Motor control method and motor control device

Abstract

The present invention provides a motor control method and a motor control device, which can fully compensate for the cogging effect generated, thereby greatly reducing the influence of the cogging effect to achieve the desired action characteristics. By using an inverse correction control system and a disturbance observer control system, an inverse correction control for applying inverse correction to the cogging effect state is combined with a disturbance observer control for disturbance. Inverse correction is applied to the cogging effect state to roughly remove the influence of the cogging effect, and the influence that cannot be reduced by the inverse correction control is reduced by the disturbance observer control for the disturbance.

Description

Technical Field

[0001] The present invention relates to a motor control method and a motor control device for controlling a motor to reduce a cogging effect generated in the motor. Background Art

[0002] A motor is a structure that includes a stator and a mover, and that generates thrust magnetically between the stator and the mover to move the mover relative to the stator. A representative example of a motor is a linear motor that is configured such that a mover having a plurality of permanent magnets arranged in a manner that changes magnetic properties alternately and a stator having coils wound around a plurality of magnetic pole teeth are arranged in correspondence with each other at a predetermined distance, and an alternating current is passed through the coil of the stator to generate thrust by the attraction and repulsion between the stator and the permanent magnet, thereby causing the mover to move linearly relative to the stator.

[0003] It is well known that cogging generally occurs in motors including such linear motors. Cogging refers to the periodic variation of thrust that occurs with the periodic variation of magnetic attraction, wherein the periodic variation of magnetic attraction is dependent on the position of the mover relative to the stator. The generation of cogging has an adverse effect on the operation of the motor, and sometimes the desired operation characteristics cannot be obtained. For example, in a linear motor, stable constant speed control cannot be performed. Such cogging is an inevitable event for the motor, and therefore various methods have been proposed for correcting the generated cogging to obtain the desired operation characteristics (Japanese Patent Gazette No. 2004-120861, Japanese Patent Gazette No. 2019-221032, etc.). Summary of the invention

[0004] However, in these prior arts, the status quo is that sufficient compensation for the generated cogging has not yet been achieved.

[0005] The present invention has been made in view of such circumstances, and an object of the present invention is to provide a motor control method and a motor control device that can fully compensate for the generated cogging effect, thereby significantly reducing the influence of the cogging effect and realizing desired operating characteristics.

[0006] The motor control method involved in the present invention is used to control the motor to reduce the slot effect generated in the motor. The control method is characterized in that an inverse correction control that applies an inverse correction to the state of the slot effect is combined with a disturbance observer control that corrects the disturbance when the motor is in motion.

[0007] The motor control method according to the present invention is characterized in that the speed and position of the motor are controlled by a combination of the inverse correction control and the disturbance observer control.

[0008] The motor control method according to the present invention is characterized in that a steady-state Kalman filter is used in the disturbance observer control.

[0009] The motor control method according to the present invention is characterized in that the motor is a linear motor including a mover formed by arranging a plurality of permanent magnets and a stator formed by winding coils around a plurality of magnetic pole teeth.

[0010] The motor control device of the present invention is used to control the motor to reduce the slot effect generated in the motor. The control device includes: an inverse correction control system that applies inverse correction to the state of the slot effect; and a disturbance observer control system that corrects the disturbance when the motor is in motion.

[0011] The motor control device according to the present invention is characterized by further comprising: a speed control system for controlling the speed of the motor; and a position control system for controlling the position of the motor.

[0012] The motor control device according to the present invention is characterized in that the disturbance observer control system includes a steady-state Kalman filter.

[0013] The motor control device according to the present invention is characterized in that the motor is a linear motor including a mover formed by arranging a plurality of permanent magnets and a stator formed by winding coils around a plurality of magnetic pole teeth.

[0014] In the present invention, the inverse correction control for applying inverse correction to the cogging state is combined with the disturbance observer control for the disturbance. That is, inverse correction is applied to the cogging state to roughly remove the influence of the cogging, and the influence that cannot be reduced by the inverse correction is reduced by the disturbance observer control. Therefore, the inevitable cogging that is generated can be fully compensated, so that the influence of the cogging can be greatly reduced.

