753results about How to "Oscillation suppression" patented technology

A surface-emitting laser diode device that oscillates in a direction perpendicular to the substrate is provided. This surface-emitting laser diode device includes: an active layer; a resonator structure including a first distributed Bragg reflector and a second distributed Bragg reflector that face each other and sandwich the active layer; a hole passage that extends from a first electrode to the active layer; an electron passage that extends from a second electrode to the active layer; a hole restricting structure that is located in the hole passage and defines a region for confining holes to the active layer; and an optical mode control structure that includes a non-oxide region provided in the resonator structure and an oxide region surrounding the non-oxide region, each region containing Al as a constituent element. In this surface-emitting laser diode, the area of the non-oxide region is smaller than the area of the hole restricting structure.

Provided are a classifying method and apparatus for an audio signal, and an encoding / decoding method and apparatus for an audio signal using the classifying method and apparatus. In the classification method, an audio signal is classified by adaptively adjusting a classification threshold for a frame of the audio signal that is to be classified according to a long-term feature of the audio signal, thereby improving a hit rate of signal classification, suppressing frequent mode switching per frame, improving noise tolerance, and providing smooth reconstruction of the audio signal.

A control device of a variable damping force damper for controlling a damping force of a damper used in a vehicle suspension system comprises: relative displacement detection means for detecting a value corresponding to a relative displacement between a vehicle body and a wheel in a vertical direction; relative speed detection means for detecting a value corresponding to a relative speed between the vehicle body and the wheel in the vertical direction; multiplying means for multiplying the value corresponding to the relative displacement and the value corresponding to the relative speed; and means for setting a damping force control target value of the damper based on the output from the multiplying means.

An optical waveguide propagates a laser beam. Main diffraction grating and sub-diffraction grating couple light propagating in the optical waveguide. The main diffraction grating and the sub-diffraction grating couple the light in such a manner that propagation in a second order transverse mode of the light propagating in the optical waveguide when both the main diffraction grating and the sub-diffraction grating are disposed, is suppressed more than propagation in the second order transverse mode of the light propagating in the optical waveguide when only the main diffraction grating is disposed.

A transistor being one of an IGBT and a MOSFET and arranged near a gate control circuit applies a gate control signal from the gate control circuit to the gate of a transistor arranged far from the gate control circuit. A gate control signal is applied via a resistive element to the transistor arranged near the gate control circuit.

In a gas turbine control apparatus, a frequency analyzing section frequency-analyzes at least one of pressure oscillation in combustors of a gas turbine and acceleration oscillation of each of the combustors and outputs a first frequency analysis result as the result of frequency analysis for a plurality of predetermined frequency bands. A control unit controls at least one of a first fuel flow rate of fuel and a first air flow rate of air based on the first frequency analysis result for the plurality of frequency bands. The fuel and the air are supplied to the gas turbine.

A method for fabricating a multiple MEMS device. A semiconductor substrate having a first and second MEMS device, and an encapsulation wafer with a first cavity and a second cavity, which includes at least one channel, can be provided. The first MEMS can be encapsulated within the first cavity and the second MEMS device can be encapsulated within the second cavity. These devices can be encapsulated within a provided first encapsulation environment at a first air pressure, encapsulating the first MEMS device within the first cavity at the first air pressure. The second MEMS device within the second cavity can then be subjected to a provided second encapsulating environment at a second air pressure via the channel of the second cavity.

A system and method for actively damping driveline oscillations in a motor vehicle having a traction motor to drive a vehicle's drive wheels and an antilock brake system (ABS). A traction motor controller controls a torque output signal of the motor to effectively to dampen driveline oscillations during an ABS operation. A proportional, a proportional derivative, or a derivative controller may be used to generate the torque output signal based on at least one of motor speed, an average of the drive wheel speeds, a difference in the two speeds, a motor angular acceleration, an average wheel angular acceleration, and a difference in the angular accelerations. Motor speed signals and average drive wheel speed signals may be filtered to eliminate high frequency components of each speed signal. Additionally, amplitude of the torque output signal may be limited within a positive upper and a negative lower active motor damping limit.

