Abstract: An underwater robotic system includes a frame for deployment in a body of water and having a control panel with multiple controls. A first actuator on the frame selectively actuates a control from a front side of the panel. A second actuator on the frame selectively actuates a control from a back side of the panel. One or more controls on the panel is configured to regulate distribution of a fluid. The frame is configured to couple to a blowout preventer. A method for robotic fluid distribution in an underwater environment.

Abstract: Described is a method of determining an initial rotor position on start-up of a synchronous motor. The method comprises applying at each of a plurality of pre-set motor angles a pair of voltage vector pulses, the pair of voltage vector pulses comprising a first and second pulses, each having the same amplitude but opposite polarities, the second pulse being applied immediately or near immediately after the first pulse. The method includes determining the stator current responses to said pairs of applied voltage vector pulses at said plurality of pre-set motor angles. Then, the initial rotor position can be determined from either of a stator angle corresponding to a pair of vector voltage pulses resulting in (a) a largest sum of stator currents or (b) where the sum of stator currents changes from a negative to a positive motor angle.

Abstract: Described is a method of determining an initial speed of a synchronous motor having a permanent magnet rotor. The method comprises controlling said motor to cause the rotor to rotate or observing that the rotor is rotating. The method includes sensing stator winding currents and transforming the sensed stator winding currents into a two-dimensional (2D) coordinate system using an alpha-beta (?-?) transformation. The rotor angle ? is determined from an arc tangent (Atan) of the ratio of the current in the ?-axis to the current in the ?-axis. The initial motor speed ? is determined from the determined rotor angle ?.

Abstract: A closed-loop method of starting a permanent magnet synchronous motor comprises driving the rotor by energizing stator windings using motor control signals based on an initial standstill rotor angle. Periodically estimating values of rotor flux linkage magnitude and/or angle based on back-electromotive force (emf) induced in the stator windings by the rotating rotor. The estimated values of rotor flux linkage magnitude are used to estimate respective new rotor angles which are used to generate updated motor control signals to drive the rotor. Control of the motor is switched-over to a closed-loop synchronous operation motor control algorithm in response to any one or any combination of the following conditions: at a predetermined period of time from initiation of the closed-loop start-up method; or upon determination that the rotor has reached a minimum operating speed; or upon determination that the estimated value of rotor flux linkage magnitude reaches or exceeds a threshold value.

Abstract: An active sitting chair is provided that encourages a sitter/user to sit actively by requiring balance adjustments and core engagement. The active sitting chair can be efficiently produced while being relatively sturdy and lightweight. The main body may be a monocoque shell that includes a rounded lower portion that contacts the surface the chair is on and promotes wobble of the chair when a sitter is seated on the chair. The chair may also include built-in handles for ease of lifting and a seat portion at the top of the chair that may include a cushion or similar component for increasing the stability and/or comfort of a sitter.

Abstract: A ski pole holder is provided. The ski pole holder is positioned toward a toe side of a ski footwear, to secure a portion of the ski pole within a channel of the ski pole holder. The ski pole holder includes a housing with the channel that extends towards the skier. When the skier is riding a ski lift, the ski pole is received within the housing to retain the ski pole. Fasteners within the channel secure the ski pole to the ski pole holder. The housing also includes a front sidewall and guides to help ensure that the tip of the ski pole is easily positioned within the channel. A lateral sidewall includes an open slot to provide for removal of snow that accumulates within the channel. The ski pole holder is attachable to the upper side of the ski footwear or is permanently integrated.

Abstract: A multi-phase permanent magnet rotor motor comprises a plurality of phase coil windings with each phase coil winding having two free ends and the plurality of phase coil windings being without a common node. A controller is provided comprising a plurality of full-bridge inverters. Each full-bridge inverter has two output ends electrically connected to the two free ends of a corresponding phase coil winding. The controller is configured to operate the plurality of full-bridge inverters to output pulse modulated control signals to their respective phase coil windings. The outputted pulse modulated control signals can comprise a combination of sine wave signals and full-bridge space vector modulation signals.

Abstract: A blowout preventer includes a main body having a through bore. A pressure chamber is located adjacent to and transverse to the through bore. A gate is disposed in the pressure chamber. An insert is disposed in the main body and defines an opening therethrough parallel to the through bore. The insert also defines a passage therethrough transverse to the through bore for passage of the gate.

Abstract: According to the present invention there is provided an electro-mechanical cross-steer device for a vehicle. The device may include a first and a second motor and first and second output planetary gear set, each having a transfer gear assembly mechanically connected to the first and second motors, respectively. Additionally, a differential may be included which is mechanically connected to the first and second output planetary gear sets via a mainshaft connected to the first and second output planetary gear sets. First and second input shafts may be mechanically connected to the first and second transfer gear assemblies and to the differential. First and second output shafts may be respectively connected to the first and second output planetary gear sets with each of the output shafts operable to drive a particular side of a vehicle.

