CN110850427A - Amplifying circuit for laser radar, laser radar and control method - Google Patents
Amplifying circuit for laser radar, laser radar and control method Download PDFInfo
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- CN110850427A CN110850427A CN201911175198.6A CN201911175198A CN110850427A CN 110850427 A CN110850427 A CN 110850427A CN 201911175198 A CN201911175198 A CN 201911175198A CN 110850427 A CN110850427 A CN 110850427A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
- G01S17/06—Systems determining position data of a target
- G01S17/08—Systems determining position data of a target for measuring distance only
- G01S17/10—Systems determining position data of a target for measuring distance only using transmission of interrupted, pulse-modulated waves
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/483—Details of pulse systems
- G01S7/484—Transmitters
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/483—Details of pulse systems
- G01S7/486—Receivers
- G01S7/4861—Circuits for detection, sampling, integration or read-out
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/483—Details of pulse systems
- G01S7/486—Receivers
- G01S7/489—Gain of receiver varied automatically during pulse-recurrence period
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03G—CONTROL OF AMPLIFICATION
- H03G3/00—Gain control in amplifiers or frequency changers
- H03G3/20—Automatic control
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- Computer Networks & Wireless Communication (AREA)
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- Radar, Positioning & Navigation (AREA)
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- Electromagnetism (AREA)
- Optical Radar Systems And Details Thereof (AREA)
Abstract
The present disclosure provides an amplifying circuit applicable to a laser radar, and a control method applicable to a laser radar. The amplifying circuit for laser radar comprises: a variable gain amplifier configured to receive an input signal and output an amplified signal; a gain adjustment unit coupled with the variable gain amplifier and configured to adjust a gain of the variable gain amplifier according to the amplified signal. The invention can solve the timing error caused by different signal amplitudes in the amplifying circuit of the laser radar.
Description
Technical Field
The disclosure relates to the field of laser, and particularly provides an amplifying circuit applicable to a laser radar, the laser radar and a control method applicable to the laser radar.
Background
In the laser ranging technology, the same laser pulse is emitted, objects with different reflectivities at different positions are measured, the amplitude of the received pulse has difference of tens of times, and if a timing method of a fixed threshold value is adopted, the wandering of the trigger moment is large.
As shown in fig. 1, timing errors due to a fixed threshold are shown. Three echo pulses with same pulse width and different amplitudes (the pulse width of the echo signal represents the strength of the signal, the leading edge of the pulse width is mainly used for obtaining the time of the echo signal, the strength of the signal is related to the distance reflectivity of a target object and the intensity of the transmitted pulse, etc.), and the three echo pulses are at the same level V0Is triggered, its corresponding trigger time t1、t2And t3Is different, this introduces timing errors. The actual return time of the echo signal is processed according to the time of the threshold value. If the threshold time of each echo is different, the subsequent processing is particularly troublesome; if all are the same, then no correction is subsequently required for each echo to get the actual return time.
In addition, in circuit design, the over-threshold triggering function is usually realized by a comparator. The propagation delay of the comparator is affected by the amplitude of the input signal and the slope of the edge, and generally, the larger the amplitude of the input signal, the larger the slope of the edge, and the smaller the propagation delay of the comparator, which also introduces timing error.
At present, a constant fraction Compensation (CFD) method is generally adopted to solve the problem of timing errors caused by different signal amplitudes. CFD firing patterns, i.e., firing at a fixed proportion of the waveform, so that waveforms of different amplitudes have close firing moments.
A common CFD implementation is as follows: the input signal is divided into two paths, one path of signal is reduced according to a certain proportion f, and the amplitude of one path of signal is unchanged after passing through a delay td. The specific delay time is selected, so that the pulse delayed by td and the pulse attenuated by f times are intersected at the top of the pulse, the intersection point is a constant ratio timing point, and the constant ratio coefficient is f.
The CFD scheme described above has some disadvantages. First, the delay td is related to the signal rising edge, and the rising edge varies greatly with different signal amplitudes, which can cause large errors if td is fixed. In addition, as described in the first section, the propagation delay of the comparator is limited by the input signal amplitude and slope, and CFD cannot account for the timing error introduced by the comparator.
Disclosure of Invention
The disclosure provides an amplifying circuit for a laser radar, the laser radar and a control method for the laser radar, so as to solve timing errors caused by different signal amplitudes in the amplifying circuit for the laser radar.
In one aspect, the present invention provides an amplifying circuit for a laser radar, including:
a variable gain amplifier configured to receive an input signal and output an amplified signal;
a gain adjustment unit coupled with the variable gain amplifier and configured to adjust a gain of the variable gain amplifier according to the amplified signal.
According to another aspect of the present invention, the amplifying circuit further includes a plurality of comparators having different comparison thresholds, input terminals coupled to the output terminals of the variable gain amplifier to receive the amplified signals, respectively, output terminals of the plurality of comparators coupled to the gain adjusting unit to adjust the gain of the variable gain amplifier according to outputs of the plurality of comparators.
According to another aspect of the invention, the input signal comprises a plurality of sets of echo pulse signals, each set of echo pulse signals comprising a plurality of echo pulses, the gain adjustment unit is configured to: after the first echo pulse in each group of echo pulse signals is input into the variable gain amplifier, the gain of the variable gain amplifier is adjusted according to the amplified amplitude of the first echo pulse.
According to another aspect of the invention, the amplification circuit comprises three comparators with comparison thresholds of VFS/2, VFS/4 and VFS/8, respectively, where VFS is the maximum amplitude output range of the variable gain amplifier.
