Active and passive vibration control device and vibration control method for printed circuit board

Abstract

The present invention discloses a printed circuit board active and passive vibration control device and a vibration control method, the device comprises a piezoelectric control patch, a piezoelectric sensing patch, a shunt piezoelectric damping circuit, a DSP control module, and an amplifier module, wherein: the piezoelectric control patch comprises an active control piezoelectric drive patch and a passive control piezoelectric control patch; the piezoelectric sensing patch comprises an active control piezoelectric sensing patch and a passive control piezoelectric sensing patch; the passive control piezoelectric control patch is connected to the shunt piezoelectric damping circuit to form a passive vibration control part of the printed circuit board; the active control piezoelectric drive patch and the active control piezoelectric sensing patch are respectively connected to the amplifier module and the DSP control module, and the amplifier module is connected to the DSP control module to form an active vibration control part of the printed circuit board. The present invention can effectively suppress the vibration of the PCB, significantly improve the dynamic environment of the printed circuit board and the electronic equipment, and improve the reliability and stability of the equipment operation.

Description

Technical Field

[0001] The invention belongs to the field of flexible structure vibration control, and relates to an active and passive control device and method for a printed circuit board and a flexible structure. Background Art

[0002] Printed circuit boards are the carriers of all electronic products. With the development and progress of society, the integration of electronic products is getting higher and higher, the functions are becoming more and more complex, and the size is getting smaller and smaller. This has led to more and more components integrated on printed circuit boards, and the mechanical properties are becoming more complex. Most of the components on printed circuit boards are developing in the direction of miniaturization, lightness, intelligence and high-density integration. Under the condition of long-term service, dynamic loads such as vibration and impact will cause large alternating stresses on printed circuit boards and accompanying devices, resulting in broken solder joints, damaged seals, broken wires, etc., affecting their reliability.

[0003] Direct structural damage: When an electronic device is subjected to a certain external excitation frequency, it will resonate and its amplitude will gradually increase. When its vibration acceleration exceeds the limit allowable acceleration, or the impact force generated by the impact excitation exceeds the strength limit of the device itself, the electronic device will be damaged.

[0004] Internal fatigue damage: mainly manifested in printed circuit boards and components on them. Although the stress caused by vibration acceleration or impact force is far lower than the static load strength of the material, long-term repeated vibration or impact will cause fatigue damage to electronic equipment.

[0005] Electrical function failure: Printed circuit boards are the main components of electronic equipment. There are some sensitive areas on the board. Under certain vibration loads or impact forces, the wires installed in this area are deformed and displaced, resulting in changes in relative positions, causing changes in electrical distribution parameters. When the parameter displacement exceeds the allowable range, the circuit board will fail due to electronic failure.

[0006] For flexible structures, conventional active and passive control systems generally need to add dampers that have a greater impact on the mass of the mechanical structure or paste large elastic materials. Such structures have an important impact on the statics and dynamics of the controlled object. However, for PCBs with extremely strict weight and performance requirements, it is difficult or even impossible to use active structural vibration control methods.

[0007] Due to the existence of positive and negative piezoelectric effects, piezoelectric materials have the characteristics of low power consumption, electrical operation, wide bandwidth and the ability to generate force by themselves. They can not only be used as sensitive sensing materials, but also as actuators and energy harvesters. They are widely used in deformation and vibration control of flexible structures.

[0008] Although a variety of intelligent algorithms have been adopted in existing vibration control strategies, most of them have only been preliminarily implemented and have their own limitations in application, and further in-depth exploration and research are needed.

[0009] Once the onboard electronic equipment fails, it may cause the equipment to stop working or not operate according to the preset functions, which may further cause major economic losses or failure of scientific research experiments, or even lead to unpredictable safety accidents. Piezoelectric active vibration reduction intelligent mechanism has rich research connotations and complex control problems. It can not only explore new methods of shape, quantity and position of piezoelectric structure in academia, but also obtain innovative ability and development experience of cross-integration of knowledge in technology, and provide key technical foundation for other scientific research and engineering fields in application expansion. Summary of the invention

[0010] In order to improve the dynamic environment of a printed circuit board and the electronic components thereon, and to enhance the overall reliability of the printed circuit board as well as the safety and stability of its operation, the present invention provides an active and passive vibration control device and a vibration control method for a printed circuit board, which can be used to suppress the vibration of printed circuit boards such as computer mainboards, vehicle control boards, and aircraft circuit boards.

