1. A lidar, comprising:

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 a second laser pulse train;

a processing unit configured to determine an 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 formed by an obstacle reflecting the first laser pulse sequence.

2. The lidar of claim 1, wherein the first sequence of laser pulses comprises at least two single pulses, the pulse width information comprising pulse width information for each single pulse and spacing information between the single pulses; and

the processing unit is further configured to: determining an echo of the first laser pulse train from the second laser pulse train based on pulse width information of the individual single pulses and interval information between the single pulses.

3. The lidar according to claim 1 or 2, wherein the transmission unit comprises a control section and a laser, the control section being configured to control the laser to emit light based on the pulse width information.

4. The lidar according to claim 3, wherein the control section 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 opening and closing of the switching device, the opening and closing of the switching device controlling a light emission state of the laser.

5. The lidar of 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 matched with the preset binary code sequence according to a clock beat, wherein each code in the preset binary code sequence corresponds to a single clock beat.

6. The lidar of claim 5, wherein the processing unit is further configured to: and determining a binary value corresponding to the optical signal received by each clock beat according to a preset light intensity threshold, and generating a receiving binary code sequence corresponding to the second laser pulse sequence according to the determined binary value.

7. The lidar of claim 6, wherein the processing unit is further configured to: intercepting a sequence to be detected with a preset length from the received binary coding sequence; determining whether the sequence to be detected is matched with the preset binary coding sequence; and if so, determining that the laser pulse sequence corresponding to the sequence to be detected is the echo of the first laser pulse sequence.

8. The lidar of claim 7, wherein the length of the sequence to be detected is the same as the length of the predetermined binary code sequence; and

the processing unit is further configured to: aligning the sequence to be detected and the preset binary coding sequence, and carrying out bitwise calculation; and if the bitwise and the calculation result are the same as the preset binary coding sequence, determining that the sequence to be detected is matched with the preset binary coding sequence.

9. An anti-interference method applied to a laser radar is characterized by comprising the following steps:

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

receiving a second laser pulse sequence;

determining an echo of the first laser pulse train from the second laser pulse train based on the pulse width information, wherein the echo of the first laser pulse train is formed by an obstacle reflecting the first laser pulse train.

10. The tamper resistant method of claim 9 wherein the first sequence of laser pulses comprises at least two single pulses, the pulse width information comprising pulse width information for each single pulse and spacing information between the single pulses; and

said determining an echo of said first sequence of laser pulses from said second sequence of laser pulses based on said pulse width information comprises:

determining an echo of the first laser pulse train from the second laser pulse train based on pulse width information of the individual single pulses and interval information between the single pulses.

11. The tamper-resistant method according to claim 9 or 10, wherein the pulse width information comprises a preset binary code sequence; and

said determining an echo of said first sequence of laser pulses from said second sequence of laser pulses based on said pulse width information comprises:

and determining a binary value corresponding to the optical signal received by each clock beat according to a preset light intensity threshold, and generating a receiving binary code sequence corresponding to the second laser pulse sequence according to the determined binary value.

12. The tamper-resistant method of claim 11, wherein determining the echo of the first laser pulse sequence from the second laser pulse sequence based on the pulse width information further comprises:

intercepting a sequence to be detected with a preset length from the received binary coding sequence;

determining whether the sequence to be detected is matched with the preset binary coding sequence;

and if so, determining that the laser pulse sequence corresponding to the sequence to be detected is the echo of the first laser pulse sequence.

13. The method for resisting interference according to claim 12, wherein the length of the sequence to be detected is the same as the length of the predetermined binary code sequence; and

the determining whether the sequence to be detected is matched with the preset binary coding sequence comprises the following steps:

aligning the sequence to be detected and the preset binary coding sequence, and carrying out bitwise calculation;

and if the bitwise and the calculation result are the same as the preset binary coding sequence, determining that the sequence to be detected is matched with the preset binary coding sequence.

Background

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

In the automatic driving technology, an environment sensing system is a basic and crucial ring and is a guarantee for the safety and intelligence of an automatic driving automobile, and a laser radar in an environment sensing sensor has incomparable advantages in the aspects of reliability, detection range, distance measurement precision and the like. The laser radar analyzes the turn-back time of the laser after encountering a target object by transmitting and receiving laser beams, and calculates the distance between the target object and the laser radar.