According to another aspect of the invention, the gain adjustment unit is further configured to: after the last echo pulse of each set of echo pulse signals is input, the gain of the variable gain amplifier is reset to its initial value.
According to another aspect of the invention, the gain adjustment unit is configured to: adjusting the gain of the variable gain amplifier to make the amplitudes of the echo pulses other than the first echo pulse in each group of echo pulses after being amplified by the variable gain amplifier approximate,
wherein the initial value is a minimum value of a gain adjustable range of the variable gain amplifier
The present invention also provides a laser radar comprising:
a signal receiving unit configured to receive a radar echo and convert the radar echo into an electric signal; and
an amplification circuit coupled with the signal receiving unit and receiving the electrical signal, the amplification circuit including:
a variable gain amplifier configured to receive an electrical signal and output an amplified signal;
a gain adjustment unit coupled with the variable gain amplifier and configured to adjust a gain of the variable gain amplifier according to the amplified signal.
According to another aspect of the present invention, the amplifying circuit further includes a plurality of comparators having different comparison thresholds, input terminals coupled to the output terminals of the variable gain amplifier to receive the amplified signals, respectively, output terminals of the plurality of comparators coupled to the gain adjusting unit to adjust the gain of the variable gain amplifier according to outputs of the plurality of comparators.
According to another aspect of the present invention, the lidar further includes a transmitting unit configured to generate and transmit a plurality of sets of multi-pulse laser signals to an outside of the lidar, the transmitting unit is coupled to the gain adjusting unit of the amplifying circuit and generates a reset signal before generating each set of multi-pulse laser signals, and the gain adjusting unit resets the gain of the variable gain amplifier to its initial value according to the reset signal.
According to another aspect of the invention, the electrical signal comprises a plurality of sets of echo pulse signals, each set of echo pulse signals comprising a plurality of echo pulses, corresponding to the plurality of sets of multi-pulse laser signals, the gain adjustment unit is configured to: after the first pulse in each group of echo pulse signals is input into the variable gain amplifier, the gain of the variable gain amplifier is adjusted according to the amplified amplitude of the first echo pulse.
According to another aspect of the present invention, the amplifying circuit includes three comparators having comparison thresholds of VFS/2, VFS/4 and VFS/8, respectively, where VFS is a maximum amplitude output range of the variable gain amplifier, and the gain adjusting unit adjusts the gain of the variable gain amplifier according to outputs of the three comparators, the comparators having a delay.
According to another aspect of the present invention, the multi-pulse laser signal is a double-pulse laser signal, and the laser radar further includes a calculation unit configured to calculate the target distance by using a transmission time of a second transmission pulse in the double-pulse laser signal as a start time, using a time at which one of the plurality of comparators having a smallest comparison threshold generates an output as an end time, and using a time difference between the start time and the end time as a flight time.
According to another aspect of the invention, the gain adjustment unit is configured to: adjusting the gain of the variable gain amplifier to make the amplitudes of the echo pulses other than the first echo pulse in each group of echo pulses after being amplified by the variable gain amplifier approximate,
wherein the initial value is a minimum value of a gain adjustable range of the variable gain amplifier
The invention also provides a control method for the laser radar, which comprises the following steps:
receiving a first radar echo pulse, amplifying the first radar echo pulse through a variable gain amplifier, and generating an amplified signal;
adjusting a gain of the variable gain amplifier based on the amplified signal; and
and receiving a second radar echo pulse, and amplifying the second radar echo pulse through the variable gain amplifier.
According to another aspect of the present invention, the control method further includes:
resetting the gain of the variable gain amplifier to its initial value, preferably the minimum value of the gain adjustable range of the variable gain amplifier, before receiving the first radar echo pulse.
According to another aspect of the present invention, the control method further includes: generating and transmitting a double-pulse laser signal to the outside of the laser radar, wherein the double-pulse laser signal comprises a first transmission pulse and a second transmission pulse, and the first radar echo pulse and the second radar echo pulse respectively correspond to the first transmission pulse and the second transmission pulse;
wherein the step of resetting the gain of the variable gain amplifier to its initial value comprises: before the double-pulse laser signal is generated, a reset signal is generated, and the gain of the variable gain amplifier is reset to an initial value.
According to another aspect of the present invention, the control method further includes:
and calculating the target distance by taking the transmitting time of the second transmitting pulse as the starting time, taking the time when one comparator with the minimum comparison threshold value in the plurality of comparators generates output as the ending time, and taking the time difference between the starting time and the ending time as the flight time.
In the invention, the gain adjusting unit can adjust the gain of the variable gain amplifier in real time, so that the amplitude of each group of echo pulses input by the variable gain amplifier after being amplified by the variable gain amplifier is approximate, and the timing error caused by different signal amplitudes in an amplifying circuit of the laser radar can be solved.
Drawings
The accompanying drawings, which are included to provide a further understanding of the disclosure, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure and are not to limit the disclosure. In the drawings:
FIG. 1 is a schematic diagram of timing errors caused by a fixed threshold in a laser ranging technique in the prior art;
FIG. 2 is a schematic diagram of an amplifier circuit that may be used in a lidar in accordance with an embodiment of the present invention;
FIG. 3 is a schematic flow chart of a control method for lidar according to the present disclosure;
FIG. 4 is a schematic diagram of an implementation circuit of a multi-pulse automatic gain control laser ranging system according to an application scenario of the present invention;
FIG. 5 is a waveform diagram of the dual pulse AGC laser ranging system of FIG. 4.
Detailed Description
In the following, only certain exemplary embodiments are briefly described. As those skilled in the art can appreciate, the described embodiments can be modified in various different ways, without departing from the spirit or scope of the present disclosure. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.
