CN211264126U

CN211264126U - Portable multi-channel high-precision acquisition system based on FPGA

Info

Publication number: CN211264126U
Application number: CN202020005266.6U
Authority: CN
Inventors: 李宁; 邹威
Original assignee: Guangzhou Haifei Network Technology Co ltd
Current assignee: Guangzhou Haifei Network Technology Co ltd
Priority date: 2020-01-03
Filing date: 2020-01-03
Publication date: 2020-08-14
Anticipated expiration: 2030-01-03

Abstract

The utility model discloses a portable multichannel high accuracy acquisition system based on FPGA, which relates to the technical field of information acquisition and comprises a plurality of channels of sensitive signals to be measured, a signal conditioning module, a filtering gating module, an ADC acquisition module, an FPGA control module, a data transmission interface, a power management module and a stabilized voltage supply module; the utility model has the functions of program control gain amplification, low-pass filtering and the like, can carry out high-speed parallel acquisition on multi-path AC/DC signals, and still has good performance indexes such as amplitude precision higher than 0.1%, SFDR larger than 60 dBc and the like in the environment with larger interference such as high-speed rotation and the like; the portable design is adopted, the system has small volume and space, is convenient to carry and install, is based on the modular design of the FPGA, has strong expandability, stable performance and easy maintenance, and has good application value.

Description

Portable multi-channel high-precision acquisition system based on FPGA

Technical Field

The utility model relates to an information acquisition technical field, more specifically say, the utility model relates to a portable multichannel high accuracy collection system based on FPGA.

Background

With the rapid development of electronic information technology, data acquisition systems are increasingly and widely applied to the fields of industrial control, measurement, communication, military and the like. A system with the capacity of multi-channel, high-precision and mass data acquisition is designed in the environment with limited volume, limited energy consumption and large interference, and still has certain research value. In the present document, the background of collecting signals of a plurality of sensitive air pressure sensors mounted on the surface of a rotor blade is taken, and a simplified schematic of an application scenario is shown in fig. 1. If the sensor signal is directly led to the lower end for collection, the signal quality is seriously damaged due to the influence of the line length loss and the slip ring, so that a system which is provided with a front-mounted collection device at the top end of a central shaft of a rotor wing, rotates with a blade during working and directly conditions and collects the signal to be measured at the front end is provided. Therefore, the system is required to be small in size, low in weight, good in heat dissipation, convenient to carry and install, stable in structure and capable of completing high-precision acquisition of multiple paths of signals to be measured in a high-speed rotating environment. Common high-precision acquisition equipment is large in size, high in price, complex in structure and not portable, and is difficult to apply to the environment.

Logic programmable devices such as FPGA and the like have an important position in the field of data acquisition, and compared with a single chip microcomputer, a DSP and an ASIC chip, the FPGA has the advantages of short development period, small risk, large upgrading space, capability of concurrent execution, flexibility and reconfiguration and the like.

SUMMERY OF THE UTILITY MODEL

In order to overcome the above-mentioned defect of prior art, the utility model provides a portable multichannel high accuracy collection system based on FPGA contains functions such as two-stage programme-controlled enlargies, optional low pass filtering, multichannel AD collection, real-time data transmission, provides the solution of a low cost, easy realization for the application scene that requires height to volume, energy consumption, collection precision, interference killing feature in the collection field.

In order to achieve the above object, the utility model provides a following technical scheme:

a portable multi-path high-precision acquisition system based on FPGA comprises a plurality of paths of sensitive signals to be detected, a signal conditioning module, a filtering gating module, an ADC acquisition module, an FPGA control module, a data transmission interface, a power supply management module and a voltage-stabilized power supply module;

the output end of the multi-path sensitive signal to be measured is connected with the input end of the signal conditioning module, the output end of the signal conditioning module is connected with the input end of the filtering gating module, the output end of the filtering gating module is connected with the input end of the ADC acquisition module, the output end of the ADC acquisition module is connected with the input end of the FPGA control module, and the output end of the FPGA control module is connected with the data transmission interface;

the voltage-stabilizing power supply module is respectively connected with the signal conditioning module, the filtering gating module, the ADC acquisition module and the FPGA control module through the power supply management module and is used for providing required electric energy.

As the utility model relates to a portable multichannel high accuracy collection system's further excellent based on FPGA

According to the scheme, the power management module comprises a switching power supply and a linear power supply; the switch power supply and the linear power supply are respectively connected with the signal conditioning module, the filtering gating module, the ADC acquisition module and the FPGA control module, and the chip model of the switch power supply is TPS 75003.

And the signal conditioning module comprises a primary program control gain amplifier and a secondary program control gain amplifier which are connected in sequence, and the multiple paths of sensitive signals to be tested are connected with the filtering gating module through the primary program control gain amplifier and the secondary program control gain amplifier in sequence.

And the signal conditioning module is connected with the ADC acquisition module through the anti-aliasing filtering unit and the signal gating unit in sequence.

In a selected scheme, the chip model of the anti-aliasing filtering unit is OPA2277, and the chip model of the signal gating unit is ADG1634 BCPZ.

