US20100293742A1 - Cleaning apparatus and detecting method thereof - Google Patents

Abstract

The disclosure provides a cleaning apparatus and detecting method thereof. The cleaning apparatus includes a fan, a motor, a detecting device and a control unit. The motor drives the fan to create an air flow through the cleaning apparatus. The detecting device is electrically connected to the motor, and is utilized detected an impedance of the motor. The control unit is electrically connected to the motor and the detecting device respectively, for comparing the impedance of the motor with a predetermined value and outputting a signal indicative of a comparison result.

Description

CROSS REFERENCE TO RELATED APPLICATIONS
• This Application claims priority of Taiwan Patent Application No. 098116839, filed on May 21, 2009, the entirety of which is incorporated by reference herein.
BACKGROUND OF THEINVENTION1. Field of the Invention
• The disclosure relates to cleaning apparatus and detecting method, and in particular relates to an auto-cleaning device and detecting method.
• 2. Description of the Related Art
• Particles detection technology is currently being used in traditional vacuum cleaners, air cleaners, self-propelled vacuum cleaners, and clean rooms. The detection of amount of particles and environmental control is to make cleaning more efficient. With a simple and effective way to measure the amount of dust and the size, the cleaning performed by the traditional vacuum cleaners, air cleaners, or self-propelled vacuum cleaners can be more efficient, and thus it can promote environment protection by energy-saving and carbon emission reduction.
• Known particle detection technology can be broadly divided into the following three categories:
• (1) Optical detection: The main principle is to use a pair of optical transmitter and receiver devices, where each receiver detects intensity of light emitted by the corresponding optical transmitter. In principle, the detected intensity increases when the density of dust grains declines, thereby identifying the amount of dust present. For example, in U.S. Pat. No. 4,601,082, optical sensors are used to detect dust. Further, in U.S. Pat. No. 5,608,944 and U.S. Pat. No. 6,571,422, circuits of signal processing, such as amplification, filtering, and other methods, are introduced to improve the sensor's sensitivity.
  (2) Pressure-Difference detection: The principle determines whether the filter needs to be replaced or the amount of waste dust collection box is full by comparing the pressure difference between the dust collection box and the suction inlet.
  (3) Piezoelectric pressure sensing: The PZT (Lead Zirconate Titanate) pressure sensing element is placed at the inner wall of the vacuum suction inlet. The amount of dust inhaled is determined by the pressures applied to the PZT pressure sensing element by the impact of dust.
BRIEF SUMMARY OF THE INVENTION
• In an embodiment, the cleaning apparatus includes a fan, a motor, a detecting device, and a control unit. The motor is for driving the fan to create an air flow through the cleaning apparatus; the detecting device is electrically connected to the motor to detect an impedance of the motor; and the control unit is electrically connected to the detecting device, for comparing the impedance of the motor with a predetermined value and outputting a signal indicative of a comparison result.
• In another embodiment, the cleaning apparatus further includes a dust collecting unit positioned in a path of the air flow to trap dust from the air, and the signal indicates a state of the dust collecting unit or filter.
• In another embodiment, the cleaning apparatus further includes a blowing device for directing exhaust air of the fan to a sensing surface of the at least one optical sensor.
• In another embodiment, a method for debris detection in a cleaning apparatus includes measuring an impedance of a motor of a fan of the cleaning apparatus; determining a level of debris accumulation in the cleaning apparatus based on the impedance of the motor; and issuing a signal indicative of the level of debris accumulation exceeding a predetermined value.
• In another embodiment, a method for debris detection in a cleaning apparatus includes arranging multiple optical sensors at different locations in the inlet for detecting the sensing surface at said different locations. The cleaning operation of the cleaning apparatus is controlled based on the determined dust covered surface areas received from said optical sensors.
