KR20150053558A - Laundry treatment machine and the method for operating the same - Google Patents

Abstract

The present invention relates to a laundry treatment machine and a method for operating the same. The method for operating the laundry treatment machine according to the present invention comprises the steps of: rotating a drum at accelerating speeds; rotating the drum at a constant speed after the rotation is accelerated; and calculating the amount of bubbles in the drum based on a gradient of the current command value of the motor for the drum′s rotation or a gradient of the output current flowing in the motor, during the constant speed rotation. Therefore, bubble sensing can be possible.

Description

[0001] The present invention relates to a laundry treatment apparatus and a method of operating the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laundry processing apparatus and a method of operating the same, and more particularly, to a laundry processing apparatus capable of performing foam detection and an operation method thereof.

In general, the laundry processing apparatus performs washing using the friction force of the laundry and the washing machine, which is rotated by receiving the driving force of the motor, in a state where the detergent, the washing water and the laundry are put in the drum, so that the laundry is hardly damaged, You can get a washing effect.

On the other hand, when foam is excessively generated by the introduction of the detergent during washing, frictional force is generated, and dehydration entry may become difficult. Accordingly, various methods for detecting bubble generation have been discussed.

It is an object of the present invention to provide a laundry processing apparatus capable of performing foam detection and an operation method thereof.

According to another aspect of the present invention, there is provided a method of operating a laundry processing apparatus, comprising: accelerating and rotating a drum; rotating the drum at an equal speed after accelerated rotation; And calculating the amount of foam in the drum based on the slope of the current command value of the drum or the slope of the output current value flowing to the motor.

According to another aspect of the present invention, there is provided a laundry processing apparatus including a drum, a motor for rotating the drum, a drum for accelerating and rotating the drum, rotating the drum at a constant speed after accelerated rotation, And a driving unit for calculating the amount of foam in the drum based on the slope of the current command value of the motor for drum rotation or the slope of the output current value flowing to the motor.

According to one embodiment of the present invention, the laundry processing device is configured to rotate the drum at a constant speed after accelerated rotation, based on the slope of the current command value of the motor for rotating the drum or the slope of the output current value flowing to the motor , It is possible to perform foam detection by calculating the amount of foam in the drum.

In particular, bubble detection can be performed easily and accurately by exuding the amount of bubbles in the drum based on the slope of the current command value of the motor or the slope of the output current value in the constant speed rotation period instead of the acceleration period.

When the foam amount is equal to or larger than a predetermined value, the laundry processing apparatus can be stably operated by performing the dewatering process after removing the foam.

1 is a perspective view illustrating a laundry processing apparatus according to an embodiment of the present invention.
2 is an internal block diagram of the laundry processing apparatus of FIG.
3 is an internal circuit diagram of the driving unit of FIG.
4 is an internal block diagram of the inverter control unit of FIG.
5A is a view for explaining an example of the foam amount detecting method.
FIG. 5B is a view for explaining the amount of foam detected according to FIG. 5A.
6 is a flowchart illustrating an operation method of a laundry processing apparatus according to an embodiment of the present invention.
Figs. 7 to 9 are drawings referred to explain the operation method of Fig.

Hereinafter, the present invention will be described in detail with reference to the drawings.

The suffix "module" and " part "for components used in the following description are given merely for convenience of description, and do not give special significance or role in themselves. Accordingly, the terms "module" and "part" may be used interchangeably.

1 is a perspective view illustrating a laundry processing apparatus according to an embodiment of the present invention.

The laundry processing apparatus 100 is a drum type laundry processing apparatus which includes a cabinet 110 forming an outer appearance of the laundry processing apparatus 100 and a cabinet 110 disposed inside the cabinet 110, A motor 130 for driving the drum 122 and a drum 120 disposed inside the cabinet body 111 and disposed in the cabinet body 111. The cabinet body 111 includes a tub 120 supported by the tub 120, (Not shown) for supplying washing water to the inside of the tub 110, and a drain (not shown) formed below the tub 120 for discharging washing water to the outside.

