CN112585495B - Laser radar system calibration method and calibration device, medium and ranging equipment - Google Patents
Laser radar system calibration method and calibration device, medium and ranging equipment Download PDFInfo
- Publication number
- CN112585495B CN112585495B CN201980050174.XA CN201980050174A CN112585495B CN 112585495 B CN112585495 B CN 112585495B CN 201980050174 A CN201980050174 A CN 201980050174A CN 112585495 B CN112585495 B CN 112585495B
- Authority
- CN
- China
- Prior art keywords
- calibration
- ranging
- measured value
- value
- distance
- 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
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
- 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
- G01S7/497—Means for monitoring or calibrating
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/10—Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Optical Radar Systems And Details Thereof (AREA)
Abstract
A calibration method of a laser radar system comprises the following steps: the laser radar system (230) sequentially performs N ranging steps by using the calibration box (210), the outgoing laser of each ranging step is delayed for different time to obtain ranging values at N different distances, and N calibration matrixes are obtained according to the difference between the ranging values and the corresponding actual values (S120); wherein N is more than or equal to 1 and N is an integer; a calibration matrix of the measured values is acquired, and calibration compensation is performed on the measured values (S140).
Description
Technical Field
The present invention relates to the field of laser radar ranging technologies, and in particular, to a calibration method and device for a laser radar system, a storage medium, and a ranging device.
Background
The laser radar system is a system for detecting the position, speed and other characteristic quantities of a target object by emitting laser beams, and is widely applied to the laser detection field, such as the fields of ranging systems, tracking measurement of low flying targets, weapon guidance, atmosphere monitoring, mapping, early warning, traffic management and the like.
In the ranging process of the laser radar system, the measured value and the actual value are deviated due to system difference and environmental influence, so that the detection result is inaccurate. The traditional calibration method utilizes the distance between the moving variable target object of the slide rail and the laser radar system to perform calibration compensation. However, the calibration in this way requires a large space and a complicated process, and the calibration error at a long distance is large.
Disclosure of Invention
According to various embodiments of the application, a calibration method and a calibration device of a laser radar system, a storage medium and a ranging device are provided.
A calibration method of a laser radar system comprises the following steps:
the laser radar system sequentially performs N ranging operations by using a calibration box, the outgoing laser of each ranging operation is delayed for different time to obtain ranging values at N different distances, and N calibration matrixes are obtained according to the difference between the ranging values and corresponding actual values; wherein N is more than or equal to 1 and N is an integer;
and acquiring the calibration matrix of the measured value, and performing calibration compensation on the measured value.
A calibration device for a lidar system, comprising:
the processing module is used for controlling the laser radar system to sequentially perform N times of ranging by using the calibration box, delaying the emergent laser of each ranging for different times to obtain ranging values at N different distances, and obtaining N calibration matrixes according to the difference between the ranging values and the corresponding actual values; wherein N is more than or equal to 1 and N is an integer;
and the calibration module is used for acquiring the calibration matrix of the measured value and performing calibration compensation on the measured value.
A storage medium having stored thereon a computer program which, when executed by a processor, implements the steps of the method as described above.
A ranging apparatus comprising a memory and a processor; the processor has stored thereon a computer program executable on the processor, which when executed implements the steps of the method as described above.
The details of one or more embodiments of the application are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the application will be apparent from the description and drawings, and from the claims.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required for the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other embodiments of the drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a flowchart of a method for calibrating a lidar system in an embodiment.
FIG. 2 is a schematic diagram of a calibration box in an embodiment.
Fig. 3 is a flowchart of a calibration method of the lidar system in an embodiment.
Fig. 4 is a schematic diagram of the working principle of the laser radar system according to an embodiment.
Fig. 5 is a flowchart showing specific steps of step S342 in an embodiment.
FIG. 6 is a partial functional diagram of a data fitting process in one embodiment.
Fig. 7 is a flowchart showing specific steps of step S344 in an embodiment.
Fig. 8 is a flowchart of a method of calibrating a lidar system in another embodiment.
Fig. 9 is a block diagram of a calibration device of a lidar system in an embodiment.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.
In the description of the present application, it should be understood that the terms "center," "lateral," "upper," "lower," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc. indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate description of the present application and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application. Furthermore, it will be understood that when an element is referred to as being "formed on" another element, it can be directly connected to the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present.
Lidars are classified into mechanical lidar, microelectromechanical system (MEMS, micro-Electro-Mechanical System) lidar, flash lidar, and phased array lidar according to the scanning method. The working principle of the Flash laser radar is that the outgoing laser irradiates the whole detected field area once, all echo lasers in the detected field area are received at the same time, and the distance measurement is completed by directly or indirectly calculating the flight time of photons. The Flash laser radar has the advantages that the transmitting device does not have mechanical motion and can quickly record the whole detection scene, the imaging information of gray level can be obtained while the distance information of the target object is obtained, the interference caused by the movement of the target object or the laser radar system in the scanning process is avoided, the structure is simple, the load is low, the service life of the optical machine is long, the miniaturization and modularization are convenient, the time cost of manual adjustment is low, and the cost performance is high. The F1ash laser radar is used as a laser radar technology capable of simultaneously outputting imaging information of a target object, and has great application potential in various aspects of social production and life in the future, such as civil fields of topographic mapping, urban modeling, highway detection and the like, military aspects of weapon guidance, battlefield reconnaissance, underwater detection and the like.
The type of the detector at the receiving end of the Flash laser radar is related to the working principle adopted by the detector. The basic principle of the continuous wave Flash laser radar is that the emergent laser is an optical signal modulated by a carrier wave with a specific frequency, and the distance between the light source and the target object is obtained by calculating the phase difference between the echo laser and the emergent laser. The pulsed Flash lidar can be subdivided into two types, one of which is called the iTOF type, i.e. pulse integral ranging. The light source periodically and continuously emits wide pulse laser, echo laser is collected in different integration time windows, and the flight time of photons can be obtained through a proportional relationship so as to calculate distance information. The second type is called DTOF type, which is the same as the ranging principle of the traditional mechanical laser radar, the light source is a pulse light source with high peak power, and the distance information is calculated by emitting periodic narrow pulse laser and measuring the flight time of photons by detecting echo laser. The pulse type Flash laser radar detector may be a two-dimensional silicon photomultiplier (SIPM, silicon photomuitiplier) or an avalanche photodiode (APD, avalanche Photon Diode) array, and the continuous wave type Flash laser radar generally employs a Charge-coupled Device (CCD) or a complementary metal oxide semiconductor (CMOS, complementary Metal Oxide Semiconductor).