• While the disclosure has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
• The present invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
• FIG. 1ais a perspective view of a cleaning apparatus according to an embodiment;
• FIG. 1bis an explosive view of a cleaning apparatus according to the embodiment depicted inFIG. 1a;
• FIG. 1cis a perspective view of a cleaning apparatus according to another embodiment;
• FIG. 1dis an explosive view of a cleaning apparatus according to the embodiment depicted inFIG. 1c;
• FIG. 2 is a circuit block diagram of a cleaning apparatus according to an embodiment;
• FIG. 3ais a block diagram of the control unit according to the embodiment depicted inFIG. 2;
• FIG. 3bis a function diagram of the band pass filter according to the embodiment depicted inFIG. 3a;
• FIG. 3cis a block diagram of the control unit according to another embodiment;
• FIG. 4 is a cross-sectional view of an intake of the cleaning apparatus according to an embodiment;
• FIG. 5 is a flow chart of a detecting method of a cleaning apparatus according to an embodiment;
• FIG. 6 is a flow chart of a detecting method of a cleaning apparatus according to another embodiment; and
• FIG. 7 is a flow chart of a detecting method of a cleaning apparatus according to yet another embodiment.
DETAILED DESCRIPTION OF THE INVENTION
• The descriptions below are made to illustrate exemplary embodiments of the disclosure. It is noted that the drawings of the disclosure are not to scale. The drawings are intended to depict only typical aspects of the disclosure, and therefore should not be considered as limiting the scope of the disclosure. In the drawings, like numbering represents like elements between the drawings.
• Referring toFIG. 1a,1bandFIG. 2,cleaning apparatus1 includes ahousing10, afan20, amotor30, a detectingdevice40, acontrol unit50, two pairs ofoptics sensor60, adust collecting unit70, threewarning members80, four blowingdevices90, and adriving system110. Although, in the following illustration,cleaning apparatus1 is sometimes referred to as an auto-cleaning device, in some embodiments,cleaning apparatus1 can be a vacuum cleaner or an air cleaning machine. Thus, other embodiments are also within the scope of the following claims.
• Thehousing10 substantially encloses thefan20, themotor30, the detecting isdevice40, and thecontrol unit50 therein. Further, thehousing10 has aninlet11, which has a shape of a long strip and includes aleft area11aand aright area11b.
• Referring toFIG. 1a, themotor30 is configured to drive thefan20 to create an air flow through the cleaning apparatus so that dust can be sucked in through theinlet11. Themotor30 is set below thefan20 inside thehousing10. As shown inFIG. 2, themotor30 is coupled to thefan20 in order to drive thefan20.
• The detectingdevice40 is disposed beside thecontrol unit50 and themotor30 inside thehousing10, and is electrically connected to themotor30 and thecontrol unit50, respectively, in order to detect the an impendence of themotor30. In some embodiments, if themotor30 is a brushless motor, the detectingdevice40 is integrated into the circuit of the brushless motor.
• Thecontrol unit50 is disposed below themotor30 inside thehousing10, and is electrically connected to themotor30, the detectingdevice40, and thedriving system110, respectively, in order to control the operation of thefan20 and the moving speed of thecleaning apparatus1. Thecontrol unit50 is configured to compare the detected impedance of the motor with a predetermined value and output a signal indicative of the comparison result.
• The detectingdevice40 of thecleaning apparatus1 according to at least one embodiment is configured to detect an impedance of themotor30 for measuring debris accumulation inside a dust collecting unit. The dust collecting unit could include afilter72 and abox71. The impedance of themotor30 increases when the debris accumulation inside the dust collecting unit or the blockage of the air outlet and inlet increases. When the voltage of themotor30 is fixed, it leads to the decrease of the current and increase of the resistance. The resistance of themotor30 can be measured after the current value of themotor30 detected by the detectingdevice40. In some embodiments, the detecting device is a current detecting device that detects a current value of the fan. When the detecting device detects a current value that is below a predetermined current value, thecontrol unit50 may stop driving themotor30.
