Abstract: The present disclosure is directed to a system for fracturing operation in oil/gas fields. The disclosed fracturing system is integrated onto a semitrailer that can be conveniently transported to any oil field. The disclosed fracturing system further includes major components needed for delivering high-pressure fracturing fluid into a wellhead, including but not limited to at least one power generation source and at least one plunger pump driven by the at least one power generation source via simple transmission mechanisms utilizing reduction gearbox and/or transmission shafts. The power generation source, in particular, includes a turbine engine capable of being powered by 100% natural gasified liquid fuel. The fracturing system further includes hydraulic and cooling component for serving the various needs for the turbine engine, the reduction gearbox, and the plunger pump, such as lubrication of various moving parts.

Abstract: The present invention relates to a method of controlling a wind turbine by automatic online selection of a controller that minimizes the wind turbine fatigue. The method therefore relies on an (offline constructed) database (BDD) of simulations of a list (LIST) of controllers, and on an online machine learning step for determining the optimal controller in terms of wind turbine (EOL) fatigue. Thus, the method allows automatic selection of controllers online, based on a fatigue criterion, and switching between the controllers according to the measured evolution of wind condition.

Abstract: The present disclosure is directed to a system for fracturing operation in oil/gas fields. The disclosed fracturing system is integrated onto a semitrailer that can be conveniently transported to any oil field. The disclosed fracturing system further includes major components needed for delivering high-pressure fracturing fluid into a wellhead, including but not limited to at least one power generation source and at least one plunger pump driven by the at least one power generation source via simple transmission mechanisms utilizing reduction gearbox and/or transmission shafts. The power generation source, in particular, includes a turbine engine capable of being powered by 100% natural gasified liquid fuel. The fracturing system further includes hydraulic and cooling component for serving the various needs for the turbine engine, the reduction gearbox, and the plunger pump, such as lubrication of various moving parts.

Abstract: The present innovation relates generally to propulsion mechanisms for propeller-driven vehicles and vessels, and, more particularly, to gear-driven transmissions for airboats.

Abstract: A adjustment unit for an azimuth adjustment and/or for a pitch adjustment of a wind turbine, to an adjustment apparatus, to a pitch adjustment apparatus, to an azimuth adjustment apparatus, to a wind turbine, and to methods for the rotor blade adjustment and wind direction tracking, and to the use of an adjustment unit and/or adjustment apparatus.

Abstract: A propeller assembly is provided for mounting on a rotatable propeller shaft of a watercraft. The propeller assembly includes a hub structure having a plurality of circumferentially spaced blades projecting therefrom and an inner surface defining a passage. An adaptor is receivable in the passage of the hub structure. The adaptor a plurality of key pairs extending along the outer surface thereof the adaptor which define slots for receiving inserts therein. An inner portion of the first side of each insert forms mating relationship with first portion of the first sidewall of a first key of a corresponding key pair and an inner portion of the second side of the insert forms a mating relationship with the first portion of the second sidewall of a second key of the corresponding key pair with the insert received in the corresponding slot.

Abstract: A propeller pitch control system for a turboprop engine of an aircraft includes a negative torque sensor, a full feather control valve assembly, and a feather valve assembly. The feather valve assembly is responsive to fluid pressures from the negative torque sensor and the control valve assembly to move between a plurality of positions. An engine control unit or a manual user interface can also be used to control the position of the feather.

Abstract: The present disclosure is directed to a system for controlling a pitch angle of a rotor blade of a wind turbine. The system includes a pitch adjustment mechanism for adjusting the pitch angle of the rotor blade and a controller communicatively coupled to the pitch adjustment mechanism. The controller is configured to determine a wind asymmetry parameter based on an operating parameter of the wind turbine. The controller is also configured to determine first and second signal components of the wind asymmetry parameter, which are respectively indicative of a maximum load on a first wind turbine component and fatigue on a second wind turbine component. The controller is also configured to calculate a wear parameter based on the first and second signal components and initiate an adjustment of the pitch angle of the rotor blade based on the wear parameter.

Abstract: A robust amphibious air vehicle incorporates a fuselage with buoyant stabilizers and wings extending from the fuselage. At least one lift fan is mounted in the fuselage. Movable propulsion units carried by the wings are rotatable through a range of angles adapted for vertical and horizontal flight operations.

