Multi-line laser radar device

Abstract

The application provides a multi-line laser radar device, which comprises a laser emission circuit, a laser receiving circuit and a controller, the laser receiving circuit comprises a multiplexing circuit, a multi-stage amplification circuit and a plurality of laser receiving components, the laser receiving components convert received optical signals into echo signals, and the echo signals are output through the multiplexing circuit in the same channel, the multi-stage amplification circuit realizes signal amplification functions of different levels, the controller can determine effective feedback signals according to the power of the received echo signals, and determine a detection distance according to the effective feedback signals, the dynamic adaptive range of the multi-stage amplification circuit is improved, the system blind area is reduced, the accuracy of the detection distance is improved, and the adaptability of the multi-line laser radar device is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of laser radar, and particularly relates to a multi-line laser radar device. BACKGROUND

[0002] With the development of artificial intelligence and unmanned driving, the requirements for the detection precision and detection distance of laser radars are also increasing.

[0003] To improve the detection distance of the laser radar, the peak power of the laser can be improved. With the increase of the peak power, the saturation area of the received signal in the near distance becomes larger, the visual field blind area increases, the adaptability is low, and the detection precision is limited. SUMMARY

[0004] The present application aims to provide a multi-line laser radar device, and aims to solve the problems of low adaptability and limited detection precision of the conventional laser radar.

[0005] The first aspect of the embodiment of the present application provides a multi-line laser radar device, comprising:

[0006] A laser emission circuit, the laser emission circuit comprising a laser driving circuit and a plurality of laser emission components connected with the laser driving circuit;

[0007] The laser driving circuit is configured to charge and discharge according to the level sequence of a first charging control signal and a first discharging control signal, so as to control each laser emission component to emit light according to the corresponding time sequence;

[0008] A laser receiving circuit, the laser receiving circuit comprising a multiplexing circuit, a multi-stage amplification circuit and a plurality of laser receiving components corresponding to the plurality of laser emission components;

[0009] Each laser receiving component is configured to receive the optical signal of each corresponding laser emission component and convert it into a corresponding echo signal to the multiplexing circuit;

[0010] The multiplexing circuit is configured to output the echo signals output by each laser receiving component to the multi-stage amplification circuit in time-sharing manner;

[0011] The multi-stage amplification circuit is configured to amplify and convert the echo signals in different amplification levels respectively, and output a plurality of echo signals with different power levels;

[0012] a controller connected with the multi-stage amplification circuit and the laser driving circuit respectively, the control circuit being configured to output the first charging control signal and the first discharging control signal to adjust the light output power of each laser emitting component to a preset power, and determine an echo signal having a power within a preset echo signal threshold from a plurality of echo signals amplified to different power levels as an effective feedback signal, and determine a detection distance according to the effective feedback signal.

[0013] Optionally, the laser driving circuit comprises:

[0014] a decoding circuit and at least one multi-channel driving circuit connected with the controller, each multi-channel driving circuit being connected with a plurality of laser emitting components;

[0015] the decoding circuit being configured to decode one of the received first discharging control signals and one of the received first charging control signals into at least one group of charging and discharging control signals and output each group of charging and discharging control signals to at least one multi-channel driving circuit, wherein each group of charging and discharging control signals comprises one second charging control signal and a plurality of second discharging control signals;

[0016] the multi-channel driving circuit being configured to charge and discharge according to the level sequence of the second charging control signal and the plurality of second discharging control signals, so as to control each laser emitting component to emit light according to a corresponding time sequence.

[0017] Optionally, each multi-channel driving circuit comprises:

[0018] a charging circuit configured to charge according to the level sequence of the second charging control signal, an output end of the charging circuit being connected with a first end of each laser emitting component respectively;

[0019] a plurality of discharging circuits, an input end of each discharging circuit being connected with a second end of each laser emitting component respectively, an output end of each discharging circuit being grounded, and each discharging circuit being configured to discharge according to the level sequence of the corresponding received second discharging control signal to drive the corresponding laser emitting component to emit light.

[0020] Optionally, each charging circuit comprises an inductor, a first field effect transistor, a diode, a first resistor and a first capacitor.

