CN114428243A

CN114428243A - Laser radar, pulse sampling method and device thereof and storage medium

Info

Publication number: CN114428243A
Application number: CN202111674499.0A
Authority: CN
Inventors: 任建峰
Original assignee: O Net Communications Shenzhen Ltd
Current assignee: O Net Technologies Shenzhen Group Co Ltd
Priority date: 2021-12-31
Filing date: 2021-12-31
Publication date: 2022-05-03

Abstract

The invention discloses a laser radar and a pulse sampling method, a device and a storage medium thereof, wherein a photoelectric conversion circuit of the laser radar comprises: the signal multiplexing circuit is connected with the amplifier and is used for multiplexing and sending the signals to be sampled to different channels for transmission; the delay circuit is connected with the signal multiplexing circuit and is used for carrying out phase delay transmission on the signals to be sampled according to different preset phase delays on different channels; the input end of the adding circuit is connected with the delay circuit, the output end of the adding circuit is connected with the sampling chip, and the adding circuit is used for adding the signals to be sampled after phase delay in each channel and collecting the signals to be sampled to the sampling chip; the sampling chip is used for collecting the added signals to be sampled to generate a sampling pulse sequence, and the control unit respectively carries out delay movement on each sampling pulse in the sampling pulse sequence according to the corresponding preset phase so as to recombine to obtain the sampling signals. Thereby the equivalent sampling rate of the pulse signal can be improved.

Description

Laser radar, pulse sampling method and device thereof and storage medium

Technical Field

The invention relates to the technical field of laser measurement, in particular to a laser radar, a pulse sampling method and device thereof and a storage medium.

Background

Along with the development of novel intelligent products such as mobile robot, laser ranging technique wide application is unmanned, and unmanned aerial vehicle keeps away the barrier planning automatically, and the while has proposed new requirement to laser ranging technique range finding performance, range finding precision, consumption, volume, stability, reliability. The pulse laser radar has the advantages of large measurement range, low requirement on light source coherence and the like, and is widely applied to the fields of military exploration, aerospace, robots and the like, so that the improvement of the pulse laser ranging precision is one of the future key development directions of the laser ranging technology.

The current common laser detection is a pulse direct detection mode. The system emits one or more laser pulse signals in the working process, when the emitted pulses irradiate a target object, a part of energy is correspondingly reflected and received by the detection system, and the detection system acquires the flight time of the laser pulses by measuring the time difference between the emitting time and the receiving time to measure the target distance D, Delta T, c/2 according to the speed of light in the air.

The method for calculating and acquiring the flight time of the received laser pulse is divided into two methods. One method is to use the laser emission time as the starting time, perform photoelectric conversion on the received laser pulse signal, obtain the time of laser pulse return by a comparator, and then obtain the laser pulse flight time delta T by a TDC (time-digital conversion) chip. The other method is that the laser emission time is used as the starting time, after the received laser pulse signal is subjected to photoelectric conversion, the waveform information of the echo pulse signal is acquired by an ADC (analog-digital conversion) chip, and the time information returned by the laser pulse is obtained by a digital signal processing method, so that the laser pulse flight time delta T is obtained according to ADC sampling clock information.

When the TDC circuit is used to acquire the laser flight time, a strict signal reception threshold needs to be set. Small signals will not be received when the threshold is set too large; when the threshold value is set too small, the noise signal often exceeds the set threshold value, so that more noise pulses are introduced, and more noise points are introduced when the processing is not good.

When the ADC scheme is used, because the pulse transmitted by the laser radar is narrow and is often only a plurality of ns (5 ns), a relatively high-speed ADC chip is needed to effectively capture the pulse waveform of the echo pulse signal, and the cost and the power consumption are high.

Disclosure of Invention

The invention provides a laser radar, a pulse sampling method and device thereof and a storage medium, and aims to solve the problem that all information of echo pulses is difficult to acquire due to the limited sampling rate of an ADC chip.

