KR20190000004A - Moving magnet encoderless linear motor and control method using the same - Google Patents

Abstract

The present invention relates to a permanent magnet moving type encoderless linear motor and a control method using the same. The permanent magnet moving type encoderless linear motor has no limits for a moving range by configuring a mover with a magnet plate and reduces costs without using an encoder and a resolver. According to an embodiment of the present invention, the permanent magnet moving type encoderless linear motor comprises: a stator; a mover; and a sensor board including a plurality of linear hall sensors.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a permanent magnet moving type encoderless linear motor,

The present invention relates to a permanent magnet moving type encoderless linear motor and a control method using the same. Specifically, the moving distance is measured by using a linear hall sensor constituted by a magnet plate, To a permanent magnet moving type encoderless linear motor and a control method using the same.

The linear motor can generate linear driving force, and it can be operated at high speed and constant speed because it performs linear driving by non-contact type motion method. Also, it is used in transportation systems in various industrial fields because of its advantage of being able to operate precisely.

A general linear motor includes a stator in which a permanent magnet is disposed alternately in polarity and a mover in which a mover coil is wound on a mover core. The mutual relationship between the magnetic force generated in the mover coil and the magnetic force of the permanent magnet as current is applied to the mover coil A linear thrust is generated by the action.

On the other hand, in the linear motor, the velocity and position information of the mover must determine the moment when the magnetic force is generated in the stator and are essential information of the system for magnetic flux and torque control, so that the velocity and position information of the mover must be accurately detected. When the position information of the mover is not accurately detected at the time of driving the linear motor, it is difficult to move to the required correct position and the stability of the thrust and speed is deteriorated. Therefore, in the linear motor, the absolute position of the mover (position relative to an arbitrary coordinate reference point) and the movement position must be accurately detected.

An optical position sensor such as an encoder or a resolver is mainly used for measuring the velocity and position information of the mover of the linear motor. However, there are problems in size and durability, and there are difficulties in assembly.

Further, in order to detect the position information of the mover in the linear motor, the phase of the mover is detected by using a linear hall sensor which is provided on the mover side and measures the magnetic flux of the permanent magnet of the stator, and the linear scale and the mover And a sensor head for detecting the linear scale is used to detect the moving position of the mover.

In most linear motors, the mover coil is moved by the thrust of the straight line generated by the interaction between the magnetic force generated in the mover coil and the magnetic force of the permanent magnet. Therefore, when such a linear motor is used for transportation such as a shaft of a machine tool, an optical inspection equipment, or a semiconductor transfer device, there is a problem that it is difficult to apply a load or an object when the object is transferred horizontally or vertically.

In addition, when using an encoder and a linear scale, the price is expensive and can be used only in a limited range. For example, there is a problem that the encoder and linear scale used in a machine tool or a refueling facility are not able to be used in such a place because they cause trouble due to condensation or dust.

Korean Patent No. 10-0720942 (May 16, 2007)

SUMMARY OF THE INVENTION An object of the present invention is to provide a permanent magnet moving type encoderless linear motor and a control method using the permanent magnet moving type, in which the magnet plate is constituted by a mover.

Another object of the present invention is to provide a permanent magnet moving type encoderless linear motor which can reduce costs without using an encoder and a linear scale, and a control method using the same.

It is still another object of the present invention to provide a permanent magnet moving type encoderless system which can stably and efficiently control precisely within a rated speed range by estimating the velocity and position of a mover by employing a vector control method using two linear Hall sensors A linear motor and a control method using the same.

In the permanent magnet moving type encoderless linear motor according to the embodiment of the present invention,

A stator including a stator core having a plurality of main teeth formed therein and a stator coil wound around the main teeth and supplying a current, a magnet plate, and a plurality of permanent magnets alternately arranged on the lower surface of the magnet plate, And a plurality of linear hall sensors positioned in the longitudinal direction of the moving direction of the mover capable of measuring the moving position and the velocity of the permanent magnet and the sensor board.

The plurality of linear hall sensors may include a first linear hall sensor for reading the phase of the magnetic flux of the permanent magnet and a second linear hall sensor positioned adjacent to the first linear hall sensor for sensing the movement of the magnet plate .

The linear hall sensor senses the magnetic flux according to the polarity of each permanent magnet through the plurality of linear hall sensors to generate a sinusoidal analog signal with respect to a change in polarity of each permanent magnet, and converts the sinusoidal analog signal into a pulse signal And a control unit for controlling the movement distance of the mover using the pulse signal.

