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

Abstract

The present invention discloses a laser radar and its pulse sampling method, device and storage medium. The photoelectric conversion circuit of the laser radar includes: a signal multiplexing circuit connected to the amplifier for multiplexing the sampled signal and sending it to different channels for transmission; a delay circuit connected to the signal multiplexing circuit for phase-delayed transmission of the sampled signal to different channels according to different preset phase delays; an adding circuit, the input end of which is connected to the delay circuit and the output end of which is connected to the sampling chip, for adding the phase-delayed sampled signal in each channel and summing the summed signal to the sampling chip; the sampling chip is used to collect the added sampled signal to generate a sampling pulse sequence, and a control unit shifts each sampling pulse in the sampling pulse sequence according to its corresponding preset phase delay to reconstruct the sampled signal. This can improve the equivalent sampling rate of the pulse signal.

Description

Technical Field

[0001] The present invention relates to the field of laser measurement technology, and in particular to a laser radar and a pulse sampling method, device and storage medium thereof. Background Art

[0002] With the development of new intelligent products such as mobile robots, laser ranging technology is widely used in unmanned driving and automatic obstacle avoidance planning for drones. This has also put forward new requirements for laser ranging technology in terms of ranging performance, ranging accuracy, power consumption, size, stability, and reliability. Pulse laser radar has advantages such as a large measurement range and low light source coherence requirements. It is widely used in military exploration, aerospace, robotics and other fields. Therefore, improving the accuracy of pulse laser ranging is one of the key future development directions of laser ranging technology.

[0003] Currently, the most common laser detection method is direct pulse detection. During operation, the system transmits one or more laser pulse signals. When these transmitted pulses hit the target, a portion of the energy is reflected and received by the detection system. The detection system measures the time difference between the emission and reception moments to obtain the flight time of the laser pulse and measures the target distance D = △T*c / 2 based on the speed of light in air.

[0004] There are two methods for calculating the flight time of the received laser pulse. One method uses the laser emission moment as the starting moment, performs photoelectric conversion on the received laser pulse signal, uses a comparator to obtain the time when the laser pulse returns, and then uses a TDC (time-to-digital conversion) chip to obtain the laser pulse flight time ΔT. The other method uses the laser emission moment as the starting moment, performs photoelectric conversion on the received laser pulse signal, uses an ADC (analog-to-digital conversion) chip to collect the waveform information of the echo pulse signal, and then uses digital signal processing to obtain the time information when the laser pulse returns, thereby obtaining the laser pulse flight time ΔT based on the ADC sampling clock information.

[0005] When using a TDC circuit to acquire the laser time of flight, a strict signal reception threshold must be set. If the threshold is set too high, small signals will not be received; if the threshold is set too low, the noise signal will often exceed the set threshold, introducing more noise pulses. If not handled properly, more noise points will be introduced.

[0006] When using the ADC solution, since the pulses emitted by the lidar are relatively narrow, often only a few nanoseconds (~5ns), effectively capturing the pulse waveform of the echo pulse signal requires a very high-speed ADC chip, which is both costly and power-intensive. Summary of the Invention

[0007] The present invention provides a laser radar and a pulse sampling method, device and storage medium thereof, aiming to solve the problem that it is difficult to collect all the information of the echo pulse due to the limited sampling rate of the ADC chip.

[0008] In the first aspect, the present invention provides a laser radar, comprising: a control unit, a sampling chip and a photoelectric conversion circuit, wherein the control unit, the sampling chip and the photoelectric conversion circuit are connected in sequence, and the photoelectric conversion circuit comprises a photodiode, a transimpedance amplifier and an amplifier connected in sequence, wherein the photodiode is used to receive an echo pulse signal for photoelectric conversion to obtain a signal to be sampled, and the photoelectric conversion circuit further comprises: a signal multiplexing circuit connected to the amplifier, for multiplexing the signal to be sampled and sending it to different channels for transmission; a delay circuit connected to the signal multiplexing circuit, for phase-delaying the transmission of the signal to be sampled according to different preset phase delays for different channels; an adding circuit, the input end of which is connected to the delay circuit and the output end of which is connected to the sampling chip, for adding the phase-delayed signal to be sampled in each channel and summing it to the sampling chip; the sampling chip is used to collect the added signal to be sampled to generate a sampling pulse sequence; the control unit shifts each sampling pulse in the sampling pulse sequence according to its corresponding preset phase delay to reorganize and obtain a sampling signal.

