Recently Issued Patents

Metallic Wall Hall Thrusters

  • US Patent Number: 9,874,202

  • Date Issued: 1/23/2018

  • Inventors: Dan M. Goebel, Richard R. Hofer, Ioannis G. Mikellides

A Hall thruster is an electric engine used for rocket or spacecraft propulsion. They generate thrust through the formation of an electron current that interacts with an applied radial magnetic field to produce an electromagnetic force on a plasma. The plasma is a very hot, fast-moving noble element gas, typically Xenon or Krypton. From Newton’s third law, the ejected gas with low mass but high velocity yields a thrust acting in the opposite direction on the engine and spacecraft. The thrust is quite small compared to large chemical rocket motors, but the Hall thruster can operate for a comparatively long time.

Hall thruster technology provides an attractive combination of thrust and specific impulse for a variety of near-Earth missions and, in many cases, allows for significant reductions in propellant mass and overall system cost compared to conventional chemical propulsion. This innovation improves both the magnetic shielding and erosion resistance in the engine components.

Development of this technology has battled two major wear processes known to exist in Hall thrusters: erosion of the acceleration channel and erosion of the hollow cathode. The importance of understanding the erosion physics also motivated the development of a Hall thruster plasma solver named “Hall2De.” Using this software, several new Hall thruster designs have been developed and tested that show promise to mitigate or overcome the wear problem.

Metallic Wall Hall Thrusters

Surrogate: A Body-Dexterous Mobile Manipulation Robot With A Tracked Base

  • US Patent Number: 9,862,090

  • Date Issued: 01/09/2018

  • Inventors: Brett A. Kennedy, Paul Hebert, Jeremy C. Ma, James W. Borders, Charles F. Bergh, Nicolas H. Hudson

The term “robot” is typically used to describe an electro-mechanical machine that is guided by a computer program. Robots can be autonomous or semi-autonomous and range from humanoid to industrial robots. Mobile robots have the capability to move around in their environment and are increasingly being developed for mobility over inhospitable terrain.

Robots utilize manipulators both for mobility and manipulation, and have also been developed at JPL with the assistance of a variety of collaborators. For example, the ATHLETE robot incorporates six 6-degree of freedom (DOF) limbs with an additional one DOF wheel as an end-effector. The LEMUR robotics platform was used to build the Lemur I and Lemur IIa robots that both included six 4-DOF limbs and the Lemur IIb robot that included four 4-DOF limbs.

The Surrogate robot, nicknamed "Surge," is also a robot designed and built at JPL. It has an upright spine, two arms and a head. Surrogate stands about 4.5 feet tall (1.4 meters) and weighs about 200 pounds (90.7 kilograms). Its strength is in handling objects, and its flexible spine allows for extra manipulation capabilities. It has a tracked, motorized base.

Dexterous robots (with skilled “hands”) capable of whole-body motion have been developed. Also in development are robots that can act autonomously, which can perform behaviors with little or no human intervention; the robot makes decisions on how to perform tasks on its own.

Surrogate robot
Surrogate robot (image credit: NASA/JPL)

Systems And Methods For Automated Vessel Navigation Using Sea State Prediction

  • US Patent Number: 9,816,812

  • Date Issued: 11/14/2017

  • Inventors: Terrance L. Huntsberger, Andrew B. Howard, Hrand Aghazarian, Felix Reinhart, Arturo L. Rankin

Boats and ships in shallow or coastal waters can encounter significant waves. Faster or smaller ocean-going vessels are especially vulnerable to damage from severe sea conditions. The damage caused by kinetic wave energy can include crew injuries, capsizing, bow diving or damage to the vessel. Waves can at least slow a vessel down from reaching its target destination. Severe wave conditions can apply to any body of water, such as oceans, seas, lakes or rivers.

This invention performs wave and sea state prediction, and can also perform autonomous water navigation.

A method of predicting a future sea state has been developed using multiple 3D image sequences of a sea surface. Peaks and troughs in the images are detected, identified, and analyzed, focusing on propagating waves. As a final step, a future sea state is predicted.

After sea state prediction, this information can be used to derive an optimal navigation path to the destination.

Systems And Methods For Automated Vessel Navigation
An unmanned boat operates autonomously during a demonstration. (image credit: US Navy)

Method For Manufacturing Bulk Metallic Glass-Based Strain Wave Gear Components

  • US Patent Number: 9,791,032

  • Date Issued: 10/17/2017

  • Inventors: Douglas C. Hofmann, Brian H. Wilcox

Strain wave gears, also known as harmonic drives, are unique gearing systems that can provide high reduction ratios, high torque-to-weight and torque-to-volume ratios, near-zero backlash (which can mitigate the potential wearing of the components), and a host of other benefits. The operation of a strain wave gear relies on a very precisely engineered gearing system. The geometries of the constituent parts of strain wave gears must be fabricated with extreme accuracy in order to provide the desired operation.

Previously, strain wave gears have largely been fabricated from steel, as steel has been demonstrated to possess the requisite materials properties, and steel can be machined into the desired geometries. However, the machining of steel into the constituent components can be fairly expensive. Bulk metallic glass-based (BMG) strain wave gears and strain wave gear components are less expensive to manufacture, can be manufactured in several ways, and last longer.

Manufacturing Bulk Metallic Glass-Based Strain Wave Gear Components

Point-Wise Phase Matching for Nonlinear Frequency Generation in Dielectric Resonators

  • US Patent Number: 9,285,652

  • Date Issued: 3/15/2016

  • Inventors: Nan Yu, Dmitry Strekalov, Guoping Lin, Josef Furst

An optical resonator fabricated from a uniaxial birefringent crystal, such as beta barium borate. The crystal is cut with the optical axis not perpendicular to a face of the cut crystal. In some cases the optical axis lies in the plane of the cut crystal face. An incident (input) electromagnetic signal (which can range from the infrared through the visible to the ultraviolet) is applied to the resonator. An output signal is recovered which has a frequency that is an integer multiple of the frequency of the input signal. In some cases a prism is used to evanescently couple the input and the output signals to the resonator.

Point Wise Phase Matching Diagram

Method and Circuit for Injecting a Precise Amount of Charge Onto a Circuit Node

  • US Patent Number: 9,294,077

  • Date Issued: 3/22/2016

  • Inventors: Bruce Hancock

A method and circuit for injecting charge into a circuit node, comprising (a) resetting a capacitor's voltage through a first transistor; (b) after the resetting, pre-charging the capacitor through the first transistor; and (c) after the pre-charging, further charging the capacitor through a second transistor, wherein the second transistor is connected between the capacitor and a circuit node, and the further charging draws charge through the second transistor from the circuit node, thereby injecting charge into the circuit node.

A method and circuit for injecting charge into a circuit node

Electrolytes for Wide Operating Temperature Lithium-Ion Cells

  • US Patent Number: 9,293,773

  • Date Issued: 3/22/2016

  • Inventors: Marshall Smart and Ratnakumar Bugga

Provided herein are electrolytes for lithium-ion electrochemical cells, electrochemical cells employing the electrolytes, methods of making the electrochemical cells and methods of using the electrochemical cells over a wide temperature range. Included are electrolyte compositions comprising a lithium salt, a cyclic carbonate, a non-cyclic carbonate, and a linear ester and optionally comprising one or more additives.

Electrolytes for Lithium-ion Electrochemical cells


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