CN113802329A - Washing machine - Google Patents

Abstract

The invention provides a washing machine which can restrain the complexity of the structure and the cost increase and can carry out various monitoring controls with high precision. The washing machine of the present invention comprises: the laundry machine includes a rotary tub for accommodating laundry, a motor that is a brushless DC motor for rotationally driving the rotary tub, a current detection unit for detecting a current flowing through the motor, a control unit for vector-controlling the motor based on the current detected by the current detection unit, and 1-position sensor for detecting a rotational position of a rotor of the motor and outputting a sensor signal, wherein the control unit performs predetermined monitoring control based on the sensor signal.

Description

Washing machine

Technical Field

The present invention relates to a washing machine.

Background

The washing machine is composed of: as a motor for rotationally driving a rotary tub accommodating laundry, a brushless DC motor is used. Conventionally, as a method of controlling the driving of such a motor, there are a sensor-driven configuration and a sensorless configuration, in which: a plurality of position sensors for detecting a rotational position of a motor rotor, the plurality of position sensors being configured to drive a motor based on sensor signals output from the plurality of position sensors; the sensorless drive is configured as follows: the vector control is performed by detecting the current of the motor without providing a position sensor. The sensorless drive configuration does not require a position sensor as compared to the sensor drive configuration, and therefore has the following advantages: the constitution can be simplified and the manufacturing cost can be suppressed to be low.

Patent document

Patent document 1: japanese patent No. 4795628

Patent document 2: japanese patent No. 6295407

In the structure of the sensorless drive, there is a problem that: the problem is that the accuracy of various monitoring controls such as an abnormality monitoring control for monitoring an abnormality related to the rotation of the motor, for example, a step-out, a stop monitoring control for monitoring the stop of the motor due to braking, and an unbalance monitoring control for monitoring an unbalance due to the deviation of the laundry in the spin basket cannot be sufficiently improved. That is, it is conceivable that: in the configuration of the sensorless drive, various kinds of monitoring control are performed based on a detection result of a motor current, which is a current flowing through the motor.

However, the detection accuracy of the motor current may be lowered by the influence of noise mixed during a/D conversion, for example, and in this case, the accuracy of the abnormality monitoring control and the stop monitoring control may be lowered or erroneous monitoring may occur. Further, the motor current may not vary depending on the presence or absence of the imbalance due to various operating conditions and the like, and in this case, the accuracy of the imbalance monitoring control may be low or erroneous monitoring may occur.

Disclosure of Invention

Therefore, a washing machine capable of performing various monitoring controls with high accuracy while suppressing the complexity of the structure and the increase in cost is provided.

The washing machine of the embodiment comprises: the laundry machine includes a rotary tub for accommodating laundry, a motor that is a brushless DC motor for rotationally driving the rotary tub, a current detection unit for detecting a current flowing through the motor, a control unit for vector-controlling the motor based on the current detected by the current detection unit, and 1 position sensor for detecting a rotational position of a rotor of the motor and outputting a sensor signal. The control unit executes predetermined monitoring control based on the sensor signal.

According to the above configuration, even with a small number of sensors, imbalance can be monitored.

Drawings

Fig. 1 is a partial vertical sectional side view schematically showing the structure of a washing machine according to embodiment 1.

Fig. 2 is a circuit diagram schematically showing an electrical configuration of the washing machine according to embodiment 1.

Fig. 3 is a diagram schematically showing the structure of the motor according to embodiment 1.

Fig. 4 is a view schematically showing the structure of the rotor of the motor according to embodiment 1.

Fig. 5 is a block diagram schematically showing a specific configuration of the control circuit according to embodiment 1.

Fig. 6 is a diagram schematically showing the contents of motor control executed by the control circuit according to embodiment 1.

Fig. 7 is a diagram schematically showing the specific processing contents related to the stop monitoring control according to embodiment 1.

Fig. 8 is one of diagrams schematically showing specific processing contents related to the abnormality monitoring control according to embodiment 1.

Fig. 9 is a second diagram schematically showing the specific processing contents related to the abnormality monitoring control according to embodiment 1.

Fig. 10 is a diagram schematically showing the specific processing contents related to the weight monitoring control according to embodiment 1.

Fig. 11 is a diagram of phase current waveforms of the motor when there is no imbalance according to embodiment 2.

Fig. 12 is a diagram schematically showing a phase current waveform of the motor when there is an imbalance according to embodiment 2.

Fig. 13 is a diagram schematically showing a transition of the motor rotation speed in the dehydration stroke according to embodiment 2.

Fig. 14 is a diagram schematically showing a waveform of a sensor signal output from the position sensor according to embodiment 2.

Fig. 15 is a diagram schematically showing waveforms of the detected rotation speed signal and the determination value signal when there is no imbalance according to embodiment 2.

Fig. 16 is a diagram schematically showing waveforms of the detected rotation speed signal and the determination value signal when there is an imbalance according to embodiment 2.

Fig. 17 is a diagram for explaining the contents of the digital filter processing according to embodiment 2.

Fig. 18 is a diagram schematically showing specific processing contents related to the imbalance monitor control according to embodiment 2.

Fig. 19 is a diagram for explaining the contents of the digital filter processing according to embodiment 3.

Description of the reference numerals

In the drawing, 7 denotes a control circuit, 9 denotes a position sensor, 31 denotes a stator, 32 denotes a rotor, 33 denotes a magnet, 100 denotes a washing machine, 104 denotes a spin basket, 108 denotes a pulsator, and 113 denotes a motor.

Detailed Description

Hereinafter, a plurality of embodiments will be described with reference to the drawings. In each embodiment, substantially the same components are denoted by the same reference numerals, and description thereof is omitted.

(embodiment 1)

Next, embodiment 1 will be described with reference to fig. 1 to 10.

< constitution of washing machine >

As shown in fig. 1, inside an outer casing 101 constituting an outer contour of a washing machine 100, there are elastically supported by an elastic suspension mechanism 103: a water tank 102 having a bottomed cylindrical shape with an open upper surface. The water tank 102 is provided with: a closed-end cylindrical rotary vessel 104 having an open upper surface. Laundry as laundry is accommodated in the rotary tub 104 so as to be loaded into and unloaded from the tub.

At the bottom of the rotary tub 104 are provided: a reinforcing member 105 for reinforcing the bottom of the rotary groove 104. The rotary chute 104 is constituted by: the washing machine rotates around a vertical axis and is used as a washing tank and a dewatering tank, wherein the washing tank is characterized in that: a washing tank in a washing stroke for performing a washing operation for washing laundry and a rinsing stroke for performing a rinsing operation for rinsing the laundry, the dewatering tank comprising: a dewatering tank for dewatering the washed object in the dewatering course. That is, the washing machine 100 is: the washing machine is a so-called vertical axis type washing machine in which the rotation center axis of the spin basket 104 extends in the vertical direction.

The rotary tub 104 has a plurality of holes 106 in its peripheral wall. These holes 106 are through holes, and allow water and air to flow therethrough. In addition, only a portion of the plurality of holes 106 is shown in fig. 1. The rotary tub 104 is provided with: for example, a balance ring 107 made of synthetic resin in which a liquid such as saline is sealed. Inside the rotary tub 104, specifically, at the inner bottom, there are rotatably provided: a pulsator (pulsator)108 made of, for example, synthetic resin is used as the agitator. A drain passage 109 is provided in a lower portion of the water tank 102. The drain path 109 is provided with a drain valve 110, and by opening the drain valve 110, the water in the water tank 102 can be drained to the outside of the washing machine. An air trap (air trap)111 for monitoring the water level is provided at the bottom of the water tank 102.

