WO2021169714A1

WO2021169714A1 - Laser radar and anti-interference method applied thereto

Info

Publication number: WO2021169714A1
Application number: PCT/CN2021/073948
Authority: WO
Inventors: 陶俊; 向少卿
Original assignee: 上海禾赛科技有限公司
Priority date: 2020-02-28
Filing date: 2021-01-27
Publication date: 2021-09-02
Also published as: CN113406652A

Abstract

A laser radar and an anti-interference method applied thereto. The laser radar comprises: a transmitting unit (1), configured to transmit a first laser pulse sequence, wherein the first laser pulse sequence is generated on the basis of preset pulse width information; a receiving unit (2), configured to receive a second laser pulse sequence; and a processing unit (3), configured to determine an echo of the first laser pulse sequence from the second laser pulse sequence on the basis of the pulse width information, wherein the echo of the first laser pulse sequence is formed by an obstacle (4) reflecting the first laser pulse sequence. Therefore, laser radars having a high anti-interference capability can be provided.

Description

Lidar and anti-jamming method applied to Lidar

Cross-references to related applications

This application claims the priority of the Chinese patent application filed on February 28, 2020 with the application number 202010133545.5 and the invention title "Lidar and anti-jamming method applied to Lidar". The full text of the application is incorporated by reference in In this application.

Technical field

The present disclosure relates to the field of laser detection technology, and in particular to laser radar and an anti-jamming method applied to laser radar.

Background technique

This section provides background information related to the present disclosure, which does not necessarily constitute prior art.

In autonomous driving technology, the environmental perception system is a basic and vital part, and it is the guarantee of the safety and intelligence of autonomous vehicles. The lidar in the environmental perception sensor has the advantages of reliability, detection range, ranging accuracy, etc. Incomparable advantages. The lidar transmits and receives the laser beam, analyzes the turn-back time after the laser encounters the target object, and calculates the distance between the target object and the lidar.

Lidar has been widely used in the field of autonomous driving, but due to the overlap of the field of view between multiple radars, mutual interference between radars is inevitable.

For the lidar of direct time-of-flight measurement technology, the technique of modulating the pulse position in the pulse sequence can be used to encode the laser pulse sequence emitted each time, so that the laser pulse sequence for each measurement is unique.

Summary of the invention

The present disclosure provides a laser radar with high anti-interference ability and an anti-interference method applied to the laser radar.

In a first aspect, an embodiment of the present application provides a laser radar, including: a transmitting unit configured to transmit a first laser pulse sequence, wherein the first laser pulse sequence is generated based on preset pulse width information; a receiving unit, configured To receive the second laser pulse sequence;

The processing unit is configured to determine the echo of the first laser pulse sequence from the second laser pulse sequence based on the pulse width information, wherein the echo of the first laser pulse sequence is that an obstacle reflects the first laser Formed by a sequence of pulses.

In some embodiments, the first laser pulse sequence includes at least two single pulses, and the pulse width information includes pulse width information of each single pulse and interval information between the single pulses; and the processing unit is further configured to: Based on the pulse width information of each single pulse and the interval information between the single pulses, the echo of the first laser pulse sequence is determined from the second laser pulse sequence.

In some embodiments, the emission unit includes a control unit and a laser, and the control unit is configured to control the laser to emit light based on the pulse width information.

In some embodiments, the control unit includes a controller and a switching device, wherein the controller is configured to drive the switching device based on the pulse width information to control the opening and closing of the switching device, and the switching control of the switching device is The light-emitting state of the above-mentioned laser.

In some embodiments, the pulse width information includes a preset binary code sequence; and the controller is configured to drive the switching device with a voltage matching the preset binary code sequence according to a clock beat, and the preset binary code Each code in the sequence corresponds to a single clock tick.

In some embodiments, the above-mentioned processing unit is further configured to: according to a preset light intensity threshold, determine a binary value corresponding to the light signal received at each clock tick, and generate the corresponding second laser pulse sequence according to the determined binary value. The received binary code sequence.

In some embodiments, the processing unit is further configured to: intercept a predetermined length of the sequence to be detected from the received binary code sequence; determine whether the sequence to be detected matches the preset binary code sequence; if it matches, determine the sequence to be detected. The laser pulse sequence corresponding to the detection sequence is the echo of the above-mentioned first laser pulse sequence.

In some embodiments, the length of the sequence to be detected is the same as the length of the preset binary code sequence; and the processing unit is further configured to: align the sequence to be detected and the preset binary code sequence, and perform bitwise AND calculation ; If the bitwise AND calculation result is the same as the preset binary code sequence, it is determined that the sequence to be detected matches the preset binary code sequence.