[0009] Furthermore, the signal multiplexing circuit includes a power divider, the input end of the power divider is connected to the output end of the amplifier, and the output end of the power divider is connected to the delay circuit.

[0010] Furthermore, the delay circuit 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.

[0011] Furthermore, the adding circuit includes an adder, an input end of the adder is connected to the delay line, and an output end of the adder is connected to the sampling chip.

[0012] Furthermore, the laser radar also includes a laser, a light receiving and emitting module and a scanning module. The control unit controls the laser to emit a detection light pulse through the light receiving and emitting module to the scanning module. The scanning module uses the detection light pulse to detect the object to be detected and receives the echo pulse signal returned by the detected object, and sends it to the photoelectric conversion circuit through the light receiving and emitting module.

[0013] Furthermore, the delay time difference between adjacent channels is greater than the pulse width of the signal to be sampled transmitted in the channel.

[0014] Furthermore, the delay time difference between adjacent channels is:

[0015] ΔT 延 =X Y *T+Y*T / n

[0016] Where ΔT 延 is the delay time difference, n is the number of channels, T is the sampling interval of the sampling chip, Y is the channel number, and X is the integer corresponding to this channel Y.

[0017] In a second aspect, the present invention also provides a pulse sampling method for a laser radar, comprising: acquiring an echo pulse signal and performing photoelectric conversion to obtain a signal to be sampled; multiplexing the signal to be sampled and sending it to different channels for transmission; performing phase-delayed transmission on the signal to be sampled according to different preset phase delays for different channels; adding the phase-delayed signals to be sampled in each channel; collecting the added signals to be sampled to generate a sampling pulse sequence; and moving each sampling pulse in the sampling pulse sequence according to its corresponding preset phase delay to reorganize and obtain a sampling signal.

[0018] In a third aspect, the present invention also provides a pulse sampling device for a laser radar, comprising: a photoelectric conversion unit for acquiring an echo pulse signal and performing photoelectric conversion to obtain a signal to be sampled; a multiplexing unit for multiplexing the signal to be sampled and sending it to different channels for transmission; a delay unit for performing phase-delayed transmission of the signal to be sampled according to different preset phase delays for different channels; an adding unit for adding the phase-delayed signal to be sampled in each channel; a collection unit for collecting the added signal to be sampled to generate a sampling pulse sequence; and a recombination unit for moving each sampling pulse in the sampling pulse sequence according to its corresponding preset phase delay to recombinantly obtain a sampling signal.

[0019] In a fourth aspect, the present invention further provides a storage medium storing a computer program, wherein the computer program includes program instructions, and when the program instructions are executed by a processor, the steps of the method described in the second aspect can be implemented.

[0020] Compared with the prior art, the present invention has the following beneficial effects: by providing a signal multiplexing circuit, a delay circuit, and an addition circuit, the signal multiplexing circuit multiplexes the signal to be sampled and sends it to different channels for transmission; the delay circuit performs phase-delayed transmission of the signal to be sampled on different channels according to different preset phase delays; the addition circuit adds the phase-delayed signal to be sampled in each channel and aggregates the signals to be sampled to the sampling chip; the sampling chip collects the added signal to be sampled to generate a sampling pulse sequence; the control unit shifts each sampling pulse in the sampling pulse sequence according to its corresponding preset phase delay to reassemble and obtain a sampling signal; thereby, compared with the prior photoelectric conversion circuit, the present invention adds signal multiplexing, delay, and accumulation functions; by means of multiple delays, the same signal to be sampled is repeatedly sampled with different phase delays; the same effect of a high sampling rate can be achieved with lower sampling rate ADC hardware, thereby reducing the system software and hardware costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 A schematic diagram of a laser radar system according to an embodiment of the present invention is shown;

