KR20210101886A - Washing machine and controlling method for the same - Google Patents

Abstract

A control method of a washing machine according to an embodiment of the present invention comprises the steps of: rotating a drum at a maximum rotational speed corresponding to a first rpm during at least a part of a first dehydration period; decelerating the rotational speed of the drum during at least a part of a first unbalance detection period after the first dehydration period; rotating the drum at the maximum rotational speed corresponding to a second rpm higher than the first rpm during at least a part of a second dehydration period; and selectively performing a load shaking operation before starting the second dehydration period according to the degree of unbalance of laundry detected in the first unbalance detection period. According to an embodiment of the present invention, when a washing machine performs a dehydration process, unbalance of a fabric can be effectively detected, and the efficiency of the dehydration process can be increased by performing an operation corresponding thereto.

Description

Washing machine and controlling method thereof

An embodiment of the present specification relates to a washing machine and a method for controlling the same. More specifically, embodiments of the present specification relate to a washing machine that performs a dehydration process and a method for controlling the same.

In general, a washing machine is a device for processing laundry through various actions such as washing, dehydration, and/or drying. The washing machine includes an outer tub containing water, and an inner tub rotatably provided in the outer tub and having a plurality of through holes through which water passes.

The washing machine includes a top load type washing machine in which the inner tub is rotated about a vertical axis and the laundry (or cloth) is put in from the upper side, and the inner tub (or laundry) is put in from the front. , drum) may include a front load type washing machine that rotates about a horizontal axis.

In such a washing machine, when a user selects a desired course using a control panel in a state in which laundry such as clothes or bedding is put in the inner tub, a preset algorithm is executed in response to the selected course, thereby supplying/discharging, washing, and rinsing. , dehydration and other processes are carried out.

In general, the operation of the washing machine may be divided into a washing process, a rinsing process, and a dehydration process. The progress of this process can be confirmed by a display provided on the control panel.

In the washing process, detergent is supplied along with water into the inner tub, and contaminants attached to the laundry are removed using a chemical action of the detergent and a physical action by rotation of the pulsator and/or the inner tub.

In the rinsing process, clean water in which detergent is not dissolved is supplied into the inner tub to rinse the laundry. In particular, due to the rinsing process, the detergent absorbed in the laundry can be removed during the washing process. During the rinsing process, a fabric softener is sometimes supplied along with water into the inner tub.

In the dewatering process, after the rinsing process is completed, the inner tub is rotated at a high speed to dehydrate the laundry. In general, as the dehydration process is completed, all operations of the washing machine may be terminated. However, in the case of a washing machine combined with drying, a drying process may be further added after the dehydration process.

On the other hand, during the high-speed rotation of the inner tub for the dehydration process, if the laundry inside the inner tub is tilted to one side, the rotating central axis of the inner tub may deviate from the center (or biased) and vibration may occur in the washing machine cabinet. Due to this vibration, not only noise is generated, but also a problem that the dehydration effect is lowered may occur. In addition, due to the vibration of the washing machine cabinet, the mechanical lifespan of the washing machine may be reduced.

In order to solve such a problem, the present applicant has previously filed an application (hereinafter referred to as a prior document). Information on prior literature is as follows.

1. Publication number (published date): 10-2016-0088155 (July 25, 2016)

2. Title of invention: control method of washing machine

The washing machine of the prior literature discloses a control method of a washing machine capable of detecting the amount and eccentricity of a cloth during a dehydration process and effectively distributing a load therefor. Through such a control method, by applying a rotation pattern considering the amount of cloth, the unbalanced distribution of cloth was quickly resolved, and then the dewatering operation was performed in earnest, thereby reducing the load caused by dewatering and improving the dewatering performance. However, in the case of the dehydration process through such a control method, an additional operation had to be performed to detect the amount of laundry. In addition, when the main dewatering process is performed multiple times, there is a problem in that the time required for the dewatering process is increased by performing the cloth unwinding operation even when there is no unbalanced distribution of the cloth.

An embodiment of the present specification has been proposed to solve the above-described problems, and an object of the present specification is to provide a control method and an apparatus using the same for effectively detecting unbalancing of fabrics and performing an operation corresponding thereto when performing a dewatering process of a washing machine do it with

Another embodiment of the present specification aims to provide a control method and an apparatus using the same for performing a dewatering operation differently according to a result of detecting unbalance of a fabric when performing a dewatering process, and preventing unnecessary foaming operation.

In order to achieve the above object, a control method of a washing machine according to an embodiment of the present specification includes rotating a drum at a maximum rotation speed corresponding to a first rpm during at least a part of a first dehydration section; decelerating the rotational speed of the drum during at least a part of a first unbalance detection section after the first dehydration section; rotating the drum at a maximum rotation speed corresponding to a second rpm higher than the first rpm during at least a part of a second dehydration section; and selectively performing a load-shaking operation before the start of the second dehydration period according to the degree of unbalance of laundry detected in the first unbalance detection period.

A washing machine according to another embodiment of the present specification includes a cabinet; a tub accommodated in the cabinet; a drum rotatably provided inside the tub; a motor installed in the tub and providing rotational power to the drum; and the drum rotates at the highest rotational speed corresponding to the first rpm during at least a part of the first dehydration period, and the rotational speed of the drum is reduced during at least a part of the first unbalance detection period after the first dehydration period, During at least a part of the second spin-drying section, the drum rotates at a maximum rotation speed corresponding to a second rpm higher than the first rpm, and the second spin-drying section starts according to the degree of unbalance of laundry detected in the first unbalance detection section and a control unit for controlling the motor to selectively perform a load shedding operation before.

According to an embodiment of the present specification, when the washing machine performs the dewatering process, unbalance of the fabric can be effectively detected, and the efficiency of the dewatering process can be increased by performing an operation corresponding thereto. According to another embodiment of the present specification, when the dehydration process of the washing machine is performed, the time required for the entire dewatering process can be reduced by selectively performing the load-shaping operation performed in the dewatering process according to whether or not unbalance of the fabric is detected. It is possible to effectively control the load of the motor according to the process.