A driving mechanism 112 is provided in the center of the lower part of the water tank 102. The drive mechanism 112 includes: a motor 113 for rotationally driving the rotary tub 104, and a clutch mechanism 112a including a clutch and a reduction gear. The drive mechanism 112 transmits a rotational force to the pulsator 108 through the clutch mechanism 112a during the washing stroke or the rinsing stroke. In this way, in the washing stroke or the rinsing stroke, only the pulsator 108 is rotationally driven without rotationally driving the rotary tub 104. At this time, the pulsator 108 is decelerated 1/5 and is driven to rotate. In the dehydration stroke, the drive mechanism 112 transmits the rotational force of the motor 113 to the pulsator 108 and the spin tank 104 via the clutch mechanism 112 a. In this way, the pulsator 108 is rotationally driven integrally with the rotary tub 104 during the dehydration stroke. At this time, the rotary tub 104 is rotationally driven without being decelerated.

A top cover 114 is provided on the upper portion of the outer case 101. The top cover 114 is provided with: a lid 115 of, for example, a folding type for opening and closing the laundry entrance. A tank cover, not shown, is openably and closably attached to an upper portion of the water tank 102. An operation panel 116 is provided at the front of the top cover 114. On the back side of the operation panel 116 are disposed: and a control unit 117 for controlling the overall operation of the washing machine 100. At the rear within the top housing 114 are provided: a water supply mechanism 118 for supplying water from a water source into the water tank 102. Water supply mechanism 118 includes a water supply valve, not shown, and a water supply path, not shown, communicating with water tank 102, and control unit 117 controls the supply of water into water tank 102 by controlling the opening and closing of the water supply valve.

Electric constitution relating to control system of washing machine

Fig. 2 is a block diagram showing the functions of the drive control system of the motor 113. In this case, the control unit 117 includes the inverter circuit 1 which is a PWM control inverter. PWM is an abbreviation for Pulse Width Modulation. The inverter circuit 1 is configured by connecting 6 IGBTs 2a to 2f as semiconductor switching elements in a three-phase bridge manner, and freewheeling diodes 3a to 3f are connected between the collector and emitter of each of the IGBTs 2a to 2 f. The phase output terminals of the inverter circuit 1 are connected to motor windings 113u, 113v, and 113w of the motor 113, respectively. In the present embodiment, for example, an outer rotor type three-phase brushless DC motor is used as the motor 113.

The emitters of the IGBTs 2d, 2e, 2f on the lower arm side are connected to the ground via a shunt resistor 4 as a current detection element. The common connection point between the emitters of the IGBTs 2d, 2e, and 2f and the shunt resistor 4 is connected to ground via the resistor element 5 and the capacitor 6. A common connection point of the resistance element 5 and the capacitor 6 is connected to an a/D input 2 terminal of the control circuit 7 and also to an input terminal of the overcurrent determination circuit 8. The overcurrent determination circuit 8 is constituted by a comparator and the like. The output signal of the overcurrent determination circuit 8 is: based on the emergency stop signal of the overcurrent detection, the control circuit 7 stops outputting the PWM signal to the inverter circuit 1 when the emergency stop signal is input.

The motor 113 is provided with: and 1 position sensor 9 for detecting the rotational position of the rotor. The position sensor 9 is a magnetic sensor, for example, composed of a hall IC, and outputs: a sensor signal which is a digital signal corresponding to the detection result of the rotational position. The sensor signal output from the position sensor 9 is input to the control circuit 7 via the not gate 10. The output terminal of the not gate 10 is connected to ground via a capacitor 11.

The driving power supply circuit 12 is connected to the input side of the inverter circuit 1. The driving power supply circuit 12 performs voltage-doubling full-wave rectification on a 100V ac power supply 13 by a full-wave rectification circuit 14 composed of a diode bridge and 2 capacitors 15a and 15b connected in series, and supplies a dc voltage of about 280V to the inverter circuit 1. The phase output terminals of the inverter circuit 1 are connected to phase windings 113u, 113v, and 113w of the motor 113. The 1 st power supply circuit 16 steps down the driving power of about 280V supplied to the inverter circuit 1 to generate a 15V power, and supplies the 15V power to the drive circuit 17 and the high voltage drive circuit 19. The 2 nd power supply circuit 18 is a three-terminal regulator for stepping down the driving power supply to generate a control power supply of 5V, and supplies the control power supply to the control circuit 7, the rotational position sensor 9, the 3 rd power supply circuit 20, and the like.

The high voltage drive circuit 19 is disposed to drive the IGBTs 2 a-2 c on the upper arm side in the inverter circuit 1. The 3 rd power supply circuit 20 generates 3.3V power by the above-described 5V, and supplies the power to the overcurrent determination circuit 8. The a/D input 2 terminal of the control circuit 7 is pulled up to the 3.3V supply through the resistive element 21. A series circuit of resistance elements 22a and 22b is connected between the output terminal of the driving power supply circuit 12 and the positive dc bus of the inverter circuit 1 and the ground, and the common connection point of the two is connected to the a/D input 1 terminal of the control circuit 7.

The control circuit 7 detects a 3-phase current for energizing the motor 113 based on the terminal voltage of the shunt resistor 4, and performs vector control, thereby generating upper and lower three-phase PWM signals whose voltage rates change in a sine wave form. The control circuit 7 outputs the PWW signal to the gates of the IGBTs 2a to 2f constituting the inverter circuit 1 via the drive circuit 17 and the high-voltage drive circuit 19 on the upper side. In the drive circuit 17, each input terminal for inputting each PWM signal is pulled down to ground through the resistor 23.

In the above configuration, bootstrap capacitors 24d, 24e, and 24f are connected between the emitters of IGBTs 2d, 2e, and 2f on the lower arm side and high-voltage drive circuit 19, respectively. In the above configuration, the bootstrap capacitors 24d to 24f are charged with the switching operation of the IGBTs 2a to 2f, thereby generating: and a power supply voltage for causing the high-voltage drive circuit 19 to drive the gates of the IGBTs 2a to 2c on the upper arm side.

In the present embodiment, the control circuit 7 functions as a current detection unit that detects a current flowing through the motor 113, and also functions as a control unit that performs vector control on the motor 113 based on the current detected by the current detection unit. In this case, the control circuit 7 controls the motor 113 so that the rotation speed of the motor 113 follows a desired target speed. The control circuit 7 executes predetermined monitoring control based on the sensor signal. Specifically, the control circuit 7 executes one or both of the abnormality monitoring control and the stop monitoring control as the predetermined monitoring control. Further, the control circuit 7 executes weight monitor control as predetermined monitor control.

The abnormality monitoring control is: and a control for monitoring an abnormality related to the rotation of the motor 113, such as a step-out. The stop monitoring control is: the motor 113 is controlled to stop due to braking such as friction braking or electromagnetic braking. The weight monitoring control is as follows: after laundry is loaded into the spin tank 104, the rotation speed of the spin tank 104 is calculated based on a sensor signal when the pulsator 108 is rotated, and control of the amount of laundry is determined based on the calculated rotation speed.