[0015] In the present invention, the speed and position of the motor are controlled by combining the inverse correction control and the disturbance observer control as described above, so that the influence of the cogging effect can be suppressed, and the speed and position of the motor can be controlled with high accuracy.

[0016] In the present invention, a steady-state Kalman filter is used in the disturbance observer control, so that the disturbance during the operation of the motor can be compensated efficiently.

[0017] In the present invention, a linear motor including a mover formed by arranging a plurality of permanent magnets and a stator formed by winding coils around a plurality of magnetic pole teeth is controlled, thereby achieving reduction of the inevitable cogging in the linear motor.

[0018] According to the present invention, control for applying an inverse correction to a cogging state is combined with observer control for disturbances, so that the influence of the inevitable cogging that occurs can be significantly reduced, and desired operating characteristics can be reliably obtained in the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a perspective view showing the structure of a linear motor to which the present invention is applied.

[0020] Figure 2 is a side view showing the structure of a linear motor.

[0021] Figure 3 This is a block diagram showing the structure of one embodiment of a motor control device according to the present invention.

[0022] Figure 4 is a block diagram showing the internal structure of the disturbance observer.

[0023] Figure 5 This is a diagram showing an operation waveform of an output (actual operation model) from a controlled object and an operation waveform of an estimated model serving as a comparison.

[0024] Figure 6 : is a diagram showing an inverse correction waveform of the cogging effect and an estimated waveform obtained by the disturbance observer control.

[0025] Figure 7 It is a diagram showing the waveform of the input command and the waveform of the current command.

[0026] Figure 8 This is a diagram showing an operation waveform when the linear motor is operated.

[0027] Fig. 9 This is a diagram showing a comparison between the operation waveform in the example of the present invention and the operation waveform in the ideal operation model.

[0028] Fig.10 is a block diagram showing the internal structure of a disturbance observer using a steady-state Kalman filter.

[0029] Fig.11 This is a block diagram showing the structure of another embodiment of the motor control device according to the present invention.

[0030] Fig.12 It is a diagram showing the result of speed control.

[0031] Fig.13 It is a diagram showing the result of speed control.

[0032] Fig.14 It is a diagram showing the result of position control. DETAILED DESCRIPTION

[0033] The present invention will be described in detail based on the accompanying drawings showing embodiments of the present invention. In addition, the following describes a case where the present invention is applied to a linear motor as an example of a motor. First, the structure of the linear motor will be briefly described.

[0034] Figure 1 and Figure 2 1 and 2 are a perspective view and a side view showing the structure of the linear motor 1. The linear motor 1 includes a mover 2 and a stator 3 which face each other with a predetermined distance therebetween.

[0035] The mover 2 is, for example, a structure in which 14 rectangular permanent magnets 21 are supported and fixed to a thin plate-shaped back yoke 22 at equal intervals and are movable in the movable direction ( Figure 2 Each permanent magnet 21 is arranged along the thickness direction ( Figure 2 The magnetization directions of the adjacent permanent magnets 21, 21 are opposite to each other. That is, the magnetization direction of the adjacent permanent magnets 21, 21 is opposite to each other. Figure 2 The permanent magnet 21 magnetized along the direction from the stator 3 side to the mover 2 side (from the upper side to the lower side) is connected to the permanent magnet 21 magnetized along the direction from the stator 3 side to the mover 2 side (from the upper side to the lower side) Figure 2 The permanent magnets 21 magnetized in a direction from the bottom to the top) are arranged alternately.

[0036] On the other hand, the stator 3 is configured by integrally providing, for example, 30 rectangular magnetic pole teeth 32 at equal intervals in the movable direction on a thin plate-like core 31 , and by winding a coil 33 around each magnetic pole tooth 32 . Figure 2 U, V, and W in the figure represent the U phase, V phase, and W phase of the three-phase AC power supply, respectively, and three pairs of positive and negative two slots are set as one group to conduct three-phase parallel power supply. In addition, in the linear motor 1, a 7-pole 6-slot structure having seven permanent magnets 21, six magnetic pole teeth 32, and six coils 33 is set as a basic unit.

[0037] When three-phase AC is supplied to the coil 33 of the stator 3 to generate a magnetic field at the magnetic pole teeth 32 , the permanent magnets 21 of the mover 2 are magnetically attracted and repelled in sequence in the magnetic field, thereby generating thrust on the mover 2 , so that the mover 2 moves linearly relative to the stator 3 .

