CZ303923B6 - Circuit arrangement for controlling weight in vibrating electromechanical systems - Google Patents

Abstract

In the present invention, there is disclosed a circuit arrangement for controlling weight in vibrating electromechanical systems, wherein cascade-type connection of an electromechanical converter (2) with a variable electrical impedance produced by an electric parametric transformation two-port (3) with an impedance load (4) is connected to a controlled mechanical system (1) in nodes at which act the force (Fi1) and the velocity (vi1), and wherein said electric parametric transformation two-port (3) has a variable conversion constant. The electric parametric transformation two-port (3) transforms electrical impedance from output terminals to input terminals of the electromechanical converter (2) such that said electromechanical converter (2), disposed upstream said cascade connection, produces a mechanical expression in the form of a change in weight of the vibrating mechanical system on the converter mechanical side. Said electric parametric transformation two-port (3) can have a continuously or stepwise variable conversion or gyration constant in dependence on connection of the impedance converter or inverted rectifier with a converter of the second kind such as piezoelectric or electrostatic converter or on connection of a gyrator with a converter of the first kind, such as electromagnetic, magnetostrictive and the like.

Description

The invention relates to an electromechanical circuit with a converter which transforms a suitably controlled electrical impedance Z _E such that it acts on the "mechanical side" of the converter as a "additional" dynamic stiffness m _d , acting in a mechanical impedance Z _M on vibrations.

BACKGROUND OF THE INVENTION

A change in the mass of the oscillating mechanical element is virtually impossible during operation. In the case of existing systems, this is done in the case of hydromechanical systems, for example by adding or removing liquid medium or in electromechanical filters by abrasion by means of "sanding", etc. This is always a costly process in the operation of the equipment difficult to implement.

Solutions using negative impedance converters or gyrators loaded with variable impedance allow for some improvement - see examples of publications:

• Active and Passive Vibration Isolation and Damping via Shunted Transducers - Bruno de Mameffe, University of Libre de Bruxelles, 14 December 2007 • Vibration Control using Shunted Piezoelectric and Electromagnetic Transducers -Sam Behrens, The University of Newcastle - Australia, May 2004 • Proof- Mass Inertial Vibration Control Using A Shunted Electromagnetic Transducer, Andrew J. Fleming, and SO Reza Moheimani, University of Newcastle - Australia, 2005 • A Novel Adaptive Impedance Control Approach for Active Vibration Suppression Applications, Viresh Wickramasinghea, Chen Yonga, David Zimcika, Tim Haroldb, Fred Nitzscheb, Ottawa - CANADA • A Novel Adaptive Structural Impedance Control Approach to Suppress Aircraft Vibration and Noise, Viresh Wickramasinghea, RTO AVT Symposium on 'Hability of Combat and Transport Vehicles: Noise, Vibration', Prague, 4.-7. Oct. 2004 • A Multi-Mode Blade Damping Control Using Shunted Piezoelectric Transducers with Activ Feedback Structure, Benjamin Choi, NASA's Glenn Research Center, P-SAR Conference, Myrtle Beach, 24-26. Mar. 2009 • US 2009321555 A (NITZSCHE FRED [CA]; FESZTY DAN1EL [CA]; Dec. 31, 2009 • WO 2009/024 537 A (EADS DEUTSCHLAND GMBH [DE]; CONSTANZER PETER [DE]; STORM STEFAN [DE], 26. 2. 2009

However, the solutions published so far deal with damping problems and are limited to variable load resistances or capacities, which limits the range of options for controlling the resonant frequencies of oscillating mechanical systems.

SUMMARY OF THE INVENTION

-1 CZ 303923 B6

The above drawbacks eliminate the weight control circuitry in oscillating electromechanical systems of the present invention, where an electromechanical transducer is connected to a controlled mechanical system in the nodes where the force / / and the velocity v / is connected, to whose electrical output a variable electrical impedance is connected. The essence of the new solution is that this impedance variable is realized through an electrical transformer double gate with a constant impedance load.

In one embodiment, the electromechanical transducer is a type 1 converter and the electrical parametric transformer double gate is formed by a negative impedance converter with a variable conversion constant realized by a second resistor in the positive feedback branch of the negative impedance converter. The impedance load is formed by a capacitor.

In another embodiment, the electromechanical transducer is also a type 1 transducer and the electrical parametric transformer double gate is formed by a negative impedance converter having a variable conversion constant realized by a numerically controlled resistive structure in the positive feedback branch of the negative impedance converter. The impedance load here is also a capacitor.

