Laser emission circuit and control method thereof, and laser radar

Abstract

The invention discloses a laser emission circuit and a control method thereof, and a laser radar, and the circuit comprises one or more charging branches, each charging branch is connected with one or more discharging branches, and each discharging branch is connected with a light-emitting branch; the charging branch comprises an energy acquisition module and a boost control module; the discharge branch comprises an energy storage module; the light-emitting branch comprises an emission module and an emission control module; the boost control module is configured to be electrically connected with the energy acquisition module and an external power supply, control the energy acquisition module to be electrically connected with the external power supply to acquire energy, or control the energy acquisition module to transmit the acquired energy to the energy storage module; the boost control module adjusts the amount of energy acquired by the energy acquisition module by adjusting the time length of electrical connection between the energy acquisition module and the external power supply. According to the scheme, the light emitting intensity of the laser can be rapidly and flexibly adjusted under the condition of a single power supply, and the problem of secondary light emitting is avoided.

Description

Technical Field

[0001] The present application relates to the field of circuit technology, and in particular to a laser emission circuit and a control method thereof, and a laser radar. Background Art

[0002] With the rise of autonomous driving and robotics, LiDAR has become an important sensor for 3D perception. LiDAR actively emits a certain amount of detection light and analyzes the echo light reflected by an object to obtain information such as the distance, position, and reflectivity of the object.

[0003] In order to improve the detection performance of LiDAR, LiDAR needs to adjust the energy or intensity of the emitted detection light, which can be achieved by adjusting the power supply voltage of the laser. The power supply voltage of the laser can be generated by the BOOST chip, and the BOOST chip usually needs hundreds of microseconds to adjust the voltage. The time window used by LiDAR for ranging is usually short, and it is difficult to provide the time required for the BOOST chip to adjust the voltage. The power supply voltage of the laser can also be provided by a traditional resonant circuit. Although the traditional resonant circuit can quickly adjust the light intensity, it has the risk of secondary light emission (abnormal light emission) of the laser, which will seriously reduce the accuracy of LiDAR distance measurement. Summary of the invention

[0004] The present application provides a laser emission circuit and a control method thereof, and a laser radar, which can quickly adjust the light emission intensity of the laser and avoid the problem of secondary light emission of the laser.

[0005] To this end, this application provides the following technical solutions:

[0006] On the one hand, the present application provides a laser emission circuit, the laser emission circuit comprising: one or more charging branches, each charging branch is connected to one or more discharging branches, each discharging branch is connected to a light-emitting branch; the charging branch comprises an energy acquisition module and a boost control module; the discharging branch comprises an energy storage module; the light-emitting branch comprises a transmitting module and a transmitting control module;

[0007] The boost control module is configured to electrically connect the energy acquisition module with an external power source, or control the energy acquisition module to transfer the acquired energy to the energy storage module; wherein the boost control module adjusts the amount of energy acquired by the energy acquisition module by adjusting the length of time the energy acquisition module is electrically connected to the external power source;

[0008] The emission control module is configured to control the emission module to emit laser pulses using the energy stored in the energy storage module after the energy storage module completes energy storage.

[0009] Optionally, the boost control module includes: a first switch unit and a second switch unit;

[0010] When the first switch unit is closed and the second switch unit is open, the energy acquisition module is connected to the external power supply;

[0011] When the first switch unit is opened and the second switch unit is closed, the energy acquisition module transmits the energy to the energy storage module.

[0012] Optionally, the boost control module further includes:

[0013] A first driving unit, used for driving the first switch unit to close or open;

[0014] The second driving unit is used to drive the second switch unit to close or open.

[0015] Optionally, the transmission control module includes: a transmission switch unit and a transmission switch driving unit;

[0016] The transmitting switch driving unit is used to drive the transmitting switch unit to close or open;

[0017] The transmitting module transmits laser pulses after the transmitting switch unit is closed.

[0018] Optionally, during the process of the transmitting module transmitting laser pulses, the first driving unit drives the first switch unit to be opened, and the second driving unit drives the second switch unit to be closed.

[0019] Optionally, the first switch unit is any one of the following: a field effect transistor, a triode; the second switch unit is any one of the following: a field effect transistor, a triode.

[0020] Optionally, the energy acquisition module includes: an inductor; and the energy storage module includes a capacitor.

