Setting method and device for controller parameters in servo system and computing equipment

Abstract

The invention relates to the technical field of controller parameter setting, and discloses a setting method and device for controller parameters in a servo system and computing equipment. The setting method comprises the following steps: sweeping frequency characteristics of a controlled object in the servo system, and determining an open-loop transfer function for the controlled object according to the frequency characteristics; determining a full-band constraint boundary of the servo system according to constraint conditions of a user on stability and immunity of the servo system; the coordinates of the open-loop transfer function are made to be equal to the real part and the imaginary part of the coordinates of the full-band constraint boundary, the slopes of the open-loop transfer function and the full-band constraint boundary at the intersection point are made to be equal, and a full-rank equation set is determined; and solving the full-rank equation set to obtain a target solution set of the controller parameters, and screening out the target controller parameters from the target solution set according to a maximum bandwidth criterion. According to the invention, the time for redesigning parameters of the controller and the production cost of manpower can be reduced when the controlled object is replaced, and the production efficiency of industrial manufacturing is improved.

Description

Technical Field

[0001] The present application relates to the technical field of controller parameter tuning, for example, to a method and device for tuning controller parameters in a servo system, and a computing device. Background Art

[0002] In related technologies, for diverse industrial manufacturing scenarios, different controlled objects have significant differences. The controlled objects corresponding to the outer loop (i.e., speed and position loop) of the servo system need to consider the load-side characteristics, and the modeling often needs to consider the influence of flexible transmission links (such as elastic shafts, gear boxes, roller screws and their transmission belts, etc.). Therefore, when replacing the controlled object in the servo system, it is necessary to redesign the controller parameters of the servo system.

[0003] In the process of implementing the embodiments of the present disclosure, it is found that there are at least the following problems in the related art:

[0004] Frequent redesign of controller parameters will increase time and labor costs. Therefore, how to provide a universal controller parameter tuning method to reduce the time and labor production costs of redesigning controller parameters when changing the controlled object and improve the production efficiency of industrial manufacturing has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not an extensive review, nor is it intended to identify key / critical components or delineate the scope of protection of these embodiments, but rather serves as a prelude to the detailed description that follows.

[0006] The embodiments of the present disclosure provide a method and apparatus for adjusting controller parameters in a servo system, and a computing device, which can reduce the production cost of time and manpower required to redesign controller parameters when replacing a controlled object, thereby improving the production efficiency of industrial manufacturing.

[0007] In some embodiments, a method for tuning controller parameters in a servo system includes: determining the frequency characteristics of a controlled object in a swept frequency servo system, determining the controlled object and an open-loop transfer function for the controlled object; determining the full-band constraint boundary of the servo system based on user constraints on the stability and anti-interference performance of the servo system; making the real and imaginary parts of the coordinates of the open-loop transfer function equal to those of the full-band constraint boundary, making the slopes of the open-loop transfer function and the full-band constraint boundary at the intersection equal, and determining a full-rank equation group; solving the full-rank equation group to obtain a target solution set of controller parameters, and filtering out target controller parameters from the target solution set according to the maximum bandwidth criterion.

[0008] Optionally, the constraints on the stability of the servo system include: closed-loop amplitude constraint, phase margin constraint and gain margin constraint; the constraints on the anti-interference performance of the servo system include: anti-interference performance constraint; based on the user's constraints on the stability and anti-interference performance of the servo system, determine the full-band constraint boundary of the servo system, including: according to the upper limit value of the closed-loop amplitude constraint, use the open-loop transfer function of the servo system to draw a closed-loop amplitude circle; according to the phase margin constraint and the gain margin constraint, limit the gain margin and phase margin of the closed-loop amplitude circle to determine the stability constraint boundary; construct an anti-interference constraint circle according to the anti-interference performance constraint, and on the basis of the stability constraint boundary, extend the maximum phase line and connect the arc segment of the anti-interference constraint circle to determine the full-band constraint boundary.

[0009] Optionally, solving the full-rank equations to obtain a target solution set of controller parameters includes: receiving an angle step and a frequency step input by a user; solving the full-rank equations based on the angle step and the frequency step according to a preset search algorithm to obtain a target solution set of controller parameters.

[0010] Optionally, target controller parameters are selected from the target solution set according to the maximum bandwidth criterion, including: for each solution in the target solution set, calculating the frequency when the closed-loop amplitude of the servo system decays to a set decibel for the first time as the bandwidth of the servo system; and selecting the solution corresponding to the maximum bandwidth in the target solution set as the target controller parameter.

[0011] Optionally, before selecting the target controller parameters from the target solution set according to the maximum bandwidth criterion, the tuning method further includes: correcting the target solution set.

[0012] Optionally, the target solution set is corrected, including: determining a frequency point to be corrected corresponding to each solution in the target solution set; calculating the complex plane coordinates of the open-loop transfer function at the frequency point to be corrected; and removing the solution corresponding to the frequency point to be corrected from the target solution set when the complex plane coordinates are within the stability constraint boundary of the servo system.

