56results about How to "Reduce oscillation amplitude" patented technology

A mass flowmeter and a method for operating a mass flowmeter is based on the Coriolis principle and incorporates a Coriolis measuring tube, an oscillator associated with and stimulating said Coriolis measuring tube, and a transducer associated with the Coriolis measuring tube and which collects Coriolis forces and / or oscillations based on Coriolis forces. The electric power consumed in the mass flowmeter is controlled as a function of the available electric power. This permits the efficient use of the available electric power, thus permitting the operation of the mass flowmeter via a two wire interface that serves for both the input of electric power and the output of measuring data.

The invention discloses an MEMS gyroscope robust self-adaptation control method based on neural network upper bound learning. The method includes the following steps that an ideal kinetic model and an MEMS gyroscope kinetic model are established, a sliding mode function is designed, a control law is obtained based on the sliding mode function, and an RBF neural network upper bound estimated value is used as a gain of a robust item on the basis of the control law together with a feedback item and the robust item; a parameter self-adaptation law and a network weight self-adaptation law are designed based on a Lyapunov method. According to the MEMS gyroscope robust self-adaptation control method based on neural network upper bound learning, the feedback item is added in the control law, the two-shaft vibration trajectory tracking speed and the parameter estimation speed of an MEMS gyroscope are greatly increased, and the vibration amplitude is decreased; the robust item based on RBF neural network upper bound learning is added in the control law, the buffeting problem caused by large external disturbance and fluctuation and the problem that the dynamic characteristics are changed worse are solved, the uncertainty of a structural formula and the uncertainty of a non-structured formula are eliminated, and therefore the robustness of the system is further improved.

An electrical hand held tool for producing at least a percussion movement of a working tool includes an electrical drive, a first, oscillating subassembly including a percussion mechanism (2) and a rotor (5) of the electrical drive for transmitting torque to the percussion mechanism and rotatable about a rotor axis (B) extending parallel to an oscillation path (I) of the first subassembly, and a second subassembly including a housing (6) in which the first subassembly is supported for a limited oscillating movement along a tool axis (A).

The invention discloses a micro gyroscope robust self-adaptive control method, and the method is applied to a controller comprising a micro gyroscope. The method includes the following steps of establishing an ideal dynamics model, establishing a dimensionless dynamics model of the micro gyroscope, designing a sliding mode function and making the derivative of the sliding mode function to time be zero to acquire a control law, adding a feedback item and a robust item to the control law, wherein the control law with feedback item and the robust item is used as a robust self-adaptive control law, controlling the micro gyroscope based on the Lyapunov function method, and designing an self-adaptive law. According to the micro gyroscope robust self-adaptive control method, the feedback item is added to the control law, so that micro gyroscope two axle vibration trajectory tracking and parameter estimation speed is greatly improved, and vibration amplitude is reduced; the robust item is added to the control law, so that external interference and parameter uncertainty are removed, and robustness and dynamic characteristics of a system are improved; the self-adaptive law is designed based on the Lyapunov function method, so that globally asymptotic stability of the whole system is guaranteed, and reliability of the system and robustness to parameter change are improved.

An electric toothbrush is provided with a brush portion, a motor including a rotary shaft, a battery, which supplies the motor with power supply voltage, and an eccentric shaft, which rotates together with the rotary shaft. The eccentric shaft has a center of gravity located at a position deviated from an axis of the rotary shaft of the motor. An oscillation transmission mechanism transmits oscillations generated by the rotation of the eccentric shaft. An oscillation amplitude regulation circuit regulates an oscillation amplitude of the brush portion to be constant regardless of changes in the power supply voltage in a state in which the brush portion is free from external loads.

The invention relates to a drive circuit for preventing the oscillation of grid drive signals. The drive circuit is characterized by comprising a buffer circuit, an amplitude limiting circuit and a rapid discharge circuit, wherein the buffer circuit receives and processes a drive signal PWM (Pulse Width Modulation) and then outputs the signal to the amplitude limiting circuit; the amplitude limiting circuit processes the received signal and then respectively outputs the signal to the grid of an MOS (Metal Oxide Semiconductor) transistor and the rapid discharge circuit; and the rapid discharge circuit also receives the drive signal PWM. The drive circuit has the advantages of lowering the voltage change rate of the MOS transistor, decreasing the open surge in the opening process, reducing the impact and damage to the MOS transistor, improving the EMC (Electro Magnetic Compatibility) property of the whole switch power supply, decreasing the turnoff loss, effectively avoiding the abnormal oscillation of drive signals, protecting normal working states of the MOS transistor and the circuit, and the like.

