41results about How to "Does not affect dynamic performance" patented technology

The invention discloses a data fusion method for a flush air data system and an inertial navigation system. The method comprises the steps that 1, navigation information outputted by the inertial navigation system is collected; 2, the air temperature, the static pressure, the density and the sound velocity are calculated on the basis of a selected air model according to the navigation information; 3, the true airspeed, the mach number, the dynamic pressure, the attack angle and the sideslip angle are calculated according to the navigation information, the air temperature, the static pressure, the density and the sound velocity; 4, a resolving initial value is selected according to an air data resolving result of the inertial navigation system at the current moment and an air data fusion processing result at the last moment; 5, the mach number, the attack angle, the sideslip angle, the static pressure and the dynamic pressure are resolved according to the resolving initial value and a surface pressure value at a pressure tap of a flight vehicle; 6, the air data resolving data of the inertial navigation system and a resolving result of the flush air data system are fused. According to the data fusion method for the flush air data system and the inertial navigation system, the common problems existing in the flush air data system can be solved, and the air data measuring performance can be improved.

The invention relates to a permanent magnet zero-position retaining mechanism of a two-dimensional digital servo valve. The mechanism comprises an upper balance wheel, an oscillating axle and a lower balance wheel, wherein the upper balance wheel is connected with a motor shaft; the lower balance wheel is connected with a valve plug; the middle part of the upper balance wheel is provided with a mounting hole for the motor shaft to penetrate; the lower end of the upper balance wheel is provided with a groove opening; the groove opening is provided with a oscillating axle internally; one end ofthe oscillating axle extends into a limiting hole of a motor mounting plate; the upper part of the lower balance wheel can be rotatably sleeved on the oscillating axle; the lower part of the lower balance wheel is provided with a mounting hole for a valve plug to penetrate; a left retainer and a right retainer are installed on the motor mounting plate, and are positioned at the left side and the right side of the lower end of the lower balance wheel; a groove of the left retainer is provided with a first permanent magnet internally; a groove of the right retainer is provided with a second permanent magnet; grooves at the left side and the right side of the lower balance wheel are respectively provided with a third permanent magnet and a fourth permanent magnet internally; the first permanent magnet and the second permanent magnet are arranged oppositely; and the second permanent magnet and the fourth permanent magnet are arranged oppositely. The mechanism provided by the invention hasthe advantages of good safety and is reliable in working.

The invention relates to a zero maintaining mechanism of a2D digital servo valve, which comprises an upper balance wheel connected with a motor shaft, a lower balance wheel connected with a valve plug, a swing shaft and a zero maintaining spring, wherein the middle of the upper balance wheel is provided with a mounting hole for the motor shaft to pass through, the upper end of the upper balance wheel is provided with a through groove in a cutting way, two half parts of the upper end of the upper balance wheel are fixedly connected, the lower end of the upper balance wheel is provided with a notch which is internally provided with the swing shaft, one end of the swing shaft extends into a limit hole of a motor mounting plate, the upper part of the lower balance wheel can be rotatably sleeved on the swing shaft, the lower part of the lower balance wheel is provided with a mounting hole for the valve plug to pass through, the lower end of the lower balance is provided with a through groove in a cutting way, two half parts of the lower end of the lower balance wheel are fixedly connected, the upper end of the zero maintaining spring is fixedly connected with the lower part of the lower balance wheel, and the lower end of the zero maintaining spring is fixedly connected with the motor mounting plate. The invention can effectively ensure zero stability when a digital electro-hydraulic servo system is initialized, and prevent false operation of an executing mechanism, caused by zero offset, from causing potential safety hazards of the masses and equipment.

The invention provides a novel FCS-MPC low switching frequency control method, and relates to the field of the control of electric power and electronic converters. The method includes following steps: sampling a practical value and applying an optimal switch combination selected at the previous period; controlling time-delay compensation; realizing current prediction in two future control periods based on a prediction time domain extending principle; evaluating the selected effective switch combination according to a system value function, and selecting the optimal switch combination for the effect in the next control period; and repeating the above process in the next control period. According to the method, unnecessary switching of switches between adjacent control periods is effectively avoided, the switching frequency of the system is reduced, the method is not limited by an electric power and electronic converter topology structure and a prediction model and is irrelevant to the problem of setting of a weight factor, the algorithm concept is clear, the realization is easy, the operation burden of the control system is not increased, and the dynamic performance of the control system is not affected.

