A washing machine control method

Abstract

The present invention relates to a washing machine control method which is suitable for use in controlling a washing machine (1) comprising a body (2), an oscillating group (6) having a tub (3) and a drum (5) suitable for being rotated in the tub (3) by means of a motor (4), at least one transport safety member (7) which is suitable for being removably connected between the body (2) and the oscillating group (6) and which secures the oscillating group (6) to the body (2), at least one displacement sensor (8) which is suitable for measuring the displacement of the oscillating group (6), at least one unbalanced load detection circuit (9) which is suitable for measuring the amount of unbalanced load inside the rotated drum (5), and a control unit (10) which is configured to operate in communication with the motor (4), the displacement sensor (8), and the unbalanced load detection circuit (9), comprising the step of measuring the displacement at least once by the displacement sensor (8) while the drum (5) is rotated at a speed not falling below a minimum displacement measurement speed.

Description

[0001] 7.3635

[0002] DESCRIPTION

[0003] A WASHING MACHINE CONTROL METHOD

[0004] The present invention relates to a control method for a washing machine which enables the detection of the transport safety bolt.

[0005] In washing machines, generally, the oscillating group comprising the tub which receives the washing water and the drum which rotates in the tub is flexibly connected to the body of the washing machine by components such as springs and dampers in order to absorb the oscillating movements that occur during washing and spin-drying. However, the flexible connection which enables the oscillating group to perform oscillating motion may result in damaging the oscillating group as the same hits the body during transportation of the washing machine. Therefore, manufacturers generally use transport safety members which temporarily fix the oscillating group to the body in order to ensure transportation safety. Enabling the oscillating group to oscillate by removing the transport safety member during the post-transport installation stage is critically important for the washing machine to operate in a balanced and safe manner. If the transport safety member is not removed, the oscillating group remains fixed to the body despite the driving force of the motor, resulting in damage to the oscillating group, and the washing machine may become inoperable upon the very first operation. This type of problem is frequently encountered especially in cases where the installation is performed by users since most users are not aware that the transport safety member must be removed prior to use. Therefore, the manufacturers have developed various control methods to detect whether the transport safety member has been removed, by means of different sensors, in order to prevent incorrect operation. However, in the state of the art, the said methods may lead to incorrect detection and misguide users in cases where the transport safety member has been removed, but the washing machine is not placed evenly on the floor, or the load distribution inside the drum is unbalanced. Therefore, there is a need for a washing machine control method which detects with high accuracy whether the transport safety is removed or not.

[0006] In the state of the art European Patent No. EP2175061B1, a washing machine is disclosed, wherein it is detected whether the tub is connected to the body based on the measured load amount and displacement. In the said method, when it is determined that the displacement is low despite the inertia varying with the amount of load, it is decided that the tub is connected to the body. However, since in the said method the inertia is directly proportional to the laundry load 7.3635 inside the drum, it may result in failure of detection under low load, and may also cause incorrect detection when the inertia is altered by other factors such as the balance of the body or load imbalance.

[0007] The aim of the present invention is the realization of a washing machine control method which detects with high accuracy whether the transport safety is removed or not.

