Multi-channel micro-signal high-performance acquisition system and method
By designing a multi-channel WeChat account high-performance acquisition system with multi-layer wiring and independent layered power, the existing equipment has insufficient sensitivity and low resource utilization rate has been solved, real-time and rapid acquisition of multiple WeChat account numbers has been achieved, and the sensitivity and integration of the equipment has been improved.
Patent Information
- Application Number
- CN202411496587.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-25
- Publication Date
- 2025-02-28
AI Technical Summary
The existing sensor acquisition equipment has insufficient sensitivity when collecting signals, has fewer channels, and a single acquisition method, resulting in low resource utilization, large equipment size and power consumption, making it difficult to achieve real-time and rapid acquisition of multiple WeChat signals.
A multi-channel WeChat account high-performance acquisition system is designed to achieve electromagnetic compatibility through multi-layer wiring, independent layered power supply and ground plane, multi-stage decoupling capacitors and single-point grounding methods. The system adopts low-noise preamplifier, electrical analog filter, multi-channel sampling switch and analog-to-digital converter A/D, combining digital and analog segmentation layouts to achieve efficient signal acquisition and processing.
It realizes real-time and rapid collection of multiple WeChat accounts, improves the sensitivity and resource utilization of the equipment, reduces the size and power consumption of the equipment, and is suitable for a variety of sensor types, with strong anti-interference ability and high integration.
Smart Images
Figure CN119543941A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of sensor signal acquisition, and in particular to a multi-channel micro-signal high-performance acquisition system and method. Background Art
[0002] At present, the sensitivity of sensor acquisition equipment on the market is not accurate enough when collecting signals, the channels used for data acquisition are relatively few, and the way of collecting signals is relatively simple, so each sensor needs to add a set of corresponding acquisition circuits, and the resource utilization rate is low. When collecting multi-channel signals, multi-channel acquisition circuits are required, which increases the size and power consumption of the equipment. In order to reduce the size and power consumption of the equipment and realize the real-time and rapid acquisition of multiple micro signals at the same time, it is necessary to develop a new signal acquisition method or improve the existing signal acquisition equipment. Summary of the invention
[0003] In order to solve the problem of realizing real-time and rapid collection of multiple WeChat signals simultaneously on the basis of reducing the volume and power consumption of the device, the present invention provides a multi-channel WeChat signal high-performance collection system and method.
[0004] The present invention is realized by the following technical scheme: a multi-channel micro signal high-performance acquisition system, including multiple sensor inputs, each sensor outputs a signal to a corresponding instrument input circuit, the instrument input circuit outputs a signal to a corresponding low-noise preamplifier, the low-noise preamplifier outputs a signal to a corresponding electrical analog filter, and the connecting lines of the output signals of multiple electrical analog filters are connected to a multi-channel sampling switch, and the multi-channel sampling switch outputs the corresponding signal to an analog-to-digital converter A / D according to the switching conditions of different lines, and the analog-to-digital converter A / D outputs data to a data recording system. The entire device adopts multi-layer wiring, the power supply and ground plane are independently layered, and multi-level decoupling capacitors and single-point grounding are used to achieve good electromagnetic compatibility. The internal circuit of the device adopts a digital and analog split layout, an analog power supply and a digital power supply partition layout, and a single-point grounding of the analog ground and the digital ground. Signal acquisition adopts low-voltage differential routing, and the A / D sampling clock adopts differential line transmission to ensure the integrity of the clock signal.
[0005] Furthermore, the instrument input circuit is the front-end input circuit of the sensor acquisition, which is the matching circuit between the sensor and the sensor acquisition device. As the output load of the sensor, it must have a sufficiently high input impedance, a sufficiently high sensitivity, a sufficiently high dynamic range, etc. At the same time, as the front-end input circuit of the sensor acquisition device, the instrument input circuit requires it to have a very small output impedance. The input circuit has a strong suppression ability for common-mode interference signals and noise signals brought by the power supply, and has a high conjugate suppression ratio. The specific working process is: under the control of the program-controlled switch, the analog signal input collected by the sensor first passes through the matching attenuation network to achieve impedance matching and attenuation, and then performs AC-DC coupling, and then through impedance transformation and program-controlled amplification circuit, the signal enters the optimal input range of the A / D converter, and finally through the filtering circuit, the high-frequency components in the signal are removed to achieve analog output.
