electric cylinder via the ball screw. Simultaneously, the response frequency of the motor current loop is much higher than the actual motion frequency of the ball screw; therefore, this invention approximates the current loop as a proportional element, simplifying the dynamic modeling of the control system. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a block diagram of a fault-tolerant synchronous control system for demagnetization of three electric cylinders; Figure 2 It is the displacement tracking curve of the three electric cylinders; Figure 3 It is the synchronization error curve of three electric cylinders; Figure 4 These are the demagnetization perturbation estimation curves; where (a) compares the estimated demagnetization value of cylinder 1 with the actual value, and (b) compares the estimated demagnetization value of cylinder 2 with the actual value. Figure 5 This is the q-axis current curve of a three-cylinder electric cylinder. Detailed Implementation

[0020] It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Figure 1 This is a block diagram of a fault-tolerant synchronous control system for demagnetization of three electric cylinders; A fault-tolerant synchronization control method for demagnetization faults in three electric cylinders includes the following steps: S1: Construct a mathematical model of the synchronous control system under the demagnetization fault of three electric cylinders; S2: Based on the synchronization control objective of the three-phase permanent magnet synchronous motor, calculate the dynamic equation of the core fusion error of the three-phase permanent magnet synchronous motor. S3: Based on the linear dynamics model of the electric cylinder and the dynamic equation of the core fusion error of the three-phase permanent magnet synchronous motor, the backstepping adaptive law and control law of Lyapunov stability are designed. S4: Based on the final control law of the three-phase permanent magnet synchronous motor system, the synchronous control and demagnetization fault-tolerant compensation of the three electric cylinders are finally realized.

[0023] Furthermore, the process of constructing the mathematical model of the synchronous control system under the demagnetization fault of the three electric cylinders is as follows: S11: Define the relevant physical quantities of the electric cylinder, and obtain the following conversion relationship between the linear motion of the electric cylinder and the rotational motion of the three-phase permanent magnet synchronous motor; Define the conversion relationship between physical quantities and linear-rotational quantities. Define the linear load displacement of an electric cylinder as... (unit: , (Corresponding to three electric cylinders), linear motion speed is (unit: Its internal ball screw lead is (unit: The rotation angle of the PMSM inside the electric cylinder is... (Unit: rad), rotational angular velocity is (unit: ), angular acceleration is (unit: ).

[0024] Since the PMSM and the ball screw are rigidly connected with no transmission backlash, the linear motion of the electric cylinder and the rotary motion of the PMSM satisfy the following conversion relationship:

[0025] S12: Establish the dynamic model of the three-cylinder fully connected synchronous system; Based on the vector control strategy, neglecting stator resistance voltage drop and flux linkage cross-coupling, the dynamic relationship between q-axis voltage and current is as follows:

[0026] in, This represents the q-axis voltage of the PMSM inside the i-th electric cylinder. This represents the q-axis inductance of the PMSM. This represents the q-axis current of the PMSM inside the i-th electric cylinder. This represents the number of pole pairs of the PMSM. This represents the mechanical angular velocity of the PMSM inside the i-th electric cylinder. The nominal flux linkage of a permanent magnet.

[0027] S13 establishes a rotary side mechanical dynamics model of a three-cylinder fully connected synchronous system; Its dynamic equilibrium equation is:

[0028] in, This represents the moment of inertia of the PMSM. This indicates the mechanical angular velocity of the PMSM. This represents the output electromagnetic torque of the PMSM inside the i-th electric cylinder. This represents the viscous damping coefficient of PMSM. This represents the load torque of the i-th electric cylinder. This indicates unmodeled dynamic disturbances.

[0029] Relationship between electromagnetic torque and q-axis current (where the nominal torque coefficient of the PMSM is used), the mechanical motion equation can be simplified to:

[0030] in: This represents the q-axis current of the PMSM inside the electric cylinder; The load torque of the electric cylinder; S14: Substitute the following conversion relationship between the linear motion of the electric cylinder and the rotational motion of the three-phase permanent magnet synchronous motor into the rotating side mechanical dynamics model of the three-cylinder fully connected synchronous system to establish the linear side mechanical dynamics model of the electric cylinder. S11 Substituting into the equation for the rotating side of S13 and rearranging, we get:

[0031] in, For the equivalent quality after conversion, This is the equivalent damping coefficient. This is the equivalent thrust coefficient. This represents the total disturbance on the straight side.