Abstract: A method for controlling loads of a wind turbine includes receiving sensor signals from one or more sensors being indicative of a movement of a nacelle of the wind turbine from a reference point. More particularly, the movement corresponds, at least, to a tilt and/or a displacement of the wind turbine tower and/or nacelle. The method also includes generating a deflection profile of the tower along its overall length from a bottom end to a top end thereof based on the sensor signals. Further, the method includes determining at least one of a thrust or a tower load of the wind turbine from the deflection profile. In addition, the method includes implementing a control action for the wind turbine based on the thrust and/or the tower load.

Abstract: Embodiments of the present disclosure include a data processing and control augmentation system capable of identifying overloading of one or more wind turbine assemblies and providing information to a wind farm controller to reduce a power output of each overloaded turbine. The augmentation system thus reduces the power output of each overloaded turbine and, in turn, reduces loads applied to the wind turbine assembly, such as for a period of time until conditions favorably change. A described analysis of the present disclosure is able to utilize several incoming data streams from sensors so arranged to measure wind effects on blades to calculate and compare cyclic loads to threshold limits to o keep the loads within design limits. The control strategy reduces premature failure of components within the wind turbine assembly, and can be applied across an entire wind farm, even with only a subset of wind turbine assemblies being retrofitted.

Abstract: The present disclosure is directed to a method for determining an estimated rotor shaft position of a rotor shaft of a wind turbine. The method includes generating, with a rotor shaft position sensor, a measured rotor shaft position signal associated with a measured rotor shaft position of the rotor shaft. The method also includes generating, with a plurality of accelerometers positioned in an axisymmetric arrangement, a plurality of rotor hub acceleration signals associated with a plurality of rotor hub accelerations of a rotor hub coupled to the rotor shaft. The method further includes determining, with a controller, a phase adjustment based on one of the plurality of rotor hub acceleration signals or a predetermined correction value. Furthermore, the method includes adjusting, with the controller, the measured rotor shaft position by the phase adjustment to determine the estimated rotor shaft position of the rotor.

Abstract: A wind turbine system is presented. The wind turbine system includes a wind turbine comprising a plurality of blades and a tower, and a processing subsystem configured to shut down the wind turbine by non-linearly pitching out the plurality of blades in the wind turbine towards a feather position at a pitch rate determined based upon a tower-fore-aft velocity of a top-portion of the tower during oscillations of the tower.

Abstract: The invention provides a wind turbine, a control system for a wind turbine and a method for controlling a wind turbine where asymmetry in load on the rotor is compensated by individual pitching by comparing a load distribution over the rotor plane with a threshold value. To avoid unnecessary compensation, the threshold value is adjusted based on a loading of the wind turbine or based on climate conditions under which the turbine operates.

Abstract: Embodiments of wind turbine control systems, and related methods, are disclosed herein. For example, a wind turbine control system may include: a measurement system, including one or more measurement devices disposed on a blade of a wind turbine, to generate a measurement signal representative of a response of the blade to turbulence or flow non-uniformity; a force generation system to generate lift proximate to a trailing edge of the blade by generating a blowing jet of air at the trailing edge of the blade in response to a control signal; and a controller device to generate the control signal, based at least in part on the measurement signal, for provision to the force generation system to reduce the response of the blade to turbulence or flow non-uniformity. Other embodiments may be disclosed and/or claimed.

Abstract: A method of operating a wind turbine is provided. The wind turbine comprises a turbine rotor with at least two blades, each blade having a variable pitch angle. The method comprises determining mechanical loads on the blades, determining an asymmetric load moment experienced by the turbine rotor based on the mechanical loads on the blades, determining high order harmonics from the asymmetric load moment, and determining an individual pitch control signal for each of the blades for varying the pitch angle of each blade to compensate for the asymmetric load moment. The individual pitch control signal for each blade is determined at least based on the high order harmonics.

Abstract: A wind turbine blade assembly comprises a rotatable hub, a blade secured to the hub, and a pitch system. The pitch system is disposed to rotate the blade with respect to the hub about a pitch axis not extending through an aerodynamic centroid of the blade. The pitch system comprises a hydraulic cylinder pitch actuator and a relief valve. The hydraulic cylinder pitch actuator has first and second pressure chambers. The relief valve is configured to aerodynamically unload the blade by equilibrating the first and second pressure chambers in response to a pressure differential between the first and second pressure chambers exceeding a critical threshold corresponding to a pre-strain blade twist.

