An improved ESO-based high-precision rotary table intelligent control method and device

Abstract

The present application relates to the technical field of rotary table control, and particularly relates to a high-precision rotary table intelligent control method and equipment based on improved ESO, which comprises the following steps: constructing a mathematical model of a rotary table motor to derive a transfer function of the motor; collecting current and angle data of the rotary table motor respectively; building a rotary table control system, which is composed of a current loop, a position loop and a virtual control law based on ESO; designing the virtual control law based on ESO; superimposing the output of the designed virtual control law of ESO to the output of the rotary table current loop and position loop, and embedding the control algorithm into a processing module of an upper industrial computer of the rotary table to complete the intelligent control of the rotary table. The method establishes the transfer function of the motor, designs the virtual control law based on improved ESO based on the extended state observation theory, realizes the cooperative control of the rotary table with PID control, and realizes the high-precision pointing of the rotary table.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of rotary table control, and particularly relates to a high-precision rotary table intelligent control method and device based on improved ESO. BACKGROUND

[0002] A rotary table is a complex mechatronic integrated device, which is used for physical simulation and simulation test in the fields of vehicle, shipboard, aerospace, plays a key role in the development of various vehicle, shipboard, aerospace products, can simulate various attitude angle movements, reproduce various dynamic characteristics during the movements, repeatedly test the performance of the guidance system, control system and corresponding devices of the vehicle, shipboard, aerospace products, obtain sufficient test data, and redesign and improve the system according to the data to meet the performance index requirements of the overall design.

[0003] Active disturbance rejection control is a control strategy independent of accurate models and having strong anti-disturbance performance, which observes and compensates disturbances other than the series integral type through an extended state observer (ESO), and therefore the disturbance observation accuracy of the ESO determines the compensation effect of the disturbance. However, when the classical ESO is applied to a simulation rotary table, there are problems of large compensation amount and limited anti-disturbance performance, which limit its performance and application scenarios. SUMMARY

[0004] The application provides a high-precision rotary table intelligent control method and device based on improved ESO, to solve the defects of large compensation amount and limited anti-disturbance performance of ESO when applied to a simulation rotary table in the prior art, and improve the position tracking accuracy of the rotary table.

[0005] The application provides a high-precision rotary table intelligent control method based on improved ESO, comprising the following steps:

[0006] A mathematical model of a rotary table motor is constructed to obtain a transfer function of the rotary table motor;

[0007] Current and angle data of the rotary table motor are collected respectively;

[0008] A rotary table control system is built, including a rotary table current loop and a position loop and a virtual control law based on ESO;

[0009] The virtual control law based on ESO is determined;

[0010] The output of the virtual control law based on ESO is superimposed to the output of the rotary table current loop and the position loop, and a control algorithm is embedded into a processing module of an upper computer of the rotary table to complete the control of the rotary table.

[0011] According to the high-precision rotary table intelligent control method based on improved ESO provided by the application, the transfer function of the rotary table motor is represented as follows:

[0012] 1) The voltage balance of the motor is:

[0013] (1)

[0014] wherein, v m is the control voltage on the motor armature, E is the back electromotive force of the motor, i m is the armature current of the motor, R m is the armature resistance of the motor, L m is the armature inductance of the motor, d denotes the differential symbol, t denotes the time variable;

[0015] 2) The back electromotive force of the motor is:

[0016] (2)

[0017] wherein, k e is the back electromotive force constant of the motor, is the motor speed;

[0018] 3) The torque equation and the torque balance equation of the motor are respectively:

[0019] The torque equation of the motor is:

[0020] (3)

[0021] wherein, is the torque of the motor, k m is the torque constant of the torque motor;

[0022] The torque balance equation of the motor is:

[0023] (4)

[0024] wherein, J is the rotor and load inertia of the torque motor, F is the friction torque and disturbance torque acting on the torque motor, denotes the first derivative of the motor speed;

[0025] The Laplace transform of equations (1) to (4) is:

[0026] (5)

[0027] wherein, sIt is the Laplace operator.

[0028] According to the present invention, a high-precision intelligent control method for a turntable based on an improved ESO is provided, which collects current and angle data of the turntable motor respectively, including: collecting current data of the motor through a sensor and collecting angle data of the motor through a circular grating.

