CN108008398B - Timing method and device applied to laser radar - Google Patents
Timing method and device applied to laser radar Download PDFInfo
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
- G01S17/06—Systems determining position data of a target
- G01S17/08—Systems determining position data of a target for measuring distance only
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/4802—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section
Abstract
The invention provides a timing method and a timing device applied to a laser radar, wherein the method comprises the following steps: acquiring a laser echo signal transmitted by a signal conditioning circuit by using a high-speed ADC (analog to digital converter) to obtain a digital waveform S1; preprocessing the digital waveform S1 to obtain a digital waveform S2; performing data processing on the digital waveform S2 to obtain a digital quantity A1 representing the waveform intensity of the digital waveform S2; multiplying a digital quantity A1 for representing the waveform intensity of the digital waveform S2 to obtain a digital quantity A2, wherein A2 is A1F 1; and searching a point P1 on the rising edge of the digital waveform S2, so that the numerical value of a point P1 is equal to the digital quantity A2, and the time corresponding to the point P1 is the receiving time of the laser echo signal. The invention can provide a simple, quick, stable and high-precision timing result.
Description
Technical Field
The invention relates to the technical field of laser ranging, in particular to a timing method and a timing device applied to a laser radar.
Background
The laser radar is a photoelectric system for distance sensing by applying laser, and is more and more widely applied in the fields of military affairs, agriculture, engineering and traffic. Particularly in the traffic field, with the rapid development of unmanned technology, higher requirements are put forward on the speed, precision, anti-interference capability, multi-dimensional detection capability and the like of the laser radar. Conventional lidar based on analog technology has not been able to meet the requirements. With the rapid development of modern photoelectric acquisition technology, especially high-speed Flash ADC technology, lidar based on digital receiving and processing technology is becoming a hotspot for research and application of lidar. The digital laser radar acquires an echo signal detected by a photoelectric detector by using an ADC (analog to digital converter) with a sampling rate of more than 1GSPS (generalized sampling per second) to form a digital signal, and then the digital signal is transmitted to a digital processing unit for processing to obtain the flight time and calculate the target distance.
In the design of a laser radar system based on a high-speed ADC, a data processing method becomes a key for acquiring flight time or timing, however, the disclosure of this section is less discussed. The Harbin industry university designs a laser radar based on an ADC (analog to digital converter) with a sampling rate of 1 Gbps, and processes data by using a wavelet analysis method to obtain the standard deviation of the flight time of more than 0.5 ns.
However, the wavelet analysis method is more complex and time-consuming in the application of the embedded system, and is not capable of meeting the requirements of timing and ranging of the laser radar.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a timing method and a timing device applied to a laser radar, and the timing method and the timing device can provide a simple, quick, stable and high-precision timing result.
In order to solve the technical problems, the invention provides the following technical scheme:
in a first aspect, the present invention provides a timing method applied to a laser radar, including:
step 1, acquiring a laser echo signal transmitted by a signal conditioning circuit by using a high-speed ADC (analog to digital converter) to obtain a digital waveform S1;
step 2, preprocessing the digital waveform S1 to obtain a digital waveform S2;
step 3, carrying out data processing on the digital waveform S2 to obtain a digital quantity A1 representing the waveform intensity of the digital waveform S2;
step 4, multiplying a digital quantity A1 for representing the waveform intensity of the digital waveform S2 to obtain a digital quantity A2, wherein A2 is A1 × F1, and 0 is more than F1 and less than 1;
and 5, searching a point P1 on the rising edge of the digital waveform S2, so that the numerical value of a point P1 is equal to the digital quantity A2, and the time corresponding to the point P1 is the receiving time of the laser echo signal.
Further, the step 3 performs data processing on the digital waveform S2 to obtain a digital quantity a1 representing the waveform intensity of the digital waveform S2, and specifically includes:
and performing an integration operation on the digital waveform S2 to obtain a waveform area, wherein the waveform area is a digital quantity A1 representing the waveform intensity of the digital waveform S2.
Further, the step 3 performs data processing on the digital waveform S2 to obtain a digital quantity a1 representing the waveform intensity of the digital waveform S2, and specifically includes:
and accumulating and processing the digital waveform S2 to obtain an accumulated sum value, wherein the accumulated sum value is a digital quantity A1 representing the waveform intensity of the digital waveform S2.
