CN111443355B - Ranging method based on TOF module and computer storage medium - Google Patents
Ranging method based on TOF module and computer storage medium Download PDFInfo
- Publication number
- CN111443355B CN111443355B CN202010438654.8A CN202010438654A CN111443355B CN 111443355 B CN111443355 B CN 111443355B CN 202010438654 A CN202010438654 A CN 202010438654A CN 111443355 B CN111443355 B CN 111443355B
- Authority
- CN
- China
- Prior art keywords
- time
- module
- light
- sensor
- tof
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- 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
-
- 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
- G01S17/46—Indirect determination of position data
- G01S17/48—Active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves
Abstract
The application provides a distance measuring method of a TOF module and a computer storage medium. The TOF module comprises a light emitter module, a sensor module and a processor module, wherein the processor module is respectively electrically connected with the light emitter and the sensor module and controls the light emitter module to emit light and the sensor module to receive reflected light based on instructions, and the distance measuring method comprises the following steps: s1, establishing an optical waveform; s2, the processor module sequentially adjusts the time points of the first sampling point and the second sampling point for starting light sensing based on a preset program so as to calculate the time of the reflected light reaching the sensor for the first time; and S3, directly calculating the measured distance based on the calculated time. The distance measurement method is based on an indirect TOF measurement system, the starting point of the light pulse is calculated by describing the light waveform, and the combination of the calculated time and the indirect light waveform achieves the purpose of direct TOF measurement. The distance measuring method reduces the influence of the multipath effect of the indirect TOF module during measurement, so that the indirect TOF module can be suitable for more complex application scenes.
Description
Technical Field
The invention relates to the technical field of measurement, in particular to a ranging method based on a TOF module and a computer storage medium.
Background
In recent years, with the gradual expansion of application scenes such as unmanned aerial vehicles, face recognition, intelligent furniture and logistics, the demand of medium-short distance three-dimensional distance measurement is more and more big, and the requirement on distance measurement speed and precision is more and more high. Most of the existing distance measuring methods actively polish and receive reflected light, and calculate distance information according to various characteristics of the reflected light and the emitted light. Among them, the time of Flight (TOF) ranging method gradually shows its superiority because of high precision and high speed.
The TOF method is divided into indirect TOF and direct TOF, wherein the measuring mechanism of the direct TOF is shown in figure 1, a pulse with a short width is emitted during measurement, reflected light of an object is received through a sensor, and then the distance between the object and equipment is directly calculated according to the time difference between the object and the reflected light; the measurement mechanism of the indirect TOF is shown in figure 2, a pulse with a longer width (delta t) is emitted during measurement, a plurality of channels are opened at different times at the receiving end of the sensor, and the distance between an object and equipment is calculated according to the quantity of light received in the channels. Generally, the measurement quantity of the direct TOF module is the time interval between the emission and the reception of the light pulse, corresponding to the real distance; the measurement quantity of the indirect TOF module is the received light ratio of different channels, the mapping relation between the ratio and the distance needs to be calibrated in advance before use, and the same ratio corresponds to different distances under different ranges.
The direct TOF method measures the light-emitting starting time and the receiving time and directly calculates the distance, so that the direct TOF method has the advantages of being fast in calculation, strong in anti-interference capability and the like. But in the course of the actual measurement its accuracy is proportional (subject to) the clock frequency. In order to achieve high precision measurement, the circuit structure is required to have a very high clock frequency, which is much higher than that of the indirect TOF module. And the indirect TOF module can select the pulse width of the emitted light according to the range, the longer the range is, the longer the light pulse is, and the more stable the mapping from the light ratio received by the two receivers to the measured distance is by adjusting the switching time of the two receivers. However, when there are multiple adjacent reflecting surfaces, light may be reflected multiple times between the reflecting surfaces, and the multiple reflected light may reach the sensor later than the single reflected light, which may result in inaccurate measurement results (i.e., multipath effect). In addition, the indirect TOF module has longer light-emitting pulse and receiving time, so that more external stray light signals enter the sensor during receiving, and the measurement error is increased.