[0006] Furthermore, the weak electrical signal detected from the output circuit of the instrument is amplified with a fixed gain, so the low-noise preamplifier must be placed at the front end of the sensor acquisition device, because the input noise coefficient of the low-noise preamplifier can be less than 0.8, so the signal-to-noise ratio of the low-noise preamplifier determines the noise suppression of the entire sensor acquisition device. Generally, a low-noise amplifier is placed at the input port of all receiving devices. There are two sources of amplifier noise, one is external noise, which is irrelevant to the amplifier and comes from the outside of the amplifier circuit; the other is the noise generated inside the amplifier, which comes from the device itself. The main discussion here is internal noise, that is, the noise generated when the amplifier is working. For the system designed by the present invention, the input noise coefficient of the low-noise preamplifier is less than 0.8, and the low-noise preamplifier includes a Wheatstone bridge, and the Wheatstone bridge outputs an electrical signal to a signal conditioning module. The signal conditioning module is provided with multiple signal amplifiers for amplifying tiny electrical signals. After the signal is amplified, it is transmitted to the ADC for collection. The signal amplifier ensures that no saturation cutoff distortion occurs during amplification, and the output voltage is within the recognition range of the acquisition circuit. After the signal is amplified, it is transmitted to the ADC for collection. Therefore, the level of amplifier noise will directly affect the measurement results. The general requirements for the amplifier are to reduce the impact of the input signal-to-noise ratio, and at the same time ensure that the frequency characteristics of the amplifier are stable; no saturation cutoff distortion occurs during amplification, and the dynamic range is as large as possible, and the output voltage is within the recognition range of the acquisition circuit; there must be a fast enough adjustment response speed, and at the same time ensure the stability of the system operation.
[0007] Furthermore, the electrical analog filter includes a low-pass filter, a high-pass filter and a notch filter; the low-pass filter is used to filter out low-frequency interference signals, including suppressing interference sources and cutting off interference propagation paths, wherein suppressing interference sources is to reduce du / dt and di / dt of the interference sources, and reducing du / dt of the interference sources is achieved by connecting capacitors in parallel at both ends of the interference sources; reducing di / dt of the interference sources is achieved by connecting an inductor or resistor in series in the interference source loop and adding a freewheeling diode; cutting off interference propagation paths includes cutting off conducted interference and cutting off radiated interference, and cutting off conducted interference is achieved by adding a filter or adding an isolation optocoupler. To solve it; cutting off the radiation interference is solved by the following methods: ①Increase the distance between the interference source and the sensitive device; ②Use the ground wire to isolate the interference source and the sensitive device; ③Add a shielding cover to the sensitive device; The high-pass filter is used to filter out high-frequency interference. In sensor acquisition, high-frequency interference includes the A / D adoption frequency, the ARM working crystal frequency and the communication transmission signal frequency. The high-frequency filter mainly filters out these high-frequency signals to prevent these high-frequency signals from affecting the sensor acquisition data; Therefore, the high-pass filter uses a notch filter to filter out the 50Hz frequency inside the AC power supply in the equipment power supply. The influence of the useful signal of the sensor acquisition equipment.
[0008] Furthermore, the functions realized by the multi-channel sampling switch are: within a sampling cycle, each signal of all channels is sampled once in sequence, and the data of multiple sensors are serially input into the ARM to realize multi-channel integration, and at the same time, the continuous analog signal is converted into a discrete analog pulse signal; the binary code of the input collected by the sensor through the analog converter in the processor chip is organized and encoded according to professional technical organization planning, and the binary data of a certain length is organized into a byte form that is convenient for computer data processing, and the encoding is for the convenience of data transmission and reading.
[0009] Furthermore, the analog-to-digital converter A / D is used to convert a continuous signal in analog form into a discrete signal in digital form. In the sensor acquisition device, the analog converter converts the analog signal into a digital signal representing a certain proportional voltage value; the analog-to-digital converter A / D has the following indicators: ① Resolution: The resolution of an analog-to-digital converter with 8 discrete signal value outputs refers to the number of discrete digital signal values it can output for analog signals within the allowable range; these signal values are usually stored in binary numbers, so the resolution is often expressed in bits, and the number of these discrete values is a power of 2; ②Response type: The response type of the analog-to-digital converter is linear. Here, linearity means that the size of the output signal is linearly proportional to the size of the input signal. ③ Sampling rate: The analog signal is continuous in the time domain, so to convert it into a series of digital signals that are continuous in time, it is required to define a parameter to represent the rate at which the new digital signal is sampled from the analog signal. This rate is called the sampling rate or sampling frequency of the converter. Since the analog converters actually used cannot perform real-time conversion, some external methods must be used to keep the input signal constant during the conversion process. The commonly used one is the sample-and-hold circuit. In most cases, a capacitor can be used to store the input analog voltage, and a switch or gate circuit can be used to close or disconnect the connection between the capacitor and the input signal.