[0021] Optionally, the discharge branch further includes a diode, an anode of the diode is connected to the inductor, and a cathode of the diode is connected to the capacitor.

[0022] Optionally, energy acquisition modules of different charging branches are electrically connected to the external power supply simultaneously or in a time-sharing manner.

[0023] On the other hand, the present application also provides a laser emission circuit control method, the laser emission circuit comprising: one or more charging branches, each charging branch connected to one or more discharging branches, each discharging branch connected to a light-emitting branch; the charging branch comprises an energy acquisition module and a boost control module; the discharging branch comprises an energy storage module; the light-emitting branch comprises a transmitting module and a transmitting control module; the boost control module is configured to electrically connect the energy acquisition module to an external power supply, or control the energy acquisition module to transfer the energy to the energy storage module;

[0024] The method comprises:

[0025] The boost control module is electrically connected to the energy acquisition module and the external power supply, and the energy acquisition module acquires energy;

[0026] After a preset time period, the boost control module disconnects the electrical connection between the energy acquisition module and the external power source, and the energy acquisition module transmits energy to the energy storage module;

[0027] The emission control module is electrically connected to the energy storage module and the emission module, and the emission module emits laser pulses.

[0028] Optionally, the method further comprises: adjusting the length of the preset time period according to the energy required for emitting the laser pulse.

[0029] Optionally, the method further comprises: after the laser pulse is emitted, disconnecting the electrical connection between the energy storage module and the emission module.

[0030] Optionally, the method further comprises: repeatedly executing the steps of acquiring energy, transmitting energy, and emitting laser pulses, so as to emit the laser pulses multiple times.

[0031] Optionally, the duration of the preset time period corresponding to each emission of the laser pulse remains the same or different.

[0032] Optionally, the method further includes: controlling the energy acquisition modules of different charging branches to acquire energy from the external power supply simultaneously or in different time periods.

[0033] On the other hand, the present application also provides a laser radar, which includes the laser transmitting circuit and the laser receiving circuit described above;

[0034] The laser receiving circuit is configured to receive an echo pulse formed after the laser pulse is reflected by an object and generate an electrical signal.

[0035] The laser emission circuit and control method thereof, and laser radar disclosed in the present application, the charging branch is connected to one or more discharge branches, each discharge branch is connected to a light-emitting branch, so that multiple light-emitting branches can reuse one charging branch, thereby improving the circuit reuse capability and effectively reducing the circuit occupied area. In addition, the boost control module in the charging branch is configured to electrically connect the energy acquisition module and the external power supply, control the energy acquisition module to be electrically connected to the external power supply to acquire energy, or control the energy acquisition module to transfer the acquired energy to the energy storage module on each discharge branch connected thereto, and adjust the amount of energy acquired by the energy acquisition module by adjusting the length of time the energy acquisition module is electrically connected to the external power supply, so that the laser emission circuit can quickly and flexibly adjust the laser luminous intensity under the condition of a single power supply, so that the same laser can achieve two consecutive different luminous intensities, meet the needs of different application scenarios, and avoid the problem of the laser generating secondary luminescence in one luminous control cycle, thereby ensuring the accuracy of the laser radar distance measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings are used to provide a further understanding of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the accompanying drawings:

[0037] Figure 1 It is a circuit structure diagram of a resonant laser transmitting circuit;

[0038] Figure 2 is a schematic diagram of the structure of a laser emission circuit in some embodiments disclosed in the present application;

[0039] Figure 3 is a circuit structure schematic diagram of a laser emission circuit in some embodiments disclosed in the present application;

[0040] Figure 4 is another circuit structure schematic diagram of the laser emission circuit in some embodiments disclosed in the present application;

[0041] Figure 5 is another circuit structure schematic diagram of the laser emission circuit in some embodiments disclosed in the present application;

[0042] Figure 6 is a flow chart of a laser emission circuit control method in some embodiments disclosed in the present application;

[0043] Figure 7 It is a structural schematic diagram of a laser radar in some embodiments disclosed in this application. DETAILED DESCRIPTION

[0044] In order to make the above-mentioned objects, features and beneficial effects of the present application more obvious and easy to understand, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0045] A resonant laser transmitting circuit such as Figure 1 As shown, two transmission branches are shown in this example, but of course, there may be one or more than two transmission branches.