In a second aspect, an embodiment of the present application provides an anti-jamming method applied to lidar, including: transmitting a first laser pulse sequence, wherein the first laser pulse sequence is generated based on preset pulse width information; and receiving a second laser pulse sequence. Laser pulse sequence; based on the pulse width information, the echo of the first laser pulse sequence is determined from the second laser pulse sequence, wherein the echo of the first laser pulse sequence is that an obstacle reflects the first laser pulse The sequence is formed.

In some embodiments, the first laser pulse sequence includes at least two single pulses, the pulse width information includes the pulse width information of each single pulse and the interval information between the single pulses; and the foregoing pulse width information is based on the pulse width information. In the second laser pulse sequence, determining the echo of the first laser pulse sequence includes: determining from the second laser pulse sequence based on the pulse width information of the individual single pulses and the interval information between the single pulses The echo of the first laser pulse sequence described above.

In some embodiments, the pulse width information includes a preset binary code sequence; and the foregoing determination of the echo of the first laser pulse sequence from the second laser pulse sequence based on the pulse width information includes: The light intensity threshold determines the binary value corresponding to the light signal received at each clock tick, and generates the received binary code sequence corresponding to the second laser pulse sequence with the determined binary value.

In some embodiments, the foregoing determining the echo of the first laser pulse sequence from the second laser pulse sequence based on the foregoing pulse width information further includes: intercepting the predetermined length of the to-be-detected sequence from the received binary code sequence Sequence; determine whether the sequence to be detected matches the preset binary code sequence; if it matches, it is determined that the laser pulse sequence corresponding to the sequence to be detected is the echo of the first laser pulse sequence.

In some embodiments, the length of the sequence to be detected is the same as the length of the preset binary coding sequence; and the determining whether the sequence to be detected matches the preset binary coding sequence includes: aligning the sequence to be detected with the preset binary coding sequence. Set a binary code sequence, and perform bitwise AND calculation; if the bitwise AND calculation result is the same as the preset binary code sequence, it is determined that the sequence to be detected matches the preset binary code sequence.

The laser radar and the anti-jamming method applied to the laser radar of the present disclosure can encode (or modulate) the pulse width of the emitted first laser pulse sequence based on preset pulse width information. The transmitted first laser pulse sequence is not related to the external interference sequence in terms of pulse width. Therefore, the pulse width matching analysis can quickly and accurately determine the first laser pulse sequence from the received second laser pulse sequence. Echo.

Description of the drawings

The foregoing and additional features and characteristics of the present disclosure will be better understood from the following detailed description with reference to the accompanying drawings, which are merely examples and are not necessarily drawn to scale. In the drawings, the same reference numerals are used to indicate the same parts. In the drawings:

Fig. 1 is a schematic diagram of an exemplary structure of a lidar according to an embodiment of the present disclosure;

2A and FIG. 2B are schematic diagrams of recognition errors caused by encoding methods in the prior art;

3A and 3B are schematic diagrams of the anti-interference ability of the coding method of the present application;

Fig. 4 is an exemplary structure diagram of a series circuit of a switching device and a laser;

Fig. 5 is an exemplary structure diagram of another series circuit of a switching device and a laser;

Fig. 6 is a schematic diagram of an exemplary relationship among clock beats, a preset binary code sequence, and a first laser pulse sequence;

Fig. 7 is an exemplary schematic diagram of receiving a binary code sequence;

FIG. 8 is a schematic diagram of an exemplary situation where the sequence to be detected does not match the preset binary code sequence;

FIG. 9 is a schematic diagram of an exemplary situation where the sequence to be detected matches the preset binary code sequence;

Fig. 10 is a schematic flowchart of an anti-jamming method applied to lidar according to an embodiment of the present disclosure.

Detailed ways

The preferred embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The following description is merely exemplary in nature and is not intended to limit the present disclosure and its applications or uses.

In the description of the present disclosure, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "top", "bottom", etc. are based on the orientation or positional relationship shown in the drawings, and are only for It is convenient to describe the present disclosure and simplify the description, instead of indicating or implying that the referred device or element must have a specific orientation, be configured and operate in a specific orientation, and therefore cannot be understood as a limitation of the present disclosure. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of these features. Moreover, the terms "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances so that the embodiments of the present disclosure described herein can be implemented in a sequence other than those illustrated or described herein.

Please refer to FIG. 1, an embodiment of the present disclosure may provide a laser radar, and the laser radar may include a transmitting unit 1, a receiving unit 2 and a processing unit 3.

In this embodiment, the above-mentioned emitting unit may be configured to emit the first laser pulse sequence. Here, the first laser pulse sequence may be generated based on preset pulse width information.

