JP2004102321A - Linear motor control device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a servo control stably operable even in the offset of a position detecting means and before the adjustment of gain variation, and to achieve a servo action of high accuracy after the adjustment. <P>SOLUTION: This linear motor control device is provided with a correction amount measuring means for measuring the correction amount data to an output signal of a position detecting sensor, and a control means for controlling the position of a linear motor on the basis of the output signal of a position sensor corrected on the basis of the correction amount data measured by a correction amount measuring means. The control means controls the linear motor on the basis of a first servo characteristic parameter in an adjustment mode for measuring the correction amount by the correction amount measuring means, and controls the linear motor on the basis of a second servo characteristic parameter different from the first servo characteristic parameter after the termination of the adjustment mode. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a linear motor control device suitable for use in lens position control and the like.
[0002]
[Prior art]
Conventionally, various actuators, motors, and the like have been used for high-precision control of a camera lens and the like.In recent years, however, linear motors have been used for reasons such as high-speed driving, responsiveness, and quietness. ing.
[0003]
In general, when a linear motor is used, the position detection method is important. As the method, the position of the lens movable section is obtained by taking the repetitive periodic waveform of an optical encoder or a magnetic encoder and processing the data. A position detection method is used. As the position (offset) adjustment, there is provided a step of moving the lens movable portion by one cycle or more of a repetitive waveform, and performing offset adjustment and gain adjustment from the repetitive cycle waveform captured at that time. ing.
[0004]
Japanese Patent Application Laid-Open No. 6-105206 discloses a prior art relating to such a lens position detecting method.
[0005]
[Problems to be solved by the invention]
However, in the state where the offset and gain are not adjusted, since the waveform is cut out from the repetitive waveform in which the offset and gain do not match, and a straight line approximation is performed, a discontinuous point or a level difference of the position detection value appears, and the servo becomes unstable. Or in the worst case, an oscillation phenomenon may occur.
[0006]
For this reason, conventionally, it has been necessary to strictly adjust the component standards and control circuits so that the servo operation does not become unstable. To avoid this, there is a method of turning off the feedback control and driving with a constant control value.However, in the open loop control without feedback, the speed rapidly increases and the amplitude of the repetitive periodic waveform signal is attenuated by the high frequency noise suppression filter. In some cases, correct offset adjustment and gain adjustment cannot be performed.
[0007]
Therefore, an object of the present invention is to enable a servo control that moves stably even before the offset or gain variation of the position detecting means is adjusted, and to allow the servo operation to move stably before the position detecting means is adjusted. It is an object of the present invention to enable a highly accurate servo operation in the subsequent position control.
[0008]
[Means for Solving the Problems]
In order to solve such a problem, according to the invention described in claim 1 of the present application, a correction amount measuring unit that measures correction amount data for an output signal of a position detection sensor, and a correction amount measurement unit that measures the correction amount data. Control means for controlling the position of the linear motor based on the output signal of the position sensor corrected by the correction amount data, wherein the control means is in an adjustment mode in which the correction amount is measured by the correction amount measuring means. A linear motor configured to control the linear motor with a first servo characteristic parameter, and to control the linear motor with a second servo characteristic parameter different from the first servo characteristic parameter after the adjustment mode ends; A control device is characterized.
[0009]
According to a second aspect of the present invention, in the first aspect of the present invention, there is provided a correction amount storing means for storing correction amount data measured by the correction amount measuring means, When the correction amount data is not stored in the amount storage means, the linear motor is controlled by the first servo characteristic parameter, and when the correction amount data is stored in the correction amount storage means, Is characterized by a linear motor control device configured to control the linear motor with the second servo characteristic parameter.
[0010]
According to the invention of claim 3 of the present application, in the invention of claim 1, the first servo characteristic parameter is a servo characteristic parameter for an unmeasured correction amount state, and the second servo characteristic parameter is It is characterized by a linear motor control measure that is a servo characteristic parameter for a correction amount measurement completion state.
[0011]
According to a fourth aspect of the present invention, in the first aspect of the present invention, the output signal of the position detection sensor is characterized by a linear motor control device having a repetitive waveform.
[0012]
According to a fifth aspect of the present invention, in the first to third aspects, a linear motor control device is characterized in that the correction amount is an offset amount and an amplification factor.
[0013]
According to a sixth aspect of the present invention, there is provided the linear motor control device according to the first aspect, wherein after the power is turned on, the stored correction amount is erased and initialized, and the correction amount is measured. I do.