The invention relates to an automatic gearbox oil cooling heat dissipation electromagnetic valve and a heat dissipation method, and belongs to the field of automatic gearbox electromagnetic valves. The problems are solved that in the prior art, an ordinary electromagnet dissipates heat mainly in dependence on air, the heat dissipation efficiency is low, a coil is easily damaged, a valve element iseasily clamped tightly, and the service life is shortened. According to the automatic gearbox oil cooling heat dissipation electromagnetic valve, two connection holes are formed in the portion between an electromagnet internal space of the electromagnetic valve and an oil discharging port of a valve body so that the electromagnet internal space of the electromagnetic valve can be communicated with the oil discharging port of the valve body. By the adoption of the automatic gearbox oil cooling heat dissipation electromagnetic valve and the heat dissipation method, little working oil fluid flows in the electromagnet, heat in the electromagnet is taken away, and meanwhile the cooling and lubricating functions are achieved. The overheat phenomenon of the electromagnet valve coil and the clamping phenomenon of armature iron are avoided, and the service life of the electromagnetic valve is prolonged.

The invention discloses an ethylene propylene diene rubber for absorbing the shock of an automobile engine. The ethylene propylene diene rubber for absorbing the shock of the automobile engine is composed of, by weight, 44-50% of ethylene propylene diene rubber, 35-41% of carbon black, 5-10% of a softening and plasticizing agent, 2.5-3% of an active agent and 2.2-2.5% of a vulcanizing agent. The ethylene propylene diene rubber for absorbing the shock of the automobile engine in the invention has the characteristics of high strength, resistance to high temperature aging and low deformation in high temperature compression in a use environment, and is long in service life.

The invention discloses a modulation method for a cascaded PWM (pulse-width modulation) rectifier. The modulation method for the cascaded PWM rectifier comprises the following steps of: extracting the modulation signal of each H bridge unit in real time; calculating to obtain the carrier wave phase updating value of a cascading unit; updating the carrier wave phase; and taking the updated value as the practical carrier wave signal of the unit. Because each unit load of the cascaded PWM rectifier can not be completely consistent, each H bridge modulation model can not be completely consistent according to the power equivalence principle, and therefore, the corresponding switching subharmonic can not be offset when a traditional carrier wave phase-shifting algorithm is adopted. On the basis of the novel modulation algorithm adopted by the modulation method disclosed by the invention, influence on net side current due to inconsistent modulation signals can be effectively lowered, and primary harmonic and the WTHD (weighted total harmonic distortion) value of the net side current are lowered.

The invention discloses a method for determining a q-axis current compensation value of a permanent magnet synchronous motor and a pulsation suppression method. The method comprises the following steps: synchronously acquiring a q-axis current feedback signal iq and a rotor position signal theta m, determining a position interval of a rotor based on the theta m, accumulating the interval times by1 and performing synchronous averaging on the iq, and repeatedly acquiring until the accumulated value of the interval times is greater than a threshold value and all the intervals are not overlappedto form a circle of the rotor; performing fast Fourier transform on the synchronous average value corresponding to each interval arranged in sequence to obtain frequency domain characteristic information, determining the amplitude and the phase angle of a to-be-compensated spatial frequency component from the frequency characteristic information, and constructing a q-axis current compensation function; and obtaining a q-axis current compensation value based on the position of the actual compensation moment of the motor rotor and the current compensation function. Time domain information is converted into a space domain, time lag is avoided, the whole process does not affect the dynamic performance of the system, extra devices are not needed, structures and parameters of all control links do not need to be adjusted, and operation is easy.