[0013] Optionally, determining the frequency point to be corrected corresponding to each solution in the target solution set includes: determining the phase angle range of the stability constraint boundary of the servo system; calculating the phase angle of each solution in the target solution set at each frequency point; and taking the frequency point whose phase angle is within the phase angle range as the frequency point to be corrected.

[0014] In some embodiments, a device for adjusting controller parameters in a servo system includes: a frequency sweep module configured to sweep the frequency characteristics of a controlled object in the servo system to determine the controlled object and an open-loop transfer function for the controlled object; a constraint module configured to determine the full-band constraint boundary of the servo system based on the user's constraints on the stability and anti-interference of the servo system; a determination module configured to make the real and imaginary parts of the coordinates of the open-loop transfer function equal to those of the full-band constraint boundary, and to make the slopes of the open-loop transfer function and the full-band constraint boundary at the intersection point equal, to determine a full-rank equation group; and a solution module configured to solve the full-rank equation group to obtain a target solution set of controller parameters, and filter out target controller parameters from the target solution set according to the maximum bandwidth criterion.

[0015] In some embodiments, a device for tuning controller parameters in a servo system includes a processor and a memory storing program instructions, and the processor is configured to execute the above-mentioned method for tuning controller parameters in a servo system.

[0016] In some embodiments, a computing device includes: a device body; and a device for adjusting controller parameters in a servo system as described above, which is disposed in the device body.

[0017] The method and device for setting controller parameters in a servo system and the computing device provided by the embodiments of the present disclosure can achieve the following technical effects:

[0018] In the embodiment of the present disclosure, after the controlled object in the servo system is replaced, the frequency characteristics of the controlled object will be obtained by the frequency sweep method, and the open-loop transfer function for the controlled object will be determined based on the frequency characteristics. The full-band constraint boundary will be constructed based on the user's constraints on the stability and anti-interference of the servo system. The full-rank equation group of the servo system will be constructed based on the open-loop transfer function and the full-band constraints. Finally, the target solution set will be obtained by solving the full-rank equation group, and the target controller parameters for the replaced controlled object will be screened out from the target solution set according to the maximum bandwidth criterion. In this way, when replacing the controlled object in the servo system, the user does not need to manually measure the relevant parameters of the controlled object and establish a relevant model. There is no need to rely on experience for multiple trial and error as in the traditional tuning method. Therefore, the embodiment of the present disclosure can reduce the production cost of time and manpower increased by redesigning the controller parameters, and improve the production efficiency of industrial manufacturing.

[0019] The above general description and the following description are exemplary and explanatory only and are not intended to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] One or more embodiments are exemplarily described by corresponding drawings, which do not limit the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements, and the drawings do not constitute a scale limitation, and wherein:

[0021] Figure 1 is a schematic diagram of a method for adjusting controller parameters in a servo system provided by an embodiment of the present disclosure;

[0022] Figure 2 is a schematic diagram of a unit negative feedback closed-loop system provided by an embodiment of the present disclosure;

[0023] Figure 3 is a schematic diagram of a stability region satisfying a closed-loop amplitude constraint provided by an embodiment of the present disclosure;

[0024] Figure 4 is a schematic diagram of a stability region that satisfies a closed-loop amplitude constraint and a gain margin constraint provided by an embodiment of the present disclosure;

[0025] Figure 5 is a schematic diagram of a stability region that satisfies a closed-loop amplitude constraint, a gain margin constraint, and a phase margin constraint provided by an embodiment of the present disclosure;

[0026] Figure 6 It is a schematic diagram of a stability region that satisfies a closed-loop amplitude constraint, a gain margin constraint, a phase margin constraint, and an anti-interference performance constraint provided by an embodiment of the present disclosure;

[0027] Figure 7 It is a flowchart of solving a full-rank equation system based on an angle step and a frequency step provided by an embodiment of the present disclosure;

[0028] Figure 8 is a schematic diagram of another method for tuning controller parameters in a servo system provided by an embodiment of the present disclosure;

[0029] Fig. 9 is a schematic diagram of a process for correcting a target solution set provided by an embodiment of the present disclosure;

[0030] Fig.10 is a schematic diagram of a device for adjusting controller parameters in a servo system provided by an embodiment of the present disclosure;

[0031] Fig.11 It is a schematic diagram of a device for adjusting controller parameters in a servo system provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0032] In order to be able to understand the features and technical contents of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0033] The terms "first", "second", etc. in the specification and claims of the embodiments of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the embodiments of the present disclosure described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0034] Unless otherwise stated, the term "plurality" of a feature means two or more.

[0035] In the embodiment of the present disclosure, the character " / " feature indicates that the preceding and following objects are in an "or" relationship. For example, the A / B feature indicates: A or B.

[0036] The term "and / or" is a description of the association relationship between objects, and the characteristic indicates that there can be three relationships. For example, A and / or B, the characteristic indicates: A or B, or, A and B.

[0037] The term "correspondence" may refer to an association relationship or a binding relationship. The correspondence between A and B means that there is an association relationship or a binding relationship between A and B.

[0038] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure may be combined with each other.

[0039] like Figure 1 As shown, the embodiment of the present disclosure provides a method for tuning controller parameters in a servo system. The execution subject of the tuning method may be a processor. The tuning method includes:

[0040] S101, a processor sweeps the frequency characteristics of a controlled object in a frequency servo system, and determines an open-loop transfer function for the controlled object according to the frequency characteristics.

