CN2627281Y - Intelligent torsional vibration abatement rod based on thickness shear polarization piezoelectric electrical actuation - Google Patents

Abstract

The utility model discloses an intelligent torsional vibration control rod of piezoelectric actuator based on thickness shear polarization. Two ends of a hollow round rod are separately equipped with connection blocks that can be fixed connected with other members, and the end part outer surface of the hollow round rod equipped with one end of the connection block is successively equipped with a piezoelectric torsional actuator and a piezoelectric transducer toward the hollow round rod direction. When one end of the connection end is generated with torsional deformation or torsional vibration relative to one end of the other connection end, the detected signals of the piezoelectric transducer are sent into the piezoelectric torsional actuator via the opposite phase amplification, and the piezoelectric torsional actuator generates a torsional moment with the opposite phase of torsional deformation to control the deformation or vibration. The rod integrates the transduction and actuation control into one body, which has the advantages of compact structure, good control characteristics, low work loss, as well as excellent vibration control effects etc. The utility model can be widely used for the operating rod of space robot, elementary unit in the truss frame structure, as well as the initiative vibration control domain on conducting vibration (isolation) control to the torsional vibration.

Description

Intelligent torsional oscillation based on thickness shear polarized piezoelectric driver suppresses bar

Technical field

The utility model relates to and suppresses the torsional oscillation control gear, is that a kind of intelligent torsional oscillation based on thickness shear polarized piezoelectric driver suppresses bar.

Background technique

Under the effect of complex incentive power, many members tend to produce axial stretching vibration, flexure vibrations, even torsional vibration.Because the torsional vibration performance is not too directly perceived, does not often attract much attention.But increase along with the various kinds of equipment output power, cause the increase of equipment main member volume, rigidity declines to a great extent, especially in space industry, for reducing launch cost, require space structure to realize light, low rigidity and flexibility design, make that the influence of torsional oscillation is more and more obvious on these members, some occasion even produced serious harmfulness.For example, (length can reach tens meters to the support of the solar energy sailboard that launches on the control arm of robot for space, the space station, wide several meters), bore reaches paraboloidal antenna, radio telescope of tens meters etc., the single order torsion frequency of its support is often in several hertz, therefore, extraneous little by little disturbance just very easily causes torsional resonance.The appearance of torsional oscillation will influence the decline of robot control arm control accuracy, the decline of telescope accuracy of observation, the destruction of solar energy sailboard etc.And in the space, owing to there is not resistance such as air, the decay of vibration will be extremely slowly.

The same with other vibration control, generally also can be divided into passive type control and active control to Torsional Vibration Control.Passive type control has simple in structure; reliable operation does not need to consume advantages such as additional source of energy, the normal result who obtains satisfaction in the general industry The Application of Technology; but it is suitable for suppressing the high frequency oscillating signal, and is undesirable to low frequency vibration signal suppressing effect.Active control is taked to carry out closed-loop corrected to vibration system, input by outside energy suppresses vibration, therefore under the complex incentive environment, have stronger antijamming capability, especially low-frequency vibration signal is suppressed very effective, thereby cause people's abundant attention.Since the fifties, adopt the existing a large amount of reports of examples such as the accurate vibration isolation platform of active vibration control mode, flexible plate-girder, but the report that torsional oscillation is carried out Active Vibration Control is less relatively, main cause is that to be suitable for the torsional oscillation driver that ACTIVE CONTROL uses few, in active vibration control, use ripe than broad range of techniques driver now: as the moving driver of servo gas (liquid), electromagnetic driver, super-magnetostrictive drive (GMA), based on marmen (SMA) etc., often can only produce axial force, difficulty is applied to torsional oscillation control.Document from having reported both at home and abroad at present, torsional oscillation is carried out mainly containing of ACTIVE CONTROL: a kind of is to adopt special electromagnetic drive type motor as the torsional oscillation driver axle to be carried out the torsional oscillation ACTIVE CONTROL; A kind of is to adopt centrifugal pendulum vibration bump leveller, by the resonant frequency and the next torsional oscillation that initiatively suppresses of path design of active adjustment pendulum; The damper that also has a kind of employing current liquid (ERF) is by changing the next torsional oscillation that initiatively suppresses of damping that voltage initiatively changes liquid.Has complex structure but analyze the above-mentioned driver of mentioning, characteristics such as volume is big, and particular requirement is installed, and control characteristic is general more.