In addition, the controller drives the mover from a predetermined reference position at a constant speed, sequentially scans the length between the permanent magnets with the plurality of linear hall sensors, multiplies the sinusoidal analog signal output through the plurality of linear hall sensors the unit pole pitch information corresponding to the length of each permanent magnet is calculated by multiplying the unit pole pitch information by the multiflying unit, and the signal processing unit further includes a memory unit for storing the unit pole pitch information, Can be moved to a pitch unit (n units X pole pitch, n is a natural number).

Further, as the first linear hall sensor and the second linear hall sensor generate a square wave signal at intervals of 90 degrees, a time point at which each signal is simultaneously raised or lowered is detected, and the number of pulses counted between the rising and falling signals The moving speed of the mover,

 (Where m is the number of pulses of 20 [kHz] counted between the rising and falling signals of the linear hall sensor for velocity measurement, and Ppair is the unit pole pitch corresponding to the length between the permanent magnets)

Lt; / RTI >

In addition, the rectangular wave signal generated by the linear hall sensor can be interpolated using the DSP controller of the sensor board.

A method of controlling a permanent magnet moving type encoderless linear motor according to an embodiment of the present invention includes a stator including a stator core having a plurality of main teeth formed therein and a stator coil wound around the main teeth and supplying a current, And a plurality of permanent magnets arranged alternately in the lower surface of the rotor, wherein the permanent magnets are linearly driven by interaction with the stator, A plurality of linear hall sensors positioned adjacent to the first linear hall sensor and sensing a movement of the magnet plate, the first linear hall sensor positioned to read the phase of the magnetic flux of the permanent magnet, and the second linear hall sensor positioned adjacent to the first linear hall sensor, A magnetic flux according to the polarity of each of the permanent magnets is linearly A signal processor for generating a sinusoidal analog signal with respect to a change in polarity of each of the permanent magnets and converting the sinusoidal analog signal into a pulse signal and a control unit for controlling the movement distance of the mover using the pulse signal, A method of controlling a permanent magnet moving type encoderless linear motor, comprising the steps of: initializing the permanent magnet moving type encoderless linear motor when initial power is applied;

Wherein the signal processing unit linearly senses a magnetic flux corresponding to a polarity of each of the permanent magnets through the plurality of linear Hall sensors to generate a sinusoidal analog signal with respect to polarity changes of the respective permanent magnets, Converting the analog signal into a pulse signal, and controlling the control unit to move the mover to a moving distance of a unit pole pitch unit (n units × unit pole pitch, n is a natural number) using the pulse signal .

In addition, the step of controlling the controller to move the mover to a movement distance of a unit pole pitch unit (n X unit pole pitch, n is a natural number) may be performed by synchronizing the first linear hall sensor and the second linear hall sensor signal Step < / RTI >

The permanent magnet moving type encoderless linear motor according to the present invention has an advantage that the moving range is expanded because a current supply line is not required by constituting the magnet plate as a mover.

In addition, the permanent magnet moving type encoderless linear motor according to the present invention can be expected to have a cost-saving effect by using a linear hall sensor without using an encoder or a linear scale.

Further, the permanent magnet moving type encoderless linear motor according to the present invention has an advantage that it can be used in an industrial environment where turbidity is caused by condensation or dust without using a conventional encoder or linear scale.