[0046] Reference Figure 1 Taking the first transmitting path as an example, the first transmitting path includes: a boost module 10 and a resonant light-emitting module. The boost module 10 includes a MOS tube M11, an inductor L11, a capacitor C11, and a voltage regulator diode D1; the capacitor C12 is the parasitic capacitance of the MOS tube M11, and the inductor L12 is the parasitic inductance of the first transmitting path; U11 outputs a driving signal to the MOS tube M11, and U12 outputs a control signal to the MOS tube M12; VDD is an external power supply. The resonant light-emitting module includes a laser LA1 and a MOS tube M12.

[0047] After U11 jumps from a low level to a high level, the MOS tube M11 is closed, and energy is stored in the inductor L11 through the external power supply VDD; after U11 jumps from a high level to a low level, the MOS tube M11 is disconnected, the inductor L11 charges the capacitor C11, and the energy is transferred from the inductor L11 to the capacitor C11.

[0048] After the capacitor C11 is fully charged, the control U12 changes to a high level, the MOS tube M12 is closed, and the capacitor C11 is discharged, so that the laser LA1 emits light.

[0049] The structure and working principle of the second transmitting path are the same as those of the first transmitting path. The boost module 20 and the components in the resonant light-emitting module in the second transmitting path are the same as the corresponding components in the first transmitting path, and are not described in detail here.

[0050] In the resonant laser transmitting circuit, the charging of the inductor L11 is realized by turning on the charging MOS tube M11, and then the charging energy of the inductor L11 is released to the capacitor C11 through LC resonance, and then the capacitor C11 releases energy to the laser LA1, so that the laser LA1 emits light. This method can quickly adjust the light intensity by adjusting the charging time of the inductor L11; but due to the existence of the junction capacitance (i.e., parasitic capacitance C12) of the MOS tube M11 that controls the charging, the laser LA1 has the risk of secondary light emission. In addition, each transmitting path requires one or a group of inductors, and the circuit layout requires a large space.

[0051] Below Figure 1 Take the first transmission path as an example, combined with Figure 1The process causing the laser to emit light twice is described. The secondary emission mentioned here means that the laser emits light twice when the MOS tube M12 is turned on once.

[0052] First, when the MOS tube M11 is turned on, the inductor L11 and the capacitor C11 are charged, and the current on the inductor L11 gradually increases. When the inductor L11 is charged to the required energy, the MOS tube M11 is disconnected. At this time, the inductor L11 continues to charge the capacitor C11, so that the voltage on the capacitor C11 continues to increase, and then the MOS tube M12 is closed, and the capacitor C11 supplies power to the laser LA1 to make it emit light.

[0053] During the light emission of laser LA1, capacitor C11 discharges, causing the voltage on capacitor C11 to drop. There is also parasitic inductance in laser LA1, which causes the voltage on capacitor C11 to drop to 0V and then continue to drop to negative voltage. The energy stored in the external power supply VDD and the parasitic capacitor C12 in the MOS tube M11 resonates to capacitor C11 through the parasitic inductance L12 in the circuit, causing the voltage on capacitor C11 to rise again. When the voltage on capacitor C11 is greater than the threshold voltage of laser LA1, capacitor C11 supplies power to laser LA1, causing laser LA1 to emit light for a second time. Of course, when the voltage on capacitor C11 is less than the threshold voltage of laser LA1, laser LA1 will not emit light for a second time.

[0054] exist Figure 1 In the circuit shown, when the parasitic capacitor C12 of the MOS tube M11 forms a resonant path through the parasitic inductor L12, the parasitic inductor L12 is very small, so the current flowing through the parasitic inductor L12 is large, causing the voltage on the capacitor C11 to rise more, exceeding the threshold voltage of the laser LA1 to emit light, causing secondary light emission. Secondary light emission reduces the electro-optical conversion efficiency of the laser emission circuit, and causes double echoes when the laser radar is measuring distance, reducing the accuracy of the laser radar measurement.

