KR100258990B1 - Method of detecting the weight of laundary in washing machine - Google Patents

Abstract

PURPOSE: A detecting method of the washing amount in a washing machine is provided to improve the detecting accuracy of the washing amount by increasing detecting information amount of the washing amount and to exactly detect the washing amount by improving a detecting algorithm of the washing amount. CONSTITUTION: The washing amount is detected by detecting positive and negative AC signals with an interactive photo coupler. A number of pulses through the photo coupler is integrated until a motor is stopped and time changes between the pulses are integrated. The washing amount is decided with a pulse number look-up table when the integrated entire number of pulses is larger than a first reference number of pulses. Otherwise, the number of pulses is compared with a second reference number of pulses. The washing amount is decided with the pulse number look-up table when the number of pulses is smaller than the second reference number of pulses. Otherwise, the washing amount is decided with a pulse time look-up table.

Description

Method of detecting the weight of laundary in washing machine}

The present invention relates to a quantity detection system of a washing machine, and in particular, to improve the quantity detection information by improving the current quantity detection circuit to improve the quantity detection accuracy, and also to improve the quantity detection algorithm to reduce the amount of laundry (amount) input It relates to a quantity detection method of the washing machine to detect more accurately.

As shown in FIG. 1, the conventional washing machine is driven by an operating power source obtained from a load driving unit (not shown in the drawing) under the control of a microcomputer (not shown in the drawing) that controls the entire system of the washing machine to generate power. Washing motor 1, a clutch (2) receiving power from the washing motor (1) through a pulley, V-belt and clutch pulley, and the washing tank (4) receiving power from the clutch (2) It consists of the pulsator 3 which makes the wash water vortex inside, the dehydration tank 5, the water supply valve 6, and the water level sensor 7.

In the drawings, reference numeral 8 denotes a snubber bar, 9 denotes a damper, and 10 denotes a case.

FIG. 2 is a circuit diagram of a conventional washing machine for detecting a quantity of a washing machine. As shown in FIG. 2, the washing motor 1 is turned on in accordance with a control signal output from a microcomputer (not shown). The load driving unit 2 including the first and second triacs TA1 and TA2 and the condenser C2 for controlling the driving, and the washing motor 1 when the operating voltage applied to the washing motor 1 is cut off. It consists of a diode (D1) (D2) for detecting the amount of capacity by the excitation voltage generated by the rotational inertia force of the, and the quantity detection unit (3) consisting of a unidirectional photo coupler (PC) and transistor (Q1).

Referring to Figures 1 to 3 the operation of the conventional washing machine configured as described above are as follows.

First, in order to wash laundry efficiently, it is necessary to appropriately set the quantity and detergent amount, the washing time, the number of rinses, and the water flow corresponding to the amount of laundry and the degree of contamination.

Therefore, washing has been performed by installing the user's judgment or the quantity detection means and automatically setting the water level in accordance with the detected quantity detection amount.

This laundry detection method is frequently used by the back electromotive force of the washing motor.

The method for detecting the amount of laundry by the counter electromotive force of the washing motor is described below.

First, when a user presses a washing key configured in a key input unit (not shown) and inputs a washing stroke by detection of a quantity, the microcomputer (not shown) reads a key signal of the key input unit and performs an initial operation.

That is, the microcomputer initially opens the cold and hot water valves through the cold water and hot water valves (not shown) through the load driving unit 2 to supply water to the washing tank 4 to a small level.

Then, when the water supply is completed to a small level in the washing tank 4 by the water level sensor 7 will drive the washing motor (1).

Accordingly, the pulsator 3 is rotated by being transmitted to the pulsator 3 through the belt and the clutch 2 connected to the washing motor 1.

On the other hand, when the power applied to the washing motor (1) is turned off, the pulsator (3) is rotated by the rotational inertia.

In accordance with the rotation of the pulsator (3) of the force of the pulsator (3) this time through the connected clutch (2) and the belt to rotate the washing motor (1) in reverse.