[0041] Specifically, the servo system belongs to a unit negative feedback closed-loop system, and its specific structure is as follows: Figure 2As shown in the figure, by using chirp as the injected sweep signal and setting the target frequency range and frequency step of the sweep, the sweep result of the controlled object under the discrete linear frequency set can be obtained. By performing a series of processing on the sweep result, the frequency characteristics of the controlled object can be determined.

[0042] Specifically, the frequency sweep result of the controlled object under the discrete linear frequency set is expressed by the following expression (1):

[0043] Ω={ω start ,···,ω end}, (1);

[0044] Among them, Ω is the frequency sweep result of the controlled object, ω start is the starting frequency step, ω end is the ending frequency step size.

[0045] Specifically, the frequency characteristic of the controlled object is expressed by the following expression (2):

[0046] H(jω)=X H (ω)+jY H (ω), (2);

[0047] Among them, H(jω) is the frequency characteristic of the controlled object, X H (ω) is the real part of the controlled object, Y H (ω) is the imaginary part of the controlled object.

[0048] Specifically, the real part and imaginary part of the controlled object are expressed by the following expression (3):

[0049]

[0050] Among them, |H(jω)| and ∠H(jω) are the amplitude and phase angle of the controlled object respectively.

[0051] Specifically, the frequency characteristic of the controlled object is substituted into the expression corresponding to the open-loop transfer function, so as to determine the open-loop transfer function for the controlled object.

[0052] S102: The processor determines a full-band constraint boundary for the servo system according to user constraints on the stability and anti-interference performance of the servo system.

[0053] Specifically, the stability constraint of the servo system mainly focuses on whether the servo system can quickly return to its original equilibrium state or fluctuate within an allowable range when it is subject to external interference or internal parameter changes. The anti-disturbance constraint mainly focuses on the servo system's ability to resist external interference.

[0054] Specifically, the stability constraint boundary of the servo system can be determined according to the stability constraint condition of the servo system. On the basis of the stability constraint boundary, the stability constraint boundary is further restricted according to the anti-disturbance constraint condition of the servo system to determine the full-band constraint boundary of the servo system.

[0055] Optionally, the constraints on the stability of the servo system include: closed-loop amplitude constraint, phase margin constraint and gain margin constraint; the constraints on the anti-interference performance of the servo system include: anti-interference performance constraint; based on the user's constraints on the stability and anti-interference performance of the servo system, determine the full-band constraint boundary of the servo system, including: according to the upper limit value of the closed-loop amplitude constraint, use the open-loop transfer function of the servo system to draw a closed-loop amplitude circle; according to the phase margin constraint and the gain margin constraint, limit the gain margin and phase margin of the closed-loop amplitude circle to determine the stability constraint boundary; construct an anti-interference constraint circle according to the anti-interference performance constraint, and on the basis of the stability constraint boundary, extend the maximum phase line and connect the arc segment of the anti-interference constraint circle to determine the full-band constraint boundary.

[0056] Specifically, the closed-loop transfer function is an important representation of the stability of the servo system, which is specifically reflected in the resonance peak and bandwidth parameters. When the closed-loop amplitude is too high, the servo system will vibrate violently, causing irreversible damage to the controlled object. Therefore, in order to ensure the stability of the servo system, it is necessary to set a constant value upper limit W greater than 1 for the closed-loop amplitude. threshold1 (i.e., the upper limit of the closed-loop amplitude constraint), the resulting inequality is expressed by the following expression (4):

[0057]

[0058] Where jω represents the complex frequency, feedback(jω) is the feedback signal at the complex frequency, reference(jω) is the reference signal at the complex frequency, L(jω) is the open-loop transfer function of the servo system, and L(jω)=X L (ω)+jY L (ω).

[0059] Specifically, L(jω)=X L (ω)+jY L Substituting (ω) into the above expression (4), it can be rewritten as the following expression (5):

[0060]

[0061] Specifically, when expression (5) is satisfied and the equality holds, expression (4) appears as a circle in the Nyquist diagram, which is the closed-loop amplitude circle.

[0062] For example, the upper limit value W constrained by the closed-loop amplitude is threshold1 = 1.93 as an example, the corresponding closed loop amplitude circle is as follows Figure 3 shown.

[0063] Specifically, refer to Figure 3 It can be seen that the distance between the intersection of the closed-loop amplitude circle and the negative real axis closer to the origin and the coordinate (-1, j0) corresponds to the gain margin, which is expressed by the following expression (6):

[0064]

[0065] Wherein, GM is the gain margin, the center of (4) represents the center of the closed-loop amplitude circle obtained by expression (4), and the radius of (4) represents the radius of the closed-loop amplitude circle obtained by expression (4).

[0066] Specifically, refer to Figure 3 It can be seen that the coordinates of the intersection of the closed-loop amplitude circle and the unit circle in the complex plane are (-cos(PM), -jsin(PM)), and the angle between the intersection and the negative real axis represents the phase margin. It is expressed by the following expression (7):

[0067]

[0068] Where PM is the phase margin.