The invention discloses an instantaneous current control method of a three-phase active bridge type direct-current converter. Under the situation that the three-phase active bridge type direct-current converter is in a steady state, the duty ratio instructions D1,1 and D2,1 of two three-phase bridge circuits on the V1 side and the V2 side are independently or simultaneously are changed into D1,2 and D2,2, three-phase inductive current of a transformer can be balanced only by flowing across a transition interval of 1 / 3 or 2 / 3 of a switching period by adopting two method for adjusting the duty ratio in the transition interval, the amplitude and time of direct current oscillations, caused by three-phase inductive current unbalance, on two sides of the converter are greatly reduced, and accordingly the dynamic properties of the converter are improved.

The invention discloses a sixteen-position error modulation method of a dual-axis rotation inertial navigation system. The method comprises the following steps: determining a carrier coordinate system, determining a rotating axis, determining a rotating coordinate system, defining constant errors, calibration factor errors and installation errors of a gyroscope and an accelerometer, determining arotational angular velocity, a position stopping frequency and a rotational angular velocity, sequentially determining rotating axes, rotating directions, rotating angles and stopping times under 1-16rotating orders, determining an attitude error within one rotating period, determining a velocity error within one rotating period, and determining long-endurance latitude and longitude errors. Underthe condition that the system cost and complexity are not increased, by changing the rotating orders of sixteen positions, an attitude error and a velocity accumulation error within one rotating period of the system are effectively reduced, and simultaneously, the oscillation amplitudes of the caused latitude and longitude errors are obviously reduced, thereby further improving the navigation accuracy of the dual-axis rotation inertial navigation system.

The invention relates to an anti-grid driving signal oscillation circuit, which pertains to the electric power technology field and includes a driving chip, a small grid serial resistor, a high-end switching tube, a low-end switching tube, a grid source parallel resistor, a two-way voltage regulator diode, a fast recovery diode, a current-limiting resistor, a diode and a capacitor. The driving chip outputs signals which reach the grids of the high-end switching tube through the small grid serial resistor; the low-end switching tube and the grid source parallel resistor are connected in parallel with the two-way voltage regulator diode; the two ends of the grid source parallel resistor is connected in parallel with a serial branch which is formed by the fast recovery diode and the current-limiting resistor; the positive pole of the fast recovery diode is connected with the current-limiting resistor; a serial branch which is formed by a plurality of diodes and the capacitor is connected in parallel between the source electrode of the low-end switching tube and the grid source parallel resistor; and a reference ground is connected between the diode and the capacitor. The circuit can avoid the direct current of the bridge arm which is produced by the mistaking conduction of MOSFET due to the oscillation of grid driving signals and has the advantages of simple realization, low cost and safety and reliability.

A roundness and / or dimension measuring device for in-process measurement of crank pins during a machining operation on a grinding machine having a base body, and a measuring head, which is connected to the base body via a rod assembly and which is movable between a neutral position and a measuring position. The measuring head has a measuring probe for contacting the crank pin, and the rod assembly is designed and configured in such a way that the measuring head in the measuring position follows orbital rotations of the crank pin. At least one oscillation damping element is operatively associated with the measuring head for holding it in engagement with the crank pin during the orbital rotation.

The invention relates to a quasi-zero stiffness vibration isolation system with a bending moment resistance effect. The quasi-zero stiffness vibration isolation system comprises a base, a support cylinder, a vertical elastic element, a vertical damper and at least four groups of lateral support assemblies, and the vertical elastic element, the vertical damper and the lateral support assemblies arevertically arranged; each group of lateral support assembly comprises at least one horizontal damping device; each horizontal damping device comprises a horizontal damper and a lateral elastic element; each horizontal damper is arranged in the horizontal direct; one end of each lateral elastic element is connected with a cylinder body of the horizontal damper, and the other end of each lateral elastic element is connected with the output end of the horizontal damper; and one end of each horizontal damper is hinged with the base, and the other end of each horizontal damper is hinged with the support cylinder. According to the quasi-zero stiffness vibration isolation system with the bending moment resistance function, a multilayer layout mode with lateral support is adopted and the verticaldamper and the horizontal dampers with variable damping are arranged, so that the quasi-zero stiffness vibration isolation system with the bending moment resistance function, which is close to the vibration isolation in the full frequency band range and has the bending moment resistance and lateral impact load functions is realized, the load is large, and the low-frequency vibration isolation effect is good.

