System identification and feedback control of an aerosol production process.
O'Shaughnessy-PT; Hemenway-DR; Absher-RG
Aerosol Sci Tech 1996 Oct; 25(3):292-304
A method was developed for determining the relationship between the input and output of an aerosol generating system. Discrete transfer functions that separate the input that results from the physical aspects of the generating system from the input that is a result of the noise inherent to the process is used to model the relationship. Once the relationships are estimated in the form of transfer functions, the noise component of the system can be eliminated and the response of the system can be simulated with a computer aided design software package. An animal exposure chamber was used to illustrate an application of this methodology in the field of aerosol science. There was a large difference between the desired level and the steady state level after a step increase in generator rate when simulating the aerosol generating system as a closed loop control system. A proportional integral derivative (PID) algorithm was used to solve this problem. The findings indicated that this technique is able to increase and decrease chamber concentrations relatively fast and eventually with stability. The authors note that controller designs that incorporate the noise component in the system may be more applicable in the majority of cases where a low signal to noise ratio is evident.
NIOSH-Publication; NIOSH-Grant; Grants-other; Aerosol-generators; Exposure-chambers; Computer-models; Inhalation-studies
Civil Engineering University of Vermont RM 226 Votey Bldg Burlington, VT 05405
Other Occupational Concerns; Grants-other
Aerosol Science and Technology
University of Vermont & St Agric College, Burlington, Vermont