• As shown inFIG. 3a,in at least one embodiment, thecontrol unit50 including a band-pass filter51, anamplifier52, apulse expander53, an analog/digital converter54, and amicro controller55. The band-pass filter51 is a multi-level filter circuit that is configured to remove the electronic noise from other components (e.g. the motor30). In one embodiment, asFIG. 3bshown, the band-pass filter51 is a four-level filter circuit, including a high-pass filter51a,a low-pass filter51b,a band-pass circuit51c,and a wave-shapingcircuit51d.In some embodiments, regarding the band-pass filter51, the gain is 2±3%, the central frequency is 110 kHz±3%, the bandwidth of 3 dB is 90 kHz±3%, and an electronic bandwidth is 20 kHz˜200 kHz. It should be realized that although the embodiment disclosed herein is a four-level filter circuit, it is not limited to such design. Any other circuit design is workable as long as the gain, central frequency, 3 dB bandwidth, and electronic bandwidth comply with standards previously stated.
• Referring toFIG. 3a,theamplifier52 amplifies signals from the band-pass filter51; thepulse expander53 adjusts the sampling frequency of signals from other components (ex: optical sensor60); the analog/digital converter54 performs a analog/digital conversion for signals from other components; and themicro controller55 utilizes signals processed by the analog/digital converter54 to control the suction and the moving speed of thecleaning apparatus1. Furthermore, in some embodiments, it is also desirable to utilize PWM (Pulse Width Modulation) to control the suction and the moving speed stated above. When thecleaning apparatus1 detects a rather dusty condition, it will be adjusted to have a stronger suction power and slower moving speed, therefore improving the cleaning efficiency.
• It should be realized that internal configuration ofcontrol unit50 is not limited to the wayFIG. 3ashown. Any configuration accomplished substantially the same result is desirable. For example,FIG. 3cshows another example of the control unit. Thecontrol unit50′ includes two band-pass filters51, twoamplifiers52, apulse expander53, an analog/digital converter54, amicro controller55, and acomparator56. The difference between thecontrol unit50′ inFIG. 3cand thecontrol unit50 inFIG. 3ais that thecontrol unit50′ further includes acomparator56. Thecomparator56 compares the signal after the suction operation is commenced with the signal before the suction motion is commenced.
• Referring toFIG. 1a, two pairs ofoptical sensors60 are disposed inside theinlet11 of thehousing10, in order to detect the amount of duct passing though the inlet. While the surface area of any of the twooptical sensors60 is covered by dust over a predetermined percentage (ex: over 90%), thecontrol unit50 ceases themotor30 that drives thefan20. The twooptical sensors60 are separately disposed on theleft area11aand theright area11binside theinlet11. It should be realized that although the embodiment disclosed herein utilizes two optical sensors, the number of optical sensor is not limited to two, and it's also desirable to change the number of optical sensors used.
• AsFIG. 4 shown, eachoptical sensor60 comprises atransmitter61 and areceiver62, wherein thetransmitter61 and thereceiver62 are placed facing each other inside theinlet11. It is realized that the location oftransmitter61 andreceiver62 is not limited to what figures illustrated. ReferringFIG. 1candFIG. 1d, in some embodiments, thetransmitter61 andreceiver62 are disposed in a manner that they both face the same direction. In that case, thereceiver62 receives signals from thetransmitter61 by reflection.
• ReferringFIG. 1a, thedust collecting unit70, which is positioned in a path of the air flow to trap dust from air inhaled by to thefan20, comprises abox71 and afilter72. When thecontrol unit50 ceases themotor30 that drives thefan20, thedust collecting unit70 is configured to be cleaned up. That is, thebox71 is cleaned and/or thefilter72 is replaced by another one.
• ReferringFIG. 2 is a circuit block diagram of the cleaning apparatus. There are three warningmembers80 disposed on thehousing10 and electrically connected to thecontrol unit50. The warningmember80 is activated (e.g. switched on) by thecontrol unit50 when the signal indicates that the impedance of the motor is higher than the predetermined value. In some embodiments, three warningmembers80 may be light emitting diodes respectively and can emit light when switched on by thecontrol unit50. In some other embodiments, the warningmember80 can be buzzers, indicators, or other devices according to various applications. Also, although only three warningmembers80 are depicted for an exemplary embodiment, the number of thewarning members80 can be more or less than three.
