Laser receiving circuit and laser radar

Abstract

The utility model proposes a laser receiving circuit and a laser radar, and the laser receiving circuit comprises a plurality of photoelectric detection circuits, a plurality of blocking circuits, an analog switch circuit, and a bandwidth compensation circuit, and the photoelectric detection circuits carry out photoelectric conversion and output echo electric signals. The multi-path echo electric signals are selectively output through the analog switch circuit after direct blocking processing, the bandwidth compensation circuit carries out bandwidth compensation on the echo electric signals output by the analog switch circuit, the equivalent bandwidth of the analog switch circuit is improved, and therefore the influence of the analog switch circuit on the echo electric signals is reduced. And the echo electric signal can meet the requirements of narrow pulse width and fast rising edge.

Description

Technical Field

[0001] The utility model belongs to the technical field of laser radar, and in particular relates to a laser receiving circuit and a laser radar. Background Art

[0002] The resolution and ranging accuracy of the LiDAR system are one of the most core indicators. Improving the resolution of the LiDAR means increasing the number of LiDAR lines and the repetition rate of light emission. The narrower the pulse width of the echo signal, the more conducive it is to improving the repetition rate and the number of lines. At the same time, in order to improve the dToF ranging accuracy and time identification accuracy, the echo signal needs to have a faster rising edge. Therefore, echo signals with narrower pulse widths and steeper rising edges play an important role in improving the resolution and ranging accuracy of the LiDAR. For multi-line LiDARs, the laser receiving circuit needs to merge multiple receiving channels to reduce the number of post-stage amplifiers. Analog switches are usually used to switch the receiving channels, but the bandwidth of analog switches is usually low (<100MHz), which is difficult to meet the requirements of narrow pulse width and fast rising edge of the LiDAR echo signal. Utility Model Content

[0003] The utility model aims to provide a laser receiving circuit, aiming to solve the problem of low bandwidth existing in the traditional laser receiving circuit.

[0004] A first aspect of an embodiment of the utility model provides a laser receiving circuit, comprising:

[0005] a plurality of photodetection circuits, each of the photodetection circuits being configured to convert a received laser pulse into an echo electrical signal;

[0006] A plurality of DC isolation circuits, each of which is connected to one of the photoelectric detection circuits, and the DC isolation circuit is configured to perform DC isolation processing on the received echo electrical signal;

[0007] An analog switch circuit, the analog switch circuit comprising a plurality of input terminals and an output terminal, an input terminal of the analog switch circuit being connected to an output terminal of the DC blocking circuit, the analog switch circuit being configured to be triggered by a received selection signal to sequentially select an input terminal and an output terminal thereof, and select and output the plurality of echo electrical signals;

[0008] The bandwidth compensation circuit is connected to the output end of the analog switch circuit and is configured to perform bandwidth compensation on each echo electrical signal output by the analog switch circuit.

[0009] Optionally, the photoelectric detection circuit includes a photoelectric detector and a first resistor;

[0010] The first end of the photodetector is connected to the power supply end, the second end of the photodetector and the first end of the first resistor are connected to form the output end of the photodetection circuit, and the second end of the first resistor is grounded.

[0011] Optionally, the photodetector comprises at least one of an avalanche diode, a silicon photomultiplier tube, a single photon avalanche diode and a photodiode.

[0012] Optionally, the DC blocking circuit includes a capacitor;

[0013] The first end and the second end of the capacitor constitute the input end and the output end of the DC blocking circuit respectively.

[0014] Optionally, the analog switch circuit includes at least one analog switch, multiple input terminals of at least one analog switch are respectively connected to the output terminal of one of the DC isolation circuits, and the output terminals of each analog switch are connected together to form the output terminal of the analog switch circuit.

[0015] Optionally, the bandwidth compensation circuit includes a second resistor;

[0016] A first end of the second resistor is connected to the output end of the analog switch circuit, and a second end of the second resistor is grounded.

[0017] Optionally, the laser receiving circuit further includes:

[0018] The signal amplifying circuit is connected to the output end of the bandwidth compensation circuit and is configured to amplify each of the echo electrical signals output by the bandwidth compensation circuit.