The drum 122 is provided with a plurality of through holes 122A through which wash water is passed. The drum 122 is lifted up to a certain height during rotation of the drum 122, (124) may be disposed.

The cabinet 110 includes a cabinet body 111 and a cabinet cover 112 disposed on the front surface of the cabinet body 111 and coupled to the cabinet body 111. The cabinet 110 is disposed above the cabinet cover 112, And a top plate 116 disposed on the control panel 115 and coupled to the cabinet main body 111. The cabinet main body 111 includes a top plate 116,

The cabinet cover 112 includes a catch and release hole 114 formed so as to be able to move in and out of the can and a door 113 arranged to be rotatable in the left and right direction so that the catch and release hole 114 can be opened and closed.

The control panel 115 is provided with operation keys 117 for operating the laundry processing apparatus 100 and a display device (not shown) disposed on one side of the operation keys 117 and for displaying the operating state of the laundry processing apparatus 100 118).

The operation keys 117 and the display device 118 in the control panel 115 are electrically connected to a control unit (not shown), and a control unit (not shown) electrically controls each component of the laundry processing apparatus 100 do. The operation of the control unit (not shown) will be described later.

On the other hand, the drum 122 may be provided with autobalance (not shown). The autobalance (not shown) is for reducing vibrations caused by the amount of eccentricity of the laundry contained in the drum 122, and may be realized by liquid balance, ball balance, or the like.

The laundry processing apparatus 100 may further include a vibration sensor for measuring the vibration amount of the drum 122 or the vibration amount of the cabinet 110 although not shown in the drawing.

2 is an internal block diagram of the laundry processing apparatus of FIG.

Referring to the drawings, in the laundry processing apparatus 100, the driving unit 220 is controlled by a control operation of the control unit 210, and the driving unit 220 drives the motor 230. Thus, the drum 122 is rotated by the motor 230.

The control unit 210 receives an operation signal from the operation key 1017 and performs an operation. Thus, washing, rinsing and dewatering can be performed.

In addition, the control unit 210 may control the display 118 to display a wash course, a wash time, a dehydration time, a rinse time, or a current operation state.

On the other hand, the control unit 210 controls the driving unit 220 to operate the motor 230. For example, based on the current detection unit 225 for detecting the output current flowing through the motor 230 and the position sensing unit 235 for sensing the position of the motor 230, the driving unit 220 Can be controlled. The detected current and the detected position signal are inputted to the driving unit 220. The present invention is not limited thereto and may be applied to either the control unit 210 or the control unit 210 and the driving unit 220 It is also possible.

The driving unit 220 is for driving the motor 230 and may include an inverter (not shown) and an inverter control unit (not shown). Further, the driving unit 220 may be a concept further including a converter or the like that supplies DC power input to an inverter (not shown).

For example, when an inverter control unit (not shown) outputs a switching control signal (Sic in Fig. 3) of a pulse width modulation (PWM) method to an inverter (not shown), the inverter (not shown) It is possible to supply AC power of a predetermined frequency to the motor 230.

The driving unit 220 will be described later with reference to Fig.

3 is an internal circuit diagram of the driving unit of FIG.

The driving unit 220 according to the embodiment of the present invention includes a converter 410, an inverter 420, an inverter control unit 430, a dc voltage detection unit B, a smoothing capacitor C, And an output current detection unit E. The driving unit 220 may further include an input current detection unit A, a reactor L, and the like.

The reactor L is disposed between the commercial AC power source 405 (v _s ) and the converter 410, and performs a power factor correcting or boosting operation. The reactor L may also function to limit the harmonic current due to the fast switching of the converter 410.

The input current detection section A can detect the input current (i _s ) input from the commercial AC power source 405. To this end, a current transformer (CT), a shunt resistor, or the like may be used as the input current detector A. The detected input current i _s can be input to the inverter control unit 430 as a discrete signal in the form of a pulse.

The converter 410 converts the commercial AC power source 405, which has passed through the reactor L, into DC power and outputs the DC power. Although the commercial AC power source 405 is shown as a single-phase AC power source in the figure, it may be a three-phase AC power source. The internal structure of the converter 410 also changes depending on the type of the commercial AC power source 405.