[0038] Next, a method and a device for reducing the influence of the cogging effect that is inevitably generated in the linear motor 1 having such a structure will be described in detail.

[0039] In the present invention, the control of applying inverse correction to the cogging state is combined with the disturbance observer control for the disturbance. That is, inverse correction is applied to the cogging state to roughly remove the influence of the cogging, and the influence of the disturbance that cannot be reduced by the inverse correction is reduced by the disturbance observer control. Therefore, the inevitable cogging that is generated can be fully compensated, and the influence of the cogging can be greatly reduced.

[0040] Disturbance observer control is a control that relatively simply removes disturbances from a working mechanism such as a feedback system to achieve stabilization of the action. In the case of a linear motor 1, as disturbances, there are the influence of the tension of the power cable (a phenomenon in which the thrust in the forward direction and the backward direction of the linear motor 1 is different due to the tension), the influence of the linear guide (a phenomenon in which the linear motor 1 has positional deviations due to the assembly of the linear guide), etc. In the present invention, the influence of such disturbances in the linear motor 1 is compensated by the disturbance observer control.

[0041] Figure 3 1 is a block diagram showing the structure of an embodiment of a motor control device according to the present invention. The control device includes a linear motor 1, a cogging element 41, an adder 42, a nonlinear compensator 51, a disturbance observer 61, a differentiator 62, and a subtractor 71. The linear motor 1, the cogging element 41, and the adder 42 constitute a control object + cogging 40, the nonlinear compensator 51 constitutes an inverse correction control system 50, and the disturbance observer 61 and the differentiator 62 constitute a disturbance observer control system 60.

[0042] The input end of the linear motor 1 and the input end of the cogging element 41 as the control object are connected to the output terminal of the subtractor 71. The output end of the linear motor 1 is connected to one input terminal of the adder 42, and the output end of the cogging element 41 is connected to the other input terminal of the adder 42. The output terminal of the adder 42 is connected to the input end of the nonlinear compensator 51 and the input end of the differentiator 62. The output end of the nonlinear compensator 51 is connected to one subtraction input terminal of the subtractor 71. The output end of the differentiator 62 is connected to the input end of the disturbance observer 61. In addition, the output end of the disturbance observer 61 is connected to the other subtraction input terminal of the subtractor 71.

[0043] An input command u′ is input from the outside to an addition input terminal of the subtractor 71 and the disturbance observer 61, and a correction output u′ is input from the nonlinear compensator 51 to one subtraction input terminal of the subtractor 71. cog(estimated value of periodic correction of cogging) and the control output ^d (estimated value of disturbance) is input from the disturbance observer 61 to the other subtraction input terminal of the subtractor 71. In addition, the "^" symbol represents an estimated value.

[0044] The current command u is output from the output terminal of the subtractor 71 to the linear motor 1 and the cogging element unit 41. The output from the linear motor 1 is added to the output from the cogging element unit 41 (cogging element C) in the adder 42, and the position x is output from the adder 42 to the nonlinear compensator 51, the differentiator 62, and the outside.

[0045] The nonlinear compensator 51 is used to correct the periodically generated portion of the cogging element. The nonlinear compensator 51 applies an inverse correction (C) to the state of the cogging (cogging element C). -1 ), the estimated value of the cogging correction is cog Output to the subtractor 71. The estimated value ^i cog Derived from a model based on cogging elements.

[0046] On the other hand, the disturbance observer 61 performs disturbance observer control for the disturbance, and outputs the estimated value Δt of the disturbance to the subtractor 71. The details of the disturbance observer control for the disturbance will be described later.

[0047] In the present invention, the inverse correction control performed by the inverse correction control system 50 for applying inverse correction to the state of the cogging effect is combined with the observer control performed by the disturbance observer control system 60 for the disturbance. That is, the inverse correction control system 50 (nonlinear compensator 51) is used to apply inverse correction to the state of the cogging effect to roughly remove the influence of the cogging effect, and the disturbance observer control system 60 (disturbance observer 61) is used to reduce the influence caused by the disturbance that cannot be reduced by the inverse correction. As a result, the inevitable cogging effect can be fully compensated, so that the influence of the cogging effect can be greatly reduced.

