Laser emission circuit and laser radar

Abstract

The invention provides a laser emission circuit and a laser radar, the laser emission circuit comprises a charging circuit, a light emitting module, a multiplexing circuit and a control circuit, the light emitting module comprises an energy storage unit and a plurality of light emitting units connected with the energy storage unit, the control circuit sequentially outputs a charging signal to control the charging circuit to charge the energy storage unit according to the trigger signal, and outputs an address selection signal and a discharging signal, so that the corresponding transmission channel is gated to output the discharging signal to the specified light-emitting unit, and the light-emitting unit is triggered to be conducted and emits a laser pulse. The driving work of different light-emitting units is realized by gating different transmission channels of the multiplexing circuit, and only one charging circuit needs to be configured, so that the structures and the design cost of the laser emission circuit and the laser radar are simplified.

Description

Technical Field

[0001] The present invention belongs to the technical field of lidar, and particularly relates to a laser emission circuit and a lidar. Background Art

[0002] With the increasing popularity of autonomous driving, its application scenarios have become richer. As an important sensing component, the point cloud density requirement for lidar is getting higher and higher.

[0003] To increase the point cloud density of lidar, usually the number of laser emission units is increased. With the increase in the number of laser emission units, it is necessary to improve the integration of the laser driving device, and at the same time, the consistency of each channel needs to be ensured.

[0004] At the same time, to realize the driving control of each laser, a plurality of matching laser driving circuits need to be set. The laser driving circuit and the laser emission unit form a laser emission circuit, resulting in a complex structure and high cost of the laser emission circuit and the lidar. Summary of the Invention

[0005] The purpose of the present invention is to provide a laser emission circuit, aiming to solve the problems of complex structure and high cost existing in the traditional laser emission circuit and lidar.

[0006] The first aspect of the embodiment of the present invention provides a laser emission circuit, including:

[0007] A charging circuit, which is triggered by a charging signal to charge and store energy and output;

[0008] A light emitting module, which includes an energy storage unit and a plurality of light emitting units. The energy storage unit is connected to the output end of the charging circuit, the plurality of light emitting units are connected in parallel and then connected to the energy storage unit. The light emitting unit is triggered by a discharge signal to conduct and obtain electricity to emit laser pulses;

[0009] A multiplexing circuit, which includes a plurality of transmission channels. The output end of each transmission channel is connected to one of the light emitting units, and the input ends of the plurality of transmission channels are connected in parallel and used to input the discharge signal. The multiplexing circuit is gated by an address selection signal to select a corresponding transmission channel to output the discharge signal;

[0010] A control circuit, which is respectively connected to the charging circuit and the multiplexing circuit. The control circuit outputs the charging signal, the address selection signal and the discharge signal in sequence under the trigger signal to store energy in the energy storage unit and select one of the corresponding light emitting units to obtain electricity and emit laser pulses.

[0011] Optionally, the control circuit is further configured to:

[0012] Sequentially select each transmission channel according to a preset light emission mode and output a discharge signal to each light emitting unit to sequentially select each light emitting unit to emit laser pulses.

[0013] Optionally, the control circuit is further configured to:

[0014] According to the circuit layout difference, output the charging signals with multiple preset durations to the charging circuit through the preset light emission mode, so that the output peak power of the light emitting unit is the same.

[0015] Optionally, the control circuit is further configured to:

[0016] Output the discharge signals at intervals, so that the same light emitting unit emits laser pulses at intervals, and change the magnitudes of the light emission powers twice by adjusting the pulse width of the discharge signal.

[0017] Optionally, the control circuit is further configured to:

[0018] Set the light emission interval times of different light emitting units to achieve optical coding.

[0019] Optionally, the charging circuit includes an energy storage inductor, a first switching tube, and a diode;

[0020] The first end of the energy storage inductor constitutes the input end of the charging circuit, the second end of the energy storage inductor, the first end of the first switching tube, and the anode of the diode are connected, the second end of the first switching tube is grounded, the cathode of the diode constitutes the output end of the charging circuit, and the control end of the first switching tube constitutes the control end of the charging circuit.