In this embodiment, the above-mentioned receiving unit may be configured to receive the second laser pulse sequence.

In this embodiment, the processing unit may be configured to determine the echo of the first laser pulse sequence from the second laser pulse sequence based on the pulse width information. Here, the echo of the first laser pulse sequence may be formed by the obstacle 4 reflecting the first laser pulse sequence.

It should be noted that the direction of each arrow in FIG. 1 does not represent the actual transmission direction of the light, but is only an exemplary description of the signal transmission relationship between the various units.

Here, the emitting unit may emit a laser pulse sequence, that is, the emitting unit may include a laser. The type and number of lasers in the transmitting unit can be set according to actual conditions, and are not limited here. The specific structure of the above-mentioned transmitting unit can be various, which is not limited here.

Here, the preset pulse width information can be used to modulate the pulse width, that is, the pulse width of the first laser pulse sequence is modulated. As for the specific value of each pulse width after modulation, it is not limited here.

Here, the above-mentioned receiving unit may convert the received optical signal into an electrical signal, that is, the transmitting unit may include a photoelectric sensor. The type and number of photoelectric sensors can be set according to the actual situation, which is not limited here. The specific structure of the receiving unit can be various, which is not limited here.

As an example, the receiving unit may include a detection subunit; optionally, the receiving unit may also include a convergence subunit and a filtering subunit. Optionally, the order between the convergence subunit and the filtering subunit can be interchanged, that is, it can filter first and then converge, or converge first and then filter. For example, in the case of first converging and then filtering, the converging sub-unit can converge the received optical signal, the converged optical signal can pass through the filtering sub-unit, and the filtering sub-unit can filter out a part of the interference light. The optical signal filtered by the filter subunit is detected by the detection subunit, and the detection subunit can perform photoelectric conversion on the received optical signal, and transmit the converted electrical signal to the processing unit.

Here, the above-mentioned processing unit may read the electrical signal from the receiving unit. It should be noted that the processing unit processes electrical signals, but the electrical signals are used to characterize optical signals. Therefore, the processing of electrical signals by the processing unit can be understood as processing the second laser pulse sequence. The specific structure of the foregoing processing unit may be various, which is not limited here.

It can be understood that the echo of the first laser pulse sequence is consistent with the first laser pulse sequence in terms of pulse characteristics (such as single pulse width, pulse interval, etc.); the above-mentioned pulse width information may indicate the pulses of the first laser pulse sequence feature. The second laser pulse sequence may include an interference sequence, and the characteristics of the interference sequence and the first laser pulse sequence are generally inconsistent. Therefore, the echo of the first laser pulse sequence can be determined from the second laser pulse sequence based on the above-mentioned pulse width information.

It should be noted that the laser radar provided in the above embodiment can encode (or modulate) the pulse width of the first laser pulse sequence emitted based on preset pulse width information. Therefore, the laser radar emitted The first laser pulse sequence is not related to the interference sequence in terms of pulse width. Therefore, the processing unit can quickly and accurately determine the return of the first laser pulse sequence from the received second laser pulse sequence through pulse width matching analysis. Wave.

Please refer to Figures 2A and 2B, and refer to Figures 3A and 3B. Figures 2A and 2B are schematic diagrams of prior art encoding methods leading to identification errors; Figures 3A and 3B are the anti-interference effects of the encoding methods of this application Schematic diagram of capabilities. In order to more clearly illustrate the anti-jamming capability of the lidar using the method provided in this application, we will explain with reference to FIGS. 2A and 2B, and with reference to FIGS. 3A and 3B.