< construction of Motor >

As a specific configuration of the motor 113, for example, a configuration as shown in fig. 3 and 4 can be adopted. As shown in fig. 3, the motor 113 includes: a stator 31 and a rotor 32 disposed on the outer periphery thereof. The stator 31 is configured to: the stator core and the stator winding are integrated by a molding resin. The rotor 32 is constituted: the frame, the rotor core, and the plurality of magnets are integrated with a molding resin.

In this case, as shown in fig. 3 and 4, the rotor includes: and magnets 33, which are 12 permanent magnets, arranged at equal intervals on 1 circumference thereof. As shown in fig. 3, 1 position sensor 9 is attached to the stator 31 at a position on the end side of the magnet 33. The position sensor 9 is: the magnetic hall IC can be sensed as described above, and outputs: the level of the sensor signal is inverted according to the N-pole and S-pole of the magnet 33. According to the above configuration, when the rotor 32 rotates 1 revolution, the sensor signal output from the position sensor 9 appears: the same number of magnets 33, i.e., 12 pulse edges.

< concrete constitution and function of control Circuit >

As a specific configuration of the control circuit 7 having a function of vector-controlling the motor 113, for example, a configuration as shown in fig. 5 can be adopted. In fig. 5, (α, β) indicates: an orthogonal coordinate system obtained by orthogonal conversion of a three-phase (UVW) coordinate system having motor phase angles of 120 degrees intervals corresponding to respective phases of a motor 113 as a three-phase brushless DC motor. Further, (d, q) represent: a coordinate system of the secondary magnetic flux that rotates with the rotation of the rotor of the motor 113.

The target speed command ω ref output from the microcomputer 41 is configured to: is supplied to the subtractor 42 as a subtracted value. In this specification, the microcomputer may be simply referred to as a microcomputer. The detected speed ω of the motor 113 detected by the estimator 43 is supplied to the subtractor 42 as a subtracted value. The subtraction result of the subtractor 42 is supplied to the speed PI control unit 44. The speed PI control unit 44 is configured to: PI control is performed based on the difference between the target speed command ω ref and the detected speed ω, and a q-axis current command value Iqref and a d-axis current command value Idref are generated and supplied to the fixed contacts 45qa and 45da of the switching switches 45q and 45d, respectively.

The starting current command values Iqs and Ids outputted by the current control initial mode output unit 46 are supplied to the other fixed contacts 45qb and 45db of the changeover switches 45q and 45 d. Movable contacts 45qc and 45dc of the changeover switches 45q and 45d are connected to input terminals for the subtracted values of the subtractors 47 and 48. Each of the switches 45q and 45d is configured to: switching control is performed by the microcomputer 41. In addition, the d-axis current command value Idref is set to "0" during the washing or rinsing operation, and is set to a predetermined value during the spin-drying operation because the field weakening control is performed.

The q-axis current value Iq and the d-axis current value Id output from the α β/dq conversion unit 49 are supplied to subtracters 47 and 48 as subtraction values, and the subtraction results are supplied to current PI control units 50q and 50d, respectively. Then, the current PI control units 50q and 50d perform PI control based on the difference between the q-axis current reference value Iqref and the d-axis current reference value Idref, generate a q-axis voltage reference value Vq and a d-axis voltage reference value Vd, and supply the q-axis voltage reference value Vq and the d-axis voltage reference value Vd to the fixed contacts 51qa and 51da of the switching switches 51q and 51d, respectively.

The voltage command values Vqs and Vds for starting output by the voltage control initial mode output unit 52 are supplied to the other fixed contacts 51qb and 51db of the changeover switches 51q and 51 d. Movable contacts 51qc and 51dc of the changeover switches 51q and 51d are connected to the input terminal of the dq/α β conversion unit 53. The selector switches 51q and 51d are configured to: switching control is performed by the microcomputer 41.

The rotational phase angle θ, which is the rotor position angle of the magnetic flux of 2 times in the motor 113 detected by the estimator 43, is supplied to the dq/α β conversion unit 53, and is configured to: voltage command values Vd and Vq are converted into voltage command values V α and V β based on the rotational phase angle θ. The voltage command values V α and V β output from the dq/α β conversion unit 53 are supplied to an α β/UVW conversion unit 54. The α β/UVW converter 54 includes: and a function of converting the voltage command values V α and V β into three-phase voltage command values Vu, Vv, and Vw and outputting the three-phase voltage command values Vu, Vv, and Vw. The voltage command values Vu, Vv, Vw are configured as follows: is supplied to the PWM forming section 55.

The PWM forming section 55 is configured to: PWM signals Vup (+, -), Vvp (+, -), Vwp (+, -) of the respective phases, which are obtained by modulating a transmission wave, which is a triangular wave of 16kHz, based on the voltage command values Vu, Vv, Vw, are output to the inverter circuit 1. The PWM signals Vup to Vwp are output as signals having pulse widths corresponding to voltage amplitudes based on a sine wave so that, for example, a current having a sine wave is turned on to the phase windings 113u, 113v, and 113w of the motor 113.

In this case, the current flowing through the motor 113 for torque control is detected by the shunt resistor 4. That is, the a/D converter 56 performs a/D conversion or the like on the signal at the common connection point of the resistance element 5 and the capacitor 6 to obtain current data Iu and Iv, and outputs the current data Iu and Iv to the UVW/α β converter 57. The UVW/α β converter 57 includes: and a function of estimating current data Iw of the W phase from the current data Iu and Iv, and converting the current data Iu, Iv, Iw of the three phases into 2-axis current data I α, I β of an orthogonal coordinate system. As a specific method for such conversion, various known methods such as the method disclosed in patent document 1 can be used.

Then, the UVW/α β converter 57 outputs the 2-axis current data I α, I β to the α β/dq converter 49. The α β/dq conversion unit 49 includes: a function of obtaining the rotor position angle θ of the motor 113 by the estimator 43 at the time of vector control, thereby converting the 2-axis current data I α, I β into d-axis current values Id, q-axis current values Iq on the rotating coordinate system (d, q). As a specific method for such conversion, a known method such as the method disclosed in patent document 1 can be used.

The α β/dq converter 49 is configured to: the d-axis current value Id and the q-axis current value Iq are output to the estimator 43 and the subtractors 47 and 48 as described above. The estimator 43 estimates the rotor position angle θ and the rotation speed ω of the motor 113 based on the d-axis current value Id and the q-axis current value Iq, and outputs the estimated values to the respective units. Here, the motor 113 is excited by direct current at the time of starting, and after the rotational position of the rotor is initialized, that is, after the initial value is set, the starting mode is applied to perform forced commutation. When forced commutation is performed by the application of the start mode, the position angle θ is clear without estimation.

After the vector control is started, the estimator 43 is activated to estimate the rotor position angle θ and the rotation speed ω of the motor 113. In this case, the configuration is: assuming that the rotor position angle θ n output from the estimator 43 to the α β/dq conversion unit 49, the estimator 43 estimates the rotor position angle θ n based on the correlation between the rotor position angle θ n-1 estimated by vector operation and the rotor position angle θ n-2 estimated one cycle before the current value Id, Iq.

In the above configuration, the outline of the control performed mainly by the microcomputer 41 is as shown in fig. 6. First, when the microcomputer 41 starts the washing operation, the rinsing operation, or the spin-drying operation, for example, the process of starting the motor 113, which is the process of steps S101 to S105, is executed. Specifically, in step S101, the positioning control of the rotor of the motor 2 is started. In this case, the microcomputer 41 connects the movable contacts 51qc and 51dc of the changeover switches 51q and 51d to the fixed contacts 51qb and 51db, and the voltage command value of the initial mode for dc excitation is supplied to the dq/α β conversion unit 53 through the voltage control initial mode output unit 52.