[0019] Optionally, the laser receiving circuit further includes:

[0020] The processing circuit is connected to the signal amplifying circuit and the analog switch circuit respectively, and is configured to output the selection signal and determine the distance information according to the amplified echo electrical signal.

[0021] A second aspect of an embodiment of the utility model proposes a laser radar, comprising a laser transmitting circuit and the laser receiving circuit as described above.

[0022] Optionally, the laser emitting circuit includes a plurality of lasers, and the plurality of lasers are arranged corresponding to a plurality of photoelectric detection circuits of the laser receiving circuit;

[0023] The plurality of lasers are configured to receive power and emit laser pulses according to a preset timing.

[0024] Compared with the prior art, the embodiments of the utility model have the following beneficial effects: the above-mentioned laser receiving circuit includes multiple photoelectric detection circuits, multiple DC isolation circuits, an analog switch circuit and a bandwidth compensation circuit; the photoelectric detection circuit performs photoelectric conversion and outputs an echo electrical signal; the multiple echo electrical signals are selected for output through the analog switch circuit after DC isolation processing; the bandwidth compensation circuit performs bandwidth compensation on the echo electrical signal output by the analog switch circuit, thereby improving the equivalent bandwidth of the analog switch circuit, thereby reducing the influence of the analog switch circuit on the echo electrical signal, so that the echo electrical signal meets the requirements of narrow pulse width and fast rising edge. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0026] Figure 1 A schematic diagram of the first structure of a laser receiving circuit provided by an embodiment of the utility model;

[0027] Figure 2 A circuit diagram of a laser receiving circuit provided by an embodiment of the utility model;

[0028] Figure 3 A first equivalent circuit diagram of an analog switch and a bandwidth compensation circuit provided by an embodiment of the utility model;

[0029] Figure 4 A second equivalent circuit diagram of an analog switch and a bandwidth compensation circuit provided by an embodiment of the utility model;

[0030] Figure 5 A schematic diagram of an amplitude-frequency response curve of an analog switch and a bandwidth compensation circuit provided in an embodiment of the utility model;

[0031] Figure 6 A second structural schematic diagram of a laser receiving circuit provided in an embodiment of the utility model;

[0032] Figure 7 A schematic diagram of the first structure of a laser radar provided in an embodiment of the utility model;

[0033] Figure 8 A second structural schematic diagram of the laser radar provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0034] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0035] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0036] The first aspect of the embodiment of the utility model provides a laser receiving circuit 200, such as Figure 7 As shown, the laser receiving circuit 200 is set corresponding to the laser emitting circuit 100. The laser emitting circuit 100 can select to correspond to multiple lasers 110. The multiple lasers 110 emit laser pulses toward a preset angle according to a preset timing according to a driving signal. At the same time, the laser receiving circuit 200 is set corresponding to the laser emitting circuit 100 to form a multi-line laser radar. The multiple laser pulses are reflected by the object to be measured 1 and returned to the laser receiving circuit 200. The laser receiving circuit 200 performs photoelectric conversion on the laser pulses and outputs multiple echo electrical signals. The echo electrical signals are output to the back-end processing circuit 60 or controller. The processing circuit 60 or controller determines the distance information and reflectivity of the object to be measured 1 according to the echo electrical signals.

[0037] Among them, since the bandwidth of the analog switch U1 of the analog switch circuit 30 is usually low (<100MHz), it is difficult to meet the requirements of narrow pulse width and fast rising edge of the laser radar echo electrical signal. In order to solve this problem, in this embodiment, the laser receiving circuit 200 includes:

[0038] A plurality of photodetection circuits 10, each of which is configured to convert a received laser pulse into an echo electrical signal;

[0039] A plurality of DC isolation circuits 20, each of which is connected to a photoelectric detection circuit 10, and the DC isolation circuit 20 is configured to perform DC isolation processing on the received echo electrical signal;

[0040] The analog switch circuit 30 includes a plurality of input terminals and an output terminal. An input terminal of the analog switch circuit 30 is connected to an output terminal of a DC isolation circuit 20. The analog switch circuit 30 is configured to be triggered by a received selection signal to sequentially select an input terminal and an output terminal thereof, and select and output a plurality of echo electrical signals.

