CN-116300379-B - Time-to-digital converter, time measurement method and related equipment

CN116300379BCN 116300379 BCN116300379 BCN 116300379BCN-116300379-B

Abstract

The application provides a time-to-digital converter, a time measurement method and related equipment, which have higher time measurement precision. The time-to-digital converter comprises a coarse time counting unit, a fine time counting unit, a buffer unit and a processing unit, wherein the coarse time counting unit is used for receiving a first clock signal and an input signal to be detected, counting is carried out from a reference moment until the input signal to be detected is received according to one clock period t of the first clock signal as a counting clock so as to obtain a coarse time result of the input signal to be detected, the fine time counting unit comprises a carry chain, the timing length of the carry chain is greater than 2t, the carry chain comprises n adders, the n adders are cascaded, the processing unit is coupled with the buffer unit and used for monitoring output results of the n adders based on the first clock signal, and the fine time result of the input signal to be detected is determined according to the output results of the n adders obtained twice.

Inventors

XU XINGYU
FANG YONGJUN
DENG ZHIJI
ZHOU XIAOYONG
XU ZILIANG
Mei Wenxuan
WU YUNJIE

Assignees

浙江大华技术股份有限公司

Dates

Publication Date: 20260505
Application Date: 20230328

Claims (12)

1. The time-to-digital converter is characterized by comprising a coarse time counting unit, a fine time counting unit, a cache unit and a processing unit; the coarse time counting unit is used for receiving a first clock signal and an input signal to be detected, counting from a reference moment until the input signal to be detected is received according to a clock period t of the first clock signal as a counting clock so as to obtain a coarse time result of the input signal to be detected; The fine time counting unit comprises a carry chain, wherein the timing length of the carry chain is more than 2t, the carry chain comprises n adders, n is a positive integer which is more than 1, the n adders are cascaded, and the carry input end of the 1 st adder is used for receiving the input signal to be detected; The buffer unit is respectively coupled with the carry output end of each adder in the n adders and is used for buffering the output results of the carry output ends of the n adders; the processing unit is coupled with the caching unit for: monitoring output results of the n adders based on the first clock signal; Determining a fine time result of the input signal to be detected according to the output results of the n adders obtained twice, wherein the coarse time result and the fine time result are used for determining a time measurement result of the input signal to be detected; the processing unit is specifically configured to, when monitoring output results of the n adders based on the first clock signal: obtaining output results of the n adders at a first rising edge moment of the first clock signal; if the output results of the n adders obtained at the first rising edge moment are different from the preset initial result, and the adder with the largest series in the adders generating carry at the first rising edge moment is not the 1 st-stage adder, obtaining the output results of the n adders at a second rising edge moment, wherein the second rising edge moment is the first rising edge moment after the first rising edge moment; If the output results of the n adders obtained at the first rising edge moment are different from the preset initial result, and the adder with the largest series number in the adders generating carry at the first rising edge moment is the 1 st-stage adder, the output results of the n adders are obtained at the second rising edge moment and the output results of the n adders are obtained at a third rising edge moment, and the third rising edge moment is the second rising edge moment after the first rising edge moment.
2. The time-to-digital converter of claim 1, wherein the processing unit is further to: If the adder with the largest level number in the adders with carry at the first rising edge moment is not the 1 st level adder, determining the first adder with the largest level number in the adders with carry at the first rising edge moment according to the output result obtained at the first rising edge moment, or if the adder with the largest level number in the adders with carry at the first rising edge moment is the 1 st level adder, determining the first adder with the largest level number in the adders with carry at the third rising edge moment according to the output result obtained at the third rising edge moment; Determining a second adder with the largest series in adders generating carry at the second rising edge moment according to an output result acquired at the second rising edge moment; and determining a fine time result of the input signal to be detected according to the first adder and the second adder.
3. The time-to-digital converter of claim 2, wherein each adder has a preconfigured start time, wherein the start time of the 1 st adder is configured to be a first value, wherein a difference between the start time of the i-th adder and the first value is a timing length of a previous i-1 st adder, and wherein the processing unit is specifically configured to: If the difference value between the starting time of the second adder and the starting time of the first adder is smaller than t, taking the difference value between the starting time of the first adder and t as a first fine time result to be selected; if the difference between the starting time of the second adder and the starting time of the first adder is equal to or greater than t, taking the difference between the starting time of the second adder and 2t as the first fine time result to be selected; and determining a fine time result of the input signal to be detected based on the first fine time result to be selected.
4. The time-to-digital converter of claim 2 or 3, wherein each adder has a preconfigured end time, wherein a start time of the 1 st-stage adder is configured to be a first value, and wherein a difference between the end time of the 1 st-stage adder and the first value is a timing length of the 1 st-stage adder; The processing unit is further configured to: If the difference between the end time of the second adder and the end time of the first adder is smaller than t, taking the difference between the end time of the second adder and 2t as a second fine time result to be selected; if the difference value between the end time of the second adder and the end time of the first adder is equal to or greater than t, taking the difference value between the end time of the second adder and t as the second fine time to be selected result; And determining a fine time result of the input signal to be detected based on the second fine time result to be selected.
