A magnetic field decoupling control system and method for a hybrid magnetic circuit linear rotating permanent magnet motor

Abstract

The application provides a kind of hybrid magnetic circuit linear rotary permanent magnet motor magnetic field decoupling control system and method, the hybrid magnetic circuit linear rotary permanent magnet motor has the ability of independent driving and simultaneous driving of linear part and rotary motion part to realize helical motion;Including a stator and a rotor;Stator includes two sets of windings, respectively for rotary and linear motion control;Rotary motion part adopts switched reluctance motor structure, linear part adopts permanent magnet linear motor structure, two drive parts share stator teeth and rotor teeth, and nine half-bridge power converters are used for driving control, wherein three half-bridge drivers drive and control a set of windings, and the remaining six half-bridge drivers drive and control another set of windings.The application can not only suppress the periodic fluctuation of speed caused by coupling and reduce the position error, but also will not cause the distortion of dynamic response of original linear active disturbance rejection controller and other frequency band gain outside the resonance frequency.

Description

Technical Field

[0001] This invention belongs to the field of motor drive system technology, and particularly relates to a magnetic field decoupling and speed and torque ripple suppression control strategy for a linear rotating permanent magnet motor. Background Technology

[0002] With the rapid development of intelligent equipment drive systems, two-degree-of-freedom (2-DOF) drives, including linear, rotary, and helical motion, are increasingly in demand in cutting-edge equipment such as CNC machining centers, industrial robots, automotive transmissions, aerospace steering systems, and radar tracking. Generally, two-DOF drives are achieved through a combination of two or three single-motion motors and gears, which suffers from problems such as large transmission backlash, increased friction loss, and short maintenance cycles. In recent years, linear rotary permanent magnet (LRPM) motors have shown advantages such as superior dynamic performance, smaller size and weight, and longer maintenance cycles. Compared with traditional two-DOF drive systems, they have attracted widespread attention from experts and scholars.

[0003] Highly integrated linear-rotating permanent magnet motor systems present a significant challenge: the coupling between the rotating and linear components. This invention targets a hybrid magnetic circuit linear-rotating permanent magnet motor, where the rotating component employs a switched reluctance motor structure, and the linear component utilizes a permanent magnet linear motor structure. Currently, there is no comprehensive control strategy for this type of linear-rotating permanent magnet motor. While some control methods can meet the requirements of a single linear or rotary motion condition, the coupling between the linear and rotating components makes it difficult to meet the needs of helical motion conditions.

[0004] A prominent feature of coupling in hybrid magnetic circuit linear rotating permanent magnet motors is the axial and radial coupling forces generated by rotational motion. Since rotational motion is periodic, the velocity ripple in the linear portion caused by the axial coupling force is also periodic. Feedforward decoupling control can reduce the axial coupling force to some extent, but the feedforward decoupling current will produce amplitude and phase deviations through the current loop in the linear portion. Combining an active disturbance rejection controller with a resonant controller can suppress both periodic and aperiodic disturbances simultaneously; however, common combinations only consider the effect of the resonant controller's addition on the gain at the resonant frequency, without considering its impact on gain and dynamic performance in other frequency bands. Summary of the Invention

[0005] Objective: This invention addresses the problems existing in the prior art by proposing a magnetic field decoupling control system for a hybrid magnetic circuit linear-rotating permanent magnet motor. By constructing a nine-arm power converter, a magnetic field decoupling control strategy is proposed to suppress the effects of velocity ripple and position error caused by the coupling force between the linear and rotating magnetic fields in this type of motor. A control strategy tailored to the multi-condition operation characteristics of this motor is proposed. The rotating current loop adopts a combination of current chopping and angular position control. Considering that the feedforward decoupling current will produce amplitude and phase deviations after passing through the linear current loop, the closed-loop transfer function of the linear current loop is introduced into the feedforward current to reduce amplitude and phase deviations. Due to the influence of coupling model errors and changes in motor parameters, the improved feedforward decoupling control strategy cannot achieve complete decoupling. Therefore, to address the velocity ripple caused by axial coupling force, a quasi-resonant controller and a linear active disturbance rejection controller are combined in the velocity loop. By changing the connection channel between the traditional quasi-resonant controller and the linear active disturbance rejection controller, a distortion-free quasi-resonant linear active disturbance rejection controller is proposed to suppress periodic and aperiodic disturbances. This controller not only suppresses periodic speed fluctuations and reduces position errors, but also avoids distortion of the dynamic response of the original linear active disturbance rejection controller and the gain in other frequency bands outside the resonant frequency. It also possesses excellent dynamic tracking characteristics with virtually no overshoot. Considering the structural characteristics of the linear and rotating parts, a multi-mode magnetic field decoupling control system is designed based on a dual-winding hybrid magnetic circuit linear-rotating permanent magnet motor to meet various operating conditions, reducing speed ripple and position errors caused by coupling.