A fuel injection amount is controlled so that the air-fuel ratio of exhaust gas flowing into a catalyst (6) oscillates around a stoichiometric air-fuel ratio. When it is estimated that the level of oxygen storage capacity of the catalyst (6) is lower than a predetermined reference capacity, the amplitude of the air-fuel ratio of the exhaust gas which oscillates around the stoichiometric air-fuel ratio is reduced by controlling the fuel injection amount. The level of the oxygen storage capacity of the catalyst (6) is estimated based on the amplitude of the output signal from an oxygen sensor (14) disposed downstream of the catalyst (6).

The invention discloses a system for optimizing the property of a radio over fiber down transmission link, comprising a center station, a down fiber transmission link (3) and a base station, wherein the center station comprises a base band data signal (2) and a light carrying radio-frequency signal generation subsystem (1); the base station comprises a photoelectric detector (4) and an optical filter (5); and the center station carries out data transmission is conducted between the center station and the base station through the down fiber transmission link (3). The invention also discloses a method for optimizing the property of the radio over fiber down transmission link. The invention solves the problem of the property optimization of a system in a frequency modulate data modulating way under certain radio-frequency subcarrier frequency, reduces the power oscillation of the RoF (Radio Over Fiber) base station and the oscillation amplitude of the eye-opening penalty oscillation of a user receiving end, also prolongs the oscillation period and further improves the transmission property of the system and increases the capacity of the system.

The present disclosure relates to a technical field of display and in particular to a display device housing and a display device. The display device housing includes a front frame and a back plate which cooperate to form an accommodation portion for accommodating a display panel and a backlight module; and at least one elastic member mounted inside the front frame, wherein at least a portion of each of the elastic members is disposed between the front frame and a side face of the display panel to be mounted. The above display device housing can avoid the appearance of discrete bright spots in a display screen of the display device generated under long-time shock, and can also alleviate or eliminate light leakage in the display device.

The invention relates to a device for fastening at least one component of an exhaust system to at least one member of a motor vehicle, including a component leg that is designed for rigid fastening to the at least one component of the exhaust system and one member leg that is designed for rigid fastening to the at least one member of the motor vehicle. A coupling body with or made of an elastomer is provided, the coupling body being connected on the one hand fixedly to the component leg and on the other hand being fixedly connected to the member leg.

A water supply for an animal feeder includes a valve member on a nipple controlled by the animal connected to a water supply duct for supplying water to the valve member. A regulator is provided for controlling a flow rate and the nipple controls the flow rate by defining a housing through which the water passes with a resilient cylindrical body mounted in the housing. The resilient body defines a convoluted or serpentine water flow path therethrough or thereon for flow of water along the flow path through the housing with the flow path defining a rate of flow of the water. The housing has an adjustment member for adjusting application of pressure to the resilient body to change an amount of compression of the resilient body so as to distort the water flow path and change the rate of flow. The serpentine path is also of increased length to restrict the flow.

The invention discloses an E-STATCOM-based forced power oscillation suppression method and system, and further discloses an E-STATCOM-based forced power oscillation suppression system. The E-STATCOM-based forced power oscillation suppression system comprises a signal collection module, wherein an input end of the signal collection module is connected with a left power transmission line and a right power transmission line, which are connected with an E-STATCOM mounting bus, respectively; an output end of the signal collection module is connected with the input end of a control signal selection module; the output end of the control signal selection module is connected with the input end of an oscillation identification module, the input end of a reactive power control module and the input end of an active power control module respectively; the output end of the oscillation identification module is connected with the input end of the reactive power control module and the input end of the active power control module respectively; and the output end of the reactive power control module and the output end of the active power control module are connected with an E-STATCOM. Manual operation is not needed; and the E-STATCOM-based forced power oscillation suppression method and system have good suppression effects on forced power oscillation.