[0021] Optionally, the light emitting unit includes a laser and a second switching tube;

[0022] The first end of the laser is connected to the energy storage unit, the second end of the laser is connected to the first end of the second switching tube, the second end of the second switching tube is grounded, and the control end of the second switching tube constitutes the control end of the light emitting unit.

[0023] Optionally, the multiplexing circuit includes a multi-channel analog switch chip;

[0024] One signal input end of the multi-channel analog switch chip is used to input the discharge signal, multiple signal output ends of the multi-channel analog switch chip are respectively connected to the control ends of the light emitting units, and at least one enable end of the multi-channel analog switch chip is used to input the address selection signal.

[0025] Optionally, the laser emission circuit further includes:

[0026] A signal amplification circuit, the input end of the signal amplification circuit is used to input the discharge signal, the output end of the signal amplification circuit is connected to the input end of the multiplexing circuit, and the signal amplification circuit is used to amplify the discharge signal and output it to the multiplexing circuit.

[0027] A second aspect of the embodiments of the present invention provides a lidar, including a laser receiving circuit and the laser transmitting circuit as described above.

[0028] The beneficial effects of the embodiments of the present invention compared with the prior art are as follows: The above-mentioned laser transmitting circuit includes a charging circuit, a light emitting module, a multiplexing circuit and a control circuit. The light emitting module includes an energy storage unit and a plurality of light emitting units connected to the energy storage unit. The control circuit outputs a charging signal to control the charging circuit to charge the energy storage unit and outputs an address selection signal and a discharge signal in sequence after receiving a trigger signal, so as to select the corresponding transmission channel to output the discharge signal to the specified light emitting unit, so that the light emitting unit is triggered to conduct and emit laser pulses. By selecting different transmission channels of the multiplexing circuit, the driving of different light emitting units is realized, and only one charging circuit needs to be configured, which simplifies the structure and design cost of the laser transmitting circuit and the lidar. Description of the Drawings

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0030] Figure 1 It is the first structural schematic diagram of the laser transmitting circuit provided by the embodiments of the present invention;

[0031] Figure 2 It is the circuit schematic diagram of the charging circuit and the light emitting module provided by the embodiments of the present invention;

[0032] Figure 3 It is the second schematic diagram of the laser transmitting circuit provided by the embodiments of the present invention;

[0033] Figure 4 It is the third schematic diagram of the laser transmitting circuit provided by the embodiments of the present invention;

[0034] Figure 5 It is the structural schematic diagram of the lidar provided by the embodiments of the present invention. Detailed Embodiments

[0035] 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 will be further described in detail below with reference to 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.

[0036] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0037] In the first aspect of the embodiment of the present invention, a laser emission circuit 100 is proposed. Among them, the laser emission circuit 100 is correspondingly arranged with the laser reception circuit 200. The laser emission circuit 100 can select the corresponding light-emitting unit 22 and the laser driving circuit. The light-emitting unit 22 is used to receive electricity and emit laser pulses. The laser driving circuit is connected to the laser emission component and is used to trigger and output a driving power supply to the light-emitting unit 22 according to a driving signal. The light-emitting unit 22 can select a laser P1 of a corresponding type. The laser driving circuit can select a charging and discharging circuit of a corresponding structure. The charging and discharging circuit charges and discharges according to the received driving signal and controls the laser P1 to emit laser pulses at a corresponding angle according to a corresponding timing sequence.

[0038] The laser reception circuit 200 is used to receive the laser pulses emitted by the laser emission circuit 100, and perform detection and conversion into a pulse echo signal. The pulse echo signal is output to the processing circuit, and the processing circuit determines the distance information and reflectivity of the object to be measured 1 according to the pulse echo signal.