• FIG. 4 is a cross-sectional view of an intake of the cleaning apparatus according to an embodiment. In some embodiments, there are two blowingdevices90 is for directing exhaust air from thefan20 to a sensing surface of the at least one optical sensor (not shown in figures) to blow dust off said sensing surface for preventing theoptical sensor60 from being affected by the dust coverage. Each blowing device contains oneair outlet90a.The twoair outlets90arespectively located under thetransmitter61 and thereceiver62. The twoblowing devices90 are separately connecting to the air outlet (not shown in figures) of thefan20. The a portion of air-exhaust of thefan20 is guided to and blows through theair outlet90ato thetransmitter61 and thereceiver62 for cooling thetransmitter61 and /or thereceiver62 and reducing the coverage of the dust. Each of theblowing devices90 includes avalve91 as depicted inFIG. 1. Thevalve91 electrically connected with thecontrol unit50 to control the exhaust air flowing through the blowingdevice90. Theair outlet90acan be located under thetransmitter61 and thereceiver62 in this exemplary embodiment ofFIG. 4. Theair outlet90acan also be located on the side part of thetransmitter61 and thereceiver62. The location ofair outlet90acan be adjusted as long as the exhaust air of theair outlet90acan blow to thetransmitter61 and thereceiver62.
• Thedriving system110 for moving the auto-cleaning device is disposed on thehousing10, connected to thefan20 and themotor30 in the way as depicted inFIG. 1a, and electrically connected with thecontrol unit50 in the way as depicted inFIG. 2. Note that the arrangement of every element in the housing are not limited to these embodiments depicted by the figures.
• Referring toFIG. 5, it is a flowchart of a detecting method of the cleaning apparatus. The step of method comprises: turning on the power of the cleaning apparatus1(S11), measuring the impedance of themotor30 by the detecting device40(S12), determining a level of debris accumulation in thecleaning apparatus1 based on the impedance of the motor30(S13). When the level of debris accumulation exceeds a predetermined value, the process proceeds to Step S14. Then, a signal indicative of the level of debris accumulation exceeding a predetermined value is issued (in one or more embodiments to the warningmember80 such as light emitting diodes or buzzers), and stop the motor30(S14). Then, the power of thecleaning apparatus1 is turned off and thedust collecting unit70 is cleaned (S15).
• In one embodiment, Step4 (S14) is to issue a signal when the level of debris accumulation reaches 80% of the space inside thebox71. The predetermined percentage value of the space inside thebox71 can be adjusted according to various applications.
• In one or more embodiments, to decide when to clean thedust collecting unit70 by using the impedance value of themotor30 can improve the efficiency of thecleaning apparatus1.
• There are three warningmembers80 are disposed on thehousing10, and electrical connected with thecontrol unit50. When thecontrol unit50 determines thatmotor30 for thefan20 need to be stopped, thecontrol unit50 activates one ormore warning members80. In some embodiments, thewarning members80 are light-emitting diodes. When thecontrol unit50 activates one ormore warning members80, the light-emitting diodes (i.e. thewarning members80 being activated) emit light. Although only three warningmembers80 are depicted in the exemplary embodiment, in some other embodiments, there can be more or less than three warningmembers80 disposed on thehousing10. Further, thewarning members80 disclosed in the exemplary embodiment are light-emitting diodes. However, in some other embodiments, thewarning members80 can be light-emitting diodes, buzzers, other indictors, and/or combination thereof.