Regardless of the working principle, the calibration and compensation are necessary links for determining the ranging accuracy of the laser radar system. For Flash laser radar systems, the physical quantities to be calibrated and compensated include static errors (circuit wiring, signal loading path length differences, optical system distortions, etc.), temperature errors, range response non-uniformity errors, detector pixel difference errors, etc. The following describes a method for calibrating a laser radar system by taking a Flash laser radar as an example. The calibration method of the laser radar system can calibrate and compensate the measured value obtained during the ranging of the Flash laser radar system, so that the measured value of the final target object distance is more approximate to the actual value. However, it should be noted that the calibration method of the laser radar system provided in the present application is not limited to calibrating Flash laser radar, and other types of laser radar, such as phased array laser radar, may be calibrated.
FIG. 1 is a method of calibrating a lidar system according to an embodiment. As shown in fig. 1, the calibration method of the lidar system includes the steps of:
in step S120, the laser radar system sequentially performs N ranging operations using the calibration box, delays the outgoing laser of each ranging operation for different times, obtains ranging values at N different distances, and obtains N calibration matrices according to differences between the ranging values and corresponding actual values.
Specifically, the laser radar system emits outgoing laser and receives echo laser returned after the reflection of the target object, and the ranging value is calculated by the time difference between the time of emitting the outgoing laser and the time of receiving the echo laser. The laser radar system can be a Flash laser radar system, and can also be other laser radar systems, such as a phased array laser radar system, a multi-line laser radar system, a MEMS laser radar system and the like. After the emitted laser irradiates into the calibration box and is projected to the target object, the target object reflects echo laser, the laser radar system receives the echo laser, and a ranging value between the laser radar system and the target object is calculated, so that one calibration of the laser radar system is completed. In the calibration process, the outgoing laser and the echo laser are transmitted in the calibration box, and the calibration box is used for establishing a calibration environment, so that the laser radar system ranging is performed in the calibration environment, the influence of environmental factors is weakened, and for example, the calibration box can shield the environment light and the like. In the embodiment, the laser radar system sequentially performs N ranging steps by using a calibration box, and the outgoing laser of each ranging step is delayed for different time to obtain N (N is more than or equal to 1 and N is an integer) different ranging values; the laser radar system calculates the distance of the target object through the flight time of the emergent laser, so that the flight time of the emergent laser can be directly converted into the distance; the outgoing laser of each ranging is delayed for different time, which is equivalent to flying for different distances after the outgoing laser is emitted and then is emitted to the calibration box, so as to obtain ranging values corresponding to N different actual values; the actual value of each ranging is the sum of the distance corresponding to the delay time and the length of the calibration box; therefore, the different distances between the laser radar system and the target object can be simulated without actually changing the actual space distance between the laser radar system and the target object. As the delay time increases, the actual value of the simulation also increases. The delay time can be realized by a delay line, and the outgoing laser can pass through the delay line with different lengths by delaying different times. The distance measurement value obtained by each distance measurement is different from the corresponding actual value to a certain extent due to errors, and the distance measurement values are not completely equal; therefore, N calibration matrices can be obtained according to the difference between the N ranging values and the corresponding actual values.
Step S140, a calibration matrix of the measured value is obtained, and calibration compensation is performed on the measured value.
It should be noted that, the measured value refers to the ranging distance of the target object obtained in the ranging process of the laser radar system in actual application, and the ranging value refers to the ranging distance of the target object obtained in the calibration process of the laser radar system for N times to obtain the calibration matrix; the calibration process needs to be performed in a calibration box.
And calibrating and compensating the measured value through a calibration matrix corresponding to the measured value, and correcting errors in the measured value to enable the measured value to be more approximate to a corresponding actual value, thereby improving the ranging accuracy of the laser radar system.
According to the calibration method of the laser radar system, the outgoing lasers with multiple ranging are delayed for different times to simulate the actual values of different distances between the laser radar system and the target object, so that the ranging values corresponding to the actual values of N different distances can be obtained, and N calibration matrixes are obtained; calibrating the measured value in actual application according to the calibration matrix; and further, the accuracy of the measured value obtained by the laser radar system in practical application is improved. In the process of acquiring the calibration matrix, the actual value of the distance between the laser radar system and the target object is not required to be changed, so that a huge sliding rail and a large calibration space are not required, the required resource consumption is small, and the operation process is simpler; and because the actual value of the distance between the laser radar system and the target object comprises the distance corresponding to the delay time and the length of the calibration box, the emergent laser does not actually fly through the space with the same distance, and the interference and loss of the environment to the emergent laser and the echo laser are small, even when the detection distance of the laser radar system is far, the accurate distance measurement can be carried out through the actual value of the simulation distance, thereby obtaining an accurate calibration matrix and improving the accuracy of the measurement value calibration.
In one embodiment, the laser radar system is disposed at one end of the calibration box, the target is disposed at the other end of the calibration box, the outgoing laser emitted by the laser radar system is emitted from one end of the calibration box after being delayed by the delay line for a period of time, and is emitted to the target at the other end of the calibration box, and returns echo laser after being reflected by the target, and the echo laser is received by the laser radar system.
The outer surface of the calibration box is black to shield ambient light, and a light absorbing material is arranged in the calibration box to reduce interference of repeated reflection of emergent laser on the inner surface of the calibration box on echo laser. Therefore, a calibration environment is established by using the calibration box, so that interference of environmental factors is avoided in the process of calibrating the laser radar system. The shape, structure, size, etc. of the calibration box can be set according to actual needs.