[0010] ④ According to the requirements of ①~③, AD7606 is used. The AD7606 chip has 8 channels, a resolution of 16 bits, all channels are synchronized, and have a sampling frequency of 200kSPS. It provides a variety of interfaces and has strong compatibility with the FSMC of the microprocessor.
[0011] Furthermore, the data recording system uses the synchronous clock as a reference to exchange data, and the storage array is constantly refreshed to ensure that data is not lost, and the data storage is not linear, but can be read and written at a specified address. The data recording system saves all the data recorded in the test, and the data recording system uses the synchronous clock as a reference to exchange data, and the storage array is constantly refreshed to ensure that data is not lost, and the data storage is not linear, but can be read and written at a specified address. The data recording system FLASH is connected to the acquisition circuit board through a shielded wire. During the data acquisition process, the data is obtained from the sensor sampling circuit, and is transmitted to the FLASH through a wire by the microprocessor for storage. The signal line and data line of the FLASH are impedance matched to ensure signal integrity; when the user needs to display data, the data in the FLASH is read, and the data visualization of the sensor signal can be performed after the FLASH reads the data through the read instruction issued by the microprocessor. Due to the importance of the storage module, the data reading interface uses a formal reading interface and a backup interface in the storage module circuit design, and is separately protected from the storage chip.
[0012] Compared with the prior art, the present invention has the following beneficial effects: the multi-channel micro-signal high-performance acquisition system provided by the present invention has ① a wide range of applications and is applicable to a variety of sensor types; ② strong anti-interference ability, the signal from the external space will not affect the normal operation of the device, and the device will not affect other external devices; ③ high sensitivity, and the small signal transmitted by the sensor can be accurately identified; ④ small size, high device integration, and easy to carry; ⑤ low power consumption, the device has very low working power consumption, and is in a dormant state when not working. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 It is the overall structural block diagram of the present invention.
[0014] Figure 2 Enter the overall block diagram of the circuit for the instrument.
[0015] Figure 3 This is the schematic diagram of the electrical analog filter circuit.
[0016] Figure 4 This is the minimum system diagram of AD7606.
[0017] Figure 5 This is the hardware circuit diagram of the data recording system Flash. DETAILED DESCRIPTION
[0018] The present invention is further described below in conjunction with specific embodiments.
[0019] A multi-channel micro signal high-performance acquisition system, such as Figure 1 As shown, it includes multiple sensor inputs, each sensor outputs a signal to a corresponding instrument input circuit, the instrument input circuit outputs a signal to a corresponding low-noise preamplifier, the low-noise preamplifier outputs a signal to a corresponding electrical analog filter, and the connecting lines of the output signals of multiple electrical analog filters are connected to a multi-way sampling switch, the multi-way sampling switch outputs the corresponding signal to the analog-to-digital converter A / D according to the switching conditions of different lines, and the analog-to-digital converter A / D outputs data to a data recording system.
[0020] This embodiment adopts the following preferred solutions: ① The instrument input circuit is the front-end input circuit collected by the sensor, such as Figure 2 As shown, the specific working process is: under the control of the program-controlled switch, the analog signal input collected by the sensor first passes through the matching attenuation network to achieve impedance matching and attenuation, and then undergoes AC / DC coupling, and then passes through impedance transformation and program-controlled amplification circuit to allow the signal to enter the optimal input range of the A / D converter, and finally passes through the filtering circuit to remove the high-frequency component in the signal to achieve analog output.
[0021] ② The input noise coefficient of the low-noise preamplifier is less than 0.8. The low-noise preamplifier includes a Wheatstone bridge. The Wheatstone bridge outputs an electrical signal to a signal conditioning module. The signal conditioning module is provided with a plurality of signal amplifiers for amplifying tiny electrical signals. After the signal is amplified, it is transmitted to the ADC for collection. The signal amplifier ensures that no saturation cutoff distortion occurs during amplification, and the output voltage is within the recognition range of the acquisition circuit.