Accordingly, the process of step S102 is executed, and the voltage for dc excitation is output from the inverter circuit 1 to the winding of the motor 113. In this configuration, the configuration is: the output voltage is increased linearly from 0V to 80V, for example, in 2 seconds. Namely, the structure is as follows: a voltage command value required to output such a linear output voltage from the inverter circuit 1 is supplied from the voltage control initial mode output unit 52 to the dq/α β conversion unit 53 as a voltage command value in the initial mode for dc excitation. By performing the above-described dc excitation, the rotational position of the rotor of the motor 113 is initialized and positioned in step S103. During the positioning control, the rotation speed of the motor 113, i.e., the rotation speed, is 0rpm, the d-axis current is changed to increase from 0A, and the q-axis current is 0A.

Next, the process proceeds to step S104, and forced commutation control is started. In this case, the configuration is: by connecting movable contacts 45qc and 45dc of changeover switches 45q and 45d to fixed contacts 45qb and 45db by microcomputer 41, current command values for forced commutation are supplied to subtracters 47 and 48 by current control initial mode output unit 46. The selector switches 51q and 51d are configured to: by connecting the movable contacts 51qc and 51dc to the fixed contacts 51qa and 51da, the q-axis voltage command value Vq and the d-axis voltage command value Vd from the current PI control units 50q and 50d are supplied to the dq/α β conversion unit 53.

Accordingly, the motor 113 is forced to commutate, and immediately starts rotating, and the rotation speed, that is, the rotation speed gradually increases. In this configuration, the configuration is: as shown in step S105, the rotational speed of the motor 113 is linearly increased from 0rpm, for example, to 30rpm in 3 seconds, that is, the output frequency corresponding to the rotational speed of the motor is linearly increased from 0rpm, for example, to 30rpm in 3 seconds, and the d-axis current is subjected to PI control, that is, current control so as to be fixed at a predetermined constant value, for example, 7A. In addition, the q-axis current is fixed to 0A.

Namely, the structure is as follows: the current command value required for forced commutation control for obtaining the d-axis current and the q-axis current is supplied from the current control initial mode output unit 46 to the subtracters 47 and 48 as the current command value in the initial mode for forced commutation. While the forced commutation control is being performed, the rotation speed of the motor 113, that is, the rotation speed is increased from 0rpm to 30rpm, the d-axis current is maintained at substantially 7A, and the q-axis current is 0A. In the present embodiment, the motor 113 is configured to: since the electrical angle is 12 cycles with respect to the mechanical angle 1 cycle, the forced commutation at 30rpm corresponds to an output frequency of 150 Hz.

Subsequently, the flow proceeds to step S106, where: the forced commutation control is switched to torque control, that is, vector control. In the case of such a configuration, microcomputer 41 connects movable contacts 45qc and 45dc of selector switches 45q and 45d to fixed contacts 45qa and 45da, and the current command value from speed PI control unit 44 is supplied to subtracters 47 and 48. The switching control is configured to be gradually executed. Specifically, the current control, i.e., PI control, is performed so that the d-axis current is gradually decreased from 7A to 0A, and the current control, i.e., PI control, is performed so that the q-axis current is increased from 0A to a predetermined value, i.e., 7A, for example.

Then, the process proceeds to step S107, where: and performing PI control on the q-axis current based on the difference between the real rotating speed and the target rotating speed. This makes it possible to quickly respond to the target rotation speed, and to obtain good control responsiveness. While such rotation speed control is performed, the rotation speed of the motor 113, that is, the rotation speed increases so as to reach the target rotation speed. Then, the d-axis current is held at 0A, and the q-axis current is added or subtracted based on the difference between the actual rotation speed and the target rotation speed.

Next, with reference to fig. 7 to 10, description will be made of: the specific processing contents related to various monitoring controls performed by the control circuit 7 configured as described above.

[1] Specific processing contents related to stop monitoring control

The control circuit 7 performs the processing shown in fig. 7 during the dehydration operation, more specifically, during the final dehydration operation. First, when the dehydration operation is started in step S201, the flow proceeds to step S202, and the lid is locked. When the lid locking is performed, a state is assumed in which the lid 115 cannot be opened.

After step S202 is executed, the flow proceeds to step S203, where it is determined whether or not the dehydration operation is completed. If the dehydration operation is still continuing, the result is "NO" in step S203, and the determination in step S203 is performed again. When the dehydration operation is finished, the result is "YES" in step S203, and the process proceeds to step S204. In step S204, the braking for stopping the rotation of the motor 113 is started.

When the stop of the rotation of the motor 113 is started by performing the braking, the number of times the magnet 33 of the rotor 32 passes through the position sensor 9 during 1 rotation gradually decreases, and finally the magnet 33 no longer passes through the position sensor 9, and the sensor signal does not change, that is, the level of the sensor signal is fixed at the high level or the low level. Therefore, in the present embodiment, in view of these points, step S205, which is a process corresponding to the stop monitoring control for monitoring the stop of the motor 113, is executed after step S204 is executed. That is, in step S205, it is determined whether or not the sensor signal has not changed for a predetermined determination time Ta or more.

In the present embodiment, the determination time Ta as the threshold for stopping monitoring is set to: the time period for ensuring both safety and convenience of the user can be, for example, 1.2 seconds. The securing of safety corresponds to a case where the rotation of the motor 113 is completely stopped, or a case where the rotation of the motor 113 is suppressed to such an extent that there is no problem even if the user touches the rotary groove 104 or the like. The guarantee of convenience corresponds to a case where the time required to take out the laundry after the completion of the dehydration operation is not so long as to cause no inconvenience to the user. The optimum value of the determination time Ta is changed in accordance with the number of poles of the rotor 32, that is, the number of magnets 33, and the like, and therefore, it is sufficient to change the optimum value appropriately in accordance with the number of poles of the rotor 32 and the like.

When the state in which the level of the sensor signal has not changed is smaller than the determination time Ta, the value is "NO" in step S205, and the determination in step S205 is performed again. If the state in which the level of the sensor signal has not changed continues for the determination time Ta or longer, "YES" in step S205, the process proceeds to step S206. In step S206, the lid lock is released, and the lid 115 can be opened. After step S206 is executed, the present process is ended.

[2] Specific processing contents related to abnormality monitoring control

The control circuit 7 performs: any one of the specific 1 st process shown in fig. 8, the specific 2 nd process shown in fig. 9, during the washing operation, the rinsing operation, or the spin-drying operation. As shown in fig. 8, in the 1 st specific process, first, in step S301, the rotation of the motor 113 is started to rotate the rotary tub 104. When an abnormality related to the rotation of the motor 113 such as a step-out occurs, the number of revolutions of the motor 113, that is, the rotational speed is reduced from the target speed, which is an original value, and therefore the number of times the magnet 33 of the rotor 32 passes through the position sensor 9 during 1 rotation is also reduced, and the time in which the sensor signal does not change is longer than that in the normal state.

