Abstract: A plant control system includes a plant system and a control system controlling the plant system. Runtime conditions of an operating point of the plant control system are received. The runtime conditions include a runtime state of the plant system, a runtime output of the plant system, and a runtime control action applied to the plant system. Reference conditions of a reference point corresponding to the operating point are determined. Stability radius measures of a state difference, an output difference, and a control action difference are computed.

Abstract: The subject matter of this specification can be embodied in, among other things, a fluid actuator including a housing defining a first chamber having a first cavity and a first open end, a first piston assembly including a tubular first piston defining a second chamber having a second cavity and a second open end, disposed in said first housing for reciprocal movement in the first chamber through the first open end, wherein a first seal, the first cavity, and the first piston define a first pressure chamber, and a second piston assembly having an second piston disposed in said first piston assembly for reciprocal movement in the second chamber through the second open end, wherein a second seal, the second cavity, and the second piston define a second pressure chamber, and a first portion of the second piston contacts a first end effector.

Abstract: The subject matter of this specification can be embodied in, among other things, a fluid actuator including a housing defining a first chamber having a first cavity and a first open end, a first piston assembly including a tubular first piston defining a second chamber having a second cavity and a second open end, disposed in said first housing for reciprocal movement in the first chamber through the first open end, wherein a first seal, the first cavity, and the first piston define a first pressure chamber, and a second piston assembly having an second piston disposed in said first piston assembly for reciprocal movement in the second chamber through the second open end, wherein a second seal, the second cavity, and the second piston define a second pressure chamber, and a first portion of the second piston contacts a first end effector.

Abstract: The subject matter of this specification can be embodied in, among other things, a rotary actuator that includes a housing defining a first arcuate chamber portion and comprising a first cavity, a first open end, a first seal carrier assembly defining a second arcuate chamber portion and comprising a second cavity in fluid communication with the first cavity, a first piston seal, a second open end, and a third open end opposite the second open end, a first face seal in sealing contact with the housing proximal to the first open end and the second open end, a rotary output assembly, and an arcuate-shaped first piston disposed in said housing for reciprocal movement in the first arcuate chamber portion and in the second arcuate chamber portion.

Abstract: The subject matter of this specification can be embodied in, among other things, a method for characterizing a fluid injector that includes receiving a collection of waveform data, identifying a pull locus, determining a detection threshold level value, identifying a first subset of the collection of data representative of a selected first electrical waveform of the collection of electrical waveforms, identifying an opening value, identifying a representative closing value, identifying an anchor value, identifying a second subset of the collection of data based on the collection of data, the pull locus, the first subset, and the opening value, identifying a maximum electrical value, identifying an opening locus based the collection of data, the anchor value, and the maximum electrical value, identifying a hold value, and providing characteristics associated with the fluid injector comprising the pull locus, the opening locus, the hold value, the anchor value, and the representative closing value.

Abstract: The subject matter of this specification can be embodied in, among other things, an articulated joint includes a first rotary actuator having a first housing defining a first arcuate chamber comprising a first cavity, and an arcuate-shaped first piston having a first radius of curvature and disposed in said first housing for reciprocal movement in the first arcuate chamber, a second rotary actuator having a second housing defining a second arcuate chamber comprising a second cavity, and an arcuate-shaped second piston having a second radius of curvature and disposed in said second housing for reciprocal movement in the second arcuate chamber, wherein a first radial side of the first piston relative to the first radius of curvature is in bearing contact with a first radial side of the second piston relative to the second radius of curvature at a contact point between the first axis and the second axis.

Abstract: The subject matter of this specification can be embodied in, among other things, a multi-axis rotary actuator that includes a first rotary piston actuator configured to controllably actuate a first pivotal joint between a first linkage to a second linkage about a first axis, and a second rotary piston actuator configured to controllably actuate a second pivotal joint connecting the second linkage to a third linkage about a second axis.

Abstract: The subject matter of this specification can be embodied in, among other things, a fluid actuator including a housing defining a first chamber having a first cavity and a first open end, a first piston assembly including a tubular first piston defining a second chamber having a second cavity and a second open end, disposed in said first housing for reciprocal movement in the first chamber through the first open end, wherein a first seal, the first cavity, and the first piston define a first pressure chamber, and a second piston assembly having an second piston disposed in said first piston assembly for reciprocal movement in the second chamber through the second open end, wherein a second seal, the second cavity, and the second piston define a second pressure chamber, and a first portion of the second piston contacts a first end effector.

Abstract: A thermal energy storage system is proposed in which the latent heat of fusion of common salts is used to store energy within a selectable temperature range, extending both above and below the melting/freezing temperature zone of the salt mixture. The salt mixture occupies interstitial void spaces in a solid endostructure. The solid material remains in the solid state throughout the thermal cycling of the energy storage system, and preferably has properties of thermal conduction and specific heat that enhance the behavior of the salt mixture alone, while being chemically compatible with all materials in the storage system. The storage system is capable of accepting and delivering heat at high rates, thereby allowing power generation using a suitable energy transfer media to power a turbine of an electric generator or a process heat need to provide a relatively local, dispatchable, rechargeable thermal storage system, combined with a suitably sized generator.

Abstract: An apparatus for reducing pressure spikes in a fuel line having a shut-off valve is provided. The apparatus comprises a body housing a biasing member and a moveable separation member. The body has first, second, and third chambers. The first and second chambers are coupled to upstream and downstream sides of the fuel line, respectively. The third chamber is coupled to a return line. When the shut-off valve is open, the separation member is biased toward the first chamber and separates the first and second chambers. When the shut-off valve is closed, the separation member expands the first chamber and places the first chamber and the third chamber in fluid communication once the separation member has gained a significant speed. The expanded first chamber accumulates fuel and the third chamber accumulates and vents the fuel such that transient pressure spikes are reduced and unlikely to damage a turbine system.

Abstract: The invention provides a computer implemented method to automate the calibration of the drive voltage waveform of a solenoid operated valve. An initial estimate of valve electromagnetic parameters and valve closure point is derived and the drive voltage waveform is created based in part on circuit constraints and the parameters and valve closure point. The drive voltage waveform is applied to the valve coil and the coil current feedback is obtained and used to update the initial estimate. This process is repeated until the coil current feedback meets predetermined criteria. The electromagnetic parameters include the L/R ratio of the valve during the pull-in time and decay time, the valve back emf during the pull-hold time, and the average resistance during hold when current is steady. The closure point is used to anchor the drive voltage waveform and is adjusted at a slower rate than the other parameters.