Meanwhile, the converter 410 may include a diode without a switching element, and may perform a rectifying operation without a separate switching operation.

For example, in the case of a single-phase AC power source, four diodes may be used in the form of a bridge, and in the case of a three-phase AC power source, six diodes may be used in the form of a bridge.

On the other hand, the converter 410 may be, for example, a half-bridge type converter in which two switching elements and four diodes are connected, and in the case of a three-phase AC power source, six switching elements and six diodes may be used .

When the converter 410 includes a switching element, the boosting operation, the power factor correction, and the DC power conversion can be performed by the switching operation of the switching element.

The smoothing capacitor C smoothes the input power supply and stores it. In the drawing, one element is exemplified by the smoothing capacitor C, but a plurality of elements are provided so that the element stability can be ensured.

For example, when a direct current power from the solar cell is supplied to the smoothing capacitor C (not shown), the direct current power is supplied to the smoothing capacitor C It may be input directly or may be DC / DC converted and input. Hereinafter, the portions illustrated in the drawings are mainly described.

On the other hand, both ends of the smoothing capacitor C are referred to as a dc stage or a dc stage because the dc power source is stored.

The dc voltage detection unit B can detect the dc voltage Vdc at both ends of the smoothing capacitor C. [ For this purpose, the dc voltage detection unit B may include a resistance element, an amplifier, and the like. The detected dc voltage source Vdc can be input to the inverter control unit 430 as a discrete signal in the form of a pulse.

The inverter 420 includes a plurality of inverter switching elements and converts the smoothed DC power supply Vdc into a three-phase AC power supply va, vb, vc having a predetermined frequency by on / off operation of the switching element, And outputs it to the synchronous motor 230.

The inverter 420 includes a pair of upper arm switching elements Sa, Sb and Sc and lower arm switching elements S'a, S'b and S'c serially connected to each other, The switching elements are connected to each other in parallel (Sa & S a, Sb & S'b, Sc & S'c). Diodes are connected in anti-parallel to each switching element Sa, S'a, Sb, S'b, Sc, S'c.

The switching elements in the inverter 420 perform ON / OFF operations of the respective switching elements based on the inverter switching control signal Sic from the inverter controller 430. [ Thus, three-phase AC power having a predetermined frequency is output to the three-phase synchronous motor 230.

The inverter control unit 430 can control the switching operation of the inverter 420. [ To this end, the drive controller 430, and can receive the output current (i _o) detected by the output current detector (E).

The inverter control unit 430 outputs the inverter switching control signal Sic to the inverter 420 to control the switching operation of the inverter 420. [ Inverter switching control signal (Sic) is output is generated by a switching control signal of a pulse width modulation (PWM), based on the output current (i _o) detected by the output current detector (E). The detailed operation of outputting the inverter switching control signal Sic in the inverter control unit 430 will be described later with reference to FIG.

An output current detector (E) detects the inverter 420 and the three-phase motor output current (i _o) flowing between (230). That is, the current flowing in the motor 230 is detected. The output current detection unit E can detect all of the output currents ia, ib, ic of each phase or can detect the output currents of two phases using the three-phase balance.

The output current detection unit E may be located between the inverter 420 and the motor 230. For current detection, a current transformer (CT), a shunt resistor, or the like may be used.

Three shunt resistors are placed between the inverter 420 and the synchronous motor 230 or the three lower arm switching elements S'a, S'b, S'c To be connected to each other. On the other hand, it is also possible to use two shunt resistors using three phase equilibrium. On the other hand, when one shunt resistor is used, the shunt resistor may be disposed between the capacitor C and the inverter 420 described above.

The detected output current (i _o) are, as discrete signals (discrete signal) of the pulse type, may be applied to the inverter controller 430, the inverter switching control signal (Sic) based on the detected output current (i _o) Is generated. In the output current detection (i _o) will now be described in that the three-phase output currents (ia, ib, ic) of the.

