154 results about "Nutation" patented technology

The invention discloses an attitude control system for space vehicle and a method thereof. The control system has only one biased momentum wheel, one set of tri-axial magnetic torquer and one attitude controller loaded with algorithm. The method comprises a step of rate damping controlling, a step of initially capturing controlling and a step of stationarity controlling. At the rate damping stage, geomagnetism change is used to control the magnetic control of three passages of a satellite by B-dot; at the initially capturing stage, the magnetic control is realized, PD control is performed by pitching and the passages are rolled and yawed to carry out nutation and precession composite control; at the stationarity controlling stage, the magnetic control is realized, PD control is performed by pitching and the passages are rolled and yawed to carry out nutation and precession composite control. The capturing stage and the stationarity controlling stage fully depend on magnetic torquer to perform positive magnetic control, thereby changing which a satellite only uses a magnetic torquer to carry out unload of the momentum wheel or auxiliary magnetic control, so as to refine system configuration to further improve reliability of the system. Momentum of a satellite is biased to rotate on the ground, so as to ensure stable separation of the satellite without performing air injection control. Therefore, the magnetic torquer can be used for realizing fast and stable initial rate damping.

A system and method for increasing image resolution in a palm print scanner. The method of the invention requires the synchronization of a nutating mirror with a camera frame sync. A first image is scanned at a first nutation position. The mirror is nutated by a fraction of a pixel amount in one direction. Another image is scanned at a second nutation position. The process of nutating the mirror to a different nutation position and scanning an image is repeated until all sub-pixels needed to increase an image resolution are obtained. All of the sub-pixels obtained are then interlaced to obtain a higher resolution image.

The present invention relates to a centrifugal grinding mill comprising a vertical axis of revolution (1), a nutating axis (2) intersecting axis (1) at a point of nutation symmetry (3), a grinding chamber (4) symmetrical about axis (2) connecting with feed passage (5) at its upper end and having discharge openings (6) of a screening element (26) located within a plane area aligned normal to, symmetrical with, and intersected by the axis (2), and adjacent the plane containing the maximum diameter of the grinding chamber (4).

This scanning array scans an area around the array for nearby objects, collision obstructions, and terrain topography. The scanning array can scan for sounds emitted by objects in the vicinity of the scanning array, passive energy receipt sources, or it can also send out an energy beam and scan for reflections from objects within the energy beam. The energy beam can be optical, laser, radar or other energy emitting sources. The scanning array of the invention can be used for helicopter detection and avoidance of collision risk and can be used for other scanning purposes. Scanning of an entire hemisphere or greater is accomplished by manipulating the scanner platform through the coordination of either linear actuators or gimbals so as to produce nutation without rotation. This motion allows transceivers to be directly coupled to transmitting and sensing modules without the losses associated with slip rings and other coupling devices.

A drilling apparatus including a drill bit and a nutation device. The drilling apparatus is configured to enable the drill bit to be rotated at a rotation frequency while the nutation device simultaneously nutates the drill bit at a nutation frequency. The nutation device may include a vibrating device for imposing vibrations upon the drilling apparatus at a vibration frequency, thereby causing nutation of the drill bit at the nutation frequency. The drilling apparatus may include a tuning mechanism for tuning the vibration frequency of the vibrating device. A method including rotating a drill bit at a rotation frequency and simultaneously nutating the drill bit at a nutation frequency.

Disclosed is a space tumbling target de-spinning control method based on a permanent magnet eddy current effect. The method comprises the following steps: a service spacecraft docks in the working space of a mechanical arm, and is kept at a safety distance from a tumbling non-cooperative target; a visual inspection system carried by the service spacecraft measures the direction of a target angular momentum vector H and the direction of a spin axis position vector Zb, and the mechanical arm drives a permanent magnet eddy current braking device at the end to an initial de-spinning position, and the docking position is 100mm from the surface of the target in the direction of the target angular momentum vector; the permanent magnet eddy current braking device is started, the direction of a vector outputting an external torque T1 is corrected according to the real-time change of attitude angle in the tumbling process of the target until the angle of nutation attenuates completely, and the rotation state of the target is changed to a single spinning motion state; the position of the permanent magnet eddy current braking device is adjusted to the side of the tumbling non-cooperative target, the permanent magnet eddy current braking device is started to output a brake torque T2 until the single spinning motion state attenuates completely; after the target is completely de-spun, an end actuator is replaced with a grasping paw, and the target is captured directly by the mechanical arm.

