JP4683369B2 - Linear motor control device - Google Patents

Description

  According to the present invention, a mover is moved by sequentially supplying power from at least two or more amplifiers to a stator winding that is provided with a permanent magnet and is divided into a plurality of pieces and arranged continuously. The present invention relates to a linear motor control method and apparatus.

  Linear motors are used in FA transport devices such as semiconductor manufacturing devices and machine tools. In particular, they may be transported over long distances of several tens of meters in glass substrate transport applications for liquid crystal display manufacturing. In long-distance conveyance, a linear motor having a permanent magnet disposed on the mover and no power cable is often employed. However, in order to control the thrust of this linear motor, it is essential to detect the magnetic pole position of the mover. As a position detection method, there is a method in which a slit is provided in the mover and detection is performed using an optical sensor. However, since the position cannot be detected when the slit attached to the mover moves and moves away from the optical sensor, the optical sensor must be arranged at an interval shorter than the length of the slit. There was a problem that the optical sensor had to be arranged and the cost was high. In some cases, the sensor cannot be attached due to mechanical limitations.

Therefore, sensorless control of the linear motor is performed. For example, in the technique disclosed in Patent Document 1, after performing magnetic flux calculation from the sum of output voltages and the sum of output currents of a plurality of power converters (hereinafter referred to as amplifiers) that supply power to a plurality of stator windings, The estimated magnetic pole axis component is obtained by coordinate conversion of the magnetic flux calculation value, and a loop circuit for matching this with the actual magnetic pole axis is constructed to obtain the position and speed of the mover by calculation. Further, in the technique disclosed in Patent Document 2, the induced voltage is directly detected with reference to the neutral point of the multiphase winding of the stator arranged continuously, and the induced voltage of the stator winding starts to be generated. The missing timing is detected, and the mover is detected at a 180 ° / n pitch with respect to the n-phase stator winding.
Japanese Patent Laid-Open No. 9-65676 (Section 7, FIG. 1) JP 2002-223587 (Section 7, Figures 1 and 4)

  However, in any of the methods, there is a problem in switching an amplifier that supplies power to a plurality of stator windings. In the magnetic flux calculation of Patent Document 1, the sum of the output voltage and the output current of the amplifier is used as the calculation input. This is based on the assumption that the amplifier is driven one by one. However, this is not taken into consideration. In addition, a fixed value is set in advance in the memory for the current phase shift caused by amplifier switching. However, when the phase is corrected at the moment of switching, thrust fluctuation occurs. On the other hand, Patent Document 2 directly detects the induced voltage, and devise switching at the timing when the induced voltage is generated and when it is eliminated. However, since the induced voltage is directly detected by hardware, it is considered difficult to accurately detect the edge timing due to the variable speed state, the influence of noise, detection delay, and the like.

The present invention has been made in view of such problems, and includes a permanent magnet in a mover, and at least two or more amplifiers in a stator winding arranged continuously in a plurality of divisions. An object of the present invention is to provide a linear motor control device that realizes sensorless position speed estimation without thrust shock by switching when power is sequentially supplied.

According to the first aspect of the present invention, the movable element is provided with a permanent magnet, and power is sequentially supplied from at least two or more amplifiers to a stator winding that is continuously divided into a plurality of parts. In the sensorless linear motor control device that moves the child,
A voltage calculator for calculating a voltage synthesized from output voltages of the two or more amplifiers;
A current calculator for calculating a current synthesized from output currents of the two or more amplifiers;
A position / speed estimator for estimating an error and speed of the mover magnetic pole position from the combined voltage and the combined current;
A phase adjuster for adjusting a control reference angle based on an error of the mover magnetic pole position;
An amplifier switching pattern that maps a current ratio for allocating a command current corresponding to a command thrust from the estimated mover position and stator position, and the number of amplifiers to be driven,
A current command distributor that calculates a current command value to each amplifier based on the amplifier switching pattern;
Are provided.