An object of the present invention is to provide a gas turbine control device which is capable of performing correction on the basis of a fuel composition of fuel gas to be supplied to a gas turbine, and is capable of changing an amount of correction in response to variation with time of the gas turbine. To attain this, a frequency analyzing unit 25 performs a frequency analysis of combustion oscillation of a combustor and splits a result of the analysis into respective frequency bands. Then, a state grasping unit 22 checks an operating state of the gas turbine on the basis of the result of the analysis of the combustion oscillation and process value of the gas turbine, and corrects the checked operating state on the basis of a fuel composition or a heat capacity of fuel gas measured by a fuel characteristic measuring unit 200. A countermeasure determining unit 23 conducts a countermeasure for controlling an operating action of the gas turbine on the basis of the operating state thus checked.

A surface-emitting laser diode device that oscillates in a direction perpendicular to the substrate is provided. This surface-emitting laser diode device includes: an active layer; a resonator structure including a first distributed Bragg reflector and a second distributed Bragg reflector that face each other and sandwich the active layer; a hole passage that extends from a first electrode to the active layer; an electron passage that extends from a second electrode to the active layer; a hole restricting structure that is located in the hole passage and defines a region for confining holes to the active layer; and an optical mode control structure that includes a non-oxide region provided in the resonator structure and an oxide region surrounding the non-oxide region, each region containing Al as a constituent element. In this surface-emitting laser diode, the area of the non-oxide region is smaller than the area of the hole restricting structure.

The invention relates to a method for stabilizing a car-trailer combination, including a towing vehicle and a trailer moved by the towing vehicle. The rolling motions of the towing vehicle are monitored to detect an actual or expected unstable driving performance of the towing vehicle or car-trailer combination. Measures are taken to stabilize the driving performance when an unstable driving performance is detected or expected. These measures may include decelerating the towing vehicle dependent upon the amplitudes of the rolling motions.

A system and method for actively damping driveline oscillations in a motor vehicle having a traction motor to drive a vehicle's drive wheels and an antilock brake system (ABS). A traction motor controller controls a torque output signal of the motor to effectively to dampen driveline oscillations during an ABS operation. A proportional, a proportional derivative, or a derivative controller may be used to generate the torque output signal based on at least one of motor speed, an average of the drive wheel speeds, a difference in the two speeds, a motor angular acceleration, an average wheel angular acceleration, and a difference in the angular accelerations. Motor speed signals and average drive wheel speed signals may be filtered to eliminate high frequency components of each speed signal. Additionally, amplitude of the torque output signal may be limited within a positive upper and a negative lower active motor damping limit.

The invention discloses a state estimating and interfusion method based on strap down inertial navigation system that includes the following steps: using the sensor in IMU to induce the kinetic characteristic; taking strap down inertial computing; using the state signal of acceleration estimating system; judging the reliability of state estimating value; taking state information interfusion; outputting navigation parameter. The invention has the following advantages: no additional hardware cost, fully autonomy; effectively improving the navigation accuracy of the system; and supplying 50 navigation signals per second to control display device.

Disclosed is a discharge device (20) which comprises a power supply unit (22) that supplies a first voltage, a piezoelectric transducer (24) that increases the first voltage to a second voltage by means of vibrations, and a first electrode (26) for producing a discharge product (P) by performing a discharge upon application of the second voltage. The first electrode (26) and the piezoelectric transducer (24) are electrically connected with each other via a vibration damping unit (30). In other words, the first electrode (26) and the piezoelectric transducer (24) are arranged to be out of contact with each other.

A wind turbine comprising a wind turbine rotor with at least one wind turbine blade, a wind turbine tower, such as a standard tubular steel tower, positioned on a foundation and connected to the wind turbine rotor through a wind turbine nacelle, and a control for establishing oscillation control values of the wind turbine. The wind turbine being capable of altering the load for optimizing the tower eigenfrequency in response to acquired values from the controls. The invention also relates to a control system and method for altering the eigenfrequency of a tower of a wind turbine.

The invention relates to a high-lift-to-drag-ratio hypersonic stable gliding reentry guidance method based on a drag profile. The method comprises the following steps that the first step, modeling ofa hypersonic flight vehicle is conducted; the second step, gliding distance analytic solution derivation is conducted; the third step, reentry track planning and tracking guidance are conducted; and the fourth step, a stable gliding trajectory tilt angle based on an earth rotation model is derived. The high-lift-to-drag-ratio hypersonic stable gliding reentry guidance method based on the drag profile has the advantages that a gliding distance analytic solution which is higher in accuracy and is based on energy is obtained, the form is simple, and application is convenient; the drag profile isplanned by using the energy as an independent variable, the drag profile is converted into the longitudinal lift-to-drag ratio under the rotating earth background, then a heeling angle is adjusted, tracking is conducted under the condition of the maximum lift-to-drag ratio, and transverse movement is controlled by a course error threshold; and in order to solve the reentry trajectory oscillation problem, the stable gliding trajectory tilt angle based on the earth rotation model is derived, and a trajectory damping technology using the stable gliding trajectory tilt angle as the feedback item is adopted to restrain oscillation.