Illustratively, referring to FIG. 2, the calibration box 210 includes a first face 212 and an opposite second face 214. The target 220 is disposed on the first surface 212, the lidar system 230 is disposed on the second surface 214, that is, the lidar system 230 is disposed at one end of the calibration box 210, and the target 220 is disposed at the other end of the calibration box 210. The second surface 214 is provided with a through hole, the target 220 is opposite to the through hole, and the outgoing laser emitted by the laser radar system is emitted into the calibration box 210 through the through hole of the calibration box 210 and is emitted onto the target 220 inside the calibration box 210. The size of the through hole can be designed according to the caliber of the optical lens at the transmitting end of the laser radar system 230.
In one embodiment, the number of targets 220 is at least 1; when the number of the objects 220 is greater than 1, the reflectivity of each object 220 is different; exchanging the objects 220 in the calibration box 210 allows for calibration of objects of different reflectivity. For example, white paper with known reflectivity is adhered to the first surface 212 as the target 220, and N calibration matrices of the target 220 are obtained after N ranging; when the measured values of the target objects 220 with different reflectivities are required to be calibrated and compensated, the measured values of the target objects 220 with different reflectivities are only required to be replaced by the target objects 220 with the other reflectivities, so that the operation is convenient.
Specifically, lidar system 230 includes a transmitting device 232 and a receiving device 234. The junction of calibration box 210 and lidar system 230 is provided with suitable coupling structures so that the outgoing laser light emitted by emitter 232 can enter calibration box 210 to reach target 220 and the return echo laser light reflected by target 220 can be received by receiver 234. Specifically, as shown in fig. 2, the second face 214 of the calibration box 210 is provided with a through hole, the emitting device 232 is aligned with the through hole, and the outgoing laser emitted by the emitting device 232 passes through the through hole and enters the calibration box 210; the calibration box 210 is internally provided with a light path 216, and the receiving device 234 is disposed at the end of the light path 216, and the echo laser light passes through the light path 216 and is finally received by the receiving device 234 during propagation. The echo laser light may be received by the receiving device 234 after being reflected in the optical path 216 multiple times, or may be reflected from the target 220 and directly transmitted through the optical path 216 and received by the receiving device 234. Optionally, the optical conduit 216 is a black plastic tube, and its length may be 1/2, 2/3, 3/4, etc. of the length of the calibration box 210, as required.
The transmitting device 232 and the receiving device 234 may be arranged side by side, or the transmitting device 232 may be arranged around the receiving device 234. The position of the through hole on the second face 214 needs to be matched with the emitting device 232, so that enough photons in the outgoing laser emitted by the emitting device 232 can reach the tail end of the calibration box 210, namely, the target 220 in the calibration box 210 without being blocked. It should be noted that, if the outgoing laser emitted by the emitting device 232 is aligned to the specific angular direction, the calibration box 210 is not required to be designed to extend the size according to the specific angular direction, and since the calibration compensation for the measured value is irrelevant to the field angle of the lidar system 230, a set of emitting devices 232 for calibration may be separately designed according to the number of light sources of the emitting device 232; for example, the light sources of the emitting devices 232 are all mounted on the same plane.
The above-described limitations on calibration box 210 and lidar system 230 are only one of the exemplary embodiments, and the present application does not limit the internal structure of calibration box 210 and lidar system 230, but needs to ensure that enough photons in the outgoing laser light of lidar system 230 reach target 220 on first side 212 without being blocked, and that enough photons of the return laser light reflected by target 220 can be received by lidar system 230.
Fig. 3 is a flowchart of a calibration method of the lidar system in an embodiment. As shown in fig. 3, in step S120, the laser radar system sequentially performs N ranging operations by using a calibration box, delays the outgoing laser of each ranging operation for different times, obtains ranging values at N different distances, and obtains N calibration matrices according to differences between the ranging values and corresponding actual values, including: in step S320, the laser radar system sequentially performs N ranging steps, the exit laser of the ith ranging step passes through the (i-1) delay line and then irradiates the calibration box to obtain a ranging value at the distance of (i-1) L+K, and a calibration matrix is obtained according to the difference between the ranging value and the distance of (i-1) L+K. Where i=1, 2, …, N, L is the distance corresponding to the delay line and K is the length distance of the calibration box.
When calculating the calibration matrix, the calibration matrix is obtained according to the difference value between the ranging value and (i-1) L+K. Illustratively, the lidar system 230 performs multiple calibrations on the actual value of the same distance to obtain multiple ranging values corresponding to the actual value of the same distance; calculating the difference value between the ranging values and the actual values respectively, and calculating the average value of the difference values to serve as a calibration matrix; thereby improving the accuracy of the obtained calibration matrix.
The smaller the corresponding distance L of the delay line, the smaller the difference between the actual values of the N ranging measurements within range of lidar system 230 (i.e., the smaller the actual value step of the N ranging measurements), the more calibration matrices are obtained and the more accurate the calibration of the measured values of lidar system 230.
In one embodiment, the calibration box length distance K may be equal to the delay line corresponding distance L. The outgoing laser of the ith ranging is shot to the calibration box after passing through the (i-1) delay line, so as to obtain a ranging value at the distance of i x L, and a calibration matrix is obtained according to the difference value between the ranging value and the distance of i x L. The calculation process of the calibration matrix is simplified, the operation amount is reduced, and the calibration efficiency is improved.
As shown in fig. 2, the transmitting device 232 and the receiving device 234 are not located at the same position, the light paths of the outgoing laser and the echo laser are not coaxial, and a certain included angle is formed between the light paths. The sum of the distance from the light exit surface of the emitting device 232 to the target 220 and the distance from the target 220 to the light receiving surface of the receiving device 234 is the distance that the photons actually propagate within the calibration box 210. To simplify the calculation of the calibration matrix described above, half the distance that photons actually travel within the calibration box 210 is equal to the distance L corresponding to the delay line, where the length of the calibration box K is not equal to the distance L corresponding to the delay line. However, the difference between K and L is often small, and in order to simplify the calibration device, it is usually set such that the length distance K of the calibration box is equal to the corresponding distance L of the delay line.