[0032] S15: Based on the linear side mechanical dynamics model of the electric cylinder, establish a modified electric cylinder model under demagnetization fault. When a demagnetization fault occurs in the PMSM inside the electric cylinder, the permanent magnet flux linkage... Attenuation occurs, according to This, in turn, causes a perturbation in the torque coefficient of the PMSM. This invention estimates the transformed parameter perturbations using an adaptive algorithm. Essentially, it indirectly compensates for the demagnetization caused by the process. Attenuation is achieved to balance and compensate for the thrust of the electric cylinder and stabilize its position. Combining the balance relationship between electromagnetic torque and mechanical motion, the converted demagnetization parameter perturbation is substituted into the linear dynamics equation of the electric cylinder. The mechanical motion equation of the electric cylinder is expressed as:

[0033] in, This represents the time-varying torque coefficient of the PMSM. This is the nominal torque coefficient on the straight side. The perturbation of the equivalent thrust coefficient on the linear side of the i-th electric cylinder is the time-varying decrease of the torque coefficient relative to the nominal value after demagnetization, under demagnetization fault. ; The total disturbance represents the integration of load torque and unmodeled dynamic disturbance, i.e. ).

[0034] S16: Based on the modified electric cylinder model under demagnetization fault, establish the dynamic model of the three-electric cylinder synchronous system; For three electric cylinders Considering the demagnetization fault characteristics and total disturbance of each cylinder respectively, and combining the modified model of S15, a linear side dynamic model of the three-cylinder synchronous system is established:

[0035] in, Represents the linear displacement and velocity of the i-th electric cylinder; This represents the q-axis current of the PMSM inside the i-th electric cylinder; Let represent the total disturbance on the linear side of the i-th electric cylinder.

[0036] S17: Based on the dynamic model of the three-electric cylinder synchronization system, construct the communication topology and mathematical model of the fully connected synchronization control system under the demagnetization fault of the three-electric cylinder.

[0037] The mechanical dynamics model of the three electric cylinders has been established in the previous step, but synchronous control requires motion coupling through a communication link. The core of multi-electric cylinder synchronous control is to achieve state coordination among them. In step 1, only the communication topology of the three electric cylinders is defined (the error-related definition will be detailed in step 2) to provide a basis for subsequent synchronization constraints.

[0038] The three electric cylinders employ a fully connected undirected communication topology: each electric cylinder establishes a bidirectional communication link with the other two electric cylinders, eliminating the need for a central reference motor. All three machines are completely equal in status, avoiding the drawback of traditional master-slave control where "reference device failure easily leads to global synchronization failure." The communication coupling relationship of this topology is achieved through a Laplace matrix. Quantization, the Laplace matrix corresponding to the fully connected undirected topology of the three electric cylinders is:

[0039] Among them, diagonal elements Indicates the "degree" of the corresponding electric cylinder (i.e., the number of other electric cylinders directly connected to this electric cylinder); off-diagonal elements This indicates that there is a bidirectional communication link between electric cylinder i and electric cylinder j; This indicates that there is no direct communication.

[0040] Furthermore: Based on the synchronization control objective of the three-phase permanent magnet synchronous motor, the process of calculating the dynamic equation of the core fusion error of the three-phase permanent magnet synchronous motor is as follows: Figure 2 It is the displacement tracking curve of the three electric cylinders; Figure 3 It is the synchronization error curve of three electric cylinders; S21: Based on the synchronization control objective of a three-phase permanent magnet synchronous motor, define the position tracking error, speed tracking error, and synchronization error; The position tracking error is:

[0041] in, Let be the actual linear displacement of the i-th electric cylinder. This is the reference linear displacement of the electric cylinder assembly.

[0042] The speed tracking error is:

[0043] in, Let be the actual linear velocity of the i-th electric cylinder. For reference speed.