Therefore, in the specific process of 1 st, in view of this point, after step S301 is executed, a process corresponding to abnormality monitoring control that monitors an abnormality related to the rotation of the motor 113, that is, step S302, is executed. That is, in step S302, it is determined whether or not the sensor signal has not changed for a predetermined determination time Tb or more. In the present embodiment, the determination time Tb, which is a threshold for abnormality monitoring, is set to: for example 0.2 seconds. In addition, the determination time Tb is: when the motor 113 is rotationally driven at the lowest rotation speed of the motor 113 assumed during the operation performed at this time, the time from the occurrence of an abnormality such as a step-out to the detection of the abnormality may be changed as appropriate as long as the time is sufficiently longer than the time during which the state in which the sensor signal does not change and the time from the occurrence of the abnormality such as a step-out to the detection of the abnormality is not too long.

When the state in which the level of the sensor signal has not changed is less than the determination time Tb, NO is set in step S302, and the determination in step S302 is performed again. If the state in which the level of the sensor signal has not changed continues for the determination time Tb or longer, "YES" in step S302, the process proceeds to step S303. In step S303, when abnormality such as a step-out is detected, power supply to the motor 113 is stopped. After step S303 is executed, the 1 st specific processing is ended. In this way, in the abnormality monitoring control included in the 1 st specific process, the control circuit 7 detects that an abnormality related to the rotation of the motor 113 has occurred when the sensor signal in the rotation control for controlling the rotation of the motor 113 does not change for a predetermined determination time Tb or longer.

As shown in fig. 9, the 2 nd specific process is different from the 1 st specific process in that: step S312 is provided instead of step S302, which is a process corresponding to the abnormality monitoring control. As described above, when an abnormality related to the rotation of the motor 113 such as a step-out occurs, the rotation speed of the motor 113 is reduced from the target speed. Therefore, in step S312 of the 2 nd process, it is determined whether or not the difference between the rotation speed of the motor 113 and the target speed is equal to or greater than a predetermined threshold speed.

The rotational speed of the motor 113 may be calculated based on the sensor signal. In the present embodiment, as an example of determining whether or not the difference is equal to or greater than the threshold speed, it may be determined that: whether the rotation speed of the motor 113 is half or less of the target speed. Therefore, in the present embodiment, the threshold speed that is the threshold for abnormality monitoring is: a value that varies according to the rotational speed of the motor 113 and the target speed.

If the difference between the rotational speed of the motor 113 and the target speed is smaller than the threshold speed, that is, if the rotational speed of the motor 113 exceeds half of the target speed, the value is "NO" in step S312, and the determination in step S312 is performed again. If the difference between the rotational speed of the motor 113 and the target speed is equal to or greater than the threshold speed, that is, if the rotational speed of the motor 113 is equal to or less than half the target speed, "YES" in step S312, the routine proceeds to step S303. In this way, in the abnormality monitoring control included in the specific process 2, the control circuit 7 monitors that an abnormality related to the rotation of the motor 113 has occurred when the difference between the rotation speed of the motor 113 calculated based on the sensor signal in the rotation control for controlling the rotation of the motor 113 and the target speed is equal to or greater than the predetermined threshold speed.

[3] Specific treatment details relating to weight monitoring control

When starting the washing operation or the like, the control circuit 7 performs the processing as shown in fig. 10 to determine the amount of laundry loaded into the spin basket 104. In this case, the series of processing shown in fig. 10 corresponds to the aforementioned weight monitoring control. First, in step S401, monitoring of the sensor signal is started, and thereafter, the number of pulses of the sensor signal is measured.

After step S401 is executed, the process proceeds to step S402, where the motor 113 is driven for 1 second, that is, for 1 second in the normal rotation direction so that the rotary tub 104 rotates in the normal rotation direction. After step S402 is executed, the process proceeds to step S403, where the driving of the motor 113 is stopped, and 3 seconds elapse, that is, the driving is stopped for 3 seconds. At this time, although the driving force of the motor 113 is applied to the non-rotating groove 104, the non-rotating groove rotates in the normal rotation direction due to inertia, that is, idles in the normal rotation direction.

After step S403 is executed, the process proceeds to step S404, and it is determined whether or not the rotation of the rotary tub 104 has stopped. If the rotation of the rotary tub 104 is not stopped, the value is "NO" in step S404, and the determination in step S404 is performed again. If the rotation of the rotary tub 104 has stopped, YES is obtained in step S404, and the process proceeds to step S405. In step S405, the following are stored: the number of pulses of the sensor signal during the period in which the rotary tub 104 rotates in the normal rotation direction. The number of pulses stored in step S405 corresponds to the number of rotations of the rotary tub 104 in the normal rotation direction, that is, the number of rotations in the normal rotation direction.

After step S405 is executed, the process proceeds to step S406, where the motor 113 is driven for 1 second, that is, driven for 1 second in reverse rotation so that the rotary tub 104 rotates in the reverse rotation direction, which is the direction opposite to the normal rotation direction. After step S406 is executed, the process proceeds to step S407, where the driving of the motor 113 is stopped, and 3 seconds elapse, that is, the driving is stopped for 3 seconds. At this time, although the driving force of the motor 113 is not applied to the rotary tub 104, the rotary tub rotates in the reverse direction by inertia, that is, idles in the reverse direction.

After step S407 is executed, the process proceeds to step S408, and it is determined whether or not the rotation of the rotary tub 104 has stopped. If the rotation of the rotary tub 104 is not stopped, the result is "NO" in step S408, and the determination in step S408 is performed again. If the rotation of the rotary tub 104 has stopped, YES is obtained in step S408, and the process proceeds to step S409. In step S409, there is stored: the number of pulses of the sensor signal during the period in which the rotary tub 104 rotates in the reverse direction. The number of pulses stored in step S409 corresponds to the number of rotations of the rotary tub 104 in the reverse direction, that is, the number of rotations in the reverse direction. After step S409 is performed, the process proceeds to step S410.

In step S410, the weight of the laundry is estimated based on the number of pulses stored in step S405 and the number of pulses stored in step S409, that is, based on the number of pulses corresponding to the rotation speed in the normal rotation direction and the number of pulses corresponding to the rotation speed in the reverse rotation direction. The estimation here is based on the following idea. That is, when the laundry is loaded into the spin basket 104 in a large amount, that is, when the weight of the laundry is large, the time until the laundry is stopped due to the inertia becomes short, but when the laundry is loaded into the spin basket 104 in a small amount, that is, when the weight of the laundry is small, the time until the laundry is stopped due to the inertia becomes long.

Therefore, it can be estimated that the weight of the laundry is smaller as the number of pulses stored in steps S405 and S409 is larger, and that the weight of the laundry is larger as the number of pulses stored in steps S405 and S409 is smaller. Further, by performing experiments or the like in advance, a table or the like indicating the relationship between the number of pulses and the weight of the laundry may be created and stored, and by referring to the table in step S410, not only the magnitude of the weight of the laundry but also the value of the weight may be estimated. After step S410 is executed, the present process is ended.

In the present embodiment, the weight is estimated using the average value between the number of pulses corresponding to the number of rotations in the normal rotation direction and the number of pulses corresponding to the number of rotations in the reverse rotation direction, for the following reason. That is, it goes without saying that the weight estimation using the average value of both the numbers of pulses can improve the estimation accuracy, as compared with the weight estimation using only one of the number of pulses corresponding to the number of rotations in the normal rotation direction and the number of pulses corresponding to the number of rotations in the reverse rotation direction.

