Draper Laboratory Engineering Solutions to Problems of National Significance  

 
 
 
Patents

The following are abstracts of U.S. patents issued to Draper Laboratory in this year. Full texts of patents are available through the U.S. Patent Office. Contact information for Draper's Technology Licensing Office is available on the Technology Transfer page.

2003

Links to abstracts of patents published in:
2008 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 | 1999 | 1998 | 1997

Optical microcavity resonator sensor
Load relief system for a launch vehicle
Coated optical microcavity resonator chemical sensor
Capacitive ultrasound transducer
Deeply-integrated adaptive INS/GPS navigator with extended-range code tracking
Traveling wave generator
Drive feedthrough nulling system
Hybrid wafer gyroscope
Non-invasive pipe inspection system
Microcavity-based optical channel router
Flyer assembly
Miniature attitude sensing suite
Dynamically balanced microelectromechanical devices
Method of anodically bonding a multilayer device with a free mass
Balance prosthesis
Longitudinal field driven field asymmetric ion mobility filter and detection system
Optical microcavity resonator system
Transformable vehicle

Abstract

Optical microcavity resonator sensor
Patent # U.S. 6,668,111;Date Issued: December 23, 2003

An optical resonator accelerometer includes an optical microcavity and an optical waveguide that evanescently couples light incident on an input end of the waveguide core into the high-Q WGMs of the microcavity at a coupling efficiency of over 99%. The waveguide includes a waveguide core, and a multi-layer dielectric stack that has alternating high and low refractive index dielectric layers. The reflectivity of the dielectric stack is sufficient to isolate the waveguide core and the microcavity from the substrate. A flexure has a first end mounted to the substrate, and a second end arranged to interact with said optical microcavity. The flexure is responsive to an inertial input to cause a change in the coupling geometry between the microcavity and the optical waveguide.

 

Abstract

Load relief system for a launch vehicle
Patent # U.S. 6,666,410; Date Issued: December 23, 2003

A load relief system for a launch vehicle including a wind sensing system responsive to wind speed and direction at selected locations for providing an output of sensed wind speed and wind direction at the selected locations, a plant model responsive to the sensed wind speed and direction within a finite horizon, a current state of the launch vehicle, and control commands of the launch vehicle to predict the trajectory of the launch vehicle, an error circuit responsive to the predicted trajectory and a reference trajectory to produce a trajectory error, and an optimizer responsive to the trajectory error and configured to provide control commands to compensate for wind load over the finite horizon of the launch vehicle by reducing the total angle of attack.

 

Abstract

Coated optical microcavity resonator chemical sensor
Patent # U.S. 6,657,731 ; Date Issued: December 2, 2003

A miniaturized chemical sensor features an optical microcavity coated with a surface layer, and a waveguide that evanescently couples light into the microcavity. The surface layer is adapted to chemically interact with one or more molecule species in a chemical vapor surrounding the microcavity, so as to alter the evanescent light coupling between the optical microcavity and the waveguide. The chemical interaction causes a change in the index of refraction of the microcavity, resulting in a measurable phase difference readout. The refractive index sensitivity is substantially increased, because of the high Q-value of the optical microcavity.

 

Abstract

Capacitive ultrasound transducer
Patent # U.S. 6,639,339; Date Issued: October 28, 2003

A capacitive ultrasound transducer including a dielectric diaphragm with an electrode; a porous layer; and a spacer structure between the diaphragm and porous layer for defining a capacitive gap between them; the pores of the porous layer providing a compliant reservoir for the fluid in the gap.

 

Abstract

Deeply-integrated adaptive INS/GPS navigator with extended-range code tracking
Patent # U.S. 6,630,904; Date Issued: October 7, 2003

A system and method for generating a multidimensional navigation solution utilizes Global Positioning System (GPS) data to obtain highly reliable and accurate navigational solutions in high interference and dynamic environments, at a performance level which has been heretofore unattainable. Additional sensors such as inertial (gyros and accelerometers), altimeters, radars, etc. may be employed in a deeply integrated configuration. The approach taken in the present invention differs from that of previous techniques through its exploitation of nonlinear filtering methods; as a result, the navigation system architecture and processes employed yield significant improvements in navigation system performance, both in code tracking and reacquisition, and in carrier tracking and reacquisition. The improvements are particularly significant at low signal/noise ratios, where conventional approaches are especially susceptible to loss of code.