[0006] Technical Solution: To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows: A magnetic field decoupling control system for a hybrid magnetic circuit linear rotary permanent magnet motor, wherein the hybrid magnetic circuit linear rotary permanent magnet motor has the ability to independently drive and simultaneously drive the linear and rotary motion parts to achieve helical motion; it includes a stator and a mover; the stator includes two sets of windings, which are used for rotational and linear motion control respectively; the two driving parts share stator teeth and mover teeth, and are driven and controlled by nine half-bridge power converters, of which three half-bridge drivers drive and control one set of windings, and the remaining six half-bridge drivers drive and control the other set of windings;

[0007] The stator of this motor adopts a modular and dual-winding structure, while the mover adopts an axial and radial double-salient pole tooth structure. The stator is composed of six stator units arranged at a certain interval along the axial direction. Each stator unit consists of two stator core modules, with a permanent magnet magnetized along the axial direction between them. The permanent magnet is arranged along the circumferential direction, and the magnetization direction of the permanent magnet in each unit is alternately N and S along the axial direction.

[0008] The stator core module has 12 teeth along the circumference, with coils set on the teeth, forming the rotating part of the stator teeth and stator windings; the mover module has 10 teeth along the circumference, forming the rotating part of the mover teeth. When rotating, current flows through the rotating armature winding, and the change in magnetic resistance of the magnetic circuit in the circumference direction generates a rotating magnetic pull, forming torque.

[0009] The stator core module has 12 teeth along the axial direction, with coils set on the teeth, forming the linear part of the stator teeth and stator windings; the mover module has 16 teeth along the axial direction, forming the linear part of the mover teeth; during linear motion, the permanent magnet flux passes through the linear armature windings one after another. When current is passed through the linear armature windings, the change in axial magnetic circuit reluctance generates a linear magnetic pull force, forming a linear thrust force.

[0010] During helical motion, the magnetic resistance of both the circumferential and axial magnetic circuits changes; when current is simultaneously applied to the linear and rotating armatures, the mover will be subjected to both rotational and linear magnetic pull, forming a helical force.

[0011] The present invention discloses a magnetic field decoupling control method for a hybrid magnetic circuit linear rotary permanent magnet motor, wherein the magnetic field decoupling control includes the following steps:

[0012] Step 1) Construct a multi-mode magnetic field decoupling control system based on a hybrid magnetic circuit linear rotary permanent magnet motor with dual windings;

[0013] Step 2) Obtain the parameters of the hybrid magnetic circuit linear rotary permanent magnet motor, analyze the motion coupling characteristics of the rotary motion part and the linear motion part, and establish a mathematical model of the hybrid magnetic circuit linear rotary permanent magnet motor considering motion coupling;

[0014] Step 3) Use a magnetic grating and a photoelectric encoder to obtain the position p and velocity v of the linear portion, respectively. l and the rotational speed N of the rotating part r In the main control circuit, the three-phase current i of the linear section is collected respectively. la i lb i lc and the three-phase current i in the rotating part ra i rb i rc ;

[0015] Step 4) Using the given position p l * The linear portion position is measured by input p, and the linear portion velocity is obtained by input v from the P controller within the linear portion position loop. l * , using v l * and measuring speed v l The linear velocity loop input controller obtains the distortion-free quasi-resonant linear active disturbance rejection controller for the linear current loop input i. lq *Using a given rotational speed N r * and measuring rotational speed N r The input to the PI controller within the rotational speed loop is used to acquire the input i of the rotational current loop at low speeds. rk * At high speed, obtain the opening angle input θ ron ;

[0016] Step 5) The three-phase current i of the linear portion of the hybrid magnetic circuit linear rotating permanent magnet motor la i lb i lc The current component i in the two-phase rotating coordinate system is obtained through coordinate transformation. ld i lq Using the linear portion to give the current i ld * i lq * Improved feedforward decoupling current i zrc and i ld i lq After PI control of the current loop in the linear section, coordinate transformation, and SVPWM, the duty cycle of the given linear section voltage is obtained; using the given current i in the rotating section... rk * (including i) ra * i rb * i rc * ) and three-phase current i rk (including i) ra i rb i rc The given duty cycle of the rotating part voltage is obtained by combining the current chopper of the rotating part current loop with the angle position control.

[0017] Step 6) The given voltage duty cycle command is transmitted through the power converter, and pulse width modulation (PWM) technology is used to implement magnetic field decoupling control of the hybrid magnetic circuit linear-rotating permanent magnet motor, taking into account the three typical operating conditions of the motor. The three typical operating conditions of the hybrid magnetic circuit linear-rotating permanent magnet motor are linear operation, rotary operation, and helical operation. Wherein:

[0018] In linear operation mode, the linear part runs independently, while the duty cycle input of the rotating part is set to zero, and it is in an uncontrolled state.

[0019] In the rotating operation mode, the rotating part runs independently, while the duty cycle input of the linear part is set to zero, and it is in an uncontrolled state.

[0020] In the spiral operation mode, the linear part and the rotating part run simultaneously. The duty cycle of the two parts is not set to zero and is only input by their respective loop control algorithms, and they are in a state of simultaneous control.