[0021] The first end of the inductor constitutes a power input end of the charging circuit, the second end of the inductor, the anode of the diode and the drain of the first field effect transistor are connected together, the gate of the first field effect transistor and the first end of the first resistor are connected together to constitute a controlled end of the charging circuit, the source of the first field effect transistor and the second end of the first resistor are grounded, the cathode of the diode is connected with the first end of the first capacitor and a first end of a plurality of the laser emitting assemblies, and the second end of the first capacitor is grounded.

[0022] Optionally, each of the discharge circuits comprises a second field effect transistor and a second resistor.

[0023] The drain of the second field effect transistor is connected with a second end of each of the laser emitting assemblies, the gate of the second field effect transistor and the first end of the second resistor are connected together to constitute a controlled end of the discharge circuit, and the source of the second field effect transistor and the second end of the second resistor are grounded.

[0024] Optionally, the decoding circuit comprises one or more decoders in parallel input.

[0025] Optionally, each of the laser receiving assemblies comprises a positive power supply end, a third resistor, a fourth resistor, a second capacitor, a third capacitor, a photoelectric sensor and a trans-impedance amplifier.

[0026] The first end of the third resistor is connected with the positive power supply end, the second end of the third resistor, the first end of the second capacitor and the first end of the photoelectric sensor are connected together, the second end of the photoelectric sensor, the first end of the fourth resistor and the first end of the third capacitor are connected together, the second end of the third capacitor is connected with a first input end of the trans-impedance amplifier, the second input end and the output end of the trans-impedance amplifier are connected together to constitute an output end of the laser receiving assembly, and the second end of the second capacitor and the second end of the fourth resistor are both grounded.

[0027] Optionally, the multiplexing circuit comprises a multiplexer.

[0028] Optionally, the multi-stage amplification circuit comprises a plurality of amplification sub-circuits, each of the amplification sub-circuits comprises a plurality of amplifiers connected in series.

[0029] Optionally, the multi-stage amplification circuit comprises a plurality of amplifiers connected in series, and the output end of each of the amplifiers constitutes each signal output end of the multi-stage amplification circuit.

[0030] Compared with the prior art, the multi-line laser radar device has the beneficial effects that: the multi-line laser radar device is provided with a laser emitting circuit, a laser receiving circuit and a controller, the laser receiving circuit includes a multiplexing circuit, a multi-stage amplifying circuit and a plurality of laser receiving components, the laser receiving components convert the received optical signals into echo signals, and the echo signals are output through the multiplexing circuit in the same channel, the multi-stage amplifying circuit realizes signal amplification functions of different levels, the controller can determine effective feedback signals according to the power of the received echo signals, and determine the detection distance according to the effective feedback signals, the dynamic adaptive range of the multi-stage amplifying circuit is improved, the system blind area is reduced, the accuracy of the detection distance is improved, and the adaptability of the multi-line laser radar device is improved. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 A module structure schematic diagram of the multi-line laser radar device is provided for the embodiments of the present application.

[0032] Figure 2 A module structure schematic diagram of the laser driving circuit in the multi-line laser radar device is shown in Figure 1

[0033] Figure 3 A module structure schematic diagram of the multi-channel driving circuit in the laser driving circuit is shown in Figure 2

[0034] Figure 4 A timing sequence schematic diagram of the charging control signal and the discharging control signal in the multi-channel driving circuit is shown in Figure 3

[0035] Figure 5 A circuit structure schematic diagram of the charging circuit and the discharging circuit in the multi-channel driving circuit is shown in Figure 2

[0036] Figure 6 A first module structure schematic diagram of the laser receiving circuit in the multi-line laser radar device is shown in Figure 1

[0037] Figure 7 A second module structure schematic diagram of the laser receiving circuit in the multi-line laser radar device is shown in Figure 1 DETAILED DESCRIPTION

[0038] In order to make the technical problems to be solved by the present application, the technical solutions and beneficial effects more clearly understood, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0039] ​​​​​​In addition, the terms "first", "second", "third", etc. are used only for descriptive purposes and are not to be construed as indicating or implying relative importance or an indicated number of technical features. Therefore, the features defined as "first", "second", etc. can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0040] A first aspect of the embodiments of the present application provides a multi-line laser radar device.

[0041] As shown in Figure 1 , Figure 1 A module structure diagram of the multi-line laser radar device provided by the embodiments of the present application is shown in the present embodiment. The multi-line laser radar device includes a laser emission circuit 110, a laser receiving circuit 120, and a controller 130.