On the other hand, the three-phase motor 230 has a stator and a rotor, and each phase alternating current power of a predetermined frequency is applied to a coil of a stator of each phase (a, b, c) .

The motor 230 may be, for example, a Surface Mounted Permanent Magnet Synchronous Motor (SMPMSM), an Interior Permanent Magnet Synchronous Motor (IPMSM) A synchronous motor (Synchronous Reluctance Motor; Synrm), and the like. Among them, SMPMSM and IPMSM are permanent magnet applied Permanent Magnet Synchronous Motor (PMSM), and Synrm is characterized by having no permanent magnet.

On the other hand, the inverter control unit 430 can control the switching operation of the switching element in the converter 410 when the converter 410 includes a switching element. For this purpose, the inverter control unit 430 can receive the input current (i _s ) detected by the input current detection unit (A). The inverter control unit 430 may output the converter switching control signal Scc to the converter 410 to control the switching operation of the converter 410. [ The converter switching control signal (Scc) is generated by a switching control signal of a pulse width modulation method (PWM), based on the input current (i _s) to be detected from the input current detecting unit (A) can be output.

Meanwhile, the position sensing unit 235 may sense the rotor position of the motor 230. For this, the position sensing unit 235 may include a Hall sensor. The sensed rotor position H is input to the inverter control unit 430 and used based on speed calculation and the like.

4 is an internal block diagram of the inverter control unit of FIG.

4, the inverter control unit 430 includes an axis conversion unit 510, a speed calculation unit 520, a current command generation unit 530, a voltage command generation unit 540, an axis conversion unit 550, And a switching control signal output unit 560.

The axial conversion unit 510 receives the three-phase output currents ia, ib, ic detected by the output current detection unit E and converts the three-phase output currents ia, ib, ic into a two-phase current iα, iβ in the stationary coordinate system.

On the other hand, the axial conversion unit 510 can convert the two-phase current i?, I? Of the still coordinate system into the two-phase current id, iq of the rotational coordinate system.

)를 연산할 수 있다. 즉, 위치 신호에 기반하여, 시간에 대해, 나누면, 속도를 연산할 수 있게 된다.Based on the position signal H of the rotor input from the position sensing section 235, the speed calculating section 520 calculates the speed

) Can be calculated. That is, based on the position signal, it is possible to calculate the speed by dividing it with respect to time.

)와 연산된 속도(

)를 출력할 수 있다.On the other hand, the speed computing unit 520 computes the position (H) calculated based on the position signal H of the input rotor

) And the calculated speed (

Can be output.

)와 목표 속도(ω)에 기초하여, 속도 지령치(ω^* _r)를 연산하며, 속도 지령치(ω^* _r)에 기초하여, 전류 지령치(i^* _q)를 생성한다. 예를 들어, 전류 지령 생성부(530)는, 연산 속도(

)와 목표 속도(ω)의 차이인 속도 지령치(ω^* _r)에 기초하여, PI 제어기(535)에서 PI 제어를 수행하며, 전류 지령치(i^* _q)를 생성할 수 있다. 도면에서는, 전류 지령치로, q축 전류 지령치(i^* _q)를 예시하나, 도면과 달리, d축 전류 지령치(i^* _d)를 함께 생성하는 것도 가능하다. 한편, d축 전류 지령치(i^* _d)의 값은 0으로 설정될 수도 있다. On the other hand, the current command generation section 530 generates the current command

) Based on the speed command value ω ^* _r and the target speed ω and generates the current command value i ^* _q based on the speed command value ω ^* _r . For example, the current command generation unit 530 generates the current command

The PI controller 535 performs the PI control based on the speed command value? ^* _{R that} is the difference between the target speed? And the target speed?, And generates the current command value i ^* _q . In the figure, the q-axis current command value (i ^* _q ) is exemplified by the current command value, but it is also possible to generate the d-axis current command value (i ^* _d ) unlike the figure. On the other hand, the value of the d-axis current command value i ^* _d may be set to zero.

On the other hand, the current command generation unit 530 may further include a limiter (not shown) for limiting the current command value i ^* _q so that the current command value i ^* _q does not exceed the allowable range.

