阅读说明：本技术 一种电磁悬浮微质量测量系统 (Electromagnetic suspension micro-mass measurement system ) 是由 肖奇军 肖超予 罗忠辉 于 2019-10-21 设计创作，主要内容包括：本发明公开了一种电磁悬浮微质量测量系统,包括检测信号发生器、前置放大器、锁相放大器、激振信号发生器、高压放大器、控制电压合成器、移相电路及控制器；所述锁相放大器包括相连接的乘法器和低通滤波电路；所述前置放大器包括相连接的I-V转换电路和放大器；所述控制器的输入端与锁相放大器相连,控制器的输出端与激振信号发生器连接,激振信号发生器所输出的激振交流电压经高压放大器放大、控制电压合成器处理后输出到控制电极对上,通过产生的静电力控制电磁悬浮微质量的轴向振动以获取谐振频率,谐振频率的变化反映微质量大小。本发明能实现微小质量测量,且具有测量精度高的优点。(The invention discloses an electromagnetic suspension micro-mass measurement system, which comprises a detection signal generator, a preamplifier, a phase-locked amplifier, an excitation signal generator, a high-voltage amplifier, a control voltage synthesizer, a phase-shifting circuit and a controller, wherein the detection signal generator is connected with the preamplifier; the phase-locked amplifier comprises a multiplier and a low-pass filter circuit which are connected; the preamplifier comprises an I-V conversion circuit and an amplifier which are connected; the input end of the controller is connected with the phase-locked amplifier, the output end of the controller is connected with the excitation signal generator, excitation alternating-current voltage output by the excitation signal generator is amplified by the high-voltage amplifier and processed by the control voltage synthesizer and then is output to the control electrode pair, the axial vibration of the electromagnetic suspension micro-mass is controlled through the generated electrostatic force to obtain the resonance frequency, and the change of the resonance frequency reflects the size of the micro-mass. The invention can realize micro-quality measurement and has the advantage of high measurement precision.)

1. An electromagnetic suspension micro-mass measurement system is characterized by comprising a detection signal generator, a preamplifier, a phase-locked amplifier, an excitation signal generator, a high-voltage amplifier, a control voltage synthesizer, a phase-shifting circuit and a controller; the phase-locked amplifier comprises a multiplier and a low-pass filter circuit which are connected, the multiplier is respectively connected with the preamplifier and the phase-shifting circuit, and the low-pass filter circuit is connected with the controller; the detection signal generator is respectively connected with the control voltage synthesizer and the phase-shifting circuit, and the phase-shifting circuit is connected with the multiplier of the phase-locked amplifier; the preamplifier comprises an I-V conversion circuit and an amplifier which are connected, wherein the I-V conversion circuit is used for collecting the mass block amplitude information of the electromagnetic suspension micro-mass measurement system, and the amplifier is connected with the input end of the controller after passing through the phase-locked amplifier; the output end of the controller is connected with an excitation signal generator, the output excitation alternating voltage is amplified by a high-voltage amplifier and processed by a control voltage synthesizer and then is input to a control electrode pair of a mechanical structure of the electromagnetic suspension micro-mass measuring system, and the axial vibration of the electromagnetic suspension micro-mass is controlled by the generated electrostatic force.

2. The electromagnetic levitation micro-mass measurement system as claimed in claim 1, wherein the controller comprises an a/D conversion circuit and three I/O output circuits, the excitation voltage generated by the excitation frequency generator is output through the I/O output circuits, the excitation voltage is converted into equal magnitude different sign voltages through the high voltage amplifier, the equal magnitude different sign voltages are applied to the corresponding control electrode pairs, and the axial amplitude voltage signals of the mass block are converted into digital signals through the a/D conversion circuit.

3. An electromagnetically suspended micro-mass measurement system as claimed in claim 1, wherein said I-V conversion circuit is connected to a common electrode for obtaining a micro-mass axial vibration displacement signal.

4. The system of claim 1, wherein the excitation signal generator and the DDS circuit of the detection signal generator are AD9832 chips.

5. The system of claim 2, wherein the controller is a DSP or ARM controller.

1. Field of the invention

The invention relates to the field of micro-mass measurement in a micro-electromechanical system, in particular to an electromagnetic suspension micro-mass measurement system.