[0041] The bandwidth compensation circuit 40 is connected to the output end of the analog switch circuit 30 and is configured to perform bandwidth compensation on each echo electrical signal output by the analog switch circuit 30 .

[0042] In this embodiment, when performing laser ranging, the laser emitting circuit 100 is controlled to emit multiple laser pulses. After the laser pulses are reflected to the object to be measured 1, they are reflected back to the laser receiving circuit 200. The multiple photoelectric detection circuits 10 respectively perform photoelectric conversion on the reflected multiple laser pulses and output echo electrical signals respectively. The DC isolation circuit 20 at the rear end of each echo electrical signal outputs the DC component after DC isolation processing, and then outputs it to the analog switch circuit 30 connected to the multiple DC isolation circuits 20. The analog switch circuit 30 includes multiple input terminals and an output terminal. The analog switch circuit 30 also includes an enable terminal. The enable terminal receives a selection signal. The analog switch circuit 30 selects the internal transmission channel according to the received selection signal, thereby connecting the corresponding input terminal and output terminal, and selecting and outputting each echo electrical signal in sequence according to a preset timing.

[0043] For example, the analog switch circuit 30 includes 8 input terminals, and is respectively connected to a DC isolation circuit 20. Each DC isolation circuit 20 outputs an echo electrical signal, and includes three enable terminals. When the selection signal is 000, the analog switch circuit 30 selects its own first input terminal and output terminal, and the echo electrical signal input to the first input terminal is selected by the analog switch circuit 30 to be output to the rear-end bandwidth compensation circuit 40. When the selection signal is 001, the analog switch circuit 30 selects its own second input terminal and output terminal, and the echo electrical signal input to the second input terminal is selected by the analog switch circuit 30 to be output to the rear-end bandwidth compensation circuit 40. By analogy, the echo electrical signals input to the 8 input terminals of the analog switch circuit 30 can be selected and output in turn under the control of the selection signal, thereby realizing the merging of multiple different echo electrical signals into one output.

[0044] The bandwidth compensation circuit 40 is used to increase the equivalent bandwidth of the analog switch circuit 30 and realize bandwidth compensation for the echo electrical signal, thereby reducing the influence of the analog switch circuit 30 on the echo electrical signal, so that the echo electrical signal meets the requirements of narrow pulse width and fast rising edge.

[0045] The photoelectric detection circuit 10 may adopt a corresponding photoelectric detector structure. In an optional embodiment, Figure 2 As shown, the photoelectric detection circuit 10 includes a photoelectric detector and a first resistor R1, and the photoelectric detectors are respectively a first photoelectric detector D1, an nth photoelectric detector Dn, etc.;

[0046] The first end of the photodetector is connected to the power supply terminal VDD, the second end of the photodetector is connected to the first end of the first resistor R1 to form the output end of the photodetection circuit 10, and the second end of the first resistor R1 is grounded.

[0047] The photodetector converts the received laser pulse into a current signal, the first resistor R1 converts the current signal into a voltage echo signal, and the voltage echo signal is output to a corresponding input terminal of the analog switch circuit 30 after being isolated by the DC isolation circuit 20 .

[0048] The photodetector may be of a corresponding type. In an optional embodiment, the photodetector includes at least one of an avalanche diode, a silicon photomultiplier tube, a single photon avalanche diode and a photodiode.

[0049] The DC blocking circuit 20 may adopt a corresponding capacitor structure. In an optional embodiment, Figure 2 As shown, the DC blocking circuit 20 includes capacitors, such as a first capacitor C1, an nth capacitor Cn, etc.;

[0050] The first end and the second end of the capacitor constitute the input end and the output end of the DC blocking circuit 20 respectively.

[0051] The capacitors constitute a DC blocking capacitor to isolate the DC component of the voltage echo electrical signal generated by the photodetection circuit 10, and output the echo electrical signal of the pulse signal to the back-end analog switch circuit 30, and select the output through the analog switch circuit 30, and compensate the output through the bandwidth compensation circuit 40.