[0055] In response to the above problems, some embodiments of the present application provide a laser emission circuit and a control method thereof, and a laser radar, wherein a boost control module in a charging branch is configured to electrically connect an energy acquisition module and an external power supply, and the boost control module controls the energy acquisition module to electrically connect to an external power supply to acquire energy, or controls the energy acquisition module to transmit the acquired energy to energy storage modules on each discharge branch connected thereto, and adjusts the amount of energy acquired by the energy acquisition module by adjusting the length of time the energy acquisition module is electrically connected to the external power supply, so that the laser emission circuit can use a single power supply to quickly and flexibly adjust the laser's luminous intensity, so that the same laser can achieve two adjacent luminous intensities of different intensity, meet the requirements of different application scenarios, and improve the circuit's multiplexing capability, and avoid the problem of the laser generating secondary luminescence within one luminous control cycle.

[0056] like Figure 2 , which is a schematic diagram of the structure of the laser emission circuit provided in some embodiments of the present application.

[0057] The laser emission circuit comprises: one or more charging branches, each charging branch is connected to one or more discharging branches, and each discharging branch is connected to a light-emitting branch. Figure 2 The case where each charging branch is connected to a discharging branch is shown in FIG.

[0058] Figure 2 In the example shown, the charging branch includes an energy acquisition module 201 and a boost control module 202; the discharging branch includes an energy storage module 301; and the light emitting branch includes a transmitting module 401 and a transmitting control module 402. Wherein:

[0059] The boost control module 202 is configured to electrically connect the energy acquisition module 201 with the external power source VDD, or control the energy acquisition module 201 to transfer the acquired energy to the energy storage module 301. Moreover, the boost control module 202 can adjust the amount of energy acquired by the energy acquisition module 201 by adjusting the length of time the energy acquisition module 201 is electrically connected to the external power source VDD.

[0060] The emission control module 402 is configured to control the emission module 402 to emit laser pulses using the energy stored in the energy storage module 301 after the energy storage module 301 completes energy storage.

[0061] In some embodiments, the laser emission circuit includes multiple charging branches. According to different application requirements, the energy acquisition modules 201 of different charging branches can be electrically connected to the external power supply VDD simultaneously or in a time-sharing manner.

[0062] In some embodiments, the boost control module 202 includes: a first switch unit and a second switch unit. When the first switch unit is closed and the second switch unit is disconnected, the energy acquisition module 201 is electrically connected to the external power supply VDD; when the first switch unit is disconnected and the second switch unit is closed, the energy acquisition module 201 transmits the energy to the energy storage module 301.

[0063] The first switch unit may be driven to be closed or opened by a first drive unit, and the second switch unit may be driven to be closed or opened by a second drive unit.

[0064] In some embodiments, the emission control module 402 may include: an emission switch unit and an emission switch driving unit. The emission switch driving unit is used to drive the emission switch unit to close or open. The emission module 401 emits a laser pulse after the emission switch unit is closed.

[0065] During the process of emitting laser pulses by the emitting module 401, the first driving unit drives the first switch unit to be disconnected, and the second driving unit drives the second switch unit to be closed. However, this does not mean that the emitting module 401 starts to emit laser pulses when the first switch unit is disconnected and the second switch unit is closed. Whether to start emitting laser pulses is also determined by the state of the emitting switch unit in the emitting control module 402. If the emitting switch unit is closed, the laser pulses are emitted; if the emitting switch unit is disconnected, the laser pulses cannot be emitted.

[0066] Combine the following Figures 2 to 5 The working process of the laser emission circuit provided in this application is described in detail.

[0067] like Figure 3 , which is a schematic diagram of a circuit structure of a laser emission circuit provided in some embodiments of the present application.

[0068] The laser emission circuit of this embodiment includes a charging branch, which is connected to three discharging branches, and each discharging branch is connected to a light-emitting branch. In other words, one charging branch provides electrical energy to three light-emitting branches, or in other words, three light-emitting branches use one charging branch to provide energy.

[0069] Also refer to Figure 2 and Figure 3 , Figure 2 The first switch unit and the second switch unit in the boost control module 202 are implemented by field effect transistors, such as NMOS transistors or PMOS transistors. Figure 3 Take NMOS tube as an example, that is, Figure 3 The NMOS tube M1 and the NMOS tube M2 in the figure, wherein the gate of M1 is connected to the first driving unit (not shown in the figure), and the gate of M2 is connected to the second driving unit. The first driving unit and the second driving unit can be implemented by corresponding driving chips or driving circuits, which is not limited in the embodiment of the present application.

[0070] The drain of M1 is connected to the external power supply VDD, the source of M1 is connected to the drain of M2, and the source of M2 is grounded.