The invention belongs to optical technical field and specifically relates to a method for fast generating an optical starry sky background. The method comprises following steps including: a step 1, modeling a sky background in which star catalogue data of fixed stars is used as a source, by means of transformation of time and a coordinate system and correction of the apparent positions of heavenly bodies, starry sky background models at any observation point any time are constructed and a calculating result is inputted into a base in order to be used for simulation, wherein the calculating result comprises star names, star magnitudes, right ascension, and declination; and a step 2, simulating the established starry sky background model. The step 1 uses Hipparcos Catalogue as a data source of a visible light band. According to the selected Hipparcos Catalogue, the apparent positions of the fixed stars are calculated. Considered factors comprise annual parallax and proper motion caused by revolution of the earth, aberration caused by the self motion of an observer, annual aberration, precession, and nutation caused by earth revolution about the sun. The speed for generating a starry sky background by using the method may reach 50Hz.

The invention discloses a micro-motion target scattering point track association method based on a distance-instant Doppler image. The method comprises the following steps of (1) receiving an inverse synthetic aperture radar echo; (2) carrying out inverse synthetic aperture radar echo pretreatment; (3) through the distance-instant Doppler image, acquiring a two-dimension coordinate of a micro-motion target scattering point; (4) carrying out two-dimension track association; (5) using a rooting multiple signal classification Root-MUSIC method to correct a track matrix; (6) acquiring a track association result of the micro-motion target scattering point. A domain associated to the scattering point is converted into a slow time-distance-instant Doppler domain with a high separability from a distance-slow time domain; separability of the micro-motion target scattering point is enhanced; for complex motion forms of spinning, processional motion, nutation and the like, advantages that universality is possessed, track association precision is high, an association error is small and so on are achieved; forceful guarantee can be provided for subsequent high-resolution imaging and target feature extraction.

This scanning array scans an area around the array for nearby objects, collision obstructions, and terrain topography. The scanning array can scan for sounds emitted by objects in the vicinity of the scanning array, passive energy receipt sources, or it can also send out an energy beam and scan for reflections from objects within the energy beam. The energy beam can be optical, laser, radar or other energy emitting sources. The scanning array of the invention can be used for helicopter detection and avoidance of collision risk and can be used for other scanning purposes. Scanning of an entire hemisphere or greater is accomplished by manipulating the scanner platform through the coordination of either linear actuators or gimbals so as to produce nutation without rotation. This motion allows transceivers to be directly coupled to transmitting and sensing modules without the losses associated with slip rings and other coupling devices.

An inventive autonomous active manoeuvring method and system 1 for spinning spacecraft is provided having a capability to enhance the AOCMS performance of passive spinning satellites and to fulfil the emerging autonomy requirements applicable to new generation satellites. In broad terms, the invention resides in (a) the overall concept of providing autonomous execution of spin axis re-orientation manoeuvring for spinning spacecraft designed and executed autonomously on-board the spacecraft by the AOCMS and (b) in the proposed strategy set in place to execute the re-orientation manoeuvres with respect to the handling of residual nutation. Advantageously, the provision of coupling nutation avoidance manoeuvres with active nutation damping 8 on board the spacecraft reduces / minimises the manoeuvre settling time required to return the spacecraft to the steady state pointing performance, while not imposing constraints upon the particular spacecraft inertia sensor properties.

The invention discloses a racemization control method for an under-actuated satellite. The method comprises the following steps of: (1) determining an initial self-rotating shaft position of the under-actuated satellite by the adoption of an attitude sensor, and determining a direction and an amount of racemization control according to a position of a target self-rotating shaft; (2) determining geometric relationship between an injection control moment and a racemization control direction produced by each injection control engine, and selecting the injection control engine with the largest amount of the injection control moment in the racemization control direction as a racemization control engine; and (3) in a preliminary stage of racemization, adopting an integer multiple self-rotating period fully spraying method, in a final phase of racemization, adopting a symmetrical point spraying method, using the racemization control engine to carry out racemization control, after primary racemization is finished, enabling a planet to be naturally damped for a period of time, and then carrying out the next racemization control until a self-rotating shaft of a satellite reaches a target self-rotating shaft. According to the method, the operation of a racemization control strategy is simple and convenient, and nutation produced by racemization control can be reduced at the same time.