• FIG. 6 is a flowchart of an embodiment of a detecting method in a cleaning apparatus. The detecting method comprises some steps as follows. First, power thecleaning apparatus1 on in step S21. Next, in step S22, detect the amount of dust passing through aninlet11 of thecleaning apparatus1 and a sensing surface of anoptical sensor60 by theoptical sensor60. After that, in step S23, determine a dust covered surface area of theoptical sensor60. In detail,optical sensor60 senses the status of the sensing surface. When a percentage of the sensing surface which dust covered exceed a predetermined value, such as 90% in some embodiments, theoptical sensor60 outputs a sensing signal to thecontrol unit50, then go to step S24. In an embodiment, the sensing surface may separate to several equal grids. By counting the number of the grids which dust covered on the sensing surface, it may obtain the percentage to determine a dust or garbage covered surface area of the optical sensor. In some embodiments, a cleaning operation of the cleaning apparatus is controlled based on the determined dust covered surface area. In step S24, when thecontrol unit50 receives the sensing signal, themotor30 is stopped and a warningmember80 is activated. Finally, power off thecleaning apparatus1 and clean adust collecting unit70 of thecleaning apparatus1 in step S25.
• Before the step S23, in some embodiments, ablowing device90 can be activated and used to blow exhaust air of thefan20 at the sensing surface of theoptical sensor60 before said determining the dust covered surface area to decrease the amount of dust or garbage covered on the sensing surface of theoptical sensor60. It may prevent the sensitivity of theoptical sensor60 from degrading. In addition, in at least one embodiment, the predetermined value is 90%, but the predetermined value may change in various applications. It is not limited hereto.
• The detecting method in a cleaning apparatus which said before may determine when to clean thedust collecting unit70 of thecleaning apparatus1 by detecting status of the sensing surface of theoptical sensor60. It may increase the efficiency of thecleaning apparatus1 when thecleaning apparatus1 is working.
• FIG. 7 is a flowchart of another embodiment of a detecting method of a cleaning apparatus. In an embodiment, the detecting method may apply to an auto-cleaning device. The auto-cleaning device comprises multiple optical sensors arranged at different locations in the inlet for detecting the sensing surface at said different locations. TakeFIG. 1candFIG. 1dfor example, there are twooptical sensors62′ and61′ arranged at aleft area11aand aright area11bof the inlet, respectively, and a cleaning operation of thecleaning apparatus1 is controlled based on the determined dust covered surface areas received from saidoptical sensors60′. The detecting method comprises some steps as follows. First, in step S31, power thecleaning apparatus1 on. When adust collecting unit70 of thecleaning apparatus1 needs not to be cleaned, thecleaning apparatus1 remains in a walking mode. Next, in step S32, detect the amount of dust passing through aninlet11 of thecleaning apparatus1 and sensing surfaces of theoptical sensors62′ and61′ by theoptical sensors60′. Then, compare with the determined dust covered surface areas received from the optical sensors. In an embodiment, thecleaning apparatus1 turns to a direction where an optical sensor has a dust covered surface area larger than another optical sensor in step S33. For example, when the determined dust covered surface area of theoptical sensor62′ at theleft area11alarger then the determined dust covered surface area of theoptical sensor61′ at theright area11b,thecleaning apparatus1 turns left. On the contrary, when the determined dust covered surface area of theoptical sensor61′ at theright area11blarger then the determined dust covered surface area of theoptical sensor62′ at theright area11a,cleaning apparatus1 turns right. In addition, the cleaning operation of thecleaning apparatus1 further adjusts at least one suction power and/or a moving speed of thecleaning apparatus1 in said direction.
• Before the step S32, ablowing device90 may be activated to blow exhaust air of thefan20 at the sensing surface of theoptical sensors60′. It may prevent the sensitivity of theoptical sensors60′ from degrading. Furthermore, in some embodiments, when thecleaning apparatus1 turns to said direction, a turning radius of thecleaning apparatus1 is equal to a length of theinlet11.
• By the detecting method in a cleaning apparatus set forth above, the cleaning apparatus may decide which side is dirtier based on determined dust covered surface area of theoptical sensors62′ and61′ at theleft area11aand theright area11brespectively. It may increase the cleaning efficiency of thecleaning apparatus1.
• The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.