Summary of the invention

The purpose of this utility model is to provide a kind of intelligent torsional oscillation based on thickness shear polarized piezoelectric driver to suppress bar, sends into piezoelectric torsion driver same bar on from the torsional vibration signals that perceives through anti-phase amplification by the sensor on the bar and produces one and suppress its vibration with the anti-phase torsional moment of torsional vibration.

The technical solution adopted in the utility model is as follows:

Suppressing bar based on the intelligent torsional oscillation of thickness shear polarized piezoelectric driver comprises: hollow round bar, and piezoelectric transducer, piezoelectric torsion driver is contained in two contiguous blocks at hollow round bar two ends respectively; To hollow round bar direction piezoelectric torsion driver and piezoelectric transducer are installed successively at the open circles boom end outer surface that contiguous block one end is housed.

Said piezoelectric transducer and piezoelectric torsion driver apply the employing thickness shear vibration polarization mode of silver electrodes by several bi-side watt shape piezo-electric sheet becomes an annulus by identical polarised direction is bonding respectively, sticks on the end of close hollow round bar.

When connecting end had torsional deflection or torsional vibration to produce with respect to connecting end, sensor was sent into piezoelectric torsion driver to signal through anti-phase amplification, and the anti-phase torsional moment of one of piezoelectric torsion driver generation and torsional deflection suppresses its distortion or vibration.

The utlity model has following advantage:

1) simple and compact for structure: owing to adopted the piezoelectric torsion driver of thin sheet type, therefore should suppress bar and general round bar structure basically identical, not have other additional structure, therefore very convenient in use.Because it is big that piezoelectric material has a per unit volume output torque, so dimensional weight is little, and can be processed into different shape, is very suitable for the spatial structure lightweight requirements;

2) control characteristic is good: because piezoelectric material has response soon, frequency response wide (can respond) to zero-frequency, temperature characteristic is stable, do not have and lag behind, small-power can drive, and input voltage and output torque have favorable linearity, and sensor and the proportional relation of torsional vibration amount of deformation, therefore control is easy, the precision height;

3) accommodation is wide: because this inhibition bar has the intelligent characteristics from the self-driven control of perception, but can reach the high-precision requirement of shaking under the complex incentive in the external world, in addition, piezoelectricity does not produce magnetic field, also be not subjected to influence of magnetic field, this point is very beneficial for there is specific (special) requirements in the space to magnetic field occasion.

It can be widely used in the operating stem of robot for space, be used for truss structure elementary cell and to torsional vibration need press down (every) active vibration of shaking control field.

Description of drawings

Fig. 1 is a sectional drawing of the present utility model;

Fig. 2 is the schematic perspective view of piezoelectric torsion driver and transducer arrangements;

Fig. 3 is a slice watt shape piezoelectric torsion driver schematic representation;

Fig. 4 is the utility model system works principle schematic.

Embodiment

As shown in Figure 1, it comprises: hollow round bar 4, and piezoelectric transducer 3, piezoelectric torsion driver 2 is contained in two contiguous blocks 1,5 at hollow round bar 4 two ends respectively; To hollow round bar direction piezoelectric torsion driver 2 and piezoelectric transducer 3 are installed successively at the open circles boom end outer surface that contiguous block one end is housed.

It is that electromechanical coupling factor is K that the utility model adopts the thickness shear vibration polarization mode ₁₅(piezoelectric crystal d ₁₅) piezoelectric material as driver, designed a kind of intelligent torsional oscillation based on thickness shear polarized piezoelectric driver and suppressed bar.As shown in Figure 1, piezoelectric torsion driver 2 and piezoelectric transducer 3 directly are pasted on and hollow round bar 4 outer surfaces by adhesive, the end of the as far as possible approaching hollow round bar in position that piezoelectric torsion driver 2 is pasted, the torsional moment best results of Chan Shenging like this.The position that piezoelectric transducer 3 is pasted is above piezoelectric torsion driver, and it is approaching as far as possible, because the signal that can experience of sensor is bigger like this, and because the strain quantity of electric charge of torsion of bar amount of deformation and sensor is linear, so the signal of sensor size is proportional with the torsional vibration displacement size of boom end.Contiguous block 1 and contiguous block 5 are connected in the two ends of hollow round bar 4 respectively by mighty bond stick or welding manner, and can be designed to different structures according to the different connecting object in outside, as screw thread, and spline connection etc.