[0042] The laser emission circuit 110 includes a laser driving circuit 20 and a plurality of laser emission assemblies 10 connected to the laser driving circuit 20.

[0043] The laser driving circuit 20 is configured to charge and discharge according to the level sequence of a first charging control signal ctr1 and a first discharging control signal ctr2, so as to control each laser emission assembly 10 to emit light according to the corresponding time sequence.

[0044] The laser receiving circuit 120 includes a multiplexing circuit 40, a multi-stage amplification circuit 50, and a plurality of laser receiving assemblies 30 corresponding to the plurality of laser emission assemblies 10.

[0045] Each laser receiving assembly 30 is configured to receive the optical signal of each corresponding laser emission assembly 10 and convert the optical signal into a corresponding echo signal to the multiplexing circuit 40.

[0046] The multiplexing circuit 40 is configured to time-share output the echo signals output by the laser receiving assemblies 30 to the multi-stage amplification circuit 50.

[0047] The multi-stage amplification circuit 50 is configured to amplify and convert the echo signals at different amplification levels, respectively, and output a plurality of echo signals having different power levels.

[0048] The controller 130 is connected to the multi-stage amplification circuit 50 and the laser driving circuit 20, respectively. The control circuit is configured to output the first charging control signal ctr1 and the first discharging control signal ctr2 to adjust the light output power of each laser emission assembly 10 to a preset power, and determine an echo signal having a power within a preset echo signal threshold from the plurality of echo signals amplified at different power levels as an effective feedback signal, and determine a detection distance according to the effective feedback signal.

[0049] In this embodiment, the laser emitting assembly 10 and the laser receiving assembly 30 are correspondingly arranged, and the number thereof can be equal or unequal. The installation positions thereof are correspondingly arranged relative to the object to be measured, and can be symmetrically arranged or asymmetrically arranged. For example, the first laser emitting assembly and the first laser receiving assembly are symmetrically arranged, the second laser emitting assembly and the second laser receiving assembly are symmetrically arranged, and the like. A plurality of sets of the laser emitting assembly 10 and the laser receiving assembly 30 correspondingly arranged complete the emission and reception of a plurality of laser pulses, and achieve the purpose of multi-line laser radar ranging.

[0050] In the working process, the controller 130 outputs the first charging control signal ctr1 and the first discharging control signal ctr2 of the preset level sequence to the laser driving circuit 20, so as to drive the laser emitting assembly 10 to emit a laser pulse with an initial output power according to the set sequence. The laser pulse is emitted at a corresponding angle. The corresponding laser receiving assembly 30 receives the laser echo reflected by the object to be measured, and converts the laser echo into a corresponding echo signal. Different echo signals are different in sequence. Therefore, the multiplexing circuit 40 multiplexes the echo signals into one signal output. The echo signal output by the multiplexing circuit 40 is amplified by the multi-stage amplification circuit 50 at different power amplification levels, and a plurality of amplified echo signals are output to the controller 130. The amplification levels in the multi-stage amplification circuit 50 can be increased or decreased by a preset difference, or can be changed in proportion.

[0051] Due to the detection distance requirement of the laser radar, the laser emitting assembly 10 needs to output sufficient energy to ensure that the laser reaching the far end can be detected by the laser receiving assembly 30 when the laser echo is reflected back to the laser receiving circuit 120. However, as the power of the laser emitting assembly 10 becomes larger and larger, the near-end saturation region will increase, so that the blind area detected by the laser radar will also increase. In order to solve the problem of the blind area, the output power of the laser is dynamically adjusted by detecting the quality of the received signal. When the controller 130 detects that the echo signal has a broadening phenomenon in the last cycle, the output power of the laser is adjusted in the next cycle, so as to realize the self-adaptive adjustment of the power.

[0052] At the same time, frequent emission of the laser emitting assembly 10 will occupy a large amount of operation space of the controller 130, and increase the power consumption of the whole system. Therefore, increasing the dynamic range of the receiving system becomes an optimal choice. In this embodiment, the multi-stage amplification circuit 50 divides the signal into multiple segments for amplification. The echo signal fed back by the near-end region is output to the controller 130 through an amplification unit with a low amplification level. The echo signal in the middle-end region is output to the controller 130 through an amplification unit with a medium amplification level. The echo signal in the far-end region is output to the controller 130 through an amplification unit with a maximum amplification level. The amplification levels of each segment are increased in proportion. In this way, the blind area in the near-end region can be reduced, and the detection distance capability in the far-end region can be increased.