[0008] The washing machine control method realized in order to attain the aim of the present invention, explicated in the first claim and the respective claims thereof is suitable for use in a washing machine comprising a body, an oscillating group movably connected to the body and having a drum which is suitable for receiving the laundry and which is rotated by a motor at least partially about a horizontal axis and a tub wherein the drum is disposed and which receives the washing water, at least one transport safety member which is suitable for fixing the oscillating group to the body and which is removably connected between the body and the oscillating group, at least one displacement sensor which is provided on the oscillating group and which is suitable for detecting the displacement amount of the oscillating group on at least one axis, an unbalanced load detection circuit which is suitable for detecting the amount of load unevenly distributed along the rotated drum wall, and a control unit which receives data from the displacement sensor and the load detection circuit and which is suitable for controlling the operating status based on the received data; the washing method control method comprising the steps of detecting the unbalanced load amount by means of the unbalanced load detection circuit during the rotation of the drum, detecting the displacement amount of the oscillating group on at least one axis by means of the displacement sensor while the drum is rotated at a minimum displacement measurement speed or above the minimum displacement measurement speed, identifying the expected displacement value corresponding to the detected unbalanced load amount from among a plurality of expected displacement values, each corresponding to a different unbalanced load amount, which are predetermined by the manufacturer and assigned to the control unit, comparing the detected displacement amount with the corresponding expected displacement value, and detecting the transport safety member has not been removed when the detected displacement amount is found to be smaller than the expected displacement value. Thus, by directly comparing the amount of unbalanced load, which is directly related to the oscillation occurring in the oscillating group, with the displacement amount to be caused by the detected unbalanced load amount, the presence of the transport safety member can be detected with high accuracy regardless of the amount of laundry. Moreover, by means of the said method, when there is another factor such as uneven placement of the body which may contribute to load 7.3635 imbalance, the contribution of this factor to the imbalance is also included in the measurement by the unbalanced load detection circuit, and therefore, in a case where the transport safety member is installed but part of the measured displacement is not directly related to the laundry amount, the false detection that the transport safety member has been removed is also prevented.

[0009] In an embodiment of the present invention, during the displacement measurement, the drum is accelerated from the minimum displacement measurement speed to a predefined maximum measurement speed, and the displacement measurement is performed during the acceleration of the drum. Thus, by performing the displacement measurement during the acceleration, when the effect of the unbalanced load is amplified compared to the constant- speed rotation, the difference between the unbalanced load amount and the expected displacement value in the presence of the transport safety member is increased, and the measurement accuracy is improved.

[0010] In an embodiment of the present invention, the minimum displacement measurement speed is determined as 100 RPM. 100 RPM is defined as the lowest drum rotation speed which allows high-accuracy detection of displacement caused by unbalanced load distribution, when the laundry in the drum is distributed along the drum wall and remains stationary relative to the drum. Thus, the reliability of the measurement is improved.

[0011] In another embodiment of the present invention, the maximum displacement measurement speed is determined as 300 RPM. 300 RPM is determined as the highest speed that allows the oscillating group to be rotated without being damaged when the transport safety member is installed.

[0012] In an embodiment of the present invention, the step of measuring the displacement is performed sequentially after the step of measuring the unbalanced load amount. Thus, when it is detected that the load imbalance is high, it becomes possible to reduce the drum acceleration such that the displacement measurement is performed at the minimum displacement measurement speed or at a speed closer to the minimum displacement speed than to the maximum displacement speed. Consequently, in cases where the unbalanced load is high and the transport safety member is installed, possible damage to the oscillating group is minimized.

[0013] In an embodiment of the present invention, during the step of measuring the unbalanced load amount, the drum is rotated at a constant speed at an unbalanced load measurement speed lower than the minimum displacement measurement speed. Thus, the unbalanced load amount is detected before the drum reaches the minimum displacement measurement speed, and it becomes possible to accelerate the drum with low acceleration so as to reach the minimum displacement 7.3635 measurement speed more slowly in the case of a high unbalanced load. Consequently, by enabling the drum to reach the displacement measurement speed more safely under high imbalance, damage to the oscillating group during the measurement is prevented.

[0014] In an embodiment of the present invention, the step of measuring the unbalanced load amount and the step of measuring the displacement are performed simultaneously. Thus, by simultaneously determining the displacement measured in response to the detected unbalanced load, it becomes possible to detect, with higher accuracy, the possible difference between the expected displacement and the measured displacement. This embodiment is particularly advantageous when the washing machine control method is applied at the start of each washing cycle, ensuring the detection of whether the transport safety member is installed so as to achieve an optimal balance between the safety of the oscillating group and the detection speed.

[0015] In another embodiment of the present invention, at least two expected displacement values are determined by performing the step of measuring the unbalanced load amount and the step of measuring the tub displacement simultaneously and at least twice, and when it is detected that the difference between the expected displacement values is greater than a limit expected displacement value, it is determined that the transport safety member is installed. This embodiment is advantageous in cases where one of the instantaneous displacement and imbalance measurements coincides with the balance state of the harmonic motion of the load so as to enable the balancing of the expected displacement values by means of the other instantaneous displacement and imbalance measurement. Thus, the detection of whether the transport safety member is installed can be performed both rapidly and with high accuracy.