Specifically, referring to fig. 4, lidar system 230 includes a transmitting device 232, a receiving device 234, a delay line 235, and a clock device 236; the clock means 236 sends a clock signal to the delay line 235 and the receiving means 234; the delay line 235 delays according to the delay time required by the ith ranging and then transmits the clock signal to the transmitting device 232; the emitting device 232 receives the clock signal transmitted by the delay line and emits the emitted laser light. After entering the calibration box, the outgoing laser light is reflected by the target 220 and returns back to the echo laser light. The echo laser light is received by the receiving device 234, and the receiving device 234 calculates a ranging value by calculating a time difference between transmission and reception from a clock signal transmitted from the clock device 236. Delay line 235 includes N delay amounts τ, where τ=l/c, where c is the speed of light; after the clock signal is sent to the delay line 235, the i-th ranging requires delay time (i-1) τ, and the clock signal is delayed and then output; the delay line comprises N delay blocks 237 and a gating 238, each delay block 237 delays by a delay amount tau, clock signals of delay times tau, … … and N tau are all sent to the gating 238, and the gating 238 selects and outputs corresponding delay time (i-1) tau according to the delay time required by the current ranging. For example, the 5 th ranging, delay line delay time 4τ, the corresponding actual ranging value is 4l+k, and the fifth ranging value is obtained and compared with the actual value. If the length distance K of the calibration box is equal to the distance L corresponding to the delay line, the actual value of the 5 th ranging is 5L. The transmitting device 232 includes a transmitting driver 2322 and a transmitter 2324, where the transmitting driver 2322 sends a driving signal to the transmitter 2324 after receiving a clock signal, and drives the transmitter 2324 to transmit outgoing laser light. In this embodiment, the distance between the lidar system 230 and the target 220 is not increased in the calibration process, and only the delay time is increased.
Further, referring to fig. 3, in step S140, a calibration matrix of the measured values is obtained, and calibration compensation is performed on the measured values, including:
and S342, when the measured value M is less than or equal to (N-1) and L+K, adopting a calibration matrix corresponding to the measured value to calibrate and compensate the measured value.
When the measured value is in the measuring range of the calibration process, the calibration matrix corresponding to the measured value can be directly obtained.
Specifically, referring to fig. 5, step S342 includes:
step S510, generating a calibration curve according to the ranging values of the N ranging and the corresponding calibration matrix fitting.
In one embodiment, referring to fig. 6, the ranging values of the N ranging in the calibration process and the corresponding calibration matrix are fitted to obtain a calibration curve. And establishing a coordinate system by taking the calibration matrix as a Y axis and taking the measured value as an X axis, and drawing N ranging values (corresponding to the X axis) in the calibration process and the corresponding calibration matrix in the coordinate system, wherein a plurality of discrete points are formed on the coordinate system. Fitting these discrete points yields a smooth and coherent calibration curve. Specifically, the fitting may be performed using a least square method. According to the calibration curve, a calibration matrix corresponding to any measured value in the range of measurement can be obtained.
Step S520, according to the calibration curve, a calibration matrix corresponding to the measured value is obtained.
In step S530, the obtained calibration matrix is used to calibrate and compensate the measured value.
And (3) inputting a measured value in a range through a calibration curve to obtain a corresponding calibration matrix. And performing calibration compensation on the measured value by adopting the acquired calibration matrix. For example, the measurement values may be summed with a corresponding calibration matrix to obtain calibrated measurement values.
In step S344, when the measurement M > (N-1) is L+K, the measurement is calibrated and compensated by using the calibration matrix corresponding to the specified ranging value.
When the measured value exceeds the measuring range of the calibration process, a calibration matrix corresponding to the specified ranging value corresponding to the measured value can be called. Because of factors such as complexity of hardware design, size of calibration box, calibration cost, etc., the distance L corresponding to the delay line and the calibrated distance measurement frequency N cannot be set to be very large, so that the detection distance is possibly larger than the calibrated measurement range in the process of measuring distance in practical application of the laser radar system.
Specifically, referring to fig. 7, step S344 includes:
step S710, acquiring a specified ranging value according to the measured value.
The calculation formula of the specified ranging value corresponding to the measured value is as follows:
X＝M％[(N-1)*L+K]
Wherein X is a specified ranging value, and% is a remainder operation.
The specified distance measurement value X calculated by the formula is in the calibrated range, namely X is less than or equal to (N-1) and L+K.
Step S720, obtaining a calibration matrix corresponding to the specified ranging value.
Since the specified ranging value is within the range of the calibration process, N calibration matrices obtained in the calibration process can be called, and there are various methods for obtaining the calibration matrices. Illustratively, a calibration matrix corresponding to the specified ranging value X may be obtained from a calibration curve.
In step S730, the obtained calibration matrix is used to calibrate and compensate the measured value.
And calling a calibration matrix corresponding to the designated ranging value X, and performing calibration compensation on the measured value by using the acquired calibration matrix.
The calibration matrix corresponding to the designated ranging value is called to calibrate and compensate the measured value exceeding the calibration range, so that the hardware setting of the calibration process can be simplified, the size and the ranging times of the calibration box can be controlled, the calibration process is simplified, and the cost is controllable.
Further, the method for obtaining the calibration matrix corresponding to the specified ranging value may further be: when the specified ranging value is x= (j-1) l+k, the calibration matrix corresponding to the ranging value is the calibration matrix corresponding to the specified ranging value; when the specified ranging value X meets (j-1) L+K < X < j L+K, a calibration matrix corresponding to the specified ranging value is obtained by fitting a calibration matrix at the distance of (j-1) L+K and a calibration matrix at the distance of j L+K. Where j=1, 2, …, N.