Therefore, a new ranging method based on the TOF module is needed.
Disclosure of Invention
Therefore, the invention aims to provide a ranging method based on a TOF module. The method is based on the indirect TOF module, realizes direct TOF measurement, and widens the application range of the indirect TOF module.
In order to achieve the purpose, the invention adopts the following technical scheme,
the distance measuring method of the TOF module comprises a light emitter module, a sensor module and a processor module, wherein the processor module is respectively electrically connected with the light emitter module and the sensor module and controls the light emitter module to emit light and the sensor module to receive reflected light based on instructions, and the distance measuring method of the TOF module is characterized in that: the distance measuring method comprises the following steps:
s1, establishing an optical waveform;
s2, the processor module sequentially adjusts time points of the first sampling point and the second sampling point for starting receiving the optical signals based on a preset program so as to calculate the time of the reflected light reaching the sensor for the first time;
and S3, directly calculating the measured distance based on the calculated time. The direct TOF method is implemented by tracing the optical waveform and calculating the starting point of the optical pulse. Therefore, the method utilizes the combination of the direct TOF method and the indirect TOF method to reduce the influence of multipath effect, so that the indirect TOF module can adapt to more complex application scenes.
In one embodiment, S2 includes signals of different light emission or sensor switching times collected at the same position, so as to calculate the time when the reflected light first reaches the sensor.
In one embodiment, the S2 further includes:
and calculating the time for the reflected light to reach the sensor for the first time by adjusting the opening/closing time of the first sampling point and the second sampling point.
In one embodiment, the step S2 further includes:
when the device is used for measuring, the distance between the module and a measured object is kept unchanged, and the opening time of the sensor is gradually changed through a preset program so as to calculate the clock period of the first-time signal received by the sensor of the first sampling point.
In one embodiment, the step S2 further includes: the distance between the sensor and the measured object is adjusted to calculate the time when the reflected light first reaches the sensor.
In one embodiment, in step S1, multiple types of optical waveforms are preset in the processor module, and a matching optical waveform is selected based on the instruction when the TOF module is enabled.
In one embodiment, the light waveform in step S1 is a linear model, which includes a rising edge model.
In one embodiment, the rising edge time of the light wave in step S1 is greater than 3 unit times.
In one embodiment, the step S2 further includes: at the time of the measurement,
the time when the light energy received for the first time is not zero is t unit time, and the light sensing energy is a;
after the sensor is subjected to light sensing and moves backwards for one unit time, the light sensing energy is b;
after moving backward for two unit times, the photosensitive energy is c;
after three unit times of backward movement, the photosensitive energy is d,
if the time of receiving the light wave is the starting point of t unit time, a + c-2 ═ b-2 ═ a is satisfied;
and if the time when the light wave is received falls within the T unit time period, the time T (2 a/(a + c-2 b)) when the reflected light reaches the sensor for the first time is calculated according to the triangle similarity theorem and the relation between the area and the side length.
An embodiment of the present application provides a computer storage medium, which includes a computer program, where the computer program runs the control method described above.
Advantageous effects
Compared with the scheme in the prior art, the TOF ranging method realizes a direct TOF method by describing the light waveform and calculating the starting point of the light pulse. The direct TOF method and the indirect TOF method are combined to reduce the influence of multipath effect and improve the measurement accuracy of the indirect TOF, so that the indirect TOF module can adapt to more complex application scenes.
Drawings
The advantages of the above and/or additional aspects of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a schematic diagram of the mechanism of a prior art direct TOF measurement;
FIG. 2 is a schematic diagram of the mechanism of a prior art indirect TOF measurement;
FIG. 3 is a functional diagram of a TOF module according to an embodiment of the present disclosure;
FIG. 4 is a schematic view of a TOF module according to an embodiment of the present disclosure;
FIG. 5 is a timing diagram illustrating the adjustment of turn-on times of different sensors based on a program according to an embodiment of the present invention;
fig. 6 is a schematic diagram of a model for estimating the first arrival time of the reflected light at the sensor according to an embodiment of the invention.