[0016] In another embodiment of the present invention, the water is taken into the tub before the step of measuring the unbalanced load amount so as to wet the laundry. Thus, by increasing the weight of the load in the drum, the imbalance effect is enhanced, and more precise detection is enabled.

[0017] In another embodiment of the present invention, the drum is gradually accelerated before the step of measuring the unbalanced load amount, without exceeding a predetermined threshold acceleration, and brought to the unbalanced load measurement speed. The threshold acceleration provides a slow acceleration which is not suitable for homogeneous distribution of the load in the drum. The threshold acceleration is preferably determined as 10 RPM / s. Thus, by preventing homogeneous distribution of the load in the drum before the step of measuring the unbalanced load, the effect of load imbalance is not reduced, and the accuracy of detection is improved. 7.3635

[0018] In another embodiment of the present invention, when the presence of the transport safety member is detected, at least one safety step is activated, and the safety step comprises the step of stopping the motor and terminating the drum rotation. Thus, damage to the oscillating group is prevented.

[0019] In another embodiment of the present invention, the safety step preferably comprises providing an audible and / or visual warning to the user via an interface provided on the washing machine. The audible and / or visual warning is preferably provided via an interface provided on the washing machine. Thus, the user is enabled to be guided to remove the transport safety member.

[0020] By means of the present invention, a washing machine control method is realized, which enables the highly accurate detection of whether the transport safety member has been removed after installation of the washing machine.

[0021] The washing machine control method and the washing machine suitable for using the washing machine control method realized in order to attain the aim of the present invention is illustrated in the attached figures, where:

[0022] Figure 1 - is the schematic view of a washing machine suitable for using the washing machine control method of the present invention.

[0023] Figure 2 - is the flow chart of the washing machine control method of the present invention.

[0024] The elements illustrated in the figures are numbered as follows:

[0025] 1. Washing machine

[0026] 2. Body

[0027] 3. Tub

[0028] 4. Motor

[0029] 5. Drum

[0030] 6. Oscillating group

[0031] 7. Transport safety member

[0032] 8. Displacement sensor

[0033] 9. Unbalanced load detection circuit

[0034] 10. Control unit 7.3635

[0035] The washing machine control method is suitable for use in controlling a washing machine (1) comprising a body (2), an oscillating group (6) having a tub (3) and a drum (5) suitable for being rotated in the tub (3) by means of a motor (4), at least one transport safety member (7) which is suitable for being removably connected between the body (2) and the oscillating group (6) and which secures the oscillating group (6) to the body (2), at least one displacement sensor (8) which is suitable for measuring the displacement of the oscillating group (6), at least one unbalanced load detection circuit (9) which is suitable for measuring the amount of unbalanced load inside the rotated drum (5), and a control unit (10) which is configured to operate in communication with the motor (4), the displacement sensor (8), and the unbalanced load detection circuit (9), the washing machine control method comprising the step of measuring the displacement at least once by the displacement sensor (8) while the drum (5) is rotated at a speed not falling below a minimum displacement measurement speed. The displacement sensor (8) is preferably an accelerometer positioned on the oscillating group (6) and is suitable for detecting the amount of displacement of the oscillating group (6). The unbalanced load detection circuit (9) preferably comprises a current meter which monitors the current of the motor (4), and is configured to detect the current drawn by the motor (4) in relation to the unbalanced load amount in the drum (5), and to detect the unbalanced load amount according to the magnitude of the current. When a washing operation is activated in the washing machine (1), the control unit (10) is configured to regulate the operating status of the washing machine (1) in accordance with the control method. The control unit (10) is also suitable for sending signals to the displacement sensor (8) and the unbalanced load detection circuit (9) to initiate measurement of the unbalanced load amount and the displacement, and for receiving the measured unbalanced load and displacement data. When the washing operation is activated, the control unit (10) drives the motor (4) so as to rotate the drum (5) in the tub (3), and, after the drum (5) speed reaches the minimum displacement measurement speed, communicates with the displacement sensor (8) and ensures that the displacement amount of the oscillating group (6) on at least one axis is measured by means of the displacement sensor (8).