Further, the step 2 of preprocessing the digital waveform S1 to obtain a digital waveform S2 specifically includes:
and performing median filtering processing on the digital waveform S1 to obtain a digital waveform S2.
Further, the step 5 of finding a point P1 on the rising edge of the digital waveform S2, so that the value of the point P1 is equal to the digital quantity a2, and the time corresponding to the point P1 is the receiving time of the laser echo signal, specifically including:
if the numerical value of no point on the rising edge of the digital waveform S2 is exactly equal to the digital quantity A2, two points P2 and P3 are searched on the digital waveform S2, so that the numerical value of the point P2 is larger than the digital quantity A2, the numerical value of the point P3 is smaller than the digital quantity A2, then a point P1 is searched between the point P2 and the point P3 by using a linear interpolation method, so that the numerical value of the point P1 is equal to the digital quantity A2, and the time corresponding to the point P1 is the receiving time of the laser echo signal.
In a second aspect, the present invention further provides a timing device applied to a laser radar, including:
the acquisition module is used for acquiring the laser echo signal transmitted by the signal conditioning circuit by using the high-speed ADC to obtain a digital waveform S1;
the preprocessing module is used for preprocessing the digital waveform S1 to obtain a digital waveform S2;
the waveform intensity characterization module is used for performing data processing on the digital waveform S2 to obtain a digital quantity A1 for characterizing the waveform intensity of the digital waveform S2;
a data operation module, configured to multiply a digital quantity a1 that represents the waveform strength of the digital waveform S2 to obtain a digital quantity a2, where a2 is a1 × F1, and 0 < F1 < 1;
a timing module, configured to find a point P1 on a rising edge of the digital waveform S2, so that a value of the point P1 is equal to the digital quantity a2, and a time corresponding to the point P1 is a receiving time of the laser echo signal.
Further, the waveform intensity characterization module is specifically configured to:
and performing an integration operation on the digital waveform S2 to obtain a waveform area, wherein the waveform area is a digital quantity A1 representing the waveform intensity of the digital waveform S2.
Further, the waveform intensity characterization module is specifically configured to:
and accumulating and processing the digital waveform S2 to obtain an accumulated sum value, wherein the accumulated sum value is a digital quantity A1 representing the waveform intensity of the digital waveform S2.
Further, the preprocessing module is specifically configured to:
and performing median filtering processing on the digital waveform S1 to obtain a digital waveform S2.
Further, the timing module is specifically configured to:
if the numerical value of no point on the rising edge of the digital waveform S2 is exactly equal to the digital quantity A2, two points P2 and P3 are searched on the digital waveform S2, so that the numerical value of the point P2 is larger than the digital quantity A2, the numerical value of the point P3 is smaller than the digital quantity A2, then a point P1 is searched between the point P2 and the point P3 by using a linear interpolation method, so that the numerical value of the point P1 is equal to the digital quantity A2, and the time corresponding to the point P1 is the receiving time of the laser echo signal.
According to the technical scheme, the timing method applied to the laser radar acquires the echo signal through the high-speed ADC, converts the echo signal into the digital waveform, performs data processing on the obtained digital waveform to obtain the digital quantity A1 representing the waveform intensity of the digital waveform, performs scaling processing on the digital quantity A1 to obtain the digital quantity A2, and finally searches for a point on the rising edge of the digital waveform, so that the value of the point is equal to the digital quantity A2, and the corresponding time is the receiving time of the laser echo signal. Therefore, the calculation steps involved in the timing method provided by the invention are simple mathematical calculations, and a complex operation process is avoided, so that the signal processing time is reduced, and the real-time performance of signal processing is improved. In addition, the timing method provided by the invention is not influenced by the distance of the measured object and the surface reflectivity of the measured object, and can be suitable for the application of the high-dynamic-range laser radar. In addition, the timing method provided by the invention can effectively inhibit random noise interference brought by the signal conditioning circuit in the process of calculating the digital quantity A1 representing the waveform intensity, thereby improving the stability of the timing method. Therefore, the invention can provide a simple, quick, stable and high-precision timing result.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
Fig. 1 is a flowchart of a timing method applied to a laser radar according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a lidar signal processing scheme employing digitization techniques;
fig. 3 is a schematic diagram of an implementation of a timing method applied to a laser radar according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of calculating a waveform area by an integration method and using the waveform area as a waveform intensity representation;
FIG. 5 is a schematic diagram of calculating waveform strength using a sum method;
FIG. 6 is a schematic diagram of finding echo reception time points;
fig. 7 is a schematic structural diagram of a timing device applied to a laser radar according to another embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
An embodiment of the present invention provides a timing method applied to a laser radar, and referring to fig. 1, the method includes the following steps:
step 101: and acquiring a laser echo signal transmitted by the signal conditioning circuit by using the high-speed ADC to obtain a digital waveform S1.