 

Abstract

Traveling wave generator
Patent # U.S. 6,619,146; Date Issued: September 16, 2003

A traveling wave generator includes at least a base link and end link and an intermediate link; a pivot device pivotably interconnecting each pair of links; a drive mechanism interconnecting each pair of links including a drive shaft and a cam on the first link of the pair and on the second link of the pair a follower for engaging the cam for inducing a traveling wave motion in the links; a flexible power transmission device interconnects the shafts of each of the base and intermediate links; and a motive source rotates the shafts.

 

Abstract

Drive feedthrough nulling system
Patent # U.S. 6,621,279; Date Issued: September 16, 2003

The present invention relates to a method for nulling drive feedthrough error in a sensor having first and second drive electrodes which impart vibratory motion to first and second proof masses in response to first and second opposite phase drive signals, and having first and second capacitances defined between the drive electrodes and their associated proof masses. A mismatch between the first and the second capacitance is measured. Drive feedthrough caused by the measured capacitance mismatch is nulled by adjusting the relative amplitudes of the first and second opposite phase drive signals, whereby the ratio of the amplitudes is proportional to the ratio of the first and second capacitances. A servo loop may adaptively effect the ratio of amplitudes.

 

Abstract

Hybrid wafer gyroscope
Patent # U.S. 6,615,681; Date Issued: September 9, 2003

A hybrid wafer gyroscope includes a combination of micro-machined components and traditional electromechanical components to form a miniature gyroscope having a high degree of stability. The gyroscope includes a rotor, gimbal, flexures, and stop cutouts micro-machined out of one or more layers of silicon, forming a unitary, planar, and disk-shaped rotor subassembly, which spins about a drive shaft.

 

Abstract

Non-invasive pipe inspection system
Patent # U.S. 6,597,997; Date Issued: July 22, 2003

The invention is directed to a system and method for non-invasive pipe inspection. According to one embodiment, the system includes a processor, an analyzer, and a wave launcher. The wave launcher is adapted to transmit an input wideband waveform having a selected input energy into the pipe along a longitudinal axis, and to receive from the pipe a reflected component of the input waveform having a reflected energy. The analyzer is adapted to generate the input waveform, and to receive the reflected component of the input waveform from the wave launcher. The processor is adapted to compare the input waveform with the reflected component of the input waveform to determine characteristics.

 

Abstract

Microcavity-based optical channel router
Patent # U.S. 6,594,425; Date Issued: July 15, 2003

An optical channel add/drop router includes at least one optical waveguide disposed on a substrate, and an optical microcavity resonator. Each waveguide includes a waveguide core, and a multi-layer dielectric stack with alternating high and low refractive index dielectric layers. Light propagates from one of the I/O ports or add/drop port of the waveguide, through one of the waveguide channels. Frequency components of the light that match a resonant mode of the microcavity are coupled into the microcavity, and out of the microcavity onto a different waveguide channel, so that desired channels are added to or dropped from the input signal. Optical power transfer efficiency of over 95% can been achieved at a transfer linewidth of about 1 MHz.

 

Abstract

Flyer assembly
Patent # U.S. 6,576,880; Date Issued: June 10, 2003

A flyer assembly is adapted for launching with, transit in, and deployment from an artillery shell having a central void region extending along a ballistic shell axis. The flyer assembly includes a jettisonable shroud and a flyer. The shroud extends along a shroud axis, and is positionable within the central void region with the shroud axis substantially parallel to the shell axis. The flyer is adapted to withstand a launch acceleration force along a flyer axis when in a first state, and to effect aerodynamic flight when in a second state. When in the first state, the flyer is positionable within the shroud with the flyer axis parallel to the shroud axis and the shell axis. The flyer includes a body member disposed about the flyer axis, and a foldable wing assembly mounted to the body member. The wing assembly is configurable in a folded state characterized by a plurality of nested wing segments when the flyer is in the first state. The wing assembly is configurable in an unfolded state characterized by a substantially uninterrupted aerodynamic surface when the flyer is in the second state. The flyer assembly is adapted to be launched from a ballistic delivery system such as an artillery cannon, and can thus reach a target quickly, without expending system energy stored within the flyer. During launch, the flyer is coupled to the shroud so as to maintain a portion of the flyer in tension during an acceleration of the flyer along the flyer axis resulting from the launch. The flyer assembly is adapted to withstand the high g-load and high temperature environments of a cannon launch, and can tolerate a set-back g load of about 16,000 g.

