KR950007056B1 - Clothes quantity detection method and apparatus thereof for washing machine using bldc motor - Google Patents

Abstract

The method is characterized by that when the motor of the washer is turned on, the current flowing in the motor is combined with the number of pulses generated by the remainder power rotation on off state of the motor so as to detect the washing amount.

Description

Quantity detection method and apparatus for brushless direct current (BLDC) motor washing machine

1 is a block diagram of a conventional washing machine configuration circuit.

2A and 2B are an operation program flowchart and a motor on / off subprogram flowchart of a conventional washing machine, respectively.

3a and b are the counter electromotive force output waveforms of the conventional washing machine and the converted pulse waveforms, respectively.

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

5a and b are flowcharts illustrating an operation program and a motor on / off subprogram of the washing machine according to the present invention, respectively.

6a, b, c, and d are pulse waveforms at the time of motor off and current waveforms at the motor on, respectively, according to the load in the present invention.

* Explanation of symbols for main parts of the drawings

10: main part 11, 21: the first and second microcom

12: detergent display unit 14: water supply valve control unit

15: water level detection unit 20: drive unit

22: motor drive unit 23: speed detection and PT drive control unit

24 current sensing unit 25 BLDC motor

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a device for detecting a quantity of a brushless direct current (BLDC) motor-applied washing machine. In particular, an optimum washing effect is detected by detecting a dry quantity of dry condition before the initial water supply by combining a FG signal and a current flowing in a motor. It was to be expected.

The prior art is a microcomputer (1) for controlling the system as shown in Figure 1, the motor receives the motor ON / OFF (ON / OFF) and the motor rotation direction control signals (CW, CCW) coming from the motor ( 3) a motor driving unit 2 for driving the water, a water supply valve control unit 4 for controlling water input, a water level sensing unit 5 for controlling the amount of water, and a pulse for detecting counter electromotive force from the motor driving unit 2; It consists of the motor back electromotive force detection and pulse conversion part 6 to convert.

In the conventional operation, as shown in the flowchart of FIG. 2, the user turns on the pause key (step S1) and at the same time, the microcomputer 1 turns on the water supply valve via the water supply valve control unit 4 (step S2). The water supply valve 5 is kept on while the water level detection unit 5 checks whether the water reaches the quantity of water detection setting level (step S3). Variables for setting the motor rotation direction and the variable (i, j) for turning off the water supply valve (step S4) and counting the number of motor drives when the water reaches the capacity detection level. (Steps S6 and S10), the motor on / off subroutine B as shown in FIG. 2B is repeatedly executed until the number of motor driving times is four (i = 4) (steps S6-S9 and S10-S13). )do.

Where the motor is counterclockwise Clockwise after rotating 0.6 seconds on (step B1) and 0.6 seconds off (step S2) four times (i = 4) 4 cycles (i = 4) are repeated for 0.6 seconds on and 0.6 seconds off, and then the entire counterclockwise and clockwise rotation is performed three times (j = 3) as described above (step S14). Perform motor on / off.

In the process of repeatedly performing the motor on / off as described above, when the motor is turned off for 0.6 seconds, the microcomputer 1 detects the counter electromotive force generated by the rotation of the motor by the counter electromotive force detection and the pulse converter 6. The number of pulses converted and outputted as shown in FIG. 3b is countered (step S15), compared with existing data (step S16), the amount of water is detected, the water level is determined (step S17), and the water supply valve is turned on again (step S18). After the water is supplied to the set water level (step S19), the washing operation is performed (step S20).

However, the above-mentioned conventional technology requires the user to wait for the water supply time until the quantity detection level and the motor on / off repetition time (about 9 seconds) in order to put the detergent amount suitable for the quantity, so that the user usually puts the detergent amount and pauses the key. Since washing is performed on and off, there is a problem that the optimum washing effect cannot be obtained due to the excessive or insufficient detergent amount, and the accurate amount detection cannot be achieved by ignoring the back EMF lower than the comparative voltage in pulse conversion of the back EMF when the induction motor is turned off. .

The present invention is to solve the above problems, which is characterized in that it is possible in particular to combine the current flowing in the motor when driving the motor and the number of pulses due to the rotation of the force at the time of motor off to detect the amount of dry water This will be described in detail with reference to the accompanying drawings.