[0071] In this embodiment, the energy acquisition module is realized by inductor L1, the energy storage modules of the three discharge branches are realized by capacitors C1, C2, and C3 respectively, the emission control modules of the three light-emitting branches are realized by emission control switches W1, W2, and W3 and corresponding emission switch driving units (not shown in the figure), and the emission modules of the three light-emitting branches are realized by lasers LD1, LD2, and LD3 respectively.

[0072] The emission control switches W1, W2, and W3 may be implemented using MOS tubes or triodes, which is not limited in the embodiments of the present application.

[0073] Refer to the following Figure 3 , the working process of the laser emission circuit is explained in detail.

[0074] The charging process is as follows:

[0075] Control M1 to be turned on and M2 to be turned off, the inductor L1 is electrically connected to the external power supply VDD, and the external power supply VDD charges the inductor L1. The duration of the electrical connection between the inductor L1 and the external power supply VDD can be adjusted by adjusting the duration of the M1 conduction, that is, the duration of the charging time of the inductor L1 can be controlled, and the amount of energy obtained by the inductor L1 can be adjusted.

[0076] After charging for a period of time, M1 is controlled to be disconnected and M2 is turned on, the inductor L1 and the capacitors C1~C3 resonate, and the inductor L1 continues to charge the capacitors C1~C3, so that the voltage of the capacitors C1~C3 increases until the current in the inductor L1 is 0A. At this time, the voltage of the capacitors C1~C3 reaches a peak value. Theoretically, the capacitor voltage peak adjustment range is 0~2VDD.

[0077] During the process of storing energy in the energy storage module 301, for example Figure 3 In the process of storing energy in the capacitors C1 to C3 shown, the capacitors may be charged to the required voltage through one LC resonance or multiple LC resonances, which is not limited in the embodiments of the present application.

[0078] Laser emission process:

[0079] When any one or more of the emission control switches W1, W2, and W3 are turned on, the lasers connected thereto emit light. In the embodiments disclosed in the present application, the lasers of each light-emitting branch can be independently controlled to emit light, and multiple lasers connected to the same charging branch can emit light simultaneously or at different times.

[0080] Since the inductance value of the inductor L1 used to charge each capacitor is much larger than the parasitic inductance in the circuit, after the capacitor is reduced to a negative voltage, the current generated when the energy in the parasitic capacitor in the NMOS tube M2 passes through the inductor L1 is very small, and the voltage charged to the capacitors C1 to C3 is also small, which will not exceed the threshold voltage of the laser light emission, thereby effectively avoiding the secondary light emission problem.

[0081] In some embodiments, during the process of the transmitting module transmitting laser pulses, the first driving unit drives the first switch unit to be opened, and the second driving unit drives the second switch unit to be closed.

[0082] like Figure 3As shown, taking the discharge branch where the capacitor C1 is located as an example, when the laser LD1 emits light, the second driving unit ( Figure 3 (not shown) drives NMOS tube M2 to turn on, which can reduce the heat in the laser emission circuit. This is because the discharge of capacitor C1 causes the laser LD1 to emit light. As mentioned above, due to the presence of parasitic inductance in the circuit, the voltage on the capacitor C1 connected to the laser LD1 will be reduced to a negative value after the laser LD1 emits light. At this time, if M2 is not turned on, current will flow into capacitor C1 through the body diode of M2 and L1. Since the resistance of the body diode of M2 is larger than the on-resistance of M2, M2 will cause heat to be generated. For this reason, in some embodiments, during the light-emitting process of the laser on any light-emitting branch, the first switch unit can be controlled to be disconnected and the second switch unit can be turned on. Since the on-resistance of the second switch unit is very small, the heat generation of the second switch unit can be reduced.

[0083] In some embodiments, Figure 3 As shown in , each discharge branch may also include a diode, such as Figure 3 The diodes D1 to D3 in the circuit have anodes connected to the inductor L1 and cathodes connected to the corresponding capacitors. The diodes D1 to D3 can prevent the voltage of the capacitors C1 to C3 from being discharged through the inductor after it increases.

[0084] like Figure 4 , which is another circuit structure schematic diagram of the laser emission circuit in some embodiments disclosed in the present application.