[0053] For example, assuming that the multi-stage amplification circuit 50 has three amplification stages of 2, 4, and 6, when the distance of the object to be measured is relatively close, if the echo signal amplified by the 4th or 6th stage is selected as the effective feedback signal, the echo signal is too large, causing a near-end blind area. Therefore, the echo signal amplified by the 2nd stage can be selected as the effective feedback signal. Similarly, when the object to be measured is far away, if the echo signal amplified by the 2nd or 4th stage is selected as the effective feedback signal, the echo signal is too small, which does not meet the signal size requirement of the distance measurement, resulting in a failed distance measurement. Therefore, the controller 130 can select the echo signal amplified by the 6th stage as the effective feedback signal, and determine the detection distance according to the feedback duration of the signal.

[0054] To realize multi-stage selection, the controller 130 is provided with a reference echo signal threshold. When receiving echo signals amplified by multiple different amplification stages, the controller 130 compares each signal with the reference echo signal threshold, selects the echo signal within the reference echo signal threshold as the effective feedback signal, and determines the detection distance according to the effective feedback signal. This improves the dynamic adaptation range of the multi-stage amplification circuit 50, reduces the system blind area, improves the accuracy of the detection distance, and improves the adaptability of the multi-line laser radar device.

[0055] The laser driving circuit 20 can adopt corresponding charge-discharge circuits, signal processing circuits, etc. The controller 130 and the laser emitting circuit 110 are only provided with two signal lines, which realizes the purpose of the controller 130 controlling the individual light emission of the multiple laser emitting assemblies 10 by using a smaller I / O port, simplifies the line structure and cost of the multi-line radar laser device.

[0056] The laser emitting assembly 10 can adopt a laser, and correspondingly, the laser receiving assembly 30 can adopt a corresponding photoelectric conversion circuit to realize photoelectric conversion.

[0057] The multiplexing circuit 40 can adopt a multi-input single-output circuit structure, and the multi-stage amplification circuit 50 can adopt multiple amplification sub-circuits 51 or a multi-stage amplification module with multiple signal output terminals. The specific structure is not limited.

[0058] It can be understood that, to improve the vertical resolution of the laser radar and improve the accuracy of the detected object, the density of the laser emitter in the vertical direction needs to be continuously improved. The line number of the laser can be increased to achieve the purpose. However, as the line number increases, the internal space of the multi-line laser radar device and the circuit optimization become problems that need to be considered. To solve this problem, as shown in FIG. 8, the laser driving circuit 20 can include: Figure 2

[0059] The decoding circuit 21 and at least one multi-channel driving circuit 22 connected to the controller 130, and each multi-channel driving circuit 22 is connected to a plurality of laser emitting assemblies 10.​

[0060] The decoding circuit 21 is configured to decode the received one of the discharge control signals and one of the charging control signals into at least one set of charging and discharging control signals and output each of the at least one set of charging and discharging control signals to at least one of the multi-channel drive circuits 22, wherein each of the at least one set of charging and discharging control signals comprises one second charging control signal and a plurality of second discharge control signals. For example, one of the at least one set of charging and discharging control signals comprises one second charging control signal Ctr1_1 and a plurality of second discharge control signals Ctr2_1_1-Ctr2_1_n, another of the at least one set of charging and discharging control signals comprises one second charging control signal Ctr1_2 and a plurality of second discharge control signals Ctr2_2_1-Ctr2_2_n, and so on.

[0061] The multi-channel drive circuit 22 is configured to charge and discharge according to the level and timing of the second charging control signal and the plurality of second discharge control signals, thereby controlling the corresponding laser emitting assemblies 10 to emit light according to the corresponding timing.

[0062] In the embodiment, the multi-channel drive circuit 22 provides energy for the plurality of laser emitting assemblies 10, and controls the light emitting power and timing of each laser individually. The decoding circuit 21 decodes the received first discharge control signal ctr2 and first charging control signal ctr1, wherein the first charging control signal ctr1 and the first discharge control signal ctr2 output by the controller 130 correspond to specific address information, and the decoding circuit 21 decodes at least one set of charging and discharging control signals according to the address information and outputs the at least one set of charging and discharging control signals to at least one of the multi-channel drive circuits 22. The corresponding drive channel of the multi-channel drive circuit 22 is opened by selecting the address information, thereby controlling the corresponding laser emitting assembly 10 to emit light according to the corresponding timing and power.