In a first aspect, the present invention provides a lidar comprising: control unit, sampling chip and photoelectric conversion circuit, the control unit sampling chip with photoelectric conversion circuit connects gradually, photoelectric conversion circuit is including photodiode, transimpedance amplifier, the amplifier that connects gradually, photodiode is used for receiving echo pulse signal and obtains treating the sampling signal in order to carry out photoelectric conversion, photoelectric conversion circuit still includes: the signal multiplexing circuit is connected with the amplifier and is used for multiplexing and sending the signals to be sampled to different channels for transmission; the delay circuit is connected with the signal multiplexing circuit and is used for carrying out phase delay transmission on the signals to be sampled according to different preset phase delays on different channels; the input end of the adding circuit is connected with the delay circuit, the output end of the adding circuit is connected with the sampling chip, and the adding circuit is used for adding the signals to be sampled after phase delay in each channel and collecting the signals to be sampled to the sampling chip; the sampling chip is used for collecting the added signals to be sampled so as to generate a sampling pulse sequence; and the control unit respectively carries out delay movement on each sampling pulse in the sampling pulse sequence according to the corresponding preset phase so as to obtain a sampling signal through recombination.

Further, the signal multiplexing circuit comprises a power divider, an input end of the power divider is connected with an output end of the amplifier, and an output end of the power divider is connected with the delay circuit.

Further, the delay circuit comprises a delay line, an input end of the delay line is connected with an output end of the power divider, and an output end of the delay line is connected with the adding circuit.

Further, the adding circuit comprises an adder, an input end of the adder is connected with the delay line, and an output end of the adder is connected with the sampling chip.

Furthermore, the laser radar further comprises a laser, a transceiver module and a scanning module, wherein the control unit controls the laser to emit a probe light pulse to the scanning module through the transceiver module, the scanning module detects an object to be detected by using the probe light pulse, receives an echo pulse signal returned by the detected object, and sends the echo pulse signal to the photoelectric conversion circuit through the transceiver module.

Further, the delay time difference between adjacent channels is larger than the pulse width of the signal to be sampled transmitted in the channels.

Further, the delay time difference between adjacent channels is:

ΔT_{delay time}＝X_Y*T+Y*T/n

Wherein, Delta T_{Delay time}And the time delay difference is obtained, n is the number of channels, T is the sampling interval of a sampling chip, Y is the serial number of the channel, and X is an integer corresponding to the channel Y.

In a second aspect, the present invention further provides a pulse sampling method for a laser radar, including: acquiring an echo pulse signal and performing photoelectric conversion to obtain a signal to be sampled; multiplexing and sending signals to be sampled to different channels for transmission; carrying out phase delay transmission on signals to be sampled according to different preset phase delays on different channels; adding the signals to be sampled after phase delay in each channel; collecting the added signals to be sampled to generate a sampling pulse sequence; and respectively moving each sampling pulse in the sampling pulse sequence according to the corresponding preset phase delay to obtain a sampling signal through recombination.

In a third aspect, the present invention further provides a pulse sampling apparatus for a laser radar, including: the photoelectric conversion unit is used for acquiring an echo pulse signal and performing photoelectric conversion to obtain a signal to be sampled; the multiplexing unit is used for multiplexing and sending the signals to be sampled to different channels for transmission; the delay unit is used for carrying out phase delay transmission on the signal to be sampled according to different preset phase delays on different channels; the adding unit is used for adding the signals to be sampled after the phase delay in each channel; the acquisition unit is used for acquiring the added signals to be sampled so as to generate a sampling pulse sequence; and the recombination unit is used for respectively carrying out delay movement on each sampling pulse in the sampling pulse sequence according to the corresponding preset phase so as to recombine to obtain a sampling signal.

In a fourth aspect, the present invention also provides a storage medium storing a computer program comprising program instructions which, when executed by a processor, implement the steps of the method according to the second aspect.

Compared with the prior art, the invention has the beneficial effects that: by arranging a signal multiplexing circuit, a delay circuit and an adding circuit, the signal multiplexing circuit multiplexes and sends signals to be sampled to different channels for transmission, the delay circuit delays the phases of the signals to be sampled according to different preset phases of different channels for transmission, the adding circuit adds the signals to be sampled after the phases of the channels are delayed and collects the signals to be sampled to a sampling chip, the sampling chip collects the signals to be sampled after the addition to generate a sampling pulse sequence, a control unit respectively moves each sampling pulse in the sampling pulse sequence according to the corresponding preset phase delay to recombine to obtain the sampling signal, thereby increasing the functions of signal multiplexing, delay and accumulation relative to the existing photoelectric conversion circuit, and repeatedly sampling the same signal to be sampled by different phase delays in a multi-path delay way, the same effect of high sampling rate can be obtained under the condition of ADC hardware with lower sampling rate, and the cost of the system software and hardware is reduced.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 shows a system diagram of a lidar according to an embodiment of the invention;

fig. 2 shows a circuit diagram of a photoelectric conversion circuit in the prior art;

