A rotor system for aerial vehicles where two or more rotor systems are used in a coaxial or tandem arrangement on the aerial vehicle.

Actuators are components of machines, which move and/or control a mechanism or system. During operation, actuators can experience regeneration events, with the actuator actually generating excess energy (e.g., regenerative energy) which must be stored or dissipated to avoid damaging the power supply. An actuator motor controller is configured to implement field oriented voltage control and flux weakening voltage control without current sensors. Dissipating regenerative energy includes providing a motor controller to command a motor drive to modify an input voltage, or to dissipate regenerative energy in a dump circuit. This command can cause motor windings to dissipate regenerative energy. Systems having a plurality of actuators distribute regenerative energy from one actuator to another. A central controller provides centralized regeneration dissipation control for the plurality of actuators. A power distribution unit includes a dump resistor to dissipate regenerative energy in addition to or instead of in the actuators.

An actuator system for an aircraft includes an actuator, and a control valve system operatively connected to the actuator. The control valve system includes a first direct drive valve (DDV) mechanically connected to a second DDV. A backup valve system is operatively connected to the actuator. The backup valve system includes one of an electro-hydraulic servovalve (EHSV) and a DDV.

Actuators are components of machines, which move and/or control a mechanism or system. During operation, actuators can experience regeneration events, with the actuator actually generating excess energy (e.g., regenerative energy) which must be stored or dissipated to avoid damaging the power supply. An actuator motor controller is configured to implement field oriented voltage control and flux weakening voltage control without current sensors. Dissipating regenerative energy includes providing a motor controller to command a motor drive to modify an input voltage, or to dissipate regenerative energy in a dump circuit. This command can cause motor windings to dissipate regenerative energy. Systems having a plurality of actuators distribute regenerative energy from one actuator to another. A central controller provides centralized regeneration dissipation control for the plurality of actuators. A power distribution unit includes a dump resistor to dissipate regenerative energy in addition to or instead of in the actuators.

A rotor system for aerial vehicles where two or more rotor systems are used in a coaxial or tandem arrangement on the aerial vehicle.

Actuators are components of machines, which move and/or control a mechanism or system. During operation, actuators can experience regeneration events, with the actuator actually generating excess energy (e.g., regenerative energy) which must be stored or dissipated to avoid damaging the power supply. An actuator motor controller is configured to implement field oriented voltage control and flux weakening voltage control without current sensors. Dissipating regenerative energy includes providing a motor controller to command a motor drive to modify an input voltage, or to dissipate regenerative energy in a dump circuit. This command can cause motor windings to dissipate regenerative energy. Systems having a plurality of actuators distribute regenerative energy from one actuator to another. A central controller provides centralized regeneration dissipation control for the plurality of actuators. A power distribution unit includes a dump resistor to dissipate regenerative energy in addition to or instead of in the actuators.

A rotary wing aircraft includes a rotor system rotatable about an axis relative to an airframe. A plurality of blade assemblies is mounted to the rotor system. A higher harmonic control system is operable to generate a harmonic load at the rotor system according to a higher harmonic control signal. An active vibration control system is operable to generate vibration forces about the aircraft according to an active vibration control signal. A controller is operable to issue the higher harmonic control signal and the active vibration control signal to coordinate the higher harmonic control system and the active vibration control system to reduce vibration within the airframe.

An actuator system for an aircraft includes an actuator, and a control valve system operatively connected to the actuator. The control valve system includes a first direct drive valve (DDV) mechanically connected to a second DDV. A backup valve system is operatively connected to the actuator. The backup valve system includes one of an electro-hydraulic servovalve (EHSV) and a DDV.

A rotary wing aircraft is provided including a dual counter-rotating, coaxial rotor system having an upper rotor system and a lower rotor system rotatable about a common axis. A plurality of blade assemblies is mounted to a portion of either the upper rotor system or the lower rotor system. A plurality of individually controllable actuators is coupled to each of the plurality of blade assemblies. Each of the plurality of actuators is configured to control movement of the coupled blade assembly about a pitch axis. The rotary-wing aircraft additionally includes a sensor system within an airframe. A higher harmonic control (HHC) controller is arranged in communication with the sensor system and the plurality of actuators to individually control the upper rotor system and the lower rotor system to reduce vibration.

Methods and apparatus to control pitch and twist of blades are disclosed. An example apparatus includes a twist input assembly driven by a drive shaft that drives a rotation of blades of a rotorcraft, the twist input assembly comprising a twist shaft, a first gear set driven by the drive shaft, and a first frequency controller to create a first rotational speed difference between a first gear of the first gear set and the drive shaft, the first rotational speed difference to cause the twist shaft to oscillate. The examples apparatus includes a pitch input assembly driven by the drive shaft, the pitch input assembly comprising a pitch link in communication with a first one of the blades of the rotorcraft, a second gear set driven by the drive shaft, and a second frequency controller to create a second rotational speed difference between a second gear of the second gear set and the drive shaft, the second rotational speed difference to cause the pitch link to oscillate.