[0014]
According to the invention of claim 7 of the present application, in the invention of claim 4, the control means drives the linear motor based on the first servo characteristic parameter to repeatedly output the position sensor. The correction amount data of the signal is obtained, an adjustment is performed to correct the repetitive output signal of the position sensor based on the correction amount data, and the movable portion of the linear motor moves according to the corrected output signal of the position sensor. It is characterized by a linear motor control device configured to execute an origin finding operation for finding an absolute position within the range.
[0015]
According to the invention of claim 8 of the present application, in the invention of claim 7, when the movable portion of the linear motor is moved by an impact or the like and the absolute position is lost, the absolute position within the movable range of the movable portion is lost. The present invention is characterized by a linear motor control device configured to execute measurement of a correction amount before executing an origin finding operation to obtain a position.
[0016]
According to a ninth aspect of the present invention, in the first or seventh aspect of the invention, there is provided a linear motor control device wherein the servo characteristic parameter is a servo gain.
[0017]
According to the tenth aspect, in the first to ninth aspects, the servo gain of the first servo characteristic parameter before the correction amount meter in the adjustment mode is the second servo gain after the completion of the correction amount measurement. And a gain margin or a phase margin is set to be larger than the servo gain of the servo characteristic parameter.
[0018]
According to an eleventh aspect of the present invention, in the tenth aspect of the invention, the servo characteristic parameter is a linear motor control device that is a servo frequency characteristic.
[0019]
According to a twelfth aspect of the present invention, in the tenth aspect, the servo characteristic parameter is a linear motor control device in which the servo characteristic parameter is a servo sampling frequency.
[0020]
According to the invention of claim 13 of the present application, there is provided a linear motor control method for detecting a position of a movable portion by performing data processing on a repetitive periodic waveform of n phases (n is an integer of 2 or more), An adjustment processing step of correcting the position detection repetitive waveform by obtaining an offset correction amount and a gain correction amount for each phase from the maximum data and the minimum data of the repetition period waveform data captured during the movement of the movable part; Using the data of the repetitive waveform corrected in the adjustment processing step, repetitive waveform data located at an intermediate phase are synthesized by calculation, and a waveform line of a substantially linear portion of each repetitive waveform data is cut out and linearized by linear interpolation. The linear motor can be used in accordance with the waveform line linearly interpolated in the interpolation processing step and the position interpolation processing step. Detecting the position of the part features a method of controlling a linear motor comprising a control processing step of correcting.
[0021]
According to the invention of claim 14 of the present application, in the invention of claim 13, the position interpolation processing step includes the step of converting the two-phase repetitive waveform data located at an intermediate phase using the n-phase repetitive waveform data. The method is characterized by a linear motor control method that combines by calculation, cuts out a waveform line corresponding to a 90-degree phase shift from a two-phase repetitive waveform that crosses every 45-degree phase and is 90 degrees apart, and linearizes by linear interpolation.
[0022]
According to the invention as set forth in claim 15 of the present application, the adjusting processing step includes moving the movable portion at least a distance corresponding to at least one cycle of the repetitive waveform, and calculating each phase from the repetitive periodic waveform captured during the movement. It is characterized by a linear motor control method for obtaining an offset correction amount and a gain correction amount every time.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a linear motor control device according to the present invention will be described with reference to the drawings.
[0024]
FIG. 1 is a block diagram showing a case where the present invention is applied to a lens control device such as a camera and a focus lens position control device. In the figure, 100 is a focus lens, 101 is an MR sensor circuit for detecting a focus lens position that repeatedly outputs a waveform according to the position of the focus lens, 102 is an amplifier circuit that amplifies the output of the MR sensor circuit 101, and 103 is an AD circuit. A converter 104a is a waveform processing circuit for generating an intermediate phase waveform with respect to the output waveform of the MR sensor circuit 101, and 104b is a linearizing process (details will be described later) for the output waveform output from the waveform processing circuit 104a. A linearization processing circuit to be performed, 105 is an error calculating means, 106 is a position command means for instructing a moving position to a linear motor. In this embodiment, since it is used for position control of a focus lens, a focus detecting means (not shown) , Or an instruction by a manual focus position control signal.
[0025]
Reference numeral 107 denotes a high-precision position control execution instructing unit 108 and a control execution unit switching unit for switching the instruction of the adjustment process execution instructing unit 109. Is a high-precision control execution instructing means for instructing execution of an adjustment process for instructing execution of an adjustment process for correcting / adjusting an output waveform of the MR sensor during an initialization operation or the like. Execution instruction means.