Another embodiment is when the electromechanical transducer is a type 2 transducer and the electrical parametric transformer double gate is implemented by a variable conversion constant mutator. The impedance load consists of a load resistor.

The wiring can also be realized such that the electromechanical converter is a type 2 converter and the electrical parametric transformer double gate is realized by an electromechanical transformer with a variable transformation constant. The impedance load is then formed by an adjusting capacitor.

The advantage of all these connections is that the electrical part of the electromechanical circuit can be realized in the form of an integrated circuit and in power applications with relatively miniature power elements.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of embodiments for weight control in oscillating electromechanical systems according to the present invention are given in the attached drawings. Figures 1a and 1b show, for the purpose of explaining the entire function, a schematic and principled representation of electromechanical converters of the first and second types. Giant. 2a and 2b show an example of a connection with a type 1 converter with different conversion constant control options. Fig. 3 shows the cascade connection with an electromechanical transformer and a parametric gyratory with variable gyratory-conductivity.

DETAILED DESCRIPTION OF THE INVENTION

The electromechanical transducer may be a type 1 transducer characterized by a transformation matrix:

'0 to; ~ U ₂ ~ _ ^The first . ^K 2 0

or a type 2 electromechanical converter with a transformation matrix:

-2 CZ 303923 B6

X η 0 ' u ₂ ~ 3. 0 T ₂ Her.

where Fj, Vj represent the Fourier image of the mechanical force, respectively the velocity on the mechanical side of the converter, and Uj, Ij are the Fourier images of the voltage, respectively. current on the electrical side of the inverter. The constants ΚΙ, K2 represent the conversion constants of the electromechanical converter type 1 and the constants T1 and T2 represent the transformation constants of the electromechanical converter type 2, see Fig. 1a of the type 1 converter and Fig. 1 b - type 2 converter.

As already mentioned, the weight control circuit in oscillating electromechanical systems is designed such that an electromechanical transducer 2 is connected to the controlled mechanical system even in the nodes where force F _L and velocity v / are connected by a first input terminal 10 and a second input terminal 11. Its electrical output formed by the first output terminal 20 and the second output terminal 21 is connected with a variable electrical impedance which is realized by means of an electrical transformer double gate 3 with an impedance load 4. In the example shown in Fig. 2a there is shown an embodiment where the electromechanical converter 2 It is realized by a type 2 converter and its electrical parametric transformer double gate 3 uses a negative impedance converter with a variable conversion constant. This variable conversion constant is realized by the second resistor R2 in the positive feedback branch of the negative impedance converter formed by the operational amplifier with the first resistor R1. The impedance load 4 of the electromechanical transducer of the first second here is formed by a capacitor C0 connected between the first output terminal 30 and the second output terminal 31 of the electrical parametric transformer gate 3. The adjusting capacitor Co is connected between the first output terminal 20 and the second output terminal 21. weight.

Giant. 2b shows an analogous circuit except that the negative impedance converter has a variable conversion constant realized by a numerically controlled resistive structure (R ^ nx) in the positive feedback branch of the negative impedance converter. These variants can also be varied so that the negative impedance converter does not have a variable conversion constant, but the impedance load 4 is implemented by a variable capacitor Co at the output of the impedance converter.

Another possibility to create a mass control circuit in oscillating electromechanical systems is that the electromechanical transducer 2 is again a second type transducer, but the electrical parametric transformer double gate 3 is implemented by a mutator. The impedance load 4 in this case is formed by a load resistor. In order to achieve a variable electrical impedance, a mutator with a variable conversion constant is used.

FIG. 3 shows another example of wiring. Here, a second type converter is used as the electromechanical transducer 2 and the electrical parametric transformer double gate 3 is realized by an electromechanical transformer with a variable transformation constant. In the example, the impedance load 4 is formed directly by the adjusting capacitor Cg. Again, a modification is possible where the electromechanical transformer has a constant transform constant, but the impedance load 4 is formed by a variable adjusting capacitor Cg.

If the electromechanical transducer 2 formed by the first type transducer with equation (1) is mechanically coupled to the oscillating controlled mechanical system as well as the impedance Ζ ^, see Fig. 2a for its equivalent diagram consisting of mechanical resistance γ, mechanical stiffness Cm and m, and to the electrical output of the electromechanical converter 2 is connected a negative impedance converter forming an electrical parametric transformer double gate 3 an impedance load 4 formed by capacitor C /, then this capacitive load is transformed to the mechanical side of the electromechanical converter 2 3 will be controlled analogously or digitally by changing its conversion constant D (U _: j j if the conversion constant is controlled by voltage U *, or

-3 CZ 303923 B6

D (M case management digital conversion constants, then the change in conversion constants DíUy, D (NJ reflected in changes in the mechanical mass _m, m = or even = mfNx) ·

Fig. 2a shows the connection of an electromechanical converter 2 consisting of a converter of the first type with an electric parametric transformer gate 3 with a voltage controlled second resistor Rj of the negative impedance converter, which is a current type of NIKu. the resistive structure R ^^ in the branch of the negative impedance converter.