Because of the N ranging in the calibration process, N discrete points are obtained in the coordinate system of the measured value-calibration matrix; therefore, when the specified ranging value X is equal to the ranging value in the calibration process, the calibration matrix obtained in the ranging value calibration process is directly called; when the specified ranging value X is between two adjacent ranging values in the calibration process, a corresponding calibration matrix can be obtained in a fitting mode; alternatively, points in the coordinate system corresponding to the two adjacent ranging values may be fitted by linear difference values.
In the embodiment, the measured value is in the calibration range or out of the calibration range, so that the measured value can be accurately obtained and calibrated by the calibration matrix, and the accuracy of the measured value of the laser radar system is effectively improved; meanwhile, the calibration compensation of the measured value is not limited by the measuring range of the calibration process, and the measured value can be effectively calibrated and compensated when the measured value is large, so that the detection accuracy is ensured; in addition, the measured value outside the calibration range can be calibrated and compensated by using the calibration matrix corresponding to the specified ranging value in the calibration range, so that the calibration frequency N is not required to be infinitely increased in the calibration process, the calibration process is simpler, and the cost is lower.
In one embodiment, as shown in fig. 8, fig. 8 is a flowchart of a method of calibrating a lidar system. The calibration method of the lidar system may further include step S110, step S150 to step S160, in addition to the above-mentioned step S120 and step S140.
Step S110, preheating the lidar system.
For example, the laser radar system may be turned on to perform pre-calibration, but the calibration data is invalidated at this time, and may not be used in the subsequent steps, or the laser radar system may be turned on only, but the calibration is not performed. Because the characteristic of the emergent laser emitted by the emitting device of the laser radar system has a great relation with the temperature thereof; in the initial stage of the operation of the emitting device, the temperature is increased continuously along with the increase of the working time, and the characteristic of the emitted laser is changed continuously along with the increase of the temperature; after the emitting device works for a period of time, the temperature reaches balance, and the characteristics of the emitted laser are stable. Therefore, the laser radar system is preheated, and the transmitting device can reach a stable state, so that the accuracy of a calibration matrix obtained in the calibration process is improved.
Step S150, obtaining a temperature compensation coefficient according to the temperature of the laser radar system.
Step S160, calibrating the temperature compensation coefficient to compensate the measured value.
Specifically, in the ranging process of the laser radar system in practical application, the working temperature of the laser radar system also fluctuates due to different surrounding environments, so that the influence of temperature factors is also required to be considered when the measured value is calibrated and compensated. Through experience, a temperature compensation coefficient corresponding to the temperature of the laser radar system can be obtained; the laser radar system can obtain the corresponding temperature compensation coefficient through a table look-up mode. The temperature of the lidar system may be obtained by providing a temperature sensor within the lidar system, which may be provided at one or more locations within the transmitting device, the receiving device, the control device, the void within the housing of the lidar system, etc. And (3) multiplying the compensation measured value subjected to calibration compensation by the calibration matrix by a temperature compensation coefficient to obtain an output value. In the embodiment, the measured value is further corrected by introducing the temperature compensation coefficient, so that the calibration precision is improved, and the accuracy of the measured value of the laser radar system is improved.
In one embodiment, during calibration, the hardware system controls the power of the outgoing laser of the laser radar system, so that the power of the outgoing laser decreases with the increase of the delay time.
In an actual ranging scene, there is unavoidable loss due to the fact that the outgoing laser flies in the environment. In this embodiment, the power of the outgoing laser is gradually weakened along with the increase of the flight distance, so that the energy loss condition of photons in the outgoing laser and the echo laser in the actual application scene is simulated, the calibration process is closer to the actual ranging scene, the accuracy of the obtained calibration matrix is improved, and the accuracy of the measurement value calibration is improved. Illustratively, the power of the outgoing laser is in a negative quadratic power relationship with the time of the delay; in the calibration process, the actual value of the distance is related to the delay time, the power of the emergent laser is reduced along with the increase of the flight distance along with the increase of the delay time, the energy loss rule in the actual ranging scene is met, the accuracy of the acquired calibration matrix is improved, and the accuracy of the measurement value calibration is improved.
The application also provides a calibration device of the laser radar system. Fig. 9 is a block diagram of a calibration device of a lidar system in an embodiment. As shown in fig. 9, the calibration device 900 of the lidar system includes a processing module 910 and a calibration module 920, which are configured to implement the foregoing calibration method of the lidar system.
The processing module 910 is configured to control the laser radar system to sequentially perform N ranging operations by using the calibration box, delay outgoing laser of each ranging operation for different times, obtain ranging values at N different distances, and obtain N calibration matrices according to differences between the ranging values and corresponding actual values; wherein N is more than or equal to 1 and N is an integer.
The calibration module 920 is configured to obtain a calibration matrix of the measured values, and perform calibration compensation on the measured values.
The calibration device 900 of the laser radar system includes a processing module 910 and a calibration module 920, where the processing module 910 controls the laser radar system to perform N ranging operations by using a calibration box, and delays outgoing lasers of the multiple ranging operations by different times to simulate actual values of different distances between the laser radar system and a target object, so as to obtain ranging values corresponding to the actual values of the N different distances, and further obtain N calibration matrices according to differences between the ranging values and the corresponding actual values; the calibration module 920 calibrates the measured value in the practical application according to the calibration matrix, so as to improve the accuracy of the measured value obtained by the laser radar system in the practical application. In the process of acquiring the calibration matrix, the actual value of the distance between the laser radar system and the target object is not required to be changed, so that a huge sliding rail and a large calibration space are not required, the required resource consumption is small, and the operation process is simpler; and because the actual value of the distance between the laser radar system and the target object comprises the distance corresponding to the delay time and the length of the calibration box, the emergent laser does not actually fly through the space with the same distance, and the interference and loss of the environment to the emergent laser and the echo laser are small, even when the detection distance of the laser radar system is far, the accurate distance measurement can be carried out through the actual value of the simulation distance, thereby obtaining an accurate calibration matrix and improving the accuracy of the measurement value calibration.