Detailed Description
In order that the above objects, features and advantages of the present application can be more clearly understood, the present application will be described in further detail with reference to the accompanying drawings and detailed description. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.
The application provides a distance measuring method of a TOF module. The TOF module comprises a light emitter module, a sensor module and a processor module, wherein the processor module is respectively electrically connected with the light emitter module and the sensor module and controls the light emitter module to emit light and the sensor module to receive reflected light based on instructions, and the distance measuring method comprises the following steps: establishing an optical waveform; the processor module sequentially adjusts the time points of the first sampling point and the second sampling point for starting sensitization based on a preset program so as to calculate the time of reflected light reaching the sensor for the first time; the measured distance is directly calculated based on the deduced time. The distance measurement method is based on an indirect TOF measurement system, the starting point of the light pulse is calculated by describing the light waveform, and the combination of the calculated time and the indirect light waveform achieves the purpose of direct TOF measurement. The distance measurement method reduces the influence of the multipath effect of the indirect TOF module during measurement, so that the indirect TOF module can adapt to more complex application scenes. In this embodiment, the first sampling point and the second sampling point may be sampled according to different devices (e.g., different sensors).
Next, a description is given to the measurement method provided in the present application with reference to the accompanying drawings, and as shown in fig. 3, the TOF module according to an embodiment of the present application includes a light emitter module, a sensor module, and a processor module, where the processor module is electrically connected to the light emitter module and the sensor module, respectively, and the processor module controls the light emitter module to emit light and controls the sensor module to receive reflected light (also referred to as return light or sensitization) based on instructions. The ranging method during ranging of the TOF module is shown in FIG. 4, and comprises the following steps:
s1, establishing an optical waveform, for example, establishing the optical waveform based on a preset control program for determining the most suitable rising edge model;
s2, calculating the time when the reflected light reaches the sensor for the first time, and during measurement, sequentially adjusting the time points when the first sampling point A0 and the second sampling point A1 start to sense light to obtain a group of gradually changing data for statistics, wherein the statistics comprises the following steps: the time of the reflected light reaching the sensor for the first time is calculated by collecting signals of different luminescence or sensor switching time for a plurality of times at the same position;
and S3, directly calculating the measured distance based on the calculated time. In this embodiment, the light emitter module starts to emit light after receiving the light emitting command, the light emitting energy of the light emitter module gradually increases with time, remains stable until the light emitting time is over after reaching a certain value, and finally the light emitting energy gradually decreases to zero. For the measured object at the same distance, the light (reflected light) received by the receiver has the same shape as the emitted light and the intensity is in direct proportion to the emitted light signal. And according to the clock frequency, sequentially adjusting the time points of A0 and A1 for starting sensitization to obtain a group of gradually changing data, counting the difference between the next data and the previous data to obtain the light count received in the time interval, and drawing the outline of the light waveform through the light count received in each time interval. According to the distance measurement method based on the indirect TOF module, during distance measurement, firstly, the starting point of light pulse, namely the time of reflected light reaching a sensor for the first time, is calculated based on the drawn indirect light waveform, and the calculated time and the indirect light waveform are combined to achieve the purpose of direct TOF measurement. The distance measurement method reduces the influence of the multipath effect of the indirect TOF module during measurement, improves the measurement precision of the indirect TOF module, and enables the indirect TOF module to be suitable for more complex application scenes. In other embodiments, in addition to the time points of the light sensing time of the sampling points to obtain the counting information of different times, the light waveform may be calculated by adjusting the on/off time or the moving distance of a0 and a 1. In the present embodiment, the optical waveform is fixed for each module. In other embodiments, multiple types of light waveforms may be preset, with a match selected when the device is enabled. In the present embodiment, the first sampling point (a0) and the second sampling point (a1) are respectively matched with corresponding sensors.