[0029] According to the present invention, a high-precision intelligent control method for a turntable based on an improved ESO is provided, wherein the construction of the turntable control system includes:

[0030] The angular displacement and motor current of the turntable are collected in real time, and the commands are converted into the corresponding angular displacement and motor current through a transfer function. PID control is then used to achieve current closed-loop and position closed-loop control of the turntable. The PID control is represented as follows:

[0031] (6)

[0032] In the formula, k p ，k i ，k d These are the proportional, integral, and derivative parameters of the PID controller. k Sampling time, e It is the error in the control quantity of the turntable. e ( k )yes k Error in the control quantity of the turntable at any given time U ( k ) is the turntable control output.

[0033] According to the present invention, a high-precision intelligent control method for a turntable based on an improved ESO is provided. The turntable control system adopts a unified control and management by an industrial computer to complete real-time control calculation, management of the control unit, and human-machine interaction.

[0034] According to the present invention, a high-precision intelligent control method for a turntable based on an improved ESO is provided, wherein determining the virtual control law based on ESO includes:

[0035] 1) Observe motor status data through ESO.

[0036] (7)

[0037] In the formula, z 1( k )and z 2( k )yes k Estimation of the system state variables at time t. z 3( k ) is a system kthe sum of disturbances at time k, y k is the system k the measured value of the angular position at time k, k denotes the sampling time, is the k the system output error at time k, u k -1 is the input of the ESO at time k-1, unlike the common observer, k u k is delayed by one step before entering the ESO. In this equation, is the gain constant, , and are adjustable parameters, and are nonlinear parameters, where fal can be expressed as:

[0038] (8)

[0039] where si gn is the sign function;

[0040] 2) Determine the motor speed control law,

[0041] (9)

[0042] where a 1 is the control law of the speed state v 2 is the backstepping error between the speed control law and the speed state; x

[0043] 3) Determine the ESO-based virtual control law:

[0044] (10)

[0045] where k 1 is the positive feedback gain, is the adaptive model compensation term to improve the tracking performance of the system, is the robust feedback term;

[0046] 4) The output of the ESO-based virtual control law u is:

[0047] (11)

[0048] where g is the mapping function, g= (z 1 , y) = sign (z 1 ) y, u ​​​​​a a model compensation term, u s a robust feedback term to tune the error of the turntable system, z 1、 z 2 is an estimate of the system state variable, y is the actual output of the system.

[0049] The application also provides an electronic device comprising a processor, a motion control card, a memory and an improved ESO-based control program executable on the memory, wherein the processor implements the improved ESO-based high-precision turntable intelligent control method according to any one of the above when executing the program.

[0050] The application also provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement the improved ESO-based high-precision turntable intelligent control method according to any one of the above.

[0051] The application also provides a computer program product comprising a computer program, wherein the computer program is executed by a processor to implement the improved ESO-based high-precision turntable intelligent control method according to any one of the above.

[0052] Compared with the prior art, the application superimposes the virtual control law output of the extended state observer on the turntable current loop PID output and the position loop PID output. This fusion makes the ESO not only act as a state observer, but also directly participate in the control process of the system. Superimposing the virtual control law output of the improved ESO on the output of the PID controller optimizes the control performance of the system and makes it better cope with the nonlinearity, time-varying nature and uncertainty in the system. The application has the following beneficial effects:

[0053] 1. By adopting the improved ESO and PID cooperative control method, high-precision positioning control of the turntable is achieved, and the positioning accuracy and stability of the system are improved.

[0054] 2. The improved ESO delays the control signal by one beat before entering the extended state observer, improves the observation performance, and effectively realizes the estimation and compensation of the friction;

[0055] 3. The improved ESO is used to observe the turntable, and the motor speed control law and the motor torque virtual control law are used to make the system better adapt to complex working environments and changing conditions;

[0056] 4. The designed virtual control law combines the model compensation term and the robust feedback term, improves the anti-interference ability of the system to parameter changes and disturbances, and enhances the robustness and robustness of the system;

[0057] 5. Through the established transfer function of the motor, the improved ESO virtual control law is designed to realize the cooperative control of the turntable with the PID, and the control precision and anti-interference ability of the turntable are improved. BRIEF DESCRIPTION OF DRAWINGS

[0058] In order to more clearly illustrate the technical solutions of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0059] Figure 1 is a flow chart of the high-precision turntable intelligent control method based on the improved ESO provided by the embodiment of the present application;

[0060] Figure 2 is a high-precision turntable intelligent control structure block diagram based on the improved ESO provided by the embodiment of the present application;

[0061] Figure 3 is a position tracking curve provided by the embodiment of the present application;