[0044] The synchronization error is:

[0045] in, The Laplace matrix element corresponding to the fully connected topology of the three electric cylinders .

[0046] S22: The second-order dynamic equation for calculating the position tracking error; Defined by the second derivative of position tracking error And from the system dynamics model, we get:

[0047] Substituting this into the equation, we derive the second-order dynamic equation for the tracking error:

[0048] S23: Based on the second-order dynamic equation of the tracking error, calculate the dynamic equation of the error reconstructed signal; Construction error reconstructed signal That is, designing a virtual speed control law as (for error reconstruction gain), for Differentiate and substitute The dynamic equation is obtained. The dynamic equation:

[0049] S24: Based on the dynamic equation of the error reconstruction signal, calculate the dynamic equation of the core fusion error of the three-phase permanent magnet synchronous motor.

[0050] Define fusion error ( >0 represents the synchronous coupling gain; take its derivative and substitute it into... From the dynamic equation, we obtain the dynamic equation for the fusion error:

[0051] in, This is the first derivative of the synchronization error.

[0052] Furthermore, the process of designing the Lyapunov stability-based backstepping adaptive law and control law based on the linear dynamics model of the electric cylinder and the dynamic equation of the core fusion error of the three-phase permanent magnet synchronous motor is as follows: Based on the dynamic equation of fusion error and demagnetization fault characteristics, the q-axis current command is designed in stages using the backstepping method. Meanwhile, targeting demagnetization perturbation By designing an adaptive law, this step achieves the synchronous control objective and demagnetization fault tolerance objective of this invention.

[0053] S31: Based on the linear dynamics model of the electric cylinder and the dynamic equation of the core fusion error of the three-phase permanent magnet synchronous motor, the dynamic equation of the fusion error is obtained.

[0054] S32: Design of backstepping control law based on fusion error dynamic equation; because Unknown values ​​are estimated in the control law. Replacement, to reduce fusion error Convergence, design the actual control law And offset redundant items as needed, let:

[0055] in: This is an estimate of the demagnetization perturbation. To let Error decay gain with fast convergence.

[0056] Combined with demagnetization estimation error After simplification, we get:

[0057] S33: To simultaneously ensure the synchronous tracking stability of the three-phase permanent magnet synchronous motor system and the convergence of the demagnetization estimate, a composite Lyapunov function is constructed; its expression is as follows:

[0058] in: To account for the estimation error of demagnetization perturbation, For adaptive gain; Lyapunov function The physical meaning is the sum of the system tracking error energy and the demagnetization estimation error energy. .

[0059] S34: By differentiating the composite Lyapunov function, the adaptive law of demagnetization perturbation is derived. right Differentiate and substitute After sorting, we get:

[0060] To ensure (The system energy decays and tends to stabilize), making =0, offsetting the demagnetization estimation error. The influence of demagnetization perturbation is directly solved to obtain the adaptive law of demagnetization perturbation:

[0061] in: The adaptive gain is a positive real number, and its value needs to balance the estimation convergence speed and stability; the initial value of the adaptive law is set to... Default motor initial No demagnetization; to avoid divergence in estimates, in engineering, [the following can be done]: Apply saturation constraints and ensure that the denominator is... .

[0062] S35: Based on the demagnetization perturbation adaptive law, the derivative of the Lyapunov function is simplified, and then based on the backstepping control law, the final control law of the three-phase permanent magnet synchronous motor system is obtained.

[0063] After substituting the adaptive law, the derivative of the Lyapunov function finally simplifies to:

[0064] Therefore The system satisfies the Lyapunov negative definite condition and is globally stable.

[0065] The final form of the control law (derived from S3.2):

[0066] The final form of the adaptive law (obtained from S3.4):

[0067] Combining the Lyapunov stability analysis and the design of control and adaptive laws described above, the final stability conclusion of the system can be obtained: when At that time, all signals in the system: electric cylinder displacement ,speed Current command Demagnetization estimate All remain bounded; fusion error Synchronous control and demagnetization fault-tolerant compensation of three electric cylinders are achieved within a small bounded region that converges to near zero.