The present invention provides a method for designing the parameter of the wave trap of the magnetic suspension flat high-speed rotor system. The magnetic suspension flat high-speed rotor system is considered with a kinetics model of the first order elastic mode and is translated into a complex-coefficient single-variate open-loop transfer function. The double-frequency Bode chart of the open-loop transfer function of the complex coefficient in different rotary speed is drawn. The phase angle allowance of elastic mode in each rotary speed is calculated, and the series-connected progression, central frequency and polar point amortization of the elastic self-excited vibration restraining used wave trap are designed according to the phase angle allowance curve. Basing on the double-frequency Bode chart the invention presents a method for designing the parameter of the wave trap which comprises a magnetic suspension flat high-speed rotor system with strong gyroscopic effect and is used for restraining the first order elastic self-excited vibration. Compared with the common multiple-variate system designing method such as state space analyzing method and the like, not only has excellent immediacy and robustness, but also can minimize the effect of the wave trap to the nutation stability, and thus the invention the invention is more suitable to be used in the actual magnetic suspension high-speed rotor system such as posture-controlling energy-accumulating fly wheel, the magnetic suspension counteracting wheel, the magnetic suspension control moment gyroscope and the like.

The invention relates to a projectile nutation angle extraction method based on radar Doppler data. The method is characterized by comprising the following specific steps of arranging a radar tail chasing distributed station at the side rear part of an artillery or a rocket artillery, carrying out tracking measurement on a flying artillery shell or a rocket artillery shell, and estimating the radial velocity of a centroid; calculating micro motion speeds; extracting a precession period; resolving a velocity vector; calculating the nutation angle of a projectile. According to the method, the difficult problem in nutation angle measurement of the flying projectile under the conditions of long distance is solved effectively, and the motion of the rotating projectile in the air includes micro motions relative to the centroid, such as precession and nutation, besides centroid motion; radar signals are subjected to periodic modulation, namely micro-Doppler effect, by the micro motions. Internal data of the radial velocity obtained through radar measurement contain information on the micro motions, such as nutation, a nutation angle curve of the projectile can be obtained through processing the internal data, and the nutation angle of the projectile is obtained through an established micro-motion velocity equation.

A variable flip angle (VFA) MRI (magnetic resonance imaging) spin echo train is designed and / or implemented. For example, a target train of detectable spin-locked NMR (nuclear magnetic resonance) echo signal amplitudes may be defined and a corresponding designed sequence of variable amplitude (i.e., variable NMR nutation angle) RF refocusing pulses may be determined for generating that target train of spin echoes in an MRI sequence (e.g., used for acquiring MRI data for a diagnostic imaging scan or the like). Such a designed VFA sequence may be output for study and / or use by an MRI system sequence controller.

The invention relates to an electromechanical integration nutation oscillating tooth transmission device, which is characterized in that the nutation oscillating tooth transmission device composed of a fixing disc end cover, a first end cover bearing, a fixing disc, a rotating drum, a nutatoin disc, a rotating disc end cover, a second end cover bearing, a rotating disc, an outer end cover and an output shaft is installed in a box body. A bearing and the rotating drum are arranged on the outer lateral face of the nutation disc, and a motor composed of a rotor, a permanent magnet and a stator is installed along the outer lateral face of the rotating drum to achieve engagement of a roller of the nutation disc and teeth of the fixing disc, engagement of the roller of the nutation disc and teeth of the rotating disc and achieve the fact that a bolt and an output shaft fixedly connected with the rotating disc output torque. The electromechanical integration nutation oscillating tooth transmission device is novel and unique in design and compact in structure, has the advantages of no contact, small vibration and overload protection due to utilization of magnetic force transmission, avoids the fact that an inclined shaft section in the nutation oscillating tooth transmission device is difficult to machine, is capable of remarkably prolonging service life of a rotating arm bearing due to the fact that the rotating arm bearing is placed outside the nutation disc and has the advantages of being fewer in part number, high in bearing capability, low in noise, high in efficiency and thelike.

A mechanical flow battery comprises a flywheel system in which a spinning axis can be driven by an air-powered motor and the structure of the gyroscope is employed in the mechanical flow battery. The structure of the gyroscope can be constructed by coupling the housing of the flywheel system with a nutation frame which couples a precession frame so that the spinning axis in the flywheel can be isolated from any outside gyroscopic torque.

A method and a controller for controlling a magnetic bearing device, in which a rotor is suspended for rotation around a shaft, are disclosed. Sensor signals are transformed to yield tilt displacement signals (Sθx, Sθy) which correspond to tilting displacements of the shaft in predetermined directions (x, y). From the tilt displacement signals (Sθx, Sθy), tilt control signals Aθx, Aθy) are derived; these are transformed to yield actuator control signals for driving electromagnetic actuators in the magnetic bearing device. According to the invention, tilting displacements for which the tilt vector rotates about the device axis (z) with a first predetermined sense of rotation are controlled separately from tilting displacements for which the tilt direction vector rotates about the device axis (z) with a second sense of rotation opposite to the first predetermined sense of rotation. In this way, control of nutation and precession can be achieved without influence from blade vibrations or shaft bending modes.