[0069] Specifically, based on the above expressions (6) and (7), it can be seen that the upper limit value of the closed-loop amplitude constraint has a certain relationship with the gain margin and the phase margin, so the user can set the upper limit value of the closed-loop amplitude constraint according to the preset gain margin and phase margin.

[0070] Specifically, in order to expand the phase margin at a single point to a full-band constraint, the embodiment of the present disclosure introduces two points starting from the origin, with an angle of 1. Phase rays (such as Figure 4 The dashed line A in the figure will be If the phase margin is set to the user input, the stability region defined by the closed-loop amplitude constraint is incompatible with the phase margin, resulting in the loss of stability of the servo system. Therefore, in order to take into account the effectiveness of the user input phase margin and the closed-loop amplitude constraint, it is necessary to is set to the maximum phase of the closed-loop amplitude circle. In this case, It is expressed by the following expression (8):

[0071]

[0072] in, is the phase margin constraint on the closed-loop amplitude circle.

[0073] Specifically, Figure 4 As shown in The maximum phase line represented by is connected to the closed-loop amplitude circle, and the closed-loop amplitude circle can be further restricted by the phase margin constraint.

[0074] Specifically, after the closed-loop amplitude circle is further restricted by the phase margin constraint, an excessive gain margin will be introduced. It is difficult for the servo system to meet this standard. If you want to meet this standard, you need to sacrifice the dynamic response performance of the servo system. Therefore, in the embodiment of the present disclosure, a gain margin constraint is also performed to establish a gain constraint circle, adjust the gain margin to a user-defined level, and reduce the excessive gain margin.

[0075] Specifically, establishing the gain constraint circle requires compatibility with the phase margin constraint defined in Let the gain constraint circle be tangent to the maximum phase line. Therefore, the center of the gain constraint circle is on the negative real axis. Figure 5 shown.

[0076] Specifically, in order to make the established gain constraint circle satisfy the gain margin, the coordinates of the intersection of the gain constraint circle and the negative real axis closer to the origin are set as (-X circle2 , j0), the point must satisfy the following expression (9):

[0077]

[0078] Specifically, according to expression (9), we can deduce that circle2 =10 -GM / 20 . Let the radius of the gain constraint circle be R circle2 , we can determine the coordinates of the center of the gain constraint circle as (-10 -GM / 20 _R circle2 , j0). Based on the same idea as expression (8), Figure 6 In It is calculated by the following expression (10):

[0079]

[0080] in, is the phase margin constraint on the gain constraint circle, the radius of circle2 represents the radius of the gain constraint circle, and the center of circle2 represents the center of the gain constraint circle.

[0081] Specifically, based on the above expression (10), the expression (11) for calculating the radius of the gain constraint circle can be derived:

[0082]

[0083] Among them, R circle2 is the radius of the gain constraint circle.

[0084] Specifically, based on the above expressions (10) and (11), the analytical expression of the gain constraint circle can be determined, which is expressed by the following expression (12):

[0085]

[0086] Specifically, Figure 5 As shown in FIG. 1 , based on the boundary after the closed-loop amplitude circle is further restricted by the phase margin constraint, the stability constraint boundary can be obtained by removing the area on the right side of the gain constraint circle.

[0087] It should be noted that if the user-preset gain margin is less than the gain margin defined in the closed-loop amplitude constraint, then after the gain margin constraint, the part on the right side of the closed-loop amplitude circle needs to be removed. At this time, the maximum phase line is shortened to a point, and the final stability constraint boundary is the same as Figure 3 The same situation is shown.

[0088] Specifically, the stability constraint boundary can ensure the stability of the servo system. However, in the low frequency range, the anti-disturbance performance of the servo system is more concerned. Therefore, the embodiment of the present disclosure also sets an anti-disturbance performance constraint and constructs an anti-disturbance constraint circle to impose the anti-disturbance performance constraint.

[0089] Specifically, it is necessary to first introduce a sensitivity function, which is used to evaluate the sensitivity of the servo system to low-frequency disturbance signals. When its amplitude is too high, the anti-disturbance ability of the servo system is weakened, resulting in an increase in tracking error. Therefore, the embodiment of the present disclosure also sets an upper limit W for the amplitude of the sensitivity function. threshold2 The sensitivity function is expressed by the following expression (13):

[0090]

[0091] Wherein, jω represents the complex frequency, error(jω) is the error signal at the complex frequency, reference(jω) is the reference signal at the complex frequency, and |1+L(jω)| is the distance from the open-loop transfer function to the point (-1, j0) on the complex plane. The design of the anti-interference constraint circle aims to increase this distance as much as possible in the low-frequency band, thereby reducing the amplitude of the sensitivity function and improving the anti-interference ability of the servo system. In order to simplify the user setting process, the anti-interference constraint circle is directly constructed based on the conventional margin (phase margin and gain margin) in the disclosed embodiment, without the need for additional parameter configuration.

[0092] Specifically, in order to make the anti-interference constraint circle compatible with the phase margin requirement and to implement effective constraints on the low frequency band below the phase margin, the anti-interference constraint circle is designed to be tangent to the maximum phase line, and the center of the anti-interference constraint circle is located on the negative real axis. The specific situation is as follows: Figure 6 shown.

