KR101215445B1 - Washing Machine And Method For Controlling Unbalance The Same - Google Patents

Abstract

Disclosed are a washing machine and an unbalance control method for performing a dehydration stroke according to a pure speed variation due to unbalance from a speed signal of a rotary tub while balancing laundry put into a rotary tub.

The disclosed invention includes a control unit for controlling the speed of the washing motor for dewatering operation according to the inclination of the unbalance level calculated from the motor speed signal corresponding to the speed of the washing motor for rotating the rotating tub containing the laundry.

According to the present invention, since the actual dehydration operation is performed according to the slope of the unbalance level while the winding is carried out, the overall dehydration time can be shortened, and unnecessary noise and vibration occurring when the unbalance level is smaller than the reference level can be effectively prevented.

Description

Washing Machine And Method For Controlling Unbalance The Same}

1A and 1B are diagrams illustrating an unbalanced state and a balanced state.

Figure 2 is a graph showing the speed change of the washing motor according to the conventional unbalance detection method.

Figure 3 is a graph showing the motor speed, the calculated average speed and the actual average speed in the unbalance detection interval.

4 is a block diagram of a washing machine according to the present invention.

5 is a detailed block diagram of the controller of FIG. 4.

6A to 6E are diagrams illustrating a series of processes for obtaining a pure unbalance level due to unbalance from a motor speed signal.

7 is a flowchart illustrating a method for controlling an unbalance of a washing machine according to the present invention.

Description of the Related Art [0002]

200: control unit

300: motor drive unit

400: laundry motor

The present invention relates to a washing machine and an unbalance control method for performing a dehydration stroke according to a pure speed variation due to unbalance from a speed signal of a rotary tub while balancing laundry put into a rotary tub.

The washing machine includes a washing motor for rotating a rotation tub for receiving laundry. The controller, which controls the whole series of washing operations such as washing, rinsing and dehydration, controls the rotation speed of the washing motor.

When dewatering by centrifugal force by the high speed rotation of the rotary tub, in the unbalanced state in which the laundry 3 injected into the inner space 2 of the rotary tub 1 is aggregated to one side, the rotary tub vibrates violently and makes noise. Cause. In order to suppress noise, it is preferable to perform dehydration operation in a balanced state in which laundry is evenly arranged as shown in FIG. 1B.

In addition to the problem of noise caused by unbalance as well as dehydration of laundry in a condensed state, the dehydration efficiency is reduced and wrinkles of the laundry are generated. Therefore, unbalance is detected and handled at the initial stage of dehydration operation.

In the past, a method for detecting unbalance using a change in motor speed has been developed.

It is very difficult to measure the motor speed change because the change of the motor speed changes instantaneously while changing the motor speed. Therefore, the method of measuring the motor speed change with the constant motor speed in a certain section is used. .

In the conventional method of detecting unbalance, as shown in FIG. 2, the motor rotation speed is increased to carry out a cloth winding so that laundry adheres to the inner surface of the rotary tub, and then the motor speed is kept constant in the unbalance detection section. The variation of the motor speed was measured in this section, and the unbalanced state was determined according to the unbalance amount calculated based on the measured speed variation of the motor.

However, when the motor speed applied to the unbalance detection section is low, the laundry in the rotary tub moves and the actual motor speed detected by the speed sensor is not kept constant but changes as shown by the solid line in FIG. 3, and the actual speed of the motor speed is changed. The average speed also changes as indicated by the broken line in FIG. 3. However, the calculated average speed obtained by averaging the measured motor speed is constant as indicated by the dashed-dotted line in FIG. Therefore, the motor speed variation is obtained from an average speed calculated differently from the actual one, and as a result, an unbalance determination error is caused.

When the motor speed applied to the unbalance detection section is increased, the laundry is stuck in the rotary tub so that the average speed of the motor is kept constant so that the reliability of the unbalance determination can be secured. However, if excessive unbalance is detected as a result of the determination, the total time of the dehydration operation is lengthened because it is necessary to repeatedly bring the baling machine to balance.

In addition, the unbalanced level gradually decreases as most of the laundry in the rotating tub is evenly distributed during the winding operation, and then stabilizes in a balanced state through a transition period in which the unbalanced state and the balanced state alternately appear at a certain point in time. In the transition period, there was a problem that the unbalance level was not excessively large but still produced noise and vibration that could not be ignored. Therefore, in the early stage of stabilization, it is necessary to quickly switch to the actual dehydration operation to prevent unnecessary noise and vibration.