Lidar has been widely used in the field of automatic driving, but due to the overlapping of fields of view among multiple radars, mutual interference among the radars is inevitable.

For the laser radar of the direct time-of-flight measurement technology, a technology of modulating pulse positions in a pulse sequence can be adopted, and the laser pulse sequence transmitted every time is coded, so that the laser pulse sequence measured every time is unique.

Disclosure of Invention

The disclosure provides a laser radar with higher anti-interference capability 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 a second laser pulse train;

and a processing unit configured to determine an echo of the first laser pulse train from the second laser pulse train based on the pulse width information, wherein the echo of the first laser pulse train is formed by an obstacle reflecting the first laser pulse train.

In some embodiments, the first laser pulse train comprises at least two single pulses, and the pulse width information comprises pulse width information of each single pulse and interval information between the single pulses; and the processing unit, further configured to: and determining an echo of the first laser pulse train from the second laser pulse train based on pulse width information of the individual single pulses and interval information between the single pulses.

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

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 switching of the switching device, and the switching of the switching device controls the light emitting state of the laser.

In some embodiments, the pulse width information comprises a predetermined binary code sequence; and the controller is configured to drive the switching device with a voltage matched to the preset binary code sequence according to a clock beat, each code in the preset binary code sequence corresponding to a single clock beat.

In some embodiments, the processing unit is further configured to: and determining a binary value corresponding to the optical signal received by each clock beat according to a preset light intensity threshold, and generating a receiving binary code sequence corresponding to the second laser pulse sequence according to the determined binary value.

In some embodiments, the processing unit is further configured to: intercepting a sequence to be detected with a preset length from the received binary coding sequence; determining whether the sequence to be detected is matched with the preset binary coding sequence; and if so, determining 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 predetermined binary coding sequence; and the processing unit is further configured to: aligning the sequence to be detected and the preset binary coding sequence, and carrying out bitwise calculation; and if the bitwise and the calculation result are the same as the preset binary coding sequence, determining that the sequence to be detected is matched with the preset binary coding sequence.

In a second aspect, an embodiment of the present application provides an anti-interference method applied to a laser radar, including: emitting a first laser pulse sequence, wherein the first laser pulse sequence is generated based on preset pulse width information; receiving a second laser pulse sequence; and determining an echo of the first laser pulse train from the second laser pulse train based on the pulse width information, wherein the echo of the first laser pulse train is formed by an obstacle reflecting the first laser pulse train.

In some embodiments, the first laser pulse train comprises at least two single pulses, and the pulse width information comprises pulse width information of each single pulse and interval information between the single pulses; and the determining an echo of the first laser pulse train from the second laser pulse train based on the pulse width information includes: and determining an echo of the first laser pulse train from the second laser pulse train based on pulse width information of the individual single pulses and interval information between the single pulses.

In some embodiments, the pulse width information comprises a predetermined binary code sequence; and the determining an echo of the first laser pulse train from the second laser pulse train based on the pulse width information includes: and determining a binary value corresponding to the optical signal received by each clock beat according to a preset light intensity threshold, and generating a receiving binary code sequence corresponding to the second laser pulse sequence according to the determined binary value.

In some embodiments, the determining the echo of the first laser pulse train from the second laser pulse train based on the pulse width information further comprises: intercepting a sequence to be detected with a preset length from the received binary coding sequence; determining whether the sequence to be detected is matched with the preset binary coding sequence; and if so, determining 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 predetermined binary coding sequence; and the determining whether the sequence to be detected is matched with the preset binary coding sequence comprises: aligning the sequence to be detected and the preset binary coding sequence, and carrying out bitwise calculation; and if the bitwise and the calculation result are the same as the preset binary coding sequence, determining that the sequence to be detected is matched with the preset binary coding sequence.

The laser radar and the anti-interference method applied to the laser radar can encode (or modulate) the pulse width of the transmitted first laser pulse sequence based on the preset pulse width information, so that the first laser pulse sequence transmitted by the laser radar is irrelevant to an external interference sequence in terms of pulse width, and therefore, the echo of the first laser pulse sequence can be quickly and accurately determined from the received second laser pulse sequence through matching analysis of the pulse width.

Drawings

The foregoing and additional features and characteristics of the present disclosure will be better understood from the following detailed description, taken with reference to the accompanying drawings, which are given by way of example only and which are not necessarily drawn to scale. Like reference numerals are used to indicate like parts in the accompanying drawings, in which:

FIG. 1 is an exemplary schematic block diagram of a lidar according to one embodiment of the present disclosure;

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

FIGS. 3A and 3B are schematic diagrams of the interference rejection capabilities of the encoding scheme of the present application;

FIG. 4 is an exemplary block diagram of a series circuit of a switching device and a laser;

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

FIG. 6 is a schematic diagram of an exemplary relationship between clock ticks, a preset binary code sequence, and a first sequence of laser pulses;

FIG. 7 is an exemplary diagram of receiving a binary coded sequence;

FIG. 8 is a diagram illustrating an exemplary case where the sequence to be detected does not match the predetermined binary code sequence;

FIG. 9 is a schematic diagram of an exemplary case where a sequence to be detected matches a predetermined binary coding sequence;

fig. 10 is a flowchart illustrating an interference rejection method applied to a lidar according to an embodiment of the present disclosure.

Detailed Description

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, application, or uses.

In the description of the present disclosure, it is to be understood that the terms "upper", "lower", "top", "bottom", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present disclosure and simplifying the description, and do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed 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, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms "first," "second," and the like are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the disclosure described herein are capable of operation in sequences other than those illustrated or otherwise described herein.

Referring to fig. 1, an embodiment of the present disclosure may provide a lidar that 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 train. Here, the first laser pulse sequence may be generated based on preset pulse width information.

In this embodiment, the receiving unit may be configured to receive the second laser pulse train.

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

It should be noted that the directions of the arrows in fig. 1 do not represent the actual transmission directions of the light, but are merely exemplary illustrations of the signal transmission relationships between the units.

Here, the emitting unit may emit a sequence of laser pulses, i.e. the emitting unit may comprise a laser. The type and number of lasers in the emitting unit can be set according to practical situations, and are not limited herein. The specific structure of the transmitting unit can be various, and is not limited herein.

Here, the preset pulse width information may be used to modulate the pulse width, i.e. the pulse width of the first laser pulse train is modulated. The specific value of each pulse width after modulation is not limited herein.

Here, the receiving unit may convert the received optical signal into an electrical signal, i.e., the transmitting unit may include a photosensor. The type and number of the photoelectric sensors can be set according to actual conditions, and are not limited herein. The specific structure of the receiving unit may be various, and is not limited herein.

As an example, the receiving unit may comprise a probing subunit; optionally, the receiving unit may further include a convergence subunit and a filtering subunit. Optionally, the order between the convergence subunit and the filtering subunit may be interchanged, that is, filtering may be performed first and then convergence, or filtering may be performed first and then convergence. For example, for the case of converging first and then filtering, the converging subunit may converge the received optical signal, the converged optical signal may pass through the filtering subunit, and the filtering subunit may filter out a portion of the interference light. The optical signal filtered by the filtering subunit is detected by the detecting subunit, and the detecting subunit can perform photoelectric conversion on the received optical signal and transmit the converted electric signal to the processing unit.

Here, the processing unit may read the electrical signal from the receiving unit. It should be noted that the processing unit processes the electrical signal, but the electrical signal is used for characterizing the optical signal, so that the processing of the electrical signal by the processing unit can be understood as processing of the second laser pulse sequence. The specific structure of the processing unit may be various, and is not limited herein.

It will be appreciated that the echoes of the first laser pulse sequence are consistent with the first laser pulse sequence in terms of pulse characteristics (e.g., single pulse width, pulse spacing, etc.); the pulse width information may be indicative of a pulse characteristic of the first sequence of laser pulses. An interference sequence may be included in the second laser pulse sequence, the interference sequence being generally non-identical in character to the first laser pulse sequence. Thus, the echo of the first laser pulse train can be determined from the second laser pulse train on the basis of the pulse width information.

It should be noted that, the laser radar provided in the foregoing embodiment may encode (or modulate) the pulse width of the transmitted first laser pulse sequence based on the preset pulse width information, so that the first laser pulse sequence transmitted by the laser radar and the interference sequence are uncorrelated in terms of the pulse width, and therefore, the processing unit may quickly and accurately determine the echo of the first laser pulse sequence from the received second laser pulse sequence through matching analysis of the pulse width.

Referring to fig. 2A and 2B, and fig. 3A and 3B, fig. 2A and 2B are schematic diagrams illustrating recognition errors caused by a coding method of the prior art; fig. 3A and 3B are schematic diagrams of interference rejection capabilities of the encoding method of the present application. To more clearly illustrate the interference rejection of a lidar employing the methods provided herein, reference is made to fig. 2A and 2B, and to fig. 3A and 3B.

As an example, as shown in fig. 2A and fig. 2B, it shows a schematic diagram of a coding method of the prior art resulting in recognition error. Fig. 2A shows a transmitting part, and fig. 2B shows a receiving part. In fig. 2A, the first line is a clock beat, and the second line is a probe pulse sequence transmitted by the transmitting unit. The pulse width (e.g., full width at half maximum) of each single pulse in the probe pulse train is the same, and is one clock cycle. In the detection pulse sequence, a first time interval (in leading edges) between the first pulse (fpulse1) and the second pulse (fpulse2) is, for example, 10 clock cycles, and a second time interval (in leading edges) between the second pulse (fpulse2) and the third pulse (fpulse3) is, for example, 18 clock cycles. The first row in fig. 2B is the clock ticks and the second row is the echoes of the probe pulse sequence, which are consistent with the pulse width of the individual pulses, the number of individual pulses, and the time intervals between pulses of the probe pulse sequence. The third row is the interference sequence and the fourth row is the received pulse sequence (including the echo and interference sequences of the probe pulse sequence) actually received by (the probe subunit in) the receiving unit. 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, the number of single pulses and the time interval between pulses of the detection pulse sequence. The first pulse (finterfer1) and the second pulse (finterfer2) of the interference sequence have the same pulse width and are each 1 clock cycle, and the time interval (in terms of the leading edge) between the first pulse (finterfer1) and the second pulse (finterfer2) of the interference sequence is, for example, 18 clock cycles. Referring to line 4 of fig. 2B, the echo of the probe pulse sequence in the received pulse sequence and the interference sequence are superimposed, resulting in the insertion of the first pulse (finterfer1) of the interference sequence between fpulse2 and fpulse 3; the second pulse of the interference sequence (finterfer2) follows fpulse 3. In this case, the time interval (10) between finterfer1 and fpulse2 is the same as the first time interval (10) described above; the time interval (18) between finterfer1 and finterfer2 being the same as the second time interval (18) described above; thus, the processor may be caused to identify fpulse2 as fpulse1 (referred to as false fpulse1), finterfer1 as fpulse2 (referred to as false fpulse2), and finterfer2 as interference 3 (referred to as false fpulse 3). Identification errors may further lead to errors in the measured range of the lidar.

Fig. 3A and 3B are schematic diagrams of interference rejection capabilities of the encoding method of the present application. Fig. 3A shows a transmitting part, and fig. 3B shows a receiving part. In fig. 3A, the first line is a clock cycle, and the second line is a first laser pulse train emitted by the emitting unit. In the first laser pulse train, the pulse width (for example, the full width at half maximum of the single pulse) of the first pulse (pulse1) is one clock cycle, the pulse width of the single pulse of the second pulse (pulse2) is 2 clock cycles, and the pulse width of the single pulse of the third pulse (pulse3) is 4 clock cycles. The first time interval (in leading edges) of the first pulse (pulse1) and the second pulse (pulse2) is, for example, 10 clock cycles, and the second time interval (in leading edges) of the second pulse (pulse2) and the third pulse (pulse3) is, for example, 18 clock cycles. The first line in fig. 3B is the clock ticks and the second line is the echoes of the first laser pulse train that are consistent with the pulse width of the single pulses of the probe pulse train, the number of single pulses, and the time intervals between pulses. The third row is the interference sequence and the fourth row is the second laser pulse sequence, i.e. the laser pulse sequence actually received by (the detection subunit in) the receiving unit (including the echo and interference sequence of the first laser pulse sequence). . The first pulse (interference 1) of the interference sequence is between pulse2 and pulse3, the second pulse (interference 2) of the interference sequence is after pulse3, the first pulse (interference 1) and the second pulse (interference 2) of the interference sequence are the same in pulse width and both have 2 clock cycles, and the time interval (in leading edge) between the first pulse (interference 1) and the second pulse (interference 2) of the interference sequence is, for example, 18 clock cycles. Although the time interval (10) between interfer1 and pulse2 is the same as the time interval (10) between pulse1 and pulse 2; and the time interval (18) between interrupt 2 and interrupt 1 is the same as the time interval (18) between pulse2 and pulse 3. However, because pulse2 differs from pulse1 in pulse width and interfer2 differs from pulse3 in pulse width, the processor will not recognize pulse2 as pulse1 nor interfer2 as pulse 3. Therefore, the interference sequence does not interfere with the identification of the echo of the first laser pulse sequence, i.e. the interference immunity of the laser radar is enhanced.

In contrast, currently, a technology of modulating pulse positions in a laser pulse sequence is adopted, and a laser sequence emitted each time is coded, so that the laser pulse sequence measured each time is unique; pulse position is understood to mean the relative time instant occupied by each single pulse in a pulse train, the technique of modulating the pulse position being substantially the same as the random encoding of the inter-pulse time. The random encoding of the pulse interval times described above may solve the problem of interference of the lidar echo pulse sequence in most cases. However, in some cases, this encoding method may cause misidentification of a certain program.

The technology of modulating the pulse position in the laser pulse sequence is adopted, the number of pulses measured in a single time needs to be increased in the emission sequence to reduce the probability of interference, but because each independent pulse has no characteristics, a processor is required to extract a pulse combination matched with the emission sequence from the irregular pulse sequence received by the detector, and the more the number of detected pulses is, the longer the calculation time for matching is; moreover, the excessive number of pulses in the emission sequence may result in an excessively long single measurement time, and the power consumption of the single measurement may increase with the increase of the number of laser pulse emissions.

In contrast, the laser radar provided by this embodiment has the characteristics of each independent pulse due to the different pulse widths of the single pulses, and can use a smaller number of pulses to achieve a higher anti-interference capability. Referring to table 1, table 1 provides the number of combinations of pulse codes for different pulse numbers and pulse widths of single pulses.

TABLE 1

As can be seen from table 1, the interference immunity of the lidar is related to the number of pulses of the first laser pulse train emitted and the pulse width type of the single pulse. For example, the number of pulses is 2, and the types of pulse widths are 2 (i.e., the pulse widths of the 2 single pulses are different), in which case the first laser pulse train may have 4 possible forms (without considering the pulse interval). For another example, the number of pulses is 6, and the kinds of the single pulses are 6 (i.e., the pulse widths of the 6 single pulses are different), in which case, 46656 (without considering the pulse interval) are possible forms of the first laser pulse train. Therefore, the pulse width coding (the pulse intervals may be the same or different) provided by this embodiment can provide more types of first laser pulse sequences by a smaller number of pulses, thereby improving the anti-interference capability of the laser radar while reducing the number of times of light emission.

In some embodiments, the first laser pulse train 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: and determining an echo of the first laser pulse train from the second laser pulse train based on pulse width information of each single pulse and interval information between the single pulses.

It should be noted that, the emission and extraction of the laser pulse sequence are performed by using the interval information between the single pulses as the pulse characteristics, so that more abundant pulse characteristics can be referred to when extracting the echo. Therefore, the anti-interference capability of the laser radar can be improved.

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

In some embodiments, the control portion 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 opening and closing of the switching device. The switching device can control the light emitting state of the laser. Controlling the light emission state of the laser may be understood as controlling the laser to emit light or not.

It should be noted that the driving circuit of the laser is implemented by using a controller and a switching device, and in this case, the driving circuit of the laser has the capability of controlling the current injection time, so that the laser can be sensitively adjusted based on the above-mentioned pulse width information.

Here, the switching device may include, but is not limited to, at least one of: triodes, field effect transistors, etc.

By way of example, please refer to FIG. 4, whichA series circuit of a first switching device, which may be for example an N-type field effect transistor, and a Laser (Laser) is shown. In fig. 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, where the Vgs of T1 is at a high level (V1)_high) Laser emission (on); when Vgs of T1 is at low level (V)_low) The laser is off. Thus, the controller can realize that the laser emits laser light in accordance with the pulse width information by voltage-driving the gate of T1 in accordance with the pulse width information, and can emit the first laser light pulse train based on the pulse width information. Here, T1 may be a device such as a GaN or NPN transistor, in addition to a field effect transistor.

As an example, please refer to fig. 5, which shows a series circuit of a second switching device, which may be for example a P-type field effect transistor, and a Laser (Laser). In fig. 5, a pfet T2 is connected in series with the laser, the turn-on and turn-off of T2 is controlled by a voltage drop Vgs across the gate g and the source s, and the pfet T2 is turned on when the control terminal Vgs is negative. Wherein, when Vgs of T2 is at low level (V)_low) The laser is on; when Vgs of T2 is at high level (V)_high) The laser is on (off). Thus, the controller can realize that the laser emits laser light in accordance with the pulse width information by voltage-driving the gate of T2 in accordance with the pulse width information, and can emit the first laser light pulse train based on the pulse width information. Here, T2 may be a device such as a GaN or PNP transistor, in addition to a field effect transistor.

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

It can be seen that the emission time of the laser can correspond to the pulse width of a single pulse in the first sequence of laser pulses, and the dwell time of the laser can correspond to the inter-pulse time. If the controller calculates by using the light emitting time and/or the quiet time, a memory for storing the light emitting time and/or the quiet time needs to store a large amount of data; in addition, when the light emission time and/or the silence time are stored, the calculation process is also complicated when the echo of the first laser pulse train is identified.

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

In some embodiments, the controller may be configured to drive the switching device with a voltage matched to the binary code sequence according to a clock cycle. Here, each of the above-mentioned preset binary code sequences corresponds to a single clock beat. The clock pulses may also be referred to as clock cycles, which are, for example, the inherent clock cycles of the lidar system.

By way of example, reference is made to fig. 6, which shows the relationship between clock ticks, a preset binary code sequence and a first laser pulse sequence. In fig. 6, the first row is a clock tick; the third row is preset with a binary code sequence, and it can be seen from fig. 6 that each bit of the preset binary code sequence corresponds to a clock cycle; the second row is the first laser pulse sequence, and it can be seen from fig. 6 that the pulse position (at high level) of the first laser pulse matches the "1" value position in the preset binary code sequence. In other words, in the binary coding method, the laser is driven in the predetermined binary code sequence (32 bits in this example) in one order (higher order first or lower order first) at the clock beat, so that the first laser emission sequence in accordance with the predetermined binary code sequence can be obtained.

In some embodiments, the processing unit may be further configured to: and determining a binary value corresponding to the optical signal received by each clock beat according to a preset light intensity threshold, and generating a receiving binary code sequence corresponding to the second laser pulse sequence according to the determined binary value.

It will be appreciated that the receiving unit may convert the optical signal into an electrical signal and transfer the converted electrical signal to the processing unit. The electrical signal may be referred to as light intensity data, which indicates the light intensity. The processing unit may sample the received electrical signal according to the clock beat.

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

Referring to fig. 7, a binary code sequence is shown as received. In fig. 7, the first line is a clock beat, the second line is an echo of the first laser pulse sequence, the third line is an interference sequence, the fourth line is the second laser pulse sequence, and the fifth line is a received binary code sequence corresponding to the second laser pulse sequence.

In some embodiments, the processing unit may be further configured to: intercepting a sequence to be detected with a preset length from the received binary coding sequence; determining whether the sequence to be detected is matched with the preset binary coding sequence; and if so, determining that the laser pulse sequence corresponding to the sequence to be detected is the echo of the first laser pulse sequence.

Here, in the process of truncating the sequence to be detected from the received binary code sequence, the start position of truncation is not limited. It will be appreciated that in the case where the position of the start of the truncation is determined, since the sequence to be sequenced is of a predetermined length, the position of the end of the truncation 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 fragment is not changed.

As an example, data of a predetermined length (for example, 32 bits) may be extracted from a start bit of a received binary code sequence (for example, the first bit of the received binary code sequence of 1024 lengths) as a sequence to be detected; and if the first sequence to be detected is matched with the preset binary coding sequence, determining that the laser pulse sequence corresponding to the first sequence to be detected is the echo of the first laser pulse sequence. If the sequence to be detected for the first number does not match the preset binary code sequence, data with a predetermined length (for example, 32 bits) can be extracted from the second bit of the received binary code sequence (for example, the second bit of the received binary code with the length of 1024) as the sequence to be detected for the second number, and so on. And until the N number sequence to be detected is matched with the preset binary code sequence or the received binary code sequence is traversed. As an example, in the case that the received binary code is 1024 bits and the to-be-sequenced column is 32 bits, the value of N is not greater than 1024 minus 32 plus 1, that is, N is a natural number not greater than 993. The received binary code sequence is traversed, and it can be understood that the sequence to be detected No. 993 is intercepted.