In the description of the present disclosure, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "straight", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and therefore should not be considered as limiting the present disclosure. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present disclosure, "a plurality" means two or more unless specifically limited otherwise.
The preferred embodiments of the present disclosure will be described below with reference to the accompanying drawings, and it should be understood that the preferred embodiments described herein are merely for purposes of illustrating and explaining the present disclosure and are not intended to limit the present disclosure.
Throughout the description of the present disclosure, it is to be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection, either mechanically, electrically, or otherwise in communication with one another; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present disclosure can be understood by those of ordinary skill in the art as appropriate.
In the present disclosure, unless expressly stated or limited otherwise, the first feature is "on" or "under" the second feature, and may comprise the first and second features being in direct contact, or the first and second features being not in direct contact but being in contact with each other by means of another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly above and obliquely above the second feature, or simply meaning that the first feature is at a lesser level than the second feature.
Fig. 2 shows a lidar 10 according to an embodiment of the present invention, which includes a signal receiving unit 1, a transmitting unit 2, and an amplifying circuit 4 (shown as a dashed box in fig. 2). The transmitting unit 2 includes, for example, one or more lasers, and can emit a probe beam to the outside of the laser radar. The probe beam is diffusely reflected at the external obstacle of the lidar and part of the reflected beam is received by the signal receiving unit 1 (which may be referred to as radar echo). The signal receiving unit 1 comprises one or more photodetectors, such as photodiodes or avalanche photodiodes APD or SiPM, which can convert the received radar echo into an electrical signal and output it, for example a voltage signal or a current signal. The amplifying circuit 4 is coupled to the signal receiving unit 1 and receives the electrical signal. Generally, the electrical signal generated by the signal receiving unit 1 is weak, and therefore needs to be amplified for subsequent data acquisition, analog-to-digital conversion, and other operations. The structure and operation of the amplifying circuit 4 will first be described in detail below.
As shown in fig. 2, the amplifying circuit 4 includes a variable gain amplifier 41 and a gain adjusting unit 42, wherein the variable gain amplifier 41 is coupled to the signal receiving unit 1 of the laser radar 10, so that an input signal, i.e., an electrical signal output by the signal receiving unit 1, can be received from the signal receiving unit 1, and the amplified signal is amplified and output. The gain adjustment unit 42 is coupled to the variable gain amplifier 41 and configured to adjust the gain of the variable gain amplifier 42 according to the amplified signal. As will be readily understood by those skilled in the art, the "amplified signal" in the present invention refers to a signal output through the variable gain amplifier 41. Since the gain of the variable gain amplifier 41 is adjustable, it does not mean that the amplitude of the output signal must be greater than the input signal. The gain of the variable gain amplifier 41 is dynamically adjustable, and the range of adjustment may include 1, for example. When the gain is 1, the input and output of the variable gain amplifier 41 may be equal. This is also within the scope of the invention.
According to a preferred embodiment of the present invention, lidar 10 may further comprise a fixed-gain amplifier (not shown), which may be integrated in the signal receiving unit 1 or coupled between the signal receiving unit 1 and the variable-gain amplifier 41, for performing a first-order amplification of the electrical signal generated by the photodetector. After the first-stage amplification, the electric signal is supplied to a variable gain amplifier 41 for second-stage amplification.
In the above embodiment, the gain adjustment unit 42 can adjust the gain of the variable gain amplifier 41 in real time, which can bring about a significant advantage. For example, in the laser radar 10, one emission of one laser of the transmission unit 2 is not only one probe light pulse but two or more probe light pulses may be generally emitted. Correspondingly, one radar echo received by the signal receiving unit also comprises a plurality of echo pulses, and the number of the echo pulses corresponds to the number of pulses at the transmitting end. For example, three echo pulses may be referred to as a first echo pulse, a second echo pulse, and a third echo pulse. With the amplifying circuit 4 shown in fig. 2, the variable gain amplifier 41 first receives the first echo pulse, processes the first echo pulse and outputs an amplified first echo pulse (in this case, the gain of the variable gain amplifier 41 may be 1, or may be greater than 1), and the gain adjusting unit 42 may dynamically adjust the gain of the variable gain amplifier 41 according to the output amplified first echo pulse, so that the subsequent second echo pulse and third echo pulse can be appropriately amplified, for example, the amplitudes of the second echo pulse and third echo pulse after being amplified by the variable gain amplifier are ensured to be close.
The following describes in detail how the gain adjustment unit 42 adjusts the gain of the variable gain amplifier 41 according to the amplified signal, according to a preferred embodiment of the present invention.
As shown in fig. 2, the amplifying circuit 4 further includes a plurality of comparators 43, the comparators 43 respectively have different comparison thresholds, and the inputs of the comparators 43 are respectively coupled to the output of the variable gain amplifier 41 to receive the amplified signal, such as the amplified first echo pulse. The outputs of the plurality of comparators 43 are coupled to the gain adjustment unit 42. Each comparator 43 has a different comparison threshold, e.g. a plurality of comparison thresholds from small to large. Each comparator compares the amplified first echo pulse to its own comparison threshold, e.g., when the amplified first echo pulse is above the comparison threshold, the comparator may output symbol 1; when less than the comparison threshold, the comparator may output symbol 0. The plurality of comparators may thus output a sequence comprising a plurality of symbols from which it is possible to determine approximately in what range the amplified first echo pulse is located. Taking the three comparators 43 shown in fig. 2 as an example, the comparison thresholds of the comparator 1, the comparator 2, and the comparator 3 are, for example, VFS/2, VFS/4, and VFS/8, respectively, where VFS is the maximum amplitude output range of the variable gain amplifier 41. When the symbol sequence output by the three comparators is 111, the amplitude of the amplified first echo pulse is higher than VFS/2; when the output symbol sequence is 011, indicating that the amplitude of the amplified first echo pulse is between VFS/4 and VFS/2; when the output symbol sequence is 001, indicating that the amplitude of the amplified first echo pulse is between VFS/8 and VFS/4; when the output symbol sequence is 000, it indicates that the amplitude of the amplified first echo pulse is lower than VFS/8.
