Title:
MASS FLOW CONTROLLER UTILIZING NONLINEARITY COMPONENT FUNCTIONS
Document Type and Number:
WIPO Patent Application WO/2022/209321
Kind Code:
A1
Abstract:
Mass flow controllers and methods for controlling mass flow controllers are disclosed. A method includes providing a gas through a thermal mass flow sensor of the mass flow controller and processing a sensor signal from the thermal mass flow sensor to produce a flow signal. A total nonlinearity characteristic function is determined based on nonlinearity effects on the flow signal and includes a first and second nonlinearity component function based on a first and second source of nonlinearity respectively. The total nonlinearity characteristic function is calibrated, and the first nonlinearity component function is adjusted responsive to changes in the first source of nonlinearity, after which the total nonlinearity characteristic function is updated. The flow signal is corrected to produce a corrected flow signal using the total nonlinearity characteristic function. A valve of the mass flow controller is controlled using the corrected flow signal and a setpoint signal.
Inventors:
SMIRNOV ALEXEI V (US)
Application Number:
PCT/JP2022/004916
Publication Date:
October 06, 2022
Filing Date:
February 08, 2022
Export Citation:
Assignee:
HITACHI METALS LTD (JP)
International Classes:
G05D7/06
Foreign References:
| US20190331515A1 | 2019-10-31 | |||
| US20100229965A1 | 2010-09-16 | |||
| US20160001239A1 | 2016-01-07 |
Attorney, Agent or Firm:
KOHNO, Hideto et al. (JP)
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