# US 11,299,295 B2 · Thruster control device and thruster control method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,299,295 B2 - Document ID: US11299295B2 - Status: Granted - Kind: B2 - Application number: 16/223,593 - Filed: 2018-12-18 - Published: 2019-08-29 - Granted: 2022-04-12 - Earliest claimed: 2018-02-23 - Assignees: Mitsubishi Heavy Industries, Ltd. - Applicants: Mitsubishi Heavy Industries, Ltd. - Inventors: Yukihiro Okumura; Masaaki Nagase - Web page: https://patentgrep.com/patent/US11299295B2 ## CPC - B64G 1/36: using sensors, e.g. sun-sensors, horizon sensors - B64G 1/403: {Solid propellant rocket engines} - F02K 9/80: characterised by thrust or thrust vector control (burning control of solid propellants F02K9/26; feeding control of liquid or gaseous propellants F02K9/56; re-ignitable, restartable or intermittently operated rocket-engine plants F02K9/94) - F02K 9/86: using nozzle throats of adjustable cross- section {(F02K9/978 takes precedence)} - F02K 9/96: characterised by specially adapted arrangements for testing or measuring - B64G 1/26: using jets - F02K 99/00: Subject matter not provided for in other groups of this subclass - B64G: COSMONAUTICS; VEHICLES OR EQUIPMENT THEREFOR - F02K: JET-PROPULSION PLANTS (features of jet-propulsion plants common to gas-turbine plants, air intakes or fuel supply control of air-breathing jet-propulsion plants F02C7/00, F02C9/00) ## Abstract A thruster control device has an opening degree estimating section and an opening degree control section. The opening degree estimating section calculates an estimated opening degree of a valve showing a rate at which the valve is opened, based on a balance of an acting force applied to a valve element of the valve to adjust a quantity of combustion gas to be ejected from a thruster and a fluid force applied to the valve element by the ejected combustion gas. The opening degree control section determines a target opening degree based on the estimated opening degree to control the opening degree of the valve. ## Claims ### Claim 1 A thruster control device comprising: an opening degree estimating section configured to calculate an estimated opening degree of a valve showing a rate at which the valve is opened, based on a balance of an acting force applied to a valve element of the valve to adjust a quantity of combustion gas to be ejected from a thruster and a fluid force applied to the valve element by an ejected combustion gas; and an opening degree control section configured to determine a target opening degree based on the estimated opening degree to control an opening degree of the valve, wherein the opening degree estimating section calculates the fluid force based on an acceleration of the valve element and the acting force, and calculates the estimated opening degree based on the fluid force. ### Claim 2 (depends on 1) The thruster control device according claim 1, wherein the opening degree estimating section is configured to hold opening degree data showing the opening degree of the valve to the fluid force applied to the valve element by the ejected combustion gas, calculate an acceleration force giving the valve the acceleration based on the acceleration, calculate the fluid force by subtracting the acceleration force from the acting force, and calculate the estimated opening degree from the fluid force based on the opening degree data. ### Claim 3 (depends on 1) The thruster control device according claim 1, further comprising a valve element control section, wherein the valve element control section comprises: a driving section configured to apply the acting force to the valve element to control the opening and closing of the valve; and a detecting section configured to detect a velocity of the valve element, wherein the opening degree estimating section is configured to calculate the acceleration based on the velocity, and wherein the driving section is configured to control the opening and closing of the valve based on the target opening degree. ### Claim 4 (depends on 3) The thruster control device according to claim 3, further comprising a plurality of the valve element control sections, wherein the opening degree estimating section is configured to calculate the estimated opening degree for each of the plurality of valve element control sections, and wherein the opening degree control section is configured to determine the target opening degree for each of the plurality of valve element control sections. ### Claim 5 (depends on 4) The thruster control device according to claim 4, further comprising: a combustion chamber configured to store the combustion gas to be ejected from the thruster; and a pressure sensing section configured to sense a pressure in the combustion chamber, wherein the opening degree control section is configured to determine the target opening degree for each of the plurality of valve element control sections based on the sensed pressure by the pressure sensing section and the estimated opening degree for each valve element control section. ### Claim 6 (depends on 5) The thruster control device according to claim 5, wherein the opening degree control section is configured to hold a previous target opening degree of the valve set by the acting force of the driving section of each valve element control section, subtract a target pressure from pressure by the pressure sensing section to calculate a pressure difference, subtract the previous target opening degree from the estimated opening degree to calculate an opening degree difference for each valve element control section, and determine the target opening degree for each valve element control section based on the pressure difference and a rate of the opening degree difference of each valve element control section for a total of the opening degree differences of the plurality of valve element control sections. ### Claim 7 (depends on 6) The thruster control device according to claim 6, wherein the opening degree control section is configured to calculate the target opening degree based on a product of the pressure difference and the rate of the opening degree difference of each valve element control section to the total of opening degree differences and the previous target opening degree. ### Claim 8 (depends on 3) The thruster control device according to claim 3, wherein the driving section has a motor configured to generate the acting force by a current, and wherein the opening degree estimating section is configured to calculate the acting force based on a value of the current. ### Claim 9 (depends on 1) The thruster control device according to claim 1, wherein the estimated opening degree is defined based on an estimated position of the valve element, and wherein the target opening degree is defined based on a destination position of the valve element. ### Claim 10 A thruster control method comprising: calculating an estimated opening degree of a valve showing a rate at which the valve is opened, based on a balance of an acting force to applied to a valve element of the valve to adjust a quantity of combustion gas to be ejected from a thruster and a fluid force applied to the valve element by an ejected combustion gas; and determining a target opening degree based on the estimated opening degree to control an opening degree of the valve, wherein the calculating the estimated opening degree of the valve comprises: calculating the fluid force based on an acceleration of the valve element and the acting force; and calculating the estimated opening degree based on the fluid force.