The Design Of Period Measuring Instrument Based On Timing Integral

With the advent of the information age,the application of time has gradually penetrated into the field of engineering and technology from the field of basic research,high precision time and frequency has become an important parameter to measure the development of science and technology.Time is a measure of periodic motion,a cycle is the time required for a signal to complete an oscillation period,the frequency is the number of periodic processes in a unit time,the mathematical relationship between them is reciprocal,therefore,the two methods of measurement are integrated.First,this article starts with the measurement and control of the cycle time,depth study of the current cycle and frequency measurement algorithm,based on the analysis of zero-crossing detection and level-triggered integration,a new method of timing integration is proposed,and designed into a circuit,by the time integral of the software design to complete the function design of the whole cycle instrument.The new cycle measurement method is to initialize the integrator after the signal has peaked,bringing the integrated output voltage back to zero,first get a few zero-crossing time,according to the previous measurement results calculated time as the next zero point of the integration time,record the integration start time,the integration is stopped when the integrator output voltage returns to zero again,record the integration end time,a zero crossing time of the electric signal is calculated from the integration start time and the integration end time,in the way,the frequency of the electrical signal is calculated from a series of signals of the zero crossings.Then,in this paper,a new design scheme of the electrical signal frequency measurement is discussed,the hardware circuit design and software implementation flow are given in detail,design a set of periodic measurement system of the physical device,the hardware of the device is based on DSP,and the software is integrated in CCS environment.Sampling circuit acquisition signal,integral control circuit to obtain zero-crossing,the microprocessor to complete the corresponding control and data storage,to achieve the detection signal data calculation,and finaly by the liquid crystal display.Finaly,the core of the system lies in the implementation of hardware and software algorithms to improve and achieve.The hardware circuit collects the signal data and generates the integral waveform,and obtains the zero-crossing,the feasibility of the integration method is verified by hardware.The software algorithm obtains the zero crossing data to calculate the cycle value in the simulation integration method,the experimental data and market instruments measured data compared to illustrate the superiority.The influence of different triggering time on timing integral method is analyzed,at the beginning of the integral position f is 0.75,the integral measurement accuracy is the highest,the stability is the best,it is also demonstrated that the periodic measuring instrument can measure the periodic signal with harmonics and complete the design period measurement device.