[0063] The number of the multi-channel drive circuits 22 and the number of the laser emitting assemblies 10 that can be connected are set according to the number of the laser emitting assemblies 10 and the number of ports of the multi-channel drive circuit 22. Correspondingly, the decoding circuit 21 can output a corresponding number of sets of charging and discharging control signals and a corresponding number of second discharge control signals in each set of charging and discharging control signals according to the number of the laser emitting assemblies 10 connected to each of the multi-channel drive circuits 22.

[0064] For example, when the laser emitting assembly is provided with 20 laser emitting assemblies 10 and each of the multi-channel drive circuits 22 is provided with 5 output ports, 4 multi-channel drive circuits 22 are selected, and each of the 4 multi-channel drive circuits 22 is connected to 5 laser emitting assemblies 10. In this case, the decoding circuit 21 outputs 4 sets of charging and discharging control signals, and each of the 4 sets of charging and discharging control signals comprises one second charging control signal and 5 second discharge control signals.

[0065] Or when the laser emitting components are provided with 20, and the output ports of each multi-channel driving circuit 22 are provided with 6, only 4 multi-channel driving circuits 22 are selected, at this time, the decoding circuit 21 outputs 4 groups of charging and discharging control signals, and four multi-channel driving circuits are respectively connected with corresponding number of laser emitting components 10, for example, the number of connections are respectively 6, 6, 6, 3, or the number of connections are respectively 5, 5, 5, 5, correspondingly, each group of charging and discharging control signals includes one second charging control signal and corresponding number of second discharging control signals, and the output ports of one or more multi-channel driving circuits 22 which are not connected with laser emitting components can be provided with suspension.

[0066] At the same time, only two signals are provided between the controller 130 and the decoding circuit 21, which realizes the purpose of the controller 130 controlling the separate light emission of the multi-laser emitting components 10 by using smaller I / O ports, and simplifies the line structure and cost of the multi-line radar laser equipment.

[0067] Among them, the decoding circuit 21 can adopt a corresponding signal processor, and optionally, the decoding circuit 21 includes one or more parallel input decoders, each decoder receives the first charging control signal ctr1 and the discharging control signal ctr2, and decodes and outputs, realizing the decoding conversion work.

[0068] The multi-channel driving circuit 22 can be composed of at least one discharging circuit 222 and at least one charging circuit 221, so as to realize the separate light emission power and light emission timing control of the plurality of laser emitting components 10.

[0069] As shown in Figure 3 Optionally, each multi-channel driving circuit 22 includes:

[0070] The charging circuit 221 is used for charging according to the level timing of the second charging control signal, and the output end of the charging circuit 221 is respectively connected with the first end of the plurality of laser emitting components 10;

[0071] The plurality of discharging circuits 222, the input end of each discharging circuit 222 is respectively connected with the second end of each laser emitting component 10, and the output end of each discharging circuit 222 is grounded, and each discharging circuit 222 is used for discharging according to the level timing of the corresponding received second discharging control signal, so as to drive the laser emitting component 10 to emit light.

[0072] In this embodiment, one charging circuit 221 in each multi-channel driving circuit 22 completes the charging work of the plurality of laser emitting components 10, and at the same time, a plurality of discharging circuits 222 respectively complete the discharging work of the plurality of laser emitting components 10, wherein the timing of the control signals received by the discharging circuit 222 and the charging circuit 221 is as shown in Figure 4 According toFigure 4 It can be seen that, in one charging and discharging cycle, the charging work of the charging circuit 221 corresponds to the discharging work of one of the discharging circuits 222, so that the length or size of the single charging control signal can be changed in one cycle, corresponding to adjusting the light emitting power of the laser emitting assembly 10.