[0036] The washing machine control method of the present invention comprises the steps of measuring the unbalanced load amount at least once; determining the expected displacement value corresponding to the measured unbalanced load amount from among a plurality of expected displacement values predefined in the control unit (10) for different unbalanced load amounts; comparing the determined expected displacement value with the measured displacement; and detecting that the transport safety member (7) is installed if the measured displacement is smaller 7.3635 than the determined expected displacement value. While the drum (5) is rotated by the motor (4), the control unit (10) operates the unbalanced load detection circuit (9) at least once to measure the unbalanced load amount and operates the displacement sensor (8) at least once to measure the displacement of the oscillating group (6) so as to receive the measured values. A plurality of expected displacement values corresponding to a plurality of different unbalanced load amounts are predefined by the manufacturer, and the expected displacement values for each unbalanced load amount are assigned to the control unit (10). The expected displacement value corresponds to the displacement that the oscillating group (6) is expected to exhibit for each unbalanced load amount when the transport safety member (7) is not installed. The control unit (10) matches the measured unbalanced load amount received from the unbalanced load detection circuit (9) with a predefined unbalanced load amount and identifies the expected displacement value predefined for the said unbalanced load amount. By comparing the identified expected displacement value with the measured displacement obtained from the displacement sensor (8), the control unit (10) detects the possible difference between the measured displacement and the expected displacement. If the control unit (10) detects that the measured displacement is lower than the expected displacement value, it is determined that the expected displacement value could not be reached due to the movement of the oscillating group (6) being restricted by the transport safety member (7). Following the detection that the transport safety member (7) is installed, the washing operation is preferably terminated.

[0037] In an embodiment of the present invention, during the step of measuring the displacement, the drum (5) is rotated by being gradually accelerated to a speed not exceeding a maximum displacement measurement speed, which is higher than the minimum displacement measurement speed, and the displacement is measured while the drum (5) is being accelerated. The control unit (10) drives the motor (4) by gradually accelerating such that the drum (5) does not exceed the maximum displacement measurement speed, and ensures that the displacement sensor (8) performs measurement as soon as the drum (5) reaches or slightly exceeds the minimum displacement measurement speed. The displacement measurement is carried out during the accelerated motion of the drum (5) so as to enable the oscillating group (6) to exhibit greater displacement compared to motion at constant acceleration during the moment of displacement measurement, and thus the accuracy and precision of the displacement measurement are improved.

[0038] In another embodiment of the present invention, the minimum displacement measurement speed is determined as 100 RPM. The minimum displacement measurement speed is predetermined by 7.3635 the manufacturer as the lowest drum (5) speed at which the displacement sensor (8) performs the displacement measurement. Thus, the displacement measurement is enabled to be carried out at 100 RPM, which is the lowest drum (5) speed at which the oscillating group (6) starts to enter resonance, or at a speed above 100 RPM, which is closer to the speed at which the oscillating group (6) exhibits maximum resonance. Consequently, by benefiting from the resonance effect at the moment of displacement measurement, the oscillating group (6) is enabled to exhibit greater displacement, and the accuracy and precision of the displacement measurement are improved.

[0039] In another embodiment of the present invention, the maximum displacement measurement speed is determined as 300 RPM. The maximum displacement measurement speed is predetermined by the manufacturer as the highest drum (5) speed at which the displacement sensor (8) performs the displacement measurement. Thus, the displacement measurement is ensured to be performed at a drum (5) speed below 300 RPM, which is the highest speed at which the resonance of the oscillating group (6) begins to decrease, and, by limiting the maximum drum (5) speed to 300 RPM, the magnitude of opposing forces acting on the oscillating group (6) in the case where the transport safety member (7) is installed is limited, and potential motor (4) strain and oscillating group (6) damage which may occur at higher drum (5) speeds are prevented.

