CN205451768U - A electric wire netting frequency measurement system for during pronunciation are collected evidence - Google Patents

Abstract

The utility model relates to an electric wire netting frequency measurement system for during pronunciation are collected evidence, including mainboard system and bottom plate system, the mainboard system include DSP nuclear core plate, JTAG interface module, outside extension SRAM module and mains operated module, the bottom plate system include that electric wire netting frequency acquisition module in electric wire netting frequency acquisition module, the pronunciation, pronunciation record and play back module, SD card storage module, serial communication module, simulation interface module and phase -locked loop module. The utility model discloses use electric wire netting frequency processing system as the center, through electric wire netting frequency acquisition module, the electric wire netting frequency measured module among storage module and the speech signal is recorded and play back to pronunciation, through the measurement to the electric wire netting frequency in order obtaining the electric wire netting at the spectrogram of different frequency department, then carry out speech processing to the sound of recording to obtain its frequency spectrum, last frequency spectrum with the different time quantums of electric wire netting contrasts, thereby whether can judge speaker's testimony correct.

Description

A kind of grid frequency measurement system in voice is collected evidence

Technical field

This utility model relates to the grid frequency measurement system in the evidence obtaining of a kind of voice, belongs to grid frequency measurement technical field.

Background technology

More international power grid frequency measurement methods are both for noise-free environment or small noise environment, but under multi-path jamming or complicated noise, performance is the best.And China's power grid environment is more complicated, there is serious multi-path jamming and Complex Noise.During voice is collected evidence, need to obtain its frequency spectrum it is necessary to frequency spectrum can be analyzed in the middle of this environment accurately, so it is necessary to have the grid frequency measurement system of sane noise robustness, this is also technology the most crucial in voice evidence obtaining.

Utility model content

The purpose of this utility model is: for the defect of prior art, propose the grid frequency measurement system in the evidence obtaining of a kind of voice, centered by mains frequency processing system, by mains frequency acquisition module, grid frequency measurement module in speech recording and reproducing memory module and voice signal, by measuring mains frequency to obtain electrical network spectrogram at different frequency, then the sound of recording is carried out speech processes, to obtain its frequency spectrum, last and the spectral contrast of electrical network different time sections, such that it is able to judge that the testimony of speaker is the most correct.

This utility model be the technical scheme is that the grid frequency measurement system in the evidence obtaining of a kind of voice, including main board system and bottom board system, described main board system includes DSP core core, jtag interface module, outside extension SRAM module and power supply module, its peripheral extension SRAM module is for the storage of information, and DSP core core is provided with TMS320F28335 floating type control chip；Described bottom board system includes mains frequency acquisition module in mains frequency acquisition module, voice, voice recording-reproducing assembly, SD card memory module, serial communication module, analog interface module and phase-locked loop module, described voice recording-reproducing assembly is to realize the recording and reproducing function to voice by speech chip and two microphone audio interfaces, and described phase-locked loop module is to lock sample frequency.

In this utility model: be provided with UART interface on described serial communication module, serial communication module is connected with host computer.

After using technique scheme, the beneficial effects of the utility model are: this utility model is centered by mains frequency processing system, by mains frequency acquisition module, grid frequency measurement module in speech recording and reproducing memory module and voice signal, by measuring mains frequency to obtain electrical network spectrogram at different frequency, then the sound of recording is carried out speech processes, to obtain its frequency spectrum, last and the spectral contrast of electrical network different time sections, such that it is able to judge that the testimony of speaker is the most correct.

Accompanying drawing explanation

Fig. 1 is system schematic of the present utility model；

Fig. 2 is TMS320F28335 floating type control chip schematic diagram of the present utility model；

Fig. 3 is outside extension SRAM module principle schematic of the present utility model；

Fig. 4 is outside extension jtag interface module principle schematic diagram of the present utility model；

Fig. 5 is outside extension mains frequency acquisition module principle schematic of the present utility model；

Fig. 6 is outside extension phaselocked loop module principle schematic diagram of the present utility model；

Fig. 7 is outside extension serial communication module principle schematic diagram of the present utility model；

Fig. 8 is outside extension SD card memory module principle schematic of the present utility model.

