47results about How to "Suppress residual vibration" patented technology

The invention relates to a method for controlling an index time-varying slide mode of flexible spacecraft characteristic shaft attitude maneuver, and belongs to the technical field of spacecraft control. The method comprises the steps that firstly, a system dynamically equivalent model, a dynamic model and a flexible vibration model are established under a spacecraft system, then, the vibration frequency and the damping ratio parameter of a closed loop system with the index time-varying slide mode control law are calculated, and a single-shaft multi-modality filtering input shaping device with a characteristic shaft as a rotary shaft is designed according to the designing method of the single-shaft input shaping device to restrain flexible vibration in three-shaft motion. Meanwhile, a state observer is designed to estimate flexible modal information in real time, and the method for controlling an output feedback index time-varying slide mode is formed. At last, saturability analysis is conducted on control torque so as to satisfy the physical saturation constraint of the control torque. By means of the method, the application range of existing input shaping is expanded, the input shaping technology is expanded from single-shaft maneuver to three-shaft maneuver, the self-robustness of filter input shaping is enhanced, and the purpose that the attitude maneuver path of the spacecraft is the shortest is achieved.

A liquid ejecting apparatus includes a liquid ejecting head with a pressure chamber communicating with a nozzle opening and a pressure generator capable of causing a pressure fluctuation to liquid in the pressure chamber. The liquid ejecting head discharges liquid droplets by operating the pressure generator. The drive signal generator generates a drive signal including a drive pulse which includes a first expanding element that expands the pressure chamber, a first discharging element that contracts the pressure chamber expanded by the first expanding element in order to discharge a liquid droplet, a second expanding element that expands the pressure chamber, and a second contracting element that contracts the pressure chamber. The time from the beginning of the first discharging element to the end of the second contracting element is set to ½ to 1 of the natural vibration period of the liquid in the pressure chamber.

A control device for suppression of residual vibration of a piezoelectric transducer includes a capacitive energy storage component, and a switch unit. The control device is operable in a non-working mode, in which the switch unit provides voltage on the capacitive energy storage component to the piezoelectric transducer for reducing the residual vibration of the piezoelectric transducer. The capacitive energy storage component has a capacitance value that is sufficient for enabling the voltage on the capacitive energy storage component to substantially track voltage on the piezoelectric transducer under the non-working mode.

The invention provides an input shaping residual vibration suppression method adapting to trajectory errors of a motion system, comprising the following steps: S1, acquiring the inherent frequency anddamping coefficient of a mechanical system; S2, establishing a mathematical model about a linear programming problem of pulse amplitude parameters of an input shaper, and acquiring a pulse amplitudeexpression of the input shaper; S3, performing convolution operation on an input signal for reference and a pulse signal of the input shaper to obtain a shaped command curve C1; S4, using the C1 curvein the S3 to drive the system to obtain an actual motion trajectory curve P1 and a trajectory error curve C1-P1 under the current motion form; S5, using the C1-P1 curve to compensate the curve C1 toobtain a next command curve C2, using the curve C2 to drive the system to obtain a trajectory error curve C1-P2 under the current motion form, and using C1-P2 to compensate C2 to obtain a next commandcurve P3; and S6, repeating S5 to use the trajectory error curves C1-P1, 2,...n to compensate the command curves P1, 2,...n to obtain a next command curve until the value of the trajectory error curve at each moment is close to zero. According to the method for suppressing residual vibration through the input shaper, other hardware equipment does not need to be added, and cost is saved.

To provide an acceleration/deceleration control method, apparatus and the like for determining the acceleration/decelerations of motors according to, for example, the drive directions, acceleration and deceleration of the motors by a simple algorism. A gravity torque calculation unit 1A calculates gravity torque acting on a joint drive motors for operating a manipulator 100 as a machine having joints, and an acceleration/deceleration calculation unit 1D calculates an acceleration speed and/or a deceleration speed of the joint drive motor based on an acceleration/deceleration correction coefficient and a set basic acceleration/deceleration, wherein the acceleration/deceleration correction coefficient is calculated by an acceleration/deceleration correction coefficient calculation unit 1B based on the gravity compensation coefficient selected from a plurality of preset gravity compensation coefficients according to a drive condition affected by gravity and on the gravity torque.