[0093] Specifically, Figure 6 As shown, find a point on the negative real axis to the left of point (-1, j0), the distance from this point to (-1, j0) is equal to the user-defined gain margin, and let this point be the intersection of the interference rejection constraint circle and the negative real axis farther from the origin. Let the coordinates of this point be (-X circle3 , j0), then the following expression (14) can be determined:

[0094]

[0095] Specifically, according to expression (14), it can be deduced that circle3 =10 GM / 20 . Let the radius of the gain constraint circle be R circle3 , then the coordinates of the center of the anti-disturbance constraint circle can be determined as (-10 GM / 20 +R circle3 , j0). Based on the same idea as expression (8), Figure 6 In It is calculated by the following expression (15):

[0096]

[0097] in, To constrain the phase margin of the anti-disturbance constraint circle, the radius of circle3 represents the radius of the anti-disturbance constraint circle, and the center of circle3 represents the center of the anti-disturbance constraint circle.

[0098] Specifically, based on the above expression (15), the expression (16) for calculating the radius of the anti-disturbance constraint circle can be derived:

[0099]

[0100] Among them, R circle3 is the radius of the disturbance rejection constraint circle.

[0101] Specifically, based on the above expressions (15) and (16), the analytical expression of the disturbance rejection constraint circle can be determined, which is shown in the following expression (17):

[0102]

[0103] Specifically, the arc segment of the anti-interference constraint circle on the left side of the tangent point corresponds to a larger |1+L(jω)| value. Therefore, choosing this arc segment as the boundary can impose a stronger anti-interference constraint. On the basis of the stability constraint boundary, the maximum phase line is extended and connected to the arc segment to determine the final full-band constraint boundary.

[0104] S103, the processor makes the real and imaginary parts of the coordinates of the open-loop transfer function and the full-band constraint boundary equal, makes the slopes of the open-loop transfer function and the full-band constraint boundary at the intersection point equal, and determines a full-rank equation group.

[0105] Specifically, the coordinates of the open-loop transfer function of the servo system at a certain frequency ω are (X H ,jY H ), the coordinates of the full-band constraint boundary are (X qft ,jY qft ), let the real and imaginary parts of the two coordinates be equal, and we can get a system of equations with a rank of 2. However, the unknown parameters of the controller in the servo system include ω0, K p and K i , so the system of equations has a lack of rank problem. Therefore, the embodiment of the present disclosure adds an additional condition that the slopes of the open-loop transfer function and the full-band constraint boundary at the intersection point are equal.

[0106] Specifically, when determining the full-rank equations, it is first necessary to determine the coordinate selection range on the full-band constraint boundary. Specifically, in order to ensure that the phase margin and gain margin of the servo system are close to the preset values, the arc segment connecting the phase margin and the gain margin on the far right of the full-band constraint boundary can be selected as this range, so the arc segment can be determined as (X qft ,jY qft ) selection interval. qft and Y qft The value of can be determined by applying the coordinate points on the gain constraint circle through the following expression (18):

[0107]

[0108] Where θ is the distance from the center of the gain constraint circle to (X qft ,jY qft ) and the real axis, the initial angle θ start for End angle θ end =0rad. On this basis, according to the tangent equation of the gain constraint circle at this point, the slope of the tangent here is shown in the following expression (19):

[0109]

[0110] Specifically, after determining the coordinate selection range on the full-band constraint boundary, it is necessary to determine the coordinates and slope of the open-loop transfer function in the complex plane. The low-pass filter in the controller adopts a first-order form, which is shown in the following expression (20):

[0111]

[0112] Among them, ω0 is the cut-off frequency, X lpf and Y lpf are the real part and imaginary part of the low-pass filter respectively. On this basis, the PI controller adopted in the embodiment of the present disclosure can be expressed by the following expression (21):

[0113]

[0114] Specifically, the open-loop transfer function of the servo system can be expressed as in the following expression (22) based on expression (20), expression (21) and the frequency characteristics of the controlled object.

[0115]

[0116] in:

[0117] The real part of the open-loop transfer function X L and the imaginary part Y L As shown in the following expression (23):

[0118]

[0119] The slope k of the open-loop transfer function in the complex plane is ol As shown in the following expression (24):

[0120]

[0121] Specifically, after determining the coordinates and slope of the open-loop transfer function in the complex plane, let k ol =k qft , after numerical simplification, a quartic equation about ω0 can be obtained, as shown in expression (25a). Let the real and imaginary parts of the coordinates of the open-loop transfer function and the boundary be equal, respectively, and through numerical simplification, we can get the analytical expression shown in expression (25b). Expressions (25a) and (25b) are to make the real and imaginary parts of the coordinates of the open-loop transfer function and the full-band constraint boundary equal, and make the slopes of the open-loop transfer function and the full-band constraint boundary at the intersection point equal, and obtain a full-rank system of equations.

[0122]

[0123] Among them, b i express The coefficient of bi is a function of frequency ω and polar angle θ.