As a variation of the above embodiment, as shown in fig. 5, A0n/A1n in the figure indicates the number of counts received n times by the A0 sensor and the A1 sensor, respectively, and step S2 calculates the time when the reflected light reaches the sensor for the first time, and further includes, during measurement, gradually changing the sensor on time by a preset program while keeping the distance between the device and the object constant to acquire a plurality of sets of data, and thus calculating the clock cycle when the A1 sensor receives the signal for the first time. In practical applications, since the clock frequency of the indirect TOF is low, the change of the received signal of the sensor after a single modification is large, and the time for generating the count by a0 is not completely equal to the time point of receiving the signal. And calculating the arrival time of the light wave by fitting the positions of the multiple groups of data so as to calculate the measured distance. The general optical wave model is divided into three parts, namely a rising part, a gentle part and a falling part. The rising part and the falling part of the light wave of the linear model are linear, and the experiment mainly discusses the situation of the rising edge of the light wave, and only needs the rising edge of the light wave to be close to the linear model. According to the energy size data received by the sensor at different time, if a linear model is used, more accurate receiving time can be calculated according to the energy zero position.
In one embodiment, as shown in fig. 6, taking the rising edge time of the used light wave as an example greater than 3 unit times, the unit times referred to herein are the minimum time that can be identified by the system. If the system clock frequency is f, the unit time is 1/f.
The time when the light energy received for the first time is not zero is t unit time, and the light sensing energy is a;
after the sensor is subjected to light sensing and moves backwards for a unit time, the light sensing energy is b;
after moving backward for two unit times, the photosensitive energy is c;
after three unit times of backward shift, the photosensitive energy is d. Under the premise that the rising edge is more than 3 unit times, the actual size relation can accord with a < b < c < d, the increment in the rising edge stage in the unit time is equal according to the characteristics of a linear model, and the increment in the unit time is c-b- (b-a), namely a + c-2. If the time of receiving the light wave is the starting point of t unit time, the time accords with a + c-2 b-2 a; generally, the time when the light wave is received falls within t unit time period, and according to the triangle similarity theorem and the relation between the area and the side length, the actual light receiving time can be accurate to t-sqrt (2 a/(a + c-2 b)). Then directly calculating the measuring distance according to the measured distance. In the present embodiment, the optical waveform based on the linear model is not limited to the optical waveform of the linear model in other embodiments, for example, the time formula may be modified to some extent according to the rising edge model of the specific optical wave. In the implementation method, if the rising edge model of the light wave is complex and the falling edge model is simple, the formula can be popularized to the falling edge for calculation.
An embodiment of the present application provides a computer storage medium, which includes a computer program, and the computer program runs the control method described above.
Those of ordinary skill in the art will understand that: all or a portion of the steps of implementing the above-described method embodiments may be performed by hardware associated with program instructions. The aforementioned program may be stored in a computer (processor) -readable storage medium. When executed, the program performs steps comprising the method embodiments described above; and the aforementioned storage medium includes: various media that can store program codes, such as ROM, RAM, magnetic or optical disks. The above embodiments are only for illustrating the technical idea and features of the present invention, and the purpose of the present invention is to enable those skilled in the art to understand the content of the present invention and implement the present invention, and not to limit the protection scope of the present invention by this. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.
