Intelligent suction device capable of automatically adapting the suction force according to the conditions of the surface, particularly for vacuum cleaners and the like

• US 6,255,792 B1
• Filed: 02/29/2000
• Issued: 07/03/2001
• Est. Priority Date: 01/30/1998
• Status: Expired due to Term

• Current Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Inventors: Grasso, Giuseppe, Sortino, Gianfranco, Lo Presti, Matteo
• Primary Examiner(s): IP, SHIK LUEN PAUL
• Application Number:
  US09/514,972
• Time in Patent Office: 490 Days
• Field of Search: 318/479-499, 318/560-696, 98/15, 98/20.1, 98/21.1, 154/12, 153/19, 153/39, 395/900, 395/61, 395/3
• US Class Current: 318/508
• CPC Class Codes: A47L 9/2821 Pressure, vacuum level or airflow
• CPC Class Codes: A47L 9/2826 the condition of the floor
• CPC Class Codes: A47L 9/2842 Suction motors or blowers
• CPC Class Codes: G05B 13/0275 using fuzzy logic only
• CPC Class Codes: G05D 16/2066 using controlling means acting on the pressure source
• CPC Class Codes: Y10S 706/90 Fuzzy logic

Abstract

An intelligent suction device, particularly for vacuum cleaners and the like, includes a fuzzy-logic controller for controlling the motor of a fan or turbine. The suction pressure is detected by at least one pressure sensor which feeds back its measurement, in a closed loop, to the controller.

Claims

1. A method for controlling a suction force of a suction device comprising a motor driven fan, the method comprising:

measuring a pressure difference between an internal pressure within the suction device and an external pressure external to the suction device; and

controlling a speed of the motor based upon at least one derivative of the measured pressure difference.

2. A method according to claim 1, wherein controlling comprises the steps of:

bringing the motor to a fixed speed;

using a pressure value measured by a pressure sensor using a first fuzzy-logic expert system; and

maintaining a speed determined by the fuzzy-logic expert system until pressure variations are detected.

3. A method according to claim 1, further comprising determining a condition of the suction device between one of a working condition and a standby condition.

4. A method according to claim 3, wherein determining a condition comprises the steps of:

determining a first derivative and a second derivative of the at least one derivative of pressure detected by the pressure sensor;

using a second fuzzy-logic expert system to determine the condition of the device based on the first and second derivatives; and

if the device is determined to be in the standby condition, then waiting for a preset time before confirming the standby condition and setting a speed of the motor to a minimum value.

5. A method for controlling a suction force of a suction device comprising a motor driven fan, the method comprising:

bringing the motor to a fixed speed;

sensing pressure generated by the suction force;

determining at least one derivative of the sensed pressure; and

controlling a speed of the motor using a first fuzzy-logic expert system responsive to the at least one derivative.

6. A method according to claim 5, wherein controlling comprises the step of maintaining a speed determined by the first fuzzy-logic expert system until pressure variations are detected.

7. A method according to claim 5, further comprising determining a condition of the suction device between one of a working condition and a standby condition.

8. A method according to claim 7, wherein the step of determining a condition comprises:

determining a first derivative and a second derivative of the least one derivative of pressure detected by the pressure sensor;

using a second fuzzy-logic expert system to determine the condition of the device based on the first and second derivatives; and

if the device is determined to be in the standby condition, then waiting for a preset time before confirming the standby condition and setting a speed of the motor to a minimum value.

9. A method for controlling a suction force of a suction device comprising a motor driven fan, the method comprising:

measuring a pressure difference between an internal pressure within the suction device and an external pressure external to the suction device; and

controlling a speed of the motor to one of a standby condition and a working condition based upon at least one derivative of the measured pressure difference.

10. A method according to claim 9, wherein the step of controlling comprises:

determining a first derivative and a second derivative of the at least one derivative of pressure detected by the pressure sensor;

using a fuzzy-logic expert system to determine the condition of the device based on the first and second derivatives; and

if the device is determined to be in the standby condition, then waiting for a preset time before confirming the standby condition and setting the speed of the motor to a minimum value.