[0023] Figure 2 A circuit diagram of a photoelectric conversion circuit in the prior art is shown;

[0024] Figure 3 A schematic diagram showing the laser radar detection pulse waveform;

[0025] Figure 4 The pulse waveform sampled by ADC in the prior art is shown;

[0026] Figure 5 A circuit diagram showing a photoelectric conversion circuit of a laser radar according to an embodiment of the present invention is shown;

[0027] Figure 6 The pulse signal waveform diagram of the laser radar according to the embodiment of the present invention is shown;

[0028] Figure 7 A schematic flow chart showing the steps of a pulse sampling method for a laser radar according to an embodiment of the present invention is shown;

[0029] Figure 8 A schematic diagram of a pulse sampling device of a laser radar according to an embodiment of the present invention is shown;

[0030] 10. Control unit; 20. Photoelectric conversion circuit; 21. Photodiode; 22. Transimpedance amplifier; 23. Amplifier; 24. Signal multiplexing circuit; 25. Delay circuit; 26. Adding circuit; 30. Sampling chip. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0032] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described 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.

[0033] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the present invention. As used in the specification and appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0034] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0035] First, the background technology of this application is further explained. LiDAR usually includes a laser, light transmitting and receiving, system control and signal processing, power management, and a scanning module. The scanning module can be a one-dimensional scanning or a two-dimensional scanning. The scanning method can be divided into mechanical scanning, MEMS scanning, OPA scanning, etc. Figure 1 The figure shows a 2D scanning solution, which is for illustration only and not for limitation.

[0036] LiDAR operates to acquire point cloud data of the environment. To obtain three-dimensional point cloud data, the direction and distance of each detection point must be accurately determined. Direction information is determined by the scanning module; target distance information is obtained by the system control and signal processing module by processing the echo light pulses captured by the light-emitting and receiving modules.

[0037] When the pulsed laser radar is working, the laser emits a detection laser pulse through the light-receiving and light-emitting module. After the laser pulse hits the target, part of the light energy is reflected back to the laser radar system. The mirror-receiving and light-emitting module converges the light energy to the photoelectric conversion circuit, which converts the light energy signal into an electrical signal for processing.

[0038] like Figure 2 As shown in the figure, a common photoelectric conversion circuit includes an APD (avalanche photodiode), a TIA (transimpedance amplifier) ​​and an AMP (amplifier). The APD, TIA and AMP are connected in sequence, and a bias voltage is applied to the APD. The APD receives the echo pulse signal and converts it into an electrical signal through photoelectric conversion. The signal is then amplified by the TIA and AMP and fed to the sampling chip for collection.

[0039] The electrical pulse signal obtained after being processed by the photoelectric conversion circuit is as follows Figure 3 As shown, its shape is similar to the emitted laser pulse, but with a time delay. During pulsed lidar operation, the target's distance is determined by measuring the relative signal delay (ΔT), the laser pulse's flight time, and the known speed of light (c): D = ΔT*c / 2.

[0040] Due to cost considerations, the ADC chip used in the system is often limited in speed and cannot collect all the information of the echo pulse. The original continuous waveform is sampled into a discrete waveform, such as Figure 4 As shown, only a few points of the waveform can be collected, and the complete waveform cannot be collected.

[0041] For example, due to the limited sampling rate, when 1GSPS is used to collect signals, the time interval between sampling points is 1ns, and the corresponding time delay shows that the distance accuracy is 15cm, which cannot meet the application requirements. In actual use, some processing must be performed on the sampled signals to improve the distance measurement accuracy.