The invention relates to an inter-harmonic oscillation suppression method and device for a grid-connected converter. The method comprises the steps of collecting the direct-current voltage of a direct-current input end of the grid-connected converter, outputting the direct-current voltage of the grid-connected converter through a differential link, and amplifying the direct-current voltage outputted by the differential link through a proportional link; and feeding forward the differential proportional amplification value of the direct-current voltage to an instruction value of the direct-current voltage so as to suppress inter-harmonic-induced grid-connected converter oscillation. According to the invention, by setting the differential proportion feedforward mode, the converter oscillationinduced by the inter-harmonics can be well suppressed, so that the amplitude of the system oscillation is greatly reduced.

The embodiment of the invention discloses a hybrid rectifying zero-voltage switching full-bridge DC / DC converter, Its specific composition includes first to fourth switching transistors, first and second capacitors, first and second isolation transformers, first to fourth rectifying diodes, and also includes a DC power supply and a filter inductance. The first transformer adopts full-bridge rectification, the second transformer adopts full-wave rectification and connects two groups of rectifiers in series. The converter combines the advantages of the two rectifier structures, and has the characteristics of wide ZVS range, low voltage stress of rectifier diode, simple circuit structure and high conversion efficiency.

A water supply for an animal feeder includes a valve member on a nipple controlled by the animal connected to a water supply duct for supplying water to the valve member. A regulator is provided for controlling a flow rate and the nipple controls the flow rate by defining a housing through which the water passes with a resilient cylindrical body mounted in the housing. The resilient body defines a convoluted or serpentine water flow path therethrough or thereon for flow of water along the flow path through the housing with the flow path defining a rate of flow of the water. The housing has an adjustment member for adjusting application of pressure to the resilient body to change an amount of compression of the resilient body so as to distort the water flow path and change the rate of flow. The serpentine path is also of increased length to restrict the flow.

A downhole acoustic emitter including a support housing with a cavity and ports, in which housing are disposed a rod-type magnetostrictive transducer with an electrical coil on the rods, and an acoustic waveguide in the form of a cylinder which transitions into a tapering cone. The cylindrical portion of the acoustic waveguide is disposed inside the support housing, and the conical portion is disposed outside the housing. The upper end surface of the acoustic waveguide is coaxially joined to the lower emitting surface of the magnetostrictive transducer by soldering, and the acoustic waveguide is joined at its middle portion, which coincides with the zero vibration point of the waveguide, to the support housing by a threaded joint. The downhole acoustic emitter is provided with an emitting element, the upper end of which is coaxially joined to the lower end of the acoustic waveguide by a threaded joint. The magnetostrictive transducer has a length of 200-280 mm and is made of Permendur, and the ports are arranged around the perimeter of the support housing in two rows, the first of which is level with the top turns of the electrical coil of the magnetostrictive transducer, and the second row is level with the bottom turns of the coil. The emitting element is in the form of a cylinder or a prism with a square cross-section.

A speaker includes a frame, a magnetic circuit secured to the frame, a voice coil, a damper, and a diaphragm. The voice coil is inserted in a magnetic gap of the magnetic circuit. The damper is secured to the voice coil and the frame and formed with a plurality of corrugations. The diaphragm is secured to the frame and the voice coil. One of the plurality of corrugations located on an inner circumferential side of the damper is provided with a plurality of apertures, and these apertures are covered by an elastic member.

An oscillating sensor device, particularly for a proximity sensor, for sensing a dynamic change of attenuation caused by a measurable physical effect includes an oscillator including a resonance circuit and an amplifier fed back to the resonance circuit and configured to maintain oscillation of the oscillator, and a control unit configured to control the open loop gain of the oscillator. The amplifier comprises a non-linear gain characteristics defining an operating point at a preset amplitude of oscillation. The control unit is configured to control the open loop gain of the oscillator so that the operating point is set to a preset amplitude of the oscillation.

The invention discloses a virtual damping winding-based motor control method for a permanent magnet synchronous motor, and relates to the field of permanent magnet synchronous motors, the method is improved to obtain an equivalent voltage equation of the permanent magnet synchronous motor containing an action item of a virtual damping winding, and then the permanent magnet synchronous motor is controlled based on the equivalent voltage equation. Therefore, the effect of the physical damping bar can be simulated through a control method of the virtual damping winding, so that the oscillation suppression and disturbance rejection capabilities of the damping bar can be maintained on the premise of not influencing the torque density of the permanent magnet synchronous motor, and the effects of improving the damping characteristic of the motor, reducing the amplitude of oscillation and improving the response speed of the system are achieved.