Claims (8)
1. The distance measuring method of the TOF module comprises a light emitter module, a sensor module and a processor module, wherein the processor module is respectively electrically connected with the light emitter module and the sensor module and controls the light emitter module to emit light and the sensor module to receive reflected light based on instructions, and the distance measuring method of the TOF module is characterized in that:
the distance measuring method comprises the following steps:
s1, establishing optical waveforms, presetting various types of optical waveforms in the processor module, and selecting matched optical waveforms based on instructions when the TOF module is started;
s2, the processor module sequentially adjusts time points of a first sampling point and a second sampling point for starting receiving optical signals according to a clock frequency based on a preset program to obtain a group of gradually changing data, the difference between the next data and the previous data is counted to be the light count received in the time interval, the outline of the light waveform is drawn through the light count received in each time interval, and the time of reflected light reaching the sensor for the first time is calculated;
and S3, combining the calculated time with the indirect light waveform to directly calculate the measured distance.
2. The method of ranging of a TOF module of claim 1, wherein: the step S2 further includes:
and calculating the time when the reflected light reaches the sensor for the first time by adjusting the opening/closing time of the first sampling point and the second sampling point.
3. The method of ranging of a TOF module of claim 2, wherein: the step S2 further includes:
when the device is used for measuring, the distance between the module and a measured object is kept unchanged, and the opening time of the sensor is gradually changed through a preset program so as to calculate the clock period of the first-time signal received by the sensor of the first sampling point.
4. The method of ranging of a TOF module of claim 1, wherein: the step S2 further includes:
the distance between the sensor and the measured object is adjusted to calculate the time when the reflected light first reaches the sensor.
5. The method of ranging of a TOF module of claim 1, wherein: in step S1, the light waveform is a linear model, and the linear model includes a rising edge model.
6. A method for ranging a TOF module according to claim 5 wherein: the rising edge time of the light wave in the step S1 is greater than 3 unit times.
7. The method of claim 6, wherein the TOF module comprises:
the step S2 further includes: at the time of the measurement,
the time when the light energy received for the first time is not zero is t unit time, and the light sensing energy is a;
after the sensor is subjected to light sensing and moves backwards for a unit time, the light sensing energy is b;
after backward movement for two unit times, the photosensitive energy is c;
after three unit times of backward movement, the photosensitive energy is d,
if the time of receiving the light wave is the starting point of t unit time, a + c-2 ═ b-2 ═ a is satisfied;
and if the time when the light wave is received falls within the T unit time period, the time T (2 a/(a + c-2 b)) when the reflected light reaches the sensor for the first time is calculated according to the triangle similarity theorem and the relation between the area and the side length.
8. A computer storage medium comprising a computer program running the ranging method of any one of claims 1-7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010438654.8A CN111443355B (en) | 2020-05-22 | 2020-05-22 | Ranging method based on TOF module and computer storage medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010438654.8A CN111443355B (en) | 2020-05-22 | 2020-05-22 | Ranging method based on TOF module and computer storage medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111443355A CN111443355A (en) | 2020-07-24 |
| CN111443355B true CN111443355B (en) | 2022-06-10 |
Family
ID=71657074
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010438654.8A Active CN111443355B (en) | 2020-05-22 | 2020-05-22 | Ranging method based on TOF module and computer storage medium |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111443355B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113665904B (en) * | 2021-09-07 | 2023-04-07 | 钟放鸿 | Carton cigarette packet missing detection method based on TOF technology |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105723238A (en) * | 2013-10-17 | 2016-06-29 | 微软技术许可有限责任公司 | Probabilistic time of flight imaging |
