Eric Prechtl - Academia.edu (original) (raw)

Papers by Eric Prechtl

Proceedings of SPIE, Jun 6, 1997

ABSTRACT

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 200... more Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2000.Includes bibliographical references (p. 177-186).A novel new actuator for helicopter rotor control, the X-Frame Actuator, was developed, demonstrating superior performance for applications requiring compact, fast acting, large stroke actuation. The detailed experimental characterization of this actuator is described, including bench-top output energy measurements and transverse shake test performance. A Mach scaled rotor blade utilizing the X-Frame actuator to power a trailing edge servo-flap near the tip was also designed, manufactured and tested. A description of the design and composite manufacturing of the rotor blade and servo-flap is presented. Preliminary bench tests of the active blade actuation system are also presented. The hover tests of the active blade provided transfer function identification of the performance of the actuator in producing flap deflections, and the respon...

NASA Tech Briefs, March 2010 attenuator. To meet the compact size and maintain isolation between ... more NASA Tech Briefs, March 2010 attenuator. To meet the compact size and maintain isolation between the channels, a two-sided module approach was adapted. The transmit side of the module houses the four transmit channels, the control FPGA, and the power regulators and logic circuitry. It also contains the 4-way stripline power splitter. The 4dual channel receivers are packaged on the reverse side of the module along with the horizontal and vertical power combiners, and some logic and power conditioning circuits. The transmit and receive sides of the T/R module with the component identifications are shown in Figures 1 and 2. The broadband, 4-channel, highly stable self calibrating T/R module is a useful building block for other radar and communication phased-array systems operating in this band. This work was done by Constantine Andricos, Simon H. Yueh, Vladimir A. Krimskiy, of Caltech and Yahya Rahmat-Samii of UCLA for NASA’s Jet Propulsion Laboratory. For more information, contact iao...

Master of Science in Aeronautics and Astronautics An actuator using a piezoelectric bender to de ... more Master of Science in Aeronautics and Astronautics An actuator using a piezoelectric bender to de ect a trailing edge servo- ap for use on a helicopter rotor blade was designed, built, and tested. This actuator is an improvement over one developed previously at MIT. The design utilizes a new exure mechanism to connect the piezoelectric bender to the control surface. The eciency of the bender was improved by tapering its thickness properties with length. Also, implementation of a nonlinear circuit allowing the application of a greater range of actuator voltages increased the resultant strain levels. Experiments were carried out on the bench top to determine the frequency re-sponse of the actuator, as well as hinge moment and displacement capabilities. Flap de ections of 11.5 deg were demonstrated while operating under no load conditions at 10 Hz. Excessive creep at low frequencies precluded the measurement of achievable hinge moments, but extrapolation from de ection and voltage chara...

An actuator using a piezoelectric bender to de ect a trailing edge servoap for use on a helicopte... more An actuator using a piezoelectric bender to de ect a trailing edge servoap for use on a helicopter rotor blade was designed, built, and tested. This actuator is an improvement over one developed previously at MIT. The design utilizes a new exure mechanism to connect the piezoelectric bender to the control surface. The e ciency of the bender was improved by tapering its thickness properties with length. Also, implementation of a nonlinear circuit allowing the application of a greater range of actuator voltages increased the resultant strain levels. Experiments were carried out on the bench top to determine the frequency response of the actuator, as well as hinge moment and displacement capabilities. Flap de ections of 11.5 deg were demonstrated while operating under no load conditions at 10 Hz. Excessive creep at low frequencies precluded the measurement of achievable hinge moments, but extrapolation from de ection and voltage characteristics indicate that if properly scaled, the pre...

Active Materials and Smart Structures

Smart Materials and Structures, 1996

Page 1. Development of a piezoelectric servoflap for helicopter rotor control This article has be... more Page 1. Development of a piezoelectric servoflap for helicopter rotor control This article has been downloaded from IOPscience. Please scroll down to see the full text article. 1996 Smart Mater. Struct. 5 26 (http://iopscience.iop.org/0964-1726/5/1/004) ...

Spie Proceedings Series, 1998

An actuator using a piezoelectric bender to de ect a trailing edge servo-ap for use on a helicopt... more An actuator using a piezoelectric bender to de ect a trailing edge servo-ap for use on a helicopter rotor blade was designed, built, and tested. This actuator is an improvement o ver one developed previously at MIT. The design utilizes a new exure mechanism to connect the piezoelectric bender to the control surface. The e ciency of the bender was improved by tapering its thickness properties with length. Also, implementation of a nonlinear circuit allowing the application of a greater range of actuator voltages increased the resultant strain levels. Experiments were carried out on the bench top to determine the frequency response of the actuator, as well as hinge moment and displacement capabilities. Flap de ections of 11.5 deg were demonstrated while operating under no load conditions

Smart Structures and Materials 1998: Smart Structures and Integrated Systems, 1998

Smart Structures and Materials 1999: Smart Structures and Integrated Systems, 1999