Because for the negative impedance converter between the first output terminal 20 and the second output terminal 21 of the electromechanical converter 2 and between the first output terminal 30 and the second output terminal 31 of the electrical transformer double gate 3:

~ u ₂ ~ ₌ 1 0 " O - A - R ₂ (u _x) .A _

then for the impedance Z ₂ at the unloaded input terminals 20, 21 of the electromechanical converter 2 the following applies (4) or if:

Z ' ₂ (= = (5) where

R ₂ (¼)

(6)

Obviously, the transforming double gate of the first kind is essentially a "gyrator", then it transforms the electrical admittance:

T ₂ (»=

Z ₂ (yry)

7 «C / (U _X ) (7) to mechanical admittance according to the formula:

^Y M = ~ Y ₂ (ja) = ja C ₂ '(at _x )

M zp, / rp J --- 2 \ Λ / ¹ 2 ⁷ 2

The following applies to the parametric, ie additional, mass in the oscillating system:

(8)

Italy (9)

-4GB 303923 B6

If an electromechanical converter of the second type described by equation (2) is used, then a parametric electric gyrator described by the equation is switched to its electrical output as a variable electrical impedance:

W _I ₂ _

D (U _X )

D (U _X )

X Λ.

(10)

If the connection according to FIG. 3 is assumed, then the impedance Z ₂ can be determined at the unloaded output terminals 20, 21 of the electromechanical converter ₂ .

Z ₂ (JRO) =

L ₂ (U _x ) = j <aC ₀

D ² (U _X )

C _o

D ² (U _x ) is ₂ (U _x ) (11) (12)

An electromechanical converter of the second kind, the electromechanical transformer, transforms the electrical impedance into a mechanical impedance according to the formula:

ZL ^c q ^{m, d} T 2 D ² (UX) (13) (14) where equation (14) represents the relation for the additional (parametric) mass acting in the oscillating system. This stiffness m _d (U _x ) can be controlled by the control voltage on the parametric gyrator by changing the gylation constant D (U _x ).

Industrial applicability

It is envisaged that the invention can be used in the mechanical engineering industry for products with oscillating mechanical components, for devices with fine mechanics, for products with oscillating mechanical components, where weight change is preferably used. It can also be used for the production of vehicles with adjustable damping systems and for motors with variable stiffness springs. It is also expected to be used in electroacoustic devices with variable mass of membranes and oscillating electrodes in microphones and loudspeakers.

Claims (5)

PATENT CLAIMS Wiring for weight control in oscillating electromechanical systems in a regulated mechanical system (1), where in nodes where force (£ /) and speed (γ) are applied, an electromechanical converter (2) is connected to which an output variable is connected electrical impedance, characterized in that the variable electrical impedance connected to the electrical output of the electromechanical transducer (2) is realized by an electrical parametric transforming double gate (3) with an impedance load (4), wherein the electrical parametric transforming double gate (3) has a variable conversion constant. Connection according to claim 1, characterized in that the electromechanical converter (2) is a type 1 converter and the electrical parametric transformer double gate (3) is a negative impedance converter whose variable conversion constant is realized by the second resistor (R ₂ ) in the positive branch. a negative feedback impedance converter, wherein the load impedance (4) is formed by a capacitor (C _'). Connection according to claim 1, characterized in that the electromechanical converter (2) is a type 1 converter and the electrical parametric transformer double gate (3) is a negative impedance converter whose variable conversion constant is realized by a numerically controlled resistive structure (R ₂ (n) _x>) in a branch of the positive feedback of the negative impedance converter, wherein the load impedance (4) is formed by a capacitor (C _'). Connection according to claim 1, characterized in that the electromechanical transducer (2) is a type 2 transducer and the electrical parametric transformer double gate (3) is realized by a mutator, the impedance load (4) being formed by a load resistor. Connection according to claim 1, characterized in that the electromechanical transducer (2) is a type 2 transducer and the electrical parametric transformer double gate (3) is realized by an electromechanical transformer, the impedance load (4) being a setting capacitor (Co).