According to the second aspect of the present invention, the movable element is provided with a permanent magnet, and power is sequentially supplied from at least two or more amplifiers to a stator winding that is continuously divided into a plurality of pieces. In the sensorless linear motor control device that moves the child,
A voltage calculator for calculating a voltage synthesized from output voltages of the two or more amplifiers;
A current calculator for calculating a current synthesized from output currents of the two or more amplifiers;
A position speed estimator for estimating speed from the combined voltage and the combined current;
A comparator that calculates an error of the mover magnetic pole position based on a difference value between the integral value of the estimated speed and the control reference angle;
A phase adjuster for adjusting a control reference angle based on an error of the mover magnetic pole position;
An amplifier switching pattern that maps a current ratio for allocating a command current corresponding to a command thrust from the estimated mover position and stator position, and the number of amplifiers to be driven,
A current command distributor that calculates a current command value to each amplifier based on the amplifier switching pattern;
Are provided.

According to a third aspect of the present invention, the movable element is provided with a permanent magnet, and power is sequentially supplied from at least two or more amplifiers to a stator winding that is continuously divided into a plurality of parts. In the sensorless linear motor control device that moves the child,
A speed controller that generates a thrust command value based on the speed estimated by the position / speed estimator and a speed command value, a thrust current converter that converts the thrust command value into a current command value, and the current command value A current command distributor to be assigned to two or more amplifiers, a current detector installed in the two or more amplifiers, and a current calculation for calculating a current value of a control rectangular coordinate system based on a control reference angle from a detected current of each amplifier vessels and a current controller for generating a voltage command value of the amplifier from the combined current and the current command value, the voltage amplitude calculator and the voltage phase calculator for calculating a phase for calculating the amplitude from the voltage command value A voltage calculator for calculating a voltage synthesized from voltage command values of the two or more amplifiers, a position / speed estimator for estimating a position error and a speed from the synthesized voltage and the synthesized current, Said From 置誤 difference is obtained so as to include a phase adjuster for adjusting the control reference angle.

According to a fourth aspect of the present invention, the movable element is provided with a permanent magnet, and power is sequentially supplied from at least two or more amplifiers to a stator winding that is continuously divided into a plurality of parts. In the sensorless linear motor control device that moves the child,
A voltage calculator for calculating a voltage synthesized from output voltages of the two or more amplifiers;
A current calculator for calculating a current synthesized from output currents of the two or more amplifiers;
A position speed estimator for estimating speed from the combined voltage and the combined current;
The integral value of the estimated speed and the mover magnetic pole position detected based on the position sensor information are switched to the integral value when the position sensor is not installed, and the detected value is detected when the position sensor is installed. A changeover switch for switching to the mover magnetic pole position;
A comparator for calculating an error of the mover magnetic pole position based on the integral value or the difference value between the detected mover magnetic pole position and the control reference angle;
A phase adjuster for adjusting a control reference angle based on an error of the mover magnetic pole position;
An amplifier switching pattern that maps a current ratio for allocating a command current corresponding to a command thrust from the estimated mover position and stator position, and the number of amplifiers to be driven,
A current command distributor that calculates a current command value to each amplifier based on the amplifier switching pattern;
Are provided.
According to a fifth aspect of the present invention, the phase adjuster according to any one of the first to fourth aspects is a filter or a PI controller.

According to the control device for a linear motor according to any one of claims 1 to 5 , at least two or more windings of a stator including a permanent magnet and continuously arranged in a plurality of divisions are provided. It is possible to provide a linear motor control device that realizes sensorless position speed estimation without thrust shock by switching when power is sequentially supplied from the amplifier.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of a linear motor control apparatus according to an embodiment of the present invention. The symbol EST represents an estimated value, and REF represents a command value.

  In FIG. 1, a mover 101 forms a pair of magnetic poles with permanent magnets, and moves on stators 201, 202,... .. Are connected to the stator windings to supply power. The current detectors 501, 502,... Detect currents for at least two phases of each amplifier, and the result is input to the controller 400. The controller 400 calculates a thrust command value required to move the mover 101 from the position command value and the speed command value, calculates a voltage necessary for generating the thrust for each amplifier, and instructs each amplifier. .