Smart Structures and Materials 1998: Smart Structures and Integrated Systems, 1998

SAE Technical Paper Series, 2002

An actuator using a piezoelectric bender to de ect a trailing edge servo-ap for use on a helicopt... more An actuator using a piezoelectric bender to de ect a trailing edge servo-ap for use on a helicopter rotor blade was designed, built, and tested. This actuator is an improvement o ver one developed previously at MIT. The design utilizes a new exure mechanism to connect the piezoelectric bender to the control surface. The e ciency of the bender was improved by tapering its thickness properties with length. Also, implementation of a nonlinear circuit allowing the application of a greater range of actuator voltages increased the resultant strain levels. Experiments were carried out on the bench top to determine the frequency response of the actuator, as well as hinge moment and displacement capabilities. Flap de ections of 11.5 deg were demonstrated while operating under no load conditions

Page 1. CLOSED-LOOP VIBRATION CONTROL EXPERIMENTS ON A ROTOR WITH BLADE MOUNTED ACTUATION* Eric F... more Page 1. CLOSED-LOOP VIBRATION CONTROL EXPERIMENTS ON A ROTOR WITH BLADE MOUNTED ACTUATION* Eric F. Prechtly and Steven R. Hallz Department of Aeronautics and Astronautics Massachusetts Institute of Technology 77 Massachusetts Ave. ...

Future autonomous marine missions will depend on the seamless coordination of unmanned surface ve... more Future autonomous marine missions will depend on the seamless coordination of unmanned surface vehicles (USVs), unmanned underwater vehicles (UUVs) and unmanned aerial vehicles (UAVs). Applications will include autonomous refuelling, data transfer and periodic maintenance. A critical need is the capability to autonomously capture, retrieve and deploy a UUV from a USV platform. To aid in developing this new capability, we propose a performance specification to quantify the required compensation. The relative peak-to-peak vertical displacement (PVD) is a measure sea state induced vessel to vessel motion that must be regulated. Any successful autonomous capture and retrieval system will have to address this only the vertical motion for safe and secure capture, retrieval and deployment.

Proceedings of SPIE - The International Society for Optical Engineering

X-Frame-actuator servo-flap acuation system for rotor control. [Proceedings of SPIE 3329, 309 (19... more X-Frame-actuator servo-flap acuation system for rotor control. [Proceedings of SPIE 3329, 309 (1998)]. Eric F. Prechtl, Steven R. Hall. Abstract. A design is presented of a 1/6 Mach scaled CH-47D rotor blade incorporating a X-Frame ...

Proceedings of SPIE, Jun 6, 1997

ABSTRACT

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 200... more Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2000.Includes bibliographical references (p. 177-186).A novel new actuator for helicopter rotor control, the X-Frame Actuator, was developed, demonstrating superior performance for applications requiring compact, fast acting, large stroke actuation. The detailed experimental characterization of this actuator is described, including bench-top output energy measurements and transverse shake test performance. A Mach scaled rotor blade utilizing the X-Frame actuator to power a trailing edge servo-flap near the tip was also designed, manufactured and tested. A description of the design and composite manufacturing of the rotor blade and servo-flap is presented. Preliminary bench tests of the active blade actuation system are also presented. The hover tests of the active blade provided transfer function identification of the performance of the actuator in producing flap deflections, and the respon...

NASA Tech Briefs, March 2010 attenuator. To meet the compact size and maintain isolation between ... more NASA Tech Briefs, March 2010 attenuator. To meet the compact size and maintain isolation between the channels, a two-sided module approach was adapted. The transmit side of the module houses the four transmit channels, the control FPGA, and the power regulators and logic circuitry. It also contains the 4-way stripline power splitter. The 4dual channel receivers are packaged on the reverse side of the module along with the horizontal and vertical power combiners, and some logic and power conditioning circuits. The transmit and receive sides of the T/R module with the component identifications are shown in Figures 1 and 2. The broadband, 4-channel, highly stable self calibrating T/R module is a useful building block for other radar and communication phased-array systems operating in this band. This work was done by Constantine Andricos, Simon H. Yueh, Vladimir A. Krimskiy, of Caltech and Yahya Rahmat-Samii of UCLA for NASA’s Jet Propulsion Laboratory. For more information, contact iao...

Master of Science in Aeronautics and Astronautics An actuator using a piezoelectric bender to de ... more Master of Science in Aeronautics and Astronautics An actuator using a piezoelectric bender to de ect a trailing edge servo- ap for use on a helicopter rotor blade was designed, built, and tested. This actuator is an improvement over one developed previously at MIT. The design utilizes a new exure mechanism to connect the piezoelectric bender to the control surface. The eciency of the bender was improved by tapering its thickness properties with length. Also, implementation of a nonlinear circuit allowing the application of a greater range of actuator voltages increased the resultant strain levels. Experiments were carried out on the bench top to determine the frequency re-sponse of the actuator, as well as hinge moment and displacement capabilities. Flap de ections of 11.5 deg were demonstrated while operating under no load conditions at 10 Hz. Excessive creep at low frequencies precluded the measurement of achievable hinge moments, but extrapolation from de ection and voltage chara...