Abstract: Systems and methods are provided for allowing users to safely and efficiently conduct repeatable dynamic experiments involving coordinated applications of force, motion, pressure, temperature, flow, dispersion and other physical events via a testing fixture positioned within an imaging environment.

Abstract: A ball turret includes a turret shell having a rear portion and a front portion. The rear portion and the front portion are assembled to form the turret shell. The shell includes a block assembly configured to mount to a mounting element of a weapon system, and a yoke carriage assembly configured to receive and mount to the block assembly. A number of guide rods within the turret shell are configured to mount the yoke carriage assembly thereto and to provide a recoil shock absorber in response to a discharge of the weapon system. The yoke carriage assembly is releasably mounted to the block assembly.

Abstract: A method for controlling pressure in a well includes pumping fluid into a riser extending between a drilling vessel and a wellhead, pumping fluid out of the riser to the drilling vessel by operating a first jet pump disposed in a conduit extending from the riser to the drilling vessel, wherein a rate of pumping power fluid into a power fluid inlet of the first jet pump is adjusted to maintain a liquid level in the drilling riser at a selected elevation.

Abstract: A system for managing power on distributed devices may include a first device having a master logic and a second device having a slave logic. The master logic may enable the first device to communicate with multiple devices having the slave logic on one or more channels. The slave logic may enable the second device having the slave logic to communicate with the first device and to communicate with a third device having the slave logic. The slave logic may enable the multiple devices having the slave logic to manage operations of the distributed devices.

Abstract: A blowout preventer includes a main body having a through bore and defining a passage transverse to the through bore. A seal is disposed in the main body and arranged to restrict fluid flow from the through bore to the passage. The seal comprises a seal body formed as a closed loop having an upper surface and a lower surface, wherein the seal body comprises an inner wall and an outer wall. The lower surface comprises at least one wing extending laterally from the outer surface to provide a lateral sealing surface. The upper surface comprises at least one raised portion to provide a sealing surface.

Abstract: The invention is a motor/generator that includes a motor/generator housing that encloses a rotor assembly, which rotates a shaft, and a stator assembly that remains stationary, and where the motor/generator is inside a vacuum chamber, which, during normal operation, is evacuated of gas and operates at a lower air pressure than atomospheric air pressure, and a cylindrical vacuum barrier between the rotor assembly and the stator assembly that together with the motor generator housing partitions the motor/generator into an interior rotor volume and an exterior stator volume, enabling the rotor volume and stator volume to operate at different atmospheric pressures.

Abstract: In general, one aspect disclosed features an active choke circuit, including a first three-winding choke; a second three-winding choke; and an amplifier; wherein a first winding of the first three-winding choke is electrically coupled in series with a first winding of the second three-winding choke; wherein a second winding of the first three-winding choke is electrically coupled in series with a second winding of the second three-winding choke; wherein a third winding of the first three-winding choke is electrically coupled to an input of the amplifier; and wherein a third winding of the second three-winding choke is electrically coupled to an output of the amplifier.

Abstract: Voltage regulator circuits and methods therefor provided. In some embodiments, a voltage regulator circuit comprises: a first switch coupled to a power input; a second switch coupled to the first switch; a switching node between the first switch and the second switch; an inductor coupled between the switching node and an output node; a capacitor coupled between the output node and ground; a driver configured to operate the first and second switches according to a pulse-width-modulated (PWM) signal; a PWM circuit configured to generate the PWM signal based on at least an error signal; and a phase detector configured to generate the error signal based on a phase difference between the PWM signal and a clock reference signal.

Abstract: Described is a method of controlling operation of a synchronous motor. The method comprises, during constant power/speed motor operation, determining a value of a stator voltage (vs2) for an orthogonal rotating reference frame of the motor. Comparing the value of the determined stator voltage (vs2) to a threshold voltage (vs2_max1), said threshold voltage (vs2_max1) having a value between that of a maximum stator voltage (vs2_max0) for a basic speed mode of operation of the motor and that of a maximum stator voltage (vs2_max2) of the motor closed loop controller. If the determined value of the stator voltage (vs2) is greater than or equal to the value of the threshold voltage (vs2_max1), then controlling operation of the motor in a flux weakening mode of operation until a value of a current component (id??id) in a d-axis reaches a maximum negative value (?idmax), or until the value of the stator voltage (vs2) is less than the value of the threshold voltage (vs2_max1).

Abstract: An underwater robotic system includes a frame adapted to be deployed in a body of water and having guide rails and at least one movable rail movably coupled to the guide rails. An actuator module is movably coupled to the at least one movable rail. A control panel disposed proximate the frame and has a plurality of controls thereon. The plurality of controls is operable by an actuator on the actuator module. A position of each of the plurality of controls is known such that motion of the actuator module and the at least one movable rail is remotely controllable to actuate any chosen one of the plurality of controls.