[0048] Next, the disturbance observer control will be described in detail. Figure 4 61 is a block diagram showing the internal structure of the disturbance observer 61. Figure 4 In, with Figure 3 The same parts are marked with the same numbers and reference numerals.

[0049] The disturbance observer 61 includes an estimation model generation unit 81, a comparison unit 82, a disturbance estimation value determination unit 83, and a subtractor 84. The addition input terminal of the subtractor 84 is connected to the output terminal of the above-mentioned differentiator 62, and the subtraction input terminal of the subtractor 84 is connected to the output terminal of the estimation model generation unit 81. The output terminal of the subtractor 84 is connected to the input terminal of the comparison unit 82. The output terminal of the comparison unit 82 is connected to the input terminal of the disturbance estimation value determination unit 83. In addition, the output terminal of the disturbance estimation value determination unit 83 is connected to another subtraction input terminal of the above-mentioned subtractor 71.

[0050] In disturbance observer control, a target action (estimated model) is created based on modeling of the controlled object and input, and the estimated model is compared with the actual response. Then, the difference generated during the comparison is regarded as disturbance, and an error is added to the input.

[0051] The estimation model generation unit 81 creates an estimation model that becomes a target based on the modeling of the control object and the input instruction u' input from the outside, and outputs the estimated value ^vel of the speed calculated based on the estimation model to the subtraction operator 84. The estimation model is a control model that is not affected by interference. On the other hand, the speed value vel obtained by time-differentiating the output (position x) from the control object in the differentiator 62 is input from the differentiator 62 to the subtraction operator 84. The difference between the output (speed value vel) from the differentiator 62 and the output (estimated value ^vel of the speed) from the estimation model generation unit 81 is obtained in the subtraction operator 84. The obtained difference is output to the comparison unit 82.

[0052] The comparison unit 82 determines a correction value based on the difference between the output from the control target and the estimated model. Specifically, the correction value is determined according to the size of the difference between the two (the size of the area). Figure 5 : is a diagram showing the action waveform of the output (actual action model) from the controlled object and the action waveform of the estimated model as a comparison. Figure 5 In the case of , (a) shows the action waveform of the actual action model, and (b) shows the action waveform of the estimated model.

[0053] In such Figure 5 When the size (area) of the difference between the actual motion model and the estimated model is large, the influence of the disturbance is large, so a large correction value is determined. Figure 5 When the size (area) of the difference between the actual motion model and the estimated model is small as shown in B, the influence of the disturbance is small, so a small correction value is determined. The determined correction value is output to the disturbance estimated value determination unit 83.

[0054] The disturbance estimated value determination unit 83 generates the disturbance estimated value Δd based on the input correction value. The generated disturbance estimated value Δd is output to the subtractor 71 and added to the input command u′.

[0055] exist Figure 6 The inverse correction waveform of the cogging effect and the estimated waveform obtained by the disturbance observer control are shown in FIG. 1 as an action confirmation after adding the disturbance observer control. Figure 6 In the figure, the horizontal axis represents time [s] and the vertical axis represents current [A]. Figure 6 (a) and (b) show the inverse correction waveform of the cogging effect and the estimated waveform obtained by the disturbance observer control, respectively.

[0056] Both waveforms are calculated based on the model of the controlled object and are waveforms that follow the generation cycle of the cogging effect. The inverse correction waveform (a) of the cogging effect is a constant correction value because only the cogging effect is corrected. On the other hand, the estimated waveform (b) obtained by the disturbance observer control also corrects for effects other than the cogging effect as disturbances. Figure 6 As shown, the correction value also becomes larger at a position where the disturbance other than the cogging is large (the difference from the estimated model is larger), so the correction differs depending on the position.

[0057] exist Figure 7 The waveform of the current command u obtained by applying the above two corrections to the input command u' is shown together with the waveform of the input command u'. Figure 7 In the figure, the horizontal axis represents time [s] and the vertical axis represents current [A]. Figure 7 (a) and (b) in FIG. 1 show the waveform of the input command u' and the waveform of the current command u, respectively. Figure 3 The control device input shown is shown Figure 7 The input instruction u' has the waveform shown.

