CN108196264B - Laser ranging method, device and system - Google Patents
Laser ranging method, device and system Download PDFInfo
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- CN108196264B CN108196264B CN201611123213.9A CN201611123213A CN108196264B CN 108196264 B CN108196264 B CN 108196264B CN 201611123213 A CN201611123213 A CN 201611123213A CN 108196264 B CN108196264 B CN 108196264B
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Abstract
The invention provides a laser ranging method, a laser ranging device and a laser ranging system. The method comprises the following steps: sending a first laser starting signal to the barrier by using preset laser power; receiving echo light returned by the barrier, and converting the echo light into an electric signal; processing the amplified electric signal to obtain a pulse signal; acquiring time information of a first laser initial signal and time information of a pulse signal, and judging whether the amplified electric signal is saturated or not according to the time information of the first laser initial signal and the time information of the pulse signal; if the amplified electric signal is judged to be saturated, adjusting the preset laser power and the preset amplification factor so as to enable the amplified electric signal to be unsaturated; and sending a second laser starting signal to the obstacle according to the adjusted first laser power so as to obtain the distance of the obstacle. The invention can obtain the distance of the barrier under the condition of ensuring that the amplified electric signal is not saturated, and improves the accuracy of laser ranging.
Description
Technical Field
The invention relates to the technical field of laser detection, in particular to a laser ranging method, device and system.
Background
With the continuous development of laser detection technology, the laser radar technology has also been developed rapidly. The laser radar technology is gradually converted from the military field to the civil field, and is widely applied to the industries of airborne, unmanned driving, vehicle detection, port collision avoidance, tunnel detection, production and manufacturing and the like. The laser radar technology is mainly based on pulse type and phase type measuring modes, and the pulse type measuring mode has the advantages of long measuring distance, strong anti-interference performance, no need of cooperative targets and the like, and is widely applied to the field of detection with centimeter-level precision requirements.
The ranging capability of the pulse laser radar depends on factors such as laser power of a transmitting end, amplification factor of a receiving end amplification circuit, threshold voltage of a time discrimination circuit and the like. When the signal amplitude of the amplifying circuit can trigger the threshold voltage of the moment discriminating circuit, the current distance can be obtained, otherwise, the current distance cannot be obtained.
In order to satisfy the long-distance ranging of the pulse laser radar, the amplification factor of the amplifying circuit is generally larger. The received light energy is strong at a short distance, the amplified signal is saturated, the light energy is weak at a long distance, and the amplified signal is unsaturated; for short-distance ranging, the obtained distance of the obstacle is inaccurate due to the saturation of the amplified signal.
Disclosure of Invention
The embodiment of the invention provides a laser ranging method, a laser ranging device and a laser ranging system, which are used for solving the problem that the distance of an obstacle obtained when an amplified signal is saturated in the existing laser ranging method is inaccurate.
The embodiment of the invention provides a laser ranging method, which comprises the following steps:
s1: sending a first laser starting signal to the barrier by using preset laser power;
s2: receiving echo light returned by the obstacle, and converting the echo light into an electric signal;
s3: amplifying the electric signal by a preset amplification factor;
s4: processing the amplified electric signal to obtain a pulse signal;
s5: acquiring time information of the first laser starting signal and time information of the pulse signal, and judging whether the amplified electric signal is saturated or not according to the time information of the first laser starting signal and the time information of the pulse signal;
s6: if the amplified electric signal is judged to be saturated, adjusting the preset laser power and the preset amplification factor so as to enable the amplified electric signal to be unsaturated;
s7: and sending a second laser starting signal to the obstacle according to the adjusted first laser power, repeating the steps S2, S3 and S4, and acquiring the distance of the obstacle according to the time information of the second laser starting signal and the time information of the pulse signal corresponding to the second laser starting signal.
Optionally, the method further comprises:
and if the amplified electric signal is not saturated, acquiring the distance of the obstacle according to the time information of the first laser starting signal and the time information of the pulse signal.
Optionally, step S4 includes:
and processing the amplified electric signal by adopting a high-pass resistance-capacitance method or a constant ratio timing method to obtain a pulse signal.