The present invention was conceived in view of the conventional technology as described above, and an object of the present invention is to control the speed of the washing motor by controlling the speed of the washing motor according to the inclination of the unbalance level calculated from the motor speed signal of the washing motor at the same time as the winding operation. To provide a washing machine and its unbalance control method to reduce vibration.

The present invention for achieving the above object, a rotary tub for receiving laundry; A washing motor for rotating the rotary tub; A motor speed detector for outputting a motor speed signal corresponding to the speed of the washing motor; And calculating an unbalance level from the motor speed signal, and recognizing that the rotary tub is stabilized to a balanced state in an unbalanced state when the time obtained from the unbalanced level data is maintained above 0 is equal to the slope of. According to the characterized in that it comprises a control unit for controlling the speed of the washing motor for dehydration operation.

The control unit may include a speed ripple extracting unit for extracting a speed ripple from the motor speed signal provided from the motor speed detecting unit, an absolute value calculating unit for outputting a signal waveform greater than zero by squaring the extracted speed ripple, and outputting the output signal from the absolute value calculating unit. An unbalance level detector for detecting a pure unbalance level due to unbalance, an unbalance determination unit for comparing the detected unbalance level with a reference level, and determining an unbalance, a slope calculation unit for calculating a slope of the detected unbalance level, and determining the unbalance. And a motor controller for controlling the motor speed according to the unbalance determination result provided from the controller and the inclination of the unbalance level calculated by the tilt calculator, wherein the motor controller is configured to maintain data obtained from the unbalance level as zero or more. This time If the set time or more, the speed of the washing motor is increased to the set speed, and the data is characterized in that the slope of the unbalance level.

The controller further includes a timer for counting a time for which the unbalance level is maintained at zero or more.

The controller calculates the slope of the unbalance level while simultaneously winding the laundry on the rotary tub.

The present invention for achieving the above object, the unbalance control method of the washing machine having a motor speed detection unit for detecting the speed of the washing motor for rotating the rotary tub for accommodating the laundry and for controlling the unbalance caused by the imbalance of the laundry The method of claim 1, further comprising: driving the washing motor to wind the laundry on the inner surface of the rotary tub; Calculate an unbalance level from a motor speed signal corresponding to the speed of the laundry motor; And controlling the speed of the washing motor for dehydration operation by recognizing that the rotary tub is initially stabilized to a balanced state in an unbalanced state when the time obtained from the unbalanced level is maintained at 0 or more. It features.

The speed control operation of the washing motor increases the speed of the washing motor to a set speed when a time for which the data obtained from the unbalance level is kept above 0 is a set time or more, and the data is a slope of the unbalance level. It is done.

The inclination of the unbalance level is calculated simultaneously with the operation of winding the laundry on the rotary tub.

Hereinafter, the embodiment according to the present invention will be described in detail.

Figure 4 is a block diagram of a washing machine according to the present invention, showing a configuration for driving the washing motor for the dewatering operation to the well-known components not shown in Figure 4 to perform the washing and rinsing operation as well as dewatering operation Applicable

As shown in FIG. 4, the washing machine according to the present invention includes an input unit 100 for inputting a driving command of a user including setting of a dehydration operation, and a control unit for controlling overall operations of the washing machine such as washing, rinsing, and dehydration. 200, a motor driving unit 300 for driving the washing motor 400 under the control of the controller 200, and a motor speed signal corresponding to the rotation speed of the washing motor 400, to the controller 200. It includes a motor speed detector 500 for providing. Here, the motor speed detector 500 may be implemented as a hall sensor or an encoder.

As illustrated in FIG. 5, the control unit 200 includes a speed ripple extracting unit 210, an absolute value calculating unit 220, an unbalanced level detecting unit 230, an unbalance determining unit 240, an inclination calculating unit 250, and a motor. The controller 260 and the timer 270 are configured to be included.

In the case of dehydration operation after finishing washing and rinsing, first, the washing motor 400 is driven to perform a washing machine that causes the laundry to stick to the inner surface of the rotary tub. In this case, the laundry in the rotary tub is generally placed in the unbalanced state of FIG. 1A, and the laundry moves in the rotary tub when the rotation speed is low.

While changing the speed of the washing motor 400, the speed ripple detector 210 extracts the speed ripple Y2 from the motor speed signal Y1 provided from the motor speed detector 500.