5. The time-to-digital converter of claim 4, wherein the processing unit is specifically configured to: Determining a fine time result of the input signal to be detected based on a set to be selected, wherein the minimum value in the set to be selected is the first fine time result to be selected, and the maximum value in the set to be selected is the second fine time result to be selected; If the adder with the largest series number in the adder with carry at the first rising edge moment is the 1 st-stage adder, any numerical value in the to-be-selected set is a fine time result of the input signal to be detected; if the adder with the largest series number in the adder with carry occurring at the first rising edge moment is the 1 st-stage adder, the sum of any numerical value in the set to be selected and t is the fine time result of the input signal to be detected.
6. A time measurement method applied to a time-to-digital converter according to any one of claims 1-5, the method comprising: Counting the input signal to be detected according to one clock period t of the first clock signal as a counting clock so as to obtain a coarse time result of the input signal to be detected; monitoring output results of the n adders based on the first clock signal; determining a fine time result of the input signal to be detected according to the output results of the n adders obtained twice; wherein the monitoring the output results of the n adders includes: obtaining output results of the n adders at a first rising edge moment of the first clock signal; if the output results of the n adders obtained at the first rising edge moment are different from the preset initial result, and the adder with the largest series in the adders generating carry at the first rising edge moment is not the 1 st-stage adder, obtaining the output results of the n adders at a second rising edge moment, wherein the second rising edge moment is the first rising edge moment after the first rising edge moment; If the output results of the n adders obtained at the first rising edge moment are different from the preset initial result, and the adder with the largest series number in the adders generating carry at the first rising edge moment is the 1 st-stage adder, the output results of the n adders are obtained at the second rising edge moment and the output results of the n adders are obtained at a third rising edge moment, and the third rising edge moment is the second rising edge moment after the first rising edge moment.
7. The method of claim 6, wherein if the output results of the n adders obtained at the first rising edge moment are different from a preset initial result, the determining the fine time result of the input signal to be measured according to the output results of the n adders obtained twice includes: If the adder with the largest level number in the adders with carry at the first rising edge moment is not the 1 st level adder, determining the first adder with the largest level number in the adders with carry at the first rising edge moment according to the output result obtained at the first rising edge moment, or if the adder with the largest level number in the adders with carry at the first rising edge moment is the 1 st level adder, determining the first adder with the largest level number in the adders with carry at the third rising edge moment according to the output result obtained at the third rising edge moment; Determining a second adder with the largest series in adders generating carry at the second rising edge moment according to an output result acquired at the second rising edge moment; and determining a fine time result of the input signal to be detected according to the first adder and the second adder.
8. The method of claim 7, wherein each adder has a pre-configured start time, wherein the start time of the level 1 adder is configured to be a first value, wherein the difference between the start time of the level i adder and the first value is the timing length of the previous level i-1 adder; The determining, according to the first adder and the second adder, a fine time result of the input signal to be measured includes: If the difference value between the starting time of the second adder and the starting time of the first adder is smaller than t, taking the difference value between the starting time of the first adder and t as a first fine time result to be selected; if the difference between the starting time of the second adder and the starting time of the first adder is equal to or greater than t, taking the difference between the starting time of the second adder and 2t as the first fine time result to be selected; and determining a fine time result of the input signal to be detected based on the first fine time result to be selected.
9. The method of claim 7 or 8, wherein each adder has a preconfigured end time, wherein a start time of the 1 st-stage adder is configured to be a first value, wherein a difference between the end time of the 1 st-stage adder and the first value is a timing length of the 1 st-stage adder, wherein a difference between the end time of the i-stage adder and the first value is a timing length of a previous i-stage adder; the determining the fine time result of the input signal to be detected according to the first adder and the second adder further includes: If the difference between the end time of the second adder and the end time of the first adder is smaller than t, taking the difference between the end time of the second adder and 2t as a second fine time result to be selected; If the difference value between the end time of the second adder and the end time of the first adder is equal to or greater than t, taking the difference value between the end time of the first adder and t as the second fine time to be selected result; And determining a fine time result of the input signal to be detected based on the second fine time result to be selected.
10. The method of claim 9, wherein said determining fine time results of said input signal under test comprises: Determining a fine time result of the input signal to be detected based on a set to be selected, wherein the minimum value in the set to be selected is the first fine time result to be selected, and the maximum value in the set to be selected is the second fine time result to be selected; If the adder with the largest series number in the adder with carry at the first rising edge moment is the 1 st-stage adder, any numerical value in the to-be-selected set is a fine time result of the input signal to be detected; if the adder with the largest series number in the adder with carry occurring at the first rising edge moment is the 1 st-stage adder, the sum of any numerical value in the set to be selected and t is the fine time result of the input signal to be detected.
11. An electronic device comprising a transmitting module, a receiving module, and a time-to-digital converter as claimed in any one of claims 1-5; The transmitting module is used for transmitting optical signals; The receiving module is used for receiving an input signal to be detected, wherein the input signal to be detected is a signal of the optical signal reflected by an obstacle; The time-to-digital converter is used for measuring the flight time of the optical signal.
12. A computer readable storage medium storing computer instructions which, when run on a processor, cause the processor to perform the method of any one of claims 6-10.