[0026]
Further, in the present embodiment, an instruction to execute the adjustment process is issued from the adjustment process execution instructing means in response to the power ON or the state in which the position of the movable portion of the linear motor 114 is deviated due to the impact. Is completed, the high position accuracy control execution means 108 issues an instruction to execute the high position accuracy control.
[0027]
110 is a servo setting switching means, 111 is a first servo processing circuit for performing servo processing with characteristics for an adjustment process at the time of initial setting such as immediately after power-on, and 112 is servo processing for characteristics of high position accuracy control during normal operation. Is a second servo processing circuit that performs the following. 113 is a driver circuit, 114 is a linear motor, 115 is a linear motor driven based on the first servo characteristic parameter for the adjustment process, corrects / adjusts the output waveform of the MR sensor, and measures offset and gain correction amounts. An adjustment process control execution mode for storing, and after the adjustment process is completed, a linear motor is driven based on a second servo characteristic parameter for high position accuracy control, and high position accuracy for performing position control from an output waveform of the MR sensor. A mode control circuit for selectively switching between a control execution mode and a control execution mode.
[0028]
Here, the first servo processing circuit 111 is set so that the servo constants are set to stable servo constants, that is, the gain margin and the phase margin are increased, as compared with the second servo processing circuit 112. Details will be described later.
[0029]
The mode control circuit 115 selects the first and second servo processing circuits 111 and 112 in the adjustment process control execution mode at the time of the initial setting and the high position accuracy control execution mode in the normal operation after the adjustment process. , And constitute the control means of the present invention.
[0030]
Reference numeral 116 denotes an offset & gain measurement storage unit for measuring and storing an offset and a gain based on an output obtained by linearizing the output waveform of the MR sensor by the linearization processing circuit 104b.
[0031]
The waveform processing circuit 104a, the linearization processing circuit 104b, and the offset & gain measurement storage unit 116 constitute a correction amount measuring unit of the present invention.
[0032]
The MR sensor 101 repeatedly outputs a waveform according to the position of the focus lens 100 and is amplified by the amplifier 102. The amplified repetitive waveform is converted into a digital signal by the AD converter 103.
[0033]
In order to cope with an actual use temperature environment and aging of parts, it is necessary to execute a lens position sensor output correction amount measurement (adjustment process) operation at least once before photographing with a camera. In order to detect an absolute position using a lens position sensor that is a relative position sensor that only outputs a repeated waveform, it is necessary to perform an origin positioning (butting) operation of the lens after turning on the power.
[0034]
Usually, after the power is turned on, a media recording / reproducing apparatus which operates in cooperation as a camera recording system also needs an initialization operation time such as a tape path stabilizing operation and a pickup moving operation. Before the positioning operation, a series of initialization operations is performed with a lens position sensor output adjustment (adjustment step) operation interposed therebetween.
[0035]
FIG. 2 is a repetitive waveform image diagram when an initial offset amount and an initial gain other than the measured correction amount are designated by the offset & gain measurement storage unit 116. In the present embodiment, the output of the MR sensor 101 is a two-phase sine wave, but generally, n (n is an integer of 2 or more) phases may be used.
[0036]
In the state where the adjustment is not performed, the outputs of the two sine wave signals A and B having a phase difference of 90 degrees do not match the offset and the gain as shown in FIG. The intermediate phase signal C obtained by the arithmetic processing in the waveform processing circuit 104a after the AD conversion by the AD converter 103 is (A + B) / √2, and the intermediate phase signal D is (BA) / √2, but the sine Since the offset and gain of the wave signal A and the sine wave signal B are shifted, a correct intermediate phase signal cannot be obtained. As shown in FIG. 2B, one cycle is divided into a plurality of parts based on the magnitude relation of A, B, C, and D, and portions A ′ to D ′ in which the slope of the repeated sine wave is steep and the linearity is high are cut out. , And can be processed by the linearization processing circuit 104b.
[0037]
FIG. 3 is an image diagram of position information that is cut out from the repetitive waveform before the completion of the correction amount measurement in FIG. When cut out from a repetitive waveform in which the offset and the gain do not match and rearranged by the linearization processing circuit 104b, discontinuous points and steps in the position detection values appear. The maximum value of the discontinuity and the degree of the step can be calculated from the component standard or the assembly standard.