[0040] In another embodiment of the present invention, the step of measuring the unbalanced load amount is performed before the step of measuring the displacement. The unbalanced load measurement is performed at a drum (5) speed preferably lower than 100 RPM, before the relatively higher minimum displacement measurement speed is reached, which causes homogenization of the distribution of the load in the drum (5). Thus, a higher unbalanced effect is achieved at the moment of unbalanced load measurement, and the accuracy and precision of the unbalanced load measurement are improved. Consequently, by sequentially performing the unbalanced load measurement and displacement measurement while the drum (5) is gradually accelerated, the presence of the transport safety member (7) is enabled to be detected more quickly.

[0041] In another embodiment of the present invention, during the step of measuring the unbalanced load amount, the drum (5) is rotated at a constant speed at an unbalanced load measurement speed which is lower than the minimum displacement measurement speed. The unbalanced load measurement is performed while the drum (5) is rotated by the motor (4) at a constant speed at an unbalanced load measurement speed, which is predetermined by the manufacturer to be lower than 100 RPM. The non-accelerated motion of the drum (5) promotes the movement of the load 7.3635 in the drum (5) under the effect of gravity, thereby increasing the accuracy of the unbalanced load measurement.

[0042] In another embodiment of the present invention, the step of measuring the unbalanced load amount and the step of measuring the displacement are performed simultaneously. The unbalanced load measurement and the displacement measurement are performed simultaneously while the drum (5) is rotated at a speed predetermined by the manufacturer, preferably at the minimum displacement measurement speed. This embodiment is advantageous in terms of measuring the instantaneous displacement caused by the unbalanced load without any time gap between the measurements, and especially increases the accuracy of the detection result regarding whether the transport safety member (7) is installed, in the case where the difference between the measured displacement and the determined expected displacement is small.

[0043] In another embodiment of the present invention, at least two expected displacement values are determined by performing the step of measuring the unbalanced load amount and the step of measuring the displacement simultaneously at least twice, and if at least one of the measured displacements is smaller than the determined expected displacement value, it is detected that the transport safety member (7) is installed. While the drum (5) is rotated by the motor (4), at least two measurements of unbalanced load amount and displacement are performed simultaneously, at least one being performed at a speed at or above the minimum displacement measurement speed. Preferably, at least one of the simultaneous measurements of unbalanced load amount and displacement is performed at the unbalanced load measurement speed, which is detected to be below 100 RPM. If the at least two expected displacement values obtained as a result of at least two simultaneous measurements of unbalanced load amount and displacement are lower than the measured displacements, it is detected that the transport safety member (7) is installed. In a preferred version of this embodiment, the presence of the transport safety member (7) is detected by comparing the difference between the expected displacement values and the difference between the measured displacements. Thus, by increasing the number of simultaneous measurements, the possibility of erroneous detection due to coincidence with a temporary balance state during the measurement is eliminated.

[0044] In another embodiment of the present invention, the washing machine control method comprises the step of taking water into the tub (3) before the step of measuring the unbalanced load amount. Before the unbalanced load measurement, the water is taken into the tub (3) to ensure that the laundry in the drum (5) is at least partially wet. Thus, the unbalanced effect caused by 7.3635 the rotating laundry in the drum (5) is increased before the unbalanced load measurement so as to improve the sensitivity of the unbalanced load measurement.

[0045] In another embodiment of the present invention, before the step of measuring the unbalanced load amount, the drum (5) is rotated by being accelerated so as not to exceed a threshold acceleration. When a washing process is initiated in the washing machine (1), the drum (5) is rotated by the motor (4) by being gradually accelerated without exceeding a threshold acceleration. In other words, the drum (5) does not reach the unbalanced load measurement speed before the unbalanced load measurement step, and is brought to the unbalanced load measurement speed by being gradually accelerated so as not to exceed the threshold acceleration. Thus, the reduction of load imbalance caused by the distribution of the load in the drum (5) before the unbalanced load measurement is prevented.

[0046] In another embodiment of the present invention, the threshold acceleration is defined as 10 RPM / s. Thus, it is ensured that the laundry in the drum (5) is almost not distributed before the unbalanced load measurement.