A semiconductor device is disclosed in which proton implantation is performed a plurality of times to form a plurality of n-type buffer layers in an n-type drift layer at different depths from a rear surface of a substrate. The depth of the n-type buffer layer, which is provided at the deepest position from the rear surface of the substrate, from the rear surface of the substrate is more than 15 μm. The temperature of a heat treatment which is performed in order to change a proton into a donor and to recover a crystal defect after the proton implantation is equal to or higher than 400° C. In a carrier concentration distribution of the n-type buffer layer, a width from the peak position of carrier concentration to an anode is more than a width from the peak position to a cathode.

The invention relates to a generating set sub-synchronous oscillation suppression method adopting a full-controlled variable current device. The method uses the variable quantity of a rotating speed signal of a generating set as a control quantity, and performs filter, phase shift, proportional amplification and operation processing on the variable quantity of the rotating speed signal to acquire a control signal for controlling a variable current power unit by using a voltage synchronization signal as standard, then the full-controlled variable current device generates a sub-synchronous model modulation current, and the current affects the rotating speed of the generating set through a power transmission unit so as to achieve the aim of suppressing the sub-synchronous oscillation of the generating set. A controller comprises a plurality of signal processing subunits and a main control subunit, wherein each signal processing subunit comprises a filter module, a phase shift module, a proportional amplification module and an operation module; and the main control subunit accomplishes the control for the full-controlled device. The method can effectively suppress the sub-synchronous oscillation problem of a power grid system, has high response speed and high tracing precision, and can greatly improve the stability and reliability of a power grid.

A frequency tracking extended Kalman filter (35), responsive to combustor pressure (30), produces in-phase (36) and quadrature (37) components of the estimated magnitude of the undesirable combustor pressure variations, for which compensation is to be achieved; a bidirectional minimum-seeking algorithm (41) is used to select the phase (42) of a process adjusting input variable (28), such as fuel that is in addition to the main fuel flow used for power control purposes.

A semiconductor laser device comprises a laminate consisting of a semiconductor layer of first conductivity type, an active layer and a semiconductor layer of second conductivity type, which is different from the first conductivity type, that are stacked in order, with a waveguide region being formed to guide a light beam in a direction perpendicular to the direction of width by restricting the light from spreading in the direction of width in the active layer and in the proximity thereof, wherein the waveguide region has a first waveguide region and a second waveguide region, the first waveguide region is a region where light is confined within the limited active layer by means of a difference in the refractive index between the active layer and the regions on both sides of the active layer by limiting the width of the active layer, and the second waveguide region is a region where the light is confined therein by providing effective difference in refractive index in the active layer.

The invention discloses a full-firing-direction autonomous reentry guidance method based on a three-dimensional reentry trajectory analytical solution. The full-firing-direction autonomous reentry guidance method comprises the following steps of 1, building of a kinematical equation and a dynamical equation, 2, summarizing of the reentry guidance method, 3, descent stage guidance strategies, 4, steady gliding stage guidance strategies and 5 height-adjustment stage guidance strategies. The full-firing-direction autonomous reentry guidance method has the advantages that reentry guidance of an aircraft with the large lift-drag ratio can be guided effectively, low-damping and long-period trajectory oscillation caused by the high lift-drag ratio can be restrained effectively, the peak value ofthe heat flux density is reduced, and tracking of a reference track is facilitated; inertia force caused by earth rotation and actual aerodynamic force are combined into equivalent aerodynamic force,an equivalent aerodynamic section is planned through the analytical solution, and thus the aircraft has the omni-directional reentry task processing capability; and an equivalent aerodynamic section fitting formula based on the inverse proportional function is put forward, the reentry trajectory analytical solution based on the complex equivalent aerodynamic section form is further deduced, and thus high precision, all-dimensional applicability and high robustness are achieved.

Disclosed is a multilayer structured quartz glass crucible, for pulling up silicon single crystal, whose structure has at least three layers comprising: a translucent outer layer made of naturally occurring quartz glass and having a large number of pores, a translucent intermediate layer, made of synthetic quartz glass and having a large number of pores, and a transparent inner layer substantially free from pores and made of a synthetic quartz glass. Thermal convection within the silicon melt is suppressed by use of the quartz glass crucible, thereby preventing oscillation on the surface of the silicon melt. A method for producing the quartz glas crucible is also disclosed.

