CN102437781B - Based on distributed piezoelectric actuator Active Vibration Control circuit optimization structure and method - Google Patents

Abstract

An optimized structure based on a distributed piezoelectric actuator structural vibration active control circuit, which consists of a distributed piezoelectric actuator, a piezoelectric beam and a circuit structure. The distributed piezoelectric actuator connects the circuit structure with the piezoelectric electric beam. It can easily change the polarity of the piezoelectric actuator and overcome the difficulty that traditional actuators cannot excite complex vibrations. It is an optimization of the active control of distributed piezoelectric actuators with novel design and can be widely used in practice. structure, which improves the active vibration control effect of the distributed piezoelectric structure, and can meet the multi-mode control through the circuit adjustment and increase or decrease of the structure; based on the distributed piezoelectric actuator structural vibration active control circuit optimization method, there are Five steps. The invention has better practical value and broad application prospect in the field of active control of structure vibration.

Description

Optimal structure and method of vibration active control circuit based on distributed piezoelectric actuator

1. Technical field

The invention relates to an optimized structure and method based on a distributed piezoelectric actuator vibration active control circuit, including significantly improving the effect and efficiency of piezoelectric actuators in active vibration control through the application of the circuit, which belongs to the active control of structural vibration field.

2. Background technology

In recent decades, with the development and needs of science and technology, the vibration conditions of aircraft, ships and other structures have become increasingly complex and severe. How to effectively and accurately carry out active control of structural vibration has become a hot topic in many literatures. Among them, piezoelectric actuation The application of piezoelectric actuators in the field of active control of structural vibration has greatly encouraged active vibration control researchers. Compared with traditional exciters and vibration tables, piezoelectric actuators are small in size and light in weight, and can directly convert electromechanical signals. , and can be distributed and integrated in large quantities, which can meet the vibration active control requirements of most structural materials, but for complex vibration conditions, such as the forced vibration of high Mach flexible structures during flight, the control effect of piezoelectric actuators is comparable to that of The control efficiency is still not ideal.

The present invention intends to use the piezoelectric beam structure as a typical structure to explain the application of the vibration active control optimization circuit based on the distributed piezoelectric actuator, but the present invention is also applicable to other structures, especially large flexible aerospace structures. Fig. 1 is a typical piezoelectric actuator control schematic diagram used in many literatures, in which, 1 beam; 2 actuator piece; 3 measuring piece; _4,5 resistance; 6 operational amplifier _;

It can be seen from the figure:

a. A piezoelectric operating piece 2 is pasted on the lower surface of the beam 1, and a piezoelectric measuring piece 3 of the same size is pasted on the corresponding position on the upper surface, and a large resistance 4 is followed by a resistance 5 and an operational amplifier 6 to form a piezoelectric strain sensor ( Piezoelectric film can be used as measuring film and action film);

b. The output voltage u _s of the piezoelectric strain sensor is subtracted from the external excitation voltage _ue by the differential amplifier g _s s, and the piezoelectric actuator is excited by the power amplifier gain g _a to form a closed-loop control system.

Figure 2 is a simple diagram of the distribution of piezoelectric actuator actuators. In general engineering tests, the excitation structure integrated with many piezoelectric actuators will be used, consisting of multiple groups of 1, 2, 3... A vibration excitation system composed of piezoelectric actuators, each group of piezoelectric actuators is composed of two symmetrical piezoelectric sheets up and down.

3. Contents of the invention

(1) Purpose: The purpose of the present invention is to provide an optimization structure and method based on a distributed piezoelectric actuator vibration active control circuit, which can easily change the polarity of the piezoelectric actuator and overcome the traditional actuator The difficulty of being unable to excite complex vibrations is a design optimization method that can be widely used in practice for the active control of distributed piezoelectric actuators.