FIG. 3 shows a schematic diagram of a laser radar probe pulse waveform;

FIG. 4 illustrates the pulse shape of ADC sampling in the prior art;

FIG. 5 shows a circuit diagram of a photoelectric conversion circuit of a lidar according to an embodiment of the invention;

FIG. 6 shows a waveform diagram of a pulse signal of a laser radar according to an embodiment of the present invention;

FIG. 7 is a flow chart illustrating steps of a pulse sampling method for a lidar according to an embodiment of the invention;

FIG. 8 is a schematic diagram of a pulse sampling apparatus of a lidar according to an embodiment of the invention;

10. a control unit; 20. a photoelectric conversion circuit; 21. a photodiode; 22. a transimpedance amplifier; 23. an amplifier; 24. a signal multiplexing circuit; 25. a delay circuit; 26. an addition circuit; 30. and (4) sampling the chip.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It is also to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should be further understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

The background of the application is first further elucidated. Lidar generally includes a laser, transceiver, system control and signal processing, power management, and a scanning module. The scanning module may be a one-dimensional scan or a two-dimensional scan. The scanning method can be classified into mechanical scanning, MEMS scanning, OPA scanning, etc., and fig. 1 shows a 2D scanning scheme, which is only for illustration and not for limitation.

The laser radar works to acquire environmental point cloud data, and the direction and the distance of each detection point must be accurately set to acquire three-dimensional point cloud data. The direction information is determined by the scanning module; the target distance information is obtained by processing the echo light pulse obtained by the transceiver module by the system control and signal processing module.

When the pulse laser radar works, a laser transmits a detection laser pulse through the receiving and transmitting optical module, a part of light energy of the laser pulse irradiated on a target is reflected back to the laser radar system, and the mirror receiving and transmitting optical module converges and then transmits the light energy signal to the photoelectric conversion circuit to convert the light energy signal into an electric signal for processing.

As shown in fig. 2, a common photoelectric conversion circuit includes an APD (avalanche photodiode), a TIA (transimpedance amplifier), and an AMP (amplifier), where the APD, the TIA, and the AMP are connected in sequence, a bias voltage is applied to the APD, the APD receives an echo pulse signal, performs photoelectric conversion on the echo pulse signal to obtain an electrical signal, and then the electrical signal is amplified by the TIA and the AMP and then is collected by a sampling chip.

The electric pulse signal obtained after the processing by the photoelectric conversion circuit is shown in fig. 3, and its shape is similar to that of the emitted laser pulse, and is delayed in time. In the working process of the pulse laser radar, the flying time Delta T of the laser pulse and the known light speed c are obtained by obtaining the relative signal delay to obtain the distance of the target: d ═ DeltaT × c/2.

Due to the cost, the ADC chip used in the system is often limited in rate, and cannot acquire all the information of the echo pulse. The original continuous waveform is sampled into a discrete waveform, as shown in fig. 4, only a few points of the waveform are often collected, and a complete waveform cannot be collected.

Exemplarily, due to the limitation of the sampling rate, when the signal is acquired by using 1GSPS, the time interval between sampling points is 1ns, the corresponding time delay known distance accuracy is 15cm, and the application requirement cannot be met, and in actual use, some processing is performed on the sampled signal to improve the distance measurement accuracy.

In summary, in the conventional scheme, when the ADC scheme is adopted, an ADC chip with a relatively low rate (1 GSPS) is often adopted in practice, and the pulse signal collected is only a few points. To obtain the fine laser pulse flight time, a complex high-order interpolation algorithm is often needed to recover the signal pulse, and the calculation amount is large. And interpolation can not effectively restore some rapidly changing signal characteristics, which affects the improvement of the ranging precision.