[0038]
FIG. 4 is a diagram illustrating a determination flow of the mode control circuit 115. In the figure, when the process is started, the task of the mode control means is started in S400, and the process moves to S401. In S401, it is determined whether or not the correction amount measurement in the adjustment process control execution mode has been performed after the power is turned on. If the measurement has been completed, the process proceeds to S410, and if the measurement has not been completed, the process proceeds to S402. The determination of whether or not the measurement has been completed is performed by determining whether or not there is a stored value of the offset and gain correction amount in the offset & gain measurement storage unit 116.
[0039]
In step S402, the mode control circuit 115 switches the control execution unit switching unit 107 to the adjustment process control execution unit 109, and shifts the processing to step S403. In S403, the mode control circuit 115 switches the servo setting switching means 110 to the first servo processing circuit 111 side, and shifts the processing to S404.
[0040]
In S404, the offset & gain measurement storage unit 116 corrects the variation of each waveform shown in FIGS. 2 and 3 obtained through the waveform processing circuit 104a and the linearization processing circuit 104b and corrects the position as shown in FIG. The offset and gain correction amounts for obtaining linear characteristics for detection are measured, and the process proceeds to S405 to store the measured offset and gain correction values.
[0041]
Then, the offset & gain measurement storage unit 116 instructs the stored correction amount to the amplifier circuit 102 and the linearization processing circuit 104b, and shifts the processing to S406. As a result, the output waveform of the MR sensor is corrected.
[0042]
During the adjustment / correction processing of the output waveform of the MR sensor immediately after the power is turned on, the linear motor 114 is driven by the first servo processing circuit 111. In consideration of the step of each linear portion shown in FIG. 3 of the output of the previous MR sensor, the servo constant is set to be more stable than the second servo processing circuit 112 for normal operation, that is, the gain margin and the phase margin are increased. Therefore, a stable offset and gain correction amount can be measured without causing oscillation or the like.
[0043]
The settings to increase the gain margin and phase margin include reducing the proportional gain, integral gain, and differential gain, increasing the phase lead compensation in the servo frequency characteristics, and increasing the sampling frequency to reduce the phase lag. There are means. A gain that obtains the amplitude from the maximum and minimum points of the waveform from the A / D conversion data of the two-phase repetitive waveform and has a predetermined value amplitude, and a middle value from the A / D conversion data that determines the middle point from the maximum and minimum points of the waveform Determine the offset that will result in the value. After the adjustment, the offset and gain of the repetitive waveform are determined, and a non-linear position detection straight line as shown in FIG. 6 can be obtained.
[0044]
In the adjustment process mode, the offset and gain correction amounts in the linearization processing of the two-phase repetitive waveform are calculated from the component standards and the assembly standards. It may be calculated from a simulation by an analysis program, or may be obtained by experimenting with a component having a specified limit value. After the correction of the offset and the gain, the position can be detected with high accuracy.
[0045]
Subsequently, in S406, the mode control circuit 115 switches the servo setting switching unit 110 to the second servo processing circuit 112 side and switches the control execution unit switching unit 107 to the high position accuracy control execution unit 108 side.
[0046]
The offset and gain measurement storage unit 116 stores the offset and gain correction amounts obtained in the above-described adjustment process, and instructs the amplifier circuit 102 and the linearization processing circuit 104b on the correction amounts. As a result, as shown in FIG. 6, a straight line for detecting the position without a step is obtained, and the position of the movable portion of the linear motor 114 can be accurately and accurately detected using the straight line.
[0047]
In step S407, the mode control circuit 115 switches the servo setting switching unit 110 to the second servo processing circuit 112 for high position accuracy control, and shifts the processing to step S408.
[0048]
In step S408, the movable part of the linear motor is mechanically moved to the end of the movement range, and is brought into contact with the positioning part for setting the reference position to determine the origin, and the process proceeds to step S409, where the task of the mode control circuit 115 is executed. Ends.
[0049]
In S410, after the adjustment process is completed, it is determined whether or not an impact jump in which the position of the movable portion of the linear motor is largely shifted due to an external impact or the like has occurred. In this case, the process moves to S409. In S409, the task of the mode control circuit 115 ends.
[0050]
After the above-described adjustment step processing mode is completed, the difference between the position information output from the linearization processing circuit 104b and the control target value output from the drive position commanding means 106 of the linear motor is calculated by the error calculating means 105 as an error. The second servo processing circuit 112 converts the signal into a drive signal, outputs the signal to the driver circuit 113, and drives the linear motor 114.
