Background
When the drum washing machine is used for washing clothes, the water level is just higher than the clothes after the clothes are soaked by water; because the washing machine washes the clothes completely by using the friction between the clothes and the washing machine barrel, between the clothes and water, if the water is too much, the friction between the clothes is not compact, so that the friction is reduced, and the washing effect is rather poor, otherwise, if the water level does not exceed the clothes, the clothes are not fully contacted with the water, so that the dry friction and other conditions of the clothes are caused, the washing effect is even poor, and the clothes can be damaged.
At present, part of washing machines require controllers to carry out fuzzy discrimination on the weight and the material of clothes; the fuzzy detection method is implemented substantially as follows: two points are respectively connected with the output points of two silicon controlled rectifiers for controlling the positive rotation and the negative rotation of the motor, namely one end point of each of the positive rotation winding and the negative rotation winding of the motor. After MCU disconnection just, the reversal silicon controlled rectifier, the motor can also rotate because of inertia, and according to the difference of clothing volume in the bucket and material, inertia size is also different, shows that it is different that the number of turns of rotation is exactly, and this information is read by MCU, carries out analysis and judges. Although the method can realize control, the control effect is poor, misjudgment can be carried out under many conditions, such as the difference of different materials and the error of weight judgment, and due to the limitation of the judgment precision and the control precision, the method cannot realize the design original purpose that the water level just exceeds the clothes, and the optimal washing state is achieved.
Disclosure of Invention
The present invention is directed to a water quantity control system of a washing machine to solve the above problems.
In order to achieve the purpose, the invention provides the following technical scheme:
a water quantity control system of a washing machine comprises a host controller, a slave controller, a host electromagnetic valve and a slave electromagnetic valve, wherein the host electromagnetic valve is used for controlling water discharge of the washing machine, the slave electromagnetic valve is used for controlling water inlet of the washing machine, the host controller and the slave controller are preset through a key module, a host sensor measures a voltage value corresponding to the current water level, the voltage value is sent to the host controller to be compared with a set value after analog-to-digital conversion is carried out through an A/D conversion module, and the host controller controls the host electromagnetic valve to adjust the liquid level of the washing machine; the host controller transmits a set value to the slave controller through the communication interface, and the slave controller regulates the flow by controlling the slave electromagnetic valve; the water inlet data of the washing machine is collected by the slave sensor and then is sent to the host controller through the A/D converter, the slave controller and the communication interface in sequence.
As a further scheme of the invention: the main machine controller learns the liquid level fluctuation condition in the washing machine through the main machine sensor, if the liquid level fluctuation is larger than a preset value, the main machine electromagnetic valve and the slave electromagnetic valve are controlled to be kept in a closed state, if the liquid level fluctuation is smaller than the preset value, the main machine electromagnetic valve is controlled to be opened to discharge water outwards, and if the main machine sensor cannot detect the liquid level, the slave electromagnetic valve is controlled to be opened to control the washing machine to feed water.
As a further scheme of the invention: the host controller is connected with a host electromagnetic valve through a driving circuit, the driving circuit comprises a triode VT1, a resistor R1, a capacitor C1, an MOS tube VS and a triode VT2, one end of the resistor R1 is respectively connected with a resistor R3, a resistor R2 and a collector of the triode VT2, the other end of the resistor R3 is respectively connected with an emitter of the triode VT2 and the host controller, the other end of the resistor R1 is connected with a base of a triode VT1, a collector of the triode VT1 is connected with the other end of a resistor R2, an emitter of the triode VT1 is respectively connected with a resistor R5, a resistor R4 and a base of the triode VT2, the other end of the resistor R4 is respectively connected with a capacitor C4, a collector of the triode VT 4 and a G pole of the MOS tube VS, a D of the MOS tube VS is connected with the host electromagnetic valve, the other end of the host is connected with a power supply VCC, an S pole of the MOS tube VS is respectively connected with the other end of the, the base of the transistor VT3 is connected with the other end of the resistor R5.
As a further scheme of the invention: the A/D conversion module and the A/D converter both adopt a chip ICL 7135.
As a further scheme of the invention: the master controller and the slave controller both adopt single-chip microcomputers.
As a further scheme of the invention: the singlechip adopts pic16f 917.
As a further scheme of the invention: and the communication interface adopts an RS485 communication interface.
As a further scheme of the invention: the host sensor adopts an ultrasonic sensor.
As a still further scheme of the invention: the model of the ultrasonic sensor is S18 UUA.
Compared with the prior art, the invention has the beneficial effects that: the water quantity control system of the washing machine adopts the ultrasonic sensor to detect the liquid level fluctuation condition in the washing machine, thereby judging whether the water level in the washing machine can enable the washing machine to reach the optimal washing state or not and having high accuracy.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 1-2, in an embodiment of the present invention, a water quantity control system for a washing machine includes a host controller, a slave controller, a host electromagnetic valve and a slave electromagnetic valve, wherein the host electromagnetic valve is used for controlling water discharge of the washing machine, the slave electromagnetic valve is used for controlling water inlet of the washing machine, the host controller and the slave controller are preset through a key module, a host sensor measures a voltage value corresponding to a current water level, the voltage value is subjected to analog-to-digital conversion through an a/D conversion module and then sent to the host controller to be compared with a set value, and the host controller controls the host electromagnetic valve to adjust a liquid level of the washing; the host controller transmits a set value to the slave controller through the communication interface, and the slave controller regulates the flow by controlling the slave electromagnetic valve; the water inlet data of the washing machine is collected by the slave sensor and then is sent to the host controller through the A/D converter, the slave controller and the communication interface in sequence.