1 is a block diagram showing the configuration of a permanent magnet moving type encoderless linear motor according to an embodiment of the present invention.
2 is a view illustrating a structure of a permanent magnet moving type encoderless linear motor according to an embodiment of the present invention.
3 is a diagram showing signals and rising and falling detection signals generated by the first linear hall sensor and the second linear hall sensor.
Fig. 4 is a view showing the velocity measurement using the rising and falling detection signals and the counter signals generated in the linear hall sensor.
Fig. 5 is a diagram showing a rise and fall time detection circuit of the linear Hall sensor signal. Fig.
6 is a diagram for explaining the distance detection using the counter signal and the motor U phase.
7 is a view illustrating signals interpolated in the permanent magnet array of the permanent magnet moving type encoderless linear motor according to the embodiment of the present invention.
8 is a view showing positions of pole pairs of the mover according to signals interpolated in the permanent magnet array.
9 is an overall control block diagram of a magnet mover of a permanent magnet moving type encoderless linear motor according to an embodiment of the present invention.
10 is a block diagram of a sensor system for velocity calculation and position estimation of a mover in accordance with an embodiment of the present invention.
11 is a block diagram illustrating positional correction of a magnet plate of a mover according to an embodiment of the present invention.
12 is a graph showing speed and rated thrust of a permanent magnet moving type encoderless linear motor according to an embodiment of the present invention.
13 is a simulation of a permanent magnet moving type encoderless linear motor according to an embodiment of the present invention.
14 is a graph showing the detection waveform of the linear hall sensor.
Fig. 15 is a diagram showing a change in the position of the permanent magnet due to the movement of the mover.
16 is a graph showing signals of the linear Hall sensor as the mover moves.
17 to 19 are views showing a permanent magnet moving type encoderless linear motor using a plurality of magnet plates according to another embodiment of the present invention.
20 is a flowchart illustrating a method of controlling the permanent magnet moving type encoderless linear motor according to an embodiment of the present invention.
FIG. 21 is a detailed flowchart of the initialization step of the permanent magnet moving type encoderless linear motor according to the embodiment of the present invention shown in FIG. 20. FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout.

In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. It is to be noted that the accompanying drawings are only for the purpose of facilitating understanding of the present invention, and should not be construed as limiting the scope of the present invention with reference to the accompanying drawings.

1 is a block diagram showing the configuration of a permanent magnet moving type encoderless linear motor according to an embodiment of the present invention. 2 is a view illustrating a structure of a permanent magnet moving type encoderless linear motor according to an embodiment of the present invention.

1 and 2, a permanent magnet moving type encoderless linear motor according to an embodiment of the present invention includes a stator 10, a mover 20, and a sensor board 30, and includes a signal processing unit 40, And may further include a control unit 50.

The permanent magnet moving type encoderless linear motor 100 according to an embodiment of the present invention includes a stator core 12 formed with a plurality of main teeth (not shown) and a stator coil 14 wound around the main teeth and supplying current And a plurality of permanent magnets 22 whose polarities are alternately arranged on the lower surfaces of the stator 10, the magnet plate 22 and the magnet plate 22 and which are linearly driven by interaction with the stator 10 A sensor board (30) comprising a plurality of linear hall sensors (32) positioned in the longitudinal direction of the mover (20) and the moving direction of the mover (20) capable of measuring the moving position and velocity of the permanent magnet (22) . ≪ / RTI >

The stator 10 includes a stator core 12 having a plurality of main teeth formed therein and a stator coil 14 wound around the main teeth and supplying current (for example, currents of three phases (U, V, W) can do. A linear thrust is generated due to the interaction between the magnetic force generated in the stator coil 14 and the magnetic force of the permanent magnet 24 as a current is applied to the stator coil 14. [

The corner portion of the main body may be chamfered to reduce the detent force due to the main teeth of the stator 10. [ In some cases, a structure may be employed in which the edge of the permanent magnet 24 is chamfered instead of the main tooth to reduce the detent force due to the main tooth, or the tip is formed at the corner of the main tooth. The present invention is not limited or limited by the structure of the main tooth and the permanent magnet 24 and their arrangement structure.

The mover 20 may include a permanent magnet 24 whose polarity is alternately arranged on the lower surface of the magnet plate 22 and the magnet plate 22. [

The sensor board 30 is disposed on the stator 10 on both sides in a direction perpendicular to the moving direction of the mover 20 and may include a plurality of linear hall sensors 32. [

The plurality of linear hall sensors 32 are positioned in the longitudinal direction of the moving direction of the mover 20 so that the moving position and velocity of the permanent magnet 24 can be measured. On the other hand, a plurality of linear hall sensors 32 can be directly mounted on the stator 10 by two pairs so as to have a phase difference of 90 degrees. At this time, the arrangement and mounting structure of the plurality of linear hall sensors 32 can be variously changed according to required conditions and design specifications.

The plurality of linear hall sensors 32 are disposed adjacent to the first linear hall sensor A and the first linear hall sensor A capable of reading the phase of the magnetic flux of the permanent magnet 24, And a second linear hall sensor (B) for sensing the movement of the plate (22). As the linear Hall sensor 32 generates a square wave, the permanent magnet 24 of the mover 20 is sensed.

As described above, the permanent magnet moving type encoderless linear motor according to the embodiment of the present invention can replace the role of the encoder by reading the phase of the magnetic flux of the permanent magnet 24 by the linear Hall sensor 32. [ In addition, a digital signal processor (DSP) controller can be used to interpolate a signal input to the linear hall sensor 32 to perform an encoder function.