(2) Technical solution:

1. See Figure 3, an optimized structure based on distributed piezoelectric actuator vibration active control circuit, which consists of distributed piezoelectric actuators 1, 2, 3, 4...10, circuit structures A, B and pressure Composed of electric beams C, the position connection relationship between them is: distributed piezoelectric actuators 1, 2, 3, ... 10 connect circuit structures A, B and piezoelectric beam C through wires;

The distributed piezoelectric actuators 1, 2, 3, ... 10 are respectively composed of two piezoelectric actuators on the upper and lower surfaces of the piezoelectric beam C, and the piezoelectric actuators are made of ceramic piezoelectric materials , the shape is a rectangle;

The piezoelectric beam C is the object of vibration control, and it performs vibration control through piezoelectric actuators pasted on the upper and lower surfaces;

The circuit structure A, B is one of the main components of the circuit optimization structure, which is composed of a circuit board and a connector that can perform circuit conversion and provide a circuit voltage device by exchanging the plug-in, and it becomes a circuit box structure through improvement , which is connected to the positive and negative poles of the piezoelectric actuator through wires to form an optimized structure based on the active vibration control of distributed piezoelectric actuators;

Among them, the power amplifier, power supply, etc. are omitted in the drawings; and the number of pressure-reducing electric actuators and corresponding circuits can be increased according to needs, and the circuit structures A and B can be drawn out as shown in Figure 3 and 1, 2, 3 ... and other distributed piezoelectric actuators are connected, and the voltage direction of the circuit structure can be changed by means of knobs, etc., so distributed piezoelectric actuators 1, 2, 3...10, circuit structures A, B and connecting lines are all A simple active control optimization circuit structure based on distributed excitation is formed, together with an external (omitted in the figure) power amplifier, power supply and SD instrument, it can optimize the vibration active control of the piezoelectric beam.

Among them, the thickness of the piezoelectric actuator should not exceed 0.3 mm, and the area should not exceed 3 square centimeters;

Among them, the power amplifier, circuit structure A, B, etc. can meet the requirements of the function and can be purchased for general use in the market or made by yourself.

2. According to the piezoelectric effect of the piezoelectric actuator, it is known that the direction of the stress can be changed by changing the direction of the voltage. Then in the complex vibration process, in order to carry out more accurate active vibration mode control, it can be constructed as shown in the figure 3 shows the vibration active control circuit, which omits the damping control and amplification links:

The circuit structures A and B in Fig. 3 can respectively control 1, 2...5 piezoelectric actuators and 6, 7...10 piezoelectric actuators, and the circuit structures A and B can also be controlled by Change the switch or knob of the connector to change the direction of the distributed piezoelectric actuator voltage. In order to enhance the vibration control effect, generally, the piezoelectric actuators are arranged symmetrically on the upper and lower surfaces of the piezoelectric beam C (the lower surface actuators are omitted in FIG. 2 ). In this way, vibration testing instruments such as laser vibrometers can be used to roughly measure the mode shape of the piezoelectric beam C, and the mode shapes of piezoelectric beams 1, 2, 3, 4... and other orders can be obtained. Mode as an example, assuming that the second-order vibration shape is shown in Figure 4:

First, calculate the phase of the second-order mode of the piezoelectric beam. In the 1-A group and the 1-C group, the voltage in the same direction is applied to the piezoelectric beam to vibrate in the same direction. In the 1-B group, it is connected with 1-A, 1 -C opposite voltage, combined with the phase of the first-order mode of beam C to determine the initial mode shape, determine the 1-A group, 1-C group piezoelectric actuators produce the same strain direction as the initial mode shape direction of the corresponding position; the response In Figure 3, piezoelectric actuators 2 and 3 represent the position of group 1-A, piezoelectric actuators 5 and 6 represent the position of group 1-B, and piezoelectric actuators 8 and 9 represent group 1-C. . Through the circuit boxes A and B in Figure 3, the polarity and size of the circuit voltage are controlled to meet the requirements shown in Figure 4. Considering the vibration shape, it can be corrected by SD instruments. Generally, the circuit box 1-A group is adjusted. , 1-B group, 1-C group circuit voltage polarity method. In this way, the purpose of improving the active control effect of piezoelectric beam vibration can be achieved.