The main machine controller acquires the liquid level fluctuation condition in the washing machine through the main machine sensor, if the liquid level fluctuation is larger than a preset value, the liquid amount in the washing machine is in an optimal state, the friction degree between clothes and the liquid in the washing machine and between the clothes and the liquid in the washing machine are also in an optimal state, and at the moment, the main machine electromagnetic valve and the slave machine electromagnetic valve are controlled to be kept in a closed state; if the fluctuation of the liquid level is less than the preset value, the liquid amount in the washing machine is more, because more liquid is present, the liquid level can be kept stable when the washing machine works, the host computer electromagnetic valve is controlled to be opened and water is discharged outwards, in the water discharging process, the host computer sensor detects the current water level situation at any time until the set value shows that the fluctuation of the liquid level is more than the preset value, and the host computer electromagnetic valve is closed; if the master sensor cannot detect the liquid level, the liquid in the washing machine is too little at the moment, the slave electromagnetic valve is controlled to be opened to control the water inlet of the washing machine, the slave sensor calculates the flow of the inlet water in the water inlet process, meanwhile, the master sensor detects the current water level situation at all times, and the slave electromagnetic valve is closed until the set value shows that the liquid level fluctuation is larger than the preset value.
The A/D conversion module and the A/D converter both adopt a chip ICL 7135. The master controller and the slave controller both adopt a single chip microcomputer pic16f 917. And the communication interface adopts an RS485 communication interface.
The ultrasonic sensor is a small sensor, has the functions of other large sensors although the size is small, is convenient to install and use and is not influenced by the color of a measured object, and has a plurality of special functions, such as: the temperature compensation function is provided, and the output of analog quantity or switching value can be selected; the power supply voltage is 10-30V, the measurement range is 30-300 mm, the output voltage is 0-10V, the output current is 4-20 mA, the minimum load impedance is 2.5 ohm, the precision can reach 0.5mm, and the appearance is linear type and right-angle type. The induction caliber is 18 mm.
The ultrasonic sensor has the condition that the liquid level error required by design is not more than +/-0.3 cm, and the problem of inconvenient installation is solved, so that the ultrasonic sensor S18UUA with high precision and small size is selected as the sensor of the main machine of the design.
The specific principle of the ultrasonic sensor for detecting the liquid level in the invention is as follows: when the ultrasonic sensor needs to work, the ultrasonic sensor continuously sends out ultrasonic signals and receives the returned ultrasonic signals, the received returned signals are fed back to the host controller through the A/D conversion module, the host controller draws a dynamic liquid level diagram according to the time difference fed back by different signals, and the average change amplitude of the dynamic liquid level diagram is compared with a preset value within 5s, so that the specific condition of liquid level fluctuation is judged.
The 4-bit half-double integral A/D converter ICL7135 is adopted, and has the advantages of high precision, automatic polarity conversion output, automatic zero calibration, single power supply work and dynamic BCD code output. The double integration method has long second integration time, so the A/D conversion speed is slow, usually (3-10) times/s, in addition, the integration of interference signals with periodic variation is zero, the anti-interference performance is good, and the ICL7135 is lower in price than a successive approximation type A/D converter under the condition of the same precision, so the A/D converter is more suitable for being adopted in the occasions with low speed requirements.
The host controller is connected with a host electromagnetic valve through a driving circuit, the driving circuit comprises a triode VT1, a resistor R1, a capacitor C1, an MOS tube VS and a triode VT2, one end of the resistor R1 is respectively connected with a resistor R3, a resistor R2 and a collector of the triode VT2, the other end of the resistor R3 is respectively connected with an emitter of the triode VT2 and the host controller, the other end of the resistor R1 is connected with a base of a triode VT1, a collector of the triode VT1 is connected with the other end of a resistor R2, an emitter of the triode VT1 is respectively connected with a resistor R5, a resistor R4 and a base of the triode VT2, the other end of the resistor R4 is respectively connected with a capacitor C4, a collector of the triode VT 4 and a G pole of the MOS tube VS, a D of the MOS tube VS is connected with the host electromagnetic valve, the other end of the host is connected with a power supply VCC, an S pole of the MOS tube VS is respectively connected with the other end of the, the base of the transistor VT3 is connected with the other end of the resistor R5.
Under normal conditions, the host controller outputs low level to the driving circuit, and the host electromagnetic valve does not work; when the host controller sends a high level, the base electrode of the triode VT1 obtains a bias voltage, the triode VT1 is quickly conducted, the emitter current of the triode VT1 is sent to the base electrode of the triode VT2 on one hand, and is sent to the base electrode of the triode VT3 through the resistor R5 on the other hand, so that the triode VT2 is cut off, the triode VT3 is conducted, the capacitor C1 is charged through the resistor R4, and when the capacitor C1 is charged to a certain degree, the MOS tube VS is conducted to drive the host electromagnetic valve to work; although the triode VT2 is not conducted in the circuit and can be completely removed, the triode VT2 plays a role in isolation in the circuit, and the host electromagnetic valve is isolated from the emitter of the triode VT1, so that the anti-interference capability of the host electromagnetic valve is improved; the capacitor C2 is used to increase the conduction speed of the transistor VT3 by the charging current, thereby increasing the switching speed of the circuit.
In summary, the water quantity control system of the washing machine of the invention adopts the ultrasonic sensor to detect the liquid level fluctuation condition in the washing machine, thereby judging whether the water level in the washing machine can enable the washing machine to reach the optimal washing state or not, and having high accuracy.
The system of the invention is characterized in that each module is also driven by electric power, which is common knowledge in the field, the invention has no special requirement, and the technicians in the field can select proper power supply module to drive without any creative labor.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.
Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.