A vibration fundamental frequency acquisition system

Abstract

The invention relates to the technical field of signal acquisition, and discloses a vibration fundamental frequency acquisition system, which comprises: a main control MCU, a filter frequency selection circuit, a signal controllable gain circuit, a differential amplifier and an analog-to-digital conversion module, wherein the output end of the filter frequency selection circuit is connected to the output end of the signal controllable gain circuit, the output end of the signal controllable gain circuit is connected to the input end of the differential amplifier, the output end of the differential amplifier is connected to the input end of the analog-to-digital conversion module, the output end of the analog-to-digital conversion module is connected to the main control MCU, and the main control MCU is also connected to the signal controllable gain circuit. In this way, the detection accuracy of the vibration of the detected object can be improved through the designed filter frequency selection circuit, the signal controllable gain circuit and the differential amplifier.

Description

Technical Field

[0001] The present invention relates to the technical field of signal acquisition, and in particular to a vibration fundamental frequency acquisition system. Background Art

[0002] In the detection of buildings, object vibration is used as a reference factor, which will have a certain degree of impact on the building. The vibration factor is mainly used for safety status monitoring of mechanical vibration, port machinery, bridge construction, rail transit, etc. from construction to operation. For object vibration, such as bridges, buildings, tracks, etc., it is necessary to measure the displacement, velocity, and acceleration of the object to realize the time domain and frequency domain analysis of the dynamic signal. At present, due to the small vibration of the actual object, it is difficult to obtain accurate vibration information. It can be seen that the detection accuracy of the existing object vibration detection method is low. Summary of the invention

[0003] The present invention provides a vibration fundamental frequency acquisition system to solve the problem of low detection accuracy of the existing object vibration detection method.

[0004] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0005] The present invention provides a vibration fundamental frequency acquisition system, comprising: a main control MCU, a filter frequency selection circuit, a signal controllable gain circuit, a differential amplifier and an analog-to-digital conversion module, wherein the output end of the filter frequency selection circuit is connected to the output end of the signal controllable gain circuit, the output end of the signal controllable gain circuit is connected to the input end of the differential amplifier, the output end of the differential amplifier is connected to the input end of the analog-to-digital conversion module, the output end of the analog-to-digital conversion module is connected to the main control MCU, and the main control MCU is also connected to the signal controllable gain circuit.

[0006] Optionally, the filtering frequency selection circuit includes a chip J1, a capacitor C5, a resistor R1, a resistor R45, a capacitor C6, a resistor R42, a resistor R41, an amplifier chip U11B, and a diode D5;

[0007] The second pin of the chip J1 and the third pin, the fourth pin and the fifth pin of the chip J1 are all grounded, the first pin of the chip J1 is connected to the first end of the capacitor C5, the second end of the capacitor C5 is connected to the first end of the resistor R1, the second end of the resistor R1 is connected to the first end of the capacitor C6, the second end of the resistor R1 is connected to the second end of the resistor R45, the first end of the resistor R45 is connected to the signal controllable gain circuit, the second end of the capacitor C6 is grounded, the second end of the resistor R1 is also connected to the first end of the resistor R42, and the resistor R45 is connected to the first end of the resistor R45. 2 is connected to the first end of the resistor R41, and the second end of the resistor R42 is also connected to the diode D5, the second end of the resistor R41 is connected to the positive input end of the amplifier chip U11B, the negative input end of the amplifier chip U11B is connected to the signal controllable gain circuit, and the diode D5 has two diodes integrated therein, namely a first diode and a second diode, the cathode of the first diode is connected to the power supply, the anode of the first diode is connected to the second end of the resistor R42, and the anode of the first diode is also connected to the cathode of the second diode, and the anode of the second diode is grounded.

[0008] Optionally, the signal controllable gain circuit includes a MOS tube, a resistor R35, a resistor R36, a resistor R37, a resistor R38 and a capacitor C45;

[0009] The first end of the capacitor C45 is connected to the 8th pin of the MOS tube, the second end of the capacitor C45 is grounded, the 1st pin of the MOS tube is connected to the second end of the resistor R35, the first end of the resistor R35 is connected to the amplifier chip U11B, the second end of the resistor R35 is also connected to the first end of the resistor R36, the second end of the resistor R36 is connected to the 2nd pin of the MOS tube, and the second end of the resistor R36 is also connected to the first end of the resistor R37, the second end of the resistor R37 is connected to the 3rd pin of the MOS tube, and the second end of the resistor R37 is also connected to the first end of the resistor R38, the second end of the resistor R38 is connected to the filter frequency selection circuit, and the 4th pin of the MOS tube is grounded.