In summary, the present invention is based on the optimization method of the distributed piezoelectric actuator vibration active control circuit, and the specific steps of the method are as follows:

Step 1: Establish the distributed piezoelectric actuator on the piezoelectric beam C as shown in Figure 2. The piezoelectric actuator can be pasted on the piezoelectric beam C equidistantly by using strong insulating glue , the lower two sides (the lower surface is omitted in the figure);

Step 2: Use wires to connect the distributed piezoelectric actuators with the corresponding connectors of circuit structures A and B as shown in Figure 3, and change the voltage polarity of each group of piezoelectric actuators through circuit structures A and B ;

Step 3: Then externally connect power amplifiers, vibration control instruments, power supplies and damping control structures to circuit structures A and B;

Step 4: Use the laser vibrometer to measure the specific mode shape, and calculate the initial phase of the mode;

Step 5: Combining the mode shape and the initial phase, through the circuit structure A and B, the voltage polarity of each group of piezoelectric actuators is appropriately transformed, so that the starting direction of the corresponding position is the same as the initial mode shape direction of the position, and the The optimal control of the mode shape, thus constructing the optimal structure of the vibration active control circuit based on the distributed piezoelectric actuator.

Among them, the specific implementation process of "using the laser vibrometer to measure the specific mode shape and calculate the initial phase of the mode" described in step 4 is as follows:

According to the 1st, 2nd, 3rd, 4th order... modes of the test piezoelectric beam structure measured by the laser vibrometer, the transfer function characteristics are obtained by using the signal transmitter to conduct the sinusoidal vibration test of the corresponding frequency according to the modal frequency . According to the formula:

The phase-frequency characteristics of the piezoelectric beam transfer function can be obtained

α(w)=δ(w)-ε(w);

Among them, H(w) is the transfer function, Y(w) is the response signal, X(w) is the input signal; α(w) is the phase-frequency characteristic of the transfer function, δ(w) is the corresponding phase of the response function, ε( w) is the corresponding phase of the input signal. The initial phase of the response of the piezoelectric beam can be obtained by the initial phase of the input signal and the phase-frequency characteristic of the transfer function obtained from the experiment.

(3) Advantages and effects: Due to the adoption of the above-mentioned distributed piezoelectric actuator active control optimization circuit, the active vibration control effect of the distributed piezoelectric structure is improved, and the circuit adjustment and increase or decrease of the structure can be used to meet the multi-mode State control is an invention that can effectively control the structure of multi-mode piezoelectric beams.

4. Description of drawings

Figure 1a is a schematic diagram of a typical piezoelectric independent mode control

Figure 1b is a schematic diagram of piezoelectric sheet cutting

Figure 2 is a schematic diagram of the distributed piezoelectric vibration structure of multiple piezoelectric actuators applied to piezoelectric beams

Figure 3 is a schematic diagram of an active control optimization circuit based on distributed excitation

Figure 4 is a simple diagram of the second-order vibration shape of the piezoelectric beam

Fig. 5 is a flowchart of the present invention

The symbols in the figure are explained as follows:

In Fig. 1, 1 beam; 2 operating piece; 3 measuring piece; 4, 5 resistance; 6 operational amplifier; 7 gain g _s ; 8 gain g _a .

In Figure 2 and Figure 3, 1, 2, 3, 4, 5...10 are distributed piezoelectric actuators, C is a piezoelectric beam, A and B are circuit structures, 1-A, 1-B, 1-C represents the approximate position of a mode shape;

5. Specific implementation

1. The present invention is based on a distributed piezoelectric actuator vibration active control circuit optimization structure, as shown in Figure 3, consisting of distributed piezoelectric actuator groups 1, 2, 3, 4..., piezoelectric beam C, The circuit box A and B are composed, and the position connection relationship between them is:

The distributed piezoelectric actuators are 1, 2, 3, ... 10 in the figure, and they connect circuit structures A, B and piezoelectric beam C through wires;

The distributed piezoelectric actuators 1, 2, 3, ... 10 are ceramic piezoelectric materials, the thickness is not more than 0.3 mm, the area is not more than 3 square meters, and the shape is rectangular;

The piezoelectric beam C is the object of vibration control, and its upper and lower surfaces are pasted with piezoelectric actuators;

The circuit structure A is one of the main components of the circuit optimization structure. It is composed of circuit boards and connectors, which can perform circuit conversion and provide loop voltage by exchanging plug-ins. It can be improved to become a circuit box structure. The positive and negative electrodes of the piezoelectric actuator are connected together to form an optimal structure based on the active vibration control of the distributed piezoelectric actuator;