1 is a perspective view illustrating a washing machine according to an embodiment of the present specification.
FIG. 2 is a cross-sectional view of the washing machine of FIG. 1 .
3 is a block diagram illustrating a motor control apparatus according to an embodiment of the present specification.
4 is a flowchart for explaining a washing process according to an embodiment of the present specification.
5 is a flowchart for explaining a method of performing a dehydration process according to an embodiment of the present specification.
6 is a flowchart for explaining a method of determining whether a load shaking operation is performed between each dehydration step in a dehydration process according to another embodiment of the present specification.
7 is a view illustrating a rotation pattern of a drum in a dewatering process according to an embodiment of the present specification.
8 is a diagram illustrating a rotation pattern of a drum in a dewatering process according to another embodiment of the present specification.
9 is a diagram illustrating a rotation pattern of a drum in a dewatering process according to another embodiment of the present specification.

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

In describing the embodiments, descriptions of technical contents that are well known in the technical field to which the present invention pertains and are not directly related to the present invention will be omitted. This is to more clearly convey the gist of the present invention without obscuring the gist of the present invention by omitting unnecessary description.

For the same reason, some components are exaggerated, omitted, or schematically illustrated in the accompanying drawings. In addition, the size of each component does not fully reflect the actual size. In each figure, the same or corresponding elements are assigned the same reference numerals.

Advantages and features of the present invention, and a method for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains. It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

At this time, it will be understood that each block of the flowchart diagrams and combinations of the flowchart diagrams may be performed by computer program instructions. These computer program instructions may be embodied in a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, such that the instructions performed by the processor of the computer or other programmable data processing equipment are not described in the flowchart block(s). It creates a means to perform functions. These computer program instructions may also be stored in a computer-usable or computer-readable memory that may direct a computer or other programmable data processing equipment to implement a function in a particular manner, and thus the computer-usable or computer-readable memory. It is also possible that the instructions stored in the flow chart block(s) produce an article of manufacture containing instruction means for performing the function described in the flowchart block(s). The computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operational steps are performed on the computer or other programmable data processing equipment to create a computer-executed process to create a computer or other programmable data processing equipment. It is also possible that instructions for performing the processing equipment provide steps for performing the functions described in the flowchart block(s).

Additionally, each block may represent a module, segment, or portion of code that includes one or more executable instructions for executing specified logical function(s). It should also be noted that in some alternative implementations it is also possible for the functions recited in blocks to occur out of order. For example, two blocks shown one after another may in fact be performed substantially simultaneously, or it is possible that the blocks are sometimes performed in the reverse order according to the corresponding function.

At this time, the term '~ unit' used in this embodiment means software or hardware components such as FPGA or ASIC, and '~ unit' performs certain roles. However, '-part' is not limited to software or hardware. The '~ unit' may be configured to reside on an addressable storage medium or may be configured to refresh one or more processors. Thus, as an example, '~' denotes components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. In addition, components and '~ units' may be implemented to play one or more CPUs in a device or secure multimedia card.

1 is a perspective view of a washing machine according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the washing machine of FIG. 1 .

1 and 2 , a washing machine 100 according to an embodiment of the present specification includes a cabinet 111 forming an exterior, a door 112 for opening and closing one side of the cabinet so that a cloth enters and exits the cabinet, and the interior of the cabinet A tub 122 disposed in and supported by a cabinet, a drum 124 disposed inside the tub and rotating with a cloth inserted therein, a motor 113 rotating by applying a torque to the drum, and a detergent box containing detergent 133, and a control panel 114 that receives a user input and displays a washing machine state.

The cabinet 111 is formed with a cloth entry hole 120 to allow entry and exit of the cloth. A door 112 is rotatably coupled to the cabinet 111 to enable opening and closing of the fore access hole 120 . The cabinet 111 is provided with a control panel 114 . The cabinet 111 is provided with a detergent box 133 to be withdrawn.

The tub 122 is disposed so as to be buffered by the spring 115 and the damper 117 inside the cabinet 111 . The tub 122 accommodates washing water. A drum 124 is disposed inside the tub 122 .

The drum 124 rotates while receiving the cloth. The drum 124 is formed with a plurality of through-holes through which washing water passes. A lifter 125 may be disposed on the inner wall of the drum 124 to lift the cloth to a predetermined height when the drum rotates. The drum rotates by receiving rotational force by the motor 113 .

The balancer 126 is provided around the drum 124 to adjust the center of gravity of the drum when the fabric is eccentric. When the drum is rotated due to the eccentricity of the fabric, vibration and noise are generated due to unbalance in which the geometric center of the rotation axis of the drum 124 itself and the actual center of gravity do not match. The balancer 126 reduces the unbalance of the drum 124 by bringing the actual center of gravity of the drum 124 closer to the center of rotation.

The balancer 126 may be provided on the front side and/or the rear side of the drum 124 , and in this embodiment, the balancer 126 is provided on the front side of the drum 124 . When the drum 124 rotates, the cloth accommodated in the drum 124 is generally gathered on the inside, that is, on the rear side of the drum 124 , so in order to balance the cloth gathered on the rear side of the drum 124 , the balancer 126 is It is preferable to be provided on the front side of the drum (124).

The balancer 126 includes a material having a predetermined weight therein so that the center of gravity variably moves, and is configured to include a path through which the material is movable in the circumferential direction. The balancer 126 distributes the inner material so that it moves to the opposite side to the center of gravity of the fabric so that the center of gravity of the drum 124 approaches the center of rotation.

The balancer 126 may be formed of a liquid balancer containing a liquid having a predetermined weight therein or a ball balancer including a ball having a predetermined weight. In this embodiment, the balancer 126 includes a filling fluid together with the ball.

The gasket 128 seals between the tub 122 and the cabinet 111 . The gasket 128 is disposed between the inlet of the tub 122 and the fore access hole 120 . The gasket 128 mitigates the impact transmitted to the door 112 when the drum 124 rotates, and at the same time prevents the wash water in the tub 122 from leaking to the outside. The gasket 128 may be provided with a circulation nozzle 127 for introducing wash water into the drum 124 .

The motor 113 rotates the drum 124 . The motor 113 may rotate the drum 124 at various speeds or directions. The motor 113 includes a stator 113a in which a coil is wound, and a rotor 113b that rotates by generating electromagnetic interaction with the coil.

The stator 113a is provided with a plurality of wound coils. The rotor 113b is provided with a plurality of magnets for generating electromagnetic interaction with the coil. The rotor 113b rotates by electromagnetic interaction between the coil and the magnet, and the rotational force of the rotor is transmitted to the drum 124 to rotate the drum.