[0068] Figure 4 These are the demagnetization perturbation estimation curves; where (a) compares the estimated demagnetization value of cylinder 1 with the actual value, and (b) compares the estimated demagnetization value of cylinder 2 with the actual value. Figure 5 It is the q-axis current curve of a three-cylinder electric cylinder; Example 1 To verify the effectiveness of the designed backstepping control strategy, this implementation case relies on the three-electric cylinder actuation system of a certain turbofan aero-engine under development. A simulation model is built based on the actual physical parameters of the electric cylinders and the characteristics of demagnetization faults. By setting differentiated demagnetization perturbations for the three electric cylinders and comparing the error convergence effects under multiple sets of adaptive gain, synchronous coupling gain, and backstepping control gain, the system's synchronization accuracy and fault tolerance compensation capability under demagnetization faults are verified. The specific implementation process is as follows: S1: PMSM Rotary Side Parameters: Rated Power Rated speed Moment of inertia Viscous damping coefficient Nominal torque coefficient ; Mechanical structural parameters: ball screw lead ; Equivalent parameters on the linear side: derived based on the rotation-linear motion conversion relationship, including the equivalent linear mass. Equivalent linear damping coefficient , ; Demagnetization perturbation parameters: To simulate differentiated demagnetization scenarios for three electric cylinders, the equivalent thrust coefficient attenuation is set as follows: , , ; System simulation parameters: sampling time Simulation duration .

[0069] S2: Selection of Reference Trajectory and Initial Values Unified location reference trajectory: Initial position of the three motors (0)= (0)= (0) initial angular velocity ; Adaptive estimation of initial value for demagnetization amount .

[0070] S3: Controller and Synchronization Error Parameter Design Position error gain Fusion error attenuation gain This ensures rapid error convergence. Synchronization error coupling gain. Verification was made by observing the position tracking performance of the electric cylinder assembly. Impact on synchronization accuracy.

[0071] S4: Introduces external interference to the electric cylinder assembly. This represents the total disturbance on the straight side.

[0072] The effectiveness of this invention has been verified through a standardized simulation process, and the attached figures clearly illustrate the optimal synchronization coupling gain. The simulation results demonstrate the effectiveness of position trajectory synchronization, disturbance suppression, demagnetization adaptive estimation, and current response characteristics of each electric cylinder. Simulation results show that when the optimal synchronization coupling gain is selected... Even when all three electric cylinders are under load disturbance, and electric cylinder 2 has a 35% [unclear meaning - possibly referring to a specific characteristic or property], The demagnetizing perturbation and electric cylinder 1 have a 10% presence. Under demagnetization perturbation, the linear displacement synchronization error of the three electric cylinders can still be converged to within ±0.004m, and the tracking error is always kept within ±0.01m, both within the allowable range of engineering. This fully demonstrates the high-precision synchronization capability and anti-disturbance performance of this control strategy under demagnetization faults and load disturbances.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fault-tolerant synchronous control method for demagnetization faults in three electric cylinders, characterized in that: Includes the following steps: A mathematical model of the synchronous control system under demagnetization fault of three electric cylinders is constructed; Based on the synchronization control objective of a three-phase permanent magnet synchronous motor, the dynamic equation of the core fusion error of the three-phase permanent magnet synchronous motor is calculated. Based on the linear dynamics model of the electric cylinder and the dynamic equation of the core fusion error of the three-phase permanent magnet synchronous motor, the backstepping adaptive law and control law under Lyapunov stability are designed. Based on the final control law of the three-phase permanent magnet synchronous motor system, the synchronous control and demagnetization fault-tolerant compensation of the three electric cylinders are finally realized.