The circuit structure B is also one of the main components of the circuit optimization structure. It is composed of a circuit board and a connector that can perform circuit conversion and provide a circuit voltage device by exchanging the plug-in. It can be improved to become a circuit box structure. The positive and negative electrodes of the piezoelectric actuator are connected together to form an optimal structure based on the active vibration control of the distributed piezoelectric actuator;

The specific construction method is shown in Figure 3, where power amplifiers, power supplies, etc. are omitted in Figure 3; and the number of pressure-reducing electric actuators and corresponding circuit boxes can be increased according to needs, and the circuit boxes can be led out as shown in Figure 3 1, 2, 3... and other circuits, and the direction of the circuit voltage can be changed by means of knobs, etc., so piezoelectric actuators 1, 2, 3...10, circuit boxes A, B and connecting wires, etc. plus the omitted power amplifier power supply and SD The instrument constitutes a simple active control optimization circuit based on distributed excitation, and optimizes the control of the piezoelectric beam by changing the voltage polarity of the piezoelectric actuator.

Among them, the thickness of the piezoelectric actuator should not exceed 0.3 mm, and the area should not exceed 3 square centimeters;

Among them, power amplifiers, circuit boxes, etc. can meet the requirements of the function and can be purchased in the market or made by yourself.

Taking the second-order mode as an example, assume that the second-order vibration shape is shown in Figure 4:

First, calculate the phase of the first-order mode of the piezoelectric beam. In the 1-A group and the 1-C group, the voltage in the same direction is applied to make the piezoelectric beam vibrate in the same direction. In the 1-B group, it is connected with 1-A, 1 -C opposite voltage, combined with the phase of the first-order mode of beam C to determine the initial mode shape, determine the 1-A group, 1-C group piezoelectric actuators produce the same strain direction as the initial mode shape direction of the corresponding position; the response In Figure 3, piezoelectric actuators 2 and 3 represent the position of group 1-A, piezoelectric actuators 5 and 6 represent the position of group 1-B, and piezoelectric actuators 8 and 9 represent group 1-C. . Through the circuit structure A and B in Figure 3, the polarity and size of the circuit voltage are controlled to meet the requirements shown in Figure 4. Considering the problem of the mode shape, it can be corrected by the SD instrument. Generally, the circuit structure 1-A group is adjusted. , 1-B group, 1-C group circuit voltage polarity method. In this way, the purpose of improving the active control effect of piezoelectric beam vibration can be achieved.

2. The present invention is a vibration active control circuit optimization method based on distributed piezoelectric actuators. The specific steps of the method are as follows:

Step 1: Establish the distributed piezoelectric actuator on the piezoelectric beam C as shown in Figure 2. You can paste the piezoelectric actuator in the same position (up and down symmetrical) on the piezoelectric beam C by using strong insulating glue. The upper and lower sides of beam C;

Step 2: Use wires to connect the distributed piezoelectric actuators with circuit structures A and B as shown in Figure 3, and the voltage polarity of each group of piezoelectric actuators can be changed through the circuit structure;

Step 3: Then externally connect power amplifiers, vibration control instruments, power supplies and damping control structures to the circuit structure;

Step 4: Measure the 1st, 2nd, 3rd, 4th order...modes of the test piezoelectric beam structure according to the laser vibrometer, and according to the modal frequency

The frequency uses the signal transmitter to conduct the sinusoidal vibration test of the corresponding frequency to obtain the transfer function characteristics. According to the formula: The phase-frequency characteristics of the piezoelectric beam transfer function α(w)=δ(w)-ε(w) can be known;

Where H(w) is the transfer function, Y(w) is the response signal, X(w) is the input signal; α(w) is the phase-frequency characteristic of the transfer function, δ(w) is the corresponding phase of the response function, ε(w ) is the corresponding phase of the input signal. The initial phase of the response of the piezoelectric plate can be obtained by the initial phase of the input signal and the phase-frequency characteristics of the test.