[0073] In specific work, as shown in Figure 4 , the high and low level time sequences of the charging control signal and each discharging control signal have a corresponding phase difference. When the charging circuit 221 receives a high level of the charging control signal, the charging circuit 221 starts and charges the energy storage, and then the charging circuit 221 receives a low level to turn off. After one of the discharging circuits 222 receives a high level of the discharging control signal, it is turned on and starts discharging, thereby driving the connected laser emitting assembly 10 to emit light. When the discharging circuit 222 receives a low level, the discharging ends. At this time, the charging circuit 221 receives a high level again to start and charge the energy storage, and then the charging circuit 221 receives a low level to turn off. Then, the next discharging circuit 222 receives a high level of the discharging control signal, is turned on and starts discharging, thereby driving the connected another laser emitting assembly 10 to emit light, so as to control the discharging and light emitting of the corresponding number of laser emitting assemblies 10 in turn.

[0074] At the same time, by adopting one charging circuit 221 and a plurality of discharging circuits 222 structure, it is not necessary to configure a charging circuit 221 and a discharging circuit 222 corresponding to each laser emitting assembly 10, and it is not necessary to configure corresponding signal lines, thereby simplifying the overall structure of the multi-channel driving circuit 22 and the multi-line laser radar device, and reducing the design cost.

[0075] Among them, the charging circuit 221 and the discharging circuit 222 can adopt a corresponding switch structure, as shown in Figure 5 , optionally, each charging circuit 221 includes an inductor L1, a first field effect transistor Q1, a diode D1, a first resistor R1 and a first capacitor C1.

[0076] The first end of the inductor L1 constitutes the power input end of the charging circuit 221, the second end of the inductor L1, the anode of the diode D1 and the drain of the first field effect transistor Q1 are commonly connected, the gate of the first field effect transistor Q1 and the first end of the first resistor R1 are commonly connected to constitute the controlled end of the charging circuit 221, the source of the first field effect transistor Q1 and the second end of the first resistor R1 are grounded, the cathode of the diode D1 and the first end of the first capacitor C1 are commonly connected and connected with the first end of the plurality of laser emitting assemblies 10, and the second end of the first capacitor C1 is grounded.

[0077] Each discharging circuit 222 includes a second field effect transistor Q2 and a second resistor R2.

[0078] The drain of the second field effect transistor Q2 is connected with the second end of each laser emitting component 10, the gate of the second field effect transistor Q2 and the first end of the second resistor R2 are commonly connected to form the controlled end of the discharge circuit 222, the source of the second field effect transistor Q2 and the second end of the second resistor R2 are grounded.

[0079] In the embodiment, the inductor L1, the first field effect transistor Q1 and the diode D1 form a boost circuit, and the first capacitor C1 is an energy storage capacitor. When it is required to control one of the laser emitting components 10 to emit light, the first field effect transistor Q1 receives a corresponding second charging control signal and is controlled to be turned on and off, so as to convert the voltage and output the charging power to the energy storage capacitor. After the charging is completed, the second field effect transistor Q2 is turned on, the energy storage capacitor starts to discharge, and the discharge is performed to the ground through the corresponding laser emitting component 10 and the second field effect transistor Q2, and the laser emitting component 10 emits light.

[0080] Optionally, in order to match the line structure, the first field effect transistor Q1 and the second field effect transistor Q2 are both N-channel field effect transistors, and the charging control signal and the discharge control signal are both pulse signals with high and low levels corresponding to the structure of the field effect transistor.

[0081] As shown in FIG. 4, optionally, each laser receiving component 30 includes a positive power supply end VCC, a third resistor R3, a fourth resistor R4, a second capacitor C2, a third capacitor C3, a photoelectric sensor D2 and a trans-impedance amplifier TIA. Figure 6

[0082] The first end of the third resistor R3 is connected with the positive power supply end VCC, the second end of the third resistor R3, the first end of the second capacitor C2 and the first end of the photoelectric sensor D2 are connected, the second end of the photoelectric sensor D2, the first end of the fourth resistor R4 and the first end of the third capacitor C3 are commonly connected, the second end of the third capacitor C3 is connected with the first input end of the trans-impedance amplifier TIA, the second input end and the output end of the trans-impedance amplifier TIA are commonly connected to form the output end of the laser receiving component 30, and the second end of the second capacitor C2 and the second end of the fourth resistor R4 are both grounded.

[0083] The multiplexing circuit 40 includes a multiplexer U1.

[0084] In the embodiment, the positive power supply end VCC provides a bias voltage for the photoelectric sensor D2. When the photoelectric sensor D2 receives a light signal, the light signal is converted into a current signal and output, and the current signal is converted into a pulse type echo signal by the trans-impedance amplifier TIA. The echo signals output by the plurality of trans-impedance amplifiers TIA are not coincident in the time domain, and are multiplexed into one signal output by the multiplexer U1.