As shown in Figures 2 and 3, the structure to piezoelectric torsion driver 2 and piezoelectric transducer 3 describes: whole driver and sensor adopt watt shape piezo-electric sheet 6 bonding the forming of thickness shear vibration polarization mode by several.Its manufacturing process is as follows: at first each watt shape piezo-electric sheet 6 (hereinafter to be referred as tile) is polarized as follows, bi-side at each tile apply silver electrode, tile is placed silicone oil, under heating condition, the Dc bias that adds 2～3kV/mm polarizes to piezo-electric sheet, and 8 is plane of polarization (tile left and right side).Adopt the epoxy type binder that tile is become an annulus by the outer surface that identical polarised direction (arrow is represented polarised direction among the figure) directly sticks on hollow round bar 4 then, and from electrode surface 7 both ends of the surface (tile top and bottom) extraction electrode of tile.The internal diameter of tile equals the external diameter of hollow round bar.It is to be noted in addition and divide tile many more when making, shear-polarization is even more, but correspondingly bondingly becomes complicated, if divide tile less, then require polarized voltage high and polarize inhomogeneous, therefore need be according to the suitable number of the external diameter size decision tile of hollow round bar 4.According to the above piezoelectric torsion driver of making, when when its two electrode end surface adds voltage, can produce one and the proportional torsion angle of voltage between the both ends of the surface of driver, change the direction of voltage, the torsion angle direction also changes thereupon.When the contiguous block 1 that suppresses bar maintains static,, be equivalent to apply a torsional moment in the end of the close piezoelectric actuator of hollow round bar 4 by piezoelectric torsion driver is applied voltage.

As shown in Figure 4, carry out the fundamental diagram that torsional oscillation initiatively presses down vibrating system for suppressing bar.Often connect use because suppress bar with other member, for example, when this inhibition bar is used as multi-arm robot's operating arm, generally can load onto joint motor at contiguous block 5 places, this joint motor drives next operating arm again, when this arm is grasping or during the carrying object, will inevitably produce a torsional interaction in suppressing on the bar, when changing, this moment of torsion causes easily that often suppressing torsion of bar vibrates, and when the single order torsion frequency that suppresses bar is low, very easily causes single order torsional oscillation resonance especially.At this moment the terminal operating position of robot can not be asked for by the geometric position of rigidity connecting rod again, and will add the displacement that this torsional oscillation swing causes, thereby the performance accuracy of robot is descended.If can apply at the other end contiguous block 1 place that suppresses bar one with the above-mentioned constantly anti-phase control torque of interference moment of torsion that causes torsionoscillation, then just can reduce to suppress the amplitude that rod twisting vibrates, the performance accuracy of raising robot.Therefore, according to shown in Figure 4, when suppressing to twist distortion when bar is subjected to external interference power, sensor 3 will be experienced the deformation vibration signal and convert vibration to electrical signal, and amplify through signal amplifier and to send into the A/D analog-digital converter, the effect of A/D analog-digital converter is that electrical signal is converted to digital quantity by analog amount, digital quantity is exported control signal by certain control algorithm in controller, the D/A analog-digital converter converts control signal to analog amount by digital quantity, be not enough to the drive pressure electric drive because signal at this moment is fainter, so also must be through a power amplification circuit.Through making driver produce torsional moment in the control signal input piezoelectric actuator that amplifies, offset extraneous torsional deflection and vibration, thereby reached the amplitude that reduces torsional oscillation or make its quick decay.

Controller can adopt PC or other single-chip microcomputer etc., adopts digital control method, can make the algorithm in the controller abundanter.Certain above-mentioned close-loop feedback control fully also can be finished by analog circut.

Claims (2)

1. the intelligent torsional oscillation based on thickness shear polarized piezoelectric driver suppresses bar, it is characterized in that it comprises: hollow round bar (4), piezoelectric transducer (3), piezoelectric torsion driver (2) is contained in two contiguous blocks (1), (5) at hollow round bar (4) two ends respectively; To hollow round bar direction piezoelectric torsion driver (2) and piezoelectric transducer (3) are installed successively at the open circles boom end outer surface that contiguous block one end is housed.

2. the intelligent torsional oscillation based on thickness shear polarized piezoelectric driver according to claim 1 suppresses bar, it is characterized in that: said piezoelectric transducer (3) and piezoelectric torsion driver (2) apply the employing thickness shear vibration polarization mode of silver electrodes by several bi-side watt shape piezo-electric sheet (6) becomes an annulus by identical polarised direction is bonding respectively, sticks on the end of close hollow round bar (4).

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