[0124] S104, the processor solves the full-rank equation group to obtain a target solution set of controller parameters, and selects target controller parameters from the target solution set according to a maximum bandwidth criterion.

[0125] In the embodiment of the present disclosure, after the controlled object in the servo system is replaced, the frequency characteristics of the controlled object will be obtained by the frequency sweep method, and the open-loop transfer function for the controlled object will be determined based on the frequency characteristics. The full-band constraint boundary will be constructed based on the user's constraints on the stability and anti-interference of the servo system. The full-rank equation group of the servo system will be constructed based on the open-loop transfer function and the full-band constraints. Finally, the target solution set will be obtained by solving the full-rank equation group, and the target controller parameters for the replaced controlled object will be screened out from the target solution set according to the maximum bandwidth criterion. In this way, when replacing the controlled object in the servo system, the user does not need to manually measure the relevant parameters of the controlled object and establish a relevant model. There is no need to rely on experience for multiple trial and error as in the traditional tuning method. Therefore, the embodiment of the present disclosure can reduce the production cost of time and manpower increased by redesigning the controller parameters, and improve the production efficiency of industrial manufacturing.

[0126] Optionally, solving the full-rank equations to obtain a target solution set of controller parameters includes: receiving an angle step and a frequency step input by a user; solving the full-rank equations based on the angle step and the frequency step according to a preset search algorithm to obtain a target solution set of controller parameters.

[0127] Specifically, solving the full-rank equations is an iterative solution process, gradually solving each solution suitable as a controller parameter until the polar angle θ of the open-loop transfer function is greater than the end angle.

[0128] Exemplarily, according to the preset search algorithm, the iterative process of solving the full-rank equations based on the angle step and the frequency step to obtain the target solution set of the controller parameters is as follows: Figure 7 shown.

[0129] Optionally, target controller parameters are selected from the target solution set according to the maximum bandwidth criterion, including: for each solution in the target solution set, calculating the frequency when the closed-loop amplitude of the servo system decays to a set decibel for the first time as the bandwidth of the servo system; and selecting the solution corresponding to the maximum bandwidth in the target solution set as the target controller parameter.

[0130] Specifically, for each solution in the target solution set, the frequency at which the closed-loop amplitude of the servo system decays to the set decibel for the first time can reflect the response speed of the servo system. Therefore, the frequency at which the closed-loop amplitude of the servo system decays to the set decibel for the first time can be calculated as the bandwidth of the servo system under this solution.

[0131] Optionally, the decibel value range is set to -3dB to 0.707dB. Specifically, the closed-loop amplitude of the servo system is calculated according to the following expression (26).

[0132]

[0133] Among them, M cl (ω) is the closed-loop amplitude of the servo system, |L(jω)| is the open-loop transfer function value of each solution in the target solution set at each frequency point, and ∠L(jω) is the phase angle of each solution in the target solution set at each frequency point.

[0134] Specifically, the open-loop transfer function value of each solution in the target solution set at each frequency point is calculated according to the following expression (27):

[0135]

[0136] Specifically, the phase angle of each solution in the target solution set at each frequency point is calculated according to the following expression (28):

[0137] ∠L(jω)=tan -1 (Y L / X L ), expression (28);

[0138] For example, taking the setting of decibel as 0.707 dB as an example, when M cl When (ω) first decays to 0.707, record this frequency as ω m , if the frequency step length ω step Set small enough (for example, 2.5Hz), the bandwidth ω bw It can be approximated as (ω m +ω m-1 ) / 2, where ω m =ω m-1 +ω step .

[0139] Specifically, since the larger the bandwidth, the stronger the servo system's response to high-frequency signals, and the higher the tracking accuracy and stability, it is necessary to select the solution corresponding to the maximum bandwidth in the target solution set as the target controller parameter.

[0140] The disclosed embodiment provides another method for setting controller parameters in a servo system, such as Figure 8 As shown, the tuning method includes:

[0141] S801, a processor scans the frequency characteristics of a controlled object in a frequency servo system, and determines an open-loop transfer function for the controlled object according to the frequency characteristics.

[0142] S802: The processor determines a full-band constraint boundary for the servo system according to user constraints on the stability and anti-interference performance of the servo system.

[0143] S803, the processor makes the real and imaginary parts of the coordinates of the open-loop transfer function and the full-band constraint boundary equal, makes the slopes of the open-loop transfer function and the full-band constraint boundary at the intersection point equal, and determines the full-rank equation group.

[0144] S804: The processor solves the full-rank equation group to obtain a target solution set of controller parameters, and corrects the target solution set.

[0145] Specifically, when the controlled object exhibits multi-resonant modal characteristics, although the full-rank equations can locally ensure that the open-loop transfer function does not cross the stability boundary at the intersection, there is still a risk of crossing the boundary within the range of other resonant modes, causing the obtained solution to fail. Therefore, after determining the Mu Bai solution set, the target solution set needs to be corrected.

[0146] Optionally, the target solution set is corrected, including: determining a frequency point to be corrected corresponding to each solution in the target solution set; calculating the complex plane coordinates of the open-loop transfer function at the frequency point to be corrected; and removing the solution corresponding to the frequency point to be corrected from the target solution set when the complex plane coordinates are within the stability constraint boundary of the servo system.