[0010] Optionally, the differential amplifier includes a chip U8, a resistor R12, a resistor R16, a resistor R17, a capacitor C29, a capacitor C34, a resistor R24, a resistor R25, a resistor R30, a capacitor C29, a capacitor C41, and a capacitor C44;

[0011] The first end of the resistor R12 is connected to the first end of the resistor R16, the second end of the resistor R12 is connected to the first end of the capacitor C29, the second end of the capacitor C29 is connected to the second end of the resistor R16, and the second end of the resistor R12 is also connected to the 5th pin of the chip U8, the second end of the capacitor C29 is also connected to the 8th pin of the chip U8, the 6th pin of the chip U8 is grounded, and the 7th pin is connected to the positive 5 volt power supply, the second end of the resistor R16 is also connected to the first end of the resistor R17, the second end of the resistor R17 is connected to the signal controllable gain circuit, the first end of the resistor R16 is also connected to the first end of the capacitor C34, and the second end of the capacitor C34 is connected to the The first end of the resistor R24 ​​and the first end of the resistor R30 are connected, the second end of the resistor R24 ​​is connected to the first end of the resistor R25 and the first end of the capacitor C39, and the second end of the resistor R24 ​​is also connected to the first pin of the chip U8, the second end of the resistor R25 is connected to the signal-controllable gain circuit, the second end of the resistor R30 is connected to the second end of the capacitor C39, the second pin of the chip U8 is connected to the signal-controllable gain circuit, the first end of the capacitor C41 is connected to the third pin of the chip U8, the second end of the capacitor C41 is grounded, the first end of the capacitor C44 is connected to the third pin of the chip U8 and a positive 5V power supply, and the second end of the capacitor C44 is grounded.

[0012] Beneficial effects:

[0013] The vibration fundamental frequency acquisition system provided by the present invention comprises: a main control MCU, a filter frequency selection circuit, a signal controllable gain circuit, a differential amplifier and an analog-to-digital conversion module, wherein the output end of the filter frequency selection circuit is connected to the output end of the signal controllable gain circuit, the output end of the signal controllable gain circuit is connected to the input end of the differential amplifier, the output end of the differential amplifier is connected to the input end of the analog-to-digital conversion module, the output end of the analog-to-digital conversion module is connected to the main control MCU, and the main control MCU is also connected to the signal controllable gain circuit. In this way, the detection accuracy of the vibration of the detected object can be improved through the designed filter frequency selection circuit, signal controllable gain circuit and differential amplifier. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A structural diagram of a vibration fundamental frequency acquisition system according to a preferred embodiment of the present invention;

[0015] Figure 2 A circuit diagram of a filter frequency selection circuit according to a preferred embodiment of the present invention;

[0016] Figure 3 A circuit diagram of a signal controllable gain circuit according to a preferred embodiment of the present invention;

[0017] Figure 4 A circuit diagram of a differential amplifier according to a preferred embodiment of the present invention;

[0018] Figure 5 4 is a circuit diagram of a digital-to-analog converter according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] See also Figure 1 The embodiment of the present application provides a vibration fundamental frequency acquisition system, including: a main control MCU, a filter frequency selection circuit, a signal controllable gain circuit, a differential amplifier and an analog-to-digital conversion module, the output end of the filter frequency selection circuit is connected to the output end of the signal controllable gain circuit, the output end of the signal controllable gain circuit is connected to the input end of the differential amplifier, the output end of the differential amplifier is connected to the input end of the analog-to-digital conversion module, the output end of the analog-to-digital conversion module is connected to the main control MCU, and the main control MCU is also connected to the signal controllable gain circuit.

[0021] The vibration fundamental frequency acquisition system described above can improve the detection accuracy of the vibration of the detected object through the designed filtering frequency selection circuit, signal controllable gain circuit and differential amplifier.

[0022] Alternatively, if Figure 2 As shown, the filtering frequency selection circuit includes a chip J1, a capacitor C5, a resistor R1, a resistor R45, a capacitor C6, a resistor R42, a resistor R41, an amplifier chip U11B, and a diode D5;

[0023] The second pin of the chip J1 and the third pin, the fourth pin and the fifth pin of the chip J1 are all grounded, the first pin of the chip J1 is connected to the first end of the capacitor C5, the second end of the capacitor C5 is connected to the first end of the resistor R1, the second end of the resistor R1 is connected to the first end of the capacitor C6, the second end of the resistor R1 is connected to the second end of the resistor R45, the first end of the resistor R45 is connected to the signal controllable gain circuit, the second end of the capacitor C6 is grounded, the second end of the resistor R1 is also connected to the first end of the resistor R42, and the resistor R45 is connected to the first end of the resistor R45. 2 is connected to the first end of the resistor R41, and the second end of the resistor R42 is also connected to the diode D5, the second end of the resistor R41 is connected to the positive input end of the amplifier chip U11B, the negative input end of the amplifier chip U11B is connected to the signal controllable gain circuit, and the diode D5 has two diodes integrated therein, namely a first diode and a second diode, the cathode of the first diode is connected to the power supply, the anode of the first diode is connected to the second end of the resistor R42, and the anode of the first diode is also connected to the cathode of the second diode, and the anode of the second diode is grounded.

