# US 10,310,516 B2 · Systems and methods for yaw control of offshore platform > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,310,516 B2 - Document ID: US10310516B2 - Status: Granted - Kind: B2 - Application number: 15/482,766 - Filed: 2017-04-09 - Published: 2018-10-11 - Granted: 2019-06-04 - Earliest claimed: 2017-04-09 - Assignees: Makani Technologies LLC - Applicants: Makani Technologies LLC - Inventors: Charles Joseph Nordstrom; Ruth Heffernan Marsh - Web page: https://patentgrep.com/patent/US10310516B2 ## CPC - G05D 1/0875: {specially adapted to water vehicles} - B63B 1/048: {with hull extending principally vertically} - B63B 21/50: Anchoring arrangements {or methods} for special vessels, e.g. for floating drilling platforms or dredgers - B63H 9/072: Control arrangements, e.g. for launching or recovery - B64U 10/60: Tethered aircraft - B64U 70/30: for capturing UAVs in flight by ground or sea-based arresting gear, e.g. by a cable or a net - B63B 2001/044: {with a small waterline area compared to total displacement, e.g. of semi-submersible type} - B63B 2035/446: {for converting wind energy into electric energy} - B63J 99/00: Subject matter not provided for in other groups of this subclass - B64U 2101/10: for generating power to be supplied to a remote station, e.g. UAVs with solar panels - B64U 2201/202: using tethers for connecting to ground station - Y02E 10/70: Wind energy - Y02E 10/72: Wind turbines with rotation axis in wind direction - Y02E 10/727: Offshore wind turbines - Y02T 70/10: Measures concerning design or construction of watercraft hulls - Y02T 70/5236: Renewable or hybrid-electric solutions - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES - B63B: SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING (arrangements of vessel ventilation, heating, cooling, or air-conditioning B63J2/00; floating substructures as supports of dredgers or soil-shifting machines E02F9/06) - B63H: MARINE PROPULSION OR STEERING (propulsion of air-cushion vehicles B60V1/14; specially adapted for submarines, other than nuclear propulsion, B63G; specially adapted for torpedoes F42B19/00) - B64U: UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR - B63J: AUXILIARIES ON VESSELS - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract The present disclosure relates to systems and methods for rotating a floating platform. An example method includes determining a desired position of a floating platform in a yaw axis. The floating platform is fixed by an anchor leg to an underwater attachment point. The method includes receiving, from a position sensor, information indicative of an actual position of the floating platform in the yaw axis. The method also includes rotating the floating platform in a desired direction about the yaw axis based on the desired position and the actual position. Optionally, the floating platform may include a yaw member and an environmental sensor. In such scenarios, the method may include receiving information about a prevailing wind direction or water current direction. The method may include causing the actuator to adjust the yaw member based on at least one of: the prevailing wind condition or the prevailing water current direction. ## Claims ### Claim 1 A system comprising: a floating platform fixed by an anchor leg to an underwater attachment point; a yaw member coupled to the floating platform by way of an actuator, wherein the yaw member is operable to convert an aerodynamic force on the yaw member into a rotational force on the floating platform about a yaw axis; a position sensor; an environmental sensor; and a controller, wherein the controller comprises a processor and a memory, and wherein the controller executes instructions stored in the memory so as to carry out operations, the operations comprising: determining a desired position of the floating platform in the yaw axis; receiving, from the position sensor, information indicative of an actual position of the floating platform in the yaw axis; receiving, from the environmental sensor, information indicative of a wind condition; and based on the desired position, the actual position, and the wind condition, causing the actuator to move the yaw member, relative to the floating platform, to one or more target positions. ### Claim 2 (depends on 1) The system of claim 1, wherein the wind condition comprises a wind direction. ### Claim 3 (depends on 1) The system of claim 1, wherein the wind condition comprises a wind speed and a wind direction. ### Claim 4 (depends on 1) The system of claim 1, wherein moving the yaw member to the one or more target positions causes rotation of the floating platform in a desired direction about the yaw axis. ### Claim 5 (depends on 4) The system of claim 4, further comprising an underwater cable, wherein the underwater cable is initially at least partially wrapped around the anchor leg, and wherein the rotation of the floating platform in the desired direction about the yaw axis at least partially unwraps the underwater cable from the anchor leg. ### Claim 6 (depends on 1) The system of claim 1, wherein the floating platform comprises a spar buoy. ### Claim 7 (depends on 1) The system of claim 1, wherein the anchor leg is a single anchor leg mooring (SALM). ### Claim 8 (depends on 1) The system of claim 1, wherein the yaw member comprises a drag member. ### Claim 9 (depends on 1) The system of claim 1, wherein the yaw member comprises an aerodynamic lift member, wherein the aerodynamic lift member is an airfoil that generates a lift force. ### Claim 10 (depends on 1) The system of claim 1, wherein the position sensor comprises at least one of: a rotation sensor, a global positioning system, an inertial measurement unit, or a compass. ### Claim 11 (depends on 1) The system of claim 1, wherein the environmental sensor comprises at least one of: a wind gauge, a weather vane, or a pressure sensor. ### Claim 12 (depends on 1) The system of claim 1, wherein the yaw member is a first yaw member, wherein the actuator is a first actuator, wherein the system further comprises a second yaw member coupled to the floating platform by way of a second actuator, wherein the operations further comprise selecting, based on the wind condition, a target yaw member from the first and second yaw members, wherein causing the first actuator to move the first yaw member is based on the first yaw member being the selected target yaw member. ### Claim 13 (depends on 1) The system of claim 1, wherein the one or more target positions (i) cause rotation of the floating platform from the actual position to the desired position if the desired position is different from the actual position or (ii) maintain the actual position of the floating platform if the desired position is the actual position. ### Claim 14 A system comprising: a floating platform fixed by an anchor leg to an underwater attachment point; a yaw member coupled to the floating platform by way of an actuator, wherein the yaw member is operable to convert a hydrodynamic force on the yaw member into a rotational force on the floating