[0011] The objective of the present invention is achieved through the following technical solutions:

[0012] A printed circuit board active and passive vibration control device, comprising a piezoelectric control patch, a piezoelectric sensor patch, a shunt piezoelectric damping circuit, a DSP control module, and an amplifier module, wherein:

[0013] The piezoelectric control patch includes an actively controlled piezoelectric drive patch and a passively controlled piezoelectric control patch;

[0014] The piezoelectric sensor patch includes an actively controlled piezoelectric sensor patch and a passively controlled piezoelectric sensor patch;

[0015] The active control piezoelectric driving patch and the active control piezoelectric sensing patch are co-located and pasted on one side of the upper and lower surfaces of the printed circuit board;

[0016] The passive control piezoelectric control patch and the passive control piezoelectric sensing patch are co-located and pasted on the other side of the upper and lower surfaces of the printed circuit board;

[0017] The passive control piezoelectric control patch is connected to the shunt piezoelectric damping circuit to form a passive vibration control part of the printed circuit board;

[0018] The active control piezoelectric driving patch and the active control piezoelectric sensing patch are respectively connected to the amplifier module and the DSP control module, and the amplifier module and the DSP control module are connected to form an active vibration control part of the printed circuit board.

[0019] A vibration control method for the above-mentioned active and passive vibration control device for a printed circuit board comprises the following steps:

[0020] Step 1: The vibration signal caused by external excitation or free vibration acts on the piezoelectric control patch and the piezoelectric sensing patch pasted on the printed circuit board;

[0021] Step 2: Due to the existence of the positive piezoelectric effect, the mechanical signal acting on the piezoelectric control patch and the piezoelectric sensing patch is converted into an electrical signal, which can map the amplitude and frequency of the printed circuit board;

[0022] Step 3: Passive control part: Due to the external shunt piezoelectric damping circuit, the voltage formed on the passively controlled piezoelectric control patch will generate current in the closed-loop circuit, and the energy-consuming elements on the shunt piezoelectric damping circuit will dissipate energy, thereby reducing the vibration kinetic energy of the printed circuit board;

[0023] Step 3: The signals representing the amplitude and frequency of the printed circuit board on the actively controlled piezoelectric sensor patch will be collected by the DSP module, and then the voltage analog signals will be output using the LMS adaptive filtering control algorithm. These analog signals will be applied to the actively controlled piezoelectric drive patch through the amplifier module. The inverse piezoelectric effect of the actively controlled piezoelectric drive patch will convert electrical energy into mechanical energy. The vibration displacement generated by the converted mechanical energy is opposite to the original vibration displacement of the printed circuit board, thereby offsetting the vibration of the circuit board caused by external excitation.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] 1. The present invention can effectively suppress the vibration of PCB, and compared with general vibration control devices and methods, the present invention can significantly improve the dynamic environment of printed circuit boards and electronic equipment, and improve the reliability and stability of equipment operation in terms of equipment performance, economy and safety.

[0026] 2. The present invention has the advantages of simple structure, wide control frequency range, low energy consumption, small size, strong controllability, high real-time performance, active and passive regulation and high control accuracy.

[0027] 3. The device of the present invention has high robustness. Even if one of the active and passive control modes loses the control effect, the other one may provide vibration control capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural diagram of the active and passive vibration control device for a printed circuit board;

[0029] Figure 2 This is the passive control effect diagram;

[0030] Figure 3 This is the active control effect diagram;

[0031] In the figure: 1. Passive control piezoelectric control patch; 2. Shunt piezoelectric damping circuit; 3. Printed circuit board; 4. Amplifier module; 5. DSP control module; 6. Active control piezoelectric drive patch; 7. Active control piezoelectric sensing patch. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further described below in conjunction with the accompanying drawings, but is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be included in the protection scope of the present invention.