[0021] Furthermore, step 1) specifically includes the following implementation:

[0022] When rotating, current flows through the rotating armature winding. Due to the change in magnetic reluctance of the circumferential magnetic circuit, a rotating magnetic pull is generated, forming torque. When moving in a straight line, the permanent magnet flux passes through the straight armature winding successively. When current flows through the straight armature winding, the change in magnetic reluctance of the axial magnetic circuit generates a straight magnetic pull, forming a straight thrust. When moving in a helical motion, both the circumferential and axial magnetic circuit reluctances change. When current flows through both the straight and rotating armatures at the same time, the mover will be subjected to both rotational and straight magnetic pulls, forming a helical force.

[0023] Furthermore, in step 4), the distortion-free quasi-resonant linear active disturbance rejection controller within the linear velocity loop is specifically implemented as follows:

[0024] Considering the disturbances in the linear direction, the mechanical equations of the linear rotating permanent magnet motor with hybrid magnetic circuit are rewritten as follows:

[0025]

[0026] In the formula, v l i represents the measured velocity of the linear portion. lq K is the q-axis current. f Let M be the thrust coefficient, M be the mover mass, and D be the total disturbance in the linear section. d It can be seen as:

[0027]

[0028] In the formula, B l F is the coefficient of viscous friction in the linear portion. L F is the load resistance of the linear motion part. zrc As the axial coupling force, it can be seen that D d The non-periodic component load resistance F exists simultaneously. L Axial coupling force F with periodic component zrc The standard form of the mechanical state equations for the linear portion can be obtained as follows:

[0029]

[0030] In the formula, Y = X = v l f(X) = D d , Given the first derivative of X, the extended state observer ESO equations can be designed as follows:

[0031]

[0032] In the formula, Z1 is the observed velocity value, Z2 is the observed disturbance value, and e is the error between the observed and measured velocity values. and The first derivatives of Z1 and Z2 are respectively, b0 = K f / M,i lq * The reference value for the q-axis current output by the speed loop is β1, β2 are adjustable parameters. To reduce the number of adjustable parameters, the bandwidth ω of the ESO is introduced. n By reducing the tuning parameters, β1 = 2ω can be obtained using the pole placement method. n β2=ω n 2 The larger β1 and β2 are, the faster the estimation converges; if β1 and β2 are too large, the estimation may not converge.

[0033] To simultaneously suppress periodic disturbances, retain the original linear active disturbance rejection controller's good dynamic tracking capability for step responses, and maintain constant gain outside the resonant frequency range, the proposed distortion-free quasi-resonant linear active disturbance rejection velocity loop employs linear feedback control and can be designed as follows:

[0034]

[0035] In the formula, k pl For controller gain, v l * G is a reference value given for velocity. QR (s) is the transfer function of the quasi-resonant controller;

[0036] The G QR (s) Specific implementations include:

[0037]

[0038] In the formula, K R ω is the gain of the resonant part. c ω is the bandwidth of the resonant point, and ω0 is the resonant frequency, i.e., the frequency of the rotating part. r .

[0039] Furthermore, in step 4), the specific implementation of the transfer function for the velocity loop in the straight section includes:

[0040] The open-loop transfer function of the linear portion of the distortion-free quasi-resonant linear active disturbance rejection controller is:

[0041]

[0042] The closed-loop transfer functions of the velocity loop generated by the step reference and the disturbance are respectively

[0043]

[0044] In the formula, G op (s) is the open-loop transfer function of the linear velocity loop based on a distortion-free quasi-resonant linear active disturbance rejection controller, Φ r (s) and Φ d (s) represents the closed-loop transfer function of the velocity loop generated by the step reference and the disturbance, respectively.

[0045] Furthermore, the specific implementation of the improved feedforward decoupling current in step 5) includes:

[0046] Considering that the feedforward decoupling current will experience amplitude and phase deviations when passing through the linear current loop, the closed-loop transfer function of the linear current loop is incorporated into the feedforward decoupling current to reduce amplitude and phase deviations and improve the feedforward decoupling current i. zrc for:

[0047]

[0048] In the formula, G ic (s) is the closed-loop transfer function of the current loop, which can be expressed as:

[0049]

[0050] In the formula, L lq and R ls These are the q-axis inductance and stator resistance of the linear portion, respectively, k plq and k ilq These represent the q-axis PI of the linear current loop.

[0051] Furthermore, the specific implementation of the current chopping + angle position combination control in step 5) includes:

[0052] When the rotating part is moving at low speed, the current loop uses current chopper control, and the given current i for the rotating part is... rk * and detection current i rk The error input chopper function after subtraction, combined with the commutation control output duty cycle, yields the following chopper function:

[0053]

[0054] In the formula, S rk (k) and S rk (k-1) represents the duty cycle of the rotating part output at the current moment and the duty cycle Δi at the previous moment, respectively. rmax and Δi rmin These represent the upper and lower limits of the current error, respectively. When the rotating part operates at high speed, angle control is used, and the rotating part is given a varying switching angle θ. ronThe duty cycle of the commutation control output is obtained by combining current chopping and angle position control to obtain the voltage duty cycle of the rotating part.