[0039] Among them, in order to simplify the structure of the laser driving circuit, optionally, as Figure 1 shown, in this embodiment,

[0040] The laser emission circuit 100 includes:

[0041] A charging circuit 10, which is triggered by a charging signal Ctr1 to charge and store energy and output;

[0042] A light-emitting module 20, which includes an energy storage unit 21 and a plurality of light-emitting units 22. The energy storage unit 21 is connected to the output end of the charging circuit 10. The plurality of light-emitting units 22 are connected in parallel and then connected to the energy storage unit 21. The light-emitting unit 22 is triggered to conduct and receive electricity to emit laser pulses by a discharging signal Ctr2;

[0043] The multiplexing circuit 30 includes a plurality of transmission channels 31. The output end of each transmission channel 31 is connected to a light-emitting unit 22. The input ends of the plurality of transmission channels are connected in parallel and are used for inputting the discharge signal Ctr2. The multiplexing circuit 30 is gated by the address selection signal Ctr3 to correspond to one transmission channel 31 to output the discharge signal Ctr2.

[0044] The control circuit 40 is respectively connected to the charging circuit 10 and the multiplexing circuit 30. The control circuit 40 outputs the charging signal Ctr1, the address selection signal Ctr3, and the discharge signal Ctr2 in sequence under the action of the trigger signal to store energy in the energy storage unit 21 and select one of the corresponding light-emitting units 22 to be powered on to emit laser pulses.

[0045] In this embodiment, the light-emitting units 22 are arranged corresponding to preset positions, such as arranged in a square matrix, a circular array, etc. The corresponding light-emitting units 22 are powered on to emit laser pulses according to the received discharge signal Ctr2.

[0046] During operation, the control circuit 40 first outputs the charging signal Ctr1, and then outputs the discharge signal Ctr2 and the address selection signal Ctr3. Among them, the order of the address selection signal Ctr3 and the discharge signal Ctr2 is not limited, and they can be output simultaneously or sequentially.

[0047] The charging signal Ctr1 is output to the charging circuit 10, and the charging circuit 10 performs power conversion and charging. At the same time, the energy storage unit 21 in the light-emitting module 20 is charged and stored. The energy storage unit 21 is in a standby output state. Then, the control circuit 40 outputs the address selection signal Ctr3 and the discharge signal Ctr2. The address selection signal Ctr3 gates one of the transmission channels 31 to connect the control circuit 40 and the light-emitting unit 22. The discharge signal Ctr2 is output to the specified light-emitting unit 22 through the gated transmission channel 31. The light-emitting unit 22 is triggered to conduct, and the electric energy stored in the energy storage unit 21 is output to the specified light-emitting unit 22. The specified light-emitting unit 22 is powered on and emits laser pulses, completing the laser pulse emission work.

[0048] The control circuit 40 sequentially selects a plurality of specified light-emitting units 22 to sequentially emit laser pulses by sequentially outputting multiple groups of charging signals Ctr1, discharge signals Ctr2, and address selection signals Ctr3. In the laser emission circuit 100, the plurality of specified light-emitting units 22 share a set of charging circuit 10 and energy storage unit 21, simplifying the structure of the laser emission circuit 100 and the lidar and reducing the design cost of the laser emission circuit 100 and the lidar.

[0049] Among them, it is possible to select all or drive the light emission sequentially according to the drive group. For each drive group, several light-emitting units 22 are selected to emit laser pulses. For example, assuming the number of light-emitting units 22 is 8, within the first preset time period, the first light-emitting unit 22 to the fourth light-emitting unit 22 are sequentially gated to be powered on to emit laser pulses. Within the second preset time period, the fifth light-emitting unit 22 to the eighth light-emitting unit 22 are sequentially gated to be powered on to emit laser pulses. At this time, the first light-emitting unit 22 to the fourth light-emitting unit 22 stop working and dissipate heat. And within the third preset time period, the first light-emitting unit 22 to the fourth light-emitting unit 22 are again sequentially gated to be powered on to emit laser pulses. At this time, the fifth light-emitting unit 22 to the eighth light-emitting unit 22 stop working and dissipate heat. By driving the light-emitting units 22 alternately, heat accumulation is reduced, and the working duration of the light-emitting units 22 is reduced, improving the working safety of the laser emission circuit 100.

