TDC-GP22 high-precision time measurement based on FPGA and linear regression mapping

In the research of high precision pulse laser ranging system, the accuracy of time measurement determines the accuracy of distance measurement. In order to improve the accuracy of traditional time measurement methods, a complex structure combining multiple methods is often used, and it is difficult to achieve high-precision and low-cost time measurement at the same time. In order to save costs and improve the accuracy of time interval measurement, this paper proposes a linear regression mapping method to reduce the error in the time interval measurement of the TDC-GP22 chip based on FPGA. The real value of the system is as the independent variable. The measured value is as the dependent variable. After fitting the straight line, the measurement result projects onto the straight line of the relationship between the independent variable and the real value. The experimental results show that the time interval measurement of this scheme has high accuracy, the average time measurement error is 0.18ns. Pulse ranging scheme error is 0.054m.