Therefore, the method for signal delay repeated sampling is designed, and digital signals with higher equivalent sampling rate can be obtained under the condition that the ADC chip rate is limited. The method comprises the following specific steps:

referring to fig. 5, an embodiment of the present invention provides a laser radar, including: the photoelectric conversion circuit comprises a control unit 10, a sampling chip 30 and a photoelectric conversion circuit 20, wherein the control unit 10, the sampling chip 30 and the photoelectric conversion circuit 20 are sequentially connected, the photoelectric conversion circuit 20 comprises a photodiode 21, a transimpedance amplifier 22 and an amplifier 23 which are sequentially connected, the photodiode 21 is used for receiving an echo pulse signal to perform photoelectric conversion to obtain a signal to be sampled, and the photoelectric conversion circuit 20 further comprises: the signal multiplexing circuit 24 is connected to the amplifier 23, and is configured to multiplex and send signals to be sampled to different channels for transmission; the delay circuit 25 is connected with the signal multiplexing circuit 24 and is used for carrying out phase delay transmission on the signals to be sampled according to different preset phase delays on different channels; the input end of the adding circuit 26 is connected with the delay circuit 25, the output end of the adding circuit is connected with the sampling chip 30, and the adding circuit is used for adding the signals to be sampled after the phase delay in each channel and collecting the signals to be sampled to the sampling chip 30; the sampling chip 30 is configured to collect the added signals to be sampled to generate a sampling pulse sequence; the control unit 10 delays and moves each sampling pulse in the sampling pulse sequence according to the corresponding preset phase to obtain a sampling signal through recombination.

By implementing the embodiment, a signal multiplexing circuit 24, a delay circuit 25 and an adding circuit 26 are provided, the signal multiplexing circuit 24 multiplexes and transmits signals to be sampled to different channels for transmission, the delay circuit 25 performs phase delay transmission on the signals to be sampled according to different preset phase delays for different channels, the adding circuit 26 adds the signals to be sampled after phase delay in each channel and collects the added signals to be sampled to a sampling chip 30, the sampling chip 30 collects the added signals to be sampled to generate a sampling pulse sequence, a control unit respectively moves each sampling pulse in the sampling pulse sequence according to the corresponding preset phase delay to recombine to obtain a sampling signal, thereby increasing the functions of signal multiplexing, delay and accumulation relative to the existing photoelectric conversion circuit 20, repeatedly sampling the same signal to be sampled with different phase delays in a multi-path delay manner, the same effect of high sampling rate can be obtained under the condition of ADC hardware with lower sampling rate, and the cost of software and hardware of the system is reduced.

In one embodiment, the signal multiplexing circuit 24 comprises a power divider, an input of which is connected to the output of the amplifier, and an output of which is connected to the delay circuit 25. The delay circuit 25 includes a delay line, an input end of the delay line is connected to an output end of the power divider, and an output end of the delay line is connected to the adding circuit 26. The summing circuit 26 comprises an adder having an input coupled to the delay line and an output coupled to the sampling chip 30.

Specifically, the power divider has a plurality of output terminals, each output terminal represents a channel, and the power divider multiplexes and transmits the signal to be sampled through the multiple channels. In other embodiments, summing circuit 26 may also be implemented using signal splitting. A delay line is an element or device for delaying an electrical signal for a period of time. In this embodiment, optical fiber delay lines or optical waveguide delay lines may be adopted, each delay line delays a corresponding phase delay, and the phase delays are preset. Illustratively, if n channels are provided, the phase delay of the first channel is t1, the phase delay of the second channel is t2, and the phase delay of the nth channel is t (n-1). The adder accumulates the pulse signals after the phase delay of each channel, and sequentially transmits the pulse signals to the sampling chip 30 for sampling according to the sequence of the phase delay. That is, the sampling chip 30 samples the waveform corresponding to t1 first, then samples the waveform corresponding to t2, and so on. Thus, the waveform input to the sampling chip 30 is a waveform composed of a plurality of pulse signals sequentially arranged in the order of time delay. Then, the sampling chip 30 samples the input pulse signal according to a certain sampling interval to obtain a plurality of pulse waveforms arranged in sequence, that is, a sampling pulse sequence, where each pulse waveform has a sparse sampling point; and the control unit delays and moves each pulse signal according to the corresponding phase, so that a plurality of waveforms with sparse sampling points are overlapped to obtain a pulse waveform with dense sampling points, and the pulse waveform is the sampling signal. Therefore, the sampling rate of the pulse signal is improved, the pulse signal can be completely collected, the information which is rapidly changed in the pulse signal is captured, and the system measurement accuracy is improved.

In an embodiment, referring to fig. 1, the laser radar further includes a laser, a transceiver module, and a scanning module, the control unit 10 controls the laser to emit a probe light pulse to the scanning module via the transceiver module, and the scanning module detects an object to be detected by using the probe light pulse, receives an echo pulse signal returned by the detected object, and sends the echo pulse signal to the photoelectric conversion circuit 20 via the transceiver module. The laser comprises a pulse driver, a seed light source, an optical amplifier and an optical beam splitter, when the laser emits detection laser, the pulse driver controls the seed light source to emit the detection laser beam to exit out of the laser after the detection laser beam sequentially passes through the optical amplifier and the optical beam splitter, and the detection laser beam irradiates an object to be detected through a receiving and transmitting optical module and a scanning system so as to detect the distance of the object to be detected. The detection laser irradiates on the object to be detected and returns an echo pulse signal, the echo pulse signal sequentially passes through the scanning module and the transceiver module and enters the photoelectric conversion circuit 20, and then the photoelectric conversion circuit 20 performs photoelectric conversion to obtain a signal to be sampled. The scanning module in this embodiment is a two-dimensional scanning module, and scans an object to be measured in a mechanical scanning manner.

In this embodiment, the delay time difference between adjacent channels is larger than the pulse width of the signal to be sampled transmitted in the channel. Since the adding circuit 26 is used to add multiple paths of delayed signals to be sampled, if the delay time difference between each path of signals is too small, the two pulse waveforms of the signals to be sampled are overlapped after being added. Therefore, the condition of overlapping and collecting a plurality of pulses is avoided, and the delay time difference between adjacent channels needs to be ensured to be larger than the pulse width of the signal to be sampled transmitted in the channels, so that the accuracy and the reliability of pulse sampling can be improved.

In a specific implementation, the delay time difference between adjacent channels is:

ΔT_{delay time}＝X_Y*T+Y*T/n

Wherein, Delta T_{Delay time}For the delay time difference, n is the number of channels, T is the sampling interval of the sampling chip 30, Y is the number of the channel, and X is an integer corresponding to the channel Y. In the system, the ADC sampling interval is T (namely the sampling frequency is 1/T), when n (n is more than or equal to 1) paths of time delays are designed, the time difference between each path of time delay is larger than the width of a signal pulse, and the superposition and collection of a plurality of pulses are avoided. And the delay time difference between every two pulses is XY T + Y T/n. And Y is the number of the delay channel, namely n-way delay is used for carrying out n-way averaging on the sampling interval T of the ADC. X_YIs an integer corresponding to the delay path Y to ensure that each path of pulses does not overlap each other. Since the detection pulse of the laser radar is of a narrow time width, the pulse intervalThere is no laser power in between, i.e. the sampling value of ADC is 0, the adding circuit 26 has the effect of sequentially sending the pulse signals subjected to multi-path delay to ADC for sampling according to the sequence of giving phase delay, sequentially subtracting the delay integer X corresponding to the channel from the sampling pulse sequence in the signal processing process, and recombining the pulse signals into a pulse signal with equivalent sampling interval of T/n, i.e. sampling frequency increased by n times. The pulse signal equivalent sampling rate is improved, so that information which changes rapidly in the pulse signal equivalent sampling rate can be grasped, and the measurement accuracy of the system can be improved.

Referring to fig. 7, an embodiment of the present invention further provides a pulse sampling method for a laser radar, and the pulse sampling method of this embodiment may be applied to the laser radar of the foregoing embodiment, and may also be a laser radar of other embodiments. The pulse sampling method includes steps S101-S106.

And S101, acquiring an echo pulse signal and performing photoelectric conversion to obtain a signal to be sampled.

And S102, multiplexing the signals to be sampled and sending the signals to different channels for transmission.

And S103, carrying out phase delay transmission on the signal to be sampled according to different preset phase delays on different channels.

And S104, adding the signals to be sampled after the phase delay in each channel.

And S105, collecting the added signals to be sampled to generate a sampling pulse sequence.

And S106, respectively carrying out delay movement on each sampling pulse in the sampling pulse sequence according to the corresponding preset phase so as to obtain a sampling signal through recombination.

Specifically, the description is made with reference to fig. 6. First, the first waveform is a waveform diagram of an original pulse signal without delay, and the original pulse signal is transmitted through a channel. The signal to be sampled is multiplexed and then transmitted in the multiple channels, such as the second waveform and the third waveform in the figure, which respectively represent waveforms of the signal to be sampled transmitted in two different channels. Since different phase delays are provided for different channels, the pulse signal of the second waveform is delayed by time t1, and the pulse signal of the third waveform is delayed by time t (n-1). After the signals to be sampled of each channel are correspondingly delayed, the delayed signals to be sampled of each channel are added to obtain a waveform with a plurality of pulse signals, as shown in the fourth waveform. The sampling chip 30 collects the added signals to be sampled at the sampling interval T to obtain a sampling pulse sequence, i.e., a fifth waveform, and because the adoption rate of the ADC is limited, each waveform collects fewer sampling points, i.e., a few sparse sampling points on the pulse signal in the fifth waveform. Finally, the pulse signals are recombined, each pulse signal is moved according to the corresponding phase delay, namely the pulse signals are overlapped, as shown by the sixth waveform, so that a pulse waveform with dense acquisition points is obtained, namely the original sampling pulse signal is restored through the overlapping of the pulse waveforms, the sampling pulse signal has more acquisition points relative to the direct sampling of the ADC, the pulse waveform can be completely acquired, the equivalent sampling rate of the pulse signal is improved, the information of rapid change in the pulse signal can be grasped, and the measurement accuracy of the system is improved.

After obtaining the equivalent high sampling rate signal, the distance of the target can be calculated by various distance measurement algorithms. The distance measurement algorithm is commonly known as a gravity center method, a constant ratio timing method and the like, and is not limited. The waveform matching algorithm is commonly an Euler distance judgment method, a pulse compression algorithm and the like, and is not limited.

In the embodiment, the same pulse signal is repeatedly sampled by different phase delays through a multipath delay method, the same effect of high sampling rate can be obtained to a certain extent under the condition of lower sampling rate ADC hardware, and the cost of software and hardware of the system is reduced.

Fig. 8 is a schematic block diagram of a pulse sampling apparatus 200 of a lidar according to an embodiment of the present invention. As shown in fig. 8, the present invention also provides a pulse sampling apparatus 200 of a laser radar corresponding to the above pulse sampling method of a laser radar. The pulse sampling apparatus 200 of the laser radar includes a unit for performing the above-described pulse sampling method of the laser radar, and the apparatus may be configured in the laser radar. Specifically, referring to fig. 8, the pulse sampling apparatus 200 of the lidar includes: the photoelectric conversion unit 201, the multiplexing unit 202, the delay unit 203, the adding unit 204, the collecting unit 205, and the recombining unit 206.

201. And the photoelectric conversion unit is used for acquiring the echo pulse signal and performing photoelectric conversion to obtain a signal to be sampled.

202. And the multiplexing unit is used for multiplexing the signals to be sampled and sending the signals to different channels for transmission.

203. And the delay unit is used for carrying out phase delay transmission on the signal to be sampled according to different preset phase delays on different channels.

204. And the adding unit is used for adding the signals to be sampled after the phase delay in each channel.

205. And the acquisition unit is used for acquiring the added signals to be sampled so as to generate a sampling pulse sequence.

206. And the recombination unit is used for respectively carrying out delay movement on each sampling pulse in the sampling pulse sequence according to the corresponding preset phase so as to recombine to obtain a sampling signal.

It should be noted that, as can be clearly understood by those skilled in the art, the detailed implementation process of the pulse sampling apparatus 200 and each unit of the laser radar may refer to the corresponding description in the foregoing method embodiment, and for convenience and brevity of description, no further description is provided herein.

It will be understood by those skilled in the art that all or part of the flow of the method implementing the above embodiments may be implemented by a computer program instructing associated hardware. The computer program includes program instructions, and the computer program may be stored in a storage medium, which is a computer-readable storage medium. The program instructions are executed by at least one processor in the computer system to implement the flow steps of the embodiments of the method described above.

Accordingly, the present invention also provides a storage medium. The storage medium may be a computer-readable storage medium. The storage medium stores a computer program, wherein the computer program comprises program instructions. The program instructions, when executed by the processor, cause the processor to perform the steps of: acquiring an echo pulse signal and performing photoelectric conversion to obtain a signal to be sampled; multiplexing and sending signals to be sampled to different channels for transmission; carrying out phase delay transmission on signals to be sampled according to different preset phase delays on different channels; adding the signals to be sampled after phase delay in each channel; collecting the added signals to be sampled to generate a sampling pulse sequence; and respectively moving each sampling pulse in the sampling pulse sequence according to the corresponding preset phase delay to obtain a sampling signal through recombination.