Optionally, the determining whether the amplified electrical signal is saturated according to the time information of the first laser start signal and the time information of the pulse signal includes:
acquiring the estimated distance of the obstacle and the pulse width of the pulse signal according to the time information of the first laser starting signal and the time information of the pulse signal;
acquiring the reflectivity of the obstacle according to the estimated distance of the obstacle and the pulse width of the pulse signal;
acquiring the power of the echo light according to the reflectivity of the obstacle;
calculating and acquiring the amplitude of the amplified electric signal according to the power of the echo light;
and judging whether the amplified electric signal is saturated or not according to the amplitude of the amplified electric signal.
Optionally, the obtaining the reflectivity of the obstacle according to the estimated distance of the obstacle and the pulse width of the pulse signal includes:
and acquiring the reflectivity of the obstacle according to the corresponding relation between the distance of the obstacle with known reflectivity and the pulse width of the pulse signal and a laser radar ranging equation.
The embodiment of the invention provides a laser ranging device, which comprises:
the time information acquisition unit is used for acquiring time information of the first laser starting signal and time information of the pulse signal, wherein the first laser starting signal is sent to an obstacle by a laser transmitter with preset laser power;
the judging unit is used for judging whether the amplified electric signal is saturated or not according to the time information of the first laser starting signal and the time information of the pulse signal;
the adjusting unit is used for adjusting the preset laser power and the preset amplification factor when judging that the amplified electric signal is saturated, so that the amplified electric signal is unsaturated;
and the first distance acquisition unit is used for acquiring the distance of the obstacle according to the time information of a second laser starting signal and the time information of a pulse signal corresponding to the second laser starting signal, wherein the second laser starting signal is emitted by the laser emitter with the adjusted laser power.
Optionally, the apparatus further comprises:
and the second distance acquisition unit is used for acquiring the distance of the obstacle according to the time information of the first laser starting signal and the time information of the pulse signal when the amplified electric signal is judged to be unsaturated.
Optionally, the determining unit includes:
the estimated distance pulse width acquisition module is used for acquiring the estimated distance of the obstacle and the pulse width of the pulse signal according to the time information of the first laser starting signal and the time information of the pulse signal;
the reflectivity obtaining module is used for obtaining the reflectivity of the obstacle according to the estimated distance of the obstacle and the pulse width of the pulse signal;
the echo light power acquisition module is used for acquiring the power of the echo light according to the reflectivity of the obstacle;
the amplitude calculation module is used for calculating and acquiring the amplitude of the amplified electric signal according to the power of the echo light;
and the judging module is used for judging whether the amplified electric signal is saturated or not according to the amplitude of the amplified electric signal.
Optionally, the reflectivity obtaining module is further configured to:
and acquiring the reflectivity of the obstacle according to the corresponding relation between the distance of the obstacle with known reflectivity and the pulse width of the pulse signal and a laser radar ranging equation.
The embodiment of the invention provides a laser ranging system, which comprises:
the device comprises a laser transmitter, a photoelectric converter, an amplifier, a time identification circuit and the laser ranging device;
the laser transmitter is used for transmitting a laser starting signal to the barrier;
the photoelectric converter is used for receiving the echo light returned by the obstacle and converting the echo light into an electric signal;
the amplifier is used for amplifying the electric signal;
the time discrimination circuit is used for processing the amplified electric signal to obtain a pulse signal;
the laser ranging device is used for acquiring the time information of the laser initial signal and the time information of the pulse signal and judging whether the amplified electric signal is saturated or not according to the time information of the laser initial signal and the time information of the pulse signal; and if the amplified electric signal is judged to be saturated, adjusting the laser power of the laser transmitter and the amplification factor of the amplifier to enable the amplified electric signal to be unsaturated, and acquiring the distance of the obstacle according to the time information of the laser starting signal and the time information of the pulse signal under the condition of ensuring that the amplified electric signal is unsaturated.