[0085] Optionally, the photoelectric sensor D2 includes an APD, a SPAD, a SIPM and the like. ​

[0086] The multiplexer U1 comprises one or more multiplexers U1, which time-division multiplex the multipath signals to output echo signals of high frequency pulses integrating all the photoelectric converter output signals.

[0087] With reference to the foregoing Figure 6 Optionally, the multi-stage amplification circuit 50 comprises a plurality of amplification sub-circuits 51, each of which comprises a plurality of amplifiers OPA connected in series.

[0088] In this embodiment, each amplification sub-circuit 51 has an amplification level, and the more the number of amplifiers OPA in each amplification sub-circuit, the greater the amplification level. Meanwhile, the amplification sub-circuit with a greater amplification level is matched to a far-end region, and the amplification sub-circuit with a smaller amplification level is matched to a near-end region, so that the echo signal fed back by the near-end region is output to the controller 130 through the amplification sub-circuit with a low amplification level, the echo signal of the middle-end region is output to the controller 130 through the amplification sub-circuit with a medium amplification level, and the echo signal of the far-end region is output to the controller 130 through the amplification sub-circuit with a maximum amplification level. The amplification levels of each amplification sub-circuit are increased in a certain proportion, so that the blind area of the near-end region is reduced and the detection distance of the far-end region is increased.

[0089] As shown in Figure 7 Optionally, the multi-stage amplification circuit 50 comprises a plurality of amplifiers OPA connected in series, and the output end of each amplifier OPA constitutes each signal output end of the multi-stage amplification circuit 50.

[0090] In this embodiment, each amplifier OPA has an amplification level, and the more the number of amplifiers OPA, the greater the amplification level. Meanwhile, for example, the power amplification level of the echo signal output by the first amplifier OPA is the smallest, and the power amplification level of the echo signal output by the last amplifier OPA is the largest. Among them, the amplifier OPA with a greater amplification level is matched to a far-end region, and the amplifier OPA with a smaller amplification level is matched to a near-end region, so that the echo signal fed back by the near-end region is output to the controller 130 through the amplifier OPA with a low amplification level, the echo signal of the middle-end region is output to the controller 130 through the amplifier OPA with a medium amplification level, and the echo signal of the far-end region is output to the controller 130 through the amplifier OPA with a maximum amplification level. The amplification levels of each amplification sub-circuit are increased in a certain proportion, so that the blind area of the near-end region is reduced and the detection distance of the far-end region is increased.

[0091] Among them, the above-mentioned amplifier OPA can be an operational amplifier OPA, a triode amplifier OPA, etc.

[0092] The multi-line laser radar device has the laser emitting circuit 110, the laser receiving circuit 120 and the controller 130, wherein the laser receiving circuit 120 comprises the multiplexing circuit 40, the multi-stage amplification circuit 50 and a plurality of laser receiving components 30, the laser receiving components 30 convert the received optical signals into echo signals, and the echo signals are output through the multiplexing circuit 40 in the same channel, the multi-stage amplification circuit 50 realizes the signal amplification function of different levels, the controller 130 can determine the effective feedback signal according to the power of the received echo signal, and determine the detection distance according to the effective feedback signal, thereby improving the dynamic adaptation range of the multi-stage amplification circuit 50, reducing the system blind area, improving the accuracy of the detection distance, and improving the adaptability of the multi-line laser radar device.

[0093] The above-described embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A multi-line lidar device, characterized by, The application relates to a laser ranging device. The laser emission circuit comprises a laser drive circuit and a plurality of laser emission components connected with the laser drive circuit. The laser drive circuit is used for charging and discharging according to the level sequence of a first charging control signal and a first discharging control signal, so as to control the laser emission components to emit light in sequence. The laser receiving circuit comprises a multiplexing circuit, a multi-stage amplification circuit and a plurality of laser receiving components arranged correspondingly to the plurality of laser emission components. Each laser receiving component is used for receiving the optical signal of each corresponding laser emission component and converting the optical signal into a corresponding echo signal to the multiplexing circuit. The multiplexing circuit is used for outputting the echo signals output by the laser receiving components to the multi-stage amplification circuit in time sequence, and the different echo signals are different in time sequence. The multi-stage amplification circuit is used for amplifying and converting the echo signals in different amplification levels respectively, and outputting a plurality of echo signals with different power levels. A controller is connected with the multi-stage amplification circuit and the laser drive circuit respectively, and the controller is used for outputting the first charging control signal and the first discharging control signal, so as to adjust the light emitting power of each laser emission component to reach a preset power, and determine an echo signal with a size within a preset echo signal threshold from the plurality of echo signals with different power levels after amplification as an effective feedback signal, and determine a detection distance according to the effective feedback signal.

