System and method for filtering output in mass flow controllers and mass flow meters
View Patent ↗Embodiments of the present invention can include the steps of (i) filtering the indicated flow to derive an intermediate filtered indicated flow, (ii) deriving a weighted first derivative of the intermediate filtered indicated flow, and (iii) outputting a filtered indicated flow comprising the sum of the intermediate filtered indicated flow and the weighted first derivative of the intermediate filtered indicated flow. The indicated flow can be filtered using a FIR, an IIR a running average or other filtering scheme.
1. A method for filtering an indicated flow comprising:
filtering said indicated flow to derive an intermediate filtered indicated flow;
deriving a weighted first derivative of said intermediate filtered indicated flow; and
summing said intermediate filtered indicated flow and said weighted first derivative of said intermediate filtered indicated flow to derive a filtered indicated flow;
wherein said intermediate filtered indicated flow is derived using running average.
2. A method for filtering an indicated flow comprising:
filtering said indicated flow to derive an intermediate filtered indicated flow;
deriving a weighted first derivative of said intermediate filtered indicated flow; and
summing said intermediate filtered indicated flow and said weighted first derivative of said intermediate filtered indicated flow to derive a filtered indicated flow;
wherein said intermediate filtered indicated flow is derived using IIR.
3. A method for filtering an indicated flow comprising:
filtering said indicated flow to derive an intermediate filtered indicated flow;
deriving a weighted first derivative of said intermediate filtered indicated flow; and
summing said intermediate filtered indicated flow and said weighted first derivative of said intermediate filtered indicated flow to derive a filtered indicated flow;
wherein said intermediate filtered indicated flow is derived using FIR.
4. A system for filtering an indicated flow comprising a flow device operable to:
filter an indicated flow to derive an intermediate filtered indicated flow;
derive a weighted first derivative of said filtered indicated flow; and
derive a filtered indicated flow from a sum of said intermediate filtered indicated flow and said weighted first derivative of said intermediate filtered indicated flow;
wherein said intermediate filtered indicated flow is derived using running average.
5. A system for filtering an indicated flow comprising a flow device operable to:
filter an indicated flow to derive an intermediate filtered indicated flow;
derive a weighted first derivative of said filtered indicated flow; and
derive a filtered indicated flow from a sum of said intermediate filtered indicated flow and said weighted first derivative of said intermediate filtered indicated flow;
wherein said intermediate filtered indicated flow is derived using IIR.
6. A system for filtering an indicated flow comprising a flow device operable to:
filter an indicated flow to derive an intermediate filtered indicated flow;
derive a weighted first derivative of said filtered indicated flow; and
derive a filtered indicated flow from a sum of said intermediate filtered indicated flow and said weighted first derivative of said intermediate filtered indicated flow;
wherein said intermediate filtered indicated flow is derived using FIR.