The laser ranging method, the laser ranging device and the laser ranging system provided by the embodiment of the invention are used for acquiring the time information of a laser initial signal and the time information of a pulse signal and judging whether an amplified electric signal is saturated or not according to the time information of the laser initial signal and the time information of the pulse signal; and if the amplified electric signal is judged to be saturated, adjusting the laser power of the laser transmitter and the amplification factor of the amplifier to enable the amplified electric signal to be unsaturated, and acquiring the distance of the obstacle according to the time information of the laser initial signal and the time information of the pulse signal under the condition of ensuring that the amplified electric signal is unsaturated. The embodiment of the invention ensures the consistent precision of long-distance and short-distance laser ranging, avoids the problem of inaccurate distance of an obstacle obtained when an amplified signal is saturated in the prior art, and improves the stability of ranging. Meanwhile, the laser power can be adjusted according to the distance of the barrier, and the damage to human eyes is avoided.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a schematic flow chart of a laser ranging method according to an embodiment of the present invention;
FIG. 2 is a schematic flow chart illustrating the process of determining whether the amplified electrical signal is saturated according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of signal waveform sampling according to one embodiment of the present invention;
FIG. 4 is a graph of distance to an obstacle versus pulse width of a pulse signal in accordance with one embodiment of the present invention;
FIG. 5 is a schematic diagram of a high RC process according to an embodiment of the present invention;
FIG. 6 is a schematic diagram of a constant fraction timing method according to an embodiment of the present invention;
FIG. 7 is a schematic structural diagram of a laser ranging device according to an embodiment of the present invention;
fig. 8 is a schematic structural diagram of a laser ranging system according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Fig. 1 is a schematic flow chart of a laser ranging method according to an embodiment of the present invention. As shown in fig. 1, the method of this embodiment includes:
s1: sending a first laser starting signal to the barrier by using preset laser power;
it should be noted that, in the embodiment of the present invention, the laser transmitter is used to transmit the first laser start signal to the obstacle with the preset laser power.
S2: receiving echo light returned by the obstacle, and converting the echo light into an electric signal;
it should be noted that the light spot converter according to the embodiment of the present invention receives the echo light returned from the obstacle, and converts the echo light into an electrical signal.
S3: amplifying the electric signal by a preset amplification factor;
it should be noted that the amplifier according to the embodiment of the present invention amplifies the electrical signal with a predetermined amplification factor.
S4: processing the amplified electric signal to obtain a pulse signal;
in addition, in the embodiment of the present invention, the amplified electrical signal is processed by a high-pass resistance-capacitance method or a constant ratio timing method to obtain a pulse signal.
S5: acquiring time information of the first laser starting signal and time information of the pulse signal, and judging whether the amplified electric signal is saturated or not according to the time information of the first laser starting signal and the time information of the pulse signal;
s6: if the amplified electric signal is judged to be saturated, adjusting the preset laser power and the preset amplification factor so as to enable the amplified electric signal to be unsaturated;
it should be noted that, when the amplified electrical signal is saturated, the distance of the obstacle obtained by using the high-pass resistance-capacitance method or the constant ratio timing method is inaccurate, so that when the amplified electrical signal is judged to be saturated, the amplified electrical signal is unsaturated by adjusting the preset laser power and amplification factor.
S7: and sending a second laser starting signal to the obstacle according to the adjusted first laser power, repeating the steps S2, S3 and S4, and acquiring the distance of the obstacle according to the time information of the second laser starting signal and the time information of the pulse signal corresponding to the second laser starting signal.
The laser ranging method provided by the embodiment of the invention ensures consistent precision of long-distance and short-distance laser ranging, avoids the problem of inaccurate distance of an obstacle obtained when an amplified signal is saturated in the prior art, and improves the stability of ranging. Meanwhile, the laser power can be adjusted according to the distance of the barrier, and the damage to human eyes is avoided.
Further, the method further comprises:
and if the amplified electric signal is not saturated, acquiring the distance of the obstacle according to the time information of the first laser starting signal and the time information of the pulse signal.