The motor 113 is provided with a hall sensor 113c for measuring the position of the rotor 113b. The hall sensor 113c generates an on/off signal by rotation of the rotor 113b. The speed and position of the rotor 113b are estimated through the on/off signal generated by the hall sensor 113c.

The detergent box 133 accommodates detergents such as laundry detergent, fabric softener, or bleach. It is preferable that the detergent box 133 is provided on the front of the cabinet 111 to be withdrawn. The detergent in the detergent box 133 is mixed with the washing water when the washing water is supplied and introduced into the tub 122 .

Inside the cabinet 111 , there is a water supply valve 131 for controlling the inflow of wash water from an external water source, a water supply passage 132 through which the wash water flowing into the water supply valve flows into the detergent box 133 , and the detergent box 133 . It is preferable that a water supply pipe 134 through which washing water mixed with detergent flows into the tub 122 is provided.

Inside the cabinet 111, a drain pipe 135 through which the wash water in the tub 122 flows out, a pump 136 through which the wash water in the tub flows out, a circulation passage 137 through which the wash water circulates, and the wash water in a drum ( 124), it is preferable that a circulation nozzle 127 flowing into the inside and a drain passage 138 through which the wash water is drained to the outside are provided. According to an embodiment, the pump 136 is provided as a circulation pump and a drain pump, and may be connected to the circulation passage 137 and the drain passage 138 , respectively.

The control panel 114 includes an input unit 114b for receiving various operation commands such as selection of a washing course or operation time and reservation for each process through the user, and a display unit 114a for displaying the operating state of the washing machine 100 . can be provided.

The operation of the washing machine according to the above-described embodiment of the present invention will be described as follows.

After the user opens the door 112 and inserts the cloth into the drum 124 , the washing machine is operated by manipulating the control panel 114 . When the washing machine is operated, a washing process in which the cloth is wetted with laundry water mixed with laundry detergent and then the drum 124 is rotated to remove contamination from the cloth, and the drum 124 after soaking the cloth with wash water mixed with a fabric softener A rinsing process of removing the residual laundry detergent from the fabric by rotating the , and a dehydration process of dehydrating the fabric by rotating the drum 124 at a high speed are sequentially performed. In each process, water supply, washing, rinsing, draining, dehydration and drying are performed.

The dewatering is performed by rotating the drum 124 at high speed so that the wash water soaked in the cloth is discharged, and is performed during the washing process, the rinsing process, and the dehydration process. Since the drum 124 is rotated at 400 rpm or more during dehydration, and at most about 1000 rpm, when the unbalance of the drum 124 is large, vibration and noise are greatly generated. In addition, in the embodiment, when performing the dehydration process, the drum 124 may rotate within a speed range of 560 to 640 rpm, and the wash water soaked in the cloth may escape to the outside by the centrifugal force generated through such rotation. have. The dewatering process can also allow wash water to drain while maintaining a certain speed range.

Therefore, when dehydration is started, the rotational speed of the motor 113 is maintained constant to measure the degree of unbalance of the drum 124 , and the motor 113 is accelerated when the balancer 126 is in an appropriate position. That is, the motor 113 is accelerated by determining an appropriate acceleration time according to the degree of unbalance of the drum. The rotational speed for measuring the degree of unbalance of the drum 124 may be 108 rpm, which is the maximum speed at which the carriage rotates attached to the drum 124 and does not significantly generate noise and vibration, but is not limited thereto.

3 is a block diagram illustrating a motor control apparatus according to an embodiment of the present specification.

Referring to FIG. 3 , the motor control device according to an embodiment of the present specification includes a motor control unit 230 , a PWM calculating unit 240 , an inverter 250 , a current sensing unit 260 , and an unbalance sensing unit. (270).

The motor control unit 230 controls power input to the motor 113 . The motor control unit 230 includes a voltage control unit 239 , a speed/position detection unit 231 , a speed control unit 233 , a current control unit 235 , and a coordinate conversion unit 237 .

The voltage control unit 239 outputs a command voltage value for the command speed. The voltage control unit 239 stores a command voltage value for each command speed experimentally obtained. It is preferable that the voltage control unit 239 stores the command voltage value for the command speed for each rotation direction of the drum 124 . Also, the voltage controller 239 may store each command voltage value for the command speed according to the amount of laundry accommodated in the drum 124 .

The voltage control unit 239 stores the d-axis command voltage value and the q-axis command voltage value on the dq-axis rotational coordinate system defined by the d-axis parallel to the magnetic flux direction and the q-axis perpendicular to the magnetic flux direction of the permanent magnet, and the command speed is When requested, the d-axis command voltage value and the q-axis command voltage value are output to the coordinate conversion unit 237 . As will be described later, the voltage control unit 239 may newly store the command voltage value for the command speed and output the newly stored command voltage value when the same command speed is input.

The coordinate conversion unit 237 converts the d-q-axis rotational coordinate system and the uvw fixed coordinate system to each other. The coordinate conversion unit 237 converts the command voltage value input to the d-q axis rotation coordinate system into a three-phase command voltage value. In addition, the coordinate conversion unit 237 converts the current current in the fixed coordinate system sensed by the current sensing unit 260, which will be described later, into the d-q-axis rotational coordinate system. The coordinate conversion unit 237 receives the position θ of the rotor 113b detected by the speed/position detection unit 231, which will be described later, and transforms the coordinate system.

The PWM (Pulse Width Modulation) operation unit 240 receives the uvw fixed coordinate system signal output from the motor control unit 230 and generates a PWM signal. The inverter 250 receives the PWM signal from the PWM operation unit 240 and directly controls the power input to the motor 113 . The current sensing unit 260 senses the current output from the inverter 250 . According to an embodiment, the PWM calculating unit 240 may be included in the inverter 250 .

The speed/position detection unit 231 detects the rotational speed and position of the rotor 113b of the motor 113 . The speed/position detection unit 231 detects the rotational speed and position of the rotor 113b based on the position of the rotor 113b sensed by the Hall sensor 113c. According to an embodiment, the speed/position detection unit 231 may detect the rotation speed of the motor 113 through the current detected by the current detection unit 260 .

