39results about How to "Improve time measurement accuracy" patented technology

The invention provides a high-precision and high-integrality time-digital converter based on an FPGA (Field Programmable Gate Array), and an implementation method. The time-digital converter comprises a fine time measuring unit, wherein the fine time measuring unit consists of a time alternate sampling unit, a multi-stage sampling data buffering unit and a snapshot and encoding unit. The invention aims to provide the high-integrality precision time-digital converter based on an FPGA. Innovation points lie in that: a fine time measuring part adopts a technology of a latch snapshot and rapid encoding combined architecture based on phase splitting clock alternate sampling, multi-stage sampling data caching and cached multi-stage sampling data. The high-precision and high-integrality time-digital converter has the characteristics of simple structure, design flexibility, high portability, short measuring dead time, large dynamic range, low cost, flexible interface and the like, and can be applied to the fields of aerospace, space research, communication, biomedicine, earth dynamics, relativity research and the like.

The invention discloses a method and a device for measuring a flight time of ultrasonic echo. The method is performed in the manner of layering time and interpolating. The time measuring range is expanded by adopting the direct counting method in a first layer. The time delay interpolation method is adopted in a second layer. A bran-new two-dimensional matrix manner is adopted on a topological structure. A timing quantization error of the flight time to be measured is further subdivided into two layers. The length of a delay line is shortened so the linear of the delay line is increased. The ps level resolution ratio limitation is broken through because a cursor delay line structure is adopted at 2-2nd Level. For realizing the method, the invention further provides a set of measuring device which comprises a signal receiving and sending part, a digital signal processing part and a man-machine interaction part. The measuring result precision of flight time can be promoted.

The invention is suitable for the technical field of time precision measurement and provides a time-to-digit conversion device and a digital phase-locked loop. The device comprises a power supply control circuit, a first delay circuit, a second delay circuit and a time detection circuit; the power supply control circuit generates a first voltage and a second voltage and transmits the first voltageand the second voltage to the first delay circuit and the second delay circuit respectively; the first delay circuit is used for carrying out delay processing on a received first clock signal according to the first voltage; the second delay circuit is used for carrying out delay processing on a received second clock signal according to the second voltage; the time detection circuit is used for receiving the first clock signal and the second clock signal obtained after delay processing, and the time difference between the first clock signal and the second clock signal is detected. According tothe device, different voltages are input into the two delay circuits so that the two delays can be different, and higher and more stable measurement precision is obtained; meanwhile, requirements ofa circuit technology and layout are reduced.

A time-to-digital converter includes a first oscillation circuit that starts oscillating at the transition timing of a first signal and generates a first clock signal having a first clock frequency, a second oscillation circuit that starts oscillating at the transition timing of a second signal and generates a second clock signal having a second clock frequency, a first adjustment circuit that adjusts the oscillation frequency of the first oscillation circuit based on a reference clock signal, a second adjustment circuit that adjusts the oscillation frequency of the second oscillation circuit based on the reference clock signal, and a processing circuit that converts the time difference between the transition timing of the first signal and the transition timing of the second signal into a digital value based on the first and second clock signals.

The invention provides a time digital converter adjusting method. The method comprises the steps that for each delay chain, after each time the input position of the delay chain is adjusted, N triggersignals are input into the adjusted input position, and the carry number of each trigger signal on the delay chain is acquired; the optimal input position is selected according to the carry number ofeach adjustment to configure the delay chain; after each time the tap position of a main delay chain is adjusted, M trigger signals are input into the optimal input position of the main delay chain to acquire the average of the carry number of each trigger signal on each delay chain; and the optimal tap position is selected according to the average of each adjustment to configure the main delaychain. The input position of each delay chain is changed to achieve in-chain adjustment optimization, and then the tap position of the main delay chain is changed to achieve inter-chain adjustment optimization. The delay of each delay unit in TDC is kept as consistent as possible, and the TDC time measurement accuracy is improved.

A method for measuring long-pulse fine structure with time-spectral coding, which is implemented by the following steps: Step 1: Synchronize the long-pulse laser to be measured with the femtosecond laser in the ICF driver, and make the long-pulse laser to be measured and the femtosecond laser emit Time synchronization of pulses; Step 2: The femtosecond laser generates femtosecond pulses, and transmits the femtosecond pulses to the supercontinuum generation device to generate supercontinuum white light with a spectral width of several hundred nanometers, and transmits the generated supercontinuum white light Emitted to the grating stretcher; step 3: the grating stretcher produces a broadband linear chirped pulse with a pulse width equivalent to the long pulse to be measured produced by the long pulse laser to be measured; step 4: the broadband linear chirped pulse and the pulse to be measured The length measurement pulse is incident into the nonlinear crystal at a certain non-collinear angle, and the sum frequency is performed in the nonlinear crystal, and the generated sum frequency pulse is sent to the spectrometer to measure the sum frequency pulse spectrum; Step 5: Calculate the length to be measured The time domain structure of the pulse.

The invention relates to a time-domain modulation time-dependent single-photon counting device and a time-domain modulation time-dependent single-photon counting system. The invention mainly relates to the technical field of transient photon measurement. The single-photon counting device of the present application comprisesa drive circuit, a single-photon detector and a timing circuit, wherein thedrive circuit, the single-photon detector and the timing circuit are electrically connected in sequence, the single-photon detector is electrically connected with the timing circuit, and the time domain modulation time-dependent single-photon counting realizes the time amplification of a photon event to be measured through the time domain modulation single-photon detector and the corresponding time domain modulation drive circuit so as to improve the time measurement precision of the whole system. A photon event to be measured is amplified in time, the influence of electron transit time dispersion in the detector and timing precision errors of the timing circuit module on the timing precision of the single-photon counting device is effectively reduced, and the measurement precision of thesingle-photon counting device is improved.

The invention relates to the field of time measurement, in particular to a split-phase clock TDC based on an ISERDES tandem chain and a measurement method. ISERDES cores in a plurality of FPGAs are connected in series through technical means to achieve multiple measurements of input signals and improve the time measurement precision, the TDC is subjected to performance test in a K7 FPGA, and the result shows that the time measurement precision is better than 40 ps RMS. The dead time is less than 20 ns.

A sound wave distance measuring device comprises a time measurement and data processing module, a sound wave transmitting circuit, a sound wave transmitting sensor, a sound wave receiving sensor and asound wave receiving circuit. The sound wave receiving circuit comprises an amplifying circuit, also comprises a phase shift circuit and electric signal-to-direct current level circuits, the electricsignal before phase shift outputs discontinuous direct current signal level through the first electric signal-to-direct current level circuit, the phase shift circuit changes a phase electric signal,the electric signal subjected to phase position change through the phase shift circuit outputs discontinuous direct current signal level through the second electric signal-to-direct current level circuit, the two paths of discontinuous direct current levels are combined and then are output to the time measurement and data processing module, to realize distance measuring. The sound wave distance measuring device has the technical effects that by adopting the combination of the phase shift circuit and the periodically changed electric signal-to-direct current level circuits, the periodically changed electric signals before and after phase shift are respectively converted into discontinuous direct current signal levels, combined and output or respectively output, so that the input sine can be converted into the direct current signal levels.