Specifically, the step S5 of determining whether the amplified electrical signal is saturated according to the time information of the first laser start signal and the time information of the pulse signal includes (as shown in fig. 2):
s51: acquiring the estimated distance of the obstacle and the pulse width of the pulse signal according to the time information of the first laser starting signal and the time information of the pulse signal;
as shown in fig. 3, S200 is a laser start signal, where t0 is the leading edge time of the laser start signal, S201 is a pulse signal generated after the echo amplified signal passes through the time discriminator circuit, where t1 is the leading edge time of the pulse, and t2 is the trailing edge time of the pulse; from the above information, the approximate flight time of the laser is t 10-t 1-t0, and the estimated distance of the obstacle is s 1/2 ct-1/2 c (t1-t 0); the pulse width fw of the pulse signal is t2-t 1.
S52: acquiring the reflectivity of the obstacle according to the estimated distance of the obstacle and the pulse width of the pulse signal;
specifically, the embodiment of the invention obtains the reflectivity of the obstacle according to the corresponding relation between the distance of the obstacle with known reflectivity and the pulse width of the pulse signal and a laser radar ranging equation.
As shown in fig. 4, the distance of the obstacle with a reflectivity of 10% corresponds to the pulse width of the pulse signal;
obtaining a current obstacleAfter the pulse width fw of the pulse signal of the object, the closest calibration pulse width value f is searchedwbAnd corresponding distance Sb；
The laser radar ranging equation is as follows:
wherein P isrFor received laser power, PtFor the emitted laser power, ρ is the reflectivity of the obstacle, ArThe area of a lens for receiving laser, S is the distance of an obstacle, and η is an atmospheric attenuation coefficient;
as can be seen from the above formula, the reflectivity ρ is inversely proportional to the square of the distance S for the same transmission power and reception power:
the reflectivity of the current obstacle can be obtained through the formula as follows:
for example, the leading edge time t0 of the laser start signal is 0, the pulse signal time information t 1ns is 40ns, and t2 ns is 81ns, so that the estimated distance S and pulse width fw of the obstacle can be obtained.
S＝1/2c(t1-t0)＝6m，
fw＝t2-t1＝41ns
As can be seen from fig. 4, on the nominal 10% reflecting surface, when the pulse width of the returned pulse signal is 41ns, the distance is 10 meters, and therefore, the reflectivity of the current obstacle can be obtained:
s53: acquiring the power of the echo light according to the reflectivity of the obstacle;
it should be noted that the power of the echo light can be obtained according to the lidar ranging equation:
s54: calculating and acquiring the amplitude of the amplified electric signal according to the power of the echo light;
the amplitude V of the amplified electrical signalrComprises the following steps:
s55: judging whether the amplified electric signal is saturated or not according to the amplitude of the amplified electric signal;
it should be noted that the amplitude of the amplified electrical signal does not increase after exceeding a certain value, the pulse width widens, and the signal is in a saturated state.
The unsaturated signal ranging adopts more time discrimination circuits, and the two most commonly used methods are a high-pass resistance-capacitance method and a constant ratio timing method.
Fig. 5 shows the time discrimination principle of the high-pass rc method, and it can be seen from the figure that the amplification signals S401 and S402 are not saturated, and the laser energy or amplification factor is changed at the same distance, and when the amplitude of the unsaturated amplification signal changes, the time corresponding to the peak point is unchanged, so that after passing through the high-pass rc circuit, the trailing edge zeros of the obtained bipolar signals S404 and S405 coincide, and after passing through the zero comparison circuit, the trailing edge times of the obtained pulses S407 and S408 are basically unchanged, so that accurate distance measurement can be realized, and the obstacle distance can be obtained:
S＝C*(t2-t0-tg)/2
wherein C is the speed of light, tgThe time offset is fixed, and the time offset is composed of fixed time delay of an operational amplifier, zero offset of front and rear edges of a bipolar signal and the like.
Fig. 6 is a schematic diagram of time discrimination in a constant ratio timing method, and it can be seen from the diagram that the amplified signal S501 is an original unsaturated signal, S502 is a signal in which S501 takes a ratio of 50%, and S503 is a signal in which S501 has a fixed delay time, where the delay time is less than the leading edge time of S501, and since the value of the intersection of S502 and S503 on the time axis is relatively fixed and has no relation with the amplitude of the signal, the leading edge time value of the obtained pulse signal S504 is substantially fixed after S502 and S503 pass through a comparison circuit, and an accurate obstacle distance can be obtained:
S＝C*(t1-t0-tg)/2
wherein C is the speed of light, tgThe time offset is fixed, and is composed of fixed delay of the operational amplifier, delay time of S503 and the like.