[0052] The analog switch circuit 30 is used to realize the gated output of the echo electrical signal, and the analog switch U1 of the corresponding structure can be selected, such as Figure 2 As shown, in an optional embodiment, the analog switch circuit 30 includes at least one analog switch U1, and multiple input ends of the at least one analog switch U1 are respectively connected to the output end of a DC isolation circuit 20, and the output ends of each analog switch U1 are connected together to form the output end of the analog switch circuit 30.

[0053] In this embodiment, the analog switch U1 also includes an enable terminal, which receives a selection signal. The analog switch U1 selects the internal transmission channel according to the received selection signal, thereby connecting the corresponding input terminal and output terminal, and selects and outputs each echo electrical signal in sequence according to a preset timing.

[0054] For example, the analog switch U1 includes 8 input terminals, and is respectively connected to a DC isolation circuit 20. Each DC isolation circuit 20 outputs an echo electrical signal, and includes three enable terminals. When the selection signal is 000, the analog switch U1 selects its own first input terminal and output terminal, and the echo electrical signal input to the first input terminal is selected and output to the rear-end bandwidth compensation circuit 40 through the analog switch U1. When the selection signal is 001, the analog switch U1 selects its own second input terminal and output terminal, and the echo electrical signal input to the second input terminal is selected and output to the rear-end bandwidth compensation circuit 40 through the analog switch U1. Similarly, the echo electrical signals input to the 8 input terminals of the analog switch U1 can be selected and output in turn under the control of the selection signal, thereby realizing the merging of multiple different echo electrical signals into one output.

[0055] Among them, the number of analog switches U1 can be set according to the number of paths of the echo electrical signal and the number of its own input terminals. For example, the analog switch U1 includes 8 input terminals. When the number of paths of the photoelectric detection circuit 10 is less than 8, the number of analog switches U1 is 1. When the number of paths of the photoelectric detection circuit 10 is greater than 8, the number of analog switches U1 needs to be greater than 1. For example, when the number of paths of the photoelectric detection circuit 10 is 20, the analog switches U1 include at least 3. The number of DC isolation circuits 20 connected to the 3 analog switches U1 can be 8, 8, 4, 7, 7, 6, 6, 6, 8, etc. respectively. The number of DC isolation circuits 20 connected to each analog switch U1 can be set according to the needs. At the same time, when multiple analog switches U1 are included, the multiple analog switches U1 respectively select and output their own echo electrical signals according to the received selection signals, so that the multi-path echo electrical signals are selected and output according to the preset timing and bandwidth compensation is performed.

[0056] The bandwidth compensation circuit 40 may select corresponding capacitors, resistors, inductors and other structures. In an optional embodiment, Figure 2 As shown, the bandwidth compensation circuit 40 includes a second resistor R2;

[0057] A first end of the second resistor R2 is connected to the output end of the analog switch circuit 30 , and a second end of the second resistor R2 is grounded.

[0058] In this embodiment, Figure 3 As shown, when the analog switch U1 is turned on, the input to output circuit is equivalent to a low-pass filter composed of a third resistor R3 and a second capacitor C2, wherein R3 is the on-resistance of the analog switch U1, C2 is the on-capacitance to ground of the analog switch U1, and R2 is the bypass resistor of the bandwidth compensation circuit 40.

[0059] In order to calculate the -3dB bandwidth of the circuit, Laplace transform is performed on the above circuit, as shown in Figure 4 As shown, Figure 4The s-domain transfer function is:

[0060]

[0061] Right now

[0062]

[0063] The above transfer function has only one real pole and no zero, so the equivalent model is still a first-order low-pass filter, and its amplitude-frequency response curve is as follows: Figure 5 shown.

[0064] The -3dB cutoff frequency of this first-order low-pass filter can be calculated by the following formula,

[0065]

[0066] Therefore, the -3dB bandwidth of the above circuit is When there is no bypass resistor, the -3dB bandwidth of the analog switch U1 is It can be seen that the second resistor R2 can improve the bandwidth of the analog switch U1. The smaller the resistance of the second resistor R2 is, the more obvious the improvement of the bandwidth of the circuit is. When R2=R3, the bandwidth can be doubled.

[0067] Therefore, according to the bandwidth compensation requirements, a small resistance can be selected, and the specific size is set according to the corresponding requirements.

[0068] In order to achieve the amplitude of the back-end echo electrical signal reaching a preset amplitude and satisfying the detection value of the back-end processing circuit 60 or the controller, in an optional embodiment, as Figure 6 As shown, the laser receiving circuit 200 further includes:

[0069] The signal amplifying circuit 50 is connected to the output end of the bandwidth compensation circuit 40 , and is configured to amplify each echo electrical signal output by the bandwidth compensation circuit 40 .

[0070] In this embodiment, the signal amplification circuit 50 implements signal amplification, amplifying the small-amplitude echo electrical signal to a preset amplitude, so that the back-end processing circuit 60 or controller can detect and identify it, thereby reducing the ranging blind area.

[0071] The signal amplifying circuit 50 may adopt a corresponding signal amplifier, such as a signal amplifier, and the specific structure is not limited.

[0072] Among them, in order to achieve laser ranging and select signal output, such as Figure 6 As shown, in an optional embodiment, the laser receiving circuit 200 further includes:

[0073] The processing circuit 60 is connected to the signal amplifying circuit 50 and the analog switch circuit 30 respectively, and is configured to output a selection signal and determine distance information according to the amplified echo electrical signal.

[0074] In this embodiment, the processing circuit 60 outputs a selection signal on the one hand to control the analog switch circuit 30 to select and output each echo electrical signal to the bandwidth compensation circuit 40 and the signal amplification circuit 50 at the back end, and outputs the signal to the processing circuit 60 after bandwidth compensation and signal amplification. The processing circuit 60 performs corresponding processing such as digital-to-analog conversion and timing to obtain corresponding ranging data, and determines the distance information and / or reflectivity based on the ranging data. The processing circuit 60 can select structures such as an analog-to-digital converter and a timing circuit, and the specific structure is not limited.

[0075] Compared with the prior art, the embodiment of the utility model has the following beneficial effects: the above-mentioned laser receiving circuit 200 includes multiple photoelectric detection circuits 10, multiple DC isolation circuits 20, an analog switch circuit 30 and a bandwidth compensation circuit 40; the photoelectric detection circuit 10 performs photoelectric conversion and outputs an echo electrical signal; the multiple echo electrical signals are selected for output through the analog switch circuit 30 after DC isolation processing; the bandwidth compensation circuit 40 performs bandwidth compensation on the echo electrical signal output by the analog switch circuit 30, improves the equivalent bandwidth of the analog switch circuit 30, thereby reducing the influence of the analog switch circuit 30 on the echo electrical signal, so that the echo electrical signal meets the requirements of narrow pulse width and fast rising edge.

[0076] like Figure 7 As shown, the second aspect of the embodiment of the utility model proposes a laser radar, including a laser transmitting circuit 100 and the laser receiving circuit 200 as described above.

[0077] In this embodiment, the laser receiving circuit 200 is configured corresponding to the laser transmitting circuit 100. The laser transmitting circuit 100 transmits laser pulses toward a preset angle according to a preset timing. At the same time, the laser receiving circuit 200 is configured corresponding to the laser transmitting circuit 100 to form a multi-line laser radar. The multiple laser pulses are reflected by the object to be measured 1 and return to the laser receiving circuit 200. The laser receiving circuit 200 performs photoelectric conversion on the laser pulses and outputs multiple echo electrical signals. The echo electrical signals are output to the back-end processing circuit 60 or controller. The processing circuit 60 or controller determines the distance information and reflectivity of the object to be measured 1 based on the echo electrical signals.

[0078] The laser emitting circuit 100 can select a corresponding laser 110, such as Figure 8 As shown, in an optional embodiment, the laser emitting circuit 100 includes a plurality of lasers 110, and the plurality of lasers 110 are arranged corresponding to the plurality of photoelectric detection circuits 10 of the laser receiving circuit 200;

[0079] The plurality of lasers 110 are configured to receive power and emit laser pulses according to a preset timing.