Further, depending on the type of washing machine, the inertial rotation may take different time until the rotation stops between the time of rotation in the normal rotation direction and the time of rotation in the reverse rotation direction. Thus, compared to: in the case where one of the number of pulses corresponding to the number of rotations in the normal rotation direction or the number of pulses corresponding to the number of rotations in the reverse rotation direction is obtained 2 times and weight estimation is performed using the average value, as in the present embodiment, it is possible to further improve estimation accuracy in the case where weight estimation is performed using the average value of the number of pulses corresponding to the number of rotations in the normal rotation direction and the number of pulses corresponding to the number of rotations in the reverse rotation direction.

According to the present embodiment described above, the following effects can be obtained.

In the washing machine 100 of the present embodiment, the control circuit 7 for controlling the driving of the motor 113 for rotationally driving the rotary tub 104 detects the current flowing through the motor 113 and performs vector control, that is, the present embodiment adopts a configuration of sensorless driving. However, in the present embodiment, there are provided: and 1 position sensor 9 for detecting the rotational position of the rotor 32 of the motor 113 and outputting a sensor signal. According to the 1-position sensor 9, since an error in magnetic pole position becomes large, it cannot be used for torque generation or rotational driving, but it can be sufficiently used as long as it is subjected to various kinds of monitoring control.

Therefore, the control circuit 7 performs prescribed monitoring control based on the sensor signals output from the 1-position sensors 9. In this way, it is possible to suppress: in the case where various kinds of monitoring control are performed based on the detection result of the motor current, which is the current flowing through the motor, there is a possibility that the accuracy may be lowered or erroneous monitoring may occur, and the reliability of the various kinds of monitoring control can be improved. In this case, 1 position sensor 9 is added to the general sensorless drive configuration, but the configuration is simplified and the manufacturing cost is reduced compared to the sensor drive configuration in which 3 position sensors are provided. Therefore, according to the present embodiment, it is possible to obtain: the excellent effect of performing various monitoring controls with high accuracy is achieved.

In the present embodiment, the control circuit 7 executes: the stop monitoring control for monitoring the stop of the motor 113 due to braking is defined as the predetermined monitoring control. In the stop monitoring control, the control circuit 7 monitors the stop of the motor 11 due to braking when the sensor signal does not change for a predetermined determination time Ta or more. In this case, the control circuit 7 detects the stop of the motor 113 due to braking, and then releases the lid lock. In this way, since the stop of the motor 113 due to braking can be reliably monitored, the safety of the lid lock is improved.

In addition, in the present embodiment, the control circuit 7 executes: as the predetermined monitoring control, abnormality monitoring control is performed that monitors an abnormality related to the rotation of the motor 113. The control circuit 7 can perform, as the abnormality monitoring control, the 1 st specific process of monitoring occurrence of an abnormality related to rotation of the motor 113 when the sensor signal does not change for a predetermined determination time Tb or more in the rotation control for controlling the rotation of the motor 113. Further, the control circuit 7 may perform, as the abnormality monitoring control, the following specific 2 processing in which, when a difference between the rotation speed of the motor 113 and the target speed calculated based on the sensor signal in the rotation control for controlling the rotation of the motor 113 is equal to or greater than a predetermined threshold speed, it is monitored that an abnormality related to the rotation of the motor 113 has occurred.

According to the 1 st and 2 nd detailed processes, it is possible to quickly and reliably monitor an abnormality related to the rotation of the motor 113. In this case, since the offset or the like can be monitored quickly and reliably, the occurrence of overheat due to the flow of an excessive current can be prevented, and the safety can be improved. In the present embodiment, as a specific method for determining whether or not the difference in the specific process of fig. 2 is equal to or greater than the threshold speed, a method for determining whether or not the rotation speed of the motor 113 is equal to or less than half of the target speed is employed.

According to this specific technique, the threshold speed to be used as the threshold for abnormality monitoring is: a value that varies according to the rotational speed of the motor 113 and the target speed. That is, in this case, even if the rotation speed of the motor 113 changes according to the operating state of the washing machine 100, the threshold speed changes similarly according to the change, and therefore: the accuracy of abnormality monitoring decreases with the change in the rotation speed. In other words, according to the above-described technique, even when the rotation speed of the motor 113 changes, the accuracy of abnormality monitoring can be maintained well.

In the present embodiment, the control circuit 7 executes weight monitor control as predetermined monitor control, wherein the weight monitor control is: after laundry is loaded into the spin tub 104, the rotation speed of the spin tub 104 is calculated based on a sensor signal when the pulsator 108 is rotated, and the amount of laundry is determined based on the calculated rotation speed. In this way, the amount of rotation of the motor 113, which is difficult to monitor in the configuration of the ordinary sensorless drive, can be reliably monitored, and the accuracy of monitoring the amount of laundry is improved, and as a result, it is possible to obtain: saving water and detergent used for washing.

(embodiment 2)

Next, embodiment 2 will be described with reference to fig. 11 to 18.

The embodiment 2 is different from the embodiment 1 in that: the control circuit 7 performs control. The structure of washing machine 100 is common to embodiment 1, and therefore, it can be described with reference to the drawings related to embodiment 1, such as fig. 1 to 5.

The structure of the sensorless drive has the following problems. That is, even if an unbalance occurs due to the deviation of the laundry in the spin basket, there is a case where the current flowing through each phase of the motor, that is, the phase current of the motor does not fluctuate due to the unbalance. FIG. 11 shows: in the configuration of the present embodiment, there is no unbalanced phase current waveform of the motor 113. Further, fig. 12 shows: in the configuration of the present embodiment, for example, a phase current waveform of the motor 113 when there is an imbalance of about 3000g in the lower portion.

In the present embodiment, when the rotary tub 104 is rotated during the dehydration process of dehydrating the laundry, the rotation speed of the motor 113 is advanced as shown in fig. 13. That is, when the spin-drying operation is started, the rotation speed of the motor 113 is temporarily increased at a predetermined slope, and then, when the rotation speed reaches the acceleration period after a constant speed period of, for example, 130rpm, the rotation speed is increased at a steeper slope than the initial slope. The phase current waveform of the motor 113 in fig. 11 and 12 shows a waveform during such an acceleration period.

As shown in fig. 11 and 12, the phase current waveform of the motor 113 shows a monotonous increase in current due to acceleration, but does not increase or decrease per 1 rotation due to the presence or absence of imbalance, and a large difference due to the presence or absence of imbalance is not observed. In this case, in the configuration of the sensorless drive, it is difficult to monitor the imbalance with high accuracy based on the detection result of the current flowing through the motor 113.

Therefore, the control circuit 7 of the present embodiment executes, as predetermined monitoring control, imbalance monitoring control in which: when the spin basket 104 is rotated during the spin-drying process of the laundry, the rotation speed of the motor 113 is obtained based on the sensor signal output from the position sensor 9, and the imbalance caused by the deviation of the laundry in the spin basket 104 is monitored based on the fluctuation of the obtained rotation speed.

The sensor signal output from the position sensor 9 has a pulse waveform as shown in fig. 14, for example. In this case, the rotational speed of the motor 113, i.e., the rotational speed, is detected by, for example, the time tx between the falling edge and the next rising edge of the sensor signal, i.e., the time between the edges. In the configuration of the present embodiment, since the motor 113 is a multi-pole motor, the sensor signal is represented by: the waveform of a plurality of pulses occurs during 1 rotation. Therefore, in the configuration of the present embodiment, a plurality of detected rotational speeds can be obtained during 1 rotation.