The speed control unit 233 controls the rotation speed of the rotor 113b detected by the speed/position detection unit 231 in proportional-integral-derivative (PID) control so that the rotation speed follows the command speed on the d-axis rotation coordinate system on the dq-axis rotation coordinate system. The command current value and the q-axis command current value are generated respectively. When the rotation speed of the rotor 113b detected by the speed/position detection unit 231 is maintained with a slight fluctuation, the speed control unit 233 compares the average value of the changed values with the command speed.

The current control unit 235 generates a d-axis command voltage value and a q-axis command voltage value by proportional-integration-differential (PID) control of the current current detected by the current sensing unit 260 .

The unbalance detection unit 270 measures the degree of unbalance of the drum 124 through the rotation speed of the rotor 113b detected by the speed/position detection unit 231 . The unbalance detection unit 270 measures the degree of unbalance of the drum 124 by measuring the amount of change in the rotational speed of the rotor 113b.

When the drum 124 is rotated at a constant speed, if the drum 124 is unbalanced, the rotational speed of the rotor 113b has a slight fluctuation, and the unbalance detection unit 270 is the rotor 113b. The degree of unbalance is measured through the amount of change in the rotational speed of The unbalance detection unit 270 measures the degree of unbalance as a difference between the change amount of the rotational speed of the rotor 113b and the pre-stored reference speed change amount. The amount of change in the reference speed is stored differently depending on the amount of laundry. Since the difference between the change amount of the rotation speed of the rotor 113b and the reference speed change amount changes with time, the unbalance detection unit 270 determines the difference between the change amount of the rotation speed of the rotor 113b and the reference speed change amount. The average of the maximum and minimum values is calculated as an unbalanced value.

When the unbalance detection unit 270 measures the degree of unbalance, the drum 124 rotates attached to the carriage drum and preferably rotates at a maximum speed at which noise and vibration do not occur significantly, and in this embodiment, the drum 124 ) can rotate at 108 rpm.

The laundry amount sensing unit 280 includes the motor 113 driving the drum 124, and the cloth accommodated in the drum 124 based on the current applied to the motor 113 in at least one of the acceleration and deceleration phases of the drum's rotation. can be calculated for the For example, when the rotation of the drum is accelerated or decelerated, the amount of laundry contained in the drum may be calculated based on the motor torque that is checked based on the current. When the drum rotates by driving the motor, various forces are applied to the drum into which the laundry is loaded. When the drum rotates, motor torque, inertia torque, friction torque, and load torque act on the drum. Meanwhile, while the drum rotates, at an angle θm, the force acting on the laundry is as follows. This is the force acting when the drum moves by an angle θm from a standstill.

Since the motor torque is a force required to operate the motor, the inertia torque, friction torque, and load torque appear as the summed value. More specifically, the motor torque Te for rotation of the motor is expressed by the following equation.

[Equation 1]

In the above equation, Jm is the coefficient of inertia ωm is the angular speed of the motor, Bm is the friction coefficient of the laundry, TL is the load torque, P is the power supplied to the motor, Ke is the torque constant, and iqe is the torque current supplied to the motor do.

은 관성토크,

은 마찰토크,

은 부하토크에 대응한다. 실시 예에서 마찰 토크부분은 세탁물의 종류에 따라 편차가 발생할 수 있기 때문에 정확한 측정을 위해서는 해당 부분에 대한 보상이 필요하다. Looking at the components of the above torque Te

is the inertia torque,

is the friction torque,

corresponds to the load torque. In an embodiment, since the friction torque part may have a deviation depending on the type of laundry, it is necessary to compensate the corresponding part for accurate measurement.

Motor torque is the value multiplied by the radius of the drum by the force to lift the laundry. Inertia torque is a force of inertia acting on the drum or according to the distribution of laundry when accelerating or decelerating during a rotational operation, and acts as a force that interferes with the rotational operation. At this time, the inertia torque is proportional to the square of the mass and the radius of the drum. Friction torque is a frictional force acting between the laundry and the tub, between the laundry and the door, and between the drive belt and the drum, so it is proportional to the rotational speed. The friction torque can be calculated as the product of the friction coefficient and the rotation speed. The load torque is the gravity acting according to the distribution of laundry when starting, and can be calculated from the weight of the laundry, the gravitational acceleration, the radius of the drum, and the angle.

More specifically, the motor torque is a force applied to rotate the motor connected to the drum, and the inertia torque is a force interrupted by inertia to maintain the existing state of motion (rotation) during rotation, when accelerating or decelerating, Friction torque is a force that prevents rotation due to friction between drum and laundry, door and laundry, or friction between the drive belt and drum, and load torque is a force that prevents rotation due to the weight of laundry.

The controller 230 may measure iqe to estimate the torque Te. Accordingly, a change in the weight of the laundry may be detected based on the measured torque value, and the laundry weight may be sensed based on the detected weight change. Accordingly, the control unit 230 may measure the provisional current and the holding current value based on the torque constant, determine the torque value based on this, and detect the laundry amount based on the determined torque value. Meanwhile, in relation to the measured current value, the influence of the torque constant Ke must be considered, and the effect of Ke can be considered by compensating for the dispersion of the motor back EMF by compensating the current in the holding section from the current in the acceleration section. More specifically, the load related to the rotation of the motor may be expressed as "acceleration section current average - holding section current average/2".

At a predetermined angle (θm), the force acting on the laundry is a force due to gravity, but since the drum is rotating, it can be calculated as a value obtained by multiplying gravity by sin(θm). The force due to gravity is determined by the acceleration due to gravity and the radius and mass of the drum.

As the drum rotates, the motor torque, the inertia torque, the friction torque, and the load torque act simultaneously, and the components of these forces are reflected in the current value of the motor. calculate the amount

In the case of motor torque, there is a problem in that the effect of gravity due to the weight is large, and when the laundry weighs more than a certain weight, the resolution according to the measurement is lowered. That is, when the weight of the laundry increases by more than a specific value, as the weight of the laundry increases, the measurement error of the weight may increase.

Since friction torque between the laundry and the door, and the change in value when the laundry is caught in the door, increase, the spread (dispersion) according to the type of laundry may increase. In particular, when the amount of laundry increases, friction The dispersion of torque is greatly increased.

