# US 2013/0153040 A1 · Flow rate control using mass flow rate control device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0153040 A1 - Document ID: US20130153040A1 - Status: Published application - Kind: A1 - Application number: 13/765,673 - Filed: 2013-02-12 - Published: 2013-06-20 - Earliest claimed: 2006-08-03 - Assignees: Hitachi Metals, Ltd. - Inventors: Takao GOTO; Makoto TANAKA - Web page: https://patentgrep.com/patent/US20130153040A1 ## CPC - F17D 3/01: for controlling, signalling, or supervising the conveyance of a product - G01F 1/6847: {where sensing or heating elements are not disturbing the fluid flow, e.g. elements mounted outside the flow duct} - G01F 1/6965: {comprising means to store calibration data for flow signal calculation or correction} - G01F 5/00: Measuring a proportion of the volume flow - G01F 25/15: {specially adapted for gas meters (G01F25/11 - G01F25/14, G01F25/17 take precedence)} - G05D 7/0635: {by action on throttling means (G05D7/0688, G05D7/0694 take precedence)} - Y10T 137/0324: With control of flow by a condition or characteristic of a fluid - Y10T 137/0357: For producing uniform flow - Y10T 137/0363: For producing proportionate flow - Y10T 137/7722: Line condition change responsive valves - Y10T 137/7761: Electrically actuated valve - Y10T 137/85986: Pumped fluid control - F17D: PIPE-LINE SYSTEMS; PIPE-LINES (pumps or compressors F04; fluid dynamics F15D; valves or the like F16K; pipes, laying pipes, supports, joints, branches, repairing, work on the entire line, accessories F16L; steam traps or the like F16T; fluid-pressure electric cables H01B9/06) - G01F: MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A process and device enabling accurate mass flow control is described. A mass flow controller can be re-specified corresponding to multiple types of actual process gases and multiple flow rate ranges, even after the mass flow controller has been shipped. Calibration gas data is derived using actual flow rate versus a flow rate setting signal to generate calibration gas data. Actual gas data is derived by measuring actual flow rate versus a flow rate setting signal for each actual gas and saving. Subsequently, prior to operating the mass flow rate control device, the characteristic data for an actual and the calibration gas characteristic data is recalled. The calibration gas characteristic data is then converted to controlled flow rate correction data based on the actual gas characteristic data that is saved to the control unit and the actual gas flow rate is corrected based on this controlled flow rate correction data. ## Claims ### Claim 1 A method for controlling flow rate of a gas flowing on a flow path, comprising the steps of: (a) providing a flow rate control device configured to perform feedback control of a flow rate of a gas flowing on a flow path based on a target flow rate that is a target value for mass flow rate of the gas flowing on the flow path, and a sensed flow rate that is a sensed mass flow rate of the gas flowing on the flow path; (b) providing control data that includes a plurality of control parameters respectively associated with mutually different mass flow rates wherein the control data is provided according to a type of the gas flowing on the flow path, and comprising the steps of: (b1) providing first characteristic data that includes a plurality of first characteristic parameters respectively associated with mutually different mass flow rates, wherein the first characteristic parameters reflect characteristics of the provided flow rate control device premised on a use of a standard gas and saving the first characteristic data to a first storage unit of the flow rate control device provided in the step (a); (b2) providing second characteristic data that includes a plurality of second characteristic parameters respectively associated with mutually different mass flow rates, wherein the second characteristic parameters reflect characteristics depending on the type of the gas premised on standard characteristics of the flow rate control device further includes the step of: saving the second characteristic data to a second storage unit on which data can be swapped or updated more easily than that on the first storage unit; and (b3) with reference to the first and second characteristic data, generating the control parameter based on the first and second characteristic parameters in order to generate the control data, reading the first characteristic data from the first storage unit; and reading the second characteristic data from the second storage unit; (c) generating a corrected sensed flow rate based on the sensed flow rate and a control parameter that is determined based on at least one of the sensed flow rate and the target flow rate from among the plurality of control parameters; and controlling the flow rate of the gas flowing on the flow path by using feedback control using the flow rate control device and referring to the control data, based on at least one of the target flow rate, the corrected sensed flow rate, and a control parameter that is determined based on at least one of the target flow rate and the sensed flow rate from among the plurality of control parameters. ### Claim 2 (depends on 1) The method according to claim 1 wherein the step (b1) includes the steps of: (b4) inputting the target flow rate to the flow rate control device; (b5) circulating the standard gas through the flow path and causing the flow rate control device to control the flow rate of the standard gas without using the control parameter; (b6) deriving the sensed flow rate; (b7) generating the first characteristic parameter based on the input target flow rate and the derived sensed flow rate; and (b8) repeating the steps (b4) to (b7) for