As an example, as shown in FIG. 2A and FIG. 2B, it shows a schematic diagram of a coding method in the prior art causing a recognition error. Figure 2A is the transmitting part, and Figure 2B is the receiving part. Among them, the first row in FIG. 2A is the clock beat, and the second row is the detection pulse sequence emitted by the transmitting unit. The pulse width of each single pulse in the detection pulse sequence (for example, the full width at half maximum of the single pulse) is the same, and they are all one clock cycle. In the detection pulse sequence, the first time interval (in terms of the leading edge) between the first pulse (fpulse1) and the second pulse (fpulse2) is, for example, 10 clock cycles, and the second pulse (fpulse2) is connected to the first pulse (fpulse2). The second time interval (in terms of leading edge) between three pulses (fpulse3) is, for example, 18 clock cycles. The first row in FIG. 2B is the clock beat, and the second row is the echo of the detection pulse sequence, which is consistent with the pulse width, the number of single pulses, and the time interval between pulses of the detection pulse sequence. The third row is the interference sequence, and the fourth row is the received pulse sequence (including the echo of the probe pulse sequence and the interference sequence) actually received by the receiving unit (the detection subunit in). If there is no interference sequence, the received pulse sequence received by the receiving unit should be consistent with the pulse width of the single pulse of the detection pulse sequence, the number of single pulses, and the time interval between pulses. The pulse width of the first pulse (finterfer1) and the second pulse (finterfer2) of the interference sequence is the same, both are 1 clock period, and the time of the first pulse (finterfer1) and the second pulse (finterfer2) of the interference sequence The interval (in terms of leading edge) is, for example, 18 clock cycles. Referring to the fourth row in Figure 2B, the echo of the detection pulse sequence in the received pulse sequence and the interference sequence are superimposed, causing the first pulse (finterfer1) of the interference sequence to be inserted between fpulse2 and fpulse3; the second pulse of the interference sequence (finterfer2) is after fpulse3. In this case, the time interval (10) between finterfer1 and fpulse2 is the same as the above-mentioned first time interval (10); the time interval (18) between finterfer1 and finterfer2 is the same as the above-mentioned second time interval (18) ; Therefore, it may cause the processor to recognize fpulse2 as fpulse1 (called false fpulse1), the finterfer1 of the interference sequence as fpulse2 (called false fpulse2), and the finterfer2 of the interference sequence as fpulse3 (called false fpulse3) . Recognition errors may further lead to errors in the distance measured by the lidar.

3A and 3B are schematic diagrams of the anti-interference ability of the coding method of the present application. Figure 3A is the transmitting part, and Figure 3B is the receiving part. Among them, the first row in FIG. 3A is the clock beat, and the second row is the first laser pulse sequence emitted by the emitting unit. The pulse width of the single pulse of the first pulse (pulse1) in the above-mentioned first laser pulse sequence (for example, the full width at half maximum of the single pulse) is one clock cycle, and the pulse width of the single pulse of the second pulse (pulse2) is 2 The pulse width of the single pulse of the third pulse (pulse3) is 4 clock cycles. The first time interval (in terms of the leading edge) of the first pulse (pulse1) and the second pulse (pulse2) is, for example, 10 clock cycles, and the second time interval of the second pulse (pulse2) and the third pulse (pulse3) ( In terms of leading edge), for example, 18 clock cycles. The first row in FIG. 3B is the clock beat, and the second row is the echo of the first laser pulse sequence, which is consistent with the pulse width, the number of single pulses, and the time interval between pulses of the detection pulse sequence. The third row is the interference sequence, and the fourth row is the second laser pulse sequence, that is, the laser pulse sequence actually received by the receiving unit (the detection subunit) (including the echo and interference sequence of the first laser pulse sequence). . The first pulse (interfer1) of the interference sequence is between pulse2 and pulse3, the second pulse (interfer2) of the interference sequence is after pulse3, and the first pulse (interfer1) and the second pulse (interfer2) of the interference sequence The pulse width is the same, both are 2 clock cycles, and the time interval (in terms of the leading edge) between the first pulse (interfer1) and the second pulse (interfer2) of the interference sequence is, for example, 18 clock cycles. Although the time interval between interfer1 and pulse2 (10) is the same as the time interval between pulse1 and pulse2 (10); and the time interval between interfer2 and interfer1 (18) is the same as the time interval between pulse2 and pulse3 ( 18) Same. However, because the pulse widths of pulse2 and pulse1 are different, and the pulse widths of interfer2 and pulse3 are different, the processor will not recognize pulse2 as pulse1, nor will it recognize interfer2 as pulse3. Therefore, the interference sequence will not interfere with the identification of the echo of the first laser pulse sequence, that is, the anti-interference ability of the laser radar is enhanced.

In contrast, the current technology of modulating the pulse position in the laser pulse sequence is used to encode the laser sequence emitted each time to achieve the unique laser pulse sequence for each measurement; the pulse position can be understood as each single pulse sequence in the pulse sequence. The relative time occupied by the pulse, the technique of modulating the pulse position is essentially the same as the random encoding of the pulse interval time. Although the above random encoding of the pulse interval time may solve the problem of interference of the laser radar echo pulse sequence in most cases. However, in some cases, this encoding method will cause a certain program misrecognition.

Using the technique of modulating the pulse position in the laser pulse sequence, it is necessary to increase the number of pulses for a single measurement in the transmission sequence to reduce the probability of interference. However, since each independent pulse has no characteristic, it requires the processor to detect From the irregular pulse sequence received by the transmitter, extract the pulse combination that matches the transmission sequence. The more pulses detected, the longer the calculation time for matching; and the excessive number of pulses in the transmission sequence , May cause a single measurement time to be too long, and the power consumption of a single measurement will increase with the increase of the number of laser pulses.

In contrast, in the laser radar provided in this embodiment, due to the different pulse widths of single pulses, each independent pulse has characteristics, and a smaller number of pulses can be used to achieve higher anti-interference ability. Please refer to Table 1. Table 1 provides the number of pulse encoding combinations under different pulse numbers and single pulse pulse width types.

Table 1

It can be seen from Table 1 that the anti-interference ability of the lidar is related to the number of pulses of the first laser pulse sequence and the pulse width type of the single pulse. For example, the number of pulses is two, and the types of pulse widths are two (that is, the pulse widths of the two single pulses are different). In this case, there are four possible forms of the first laser pulse sequence (without considering the pulse interval in the case of). For another example, the number of pulses is 6, and the types of single pulse widths are 6 (that is, the pulse widths of these 6 single pulses are different). In this case, there are 46656 possible forms of the first laser pulse sequence (without considering In the case of pulse interval). Therefore, the pulse width coding provided by this embodiment (the pulse interval can be the same or different) can provide more types of first laser pulse sequences with a smaller number of pulses, thereby enabling the laser radar to reduce light emission. In the case of the number of times, improve the anti-interference ability.

In some embodiments, the first laser pulse sequence may include at least two single pulses, and the pulse width information may include pulse width information of each single pulse and interval information between the single pulses.

In some embodiments, the processing unit may be configured to determine the return of the first laser pulse sequence from the second laser pulse sequence based on the pulse width information of each single pulse and the interval information between the single pulses. Wave.

It should be noted that the interval information between single pulses is used as the pulse feature to transmit and extract the laser pulse sequence. When extracting the echo, it can refer to more abundant pulse features. Thus, the anti-jamming capability of the lidar can be improved.

In some embodiments, the above-mentioned emitting unit may include a control part and a laser. Here, the control unit is configured to control the laser to emit light based on the pulse width information.

In some embodiments, the above-mentioned control part may include a controller and a switching device. Here, the controller may be configured to drive the switching device based on the pulse width information to control the opening and closing of the switching device. The opening and closing of the above-mentioned switching device can control the light-emitting state of the above-mentioned laser. Controlling the light-emitting state of the above-mentioned laser can be understood as controlling the light-emitting or non-lighting of the above-mentioned laser.

It should be noted that the drive circuit of the laser is realized by the controller and the switching device. In this case, the drive circuit of the laser has the ability to control the current injection time, so that the laser can be sensitively adjusted based on the above-mentioned pulse width information.

Here, the above-mentioned switching device may include, but is not limited to, at least one of the following: a triode, a field effect tube, a transistor, and the like.

As an example, please refer to FIG. 4, which shows a series circuit of a first switching device and a laser (Laser). The first switching device may be, for example, an N-type field effect tube. In Figure 4, the N-type FET T1 is connected in series with the laser, and the turn-on and turn-off of T1 is controlled by the voltage drop Vgs across the gate g and source s. When the Vgs of T1 is at a high level (V _high ), The laser emits light (on); when the Vgs of T1 is at a low level (V _low ), the laser goes out (off). Therefore, the controller can drive the gate of T1 with voltage according to the pulse width information, so that the laser can emit laser according to the pulse width information, so that the first laser pulse sequence based on the pulse width information can be sent out. In addition to the field effect tube, T1 can also be GaN, NPN transistors and other devices.

As an example, please refer to FIG. 5, which shows a series circuit of a second switching device and a laser (Laser). The second switching device may be, for example, a P-type field effect tube. In Figure 5, the P-type FET T2 is connected in series with the laser. The opening and closing of T2 is controlled by the voltage drop Vgs across the gate g and the source s. When the control terminal Vgs is negative, the P-type FET T2 conducts Pass. Among them, when the Vgs of T2 is at a low level (V _low ), the laser is turned on (on); when the Vgs of T2 is at a high level (V _high ), the laser is turned on (off). Therefore, the controller can drive the gate of T2 with voltage according to the pulse width information, so that the laser can emit laser according to the pulse width information, so that the first laser pulse sequence based on the pulse width information can be sent out. In addition to the field effect tube, T2 can also be GaN, PNP transistors and other devices.

In some embodiments, the above-mentioned pulse width information can be directly provided by the light-emitting time and/or silent time of the laser. The above-mentioned controller may drive the switching device according to the above-mentioned light-emitting time and/or the above-mentioned silent time. Here, the light-emitting time and/or silent time of the above-mentioned laser can be recorded by relative time. The time starting point of the relative time may be the starting time of the first laser pulse sequence.