Those skilled in the art will readily appreciate that the number of comparators 43 and the comparison threshold may be set as desired. For example, when the gain of the variable gain amplifier needs to be adjusted more accurately, a larger number of comparators 43 may be provided so that the thresholds between adjacent comparators 43 may be closer, so that the gain of the variable gain amplifier may be adjusted more finely. These are all within the scope of the present invention.
As described above, the output sequence of the plurality of comparators 43 may characterize the amplitude range of the amplified signal. The gain adjustment unit 42 thereby adjusts the gain of the variable gain amplifier 41 in accordance with the outputs of the plurality of comparators 43. For example, when the amplified first echo pulse is between VFS/8 and VFS/4, the gain of the gain amplifier 41 may be set to 4; when the amplified first echo pulse is between VFS/4 and VFS/2, the gain of the gain amplifier 41 may be set to 2; when the amplified first echo pulse is between VFS and VFS/2, the gain of the gain amplifier 41 may be set to 1. The gain adjustment unit 42 performs the gain adjustment of the gain amplifier 41 before the second echo pulse arrives, so that the input of different signal amplitudes, such as the input second and third echo pulses, always falls within the range between VFS and VFS/2, i.e. the amplitude of the echo pulses other than the first echo pulse in each group of echo pulses amplified by the variable gain amplifier 41 is close, so that the timing error is negligible. According to an embodiment of the present invention, the other echo pulses may be considered to be close when the difference between the amplitudes of the echo pulses amplified by the variable gain amplifier 41 is within 20%. Those skilled in the art will readily understand that the above range can be determined according to the system accuracy, and when the system accuracy is required to be high, the difference can be limited to 10% or 15%, i.e. the difference is less than or equal to 10% or 15%, and the two can be considered to be close; when the system accuracy requirement is not so high, the requirement for this difference can be suitably amplified, e.g. 25% or 30% or 40%, both can be considered close.
Those skilled in the art will readily understand that the gain values 1, 2, and 4 of the variable gain amplifier 41 are not absolute values of their amplification factors, but relative amplification factors. For example, the gain values 1, 2, 4 may be multiples of the initial gain value of the variable gain amplifier. For example, when the amplitude of the variable gain amplifier after amplifying the first echo pulse by the initial gain value is between VFS/4 and VFS/2, the gain adjusting unit 42 may adjust the gain of the variable gain amplifier 41 to be twice the initial gain value thereof.
Further in accordance with a preferred embodiment of the present invention, wherein the gain adjustment unit 42 is further configured to: after the last echo pulse of each group of echo pulse signals is input, the gain of the variable gain amplifier 42 is reset to its initial value, for example, the minimum value of the gain adjustable range of the variable gain amplifier. In addition, the transmitting unit may generate a reset signal before each set of probe pulses is transmitted, and the gain adjusting unit 42 may reset the gain of the variable gain amplifier 41 to 1 according to the reset signal.
In the above embodiment, when performing laser ranging, the transmitting unit transmits multiple pulses, and at the receiving end, the gain is changed by using the information of the previous echo pulse, so that the subsequent echo pulse is amplified to an ideal value, thereby eliminating the timing error caused by the difference in pulse amplitude. In addition, the invention has simple structure and good real-time performance. Timing errors caused by different pulse amplitudes in laser ranging application can be effectively inhibited, and propagation delay changes of the comparator caused by different pulse amplitudes are inhibited, so that a more accurate ranging result is obtained.
In the above embodiment, the gain adjusting unit 42 may adjust the gain of the variable gain amplifier 41 in real time, so that the amplitude of each echo pulse input by the variable gain amplifier 41 after the first echo pulse is amplified by the variable gain amplifier 41 is close to the amplitude, for example, the first echo pulse in each echo pulse is amplified with an initial gain, and the signal of the subsequent echo pulse is adjusted in real time according to the requirement, so as to solve the timing error caused by the difference in signal amplitude in the amplifying circuit 4 of the laser radar.
According to a preferred embodiment of the invention, the lidar 10 further comprises a calculation unit (not shown) for calculating the distance to an obstacle based on the time interval between the probe pulse and the echo pulse. For example, when the transmitting unit 2 transmits a double-pulse laser signal, the calculating unit may calculate the target distance by using the transmitting time of the second transmitting pulse in the double-pulse laser signal as a starting time, using the time when one of the comparators 43 having the smallest comparison threshold detects the second echo pulse (i.e., generates an output corresponding to the second echo pulse) as an ending time, and using the time difference between the starting time and the ending time as a flight time, so that the laser ranging may be implemented.
The invention can effectively inhibit the problem of timing error caused by different pulse amplitudes in laser ranging application, and simultaneously inhibit the propagation delay change of the comparator caused by different pulse amplitudes, thereby obtaining more accurate ranging result.