[0055] The beneficial effects of this invention are:

[0056] 1) This invention considers the control requirements of a hybrid magnetic circuit linear rotating permanent magnet motor under different operating conditions. Combining the linear and rotating parts of the motor and the coupling characteristics of the two parts, a magnetic field decoupling control system for the hybrid magnetic circuit linear rotating permanent magnet motor is proposed. The control requirements and performance objectives no longer only meet a single operating condition, but consider multiple complex operating conditions during the operation of the hybrid magnetic circuit linear rotating permanent magnet motor.

[0057] 3) This invention considers that the amplitude and phase deviations will occur when the traditional feedforward decoupling current passes through the straight current loop. Therefore, the closed-loop transfer function of the straight current loop is introduced into the feedforward current to reduce the amplitude and phase deviations.

[0058] 4) This invention proposes a distortion-free quasi-resonant linear active disturbance rejection controller to simultaneously suppress both periodic and aperiodic disturbances. This controller can not only suppress periodic velocity fluctuations and reduce position errors, but also avoid distortion of the dynamic response of the original linear active disturbance rejection controller and the gain in other frequency bands outside the resonant frequency. It also has good dynamic tracking characteristics and no overshoot.

[0059] 5) The proposed method provides a new approach to the overall control and decoupling control of linear rotating permanent magnet motors under multiple operating conditions, and is also conducive to the application of multi-degree-of-freedom drive systems. Attached Figure Description

[0060] Figure 1 This is a block diagram of the multi-mode magnetic field decoupling control system for a hybrid magnetic circuit linear rotary permanent magnet motor with dual windings, as described in this invention.

[0061] Figure 2 This is a schematic diagram of the linear rotating permanent magnet motor based on a dual-winding hybrid magnetic circuit according to the present invention;

[0062] Figure 3 This is a schematic diagram of the coupling force of the hybrid magnetic circuit linear rotating permanent magnet motor of the present invention;

[0063] Figure 4 This is a harmonic analysis diagram of the motion coupling force of the hybrid magnetic circuit linear rotating permanent magnet motor, obtained experimentally in this invention.

[0064] Figure 5 This is a schematic diagram of the distortion-free quasi-resonant linear active disturbance rejection controller of the present invention;

[0065] Figure 6The Bode plots are shown for the closed-loop transfer function of the velocity loop disturbance in the linear portion of the conventional linear active disturbance rejection control and the distortion-free quasi-resonant linear active disturbance rejection control of the present invention, respectively.

[0066] Figure 7 The Bode plots of the linear velocity loop step reference closed-loop transfer function of the conventional linear active disturbance rejection control and the distortion-free quasi-resonant linear active disturbance rejection control of the present invention are shown respectively.

[0067] Figure 8 The experimental waveforms of velocity in the linear portion of helical motion are analyzed by FFT, respectively, using traditional linear active disturbance rejection control and the method proposed in this invention. Detailed Implementation

[0068] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0069] This invention proposes a magnetic field decoupling control system for a hybrid magnetic circuit linear rotary permanent magnet motor, the structural block diagram of which is shown below. Figure 1 As shown, it includes a hybrid magnetic circuit linear rotary permanent magnet motor, a P controller, a PI controller, a DFQL controller, an improved feedforward decoupling current, a CCC controller, an APC controller, a coordinate transformation module, a photoelectric encoder and a magnetic grating module, an inverter, and a PWM pulse generation module.

[0070] This invention proposes a magnetic field decoupling control system for a hybrid magnetic circuit linear rotating permanent magnet motor, comprising the following steps:

[0071] Step 1) Construct a multi-mode magnetic field decoupling control system based on a hybrid magnetic circuit linear-rotating permanent magnet motor with dual windings; the hybrid magnetic circuit linear-rotating permanent magnet motor has the ability to drive linear and rotational motion independently and simultaneously to achieve helical motion; the hybrid magnetic circuit linear-rotating permanent magnet motor is constructed using different motor principles; the hybrid magnetic circuit linear-rotating permanent magnet motor includes a stator (2-1) and a mover (2-2); the stator of the hybrid magnetic circuit linear-rotating permanent magnet motor includes two sets of windings for rotational and linear motion control respectively.

[0072] The rotating part of the hybrid magnetic circuit linear-rotating permanent magnet motor based on dual windings adopts a switched reluctance motor structure, while the linear part adopts a permanent magnet linear motor structure. The two drive parts share stator teeth and mover teeth. Nine half-bridge power converters are used for drive and control, with three half-bridge drivers driving and controlling one set of windings, and the remaining six half-bridge drivers driving and controlling the other set of windings.

[0073] The specific implementation of the operating principle of the multi-mode magnetic field decoupling control system based on the dual-winding hybrid magnetic circuit linear rotary permanent magnet motor includes:

[0074] During rotational motion, current flows through the rotating armature winding. The change in magnetic reluctance along the circumferential magnetic circuit generates a rotating magnetic pull, forming torque. During linear motion, the permanent magnet flux successively enters and exits the linear armature winding. When current flows through the linear armature winding, the change in axial magnetic reluctance generates a linear magnetic pull, forming a linear thrust. During helical motion, both the circumferential and axial magnetic reluctances change; when current flows through both the linear and rotating armatures simultaneously, the mover will be simultaneously subjected to rotational and linear magnetic pulls, forming a helical force.