Abstract: A wind turbine system is presented. The wind turbine system includes a rotor comprising a plurality of blades and a hub, and a turbine controller configured to reduce an abnormal amplitude modulation of the wind turbine by adjusting pitch angles of the plurality of blades during a rotation of the rotor based upon aerodynamic loads acting on the rotor.

Abstract: A method for dampening oscillations in a wind turbine, the wind turbine having a tower (1), a rotor (3) rotating about an X axis, and a plurality of blades (4) with adjustable pitch, said method comprising monitoring the fore-aft oscillation of the tower in the direction of the X axis, at the 2nd or a higher bending mode frequency; determining a compensating torque to be applied by the rotor to the tower about a Y axis, which is horizontal and at right angles to the X axis, for dampening said oscillation at the 2nd or higher bending mode frequency; determining for each rotor blade an adjustment of the pitch angle suitable to generate said compensating torque about the Y axis; and adjusting the pitch angle ?1, ?2, ?3 of at least one of the individual blades to generate at least part of said compensating torque.

Abstract: The invention relates to a method of controlling a wind turbine comprising one or more blades attached to a rotor hub, the one or more blades being arranged to pitch relative to the hub, the method comprising the steps of obtaining a blade load signal comprising data on an absolute load on the one or more blades; processing the blade load data to detect a high thrust wind event, and generating a control signal comprising a pitch contribution for affecting the blades to pitch out of the wind in response to the detected wind event. The invention also relates to a wind turbine, a control system for a wind turbine and a computer program product being adapted to enable a computer system to perform the method of the invention.

Abstract: A wind turbine yaw system is provided that includes a yaw gear, at least two pinion gears, and at least two drive units, each of which is associated to one of the pinion gears for driving that pinion gear. The yaw system also includes a control system with a controller for generating a drive unit control signal for each drive unit for controlling the respective drive unit according to a reference signal having a desired operational parameter value for the respective drive unit, so as to realize the desired operational parameter value in the respective drive unit. The control system includes a feedback loop for each drive unit feeding a drive unit feedback signal including at least the actual value of one operational parameter of the respective drive unit back to the controller. The controller generates the drive unit control signals based on the reference signal and the feedback signals.

Abstract: The present invention provides a method of operating a wind turbine having a rotor with a plurality of blades, a system for determining one or more loads on the wind turbine, a historical register of data on the wind turbine operation, and a control system for controlling one or more operational parameters of the wind turbine. The method comprises determining the loads on the wind turbine, and storing the determined loads on the wind turbine in the historical register. The method further comprises obtaining, from the historical register, a characteristic indicative of the loads on the wind turbine accumulated over time, and determining one or more wind thrust limits depending on the obtained characteristic indicative of the loads accumulated over time. One or more operational parameters of the wind turbine are controlled to keep the wind thrust on the wind turbine within the determined wind thrust limits.

Abstract: A wind turbine for power generation is provided. The wind turbine includes a power generating unit and a rotor having a plurality of blades. To control power output of the wind turbine, the blades are capable of being pitched by a blade pitch adjusting device. The wind turbine also includes a pitch control unit for controlling the blade pitch adjusting device. Furthermore, the wind turbine includes a load determining device for determining the blade load from the pitch activity of the blades.

Abstract: Control methods and systems of a wind turbine belonging to an off-shore wind park that use, in case of malfunction of the load measuring system, one of the following pitch vectors for the calculation of the individual pitch command of each blade: the pitch vector being applied at the same time in one wind turbine of the wind park where the load measuring system works properly a mean value of the pitch vectors being applied at the same time in a group of wind turbines of the wind park where the load measuring system works properly; the pitch vector resulting from a control law, obtained from historic records of the wind turbine when the load measuring system worked properly, defining the pitch vector as a function of at least the wind speed V, if the former pitch vectors are not available.

Abstract: The present invention relates a wind turbine comprising a wind turbine tower with a nacelle provided on the top to which a rotor hub with one or more wind turbine blades is rotatably mounted so that they form a rotor plane. A floating foundation having a upper section is mounted to the bottom of the wind turbine tower, wherein the foundation has a buoyant body configured to be installed at an offshore position having a water depth of about 40 m or more. The wind turbine blade comprises an inner blade section coupled to an outer blade section by a pitch junction in which a pitch mechanism is coupled to a pitch control system configured to regulate the pitch of the outer blade section relative to the inner blade section at wind speeds above a first wind speed. This allows the pitching to be used to counteract the tilting of the wind turbine caused by the different thrusts acting on the structure.