That is, as shown in Figure 4 the washing machine configuration circuit according to the present invention is largely divided into the main unit 10 and the drive unit 20, the main unit 10 so that the appropriate detergent can be injected after the detection of the quantity. Detergent display unit 12 for displaying the detergent input amount, the water level detection unit 15 to detect the water level sensor so that the water in the washing tank to the set water level, and a water supply valve control unit for supplying water into the washing tank from the water supply hose ( 14) and a first microcomputer 11 which receives the quantity detection signal from the drive unit 20 and transmits and receives a speed signal while controlling the main unit having the above-described configuration as a whole, and the drive unit 20 detects the speed. And a motor driver 22 for applying power to the BLDC motor 25 by sequentially turning on / off the power transistor by receiving a signal from the power transistor driving controller, and a speed signal FG from the motor Hall sensor. A speed detection and PT drive control unit 23 for receiving a feedback signal and transmitting the feedback signal to the second microcomputer and receiving the speed control reference signal Vref from the second microcom in order to turn on / off the power transistor PT accordingly; A current sensing unit 24 which senses a difference in current flowing through the motor according to a load and transmits it to the first and second microcomputers 11 and 21 to determine the water level and washing time, and a drive having the above configuration The second microcom 21 is configured to output the speed control reference signal Vref or the clockwise, counterclockwise and on / off signals of the motor while the unit 20 is controlled as a whole.

The operation of the present invention configured as described above will be described with reference to the flowchart of FIG. 5.

First, the user presses the start key (journal stop key) (step S101) and detects the airborne level through the water level sensing unit 15 in the first microcomputer 11 of the main unit 10 (step S102), not the airborne level. In this case, the high water level is set and the detergent amount corresponding to the high water level is immediately displayed through the detergent display unit 12 (step S114), and when the airborne level is detected, the number of motor driving is counted through the second microcomputer 21 of the drive unit 20. Variable (i) to set and variable to set motor rotation direction Motor on / off subroutine (A: A1 ← motor 0.6 s on, A2 ← motor 0.6 s off) as shown in Fig. 5b until the number of motor drives is twice (i = 2). , A3? (Return to main program) is repeated (steps S104-S106, S108-S110).

Where the motor is counterclockwise Clockwise after rotating it for 2 seconds (i = 2) Then, 0.6 seconds on and 0.6 seconds off are rotated twice (i = 2).

During the above and repetitive process, the second microcomputer 21 detects the speed and PT driving the number of pulses represented by the Hall sensor of the motor 25 and the motor current flowing when the motor is on for four times (about 2 seconds). After detecting (step S111) and storing through the control unit 23 and the current sensing unit 24, and after the continuous on / off operation of the motor is finished, the detected data is compared with the existing data (step 122) to The amount of water and the water level to be supplied are determined (step 113), and the detergent amount suitable for the determined amount and the water level is output to the detergent amount display unit 12 through the first microcomputer 11 of the main unit 10 and displayed to the outside (step 114). The water supply valve is turned on via the water supply valve control unit 14 (step 115), and when water supply is completed up to the set water level determined above (step 116), the washing operation is performed (step 116).

At this time, the pulse waveform when the motor is detected through the speed detection and the PT drive control unit 23 and the current waveform flowing through the motor when the motor is detected through the current sensor 24 are loaded as shown in FIG. Since the RPM of the motor is higher and the rotation speed is longer, the number of pulses is higher as shown in the drawing a, and the additional motor load is smaller as shown in the drawing. As the rotation becomes shorter, the number of pulses is smaller as shown in the c drawing, and the load on the motor is greater. Therefore, the average motor current is also larger as in the e drawing. Therefore, when the quantity is detected by combining the motor current and the number of pulses, more accurate quantity detection is possible. do.

Therefore, the present invention can detect the amount of detergent and display the amount of detergent within a short time in a dry state, not only can shorten the waiting time to input the amount of detergent suitable for the appropriate level, but also the user can input the amount of detergent suitable for the level and amount There is an effect that can obtain the optimal washing effect.

Claims (4)

A quantity detection method of a washing machine applied to a brushless direct current (BLDC) motor, characterized in that for detecting a quantity by combining the current flowing in the motor when the motor of the washing machine on the motor and the number of pulses due to the rotation of the power when the motor off. The method of claim 1, wherein when the quantity of water is detected, the quantity of water is detected in a dry state before the water supply valve is driven. A washing machine equipped with a BLDC motor, a water level sensing means, and a water supply valve control means, comprising: a current sensing unit 24 for sensing a current flowing in the motor 25 when the motor is driven, and a motor 25 when the motor is stopped. Speed detection and PT drive control unit 23 for controlling the motor driving power transistor while detecting the pulse caused by the rotation of the force is provided, it is possible to detect the amount of dry conditions by the motor current and back electromotive force The quantity detection device of the washing machine applied brushless direct current (BLDC) motor. 4. The apparatus of claim 3, wherein the detergent display unit (12) is provided for displaying an appropriate amount of detergent input to the detected amount of the brushless direct current (BLDC) motor.