Fig. 3 shows a control method for a lidar according to the present invention, such as may be applied to lidar 10 as described above. The control method comprises the following steps:
in step S60A, before the first radar echo pulse is received, the gain of the variable gain amplifier is reset to its initial value, which is preferably the minimum value of the gain adjustable range of the variable gain amplifier. Wherein the step of resetting the gain of the variable gain amplifier to its initial value comprises: before the multi-pulse laser signal is generated, a reset signal is generated, and the gain of the variable gain amplifier is reset to an initial value.
In step S60B, a double-pulse laser signal is generated and transmitted to the outside of the laser radar, wherein the double-pulse laser signal includes a first transmission pulse and a second transmission pulse. The received radar echo also includes a first radar echo pulse and a second radar echo pulse corresponding to the double-pulse laser signal. Those skilled in the art will readily appreciate that multiple pulses of laser light may also be generated in step S60B, and such is within the scope of the present invention.
In step S61, a first radar echo pulse is received, amplified by a variable gain amplifier, and an amplified signal is generated.
When the multi-pulse laser signal is transmitted in step S60B, the receiving end of the laser radar will receive a sequence of a set of laser radar echo pulses corresponding to the multi-pulse laser signal. In step S61, the first pulse in the sequence, i.e., the first radar echo pulse, is amplified by a variable gain amplifier.
In step S62, the gain of the variable gain amplifier is adjusted according to the amplified signal. The specific adjustment manner, as described above with reference to fig. 2, is not described herein again.
In step S63, a second radar echo pulse is received and amplified by the variable gain amplifier. At this point, the gain of the variable gain amplifier has been adjusted so that proper amplification of the second radar echo is ensured. In step S63, the second pulse in the sequence, i.e., the second radar echo pulse, is amplified according to the adjusted gain.
In step S64, the transmission time of the second transmission pulse is used as a start time, the output time of the comparator with the smallest comparison threshold among the plurality of comparators is used as an end time (i.e., the time when the comparator with the smallest comparison threshold detects the second radar echo), and the time difference between the start time and the end time is used as a flight time to calculate the target distance.
In the above embodiment, when performing laser ranging, multiple pulses are transmitted, and the gain of the receiving end is changed by using the information of the front pulse, so that the rear pulse is amplified to an ideal value, thereby eliminating the timing error caused by the difference in pulse amplitude. In addition, the invention has simple structure and good real-time performance. Timing errors caused by different pulse amplitudes in laser ranging application can be effectively inhibited, and propagation delay changes of the comparator caused by different pulse amplitudes are inhibited, so that a more accurate ranging result is obtained.
The following describes an application scenario of the present invention, applied to a laser ranging scenario based on multi-pulse automatic gain adjustment. Fig. 4 is a schematic diagram of an implementation circuit of a multi-pulse automatic gain adjustment laser ranging system according to an application scenario of the present invention. The signal receiving and amplifying system can be a fixed gain stage amplifier, and the amplification factor of a Variable Gain Amplifier (VGA) can be adjusted. The automatic gain control unit is equivalent to the gain adjustment unit described above.
The laser emits multi-pulse laser signals, and a receiving end receives a plurality of echo pulses, and the echo pulses are converted into voltage signals which can be processed by a circuit through a signal receiving and amplifying system and are sent to a Variable Gain Amplifier (VGA). The initial gain of the VGA is set to 1 (i.e. its initial gain value), and the first echo pulse is input to the input of the comparator array via the VGA. Here, 3 comparators are taken as an example. VFS is the full-amplitude output range of the VGA, and 3 compared thresholds are respectively set as VFS/2, VFS/4 and VFS/8. If the output of the VGA is less than VFS/8, the signal is not detected, and the outputs of the three comparators are zero. If the output of comparator 3 is greater than VFS/8 and less than VFS/4, the output of comparator 3 is 1, delayed by td1, and the outputs of comparators 1 and 2 are sampled as the clock signal for the D flip-flop. The effect of the delay td1 is to ensure that comparators 1 and 2 have output the correct result. The output of the comparator 3 and the outputs of the D flip- flops 1 and 2 are fed into an automatic gain control unit (equivalent to the gain adjustment unit described above).
The automatic gain control unit realizes the VGA gain adjustment, which is specifically adjusted as follows.
If the input Q <1:0> is 00, the output of the signal VGA is between VFS/8 and VFS/4, and the gain of the VGA can be set to be 4;
if the input Q <1:0> is 10, the output of the signal VGA is between VFS/4 and VFS/2, and the gain of the VGA can be set to be 2;
if the input Q <1:0> is 11, indicating that the output of the signal VGA is between VFS and VFS/2, the gain of the VGA may be set to 1.
The automatic gain control unit performs the gain adjustment of the VGA before the next pulse arrives, so that the subsequent inputs of different signal amplitudes, for example the second echo pulse and the third echo pulse, always fall within the amplitude range amplified by the VGA between VFS and VFS/2. In addition, the transmitting terminal can generate a reset signal before pulse transmission to reset the gain of the VGA to 1.
The working steps of the multi-pulse automatic gain adjustment laser ranging system are preferably as follows:
step 2: the first echo pulse is amplified and a comparator generates a set of outputs B <1: n >. If the amplitude of the echo pulse is larger than the initial threshold value of the comparator, 1 is output; if less than the initial threshold of the comparator, 0 is output. The outputs of all comparators may form a sequence, and the gain of the variable gain amplifier B <1: n > may be logically transformed, and this may be done before the second pulse arrives.
And step 3: the subsequent echo pulse or pulses are amplified to a set amplitude range and the difference between the different amplitude pulses is attenuated.
And 4, step 4: the second pulse is compared to a fixed threshold and a timing signal is generated at the time of the over-threshold for calculating the distance to the obstacle by the distance-of-flight method.