Fig. 7 is a schematic structural diagram of a laser ranging device according to an embodiment of the present invention. As shown in fig. 7, the laser ranging apparatus according to the embodiment of the present invention includes a time information acquiring unit 71, a determining unit 72, an adjusting unit 73, and a first distance acquiring unit 74, specifically:
a time information obtaining unit 71, configured to obtain time information of the first laser start signal and time information of the pulse signal, where the first laser start signal is sent to an obstacle by a laser transmitter with a preset laser power;
a determining unit 72, configured to determine whether the amplified electrical signal is saturated according to the time information of the first laser start signal and the time information of the pulse signal;
an adjusting unit 73, configured to adjust the preset laser power and a preset amplification factor when it is determined that the amplified electrical signal is saturated, so that the amplified electrical signal is not saturated;
a first distance obtaining unit 74, configured to obtain the distance to the obstacle according to time information of a second laser start signal and time information of a pulse signal corresponding to the second laser start signal, where the second laser start signal is emitted by the laser emitter with the adjusted laser power.
The laser ranging device provided by the embodiment of the invention ensures consistent precision of long-distance and short-distance laser ranging, avoids the problem of inaccurate distance of an obstacle obtained when an amplified signal is saturated in the prior art, and improves the stability of ranging. Meanwhile, the laser power can be adjusted according to the distance of the barrier, and the damage to human eyes is avoided.
In an optional implementation manner of the embodiment of the present invention, the apparatus further includes:
and the second distance acquisition unit is used for acquiring the distance of the obstacle according to the time information of the first laser starting signal and the time information of the pulse signal when the amplified electric signal is judged to be unsaturated.
Specifically, the judgment unit 72 includes:
the estimated distance pulse width acquisition module is used for acquiring the estimated distance of the obstacle and the pulse width of the pulse signal according to the time information of the first laser starting signal and the time information of the pulse signal;
the reflectivity obtaining module is used for obtaining the reflectivity of the obstacle according to the estimated distance of the obstacle and the pulse width of the pulse signal;
the echo light power acquisition module is used for acquiring the power of the echo light according to the reflectivity of the obstacle;
the amplitude calculation module is used for calculating and acquiring the amplitude of the amplified electric signal according to the power of the echo light;
and the judging module is used for judging whether the amplified electric signal is saturated or not according to the amplitude of the amplified electric signal.
The reflectivity acquisition module is further configured to:
and acquiring the reflectivity of the obstacle according to the corresponding relation between the distance of the obstacle with known reflectivity and the pulse width of the pulse signal and a laser radar ranging equation.
The apparatus of the embodiment of the present invention may be used to implement the above method embodiments, and the principle and technical effect are similar, which are not described herein again.
Fig. 8 is a schematic structural diagram of a laser ranging system according to an embodiment of the present invention. As shown in fig. 8, the laser ranging system according to the embodiment of the present invention includes:
a laser transmitter 81, a photoelectric converter 82, an amplifier 83, a time discrimination circuit 84, and the laser ranging device 85;
the laser transmitter 81 is used for sending a laser starting signal to the barrier 86;
the photoelectric converter 82 is used for receiving the echo light returned by the obstacle 86 and converting the echo light into an electric signal;
the amplifier 83 is used for amplifying the electric signal;
the time discriminating circuit 84 is configured to process the amplified electrical signal to obtain a pulse signal;
the laser ranging device 85 is configured to obtain time information of the laser start signal and time information of the pulse signal, and determine whether the amplified electrical signal is saturated according to the time information of the laser start signal and the time information of the pulse signal; if the amplified electrical signal is judged to be saturated, the laser power of the laser transmitter 81 and the amplification factor of the amplifier 83 are adjusted to make the amplified electrical signal unsaturated, and under the condition that the amplified electrical signal is ensured to be unsaturated, the distance of the obstacle 86 is obtained according to the time information of the laser starting signal and the time information of the pulse signal.