[0075] Step 2) Obtain the parameters of the hybrid magnetic circuit linear-rotating permanent magnet motor and analyze the motion coupling characteristics of the rotary motion part and the linear motion part. Figure 3 It shows the motion coupling force F erc In the radial component F xrc F yrc and axial component F zrc , Figure 4 The experiment shows the force in the linear part during helical motion (rotation speed 600 rpm). It can be seen that in addition to DC friction, the axial coupling force is mainly based on the fundamental frequency of the rotating part. A mathematical model of a hybrid magnetic circuit linear rotating permanent magnet motor considering motion coupling is established.

[0076] Step 3) Use a magnetic grating and a photoelectric encoder to obtain the position p and velocity v of the linear portion, respectively. l and the rotational speed N of the rotating part r In the main control circuit, the three-phase current i of the linear section is collected respectively. la i lb i lc and the three-phase current i in the rotating part ra i rb i rc ;

[0077] Step 4) Using the given position p l * The linear portion position is measured by input p, and the linear portion velocity is obtained by input v from the P controller within the linear portion position loop. l * Using a given velocity v l * and measuring speed v l The linear velocity loop input controller obtains the distortion-free quasi-resonant linear active disturbance rejection controller for the linear current loop input i. lq * Using a given rotational speed N r * and measuring rotational speed N r The input to the PI controller within the rotational speed loop is used to acquire the input i of the rotational current loop at low speeds. rk *At high speed, obtain the opening angle input θ ron ;

[0078] The linear portion of the distortion-free quasi-resonant linear active disturbance rejection controller (e.g.) Figure 5 The specific implementation (as shown) includes:

[0079] Considering the disturbances in the linear direction, the mechanical equations of the linear rotating permanent magnet motor with hybrid magnetic circuit are rewritten as follows:

[0080]

[0081] In the formula, v l i represents the measured velocity of the linear portion. lq K is the q-axis current. f Let M be the thrust coefficient, M be the mover mass, and D be the total disturbance in the linear section. d It can be seen as:

[0082]

[0083] In the formula, B l F is the coefficient of viscous friction in the linear portion. L F is the load resistance of the linear motion part. zrc As the axial coupling force, it can be seen that D d The non-periodic component load resistance F exists simultaneously. L Axial coupling force F with periodic component zrc The standard form of the mechanical state equations for the linear portion can be obtained as follows:

[0084]

[0085] In the formula, Y = X = v l f(X) = D d , Given the first derivative of X, the extended state observer ESO equations can be designed as follows:

[0086]

[0087] In the formula, Z1 is the observed velocity value, Z2 is the observed disturbance value, and e is the error between the observed and measured velocity values. and The first derivatives of Z1 and Z2 are respectively, b0 = K f / M,i lq * The reference value for the q-axis current output by the speed loop is β1, β2 are adjustable parameters. To reduce the number of adjustable parameters, the bandwidth ω of the ESO is introduced. n By reducing the tuning parameters, β1 = 2ω can be obtained using the pole placement method. n β2=ωn 2 The larger β1 and β2 are, the faster the estimation converges; if β1 and β2 are too large, the estimation may not converge.

[0088] To simultaneously suppress periodic disturbances, retain the original linear active disturbance rejection controller's good dynamic tracking capability for step responses, and maintain constant gain outside the resonant frequency range, the proposed distortion-free quasi-resonant linear active disturbance rejection velocity loop employs linear feedback control and can be designed as follows:

[0089]

[0090] In the formula, k pl For controller gain, v l * G is a reference value given for velocity. QR (s) is the transfer function of the quasi-resonant controller.

[0091] The G QR (s) Specific implementations include:

[0092]

[0093] In the formula, K R ω represents the gain of the resonant component. c ω is the bandwidth of the resonant point, and ω0 is the resonant frequency, i.e., the frequency of the rotating part. r .

[0094] The specific implementation of the transfer function of the linear velocity loop includes:

[0095] The open-loop transfer function of the velocity loop in the linear portion of the distortion-free quasi-resonant linear active disturbance rejection controller is:

[0096]

[0097] The closed-loop transfer functions of the velocity loop generated by the step reference and the disturbance are respectively

[0098]

[0099] In the formula, G op (s) is the open-loop transfer function of the linear velocity loop based on a distortion-free quasi-resonant linear active disturbance rejection controller, Φ r (s) and Φ d (s) represents the closed-loop transfer function of the velocity loop generated by the step reference and the disturbance, respectively. Figure 6The Bode plots of the closed-loop transfer function of the velocity loop disturbance in the linear portion of the conventional linear active disturbance rejection control and the distortion-free quasi-resonant linear active disturbance rejection control of the present invention are shown respectively. It can be seen that the gain of the distortion-free quasi-resonant linear active disturbance rejection controller is small only near the resonant frequency, which indicates that it has a strong disturbance suppression capability in this frequency band, that is, a strong speed ripple suppression capability caused by coupling in this frequency band. Figure 7 The Bode plots of the linear velocity loop step reference closed-loop transfer function of the conventional linear active disturbance rejection control and the distortion-free quasi-resonant linear active disturbance rejection controller of the present invention are shown respectively. It can be seen that the step response of the distortion-free quasi-resonant linear active disturbance rejection controller is consistent with that of the conventional linear active disturbance rejection controller, which indicates that the controller does not destroy the dynamic response of the original active disturbance rejection controller.