[0050] Alternatively, within the first preset time period, the first light-emitting unit 22 to the sixth light-emitting unit 22 are sequentially gated to be powered on to emit laser pulses. Within the second preset time period, the second light-emitting unit 22 to the seventh light-emitting unit 22 are sequentially gated to be powered on to emit laser pulses. And within the third preset time period, the third light-emitting unit 22 to the eighth light-emitting unit 22 are sequentially gated to be powered on to emit laser pulses. By gating several light-emitting units 22 each time and sequentially selecting the remaining light-emitting units 22 to switch to the stop working state, the working duration of the light-emitting units 22 is reduced, improving the working safety of the laser emission circuit 100.

[0051] In an alternative embodiment, the control circuit 40 is further configured to:

[0052] Sequentially gate each transmission channel and output a discharge signal Ctr2 to each light-emitting unit 22 according to a preset light emission mode, so as to sequentially select each light-emitting unit 22 to emit laser pulses.

[0053] In this embodiment, within each driving cycle, all the light-emitting units 22 are selected to be powered on and emit light in sequence. For example, if there are three light-emitting units 22, during the first preset time period within the driving cycle, the control circuit 40 outputs a charging signal Ctr1 to the charging circuit 10. The charging circuit 10 is powered on to perform power conversion and charge the energy storage unit 21. The control circuit 40 outputs an address selection signal Ctr3 and a discharge signal Ctr2. At this time, the transmission channel 31 connected to the first light-emitting unit 22 is selected and gated. The discharge signal Ctr2 is output to the first light-emitting unit 22 through the selected and gated transmission channel 31. The light-emitting unit 22 is turned on and receives the electrical energy of the energy storage unit 21 to be powered on and emit laser pulses. Then, during the second preset time period within the driving cycle, the control circuit 40 outputs a charging signal Ctr1 to the charging circuit 10. The charging circuit 10 is powered on to perform power conversion and charge the energy storage unit 21. The control circuit 40 outputs an address selection signal Ctr3 and a discharge signal Ctr2. At this time, the transmission channel 31 connected to the second light-emitting unit 22 is selected and gated. The discharge signal Ctr2 is output to the second light-emitting unit 22 through the selected and gated transmission channel 31. The light-emitting unit 22 is turned on and receives the electrical energy of the energy storage unit 21 to be powered on and emit laser pulses.

[0054] During the third preset time period within the driving cycle, the control circuit 40 outputs a charging signal Ctr1 to the charging circuit 10. The charging circuit 10 is powered on to perform power conversion and charge the energy storage unit 21. The control circuit 40 outputs an address selection signal Ctr3 and a discharge signal Ctr2. At this time, the transmission channel 31 connected to the third light-emitting unit 22 is selected and gated. The discharge signal Ctr2 is output to the third light-emitting unit 22 through the selected and gated transmission channel 31. The light-emitting unit 22 is turned on and receives the electrical energy of the energy storage unit 21 to be powered on and emit laser pulses, and the above driving operation is repeated in the next driving cycle.

[0055] Among them, there may be problems such as parameter deviations of components, differences in connection lines, and circuit layout differences in each light-emitting unit 22 and the overall laser emission circuit 100. When the energy storage unit 21 is charged with the same charging time, the output peak power of each light-emitting unit 22 may be unequal, resulting in non-uniformity. Therefore, in an alternative embodiment, the control circuit 40 is further configured to:

[0056] According to the circuit layout differences, through a preset light-emitting mode, output charging signals Ctr1 with multiple preset durations to the charging circuit 10 to make the output peak power of the light-emitting units 22 the same.

[0057] In this embodiment, before driving the light-emitting module 20 to perform laser pulse emission work, by pre-acquiring or detecting the parameters of each light-emitting unit 22 and the laser emission circuit 100, the preset power of the energy storage unit 21 is determined. For example, the equivalent impedance of the first light-emitting unit 22 is greater than that of the second light-emitting unit 22. At this time, before the first light-emitting unit 22 is selected, the control circuit 40 outputs a charging signal Ctr1 with a first preset duration to the charging circuit 10. The charging circuit 10 charges the energy storage unit 21 and enables the energy storage unit 21 to obtain the first preset power. Then, an address selection signal Ctr3 and a discharge signal Ctr2 are output, and the first light-emitting unit 22 receives power and emits a laser pulse with a first emission peak power.

[0058] And before the second light-emitting unit 22 is selected, the control circuit 40 outputs a charging signal Ctr1 with a second preset duration to the charging circuit 10. The first preset duration is greater than the second preset duration. The charging circuit 10 charges the energy storage unit 21 and enables the energy storage unit 21 to obtain the second preset power. The first preset power is greater than the second preset power. Then, an address selection signal Ctr3 and a discharge signal Ctr2 are output, and the second light-emitting unit 22 receives power and emits a laser pulse with an emission peak power equal to the first emission peak power. And so on. By adjusting the charging time of the energy storage capacitor C1 each time, the emission power of each light-emitting unit 22 is adjusted to ensure the peak power consistency of all light-emitting units 22, reduce the influence of the emission power caused by the circuit layout difference, and improve the reliability of ranging.

[0059] Wherein, in order to reduce the number of charging times and improve the emission efficiency, optionally, the control circuit 40 is further configured to:

[0060] Output the discharge signal Ctr2 at intervals, so that the same light-emitting unit 22 emits laser pulses at intervals, and by adjusting the pulse width of the discharge signal Ctr2, the magnitudes of the two emission powers are changed.

[0061] In this embodiment, the control circuit 40 outputs one charging signal Ctr1 and multiple discharge signals Ctr2, and can select one light-emitting unit 22 to emit laser pulses at intervals. The laser receiving circuit 200 can sequentially receive a continuous plurality of laser pulses, improve the emission efficiency of the laser pulses, and complete the emission work of two laser pulses with one charge.

[0062] At the same time, the laser receiving circuit 200 can also determine whether an interference signal appears according to the time interval between two laser pulses. When a laser pulse appears within the time interval between two laser pulses, it can be determined as an interference signal, and the laser receiving circuit 200 can perform corresponding filtering or discarding processing.

[0063] Moreover, in order to achieve that the laser pulses emitted at two intervals reach the preset intensity, the control circuit also adjusts the pulse width of the discharge signal Ctr2 during each discharge to change the magnitude of the light emission power each time, so that the light emission powers at two times reach the preset power, meeting the ranging requirements.

[0064] Among them, in order to improve the ranging accuracy, optionally, the control circuit 40 is further configured to:

[0065] Set the light emission interval time of different light emitting units 22 to achieve optical coding.

[0066] For each light emitting unit 22, at each scanning angle in a light emitting unit 22, within a preset time period, time coding or energy coding is performed on the laser beam of the light emitting unit 22 based on the optical coding frequency to achieve optical coding of the laser beam. Among them, the laser beam emitted by the light emitting unit 22 includes the laser beam subjected to optical coding, and then the light emitting unit 22 emits the optically coded laser beam; then after emitting the laser beam, the echo signal is received, and the echo signal within the preset time period is obtained to obtain an echo signal set.

[0067] Among them, the echo signal set includes the echo signal corresponding to the laser beam emitted by the light emitting unit 22, or includes the echo signal corresponding to the laser beam emitted by the light emitting unit 22 and the interference signal brought by the external environment.

[0068] Ranging is achieved by the light emitting unit 22 emitting a laser beam and receiving an echo signal. If ranging is performed m times and optical coding laser beams are used for x times of ranging, and each of the x times of ranging is optically coded z times, then x*z + n echo signals are received, where n is the number of interference signals received.

