Patents by Inventor Aaron L. Greenfield

Aaron L. Greenfield has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20190155289
    Abstract: The present disclosure is directed to a vehicle dynamics monitor for an autonomous vehicle. In particular, the systems and methods of the present disclosure can determine, based on data received from one or more sensors of an autonomous vehicle, that an anomaly exists in an interface between at least one tire of the autonomous vehicle and a road surface. Responsive to determining that the anomaly exists: a motion plan for the autonomous vehicle that takes into account the anomaly can be determined; and one or more controls of the autonomous vehicle can be interfaced with to implement the motion plan.
    Type: Application
    Filed: January 29, 2018
    Publication date: May 23, 2019
    Inventors: Sean McNeil, Aaron L. Greenfield
  • Publication number: 20190086924
    Abstract: The present disclosure provides systems and methods that employ tolerance values defining a level of vehicle control precision for motion control of an autonomous vehicle. More particularly, a vehicle controller can obtain a trajectory that describes a proposed motion path for the autonomous vehicle. A constraint set of one or more tolerance values (e.g., a longitudinal tolerance value and/or lateral tolerance value) defining a level of vehicle control precision can be determined or otherwise obtained. Motion of the autonomous vehicle can be controlled to follow the trajectory within the one or more tolerance values (e.g., longitudinal tolerance value(s) and/or a lateral tolerance value(s)) identified by the constraint set. By creating a motion control framework for autonomous vehicles that includes an adjustable constraint set of tolerance values, autonomous vehicles can more effectively implement different precision requirements for different driving situations.
    Type: Application
    Filed: September 15, 2017
    Publication date: March 21, 2019
    Inventors: Aaron L. Greenfield, Frederic Tschanz, David McAllister Bradley, Diana Yanakiev
  • Publication number: 20190079513
    Abstract: In one example embodiment, a computer-implemented method includes receiving data representing a motion plan of the autonomous vehicle via a plurality of control lanes configured to implement the motion plan to control a motion of the autonomous vehicle, the plurality of control lanes including at least a first control lane and a second control lane, and controlling the first control lane to implement the motion plan. The method includes detecting one or more faults associated with implementation of the motion plan by the first control lane or the second control lane, or in generation of the motion plan, and in response to one or more faults, controlling the first control lane or the second control lane to adjust the motion of the autonomous vehicle based at least in part on one or more fault reaction parameters associated with the one or more faults.
    Type: Application
    Filed: September 10, 2018
    Publication date: March 14, 2019
    Inventors: Aaron L. Greenfield, Diana Yanakiev, Frederic Tschanz
  • Publication number: 20190064825
    Abstract: The present disclosure provides a vehicle interface for an autonomous vehicle. In particular, the systems and methods of the present disclosure can, responsive to receiving, from an autonomy computing system of an autonomous vehicle, a time-based trajectory for the autonomous vehicle, verify that execution of the time-based trajectory is within parameters of the autonomous vehicle. Responsive to verifying that execution of the time-based trajectory is within the parameters of the autonomous vehicle, the time-based trajectory can be converted into a spatial path for the autonomous vehicle, and one or more controls of the autonomous vehicle can be interfaced with such that the autonomous vehicle tracks the spatial path.
    Type: Application
    Filed: September 28, 2017
    Publication date: February 28, 2019
    Inventors: Frederic Tschanz, Aaron L. Greenfield, Diana Yanakiev, Dillon Collins
  • Patent number: 10189559
    Abstract: Examples of rotor speed reduction using a feed-forward rotor speed control command are provided. In one example, a computer-implemented method includes: receiving, by a processing device, flight command indicative of a change in a flight characteristic of an aircraft comprising a rotor; generating, by the processing device, a change in load factor based on the flight command; generating, by the processing device, a change in rotor speed based on the change in load factor; generating, by the processing device, a rotor speed command based on the change in rotor speed to a flight controller to cause the aircraft to change a rotor speed of the rotor; and changing, by the processing device, the rotor speed of the rotor responsive to the rotor speed command.
