REAL-TIME MONITORING DC OFFSET OF ADC DATA OF LIDAR SYSTEM

1 . A light detection and ranging (LiDAR) system comprising:

a light source configured to provide transmission light signals in a plurality of firing cycles;

a detector configured to detect return signals formed based on the transmission light signals;

an analog-to-digital converter (ADC) configured to obtain ADC data representing the detected return signals; and

one or more processors and memory device, and processor-executable instructions stored in the memory device, the processor-executable instructions, when executed by the one or more processors, cause the one or more processors to perform, for at least one firing cycle of the plurality of firing cycles:

determining a multiple-point time window using the ADC data;

based on the multiple-point time window, determining an offset of the ADC data;

at least partially correcting the ADC data based on the offset; and

providing the corrected ADC data for constructing a point cloud representing an external environment of the LiDAR system.

2 . The system of claim 1 , wherein determining the multiple-point time window using the ADC data comprises positioning the multiple-point time window based on time positions of digital signals representing one or more of the detected return signals.

3 . The system of claim 2 , wherein the multiple-point time window is positioned within a previous firing cycle before a time position associated with a triggering of a current firing cycle.

4 . The system of claim 2 , wherein the multiple-point time window is positioned between a previous firing cycle and a current firing cycle or within the current firing cycle.

5 . The system of claim 2 , wherein the multiple-point time window is positioned before a time position associated with digital signals representing a first pulse of the detected return signals in the current firing cycle.

6 . The system of claim 1 , wherein based on the multiple-point time window, determining the offset of the ADC data comprises:

obtaining time positions of the determined multiple-point time window;

obtaining signal intensities of the ADC data corresponding to the time positions of the multiple-point time window; and

computing the offset based on of the signal intensities of the ADC data corresponding to the time positions of the multiple-point time window.

7 . The system of claim 6 , wherein computing the offset based on of the signal intensities of the ADC data corresponding to the time positions of the multiple-point time window comprises computing at least one of:

a mean value of the signal intensities;

a weighted mean value of the signal intensities;

a median value of the signal intensities; and

a mode of the signal intensities.

8 . The system of claim 6 , wherein computing the offset is further based on a preset initial value of the offset.

9 . The system of claim 1 , wherein at least partially correcting the ADC data based on the offset comprises:

subtracting the offset from the ADC data representing detected return signals in a first firing cycle from the ADC data representing detected return signals in a second firing cycle, the first firing cycle preceding the second firing cycle.

10 . The system of claim 1 , wherein the processor-executable instructions comprise further instructions, when executed by the one or more processors, cause the one or more processors to perform:

obtaining offsets associated with a group of firing cycles of the plurality of firing cycles, the group of firing cycles being associated with a frame of the point cloud;

determining a plurality of lowest offsets associated with the group of firing cycles associated with the frame;

computing a frame offset value based on the plurality of the lowest offsets, the frame offset representing an offset of the ADC data representing the frame; and

at least partially correcting the ADC data representing the frame based on the frame offset.

11 . The system of claim 1 , wherein the processor-executable instructions comprise further instructions, when executed by the one or more processors, cause the one or more processors to perform, for a group of firing cycles of the plurality of firing cycles, the group of firing cycles being associated with a frame of the point cloud:

computing standard deviations of signal intensities of the ADC data associated with the group of firing cycles;

selecting, from the computed standard deviations, a plurality of smallest standard deviations of signal intensities of the ADC data associated with the group of firing cycles;

identifying, from multiple-point time windows associated with the group of firing cycles, a group of multiple-point time windows corresponding to the plurality of the smallest standard deviations of the signal intensities of the ADC data associated with the group of firing cycles;

determining offsets of the ADC data associated with the identified group of multiple-point time windows;

computing a frame offset based on the offsets of the ADC data associated with the identified group of multiple-point time windows;, the frame offset representing an offset of the ADC data representing the frame; and

at least partially correcting the ADC data representing the frame based on the frame offset.