[0042] In summary, existing ADC solutions often rely on relatively low-rate (~1GSPS) ADC chips, capturing only a few pulse signals. Accurately determining the laser pulse's time-of-flight requires complex, high-order interpolation algorithms to recover the signal pulses, which is computationally intensive. Furthermore, interpolation cannot effectively restore certain rapidly changing signal characteristics, hindering improvements in ranging accuracy.

[0043] To this end, this application designs a method for signal delay and repeated sampling, which can obtain digital signals with higher equivalent sampling rates when the ADC chip rate is limited. The details are as follows:

[0044] Reference Figure 5An embodiment of the present invention provides a laser radar, comprising: 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 connected in sequence, and the photoelectric conversion circuit 20 comprises a photodiode 21, a transimpedance amplifier 22, and an amplifier 23 connected in sequence, wherein the photodiode 21 is used to receive an echo pulse signal to perform photoelectric conversion to obtain a signal to be sampled, and the photoelectric conversion circuit 20 further comprises: a signal multiplexing circuit 24 connected to the amplifier 23, and configured to multiplex the signal to be sampled and send it to different channels for transmission; a delay circuit The circuit 25 is connected to the signal multiplexing circuit 24 and is used to perform phase-delayed transmission of the signals to be sampled according to different preset phase delays for different channels. The adding circuit 26 has an input end connected to the delay circuit 25 and an output end connected to the sampling chip 30 and is used to add the phase-delayed signals to be sampled in each channel and aggregate them to the sampling chip 30. The sampling chip 30 is used to collect the added signals to be sampled to generate a sampling pulse sequence. The control unit 10 shifts each sampling pulse in the sampling pulse sequence according to its corresponding preset phase delay to reconstruct the sampling signal.

[0045] By implementing this embodiment, a signal multiplexing circuit 24, a delay circuit 25, and an adding circuit 26 are provided. The signal multiplexing circuit 24 multiplexes the signal to be sampled and transmits it to different channels for transmission. The delay circuit 25 performs phase delay transmission on the signal to be sampled according to different preset phase delays for different channels. The adding circuit 26 adds the phase-delayed signal to be sampled in each channel and aggregates the summed signal to be sampled to generate a sampling pulse sequence. The control unit shifts each sampling pulse in the sampling pulse sequence according to its corresponding preset phase delay to reconstruct the sampling signal. Thus, compared with the existing photoelectric conversion circuit 20, signal multiplexing, delay, and accumulation functions are added. By means of multiple delays, the same signal to be sampled is repeatedly sampled with different phase delays. The same effect of a high sampling rate can be achieved with lower sampling rate ADC hardware, thereby reducing the system software and hardware costs.

[0046] In one embodiment, the signal multiplexing circuit 24 includes a power divider, the input end of the power divider is connected to the output end of the amplifier, and the output end of the power divider is connected to the delay circuit 25. The delay circuit 25 includes a delay line, the input end of the delay line is connected to the output end of the power divider, and the output end of the delay line is connected to the adding circuit 26. The adding circuit 26 includes an adder, the input end of the adder is connected to the delay line, and the output end of the adder is connected to the sampling chip 30.

[0047] Specifically, the power divider has multiple output terminals, each representing a channel. The power divider multiplexes the signals to be sampled and transmits them through multiple channels. In other embodiments, the adding circuit 26 can also be implemented using signal splitting. A delay line is an element or device used to delay an electrical signal for a period of time. This embodiment can use an optical fiber delay line or an optical waveguide delay line, each delaying a corresponding phase delay, and the phase delay is pre-set. For example, if there are n channels, 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 phase-delayed pulse signals of each channel and transmits them to the sampling chip 30 for sampling in the order of phase delay. This means that the sampling chip 30 first samples the waveform corresponding to t1, then samples the waveform corresponding to t2, and so on. As a result, the waveform input to the sampling chip 30 is a waveform composed of multiple pulse signals arranged in order of delay. The sampling chip 30 then samples the input pulse signal at a specific sampling interval, generating a sequence of multiple pulse waveforms, or sampling pulse sequences, each with sparse sampling points. The control unit then shifts each pulse signal by its corresponding phase delay, allowing the multiple waveforms with sparse sampling points to overlap to form a pulse waveform with dense sampling points. This pulse waveform is the sampling signal. This improves the sampling rate of the pulse signal, enabling the complete acquisition of the pulse signal and capturing its rapidly changing information, thereby improving the system's measurement accuracy.