Abstract: A constant torque propeller mechanism allows a propeller to operate very efficiently in both takeoff and cruise flight conditions, which significantly improves aircraft performance. The constant torque propeller mechanism introduces a lightweight and passive propeller control system which requires no electrical power to operate, but at the same time improves the efficiency of the motor propeller combination over the flight envelope.

Abstract: A method of controlling a wind turbine comprising blades attached to a rotor hub for rotation in a rotor plane and a control system for individually pitching the blades relative to the hub. The method comprises dividing the rotor plane into a number of sectors, determining the individual sectors for each blade during the rotation by means of an azimuth angle sensor, and obtaining blade sensor data from a blade sensor on an individual blade relating to a sector, and comparing the obtained data with data relating to the same sector and representing blade sensor data on other blades. When an event is detected in a given sector, an individual pitch contribution is determined in the sector, and the blades are then pitched according to this individual pitch contribution for that given sector at least partly during passage of the sector.

Abstract: A collaborative robotized system comprises: a mobile platform furnished with running device, with an electric motor propulsion assembly, and with a longitudinal mechanical linkage assembly comprising an articulation; an electrical power source; manual control device of the system; remote control device of the system; a computer assembly of at least one computer; hardware-incorporating device suitable for integrating sensors and effectors, and software-incorporating device suitable for integrating software elements; and management device for managing integrated sensorimotor behaviors, suitable for arbitrating implementations of several sensorimotor behaviors in parallel.

Abstract: A method and system for reducing a torsional movement and/or a torsional loading of a tower of a wind turbine is disclosed includes generating a tower torsion signal with a detection system and providing the signal to an asymmetric load control assembly. The tower torsion signal may correspond to an actual torsional movement of the tower or a torsional loading of the tower. The asymmetric load control assembly is configured to mitigate an asymmetric load acting on the wind turbine using the tower torsion signal.

Abstract: A position control method for controlling a position of a movable portion, includes: performing control of allowing the movable portion to approach a predetermined position by moving the movable portion; and performing control of moving the movable portion to the predetermined position by moving the movable portion and detecting a relative position of the movable portion with respect to the predetermined position by using an imaging unit.

Abstract: A technique is provided for operating a wind farm at increased rated power output. The technique includes sensing a plurality of operating parameters of the wind turbine generator, assessing the plurality of operating parameters with respect to respective design ratings for the operating parameters, and intermittently increasing a rated power output of the wind turbine generator based upon the assessment.

Abstract: The disclosure relates to a method for controlling a wind farm, the wind farm includes at least two wind turbines, the method includes determining the required power, determining fatigue load versus power curves for each wind turbine, and based on the determined fatigue load versus power curves attributing different power settings to the wind turbines such that sum of the power settings of all wind turbines is equal to the required power. Furthermore, the invention concerns a park controller for controlling a wind farm and a program element for controlling a wind farm.

Abstract: In one aspect, a system for detecting loads transmitted through a blade root of a rotor blade of a wind turbine is disclosed. The system may include a root attachment assembly configured to couple the blade root to a hub of the wind turbine. The root attachment assembly may include a barrel nut mounted within a portion of the blade root and a root bolt extending from the barrel nut. In addition, the system may include a sensor associated with the root attachment assembly. The sensor may be configured to detect loads transmitted through at least one of the barrel nut and the root bolt.

Abstract: The present invention relates to a control and regulation method for a rotorcraft having at least one variable-pitch propulsive propeller driven by at least one power source, said method consisting in generating at least one mean pitch setpoint ?tcl* for the propeller(s) as a function of a thrust variation control order Tcl, wherein the method consists in defining a plurality of operating modes, including: a direct mode in which the value of the mean pitch value is a direct result of the control order Tcl; a forced mode in which the mean pitch is automatically forced to a calculated pitch value; a regulated mode in which the power of the propulsive propeller(s) is regulated as a function of a power setpoint from a pilot and of servo-controlling the mean pitch of the propeller(s); and a protected mode.