Detailed description of the invention

Below in conjunction with accompanying drawing, this utility model is further described.

From Fig. 1-8, a kind of grid frequency measurement system in voice evidence obtaining, including main board system and bottom board system, described main board system includes DSP core core, jtag interface module, outside extension SRAM module and power supply module, its peripheral extension SRAM module is for the storage of information, and DSP core core is provided with TMS320F28335 floating type control chip；Described bottom board system includes mains frequency acquisition module in mains frequency acquisition module, voice, voice recording-reproducing assembly, SD card memory module, serial communication module, analog interface module and phase-locked loop module, described voice recording-reproducing assembly is to realize the recording and reproducing function to voice by speech chip and two microphone audio interfaces, and described phase-locked loop module is to lock sample frequency.Described serial communication module is provided with UART interface, and serial communication module is connected with host computer.

Acoustical signal can be become the signal of telecommunication by mike by the grid frequency measurement in voice signal, its output voltage typically only has several mA, then by second-order low-pass filter amplify by its FREQUENCY CONTROL in 300Hz Control of Voltage between 0～3V, finally send into the AD interface on DSP core core, utilize AD sampling and FFT its frequency to be calculated.Phase-locked loop module is primarily to lock sample frequency, this part of speech recording and reproducing is to realize the recording and reproducing function to voice by WM8731 speech chip and two microphone audio interfaces, WM8731 carries D/A module, can communicate with the inside McBSP of TMS320F28335 floating type control chip on DSP core core, digital signal is passed to TMS320F28335 floating type control chip, so that it is determined that sample frequency.Small size, massive store now all be unable to do without SD card etc., devise the interface of microSD card the most here, and in the present system, SD card memory module and DSP core core can be joined directly together.

In the specific implementation, main board system uses TMS320F28335 floating type control chip to produce the output of 3.3V and 1.9V DC voltage by the input of 5V voltage, thinks that TMS320F28335 floating type control chip provides I/O pin voltage and core voltage respectively；Because there being the forceful electric power of 220V on base plate in bottom board system, so individually separating with the power supply on main board system, the alternating current of 220V produces the AC sine wave of 6V by transformator, by becoming DC voltage after rectifier bridge rectification, produce the voltage of 5V and 3.3V respectively in case each chip power supply by AMS1117-5V and AMS1117-3.3V voltage stabilizing chip the most respectively.

Grid frequency measurement module uses the accurate voltage transformer of ZMPT107, asks for voltage by electric current, in case with the sampling of ADC, realized voice signal recording playback by numeral codec speech chips W M8731 chip；Simultaneously constant in order to ensure counting of sampling, the peripheral expansion used in system connects phaselocked loop CD4046 chip.

Above detailed description of the invention of the present utility model is described, but this utility model is not limited to above description.For a person skilled in the art, any equal amendment to the technical program and replacement are all among scope of the present utility model.Therefore, the impartial conversion made under without departing from spirit and scope of the present utility model and amendment, all should contain in the range of this utility model.

Claims (2)

1. the grid frequency measurement system in voice is collected evidence, it is characterized in that: include main board system and bottom board system, described main board system includes DSP core core, jtag interface module, outside extension SRAM module and power supply module, its peripheral extension SRAM module is for the storage of information, and DSP core core is provided with TMS320F28335 floating type control chip；Described bottom board system includes mains frequency acquisition module in mains frequency acquisition module, voice, voice recording-reproducing assembly, SD card memory module, serial communication module, analog interface module and phase-locked loop module, described voice recording-reproducing assembly is to realize the recording and reproducing function to voice by speech chip and two microphone audio interfaces, and described phase-locked loop module is to lock sample frequency.

A kind of grid frequency measurement system in voice is collected evidence the most according to claim 1, it is characterised in that: described serial communication module is provided with UART interface, and serial communication module is connected with host computer.