[0058] Next, the results of the control according to the present invention will be described. Figure 8 Based on Figure 7 The actual linear motor 1 is operated by the current command u shown in FIG. Figure 8 Also shown are the action waveforms when the linear motor 1 is operated without any correction (first comparative example) and the action waveforms when the linear motor 1 is operated by only performing the inverse correction control of the cogging effect (second comparative example). Figure 8 In the figure, the horizontal axis represents time [s], the vertical axis represents speed [m / s], and Figure 8 (a), (b), and (c) show the operation waveforms of the present invention example, the first comparative example, and the second comparative example, respectively.

[0059] When comparing the action waveform (b) in the first comparative example with the action waveform (c) in the second comparative example, the second comparative example can reduce the influence of the cogging effect to a certain extent compared with the first comparative example, and the responsiveness during acceleration and deceleration is also improved to a certain extent, but it cannot be said to be sufficient. In contrast, when trying to compare the action waveform (a) in the example of the present invention with the action waveforms (b) and (c) in the first and second comparative examples, it can be found that in the example of the present invention, the influence of the cogging effect can be further reduced, the fluctuation during constant speed action is also greatly reduced, and the responsiveness during acceleration and deceleration is also greatly improved.

[0060] exist Fig. 9 A comparison between the action waveform in the above-mentioned example of the present invention and the action waveform in the ideal action model is shown in FIG. Fig. 9 In the figure, the horizontal axis represents time [s], the vertical axis represents speed [m / s], and Fig. 9 (a) and (b) show the operation waveform of the example of the present invention and the operation waveform of the ideal operation model, respectively.

[0061] If reference Fig. 9 , it can be understood that the ideal motion model is followed at any time during constant speed, acceleration, and deceleration in the present invention. Based on this, it is confirmed that the control of the present invention combining the inverse correction control for the cogging state and the disturbance observer control for the disturbance is extremely effective.

[0062] Other embodiments of the present invention are described below. In this embodiment, the disturbance observer uses a steady-state Kalman filter. A steady-state Kalman filter is a type of infinite impulse response filter used to estimate or control the state of a dynamic system using actual measured values ​​containing errors. The steady-state Kalman filter is widely used to estimate a quantity that changes over time (such as the position and velocity of an object) based on actual measured results with discrete errors.

[0063] Fig.10 is a block diagram showing the internal structure of a disturbance observer using a steady-state Kalman filter. Fig.10 In, with Figure 3 and Figure 4 The same parts are marked with the same numbers and reference numerals.

[0064] The disturbance observer 61 includes a first parameter unit 86, a second parameter unit 87, a third parameter unit 88, a fourth parameter unit 89, a fifth parameter unit 90, a first adder 91, a second adder 92, a subtractor 93, a first integrator 94, and a second integrator 95. Among these components, the first parameter unit 86, the second parameter unit 87, the third parameter unit 88, the fourth parameter unit 89, the first adder 91, the second adder 92, the subtractor 93, and the first integrator 94 constitute a steady-state Kalman filter 100.

[0065] The output end of the second parameter unit 87 is connected to one addition input terminal of the first adder 91. The output terminal of the first adder 91 is connected to the input end of the first integrator 94, and the output end of the first integrator 94 is connected to the input end of the first parameter unit 86 and the input end of the third parameter unit 88. The output end of the third parameter unit 88 is connected to the subtraction input terminal of the subtractor 93. The addition input terminal of the subtractor 93 is connected to the output end of the above-mentioned differentiator 62. The output terminal of the subtractor 93 is connected to the input end of the fourth parameter unit 89 and the input end of the fifth parameter unit 90. The output end of the first parameter unit 86 is connected to one addition input terminal of the second adder 92, and the output end of the fourth parameter unit 89 is connected to the other addition input terminal of the second adder 92. The output terminal of the second adder 92 is connected to the other addition input terminal of the first adder 91. The output terminal of the fifth parameter unit 90 is connected to the input terminal of the second integrator 95 , and the output terminal of the second integrator 95 is connected to the subtraction input terminal of the subtractor 71 described above.

[0066] The first parameter unit 86, the second parameter unit 87, and the third parameter unit 88 respectively store state variable parameters A, B, and C of the model (input: current, output: speed). These parameters A, B, and C are derived using a MATLAB (registered trademark) program.