[0147] Optionally, determining the frequency point to be corrected corresponding to each solution in the target solution set includes: determining the phase angle range of the stability constraint boundary of the servo system; calculating the phase angle of each solution in the target solution set at each frequency point; and taking the frequency point whose phase angle is within the phase angle range as the frequency point to be corrected.

[0148] Specifically, although the reliability of the algorithm can be ensured by correcting each frequency point of each solution in the target solution set, this will significantly prolong the execution time of the algorithm. Therefore, the embodiment of the present disclosure introduces a phase angle criterion to optimize this process. Specifically, according to the above expression (8), the phase angle range of the stability constraint boundary is

[0149] Specifically, correcting the target solution set is also an iterative process, and the overall process can be described as follows: Fig. 9 shown.

[0150] S805: The processor selects target controller parameters from the target solution set according to the maximum bandwidth criterion.

[0151] In the disclosed embodiment, after solving the full-rank equations to obtain the target solution set of the controller parameters, the target solution set is also corrected, thereby improving the accuracy of the determined target solution set and further improving the accuracy of the final target controller parameters.

[0152] Combination Fig.10 As shown, the embodiment of the present disclosure provides a safety assessment device 1000 for a large model, including: a frequency sweep module 1001, a constraint module 1002, a determination module 1003 and a solution module 1004. The frequency sweep module 1001 is configured to sweep the frequency characteristics of the controlled object in the servo system, and determine the open-loop transfer function for the controlled object according to the frequency characteristics. The constraint module 1002 is configured to determine the full-band constraint boundary of the servo system according to the user's constraints on the stability and anti-interference of the servo system. The determination module 1003 is configured to make the coordinates of the open-loop transfer function equal to the real and imaginary parts of the coordinates of the full-band constraint boundary, make the slopes of the open-loop transfer function and the full-band constraint boundary at the intersection point equal, and determine the full-rank equation group. The solution module 1004 is configured to solve the full-rank equation group to obtain the target solution set of the controller parameters, and filter out the target controller parameters from the target solution set according to the maximum bandwidth criterion.

[0153] Combination Fig.11 As shown, the embodiment of the present disclosure provides a device 1100 for setting controller parameters in a servo system, including: a processor 1101 and a memory 1102. Optionally, the device may also include a communication interface 1103 and a bus 1104. The processor 1101, the communication interface 1103, and the memory 1102 may communicate with each other through the bus 1104. The communication interface 1103 may be used for information transmission. The processor 1101 may call the logic instructions in the memory 1102 to execute the method for setting controller parameters in the servo system of the above embodiment.

[0154] In addition, the logic instructions in the memory 1102 described above may be implemented in the form of software functional units and when sold or used as independent products, may be stored in a computer-readable storage medium.

[0155] The memory 1102 is a computer-readable storage medium that can be used to store software programs and computer executable programs, such as program instructions / modules corresponding to the method in the embodiment of the present disclosure. The processor 1101 executes the function application and data processing by running the program instructions / modules stored in the memory 1102, that is, the method for setting the controller parameters in the servo system in the above embodiment is implemented.

[0156] The memory 1102 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and an application required for at least one function; the data storage area may store data created according to the use of the terminal device, etc. In addition, the memory 1102 may include a high-speed random access memory and may also include a non-volatile memory.

[0157] An embodiment of the present disclosure provides a computing device, including: a device body; and a device for adjusting controller parameters in a servo system as described above, which is arranged in the device body.

[0158] An embodiment of the present disclosure provides a computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are configured to execute the above-mentioned security assessment method for a large model.

[0159] The technical solution of the embodiment of the present disclosure can be embodied in the form of a software product, which is stored in a storage medium and includes one or more instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the embodiment of the present disclosure. The aforementioned storage medium may be a non-transient storage medium, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk, and other media that can store program codes.

[0160] The above description and the accompanying drawings fully illustrate the embodiments of the present disclosure so that those skilled in the art can practice them. Other embodiments may include structural, logical, electrical, process and other changes. The embodiments represent only possible changes. Unless explicitly required, separate components and functions are optional, and the order of operation may vary. The parts and features of some embodiments may be included in or replace the parts and features of other embodiments. Moreover, the words used in this application are only used to describe the embodiments and are not used to limit the claims. As used in the description of the embodiments and the claims, unless the context clearly indicates, the singular forms of "a", "an" and "the" are intended to include plural forms as well. Similarly, the term "and / or" as used in this application refers to any and all possible combinations of listings containing one or more associated ones. In addition, when used in the present application, the term "comprise" and its variants "comprises" and / or comprising refer to the presence of stated features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or groups thereof. In the absence of further restrictions, the elements defined by the sentence "comprising a ..." do not exclude the presence of other identical elements in the process, method or device comprising the elements. In this article, each embodiment may focus on the differences from other embodiments, and the same and similar parts between the various embodiments may refer to each other. For the methods, products, etc. disclosed in the embodiments, if they correspond to the method part disclosed in the embodiments, then the relevant parts can refer to the description of the method part.