In one embodiment, the calibration box is used for establishing a calibration environment, the laser radar system is arranged at one end of the calibration box, and the target object is arranged at the other end of the calibration box. The processing module 910 controls the laser radar system to sequentially perform N ranging, the outgoing laser of the ith ranging passes through the (i-1) delay line and then irradiates the calibration box to obtain a ranging value at the distance of (i-1) L+K, and a calibration matrix is obtained according to the difference value between the ranging value and the distance of (i-1) L+K; where i=1, 2, …, N, L is the distance corresponding to the delay line and K is the length distance of the calibration box.
In one embodiment, when the measured value M is less than or equal to (N-1) and L+K, the calibration module 920 performs calibration compensation on the measured value by using a calibration matrix corresponding to the measured value; when the measured value M > (N-1) is L+K, the calibration module adopts a calibration matrix corresponding to the designated ranging value to calibrate and compensate the measured value.
In one embodiment, when the measured value M is less than or equal to (N-1) ×l+k, the calibration module 920 is configured to generate a calibration curve according to the ranging values of the N ranging and the corresponding calibration matrix fitting; obtaining a calibration matrix corresponding to the measured value according to the calibration curve; and performing calibration compensation on the measured value by adopting the acquired calibration matrix.
In one embodiment, when the measured value M > (N-1) is L+K, the calibration module 920 is configured to obtain the specified ranging value according to the measured value; acquiring a calibration matrix corresponding to the designated ranging value; and performing calibration compensation on the measured value by adopting the acquired calibration matrix.
In one embodiment, a through hole is formed in one end of the calibration box, where the target object is arranged, an optical path pipeline connected with the laser radar system is arranged in the calibration box, and a light absorbing material is arranged on the inner surface of the calibration box.
In one embodiment, the calculation formula of the specified ranging value corresponding to the measured value is:
X＝M％[(N-1)*L+K]
wherein X is a specified ranging value.
In one embodiment, when the specified ranging value is x= (j-1) ×l+k, the calibration matrix corresponding to the ranging value is the calibration matrix corresponding to the specified ranging value; when the specified ranging value X meets (j-1) L+K < X < j L+K, obtaining a calibration matrix corresponding to the specified ranging value through linear interpolation fitting of the calibration matrix at the distance of (j-1) L+K and the calibration matrix at the distance of j L+K; where j=1, 2, …, N.
In one embodiment, the delay line corresponds to a distance L equal to the length distance K of the calibration box.
In one embodiment, the number of targets is at least 1; when the number of the objects is greater than 1, the reflectivity of the objects is different.
In one embodiment, the processing device 910 is further configured to control, by using a hardware system, the power of the outgoing laser beam of the lidar system, so that the power of the outgoing laser beam decreases with increasing delay time.
In one embodiment, the power of the outgoing laser is a negative power of two with respect to the time of the delay.
In one embodiment, the calibration module 920 sums the measurement values with a corresponding calibration matrix to obtain calibrated measurement values.
In one embodiment, the calibration module 920 is further configured to obtain a temperature compensation coefficient according to a temperature of the lidar system; the temperature compensation coefficient is calibrated to compensate the measured value.
In one embodiment, the processing module 910 is further configured to warm up the lidar system.
It should be noted that, each module in the calibration device 900 of the laser radar system may be implemented in whole or in part by software, hardware, or a combination thereof. The modules can be embedded in a processor of a server or independent of the server in a hardware form, and can also be stored in a memory of the server in a software form, so that the processor can call and execute the operations corresponding to the modules.
The application also provides a ranging device. The ranging apparatus comprises a memory and a processor having stored thereon a computer program executable thereon. The steps of the method in any of the embodiments described above are implemented when the processor executes a computer program.
The present application also provides a storage medium having a computer program stored thereon. The computer program, when executed by a processor, implements the steps of any of the methods described above.
Those skilled in the art will appreciate that implementing all or part of the above described methods may be accomplished by way of a computer program stored on a non-transitory computer readable storage medium, which when executed, may comprise the steps of the embodiments of the methods described above. Any reference to memory, storage, database, or other medium used in the various embodiments provided herein may include non-volatile and/or volatile memory. The nonvolatile memory can include Read Only Memory (ROM), programmable ROM (PROM), electrically Programmable ROM (EPROM), electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms such as Static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double Data Rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous Link DRAM (SLDRAM), memory bus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), among others.
It is to be understood that the dimensions of all of the figures herein are not to scale and are merely schematic.
The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples merely represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the invention. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of protection of the present application is to be determined by the claims appended hereto.
Claims (19)
1. A calibration method of a laser radar system comprises the following steps:
the laser radar system sequentially performs N ranging operations by using a calibration box, the outgoing laser of the ith ranging operation is emitted to the calibration box after passing through (i-1) delay lines, ranging values at N different distances are obtained, and N calibration matrixes are obtained according to the difference between the ranging values and corresponding actual values; wherein N is greater than or equal to 1 and N is an integer, i=1, 2, …, N;
Acquiring the calibration matrix of the measured value, and performing calibration compensation on the measured value; the measured value is a distance measurement distance of a target object obtained in the process of measuring the distance of the laser radar system in actual application;
when the measured value M > (N-1) is L+K, acquiring a specified ranging value according to the measured value, and performing calibration compensation on the measured value by adopting a calibration matrix corresponding to the specified ranging value; wherein L is the distance corresponding to the delay line, K is the length distance of the calibration box, the laser radar system is arranged at one end of the calibration box, and the target object is arranged at the other end of the calibration box;
the specific ranging value is obtained according to the measured value, specifically:
the calculation formula of the specified ranging value corresponding to the measured value is as follows: x=m% [ (N-1) ×l+k ], X being the specified ranging value.
2. The method according to claim 1, wherein the obtaining the ranging values at N different distances and obtaining N calibration matrices according to differences between the ranging values and corresponding actual values includes:
obtaining the ranging value at the distance (i-1) L+K, and obtaining the calibration matrix according to the difference between the ranging value and the distance (i-1) L+K.