The linear Hall sensor 32 is a linear Hall sensor that outputs a magnetic flux according to the polarity of each permanent magnet 24 in a linear manner, unlike a conventional Hall sensor that simply outputs a change in polarity of the permanent magnet 24 as an on / off signal. And generates a sine curve analog signal with respect to a change in polarity of each permanent magnet 24.

The signal processing unit 40 processes the signal sensed by the linear hall sensor 32 into a specific signal. That is, the signal processing unit 40 linearly senses the magnetic flux according to the polarity of each permanent magnet 24 through the linear hall sensor 32 and outputs a sinusoidal analog signal to the polarity change of each permanent magnet 24, Signal, and converts the sinusoidal analog signal into a pulse signal. In addition, the signal processing unit 40 may include a memory unit 42 for storing unit pitch information, which will be described later.

The control unit 50 can control the driving (moving distance) of the mover 20 through a normal sub-driver by using the pulse signal processed in the signal processing unit 40. [

After the mover 20 is placed at a predetermined reference position, the mover 20 is driven at a constant speed to sequentially scan the lengths of all the permanent magnets 24.

The lengths L1, L2, L3, ..., Ln between the permanent magnets 24 can be detected using signals detected by the linear hall sensor 32 while the permanent magnets 24 are being scanned, A sinusoidal analog signal with respect to a change in the polarity of the permanent magnet 24 can be output through the signal line 32.

The sinusoidal analog signal output at this time is multiplied to calculate the unit pole pitch corresponding to the length between the permanent magnets 24. A method of calculating the unit pole pitch by multiplying the sinusoidal analog signal may be applied to various methods depending on required conditions and processing environments.

In addition, the unit pole pitches P1, P2, P3, ... can be separately calculated for each of the lengths of the permanent magnets 24. 10, when the length sections L1, L2, L3, ..., Ln of the respective permanent magnets 24 have different lengths, the respective sections L1, L2, L3 ... Ln have different lengths. The unit pole pitches P1, P2, P3,... Corresponding to the pitches Ln may be calculated to have different lengths (widths) (P1? P2? P3 ...).

The unit pole pitch P 'is calculated by dividing the unit pole pitch P' between the permanent magnets 24 and the unit pole pitch P ' Can be calculated on the basis of the entire length as averages. That is, when the length sections L1, L2, L3 ... Ln between the permanent magnets 24 have different lengths, the unit pole pitch corresponding to each of the sections L1, L2, L3 ... Ln is Can be calculated to have the same length (width) (P ').

The calculated unit pole pitch information may be stored in the memory unit 42 and the mover 20 may calculate the unit pole pitch information based on the unit pole pitch information stored in the memory unit 42, Pitch, n = 1, 2, 3 ...).

Meanwhile, in the step of calculating the unit pole pitch by multiplying the sinusoidal analog signal, the sinusoidal analog signal can be multiplied by various bits according to required conditions and design specifications. The precision of the sinusoidal analog signal can be improved as the sine wave of the sinusoidal analog signal increases. However, since the signal amount to be processed increases as the sinusoidal analog signal increases, the driving speed of the mover 20 may decrease. It should be able to be done properly according to the required conditions and design specifications.

In addition, although the mover 20 may be driven on the basis of the unit pole pitch information described above in the operation of the permanent magnet moving type encoderless linear motor according to the embodiment of the present invention, when the permanent magnet moving type encoderless linear motor 100 is driven, If the power is turned off or rebooted during the driving of the motor, the motor may be driven after the initialization step described above is performed again.

Thereafter, the movement distance of the mover 20 can be controlled using the pulse signal. That is, the phase of the mover 20 can be detected by counting the intersection points of the pulse signals of the two detected first linear hall sensors A and second linear hall sensors B, respectively. The two sinusoidal analog signals thus detected can be combined through an ordinary calculation method to generate an input analog signal. By converting the input analog signal into a pulse signal, an input pulse signal necessary for driving the mover 20 is calculated can do. Therefore, the moving distance of the mover 20 can be controlled by the number of input pulse signals. In addition, the combination of the two sinusoidal analog signals can be implemented by a conventional calculation method, and the present invention is not limited or limited by the types and characteristics of the calculation methods.