The invention discloses a method for controlling mechanical residual vibration of a linear servo system, and belongs to the technical field of mechanical device control. Most of current control methods for restraining residual vibration of the servo system are restraining methods based on input shapers, the methods have the shortcomings that pulse amplitudes and time period parameters are difficultly controlled, running errors are large, and control requirements of the linear servo system cannot be met. The method includes the steps: firstly, connecting the linear servo system, and downloading parameters into a chip on a motion control card; secondly, enabling the servo system to close a motor after controller parameters are downloaded; thirdly, collecting sampling points; fourthly, iterating error signals used for optimizing; fifthly, issuing iterative learning correction driving force to the motion control card again, and repeatedly iterating iterative learning processes to restrain resonance. Input signals subtract output signals to serve as error signals. The method is simple, practical and high in accuracy.

A liquid ejecting apparatus includes a liquid ejecting head having a nozzle, a pressurizing chamber that communicates with the nozzle, and a pressurizing element that causes a pressure change in liquid within the pressurizing chamber, the liquid ejecting head being capable of ejecting liquid from the nozzle by operating the pressurizing element; and a driving signal generation unit that generates a driving signal including a driving pulse that drives the pressurizing element. The driving signal includes an ejection driving pulse that ejects a liquid droplet and a non-ejection driving pulse that drives the pressurizing element to a degree whereby a liquid droplet is not ejected. The ejection driving pulse is a pulse waveform having an expansion element that causes the pressurizing chamber to expand and retract a meniscus toward the pressurizing chamber and a constriction element that causes the pressurizing chamber expanded by the expansion element to constrict and push the meniscus in the direction of ejection. The non-ejection driving pulse is a pulse waveform having an expansion element that causes the pressurizing chamber to expand and retract the meniscus toward the pressurizing chamber, a holding element that holds the voltage at the end of the expansion element for a set amount of time, and a constriction element that causes the pressurizing chamber expanded by the expansion element to constrict and push the meniscus in the direction of ejection. When the length of time from the end of the constriction element in the ejection driving pulse to the beginning of the expansion element in the non-ejection driving pulse is taken as t, the lengths of time of the expansion element, holding element, and constriction element in the non-ejection driving pulse are taken as a, b, and c, respectively, and the inherent vibration cycle of the liquid within the pressurizing chamber is taken as Tc, t, a, b, and c are within the ranges defined by the following equations (1) through (3):

Tc/4≦t≦Tc/2  (1)

(5Tc/8)−t≦a≦(3Tc/4)−t  (2)

b+c=Tc−t−a  (3)

A liquid droplet ejection apparatus comprises: a nozzle from which a liquid droplet is ejected; a pressure chamber filled with liquid to which a pressure is applied in order to eject the liquid in a form of the liquid droplet from the nozzle; and a supply port which supplies the liquid to the pressure chamber, wherein inertance Mn of the nozzle, resistance Rn of the nozzle, compliance Cn of a nozzle section due to surface tension, inertance Ms of the supply port, and resistance Rs of the supply port satisfy the following two formulas: $\frac{1}{\mathrm{Mn}+\mathrm{Ms}}\sqrt{\frac{\mathrm{Mn}+\mathrm{Ms}}{\mathrm{Cn}}-\frac{{\left(\mathrm{Rn}+\mathrm{Rs}\right)}^2}{4}}>\pi f-\frac{\mathrm{Rn}+\mathrm{Rs}}{2\left(\mathrm{Mn}+\mathrm{Ms}\right)}\times \frac{1}{f}<\log 0.01.$

A varifocal lens which uses an interface between a first fluid and a second fluid that are mutually immiscible, as a light refracting surface, includes: a sealed vessel in which a first chamber into which the first fluid is filled is connected via an opening to a second chamber into which the second fluid is filled; and an elastic deformation section which is provided in elastically deformable fashion in a portion of a partition wall that divides the first chamber and the second chamber in the sealed vessel and which deforms in contact with both the first fluid filled into the first chamber and the second fluid filled into the second chamber, wherein: a lens section having the interface is formed in the opening, and a focal length of the lens section is changed by causing the interface to deform through altering volumes of the first chamber and the second chamber in mutually opposite directions by deformation of the elastic deformation section.

The invention relates to an air-suspending vibration signal inhibition-based method and system, a vibration signal of an air-suspending system and damping rate are analyzed by inputting designed improved negative pulse into a reshaper, a pulse sequence is obtained, the pulse sequence and a certain value of expectation are input to phase convolution to obtain a corresponding command and serve as motion system input of the air-suspending system, and inhibition of an air-suspending vibration signal is realized; the method has the advantages of improving rise time of the system and reducing the delay of motion response time of the system besides the characteristic of effectively inhibiting residual vibration of the air-suspending motion system, the improved negative pulse is input to the reshaper to obtain shorter delay time, and pulse number in the pulse sequence can be flexibly selected.