2. The demagnetization fault-tolerant synchronous control method for three electric cylinders according to claim 1, characterized in that: The process of constructing the mathematical model of the synchronous control system under the demagnetization fault of the three electric cylinders is as follows: Define the relevant physical quantities of the electric cylinder, and obtain the following conversion relationship between the linear motion of the electric cylinder and the rotational motion of the three-phase permanent magnet synchronous motor; Establish a dynamic model of a fully connected synchronous system of three electric cylinders; Establish a rotary side mechanical dynamics model for a fully connected synchronous system of three electric cylinders; Substitute the following conversion relationship between the linear motion of the electric cylinder and the rotational motion of the three-phase permanent magnet synchronous motor into the rotating side mechanical dynamics model of the three-cylinder fully connected synchronous system to establish the linear side mechanical dynamics model of the electric cylinder. Based on the linear side mechanical dynamics model of the electric cylinder, a modified electric cylinder model under demagnetization fault is established. Based on the modified electric cylinder model under demagnetization fault, a dynamic model of a three-electric cylinder synchronous system is established. Based on the dynamic model of the three-cylinder synchronization system, the communication topology and mathematical model of the fully connected synchronization control system under the demagnetization fault of the three-cylinder system are established.

3. The demagnetization fault-tolerant synchronous control method for three electric cylinders according to claim 1, characterized in that: The linear dynamics model of the three-electric cylinder synchronization system is as follows: in, Represents the linear displacement and velocity of the i-th electric cylinder; This represents the q-axis current of the PMSM inside the i-th electric cylinder; Let represent the total disturbance on the linear side of the i-th electric cylinder; For the equivalent quality after conversion, This is the equivalent damping coefficient. This is the equivalent thrust coefficient. This represents the total disturbance on the straight side.

4. The demagnetization fault-tolerant synchronous control method for three electric cylinders according to claim 1, characterized in that: Based on the synchronization control objective of a three-phase permanent magnet synchronous motor, the process of calculating the dynamic equation of the core fusion error of the three-phase permanent magnet synchronous motor is as follows: Based on the synchronization control objective of a three-phase permanent magnet synchronous motor, position tracking error, speed tracking error, and synchronization error are defined. Calculate the second-order dynamic equation for the position tracking error; Based on the second-order dynamic equation of the tracking error, the dynamic equation of the error reconstructed signal is calculated. Based on the dynamic equation of the error reconstruction signal, the dynamic equation of the core fusion error of the three-phase permanent magnet synchronous motor is calculated.

5. The demagnetization fault-tolerant synchronous control method for three electric cylinders according to claim 1, characterized in that: The process of designing the Lyapunov stability-based backstepping adaptive law and control law, based on the linear dynamics model of the electric cylinder and the dynamic equation of the core fusion error of the three-phase permanent magnet synchronous motor, is as follows: Based on the linear dynamics model of the electric cylinder and the dynamic equation of the core fusion error of the three-phase permanent magnet synchronous motor, the dynamic equation of the fusion error is obtained. Based on the fusion error dynamic equation, the backstepping control law is designed; To simultaneously ensure the synchronous tracking stability of the three-phase permanent magnet synchronous motor system and the convergence of the demagnetization estimate, a composite Lyapunov function is constructed. By differentiating the composite Lyapunov function, the adaptive law of demagnetization perturbation is derived. Based on the demagnetization perturbation adaptive law, the derivative of the Lyapunov function is simplified, and then based on the backstepping control law, the final control law of the three-phase permanent magnet synchronous motor system is obtained.

6. The demagnetization fault-tolerant synchronous control method for three electric cylinders according to claim 1, characterized in that: The expression for the final control law is as follows: in: This is an estimate of the demagnetization perturbation. To let Error decay gain for fast convergence; This is the first derivative of the synchronization error.

7. A fault-tolerant synchronous control device for demagnetization faults in three electric cylinders, characterized in that: include: Building Module: Used to construct the mathematical model of the synchronous control system under the demagnetization fault of the three electric cylinders; Calculation module: Used to calculate the dynamic equation of the core fusion error of a three-phase permanent magnet synchronous motor based on the synchronization control target of the three-phase permanent magnet synchronous motor; Design module: Used to design the inverse step adaptive law and control law under Lyapunov stability based on the linear dynamics model of the electric cylinder and the dynamic equation of the core fusion error of the three-phase permanent magnet synchronous motor. Implementation module: Used for the final control law of the three-phase permanent magnet synchronous motor system, ultimately realizing the synchronous control and demagnetization fault-tolerant compensation of the three electric cylinders.

Images