Conventionally, the phase of the mover with respect to the permanent magnet 24 is checked using a general Hall sensor that outputs a change in the polarity of the magnet simply as an on / off signal, and the movement amount of the mover The moving distance of the mover 20 can be controlled by using the linear Hall sensor 32 which excludes the linear scale and senses the permanent magnet 24. [ In addition, the phase of the mover 20 with respect to the permanent magnet 24 is confirmed by using the sinusoidal analog signal detected through the linear Hall sensor 32, and the input pulse signal is calculated to calculate the movement amount of the mover 20 Can be controlled.

The permanent magnet moving type encoderless linear motor according to an embodiment of the present invention measures the velocity using square waves generated at intervals of 90 degrees in the two linear Hall sensors 32.

3 is a diagram showing signals and rising and falling detection signals generated in a pair of linear hall sensors. FIG. 4 is a view showing the velocity measurement using the rising and falling detection signals and the counter signals in the linear hall sensor, and FIG. 5 is a diagram showing the rising and falling time detection circuits of the linear hall sensor.

As shown in FIG. 3, the first linear hall sensor A and the second linear hall sensor B detect a rising or falling portion of a square wave signal generated at intervals of 90 degrees, and determine a signal measuring cycle based on the detected signal do. At this time, the detected signal serves as a rising edge of the T-system for measuring the pulse interval of the encoder.

Referring to FIG. 4, the number of pulses of the predetermined frequency generated in the circuit configured for each detection signal, that is, the number of pulses of 20 [kHz] is 32,767.

5, when the linear hall sensor signal is calculated by the logical operator XOR through the D-flipflop, the first linear hall sensor A and the second linear hall sensor B, Signal can be obtained.

When the counter signal for speed measurement is decomposed to 20 [kHz] by using a logic circuit, the signals of the first linear hall sensor A and the second linear hall sensor B rise or fall The period of the signal for detecting the viewpoint is expressed by the following equation (1).

(1)

(One)

Here, m represents the number of pulses of 20 [kHz] counted between the rising and falling signals of the linear Hall sensor 32 for velocity measurement.

If the period of equation (1) is changed to the equation of frequency, equation (2) is obtained.

(2)

(2)

The moving speed of the mover 20 of the permanent magnet moving type encoderless linear motor 100 according to the embodiment of the present invention using the frequency of the equation (2) is obtained as shown in equation (3).

Here, Ppair represents the unit pole pitch corresponding to the length between the permanent magnets 24. The position of the mover 20 can be obtained by integrating the moving speed of the mover 20 of the permanent magnet moving type encoderless linear motor 100 according to the embodiment of the present invention by using Equation (3).

Meanwhile, the permanent magnet moving type encoderless linear motor 100 according to the embodiment of the present invention can calculate the unit pole pitch of the magnet plate 22 using the signals detected through the two linear hall sensors 32 And the machining error, the manufacturing error, and the drive error of the permanent magnet 24 can be corrected.

6 is a view for explaining the distance detection using the counter signal and the motor U phase, and FIG. 7 is a diagram showing a signal interpolated in the arrangement of the permanent magnets 24 of the permanent magnet type synchronous linear motor according to the embodiment of the present invention And FIG. 8 is a view showing positions of pole pairs of the mover according to signals interpolated in the permanent magnet array.

In other words, it is not easy to obtain a high precision because the arrangement between the permanent magnets 24 is generally not constant due to processing errors and manufacturing errors. However, as shown in FIG. 6, It can be displayed linearly from 0 to 32767, and the distance of the motor can be precisely calculated by aligning the starting point of the counter with the U phase of the motor.

Referring to FIG. 7, there is shown a sinusoidal / cosine waveform generated from a permanent magnet 24 of a permanent magnet moving type encoderless linear motor 100 according to an embodiment of the present invention. The interpolated signal can be confirmed. The interpolated signal can be used to acquire high resolution data, and the high resolution data can precisely control the position and speed of the mover 20.

Referring to FIG. 8, the positions of the pole pairs of the mover are shown according to signals interpolated in the arrangement of the permanent magnets 24, and the arrangement of the permanent magnets 24 in which the four poles of the NSNS are composed of 360 degrees is shown have. This N-S-N-S period can precisely interpolate the distance by arranging the linear hall sensor 32 at a phase difference of 90 degrees. In this regard, a method of calculating the unit pole pitch using the signals detected by the linear hall sensor 32 by sequentially scanning the lengths of all the permanent magnets 24 has been described.

9 is an overall control block diagram of a magnet mover of a permanent magnet moving type encoderless linear motor according to an embodiment of the present invention.