2. Background of the invention

MEMS, that is, micro electro Mechanical Systems (micro electro Mechanical Systems), is a leading-edge research field of multidisciplinary crossing developed on the basis of microelectronic technology, and has become one of the major scientific fields of world attention after more than forty years of development. It relates to various subjects and technologies such as electronics, machinery, materials, physics, chemistry, biology, medicine and the like, and has wide application prospect. The micro device is manufactured by micro processing technology and corresponding processing circuit design is carried out, and the micro device can be widely applied to sensors and drivers. MEMS resonance type quality measurement is a typical application, and the main principle is that the frequency shift is regarded as a sensing output measure by changing the inherent physical characteristics of the MEMS resonator, such as effective mass and stiffness, and changing the corresponding resonance frequency of the resonator, and the MEMS resonance type quality measurement is widely applied to micro-quality measurement.

In order to realize the measurement of the micro mass, the existing method generally installs a mass block on a cantilever beam, and the mass block generates resonance under the electrostatic driving of alternating voltage to obtain the resonance frequency. After the micro-mass is installed, the resonant frequency is measured again, and the obtained frequency difference reflects the measured micro-mass. The precision of the micro mass measured by the method is limited by the rigidity of the mechanical torsion beam, and the method also has the defects of complex processing technology, low yield and difficulty in replacing the mass block.

3. Summary of the invention

In order to solve the problems in the prior art, the invention provides an electromagnetic suspension micro-mass measurement system which can realize the measurement of micro-mass and has high measurement precision.

The technical scheme adopted by the invention is as follows: an electromagnetic suspension micro-mass measurement system comprises a detection signal generator, a preamplifier, a phase-locked amplifier, an excitation signal generator, a high-voltage amplifier, a control voltage synthesizer, a phase-shifting circuit and a controller; the detection signal generator is respectively connected with the phase-shifting circuit and the control voltage synthesizer, and the phase-shifting circuit is connected with the phase-locked amplifier; the phase-locked amplifier comprises a multiplier and a low-pass filter circuit which are connected, the multiplier is respectively connected with the preamplifier and the phase-shifting circuit, and the low-pass filter circuit is connected with the controller; the preamplifier comprises an I-V conversion circuit and an amplifier which are connected, wherein the I-V conversion circuit is used for collecting the axial vibration displacement information of the electromagnetic suspension micro mass, and the amplifier is connected with the input end of the controller after passing through the phase-locked amplifier; the output end of the controller is connected with an excitation signal generator, the output excitation alternating voltage is amplified by a high-voltage amplifier and processed by a control voltage synthesizer and then is input to a resonance control electrode of the electromagnetic suspension micro-mass measuring mechanical structure, and the axial vibration of the electromagnetic suspension micro-mass is controlled by the generated electrostatic force.

Preferably, the controller includes an a/D conversion circuit and three I/O output circuits, the excitation signal generator is controlled by the I/O output digital signal to generate a corresponding excitation frequency signal, and the mass block axial amplitude analog signal is converted into a digital signal by the a/D conversion circuit to obtain the resonant frequency.

Preferably, the controller is a DSP or ARM controller.

Preferably, the detection signal generator comprises a main control chip and a DDS chip which are connected, wherein the main control chip is a single chip microcomputer.

Preferably, the excitation signal generator comprises a DDS chip and a band-pass filter connected to each other.

Preferably, the detection signal generator further comprises two paths of band-pass filters, wherein one path of band-pass filter is connected with the control voltage synthesizer, and the other path of band-pass filter is connected with the phase-locked amplifier through the phase-shifting circuit.

Compared with the prior art, the invention has the following beneficial effects:

the invention detects the axial amplitude signal of the mass block through the public electrode, enters the controller after processing to obtain a digital signal, and then forms a frequency-amplitude relation with the corresponding excitation frequency, the excitation frequency corresponding to the maximum amplitude is the resonance frequency, because of adopting the full-digital closed-loop measuring method, the resonance frequency has high measuring precision, and the micro-mass can be measured by utilizing the deviation of the resonance frequency.

4. Description of the drawings

FIG. 1 is a schematic diagram of a mechanical structure of an electromagnetic levitation micro-mass detection system;

FIG. 2 is a schematic block diagram of an electromagnetic levitation micro-mass measurement system of the present invention.

5. Detailed description of the preferred embodiments

The present invention will be described in further detail below with reference to the drawings and examples, but the embodiments of the present invention are not limited thereto.