Cleaning apparatus and detecting method thereof

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.

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 in  claim 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 in  claim 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 of  claim 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 in  claim 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 in  claim 5 , wherein the blowing device comprises an air outlet located under the optical sensor. 
     
     
         7 . The cleaning apparatus as claimed in  claim 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 in  claim 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 in  claim 1 , wherein the control unit comprises a band pass filter leaching off the electrical noise from the motor. 
     
     
         10 . The cleaning apparatus as claimed in  claim 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 in  claim 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 in  claim 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 in  claim 13 , further comprising:
 stopping the motor in response to said signal.   
     
     
         15 . The method as claimed in  claim 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 in  claim 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 in  claim 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 in  claim 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 in  claim 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 in  claim 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.