The load torque has a deviation in its value due to the movement of the laundry. In addition, in the case of the load torque, when the weight of the laundry exceeds a certain size, the movement of the laundry decreases, and thus, a reverse phenomenon in which the load torque decreases may occur.

On the other hand, although the inertia torque is affected by the flow of laundry, it shows linearity with respect to the amount (weight) of the laundry, so the amount of laundry can be measured more accurately, and the weight of the laundry can be more accurately measured through the estimation of the inertia torque. can be measured

At this time, since the inertia torque is a force to be maintained, it acts during acceleration or deceleration. That is, the inertia torque acts in the acceleration section and the deceleration section, but when the rotation speed is kept constant, the inertia torque does not act, and the motor torque, friction torque, and load torque by gravity act.

Therefore, the characteristic of the inertia torque can be calculated by excluding the data of the maintenance section from the data of the acceleration section. The inertia can be calculated by subtracting the current value of the sustain section from the current value of the acceleration section and the current value of the deceleration section, dividing the speed change per hour, that is, the acceleration, and multiplying the counter electromotive force.

Therefore, the control unit 230 analyzes the force acting on the acceleration section, the deceleration section, and the maintenance section to determine the amount of laundry based on the inertia torque, and also calculates the force of gravity according to the amount of laundry in the maintenance section. . In the maintenance section, the inertia characteristic is minimized, and in the acceleration section and the deceleration section, the inertia is large, so the amount of the final laundry can be determined by calculating the laundry weight detection value based on different data and comparing them with each other.

In addition, since the control unit 230 calculates the amount of laundry by measuring the current value during the motor rotation operation, it is possible to exclude an error due to the position alignment of the motor during startup, and also to change the load state through the maintenance section, that is, laundry As the flow does not flow irregularly, but flows in a constant state, it is possible to minimize an error due to a change in load.

In an embodiment, the controller 230 may rotate in the same pattern every 10 seconds. One pattern may include at least one of an acceleration section, a deceleration section, and a maintenance section, and at least one of the amount and weight of laundry may be estimated based on the inertia torque derived from the corresponding section.

On the other hand, in the embodiment, there may be an acceleration section and a deceleration section in relation to the drum rotation, the rotational speed of the drum may increase in the acceleration section, and the rotational speed of the drum may decrease in the deceleration section. When the speed changes in the acceleration section and the deceleration section correspond to each other, the inertia torque can be estimated based on the difference in the corresponding rotation torque.

More specifically, the motor torque TACC in the acceleration section is as follows.

[Equation 2]

The motor torque TDEC in the deceleration section is as follows.

[Equation 3]

At this time, when the degree of angular velocity change in the acceleration section and the deceleration section correspond to each other, the inertia torque can be estimated in the following way.

[Equation 3]

In this way, when the motor rotation is controlled in the acceleration section and the deceleration section of the slope corresponding to each other, the pure inertia torque can be measured with the sample deviation and the like removed. Meanwhile, in an embodiment, the controller may estimate the inertia torque based on current values corresponding to the acceleration section and the deceleration section based on the above relationship.

Through the torque estimation, the washing machine controller can check the state of the laundry in the drum, and through this, the laundry amount and the unbalance of the laundry can be detected.

4 is a flowchart for explaining a washing process according to an embodiment of the present specification.

Referring to FIG. 4 , a method of performing a washing process in a washing machine is illustrated.

In step 405, the control unit may receive laundry process related setting information. In an embodiment, the setting information may be received based on a user input, and the washing process related setting information may be checked based on information preset in the washing machine and the user input. In an embodiment, the setting information may include at least one of information about the number and intensity of each of the washing process, the rinsing process, the dehydration process, and the drying process.

In step 410, the controller may drive a motor to perform the washing process. The controller may control to drive at least one of the motors included in the washing machine throughout the washing process, and the drum may rotate according to the driving of the motor. Also, in an embodiment, the controller may adjust the rotation of the motor in a manner corresponding to each process.

In operation 415, the controller may perform a washing process. The washing process may be performed to wash the laundry inside the drum using water and detergent.

In operation 420, the controller may perform a rinsing process. The rinsing process may be performed to wash away the detergent absorbed into the laundry by washing with water.

In step 425, the control unit may perform a dehydration process. In an embodiment, the dewatering process may discharge the water absorbed in the laundry to the outside through the rotation of the drum. In order to discharge the absorbed water, the drum may rotate at a high speed, and the water absorbed in the laundry may be discharged to the outside by the centrifugal force. The controller may check the degree of dewatering by measuring the weight of the fabric at least once during the dewatering process. For example, it is possible to measure the weight of the fabric twice during the dehydration process and check the degree of dehydration based on the difference in weight. For this, a procedure for measuring the weight of the fabric in the dewatering process is required. In order to perform such a procedure, the controller may control the motor to adjust the pattern in which the drum rotates.

In addition, a drying process may be additionally performed according to an embodiment. The drying process is an operation of drying laundry while passing hot air into the drum together with the rotation of the drum, and the drying process can be performed while maintaining the rotation speed of the drum within a specific range.

5 is a flowchart for explaining a method of performing a dehydration process according to an embodiment of the present specification.

Referring to FIG. 5 , a method of performing a dewatering process is shown.

In operation 505 , the controller may control the rotation of the motor to perform a laundry amount sensing operation. In an embodiment, the controller may control the rotation of the motor to detect the amount of fabric in the drum before dehydration is performed in earnest. In an embodiment, an operation for draining water and an operation for detecting the amount of laundry may be performed to detect the amount of laundry. The water draining operation is an operation of removing water from the cloth through the rotation of the drum, and may include an acceleration section, a maintenance section, and a deceleration section, and may rotate at a lower rpm compared to a full-scale dehydration operation. For example, the rpm of the maintenance section may be 46 or less. The water draining operation may include such an acceleration section, a maintenance section, and a deceleration section at least once. Through such a water draining operation, it is possible to remove the accumulated water along with the cloth in the drum, and through this, it is possible to accurately measure the amount of cloth.

The sensing operation may include at least one acceleration section and a sensing section, and may include a maintenance section, but the rotation speed may be maintained for a shorter period than the maintenance section in the draining operation. Through the repetition of the acceleration section and the deceleration section, it is possible to accurately detect the fabric in the rotating drum. The highest rpm in the sensing operation may be 46 or less.