[0067] In addition, the fourth parameter unit 89 stores the state estimation parameters L of the model. x The fifth parameter unit 90 stores the disturbance estimation parameter L of the linear motor 1. d Parameter L x The model gain is used to define the sensitivity to the error between the waveform of the model being compared and the actual waveform. If you want to correct even a small error, set this parameter L x In addition, the parameter L d Also with parameter L x Likewise, is the model gain used to define the sensitivity in the calibration.

[0068] In actual implementation, it is preferable to use discretized parameters as each of these parameters.

[0069] The estimated value of the speed waveform when the input command u' is input to the model (the speed waveform without the influence of the cogging effect) is calculated. The calculated speed waveform of the model is compared with the actual speed waveform of the linear motor 1 obtained by differentiating the position information x by the differentiator 62, and the difference between them is calculated by the subtractor 93. In this way, the motion of the dynamic system (control object) is estimated using the estimated value from the model. x Since the value is determined by the model gain, a method as a steady-state Kalman filter is obtained.

[0070] The difference (error) obtained by the subtractor 93 is used to determine the estimated value of the disturbance ^d, and the subtractor 71 subtracts the determined estimated value of the disturbance ^d from the input instruction u', thereby achieving reduction of the cogging effect.

[0071] Next, an embodiment of controlling the speed and position of the linear motor 1 by combining the above-described inverse correction control and observer control will be described.

[0072] Fig.11 1 is a block diagram showing the structure of another embodiment of the motor control device according to the present invention. Fig.11 In, with Figure 3 and Figure 4 The same parts are marked with the same numbers and reference numerals.

[0073] This embodiment has the following features in addition to Figure 3 In addition to the same control object + cogging 40, inverse correction control system 50 and disturbance observer control system 60, there are also a speed control unit 111, a subtractor 112, a position control unit 121 and a subtractor 122. The speed control unit 111 and the subtractor 112 constitute the speed control system 110, and the position control unit 121 and the subtractor 122 constitute the position control system 120.

[0074] The output end of the speed control unit 111 is connected to the addition input terminal of the above-mentioned subtractor 71 and the input end of the above-mentioned disturbance observer 61. The input end of the speed control unit 111 is connected to the output terminal of the subtractor 112. The subtraction input terminal of the subtractor 112 is connected to the output terminal of the above-mentioned differentiator 62, and the addition input terminal of the subtractor 112 is connected to the output end of the position control unit 121. The input end of the position control unit 121 is connected to the output terminal of the subtractor 122. In addition, the subtraction input terminal of the subtractor 122 is connected to the output end of the above-mentioned control object + cogging effect 40 (the output terminal of the adder 42).

[0075] The reference value r of the position is inputted from the outside to the subtractor 122. p , and the position output x from the adder 42 is input to the subtractor 122. p , the subtractor 122 will take the difference between the two (=r p -x p ) position command e p The speed reference value r is output to the position control unit 121. The speed reference value r is input to the subtractor 112 as the output of the position control unit 121. v , and the speed output x from the differentiator 62 is input to the subtractor 112. v , the subtractor 112 will take the difference between the two (=r v -x v ) speed command e v Output to the speed control unit 111.

[0076] exist Fig.11 In the structure shown, by utilizing the combination of inverse correction control and observer control, the speed control unit 111 and the position control unit 121 of the linear motor 1 can be simply designed as a PI controller and a P controller, respectively. In the following (1), the function in the PI controller is expressed as a function of time s, and in the following (2), the function in the P controller is expressed as a function of time s.

[0077] u'(S)=K p v (1+T / T Is ) (1)

[0078] r v (s)=K p p e p (s) (2)

[0079] Among them, K P v : Gain constant of PI control,

[0080] T I : Integral coefficient of PI control,

[0081] K P p : Gain constant of P control.

[0082] Below, the instructions for using Fig.11 A specific example of control performed by the structure shown.