9, a permanent magnet moving type encoderless linear motor 100 according to an embodiment of the present invention includes a linear hall sensor 32 The position and speed of the mover 20 can be measured. Since the magnetic plate 22 moves in this manner, the self-load is reduced, so that the torque control with quick transient response of the permanent magnet type synchronous linear motor 100 is possible.

10 is a block diagram of a sensor system for velocity calculation and position estimation of a mover. Referring to FIG. 10, the position of the mover 20 can be confirmed by receiving signals from the linear hall sensors 32 of the sensor board 30. In addition, the DSP controller MICOM transfers the input signal to the host controller DRIVE, and the host controller calculates the speed and the position of the mover 20.

FIG. 11 is a block diagram showing a positional correction of a magnet plate of a mover according to an embodiment of the present invention, and shows a method of obtaining positional information of the mover 20 by integrating a velocity using Equation (3).

At this time, in the case of the reset signal (1) in Fig. 11, when the signal detecting the rising or falling time of the signals of the first linear hall sensor (A) and the second linear hall sensor (B) Lt; / RTI > 11, when the signal of the first linear hall sensor A rises, it is initialized to the integral output when it is input at intervals of 360 degrees. This is to correct the position of the mover through the signal of the linear hall sensor 32 inputted at 90 degrees and every 360 degrees.

12 is a graph showing speed and rated thrust of a permanent magnet moving type encoderless linear motor according to an embodiment of the present invention. Referring to FIG. 12, the position of the mover 20 can be confirmed by receiving signals from the first linear hall sensor A and the second linear hall sensor B.

Table 1 shows specifications such as the rating and parameters of the permanent magnet moving type encoderless linear motor used in the experiment.

When the time for driving the permanent magnet moving type encoderless linear motor 100 is calculated using the parameters in Table 1, equation (4) is obtained.

T = ta + tf + td + tdwell (4)

In this case, tf is a constant speed section.

(5) is obtained by calculating the rated thrust of the permanent magnet moving type encoderless linear motor according to the embodiment of the present invention in accordance with the driving time.

(5)

(5)

In this way, the rated thrust and the maximum thrust of the motor are calculated and the permanent magnet moving type encoderless linear motor 100 is selected. Referring to FIG. 12, as a result of the simulation using Equations (1) to (5), the speed and the rated thrust of the permanent magnet moving type encoderless linear motor 100 can be confirmed.

13 is a diagram showing a simulation of a permanent magnet moving type encoderless linear motor according to an embodiment of the present invention. This was simulated using the MAXWELL program.

14 is a graph showing the detection waveform of the linear hall sensor. The waveforms of the signals detected by the first linear hall sensor A and the second linear hall sensor B are detected.

14, when the waveforms of the first linear hall sensor A and the second linear hall sensor B are kept at an interval of 90 degrees, the rise and fall signals of the signals of the linear Hall sensors 32 are detected Can be confirmed. It can also be seen that the signals of the first linear hall sensor A and the second linear hall sensor B are corrected at regular intervals according to the position of the mover 20. This is because, when the position of the mover 20 is obtained by integrating the speed, the position of the mover is corrected through the signal inputted every 90 degrees.

Fig. 15 is a view showing a change in the position of the permanent magnet due to the movement of the mover. The mover 20 moves the motor UVW image signal from the stator coil i (Motor Coil i) to the stator coil k (Motor Coil k) . When the UVW phase signal is synchronized, the same signal is generated from that point and the position is corrected.

16 is a graph showing a signal of the linear Hall sensor according to the movement of the mover. When the mover 20 moves, the signal of the first linear hall sensor A is synchronized with the signal of the second linear hall sensor B, The movement of the magnet plate 22 can be grasped precisely. At this time, the magnet plate 22 can be stopped at an arbitrary position, and when it is stopped, a brake signal is generated at a position where the magnet plate 22 stops.

In an embodiment of the present invention, the pitch of the magnet plate is set to 30 mm, multiplied by four using a DSP controller, and the feed rate is driven at a minimum of 100 mm / sec to a maximum of 1 to 2 m / sec.

Table 2 compares the performance of the conventional linear motor and the permanent magnet moving type encoderless linear motor 100 according to an embodiment of the present invention. According to one embodiment of the present invention, It can be seen that it is much improved than the linear motor.