At this time, even after the power is turned off by the current flowing when the power is turned on, the washing motor 1 is gradually reduced in the amount of current remaining in the rotor.

As shown in FIG. 2, the attenuation voltage forms as shown in (a) and (b) of FIG.

In other words, this signal is the amount of information that appears through friction between the laundry and the dehydration tank.

This information is transmitted to the microcomputer in order to determine the quantity of current through the resistors at the two terminals A and B of FIG. 2 and through the photocoupler PC of the quantity sensing unit 3 for power separation. Convert to square wave pulse signal as shown in b).

Thereafter, the amount of signal transmitted to the microcomputer is compared with the data table previously stored by the control experiment to determine the quantity of the dose.

However, the conventional laundry laundry detection method of the washing machine has a large error in the variation of the parts of the washing machine, the assembly state, the use environment, and the detected amount of the signal signal, so that it is difficult to determine the appropriate washing level and detergent amount, Correct setting was difficult.

In addition, if the amount of water detected is smaller than the actual amount, the cloth is damaged by heavy friction between the laundry and the pulsator. there was.

Accordingly, the present invention improves the current quantity detection circuit to increase the amount of detection information by improving the quantity detection accuracy, and also by improving the quantity detection algorithm to detect the amount of laundry to be input more accurately, The purpose is to provide.

Operation method of the present invention for achieving the above object, in the washing machine for detecting the quantity using the back electromotive force appearing when the operation / stop of the motor, bidirectional forward and negative AC signal generated by the rotation of the motor power Detecting a quantity by detecting with a photo coupler, accumulating the number of pulses generated by the photo coupler until the motor stops, and integrating the time variation between pulses; Determining the amount of dose using the pulse number look-up table, which is a standard experimental value when it is larger than the first reference pulse number set in advance, and when the total number of pulses is smaller than the first reference pulse number, The number of pulses is compared with the preset second reference pulse number, and when the result is small, the standard pulse number look-up table is used. Determining a dose, and determining a dose using an inter-pulse time look-up table which is a standard experimental value when each pulse number is greater than the second reference pulse number. .

1 is a schematic configuration diagram of a conventional washing machine,

2 is a circuit diagram showing a quantity detection device of a conventional washing machine,

3 is a voltage waveform diagram according to the counter electromotive force of the conventional washing motor, (a) is the output waveform diagram of the A, B two terminals, (b) is an output waveform diagram by the photo coupler,

4 is a circuit diagram showing a quantity detection device of a washing machine applied to the present invention,

5 is a voltage waveform diagram according to the counter electromotive force of the washing motor applied to FIG. 4, (a) is an output waveform diagram of two E and F terminals, (b) is an output waveform diagram by a bidirectional photo coupler,

6 is a driving pattern diagram of the quantity sensing motor of the present invention;

7 is a time variation diagram between pulses in the quantity detection interval of the present invention,

8 is a graph showing the number of pulses and the time between pulses according to the quantity of the present invention,

9 is a flowchart illustrating a method of detecting a quantity of washing machine according to the present invention.

Explanation of symbols on the main parts of the drawings

101: washing motor 102: load driving unit

103: quantity detection unit

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

FIG. 4 is a circuit diagram of the apparatus for detecting a quantity of washing machine applied to the present invention, wherein the first and second triacs TA1 TA1 operate in response to an external control signal to control the driving of the washing motor 101. Load driving unit (102) consisting of a capacitor (C1), and the washing tank (freeness shown in the drawing) at the excitation voltage generated by the rotational inertia force of the washing motor 101 when the operating voltage applied to the washing motor 101 is cut off. In the case of the detection unit 103 consisting of a bidirectional photo coupler (PC), a switching element (Q1), a capacitor (C1) and a resistor (R1) (R2) for detecting the amount of internal capacity, It is comprised by the microcomputer (not shown in figure) which determines a quantity based on the output quantity detection signal, and controls the system as a whole.