[0062] Figure 4 is a position tracking local magnification provided by the embodiment of the present application;

[0063] Figure 5 is a position tracking error curve provided by the embodiment of the present application;

[0064] Figure 6 is a position tracking error local magnification provided by the embodiment of the present application;

[0065] Fig. 7(a) is an angular position error signal Matlab statistical result graph under the angular position error PID control mode provided by the embodiment of the present application;

[0066] Fig. 7(b) is an angular position error signal Matlab statistical result graph under the ADRC control mode provided by the embodiment of the present application;

[0067] Fig. 7(c) is an angular position error signal Matlab statistical result graph under the improved ESO+PID control mode provided by the embodiment of the present application;

[0068] Figure 8 is a structure schematic diagram of the electronic equipment provided by the embodiment of the present application. DETAILED DESCRIPTION

[0069] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below in conjunction with the drawings in the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the protection scope of the present application.

[0070] The embodiment proposes an intelligent control method of high-precision rotary table based on improved ESO to improve the position tracking accuracy of the rotary table. An intelligent rotary table performance improvement method combining ESO virtual control and traditional PID control is proposed on the basis of improved ESO. By establishing the transfer function of the motor, a virtual control law based on improved ESO is designed based on the extended state observation theory, and the PID control is used to realize the cooperative control of the rotary table, so as to ensure the high-precision pointing of the rotary table. Figure 1 The flowchart of the embodiment is described below in conjunction with the drawings and the specific embodiments.

[0071] Step 1, constructing the mathematical model of the rotary table motor to derive the transfer function of the motor, and analyzing the mathematical model of the rotary table motor, the driver and the current loop;

[0072] Further, the transfer function corresponding to step 1 is expressed as follows:

[0073] Step 1.1 analyzes the voltage balance of the motor:

[0074] (1)

[0075] wherein, v m is the control voltage on the motor armature, E is the back electromotive force of the motor, i m is the motor armature current, R m is the motor armature resistance, L m is the motor armature inductance, d represents the differential symbol, and t represents the time variable.

[0076] Step 1.2 analyzes the back electromotive force of the motor:

[0077] (2)

[0078] wherein, k e is the motor back electromotive force constant, is the motor speed.

[0079] Step 1.3 analyzes the torque equation and torque balance equation of the motor, and the torque equation is expressed as follows:

[0080] (3)

[0081] wherein, is the torque of the motor, k m is the torque constant of the torque motor; the torque balance equation of the motor can be expressed as follows:

[0082] (4)

[0083] wherein, J is the rotor and load inertia of the torque motor, F is the friction torque and disturbance torque acting on the torque motor, represents the first derivative of the motor speed; the Laplace transform of formula (1) to formula (4) can be obtained

[0084] (5)

[0085] in the formula, s is the Laplace operator.

[0086] Step 2, respectively, collect the current and angle data of the motor of the turntable, collect the motor current through the sensor, and collect the angle through the circular grating;

[0087] Step 3, build a turntable control system: the three-axis turntable control system is composed of a current loop, a position loop and a virtual control law based on ESO, and is controlled and managed by an industrial computer, which completes real-time control calculation, management of control unit and human-computer interaction and the like;

[0088] Further, the three-axis turntable control system corresponding to step 3 is composed of a current loop and a position loop, and is expressed as follows:

[0089] The angular displacement and motor current of the turntable are collected in real time, and the command is converted into the corresponding angular displacement and motor current through the transfer function, and the current closed loop and position closed loop control of the turntable are realized through PID, which can be expressed as follows:

[0090] (6)

[0091] in the formula, k p ，k i ，k d is the proportional, integral and differential parameters of the PID, k is the sampling time, e is the error of the control amount of the turntable, e(k) is the error of the control amount of the turntable at time k, and U(k) is the output of the control amount of the turntable.

[0092] Step 4, Designing ESO-based virtual control law: Designing motor speed virtual control law and motor torque virtual control law according to the motor data observed by ESO, the control structure block diagram is shown in Figure 2

[0093] Further, the virtual control law corresponding to ESO in step 4 is shown as follows:

[0094] Step 4.1, first observing motor data by ESO

[0095] (7)

[0096] In the formula, z1(k) and z2(k) are the estimates of the system state variables at time k, z3(k) is the disturbance sum of the system at time k, y(k) is the measured value of the angular position of the system at time k, k represents the sampling time, is the system output error at time k, u(k-1) is the input of ESO at time k-1, unlike ordinary observers, u(k) is delayed for one step before entering the extended state observer. In the formula, is a gain constant, 、 and are adjustable parameters, and are nonlinear parameters, where fal can be represented as:

[0097] (8)

[0098] Where sign is the sign function.