[0161] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software may depend on the specific application and design constraints of the technical solution. The technicians may use different methods for each specific application to implement the described functions, but such implementations should not be considered to exceed the scope of the embodiments of the present disclosure. The technicians may clearly understand that, for the convenience and simplicity of description, the specific working processes of the systems, devices and units described above may refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here.

[0162] In the embodiments disclosed herein, the disclosed methods and products (including but not limited to devices, equipment, etc.) can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units can be only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between each other shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms. The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to implement this embodiment. In addition, each functional unit in the embodiment of the present disclosure may be integrated in a processing unit, or each unit may exist physically alone, or two or more units may be integrated in one unit.

[0163] The flowchart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system, method and computer program product according to the embodiment of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. In some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. In the description corresponding to the flowchart and the block diagram in the accompanying drawings, the operations or steps corresponding to different boxes can also occur in a different order from the order disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. Each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified functions or actions, or may be implemented by a combination of dedicated hardware and computer instructions.

Claims

1. A method for setting controller parameters in a servo system, characterized in that: include: The frequency characteristics of the controlled object in the swept frequency servo system, and the open-loop transfer function for the controlled object is determined according to the frequency characteristics; According to the user's constraints on the stability and anti-interference of the servo system, determine the full-band constraint boundary of the servo system; The real and imaginary parts of the coordinates of the open-loop transfer function and the full-band constraint boundary are made equal, and the slopes of the open-loop transfer function and the full-band constraint boundary at the intersection point are made equal, and the full-rank equation system is determined; The full-rank equations are solved to obtain the target solution set of controller parameters, and the target controller parameters are selected from the target solution set according to the maximum bandwidth criterion.

2. The setting method according to claim 1, characterized in that: The constraints on the stability of the servo system include: closed-loop amplitude constraint, phase margin constraint and gain margin constraint; the constraints on the anti-interference performance of the servo system include: anti-interference performance constraint; according to the user's constraints on the stability and anti-interference of the servo system, determine the full-band constraint boundaries of the servo system, including: According to the upper limit of the closed-loop amplitude constraint, a closed-loop amplitude circle is drawn using the open-loop transfer function of the servo system; According to the phase margin constraint and the gain margin constraint, the gain margin and the phase margin of the closed-loop amplitude circle are restricted to determine the stability constraint boundary; An anti-interference constraint circle is constructed according to the anti-interference performance constraint, and on the basis of the stability constraint boundary, the maximum phase line is extended and connected to the arc segment of the anti-interference constraint circle to determine the full-band constraint boundary.

3. The setting method according to claim 1, characterized in that: Solve the full-rank equations to obtain the target solution set of controller parameters, including: Receive the angle step and frequency step input by the user; According to the preset search algorithm, the full-rank equations are solved based on the angle step and frequency step to obtain the target solution set of the controller parameters.

4. The setting method according to claim 1, characterized in that: The target controller parameters are selected from the target solution set according to the maximum bandwidth criterion, including: For each solution in the target solution set, the frequency at which the closed-loop amplitude of the servo system decays to a set decibel for the first time is calculated as the bandwidth of the servo system; The solution corresponding to the maximum bandwidth in the target solution set is selected as the target controller parameter.

5. The setting method according to any one of claims 1 to 4, characterized in that: Before selecting the target controller parameters from the target solution set according to the maximum bandwidth criterion, the tuning method further includes: Correct the target solution set.

6. The setting method according to claim 5, characterized in that: Correct the target solution set, including: Determine the frequency point to be corrected corresponding to each solution in the target solution set; Calculate the complex plane coordinates of the open-loop transfer function at the frequency point to be corrected; When the complex plane coordinates are within the stability constraint boundary of the servo system, the solution corresponding to the frequency point to be corrected is removed from the target solution set.

7. The setting method according to claim 6, characterized in that: Determine the frequency point to be corrected corresponding to each solution in the target solution set, including: Determine the phase angle range of the stability constraint boundary of the servo system; Calculate the phase angle of each solution in the target solution set at each frequency point; The frequency point whose phase angle is within the phase angle range is taken as the frequency point to be corrected.

8. A device for setting controller parameters in a servo system, characterized in that: include: A frequency sweep module, configured to sweep the frequency characteristics of a controlled object in the frequency servo system, and determine an open-loop transfer function for the controlled object according to the frequency characteristics; A constraint module is configured to determine a full-band constraint boundary for the servo system according to user constraints on stability and anti-interference of the servo system; A determination module is configured to make the real and imaginary parts of the coordinates of the open-loop transfer function and the coordinates of the full-band constraint boundary equal, make the slopes of the open-loop transfer function and the full-band constraint boundary at the intersection point equal, and determine the full-rank equation group; The solution module is configured to solve the full-rank equation group to obtain a target solution set of controller parameters, and select target controller parameters from the target solution set according to a maximum bandwidth criterion.

9. A device for setting controller parameters in a servo system, comprising a processor and a memory storing program instructions, characterized in that: The processor is configured to execute the method for tuning controller parameters in a servo system according to any one of claims 1 to 7.

10. A computing device, characterized in that: include: Equipment body; The device for setting controller parameters in a servo system as claimed in claim 9 is arranged on the device body.

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