In step 510, the controller may control the rotation of the motor to perform the first dehydration operation. The primary dehydration operation may include a rush section and a dehydration section, and each section may include at least one of an acceleration section, a maintenance section, and a deceleration section. In the maintenance section of the first dehydration operation, the rotation speed may be higher than the rpm of the laundry amount sensing operation, and the maximum rpm in the maintenance section in the first dehydration operation may be 350 or less. On the other hand, when performing the dewatering process, since the amount of water contained in the initial cloth may be relatively large, the maximum rpm of the first dewatering operation may be lower than the maximum rpm of the subsequent dewatering operation.

In step 515, the control unit may detect the degree of unbalance of the fabric inside the drum. In an embodiment, the control unit may control the rotation of the drum to detect unbalance of the fore, and the unbalance detection operation may include at least one of a deceleration section, a maintenance section, and an acceleration section, and in such a section, The degree of unbalance of the gun can be checked through the torque detection. In an embodiment, the unbalance detection operation may be configured to sequentially proceed in a deceleration section, a maintenance section, and an acceleration section, and the deceleration slope in the deceleration section may correspond to the acceleration slope in the acceleration section. In addition, the length of the maintenance section may be longer than the length of the deceleration section and the acceleration section, but is not limited thereto. Through such an unbalance detection operation, the controller may detect the degree of unbalance of the fabric inside the drum.

In step 520, the controller may determine whether the detected degree of unbalance is equal to or greater than a reference value. In the embodiment, when the detected degree of unbalance is greater than or equal to the reference value, when dehydration is performed at a high rpm, a heavy load is applied to the motor and noise is generated. When the degree of unbalance is less than or equal to the reference value, dehydration may be performed at the next higher rpm. In an embodiment, the reference value may be determined differently depending on the washing environment, and may also be determined differently depending on the amount of fabric in the drum. In addition, a different reference value may be set according to the rpm of the next dehydration operation. Also, in an embodiment, the reference value may be set in consideration of noise generation due to unbalance.

When the degree of unbalance is equal to or greater than the reference value, in step 525 , the controller may control the motor to perform a load shedding operation. In an embodiment, the load shedding operation may include rotating and stopping the drum for a short time at a maximum speed of 65 rpm and repeating at least twice. The fabric in the drum may be uniformly disposed through the load sweeping operation.

When the degree of unbalance is less than or equal to the reference value, or when the load is shaken, the controller may perform a secondary dehydration operation in step 530 . In an embodiment, the secondary dewatering operation may rotate the drum at a higher rpm than the primary dewatering operation. In an embodiment, when the degree of unbalance is less than or equal to the reference value, the secondary spin-drying operation may be performed without stopping the drum after the primary spin-drying operation, thereby reducing the time required for spin-drying.

The embodiment described above may be applied to a continuous dehydration operation, and the laundry amount sensing operation may be selectively performed. For example, even when the third spin-drying operation is performed after the second spin-drying operation, the control unit may detect the degree of unbalance and determine whether to perform the load shedding operation accordingly.

6 is a flowchart for explaining a method of determining whether a load shaking operation is performed between each spin-drying step in a dehydration process according to another embodiment of the present specification.

Referring to FIG. 6 , a method of performing a subsequent spin-drying operation by checking the degree of unbalance after each stage of the dehydration operation in the dehydration process is illustrated.

In step 605, the controller may control the motor to perform the current step spin-drying operation. The dehydration operation may include a section in which 300 rpm or more is maintained.

In step 610, the controller may control the motor to detect unbalance. In an embodiment, the unbalance detection operation may include at least one of a section in which the vehicle decelerates from the highest rotational rpm and a section in which it accelerates again. In an embodiment, the slopes of the deceleration section and the acceleration section may correspond to each other, and a maintenance section may be included between the deceleration section and the acceleration section. In an embodiment, the rpm of the maintenance section may be 100 to 115. The degree of unbalance inside the drum can be detected through such acceleration, maintenance, and acceleration sections.

In step 615, the controller may determine whether the degree of unbalance is equal to or greater than a reference value. The reference value may be determined according to the method described in the previous embodiment.

If it is equal to or greater than the reference value, in step 620 , the control unit may stop the motor, perform a load shedding operation, and then perform the next spin-drying operation. In an embodiment, a load shedding operation may be performed while maintaining a low rotational speed without stopping the motor. As an example, the load shedding operation may be performed while maintaining the lowest rmp of 1 to 5. After the load whisking operation is performed, the next stage dehydration may be performed, and the maximum rotation speed of the drum in the next stage dewatering operation may be higher than the maximum rotation speed of the drum in the current stage dehydration operation.

If it is less than the reference value, in step 625 , the controller may perform the next step spin-drying operation without stopping the motor.

During the dehydration process in which a plurality of dewatering operations in which the maximum rotation speed is increased step by step as described above, the degree of unbalance is detected between dewatering operations and accordingly, the load shedding operation is performed when the unbalance is not severe by determining whether to perform the load shedding operation. The time required for the dewatering process can be reduced by performing the next dewatering operation without it.

7 is a view illustrating a rotation pattern of a drum in a dewatering process according to an embodiment of the present specification.

Referring to FIG. 7 , a rotation pattern of the drum over time when performing a dewatering process according to an embodiment is illustrated.

In an embodiment, the dehydration process may include a laundry weight detection section 710 , a first dehydration section 720 , a second dehydration section 730 , and a third dehydration section 740 . In an embodiment, each section may be selectively performed, and an additional dehydration section may be included after the third dehydration section 740 .

The laundry amount detection section 710 may include a water draining section 712 and a detection section 714 . The water draining section 712 is an operation for draining water flowing in the drum or coming out of the gun with a small external force, and may include an acceleration section, a maintenance section, and a deceleration section. can be rotated The sensing section 714 is a section for detecting the amount of laundry while repeating acceleration and deceleration, and may include an acceleration section and a deceleration section, and the drum can be rotated at a speed of up to 50 rpm or less. In an embodiment, the maximum rotation speed in the laundry amount sensing section may be 46 rpm.

The primary dehydration section 720 may include a rush section 722 , a dehydration section 724 , and a load sweeping section 726 .