[0100] Step 5) The three-phase current i of the linear portion of the hybrid magnetic circuit linear rotating permanent magnet motor la i lb i lc The current component i in the two-phase rotating coordinate system is obtained through coordinate transformation. ld i lq Using the linear portion to give the current i ld * i lq * Improved feedforward decoupling current i zrc and i ld i lq After PI control of the current loop in the linear section, coordinate transformation, and SVPWM, the duty cycle of the given linear section voltage is obtained; using the given current i in the rotating section... rk * (including i) ra * i rb * i rc * ) and three-phase current i rk (including i) ra i rb i rc The given duty cycle of the rotating part voltage is obtained by combining the current chopper of the rotating part current loop with the angle position control.

[0101] The specific implementation of the improved feedforward decoupling current includes:

[0102] Considering that the feedforward decoupling current will experience amplitude and phase deviations when passing through the linear current loop, the closed-loop transfer function of the linear current loop is incorporated into the feedforward decoupling current to reduce amplitude and phase deviations and improve the feedforward decoupling current i. zrc for:

[0103]

[0104] In the formula, G ic (s) is the closed-loop transfer function of the current loop, which can be expressed as:

[0105]

[0106] In the formula, L lq and R ls These are the q-axis inductance and stator resistance of the linear portion, respectively, k plq and k ilq These represent the q-axis PI of the linear current loop.

[0107] The specific implementation of the current chopping + angle position combination control includes:

[0108] When the rotating part is moving at low speed, the current loop uses current chopper control, and the given current i for the rotating part is... rk * and detection current i rk The error input chopper function after subtraction, combined with the commutation control output duty cycle, yields the following chopper function:

[0109]

[0110] In the formula, S rk (k) and S rk (k-1) represents the duty cycle of the rotating part output at the current moment and the duty cycle Δi at the previous moment, respectively. rmax and Δi rmin These represent the upper and lower limits of the current error, respectively. When the rotating part operates at high speed, angle control is used, with the rotating part given a varying switching angle θ. ron The duty cycle of the commutation control output is obtained by combining current chopping and angle position control to obtain the voltage duty cycle of the rotating part.

[0111] Step 6) The given voltage duty cycle command is transmitted through the power converter, and pulse width modulation (PWM) technology is used to implement magnetic field decoupling control of a hybrid magnetic circuit linear rotary permanent magnet motor, combining the three typical operating conditions of the motor. The three typical operating conditions of the hybrid magnetic circuit linear rotary permanent magnet motor are linear operation, rotary operation, and helical operation.

[0112] in:

[0113] In linear operation mode, the linear part runs independently, while the duty cycle input of the rotating part is set to zero, and it is in an uncontrolled state.

[0114] In the rotating operation mode, the rotating part runs independently, while the duty cycle input of the linear part is set to zero, and it is in an uncontrolled state.

[0115] In the spiral operation mode, the linear part and the rotating part run simultaneously. The duty cycle of the two parts is not set to zero and is only input by their respective loop control algorithms, and they are in a state of simultaneous control.

[0116] Figure 8 The FFT analysis of the velocity experimental waveforms in the linear portion of the spiral motion of the traditional linear active disturbance rejection control and the method proposed in this invention are respectively. It can be seen that compared with the traditional linear active disturbance rejection control, the method proposed in this invention reduces the content of the velocity frequency (6Hz) harmonic caused by the axial coupling force from 8.6% to 0.82%, a reduction of 90.46%, while also reducing the velocity tracking error.

[0117] In summary, this invention considers the control requirements of a hybrid magnetic circuit linear rotating permanent magnet motor under different operating conditions. Combining the linear and rotating parts of the motor and the coupling characteristics of these two parts, a magnetic field decoupling control system for the hybrid magnetic circuit linear rotating permanent magnet motor is proposed. The control requirements and performance targets no longer only satisfy a single operating condition but consider multiple complex operating conditions during the operation of the linear rotating permanent magnet motor. Considering that the feedforward decoupling current will produce amplitude and phase deviations through the current loop of the linear part, the closed-loop transfer function of the current loop of the linear part is introduced into the feedforward current to reduce amplitude and phase deviations. A distortion-free quasi-resonant linear active disturbance rejection controller is proposed to simultaneously suppress periodic and aperiodic disturbances. This controller not only suppresses periodic speed fluctuations and reduces position errors but also does not degrade the gain of other frequency bands of the original linear active disturbance rejection controller, while possessing good dynamic tracking characteristics and almost no overshoot. The proposed method provides a new approach to the overall control and decoupling control of linear rotating permanent magnet motors under multiple operating conditions, and is conducive to accelerating the engineering process of multi-degree-of-freedom drive systems.

[0118] The above embodiments are only used to illustrate the design concept and features of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The protection scope of the present invention is not limited to the above embodiments. Therefore, all equivalent changes or modifications made based on the principles and design ideas disclosed in the present invention are within the protection scope of the present invention.