platform about a yaw axis; a position sensor; an environmental sensor; and a controller, wherein the controller comprises a processor and a memory, and wherein the controller executes instructions stored in the memory so as to carry out operations, the operations comprising: determining a desired position of the floating platform in the yaw axis; receiving, from the position sensor, information indicative of an actual position of the floating platform in the yaw axis; receiving, from the environmental sensor, information indicative of a hydrodynamic condition; and based on the desired position, the actual position, and the hydrodynamic condition, causing the actuator to move the yaw member, relative to the floating platform, to one or more target positions. ### Claim 15 (depends on 14) The system of claim 14, wherein the hydrodynamic condition comprises a water current direction. ### Claim 16 (depends on 14) The system of claim 14, wherein the hydrodynamic condition comprises water current speed and a water current direction. ### Claim 17 (depends on 14) The system of claim 14, wherein moving the yaw member to the one or more target positions causes rotation of the floating platform in a desired direction about the yaw axis. ### Claim 18 (depends on 17) The system of claim 17, further comprising an underwater cable, wherein the underwater cable is initially at least partially wrapped around the anchor leg, and wherein the rotation of the floating platform in the desired direction about the yaw axis at least partially unwraps the underwater cable from the anchor leg. ### Claim 19 (depends on 14) The system of claim 14, wherein the floating platform comprises a spar buoy. ### Claim 20 (depends on 14) The system of claim 14, wherein the anchor leg is a single anchor leg mooring (SALM). ### Claim 21 (depends on 14) The system of claim 14, wherein the yaw member comprises a drag member. ### Claim 22 (depends on 14) The system of claim 14, wherein the yaw member comprises a hydrodynamic lift member, wherein the hydrodynamic lift member is a hydrofoil that generates a hydrodynamic lift force. ### Claim 23 (depends on 14) The system of claim 14, wherein the position sensor comprises at least one of: a rotation sensor, a global positioning system, an inertial measurement unit, or a compass. ### Claim 24 (depends on 14) The system of claim 14, wherein the environmental sensor comprises a pressure sensor. ### Claim 25 (depends on 14) The system of claim 14, wherein the yaw member is a first yaw member, wherein the actuator is a first actuator, wherein the system further comprises a second yaw member coupled to the floating platform by of a second actuator, wherein the operations further comprise selecting, based on the hydrodynamic condition, a target yaw member from the first and second yaw members, wherein causing the first actuator to move the first yaw member is based on the first yaw member being the selected target yaw member. ### Claim 26 (depends on 14) The system of claim 14, wherein the one or more target positions (i) cause rotation of the floating platform from the actual position to the desired position if the desired position is different from the actual position or (ii) maintain the actual position of the floating platform if the desired position is the actual position. ### Claim 27 A system comprising: a floating platform fixed by an anchor leg to an underwater attachment point; a position sensor; an aerial vehicle; a yaw member coupled to the floating platform; and a controller, wherein the controller comprises a processor and a memory, and wherein the controller executes instructions stored in the memory so as to carry out operations, the operations comprising: determining a desired position of the floating platform in a yaw axis; receiving, from the position sensor, information indicative of an actual position of the floating platform in the yaw axis; and based on the desired position and the actual position, causing the aerial vehicle to generate a downward thrust force on the yaw member, wherein the yaw member is operable to convert the downward thrust force on the yaw member into a rotational force on the floating platform about the yaw axis. ### Claim 28 (depends on 27) The system of claim 27, wherein the rotational force on the floating platform is in a desired direction about the yaw axis. ### Claim 29 (depends on 27) The system of claim 27, further comprising an underwater cable, wherein the underwater cable is initially wrapped around the anchor leg, and wherein the rotational force causes rotation of the floating platform in the desired direction to at least partially unwrap the underwater cable from the anchor leg. ### Claim 30 (depends on 27) The system of claim 27, wherein the rotational force (i) causes rotation of the floating platform from the actual position the desired position if the desired position is different from the actual position or (ii) maintains the actual position of the floating platform if the desired position is the actual position. ### Claim 31 A method comprising: determining a desired position of a floating platform in a yaw axis, wherein the floating platform is fixed by an anchor leg to an underwater attachment point, and wherein a yaw member is coupled to the floating platform; receiving, from a position sensor, information indicative of an actual position of the floating platform in the yaw axis; and based on the desired position and the actual position, causing an aerial vehicle to generate a downward thrust force on the yaw member, wherein the yaw member is operable to convert the downward thrust force on the yaw member into a rotational force on the floating platform in a desired direction about the yaw axis. ### Claim 32 (depends on 31) The method of claim 31, wherein the yaw member is coupled to the floating platform by way of an actuator, wherein the floating platform comprises an environmental sensor, and wherein the method further comprises: receiving, from the environmental sensor, information indicative of at least one of: a wind condition or a hydrodynamic condition; determining, based on the received information, at least one of: a prevailing wind direction or a prevailing water current direction; and causing the actuator to move the yaw member, relative to the floating platform, to one or more target positions based on at least one of: the prevailing wind condition or the prevailing water current direction. ### Claim 33 (depends on 31) The method of claim 31, wherein an underwater cable is initially wrapped around the anchor leg, and wherein the rotational force causes rotation of the floating platform in the desired direction to at least partially unwrap the underwater cable from the anchor leg. ### Claim 34 (depends on 31) The method of claim 31, wherein the rotational force (i) causes rotation of the floating platform from the actual position to the desired position if the desired position is different from the actual position or (ii) maintains the actual position of the floating platform if the desired position is the actual position.