12 . The system of claim 1 , wherein the multiple-point time window comprises a 16-point time window.

13 . A method for real-time offset monitoring for light detection and ranging (LiDAR), the method comprising:

providing, by a light source, transmission light signals in a plurality of firing cycles;

detecting, by a detector, return signals formed based on the transmission light signals;

obtaining, by an analog-to-digital converter (ADC), ADC data representing the detected return signals; and

executing, by one or more processors and memory device, processor-executable instructions to cause the one or more processors to perform, for at least one firing cycle of the plurality of firing cycles:

determining a multiple-point time window using the ADC data;

based on the multiple-point time window, determining an offset of the ADC data;

at least partially correcting the ADC data based on the offset; and

providing the corrected ADC data for constructing a point cloud representing an external environment of the LiDAR system.

14 . The method of claim 13 , wherein determining the multiple-point time window using the ADC data comprises positioning the multiple-point time window based on time positions of digital signals representing one or more of the detected return signals.

15 . The method of claim 14 , wherein the multiple-point time window is positioned within a previous firing cycle before a time position associated with a triggering of a current firing cycle.

16 . The method of claim 14 , wherein the multiple-point time window is positioned between a previous firing cycle and a current firing cycle.

17 . The method of claim 14 , wherein the multiple-point time window is positioned before a time position associated with digital signals representing a first pulse of the detected return signals in the current firing cycle.

18 . The method of claim 13 , wherein based on the multiple-point time window, determining the offset of the ADC data comprises:

obtaining time positions of the determined multiple-point time window;

obtaining signal intensities of the ADC data corresponding to the time positions of the multiple-point time window; and

computing the offset based on of the signal intensities of the ADC data corresponding to the time positions of the multiple-point time window.

19 . The method of claim 18 , wherein computing the offset based on of the signal intensities of the ADC data corresponding to the time positions of the multiple-point time window comprises computing at least one of:

a mean value of the signal intensities;

a weighted mean value of the signal intensities;

a median value of the signal intensities; and

a mode of the signal intensities.

20 . The method of claim 18 , wherein computing the offset is further based on a preset initial value of the offset.

21 . The method of claim 13 , wherein at least partially correcting the ADC data based on the offset comprises: subtracting the offset from the ADC data representing detected return signals in a first firing cycle from the ADC data representing detected return signals in a second firing cycle, the first firing cycle preceding the second firing cycle.

22 . A non-transitory computer readable medium storing processor-executable instructions for performing correction of analog-to-digital (ADC) data obtained based on transmission light signals associated with a plurality of firing cycles, wherein the instructions, when executed by one or more processors of an electronic device, cause the electronic device to perform:

providing, by a light source, transmission light signals in a plurality of firing cycles;

detecting, by a detector, return signals formed based on the transmission light signals;

obtaining, by an analog-to-digital converter (ADC), ADC data representing the detected return signals; and

executing, by the one or more processors and memory device, processor-executable instructions to cause the one or more processors to perform, for at least one firing cycle of the plurality of firing cycles:

determining a multiple-point time window using the ADC data;

based on the multiple-point time window, determining an offset of the ADC data;

at least partially correcting the ADC data based on the offset; and

providing the corrected ADC data for constructing a point cloud representing an external environment of the LiDAR system.

23 . A vehicle comprising a light detection and ranging (LiDAR) system, wherein the LiDAR system comprises:

a light source configured to provide transmission light signals in a plurality of firing cycles;

a detector configured to detect return signals formed based on the transmission light signals;

an analog-to-digital converter (ADC) configured to obtain ADC data representing the detected return signals; and

one or more processors and memory device, and processor-executable instructions stored in the memory device, the processor-executable instructions, when executed by the one or more processors, cause the one or more processors to perform, for at least one firing cycle of the plurality of firing cycles:

determining a multiple-point time window using the ADC data;

based on the multiple-point time window, determining an offset of the ADC data;

at least partially correcting the ADC data based on the offset; and

providing the corrected ADC data for constructing a point cloud representing an external environment of the LiDAR system.