2. The multi-line lidar apparatus of claim 1, wherein, The laser drive circuit comprises: A decoding circuit and at least one multi-channel drive circuit connected with the controller, and each multi-channel drive circuit is connected with a plurality of laser emission components. The decoding circuit is used for decoding a received first discharging control signal and a first charging control signal into at least one group of charging and discharging control signals and outputting the charging and discharging control signals to at least one multi-channel drive circuit respectively, wherein each group of charging and discharging control signals comprises a second charging control signal and a plurality of second discharging control signals. The multi-channel drive circuit is used for charging and discharging according to the level sequence of the second charging control signal and the plurality of second discharging control signals, so as to control the laser emission components to emit light according to the corresponding time sequence.

3. The multi-line lidar apparatus of claim 2, wherein, Each multi-channel drive circuit comprises: A charging circuit used for charging according to the level sequence of the second charging control signal, and the output end of the charging circuit is connected with the first end of a plurality of laser emission components respectively. A plurality of discharging circuits, wherein the input end of each discharging circuit is connected with the second end of each laser emission component respectively, the output end of each discharging circuit is grounded, and each discharging circuit is used for discharging according to the level sequence of the corresponding received second discharging control signal, so as to drive the corresponding laser emission component to emit light.

4. The multi-line lidar apparatus of claim 3, wherein, Each charging circuit comprises an inductor, a first field effect transistor, a diode, a first resistor and a first capacitor. The first end of the inductor constitutes a power input end of the charging circuit, the second end of the inductor, the anode of the diode and the drain of the first field effect transistor are connected together, the gate of the first field effect transistor and the first end of the first resistor are connected together to constitute a controlled end of the charging circuit, the source of the first field effect transistor and the second end of the first resistor are grounded, the cathode of the diode is connected with the first end of the first capacitor and connected with the first end of a plurality of the laser emitting assemblies, and the second end of the first capacitor is grounded.

5. The multi-line lidar apparatus of claim 3, wherein, Each of the discharge circuits comprises a second field effect transistor and a second resistor; The drain of the second field effect transistor is connected with the second end of each of the laser emitting assemblies, the gate of the second field effect transistor and the first end of the second resistor are connected together to constitute a controlled end of the discharge circuit, and the source of the second field effect transistor and the second end of the second resistor are grounded.

6. The multi-line lidar apparatus of claim 2, wherein, The decoding circuit comprises one or more parallel input decoders.

7. The multi-line lidar apparatus of claim 1, wherein, Each of the laser receiving assemblies comprises a positive power supply end, a third resistor, a fourth resistor, a second capacitor, a third capacitor, a photoelectric sensor and a trans-impedance amplifier; The first end of the third resistor is connected with the positive power supply end, the second end of the third resistor, the first end of the second capacitor and the first end of the photoelectric sensor are connected together, the second end of the photoelectric sensor, the first end of the fourth resistor and the first end of the third capacitor are connected together, the second end of the third capacitor is connected with the first input end of the trans-impedance amplifier, the second input end and the output end of the trans-impedance amplifier are connected together to constitute an output end of the laser receiving assembly, and the second end of the second capacitor and the second end of the fourth resistor are both grounded.

8. The multi-line lidar apparatus of claim 1, wherein, The multiplexing circuit comprises a multiplexer.

9. The multi-line lidar apparatus of claim 1, wherein, The multi-stage amplifying circuit comprises a plurality of amplifying sub-circuits, each of the amplifying sub-circuits comprises a plurality of amplifiers connected in series.

10. The multi-line lidar apparatus of claim 1, wherein, The multi-stage amplifying circuit comprises a plurality of amplifiers connected in series, and the output end of each of the amplifiers constitutes each signal output end of the multi-stage amplifying circuit.

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