Claims

1. A method for decoupling the magnetic field of a hybrid magnetic circuit linear rotary permanent magnet motor, characterized in that, The magnetic field decoupling control includes the following steps: Step 1) Construct a multi-mode magnetic field decoupling control system based on a hybrid magnetic circuit linear rotary permanent magnet motor with dual windings; Step 2) Obtain the parameters of the hybrid magnetic circuit linear rotary permanent magnet motor, analyze the motion coupling characteristics of the rotary motion part and the linear motion part, and establish a mathematical model of the hybrid magnetic circuit linear rotary permanent magnet motor considering motion coupling; Step 3) Use a magnetic grating and a photoelectric encoder to obtain the position p and velocity v of the linear portion, respectively. l and the rotational speed N of the rotating part r In the main control circuit, the three-phase current i of the linear section is collected respectively. la i lb i lc and the three-phase current i in the rotating part ra i rb i rc ; Step 4) Using the given position p l * The linear portion position is measured by input p, and the linear portion velocity is obtained by input v from the P controller within the linear portion position loop. l * , using v l * and measuring speed v l The linear velocity loop input controller obtains the distortion-free quasi-resonant linear active disturbance rejection controller for the linear current loop input i. lq * Using a given rotational speed N r * and measuring rotational speed N r The input to the PI controller within the rotational speed loop is used to acquire the input i of the rotational current loop at low speeds. rk * At high speed, obtain the opening angle input θ. ron ; Step 5) The three-phase current i of the linear portion of the hybrid magnetic circuit linear rotating permanent magnet motor la i lb i lc The current component i in the two-phase rotating coordinate system is obtained through coordinate transformation. ld i lq Using the linear portion to give the current i ld * i lq * Improved feedforward decoupling current i zrc and i ld i lq After PI control of the current loop in the linear section, coordinate transformation, and SVPWM, the duty cycle of the given linear section voltage is obtained; using the given current i in the rotating section... rk * Including i ra * i rb * i rc * and three-phase current i rk Including i ra i rb i rc The given duty cycle of the rotating part voltage is obtained by combining current chopping of the rotating part current loop with angle position control. Step 6) The given voltage duty cycle command is transmitted through the power converter. Combined with the three typical operating conditions of the motor, pulse width modulation (PWM) technology is used to achieve magnetic field decoupling control of the hybrid magnetic circuit linear-rotating permanent magnet motor. The three typical operating conditions of the hybrid magnetic circuit linear-rotating permanent magnet motor are linear operation, rotary operation, and helical operation. In linear operation mode, the linear part runs independently, while the duty cycle input of the rotating part is set to zero, and it is in an uncontrolled state. In the rotating operation mode, the rotating part runs independently, while the duty cycle input of the linear part is set to zero, and it is in an uncontrolled state. In the spiral operation mode, the linear part and the rotating part run simultaneously. The duty cycle of the two parts is not set to zero and is only input by their respective loop control algorithms, and they are in a state of simultaneous control.

2. The method for decoupling the magnetic field of a hybrid magnetic circuit linear rotary permanent magnet motor according to claim 1, characterized in that, Step 1) Specific implementation includes: When rotating, current flows through the rotating armature winding. Due to the change in magnetic reluctance of the circumferential magnetic circuit, a rotating magnetic pull is generated, forming torque. When moving in a straight line, the permanent magnet flux passes through the straight armature winding successively. When current flows through the straight armature winding, the change in magnetic reluctance of the axial magnetic circuit generates a straight magnetic pull, forming a straight thrust. When moving in a helical motion, both the circumferential and axial magnetic circuit reluctances change. When current flows through both the straight and rotating armatures at the same time, the mover will be subjected to both rotational and straight magnetic pulls, forming a helical force.

3. The method for decoupling the magnetic field of a hybrid magnetic circuit linear-rotating permanent magnet motor according to claim 1, characterized in that, In step 4), the distortion-free quasi-resonant linear active disturbance rejection controller within the linear velocity loop is specifically implemented as follows: Considering the disturbances in the linear direction, the mechanical equations of the linear rotating permanent magnet motor with hybrid magnetic circuit are rewritten as follows: ； In the formula, v l i represents the measured velocity of the linear portion. lq K is the q-axis current. f Let M be the thrust coefficient, M be the mover mass, and D be the total disturbance in the linear section. d It can be seen as: ； In the formula, B l F is the coefficient of viscous friction in the linear portion. L F is the load resistance of the linear motion part. zrc As the axial coupling force, it can be seen that D d The non-periodic component load resistance F exists simultaneously. L Axial coupling force F with periodic component zrc We can obtain the standard form of the mechanical state equations for the linear portion: ； In the formula, Y=X=v l f(X)=D d , Given the first derivative of X, the extended state observer ESO equations are designed as follows: ； In the formula, Z1 is the observed velocity value, Z2 is the observed disturbance value, and e is the error between the observed and measured velocity values. and The first derivatives of Z1 and Z2 are respectively, and b0=K f / M,i lq * The reference value for the q-axis current output by the speed loop is β1, β2 are adjustable parameters. To reduce the number of adjustable parameters, the bandwidth ω of the ESO is introduced. n By reducing the tuning parameters, β1 = 2ω can be obtained using the pole placement method. n β2=ω n 2 ; To simultaneously suppress periodic disturbances, retain the original linear active disturbance rejection controller's good dynamic tracking capability for step responses, and maintain constant gain outside the resonant frequency range, the proposed distortion-free quasi-resonant linear active disturbance rejection velocity loop employs linear feedback control and can be designed as follows: ; In the formula, k pl For controller gain, v l ∗ G is a reference value given for velocity. QR (s) is the transfer function of the quasi-resonant controller; The G QR (s) Specific implementations include: ; In the formula, K R ω is the gain of the resonant part. c ω is the bandwidth of the resonant point, and ω0 is the resonant frequency, i.e., the frequency of the rotating part. r .