The laser ranging method, the laser ranging device and the laser ranging system provided by the embodiment of the invention are used for acquiring the time information of a laser initial signal and the time information of a pulse signal and judging whether an amplified electric signal is saturated or not according to the time information of the laser initial signal and the time information of the pulse signal; and if the amplified electric signal is judged to be saturated, adjusting the laser power of the laser transmitter and the amplification factor of the amplifier to enable the amplified electric signal to be unsaturated, and acquiring the distance of the obstacle according to the time information of the laser initial signal and the time information of the pulse signal under the condition of ensuring that the amplified electric signal is unsaturated. The embodiment of the invention ensures the consistent precision of long-distance and short-distance laser ranging, avoids the problem of inaccurate distance of an obstacle obtained when an amplified signal is saturated in the prior art, and improves the stability of ranging. Meanwhile, the laser power can be adjusted according to the distance of the barrier, and the damage to human eyes is avoided.
As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
It is to be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
In the description of the present invention, numerous specific details are set forth. It is understood, however, that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description. Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. However, the disclosed method should not be interpreted as reflecting an intention that: that the invention as claimed requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.
The above examples are only for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (9)
1. A laser ranging method, comprising:
s1: sending a first laser starting signal to the barrier by using preset laser power;
s2: receiving echo light returned by the obstacle, and converting the echo light into an electric signal;
s3: amplifying the electric signal by a preset amplification factor;
s4: processing the amplified electric signal to obtain a pulse signal;
s5: acquiring time information of the first laser starting signal and time information of the pulse signal, and judging whether the amplified electric signal is saturated or not according to the time information of the first laser starting signal and the time information of the pulse signal;
s6: if the amplified electric signal is judged to be saturated, adjusting the preset laser power and the preset amplification factor so as to enable the amplified electric signal to be unsaturated;
s7: sending a second laser starting signal to the obstacle according to the adjusted first laser power, repeating the steps S2, S3 and S4, and acquiring the distance of the obstacle according to the time information of the second laser starting signal and the time information of the pulse signal corresponding to the second laser starting signal;
the determining whether the amplified electrical signal is saturated according to the time information of the first laser start signal and the time information of the pulse signal includes:
acquiring the estimated distance of the obstacle and the pulse width of the pulse signal according to the time information of the first laser starting signal and the time information of the pulse signal;
acquiring the reflectivity of the obstacle according to the estimated distance of the obstacle and the pulse width of the pulse signal;
acquiring the power of the echo light according to the reflectivity of the obstacle;
calculating and acquiring the amplitude of the amplified electric signal according to the power of the echo light;
judging whether the amplified electric signal is saturated or not according to the amplitude of the amplified electric signal;
the amplitude of the amplified electrical signal is:
wherein, PrFor the received laser power, η0For receiving the attenuation coefficient, A1 is a predetermined multiple, PtFor the emitted laser power, ρ is the reflectivity of the obstacle, ArFor the lens area receiving the laser, S is the distance of the obstacle, and η is the atmospheric attenuation coefficient.
2. The method of claim 1, further comprising:
and if the amplified electric signal is not saturated, acquiring the distance of the obstacle according to the time information of the first laser starting signal and the time information of the pulse signal.
3. The method according to claim 1, wherein step S4 includes:
and processing the amplified electric signal by adopting a high-pass resistance-capacitance method or a constant ratio timing method to obtain a pulse signal.
4. The method of claim 1, wherein said obtaining the reflectivity of the obstacle based on the estimated distance of the obstacle and the pulse width of the pulse signal comprises:
and acquiring the reflectivity of the obstacle according to the corresponding relation between the distance of the obstacle with known reflectivity and the pulse width of the pulse signal and a laser radar ranging equation.