[0022] ③ The electrical analog filter includes a low-pass filter, a high-pass filter and a notch filter; the low-pass filter is used to filter out low-frequency interference signals, including suppressing interference sources and cutting off interference propagation paths. The interference source suppression is to reduce du / dt and di / dt of the interference source. Reducing du / dt of the interference source is achieved by connecting capacitors in parallel at both ends of the interference source; reducing di / dt of the interference source is achieved by connecting an inductor or resistor in series in the interference source loop and adding a freewheeling diode; the cutting off of the interference propagation path includes cutting off conducted interference and cutting off radiated interference. Cutting off conducted interference is solved by adding a filter or adding an isolation optocoupler; cutting off radiated interference is solved by the following methods: ① increasing the distance between the interference source and the sensitive device; ② isolating the interference source from the sensitive device with a ground wire; ③ adding a shielding cover to the sensitive device; the high-pass filter is used to filter out high-frequency interference. In sensor acquisition, high-frequency interference includes the A / D adoption frequency, the ARM working crystal oscillator frequency and the communication transmission signal frequency. Therefore, the high-pass filter uses a notch filter to filter out the influence of the 50Hz frequency inside the AC power supply in the equipment power supply on the useful signal of the sensor acquisition device.
[0023] ④ The functions realized by the multi-channel sampling switch are: within a sampling cycle, each signal of all channels is sampled once in sequence, and the data of multiple sensors are serially input into the ARM to realize multi-channel integration, and at the same time, the continuous analog signal is converted into a discrete analog pulse signal; the electrical signal collected by the sensor is collected by the analog converter in the processor chip, and the input binary code is arranged and encoded according to the professional and technical organization planning, and the binary data of a certain length is arranged into a byte form that is convenient for computer data processing.
[0024] ⑤ The analog-to-digital converter A / D is used to convert a continuous analog signal into a discrete digital signal. In the sensor acquisition device, the analog converter converts the analog signal into a digital signal representing a certain proportional voltage value; the analog-to-digital converter A / D has the following indicators: a: Resolution: The resolution of an analog-to-digital converter with 8 discrete signal value outputs refers to the number of discrete digital signal values it can output for analog signals within the allowable range; these signal values are usually stored in binary numbers, so the resolution is often expressed in bits, and the number of these discrete values is a power of 2; b: Response type: The response type of the analog-to-digital converter is linear. Here, linearity means that the magnitude of the output signal is linearly proportional to the magnitude of the input signal. c: Sampling rate: The analog signal is continuous in the time domain, so to convert it into a series of digital signals that are continuous in time, it is required to define a parameter to represent the rate at which the new digital signal is sampled from the analog signal. This rate is called the sampling rate or sampling frequency of the converter; d: According to the requirements of a~c, AD7606 is used. The AD7606 chip has 8 channels, a resolution of 16 bits, all channels are synchronized, and have a sampling frequency of 200kSPS. It provides a variety of interfaces. The minimum system diagram of AD7606 is as follows: Figure 4 shown.
[0025] ⑥ The data recording system saves all the data recorded in the test. The data recording system FLASH is connected to the acquisition circuit board through shielded wires. During the data acquisition process, data is acquired from the sensor sampling circuit, transmitted to the FLASH through wires by the microprocessor for storage. The signal line and data line of the FLASH are impedance matched to ensure signal integrity and reduce the occurrence of overshoot and ringing. Figure 5 Design for FLASH hardware circuit. When the user needs to display data, the data in FLASH is read, and the data visualization of the sensor signal can be performed after the FLASH reads the data through the read instruction issued by the microprocessor. In the storage module circuit design, the data reading interface uses a formal reading interface and a backup interface, and is separately protected from the storage chip.
[0026] The scope of protection claimed by the present invention is not limited to the above specific embodiments. For those skilled in the art, the present invention may have various deformations and changes. Any modifications, improvements and equivalent substitutions made within the concept and principle of the present invention should be included in the protection scope of the present invention.
Claims
1. A multi-channel micro signal high-performance acquisition system, characterized by: It includes multiple sensor inputs, each sensor outputs a signal to a corresponding instrument input circuit, the instrument input circuit outputs a signal to a corresponding low-noise preamplifier, the low-noise preamplifier outputs a signal to a corresponding electrical analog filter, the connecting lines of the multiple electrical analog filter output signals are connected to a multi-way sampling switch, the multi-way sampling switch outputs the corresponding signal to an analog-to-digital converter A / D according to the switching conditions of different lines, and the analog-to-digital converter A / D outputs data to a data recording system.
2. A multi-channel micro signal high-performance acquisition system according to claim 1, characterized in that: The instrument input circuit is the front-end input circuit of the sensor collection. The specific working process is: under the control of the program-controlled switch, the analog signal input collected by the sensor first passes through the matching attenuation network to achieve impedance matching and attenuation, and then performs AC and DC coupling, and then passes through the impedance transformation and program-controlled amplification circuit to make the signal enter the optimal input range of the A / D converter, and finally passes through the filtering circuit to remove the high-frequency components in the signal to achieve analog output.