  FIG. 2 explains means for estimating the position speed in the controller 400 shown in FIG. The position / speed estimator receives as input the voltage obtained by synthesizing the output voltage command value of each amplifier and the current obtained by synthesizing the current detection value of each amplifier. The voltage calculator 402 receives as input the voltage command value of each amplifier generated by a current controller described later. The voltage command value of each amplifier is generated in the control orthogonal coordinate system, and is expressed by each scalar component of the γ-axis that is the control reference axis and the δ-axis that is orthogonal to the control reference axis as shown in Equation (1).

  The synthesis of these voltages is calculated as in Equation (2).

  On the other hand, the current calculator 405 inputs the current detected by each amplifier. When the detected current is only two phases, the three phases are calculated as shown in Equation (3), and the current in the control orthogonal coordinate system is calculated as shown in Equation (4) based on the control reference angle θ (REF2).

The synthesis of these currents must take into account the switching pattern of each amplifier. FIG. 3 shows an example of an amplifier switching pattern. The switching pattern is obtained by mapping a current ratio for assigning a command current corresponding to the command thrust to each amplifier from the estimated mover position and stator position and the number of amplifiers to be driven. In FIG. 3, the stator 1 is supplied with electric power from the amplifier 1, the stator 2 is supplied with electric power from the amplifier 2, and in order to simplify the explanation, the length of the mover is equal to the length of each stator. ing. At this time, the switching pattern gives the ratio of assigning the command current corresponding to the command thrust to each amplifier by Fg, and the ratio Fg1 to the amplifier 1 and the ratio Fg2 to the amplifier 2 are mapped in advance. When the mover is positioned exactly between the stator 1 and the stator 2, the current ratio of the amplifier 1 and the amplifier 2 is both 50%. Therefore, since the sum of the amplifier currents matches the command current, the combined current is calculated as shown in Equation (5).
Iγδ = Iγ + jIδ = (Iγ1 + Iγ2 +… + Iγn) + j (Iδ1 + Iδ2 +… + Iδn) (5)
However, a current command distributor, which will be described later, is required in order for Formula (5) to hold.
The actual magnetic pole position error of the mover can be calculated from the control axis from the combined voltage and combined current in the control rectangular coordinate system.
The position / speed estimator 403 applies a method based on the induced voltage estimation. The voltage-current equation of the motor is Equation (6)

Here, Rs is the stator winding resistance, Ld is the magnetic pole axis inductance, Lq is the inductance in the direction orthogonal to the magnetic pole axis, ω is the electrical angular velocity, Eγ is the γ axis component of the induced voltage in the control orthogonal coordinate system, and Eδ is Δ-axis component of the induced voltage in the control rectangular coordinate system, E is the amplitude of the induced voltage,
Δθ is an error angle between the control reference angle and the actual mover magnetic pole position.

  Therefore, assuming that the motor constant is known, the error angle Δθ is calculated as shown in Equation (7) based on Equation (6).

  The estimated speed value ω (EST) is calculated as in Expression (8) or Expression (9).

Here, Ke is an induced voltage constant, Kg and Kw are control adjustment gains, and τ is an integration time constant.
Equations (8) and (9) both estimate the speed so that the control reference axis and the actual magnetic pole position of the mover coincide with each other. The estimated speed value is replaced with ω in Equation (4) and is adjusted successively. To do. Although each motor constant is known, a value measured from each stator or a design value is used as the value. If the motor constants of the arranged stators are the same, the constants of one stator may be set in Equation (6), but if they are different, the constant change ratio is mapped in advance as in FIG. Alternatively, a level that is less affected by constant changes is verified on a trial basis, and an averaged fixed value, for example, is set.

  The phase adjuster 404 adjusts the first control reference angle θ (REF1) based on the estimated position error angle Δθ, and uses a filter, a PI controller, or the like. The output of the phase adjuster 404 is added by the control reference angle θ (REF1) and the adder 401, and the addition result is set as the second control reference angle θ (REF2).