The invention discloses a vibration control method for a rigid-flexible coupling electromechanical servo system. The vibration control method comprises the steps of separately collecting encoder dataon a drive motor and a load motor, acquiring torsion angles of two ends of a flexible shaft rod, computing the torsion angle of a micro unit located at any position of the flexible shaft rod, and computing a frequency domain characteristic equation according to the length, polar moment of inertia, elasticity modulus and rotational inertia of the flexible shaft rod; by using the frequency domain characteristic equation, computing a coupling torque between the flexible shaft rod and a rigid driving flywheel; building a rigid driving flywheel balance equation; putting the coupling torque into thebalance equation to acquire a frictional order transfer function model of the system; and according to the frictional order transfer function model, building a fractional order controller, and controlling the vibration of the system by using the controller. According to the method provided by the invention, the dynamic behaviors of the viscous-elastic material is accurately described via the frictional order model, and the residual vibration of the system is effectively suppressed.

A driving pulse signal for forming one dot includes a first, a second, and a third main pulses applied intermittently with an intervals to eject an ink droplet, and a stabilizing pulse which is inserted between the main pulses, and which suppresses a residual vibration of an ink in a pressure chamber, generated by a main pulse applied previously. The third main pulse suppresses the residual vibration of the ink generated by the second main pulse, and also a pulse width of the third pulse is adjusted such that there is no residual vibration remained, due to application of the last main pulse. Consequently, it is possible to suppress effectively the residual vibration of the ink by the less number of the stabilizing pulses compared to the number of main pulses. As a result, an overall pulse width becomes short, and it is possible to increase the recording speed.

A method for driving a droplet ejecting head that includes a liquid pressure chamber communicating with a nozzle hole, and a pressure application unit applying pressure on liquid stored in the liquid pressure chamber for ejecting a droplet from the nozzle hole, includes applying on the liquid stored in the liquid pressure chamber pressure having a waveform whose phase is delayed by 90 degrees from a waveform of a residual vibration of the liquid by the pressure application unit after an ejection of the droplet from the nozzle hole.

A moving body guide mechanism of a machine tool includes at least two bar-shaped guide members, and sliders engaged with the two guide members, respectively, movably with respect to the guide members so that a moving body is guided along an axis parallel to a moving axis extending in a longitudinal direction of the guide members. Attaching surfaces of the two guide members or the sliders to the moving body are provided symmetrically across a plane including the axis parallel to the moving axis in such a manner that an angle formed by the attaching surfaces becomes smaller than 180°.

The invention discloses a servo system residual vibration suppression method based on parameterized feedforward, and belongs to the technical field of mechanical equipment control. The invention discloses a servo system residual vibration suppression method based on parameterized feedforward, which comprises the following steps of: calculating a feedforward force through an input track and a parameterized feedforward controller by utilizing a primary function parameterized feedforward controller; introducing a performance objective function of a parameterized feed-forward control algorithm according to an optimal control theory to identify parameters of the input shaping filter and the feed-forward controller; analyzing the error of the parameterized feedforward control and the convergence of the identification parameters; and solving the optimal value of each parameter. Through continuous exploration and test, a parameterized feed-forward control algorithm is adopted, the control difficulty of the servo system can be effectively reduced, the calculated amount of a processor is reduced, the flexibility is high, the operation speed is high, the robustness is good, the control effect is good, and the control requirement of the servo system can be met.

The invention provides a liquid ejection head and a liquid ejection device, by which, the discharge amount can be changed without changing the nozzle structure. According to one embodiment, a drive signal includes an auxiliary pulse, an ejection pulse, a cancel pulse, and a damping pulse, in this order. The auxiliary pulse drives an actuator so that the pressure is increased. The ejection pulse drives the actuator so that the pressure is reduced to eject the liquid. The cancel pulse drives the actuator so that the pressure is increased to suppress residual vibration of the liquid. The damping pulse drives the actuator so that the pressure is reduced to suppress the residual vibration. A pulse width of the auxiliary pulse is AL or less . A pulse width of the cancel pulse is 2 AL. A length from an end of the application of the cancel pulse to a start of the application of the damping pulse is 0.2 AL to 0.4 AL. A pulse width of the damping pulse is 0.2 AL to 0.4 AL.

An apparatus for supporting a semiconductor workpiece includes a heating system configured to cause thermally-induced motion of the semiconductor workpiece by heating a surface of the workpiece relative to a bulk of the workpiece. The thermally-induced motion includes vertical motion of an outer edge region of the workpiece and a center of the workpiece relative to each other. The apparatus further includes a support system configured to allow the thermally-induced motion including the vertical motion of the outer edge region of the workpiece and the center of the workpiece relative to each other while supporting the workpiece.