3. A multi-channel micro signal high-performance acquisition system according to claim 2, characterized in that: The input noise coefficient of the low-noise preamplifier is less than 0.
8. The low-noise preamplifier includes a Wheatstone bridge. The Wheatstone bridge outputs an electrical signal to a signal conditioning module. The signal conditioning module is provided with a plurality of signal amplifiers for amplifying tiny electrical signals. After the signals are amplified, they are transmitted to the ADC for collection. The signal amplifier ensures that no saturation cutoff distortion occurs during amplification, and the output voltage is within the recognition range of the collection circuit.
4. A multi-channel micro signal high-performance acquisition system according to claim 3, characterized in that: The electrical analog filter includes a low-pass filter, a high-pass filter and a notch filter; the low-pass filter is used to filter out low-frequency interference signals, including suppressing interference sources and cutting off interference propagation paths, wherein suppressing interference sources is to reduce du / dt and di / dt of the interference sources, and reducing du / dt of the interference sources is achieved by connecting capacitors in parallel at both ends of the interference sources; reducing di / dt of the interference sources is achieved by connecting an inductor or resistor in series in the interference source loop and adding a freewheeling diode; cutting off interference propagation paths includes cutting off conducted interference and cutting off radiated interference, and cutting off conducted interference is solved by adding a filter or adding an isolation optocoupler; Cutting off radiation interference can be solved by the following methods: ① Increasing the distance between the interference source and the sensitive device; ② Use ground wire to isolate interference sources from sensitive devices; ③Add shielding cover to sensitive devices; The high-pass filter is used to filter out high-frequency interference. In sensor acquisition, high-frequency interference includes the A / D sampling frequency, the ARM working crystal frequency and the communication transmission signal frequency. Therefore, the high-pass filter uses a notch filter to filter out the influence of the 50Hz frequency inside the AC power supply in the equipment power supply on the useful signal of the sensor acquisition equipment.
5. A multi-channel micro signal high-performance acquisition system according to claim 4, characterized in that: The function of the multi-channel sampling switch is: in one sampling cycle, each channel signal of all channels is sampled once in sequence, and the data of the multi-channel sensors are serially input into the ARM to realize multi-channel integration, and at the same time, the continuous analog signal is converted into a discrete analog pulse signal; In the processor chip, the electrical signal collected by the sensor is collected by the analog converter, and the input binary code is arranged and encoded according to professional technical organization planning. The binary data of a certain length is arranged into a byte form that is convenient for computer data processing.
6. A multi-channel micro signal high-performance acquisition system according to claim 5, characterized in that: The analog-to-digital converter (A / D) is used to convert a continuous analog signal into a discrete digital signal. In the sensor acquisition device, the analog converter converts the analog signal into a digital signal representing a certain proportional voltage value. The analog-to-digital converter (A / D) has the following indicators: ① Resolution: The resolution of an analog-to-digital converter with 8 discrete signal value outputs refers to the number of discrete digital signal values it can output for analog signals within the allowable range; these signal values are usually stored in binary numbers, so the resolution is often expressed in bits, and the number of these discrete values is a power of 2; ②Response type: The response type of the analog-to-digital converter is linear. Here, linearity means that the size of the output signal is linearly proportional to the size of the input signal. ③ Sampling rate: The analog signal is continuous in the time domain, so to convert it into a series of digital signals that are continuous in time, it is required to define a parameter to represent the rate at which the new digital signal is sampled from the analog signal. This rate is called the sampling rate or sampling frequency of the converter. ④ According to the requirements of ①~③, AD7606 is used. The AD7606 chip has 8 channels, a resolution of 16 bits, all channels are synchronized, and have a sampling frequency of 200kSPS, and provides multiple interfaces.
7. A multi-channel micro signal high-performance acquisition system according to claim 6, characterized in that: The data recording system saves all the data recorded in the test. The data recording system FLASH is connected to the acquisition circuit board through a shielded wire. During the data acquisition process, the data is acquired from the sensor sampling circuit and transmitted to the FLASH through the wire by the microprocessor for storage. The signal line and data line of the FLASH are impedance matched to ensure signal integrity. When the user needs to display data, the data in FLASH is read. The data visualization of the sensor signal can be performed after the FLASH reads the data through the read instruction issued by the microprocessor. In the storage module circuit design, the data reading interface uses a formal reading interface and a backup interface, and is separately protected from the storage chip.