Next, the voltage command generation unit 540 generates the voltage command generation unit 540 based on the d-axis and q-axis currents (i _d , i _q ) axially transformed into the two-phase rotational coordinate system in the axial conversion unit and the current command value based on ^{_{i * d, i * q)}} , and generates a d-axis, q-axis voltage command value ^{_{(v * d, v * q}} ). For example, the voltage command generation unit 540 performs PI control in the PI controller 544 based on the difference between the q-axis current (i _q ) and the q-axis current command value (i ^* _q ) It is possible to generate the axial voltage command value v ^* _q . Further, voltage command generation unit 540, on the basis of the difference between the d-axis current (i _d) and, the d-axis current command value (i ^* _d), and performs the PI control in the PI controller (548), d-axis voltage It is possible to generate the command value v ^* _d . On the other hand, the value of the d-axis voltage command value v ^* _d may be set to zero corresponding to the case where the value of the d-axis current command value i ^* _d is set to zero.

The voltage command generator 540 may further include a limiter (not shown) for limiting the level of the d-axis and q-axis voltage command values v ^* _d and v ^* _q so as not to exceed the permissible range .

On the other hand, the generated d-axis and q-axis voltage command values (v ^* _d , v ^* _q ) are input to the axial conversion unit 550.

)와, d축, q축 전압 지령치(v^* _d,v^* _q)를 입력받아, 축변환을 수행한다.The axis transforming unit 550 transforms the position computed by the velocity computing unit 520

) And the d-axis and q-axis voltage command values (v ^* _d , v ^* _q ).

)가 사용될 수 있다.First, the axis converting unit 550 performs conversion from a two-phase rotating coordinate system to a two-phase stationary coordinate system. At this time, the position computed by the speed calculator 520

) Can be used.

Then, the axis converting unit 550 performs conversion from the two-phase stationary coordinate system to the three-phase stationary coordinate system. Through this conversion, the axial conversion unit 1050 outputs the three-phase output voltage instruction values v ^* a, v ^* b, v ^* c.

The switching control signal output unit 560 generates an inverter switching control signal Sic according to the pulse width modulation (PWM) method based on the three-phase output voltage set values v ^* a, v ^* b and v ^* c And outputs it.

The output inverter switching control signal Sic may be converted into a gate driving signal in a gate driving unit (not shown) and input to the gate of each switching element in the inverter 420. As a result, the switching elements Sa, S'a, Sb, S'b, Sc, and S'c in the inverter 420 perform the switching operation.

On the other hand, when the detergent is put into the drum 122 at the time of the washing, the foam due to the detergent acts as a frictional force. Particularly, when the detergent is put in an excessive amount, since the frictional force is increased, entry of the dehydration step may become difficult. Accordingly, conventionally, the foam detection method as shown in Fig. 5A is used.

FIG. 5A is a view for explaining an example of the foam amount detecting method, and FIG. 5B is a view for explaining the foam amount sensed according to FIG. 5A.

5A shows a graph of the rotation speed of the drum. The Tac interval represents the acceleration rotation period of the drum, and the Tsus interval represents the constant velocity rotation period of the drum. In the figure, during the constant-speed rotation period of the drum 122, the drum 122 rotates at the speed of? _MA .

5A illustrates a graph of the output current iox corresponding to the rotational speed of the drum of FIG. 5A.

Conventionally, the bubble amount was calculated using the maximum value (imax) of the output current value during the acceleration period Tac of the drum 122 for bubble detection. This maximum value (imax) eventually occurred in the last section (Tx) of the acceleration section Tac.

On the other hand, bubble generation is related to the rotation speed of the drum 122, and usually occurs in the acceleration section after 300 rpm. Therefore, conventionally, the foam amount was calculated by using the maximum value (imax) of the output current flowing through the motor during the acceleration period after 300 rpm.

However, when the ending speed of the acceleration section is in the vicinity of 300 rpm, for example, about 350 rpm, there is a disadvantage that the maximum value (imax) of the output current value is detected to shorten the section in which the foam amount can be calculated .