The storage medium may be a usb disk, a removable hard disk, a Read-Only Memory (ROM), a magnetic disk, or an optical disk, which can store various computer readable storage media.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the examples described in connection with the embodiments disclosed herein may be embodied in electronic hardware, computer software, or combinations of both, and that the components and steps of the examples have been described in a functional general in the foregoing description for the purpose of illustrating clearly the interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

In the embodiments provided in the present invention, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative. For example, the division of each unit is only one logic function division, and there may be another division manner in actual implementation. For example, various elements or components may be combined or may be integrated into another system, or some features may be omitted, or not implemented.

The steps in the method of the embodiment of the invention can be sequentially adjusted, combined and deleted according to actual needs. The units in the device of the embodiment of the invention can be merged, divided and deleted according to actual needs. In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a storage medium. Based on such understanding, the technical solution of the present invention essentially or partially contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a terminal, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. A lidar comprising: control unit, sampling chip and photoelectric conversion circuit, the control unit the sampling chip with photoelectric conversion circuit connects gradually, photoelectric conversion circuit is including photodiode, transimpedance amplifier, the amplifier that connects gradually, photodiode is used for receiving echo pulse signal and obtains treating the sampling signal in order to carry out photoelectric conversion, its characterized in that, photoelectric conversion circuit still includes:

the signal multiplexing circuit is connected with the amplifier and is used for multiplexing and sending the signals to be sampled to different channels for transmission;

the delay circuit is connected with the signal multiplexing circuit and is used for carrying out phase delay transmission on the signals to be sampled according to different preset phase delays on different channels;

the input end of the adding circuit is connected with the delay circuit, the output end of the adding circuit is connected with the sampling chip, and the adding circuit is used for adding the signals to be sampled after phase delay in each channel and collecting the signals to be sampled to the sampling chip;

the sampling chip is used for collecting the added signals to be sampled so as to generate a sampling pulse sequence;

and the control unit respectively carries out delay movement on each sampling pulse in the sampling pulse sequence according to the corresponding preset phase so as to obtain a sampling signal through recombination.

2. The lidar of claim 1, wherein the signal multiplexing circuit comprises a power splitter, an input of the power splitter coupled to an output of the amplifier, and an output of the power splitter coupled to the delay circuit.

3. The lidar of claim 2, wherein the delay circuit comprises a delay line, an input of the delay line coupled to the output of the power divider, and an output of the delay line coupled to the summing circuit.

4. The lidar of claim 3, wherein the summing circuit comprises a summer having an input coupled to the delay line and an output coupled to the sampling chip.

5. The lidar of claim 4, further comprising a laser, a transceiver module and a scanning module, wherein the control unit controls the laser to emit a probe light pulse to the scanning module via the transceiver module, and the scanning module detects an object to be detected by using the probe light pulse and receives an echo pulse signal returned by the detected object, and sends the echo pulse signal to the photoelectric conversion circuit via the transceiver module.

6. Lidar according to any of claims 1 to 5, wherein the delay time difference between adjacent channels is larger than the pulse width of the signal to be sampled transmitted in the channel.

7. Lidar according to claim 6, wherein the delay time difference between adjacent channels is:

ΔT_{delay time}＝X_Y*T+Y*T/n

8. A method of pulse sampling for a lidar comprising:

acquiring an echo pulse signal and performing photoelectric conversion to obtain a signal to be sampled;

multiplexing and sending signals to be sampled to different channels for transmission;

carrying out phase delay transmission on signals to be sampled according to different preset phase delays on different channels;

adding the signals to be sampled after phase delay in each channel;

collecting the added signals to be sampled to generate a sampling pulse sequence;

and respectively moving each sampling pulse in the sampling pulse sequence according to the corresponding preset phase delay to obtain a sampling signal through recombination.

9. A pulse sampling apparatus for a lidar, comprising:

the photoelectric conversion unit is used for acquiring an echo pulse signal and performing photoelectric conversion to obtain a signal to be sampled;

the multiplexing unit is used for multiplexing and sending the signals to be sampled to different channels for transmission;

the delay unit is used for carrying out phase delay transmission on the signal to be sampled according to different preset phase delays on different channels;

the adding unit is used for adding the signals to be sampled after the phase delay in each channel;

the acquisition unit is used for acquiring the added signals to be sampled so as to generate a sampling pulse sequence;

and the recombination unit is used for respectively carrying out delay movement on each sampling pulse in the sampling pulse sequence according to the corresponding preset phase so as to recombine to obtain a sampling signal.

10. A storage medium, characterized in that the storage medium stores a computer program comprising program instructions which, when executed by a processor, implement the steps of the method as claimed in claim 8.