[0048] In one embodiment, referring to Figure 1 The laser radar also includes a laser, a light-receiving and light-emitting module, and a scanning module. The control unit 10 controls the laser to emit a probe light pulse, which is transmitted through the light-receiving and light-emitting module to the scanning module. The scanning module uses the probe light pulse to detect the object to be measured and receives the echo pulse signal returned by the detected object, which is then transmitted to the photoelectric conversion circuit 20 through the light-receiving and light-emitting module. The laser includes a pulse drive, a seed light source, an optical amplifier, and an optical beam splitter. When the laser emits a probe laser, the pulse drive controls the seed light source to emit a probe laser beam, which passes through the optical amplifier and the optical beam splitter in sequence and then exits the laser. The probe laser beam then passes through the light-receiving and light-emitting module and the scanning system to illuminate the object to be measured, thereby detecting the distance to the object to be measured. When the probe laser is irradiated on the object to be measured, an echo pulse signal is returned. The echo pulse signal passes through the scanning module and the light-receiving and light-emitting module in sequence and enters the photoelectric conversion circuit 20. The photoelectric conversion circuit 20 then performs photoelectric conversion to obtain a signal to be sampled. The scanning module in this embodiment is a two-dimensional scanning module that scans the object to be measured through mechanical scanning.

[0049] In this embodiment, the delay time difference between adjacent channels is greater than the pulse width of the signal to be sampled transmitted in each channel. Because adding circuit 26 is used to add multiple delayed signals to be sampled, if the delay time difference between each channel is too small, the two pulse waveforms of the added signal to be sampled may overlap. Therefore, to avoid the situation where multiple pulses are superimposed on each other, it is necessary to ensure that the delay time difference between adjacent channels is greater than the pulse width of the signal to be sampled transmitted in the channel, thereby improving the accuracy and reliability of pulse sampling.

[0050] In a specific implementation, the delay time difference between adjacent channels is:

[0051] ΔT 延 =X Y *T+Y*T / n

[0052] Where ΔT 延 is the delay time difference, n is the number of channels, T is the sampling interval of the sampling chip 30, Y is the channel number, and X is the integer corresponding to this channel Y. In the system, the ADC sampling interval is T (i.e., the sampling frequency is 1 / T). When the design has n (n ≥ 1) delay channels, the time difference between each delay channel must be greater than the width of the signal pulse to avoid the superposition of multiple pulses. The delay time difference between each pulse channel is XY*T+Y*T / n. Where Y is the delay channel number, that is, the ADC sampling interval T is divided into n equal parts by n delay channels. X Y is an integer corresponding to this delay channel Y, ensuring that each pulse does not overlap. Because the laser radar's detection pulse has a narrow time width, there is no laser power between pulse intervals, that is, the ADC sampling value is 0. The effect of the adding circuit 26 is to send the pulse signals that have undergone multiple delays to the ADC for sampling in the order given to the phase delay. During the signal processing process, the sampled pulse sequence is sequentially subtracted from the delay integer X corresponding to the channel, and recombined into a pulse signal with an equivalent sampling interval of T / n, that is, the sampling frequency is increased by n times. Increasing the equivalent sampling rate of the pulse signal is beneficial for capturing rapidly changing information and improving the measurement accuracy of the system.

