脉冲激光测距中高精度时间间隔测量_宋建辉.pdfVIP

17 5 Vol. 17 No. 5 2009 5 Optics and Precision Engineering May 2009 100 -92 X( 2009) 05- 10 6-05 宋建辉, 袁 峰, 丁振良 ( 哈尔滨工业大学 自动化测试与控制系, 黑龙江 哈尔滨 150001) : , ( FPGA) / 0 , FPGA N , , , Tclk / N FlipFlop , , , , 163. 8 Ls, , , 71 ps , : 激光测距; 时间间隔测量; 多相采样; 延迟链 :T N2 7 :A High precision time interval measurement in pulsed laser ranging SONG Jian-hui, YU AN Feng, DING Zhen-liang (Dep ar tment of A utomatic Testing and Control , H arbin I nst itute of Technology , H ar bin 150001, China) Abstract : T he high accuracy time interval measurement is a key technique to a pulsed laser ranging. In this paper , a new high precision time interval measurement method combining w ith a pulse counting method, a mult-i phase sampling and a delay method is proposed to use in the mult-i level time interval measurement in a Field Programming Gate Array( FPGA) . The pluse counting method is used to real- ize the coarse counter to guarantee a large dynamic range, and a Phase Locked Loop( PLL) in the FP- GA is used to generate the N clock pulses w ith the same frequency and uniform distribution phase as counting clocks. Based on the equal precision frequency measuring, the resolution of the time conver- sion is improved to T clk/ N . Moreover, a latch Flip Flops is used to form a delay chain to measure the fine time interval. Experiments show that the proposed method has solved the problem of the tradi- tional mult-i phase sampling approach, to w hich phase shift resolution is decreased w ith the frequency increasing, so that the fine resolution can be obtained by limiting delay lines and no increase of count- ing clocks. T he test results show that the maximum measuring time of the module is 163.