CONTROL METHODS FOR CALIBRATING MOTOR SPEED IN AN AIR TREATMENT SYSTEM

• US 20100042262A1
• Filed: 10/21/2009
• Published: 02/18/2010
• Est. Priority Date: 07/14/2005
• Status: Abandoned Application

• Current Assignee: Access Business Group International LLC (Alticor Incorporated)
• Original Assignee: Access Business Group International LLC (Alticor Incorporated)
• Inventors: Niezgoda, Thomas A., Evans, Gregory K., Leppien, Thomas J.
• Application Number:
  US12/582,780
• Publication Number:
  US 20100042262A1
• Time in Patent Office: Days
• US Class Current: 700/282
• CPC Class Codes: B01D 2267/40 Different types of filters
• CPC Class Codes: B01D 46/0038 with means for influencing the odor, e.g. deodorizing substances
• CPC Class Codes: B01D 46/0086 Filter condition indicators
• CPC Class Codes: B01D 46/442 by measuring the concentration of particles
• CPC Class Codes: B01D 46/46 automatic
• CPC Class Codes: F24F 11/74 for controlling air flow rate or air velocity
• CPC Class Codes: G01N 21/53 within a flowing fluid, e.g. smoke

Abstract

A control system and associated methods for an air treatment system. In one aspect, the present invention provides a control system and method for controlling blower speed as a function of separately determined smoke and dust concentrations. In one embodiment, the control system and method provides a variable delayed between changes in motor speed to address undesirable rapid changes between speeds. In another aspect, the present invention provides a system and method for calibrating a sensor to provide more uniform operation over time. In yet another aspect, the present invention provide a system and method for calibrating motor speed to provide more consistent and uniform motor speed over time. The present invention also provides a system and method for tracking filter life by as a function of time, motor speed and/or a sensed variable, such as particulate concentration in the environment.

Claims

1. A method for calibrating motor speed for a blower motor in an air treatment system, comprising the steps of:

collecting a plurality of readings indicative of the motor speed over a period of time;

computing a comparison value as a function of the collected readings;

comparing the comparison value to a predetermined acceptable range; and

adjusting the speed of the motor if the comparison value falls outside the predetermined acceptable range.

2. The method of claim 1 further including the step of repeating said collecting, computing, comparing and adjusting steps until the comparison value falls within the predetermined acceptable range.

3. The method of claim 2 wherein said adjusting step includes varying the duty cycle of the power applied to the motor.

4. The method of claim 3 further including the step of waiting a predetermined period of time after a motor speed change occurs before undertaking said collecting step.

5. The method of claim 4 further comprising varying the predetermined period of time.

6. The method of claim 4 wherein said collecting step includes taking a plurality of readings from an RPM sensor.

7. The method of claim 6 wherein said taking step includes taking a plurality of readings from an RPM sensor at predetermined intervals.

8. The method of claim 7 wherein the RPM sensor produces a pulse signal at a frequency indicative of motor speed.

9. The method of claim 8 further including the step of providing the pulse signal of the RPM sensor to a microcontroller.

10. The method of claim 4 wherein said computing step includes the steps of computing the average of the plurality of readings and setting the comparison value as the computed average.

11. The method of claim 3 further comprising performing said collecting, computing, comparing and adjusting steps each time the blower motor speed setting changes.

12. The method of claim 3 wherein said collecting, computing, comparing and adjusting steps are performed continuously to maintain consistent blower motor operation over a life of the system.

13. The method of claim 3 further comprising performing said collecting, computing, comparing and adjusting steps for each motor speed setting each time the air treatment system is activated.

14. A method for calibrating motor speed for blower motor in an air treatment system, comprising the steps of:

providing a blower motor capable of operating at a plurality of different motor speed settings;

predetermining an acceptable range of blower motor speeds for each of the different motor speed settings;

taking a plurality of readings at predetermined intervals from a sensor indicative of motor speed;

computing a comparison value as a function of the readings, the comparison value being indicative of average motor speed over a period of time;

comparing the comparison value to the predetermined acceptable range for the corresponding motor speed setting;

adjusting the actual speed of the motor if the comparison value falls outside the predetermined acceptable range by a predetermined amount; and

repeating said collecting, computing, comparing and adjusting steps until the comparison value falls within the predetermined acceptable range.

15. The method of claim 14 wherein said taking, computing, comparing, adjusting and repeating steps are undertaken each time a motor speed setting change occurs.

16. The method of claim 15 further comprising waiting at least a predetermined period of time after a motor speed setting change occurs before undertaking said taking, computing, comparing, adjusting and repeating steps.

17. The method of claim 14 wherein said taking step is further defined as taking readings from an RPM sensor.

18. A method for calibrating motor speed for blower motor in an air treatment system, comprising the steps of:

determining average motor speed over a period of time;

comparing the average motor speed to a predetermined acceptable range; and

adjusting the actual speed of the motor if the average motor speed falls outside the predetermined acceptable range.

19. The method of claim 18 wherein said determining, comparing and adjusting steps are performed at least a predetermined amount of time after each operating motor speed change.

20. The method of claim 18 wherein said adjusting step includes varying the duty cycle of the power applied to the blower motor.

21. The method of claim 20 wherein said adjusting step is further defines as increasing duty cycle by a predetermined amount if average motor speed is below the predetermined acceptable range, and decreasing duty cycle by a predetermined amount if average motor speed is above the predetermined acceptable range.

22. The method of claim 18 further comprising the step of repeating said determining, comparing and adjusting steps until the average motor speed is within the predetermined acceptable range.

23. The method of claim 18 further comprising the step of repeating said determining, comparing and adjusting steps continuously.