According to the scheme, the chip model of the primary programmable gain amplifier is AD8250, and the chip model of the secondary programmable gain amplifier is AD 8253.

According to the scheme, the ADC acquisition module adopts a successive approximation type A/D chip LTC2358-18, wherein the successive approximation type A/D chip LTC2358-18 is provided by Linear company, the chip is an 18-bit low-noise ADC with 8-channel synchronous sampling, the data throughput rate reaches 200 KS/s/channel, and two interfaces of CMOS and LVDS are provided.

According to the scheme, the FPGA control module selects XC3S400AN-4FTG256I based on the Xilinx company Spartan-3AN series.

The utility model discloses a technological effect and advantage:

1. the utility model relates to a portable multichannel high accuracy collection system based on FPGA, contain functions such as two-stage programme-controlled amplification, optional low pass filtering, multichannel AD collection, real-time data transmission, provide a low-cost, easy solution that realizes for the application scene that requires high volume, energy consumption, collection precision, interference killing feature in the collection field;

2. the utility model has the functions of program control gain amplification, low-pass filtering and the like, can carry out high-speed parallel acquisition on multi-path AC/DC signals, and still has good performance indexes such as amplitude precision higher than 0.1%, SFDR larger than 60 dBc and the like in the environment with larger interference such as high-speed rotation and the like; the portable design is adopted, the system has small volume and space, is convenient to carry and install, is based on the modular design of the FPGA, has strong expandability, stable performance and easy maintenance, and has good application value.

Drawings

Fig. 1 is the utility model discloses portable multichannel high accuracy collection system's overall structure schematic diagram based on FPGA.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The utility model discloses use FPGA as core control unit, contain power management module, signal processing module, filtering gating module and ADC collection module. The FPGA core control module not only completes coordinated operation and logic control of each front-end module, but also communicates with the main control board card by adopting an SPI bus protocol to realize command interaction and real-time uploading of multi-path collected data.

When the system works, the system is in a high-speed rotation state and supplies power through the slip ring, so that a stable power supply network is provided. In view of weak and sensitive signals to be detected and large interference of application environment, the signal conditioning module and the filtering gating module are designed to improve performance indexes such as signal-to-noise ratio, spurious-free dynamic range and common mode rejection ratio of the signals to be detected, and the method is the key for realizing high-precision acquisition. The multi-path parallel sampling is realized through the ADC acquisition module, the FPGA control module uploads the acquired data in real time through the SPI bus, the control and data storage of a plurality of acquisition card systems are realized through the main control board card, and the combined data is sent to the PC end. And finally, analyzing, processing and displaying the data through an upper computer.

The power supply management module comprises a switching power supply and a linear power supply; the chip type of the switching power supply is

TPS 75003. The utility model discloses a realize stable power supply network, in the power management module design, high efficiency DC power chip is chooseed for use to digital power supply, and the analog power source chooses for use TI high accuracy low noise LDO TPS7A4700 and TPS7A3301 etc. chips, and the outside adopts 10A constant voltage power supply of 15V to provide the electric energy, provides 12V for the system, 5V, 3.3V and 1.2V's stable operating voltage. Meanwhile, in order to ensure the quality of the power supply, all devices of the power supply are placed on the same layer of a PCB (printed circuit board) in the circuit design, the routing is as short as possible, and low ESR (equivalent Series resistance) and high-quality inductance and capacitance elements are used.

The signal conditioning module comprises a primary program control gain amplifier and a secondary program control gain which are connected in sequence

An amplifier. The chip model of the first-stage programmable gain amplifier is AD8250, and the chip model of the second-stage programmable gain amplifier is AD 8253. The air pressure sensor has sensitive and weak signals, and in order to improve the acquisition precision and the anti-interference capability of the signals, the high-precision amplifiers AD8250 and AD8253 for the program control instrument are designed and selected to form two-stage amplification, so that the gain amplification times (1 multiplied by 1-10 multiplied by 100) of various combinations are provided, and the functions of inhibiting noise, improving the signal-to-noise ratio and reducing the transmission loss are realized. The AD8250 has stronger noise suppression capability and is suitable for pre-stage amplification; the AD8253 has wide gain range and optimal performance as secondary amplification. The amplifiers are cascaded, and the A0, A1 and WR ports are connected with the FPGA to realize the programmable configuration of the gain.

The filtering gating module comprises an anti-aliasing filtering unit and a signal gating unit which are connected in sequence. The above-mentioned

The chip model of the anti-aliasing filtering unit is OPA2277, and the chip model of the signal gating unit is ADG1634 BCPZ. In order to improve the sampling quality of signals, a second-order active Butterworth low-pass filter is invented to filter high-frequency noise. A TI high-performance OPA2227 operational amplifier is selected, the temperature drift is +/-0.1 muV/DEG C, the open-loop gain is 134dB, the common-mode rejection ratio is 140 dB, and a low-pass filter with the cutoff frequency of 25 kHz is realized by combining high-precision 7.5 k omega, 133 k omega resistors, 620 pF capacitors and 62 pF capacitors. In order to realize the function of selectable filtering, an ADG1634BCPZ gating chip is adopted, and channel selection is realized through the control of an FPGA.