4. The method for decoupling the magnetic field of a hybrid magnetic circuit linear rotary permanent magnet motor according to claim 3, characterized in that, In step 4), the specific implementation of the transfer function for the velocity loop in the straight section includes: The open-loop transfer function of the linear portion of the distortion-free quasi-resonant linear active disturbance rejection controller is: ； The closed-loop transfer functions of the velocity loop generated by the step reference and the disturbance are respectively ； In the formula, G op (s) is the open-loop transfer function of the linear velocity loop based on a distortion-free quasi-resonant linear active disturbance rejection controller, Φ r (s) and Φ d (s) represents the closed-loop transfer function of the velocity loop generated by the step reference and the disturbance, respectively.

5. The magnetic field decoupling control method for a hybrid magnetic circuit linear rotary permanent magnet motor according to claim 4, characterized in that, Step 5) The specific implementation of the improved feedforward decoupling current includes: Considering that the feedforward decoupling current will experience amplitude and phase deviations when passing through the linear current loop, the closed-loop transfer function of the linear current loop is incorporated into the feedforward decoupling current to reduce amplitude and phase deviations and improve the feedforward decoupling current i. zrc for: ； In the formula, G ic (s) is the closed-loop transfer function of the current loop, expressed as: ； In the formula, L lq and R ls These are the q-axis inductance and stator resistance of the linear portion, respectively, k plq and k ilq These represent the q-axis PI of the linear current loop.

6. The magnetic field decoupling control method for a hybrid magnetic circuit linear rotary permanent magnet motor according to claim 5, characterized in that, Step 5) The specific implementation of the current chopping + angle position combination control includes: When the rotating part is moving at low speed, the current loop uses current chopper control, and the given current i for the rotating part is... rk * and detection current i rk The error input chopper function after subtraction, combined with the commutation control output duty cycle, yields the following chopper function: ； In the formula, S rk (k) and S rk (k-1) represents the duty cycle of the rotating part output at the current moment and the duty cycle Δi at the previous moment, respectively. rmax and Δi rmin These represent the upper and lower limits of the current error, respectively. When the rotating part operates at high speed, angle control is used, and the rotating part is given a varying switching angle θ. ron The duty cycle of the commutation control output is obtained by combining current chopping and angle position control to obtain the voltage duty cycle of the rotating part.

7. A magnetic field decoupling control system for a hybrid magnetic circuit linear rotary permanent magnet motor, used to implement the control method according to any one of claims 1 to 6, characterized in that, The hybrid magnetic circuit linear rotary permanent magnet motor has the ability to drive the linear part and the rotary motion part independently or simultaneously to achieve helical motion; it includes a stator and a mover; the stator includes two sets of windings, which are used for rotary and linear motion control respectively; the two drive parts share stator teeth and mover teeth, and are driven and controlled by nine half-bridge power converters, of which three half-bridge drivers drive and control one set of windings, and the remaining six half-bridge drivers drive and control the other set of windings. The stator of this motor adopts a modular and dual-winding structure, and the mover adopts an axial and radial double salient pole tooth structure. The stator is composed of six stator units arranged at a certain interval along the axial direction. Each stator unit consists of two stator core modules, and a permanent magnet that is magnetized along the axial direction is set between the two modules. The permanent magnet is arranged along the circumferential direction, and the magnetization direction of the permanent magnet in each unit is alternately set with N and S along the axial direction. The stator core module has 12 teeth along the circumference, with coils set on the teeth, forming the rotating part of the stator teeth and stator windings; the mover module has 10 teeth along the circumference, forming the rotating part of the mover teeth. When rotating, current flows through the rotating armature winding, and the change in magnetic resistance of the magnetic circuit in the circumference direction generates a rotating magnetic pull, forming torque. The stator core module has 12 teeth along the axial direction, with coils set on the teeth, forming the linear part of the stator teeth and stator windings; the mover module has 16 teeth along the axial direction, forming the linear part of the mover teeth; during linear motion, the permanent magnet flux passes through the linear armature windings one after another. When current is passed through the linear armature windings, the change in axial magnetic circuit reluctance generates a linear magnetic pull force, forming a linear thrust force. During helical motion, the magnetic resistance of both the circumferential and axial magnetic circuits changes; when current is simultaneously applied to the linear and rotating armatures, the mover will be subjected to both rotational and linear magnetic pull, forming a helical force.

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