In this step, the laser echo signal is collected by the photodetector, processed by the signal conditioning circuit, and collected by the high-speed ADC into a digital waveform S1, see fig. 2; the purpose of the signal conditioning circuit is to process the laser echo signal into a voltage signal which can be collected by the high-speed ADC. Wherein, the data processing unit shown in fig. 2 is used for processing the contents of the following steps 102-105.
Step 102: and preprocessing the digital waveform S1 to obtain a digital waveform S2.
In this step, the digital waveform S1 obtained in step 101 is subjected to preprocessing, such as noise removal and signal enhancement, to obtain a digital waveform S2.
Step 103: and performing data processing on the digital waveform S2 to obtain a digital quantity A1 representing the waveform intensity of the digital waveform S2.
The purpose of this step is to obtain a digital quantity a1 that is capable of characterizing the waveform strength of the digital waveform S2. In obtaining the digital quantity a1 that can characterize the waveform strength of the digital waveform S2, various methods can be adopted, for example, two different implementation methods (one for integration and the other for accumulation and processing) are provided in the following embodiments.
Because the signal conditioning circuit in the step 101 may bring an interference signal close to white noise, in the process of calculating the digital quantity a1 representing the waveform strength of the digital waveform S2 in the step, the random noise interference brought by the signal conditioning circuit can be effectively suppressed, thereby enhancing the stability of the timing method.
Step 104: and multiplying the digital quantity A1 for representing the waveform intensity of the digital waveform S2 to obtain a digital quantity A2, wherein A2 is A1F 1, and 0 < F1 < 1.
In this step, the coefficient F1 is a constant less than 1, and the selection range of F1 is related to the dynamic range of the system. The selection of the coefficient F1 is such that the point P1 found in step 105 is halfway or slightly below the rising edge of the digital waveform S2. In this step, it can be seen that the digital quantity a1 representing the waveform intensity of the digital waveform S2 is scaled down in equal proportion, and the scaled-down digital quantity a2 is obtained.
Step 105: and searching a point P1 on the rising edge of the digital waveform S2, so that the numerical value of a point P1 is equal to the digital quantity A2, and the time corresponding to the point P1 is the receiving time of the laser echo signal.
In this step, according to the reduced digital quantity a2 calculated in step 104, a point P1 is found on the rising edge of the digital waveform S2, so that the value of the point P1 is equal to the digital quantity a2, and the time corresponding to the point P1 is the receiving time of the laser echo signal.
Therefore, through the steps, the timing of the laser radar echo signals is completed. After the timing information of the laser radar echo signal is obtained, the distance information of the relevant distance measurement can be calculated.
In addition, it should be mentioned that one advantage of the timing method provided by the present invention is that, due to the difference in the distance between the measured object and the surface reflectivity, the received signal may be a saturated distortion signal after passing through the conditioning circuit, but the timing method provided by the present invention can still process the signal, which indicates that the present invention can be adapted to the application of the high dynamic range laser radar.
Fig. 3 shows a schematic diagram of an implementation of the timing method provided in this embodiment, and as can be seen from the above description and shown in fig. 3, in the timing method applied to the laser radar provided in this embodiment, an echo signal is acquired by the high-speed ADC, the echo signal is converted into a digital waveform, then data processing is performed on the obtained digital waveform, so as to obtain a digital quantity a1 representing the waveform intensity of the digital waveform, then scaling is performed on the digital quantity a1, so as to obtain a digital quantity a2, and finally, a point is found on a rising edge of the digital waveform, so that the value of the point is equal to the digital quantity a2, and then the time corresponding to the point is the receiving time of the laser echo signal. Therefore, the calculation steps involved in the timing method provided by the invention are simple mathematical calculations, and a complex operation process is avoided, so that the signal processing time is reduced, and the real-time performance of signal processing is improved. In addition, the timing method provided by the invention is not influenced by the distance of the measured object and the surface reflectivity of the measured object, and can be suitable for the application of the high-dynamic-range laser radar. In addition, the timing method provided by the invention can effectively inhibit random noise interference brought by the signal conditioning circuit in the process of calculating the digital quantity A1 representing the waveform intensity, thereby improving the stability of the timing method.