Abstract: The invention relates to a method of reducing oscillations in an offshore wind turbine comprising one or more thrusters, the method comprising determining an oscillation of the offshore wind turbine and operating the one or more thrusters such that the oscillation is reduced. The invention further relates to an offshore wind turbine comprising one or more underwater thrusters, oscillation determination system for determining an oscillation of the wind turbine and a control system for operating the underwater thrusters in response to signals received from the oscillation determination system.

Abstract: A device for reducing loads in a drive train of a wind turbine includes a machine support. The wind turbine includes a sensor means, a controllable damper means, an actuating means. The sensor means is configured to detect at least one variable characterizing vibrations and/or misalignments in the drive train. The controllable damper means is configured to produce at least one adjusting torque which compensates at least one torque associated with the load in the drive train. The actuating means is configured to actuate the damping means based on the at least one variable detected by the sensor means.

Abstract: A wind turbine system comprising a rotatable hub, wind turbine blades attached to the hub, a rotatable shaft mechanically coupled to the hub, a non-shaft-contacting sensor assembly comprising sensors for detecting signals representative of loads induced in the rotatable shaft and a processor for analyzing the signals representative of the loads induced in the rotatable shaft and providing control signals to in response to the induced loads.

Abstract: Variable-pitch propeller (1) of the type comprising at least one blade (6a, 6b, 6c) rotatably pivoted (20a, 20b, 20c) to a cylindrical casing of the propeller (3a, 3b, 4), a shaft coupled to an engine and coaxial to that propeller casing, a kinematic system (7, 8a, 8b, 8c, 10a, 10b, 10c, 11), coupled to the shaft, or to the propeller casing, and to above mentioned at least one blade, for regulating the rotary motion of said at least one blade around its own pivot axis to the propeller casing, as well as means (2, 14, 15) for transmitting the rotary motion of the shaft to the propeller casing, the propeller being shaped to provide at least one not null angular range for the free relative rotation of the above mentioned at least one blade (6a, 6b, 6c) around its pivot axis, relatively to the propeller casing (3a, 3b, 4). The propeller also comprises at least one elastic element (18, 18?) countering the relative rotation of said at least one blade relatively to the propeller casing (3a, 3b, 4), or vice versa.

Abstract: A position control method for controlling a position of a movable portion, includes: performing control of allowing the movable portion to approach a predetermined position by moving the movable portion; and performing control of moving the movable portion to the predetermined position by moving the movable portion and detecting a relative position of the movable portion with respect to the predetermined position by using an imaging unit.

Abstract: A variable transmission is described having a transmission mechanism and a phase adjustment mechanism. The transmission mechanism has supports that are movable toward or away from one another to vary the effective size of an effective cog. The phase adjustment mechanism has a differential type gear arrangement that creates a phase change to adjust the transmission mechanism. Another configuration is described which includes a subassembly with a phase adjustment mechanism for adjusting the pitch of propellers. Counter-rotating elements to control relative gear phase or pitch are provided externally, internally, distally or proximally relative to the source of mechanical torque in various configurations.

Abstract: A system for detecting loads in a wind turbine is disclosed. In one aspect, the system may generally include a shaft and first and second pillow blocks receiving portions of the shaft. The second pillow block may be spaced axially apart from the first pillow block. Additionally, the system may include at least one sensor configured to indirectly detect loads transmitted through at least one of the first pillow block and the second pillow block.

Abstract: The invention relates to a method for the operation of a wind power plant (11) with a rotor (10) and a rotating apparatus (20, 22, 24) connected with the rotor (10), wherein a rotor speed (nR) and a rotating apparatus speed (n) are interrelated via a specifiable transmission ratio, wherein the rotating apparatus speed (n) is determined, and wherein a rotational speed measurement value (rpmi) is captured for the determination of the rotating apparatus speed (n). The method according to the invention is characterized in that the rotational speed measurement value (rpmi) is corrected with an intermittently variable correction value (rpmi,c) so that the determined rotating apparatus speed (rpmi,f) results, and wherein the determined rotating apparatus speed (rpmi,f) is fed as the actual value into a regulation apparatus (36) of the wind power plant (11).

Abstract: A watercraft propulsion device includes an engine, a drive shaft, a propeller shaft, a shift mechanism, an operation force transmitting mechanism, and a magnetostrictive sensor. The drive shaft transmits power from the engine. The propeller shaft is rotationally driven by power transmitted from the drive shaft. The shift mechanism changes a rotation direction of power transmitted from the drive shaft to the propeller shaft. The operating force transmitting mechanism connects to the shift mechanism and transmits a shift operation force to the shift mechanism to cause the shift mechanism operate. The magnetostrictive sensor detects a load acting on the operation force transmitting mechanism.