An actuator using a piezoelectric bender to de ect a trailing edge servoap for use on a helicopte... more An actuator using a piezoelectric bender to de ect a trailing edge servoap for use on a helicopter rotor blade was designed, built, and tested. This actuator is an improvement over one developed previously at MIT. The design utilizes a new exure mechanism to connect the piezoelectric bender to the control surface. The e ciency of the bender was improved by tapering its thickness properties with length. Also, implementation of a nonlinear circuit allowing the application of a greater range of actuator voltages increased the resultant strain levels. Experiments were carried out on the bench top to determine the frequency response of the actuator, as well as hinge moment and displacement capabilities. Flap de ections of 11.5 deg were demonstrated while operating under no load conditions at 10 Hz. Excessive creep at low frequencies precluded the measurement of achievable hinge moments, but extrapolation from de ection and voltage characteristics indicate that if properly scaled, the pre...

Active Materials and Smart Structures

Smart Materials and Structures, 1996

Page 1. Development of a piezoelectric servoflap for helicopter rotor control This article has be... more Page 1. Development of a piezoelectric servoflap for helicopter rotor control This article has been downloaded from IOPscience. Please scroll down to see the full text article. 1996 Smart Mater. Struct. 5 26 (http://iopscience.iop.org/0964-1726/5/1/004) ...

Spie Proceedings Series, 1998

An actuator using a piezoelectric bender to de ect a trailing edge servo-ap for use on a helicopt... more An actuator using a piezoelectric bender to de ect a trailing edge servo-ap for use on a helicopter rotor blade was designed, built, and tested. This actuator is an improvement o ver one developed previously at MIT. The design utilizes a new exure mechanism to connect the piezoelectric bender to the control surface. The e ciency of the bender was improved by tapering its thickness properties with length. Also, implementation of a nonlinear circuit allowing the application of a greater range of actuator voltages increased the resultant strain levels. Experiments were carried out on the bench top to determine the frequency response of the actuator, as well as hinge moment and displacement capabilities. Flap de ections of 11.5 deg were demonstrated while operating under no load conditions

Smart Structures and Materials 1998: Smart Structures and Integrated Systems, 1998

Smart Structures and Materials 1999: Smart Structures and Integrated Systems, 1999

Smart Structures and Materials 1998: Smart Structures and Integrated Systems, 1998

SAE Technical Paper Series, 2002

An actuator using a piezoelectric bender to de ect a trailing edge servo-ap for use on a helicopt... more An actuator using a piezoelectric bender to de ect a trailing edge servo-ap for use on a helicopter rotor blade was designed, built, and tested. This actuator is an improvement o ver one developed previously at MIT. The design utilizes a new exure mechanism to connect the piezoelectric bender to the control surface. The e ciency of the bender was improved by tapering its thickness properties with length. Also, implementation of a nonlinear circuit allowing the application of a greater range of actuator voltages increased the resultant strain levels. Experiments were carried out on the bench top to determine the frequency response of the actuator, as well as hinge moment and displacement capabilities. Flap de ections of 11.5 deg were demonstrated while operating under no load conditions

Page 1. CLOSED-LOOP VIBRATION CONTROL EXPERIMENTS ON A ROTOR WITH BLADE MOUNTED ACTUATION* Eric F... more Page 1. CLOSED-LOOP VIBRATION CONTROL EXPERIMENTS ON A ROTOR WITH BLADE MOUNTED ACTUATION* Eric F. Prechtly and Steven R. Hallz Department of Aeronautics and Astronautics Massachusetts Institute of Technology 77 Massachusetts Ave. ...

Future autonomous marine missions will depend on the seamless coordination of unmanned surface ve... more Future autonomous marine missions will depend on the seamless coordination of unmanned surface vehicles (USVs), unmanned underwater vehicles (UUVs) and unmanned aerial vehicles (UAVs). Applications will include autonomous refuelling, data transfer and periodic maintenance. A critical need is the capability to autonomously capture, retrieve and deploy a UUV from a USV platform. To aid in developing this new capability, we propose a performance specification to quantify the required compensation. The relative peak-to-peak vertical displacement (PVD) is a measure sea state induced vessel to vessel motion that must be regulated. Any successful autonomous capture and retrieval system will have to address this only the vertical motion for safe and secure capture, retrieval and deployment.

Proceedings of SPIE - The International Society for Optical Engineering

X-Frame-actuator servo-flap acuation system for rotor control. [Proceedings of SPIE 3329, 309 (19... more X-Frame-actuator servo-flap acuation system for rotor control. [Proceedings of SPIE 3329, 309 (1998)]. Eric F. Prechtl, Steven R. Hall. Abstract. A design is presented of a 1/6 Mach scaled CH-47D rotor blade incorporating a X-Frame ...