When the amount of eccentricity in the drum 122 is large, there is an influence on the output current value due to a large eccentricity, and therefore, there is a high possibility that a mistake is made in calculating the amount of foam.

FIG. 5B illustrates a foam amount calculation graph according to the method of FIG. 5A.

Wc1 is a non-detergent, Wc2 is a first detergent, Wc3 is a second detergent, and Wc4 is a third detergent. In the experiment, the performance of the detergent was increased from the first detergent to the third detergent.

As a result of measuring the foam amount using the maximum value (imax) of the output current value applied to the motor during the acceleration period Tac of the drum 122 according to the method of FIG. 5A, BLa, BLb, BLc and BLd were detected.

That is, the foam amount BLc was the largest in the second detergent Wc3, and the amount of foam was detected to be similar in the non-detergent Wc1, the first detergent Wc2, and the third detergent Wc4.

5B, it can be seen that the foaming amount is similar in the detergent Wc1, the first detergent Wc2 and the third detergent Wc4, and the discriminating power is weak.

In order to solve such a problem, in the present invention, the foam amount is calculated not at the acceleration rotation section of the drum but at the constant speed rotation section after the acceleration rotation of the drum. This will be described with reference to FIG. 6 and the following figures.

FIG. 6 is a flowchart showing an operation method of the laundry processing apparatus according to an embodiment of the present invention, and FIGS. 7 to 9 are views referred to explain the operation method of FIG.

Referring to the drawing, the driving unit 220 accelerates and rotates the drum (S610).

After the detergent is put into the drum 122 in accordance with the washing cycle, the driving unit 220 can accelerate and rotate the drum 122.

To this end, the inverter control unit 430 can continuously increase the q-axis current command value (i ^* _q ) corresponding to the torque. As a result, the output current applied to the motor 230 also increases continuously.

Next, the driving unit 220 rotates the drum at a constant speed (S615).

After accelerated rotation, the driving unit 220 rotates the drum at a constant speed. In a speed range of approximately 300 rpm or more, the drive unit 220 rotates the drum at a constant speed.

To this end, the inverter control unit 430 can vary the q-axis current command value (i ^* _q ) corresponding to the torque. As a result, the output current value applied to the motor 230 fluctuates.

Next, the drive unit 220 calculates the amount of foam in the drum based on the slope of the current command value of the motor for drum rotation or the slope of the output current value flowing to the motor at the constant speed rotation (S620). In particular, the inverter control unit 430 or the control unit 210 in the driving unit 220 calculates the amount of foam in the drum based on the slope of the current command value of the motor or the slope of the output current value flowing in the motor.

7 is a diagram illustrating a method of detecting the amount of foam according to an embodiment of the present invention.

7 (a) shows a graph of the rotating speed of the drum. The Tac interval represents the acceleration rotation period of the drum, and the Tsus interval represents the constant velocity rotation period of the drum. In the figure, during the constant-speed rotation period of the drum 122, the drum 122 rotates at the speed of? _MA .

Fig. 7 (b) illustrates a graph of the output current io corresponding to the rotational speed of the drum in Fig. 7 (a).

In the present invention, during the constant velocity rotation period Tsus of the drum 122, instead of the acceleration period Tac of the drum 122, the gradient of the output current value or the slope of the current command value is used for bubble detection, .

The amount of foam is proportional to the slope of the output current value or the slope of the current command value. That is, the larger the slope of the output current value or the slope of the current command value, the larger the amount of foam, and the smaller the slope, the smaller the amount of foam.

On the other hand, the constant velocity rotation section Tsus can be divided into a stabilization section Ts1 for stabilizing the speed of the drum 9122 after the drum acceleration and a foam detection section Ts2 for bubble detection after the stabilization section. And, the bubble detection can be performed only in the bubble detection section Ts2.

FIG. 7B illustrates that the output current value varies during the bubble detection period Ts2, but increases in accordance with the predetermined slope S1, which is variable, and generally varies.