The rush section 722 may rotate the drum while being sequentially accelerated, and may include at least one of a first acceleration section, a maintenance section, and a second acceleration section. The slope of the second acceleration section may be greater than that of the first acceleration section, and the length of the maintenance section may be longer than the length of the other sections. Also, the rotation speed of the maintenance section may be 70 rpm or less, and the rotation speed after completing the second acceleration section may be 110 rpm or less.

The dehydration section 724 may include at least a first increase/decrease section, a second increase/decrease section, and a third increase/decrease section. The first increase/decrease section is a section for accelerating, maintaining, and decelerating the rotation of the drum so that the maximum speed rotates below 170 rpm, and the decelerated drum rotation speed may be 108 to 110 rpm. In the second increase/decrease section, the rotation of the drum can be accelerated, maintained, and decelerated so that the maximum speed is 350 rpm or less. In the 3rd increase/decrease section, the rotation of the drum can be accelerated, maintained, and decelerated so that the maximum speed is 350 rpm or less, and the length of the holding section can be longer than that of the 2nd increase/decrease section. In addition, after the third increase/decrease section, the rotation speed of the drum may be reduced to close to zero in order to perform the load sweeping operation.

The load whisking section 726 may perform an operation of instantaneously accelerating and decelerating the drum rotation to a maximum rotational speed of 70 rpm or less in order to resolve unbalance of the fabric in the drum at least once. The unbalance of the fabric in the drum can be resolved through such acceleration and deceleration operations. In the embodiment, the minimum rotation speed in the load sweeping section 726 may be 0 to 5 rpm, the maximum rotation speed may be 80 rpm or less, and the time for maintaining the speed corresponding to the maximum rotation speed may be within 3 seconds.

The secondary dehydration section 730 may include a rush section 732 , a dehydration section 734 , and a load sweep section 736 .

The rush section 732 may be performed to correspond to the operation of the rush section 722 of the primary dehydration section.

The dewatering section 734 may sequentially accelerate the rotational speed of the drum. More specifically, the dehydration section 734 may include at least one of a first maintenance section, a first acceleration section, a second maintenance section, a second acceleration section, a third maintenance section, and a deceleration section. The rotation speed of the second maintenance section may be 350 rpm or less, and the rotation speed of the third maintenance section may be 750 rpm or less. Also, the slope of the first acceleration section may be greater than the slope of the second acceleration section. In addition, the length of the third holding section may be longer than the length of the remaining holding section. Through such sequential acceleration, the load on the motor can be reduced and the dehydration operation can be effectively performed. The operation of the load whisking section 736 after the deceleration section may be performed to correspond to the operation of the load whisking section 726 of the primary dehydration section.

The third dehydration section 740 may include a rush section 742 , a dehydration section 744 , and a load sweeping section 746 .

The rush section 742 may be performed to correspond to the operation of the rush section 722 of the primary dehydration section.

The dewatering section 744 may sequentially accelerate the rotational speed of the drum. More specifically, the dehydration section 744 may include at least one of a first maintenance section, a first acceleration section, a second maintenance section, a second acceleration section, a third maintenance section, and a deceleration section. The rotation speed of the secondary maintenance section may be 350 rpm or less, and the rotation speed of the third maintenance section may be 1110 rpm or less. Also, the acceleration may be changed at least once during the second acceleration section. Also, the slope of the first acceleration section may be greater than the slope of the second acceleration section. In addition, the length of the third holding section may be longer than the length of the remaining holding section. Through such sequential acceleration, the load on the motor can be reduced and the dehydration operation can be effectively performed. After the deceleration section, the operation of the load sweeping section 746 may be performed to correspond to the operation of the load sweeping section 726 of the primary dehydration section.

By performing the dehydration process through such sequential acceleration, dehydration can be performed while reducing the load on the motor.

8 is a diagram illustrating a rotation pattern of a drum in a dewatering process according to another embodiment of the present specification.

Referring to FIG. 8 , according to an embodiment, a rotation pattern of the drum according to time is shown when detecting unbalance of laundry in the drum between the spin-drying sections.

In an embodiment, the dehydration process may include a weight detection section 810 , a first dehydration section 820 , a second dehydration section 830 , and a third dehydration section 840 . In an embodiment, each section may be selectively performed, and an additional dehydration section may be included after the third dehydration section 840 .

The laundry amount detection section 810 may include a water draining section 812 and a detection section 814 , which may be performed corresponding to the previously described embodiment.

The primary dehydration section 820 may include an inrush section 822 and a dehydration section 824 . In addition, an unbalance detection section 826 that may overlap with at least one of the dehydration section 824 and the secondary dehydration section 830 may be performed. The rush section 822 and the dehydration section 824 may be performed to correspond to the previous embodiment.

The unbalance detection section 826 may include at least one of a deceleration section, a maintenance section, and an acceleration section, and slopes of the deceleration section and the acceleration section may correspond to each other. The rotation speed of the maintenance section may be 110 rpm or less and 90 rpm or more, and according to an embodiment, the rotation speed of the maintenance section may be determined at a speed of 1/3 or less of the maximum rotation speed in the primary dehydration section 820 . Through the operation of the unbalance detection section 826 as described above, the control unit can detect unbalance of the load in the drum, and when the degree of unbalance is less than or equal to a reference value, a secondary dehydration operation can be performed.

The secondary dehydration section 830 may include an inrush section 832 and a dehydration section 834 . In addition, an unbalance detection section 836 that may overlap with at least one of the dehydration section 834 and the tertiary dehydration section 840 may be performed. The rush section 832 and the dehydration section 834 may be performed to correspond to the previous embodiment. However, since the load shedding operation is not performed, the number of maintenance sections and acceleration sections may be smaller than when the load shedding operation is performed.

The unbalance detection section 836 may include at least one of a deceleration section, a maintenance section, and an acceleration section, and slopes of the deceleration section and the acceleration section may correspond to each other. The rotation speed of the holding section may be 110 rpm or less. Through the operation of the unbalance detection section 836 as described above, the control unit may detect the unbalance of the load in the drum, and when the degree of unbalance is less than or equal to the reference value, the third dehydration operation may be performed. In an embodiment, the reference value of unbalance determined in the unbalance detection section 836 of the secondary dehydration section may be lower. This is because, since the maximum rpm of the subsequent dewatering section is higher, a large noise may be generated even when less unbalance occurs than before.