    Type: Grant
    Filed: November 22, 2016
    Date of Patent: January 29, 2019
    Assignee: SIKORSKY AIRCRAFT CORPORATION
    Inventors: Derek Geiger, Ole Wulff, Jonathan Aaron Litwin, Aaron L. Greenfield
  • Patent number: 10114382
    Abstract: Two methods of combining multiple response types into a single flexible command model are provided and include receiving a pilot stick input, generating an aircraft response to the pilot stick input that is a continuous blend of response types by including calculable time-varying coefficients set as a function of a magnitude of the pilot stick input and other aircraft states such as airspeed, imposing at least an angular acceleration command limit and using other non-linear elements to optimize the aircraft response to the pilot stick input.
    Type: Grant
    Filed: February 2, 2017
    Date of Patent: October 30, 2018
    Assignee: SIKORSKY AIRCRAFT CORPORATION
    Inventors: Aaron L. Greenfield, Kenneth S. Wittmer
  • Patent number: 10099777
    Abstract: One aspect is a flight control system for a rotary wing aircraft including a main rotor system and an elevator control system. A flight control computer of the flight control system includes processing circuitry configured to execute control logic. The control logic includes an inverse plant model that produces a main rotor feed forward command based on a pitch rate command, and a load alleviation control filter configured to reduce loads on a main rotor system and produce an elevator command for an elevator control system. A transformed elevator command filter produces a main rotor pitch adjustment command based on the elevator command, and a main rotor command generator generates an augmented main rotor feed forward command for the main rotor system based on the main rotor feed forward command and the main rotor pitch adjustment command.
    Type: Grant
    Filed: April 2, 2014
    Date of Patent: October 16, 2018
    Assignee: SIKORSKY AIRCRAFT CORPORATION
    Inventors: Erez Eller, Aaron L. Greenfield, Ole Wulff, Matthew A. White, Matthew T. Luszcz
  • Patent number: 10025320
    Abstract: A control system for a rotary wing aircraft having a reconfigurable element. The control system includes a model predictive control module receiving operator commands, objectives and constraints; and a dynamic inversion module receiving an output of the model predictive control module, the dynamic inversion module providing control commands to reconfigure the reconfigurable element of the rotary wing aircraft.
    Type: Grant
    Filed: February 15, 2012
    Date of Patent: July 17, 2018
    Assignee: SIKORSKY AIRCRAFT CORPORATION
    Inventors: Vineet Sahasrabudhe, Aaron L. Greenfield, Derek Geiger, James Rigsby
  • Publication number: 20180141640
    Abstract: Examples of rotor speed reduction using a feed-forward rotor speed control command are provided. In one example, a computer-implemented method includes: receiving, by a processing device, flight command indicative of a change in a flight characteristic of an aircraft comprising a rotor; generating, by the processing device, a change in load factor based on the flight command; generating, by the processing device, a change in rotor speed based on the change in load factor; generating, by the processing device, a rotor speed command based on the change in rotor speed to a flight controller to cause the aircraft to change a rotor speed of the rotor; and changing, by the processing device, the rotor speed of the rotor responsive to the rotor speed command.
    Type: Application
    Filed: November 22, 2016
    Publication date: May 24, 2018
    Inventors: Derek Geiger, Ole Wulff, Jonathan Aaron Litwin, Aaron L. Greenfield
  • Publication number: 20180113478
    Abstract: One aspect is a flight control system for a coaxial rotary wing aircraft including a main rotor system and an active elevator. The flight control system includes a flight control computer with processing circuitry that executes control logic. The control logic includes a gust detector that produces a gust error indicative of a wind gust encountered by the coaxial rotary wing aircraft. The control logic also includes a gust alleviation control that reduces lift on the main rotor system with collective, based on the gust error, and mixes a collective command to a main rotor cyclic and a differential cyclic to reduce an aircraft pitch response and a lift-offset change. The gust alleviation control also reduces a main rotor pitching moment with the main rotor cyclic, based on the gust error, and mixes a main rotor cyclic command to the active elevator to reduce the aircraft pitch response.