In the above embodiment, the time measuring system is used to accurately measure the flight time of the laser pulse from the emission to the reception, and the emission time of the second pulse is used as the START signal, and the time when the comparator 3 detects the second pulse is used as the STOP signal. The amplitude of the second pulse of different input signals is between VFS and VFS/2 after the second pulse is amplified by the VGA, and the time error generated by the comparator 3 is reduced, so that the precision of flight time measurement is improved.
The method for reducing the timing error caused by the input amplitude change has the following implementation mode: the laser source emits two (or more) pulses in succession, separated by a short time td, to ensure that the distance traveled by the object to be measured is negligible during the time td. The first echo received is used to detect the amplitude of the input signal, and then the gain of the amplifier at the receiving end is adjusted accordingly, so that the second echo and the subsequent other echoes can be amplified to a desired value. Thus, received pulses of different amplitudes may be amplified by different factors so that the resulting pulse amplitudes are close.
In addition, a plurality of comparators may be provided according to actual requirements, each comparator having an initial threshold, and the initial thresholds may be degrees of subdivision depending on the magnitude of the amplitude. For example, if the maximum output amplitude of the variable gain amplifier is 3v, if the threshold interval is desired to be small, 10 comparators may be provided, and 3/10 is 0.3, and the initial threshold of each comparator may be set to 0.3, 0.6, 0.9, … 2.7.7, 3.0, and so on, and the threshold range may be accurate to within 0.3 v. The maximum output amplitude of the variable gain amplifier is 3v, which can be distinguished according to the chip used.
The output sequence of the plurality of comparators 43 may characterize the amplitude range of the amplified signal. As shown in fig. 5, the amplitudes of the echo pulses of different objects are different, output result 1 corresponds to a pulse with a larger echo amplitude, and the sequence corresponding to output result 1 is 1111111; output result 2 corresponds to a pulse with a small echo amplitude, and the sequence corresponding to output result 2 is 0000111. Therefore, the size of the pulse with larger echo amplitude is judged to be about 3v, and the echo can be amplified slightly; the amplitude of the pulse with smaller echo amplitude is between 0.9 and 1.2, the pulse can be amplified greatly at this time, all the amplitudes of the echoes are adjusted to be similar, the obtained threshold-crossing time is not influenced by the signal amplitude and the delay of the comparator any more, and then the next processing of the signal can be carried out.
In addition, as shown in fig. 5, the output of the comparator is delay-sampled, as shown by "delay" in fig. 5. This is because there may be a certain delay between the input and the output of each comparator, and the delay time of each comparator may be different, so it is necessary to wait for each comparator to complete signal inversion before performing signal acquisition, so as to ensure the accuracy of data acquisition.
The embodiment of the invention has the following beneficial effects:
1. the invention can carry out laser ranging. When multiple pulses are transmitted, the gain of the receiving end is changed by using the information of the front pulse, so that the rear pulse is amplified to an ideal value, and the timing error caused by different pulse amplitudes is eliminated.
2. The invention has simple structure and good real-time performance. Timing errors caused by different pulse amplitudes in laser ranging application can be effectively inhibited, and propagation delay changes of the comparator caused by different pulse amplitudes are inhibited, so that a more accurate ranging result is obtained.
The above description is only exemplary of the present disclosure and should not be taken as limiting the disclosure, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present disclosure should be included in the scope of protection of the present disclosure.
Finally, it should be noted that: although the present disclosure has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the disclosure. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present disclosure should be included in the protection scope of the present disclosure.
Claims (17)
1. An amplification circuit usable with a lidar comprising:
a variable gain amplifier configured to receive an input signal and output an amplified signal;
a gain adjustment unit coupled with the variable gain amplifier and configured to adjust a gain of the variable gain amplifier according to the amplified signal.
2. The amplification circuit of claim 1, further comprising a plurality of comparators having different comparison thresholds, inputs coupled to outputs of the variable gain amplifier to receive the amplified signal, respectively, outputs of the plurality of comparators coupled to the gain adjustment unit to adjust the gain of the variable gain amplifier in accordance with outputs of the plurality of comparators.
3. The amplification circuit of claim 1 or 2, wherein the input signal comprises a plurality of sets of echo pulse signals, each set of echo pulse signals comprising a plurality of echo pulses, the gain adjustment unit being configured to: after the first echo pulse in each group of echo pulse signals is input into the variable gain amplifier, the gain of the variable gain amplifier is adjusted according to the amplified amplitude of the first echo pulse.
4. The amplification circuit of claim 2, wherein the amplification circuit comprises three comparators with comparison thresholds of VFS/2, VFS/4, and VFS/8, respectively, wherein VFS is a maximum amplitude output range of the variable gain amplifier.
5. The amplification circuit of claim 3, wherein the gain adjustment unit is further configured to: after the last echo pulse of each set of echo pulse signals is input, the gain of the variable gain amplifier is reset to its initial value.
6. The amplification circuit of claim 5, wherein the gain adjustment unit is configured to: adjusting the gain of the variable gain amplifier to make the amplitudes of the echo pulses other than the first echo pulse in each group of echo pulses after being amplified by the variable gain amplifier approximate,
wherein the initial value is a minimum value of a gain adjustable range of the variable gain amplifier.
7. A lidar comprising:
a signal receiving unit configured to receive a radar echo and convert the radar echo into an electric signal; and
an amplification circuit coupled with the signal receiving unit and receiving the electrical signal, the amplification circuit including:
a variable gain amplifier configured to receive an electrical signal and output an amplified signal;
a gain adjustment unit coupled with the variable gain amplifier and configured to adjust a gain of the variable gain amplifier according to the amplified signal.