The rotation speed of the motor 113 detected based on the time tx between the edges of the sensor signal, that is, the sensor signal, greatly varies depending on the presence or absence of the imbalance. The reason for this is as follows. That is, the motor 113 has a plurality of magnets 33 arranged at equal intervals on the rotor 32. Therefore, the time tx between the edges of the sensor signal is equally spaced when no imbalance occurs, but is not equally spaced when an imbalance occurs, and a deviation occurs. As a result, the rotation speed of the motor 113 detected based on the sensor signal greatly varies depending on the presence or absence of the imbalance.

This difference will be described with reference to fig. 15 and 16. In the following description, the rotation speed of the motor 113 detected based on the sensor signal may be simply referred to as a detected rotation speed. FIG. 15 shows: a detected revolution number signal that is a signal indicating the detected revolution number when there is no imbalance, and a determination value signal obtained by applying digital filter processing including various signal processing described later to the detected revolution number signal. Further, fig. 16 shows: a detected rotational speed signal and a determination value signal when an imbalance exists. As shown in fig. 15 and 16, the detected rotation speed signal when there is an imbalance exhibits a waveform that changes greatly during 1 rotation as compared with the detected rotation speed signal when there is no imbalance.

Thus, although the difference caused by the presence or absence of imbalance is clear at a glance from the waveform of the detected rotation number signal, it is difficult to perform digital processing to determine the presence or absence of imbalance while keeping the waveform unchanged. Therefore, in the present embodiment, the control circuit 7 performs digital filter processing on the detected rotation speed signal in the imbalance monitoring control to extract a determination value signal, which is a signal of a frequency component corresponding to a fluctuation during 1 rotation of the motor 113. The control circuit 7 compares the determination value signal with a threshold signal indicating a predetermined threshold value based on the extracted determination value signal, and monitors the imbalance.

In this embodiment, the digital filter processing includes: the 1 st process as a process of a low-pass filter, the 2 nd process as a process of a band-pass filter, the 3 rd process as a second multiplication process, and the 4 th process as a process of a low-pass filter. In the following description and fig. 17, the case of the low-pass filter is simply referred to as LPF and the case of the band-pass filter is simply referred to as BPF.

As shown in fig. 17, the waveform of the detected rotation speed signal contains high-frequency noise having a relatively high frequency. Therefore, in the 1 st process, the LPF process is performed on the detected rotation speed signal. The cutoff frequency of the LPF in the 1 st process is: a frequency higher than the cutoff frequency of the LPF in the 4 th process described later is set to a relatively high frequency to the extent that the high-frequency noise can be removed. In the following description and fig. 17 and the like, the cases of the processing of the LPFs in the 1 st processing and the 4 th processing are distinguished by being referred to as LPF "weak" and LPF "strong", respectively.

The signal after the 1 st process, which is a process of "weak" of the LPF, is a signal after high-frequency noise is removed from the detected rotational speed signal, as shown in fig. 17. The passing band of the BPF in the 2 nd process is set so that the frequency band corresponding to 1 rotation of the rotary groove 104 passes. As shown in fig. 17, the signal after the 2 nd processing, which is the processing of the BPF, is a signal obtained by removing a dc component from the signal after the 1 st processing and extracting an ac component in a frequency band corresponding to 1 rotation of the rotary tub 104.

In the processing of the BPF, a negative value is also output in terms of calculation. Therefore, in the 3 rd process, the second multiplication process is performed. Thus, as shown in fig. 17, the 3 rd processed signal is: the signal after removal of the negative component. The LPF "strong" cutoff frequency in the 4 th process is: the frequency lower than the "weak" cutoff frequency of the LPF in the 1 st process is set to a frequency at which only a substantially dc component passes. As shown in fig. 17, the signal after the 4 th processing, which is the processing of "strong" of the LPF, is a signal having only a substantially dc component, and corresponds to the determination value signal described above.

Next, with reference to fig. 19, description will be made of: the specific processing contents related to the imbalance monitor control performed by the control circuit 7 having the above-described configuration. The control circuit 7 performs the processing shown in fig. 19 during the dehydration operation. First, after the dehydration operation is started in step S501, the flow proceeds to step S502, and it is determined whether or not the period is a constant speed period. If the period is the constant speed period, the process proceeds to step S503 if YES in step S502. In step S503, the average value of the determination values in the latter half of the constant speed period is calculated. The reason for this is because: in the first half of the constant speed period, there is a possibility that the detected rotation speed signal and further the determination value signal are unstable, and when the determination is performed using such a signal, there is a possibility that erroneous monitoring occurs.

After step S503 is executed, the flow proceeds to step S504, where: the average value of the determination values calculated in step S503 is compared with a predetermined threshold value, and specifically, whether or not the average value of the determination values is equal to or greater than the threshold value is determined. If the average value of the determination values is smaller than the threshold value, the result is "NO" in step S504, and the process returns to step S502. On the other hand, if the average value of the determination values is equal to or greater than the threshold value, "YES" in step S504, the routine proceeds to step S505. In step S505, the rotation of the motor 113 is stopped, and further, the rotation of the rotary tub 104 is stopped, and the unbalance is corrected by the water injection. After step S505 is executed, the process returns to step S502.

When the constant speed period ends and the acceleration period is shifted to, NO in step S502, the routine proceeds to step S506. Step S506 is a process for determining which of the first half and the second half of the acceleration period is, and determines whether or not the detected rotation speed is equal to or less than a predetermined number. The predetermined rotation speed is set as follows: the rotation speed can be determined as to which of the first half and the second half of the acceleration period is. In the latter half of the acceleration period, if the detected rotation speed exceeds the predetermined number, the result is "NO" in step S506, and the present process is ended.

On the other hand, in the first half of the acceleration period, if the detected rotation speed is equal to or less than the predetermined number, "YES" in step S506, and the routine proceeds to step S507. In step S507, a comparison is made between the determination value and a predetermined threshold value, and specifically, it is determined whether or not the determination value is equal to or greater than the threshold value. If the determination value is smaller than the threshold value, the result is "NO" in step S507, and the process returns to step S506. On the other hand, if the determination value is equal to or greater than the threshold value, the result is YES in step S507, and the process proceeds to step S508.

In step S508, the rotation of the motor 113 is stopped, and further, the rotation of the rotary tub 104 is stopped, and unbalance correction by water injection is performed. After step S508 is performed, the process returns to step S506. As described above, in the present embodiment, although the unbalance monitoring control for monitoring the unbalance due to the leaning of the laundry in the spin basket 104 is performed in the first half of the acceleration period in which the detected rotation speed is equal to or less than the predetermined number, the unbalance monitoring control is not performed in the second half of the acceleration period in which the detected rotation speed exceeds the predetermined number.

According to the present embodiment described above, the control circuit 7 executes the unbalance monitoring control in which the rotation speed of the motor 113 is obtained based on the sensor signal when the spin tub 104 is rotated in the spin-drying process of the laundry drying, and the unbalance is monitored based on the fluctuation of the obtained rotation speed, as the predetermined monitoring control. In the configuration of the present embodiment, even if an imbalance occurs, the phase current of the motor 113 does not fluctuate due to the imbalance, but the rotation speed detected based on the sensor signal fluctuates greatly due to the presence or absence of the imbalance.