Step 5: Combining the mode shape and initial phase, through the circuit control structures A and B, the voltage polarity of each group of piezoelectric actuators is appropriately changed, so that the starting direction of the corresponding position is the same as the initial mode shape direction of the position, The optimal control of the mode shape is obtained, thus completing the establishment of the optimized structure of the vibration active control circuit based on the distributed piezoelectric actuator. The flowchart is shown in Figure 5 below.

Claims (2)

1., based on distributed piezoelectric actuator active control in structural vibration circuit optimization structure, it is characterized in that: comprise distributed piezoelectric actuator, piezoelectric beam C, circuit structure A and circuit structure B, the position annexation between them is:

Described distributed piezoelectric actuator is by electric wire connecting circuit structure A, circuit structure B and piezoelectric beam C;

Described distributed piezoelectric actuator is ceramic piezoelectric material, and thickness is no more than 0.3mm, and area is no more than 3 square centimeters, and shape is rectangle;

Described piezoelectric beam C is the object of vibration control, and its upper and lower surface is pasted with distributed piezoelectric actuator;

Described circuit structure A is one of part of circuit optimization structure, it is by circuit board, what connector formed can carry out circuit transformations by exchange cards and provide the device of loop voltage, carry out improvement and become circuit box structure, it to be connected with distributed piezoelectric actuator both positive and negative polarity jointly to form by electric wire optimizes structure based on distributed piezoelectric actuator Active Vibration Control;

Described circuit structure B is also one of part of circuit optimization structure, it is by circuit board, what connector formed can carry out circuit transformations by exchange cards and provide the device of loop voltage, carry out improvement and become circuit box structure, it to be connected with distributed piezoelectric actuator both positive and negative polarity jointly to form by electric wire optimizes structure based on distributed piezoelectric actuator Active Vibration Control;

Wherein, distributed piezoelectric actuator thickness does not exceed 0.3 millimeter, and area does not exceed 3 square centimeters;

Wherein, circuit structure A controls 1,2,3,4 and 5 road piezoelectric actuators respectively; Circuit structure B controls 6,7,8,9 and 10 road piezoelectric actuators respectively;

By circuit control structure A, B proper transformation respectively organize piezoelectric actuator voltage pole to, make the starting of oscillation direction of relevant position identical with this POS INT vibration shape direction, obtain the optimal control of this Mode Shape.

2., based on a distributed piezoelectric actuator Active Vibration Control circuit optimization method, the method concrete steps are as follows:

Step one: the foundation carrying out distributed piezoelectric actuator on piezoelectric beam C, adopts the mode that powerful insulative glue is pasted, and distributed piezoelectric actuator coordination is attached to piezoelectric beam C upper and lower faces;

Step 2: adopt electric wire that distributed piezoelectric actuator is connected with circuit structure A, circuit structure B, the voltage pole that can be changed distributed piezoelectric actuator by circuit structure to;

Step 3: then at the external power amplifier of circuit structure, vibration control instrument, power supply and damp controlling structure;

Step 4: the mode recording test piezoelectric beam structure according to laser vibration measurer, obtains transfer function characteristics at the sinusoidal vibration test adopting signal projector to carry out corresponding frequencies according to model frequency; According to formula: know phase-frequency characteristic α (w)=δ (the w)-ε (w) of piezoelectric beam transfer function;

Wherein, H (w) is transfer function, and Y (w) is response signal, and X (w) is input signal; The phase-frequency characteristic of α (w) transfer function, the respective phase that δ (w) is response function, the respective phase that ε (w) is input signal; The biography letter phase-frequency characteristic got by initial phase and the test of input signal is obtained piezoelectric board and responds initial phase;

Step 5: in conjunction with this Mode Shape and initial phase, by circuit structure A, circuit structure B proper transformation respectively organize piezoelectric actuator voltage pole to, make the starting of oscillation direction of relevant position identical with this POS INT vibration shape direction, obtain the optimal control of this Mode Shape, so just complete the establishment of the Active Vibration Control circuit optimization structure based on distributed piezoelectric actuator;

Wherein, circuit structure A controls 1,2,3,4 and 5 road piezoelectric actuators respectively; Circuit structure B controls 6,7,8,9 and 10 road piezoelectric actuators respectively.