Since the signal conditioning circuit may bring an interference signal close to white noise, in the process of calculating the digital quantity a1 representing the waveform strength of the digital waveform S2 in step 103, the random noise interference brought by the signal conditioning circuit can be effectively suppressed, thereby enhancing the stability of the timing method.
In one embodiment, referring to fig. 4, the step 103 specifically includes:
and performing an integration operation on the digital waveform S2 to obtain a waveform area, wherein the waveform area is a digital quantity A1 representing the waveform intensity of the digital waveform S2.
As can be seen, in the present embodiment, the waveform area of the digital waveform S2 is obtained by the integration processing method, and the obtained waveform area is used as the digital quantity a1 representing the waveform intensity of the digital waveform S2.
Since the signal conditioning circuit may bring an interference signal close to white noise, in the process of calculating the digital quantity a1 representing the waveform strength of the digital waveform S2 in step 103, the random noise interference brought by the signal conditioning circuit can be effectively suppressed, thereby enhancing the stability of the timing method.
In another embodiment, referring to fig. 5, the step 103 specifically includes:
and accumulating and processing the digital waveform S2 to obtain an accumulated sum value, wherein the accumulated sum value is a digital quantity A1 representing the waveform intensity of the digital waveform S2.
As can be seen, in the present embodiment, the waveform cumulative sum is obtained by the cumulative sum processing method, and the obtained waveform cumulative sum is used as the digital quantity a1 representing the waveform intensity of the digital waveform S2.
It will be appreciated that the waveform area and the waveform summation obtained in the above two embodiments can reflect the waveform strength of the digital waveform acquired by the ADC, but the two values are slightly different.
In a specific embodiment, the step 102 specifically includes:
and performing median filtering processing on the digital waveform S1 to obtain a digital waveform S2.
In a specific embodiment, referring to fig. 6, the step 105 specifically includes:
if the numerical value of no point on the rising edge of the digital waveform S2 is exactly equal to the digital quantity A2, two points P2 and P3 are searched on the digital waveform S2, so that the numerical value of the point P2 is larger than the digital quantity A2, the numerical value of the point P3 is smaller than the digital quantity A2, then a point P1 is searched between the point P2 and the point P3 by using a linear interpolation method, so that the numerical value of the point P1 is equal to the digital quantity A2, and the time corresponding to the point P1 is the receiving time of the laser echo signal.
It will be appreciated that since the digital waveform S2 is a discrete signal, there may not be a bit on the digital waveform S2 that exactly equals the digital quantity a 2. At this time, two points, P2 and P3, can be found, such that the P2 value is greater than a2 and the P3 value is less than a 2. Then, using a linear interpolation method, a point P1 is found between P2 and P3 to be equal to a 2. Then, the time point corresponding to the point P1 is taken as the echo signal reception time point.
Of course, if there is a point P1 on the digital waveform S2 exactly equal to the digital quantity a2, the time corresponding to the point P1 is the receiving time of the laser echo signal.
The timing accuracy of the timing method provided by the invention is tested and verified through a specific example.
Firstly, the laser radar is used for detecting an object with a fixed position, and a diaphragm at the receiving end of an echo signal is modified so as to collect the echo signal under signals with different intensities. The sampling was repeated multiple times at each intensity. The purpose of the experiment under different intensities simulates the situation that the echo signal intensities are different due to different object reflectivities. Table 1 below shows the detailed processing results of this example, and the differences in experimental numbers indicate the differences in intensity, where there are signal saturation intensity cases and weak signal cases, which gradually decrease from numbers 1-14. Wherein, the ADC sampling rate is 2.5 Gsps.
As can be seen from Table 1 below, the timing standard deviation is substantially around 0.1ns at different intensities, corresponding to a range error of 3 cm. The example shows that the timing method provided by the invention is applied to laser radar ranging and can provide a stable and high-precision timing result.