The invention discloses an optimal selection method of navigational stars of a star map simulator based on star density. The optimal selection method comprises the following steps: firstly, processing a star catalogue, extracting effective data fields, carrying out related data processing to obtain six pieces of data corresponding to each fixed star, and then performing proper motion, precession and nutation correction on extracted right ascension and declination values respectively; secondly, according to given optical axis orientation and the size of a field range, extracting fixed stars in the field range and establishing an observational star database; thirdly, on the basis of the observational star database, performing image surface partition and star density calculation respectively by use of an ITSI (Information Technology System Infrastructure) optimal selection method of the navigational stars, and satisfying a set navigational star threshold, and finally realizing the optimal selection of the navigational stars and establishing a navigational star database. The method is relatively simple, but the navigational star database obtained by use of the method is relatively low in standard deviation and relatively even in distribution, and both efficiency and effect are achieved; the established navigational star database is reasonable and significant for smooth implementation of star map matching.

The invention discloses a nutation loose-teeth driving device, which comprises the input and the output shafts: the offset shaft sect is connected with the nutatoin disk throuth the bearing; the end face of the disk toward the input shaft is engaged with the fixing disk through the sphere loose-teeth of the first steel ball group along the circumferential direction; the fixing disk is fixed on the base; the other end of face of the dial toward the output shaft is engaged with the turning disk through the sphere loose-teeth of the second steel ball group along the circumferential direction; the bearing is between the turning disk and the base. The invention makes use of the roller assistant steel ball as the medium to engage with the loose-teeth between the fixing disks and the planetary turning disks. The invention is suitable for the precise driving devices.

A method for judging magnetic suspension rotor system stability, includes through establishing magnetic suspension rotor system radial rotational motion dynamics differential equation model, adopting plurality conversion converting real coefficient two variable equation to complex system monovariant form, to obtain monovariant equivalent system, then drawing open loop transfer function dual frequency Bode chart of equifinality complex system, utilizing generalized classic frequency field stability criteria judging rotor precession and nutation stability, providing require condition for designing raising system stability correction link. The present invention converts multivariable system to equifinality monovariant system, thereby capable of using classical monovariant control theory to proceed stability analysis, relative usual multivariable method such as state space analysis method etc, not only very visual but also having good robustness, thus more fitting real system application.

The invention discloses a gain scheduling control method for a magnetic suspension molecular pump. The method comprises the following steps of: calling a high-rigidity and high-damping control parameter to control the magnetic suspension molecular pump by using a dispersion PID (Proportion Integration Differentiation) controller when a rotor rotates at a low rotating speed, and gradually starting a displacement cross feedback controller when the speed of the rotor rises to a medium-low speed to effectively suppress rotor precession in the rotating process of the rotor and vibration caused by the structural mode of a system; when the rotating speed of the rotor reaches a medium speed, gradually switching the parameter of the dispersion PID controller to a low-rigidity and low-damping control parameter; and when the rotating speed of the rotor reaches a medium-high speed, gradually starting a speed cross feedback controller to suppress rotor nutation in the rotating process of the rotor and ensure that the rotor can stably reach a rated working rotating speed. Due to the adoption of the method, the technical problem of vibration caused by the rotor gyroscopic action in the working process of the molecular pump and the structural mode of the system is solved, the rotor vibration can be effectively suppressed in the working process of the molecular pump, and stable running of the magnetic suspension molecular pump can be ensured.

A first gear set includes an input member that serves as a first gear and an inner ring that serves as a second gear. A first end of the inner ring is inclined with respect to the input member and is in mesh with the input member. The input member has a plurality of retention grooves that are formed in an input member body and a plurality of pins that are retained in the respective retention grooves and that respectively constitute teeth of the input member. The first end has a plurality of tooth grooves that are engageable with the pins. A resultant force of forces applied to each pin from the retention groove and the tooth groove urges the pin toward the retention groove.