Abstract: The present invention relates to a method and a system for operating a Wind Turbine (WTG), which WTG comprises a rotor comprising at least two blades, which blades are pitch regulated, where the rotor is connected to a shaft, which shaft is supported by bearings, and which shaft drives at least one generator, where the WTG uses a load regulation system for regulating the individual pitch of at least two blades. The object of the invention is to compensate for asymmetric load on the rotor in a wind turbine, a second object is to reduce wearing at shaft bearings in the wind turbine, and a third object is to increase the power production of a wind turbine. This can be achieved if the load regulation system measures the actual rotor load by at least one displacement sensor, which displacement sensor is measuring the bending of the main shaft, where the load regulation system based on the shaft bending regulates the individual pitch of the blades for compensating asymmetric load at the rotor.

Abstract: A turbomachine has a housing, a rotor shaft extending along and rotatable about an axis in the housing, and a pair of axially spaced axial-thrust bearings in the housing carrying the shaft and normally only permitting a predetermined small axial displacement of the shaft in the housing. An impeller is rotationally fixed on the shaft. An axially fixed transmission gear is rotationally coupled to the shaft and has an axially directed gear face. A collar fixed axially on the shaft has an axially directed collar face confronting the gear face and normally spaced from the gear face by a clearance equal to more than the predetermined axial displacement. Thus on failure of one of the bearings and axial overtravel of the shaft the gear face and collar face engage each other and limit axial movement of the shaft.

Abstract: A method of controlling blade pitch angle, including comparing demanded and measured blade pitch angle and calculating any difference therebetween, in a primary electrical control system, where there is a difference, applying torque to a blade pitch regulator to reduce the magnitude of the difference to zero, and in a secondary electrical control system, where the difference is greater than a pre-determined threshold, applying torque to a blade pitch regulator to reduce the magnitude of the difference to the threshold. Also an electrical system of blade pitch angle control for a set of blades including primary and secondary electrical control systems, means for comparing demanded and measured blade pitch angle and calculating any difference therebetween, a look-up function having the difference as its input and outputting a required torque, and a torque regulator to apply the required torque to the set of blades.

Abstract: An apparatus and method for reducing asymmetric rotor load in a wind turbine includes calculating a time delay for pitching each blade toward feather upon initiation of a shutdown condition. The blades with the larger blade angle begin moving toward feather with an initial pitch rate, while the blade with the smallest blade angle begins moving toward feather with a final pitch rate. Once all the blades have reached approximately an identical blade angle, the blades move simultaneously together to feather at the final pitch rate. By introducing the time delay for pitching the blades having higher blade angles at the final pitch rate, a simple, time-based correction of initial conditions during shutdown reduces the extreme loads on turbine components.

Abstract: A method, system and computer program product for operating a wind turbine is disclosed. For operating the wind turbine a set of operational data points are sensed via a sensing module. The set of operational data points may include bending stress values. Based on the bending stress values, a load scenario indicator value may be computed. Further, based on the set of operational data points a loading threshold value may be obtained. At least one operating parameter of the wind turbine is changed if the load scenario indicator value exceeds the loading threshold.

Abstract: A method for determining and applying a pitch angle offset signal for controlling a rotor frequency of a rotor of a wind turbine is disclosed. The method includes obtaining a motion quantity indicative of a motion of the rotor and determining the pitch angle offset signal based on the motion quantity such that the pitch angle offset signal is adapted to be used for adjusting a blade pitch angle of a rotor blade mounted at the rotor for controlling the rotor frequency in order to reduce a time span during which the rotor is in a critical motion region. A corresponding system and a method for controlling a rotor frequency are also disclosed.

Abstract: Helicopter rotating hub mounted vibration control system for a rotary wing hub having periodic vibrations while rotating at an operational rotation frequency. The vibration control system includes a housing attachable to the rotary wing hub and rotating with the hub at the operational frequency. The housing is centered about the rotary wing hub axis of rotation and has an electronics housing cavity subsystem and an adjacent rotor housing cavity subsystem. The rotor housing cavity contains a first coaxial ring motor with a first rotor and imbalance mass and a second coaxial ring motor with a second rotor and imbalance mass.