[0053] Reference Figure 7 The present invention also provides a pulse sampling method for a laser radar. The pulse sampling method of this embodiment can be applied to the laser radar of the above embodiment or to the laser radar of other embodiments. The pulse sampling method includes steps S101-S106.

[0054] S101 , acquiring an echo pulse signal and performing photoelectric conversion to obtain a signal to be sampled.

[0055] S102: Multiplex the signal to be sampled and send it to different channels for transmission.

[0056] S103 , performing phase-delay transmission on the signal to be sampled according to different preset phase delays for different channels.

[0057] S104: Add the phase-delayed signals to be sampled in each channel.

[0058] S105 , sampling the added signals to be sampled to generate a sampling pulse sequence.

[0059] S106 , respectively delay and shift each sampling pulse in the sampling pulse sequence according to its corresponding preset phase to reconstruct a sampling signal.

[0060] Specifically, combined Figure 6 To explain. First, the first waveform is a waveform diagram of the original pulse signal that has not been delayed, and the original pulse signal is transmitted through one channel. The signal to be sampled is transmitted in multiple channels after multiplexing, as shown in the second waveform and the third waveform in the figure, which respectively represent the waveforms of the signal to be sampled being transmitted in two different channels. Among them, since different phase delays are set for different channels, the pulse signal of the second waveform has been delayed for a time of t1, and the pulse signal of the third waveform has been delayed for a time of t(n-1). After the signal to be sampled of each channel is delayed accordingly, the delayed signal to be sampled of each channel is added together to obtain a waveform with multiple pulse signals, as shown in the fourth waveform. Then, the sampling chip 30 collects the added signal to be sampled at a sampling interval T to obtain a sampling pulse sequence, i.e., the fifth waveform. Due to the limited sampling rate of the ADC, each waveform collects fewer sampling points, i.e., the relatively sparse sampling points on the pulse signal in the fifth waveform. Finally, multiple pulse signals are recombined, and each pulse signal is shifted according to its corresponding phase delay, that is, multiple pulse signals are overlapped, as shown in the sixth waveform, thereby obtaining a pulse waveform with dense acquisition points. In other words, the original sampling pulse signal is restored by overlapping multiple pulse waveforms. Compared with direct sampling by ADC, this sampling pulse signal has more acquisition points and can completely acquire the pulse waveform. Increasing the equivalent sampling rate of the pulse signal is conducive to capturing the rapidly changing information therein and improving the measurement accuracy of the system.

[0061] After obtaining an equivalent high-sampling-rate signal, various distance measurement algorithms can be used to calculate the target's distance. Common distance measurement algorithms include the center of gravity method and the constant ratio timing method, but are not limited to any specific method. Common waveform matching algorithms include the Euler distance method and the pulse compression algorithm, but are not limited to any specific method.

[0062] This embodiment uses a multi-path delay method to repeatedly sample the same pulse signal with different phase delays. To a certain extent, it can achieve the same effect of a high sampling rate with lower sampling rate ADC hardware, thereby reducing the system hardware and software costs.

[0063] Figure 8 FIG. 2 is a schematic block diagram of a pulse sampling device 200 for a laser radar provided by an embodiment of the present invention. Figure 8 As shown, corresponding to the above laser radar pulse sampling method, the present invention also provides a laser radar pulse sampling device 200. The laser radar pulse sampling device 200 includes a unit for executing the above laser radar pulse sampling method, and the device can be configured in the laser radar. Specifically, please refer to Figure 8 The pulse sampling device 200 of the laser radar includes: a photoelectric conversion unit 201, a multiplexing unit 202, a delay unit 203, an adding unit 204, a collection unit 205 and a recombination unit 206.

[0064] 201. A photoelectric conversion unit, configured to obtain an echo pulse signal and perform photoelectric conversion to obtain a signal to be sampled.

[0065] 202. A multiplexing unit is used to multiplex the signal to be sampled and send it to different channels for transmission.

[0066] 203. A delay unit, configured to perform phase-delay transmission on the signal to be sampled according to different preset phase delays for different channels.