8. The lidar of claim 7, wherein the amplification circuit further comprises a plurality of comparators each having a different comparison threshold, inputs respectively coupled to the outputs of the variable gain amplifiers to receive the amplified signals, outputs of the plurality of comparators coupled to the gain adjustment unit, the gain adjustment unit thereby adjusting the gain of the variable gain amplifiers in accordance with the outputs of the plurality of comparators.
9. The lidar according to claim 7 or 8, further comprising a transmitting unit configured to generate and transmit a plurality of sets of multi-pulse laser signals to an outside of the lidar, the transmitting unit being coupled to the gain adjusting unit of the amplifying circuit and generating a reset signal before generating each set of multi-pulse laser signals, the gain adjusting unit resetting the gain of the variable gain amplifier to its initial value according to the reset signal.
10. The lidar of claim 9, wherein the electrical signal comprises a plurality of sets of echo pulse signals corresponding to the plurality of sets of multi-pulse laser signals, each set of echo pulse signals comprising a plurality of echo pulses, the gain adjustment unit is configured to: after the first pulse in each group of echo pulse signals is input into the variable gain amplifier, the gain of the variable gain amplifier is adjusted according to the amplified amplitude of the first echo pulse.
11. The lidar of claim 8, wherein the amplification circuit comprises three comparators with comparison thresholds VFS/2, VFS/4, and VFS/8, respectively, wherein VFS is a maximum amplitude output range of the variable gain amplifier, the gain adjustment unit adjusting the gain of the variable gain amplifier based on the outputs of the three comparators, the comparators having a delay.
12. The lidar of claim 10, wherein the multi-pulse laser signal is a double-pulse laser signal, the lidar further comprising a calculation unit configured to calculate a target distance by taking a transmission time of a second transmission pulse in the double-pulse laser signal as a start time, taking a time at which one of the plurality of comparators having a smallest comparison threshold generates an output as an end time, and taking a time difference between the start time and the end time as a flight time.
13. The lidar of claim 10, wherein the gain adjustment unit is configured to: adjusting the gain of the variable gain amplifier to make the amplitudes of the echo pulses other than the first echo pulse in each group of echo pulses after being amplified by the variable gain amplifier approximate,
wherein the initial value is a minimum value of a gain adjustable range of the variable gain amplifier.
14. A control method usable with a lidar comprising:
receiving a first radar echo pulse, amplifying the first radar echo pulse through a variable gain amplifier, and generating an amplified signal;
adjusting a gain of the variable gain amplifier based on the amplified signal; and
and receiving a second radar echo pulse, and amplifying the second radar echo pulse through the variable gain amplifier.
15. The control method according to claim 14, further comprising:
resetting the gain of the variable gain amplifier to its initial value, preferably the minimum value of the gain adjustable range of the variable gain amplifier, before receiving the first radar echo pulse.
16. The control method according to claim 15, further comprising: generating and transmitting a double-pulse laser signal to the outside of the laser radar, wherein the double-pulse laser signal comprises a first transmission pulse and a second transmission pulse, and the first radar echo pulse and the second radar echo pulse respectively correspond to the first transmission pulse and the second transmission pulse;
wherein the step of resetting the gain of the variable gain amplifier to its initial value comprises: before the double-pulse laser signal is generated, a reset signal is generated, and the gain of the variable gain amplifier is reset to an initial value.
17. The control method according to claim 16, further comprising:
and calculating the target distance by taking the transmitting time of the second transmitting pulse as the starting time, taking the time when one comparator with the minimum comparison threshold value in the plurality of comparators generates output as the ending time, and taking the time difference between the starting time and the ending time as the flight time.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US11709235B2 (en) | 2020-08-10 | 2023-07-25 | Analog Devices, Inc. | Data reduction techniques in a LIDAR system |
Citations (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0501743A2 (en) * | 1991-02-25 | 1992-09-02 | Salubre Investments Limited | A circuit for processing pulses |
| US20020136251A1 (en) * | 2001-01-25 | 2002-09-26 | Science And Technology Corporation | Automatic gain control system for use with multiple wavelength signal detector |
| CN102386869A (en) * | 2010-08-27 | 2012-03-21 | 杭州中科微电子有限公司 | Analog/digital configurable variable-gain amplifier |
| CN102624407A (en) * | 2012-03-30 | 2012-08-01 | 江苏物联网研究发展中心 | Radio-frequency emission front-end circuit with automatic gain control |