different target flow rates to generate the plurality of first characteristic parameters. ### Claim 3 (depends on 2) The method according to claim 2 wherein the step (b2) includes the steps of: (b9) providing a standard flow rate control device configured to perform feedback control of flow rate of a gas flowing on a standard flow path based on a standard target flow rate that is a target value for mass flow rate of the gas flowing on the standard flow path, and a standard sensed flow rate that is sensed mass flow rate of the gas flowing on the standard flow path; (b10) inputting the standard target flow rate to the standard flow rate control device; (b11) circulating a gas different from the standard gas through the standard flow path and causing the standard flow rate control device to control the flow rate of the gas; (b12) deriving the standard sensed flow rate; (b13) generating the second characteristic parameter based on the input standard target flow rate and the derived standard sensed flow rate; and (b14) repeating the steps (b10) to (b13) for different standard target flow rates to generate the plurality of second characteristic parameters. ### Claim 4 (depends on 3) The method according to claim 3 wherein the step (b2) further includes the step of: (b15) prior to steps (b10) to (b14), carrying out the step (b1) for the standard flow rate control device to prepare the first characteristic data in relation to the standard flow rate control device; and the step (b11) includes the step of: causing the standard flow rate control device to control the flow rate of the gas using the first characteristic data in relation to the standard flow rate control device. ### Claim 5 (depends on 3) The method according to claim 3 wherein the step (b2) includes the step of: (b16) carrying out the step (b14) for a plurality of types of gas in order to generate a plurality of sets of the second characteristic data relating to the plurality of types of gas; and the step (b3) includes the step of: (b17) selecting some of the second characteristic data from among the plurality of sets of second characteristic data according to the type of the gas controlled by the flow rate control device provided in the step (a), as the second characteristic data to be used for reference. ### Claim 6 (depends on 3) The method according to claim 3 wherein the step (b2) further includes the step of: (b18) generating a plurality of sets of the second characteristic data that respectively include some of the plurality of second characteristic parameters generated in the step (b14) wherein the plurality of sets of the second characteristic data have mutually different ranges of the standard target flow rate during generation of the respectively included second characteristic parameters; and the step (b3) includes the step of: (b19) according to the range of flow rates of gas controlled by the flow rate control device provided in the step (a), selecting some of the second characteristic data from among the plurality of sets of second characteristic data, as the second characteristic data to be used for reference. ### Claim 7 (depends on 1) The flow rate control device according to claim 1 wherein the step (c) includes the steps of: generating a corrected target flow rate based on the target flow rate and a control parameter that is determined based on at least one of the sensed flow rate and the target flow rate from among the plurality of control parameters; and performing feedback control of the flow rate of gas flowing through the flow path, based on the corrected target flow rate and the sensed flow rate. ### Claim 8 (depends on 1) The method according claim 1 wherein the step (c) includes the steps of: generating a corrected sensed flow rate based on the sensed flow rate and a control parameter that is determined based on at least one of the sensed flow rate and the target flow rate from among the plurality of control parameters; and performing feedback control of the flow rate of gas flowing through the flow path, based on the target flow rate and the corrected sensed flow rate. ### Claim 9 A flow rate control device for controlling flow of a gas flowing through a flow path, comprising: a flow rate sensing unit that senses as a sensed flow rate a mass flow rate of a gas flowing through a flow path; a flow rate modifying unit that controls a flow rate of gas flowing through the flow path; and a control unit that performs feedback control of the flow rate modifying unit based on the sensed flow rate, and a target flow rate that is a target value for mass flow rate of the gas flowing on the flow path; a control data generating unit that generates the control data; wherein, while referring to first and second characteristic data, the first characteristic data including a plurality of first characteristic parameters respectively associated with mutually different mass flow rates wherein the first characteristic parameters reflect characteristics of the each flow rate control devices premised on a use of a prescribed gas designated as a standard, the second characteristic data that including a plurality of second characteristic parameters respectively associated with mutually different mass flow rates, wherein the second characteristic parameters reflect characteristics depending on the type of the gas premised on standard characteristics of the flow rate control devices, the control data generating unit generates the control parameter based on the first and second characteristic parameters in order to generate the control data; a first storage unit that stores the first characteristic data; and a second storage unit that stores the second characteristic data, wherein, data on the second storage unit can be swapped or updated more easily than that on the first storage unit; generating a corrected sensed flow rate based on the sensed flow rate and a control parameter that is determined based on at least one of the sensed flow rate and the target flow rate from among the plurality of control parameters; and wherein while referring to control data prepared individually for each of the flow rate control devices according to a type of the gas flowing through the flow path and including a plurality of control parameters respectively associated with mutually different mass flow rates, the control unit controls the flow rate modifying unit using a control parameter determined based on at least one of the target flow rate, the corrected sensed flow rate, and the sensed flow rate from among the plurality of control parameters. ### Claim 10 (depends on 9) The flow rate control device according to claim 9 wherein the flow rate sensing unit senses the mass flow rate of the gas based on a quantity of heat transported by at least some of the gas flowing through the flow path. ### Claim 11 (depends on 9) The flow rate control device according to claim 9 wherein the flow rate sensing unit senses the mass flow rate of the gas based on pressures of the gas at different locations in the flow path. ### Claim 12 (depends on 11) The flow rate control device according to claim 11 wherein the second characteristic data is data selected from among a plurality of sets of second characteristic candidate data in which the second characteristic parameters are respectively stored, wherein the sets of second characteristic candidate data reflect characteristics of mutually different types of gas. ### Claim 13 (depends on 11) The flow rate control device according to claim 11 wherein the second characteristic data is data selected from among a plurality of sets of second characteristic candidate data in which the second characteristics are respectively stored, wherein the mass flow rates of the second characteristic parameters respectively stored in each of the plurality of sets of the second characteristic candidate data have mutually different ranges. ### Claim 14 (depends on 11) The flow rate control device according to claim 11 wherein the control unit generates a corrected target flow rate based on the target flow rate and a control parameter that is determined based on at least one of the sensed flow rate and the target flow rate from among the plurality of control parameters; and performs the control of the flow rate modifying unit based on the corrected target flow rate and the sensed flow rate. ### Claim 15 (depends on 11) The flow rate control device according to claim 11 wherein the control unit generates a corrected sensed flow rate based on the sensed flow rate and a control parameter that is determined based on at least one of the sensed flow rate and the target flow rate from among the plurality of control parameters; and performs the control of the flow rate modifying unit based on the target flow rate and the corrected sensed flow rate. ### Claim 16 A computer program product for controlling flow rate of a gas flowing on a flow path, wherein the computer program product includes: a computer-readable storage medium; and a computer program recorded onto the storage medium; wherein the computer program includes a module that, in a flow rate control device having a flow rate modifying unit that controls a flow rate of gas flowing through the flow path, and being configured to perform feedback control of a flow rate of a gas flowing on a flow path based on a target flow rate that is a target value for mass flow rate of the gas flowing on the flow path, and sensed flow rate that is a sensed mass flow rate of the gas flowing on the flow path, accomplishes a function by which, while referring to control data prepared according to a type of the gas flowing through the flow path and including a plurality of control parameters respectively associated with mutually different mass flow rates, wherein the control data is obtained by (i) providing first characteristic data that includes a plurality of first characteristic parameters respectively associated with mutually different mass flow rates, wherein the first characteristic parameters reflect characteristics of the provided flow rate control device premised on a use of a standard gas and saving the first characteristic data to a first storage unit of the flow rate control device provided in the step (a); (ii) providing second characteristic data that includes a plurality of second characteristic parameters respectively associated with mutually different mass flow rates, wherein the second characteristic parameters reflect characteristics depending on the type of the gas premised on standard characteristics of the flow rate control device; (iii) saving the second characteristic data to a second storage unit on which data can be swapped or updated more easily than that on the first storage unit; and, with reference to the first and second characteristic data, (iv) generating the control parameter based on the first and second characteristic parameters in order to generate the control data; (v) reading the first characteristic data from the first storage unit; (vii) reading the second characteristic data from the second storage unit; and (viii) generating a corrected sensed flow rate based on the sensed flow rate and a control parameter that is determined based on at least one of the sensed flow rate and the target flow rate from among the plurality of control parameters; and the flow rate modifying unit is controlled using a control parameter determined based on at least one of the target flow rate, corrected sensed flow rate, and the sensed flow rate from among the plurality of control parameters.