5. A laser ranging device, comprising:
the device comprises a time information acquisition unit, a pulse signal acquisition unit and a control unit, wherein the time information acquisition unit is used for acquiring time information of a first laser starting signal and time information of a pulse signal, and the first laser starting signal is sent to an obstacle by a laser transmitter with preset laser power;
the judging unit is used for judging whether the amplified electric signal is saturated or not according to the time information of the first laser starting signal and the time information of the pulse signal;
the adjusting unit is used for adjusting the preset laser power and the preset amplification factor when judging that the amplified electric signal is saturated, so that the amplified electric signal is unsaturated;
a first distance obtaining unit, configured to obtain a distance to the obstacle according to time information of a second laser start signal and time information of a pulse signal corresponding to the second laser start signal, where the second laser start signal is emitted by the laser emitter with the adjusted laser power;
the determining whether the amplified electrical signal is saturated according to the time information of the first laser start signal and the time information of the pulse signal includes:
acquiring the estimated distance of the obstacle and the pulse width of the pulse signal according to the time information of the first laser starting signal and the time information of the pulse signal;
acquiring the reflectivity of the obstacle according to the estimated distance of the obstacle and the pulse width of the pulse signal;
acquiring the power of the echo light according to the reflectivity of the obstacle;
calculating and acquiring the amplitude of the amplified electric signal according to the power of the echo light;
judging whether the amplified electric signal is saturated or not according to the amplitude of the amplified electric signal;
the amplitude of the amplified electrical signal is:
wherein, PrFor the received laser power, η0For receiving the attenuation coefficient, A1 is a predetermined multiple, PtFor the emitted laser power, ρ is the reflectivity of the obstacle, ArFor the lens area receiving the laser, S is the distance of the obstacle, and η is the atmospheric attenuation coefficient.
6. The apparatus of claim 5, further comprising:
and the second distance acquisition unit is used for acquiring the distance of the obstacle according to the time information of the first laser starting signal and the time information of the pulse signal when the amplified electric signal is judged to be unsaturated.
7. The apparatus according to claim 5, wherein the judging unit includes:
the estimated distance pulse width acquisition module is used for acquiring the estimated distance of the obstacle and the pulse width of the pulse signal according to the time information of the first laser starting signal and the time information of the pulse signal;
the reflectivity obtaining module is used for obtaining the reflectivity of the obstacle according to the estimated distance of the obstacle and the pulse width of the pulse signal;
the echo light power acquisition module is used for acquiring the power of the echo light according to the reflectivity of the obstacle;
the amplitude calculation module is used for calculating and acquiring the amplitude of the amplified electric signal according to the power of the echo light;
and the judging module is used for judging whether the amplified electric signal is saturated or not according to the amplitude of the amplified electric signal.
8. The apparatus of claim 7, wherein the reflectivity acquisition module is further configured to:
and acquiring the reflectivity of the obstacle according to the corresponding relation between the distance of the obstacle with known reflectivity and the pulse width of the pulse signal and a laser radar ranging equation.
9. A laser ranging system, comprising: a laser transmitter, an opto-electrical converter, an amplifier, a time discrimination circuit and a laser ranging device as claimed in any one of claims 5 to 8;
the laser transmitter is used for transmitting a laser starting signal to the barrier;
the photoelectric converter is used for receiving the echo light returned by the obstacle and converting the echo light into an electric signal;
the amplifier is used for amplifying the electric signal;
the time discrimination circuit is used for processing the amplified electric signal to obtain a pulse signal;
the laser ranging device is used for acquiring the time information of the laser initial signal and the time information of the pulse signal and judging whether the amplified electric signal is saturated or not according to the time information of the laser initial signal and the time information of the pulse signal; if the amplified electric signal is judged to be saturated, adjusting the laser power of the laser transmitter and the amplification factor of the amplifier to enable the amplified electric signal to be unsaturated, and acquiring the distance of the obstacle according to the time information of the laser starting signal and the time information of the pulse signal under the condition that the amplified electric signal is ensured to be unsaturated; the determining whether the amplified electrical signal is saturated according to the time information of the first laser start signal and the time information of the pulse signal includes: acquiring the estimated distance of the obstacle and the pulse width of the pulse signal according to the time information of the first laser starting signal and the time information of the pulse signal; acquiring the reflectivity of the obstacle according to the estimated distance of the obstacle and the pulse width of the pulse signal; acquiring the power of the echo light according to the reflectivity of the obstacle; calculating and acquiring the amplitude of the amplified electric signal according to the power of the echo light; judging whether the amplified electric signal is saturated or not according to the amplitude of the amplified electric signal;
the amplitude of the amplified electrical signal is:
wherein, PrFor the received laser power, η0For receiving the attenuation coefficient, A1 is a predetermined multiple, PtFor the emitted laser power, ρ is the reflectivity of the obstacle, ArFor the lens area receiving the laser, S is the distance of the obstacle, and η is the atmospheric attenuation coefficient.