[0069] According to the occurrence frequency of the interference signal in the echo signal set, the optical coding frequency is adjusted by adjusting the light emission interval time between different light emitting units 22.

[0070] If the occurrence frequency of the interference signal is high, then increase the light emission interval time between different light emitting units 22 to increase the optical coding frequency and reduce the interference brought by the external environment.

[0071] If the occurrence frequency of the interference signal is low, then reduce the light emission interval time between different light emitting units 22 to reduce the unnecessary loss of the lidar when the interference degree of the external environment on the laser P1 is low.

[0072] Among them, the charging circuit 10 is used to achieve voltage conversion, and a corresponding boost circuit, buck circuit, buck-boost circuit, etc. can be selected. In an alternative embodiment, as Figure 2 shown, the charging circuit 10 includes a storage inductor L1, a first switching transistor Q1, and a diode D1;

[0073] The first end of the energy storage inductor L1 constitutes the input end of the charging circuit 10. The second end of the energy storage inductor L1, the first end of the first switching transistor Q1, and the anode of the diode D1 are connected. The second end of the first switching transistor Q1 is grounded. The cathode of the diode D1 constitutes the output end of the charging circuit 10. The control end of the first switching transistor Q1 constitutes the control end of the charging circuit 10.

[0074] In this embodiment, the energy storage inductor L1, the first switching transistor Q1, and the diode D1 constitute a boost circuit. When the charging signal Ctr1 is input, the first switching transistor Q1 is turned on, and the energy storage inductor L1 starts to store energy. And when the input turn-off signal is received, the first switching transistor Q1 is turned off, and the energy stored in the energy storage inductor L1 is transferred to the light-emitting module 20 through the diode D1.

[0075] The energy storage unit 21 can adopt corresponding structures such as a battery, a capacitor C1, etc. In an alternative embodiment, the energy storage unit 21 includes a capacitor C1. The first end of the capacitor C1 constitutes the power supply end of the energy storage unit 21, and the second end of the capacitor C1 is grounded. The light-emitting unit 22 includes corresponding switching devices and a laser P1. Please continue to refer to Figure 2 Optionally, the light-emitting unit 22 includes a laser P1 and a second switching transistor Q2;

[0076] The first end of the laser P1 is connected to the energy storage unit 21. The second end of the laser P1 is connected to the first end of the second switching transistor Q2. The second end of the second switching transistor Q2 is grounded. The control end of the second switching transistor Q2 constitutes the control end of the light-emitting unit 22.

[0077] Wherein, the control end of each second switching transistor Q2 is connected to a transmission channel 31 of the multiplexing circuit 30 for receiving the corresponding discharge signal Ctr2. After the discharge signal Ctr2 is input, the second switching transistor Q2 is turned on. After the capacitor C1 is charged, the electric charge stored in the capacitor C1 is transmitted to the laser P1, and the laser P1 is powered on to emit laser pulses.

[0078] The multiplexing circuit 30 can be composed of multiple switching structures, or a corresponding analog switch K1 can be selected. In an alternative embodiment, as Figure 3 shown, the multiplexing circuit 30 includes a multi-channel analog switch chip U1;

[0079] One signal input end of the multi-channel analog switch chip U1 is used for inputting the discharge signal Ctr2. The multiple signal output ends of the multi-channel analog switch chip U1 are respectively connected to the control ends of the light-emitting units 22. At least one enable end of the multi-channel analog switch chip U1 is used for inputting an address selection signal Ctr3.

[0080] Inside the multi-channel analog switch chip U1, there are multiple analog switches K1. Each analog switch K1 constitutes a transmission channel 31 and is connected to a light-emitting unit 22. The control end of the analog switch K1 is used to receive the address selection signal Ctr3. For example, the address selection signal Ctr3 includes D0 to Dn-1. By adjusting the combination of the corresponding digital code values 0 and 1 of the address selection signal Ctr3, different analog switches K1 are selected to conduct, and the discharge signal Ctr2 is transmitted to the specified light-emitting unit 22.