FIG. 4 explains a second embodiment of the means for estimating the position speed in the controller shown in FIG. The difference from the first embodiment is that the speed estimated value ω (EST) calculated by the equation (6) is integrated by the integration calculator 406 and the result is calculated by the comparator 407 at the first control reference angle. This is where the deviation from θ (REF1) is calculated. The phase adjuster 404 adjusts the control reference angle θ (REF1) based on the estimated position error angle Δθ, and uses a filter, a PI controller, or the like. The output of the phase adjuster 404 is added by the control reference angle θ (REF1) and the adder 401, and the addition result is set as a new control reference angle θ (REF2). The second embodiment is characterized in that the calculation of Expression (7) can be omitted, so that the calculation of tan ⁻¹ is unnecessary. In both the first and second embodiments, the main control reference angle is the first control reference angle θ (REF1), and the position / speed estimator 403 has a function of calculating the correction amount. This is because the stator switches, and a switching thrust shock occurs when the estimated magnetic pole position is directly used as the control reference angle. Therefore, the control reference angle can be smoothly changed by using it as a correction amount so that the mover does not step out. Further, even if the correction amount is not accurate due to the influence of the setting error due to the motor constant, the influence on the control can be reduced by the phase adjuster 404.

  FIG. 5 explains a third embodiment of the means for estimating the position speed in the controller shown in FIG. The difference from the first and second embodiments is that a position or speed sensor is installed in a part of the stator along the traveling direction of the mover, and accurate positioning is performed based on the actual position θ (REAL) measured. In the case of implementation, since it is necessary to switch between the estimated magnetic pole position and the actually measured position in the sensorless drive section and the sensor-equipped drive section, a changeover switch 408 is added to cope with this. FIG. 5 corresponds to the second embodiment, but can also be applied to the first embodiment.

FIG. 6 is a control block diagram in the controller 400 shown in FIG. The speed controller 601 calculates a thrust command value F (REF) based on the speed command value ω (REF) and the speed estimated value ω (EST), and the thrust current converter thrusts on the thrust command value F (REF). Current command value multiplied by current conversion coefficient Iγδ (REF) = Iγ (REF) + jIδ (REF) (10)
It is to convert to. Usually, Iγ (REF) = 0 is commanded, but a command may be given to increase the magnetic flux. The current command distributor 603 calculates a current command value to each amplifier, and calculates a distribution ratio Fg based on the second control reference angle θ (REF2) from a preset switching pattern as shown in FIG. select. Based on the result, the calculation is performed as in Expression (11).

  Here, although two amplifiers are assumed, it can be expanded to a plurality of amplifiers as shown in Equation (11).

  The current control 604 calculates the voltage command value of each amplifier based on the current command value of each amplifier distributed by Expression (11) and the detected current of each amplifier in the control rectangular coordinate system calculated by Expression (4). It is. The voltage phase calculator 605 calculates the voltage phase in the control rectangular coordinate system from the voltage command value of each amplifier, and the voltage amplitude calculator 606 calculates the amplitude from the voltage command value of each amplifier. Each amplifier is instructed with a voltage amplitude, a voltage phase, and a control reference angle, and electric power is supplied to a stator based on the command.

  According to the present invention, a thrust shock is generated by switching when power is sequentially supplied from at least two or more amplifiers to a stator winding that is provided with a permanent magnet in a mover and is continuously arranged in a plurality of divisions. The position and speed can be estimated without a sensor, and a highly accurate positioning part is provided with a sensor, and the transport part can be moved without a sensor, so that a low-cost transport device can be provided. As an application, it can be used for a long-distance conveying apparatus such as a conveying apparatus for FA such as a semiconductor manufacturing apparatus and a machine tool, especially a glass substrate conveying application for manufacturing a liquid crystal display.

It is a structure of the control apparatus of the linear motor in one Embodiment of this invention. It is a figure explaining the 1st Example of the means to estimate the position speed in this invention. It is an example which shows the switching pattern of amplifier. It is a figure explaining the 2nd Example of the means to estimate the position speed in this invention. It is a figure explaining the 3rd Example of the means to estimate the position speed in this invention. It is a control block diagram in the present invention.