TABLE 1
| Experiment number | Mean time (ns) | Number of repeated sampling | Timing standard deviation (ns) |
| 1 | 17.42 | 31 | 0.09 |
| 2 | 17.45 | 31 | 0.07 |
| 3 | 17.44 | 33 | 0.10 |
| 4 | 17.41 | 31 | 0.09 |
| 5 | 17.42 | 32 | 0.12 |
| 6 | 17.52 | 34 | 0.11 |
| 7 | 17.51 | 35 | 0.09 |
| 8 | 17.52 | 33 | 0.08 |
| 9 | 17.49 | 30 | 0.08 |
| 10 | 17.53 | 25 | 0.08 |
| 11 | 17.53 | 37 | 0.11 |
| 12 | 17.54 | 30 | 0.13 |
| 13 | 17.49 | 29 | 0.13 |
| 14 | 17.56 | 36 | 0.20 |
Another embodiment of the present invention provides a timing device applied to a laser radar, referring to fig. 7, the device including: the device comprises an acquisition module 71, a preprocessing module 72, a waveform intensity representation module 73, a data operation module 74 and a timing module 75; wherein:
the acquisition module 71 is configured to acquire a laser echo signal transmitted from the signal conditioning circuit by using a high-speed ADC to obtain a digital waveform S1;
a preprocessing module 72, configured to preprocess the digital waveform S1 to obtain a digital waveform S2;
the waveform intensity characterization module 73 is configured to perform data processing on the digital waveform S2 to obtain a digital quantity a1 that characterizes the waveform intensity of the digital waveform S2;
a data operation module 74, configured to multiply a digital quantity a1 that represents the waveform strength of the digital waveform S2 to obtain a digital quantity a2, where a2 is a1 × F1, and 0 < F1 < 1;
the timing module 75 is configured to search for a point P1 on a rising edge of the digital waveform S2, so that a value of the point P1 is equal to the digital quantity a2, and a time corresponding to the point P1 is a receiving time of the laser echo signal.
According to the process described in the above timing method embodiment, the timing device applied to the laser radar provided by this embodiment has the advantages of being adaptive to a high dynamic range, high in stability, small in application difficulty, and the like.
In a specific embodiment, the waveform intensity characterization module 73 is specifically configured to:
and performing an integration operation on the digital waveform S2 to obtain a waveform area, wherein the waveform area is a digital quantity A1 representing the waveform intensity of the digital waveform S2.
In another specific embodiment, the waveform intensity characterization module 73 is specifically configured to:
and accumulating and processing the digital waveform S2 to obtain an accumulated sum value, wherein the accumulated sum value is a digital quantity A1 representing the waveform intensity of the digital waveform S2.
In one embodiment, the preprocessing module 72 is specifically configured to:
and performing median filtering processing on the digital waveform S1 to obtain a digital waveform S2.
In an embodiment, the timing module 75 is specifically configured to:
if the numerical value of no point on the rising edge of the digital waveform S2 is exactly equal to the digital quantity A2, two points P2 and P3 are searched on the digital waveform S2, so that the numerical value of the point P2 is larger than the digital quantity A2, the numerical value of the point P3 is smaller than the digital quantity A2, then a point P1 is searched between the point P2 and the point P3 by using a linear interpolation method, so that the numerical value of the point P1 is equal to the digital quantity A2, and the time corresponding to the point P1 is the receiving time of the laser echo signal.
The timing device applied to the laser radar provided by the embodiment can be used for executing the method described in the above embodiment, and the principle and technical effects are similar, and are not described in detail here.
The above examples are only for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (6)
1. A timing method applied to laser radar is characterized by comprising the following steps:
step 1, acquiring a laser echo signal transmitted by a signal conditioning circuit by using a high-speed ADC (analog to digital converter) to obtain a digital waveform S1;
step 2, preprocessing the digital waveform S1 to obtain a digital waveform S2;
step 3, carrying out data processing on the digital waveform S2 to obtain a digital quantity A1 representing the waveform intensity of the digital waveform S2;
step 4, multiplying a digital quantity A1 for representing the waveform intensity of the digital waveform S2 to obtain a digital quantity A2, wherein A2 is A1 × F1, and 0 is more than F1 and less than 1;
step 5, searching a point P1 on the rising edge of the digital waveform S2, so that the numerical value of a point P1 is equal to the digital quantity A2, and the time corresponding to the point P1 is the receiving time of the laser echo signal;
wherein, the step 3 performs data processing on the digital waveform S2 to obtain a digital quantity a1 representing the waveform intensity of the digital waveform S2, and specifically includes:
performing an integration operation on the digital waveform S2 to obtain a waveform area, wherein the waveform area is a digital quantity A1 representing the waveform intensity of the digital waveform S2;
or the like, or, alternatively,
and accumulating and processing the digital waveform S2 to obtain an accumulated sum value, wherein the accumulated sum value is a digital quantity A1 representing the waveform intensity of the digital waveform S2.