[0099] Step 4.2, design motor speed control law

[0100] (9)

[0101] Where a 1 is the virtual control law of the speed state v; x 2 is the backstepping error between the speed virtual control law and the speed state.

[0102] Step 4.2, design motor torque virtual control law:

[0103] (10)

[0104] Where k 1 is a positive feedback gain, α 2a is an adaptive model compensation term to improve the tracking performance of the system, α 2s is a robust feedback term.

[0105] ​Step 4.3, output of the ESO-based virtual control law u may be designed to

[0106] (11)

[0107] wherein g is a mapping function, u a is a model compensation term, u s is a robust feedback term for tuning the error of the turntable system, z 1、 z2 is an estimation of the system state variable, and y is the actual output of the system.

[0108] Step 5, superimpose the output of the designed ESO-based virtual control law to the turntable current loop and position loop output, and embed the control algorithm into the processing module of the turntable upper industrial computer to complete the intelligent control of the turntable.

[0109] The following verifies the improved ESO-based turntable high-precision control method of the application by combining a specific embodiment. An intelligent control simulation model based on the improved ESO is built in Simulink, wherein the motor armature resistance R m is 2.6Ω, the motor armature inductance L m is 0.1mH, the motor torque constant k m is 0.00767N•m / A, the motor back electromotive force constant k e is 0.00767V•s / rad, the rotor and load inertia of the torque motor J is 0.7kg·m², and the turntable motor transfer function is constructed based on the above parameters.

[0110] The control structure block diagram of the embodiment is shown in Figure 2 . When the angle set value is a sine signal, the position tracking curve of the system is shown in Figure 3 , Figure 4 , and the position tracking error curve is shown in Figure 5 , Figure 6 . In the figure, the improved ESO+PID control effect of the embodiment is compared with PID control and ADRC control. By analyzing the position tracking error curve in Figure 5 , the angular position error signals under the three control modes of PID control, ADRC control, and improved ESO+PID control are counted by using matlab, and the results are shown in Figs. 7(a), 7(b), and 7(c), respectively.

[0111] It can be seen that compared with PID control and ADRC control, the maximum value, minimum value, peak-to-peak value, mean value, median value and RMS value of the angle position error of the improved ESO+PID control are all significantly reduced, wherein the maximum error of the angle position is 0.02275 rad, and the root mean square error is only 0.002059 rad, so the method effectively improves the control precision of the rotary table.

[0112] Figure 8 An example of a schematic diagram of a physical structure of an electronic device is shown in Figure 8 The electronic device can include a processor, a motion control card, a memory, a communications interface and a system bus, as shown in the figure. The processor, the motion control card, the memory, the communications interface and the system bus complete mutual communication through the system bus. The processor executes the high-precision rotary table intelligent control method based on the improved ESO using the program code and data in the memory. The motion control card receives a large amount of rotary table monitoring operation data and feedback information from the outside in real time, and outputs a motion control instruction to the rotary table. The communications interface communicates with other external devices.

[0113] In addition, the logical instructions in the memory described above can be implemented in the form of a software function unit and sold or used as an independent product, and can be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or part of the technical solutions can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk and various program code storage media.

[0114] On the other hand, the present application also provides a computer program product, which comprises a computer program, the computer program can be stored on a non-transient computer readable storage medium, and the computer program is executed by a processor, so that the computer can execute the high-precision rotary table intelligent control method based on the improved ESO provided by the above-mentioned methods.

[0115] In yet another aspect, the application also provides a non-transitory computer readable storage medium having stored thereon a computer program, which, when executed by a processor, implements the improved ESO-based high-precision rotary table intelligent control method provided by the above method.

[0116] The device embodiments described above are merely illustrative, wherein the units described as separate components can or can not be physically separate, and the components displayed as units can or can not be physical units, i.e., can be located in one place or distributed on multiple network units. Part or all of the modules can be selected to achieve the purpose of the embodiment scheme according to actual needs. Those skilled in the art can understand and implement without creative labor.