[0051]
Here, the above-described adjustment step processing mode will be further described. FIG. 5A is a repetitive waveform image diagram when the offset and gain stored in the offset & gain instructing means 116 are instructed. The outputs of the two sine wave signals A and B having a phase difference of 90 degrees have the same offset and gain as shown in FIG.
[0052]
After the A / D conversion by the A / D converter 103, the intermediate phase signal C obtained by the arithmetic processing in the waveform processing circuit 104a is (A + B) / √2, and the intermediate phase signal D is (BA) / √2, but the sine Since the offset and gain of the wave signal A and the sine wave signal B are adjusted, a correct intermediate phase signal is obtained. From the magnitude relationship of A ″, B ″, C ″, and D ″, one period is divided into a plurality as shown in FIG. 5B, and a portion where the slope of the repeated sine wave is steep and the linearity is high is cut out. By doing so, the linearization processing can be performed by the linearization processing circuit 104b.
[0053]
FIG. 6 is an image diagram of position information cut out from the adjusted repetitive waveform of FIG. 5 and linearized to make absolute positions. Since the offset and the gain have been corrected, when the waveform is repeatedly cut out and rearranged by the linearization processing circuit 104a, the position detection value is continuous.
[0054]
Since the level difference disappears, the second servo processing circuit 112 sets the servo constant to a more accurate servo constant setting, for example, increases the proportional gain as compared with the first servo processing circuit 111, and sets the servo gain to a servo gain suitable for high position accuracy control. .
[0055]
As described above, switching to the servo constant setting for the adjustment process according to the component standard and assembly accuracy standard does not require strict conditions for the component standard and assembly accuracy standard according to the servo constant. And yield deterioration can be prevented.
[0056]
In addition, since the servo constant is changed to a servo constant suitable for the high-position accuracy control after the adjustment is completed, there is an effect that high-position accuracy can be achieved in the focus control.
[0057]
When a process of correcting and adjusting the waveform output from the position sensor is performed, an operation pattern for waveform adjustment is instructed, and the servo constant setting unit sets a servo constant for the waveform adjustment process by this. The waveform correction / adjustment operation can be performed while the servo is stably applied while avoiding the oscillation phenomenon.
[0058]
Also, when the process of correcting and adjusting the waveform output from the position sensor is performed, an operation pattern for waveform adjustment is instructed, whereby the servo constant setting means sets the servo constant for the waveform adjustment process. It is possible to perform the waveform correction / adjustment operation while applying the servo stably, and when the high position accuracy control is executed, the high position accuracy control position is indicated, and the high position accuracy control servo constant setting means is provided. Set to the servo constant for high position accuracy control. This enables a highly accurate servo operation in the position control after the waveform adjustment.
[0059]
In the above-described embodiment, for convenience of explanation, the configuration is shown in a block diagram as shown in FIG. 1, but the waveform processing circuit 104a, the linearization processing circuit 104b, the error calculation means 105, the position command means 106, Execution means switching means 107, high position accuracy control execution means 108, adjustment step execution instructing means 109, servo setting switching means 110, first servo processing circuit 111, second servo processing circuit 112, mode control circuit 115, offset & gain measurement The storage unit 116 can be configured by software using a microcomputer. The present invention can be realized by executing the program shown in the flowchart shown in FIG. 4 by the microcomputer.
[0060]
【The invention's effect】
As described above, according to the present invention, when correcting and adjusting the waveform of the sensor, the servo constant for the waveform adjustment is set, so that the oscillation phenomenon can be avoided and the waveform adjustment can be performed while applying the servo stably. When performing high-precision position control, the servo constants for high-precision position control are set, so that high-precision servo operation can be performed stably in position control after waveform adjustment. There is.
[Brief description of the drawings]
FIG. 1 is a block diagram of a focus lens position control device according to an embodiment of the present invention.
FIG. 2 is an image diagram of a repetitive waveform before adjustment and an image of a cut-out straight line.
FIG. 3 is an image diagram of position information subjected to linearization processing before adjustment.
FIG. 4 is a diagram illustrating a determination flow of a mode selection unit.
FIG. 5 is an image diagram of a repetitive waveform image after adjustment and a cut-out straight line.