The velocity ripple detector 210 may be implemented using a high pass filter (HPF) or a band pass filter (BPF). In an embodiment, a high pass filter HPF having a predetermined cutoff frequency Fcutoff-H is applied, and the cutoff frequency Fcutoff-H is set to less than 1/4 of the rotation frequency Ftub of the rotary tub.

The speed ripple Y2 provided by the speed ripple detection unit 210 to the absolute value calculating unit 220 is a signal waveform from which a DC component has been removed as shown in FIG. 6B.

The absolute value calculator 220 squares the velocity ripple (Y2 * Y2) and supplies a signal waveform Y3 greater than zero to the unbalanced level detector 230.

The unbalance level detector 230 removes components other than signal components due to unbalance and outputs the pure unbalance level Y4 due to unbalance to the unbalance determination unit 240 and the slope calculator 250. Here, the other component means a component generated due to mechanical characteristics such as a belt and a pulley for transmitting the motor power to the rotary tub. The unbalance level detector 230 may be implemented using a low pass filter LPF having a predetermined cutoff frequency Fcut-L.

The unbalance level Y4 supplied by the unbalance level detector 230 reflects the speed change of the motor in real time.

The unbalance determination unit 240 compares the provided unbalance level Y4 with a preset reference level and determines whether or not it is unbalanced. As a result, if the unbalance level is greater than the reference level, for example, if the unbalance level is 310gd and the reference level is 300g, the laundry on the rotating tub is not wound evenly, and the unbalance determination signal can be continued to perform the cold winding operation. To the motor control unit 260. In addition, the unbalance determination unit 240 recognizes that the laundry of the rotary tub is wound evenly if the unbalance level is not greater than the reference level (for example, 300g), the motor control unit (unbalance determination signal to perform a dehydration operation). 260).

The slope calculating unit 250 calculates the slope of the provided unbalance level Y4, and calculates whether the calculated unbalance level has a positive slope greater than zero or the unbalance level has a negative slope less than zero. The slope signal corresponding thereto is provided to the motor controller 260.

The slope of the unbalanced level not greater than the reference level tends to change from time to time, as shown in FIG. 6E, and then to remain positive for a certain time with respect to the inflection point TP, and then to stabilize thereafter. Accordingly, the motor controller 260 counts the time using the timer 270 when the unbalance level slope X is positive, and recognizes that the motor control unit 260 stabilizes in a balanced state when the counted time is greater than or equal to the set time ts. And by outputting the motor drive signal to the motor drive unit 300 to rotate the rotary tub at high speed to perform a substantial dehydration operation.

The present invention detects an unbalance level from a motor speed signal while driving a washing motor, thereby determining unbalance in real time, and extracts a speed ripple from a motor speed signal to determine whether it is unbalanced therefrom. Judgment errors that occur at the time can be prevented.

In addition, since the present invention filters the velocity ripple using an absolute value calculation and a low pass filter, it is possible to prevent an unbalance determination error due to mechanical characteristics rather than unbalance.

In addition, the present invention can determine the unbalance at the same time while varying the motor speed, and if the balance is recognized as a result of the determination, it is possible to shorten the overall dehydration time because the tub can be rotated at a high speed to enter the actual dehydration operation immediately. have.

Hereinafter will be described the operation of the washing machine according to the present invention.

After finishing the washing and rinsing operation, the control unit 200 sets the dehydration operation mode (600).

Subsequently, the motor controller 260 controls the motor driver 300 to start driving the stopped washing motor 400 (610).

While driving the washing motor 400, the motor speed detector 500 supplies the detected motor speed signal Y1 to the controller 200 (620).

The speed ripple extracting unit 210 of the control unit 200 cutoff frequency (Fcutoff-H) set to less than 1/4 with respect to the rotation frequency (Ftub) of the rotary tub to extract the high speed velocity ripple (Y2) from the motor speed signal Pass through the high pass filter having a), and supplies the velocity ripple (Y2) from which the DC component is removed while passing through the high pass filter to the absolute value calculating unit 220 (630).

The absolute value calculating unit 220 squares the velocity ripple Y2 to calculate an absolute value such that all signals have a value greater than zero, and supplies the absolute value calculated signal Y3 to the unbalance level detecting unit 230 (640). ).

The unbalance level detector 230 passes a low pass filter (LPF) having a predetermined cutoff frequency (Fcutoff-L) to remove other components while leaving pure components due to unbalance in the received signal (Y3), and a low pass filter. The pure water unbalance level filtered while passing through is supplied to the unbalance determination unit 240 and the slope calculation unit 250 (650).