The tertiary dehydration section 840 may include a rush section 842 , a dehydration section 844 , and a load shaking section 846 , which may be respectively performed corresponding to the previously described embodiments.

In this way, by providing an unbalance detection section between each dehydration section having a different maximum rpm, it is determined whether the degree of unbalance is suitable for proceeding to the next dehydration section, and the degree of unbalance is not a problem in proceeding with the next dehydration section. It is possible to reduce the time required for the entire spin-drying section by performing the next spin-drying section without performing the load sweeping operation.

9 is a diagram illustrating a rotation pattern of a drum in a dewatering process according to another embodiment of the present specification.

Referring to FIG. 9 , a method of detecting unbalance of laundry in a drum between spin-drying sections and determining whether to perform an additional operation when entering the next spin-drying section according to whether unbalance is performed according to an embodiment is illustrated.

In an embodiment, the dehydration process may include a laundry weight detection section 910 , a first dehydration section 920 , a second dehydration section 930 , and a third dehydration section 940 . In an embodiment, each section may be selectively performed, and an additional dehydration section may be included after the third dehydration section 940 . Specific operations within each section may be performed to correspond to the previously described embodiments.

The laundry amount detection section 910 may include a water draining section 912 and a detection section 914 , which may be performed corresponding to the previously described embodiment.

The first dehydration section 920 may be performed to correspond to the previously described embodiment, and after rotating the drum at the highest rpm in the first dehydration section 920, the drum through the operation of the unbalance detection section 922 I can detect the unbalance of my laundry. In the embodiment, the sensed soft balancing degree is not suitable for performing the next dehydration section, so the operation of the load shedding section 924 may be performed. The unbalance of laundry in the drum can be controlled through this load-shaping operation.

In an embodiment, the unbalance detection section 922 performs the operation of the load shedding section 924 after maintaining rotation for a certain time thereafter, but according to the embodiment, the degree of unbalance detected in the middle of the unbalance detection section 922 is Accordingly, the detection operation may be stopped even in the middle of the unbalance detection period 922 and the load shedding period 922 may be performed.

Thereafter, the operation of the secondary dehydration section 930 may be performed, and this may also be performed correspondingly to the previously described embodiment. In the second half of the secondary dehydration section 930, a corresponding operation can be performed in the unbalance detection section 932, and the unbalance detection section 932 corresponds to the operation of the unbalance detection section 922 of the previous step. manner, but the starting rpm may be different.

If the degree of unbalance detected in the unbalance detection section 932 is suitable for performing the operation of the third dehydration section 930, the corresponding operation is performed by immediately entering the third dehydration section 930 without performing the load sweep operation. can be done

In this way, after performing the dehydration operation in the dehydration section, the corresponding operation is performed in the unbalance detection section before entering the next dehydration section, and it is determined whether or not to perform the operation of the load shaking section according to the detected unbalance degree. By performing load sweeping only in this case, the dehydration section can be efficiently performed and the time required can be reduced.

On the other hand, in the present specification and drawings, preferred embodiments of the present invention have been disclosed, and although specific terms are used, these are only used in a general sense to easily explain the technical content of the present invention and help the understanding of the present invention, It is not intended to limit the scope of the invention. It will be apparent to those of ordinary skill in the art to which the present invention pertains that other modifications based on the technical spirit of the present invention can be implemented in addition to the embodiments disclosed herein.

Claims (10)

A washing machine control method comprising:
rotating the drum at the highest rotation speed corresponding to the first rpm during at least a part of the first dehydration section;
decelerating the rotational speed of the drum during at least a part of a first unbalance detection section after the first dehydration section;
rotating the drum at a maximum rotation speed corresponding to a second rpm higher than the first rpm during at least a part of a second dehydration section; and
and selectively performing a load shedding operation before starting the second spin-drying section according to the degree of laundry unbalance detected in the first unbalance detection section. According to claim 1,
The first unbalance detection section is
a first section for decelerating the rotational speed of the drum;
a second section for maintaining the rotational speed of the drum at a speed corresponding to the unbalance detection speed; and
A third section for accelerating the rotational speed of the drum,
The second section is a control method of a washing machine, characterized in that located between the first section and the third section. According to claim 1,
The first unbalance detection section is
a first section for decelerating the rotational speed of the drum with an acceleration corresponding to the first acceleration; and
and a second section for accelerating the rotational speed of the drum with an acceleration corresponding to the first acceleration. According to claim 1,
The first unbalance detection section is
and a holding section rotating at a speed corresponding to 1/3 or less of the first rpm. According to claim 1,
The method of controlling the washing machine, characterized in that the load sweeping operation comprises rotating the drum to maintain a maximum rotation speed of 80 rpm or less within 3 seconds. According to claim 1,
When the unbalancing operation detected in the first unbalance detection period is less than or equal to a reference value, the operation corresponding to the second spin-drying period is performed without stopping the rotation of the drum. 7. The method of claim 6,
The reference value is a control method of a washing machine, characterized in that the value is changed in response to the maximum rotation speed of the second spin-drying section. According to claim 1,
maintaining the rotation speed of the drum at a speed corresponding to the first rpm during at least a part of the second dehydration section;
accelerating the rotational speed of the drum to a speed corresponding to the second rpm during at least a part of the second dehydration period; and
The method of controlling a washing machine according to claim 1, further comprising: maintaining the rotational speed of the drum at a speed corresponding to the second rpm during at least a part of the second dehydration period. According to claim 1,
The number of sections in which the rotational speed of the drum is maintained in the second dehydration section when the load-shaking operation is performed is the number in which the rotational speed of the drum is maintained in the second dehydration section when the load-shaking operation is not performed A control method for a washing machine, characterized in that more. in the washing machine,
cabinet;
a tub accommodated in the cabinet;
a drum rotatably provided inside the tub;
a motor installed in the tub and providing rotational power to the drum; and
The drum rotates at the highest rotational speed corresponding to the first rpm during at least a part of the first spin-drying section, and during at least a part of the first unbalance detection section after the first spin-drying section, the rotating speed of the drum is reduced, and a second During at least a part of the spin-drying section, the drum rotates at the highest rotational speed corresponding to a second rpm higher than the first rpm, and before the start of the second spin-drying section according to the degree of unbalance of laundry detected in the first unbalance detection section A washing machine comprising a controller for controlling the motor to selectively perform a load shedding operation.

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