The invention discloses a measuring method for a left-right skew swing state of a rolling bearing roller. The method adopts a mode that two ultrasonic sensors are installed in parallel in the length direction of the roller; reflected signals of the two ultrasonic sensors on a contact interface between the inner surface of an outer ring of a rolling bearing and the roller are synchronously collected; the reflectivity of ultrasonic signals of the ultrasonic sensors is calculated; time difference information corresponding to the minimum value of the reflectivity measured by the parallel ultrasonic sensors is extracted; the revolution speed of the roller is used for converting the time difference information into a left-right skew swing displacement value; the left-right skew swing state of the roller under a real working condition is judged; a running state of the roller and a state of contact between a roller path and the roller in an actual operation process are judged; and a working state of the bearing at the moment can be judged. Major accidents caused by left-right skew swing of the bearing roller can be effectively reduced, so that personnel and property loss can be reduced.

The invention discloses an ultrasonic detection method for judging the lubricating state of a rolling bearing under actual working conditions. According to the method, a high-frequency focusing probe(or a micro high-frequency normal probe) is arranged on the outer ring of the bearing to obtain ultrasonic reflection echoes of the contact surface of a roller and a ferrule, and the lubrication stateof the bearing is judged according to comprehensive extraction and judgment of the amplitude and phase information of the reflection waves. The detection of the lubricating state of the rolling bearing under the actual working condition is the most direct method for judging the running state of the bearing and is a very key basic detection means in the field of bearing contact lubrication research. Therefore, the lubricating state of the rolling bearing under the real working condition can be detected, and then the lubricating state (dry friction, mixed lubrication or elastohydrodynamic full-film lubrication) between the bearing roller and the ferrule is judged.

The invention relates to an N-phase power converter, an inductor element, and an inductor cut-off control method, wherein the converter has input-parallel and output-parallel N phase. The converter includes: N switch units, wherein each phase of the N-phase power converter includes one of the N switch units; and an integrated inductor unit including M inductor subunits, M being a natural number greater than or equal to 2, each inductor subunit including i inductors, i being a natural number greater than or equal to 2, and N>M*i or N=M*i. The M*i inductors in the integrated inductor unit are respectively coupled to the M*i switch units in the N switch units, wherein the i inductors of each of the inductor subunits are inversely coupled to each other, and a coupling coefficient of the M inductor subunits is smaller than the coupling coefficient of the i inductors in each inductor subunit.

The invention belongs to the technical field of motors and specifically discloses an apparatus and method for detecting a rotor-side dynamic thermal parameter of a medium-low-speed motor in real time. A signal of a temperature sensor on a rotor thermal parameter test point is introduced to a slip ring along a rotating shaft via a signal wire, and then is connected with an experimental detecting instrument via a slip ring external wire. In order to enhance stability, a groove and a small hole are sealed by glue after a wire is introduced. The method has no influence on the dynamic performance of the rotor and may detect the rotor-side dynamic thermal parameter of the motor in real time. An acquired parameter provides conditions for the optimization of the motor rotor and a ventilation structure. The method monitors the motor rotor in real time and forecasts faults, contributes to the prolongation of the service life of the motor, and increases motor efficiency.

The invention discloses an improved method for low-voltage ride-through phase-locking of a grid-connected converter. When the voltage drop of a grid is k times higher than a rated value, double rotation coordinate transformation is performed to obtain a positive-sequence Q-axis voltage Uq for per-unit processing. When the voltage drop of the grid is k times lower than the rated value, the input ofa proportional integral part is disconnected, and the output of a phase-locked loop is maintained through the integral part. According to the invention, the problem of phase-locked failure due to unreasonable proportional-integral parameters because the voltage drop causes a decrease in the Q-axis voltage Uq is avoided through the per-unit processing, and the problem of phase-locked failure due to an over-low grid voltage is avoided by maintaining the output of the phase-locked loop through the integral link.