[0024] In this optional implementation, the parameters of R1 and C6 are adjusted to determine the frequency range that enters the subsequent circuit through the front end, thereby achieving a low-pass filtering effect.

[0025] Alternatively, if Figure 3 As shown, the signal controllable gain circuit includes a MOS tube, a resistor R35, a resistor R36, a resistor R37, a resistor R38 and a capacitor C45;

[0026] The first end of the capacitor C45 is connected to the 8th pin of the MOS tube, the second end of the capacitor C45 is grounded, the 1st pin of the MOS tube is connected to the second end of the resistor R35, the first end of the resistor R35 is connected to the amplifier chip U11B, the second end of the resistor R35 is also connected to the first end of the resistor R36, the second end of the resistor R36 is connected to the 2nd pin of the MOS tube, and the second end of the resistor R36 is also connected to the first end of the resistor R37, the second end of the resistor R37 is connected to the 3rd pin of the MOS tube, and the second end of the resistor R37 is also connected to the first end of the resistor R38, the second end of the resistor R38 is connected to the filter frequency selection circuit, and the 4th pin of the MOS tube is grounded.

[0027] In this embodiment, the MCU controls the size of the feedback resistor connected to the operational amplifier circuit to change the different gains of the operational amplifier, thereby achieving the effect of high gain for small signals and low gain for large signals, making the signal we obtain more accurate.

[0028] Alternatively, if Figure 4 As shown, the differential amplifier includes a chip U8, a resistor R12, a resistor R16, a resistor R17, a capacitor C29, a capacitor C34, a resistor R24, a resistor R25, a resistor R30, a capacitor C29, a capacitor C41, and a capacitor C44;

[0029] The first end of the resistor R12 is connected to the first end of the resistor R16, the second end of the resistor R12 is connected to the first end of the capacitor C29, the second end of the capacitor C29 is connected to the second end of the resistor R16, and the second end of the resistor R12 is also connected to the 5th pin of the chip U8, the second end of the capacitor C29 is also connected to the 8th pin of the chip U8, the 6th pin of the chip U8 is grounded, and the 7th pin is connected to the positive 5 volt power supply, the second end of the resistor R16 is also connected to the first end of the resistor R17, the second end of the resistor R17 is connected to the signal controllable gain circuit, the first end of the resistor R16 is also connected to the first end of the capacitor C34, and the second end of the capacitor C34 is connected to the The first end of the resistor R24 ​​and the first end of the resistor R30 are connected, the second end of the resistor R24 ​​is connected to the first end of the resistor R25 and the first end of the capacitor C39, and the second end of the resistor R24 ​​is also connected to the first pin of the chip U8, the second end of the resistor R25 is connected to the signal-controllable gain circuit, the second end of the resistor R30 is connected to the second end of the capacitor C39, the second pin of the chip U8 is connected to the signal-controllable gain circuit, the first end of the capacitor C41 is connected to the third pin of the chip U8, the second end of the capacitor C41 is grounded, the first end of the capacitor C44 is connected to the third pin of the chip U8 and a positive 5V power supply, and the second end of the capacitor C44 is grounded.

[0030] In this optional implementation, the chip U8 can use a THS4521IDGKR signal chip, with differential input and differential output, and the number of amplification bits can be adjusted through R16, R17, R24, and R25. The power can be reduced, negative rail input and rail-to-rail output can be achieved, and the amplification purpose of a fully differential amplifier can be achieved.

[0031] like Figure 5 As shown, the vibration fundamental frequency acquisition system also includes an analog-to-digital converter. In this embodiment, the digital-to-analog converter DAC7512E is connected to the main control via SPI, and a certain digital quantity is converted into an analog quantity and transmitted to the precision voltage-current converter, so that the required constant current source can be obtained with high accuracy and small temperature drift; CURR-S is connected to the vibration sensor to provide the sensor with a constant current excitation source.