The conventional linear motor has been measured using an encoder and a linear scale in order to measure the distance of travel. However, the permanent magnet moving type encoderless linear motor 100 according to an embodiment of the present invention includes a linear hall sensor (32) signal by using a DSP controller to perform interpolation.

17 to 19 are views showing a permanent magnet moving type encoderless linear motor using a plurality of magnet plates according to another embodiment of the present invention. The permanent magnet moving type encoderless linear motor according to another embodiment of the present invention may be used in a vacuum environment as shown in FIG. 18, or may constitute a curved loop as shown in FIG.

The permanent magnet moving type linear motor according to the present invention can be used in various fields such as various conveying devices, product assembly and process automation devices, food processing, aseptic filling, etc. since the magnet plate 22 constitutes the mover 20 have. In particular, since the plurality of magnet plates 22 constitute the mover 20 and individual speed control can be performed for each mover 20, high-speed operation can be realized, thereby improving productivity. Further, the permanent magnet moving type encoderless linear motor according to the present invention can be extended to a semiconductor and a fast recovery diode (FRD) process requiring a high temperature, high vacuum, and clean room environment.

The permanent magnet moving type encoderless linear motor 100 according to the embodiment of the present invention detects the moving position and velocity of the magnet plate 22 using the linear hall sensor 32 and also detects the error of the generated position It is possible to compensate through the position of the encoder-less method. Therefore, the accuracy is high, the error range is small, and it is efficient. Because it can be applied to a system that is structurally difficult to install encoders or resolvers, an effective and economical FA (factory automation) system or a logistics system can be realized.

The control method of the permanent magnet moving type encoderless linear motor according to the embodiment of the present invention is as follows. 20 is a flowchart for explaining a control method of the permanent magnet moving type encoderless linear motor. 21 is a detailed flowchart according to the initialization step of the permanent magnet moving type encoderless linear motor of Fig.

In step S10, the permanent magnet moving type encoderless linear motor 100 is initialized upon initial power application.

In step S20, the signal processing unit 40 linearly senses the magnetic flux corresponding to the polarity of each permanent magnet 24 through the plurality of linear hall sensors 32 and outputs a sinusoidal wave sine curve) to generate an analog signal.

In step S30, the signal processing unit 40 converts the sinusoidal analog signals generated by the plurality of linear Hall sensors 32 into pulse signals.

In step S40, the control unit 50 uses the pulse signal to control the mover to move to a moving distance of a unit pole pitch unit (n X unit pole pitch, n is a natural number).

On the other hand, the step S10 of initializing the permanent magnet moving type encoderless linear motor 100 is performed in such a manner that the interval between the permanent magnets 24 is difficult to have a high accuracy higher than a certain level due to processing errors and manufacturing errors of the permanent magnets 24 This is for correcting the drive error of the mover 20 due to the error of the permanent magnet.

4, the initialization step S10 of the permanent magnet moving type encoderless linear motor includes a step S11 of placing the mover 20 at a preset reference position, a step of driving the mover 20 at a constant speed, (Step S13) of scanning the length between the permanent magnets 24 by the sensor 32 and multiplying the sinusoidal analog signal output through the linear hall sensor 32 to correspond to the length between the permanent magnets 24 A step S15 of calculating a unit pole pitch at which the calculated unit pole pitch is calculated and a step S17 of storing the calculated unit pole pitch in the memory unit 42. [

The step of calculating the unit pole pitch by multiplying the sinusoidal analog signal (S15) may be performed in various manners depending on the required conditions and the processing environment. For example, the step (S15) of calculating the unit pole pitch includes a step of generating an input analog signal by calculating a sinusoidal analog signal, and a step of converting the input analog signal to calculate a unit pole pitch corresponding to the input pulse signal can do.

In addition, in step S15 of calculating the unit pole pitch, the unit pole pitches P1, P2, P3, ... may be separately calculated for respective lengths of the respective permanent magnets 24. In addition, the unit pole pitch P 'can be calculated on the basis of the entire length between the permanent magnets 24 on average.

Meanwhile, in step S15 of multiplying the sine wave analog signal and calculating the unit pole pitch, the sinusoidal analog signal can be multiplied by various bits in accordance with required conditions and design specifications. The precision of the sinusoidal analog signal can be improved as the sine wave of the sinusoidal analog signal increases. However, since the signal amount to be processed increases as the sinusoidal analog signal increases, the driving speed of the mover 20 may decrease. It should be able to be done properly according to the required conditions and design specifications.