The invention discloses a multi-phase staggered voltage-reduction power supply and electronic equipment. The multi-phase staggered voltage-reduction power supply is used for supplying power to an IC device and comprises a multi-phase branch power supply module. The multi-phase branch power supply module is arranged on the bottom face, away from the IC device, of a main board where the IC device islocated. According to the multi-phase staggered voltage-reduction power supply and the electronic equipment, the redundant wiring distance can be shortened and even eliminated, so that the loss is reduced, the efficiency is improved, and the pin design of an IC device is facilitated. The multi-phase branch power supply module is arranged to be far away from the IC device, so that the dynamic performance of the power supply is not influenced to the maximum extent, the number of layers of the PCB can be reduced to a certain extent, the use area of the PCB can be reduced to a certain extent, andthe cost of the PCB is reduced.

The invention discloses a non-contact device for detecting the vibration of an aircraft tail and a method. The device comprises an aircraft tail body portion, an excitation portion, a vibration detecting portion and a control portion. The aircraft tail body portion comprises an aircraft tail structure. The excitation portion comprises an exciter, a signal generator, and a power amplifier. The vibration detecting portion comprises a projector, an accelerometer, and a CCD camera. The control portion comprises a piezoelectric ceramic driver, a torsional modal driver, an amplifying circuit, and aD/A converter. According to the non-contact device for detecting the vibration of an aircraft tail and the method, the measurement and control of the vibration of the aircraft tail body portion are realized.

The invention discloses a full-compliance impact overload resistant dynamic mass compensation micro-positioning device which comprises a compliance lever mechanism, a motion platform, a mass balance weight platform, a base, a plurality of sets of guide rail sliding block assemblies, a driver and a sensor. The motion platform and the mass balance weight platform are connected with the two sides of the base through the multiple sets of guide rail sliding block assemblies respectively, and the translational degree of freedom in one direction is reserved. The left end and the right end of the compliant lever mechanism are fixedly connected with the motion platform and the mass balance weight platform respectively to form a full compliant dynamic mass compensation micro-positioning system. And the sensor is used for monitoring the displacement of the motion platform relative to the base in real time, so that the driver completes the driving action. The device has the advantages of simple structure, simplicity and convenience in operation, high positioning precision, large movement range and the like.

The invention discloses a broadside antenna. The broadside antenna comprises a first dielectric substrate, metal patches, a grounding plate, a second dielectric substrate, a magnetic dipole, an excitation source and a coaxial cable, wherein the first dielectric substrate is provided with a gap and comprises a first surface and a second surface which are opposite to each other, the metal patches are arranged in contact with the first surface, a groove hole is formed in the grounding plate and is in contact with the second surface, the second dielectric substrate is arranged in parallel to the grounding plate and comprises a third surface and a fourth surface which are opposite to each other, a partial region of the projection of the second dielectric substrate on the grounding plate is arranged in the gap, the magnetic dipole is in contact with the third surface, the excitation source is in contact with the fourth surface, and the coaxial cable is arranged in the groove hole in a penetrating way and is connected with the excitation source. The broadside antenna disclosed by the invention has the characteristics of low profile and favorable end emission radiation; and by loading an EBG (Electromagnetic Band Gap) technology, the broadside antenna has favorable side emission radiation characteristic and extremely wide beam width, and the problems of relatively high profile, relatively low radiation efficiency and the like of an existing antenna are solved.

The invention discloses a design method of a bypass broadband silencer for reducing acceleration roar noise of an exhaust tail pipe. The method comprises the following steps: determining the frequency of the acceleration roar noise of an exhaust tail pipe and the cause of the acceleration roar noise through the noise test of the exhaust tail pipe when a vehicle accelerates, then designing the initial structure parameters of a bypass broadband silencer, and constructing a three-dimensional model of the bypass broadband silencer according to the initial structure parameters and the size of the exhaust pipe; and constructing an acoustic finite element model of the bypass broadband silencer based on the three-dimensional model, then carrying out noise transmission loss simulation analysis, optimizing initial structure parameters according to an analysis structure, and when the optimized structure parameters meet a preset target, constructing a final bypass broadband silencer by using the optimized structure parameters. The exhaust tail pipe acceleration roaring noise caused by an engine is eliminated through the designed bypass broadband silencer structure, then the overall noise level of the exhaust tail pipe is greatly reduced, and the vehicle sound quality is improved.