Flow rate estimation for mass flow controller

A method for use with a mass flow controller, the method comprising:

• at a valve position sensor, measuring valve position data for a valve provided at least in part within a flow path through a block body;
• at a first temperature sensor, measuring first temperature data for a fluid flowing in the flow path;
• at a first pressure sensor located on an upstream side of the flow path from the valve, measuring first pressure data for the fluid;
• at a second pressure sensor located on a downstream side of the flow path from the valve, measuring second pressure data for the fluid;
• and
• at a processor:
• receiving the valve position data, the first temperature data, the first pressure data, and the second pressure data;
• and
• estimating a flow rate of the fluid in the flow path at least in part by applying a trained machine learning model to the valve position data, the first temperature data, the first pressure data, and the second pressure data.

A mass flow controller comprising:

• a block body having a flow path;
• a valve provided at least in part within the flow path of the block body;
• a valve position sensor;
• a first temperature sensor configured to detect a temperature of a fluid flowing in the flow path;
• a first pressure sensor located on an upstream side of the flow path from the valve;
• a second pressure sensor located on a downstream side of the flow path from the valve;
• memory storing one or more polynomial regression coefficients;
• and
• a processor configured to:
• receive valve position data from the valve position sensor;
• receive first temperature data from the first temperature sensor;
• receive, from the first pressure sensor, first pressure data for the fluid in the flow path;
• receive, from the second pressure sensor, second pressure data for the fluid in the flow path;
• and
• at a trained machine learning model, determine normalized valve position data, normalized first temperature data, normalized first pressure data, and normalized second pressure data from the valve position data, the first temperature data, the first pressure data, and the second pressure data;
• and
• determine a flow rate of the fluid in the flow path at least in part by applying a polynomial regression with the one or more polynomial regression coefficients to the normalized valve position data, the normalized first temperature data, the normalized first pressure data, and the normalized second pressure data.