[0085] The laser emission circuit of this embodiment includes two charging branches, namely Figure 4 In the charging branch where the inductor L1 and the inductor L2 are located, each charging branch is connected to four discharge branches, and each discharge branch is connected to a light-emitting branch. In other words, every four light-emitting branches reuse one charging branch to provide energy. Among them, the inductor L1 is connected to the discharge branch where the capacitors C1-C4 are located, and the corresponding light-emitting branches are the light-emitting branches where the lasers LD1-LD4 are located; the inductor L2 is connected to the discharge branch where the capacitors C5-C8 are located, and the corresponding light-emitting branches are the light-emitting branches where the lasers LD5-LD8 are located.

[0086] In this embodiment, the light-emitting process and control method of each light-emitting branch are similar to Figure 3 The same is true in the illustrated embodiments, and will not be described in detail here.

[0087] Similar to the aforementioned embodiment, the lasers in the multiple light-emitting branches connected after each inductor may be the same or different, and one or more lasers may be connected, which is not limited in the embodiment of the present application.

[0088] exist Figure 4 In the embodiment shown, the working process of the circuit corresponding to each inductor is the same as that described above. Figure 3 The same as the embodiment shown, the multi-channel inductors can be charged at the same time or not, preferably not at the same time, that is, the inductors L1 and L2 are not charged at the same time, that is, M1 and M3 are not closed at the same time, because when the inductors L1 and L2 are charged at the same time, it takes longer time when the energy to be charged remains unchanged. In order to avoid crosstalk, laser radar usually adopts a solution of multiple lasers emitting light in time. For each laser, it is sufficient to charge the corresponding capacitor before the next light emission. Therefore, the characteristics of laser time-sharing light emission can be used to charge the capacitor corresponding to the laser during the time period when other lasers emit light. For example, lasers LD1~LD4 emit light first, and lasers LD5~LD8 emit light later. Then, the capacitors C1~C4 corresponding to lasers LD1~LD4 are charged through inductor L1 first, and the capacitors C5~C8 corresponding to lasers LD5~LD8 are charged through inductor L2 during the time period when lasers LD1~LD4 emit light, which reasonably utilizes the working time of the laser radar. Among them, lasers LD1 to LD4 can emit light at the same time or at different times; similarly, LD5 to LD8 can emit light at the same time or at different times.

[0089] It should be noted that after M1 is disconnected, that is, after the inductor L1 is charged, regardless of whether M2 is closed or not, M3 can be closed and M4 can be disconnected to charge the inductor L2.

[0090] like Figure 5 , which is another specific implementation structure diagram of the laser emission circuit in some embodiments disclosed in the present application.

[0091] The laser emission circuit of this embodiment also includes two charging branches, namely Figure 5 In the charging branch where the inductor L1 and the inductor L2 are located, each charging branch is connected to four discharge branches, and each discharge branch is connected to a light-emitting branch. In other words, every four light-emitting branches reuse one charging branch to provide energy. Among them, the inductor L1 is connected to the discharge branches where the capacitors C1 to C4 are located, and the corresponding light-emitting branches are the light-emitting branches where the lasers LD1 to LD4 are located; the inductor L2 is connected to the discharge branches where the capacitors C5 to C8 are located, and the corresponding light-emitting branches are the light-emitting branches where the lasers LD5 to LD8 are located.

[0092] and Figure 4 The difference between the embodiment shown is that the first switch unit and the second switch unit in the boost control module in the embodiment are implemented by transistors, which can be NPN transistors or PNP transistors. Figure 5 Take the NPN transistor as an example, that is, Figure 5 The NPN transistors Q1 and Q2 in the first charging branch, and the NPN transistors Q3 and Q4 in the second charging branch, wherein the base of Q1 is connected to the first driving unit ( Figure 5The base of Q2 is connected to the second driving unit. The first driving unit and the second driving unit may be implemented by corresponding driving chips or driving circuits, which is not limited in the embodiment of the present application.

[0093] The collector of Q1 is connected to the external power supply VDD, the emitter of Q1 is connected to the collector of Q 2, and the emitter of Q 2 is grounded.

[0094] The connection method of Q3 and Q4 is the same as that of Q1 and Q2, so it will not be repeated here.

[0095] exist Figure 5 In the embodiment shown, the working process of the circuit corresponding to each inductor is the same as that described above. Figure 4 The same as the embodiment shown, multiple inductors can be charged simultaneously or not simultaneously.