3. The method of calibrating according to claim 2, wherein the method further comprises:
and when the measured value M is less than or equal to (N-1) L+K, adopting a calibration matrix corresponding to the measured value to calibrate and compensate the measured value.
4. A calibration method according to claim 3, wherein when the measured value M is less than or equal to (N-1) x l+k, performing calibration compensation on the measured value using a calibration matrix corresponding to the measured value, comprising:
generating a calibration curve according to the ranging values of the N ranging times and the corresponding calibration matrix fitting;
acquiring the calibration matrix corresponding to the measured value according to the calibration curve;
and performing calibration compensation on the measured value by adopting the acquired calibration matrix.
5. The method according to claim 1, wherein performing calibration compensation on the measurement values using a calibration matrix corresponding to the specified ranging values comprises:
acquiring the calibration matrix corresponding to the specified ranging value;
and performing calibration compensation on the measured value by adopting the acquired calibration matrix.
6. The method according to claim 5, wherein the obtaining the calibration matrix corresponding to the specified ranging value includes:
When the specified ranging value is x= (j-1) l+k, the calibration matrix corresponding to the ranging value is the calibration matrix corresponding to the specified ranging value;
when the specified ranging value X meets (j-1) L+K < X < j L+K, obtaining the calibration matrix corresponding to the specified ranging value by fitting the calibration matrix at the distance of (j-1) L+K and the calibration matrix at the distance of j L+K;
where j=1, 2, …, N.
7. The method of calibrating according to claim 2, wherein the delay line corresponds to a distance L equal to the length distance K of the calibration box.
8. The method of calibrating according to claim 2, wherein the number of targets is at least 1; when the number of the target objects is greater than 1, the reflectivity of the target objects is different.
9. The method of calibrating according to claim 2, further comprising:
the power of the emergent laser of the laser radar system is controlled by a hardware system, so that the power of the emergent laser is reduced along with the increase of delay time.
10. The method of calibrating according to claim 9, wherein the power of the outgoing laser and the time of the delay are in a negative quadratic power relationship.
11. The method of calibrating according to claim 2, wherein the calibration matrix for the acquisition of measurement values, performing calibration compensation for the measurement values, further comprises:
and summing the measured value with the corresponding calibration matrix to obtain a calibrated measured value.
12. The method of calibrating according to claim 1, further comprising:
acquiring a temperature compensation coefficient according to the temperature of the laser radar system;
and calibrating and compensating the temperature compensation coefficient to the measured value.
13. The calibration method according to claim 1, wherein the laser radar system sequentially performs N ranging operations using a calibration box, the outgoing laser of the ith ranging operation is directed to the calibration box after passing through the (i-1) delay line, and before obtaining the ranging values at N different distances, and obtaining the calibration matrix according to the difference between the ranging values and the corresponding actual values, the method further comprises:
preheating the lidar system.
14. A calibration device for a lidar system, comprising:
the processing module is used for controlling the laser radar system to sequentially perform N ranging operations by using the calibration box, emitting laser of the ith ranging operation to the calibration box after passing through the (i-1) delay line to obtain ranging values of N different distances, and obtaining N calibration matrixes according to the difference between the ranging values and corresponding actual values; wherein N is greater than or equal to 1 and N is an integer, i=1, 2, …, N;
The calibration module is used for acquiring the calibration matrix of the measured value and performing calibration compensation on the measured value; the measured value is a distance measurement distance of a target object obtained in the process of measuring the distance of the laser radar system in actual application;
when the measured value M > (N-1) is L+K, acquiring a specified ranging value according to the measured value, and performing calibration compensation on the measured value by adopting a calibration matrix corresponding to the specified ranging value; wherein L is the distance corresponding to the delay line, K is the length distance of the calibration box, the laser radar system is arranged at one end of the calibration box, and the target object is arranged at the other end of the calibration box;
the specific ranging value is obtained according to the measured value, specifically:
the calculation formula of the specified ranging value corresponding to the measured value is as follows: x=m% [ (N-1) ×l+k ], X being the specified ranging value.
15. The calibration device of claim 14, wherein the calibration box is used to establish a calibration environment;
the processing module is used for controlling and obtaining the ranging value at the distance of (i-1) L+K, and obtaining the calibration matrix according to the difference value between the ranging value and the distance of (i-1) L+K.
16. The calibration device of claim 15, wherein when the measured value M is less than or equal to (N-1) x l+k, the calibration module performs calibration compensation on the measured value using a calibration matrix corresponding to the measured value.
17. The calibration device according to claim 15, wherein a through hole is formed in an end of the calibration box, where the target is disposed, an optical path pipeline connected to the lidar system is disposed inside the calibration box, and a light absorbing material is disposed on an inner surface of the calibration box.
18. A storage medium having stored thereon a computer program which, when executed by a processor, implements the steps of the calibration method according to any one of claims 1 to 13.