The inverter control unit 430 or the control unit 210 in the driving unit 220 can calculate the slope S1 of the output current value in consideration of the output current value variation during the foam detection period Ts2. Then, the foam amount BB1 can be calculated based on the slope S1 of the calculated output current value.

On the other hand, in the drawing, the foam amount is calculated based on the slope of the output current value of the motor, but it is also possible to calculate the foam amount based on the slope of the current command value in the inverter control unit 430 separately.

)를 파악할 수 있다. 그리고, 거품 감지 구간(Ts2) 동안, 전류 지령치의 크기 변화를 살펴보면, 전류 지령치의 크기의 기울기를 산출할 수 있다.
The d-axis current command value i ^* _d and the q-axis current command value i ^* _q are generated according to the current command generation unit 530 of FIG.

). If the magnitude of the current command value changes during the bubble sensing period Ts2, the slope of the magnitude of the current command value can be calculated.

On the other hand, the amount of foam may vary depending on the type of detergent put into the drum 122.

8 is a view illustrating a method of detecting the amount of foam according to another embodiment of the present invention.

Fig. 8 (a) shows the rotational speed graph of the drum. The Tac interval represents the acceleration rotation period of the drum, and the Tsus interval represents the constant velocity rotation period of the drum. In the figure, during the constant-speed rotation period of the drum 122, the drum 122 rotates at the speed of? _MA .

8 (b) illustrates a graph of the output current io1 corresponding to the rotational speed of the drum of Fig. 8 (a) according to the first detergent, and Fig. 8 (c) , A graph of the output current io2 corresponding to the rotational speed of the drum in Fig. 8 (a) is illustrated. At this time, it is presumed that the detergent performance of the first detergent is better than that of the second detergent.

During the foam detection period Ts2, the slope of the output current according to the first detergent of Fig. 8 (b) is Sc1, and the slope of the output current according to the second detergent of Fig. 8 (c) shows Sc2.

On the other hand, by expanding the bubble amount detection algorithm, the kind of detergent can be grasped. That is, during the foam detection period Ts2, the type of detergent can be also classified based on the slope of the output current.

Fig. 9 illustrates a foam amount calculation graph according to a plurality of types of detergents.

Wc1 is a non-detergent, Wc2 is a first detergent, Wc3 is a second detergent, and Wc4 is a third detergent. In the experiment, the performance of the detergent was increased from the first detergent to the third detergent.

6 and 7, by using the slope of the output current value applied to the motor during the foam sensing period Ts2 in the constant velocity section Tsus in which the drum 122 rotates at a constant speed, As a result, foam amounts of BL1, BL2, BL3 and BL4 were detected for Wc1 to Wc4, respectively.

That is, the foam amount BL4 in the third detergent Wc4 is the largest, and the foam amount BL3 corresponding to the second detergent Wc3, the foam amount BL2 corresponding to the first detergent Wc2 ) And the foam amount BL1 corresponding to the detergent Wc1.

That is, it can be seen that the amount of foam is suitably detected for detergent performance. Accordingly, when the amount of foam is calculated by the method of the present invention, it is possible to perform the foam detection easily and accurately.

Next, the driving unit 220 determines whether or not the amount of foam is equal to or greater than a predetermined value (S625). If so, the drum is stopped (S630). Then, the driving unit 220 performs the foam removing operation (S635). On the other hand, after the bubble removing operation, the driving unit 220 controls to enter the dewatering stroke.

The inverter control unit 430 or the control unit 210 in the driving unit 220 stops and stops the rotation of the drum 122 at the constant speed when the calculated foam amount BB exceeds the allowable value. That is, all the switching elements in the inverter 420 are turned off.

Then, the bubble removing operation is performed. That is, a predetermined amount of water is injected into the drum 122. At this time, the amount of water introduced may be proportional to the amount of foam. Thereafter, the drum 122 may be rotated to remove the bubbles and enter the dewatering stroke.

On the other hand, such foam removing operation may be repeated several times without being performed once. As a result, the foam can be completely removed. In addition, the bubble detection operation can be repeated several times in conjunction with the bubble removing operation.

Meanwhile, the foam amount calculation according to the embodiment of the present invention is applied to the sensor-type driving unit 220 having the position sensing unit 235, but it is also applicable to the sensorless method.

That is, when the driving unit does not include the position sensing unit 235, the driving unit may further include an output voltage detection unit for detecting the ninety-phase voltage applied to the motor, in addition to the output current detection unit. Then, the position of the rotor of the motor 230 can be estimated based on the detected output current and the output voltage. Therefore, the speed calculator 520 of FIG. 4 may be replaced by an estimator for rotor position estimation and speed estimation.

Even in this case, within the constant-speed rotation section of the drum, the foam amount detection based on the slope of the output current or the slope of the current command value described above is applicable.

The laundry processing apparatus according to the embodiment of the present invention can be applied to all or some of the embodiments so that various modifications can be made to the embodiments and the methods of the embodiments described above, May be selectively combined.

Meanwhile, the method of operating the laundry processing apparatus of the present invention can be implemented as a code that can be read by a processor on a processor-readable recording medium provided in the laundry processing apparatus. The processor-readable recording medium includes all kinds of recording apparatuses in which data that can be read by the processor is stored.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present invention.

Claims (13)

Accelerating and rotating the drum;
Rotating the drum at a constant speed after the acceleration rotation; And
And calculating a foam amount in the drum based on a slope of a current command value of the motor for rotating the drum or a slope of an output current value flowing to the motor at the constant speed rotation, Lt; / RTI > The method according to claim 1,
Stopping the drum when the foam amount is equal to or greater than a predetermined value; And
And removing the bubbles in the drum. ≪ Desc / Clms Page number 20 > 3. The method of claim 2,
Further comprising: after the defoaming step, entering a dehydration process. ≪ Desc / Clms Page number 21 > The method according to claim 1,
The constant-speed rotation section during the constant-
A stabilization period for stabilizing the speed of the drum after the acceleration and a foam detection period for detecting foam after the stabilization period,
The foam amount calculating step may include:
Wherein the amount of foam in the drum is calculated based on a slope of a current command value of the motor or a slope of an output current value flowing to the motor during the foam detection period. The method according to claim 1 or 4,
Wherein the amount of foam is proportional to a slope of the current command value or a slope of the output current value. drum;
A motor for rotating the drum; And
Wherein the drum is rotated at an equal speed after the acceleration rotation, and based on a slope of a current command value of the motor for rotating the drum or a slope of an output current value flowing to the motor at the constant speed rotation, And a driving unit for calculating the amount of foam in the drum. The method according to claim 6,
Stopping the drum when the foam amount is equal to or greater than a predetermined value; And
Further comprising the step of removing bubbles in the drum. 8. The method of claim 7,
And after the bubbling step, entering a dehydration step The method according to claim 6,
The constant-speed rotation section during the constant-
A stabilization period for stabilizing the speed of the drum after the acceleration and a foam detection period for detecting foam after the stabilization period,
The foam amount calculating step may include:
Wherein the amount of foam in the drum is calculated based on a slope of a current command value of the motor or a slope of an output current value flowing to the motor during the foam detection period. 10. The method according to claim 6 or 9,
Wherein the amount of foam is proportional to a slope of the current command value or a slope of the output current value. The method according to claim 6,
The driving unit includes:
An inverter for converting a DC power source to an AC power source and outputting the AC power source to the motor;
And an inverter controller for controlling the inverter based on the detected rotor position, wherein the inverter controller includes a position sensing unit for sensing a rotor position of the motor. 12. The method of claim 11,
The inverter control unit includes:
A speed calculating unit for calculating rotor speed information of the motor based on the sensed position information;
A current command generator for generating the current command value based on the speed information and the speed command value;
A voltage command generator for generating a voltage command value based on the current command value and the detected current; And
And a switching control signal output unit for outputting a switching control signal for driving the inverter based on the voltage command value. The method according to claim 6,
The driving unit includes:
An inverter for converting a DC power source to an AC power source and outputting the AC power source to the motor;
And an inverter control unit for controlling the inverter based on an output current and an output voltage flowing through the motor.

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