Description

Time-to-digital converter, time measurement method and related equipment Technical Field The application relates to the technical field of electronics, and discloses a time-to-digital converter, a time measurement method and related equipment. Background At present, the laser radar technology has higher measurement accuracy requirements. If the laser radar technology is applied to mapping scenes, mapping target deviation can be reduced. Or a laser radar is additionally arranged on the vehicle, so that the vehicle can accurately determine the distance of the obstacle. For the laser radar technology, accurate measurement of laser flight time is beneficial to improving ranging accuracy. The time measurement precision reaches the picosecond level, so that the laser radar ranging precision can reach the centimeter level. Time measurement is seen to be critical to lidar technology. How to improve the time measurement accuracy is a problem to be solved. Disclosure of Invention The application provides a time-to-digital converter, a time measurement method and related equipment, which have higher time measurement precision. In a first aspect, an embodiment of the present application provides a time-to-digital converter, including a coarse time counting unit, a fine time counting unit, a buffer unit, and a processing unit; the coarse time counting unit is used for receiving a first clock signal and an input signal to be detected, counting from a reference moment until the input signal to be detected is received according to a clock period t of the first clock signal as a counting clock so as to obtain a coarse time result of the input signal to be detected; the fine time counting unit comprises a carry chain, wherein the timing length of the carry chain is more than 2t, the carry chain comprises n adders, n is a positive integer more than 1, the n adders are cascaded, and the carry input end of the 1 st adder is used for receiving the input signal to be detected; The buffer unit is respectively coupled with the carry output end of each adder in the n adders and is used for buffering the output results of the carry output ends of the n adders; the processing unit is coupled with the caching unit for: monitoring output results of the n adders based on the first clock signal; And determining a fine time result of the input signal to be detected according to the output results of the n adders obtained twice, wherein the coarse time result and the fine time result are used for determining a time measurement result of the input signal to be detected. In a possible implementation manner, an embodiment of the present application provides a time-to-digital converter, where the processing unit is specifically configured to: obtaining output results of the n adders at a first rising edge moment of the first clock signal; If the output results of the n adders obtained at the first rising edge moment are different from the preset initial result, and the adder with the largest series number in the adders generating carry at the first rising edge moment is the 1 st-stage adder, obtaining the output results of the n adders at a second rising edge moment, wherein the second rising edge moment is the first rising edge moment after the first rising edge moment; If the output results of the n adders obtained at the first rising edge moment are different from the preset initial result, and the adder with the largest series number in the adders generating carry at the first rising edge moment is not the 1 st-stage adder, the output results of the n adders are obtained at the second rising edge moment and the output results of the n adders are obtained at a third rising edge moment, and the third rising edge moment is the second rising edge moment after the first rising edge moment. In a possible implementation manner, an embodiment of the present application provides a time-to-digital converter, where the processing unit is further configured to: If the adder with the largest level number in the adders with carry at the first rising edge moment is not the 1 st level adder, determining the first adder with the largest level number in the adders with carry at the first rising edge moment according to the output result obtained at the first rising edge moment, or if the adder with the largest level number in the adders with carry at the first rising edge moment is the 1 st level adder, determining the first adder with the largest level number in the adders with carry at the third rising edge moment according to the output result obtained at the third rising edge moment; Determining a second adder with the largest series in adders generating carry at the second rising edge moment according to an output result acquired at the second rising edge moment; and determining a fine time result of the input signal to be detected according to the first adder and the second adder. In a possible implementation manner, the embodiment of the application p