High-precision time difference capturing and measuring device having bidirectional identification function

Abstract

The invention discloses a high-precision time difference capturing and measuring device having a bidirectional identification function, which comprises a simulation comparator, a bidirectional phase discriminator circuit, a microprogrammed control unit (MCU) control processing unit and a delta t / delta U integration converter, wherein the simulation comparator is used for shaping input ultrasonic echo signals into square signals, accessing the signals to the bidirectional phase discriminator circuit, and outputting the signals to the MCU control processing unit; the MCU control processing unitis used for generating standard delay signals according to a set standard time signal generating module and accessing the standard delay signals serving as a phase discrimination benchmark to the bidirectional phase discriminator circuit; the bidirectional phase discriminator circuit is used for subjecting the square signals and the standard delay signals to phase discrimination to obtain time quantum signals; and the delta t / delta U integration converter is used for converting the time quantum signals to voltage signals and converting the voltage signals into digital quantity by means of an analog to data (A / D) converting module in the MCU control processing unit. According to the high-precision time difference capturing and measuring device having the bidirectional identification function, the simulation comparator is used so that the ultrasonic signals can be directly processed without using additional independent signal conditioning circuits; the standard time signals are used as the phase discrimination benchmark so that the bidirectional phase discrimination on travel time of the trace and the return trace of the ultrasonic signals is achieved, the precision of the A / D converting circuit is fully utilized, and the measurement accuracy of the high-precision time difference capturing and measuring device with the bidirectional identification function is twice that of a time difference capturing and measuring device without the bidirectional identification function.

Description

technical field [0001] The invention relates to high-precision time-difference measurement, in particular to a high-precision time-difference capturing and measuring device with two-way identification function, which is suitable for the field of time-difference ultrasonic flow velocity measurement. Background technique [0002] In the time-of-flight ultrasonic flow velocity measurement system, it is necessary to accurately measure the propagation time difference between the forward journey and the reverse journey of the ultrasonic wave in the pipeline in order to calculate the flow velocity. Depending on the length of the pipeline and the measurement range of the flow velocity, the range of propagation time difference is usually 3ns--4us, so only high-precision time measurement can ensure that the accuracy of the flowmeter product meets the requirements of the national standard. At present, most of the ultrasonic flow rate measurement products use the TDC-GP2 high-resolution...

AI Technical Summary

Problems solved by technology

Obviously, the chip does not integrate an analog comparator, so there is no input signal processing mechanism, and the system needs an external signal processing circuit to process the input signal; in the design of measuring instruments, the MCU control processing unit usually integrates A / D sampling conversion, clock circuit, For functions such as SPI interface, the use of clock chips makes the functions of the MCU unable to be fully utilized; at the same time, this chip is expensive and accounts for a large proportion of the cost, which is not conducive to reducing costs in mass production

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