Claims (21)

1. A cleaning apparatus, comprising:

a fan;

a motor for driving the fan to create an air flow through the cleaning apparatus;

a detecting device electrically connected to the motor to detect an impedance of the motor; and

a control unit electrically connected to the detecting device, for comparing the impedance of the motor with a predetermined value and outputting a signal indicative of a comparison result.

2. The cleaning apparatus as claimed inclaim 1, further comprising:

a dust collecting unit positioned in a path of the air flow to trap dust from the air, wherein the signal indicates a state of the dust collecting unit or the filter.

3. The cleaning apparatus as claimed inclaim 2, further comprising:

an indicator electrically connected to the control unit to be activated by the control unit when the signal indicates that a volume occupied by dust inside the dust collecting unit has reached a predetermined level.

4. The cleaning apparatus ofclaim 1, further comprising:

a housing receiving the fan and having an inlet for the air flow; and

at least one optical sensor disposed in the inlet of the housing to detect the amount of dust passing through the inlet;

wherein the at least one optical sensor and the control unit are configured to determine a dust covered surface area of the at least one optical sensor.

5. The cleaning apparatus as claimed inclaim 4, further comprising:

a blowing device for directing exhaust air from the fan to a sensing surface of the at least one optical sensor to blow dust off the sensing surface.

6. The cleaning apparatus as claimed inclaim 5, wherein the blowing device comprises an air outlet located under the optical sensor.

7. The cleaning apparatus as claimed inclaim 5, further comprising:

a valve electrically connected to the control unit for controlling the exhaust air flowing through the blowing device.

8. The cleaning apparatus as claimed inclaim 4, wherein said at least one optical sensor comprises multiple optical sensors positioned at different locations in the inlet for detecting dust levels at said different locations, the control unit being electrically connected to said optical sensors for controlling a cleaning operation of the cleaning apparatus based on the detected dust levels received from said optical sensors.

9. The cleaning apparatus as claimed inclaim 1, wherein the control unit comprises a band pass filter leaching off the electrical noise from the motor.

10. The cleaning apparatus as claimed inclaim 9, wherein the band pass filter is a multi-stage circuit having a gain of 2±3%, a center frequency at 110±3% Hz, a 3±3% dB bandwidth of 90±3% kHz, and an electronic bandwidth from 20 kHz to 200 kHz.

11. The cleaning apparatus as claimed inclaim 1, wherein the control unit comprises a pulse extension device for adjusting a sampling frequency of the signal from the detecting device.

12. The cleaning apparatus as claimed inclaim 1, further comprising:

a warning member to be activated by the control unit when the signal indicates that the impedance of the motor is higher than the predetermined value.

13. A method for debris detection in a cleaning apparatus, said method comprising:

measuring an impedance of a motor of a fan of the cleaning apparatus;

determining a level of debris accumulation in the cleaning apparatus based on the impedance of the motor; and

issuing a signal indicative of the level of debris accumulation exceeding a predetermined value.

14. The method as claimed inclaim 13, further comprising:

stopping the motor in response to said signal.

15. The method as claimed inclaim 13, further comprising:

determining a dust covered surface area of an optical sensor, and

controlling a cleaning operation of the cleaning apparatus based on the determined dust covered surface area.

16. The method as claimed inclaim 15, further comprising:

blowing exhaust air of the fan at the sensing surface of the optical sensor before said determining the dust covered surface area.

17. The method as claimed inclaim 15, further comprising:

arranging multiple optical sensors at different locations in the inlet for detecting the sensing surface at said different locations;

wherein the cleaning operation of the cleaning apparatus is controlled based on the determined dust covered surface areas received from said optical sensors.

18. The method as claimed inclaim 17, wherein said controlling comprises:

turning the cleaning apparatus to a direction of the optical sensor with the determined dust covered surface areas larger than those determined by the other optical sensors.

19. The method as claimed inclaim 18, wherein said controlling further comprises:

adjusting at least one of suction power and a moving speed of the cleaning apparatus in said direction.

20. The method as claimed inclaim 18, wherein a turning radius of the cleaning apparatus is equal to a length of the inlet.

21. A cleaning apparatus, comprising:

a housing having an inlet;

a fan within the housing for creating an air flow into the housing through the inlet;

at least one optical sensor disposed in the inlet of the housing to determined a dust covered surface area of a sensing surface of the at least one optical sensor; and

a blowing device for directing exhaust air of the fan to the sensing surface of the at least one optical sensor to blow debris off said sensing surface.

Images