| CN205608186U (en) * | 2016-04-15 | 2016-09-28 | 中国科学院上海技术物理研究所 | Laser rangefinder based on synchronous sampling and multiple phase are measured |
| CN109814129A (en) * | 2019-03-29 | 2019-05-28 | 广西师范大学 | Three-dimensional real time imagery laser radar system based on area array CCD |
| CN109991584A (en) * | 2019-03-14 | 2019-07-09 | 深圳奥比中光科技有限公司 | A kind of jamproof distance measurement method and depth camera |
| WO2019144629A1 (en) * | 2018-01-24 | 2019-08-01 | 北京图森未来科技有限公司 | Image collection control method and device, image collection system and tof camera |
| CN110087060A (en) * | 2019-03-11 | 2019-08-02 | 歌尔股份有限公司 | Shutter triggering moment method of adjustment, device and the equipment of depth camera |
| CN110456370A (en) * | 2019-07-30 | 2019-11-15 | 炬佑智能科技(苏州)有限公司 | Flight time sensor-based system and its distance measuring method |
-
2020
- 2020-05-22 CN CN202010438654.8A patent/CN111443355B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105723238A (en) * | 2013-10-17 | 2016-06-29 | 微软技术许可有限责任公司 | Probabilistic time of flight imaging |
| CN205608186U (en) * | 2016-04-15 | 2016-09-28 | 中国科学院上海技术物理研究所 | Laser rangefinder based on synchronous sampling and multiple phase are measured |
| WO2019144629A1 (en) * | 2018-01-24 | 2019-08-01 | 北京图森未来科技有限公司 | Image collection control method and device, image collection system and tof camera |
| CN110087060A (en) * | 2019-03-11 | 2019-08-02 | 歌尔股份有限公司 | Shutter triggering moment method of adjustment, device and the equipment of depth camera |
| CN109991584A (en) * | 2019-03-14 | 2019-07-09 | 深圳奥比中光科技有限公司 | A kind of jamproof distance measurement method and depth camera |
| CN109814129A (en) * | 2019-03-29 | 2019-05-28 | 广西师范大学 | Three-dimensional real time imagery laser radar system based on area array CCD |
| CN110456370A (en) * | 2019-07-30 | 2019-11-15 | 炬佑智能科技(苏州)有限公司 | Flight time sensor-based system and its distance measuring method |
Non-Patent Citations (1)
| Title |
|---|
| 基于飞行时间法原理的三维成像系统设计;曾少青;《中国优秀博硕士学位论文全文数据库(硕士)信息科技辑》;20180215(第02期);正文全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111443355A (en) | 2020-07-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10545222B2 (en) | LIDAR data acquisition and control | |
| US5262837A (en) | Laser range finder | |
| EP2446301B1 (en) | Pulsed light optical rangefinder | |
| CN103913749B (en) | A kind of distance-finding method based on laser pulse flight time measurement | |
| CN110308456A (en) | It is a kind of for improving the bias adjustment device and laser radar system of detection range | |
| CN110456370B (en) | Flight time sensing system and distance measuring method thereof | |
| CN111443355B (en) | Ranging method based on TOF module and computer storage medium | |
| CN103197321A (en) | Full-waveform laser radar system | |
| US5852491A (en) | Distance measuring apparatus | |
| CN208013434U (en) | A kind of laser ranging system | |
| CN112147626A (en) | Electronic device, control method of electronic device, and computer-readable storage medium | |
| CN109521666B (en) | Time-to-digital converter based on delay locked loop | |
| CN209117877U (en) | A kind of multi-channel high-accuracy laser time of flight measuring system | |
| US20050088641A1 (en) | Testing method for rangefinders | |
| CN112255635A (en) | Distance measuring method, system and equipment | |
| CN111352119B (en) | Target ranging method and device based on single photon velocity accumulation | |
| CN115792938A (en) | Distance measuring method and device with error compensation function and depth sensor | |
| CN103248342B (en) | A kind of pulse delay circuit and scan method | |
| CN112099033B (en) | Ranging method for balancing resources and positioning accuracy | |
| CN111273309B (en) | Method for obtaining target distance | |
| US20210341606A1 (en) | System and method for calculating a binary cross-correlation | |
| KR20230017642A (en) | FMCW lidar system with low power consumption and method of operation thereof | |
| CN113009498A (en) | Distance measuring method, device and system | |
| RU2361237C2 (en) | Method of photo-location measurement of height of cloud layers and device to this end | |
| US6621450B1 (en) | Method of selecting a pulse repetition frequency to detect, track or search for a target |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |