Patents by Inventor Chaohong Cai

Chaohong Cai 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: 20160208717
    Abstract: A control system for a gas turbine engine including a power turbine is disclosed. The control system may also include an outer loop control module to determine a torque request. The outer loop control module may include a feedback control component operative to provide regulation of the power turbine, a feed-forward component operative to anticipate a load on the power turbine, and a hybrid control component operative to prevent output of a torque request that cannot currently be delivered by the power turbine. The control system may also include an inner loop control module to receive the torque request from the outer loop control module, to determine fuel flow and inlet guide vane schedules based at least in part on the received torque request, and to send signals to control a gas generator of the gas turbine engine according to the determined fuel flow and inlet guide vane schedules.
    Type: Application
    Filed: January 19, 2015
    Publication date: July 21, 2016
    Inventor: Chaohong Cai
  • Publication number: 20160208639
    Abstract: A control system for a gas turbine engine including a power turbine is disclosed. The control system may include a control module to receive engine operating goals and an estimated current engine state, wherein the estimated current engine state is produced by a model-based estimation module using a bandwidth signal produced by an adaptation logic module. The control module is operative to determine fuel flow, inlet guide vane schedules and stability bleed schedules based at least in part on the received engine operating goals and the estimated current engine state, and to send signals to a gas generator of the gas turbine engine in order to control the gas generator according to the determined fuel flow, inlet guide vane schedules and stability bleed schedules.
    Type: Application
    Filed: January 19, 2015
    Publication date: July 21, 2016
    Inventor: Chaohong Cai
  • Publication number: 20160138523
    Abstract: A control system for a gas turbine engine, a method for controlling a gas turbine engine, and a gas turbine engine are disclosed. The control system may include a nozzle scheduler for determining an exhaust nozzle position goal based on a nozzle schedule of exhaust nozzle positions related to flight conditions. The control system may further include a control module for determining a control command for the gas turbine engine. The control command may include, at least, a fuel flow command and an exhaust nozzle position command and the control command may be based on, at least, the exhaust nozzle position goal and an estimated thrust value. The control system may further include an actuator for controlling the gas turbine engine based on the control command.
    Type: Application
    Filed: October 23, 2015
    Publication date: May 19, 2016
    Inventors: Chaohong Cai, Timothy J. Crowley, Mark E. Lacour, David L. Ma
  • Publication number: 20160069277
    Abstract: A system and methods are provided for controlling turboshaft engines. In one embodiment, a method includes receiving input signals for a collective lever angle (CLA) command and real-time power turbine speed (NP) of an engine, determining system data for engine effectors by the control unit based on the input signals for the collective lever angle (CLA) command and the real-time power turbine speed (NP) based on an integrated model for the turboshaft engine including a model of a gas generator section of the turboshaft engine and a model of a power turbine and rotor load section of the turboshaft engine. The method may also include determining control output based on model-based multi-variable control including optimization formulation and a constrained optimization solver. The method may also include outputting one or more control signals for control of the turboshaft engine.
    Type: Application
    Filed: February 19, 2015
    Publication date: March 10, 2016
    Inventors: Richard P. MEISNER, Chaohong Cai, James W. Fuller, Timothy J. Crowley
  • Patent number: 9250002
    Abstract: A system for controlling an absorption chiller includes feedback control loops determining adjustments to system cooling and heating capacities and a controller for simultaneously adjusting positions of an energy input valve, a hot water valve, and a chilled water valve. The controller adjusts valves based on desired adjustments to system cooling and heating capacities and performance maps characterizing relationships between cooling capacity and heating capacities and valve positions. A method for controlling an absorption chiller includes the step of obtaining a performance map characterizing heat energy input to cooling and heating loops as functions of valve positions. To obtain the map, the hot water valve is held in a substantially constant position while the chilled water valve is modulated. Similarly, the hot water valve is modulated while the chilled water valve is held in a substantially constant position.
    Type: Grant
    Filed: February 27, 2012
    Date of Patent: February 2, 2016
    Assignee: CARRIER CORPORATION
    Inventors: Jiachuan Wang, Chaohong Cai, Ahmad M. Mahmoud, Junqiang Fan, Richard L. Martin, John F. Boardman, Timothy C. Wagner
  • Patent number: 9206745
    Abstract: A control system for a gas turbine engine, a method for controlling a gas turbine engine, and a gas turbine engine are disclosed. The control system may include a hybrid model predictive control (HMPC) module, the HMPC module receiving power goals and operability limits and determining a multi-variable control command for the gas turbine engine, the multi-variable control command determined using the power goals, the operability limits, actuator goals, sensor signals, and synthesis signals. The control system may further include system sensors for determining the sensor signals and a non-linear engine model for estimating corrected speed signals and synthesis signals using the sensor signals, the synthesis signals including an estimated stall margin remaining. The control system may further include a goal generation module for determining actuator goals for the HMPC module using the corrected speed signals and an actuator for controlling the gas turbine engine based on the multivariable control command.
    Type: Grant
    Filed: February 16, 2015
    Date of Patent: December 8, 2015
    Assignee: United Technologies Corporation
    Inventors: Chaohong Cai, Joshua Adams, Richard P. Meisner
  • Publication number: 20150345403
    Abstract: A control system for a gas turbine engine, a method for controlling a gas turbine engine, and a gas turbine engine are disclosed. The control system may include a hybrid model predictive control (HMPC) module, the HMPC module receiving power goals and operability limits and determining a multi-variable control command for the gas turbine engine, the multi-variable control command determined using the power goals, the operability limits, actuator goals, sensor signals, and synthesis signals. The control system may further include system sensors for determining the sensor signals and a non-linear engine model for estimating corrected speed signals and synthesis signals using the sensor signals, the synthesis signals including an estimated stall margin remaining. The control system may further include a goal generation module for determining actuator goals for the HMPC module using the corrected speed signals and an actuator for controlling the gas turbine engine based on the multivariable control command.
    Type: Application
    Filed: February 16, 2015
    Publication date: December 3, 2015
    Inventors: Chaohong Cai, Joshua Adams, Richard P. Meisner
  • Publication number: 20150113996
    Abstract: A control system for a gas turbine engine is disclosed. The control system may include a computer processor. The control system may also include an outer loop control module programmed into the computer processor to determine a torque request based at least in part on a real-time collective lever angle command. The control system may also include an inner loop control module programmed into the computer processor to receive the torque request from the outer loop control module, to determine fuel flow and inlet guide vane schedules based at least in part on the received torque request, and to send signals to a gas generator of the gas turbine engine in order to control the gas generator according to the determined fuel flow and inlet guide vane schedules.
    Type: Application
    Filed: May 20, 2014
    Publication date: April 30, 2015
    Applicant: United Technologies Corporation
    Inventors: Chaohong Cai, Timothy J. Crowley, Richard P. Meisner
  • Publication number: 20120216552
    Abstract: A system for controlling an absorption chiller includes feedback control loops determining adjustments to system cooling and heating capacities and a controller for simultaneously adjusting positions of an energy input valve, a hot water valve, and a chilled water valve. The controller adjusts valves based on desired adjustments to system cooling and heating capacities and performance maps characterizing relationships between cooling capacity and heating capacities and valve positions. A method for controlling an absorption chiller includes the step of obtaining a performance map characterizing heat energy input to cooling and heating loops as functions of valve positions. To obtain the map, the hot water valve is held in a substantially constant position while the chilled water valve is modulated. Similarly, the hot water valve is modulated while the chilled water valve is held in a substantially constant position.
    Type: Application
    Filed: February 27, 2012
    Publication date: August 30, 2012
    Applicant: CARRIER CORPORATION
    Inventors: Jiachuan Wang, Chaohong Cai, Ahmad M. Mahmoud, Junqiang Fan, Richard L. Martin, John F. Boardman, Timothy C. Wagner