[0080] In this embodiment, multiple lasers 110 are driven by a driving signal to emit laser pulses according to a preset timing and a preset angle. The laser pulses are reflected back to a corresponding photoelectric detection circuit 10 by the object to be measured 1, converted into an echo electrical signal by the photoelectric detection circuit 10, and processed by the rear-end DC isolation circuit 20, the analog switch circuit 30, the bandwidth compensation circuit 40, and the signal amplification circuit 50, and then output to the processing circuit 60 or the controller. The processing circuit 60 or the controller determines the distance information and reflectivity according to the transmission and reception time of the laser pulse and the size of the echo electrical signal.

[0081] The laser emitting circuit 100 may further include a laser driving circuit, which is connected to a plurality of lasers 110 . The laser driving circuit outputs a driving signal to each laser 110 according to a control signal, thereby driving each laser 110 to emit a laser pulse.

[0082] The laser radar may also include a controller, which is used to drive the laser emitting circuit 100 to emit laser pulses and simultaneously receive the echo electrical signal output by the laser receiving circuit 200, and determine the flight time of the echo electrical signal, as well as the distance information and reflectivity according to the echo pulse width and pulse arrival time of the echo pulse signal.

[0083] The controller and the processing circuit 60 may be the same module or separated into different modules. The configuration may be selected based on the structure and cost. For example, ADC or TDC, FPGA or SoC may be selected.

[0084] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. A laser receiving circuit, characterized in that: include: a plurality of photodetection circuits, each of the photodetection circuits being configured to convert a received laser pulse into an echo electrical signal; A plurality of DC isolation circuits, each of which is connected to one of the photoelectric detection circuits, and the DC isolation circuit is configured to perform DC isolation processing on the received echo electrical signal; An analog switch circuit, the analog switch circuit comprising a plurality of input terminals and an output terminal, an input terminal of the analog switch circuit being connected to an output terminal of the DC blocking circuit, the analog switch circuit being configured to be triggered by a received selection signal to sequentially select an input terminal and an output terminal thereof, and select and output the plurality of echo electrical signals; The bandwidth compensation circuit is connected to the output end of the analog switch circuit and is configured to perform bandwidth compensation on each echo electrical signal output by the analog switch circuit.

2. The laser receiving circuit according to claim 1, characterized in that: The photoelectric detection circuit includes a photoelectric detector and a first resistor; The first end of the photodetector is connected to the power supply end, the second end of the photodetector and the first end of the first resistor are connected to form the output end of the photodetection circuit, and the second end of the first resistor is grounded.

3. The laser receiving circuit according to claim 2, characterized in that: The photodetector includes at least one of an avalanche diode, a silicon photomultiplier tube, a single photon avalanche diode, and a photodiode.

4. The laser receiving circuit according to claim 1, characterized in that: The DC blocking circuit includes a capacitor; The first end and the second end of the capacitor constitute the input end and the output end of the DC blocking circuit respectively.

5. The laser receiving circuit according to claim 1, characterized in that: The analog switch circuit includes at least one analog switch, and multiple input terminals of at least one analog switch are respectively connected to the output terminal of one of the DC isolation circuits, and the output terminals of the analog switches are connected together to form the output terminal of the analog switch circuit.

6. The laser receiving circuit according to claim 1, characterized in that: The bandwidth compensation circuit includes a second resistor; A first end of the second resistor is connected to the output end of the analog switch circuit, and a second end of the second resistor is grounded.

7. The laser receiving circuit according to claim 1, characterized in that: The laser receiving circuit also includes: The signal amplifying circuit is connected to the output end of the bandwidth compensation circuit and is configured to amplify each of the echo electrical signals output by the bandwidth compensation circuit.

8. The laser receiving circuit according to claim 7, characterized in that: The laser receiving circuit also includes: The processing circuit is connected to the signal amplifying circuit and the analog switch circuit respectively, and is configured to output the selection signal and determine the distance information according to the amplified echo electrical signal.

9. A laser radar, characterized in that: The invention comprises a laser transmitting circuit and a laser receiving circuit as claimed in any one of claims 1 to 8.

10. The laser radar according to claim 9, characterized in that: The laser emitting circuit includes a plurality of lasers, and the plurality of lasers are arranged corresponding to the plurality of photoelectric detection circuits of the laser receiving circuit; The plurality of lasers are configured to receive power and emit laser pulses according to a preset timing.

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