19. A ranging apparatus comprising a memory and a processor; computer program executable on said processor is stored on said processor, said processor executing the steps of the calibration method according to any one of claims 1 to 13.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/CN2019/115119 WO2021081998A1 (en) | 2019-11-01 | 2019-11-01 | Calibration method and calibration apparatus for laser radar system, medium, and ranging device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112585495A CN112585495A (en) | 2021-03-30 |
| CN112585495B true CN112585495B (en) | 2023-08-04 |
Family
ID=75117227
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201980050174.XA Active CN112585495B (en) | 2019-11-01 | 2019-11-01 | Laser radar system calibration method and calibration device, medium and ranging equipment |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN112585495B (en) |
| WO (1) | WO2021081998A1 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117651882A (en) * | 2021-07-28 | 2024-03-05 | 深圳市速腾聚创科技有限公司 | Reflectivity correction method, reflectivity correction device, computer readable storage medium and terminal equipment |
| CN113916132B (en) * | 2021-09-23 | 2024-01-30 | 中国科学院微电子研究所 | Signal processing method, device, equipment and medium for measuring silicon wafer height |
| CN115166757B (en) * | 2022-07-25 | 2023-08-01 | 珠海市睿特光电技术有限公司 | Method, system and storage medium for measuring actual detection distance of laser radar |
| CN116033068B (en) * | 2022-12-28 | 2024-08-27 | 维沃移动通信有限公司 | False touch prevention method, device, electronic equipment and readable storage medium |
| CN117055061B (en) * | 2023-10-11 | 2024-03-08 | 深圳市欢创科技股份有限公司 | Ranging method, laser radar, robot and storage medium |
| CN117970350B (en) * | 2024-03-29 | 2024-07-12 | 深圳市欢创科技股份有限公司 | Ranging method, laser radar, ranging system, robot and storage medium |
| CN118283972B (en) * | 2024-06-04 | 2024-09-10 | 陕西韦诺网络科技有限公司 | Laser radar ranging system |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7738082B1 (en) * | 2006-10-20 | 2010-06-15 | Leupold & Stevens, Inc. | System and method for measuring a size of a distant object |
| CN103954945A (en) * | 2014-04-10 | 2014-07-30 | 西安空间无线电技术研究所 | Method for carrying out full-scale calibration on microwave distance-measuring radar based on optical fiber delay line |
| CN104515983A (en) * | 2014-12-25 | 2015-04-15 | 西安电子工程研究所 | Stepped frequency radar signal target extract method based on statistic optimum |
| CN109375196A (en) * | 2018-12-12 | 2019-02-22 | 北京华科博创科技有限公司 | A kind of laser radar caliberating device and scaling method based on space-time transformation |
| CN109917355A (en) * | 2019-03-04 | 2019-06-21 | 合肥嘉东光学股份有限公司 | Laser radar range error compensation system |
| CN110006451A (en) * | 2019-04-16 | 2019-07-12 | 北京遥感设备研究所 | A kind of pulsed laser ranging high-precision Calibration System based on total station |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8368876B1 (en) * | 2008-10-17 | 2013-02-05 | Odyssey Space Research, L.L.C. | Calibration system and method for imaging flash LIDAR systems |
| DE102016222136A1 (en) * | 2016-11-11 | 2018-05-17 | Robert Bosch Gmbh | Time-to-digital conversion device, LiDAR system and device |
| CN106597417A (en) * | 2017-01-10 | 2017-04-26 | 北京航天计量测试技术研究所 | Remote scanning laser radar measurement error correction method |
| CN109343036B (en) * | 2018-09-06 | 2024-07-30 | 北京理工大学 | Three-dimensional solid-state area array laser radar calibration device and method |
| CN108828565B (en) * | 2018-09-19 | 2023-11-03 | 北京聚恒博联科技有限公司 | Laser radar calibration system and method |
-
2019
- 2019-11-01 WO PCT/CN2019/115119 patent/WO2021081998A1/en active Application Filing
- 2019-11-01 CN CN201980050174.XA patent/CN112585495B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7738082B1 (en) * | 2006-10-20 | 2010-06-15 | Leupold & Stevens, Inc. | System and method for measuring a size of a distant object |
| CN103954945A (en) * | 2014-04-10 | 2014-07-30 | 西安空间无线电技术研究所 | Method for carrying out full-scale calibration on microwave distance-measuring radar based on optical fiber delay line |
| CN104515983A (en) * | 2014-12-25 | 2015-04-15 | 西安电子工程研究所 | Stepped frequency radar signal target extract method based on statistic optimum |
| CN109375196A (en) * | 2018-12-12 | 2019-02-22 | 北京华科博创科技有限公司 | A kind of laser radar caliberating device and scaling method based on space-time transformation |
| CN109917355A (en) * | 2019-03-04 | 2019-06-21 | 合肥嘉东光学股份有限公司 | Laser radar range error compensation system |
| CN110006451A (en) * | 2019-04-16 | 2019-07-12 | 北京遥感设备研究所 | A kind of pulsed laser ranging high-precision Calibration System based on total station |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2021081998A1 (en) | 2021-05-06 |
| CN112585495A (en) | 2021-03-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112585495B (en) | Laser radar system calibration method and calibration device, medium and ranging equipment | |
| AU2020103665A4 (en) | Low-altitude Light Small Area Array LiDAR Measuring System | |
| CA2650235C (en) | Distance measuring method and distance measuring element for detecting the spatial dimension of a target | |
| US20150226853A1 (en) | Laser radar apparatus and method of acquiring image thereof | |
| CN110471083B (en) | Longitudinal distance laser three-dimensional imaging device and method | |
| CN111352120B (en) | Flight time ranging system and ranging method thereof | |
| CN111352121B (en) | Flight time ranging system and ranging method thereof | |
| EP3882659A1 (en) | Method of calculating distance-correction data, range-finding device, and mobile object | |
| CN113466836A (en) | Distance measurement method and device and laser radar | |
| CN110986816B (en) | Depth measurement system and measurement method thereof | |
| CN112219135A (en) | Distance measuring device, distance measuring method and mobile platform | |
| US11252359B1 (en) | Image compensation for sensor array having bad pixels | |
| CN108226902A (en) | A kind of face battle array lidar measurement system | |
| US20220364849A1 (en) | Multi-sensor depth mapping | |
| CN115436912B (en) | Point cloud processing method and device and laser radar | |
| CN116008964A (en) | Laser radar, reflectivity calibration method and reflectivity measurement method thereof | |
| CN114612598A (en) | Point cloud processing method and device and laser radar | |
| CN118011410B (en) | Ranging method, laser radar, robot and storage medium | |
| EP3276576A1 (en) | Disparity estimation by fusion of range data and stereo data | |
| CN116679310A (en) | FMCW laser measuring device | |
| CN112213711B (en) | Calibration method of TOF camera | |
| Kawazoe et al. | Development of receiver optics for simplified 3D laser scanner composition | |
| Lee et al. | Real-time LIDAR imaging by solid-state single chip beam scanner | |
| CN118584499B (en) | Ranging method, laser radar, device and storage medium | |
| Chaldina et al. | Study of the Time-of-Flight Method for Measuring Distances to Objects Using an Active-Pulse Television Measuring System |
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 |