 

Abstract

Miniature attitude sensing suite
Patent # U.S. 6,577,929; Date Issued: June 10, 2003

The present invention provides methods of and apparatus for determining the inertial attitude of an aerospace vehicle. In one embodiment, the invention provides a rotational astronomical object-sighting concept to determine the inertial attitude of an axis of the aerospace vehicle without the star identification or dragback. In another embodiment, the invention provides an attitude measurement apparatus comprising a high sensitivity optical sensor and a low power inertial sensor.

 

Abstract

Dynamically balanced microelectromechanical devices
Patent # U.S. 6,571,630; Date Issued: June 3, 2003

Dynamic balancing reduces quadrature bias in microfabricated vibrating instruments such as tuning fork gyros so that a purity of motion is achieved in the absence of any angular rate input. Balancing is achieved by ablating (74) or depositing (72) onto support structure (62) for a tuning fork gyroscope rather than the proof mass (IL>60) itself by melting and moving material on a tuning fork beam (62). Such adjusting is advantageously done during actual operation of the gyro by laser beam application through an encapsulating transparent cover which can be either part of the chip die or an external package.

 

Abstract

Method of anodically bonding a multilayer device with a free mass
Patent # U.S. 6,548,321; Date Issued: April 15, 2003

A method of anodically bonding a multilayer device with a free mass includes positioning a support layer on either side of a free mass structure including a free mass with an electrode on each layer proximate the free mass; connecting both electrodes and the free mass to a node at a floating potential and applying a voltage across the layers and free mass structure to bond at least one of the layers to the free mass structure.

 

Abstract

Balance prosthesis
Patent # U.S. 6,546,291; Date Issued: April 4, 2003

A wearable balance prosthesis provides a information indicative of a wearer"s spatial orientation. The balance prosthesis includes an motion sensing system to be worn by the wearer and a signal processor in communication with the motion sensing system. The signal processor provides an orientation signal to an encoder. The encoder generates a feedback signal on the basis of the estimate of the spatial orientation provides that signal to a stimulator coupled to the wearer"s nervous system.

 

Abstract

Longitudinal field driven field asymmetric ion mobility filter and detection system
Patent # U.S. 6,512,224 ; Date Issued: January 28, 2003

An asymmetric field ion mobility spectrometer with an ionization source for ionizing a sample media and creating ions. An ion filter is disposed in the analytical gap downstream from the ionization source for creating an asymmetric electric field to filter the ions. An ion flow generator for creating an electric field in a direction transverse to the asymmetric electric field and which propels the ions through the asymmetric electric field towards a detector.

 

Abstract

Optical microcavity resonator system
Patent # U.S. 6,507,684; Date Issued: January 14, 2003

An optical resonator system includes a substrate, and a SPARROW optical waveguide disposed on the substrate for evanescently coupling light into an optical microcavity. The SPARROW waveguide includes a multi-layer dielectric stack formed of alternating high and low refractive index dielectric layers, and a waveguide core disposed on the dielectric stack. The waveguide core has an input end and an output end, and is adapted for transmitting optical radiation incident on the input end to the output end. The optical microcavity is disposed at a distance from the optical waveguide that is sufficiently small so as to allow evanescent coupling of light from the optical waveguide into the optical microcavity. The dielectric stack in the SPARROW waveguide isolates the waveguide core and the microcavity from the substrate, so that an optical coupling efficiency approaching 100 can be obtained.

 

Abstract

Transformable vehicle
Patent # U.S. 6,502,657; Date Issued: January 7, 2003

The transformable vehicle comprises a central chassis assembly having first and second distal ends with an axis passing therebetween, a first wheel assembly mounted to the first distal end, and a second wheel assembly mounted to second distal end. A multifunction transformable vehicle comprising at least two configurational states: a stowed state and a transformed state. In the stowed state, the transformable vehicle comprises a compact structure suitable for storage, transport or deployment. During transition from the stowed state to the transformed state, the first and second wheel assemblies move longitudinally outward along the axis to reveal the central chassis assembly.