[0032] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A vibration fundamental frequency acquisition system, characterized in that: include: A main control MCU, a filter frequency selection circuit, a signal controllable gain circuit, a differential amplifier and an analog-to-digital conversion module, wherein the output end of the filter frequency selection circuit is connected to the output end of the signal controllable gain circuit, the output end of the signal controllable gain circuit is connected to the input end of the differential amplifier, the output end of the differential amplifier is connected to the input end of the analog-to-digital conversion module, the output end of the analog-to-digital conversion module is connected to the main control MCU, and the main control MCU is also connected to the signal controllable gain circuit; The filtering frequency selection circuit includes a chip J1, a capacitor C5, a resistor R1, a resistor R45, a capacitor C6, a resistor R42, a resistor R41, an amplifier chip U11B, and a diode D5; The second pin of the chip J1 and the third pin, the fourth pin and the fifth pin of the chip J1 are all grounded, the first pin of the chip J1 is connected to the first end of the capacitor C5, the second end of the capacitor C5 is connected to the first end of the resistor R1, the second end of the resistor R1 is connected to the first end of the capacitor C6, the second end of the resistor R1 is connected to the second end of the resistor R45, the first end of the resistor R45 is connected to the signal controllable gain circuit, the second end of the capacitor C6 is grounded, the second end of the resistor R1 is also connected to the first end of the resistor R42, and the resistor R45 is connected to the first end of the resistor R45. 2 is connected to the first end of the resistor R41, and the second end of the resistor R42 is also connected to the diode D5, the second end of the resistor R41 is connected to the positive input end of the amplifier chip U11B, the negative input end of the amplifier chip U11B is connected to the signal controllable gain circuit, and the diode D5 has two diodes integrated therein, namely a first diode and a second diode, the cathode of the first diode is connected to the power supply, the anode of the first diode is connected to the second end of the resistor R42, and the anode of the first diode is also connected to the cathode of the second diode, and the anode of the second diode is grounded.

2. The vibration fundamental frequency acquisition system according to claim 1, characterized in that: The signal controllable gain circuit includes a MOS tube, a resistor R35, a resistor R36, a resistor R37, a resistor R38 and a capacitor C45; The first end of the capacitor C45 is connected to the 8th pin of the MOS tube, the second end of the capacitor C45 is grounded, the 1st pin of the MOS tube is connected to the second end of the resistor R35, the first end of the resistor R35 is connected to the amplifier chip U11B, the second end of the resistor R35 is also connected to the first end of the resistor R36, the second end of the resistor R36 is connected to the 2nd pin of the MOS tube, and the second end of the resistor R36 is also connected to the first end of the resistor R37, the second end of the resistor R37 is connected to the 3rd pin of the MOS tube, and the second end of the resistor R37 is also connected to the first end of the resistor R38, the second end of the resistor R38 is connected to the filter frequency selection circuit, and the 4th pin of the MOS tube is grounded.

3. The vibration fundamental frequency acquisition system according to claim 2, characterized in that: The differential amplifier includes a chip U8, a resistor R12, a resistor R16, a resistor R17, a capacitor C29, a capacitor C34, a resistor R24, a resistor R25, a resistor R30, a capacitor C39, a capacitor C41, and a capacitor C44; The first end of the resistor R12 is connected to the first end of the resistor R16, the second end of the resistor R12 is connected to the first end of the capacitor C29, the second end of the capacitor C29 is connected to the second end of the resistor R16, and the second end of the resistor R12 is also connected to the 5th pin of the chip U8, the second end of the capacitor C29 is also connected to the 8th pin of the chip U8, the 6th pin of the chip U8 is grounded, and the 7th pin is connected to the positive 5 volt power supply, the second end of the resistor R16 is also connected to the first end of the resistor R17, the second end of the resistor R17 is connected to the signal controllable gain circuit, the first end of the resistor R16 is also connected to the first end of the capacitor C34, and the second end of the capacitor C34 is connected to the The first end of the resistor R24 ​​and the first end of the resistor R30 are connected, the second end of the resistor R24 ​​is connected to the first end of the resistor R25 and the first end of the capacitor C39, and the second end of the resistor R24 ​​is also connected to the first pin of the chip U8, the second end of the resistor R25 is connected to the signal-controllable gain circuit, the second end of the resistor R30 is connected to the second end of the capacitor C39, the second pin of the chip U8 is connected to the signal-controllable gain circuit, the first end of the capacitor C41 is connected to the third pin of the chip U8, the second end of the capacitor C41 is grounded, the first end of the capacitor C44 is connected to the third pin of the chip U8 and a positive 5V power supply, and the second end of the capacitor C44 is grounded.

Images