    Type: Application
    Filed: February 12, 2016
    Publication date: April 26, 2018
    Inventors: Aaron L. Greenfield, Kenneth S. Wittmer
  • Publication number: 20180101180
    Abstract: A system and method of controlling flight of an aircraft is disclosed. The system includes a first inceptor that provides a direct mode command for controlling a control axis of the aircraft according to a direct mode and a second inceptor that provides a stable mode command for controlling the control axis of the aircraft according to a stable mode. A processor receives the direct mode command and the stable mode command, forms a combined command for controlling the control axis of the aircraft based on a combination of the direct mode command and the stable mode command, and controls the control axis of the aircraft according to the combined command.
    Type: Application
    Filed: September 29, 2017
    Publication date: April 12, 2018
    Inventors: Aaron L. Greenfield, Vineet Sahasrabudhe
  • Publication number: 20170334556
    Abstract: A method for controlling a differential rotor roll moment for a coaxial helicopter with rigid rotors, the method including receiving, with a processor, a signal indicative of a displacement command from a controller; receiving, with the processor via a sensor, one or more signals indicative of a longitudinal velocity, an angular velocity of one or more rotors and an air density ratio for the helicopter; determining, with the processor, a ganged collective mixing command in response to the receiving of the displacement command; determining, with the processor, a rotor advance ratio as a function of the longitudinal velocity and the angular velocity; and determining, with the processor, a corrective differential lateral cyclic command for the rigid rotors that controls the differential rotor roll moment to a desired value.
    Type: Application
    Filed: September 24, 2015
    Publication date: November 23, 2017
    Inventors: Cody Fegely, Erez Eller, Kenneth S. Wittmer, Aaron L. Greenfield, John Knag
  • Publication number: 20170329349
    Abstract: Two methods of combining multiple response types into a single flexible command model are provided and include receiving a pilot stick input, generating an aircraft response to the pilot stick input that is a continuous blend of response types by including calculable time-varying coefficients set as a function of a magnitude of the pilot stick input and other aircraft states such as airspeed, imposing at least an angular acceleration command limit and using other non-linear elements to optimize the aircraft response to the pilot stick input.
    Type: Application
    Filed: February 2, 2017
    Publication date: November 16, 2017
    Inventors: Aaron L. Greenfield, Kenneth S. Wittmer
  • Patent number: 9727059
    Abstract: One aspect is a flight control system for independent speed and attitude control of a rotary wing aircraft that includes a main rotor system and a translational thrust system. The flight control system includes a flight control computer configured to interface with the main rotor system and the translational thrust system. The flight control computer includes processing circuitry configured to execute control logic. A pitch attitude reference generator provides a pitch attitude reference to a main rotor controller to command the main rotor system based on pilot input. A longitudinal reference generator produces a longitudinal reference as a longitudinal position or longitudinal velocity based on pilot input. An attitude-to-propulsor crossfeed converts the pitch attitude reference into a propulsor trim adjustment. A propeller pitch controller combines the longitudinal reference and the propulsor trim adjustment into a propeller command, and provides the propeller command to the translational thrust system.
    Type: Grant
    Filed: June 17, 2015
    Date of Patent: August 8, 2017
    Assignee: SIKORSKY AIRCRAFT CORPORATION
    Inventors: Aaron L. Greenfield, John Knag, Stephen Kubik
  • Publication number: 20170210461
    Abstract: A method for controlling a propeller of an aircraft, comprises receiving, with a processor, one or more signals indicative of commanded collective pitch of the propeller; receiving, with the processor, one or more sensed signals indicative of propeller axial speed, propeller rotational speed, and air density; estimating, with the processor, a propeller torque and propeller thrust from one or more of the propeller axial speed, the propeller rotational speed, and the air density; determining, with the processor, information indicative of an error value between a desired torque and a measured torque in the propeller; determining, with the processor, information indicative of a corrected pitch command in response to the determining of the error value; combining, with the processor, the corrected pitch command with the propeller rotational speed into an adjustment solution; providing, with the processor, the propeller with the adjustment solution.
    Type: Application
    Filed: September 28, 2015
    Publication date: July 27, 2017
    Inventors: Sunny K. SIU, Cody FEGELY, Kenneth S. WITTMER, John KNAG, Aaron L. GREENFIELD
  • Publication number: 20170029093
    Abstract: One aspect is a flight control system for a rotary wing aircraft including a main rotor system and an elevator control system. A flight control computer of the flight control system includes processing circuitry configured to execute control logic. The control logic includes an inverse plant model that produces a main rotor feed forward command based on a pitch rate command, and a load alleviation control filter configured to reduce loads on a main rotor system and produce an elevator command for an elevator control system. A transformed elevator command filter produces a main rotor pitch adjustment command based on the elevator command, and a main rotor command generator generates an augmented main rotor feed forward command for the main rotor system based on the main rotor feed forward command and the main rotor pitch adjustment command.
    Type: Application
    Filed: April 2, 2014
    Publication date: February 2, 2017
    Applicant: Sikorsky Aircraft Corporation
    Inventors: Erez Eller, Aaron L. Greenfield, Ole Wulff, Matthew A. White, Matthew T. Luszcz
  • Patent number: 9429952
    Abstract: A method and system of controlling a rotorcraft for sea-based operations includes receiving sensed information indicative of an operation of the rotorcraft; receiving operator commands, ship models and system constraints; and determining a solution to an optimization function that avoids violating the system constraints, the solution being representative of control command signals for augmenting a flight response of the rotorcraft to a ship.
    Type: Grant
    Filed: April 4, 2014
    Date of Patent: August 30, 2016
    Assignee: SIKORSKY AIRCRAFT CORPORATION
    Inventors: Derek Geiger, James Rigsby, Aaron L. Greenfield, Vineet Sahasrabudhe, Jennifer D. Goss
  • Patent number: 9317042
    Abstract: Embodiments are directed to generating, by a processing device, a feedback command for an aircraft based on a reference input and an output response of the aircraft, and analyzing, by the processing device, the feedback command to allocate control to a plurality of control surfaces over a plurality of separate frequency bands.
    Type: Grant
    Filed: January 28, 2014
    Date of Patent: April 19, 2016
    Assignee: SIKORSKY AIRCRAFT CORPORATION
    Inventors: Aaron L. Greenfield, Ole Wulff, Matthew A. White
  • Publication number: 20150367937
    Abstract: One aspect is a flight control system for independent speed and attitude control of a rotary wing aircraft that includes a main rotor system and a translational thrust system. The flight control system includes a flight control computer configured to interface with the main rotor system and the translational thrust system. The flight control computer includes processing circuitry configured to execute control logic. A pitch attitude reference generator provides a pitch attitude reference to a main rotor controller to command the main rotor system based on pilot input. A longitudinal reference generator produces a longitudinal reference as a longitudinal position or longitudinal velocity based on pilot input. An attitude-to-propulsor crossfeed converts the pitch attitude reference into a propulsor trim adjustment. A propeller pitch controller combines the longitudinal reference and the propulsor trim adjustment into a propeller command, and provides the propeller command to the translational thrust system.
    Type: Application
    Filed: June 17, 2015
    Publication date: December 24, 2015
    Inventors: Aaron L. Greenfield, John Knag, Stephen Kubik
  • Publication number: 20150286220
    Abstract: A method and system of controlling a rotorcraft for sea-based operations includes receiving sensed information indicative of an operation of the rotorcraft; receiving operator commands, ship models and system constraints; and determining a solution to an optimization function that avoids violating the system constraints, the solution being representative of control command signals for augmenting a flight response of the rotorcraft to a ship.
    Type: Application
    Filed: April 4, 2014
    Publication date: October 8, 2015
    Applicant: Sikorsky Aircraft Corporation
    Inventors: Derek Geiger, James Rigsby, Aaron L. Greenfield, Vineet Sahasrabudhe, Jennifer D. Goss