It can be seen that the light-emitting time of the laser can correspond to the pulse width of a single pulse in the first laser pulse sequence, and the silent time of the laser can correspond to the interval time of the pulses. If the controller uses the light-emitting time and/or silent time for calculation, the memory that stores the light-emitting time and/or the silent time needs to store a large amount of data; and, in the case of storing the light-emitting time and/or the silent time, identify the first laser When the pulse sequence is echoed, the calculation process will be more complicated.

In some embodiments, the aforementioned pulse width information may include a preset binary code sequence.

In some embodiments, the above-mentioned controller may be configured to drive the above-mentioned switching device with a voltage matching the above-mentioned binary code sequence according to a clock cycle. Here, each code in the aforementioned preset binary code sequence corresponds to a single clock beat. The clock beat may also be referred to as a clock cycle, and the above-mentioned clock cycle is, for example, the inherent clock cycle of the lidar system.

As an example, please refer to FIG. 6, which shows the relationship between the clock beat, the preset binary code sequence, and the first laser pulse sequence. In Figure 6, the first row is the clock beat; the third row is preset with a binary code sequence, and it can be seen from Figure 6 that each bit of the preset binary code sequence corresponds to the clock period; the second row is the first laser pulse sequence, It can be seen from Fig. 6 that the pulse position (high level) of the first laser pulse matches the "1" value position in the preset binary code sequence. In other words, using the binary coding method, the preset binary code sequence (in this case, 32 bits) is driven in a sequence (high bit first or low bit first) under the clock beat, so that the preset binary code sequence can be obtained Consistent first laser emission sequence.

In some embodiments, the foregoing processing unit may be further configured to: determine the binary value corresponding to the optical signal received at each clock tick according to a preset light intensity threshold, and generate the foregoing second laser pulse sequence with the determined binary value The corresponding received binary code sequence.

It can be understood that the receiving unit can convert the optical signal into an electrical signal, and transfer the converted electrical signal to the processing unit. Electrical signals can be called light intensity data, which is used to indicate light intensity. The processing unit can sample the received electrical signal according to the clock beat.

Here, the processing unit can continuously collect light intensity data with a preset queue length according to the clock beat and after triggering the sampling, for example, the collection time is 1024 clocks and the preset queue length is 1024 bits. The processor can process the collected light intensity data to obtain the binary value corresponding to the light intensity data; as an example, if the light intensity data is greater than the preset light intensity threshold, it corresponds to 1; as an example, if the light intensity data is not greater than the preset light intensity threshold The light intensity threshold corresponds to 0. Thus, the binary value corresponding to the light intensity data can be obtained. It can be understood that the binary value corresponding to the light intensity data can be referred to as the binary value corresponding to the electrical signal, and can also be referred to as the binary value corresponding to the optical signal. Each binary value corresponding to the optical signal can be used as an element to generate the received binary code sequence corresponding to the second laser pulse sequence. It can be understood that the length of the received binary code sequence is consistent with the preset queue length.

Please refer to Figure 7, which shows the received binary code sequence. In Figure 7, the first row is the clock beat, the second row is the echo of the first laser pulse sequence, the third row is the interference sequence, the fourth row is the second laser pulse sequence, and the fifth row is the second laser pulse sequence The corresponding received binary code sequence.

In some embodiments, the processing unit may be further configured to: intercept a sequence to be detected of a predetermined length from the received binary code sequence; determine whether the sequence to be detected matches the preset binary code sequence; if it matches, determine the sequence to be detected; The laser pulse sequence corresponding to the sequence to be detected is the echo of the above-mentioned first laser pulse sequence.

Here, in the process of intercepting the sequence to be detected from the received binary code sequence, the starting position of the interception is not limited. It can be understood that in the case where the start position of the interception is determined, because the sequence to be detected is of a predetermined length, the end position of the interception is also determined.

Here, in the process of intercepting the sequence to be detected from the received binary code sequence, the relationship between the bits in the intercepted segment is not changed.

As an example, you can start to extract data of a predetermined length (for example, 32 bits) from the start bit of the received binary code sequence (for example, the first bit of the 1024-length received binary code sequence) as the number one sequence to be detected; if the number one is waiting If the detection sequence matches the preset binary code sequence, it is determined that the laser pulse sequence corresponding to the first sequence to be detected is the echo of the first laser pulse sequence. If the number one to-be-detected sequence does not match the preset binary code sequence, you can start to extract data of a predetermined length (for example, 32 bits) from the second bit of the received binary code sequence (for example, the second bit of the 1024-length received binary code) As the second sequence to be detected, and so on. Until the N number to be detected sequence matches the preset binary code sequence or the received binary code sequence is traversed to end. As an example, when the received binary code is 1024 bits and the sequence to be detected is 32 bits, the value of N is not greater than 1024 minus 32 plus 1, that is, the value of N is a natural number not greater than 993. The received binary code sequence is traversed to the end, which can be understood as the 993 sequence to be detected is truncated.