[0096] In the laser emission circuit provided by the embodiment of the present application, the charging branch can be connected to one or more discharge branches, and each discharge branch is connected to a light-emitting branch, so that multiple light-emitting branches can reuse one charging branch, thereby improving the reuse capability of the circuit and effectively reducing the circuit occupation area. Further, the boost control module in the charging branch is configured to electrically connect the energy acquisition module and the external power supply, control the energy acquisition module to be electrically connected to the external power supply to acquire energy, or control the energy acquisition module to transfer the acquired energy to the energy storage module on each discharge branch connected thereto, and adjust the amount of energy acquired by the energy acquisition module by adjusting the length of time the energy acquisition module is electrically connected to the external power supply, so that the luminous intensity of the laser can be adjusted quickly and flexibly under the condition of using a single power supply, so that the luminous intensity of the same laser is different twice before and after, so as to meet the needs of different application scenarios, and will not cause the problem of secondary luminescence in one luminescence control cycle.

[0097] With respect to the above-mentioned laser emission circuit, the present application also provides a control method, which can realize fast and flexible adjustment of the laser emission intensity under the condition of using a single power supply.

[0098] like Figure 6 FIG. 1 is a flow chart of a laser emission circuit control method in some embodiments disclosed in the present application, comprising the following steps:

[0099] In step 601, the boost control module electrically connects the energy acquisition module to an external power source, and the energy acquisition module acquires energy;

[0100] In step 602, after a preset period of time, the boost control module disconnects the electrical connection between the energy acquisition module and the external power source, and the energy acquisition module transmits energy to the energy storage module;

[0101] Furthermore, the length of the preset time period can be adjusted according to the energy required for emitting the laser pulse.

[0102] In step 603, the emission control module electrically connects the energy storage module and the emission module, and the emission module emits laser pulses.

[0103] Furthermore, after the laser pulse is emitted, the electrical connection between the energy storage module and the emission module is disconnected.

[0104] When it is necessary to emit laser pulses multiple times, the above steps 601 to 603 are repeated to achieve the multiple emission of laser pulses.

[0105] According to actual application requirements, the duration of the preset time period corresponding to each emission of the laser pulse can remain the same or different, and the emission light intensity each time the laser pulse is emitted can be the same or different.

[0106] In the case of multiple charging branches, energy acquisition modules of different charging branches can be controlled to acquire energy from an external power source simultaneously or in different time periods.

[0107] Accordingly, the present application also provides a laser radar, such as Figure 7 The figure shows a schematic diagram of the structure of a laser radar in some embodiments disclosed in the present application.

[0108] The laser radar 700 includes the laser transmitting circuit 701 and the laser receiving circuit 702 in the above embodiments. The laser transmitting circuit is as described in the above embodiments and will not be described in detail here; the laser receiving circuit 702 is configured to receive the echo pulse formed after the laser pulse is reflected by the object and generate an electrical signal.

[0109] The laser emission circuit 701 in the embodiment disclosed in the present application can charge multiple energy acquisition modules simultaneously or in time-sharing mode by a single power supply, can quickly and flexibly adjust the laser light intensity, and can avoid the problem of secondary light emission, thereby ensuring the accuracy of laser radar measurement. Multiple light-emitting branches can reuse one charging branch, reducing the circuit footprint and reducing costs. The lasers in the reused multiple charging branches can emit light simultaneously or at different times, making full use of the working time of each laser of the laser radar.

[0110] It should be understood that the term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article indicates that the associated objects before and after are in an "or" relationship.

[0111] The "plurality" appearing in the embodiments of the present application refers to two or more.

[0112] The first, second, etc. descriptions appearing in the embodiments of the present application are only used for illustration and distinction of the description objects. There is no order, nor do they indicate any special limitation on the number of devices in the embodiments of the present application, and cannot constitute any limitation on the embodiments of the present application.

[0113] The "connection" that appears in the embodiments of the present application refers to various connection methods such as direct connection or indirect connection to achieve communication between devices, and the embodiments of the present application do not impose any limitations on this.

[0114] Although the present application is disclosed as above, the present application is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application. Therefore, the protection scope of the present application shall be subject to the scope defined by the claims.