Referring to the accompanying drawings, the operation and effect of the present invention configured as described above with reference to Figures 1 to 9 as follows.

First, in order to automatically and properly perform the washing process in the automatic washing machine, it is necessary to accurately determine the amount of laundry to be put.

For this purpose, the signal input to the microcomputer should represent a distribution area that can be distinguished according to each dose, which always has a constant tendency with respect to the change of the dose (with an appropriate slope with the increase of the dose).

Therefore, in the present invention, while using the mechanical rotational force transmission device such as a motor, belt, clutch, pulsator in the configuration diagram of the washing machine as shown in FIG. We have devised a method for detecting insensitive quantities.

That is, as a result of analyzing the conventional washing machine dose detection circuit shown in FIG. 2, the voltage between the two terminals A and B starts at about twice the power supply voltage when the power is turned on, and immediately after the power is turned off. Back EMF) waveform as shown in Fig. 3A.

The circuit configured to input this attenuated voltage to the microcomputer as a quantity information signal is the circuit of FIG.

Here, as a result of measuring the quantity of input signal to the microcomputer while measuring the voltage between the two terminals A and B, the counter electromotive force generated by the speed decrease due to the friction between the laundry and the dehydration tank is about 26V in the conventional circuit. When it is found that the signal is not delivered to the microcomputer.

That is, when the voltage between the two terminals A and B becomes 26 V or less, the voltage between C, D, G, and H of FIGS. 2 and 4 does not become 0.7 V or less due to the characteristics of the photocoupler.

Therefore, since the switching element Q1 is not operated, the microcomputer cannot detect this even if a signal is generated.

In order to operate the switching device Q1, a voltage of 0.7V or more and a voltage of a voltage of 0.7V or less must be alternately applied to the base terminal of the switching device Q1. The voltage between G and H shown in Fig. 1 does not become 0.7 V or less under the influence of the current IC1.

In addition, when the unidirectional photo coupler is used, signals generated in the opposite direction as shown in FIG.

Therefore, in the present invention, a circuit as shown in FIG. 4 is configured to solve this problem and deliver the signal generated to the microcomputer as much as possible.

That is, the generated amount information signal is the same as the existing one, but it is possible to increase the amount of the signal transmitted to the microcomputer as much as possible.

As shown in FIG. 4, the photocoupler of the quantity detector 103 for converting a high voltage into a low voltage that can be recognized by a microcomputer and disconnecting a power source detects a bidirectional signal, that is, an AC INPUT signal. Was replaced with a bidirectional photo coupler (PC).

In this way, both positive and negative signals can be delivered to the microcomputer.

In addition, since both AC input voltages are used, the diode D1 and D2, which are part of the conventional device protection circuit, can be eliminated to save cost, and the minimum detectable voltage is also about 1.2V to about 1.2V. Lower to about 24.8V except.

In order to lower this sensing minimum voltage, the current between terminals G and H shown in FIG. 4 should be appropriately selected.

That is, by appropriately adjusting the resistance value of the resistor R2 shown in FIG. 4, the sensing minimum voltage may be significantly lower than the conventional 26V.

Therefore, if the circuit is configured as shown in FIG. 4 and the resistance value of the resistor R2 is appropriately selected, the detectable voltage shown in FIG. 5 is lowered as B, so that the signal amount can be obtained as the output of (B). have.

On the other hand, it can be seen that the increased number of pulses is increased from nine as shown in (b) of FIG.

When the increased number of pulses is measured while increasing the amount of dose, as shown in FIG. 8, the slope is increased as compared with the conventional graph, and it is understood that the discriminating power for distinguishing the amount of dose is greatly increased.

However, the influence of the belt tension, which transmits power even with the increase in the number of pulses, is significantly reduced compared to the conventional one, but has the greatest effect compared to other influence factors.