In some embodiments, determining whether the sequence to be detected matches the preset binary code sequence can be achieved in a variety of ways, which is not limited here. As an example, the sequence to be detected and the preset binary code sequence can be compared bit by bit to determine whether they match; if the preset binary code sequence is 1 for each bit, the bit corresponding to each bit in the sequence to be detected is also 1, then Determine a match; if there is a bit of 0 in the bits corresponding to each of the above-mentioned bits in the sequence to be detected, it is determined that there is no match.

In some embodiments, the length of the sequence to be detected is the same as the length of the preset binary code sequence.

In some embodiments, the processing unit may be further configured to align the sequence to be detected with the preset binary code sequence, and perform bitwise AND calculation; if the result of the bitwise AND calculation is the same as the preset binary code sequence, determine The sequence to be detected matches the preset binary code sequence. Here, the calculation idea of bitwise AND calculation is summarized as follows: the corresponding bit value is 1 and the result is 1, and if the corresponding bit is not 1, the result is 0.

Please refer to FIG. 8, which shows a situation where the above-mentioned sequence to be detected does not match the above-mentioned preset binary code sequence. In Figure 8, the part marked by the upper brackets in the first column is the sequence to be detected, the second column is the preset binary coding sequence, and the third column is the bitwise AND calculation result; it can be seen that the bitwise AND calculation result is the same as If the preset binary coding sequence is not the same, it can be determined that the sequence to be detected does not match the foregoing binary sequence.

Please refer to FIG. 9, which shows a situation where the above-mentioned sequence to be detected matches the above-mentioned preset binary code sequence. In Figure 9, the part marked by square brackets in the first column is the sequence to be detected, the second column is the preset binary coding sequence, and the third column is the bitwise AND calculation result; it can be seen that the bitwise AND calculation result is the same as If the preset binary code sequence is the same, it can be determined that the sequence to be detected matches the above-mentioned binary sequence, and then the start time of the matched sequence to be detected is used as the receiving time of the echo of the first laser pulse sequence, and according to the first laser pulse sequence The launch time obtains the distance information between the radar and the obstacle, for example, according to the time-of-flight method (TOF).

It should be noted that the provision of pulse width information based on a preset binary code sequence can be suitable for logic chips to perform operations, thereby reducing the amount of data storage and simplifying the calculation process required for identification.

Please refer to FIG. 10, which shows the flow of an anti-jamming method applied to lidar. The above process can include:

Step 101: Launch a first laser pulse sequence.

Here, the above-mentioned first laser pulse sequence is generated based on preset pulse width information.

Step 102: Receive a second laser pulse sequence.

Step 103: Determine the echo of the first laser pulse sequence from the second laser pulse sequence based on the pulse width information.

Here, the echo of the first laser pulse sequence is formed by the obstacle reflecting the first laser pulse sequence.

It should be noted that the implementation details and technical effects of the anti-jamming method applied to the lidar can be referred to related descriptions in other parts of the present disclosure, and will not be repeated here.

In some embodiments, the first laser pulse sequence includes at least two single pulses, and the pulse width information includes pulse width information of each single pulse and interval information between the single pulses.

In some embodiments, determining the echo of the first laser pulse sequence from the second laser pulse sequence based on the pulse width information includes: based on the pulse width information of each single pulse and the distance between the single pulse From the interval information of the second laser pulse sequence, the echo of the first laser pulse sequence is determined.

In some embodiments, the aforementioned pulse width information includes a preset binary code sequence.

In some embodiments, the foregoing determination of the echo of the foregoing first laser pulse sequence from the foregoing second laser pulse sequence based on the foregoing pulse width information includes: determining the echo received at each clock beat according to a preset light intensity threshold. The binary value corresponding to the optical signal, and the received binary code sequence corresponding to the second laser pulse sequence is generated with the determined binary value.

In some embodiments, determining whether the sequence to be detected matches the preset binary code sequence includes: aligning the sequence to be detected with the preset binary code sequence, and performing bitwise AND calculation; if the bitwise AND calculation result If the sequence is the same as the preset binary code sequence, it is determined that the sequence to be detected matches the preset binary code sequence.

It is obvious that by combining or modifying different embodiments and various technical features in different ways, various different embodiments can be further designed.

The scanning device according to the preferred embodiment of the present disclosure, the laser radar including the same, and the operation method are described above in conjunction with the specific embodiments. It can be understood that the above description is only exemplary and not restrictive. Without departing from the scope of the present disclosure, those skilled in the art can conceive of various variations and modifications with reference to the above description. These variations and modifications are also included in the protection scope of the present disclosure.