Claims

1. A laser emission circuit, characterized in that: The laser emission circuit includes: one or more charging branches, each charging branch is connected to one or more discharging branches, each discharging branch is connected to a light-emitting branch; the charging branch includes an energy acquisition module and a boost control module; the discharging branch includes an energy storage module; the light-emitting branch includes a transmitting module and a transmitting control module; The boost control module is configured to electrically connect the energy acquisition module with an external power source, or control the energy acquisition module to transfer the acquired energy to the energy storage module; wherein the boost control module adjusts the amount of energy acquired by the energy acquisition module by adjusting the length of time the energy acquisition module is electrically connected to the external power source; The emission control module is configured to control the emission module to emit laser pulses using the energy stored in the energy storage module after the energy storage module completes energy storage.

2. The laser emitting circuit according to claim 1, characterized in that: The boost control module includes: a first switch unit and a second switch unit; When the first switch unit is closed and the second switch unit is open, the energy acquisition module is connected to the external power supply; When the first switch unit is opened and the second switch unit is closed, the energy acquisition module transmits the energy to the energy storage module.

3. The laser emitting circuit according to claim 2, characterized in that: The boost control module further includes: A first driving unit, used for driving the first switch unit to close or open; The second driving unit is used to drive the second switch unit to close or open.

4. The laser emitting circuit according to claim 3, characterized in that: The transmission control module includes: a transmission switch unit and a transmission switch driving unit; The transmitting switch driving unit is used to drive the transmitting switch unit to close or open; The transmitting module transmits laser pulses after the transmitting switch unit is closed.

5. The laser emitting circuit according to claim 4, characterized in that: During the process of the transmitting module transmitting laser pulses, the first driving unit drives the first switch unit to be opened, and the second driving unit drives the second switch unit to be closed.

6. The laser emitting circuit according to claim 2, characterized in that: The first switch unit is any one of the following: a field effect tube, a triode; the second switch unit is any one of the following: a field effect tube, a triode.

7. The laser emitting circuit according to claim 1, characterized in that: The energy acquisition module includes: an inductor; and the energy storage module includes a capacitor.

8. The laser emitting circuit according to claim 7, characterized in that: The discharge branch further includes a diode, an anode of the diode is connected to the inductor, and a cathode of the diode is connected to the capacitor.

9. The laser emitting circuit according to any one of claims 1 to 8, characterized in that: The energy acquisition modules of different charging branches are electrically connected to the external power supply simultaneously or in different time periods.

10. A laser emission circuit control method, characterized in that: The laser emission circuit includes: one or more charging branches, each charging branch is connected to one or more discharging branches, each discharging branch is connected to a light-emitting branch; the charging branch includes an energy acquisition module and a boost control module; the discharging branch includes an energy storage module; the light-emitting branch includes a transmitting module and a transmitting control module; the boost control module is configured to electrically connect the energy acquisition module with an external power supply, or control the energy acquisition module to transfer the energy to the energy storage module; The method comprises: The boost control module is electrically connected to the energy acquisition module and the external power supply, and the energy acquisition module acquires energy; After a preset time period, the boost control module disconnects the electrical connection between the energy acquisition module and the external power source, and the energy acquisition module transmits energy to the energy storage module; The emission control module is electrically connected to the energy storage module and the emission module, and the emission module emits laser pulses.

11. The laser emission circuit control method according to claim 10, characterized in that: The method further comprises: The length of the preset time period is adjusted according to the energy required for emitting the laser pulse.

12. The laser emission circuit control method according to claim 10, characterized in that: The method further comprises: After the laser pulse is emitted, the electrical connection between the energy storage module and the emission module is disconnected.

13. The laser emission circuit control method according to claim 12, characterized in that: The method further comprises: The steps of acquiring energy, transmitting energy, and emitting laser pulses are repeatedly performed to emit the laser pulses multiple times.

14. The laser emission circuit control method according to claim 13, characterized in that: The duration of the preset time period corresponding to each emission of the laser pulse remains the same or different.

15. The laser emission circuit control method according to any one of claims 10 to 14, characterized in that: The method further comprises: The energy acquisition modules of different charging branches are controlled to acquire energy from the external power source simultaneously or in different time periods.

16. A laser radar, characterized in that: The laser radar comprises a laser transmitting circuit as claimed in any one of claims 1 to 9, and a laser receiving circuit; The laser receiving circuit is configured to receive an echo pulse formed after the laser pulse is reflected by an object and generate an electrical signal.

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