[0081] Furthermore, due to the weak driving ability of the discharge signal Ctr2 output by the control circuit 40, the second switching tube Q2 inside the light-emitting unit 22 cannot be normally turned on and off. Optionally, as Figure 4 shown, the laser emission circuit 100 further includes:

[0082] A signal amplification circuit 50. The input end of the signal amplification circuit 50 is used to input the discharge signal Ctr2, and the output end of the signal amplification circuit 50 is connected to the input end of the multiplexing circuit 30. The signal amplification circuit 50 is used to amplify the discharge signal Ctr2 and output it to the multiplexing circuit 30.

[0083] In this embodiment, the signal amplification circuit 50 amplifies the discharge signal Ctr2, converts the discharge signal Ctr2 output by the control circuit 40 into a high-current drive signal, and improves the driving ability of the light-emitting unit 22. Among them, the signal amplification circuit 50 can adopt corresponding signal amplifiers, triode amplification circuits and other structures, and the specific structure is not limited.

[0084] The beneficial effects of the embodiment of the present invention compared with the prior art are as follows: The above-mentioned laser emission circuit 100 includes a charging circuit 10, a light-emitting module 20, a multiplexing circuit 30 and a control circuit 40. The light-emitting module 20 includes an energy storage unit 21 and multiple light-emitting units 22 connected to the energy storage unit 21. The control circuit 40 outputs a charging signal Ctr1 to control the charging circuit 10 to charge the energy storage unit 21 in sequence under the trigger signal, and outputs an address selection signal Ctr3 and a discharge signal Ctr2, so as to select the corresponding transmission channel 31 to output the discharge signal Ctr2 to the specified light-emitting unit 22, so that the light-emitting unit 22 is triggered to conduct and emit laser pulses. By selecting different transmission channels 31 of the multiplexing circuit 30, the driving of different light-emitting units 22 is realized. Only one charging circuit 10 needs to be configured, which simplifies the structure and design cost of the laser emission circuit 100 and the lidar.

[0085] The present invention also proposes a lidar, as Figure 5As shown in the figure, the lidar includes a laser receiving circuit 200 and a laser transmitting circuit 100. The specific structure of the laser transmitting circuit 100 refers to the above-mentioned embodiments. Since this lidar adopts all the technical solutions of the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be elaborated here one by one.

[0086] The laser transmitting circuit 100 and the laser receiving circuit 200 are correspondingly arranged. The laser transmitting circuit 100 can select the corresponding light emitting unit 22 and laser driving circuit. The light emitting unit 22 is used to emit laser pulses when powered. The laser driving circuit is connected to the laser transmitting component and is used to trigger and output a driving power supply to the light emitting unit 22 according to the driving signal. The light emitting unit 22 can select a laser P1 of the corresponding type. The laser driving circuit can select a charging and discharging circuit of the corresponding structure. The charging and discharging circuit charges and discharges according to the received driving signal and controls the laser P1 to emit laser pulses at a corresponding angle according to the corresponding timing.

[0087] The laser receiving circuit 200 is used to receive the laser pulses emitted by the laser transmitting circuit 100, perform detection and convert them into pulse echo signals. The pulse echo signals are output to the processing circuit, and the processing circuit determines the distance information and reflectivity of the object to be measured 1 according to the pulse echo signals.

[0088] The lidar may further include a main control circuit. The main control circuit is used to drive the laser transmitting circuit 100 to emit laser pulses, and at the same time receive the echo pulse signals output by the laser receiving circuit 200. According to the echo pulse width and the arrival time of the pulses of the echo pulse signals, the flight time of the echo signals, as well as the distance information and reflectivity, are further determined.

[0089] Among them, the main control circuit can share the same processor with the control circuit 40 in the laser transmitting circuit 100, and output a driving signal to drive the laser transmitting circuit 100 to emit laser pulses. At the same time, it receives the echo signals to obtain the echo pulse width and the arrival time of the pulses, and further determines the flight time of the echo signals, as well as the distance information and reflectivity.