[0067] 204. An adding unit, configured to add the phase-delayed signals to be sampled in each channel.

[0068] 205. An acquisition unit, configured to acquire the added signals to be sampled to generate a sampling pulse sequence.

[0069] 206. A recombining unit, configured to delay and shift each sampling pulse in the sampling pulse sequence according to its corresponding preset phase to recombinantly obtain a sampling signal.

[0070] It should be noted that technical personnel in the relevant field can clearly understand that the specific implementation process of the pulse sampling device 200 and each unit of the above-mentioned laser radar can refer to the corresponding description in the aforementioned method embodiment. For the convenience and conciseness of the description, it will not be repeated here.

[0071] Those skilled in the art will appreciate that all or part of the steps in the method of the above-described embodiment can be implemented by instructing the relevant hardware through a computer program. The computer program includes program instructions, which can be stored in a storage medium that is computer-readable. The program instructions are executed by at least one processor in the computer system to implement the steps in the method of the above-described embodiment.

[0072] Therefore, the present invention also provides a storage medium. The storage medium can be a computer-readable storage medium. The storage medium stores a computer program, wherein the computer program includes program instructions. When executed by a processor, the program instructions cause the processor to perform the following steps: acquiring an echo pulse signal and performing photoelectric conversion to obtain a signal to be sampled; multiplexing the signal to be sampled and transmitting it to different channels for transmission; performing phase-delayed transmission of the signal to be sampled according to different preset phase delays for different channels; adding the phase-delayed signal to be sampled in each channel; sampling the added signal to be sampled to generate a sampling pulse sequence; and shifting each sampling pulse in the sampling pulse sequence according to its corresponding preset phase delay to reconstruct the sampled signal.

[0073] The storage medium may be any computer-readable storage medium that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a magnetic disk, or an optical disk.

[0074] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the composition and steps of each example according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0075] In the several embodiments provided herein, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the various units is merely a logical functional division, and actual implementation may employ other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be omitted or not implemented.

[0076] The steps in the methods of the embodiments of the present invention may be adjusted in order, combined, or deleted as needed. The units in the devices of the embodiments of the present invention may be combined, divided, or deleted as needed. Furthermore, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit.

[0077] If this integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the existing technology, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes a number of instructions for causing a computer device (which can be a personal computer, terminal, or network device, etc.) to execute all or part of the steps of the method described in various embodiments of the present invention.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A laser radar comprising: A control unit, a sampling chip, and a photoelectric conversion circuit, wherein the control unit, the sampling chip, and the photoelectric conversion circuit are connected in sequence, and the photoelectric conversion circuit includes a photodiode, a TIA, and an amplifier connected in sequence, and the photodiode is used to receive the echo pulse signal to perform photoelectric conversion to obtain a signal to be sampled, characterized in that the photoelectric conversion circuit also includes: A signal multiplexing circuit, connected to the amplifier, for multiplexing the signal to be sampled and sending it to different channels for transmission; A delay circuit, connected to the signal multiplexing circuit, for performing phase-delay transmission of the sampled signal on different channels according to different preset phase delays; an adding circuit, the input end of which is connected to the delay circuit, and the output end of which is connected to the sampling chip, for adding the phase-delayed signals to be sampled in each channel and summing the signals to the sampling chip; The sampling chip is used to collect the added signals to be sampled to generate a sampling pulse sequence; The control unit delays and shifts each sampling pulse in the sampling pulse sequence according to its corresponding preset phase to reconstruct a sampling signal, so that a plurality of waveforms with sparse sampling points overlap to obtain a pulse waveform with dense sampling points; Among them, the delay time difference between adjacent channels is greater than the pulse width of the signal to be sampled transmitted in the channel. The delay time difference between adjacent channels is: in, is the delay time difference, n is the number of channels, T is the sampling interval of the sampling chip, Y is the channel number, and X is the delay integer corresponding to this channel Y. During the signal processing process, the sampling pulse sequence is sequentially subtracted from the delay integer X corresponding to the channel, and recombined into a pulse signal with an equivalent sampling interval of T / n, thereby improving the equivalent sampling rate of the pulse signal.