[0033] The present invention provides a printed circuit board active and passive vibration control device, such as Figure 1 As shown, the device includes a piezoelectric control patch, a piezoelectric sensing patch, a shunt piezoresistive damping circuit 2, a DSP control module 5, and an amplifier module 4, wherein:

[0034] The shunt piezoresistive damping circuit is used in passive control to convert the electrical energy in the shunt piezoresistive damping circuit into other forms of energy for dissipation;

[0035] The DSP control module is used to collect the vibration signal of the PCB board in active control, and then output the control signal using the LMS adaptive filtering control algorithm;

[0036] The amplifier module is used to amplify the analog signal output by the DSP control module and then act on the active control piezoelectric drive patch;

[0037] The piezoelectric control patch includes an active control piezoelectric drive patch 6 and a passive control piezoelectric control patch 1;

[0038] The piezoelectric sensor patch includes an actively controlled piezoelectric sensor patch 7 and a passively controlled piezoelectric sensor patch;

[0039] The active control piezoelectric driving patch 6 and the active control piezoelectric sensing patch 7 are co-located and pasted on one side of the upper and lower surfaces of the printed circuit board 3;

[0040] The passive control piezoelectric control patch 1 and the passive control piezoelectric sensing patch are co-located and pasted on the other side of the upper and lower surfaces of the printed circuit board 3;

[0041] The shunt piezoresistive damping circuit 2, the DSP control module 5 and the amplifier module 4 are not integrated with the printed circuit board 3, but are respectively arranged around the printed circuit board 3;

[0042] The passive control piezoelectric control patch 1 is connected to the shunt piezoelectric damping circuit 2 to form a passive vibration control part of the printed circuit board;

[0043] The active control piezoelectric driving patch 6 and the active control piezoelectric sensing patch 7 are respectively connected to the analog input pin of the amplifier module 4 and the analog acquisition pin of the DSP control module 5. The amplifier module 4 and the DSP control module 5 are connected to form the active vibration control part of the printed circuit board.

[0044] Working principle:

[0045] When external excitation acts on the printed circuit board, the printed circuit board will generate mechanical vibration. Usually, this vibration frequency is in the low-frequency range. Due to the positive piezoelectric effect, the vibration of the printed circuit board will cause the upper and lower surfaces of the piezoelectric material attached to its surface to generate equal positive and negative charges, thereby forming an electric potential difference. Since the peripheral shunt circuit of the passive vibration control is a closed-loop circuit, this electric potential difference will form a certain amount of current, which will generate energy dissipation on energy-consuming components, thereby suppressing the vibration of the printed circuit board; and the piezoelectric sensor patch will also generate voltage signals. These signals are collected and processed by the DSP analog quantity acquisition port and used as feedback signals of the control algorithm. Then, the LMS adaptive filtering control algorithm is used to output voltage analog signals. These analog signals are applied to the piezoelectric drive patch through the amplifier. The inverse piezoelectric effect of the piezoelectric drive patch will convert electrical energy into mechanical energy. The vibration displacement generated by the converted mechanical energy is opposite to the original vibration displacement of the printed circuit board, thereby offsetting the vibration of the circuit board caused by external excitation.

[0046] A vibration control method for the above-mentioned active and passive vibration control device for a printed circuit board comprises the following steps:

[0047] Step 1: The vibration signal caused by external excitation or free vibration acts on the piezoelectric control patch and the piezoelectric sensor patch attached to the printed circuit board.

[0048] Step 2: Due to the existence of the positive piezoelectric effect, the mechanical signal acting on the piezoelectric control patch and the piezoelectric sensing patch is converted into an electrical signal, which can map the amplitude and frequency of the printed circuit board.

[0049] Step 3: In the passive control part, due to the external shunt piezoelectric damping circuit, the voltage formed on the passively controlled piezoelectric control patch will generate current in the closed-loop circuit, and the energy-consuming elements on the shunt piezoelectric damping circuit will dissipate energy, thereby reducing the vibration kinetic energy of the printed circuit board.

[0050] Step 3: The signals representing the amplitude and frequency of the printed circuit board on the actively controlled piezoelectric sensor patch will be collected by the DSP module, and then the voltage analog signals will be output using the LMS adaptive filtering control algorithm. These analog signals will be applied to the actively controlled piezoelectric drive patch through the amplifier module. The inverse piezoelectric effect of the actively controlled piezoelectric drive patch will convert electrical energy into mechanical energy. The vibration displacement generated by the converted mechanical energy is opposite to the original vibration displacement of the printed circuit board, thereby offsetting the vibration of the circuit board caused by external excitation.

[0051] In the present invention, the passive control is composed of a passively controlled piezoelectric control patch and a shunt piezoresistive damping circuit, wherein: the shunt piezoresistive damping circuit has various forms, which can be a combination of inductance, resistance and negative capacitance. The present invention adopts the form of negative capacitance and resistance in series.