The embodiments and the accompanying drawings are merely illustrative of some of the technical ideas included in the present invention. Therefore, it is to be understood that the embodiments disclosed herein are not intended to limit the scope of the present invention but to limit the scope of the present invention. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents. It should be interpreted.

10: Stator
12: Stator core
14: Stator coil
20: mover
22: magnet plate
24: permanent magnet
30: Sensor board
32: Linear Hall sensor
40: Signal processor
42:
50:
100: Permanent magnet moving type encoderless linear motor

Claims (8)

A stator including a stator core formed with a plurality of main teeth and a stator coil wound around the main teeth and supplying a current;
A mover comprising a plurality of permanent magnets arranged alternately in polarity on the lower surface of the magnet plate and the magnet plate and linearly driven by interaction with the stator; And
And a sensor board including a plurality of linear hall sensors positioned in a lengthwise direction of a moving direction of the mover, which can measure a moving position and a velocity of the permanent magnet. The method according to claim 1,
The plurality of linear hall sensors
A first linear hall sensor for reading the phase of the magnetic flux of the permanent magnet; And
And a second linear hall sensor positioned adjacent to the first linear hall sensor for sensing movement of the magnet plate. 3. The method of claim 2,
A linear hall sensor for linearly sensing a magnetic flux according to a polarity of each permanent magnet through the plurality of linear hall sensors to generate a sinusoidal analog signal with respect to a change in polarity of each permanent magnet and converting the sinusoidal analog signal into a pulse signal A processor; And
And a controller for controlling the movement distance of the mover using the pulse signal. The method of claim 3,
Wherein the controller drives the mover from a preset reference position at a constant speed to sequentially scan the length between the permanent magnets with the plurality of linear hall sensors and to multyflying the sinusoidal analog signal output through the plurality of linear hall sensors, A unit pole pitch corresponding to a length between the permanent magnets is calculated,
Wherein the signal processing unit further includes a memory unit for storing the unit pole pitch information,
Wherein the controller moves the mover to the unit pole pitch unit (n pieces × unit pole pitch, n is a natural number). 3. The method of claim 2,
As the first linear hall sensor and the second linear hall sensor generate a square wave signal at intervals of 90 degrees, a time point at which each signal is simultaneously raised or lowered is detected, and the number of pulses counted between the rising and falling signals is used The moving speed of the mover,

(Where m is the number of pulses of 20 [kHz] counted between the rising and falling signals of the linear hall sensor for velocity measurement, and Ppair is the unit pole pitch corresponding to the length between the permanent magnets)
Permanent magnet moving type encoderless linear motor. 6. The method of claim 5,
A permanent magnet moving type encoderless linear motor for interpolating a rectangular wave signal generated by the linear hall sensor by using a DSP controller of the sensor board. A stator including a stator core having a plurality of main teeth formed therein and a stator coil wound around the main teeth and supplying a current, a magnet plate, and a plurality of permanent magnets alternately arranged on the lower surface of the magnet plate, A first linear hall sensor which is located in the longitudinal direction of the moving direction of the mover to read the phase of the magnetic flux of the permanent magnet so as to measure the moving position and the velocity of the permanent magnet, A plurality of linear hall sensors disposed adjacent to the linear Hall sensor and including a second linear hall sensor for sensing the movement of the magnet plate, and a plurality of linear hall sensors disposed linearly along the polarities of the respective permanent magnets And generates a sinusoidal analog signal for the polarity change of each permanent magnet In a signal processing unit and a control method of a permanent magnet movable encoder-less linear motor comprising a controller for controlling the moving distance of said movement, using the pulse signal to convert the sine wave analogue signal to a pulse signal,
Initializing the permanent magnet moving type encoderless linear motor when initial power is applied;
The signal processing unit linearly sensing a magnetic flux according to a polarity of each of the permanent magnets through the plurality of linear Hall sensors and generating a sinusoidal analog signal with respect to a change in polarity of each permanent magnet;
Converting the sinusoidal analog signal into a pulse signal;
Controlling the permanent magnet moving type encoderless linear motor using the pulse signal to control the mover to move to a movement distance of unit pole pitch units (n pieces × unit pole pitch, n is a natural number) Way. 8. The method of claim 7,
Wherein the control unit controls the mover to move to a movement distance of a unit pole pitch unit (n X unit pole pitch, n is a natural number)
Wherein the first linear hall sensor and the second linear hall sensor signal are synchronized with each other.

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