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| CN110646806B (en) * | 2018-06-26 | 2021-11-30 | 深圳市速腾聚创科技有限公司 | Laser radar and laser radar control method |
| CN111208527B (en) * | 2018-11-16 | 2022-03-08 | 北京万集科技股份有限公司 | Laser radar ranging method and device, laser radar and storage medium |
| CN111198360B (en) * | 2018-11-19 | 2022-09-13 | 深圳市速腾聚创科技有限公司 | Laser radar and control method thereof |
| CN111338332B (en) * | 2018-11-30 | 2022-03-18 | 宝时得科技（中国）有限公司 | Automatic walking equipment and obstacle avoidance method and device thereof |
| CN109613517B (en) * | 2018-12-12 | 2021-01-15 | 北醒（北京）光子科技有限公司 | TOF Lidar multi-machine anti-interference working method |
| CN109799492B (en) * | 2019-02-27 | 2020-12-15 | 珠海格力电器股份有限公司 | Method and device for adjusting output power of microwave radar equipment |
| WO2020206602A1 (en) * | 2019-04-09 | 2020-10-15 | 华为技术有限公司 | Distance measurement method, apparatus and device |
| CN110361711A (en) * | 2019-08-08 | 2019-10-22 | 深圳大舜激光技术有限公司 | Method, system and the laser radar of Zigzag type measurement extinction coefficient |
| CN111427023B (en) * | 2020-05-18 | 2022-06-07 | 武汉天眸光电科技有限公司 | Laser radar anti-interference method, laser radar system and storage medium |
| CN112731412B (en) * | 2020-12-28 | 2023-09-15 | 南京苏美达智能技术有限公司 | Ultrasonic obstacle avoidance method and automatic walking equipment |
| CN112986962B (en) * | 2021-02-21 | 2023-10-10 | 中山大学 | Transmitting power adjusting circuit and method applied to laser transmitting module |
| CN117075128B (en) * | 2023-09-11 | 2024-04-09 | 深圳市速腾聚创科技有限公司 | Ranging method, ranging apparatus, electronic device, and computer-readable storage medium |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1795913A2 (en) * | 2005-12-08 | 2007-06-13 | Omron Corporation | Laser scanning device |
| CN203422470U (en) * | 2013-09-02 | 2014-02-05 | 奇瑞汽车股份有限公司 | Receiving circuit of laser distance measuring system |
| CN104142504A (en) * | 2014-03-26 | 2014-11-12 | 常州大地测绘科技有限公司 | Pulse-based laser distance measuring instrument and distance measuring method thereof |
| CN106019300A (en) * | 2016-08-05 | 2016-10-12 | 上海思岚科技有限公司 | Laser ranging device and laser ranging method thereof |
-
2016
- 2016-12-08 CN CN201611123213.9A patent/CN108196264B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1795913A2 (en) * | 2005-12-08 | 2007-06-13 | Omron Corporation | Laser scanning device |
| CN203422470U (en) * | 2013-09-02 | 2014-02-05 | 奇瑞汽车股份有限公司 | Receiving circuit of laser distance measuring system |
| CN104142504A (en) * | 2014-03-26 | 2014-11-12 | 常州大地测绘科技有限公司 | Pulse-based laser distance measuring instrument and distance measuring method thereof |
| CN106019300A (en) * | 2016-08-05 | 2016-10-12 | 上海思岚科技有限公司 | Laser ranging device and laser ranging method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 脉冲激光雷达回波处理方法与系统研究;陈向成;《中国博士学位论文全文数据库信息科技辑》;20150915;第22页第1段至第36页第5段 * |
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