Flow rate control apparatus, flow rate control method, and program recording medium

A flow rate control method using a flow rate control apparatus comprising:

• a fluid resistor provided in a flow path;
• a downstream side valve provided on a downstream side of the fluid resistor;
• and a downstream side pressure sensor provided between the fluid resistor and the downstream side valve;
• the flow rate control method comprising:
• a resistor flow rate calculation step of calculating a resistor flow rate that is a flow rate of fluid flowing through the fluid resistor;
• a change amount calculation step of calculating a time change amount of downstream side pressure measured by the downstream side pressure sensor;
• a valve flow rate estimation step of, on a basis of the resistor flow rate, a conversion flow rate that is a difference between the resistor flow rate and the time change amount of the downstream side pressure, and a weighting factor, calculating a weighted average to estimate a valve flow rate through the downstream side valve;
• and
• a flow rate control step of, on a basis of a deviation between a set flow rate and the valve flow rate, controlling the downstream side valve, wherein
• the weighting factor is changeable.

A flow rate control apparatus comprising:

• a fluid resistor provided in a flow path;
• a downstream side valve provided on a downstream side of the fluid resistor;
• a downstream side pressure sensor provided between the fluid resistor and the downstream side valve;
• a processor;
• and a memory storing software modules to be executed by the processor, the software modules comprising:
• a resistor flow rate calculation part that calculates a resistor flow rate that is a flow rate of fluid flowing through the fluid resistor;
• a change amount calculation part that calculates a time change amount of downstream side pressure measured by the downstream side pressure sensor;
• a valve flow rate estimation part that, on a basis of the resistor flow rate, a conversion flow rate that is a difference between the resistor flow rate and the time change amount of the downstream side pressure, and a weighting factor, calculates a weighted average to estimate a valve flow rate through the downstream side valve;
• and
• a flow rate control part that, on a basis of a deviation between a set flow rate and the valve flow rate, controls the downstream side valve, wherein
• the weighting factor is configured to be changeable.