2. The laser radar according to claim 1, characterized in that The signal multiplexing circuit includes a power divider, the input end of the power divider is connected to the output end of the amplifier, and the output end of the power divider is connected to the delay circuit.

3. The laser radar according to claim 2, characterized in that The delay circuit includes a delay line, an input end of the delay line is connected to the output end of the power divider, and an output end of the delay line is connected to the adding circuit.

4. The laser radar according to claim 3, characterized in that The adding circuit includes an adder, an input end of the adder is connected to the delay line, and an output end of the adder is connected to the sampling chip.

5. The laser radar according to claim 4, characterized in that It also includes a laser, a light receiving and emitting module and a scanning module. The control unit controls the laser to emit a detection light pulse through the light receiving and emitting module to the scanning module. The scanning module uses the detection light pulse to detect the object to be detected and receives the echo pulse signal returned by the detected object, and sends it to the photoelectric conversion circuit through the light receiving and emitting module.

6. A pulse sampling method for laser radar, characterized in that: include: Acquire the echo pulse signal and perform photoelectric conversion to obtain the signal to be sampled; Multiplex the signal to be sampled and send it to different channels for transmission; Perform phase delay transmission on the sampling signal according to different preset phase delays for different channels; Add the phase-delayed signals to be sampled in each channel; The added signals to be sampled are collected to generate a sampling pulse sequence; Each sampling pulse in the sampling pulse sequence is respectively delayed and shifted according to its corresponding preset phase to reconstruct a sampling signal, so that a plurality of waveforms with sparse sampling points are overlapped to obtain a pulse waveform with dense sampling points; Among them, the delay time difference between adjacent channels is greater than the pulse width of the signal to be sampled transmitted in the channel. The delay time difference between adjacent channels is: in, is the delay time difference, n is the number of channels, T is the sampling interval of the sampling chip, Y is the channel number, and X is the delay integer corresponding to this channel Y. During the signal processing process, the sampling pulse sequence is sequentially subtracted from the delay integer X corresponding to the channel, and recombined into a pulse signal with an equivalent sampling interval of T / n, thereby improving the equivalent sampling rate of the pulse signal.

7. A pulse sampling device for a laser radar, characterized in that: include: A photoelectric conversion unit is used to obtain the echo pulse signal and perform photoelectric conversion to obtain a signal to be sampled; A multiplexing unit, used for multiplexing the signals to be sampled and sending them to different channels for transmission; A delay unit is used to perform phase-delay transmission on the sampling signal according to different preset phase delays for different channels; An adding unit, used for adding the phase-delayed signals to be sampled in each channel; An acquisition unit, configured to acquire the added signals to be sampled to generate a sampling pulse sequence; a recombining unit, configured to respectively shift each sampling pulse in the sampling pulse sequence according to its corresponding preset phase delay to recombinantly obtain a sampling signal, so that a plurality of waveforms with sparse sampling points are overlapped to obtain a pulse waveform with dense sampling points; Among them, the delay time difference between adjacent channels is greater than the pulse width of the signal to be sampled transmitted in the channel. The delay time difference between adjacent channels is: in, is the delay time difference, n is the number of channels, T is the sampling interval of the sampling chip, Y is the channel number, and X is the delay integer corresponding to this channel Y. During the signal processing process, the sampling pulse sequence is sequentially subtracted from the delay integer X corresponding to the channel, and recombined into a pulse signal with an equivalent sampling interval of T / n, thereby improving the equivalent sampling rate of the pulse signal.

8. A storage medium, characterized in that: The storage medium stores a computer program, which includes program instructions. When the program instructions are executed by a processor, the steps of the method according to claim 6 can be implemented.

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