Provided is an automatic spatial light to single-mode fiber coupling system based on laser nutation. The system comprises a 1.5 micron laser, an emission collimating mirror, a vibration fast reflector, a compensation fast reflector, a nutation fast reflector, a reception collimating mirror, a 1.5 micron single-mode fiber splitter, a linear detector, a ground reception system, a data collection unit, a digital signal processing unit and a real time storage and display unit. The system is simple in structure, the tracking algorithm is simple, and spatial light can be coupled to the single-mode fiber in high efficiency. The 2D nutation fast reflector is used to complete nutation scanning of laser at the end surface of the single-mode fibers, the nutation fast reflector is used to track the laser nutation position in the real-time tracking algorithm, tracking errors can be obtained by observing change of optical power output by the single-mode fibers, and high-speed tracking can be realized.

The invention provides a three-dimension cable shooting platform and a three-dimension cable shooting system using the platform. The shooting platform (10) comprises a first peg-top (141), a second peg-top (142) and a third peg-top (143). The three peg-tops are respectively used for eccentric rotation of the shooting platform (10) in three axial directions. The first peg-top (141) and the second peg-top (142) are perpendicular to each other in the radial direction. The third peg-top (143) is horizontally arranged on an axis perpendicular to the plane where the first peg-top (141) is located and the plane where the second peg-top (142) is located. According to the shooting platform and the shooting system, the inertia principle and inertia elements (the peg-tops) are utilized to set up inertia attitude reference, so that the disturbance caused by the shooting platform in the moving process and the nutation disturbance caused by a camera in the rotating process can be overcome.

The invention provides a variable-speed tilt momentum wheel precession control method based on variable-parameter nutation damping and relates to the field of motion control of a variable-speed tilt momentum wheel in order to solve the problem of reduction of stability and control precision of the variable-speed tilt momentum wheel due to rotor gyroscopic effect and two-dimensional tilt motion coupling. According to the method, frequency characteristics of direct-axis and quadrature-axis controlled members of the variable-speed tilt momentum wheel at a certain determined rotating speed are identified respectively through a tilt loop open-loop experiment; a relation between system nutation frequency and the rotating speed is determined according to the tilt loop open-loop experiment, and nutation instability of a nutation damper suppression system is designed. The frequency characteristics of the direct-axis and quadrature-axis controlled members of the variable-speed tilt momentum wheel are identified respectively through the tilt loop open-loop experiment, the nutation frequency is determined according to the quadrature-axis frequency characteristics at different rotating speeds,a variable-parameter nutation damper is designed accordingly, the nutation instability of the variable-speed tilt momentum wheel is suppressed, and a control structure of the system is provided on thebasis of the principle of precession control. Stability and control precision of the variable-speed tilt momentum wheel are improved.

The invention discloses a full-automatic triaxial air bearing table micro-interference force moment measurement system and a method. The full-automatic triaxial air bearing table micro-interference force moment measurement system comprises an air floating ball and a ball socket, wherein a gyroscope is arranged on the air floating ball for measuring angular velocities omega m in three directions, three balancing mass blocks m1, m2 and m3 and a jet system are arranged on the air floating ball, the rotational inertia matrix of a system formed by the air floating ball, the gyroscope, the mass blocks and the jet system under coordinates of air floating ball is a 3*3 matrix Ia, the air floating ball can generate initial angular velocity by the jet system, the angular velocity omega m of the air floating ball during rotation can be measured by the gyroscope, and the interference force moments in three directions can be calculated according to Ia. According to the full-automatic triaxial air bearing table micro-interference force moment measurement system and the method, the interference problem between a bearing of the air floating ball and the ball socket can be effectively solved through nutation formed by a symmetrical structure during rotation entirely, and the interference force moment of the bearing of the air floating ball can be measured in a small-angle range.

The invention provides a rotating shaft torque measuring device based on a surface transverse wave. The rotating shaft torque measuring device comprises a measuring mechanism and a control mechanism which are matched with each other. The measuring mechanism comprises a rotating shaft body, a first surface transverse wave resonator arranged on the rotating shaft body through a binder and a second surface transverse wave resonator arranged on the rotating shaft body through the binder. The tangential Euler angles of the first surface transverse wave resonator and the second surface transverse wave resonator are characterized in that rotation angles are 0 degree, nutation angles are 38.8 degrees, and precession angles are 90 degrees. The rotating shaft torque measuring device has the advantages that: 1) a frequently-used rayleigh wave mode is no longer simply used for surface acoustic wave mode selection, and a surface transverse wave mode relatively low in propagation loss is adopted, so that the Q values of the resonators are larger, the demodulation accuracy of echo signals is improved, and the torque measuring precision is improved; and 2) the two STW resonators identical in structure are adopted, and the resonators are orthogonally arranged on the surface of the rotating shaft and form + / - 45-degree angles with the axial direction of the rotating shaft, so that the two resonators are arranged in the identical work environment.