[0083] Regarding speed control, the gain constant K of the speed control unit 111 is set to P v and the integration coefficient T I Manually adjust to K P v =100 and T I =0.0083. Fig.12 The target speed is 0.05 m / s and the maximum acceleration is 14 m / s. 2 The speed control result is obtained by setting the reference in the way of Fig.12 The result of speed control performed in the same manner without using the combination of inverse correction control and observer control as in the present invention is also shown. Fig.12 In the figure, the horizontal axis represents time [s], the vertical axis represents speed [m / s], and Fig.12 (a) and (b) in FIG. 1 respectively show an example using a combination of inverse correction control and observer control (example of the present invention) and an example not using a combination of inverse correction control and observer control (comparative example).

[0084] In addition, Fig.13 The speed change in the transition state between 6.5 seconds and 6.7 seconds in the above-mentioned Example (a) of the present invention and the Comparative Example (b) is shown in FIG. Fig.13 In the figure, the horizontal and vertical axes are Fig.12 The horizontal and vertical axes are the same.

[0085] according to Fig.12 and Fig.13 The results shown show that the overshoot of the speed response is suppressed in the example (a) of the present invention in which the inverse correction control and the observer control are combined to perform the cogging compensation, compared with the comparative example (b) in which the cogging compensation is not performed.

[0086] Regarding position control, the gain constant K of the position control unit 121 is set to P p Manually adjust to K P p =19. Fig.14The results of the position control of the present invention example obtained by setting the benchmark in such a way that the target position is 0.045m and 0.135m, and the speed is 1.25m / s and 0.1m / s are shown in FIG. Fig.14 An example of position control set as a reference is shown by a dotted line in FIG. Fig.14 In the figure, the horizontal axis represents time [s] and the vertical axis represents position [m].

[0087] according to Fig.14 From the results shown, it can be understood that in the example of the present invention using the combination of the inverse correction control and the observer control, position control that substantially matches the reference can be performed without being affected by the cogging effect.

[0088] From the above, it can be understood that by utilizing the combination of inverse correction control and observer control as described above, the influence of the slot effect can be suppressed, thereby controlling the speed and position of the linear motor 1 with high precision, confirming the effectiveness of the control method and control device in the present invention.

[0089] Furthermore, in the above-described embodiment, the control target is a linear motor, but it goes without saying that the control of the present invention can be applied to a rotary motor in the same manner as a linear motor.

[0090] The disclosed embodiments should be considered in all respects as illustrative rather than restrictive. The scope of the present invention is indicated by the claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. A control method for a linear motor, for controlling the speed and position of the linear motor to reduce the cogging effect generated in the linear motor, wherein the linear motor comprises a mover formed by arranging a plurality of permanent magnets and a stator formed by winding coils on a plurality of magnetic pole teeth, wherein the control method is characterized in that: The control method uses inverse correction control and disturbance observer control, wherein: The inverse correction control applies inverse correction to the state of the cogging effect by a nonlinear compensator, and the disturbance observer control corrects the disturbance when the linear motor is in motion. In which, the disturbance observer control creates a target estimation model based on an external input instruction based on a position reference value, compares the difference between the estimated value of the speed calculated based on the target estimation model and the speed value obtained by time-differentiating the output from the linear motor, and generates an estimated value of the disturbance based on a correction value determined based on the difference.

2. The control method of the linear motor according to claim 1, characterized in that: In the disturbance observer control, a steady-state Kalman filter is used.

3. A control device for a linear motor, for controlling the speed and position of the linear motor to reduce the cogging effect generated in the linear motor, wherein the linear motor comprises a mover formed by arranging a plurality of permanent magnets and a stator formed by winding coils on a plurality of magnetic pole teeth, the control device comprising: an inverse correction control system that applies an inverse correction to the state of the cogging effect through a nonlinear compensator; and A disturbance observer control system is used to correct the disturbance when the linear motor is in motion. The inverse correction control system and the disturbance observer control system are arranged in parallel. in, The disturbance observer control system creates a target estimation model based on an external input instruction based on a position reference value, compares the difference between the estimated value of the speed calculated based on the target estimation model and the speed value obtained by time-differentiating the output from the linear motor, and generates an estimated value of the disturbance based on a correction value determined based on the difference.

4. The linear motor control device according to claim 3, characterized in that: Also available: a speed control system that controls the speed of the linear motor; and A position control system controls the position of the linear motor.

5. The control device for a linear motor according to claim 3 or 4, characterized in that: The disturbance observer control system has a steady-state Kalman filter.

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