Design And Implementation Of High Precision Time Interval Counter

High precision time interval measurement technology not only plays an important role in the basic research field of atomic physics and geodynamics,but also has been widely used in the field of computer network and mobile communication.Even it has an important impact in laser ranging,satellite navigation,aerospace telemetry and other national defense and military applications.Now its application has been deep in people's lives,almost everywhere.In recent years,with the development of national science and technology as well as the implementation of manned spaceflight,Beidou navigation,lunar exploration engineering,the time interval measurement technology present new challenges.It is not only reflected in the precision of the instrument to further improve,the same in the number of channels increased demand.Thus we carried out the research of time interval measurement technology and design a four channel high precision time interval counter.It can be used to measure the time interval,pulse width and signal frequency of the input signal.The main research contents as follows:1.Theoretical study of time interval measurement.In this thesis,several classical time interval measurement methods are analyzed.Finally,we combine the direct counting method and the tapped delay line method to measure time.And the design scheme of each measuring function is designed.2.Design and implementation of the hardware part of counter.According to the measurement methods and development goals,we design the hardware circuit of the counter and implement it by using printed circuit board.And then we complete the circuit board welding,commissioning work,providing a good hardware foundation for the system3.Development of counter driver.According to the measurement function of the counter and the hardware circuit,we design the driver of the counter use the Keil MDK embedded software development platform to realize each measurement function of the system.And the program is simulated and debugged online,the whole system finally be achieved.Finally,the experimental platform is built to test the performance of the time interval counter we designed.Experimental data show that the counter's time interval measuring uncertainty is better than the 20 ps,range up to 3.34 s,the output data is accurate and reliable,and it has the identification function of measuring signals.The measurements for the random variation time intervals are in good agreement with the output data of the international lead time measurement equipment SR620.Basically it has met the needs of most scientific research and engineering applications on the performance of time interval measurement equipment.