Flow rate characteristic function identification method, flow rate characteristic function identification device, storage medium storing flow rate characteristic function identification program, and flow rate sensor or flow rate control device using them

A flow rate characteristic function identification device adapted to identify an actual flow rate characteristic function used in a flow rate sensor provided with an actual fluid resistance element in a flow path, the flow rate sensor configured to output an output signal corresponding to a flow rate of fluid flowing through the flow path;

• and calculate the flow rate on a basis of an output value indicated by the output signal and on a basis of the actual flow rate characteristic function determined by a characteristic of the actual fluid resistance element, the flow rate characteristic function identification device comprising:
• a reference flow rate characteristic function acquisition part that is configured to acquire a first reference flow rate characteristic function and a second reference flow rate characteristic function, wherein
• the first reference flow rate characteristic function is determined by a characteristic of a first reference fluid resistance,
• the second reference flow rate characteristic function is determined by a characteristic of a second reference fluid resistance;
• and
• an actual flow rate characteristic function identification part that is configured to identify the actual flow rate characteristic function on a basis of the first reference flow rate characteristic function, the second reference flow rate characteristic function, and predetermined weighting, and output the actual flow rate characteristic function to the flow rate sensor, so that the flow rate sensor calculates the flow rate on the basis of the output value indicated by the output signal and on the basis of the actual flow rate characteristic function determined by the characteristic of the actual fluid resistance element.

A flow rate control device comprising:

• a valve provided in a flow path;
• a flow rate characteristic function identifier configured to:
• acquire a first reference flow rate characteristic function determined by a characteristic of a first reference fluid resistance;
• acquire a second reference flow rate characteristic function determined by a characteristic of a second reference fluid resistance;
• and
• identify an actual flow rate characteristic function on a basis of the first reference flow rate characteristic function, the second reference flow rate characteristic function, and predetermined weighting;
• a flow rate sensor provided with an actual fluid resistance element in the flow path, the flow rate sensor configured to output an output signal corresponding to a flow rate of fluid flowing through the flow path, and calculate the flow rate on a basis of an output value indicated by the output signal and on a basis of the actual flow rate characteristic function determined by a characteristic of the actual fluid resistance element;
• and
• a flow rate controller that is configured to control an opening level of the valve so as to decrease a deviation between a measured flow rate value, which is the flow rate of the fluid outputted from the flow rate sensor, and a set setting flow rate value.

A non-volatile memory storing a flow rate characteristic function identification program adapted to identify an actual flow rate characteristic function used in a flow rate sensor provided with an actual fluid resistance element in a flow path, the flow rate sensor configured to output an output signal corresponding to a flow rate of fluid flowing through the flow path;

• and calculate the flow rate on a basis of an output value indicated by the output signal and on a basis of the actual flow rate characteristic function determined by a characteristic of the actual fluid resistance element,
• the flow rate characteristic function identification program instructing a computer to fulfill functions as:
• a reference flow rate characteristic function acquisition part that is configured to acquire a first reference flow rate characteristic function and a second reference flow rate characteristic function, wherein
• the first reference flow rate characteristic function is determined by a characteristic of a first reference fluid resistance,
• the second reference flow rate characteristic function is determined by a characteristic of a second reference fluid resistance;
• and
• an actual flow rate characteristic function identification part that is configured to identify the actual flow rate characteristic function on a basis of the first reference flow rate characteristic function, the second reference flow rate characteristic function, and predetermined weighting, and output the actual flow rate characteristic function to the flow rate sensor, so that the flow rate sensor calculates the flow rate on the basis of the output value indicated by the output signal and on the basis of the actual flow rate characteristic function determined by the characteristic of the actual fluid resistance element.