[0090] The above-mentioned embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; 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 invention, and should all be included in the protection scope of the present invention.

Claims

1. A laser emission circuit, It is characterized in that include: A charging circuit, wherein the charging circuit is triggered by a charging signal to charge, store energy and output; A light-emitting module, the light-emitting module comprising an energy storage unit and a plurality of light-emitting units, the energy storage unit being connected to the output end of the charging circuit, the plurality of light-emitting units being connected in parallel to the energy storage unit, the light-emitting unit being triggered to conduct by a discharge signal and electrically emitting laser pulses; A multiplexing circuit, wherein the multiplexing circuit comprises a plurality of transmission channels, wherein an output end of each transmission channel is connected to one of the light-emitting units, and input ends of the plurality of transmission channels are connected in parallel and used to input the discharge signal, and the multiplexing circuit is selected by an address selection signal to select a corresponding transmission channel to output the discharge signal; A control circuit, wherein the control circuit is connected to the charging circuit and the multiplexing circuit respectively, and the control circuit, in response to a trigger signal, sequentially outputs the charging signal, the address selection signal and the discharge signal to store energy in the energy storage unit and select a corresponding light-emitting unit to emit a laser pulse.

2. The laser emitting circuit according to claim 1, It is characterized in that The control circuit is also used for: Each transmission channel is sequentially selected according to a preset light-emitting mode and a discharge signal is output to each light-emitting unit, so as to sequentially select each light-emitting unit to emit a laser pulse.

3. The laser emitting circuit according to claim 2, It is characterized in that The control circuit is also used for: According to the difference in circuit layout, by means of preset light-emitting modes, the charging signals of multiple preset durations are output to the charging circuit so that the output peak powers of the light-emitting units are the same.

4. The laser emitting circuit according to claim 1, It is characterized in that The control circuit is also used for: The discharge signal is output at intervals so that the same light-emitting unit emits laser pulses at intervals, and the magnitude of the two light-emitting powers is changed by adjusting the pulse width of the discharge signal.

5. The laser emitting circuit according to claim 2, It is characterized in that The control circuit is also used for: The light-emitting intervals of the different light-emitting units are set to achieve light coding.

6. The laser emitting circuit according to claim 1, It is characterized in that The charging circuit includes an energy storage inductor, a first switch tube and a diode; The first end of the energy storage inductor constitutes the input end of the charging circuit, the second end of the energy storage inductor, the first end of the first switch tube and the anode of the diode are connected, the second end of the first switch tube is grounded, the cathode of the diode constitutes the output end of the charging circuit, and the control end of the first switch tube constitutes the control end of the charging circuit.

7. The laser emitting circuit according to claim 1, It is characterized in that The light emitting unit comprises a laser and a second switch tube; The first end of the laser is connected to the energy storage unit, the second end of the laser is connected to the first end of the second switch tube, the second end of the second switch tube is grounded, and the control end of the second switch tube constitutes the control end of the light-emitting unit.

8. The laser emitting circuit according to claim 1, It is characterized in that The multiplexing circuit includes a multi-channel analog switch chip; A signal input terminal of the multi-way analog switch chip is used to input the discharge signal, multiple signal output terminals of the multi-way analog switch chip are respectively connected to the control terminals of the light-emitting unit, and at least one enable terminal of the multi-way analog switch chip is used to input the address selection signal.

9. The laser emitting circuit according to claim 1, It is characterized in that The laser emission circuit also includes: A signal amplifying circuit, wherein the input end of the signal amplifying circuit is used to input the discharge signal, the output end of the signal amplifying circuit is connected to the input end of the multiplexing circuit, and the signal amplifying circuit is used to amplify the discharge signal and output it to the multiplexing circuit.

10. A laser radar, It is characterized in that The invention comprises a laser receiving circuit and a laser emitting circuit as claimed in any one of claims 1 to 9.

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