The unbalance determination unit 240 compares the provided unbalance level with a preset reference level and provides the unbalance determination signal accordingly to the motor controller 260. If the unbalance level is not less than the reference level, the motor controller 260 proceeds to operation 620 to control the motor driver 300 to continuously perform the winding operation (660).

When the unbalance level is smaller than the reference level, the slope calculator 2250 calculates the slope of the provided unbalance level (670), determines whether the calculated slope X is equal to or greater than zero, and outputs a slope determination signal according to the motor controller ( And outputs to 260 (680).

If the calculated slope X is not equal to or greater than zero, the motor controller 260 controls the motor driver 300 to proceed to operation 620 to continuously perform the winding operation.

On the other hand, if the calculated slope X is greater than or equal to zero, the motor controller 260 counts the time t using the timer 270 (690), and if the counted time t is greater than or equal to the set time ts. Determine (700). If it is determined that the counted time t is not greater than or equal to the set time ts, the operation proceeds to operation 680, and if the counted time t is greater than or equal to the set time ts, it is recognized as the initial stage of the stabilization state. Thus, the motor controller 260 controls the motor driver 300 to rotate the rotary tub at high speed, thereby performing a substantial dehydration operation.

In the above-described embodiment, a method of controlling the motor speed according to the inclination of the unbalance level while simultaneously operating the variable winding speed of the motor is described, but the present invention is not limited thereto and may be performed separately after the winding time is completed. .

As described above, the present invention can substantially reduce the total dehydration time since the dehydration operation is performed in accordance with the slope of the unbalance level while the winding is performed. In addition, the present invention can quickly enter the dehydration operation when the time of the slope is 0 or more than the set time, it is possible to effectively prevent unnecessary noise and vibration generated when the unbalance level is less than the reference level.

Claims (7)

A rotary tub to accommodate laundry; A washing motor for rotating the rotary tub; A motor speed detector for outputting a motor speed signal corresponding to the speed of the washing motor; And When the unbalance level is calculated from the motor speed signal, and the time at which the data obtained from the unbalance level is maintained at 0 or more is a set time or longer, the rotary tub is recognized as an initial stage of stabilization in an unbalanced state and dehydration operation is performed. Washing machine comprising a control unit for controlling the speed of the washing motor for. The method of claim 1, wherein the control unit Speed ripple extraction unit for extracting the speed ripple from the motor speed signal provided from the motor speed detection unit, an absolute value calculating unit for outputting a signal waveform greater than zero by squaring the extracted speed ripple, due to unbalance in the output signal of the absolute value calculating unit An unbalance level detector for detecting a pure unbalance level, an unbalance determination unit for determining whether there is unbalance by comparing the detected unbalance level with a reference level, a slope calculator for calculating a slope of the detected unbalance level, and providing the unbalance determination unit. And a motor controller for controlling the motor speed according to the unbalance determination result and the inclination of the unbalance level calculated by the inclination calculator. The motor control unit increases the speed of the washing motor to a set speed when the time obtained from the unbalanced level of the data is maintained at 0 or more is a set time or more. And said data is a slope of said unbalance level. The washing machine according to claim 2, wherein the control unit further comprises a timer for counting a time for which the unbalance level is maintained at 0 or more. The washing machine according to claim 1, wherein the controller calculates a slope of the unbalance level while simultaneously winding the laundry on the rotary tub. In the unbalance control method of the washing machine having a motor speed detection unit for detecting the speed of the washing motor for rotating the rotating tub for accommodating the laundry and for controlling the unbalance caused by the imbalance of the laundry, Driving the washing motor to perform a winding to wind laundry on an inner surface of the rotary tub; Calculate an unbalance level from a motor speed signal corresponding to the speed of the laundry motor; And When the time obtained from the unbalanced level of the data is maintained at 0 or more is a set time or more, the rotary tub is recognized as the initial stabilization to the balanced state from the unbalanced state to control the speed of the washing motor for dehydration operation Unbalance control method of the washing machine. The speed control operation of the washing motor increases the speed of the washing motor to a predetermined speed when a time for which data obtained from the unbalance level is kept above 0 is a set time or more. The data is an unbalance control method of the washing machine, characterized in that the slope of the unbalance level. 6. The method of claim 5, wherein the inclination of the unbalance level is calculated simultaneously with the operation of winding the laundry on the rotary tub.

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