[0117] From the above description of the embodiments, those skilled in the art can clearly understand that the embodiments can be realized by means of software plus the necessary general hardware platform, and of course can also be realized by hardware. Based on such understanding, the above technical solutions, essentially or in the contribution to the prior art, can be embodied in the form of a software product. The computer software product can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0118] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An improved ESO-based high-precision rotary table intelligent control method, characterized in that, The method comprises the following steps: a mathematical model of the turntable motor is constructed to obtain a transfer function of the turntable motor; current and angle data of the turntable motor are collected respectively; a turntable control system is built; an ESO-based virtual control law is determined; specifically including: 1) motor state data is observed through ESO, （7） In the formula, z 1( k )and z 2( k )yes k Estimation of the system state variables at time t. z 3( k ) is a system k The sum of disturbances at any given moment. y ( k ) is a system k Measured angular position at time [time]. k Indicates the sampling time. for k The system output error at any given time. u ( k -1) is a system k The input to ESO at time -1 is different from that of a regular observer. u ( k A one-beat delay is applied before entering the extended state observer; where, It is the gain constant. , and It is an adjustable parameter. and It is a nonlinear parameter, where fal It can be represented as: （8） wherein si gn is the sign function; 2) a motor speed control law is determined, （9） wherein a 1 is the velocity state v of the control law; x 2 is the backstepping error between the velocity control law and the velocity state; 3) an ESO-based virtual control law is determined: （10） wherein k 1 is a positive feedback gain, is an adaptive model compensation term to improve the tracking performance of the system, is a robust feedback term; 4) the output of the ESO-based virtual control law u is: （11） wherein g is a mapping function, g=(z 1 ,y)=sign(z 1 )y,u a is a model compensation term, u s is a robust feedback term to tune the error of the turntable system, z 1、 z 2is an estimate of the system state variable, y is the actual output of the system; The ESO-based virtual control law output is superimposed to the turntable current loop and position loop output, and the control algorithm is embedded into the processing module of the turntable upper industrial personal computer to complete the control of the turntable.

2. The high-precision rotary table intelligent control method based on improved ESO according to claim 1, characterized in that, The transfer function of the turntable motor is expressed as follows: 1) the voltage balance of the motor is: (1) wherein v m is a control voltage on the motor armature, E is a back electromotive force of the motor, i m is an armature current of the motor, R m is a motor armature resistance, L m is a motor armature inductance, d denotes a differential symbol, t denotes a time variable; 2) the back electromotive force of the motor is: (2) wherein, k e is the motor back electromotive force constant, is the motor rotational speed; 3) the torque equation and the torque balance equation of the motor are respectively: The torque equation of the motor is: (3) wherein is the torque of the motor, k m is the torque constant of the torque motor; The torque balance equation of the motor is: (4) wherein J is the rotor and load inertia of the torque motor, F is the friction and disturbance torque acting on the torque motor, denotes the first derivative of the motor speed; Laplace transformation is performed on equations (1) to (4): （5） In the formula, s is the Laplacian operator.

3. The high-precision rotary table intelligent control method based on improved ESO according to claim 1, characterized in that, The current and angle data of the turntable motor are collected respectively, including collecting the current data of the motor through a sensor and collecting the angle data of the motor through a circular grating.

4. The high-precision rotary table intelligent control method based on improved ESO according to claim 1, characterized in that, The turntable control system is built, including: The angle displacement and motor current of the turntable are collected in real time, and the instructions are converted into the corresponding angle displacement and motor current through the transfer function, and the current closed loop and position closed loop control of the turntable are realized through PID, and the PID control is expressed as follows: （6） In the formula, k p ，k i ，k d These are the proportional, integral, and derivative parameters of the PID controller. k Sampling time, e It is the error in the control quantity of the turntable. e ( k )yes k Error in the control quantity of the turntable at any given time U ( k ) is the turntable control output.

5. The high-precision rotary table intelligent control method based on improved ESO according to claim 4, characterized in that, The turntable control system adopts industrial personal computer unified control and management to complete real-time control calculation, management of control unit and man-machine interaction.

6. An electronic device comprising a processor, a motion control card, a memory and a control program for improved ESO executable thereon, characterized in that, The processor executes the program to realize the high-precision turntable intelligent control method based on the improved ESO according to any one of claims 1 to 5.

7. A non-transitory computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to realize the high-precision turntable intelligent control method based on the improved ESO according to any one of claims 1 to 5.

8. A computer program product comprising a computer program, characterized in that, The computer program is executed by the processor to realize the high-precision turntable intelligent control method based on the improved ESO according to any one of claims 1 to 5.

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