Vacuum cleaner and method of controlling a motor for a brush of the vacuum cleaner

Abstract

A vacuum cleaner that includes a surface cleaning head including a dirty air inlet, a brush supported by the surface cleaning head, a motor coupled to and operable to cause movement of the brush, a sensor to sense a voltage associated with a current of the motor, and a controller configured to control an amount of current provided to the motor in response to the sensed voltage. The controller is configured to control a first pulse width modulated (PWM) duty cycle provided to the motor when the sensed voltage is less than a reference voltage, control a second PWM duty cycle provided to the motor when the sensed voltage is greater than the reference voltage, the second PWM duty cycle being less than the first PWM duty cycle, and turn off the motor when the sensed voltage increases to a voltage associated with an overload current of the motor.

1 . A vacuum cleaner comprising:
 a surface cleaning head including a dirty air inlet;   a brush supported by the surface cleaning head;   a motor coupled to and operable to cause movement of the brush;   a sensor to sense a voltage associated with a current of the motor; and   a controller configured to control an amount of current provided to the motor in response to the sensed voltage, including the controller configured to:
 control a first pulse width modulated (PWM) duty cycle provided to the motor when the sensed voltage is less than a reference voltage, 
 control a second PWM duty cycle provided to the motor when the sensed voltage is greater than the reference voltage, the second PWM duty cycle being less than the first PWM duty cycle, and 
 turn off the motor when the sensed voltage increases to a voltage associated with an overload current of the motor. 
   
     
     
         2 . The vacuum cleaner of  claim 1 , wherein the controller further includes a processing unit and non-transitory memory with instructions executable by the processing unit, the instructions when executed by the processing unit include the processing unit determining whether the sensed voltage is less than, greater than, or equal to the reference voltage, and generating a signal for controlling the motor. 
     
     
         3 . The vacuum cleaner of  claim 2 , wherein the processing unit generating the signal includes decreasing the first PWM duty cycle to the second PWM duty cycle when the sensed voltage is greater than the reference voltage. 
     
     
         4 . The vacuum cleaner of  claim 2 , wherein the processing unit generating the signal includes decreasing the first PWM duty cycle to the second PWM duty cycle when the sensed voltage is equal to the reference voltage. 
     
     
         5 . The vacuum cleaner of  claim 2 , wherein the processing unit generating the signal includes increasing the second PWM duty cycle to the first PWM duty cycle when the sensed voltage is less than the reference voltage. 
     
     
         6 . The vacuum cleaner of  claim 1 , wherein the first PWM duty cycle is a maximum duty cycle and the second PWM duty cycle is a minimum duty cycle, and when the sensed voltage is greater than the reference voltage, the maximum duty cycle is decremented by a percentage value until the minimum duty cycle is obtained. 
     
     
         7 . The vacuum cleaner of  claim 6  further comprising a display configured to provide a current stall indication to a user regarding a reduction of the second PWM duty cycle to below the minimum duty cycle, the current stall indication provided after sensing a parameter related to the overload current. 
     
     
         8 . The vacuum cleaner of  claim 7 , wherein the current stall indication includes instructions for the user to open a mechanical air bleed. 
     
     
         9 . The vacuum cleaner of  claim 1 , wherein the first PWM duty cycle is a 100 percent duty cycle. 
     
     
         10 . The vacuum cleaner of  claim 1 , wherein the second PWM duty cycle is a 50 percent duty cycle. 
     
     
         11 . A method of controlling a motor for a brush of a vacuum cleaner, the method comprising:
 sensing a voltage associated with a current of the motor;   controlling a first pulse width modulated (PWM) duty cycle provided to the motor when the sensed voltage is less than a reference voltage, controlling a second PWM duty cycle provided to the motor when the sensed voltage is greater than the reference voltage, the second PWM duty cycle being less than the first PWM duty cycle, and   turning off the motor when the sensed voltage increases to a voltage associated with an overload current of the motor.   
     
     
         12 . The method of  claim 11 , further comprising:
 determining, by a controller including a processing unit and non-transitory memory with instructions executable by the processing unit, whether the sensed voltage is less than, greater than, or equal to the reference voltage; and   generating, by the controller, a signal for controlling the motor.   
     
     
         13 . The method of  claim 12 , wherein generating the signal includes decreasing, by the controller, the first PWM duty cycle to the second PWM duty cycle when the sensed voltage is greater than the reference voltage. 
     
     
         14 . The method of  claim 12 , wherein generating the signal includes decreasing, by the controller, the first PWM duty cycle to the second PWM duty cycle when the sensed voltage is equal to the reference voltage. 
     
     
         15 . The method of  claim 12 , wherein generating the signal includes increasing, by the controller, the second PWM duty cycle to the first PWM duty cycle when the sensed voltage is less than the reference voltage. 
     
     
         16 . The method of  claim 11 , wherein the first PWM duty cycle is a maximum duty cycle and the second PWM duty cycle is a minimum duty cycle, and
 wherein the method further comprises decrementing the maximum duty cycle by a percentage value until the minimum duty cycle is obtained when the sensed voltage is greater than the reference voltage.   
     
     
         17 . The method of  claim 16 , further comprising displaying, on a display of the vacuum cleaner, a current stall indication to a user regarding a reduction of the second PWM duty cycle to below the minimum duty cycle after sensing a parameter related to the overload current. 
     
     
         18 . The method of  claim 17 , wherein displaying the current stall indication includes instructing the user to open a mechanical air bleed. 
     
     
         19 . The method of  claim 11 , wherein the first PWM duty cycle is a 100 percent duty cycle. 
     
     
         20 . The method of  claim 11 , wherein the second PWM duty cycle is a 50 percent duty cycle.