| US8755037B2 (en) * | 2009-06-26 | 2014-06-17 | Trimble Ab | Distance measuring device |
| CN106656086A (en) * | 2016-12-20 | 2017-05-10 | 北京中电华大电子设计有限责任公司 | Automatic gain amplifier circuit |
| CN107131918A (en) * | 2017-07-02 | 2017-09-05 | 中国计量大学 | A kind of low-consumption ultrasonic flow measurement meter echo signal processing method and circuit |
| CN107332529A (en) * | 2017-06-09 | 2017-11-07 | 烽火通信科技股份有限公司 | A kind of automatic gain control circuit for fully differential trans-impedance amplifier |
| CN108089201A (en) * | 2017-12-08 | 2018-05-29 | 上海禾赛光电科技有限公司 | Obstacle information acquisition methods, the launching technique of laser pulse and device |
| US20180172786A1 (en) * | 2016-12-14 | 2018-06-21 | Sebastian PATULEA | Variable gain amplification for linearization of nmr signals |
| CN108896979A (en) * | 2018-07-13 | 2018-11-27 | 中山大学 | A kind of the pulse lidar reception circuit and system of ultra-wide injection measurement range |
| CN108919282A (en) * | 2018-05-17 | 2018-11-30 | 北京航空航天大学 | A kind of laser radar signal moment identification system |
| CN109407075A (en) * | 2018-09-04 | 2019-03-01 | 天津大学 | Automatic gain control circuit based on echo priori features |
| CN109900981A (en) * | 2019-01-30 | 2019-06-18 | 上海磐启微电子有限公司 | A kind of low-power consumption RSSI detection circuit based on automatic growth control |
| CN109946674A (en) * | 2019-03-25 | 2019-06-28 | 淮阴工学院 | Full wave shape laser radar apparatus |
| CN209387867U (en) * | 2018-11-13 | 2019-09-13 | 北京万集科技股份有限公司 | A kind of laser radar reception device |
| CN110308456A (en) * | 2019-07-23 | 2019-10-08 | 华镭申隆(武汉)电子科技有限公司 | It is a kind of for improving the bias adjustment device and laser radar system of detection range |
| CN110376569A (en) * | 2019-07-25 | 2019-10-25 | 桂林理工大学 | The high-order of pulse lidar amplifies-it is fitted moment discrimination circuit |
| CN110492349A (en) * | 2019-08-20 | 2019-11-22 | 上海禾赛光电科技有限公司 | Driving circuit, driving method and Optical Maser System |
-
2019
- 2019-11-26 CN CN201911175198.6A patent/CN110850427B/en active Active
Patent Citations (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0501743A2 (en) * | 1991-02-25 | 1992-09-02 | Salubre Investments Limited | A circuit for processing pulses |
| US20020136251A1 (en) * | 2001-01-25 | 2002-09-26 | Science And Technology Corporation | Automatic gain control system for use with multiple wavelength signal detector |
| US8755037B2 (en) * | 2009-06-26 | 2014-06-17 | Trimble Ab | Distance measuring device |
| CN102386869A (en) * | 2010-08-27 | 2012-03-21 | 杭州中科微电子有限公司 | Analog/digital configurable variable-gain amplifier |
| CN102624407A (en) * | 2012-03-30 | 2012-08-01 | 江苏物联网研究发展中心 | Radio-frequency emission front-end circuit with automatic gain control |
| US20180172786A1 (en) * | 2016-12-14 | 2018-06-21 | Sebastian PATULEA | Variable gain amplification for linearization of nmr signals |
| CN106656086A (en) * | 2016-12-20 | 2017-05-10 | 北京中电华大电子设计有限责任公司 | Automatic gain amplifier circuit |
| CN107332529A (en) * | 2017-06-09 | 2017-11-07 | 烽火通信科技股份有限公司 | A kind of automatic gain control circuit for fully differential trans-impedance amplifier |
| CN107131918A (en) * | 2017-07-02 | 2017-09-05 | 中国计量大学 | A kind of low-consumption ultrasonic flow measurement meter echo signal processing method and circuit |
| CN108089201A (en) * | 2017-12-08 | 2018-05-29 | 上海禾赛光电科技有限公司 | Obstacle information acquisition methods, the launching technique of laser pulse and device |
| CN108919282A (en) * | 2018-05-17 | 2018-11-30 | 北京航空航天大学 | A kind of laser radar signal moment identification system |
| CN108896979A (en) * | 2018-07-13 | 2018-11-27 | 中山大学 | A kind of the pulse lidar reception circuit and system of ultra-wide injection measurement range |
| CN109407075A (en) * | 2018-09-04 | 2019-03-01 | 天津大学 | Automatic gain control circuit based on echo priori features |
| CN209387867U (en) * | 2018-11-13 | 2019-09-13 | 北京万集科技股份有限公司 | A kind of laser radar reception device |
| CN109900981A (en) * | 2019-01-30 | 2019-06-18 | 上海磐启微电子有限公司 | A kind of low-power consumption RSSI detection circuit based on automatic growth control |
| CN109946674A (en) * | 2019-03-25 | 2019-06-28 | 淮阴工学院 | Full wave shape laser radar apparatus |
| CN110308456A (en) * | 2019-07-23 | 2019-10-08 | 华镭申隆(武汉)电子科技有限公司 | It is a kind of for improving the bias adjustment device and laser radar system of detection range |
| CN110376569A (en) * | 2019-07-25 | 2019-10-25 | 桂林理工大学 | The high-order of pulse lidar amplifies-it is fitted moment discrimination circuit |
| CN110492349A (en) * | 2019-08-20 | 2019-11-22 | 上海禾赛光电科技有限公司 | Driving circuit, driving method and Optical Maser System |
Non-Patent Citations (4)
| Title |
|---|
| 刘斌等: "通过数字增益控制提高激光脉冲测距精度", 《探测与控制学报》, no. 02, 26 April 2013 (2013-04-26), pages 135 - 530 * |
| 王旭: "用于AFE的低噪声高精度前置放大电路关键技术研究", 《中国优秀博硕士学位论文全文数据库(硕士)信息科技辑》, 15 February 2019 (2019-02-15) * |
| 王瑜: "导航接收机中可变增益放大器的研究与设计", 《中国优秀舒适学位论文全文数据库 信息科技辑》 * |
| 王瑜: "导航接收机中可变增益放大器的研究与设计", 《中国优秀舒适学位论文全文数据库 信息科技辑》, 15 March 2017 (2017-03-15) * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11709235B2 (en) | 2020-08-10 | 2023-07-25 | Analog Devices, Inc. | Data reduction techniques in a LIDAR system |
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