System, method, and computer program product for dampening oscillations of the electrical power on a power grid. The system includes a wind park with multiple wind turbines. Each wind turbine includes a rotor, a generator operatively coupled with the rotor for generating electrical power, and an inverter coupling the generator with the power grid to output the electrical power to the power grid. A controller is configured to generate a first control signal to cause the inverter of the first wind turbine to modulate the electrical power output by the first wind turbine for dampening oscillations of one frequency in electrical power on the power grid and to generate a second control signal to cause the inverter of the second wind turbine to modulate the electrical power output by the second wind turbine for dampening oscillations of a different frequency in the electrical power on the power grid.

VCSEL diode comprises a bottom electrode (10), conducting substrate material (11), a bottom mirror (12) formed by a multilayer distributed Bragg reflector (DBR) of certain conductivity and reflectivity RA, and an active region (13) comprising a plurality of layers some of which are quantum wells. It also comprises a top mirror (14) formed by a multilayer distributed Bragg reflector (DBR) with reflectivity RB<RA and conductivity of a second type. There are a number of layers (15, 18) which through a process of selective oxidation (exposure to a high temperature wet atmosphere) may be selectively converted to oxide layers, therefore producing well defined internal oxide apertures within the top mirror. There is a high-conductivity semiconductor top contact layer (17), a top electrode layer (19) with a centrally located aperture from which light is emitted, and a trench (16) which defines a mesa type VCSEL. The VCSEL comprises at least one oxide suppression layer in the top mirror whose function it is to suppress high order transverse optical modes.

A laser apparatus includes a semiconductor laser element, a surface-emitting semiconductor element including a first mirror, and a second mirror. The semiconductor laser element emits first laser light having a first wavelength. The surface-emitting semiconductor element is excited with the first laser light, and emits second laser light having a second wavelength which is longer than the first wavelength. The first mirror in the surface-emitting semiconductor element is arranged on one side of the first active layer. The second mirror is arranged outside the surface-emitting semiconductor element so that the first and second mirrors form a resonator in which the second laser light resonates. The surface-emitting semiconductor element includes a structure for controlling a spatial mode of the second laser light.

The invention is suitable for the solar energy field and provides a method and a device for tracking a maximum power point of a photovoltaic array. In an embodiment of the method and the device, the maximum power point tracking method with high dynamic steady-state performance is an electric conducting incremental method based on variable step and power forecast. The maximum power point tracking method can avoid defects of methods such as a conventional electric conducting incremental method and a variable step electric conducting incremental method, improves dynamic tracking speed and steady-state tracking accuracy, effectively restrains oscillation and erroneous judgment, and tracks the maximum power point in real time and accurately.

The improved archery bow arrow rest includes an elongated bracket having a front end portion and opposite rear end. The front portion is adapted to be secured to the sidewall of an archery bow riser on the side of the riser opposite that which defines the arrow window of the bow. The rear end of the bracket has one end of a transverse bar secured thereto, with the opposite free end of the bar extending behind the arrow window when the bracket is secured to an archery bow. The bar preferably is secured by a spring to the bracket to bias the bar against counterclockwise rotation. The rest also includes a spaced parallel pair of inflexible arrow holder arms, the rear ends of which are secured to the bar. The central portions of the holder arms extend upwardly and forwardly of the bar for positioning in the arrow window. The front portions of the holder arms are bent down to form prongs which are at an angle extending toward each other to form a V. The lower ends of the prongs are spaced apart at least about 0.125 inch to provide clear passage for an arrow vane therebetween. Each of the prongs is at an angle of about 25-30 degrees from the vertical so as to securely hold an arrow against roll-off from the rest. Preferably, the prongs are injection molded in friction-free plastic and the lower ends of the prongs preferably include removeable extensions. The lengths of the holder arms can differ to more readily accommodate arrows with helical fletching.

A vehicle includes an internal combustion engine that is variably connected, for example, via a mechanical clutch, to a drive train including a transmission. The vehicle also has a functional device operated by a torque generated by the internal combustion engine. A load applied by the functional device on the internal combustion engine when the drive train and the engine are engaged during deceleration of the vehicle and a speed of the internal combustion engine is lower than a predetermined value is controlled such that the load is reduced to a first value lower than a second value of the load applied to the engine when the speed of the internal combustion engine is equal to or higher than the predetermined value.