The above embodiments are only used to illustrate the technical solutions of the application, but not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still compare the previous embodiments. The recorded technical solutions are modified, or some of the technical features are equivalently replaced; these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

A laser radar is characterized in that it comprises:

A transmitting unit configured to emit a first laser pulse sequence, wherein the first laser pulse sequence is generated based on preset pulse width information;

A receiving unit configured to receive the second laser pulse sequence;

The processing unit is configured to determine the echo of the first laser pulse sequence from the second laser pulse sequence based on the pulse width information, wherein the echo of the first laser pulse sequence is an obstacle reflection The first laser pulse sequence is formed.
The laser radar according to claim 1, wherein the first laser pulse sequence includes at least two single pulses, and the pulse width information includes pulse width information of each single pulse and the interval between the single pulses. Information; and

The processing unit is further configured to determine the return of the first laser pulse sequence from the second laser pulse sequence based on the pulse width information of the individual single pulses and the interval information between the single pulses. Wave.
The lidar according to claim 1 or 2, wherein the emitting unit comprises a control part and a laser, and the control part is configured to control the laser to emit light based on the pulse width information.
The lidar according to claim 3, wherein the control unit comprises a controller and a switching device, wherein the controller is configured to drive the switching device based on the pulse width information to control the The opening and closing of the switching device, the opening and closing of the switching device controls the light-emitting state of the laser.
The lidar according to claim 4, wherein the pulse width information comprises a preset binary code sequence; and

The controller is configured to drive the switching device with a voltage matching the preset binary code sequence according to a clock tick, and each code in the preset binary code sequence corresponds to a single clock tick.
The lidar according to claim 5, wherein the processing unit is further configured to: according to a preset light intensity threshold, determine the binary value corresponding to the light signal received at each clock tick, and use the determined binary value The value generates a received binary code sequence corresponding to the second laser pulse sequence.
The lidar according to claim 6, wherein the processing unit is further configured to: intercept a sequence to be detected with a predetermined length from the received binary code sequence; determine the sequence to be detected and the preset sequence Whether the binary code sequence matches; if it matches, it is determined that the laser pulse sequence corresponding to the sequence to be detected is the echo of the first laser pulse sequence.
The lidar according to claim 7, wherein the length of the sequence to be detected is the same as the length of the preset binary code sequence; and

The processing unit is further configured to: align the sequence to be detected and the preset binary code sequence, and perform bitwise AND calculation; if the bitwise AND calculation result is the same as the preset binary code sequence, determine the The sequence to be detected matches the preset binary code sequence.
An anti-jamming method applied to lidar, which is characterized in that it includes:

Emitting a first laser pulse sequence, wherein the first laser pulse sequence is generated based on preset pulse width information;

Receiving the second laser pulse sequence;

Based on the pulse width information, the echo of the first laser pulse sequence is determined from the second laser pulse sequence, wherein the echo of the first laser pulse sequence is that an obstacle reflects the first laser Formed by a sequence of pulses.
The anti-interference method according to claim 9, wherein the first laser pulse sequence includes at least two single pulses, and the pulse width information includes the pulse width information of each single pulse and the distance between the single pulses. Interval information; and

The determining the echo of the first laser pulse sequence from the second laser pulse sequence based on the pulse width information includes:

Based on the pulse width information of each single pulse and the interval information between the single pulses, the echo of the first laser pulse sequence is determined from the second laser pulse sequence.
The anti-interference method according to claim 9 or 10, wherein the pulse width information includes a preset binary code sequence; and

The determining the echo of the first laser pulse sequence from the second laser pulse sequence based on the pulse width information includes:

According to the preset light intensity threshold, the binary value corresponding to the optical signal received at each clock tick is determined, and the received binary code sequence corresponding to the second laser pulse sequence is generated with the determined binary value.
The anti-interference method according to claim 11, wherein the determining the echo of the first laser pulse sequence from the second laser pulse sequence based on the pulse width information further comprises:

Intercept a sequence to be detected of a predetermined length from the received binary code sequence;

Determining whether the sequence to be detected matches the preset binary code sequence;

If they match, it is determined that the laser pulse sequence corresponding to the sequence to be detected is the echo of the first laser pulse sequence.
The anti-interference method according to claim 12, wherein the length of the sequence to be detected is the same as the length of the preset binary code sequence; and

The determining whether the sequence to be detected matches the preset binary code sequence includes:

Aligning the sequence to be detected and the preset binary coding sequence, and performing bitwise AND calculation;

If the bitwise AND calculation result is the same as the preset binary code sequence, it is determined that the sequence to be detected matches the preset binary code sequence.