[0047] In another embodiment of the present invention, the washing machine control method comprises the step of stopping the motor (4) when it is detected that the transport safety member (7) is installed. When it is detected that the transport safety member (7) is installed, the motor (4) is stopped and the ongoing washing process is terminated.

[0048] In another embodiment of the present invention, the washing machine control method comprises the step of generating an audible and / or visual warning when it is detected that the transport safety member (7) is installed. When it is detected that the transport safety member (7) is installed, a visual warning and / or an audible warning is generated by the control unit (10), preferably via an indicator, and the user is informed that the transport safety member is installed.

[0049] By means of the present invention, a washing machine control method is realized, which ensures that whether the transport safety member (7) is installed is detected with high accuracy. Moreover, the washing machine control method ensures that, during the detection of the presence of the transport safety member (7), the speed of the motor (4) is effectively controlled so as to minimize possible damages to the oscillating group (6).

Claims

35CLAIMS1. A washing machine control method which is suitable for use in controlling a washing machine (1) comprising a body (2), an oscillating group (6) having a tub (3) and a drum (5) suitable for being rotated in the tub (3) by means of a motor (4), at least one transport safety member (7) which is suitable for being removably connected between the body (2) and the oscillating group (6) and which secures the oscillating group (6) to the body (2), at least one displacement sensor (8) which is suitable for measuring the displacement of the oscillating group (6), at least one unbalanced load detection circuit (9) which is suitable for measuring the amount of unbalanced load inside the rotated drum (5), and a control unit (10) which is configured to operate in communication with the motor (4), the displacement sensor (8), and the unbalanced load detection circuit (9), comprising the step of measuring the displacement at least once by the displacement sensor (8) while the drum (5) is rotated at a speed not falling below a minimum displacement measurement speed, characterized by the steps of• measuring the unbalanced load amount at least once;• determining the expected displacement value corresponding to the measured unbalanced load amount from among a plurality of expected displacement values predefined in the control unit (10) for different unbalanced load amounts;• comparing the determined expected displacement value with the measured displacement; and• detecting that the transport safety member (7) is installed if the measured displacement is smaller than the determined expected displacement value.

2. A washing machine control method as in Claim 1, characterized by, during the step of measuring the displacement, rotating the drum (5) by being gradually accelerated to a speed not exceeding a maximum displacement measurement speed, which is higher than the minimum displacement measurement speed, and measuring the displacement while the drum (5) is being accelerated.

3. A washing machine control method as in Claim 2, characterized by the minimum displacement measurement speed is determined as 100 RPM.

4. A washing machine control method as in Claim 2 or Claim 3, characterized by the maximum displacement measurement speed is determined as 300 RPM.

355. A washing machine control method as in any one of the above claims, characterized in that the step of measuring the unbalanced load amount is performed before the step of measuring the displacement.

6. A washing machine control method as in any one of the above claims, characterized by, during the step of measuring the unbalanced load amount, rotating the drum (5) at a constant speed at an unbalanced load measurement speed which is lower than the minimum displacement measurement speed.

7. A washing machine control method as in any one of Claims 1 to 4, characterized in that the step of measuring the unbalanced load amount and the step of measuring the displacement are performed simultaneously.

8. A washing machine control method as in Claim 7, characterized by, determining at least two expected displacement values by performing the step of measuring the unbalanced load amount and the step of measuring the displacement simultaneously at least twice, and detecting that the transport safety member (7) is installed if at least one of the measured displacements is smaller than the determined expected displacement value.

9. A washing machine control method as in any one of the above claims, characterized by the step of taking water into the tub (3) before the step of measuring the unbalanced load amount.

10. A washing machine control method as in any one of the above claims, characterized by, before the step of measuring the unbalanced load amount, rotating the drum (5) by being accelerated so as not to exceed a threshold acceleration.

11. A washing machine control method as in Claim 10, characterized by the threshold acceleration which is defined as 10 RPM / s.

12. A washing machine control method as in any one of the above claims, characterized by the step of stopping the motor (4) when it is detected that the transport safety member (7) is installed.

13. A washing machine control method as in any one of the above claims, characterized by the step of generating an audible and / or visual warning when it is detected that the transport safety member (7)

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