In some embodiments, determining whether the sequence to be detected matches the predetermined binary code sequence can be achieved in various ways, and is not limited herein. As an example, the sequence to be detected may be compared bit by bit with a preset binary coding sequence to determine whether there is a match; if the bits corresponding to the bits in the sequence to be detected are all 1 aiming at the bits with the preset binary coding sequence of 1, determining matching; and if the bit with 0 exists in the bits corresponding to the bits in the sequence to be detected, determining that the sequence is not matched.

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

In some embodiments, the processing unit may be further configured to align the sequence to be detected and the predetermined binary code sequence, and perform bitwise and calculation; and if the bitwise and the calculation result are the same as the preset binary coding sequence, determining that the sequence to be detected is matched with the preset binary coding sequence. Here, the idea of bitwise and computational calculation is summarized as follows: the corresponding bit values are all 1's with a 1's result, and the corresponding bit values are not 1's with a 0's result.

Please refer to fig. 8, which shows the situation that the sequence to be detected does not match the predetermined binary code sequence. In fig. 8, the part marked by the upper bracket 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 the calculation result; it can be seen that if the bitwise and the calculation result are not the same as the predetermined binary coding sequence, it can be determined that the sequence to be detected does not match the binary sequence.

Please refer to fig. 9, which shows the matching of the sequence to be detected and the predetermined binary code sequence. In fig. 9, the part marked by the upper bracket 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 the calculation result; it can be seen that the bitwise and the calculation result are the same as the preset binary coding sequence, it can be determined that the sequence to be detected matches the binary sequence, and then the start time of the matched sequence to be detected is taken as the receiving time of the echo of the first laser pulse sequence, and the distance information between the radar and the obstacle is obtained according to the emitting time of the first laser pulse sequence, for example, according to a time of flight (TOF).

It should be noted that, providing pulse width information based on the preset binary code sequence may be suitable for the logic chip to perform operations, thereby reducing data storage capacity and simplifying the calculation process required for identification.

Referring to fig. 10, a flow of an anti-jamming method applied to a lidar is shown.

The above process may include:

step 101, a first laser pulse sequence is emitted.

Here, the first laser pulse train described above is generated based on preset pulse width information.

Step 102, a second laser pulse sequence is received.

Step 103, determining an echo of the first laser pulse train from the second laser pulse train based on the pulse width information.

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

It should be noted that details of implementation and technical effects of the anti-interference method applied to the laser radar may refer to relevant descriptions in other parts of the present disclosure, and are not described herein again.

In some embodiments, the first laser pulse train 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, the determining the echo of the first laser pulse train from the second laser pulse train based on the pulse width information includes: and determining an echo of the first laser pulse train from the second laser pulse train based on pulse width information of the individual single pulses and interval information between the single pulses.

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

In some embodiments, the determining the echo of the first laser pulse train from the second laser pulse train based on the pulse width information includes: and determining a binary value corresponding to the optical signal received by each clock beat according to a preset light intensity threshold, and generating a receiving binary code sequence corresponding to the second laser pulse sequence according to the determined binary value.

In some embodiments, the determining the echo of the first laser pulse train from the second laser pulse train based on the pulse width information further comprises: intercepting a sequence to be detected with a preset length from the received binary coding sequence; determining whether the sequence to be detected is matched with the preset binary coding sequence; and if so, determining 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 predetermined binary coding sequence.

In some embodiments, the determining whether the sequence to be detected matches the predetermined binary coding sequence comprises: aligning the sequence to be detected and the preset binary coding sequence, and carrying out bitwise calculation; and if the bitwise and the calculation result are the same as the preset binary coding sequence, determining that the sequence to be detected is matched with the preset binary coding sequence.

It is obvious that further different embodiments can be devised by combining different embodiments and individual features in different ways or modifying them.

The scanning device and the lidar including the same and the operating method according to the preferred embodiments of the present disclosure have been described above with reference to specific embodiments. It is understood that the above description is intended to be illustrative, and not restrictive, and that various changes and modifications may be suggested to one skilled in the art in view of the foregoing description without departing from the scope of the disclosure. Such variations and modifications are also intended to be included within the scope of the present disclosure.

The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.