[0052] In the present invention, the passive control piezoelectric sensing patch does not participate in the passive control. It is co-located with the passive control piezoelectric control patch on the upper and lower surfaces of the printed circuit board. On the one hand, it can play a role of structural symmetry with the passive control piezoelectric control patch, which is convenient for model establishment. On the other hand, it can be connected to an external acquisition card to collect and display vibration signals. The materials of the passive control piezoelectric control patch and the passive control piezoelectric sensing patch are both PVDF.

[0053] In the present invention, the active control is composed of an active control piezoelectric drive patch, an active control piezoelectric sensor patch, a DSP control module and an amplifier module, wherein: the material of the active control piezoelectric drive patch is PZT5, and the material of the active control piezoelectric sensor patch is PVDF; the DSP control module integrates signal acquisition and control signal output, and the CPU of the DSP control module adopts DSP28335.

[0054] In the present invention, all modules are connected by common wires.

[0055] In practical applications, after engineering calculations and simulations, when a printed circuit board generates forced vibration, the vibration suppression actuator designed by the present invention can effectively suppress the vibration of the printed circuit board, and its active and passive control effects are as follows: Figure 2 and 3 shown.

Claims

1. A printed circuit board active and passive vibration control device, characterized in that The device comprises a piezoelectric control patch, a piezoelectric sensing patch, a shunt piezoresistive damping circuit, a DSP control module, and an amplifier module, wherein: The piezoelectric control patch includes an actively controlled piezoelectric drive patch and a passively controlled piezoelectric control patch; The piezoelectric sensor patch includes an actively controlled piezoelectric sensor patch and a passively controlled piezoelectric sensor patch; The active control piezoelectric driving patch and the active control piezoelectric sensing patch are co-located and pasted on one side of the upper and lower surfaces of the printed circuit board; The passive control piezoelectric control patch and the passive control piezoelectric sensing patch are co-located and pasted on the other side of the upper and lower surfaces of the printed circuit board; The passive control piezoelectric control patch is connected to the shunt piezoelectric damping circuit to form a passive vibration control part of the printed circuit board, and the passive control piezoelectric sensor patch is used for collecting vibration signals; The active control piezoelectric driving patch and the active control piezoelectric sensing patch are respectively connected to the amplifier module and the DSP control module, and the amplifier module and the DSP control module are connected to form an active vibration control part of the printed circuit board.

2. The active and passive vibration control device for a printed circuit board according to claim 1, characterized in that The passively controlled piezoelectric control patch and the passively controlled piezoelectric sensing patch are both made of PVDF.

3. The active and passive vibration control device for a printed circuit board according to claim 1, characterized in that The material of the active control piezoelectric drive patch is PZT5.

4. The active and passive vibration control device for a printed circuit board according to claim 1, characterized in that The material of the active control piezoelectric sensor patch is PVDF.

5. The active and passive vibration control device for a printed circuit board according to claim 1, characterized in that The CPU of the DSP control module adopts DSP28335.

6. The active and passive vibration control device for a printed circuit board according to claim 1, characterized in that The shunt piezoresistive damping circuit adopts a form of a negative capacitor and a resistor connected in series.

7. A control method for the active and passive vibration control device of a printed circuit board according to any one of claims 1 to 6, characterized in that The method comprises: The vibration signal caused by external excitation or free vibration acts on the piezoelectric control patch and the piezoelectric sensor patch attached to the printed circuit board; Due to the existence of the positive piezoelectric effect, the mechanical signal acting on the piezoelectric control patch and the piezoelectric sensing patch is converted into an electrical signal, which maps the amplitude and frequency of the printed circuit board; In the passive control part, due to the external shunt piezoelectric damping circuit, the voltage formed on the passively controlled piezoelectric control patch will generate current in the closed-loop circuit, and the energy-consuming elements on the shunt piezoelectric damping circuit will dissipate energy, thereby reducing the vibration kinetic energy of the printed circuit board; The signals representing the amplitude and frequency of the printed circuit board on the actively controlled piezoelectric sensor patch will be collected by the DSP module, and then the voltage analog signals will be output using the LMS adaptive filtering control algorithm. These analog signals will be applied to the actively controlled piezoelectric drive patch through the amplifier module. The inverse piezoelectric effect of the actively controlled piezoelectric drive patch will convert electrical energy into mechanical energy. The vibration displacement generated by the converted mechanical energy is opposite to the original vibration displacement of the printed circuit board, thereby offsetting the vibration of the circuit board caused by external excitation.

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