Explanation of symbols

101 Movable element 201 Stator 1
202 Stator 2
301 Amplifier 1
302 Amplifier 2
400 controller 401 adder 402 voltage calculator 403 position velocity estimator 404 phase adjuster 405 current calculator 406 integrator 407 comparator 408 changeover switch 501 current detector 1
502 Current detector 2
601 Speed controller 602 Thrust current converter 603 Current command distributor 604 Current controller 605 Voltage phase calculator 606 Amplitude calculator

Claims (5)

A sensorless linear motor that moves a mover by sequentially supplying electric power from at least two or more amplifiers to a stator winding that is provided with a permanent magnet in a mover and is continuously divided into a plurality of segments. In the control device,
A voltage calculator for calculating a voltage synthesized from output voltages of the two or more amplifiers;
A current calculator for calculating a current synthesized from output currents of the two or more amplifiers;
A position / speed estimator for estimating an error and speed of the mover magnetic pole position from the combined voltage and the combined current;
A phase adjuster for adjusting a control reference angle based on an error of the mover magnetic pole position;
An amplifier switching pattern that maps a current ratio for allocating a command current corresponding to a command thrust from the estimated mover position and stator position, and the number of amplifiers to be driven,
A current command distributor that calculates a current command value to each amplifier based on the amplifier switching pattern;
And a linear motor control device. A sensorless linear motor that moves a mover by sequentially supplying electric power from at least two or more amplifiers to a stator winding that is provided with a permanent magnet in a mover and is continuously divided into a plurality of segments. In the control device,
A voltage calculator for calculating a voltage synthesized from output voltages of the two or more amplifiers;
A current calculator for calculating a current synthesized from output currents of the two or more amplifiers;
A position speed estimator for estimating speed from the combined voltage and the combined current;
A comparator that calculates an error of the mover magnetic pole position based on a difference value between the integral value of the estimated speed and the control reference angle;
A phase adjuster for adjusting a control reference angle based on an error of the mover magnetic pole position;
An amplifier switching pattern that maps a current ratio for allocating a command current corresponding to a command thrust from the estimated mover position and stator position, and the number of amplifiers to be driven,
A current command distributor that calculates a current command value to each amplifier based on the amplifier switching pattern;
And a linear motor control device. A sensorless linear motor that moves a mover by sequentially supplying electric power from at least two or more amplifiers to a stator winding that is provided with a permanent magnet in a mover and is continuously divided into a plurality of segments. In the control device,
A speed controller that generates a thrust command value based on the speed estimated by the position / speed estimator and a speed command value, a thrust current converter that converts the thrust command value into a current command value, and the current command value A current command distributor to be assigned to two or more amplifiers, a current detector installed in the two or more amplifiers, and a current calculation for calculating a current value of a control rectangular coordinate system based on a control reference angle from a detected current of each amplifier a vessel, and a current controller which generates a voltage command value of the amplifier from the combined current and the current command value, a voltage phase calculator for calculating the amplitude calculator and the phase for calculating the amplitude from the voltage command value A voltage calculator for calculating a voltage synthesized from voltage command values of the two or more amplifiers; a position / speed estimator for estimating a position error and a speed from the synthesized voltage and the synthesized current; position Control system for a linear motor, characterized in that a phase regulator for regulating the control reference angle from the difference. A sensorless linear motor that moves a mover by sequentially supplying electric power from at least two or more amplifiers to a stator winding that is provided with a permanent magnet in a mover and is continuously divided into a plurality of segments. In the control device,
A voltage calculator for calculating a voltage synthesized from output voltages of the two or more amplifiers;
A current calculator for calculating a current synthesized from output currents of the two or more amplifiers;
A position speed estimator for estimating speed from the combined voltage and the combined current;
The integral value of the estimated speed and the mover magnetic pole position detected based on the position sensor information are switched to the integral value when the position sensor is not installed, and the detected value is detected when the position sensor is installed. A changeover switch for switching to the mover magnetic pole position;
A comparator for calculating an error of the mover magnetic pole position based on the integral value or the difference value between the detected mover magnetic pole position and the control reference angle;
A phase adjuster for adjusting a control reference angle based on an error of the mover magnetic pole position;
An amplifier switching pattern that maps a current ratio for allocating a command current corresponding to a command thrust from the estimated mover position and stator position, and the number of amplifiers to be driven,
A current command distributor that calculates a current command value to each amplifier based on the amplifier switching pattern;
And a linear motor control device.   5. The linear motor control device according to claim 1, wherein the phase adjuster is a filter or a PI controller.