In order to realize high-speed, multi-channel parallel and high-precision signal acquisition, a successive approximation type A/D chip LTC2358-18 proposed by Linear company is selected in the design, the chip is an ADC with 18 bits, low noise and 8 channels for synchronous sampling, the data throughput rate reaches 200 KS/s/channel, and two interfaces of CMOS and LVDS are provided. In order to ensure the AD conversion precision, a high-performance chip LTC6655 with the concentration of 2 ppm/DEG C and +/-0.025 percent is selected in the design to provide conversion reference. Meanwhile, the circuit design totally adopts X7R high-quality capacitor, and the power supply of the AD chip is isolated from the power supply of the digital layer.

In order to reduce the volume and energy consumption, the XC3S400AN-4FTG256I FPGA chip based on the Spartan-3AN series of Xilinx company is selected, Flash is built in the FPGA chip, the FPGA chip has AN electric loading configuration function, AN external storage circuit is not needed, the price is low, the size of the chip is 17 mm multiplied by 17 mm, the FPGA chip has rich internal logic resources, and the design requirement of the system is met. In order to further reduce the volume space, the FPGA is independently arranged on the board in the hardware circuit design, other modules are designed into another printed board with the same size, and the whole acquisition system is connected in an opposite insertion mode, so that the wiring difficulty is reduced, and the heat dissipation area is increased. The FPGA control module comprises clock management, command configuration, AD acquisition control and data transmission control submodules. And each time the system finishes collecting, the collected data needs to be uploaded to the main control board card in time. The main control board card completes command issuing and data acquisition receiving and storing, and combines data of a plurality of acquisition systems to return to the upper computer.

The utility model relates to a portable multichannel high accuracy data acquisition system, this system possess functions such as programme-controlled gain is enlargied, low pass filter, can carry out high-speed parallel collection to multichannel alternating current-direct current signal. In the environment with large interference such as high-speed rotation, the method still has good performance indexes such as amplitude precision higher than 0.1%, SFDR larger than 60 dBc and the like. The portable design is adopted, the system has small volume and space, is convenient to carry and install, is based on the modular design of the FPGA, has strong expandability, stable performance and easy maintenance, and has good application value.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Above embodiment only is for explaining the utility model discloses a technical thought can not be injectd with this the utility model discloses a protection scope, all according to the utility model provides a technical thought, any change of doing on technical scheme basis all falls into the utility model discloses within the protection scope. Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the scope of knowledge possessed by those skilled in the art.

Claims

1. The utility model provides a portable multichannel high accuracy collection system based on FPGA which characterized in that: the device comprises a plurality of paths of sensitive signals to be detected, a signal conditioning module, a filtering gating module, an ADC (analog to digital converter) acquisition module, an FPGA (field programmable gate array) control module, a data transmission interface, a power management module and a voltage stabilizing power supply module;

2. The FPGA-based portable multi-channel high-precision acquisition system of claim 1, characterized in that: the power supply management module comprises a switching power supply and a linear power supply; the switch power supply and the linear power supply are respectively connected with the signal conditioning module, the filtering gating module, the ADC acquisition module and the FPGA control module, and the chip model of the switch power supply is TPS 75003.

3. The FPGA-based portable multi-channel high-precision acquisition system of claim 1, characterized in that: the signal conditioning module comprises a primary program control gain amplifier and a secondary program control gain amplifier which are connected in sequence, and the multiple paths of sensitive signals to be tested are connected with the filtering gating module through the primary program control gain amplifier and the secondary program control gain amplifier in sequence.

4. The FPGA-based portable multi-channel high-precision acquisition system of claim 1, characterized in that: the filtering gating module comprises an anti-aliasing filtering unit and a signal gating unit which are connected in sequence, and the signal conditioning module is connected with the ADC acquisition module through the anti-aliasing filtering unit and the signal gating unit in sequence.

5. The FPGA-based portable multi-channel high-precision acquisition system of claim 4, characterized in that: the chip model of the anti-aliasing filtering unit is OPA2277, and the chip model of the signal gating unit is ADG1634 BCPZ.

6. The FPGA-based portable multi-channel high-precision acquisition system of claim 3, characterized in that: the chip model of the first-stage programmable gain amplifier is AD8250, and the chip model of the second-stage programmable gain amplifier is AD 8253.

7. The FPGA-based portable multi-channel high-precision acquisition system of claim 1, characterized in that: the ADC acquisition module adopts a successive approximation type A/D chip LTC2358-18, which is introduced by Linear corporation, the chip is an 18-bit, low-noise and 8-channel ADC capable of sampling synchronously, the data throughput rate reaches 200 KS/s/channel, and two interfaces of CMOS and LVDS are provided.

8. The FPGA-based portable multi-channel high-precision acquisition system of claim 1, characterized in that: the FPGA control module selects XC3S400AN-4FTG256I based on Xilinx company Spartan-3AN series.