2. The method according to claim 1, wherein the step 2 of preprocessing the digital waveform S1 to obtain a digital waveform S2 specifically comprises:
and performing median filtering processing on the digital waveform S1 to obtain a digital waveform S2.
3. The method according to claim 1 or 2, wherein the step 5 of finding a point P1 on the rising edge of the digital waveform S2 so that the value of the point P1 is equal to the digital quantity a2, and the time corresponding to the point P1 is the receiving time of the laser echo signal, specifically includes:
if the numerical value of no point on the rising edge of the digital waveform S2 is exactly equal to the digital quantity A2, two points P2 and P3 are searched on the digital waveform S2, so that the numerical value of the point P2 is larger than the digital quantity A2, the numerical value of the point P3 is smaller than the digital quantity A2, then a point P1 is searched between the point P2 and the point P3 by using a linear interpolation method, so that the numerical value of the point P1 is equal to the digital quantity A2, and the time corresponding to the point P1 is the receiving time of the laser echo signal.
4. A timing device for use with a lidar comprising:
the acquisition module is used for acquiring the laser echo signal transmitted by the signal conditioning circuit by using the high-speed ADC to obtain a digital waveform S1;
the preprocessing module is used for preprocessing the digital waveform S1 to obtain a digital waveform S2;
the waveform intensity characterization module is used for performing data processing on the digital waveform S2 to obtain a digital quantity A1 for characterizing the waveform intensity of the digital waveform S2;
a data operation module, configured to multiply a digital quantity a1 that represents the waveform strength of the digital waveform S2 to obtain a digital quantity a2, where a2 is a1 × F1, and 0 < F1 < 1;
a timing module, configured to search a point P1 on a rising edge of the digital waveform S2, so that a value of a point P1 is equal to the digital quantity a2, and a time corresponding to the point P1 is a receiving time of the laser echo signal;
wherein the waveform intensity characterization module is specifically configured to:
performing an integration operation on the digital waveform S2 to obtain a waveform area, wherein the waveform area is a digital quantity A1 representing the waveform intensity of the digital waveform S2;
or the like, or, alternatively,
and accumulating and processing the digital waveform S2 to obtain an accumulated sum value, wherein the accumulated sum value is a digital quantity A1 representing the waveform intensity of the digital waveform S2.
5. The apparatus of claim 4, wherein the preprocessing module is specifically configured to:
and performing median filtering processing on the digital waveform S1 to obtain a digital waveform S2.
6. The apparatus according to claim 4 or 5, wherein the timing module is specifically configured to:
if the numerical value of no point on the rising edge of the digital waveform S2 is exactly equal to the digital quantity A2, two points P2 and P3 are searched on the digital waveform S2, so that the numerical value of the point P2 is larger than the digital quantity A2, the numerical value of the point P3 is smaller than the digital quantity A2, then a point P1 is searched between the point P2 and the point P3 by using a linear interpolation method, so that the numerical value of the point P1 is equal to the digital quantity A2, and the time corresponding to the point P1 is the receiving time of the laser echo signal.
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| CN201610955401.1A CN108008398B (en) | 2016-10-27 | 2016-10-27 | Timing method and device applied to laser radar |
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| CN103529453A (en) * | 2013-09-22 | 2014-01-22 | 北京石油化工学院 | Remote pulse laser distance measuring system |
| CN104062642A (en) * | 2013-11-22 | 2014-09-24 | 董立新 | Method for performing Gaussian echo decomposition on laser radar waveform data |
| CN104502684A (en) * | 2014-12-19 | 2015-04-08 | 中国科学院长春光学精密机械与物理研究所 | Method for identifying full-digital peak value arrival time |
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| CN103529453A (en) * | 2013-09-22 | 2014-01-22 | 北京石油化工学院 | Remote pulse laser distance measuring system |
| CN104062642A (en) * | 2013-11-22 | 2014-09-24 | 董立新 | Method for performing Gaussian echo decomposition on laser radar waveform data |
| CN104502684A (en) * | 2014-12-19 | 2015-04-08 | 中国科学院长春光学精密机械与物理研究所 | Method for identifying full-digital peak value arrival time |
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