In other words, it can be seen through the experiment that the influence of the tension is not large in the section where the motor's rotational force is large, but the effect appears when the speed is reduced by friction.

Therefore, in order to reduce the influence characteristic of the tension, a portion having a small influence of the tension should be used.

In the present invention, since the pulse signal input to the microcomputer has been greatly increased, it was used by measuring the time between the pulses, which was previously impossible to measure.

The time between these pulses is represented by t1, t2,... It can be seen that the time from t1 to t5 is most appropriate in the section in which the influence of the belt tension is the smallest and the discriminating power for detecting the quantity is the most appropriate while changing the measurement section up to tn.

Therefore, when the number of pulses detected and the time between pulses are measured while increasing the amount of dose using the dose sensing circuit according to the present invention, a result as shown in FIG. 8 can be obtained.

That is, as shown in FIG. 8, the characteristics of the number of pulses and the time between pulses indicate that there is an appropriate section and an unstable section for determining the dosage according to the increase of the dosage. It can be seen that there are properties that can be.

Therefore, it can be seen that, if appropriately selected, it is possible to determine the dose.

Based on this, a description of the dose detection method will be described with reference to the flow rate detection algorithm flowchart shown in FIG. 9.

First, the forward and negative AC signals according to the rotational force of the motor are sensed by using the bidirectional photo coupler, and the number of pulses generated according to the quantity is accumulated until the motor stops and the number of pulses is added to the number of pulses. Accordingly, the step of integrating time variation between pulses is performed by arbitrarily setting each of the dose detection sections. (ST500, ST600)

Thereafter, the accumulated pulse number is compared with a preset pulse number to determine a dose, and as a result, when the result is larger than the preset pulse number, an experimental value set arbitrarily is compared with a stored pulse number look-up table. (ST700, ST800)

On the other hand, when the number of pulses is smaller than the preset pulse number, each pulse number is again compared with the preset pulse number to determine the dose, and as a result, when the number of pulses is larger than the preset pulse number, a randomly stored lookup value is stored. The quantity is determined by comparing with the up table. (ST900, ST800)

However, when a large volume of laundry is added to the weight of the dehydrating tank of the current washing machine, the quantity of the signal is suddenly changed in characteristics and the amount of the signal is small so that the time between pulses cannot be measured.

Therefore, in this case, when the quantity is smaller than a preset number of pulses to determine the dose again, the dose is determined by comparing with the inter-pulse time look-up table in which the random value is stored. (ST900, ST1000)

By performing the optimum amount of water detection in this way, the optimum water level is determined to prevent tangling of laundry and overload of the motor.

Therefore, in the present invention, by replacing the photo coupler having the same pin structure, it is possible to use the existing washing controller without change, and also because the conventional photo coupler is unidirectional, two diodes are used, but the bidirectional photo coupler is used. By using it, the cost can be greatly reduced.

In addition, by further subdividing the amount of laundry, the water level can be set appropriately according to the amount of water to reduce the energy such as water, electricity, and washing time to a minimum. There is an effect that can prevent the damage of the laundry and tangling of the laundry generated when a large amount of water supply.

Claims (1)

In the washing machine that detects the quantity using the back electromotive force appearing during the operation / stop of the motor, Detecting a quantity of light by detecting a positive and negative AC signal generated by the rotation of the motor by a bidirectional photo coupler; Integrating the number of pulses generated through the photocoupler until the motor stops and integrating the time change between pulses; Determining a quantity using a pulse number look-up table, which is a standard experimental value, when the total number of integrated pulses is greater than the first reference pulse number set in advance; When the total number of pulses is smaller than the first reference pulse number, each pulse number is compared with the preset second reference pulse number, and as a result, when the total pulse number is small, the dose is determined using the standard pulse number look-up table. Determining; And And determining a quantity using the inter-pulse time look-up table, which is a standard experimental value, when each pulse number is greater than the second reference pulse number.

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