FIG. 6 is an image diagram of position information subjected to linearization processing after adjustment;
[Explanation of symbols]
REFERENCE SIGNS LIST 100 focus lens 101 MR sensor circuit 102 amplifier circuit 103 AD conversion 104 linearization processing circuit 105 error calculation means 106 position command means 107 control execution means switching means 108 high-precision control execution means 109 adjustment process control execution means 110 servo setting switching means 111 First servo processing circuit 112 Second servo processing circuit 113 Driver circuit 114 Linear motor 115 Mode control circuit 116 Offset & gain measurement storage means

Claims (15)

Correction amount measuring means for measuring correction amount data for the output signal of the position detection sensor,
Control means for controlling the position of the linear motor based on the output signal of the position sensor corrected by the correction amount data measured by the correction amount measurement means,
The control unit controls the linear motor with a first servo characteristic parameter in an adjustment mode in which the correction amount is measured by the correction amount measurement unit. A linear motor control device configured to control the linear motor with different second servo characteristic parameters. In claim 1,
A correction amount storage unit configured to store the correction amount data measured by the correction amount measurement unit; wherein the control unit is configured to store the correction amount data when the correction amount data is not stored in the correction amount storage unit. The linear motor is controlled by a servo characteristic parameter, and when the correction amount data is stored in the correction amount storage means, the linear motor is controlled by the second servo characteristic parameter. A linear motor control device comprising: In claim 1,
A linear motor control measure, wherein the first servo characteristic parameter is a servo characteristic parameter for an unmeasured correction amount state, and the second servo characteristic parameter is a servo characteristic parameter for a correction amount measurement completed state. In claim 1,
The output signal of the position detection sensor has a repetitive waveform. In claims 1 to 3,
A linear motor control device, wherein the correction amount is an offset amount and an amplification factor. In claim 1,
A linear motor control device, wherein after power-on, a stored correction amount is erased and initialized, and measurement of the correction amount is executed. In claim 4,
The control means obtains correction amount data of a repetitive output signal of the position sensor by driving the linear motor based on the first servo characteristic parameter, and based on the correction amount data, determines repetitive output of the position sensor. It is configured to perform an adjustment for correcting a signal, and to perform an origin finding operation for obtaining an absolute position within a movable range of a movable portion of the linear motor according to the corrected output signal of the position sensor. Characteristic linear motor control device. In claim 7,
When the movable part of the linear motor is moved due to an impact or the like and the absolute position is lost, the correction amount is measured before executing the home search operation to obtain the absolute position within the movable range of the movable part. A linear motor control device comprising: In claim 1 or 7,
The linear motor control device according to claim 1, wherein the servo characteristic parameter is a servo gain. In claims 1 to 9,
The servo gain of the first servo characteristic parameter before the correction amount meter in the adjustment mode is set to have a larger gain margin or phase margin than the servo gain of the second servo characteristic parameter after the correction amount measurement is completed. A linear motor control device. In claim 10,
2. The linear motor control device according to claim 1, wherein the servo characteristic parameter is a servo frequency characteristic. In claim 10,
The linear motor controller according to claim 1, wherein the servo characteristic parameter is a servo sampling frequency. A linear motor control method for detecting a position of a movable portion by performing data processing on a repetitive periodic waveform of n phases (n is an integer of 2 or more),
An adjustment processing step of correcting the position detection repetitive waveform by obtaining an offset correction amount and a gain correction amount for each phase from the maximum data and the minimum data of the repetition period waveform data captured during the movement of the movable unit,
Using the repetitive waveform data corrected in the adjustment processing step, repetitive waveform data located at an intermediate phase is synthesized by calculation, and a substantially straight line portion of each repetitive waveform data is cut out and linearized by linear interpolation. A position interpolation processing step;
A control processing step of detecting and correcting the position of the movable portion of the linear motor according to the waveform line linearly interpolated in the position interpolation processing step,
Control method of linear motor consisting of In claim 13,
The position interpolation processing step combines the two-phase repetitive waveform data located at the intermediate phase by calculation using the n-phase repetitive waveform data, and intersects the two-phase repetitive waveform data at 90-degree phases separated by 45-degree phases. A method for controlling a linear motor, wherein a waveform line corresponding to a 90-degree phase shift is cut out from a repeated waveform and linearized by linear interpolation. The adjusting processing step includes moving the movable unit by at least a distance corresponding to at least one cycle of the repetitive waveform, and obtaining an offset correction amount and a gain correction amount for each phase from the repetitive periodic waveform captured during the movement. Characteristic linear motor control method.

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