In the present embodiment, the imbalance is monitored based on the number of revolutions at which such large fluctuations due to the presence or absence of imbalance occur, and therefore, such an excellent effect that the monitoring accuracy is good can be obtained. In the present embodiment, the control circuit 7 performs vector control of the motor 113 to a predetermined rotation speed, and performs: imbalance monitoring control based on sensor signals. In this way, it is possible to suppress: the rotation fluctuation becomes large and the vibration and noise increase, and the imbalance monitoring control can be executed.

In the above configuration, the motor 113 is a multi-pole motor, and includes: a rotor 32 provided with a plurality of magnets 33. Further, the stator 31 of the motor 113 is provided with: the 1-position sensor 9 as a magnetic sensor performs imbalance monitoring control based on a variation in the rotation speed obtained based on the sensor signal output from the 1-position sensor 9. According to this configuration, a plurality of detected values of the rotation speed are obtained during 1 rotation by the sensor signal output from the 1-position sensor 9. Therefore, according to the present embodiment, only 1 position sensor 9 may be provided, and therefore, it is possible to monitor the imbalance with high accuracy while suppressing the complexity of the configuration and the increase in cost.

In the present embodiment, the control circuit 7 performs digital filter processing on the obtained rotation speed of the motor 113 in the imbalance monitoring control to extract a signal of a frequency component corresponding to a fluctuation during 1 rotation of the motor 113, and monitors the imbalance based on the extracted signal of the frequency component. In this way, the imbalance can be monitored while eliminating the influence of noise due to mounting errors of the position sensor 9, the magnet 33, and the like, and electrical noise superimposed on the sensor signal output from the position sensor 9, and therefore, the monitoring accuracy can be further improved.

(embodiment 3)

Next, with reference to fig. 19, description will be made of: embodiment 3 is modified from embodiment 2 in the content of the imbalance monitor control.

The control circuit 7 of the present embodiment monitors the imbalance based on the detected current flowing through the motor 113 in addition to the acquired rotation speed of the motor 113 in the imbalance monitoring control. Therefore, the present embodiment is different from embodiment 2 in that: the contents of the digital filter processing. As shown in fig. 19, in the digital filter processing of the present embodiment, multiplication processing executed before the 1 st processing is added in addition to the respective processing included in the digital filter processing of the 2 nd embodiment.

In the multiplication processing, there are performed: the detected rotation speed signal is multiplied by a motor current signal corresponding to a detected value of a torque current, which is a current flowing through the motor 113. The signal after such multiplication is a signal as shown in fig. 19. In this case, in the 1 st process, the LPF is "weak" with respect to the signal obtained by multiplying the detected rotational speed signal by the motor current signal and performing multiplication processing.

According to the present embodiment described above, the control circuit 7 monitors the imbalance based on the motor current in addition to the detected rotational speed in the imbalance monitoring control. In this way, when the motor current, that is, the torque current does not fluctuate slightly depending on the presence or absence of the imbalance, the determination value obtained finally changes greatly depending on the presence or absence of the imbalance, and it is possible to further improve: and monitoring accuracy for monitoring the presence or absence of the imbalance based on a comparison with a threshold value.

Further, when the responsiveness of the rotational speed control of the motor 113 is poor, the detected rotational speed varies due to the presence or absence of the imbalance, and when the responsiveness of the rotational speed control of the motor 113 is good, the motor current varies due to the presence or absence of the imbalance. Therefore, according to the imbalance monitoring control of the present embodiment, since the imbalance is monitored based on both the detected rotation speed and the motor current, the imbalance can be monitored with high accuracy regardless of the responsiveness of the rotation speed control of the motor 113.

In the present embodiment, both the detected rotation number signal corresponding to the detected rotation number and the motor current signal corresponding to the motor current are used for monitoring the imbalance, but for example, the amount of laundry loaded into the rotary tub 104 may be measured by a weight sensor or the like, and one of the detected rotation number signal and the motor current signal may be selected based on the measurement result, and used for monitoring the imbalance.

(other embodiments)

The present invention is not limited to the embodiments described above and shown in the drawings, and can be modified, combined, or expanded as desired without departing from the scope of the invention.

The numerical values and the like shown in the above embodiments are merely exemplary and are not limited thereto.

The present invention is not limited to the vertical axis type washing machine 100, and can be applied to: such as a drum type washing machine, and the like.

The position sensor 9 is not limited to a magnetic sensor such as a hall IC, and may be: and various sensors configured to detect a rotational position of the rotor 32 of the motor 113 and output sensor signals.

While the embodiments of the present invention have been described above, these embodiments are merely provided as examples and are not intended to limit the scope of the present invention. These new embodiments may be implemented in other various ways, and various omissions, substitutions, and changes may be made without departing from the spirit of the invention. These embodiments and modifications are included in the scope and spirit of the present invention, and are also included in the invention described in the claims and equivalents thereof.

Claims (9)

1. A washing machine is provided with:

a rotary tub for receiving the laundry,

a motor as a brushless DC motor for rotationally driving the rotary tub,

a current detection unit for detecting a current flowing through the motor,

a control unit for vector-controlling the motor based on the current detected by the current detection unit, an

1 position sensor for detecting a rotational position of a rotor of the motor and outputting a sensor signal,

the control unit executes predetermined monitoring control based on the sensor signal.

2. The washing machine as claimed in claim 1,

the control unit executes, as the predetermined monitoring control, one or both of an abnormality monitoring control that monitors an abnormality related to rotation of the motor and a stop monitoring control that monitors stop of the motor due to braking.

3. A washing machine according to claim 2,

the control unit monitors occurrence of an abnormality related to rotation of the motor when the sensor signal does not change for a predetermined determination time or longer during rotation control in which the motor is controlled to rotate during the abnormality monitoring control.

4. A washing machine according to claim 2 or 3,

the control unit controls the motor so that a rotation speed of the motor follows a desired target speed,

in the abnormality monitoring control, when a difference between the target speed and the rotation speed of the motor calculated based on the sensor signal in the rotation control for controlling the rotation of the motor is equal to or greater than a predetermined threshold speed, it is monitored that an abnormality related to the rotation of the motor has occurred.

5. A washing machine according to any one of claims 1 to 4,

further provided with: a pulsator rotatably provided inside the rotary tub,

the control unit executes, as the predetermined monitoring control, weight monitoring control in which, after laundry is loaded into the spin tub, a rotation speed of the spin tub is calculated based on the sensor signal when the pulsator is rotated, and the amount of the laundry is determined based on the calculated rotation speed.

6. A washing machine according to any one of claims 1 to 5,

the control unit executes an imbalance monitoring control in which, when the spin basket is rotated in a spin-drying process for dehydrating the laundry, the rotation speed of the motor is obtained based on the sensor signal, and an imbalance caused by the deviation of the laundry in the spin basket is monitored based on the variation of the obtained rotation speed, as a predetermined monitoring control.

7. A washing machine according to claim 6,

the motor includes: a rotor provided with a plurality of magnets, and a stator provided with the position sensor,

the position sensor is a magnetic sensor.

8. A washing machine according to claim 6 or 7,

the control unit monitors the imbalance based on the current detected by the current detection unit in addition to the obtained rotation speed of the motor in the imbalance monitoring control.

9. A washing machine according to any one of claims 6 to 8,

the control unit extracts a signal of a frequency component corresponding to a fluctuation of the motor during 1 rotation by performing digital filter processing on the obtained rotation speed of the motor in the imbalance monitoring control, and monitors the imbalance based on the extracted signal of the frequency component.

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