Laser emission circuit, method and laser radar

Abstract

The present application discloses a laser emission circuit, method and laser radar, wherein the laser emission circuit includes a first charging circuit, an energy conversion circuit, a second charging circuit and an energy release circuit. The first charging circuit includes a first energy storage element, and the first charging circuit is connected to a first voltage to perform an energy storage process on the first energy storage element. The energy conversion circuit includes a second energy storage element, and the laser emission circuit performs a first energy charging process on the second energy storage element through the first voltage and the first energy storage element. The laser emission circuit performs a second energy charging process on the second energy storage element through the second voltage and the second charging circuit. The energy release circuit includes a laser, and the laser emits light when the second energy storage element releases energy. At the beginning of the first energy charging process, the voltage at one end of the first energy storage element connected to the second energy storage element is higher than the second voltage. In the above manner, it is possible to achieve rapid and continuous emission of lasers of different powers, thereby improving the ability to distinguish the reflectivity of different objects at different distances.

Description

Technical Field

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

[0002] LiDAR is a system that emits laser beams to detect the position, speed and other characteristic quantities of target objects. Its working principle is to first emit detection light to the target object (emitted by the transmitter), and then compare the received echo light reflected from the target (received by the receiver) with the detection light. After appropriate processing, the detection information corresponding to the target object can be obtained, such as target distance, direction, height, speed and attitude information. At present, it is difficult for LiDAR to achieve rapid and continuous emission of lasers of different powers, resulting in poor ability to distinguish the reflectivity of different objects at different distances. Summary of the invention

[0003] The embodiments of the present application provide a laser emission circuit, method and laser radar, which aim to improve the current situation where it is difficult to quickly and continuously emit lasers of different powers, and to improve the ability to distinguish the reflectivity of different objects at different distances.

[0004] In the first aspect, an embodiment of the present application provides a laser emitting circuit, comprising: a first charging circuit, comprising a first energy storage element, the first charging circuit being used to access a first voltage to perform an energy storage process on the first energy storage element; an energy conversion circuit, connected to the first energy storage element, comprising a second energy storage element, the laser emitting circuit being configured to perform a first energy charging process on the second energy storage element through the first voltage and the first energy storage element; a second charging circuit, connected to the second energy storage element, the second charging circuit being used to access a second voltage, the laser emitting circuit being configured to perform a second energy charging process on the second energy storage element through the second voltage and the second charging circuit; an energy release circuit, comprising a laser, the laser being connected to the second energy storage element, the laser being configured to emit light when the second energy storage element releases energy; wherein, at the beginning of the first energy charging process, the voltage at one end where the first energy storage element is connected to the second energy storage element is higher than the second voltage.

[0005] Through the above process, the process of emitting lasers of different powers twice in succession is realized. By continuously repeating the above process in a cycle, it is possible to emit lasers of different powers multiple times in rapid succession, thereby improving the ability to distinguish the reflectivity of different objects at different distances.

[0006] In one or more embodiments, the first energy storage element is an inductor, and the first charging circuit also includes a first switching element; the first end of the inductor is used to access the first voltage, the first end of the first switching element is connected to the second end of the inductor, and the second end of the first switching element is grounded; the first switching element has a first on state and a first off state. In the first on state, the circuit between the first end and the second end of the first switching element is conductive, and the first charging circuit charges the inductor through the first voltage. In the first off state, the circuit between the first end and the second end of the first switching element is disconnected, and the first voltage and the inductor perform a first charging process on the second energy storage element.

[0007] In one or more embodiments, the first switching element is a first transistor, the base of the first transistor is used to input the first pulse signal, the collector of the first transistor is the first end of the first switching element, and the emitter of the first transistor is the second end of the first switching element; or, the first switching element is a first field effect transistor, the gate of the first field effect transistor is used to input the first pulse signal, the drain of the first field effect transistor is the first end of the first switching element, and the source of the first field effect transistor is the second end of the first switching element.

[0008] In one or more embodiments, the second energy storage element is a capacitor, and the energy conversion circuit includes a first diode, a capacitor and a second diode; the anode of the first diode is connected to the first energy storage element, the first end of the capacitor is connected to the cathode of the first diode, the anode of the second diode is connected to the second end of the capacitor, and the cathode of the second diode is grounded.

[0009] In one or more embodiments, the second charging circuit includes a first resistor and a third diode connected in series; the first end of the first resistor is used to access the second voltage, the anode of the third diode is connected to the second end of the first resistor, and the cathode of the third diode is connected to the first end of the second energy storage element.

[0010] In one or more embodiments, the energy release circuit includes a laser and a second switching element, and the second energy storage element, the laser and the second switching element are connected in series; the second switching element has a second on-state and a second off-state. In the second on-state, the circuit between the first end and the second end of the second switching element is conductive, and the second energy storage element is in the energy release process. In the second off-state, the circuit between the first end and the second end of the second switching element is disconnected, and the second energy storage element is in the first energy charging process or the second energy charging process.

[0011] In one or more embodiments, the anode of the laser is grounded, and the cathode of the laser is connected to the second end of the second energy storage element; the first end of the second switch element is connected to the first end of the second energy storage element, and the second end of the second switch element is grounded.

[0012] In one or more embodiments, the second switching element is a second triode, the base of the second triode is used to input the second pulse signal, the collector of the second triode is the first end of the second switching element, and the emitter of the second triode is the second end of the second switching element; or, the second switching element is a second field effect transistor, the gate of the second field effect transistor is used to input the second pulse signal, the drain of the second field effect transistor is the first end of the second switching element, and the source of the second field effect transistor is the second end of the second switching element.

[0013] In one or more embodiments, a first voltage connected to the first charging circuit is lower than a second voltage connected to the second charging circuit.

[0014] In one or more embodiments, at the beginning of the first charging process, the voltage at one end of the first energy storage element connected to the second energy storage element is the sum of the first voltage and the voltage of the first energy storage element; in the second charging process, the voltage at one end of the second charging circuit connected to the second energy storage element is a constant second voltage.

[0015] Through the above process, it is possible to achieve higher working efficiency when emitting high-power laser and higher control accuracy when emitting low-power laser.

[0016] In the second aspect, an embodiment of the present application provides a laser emission method, which is applied to the laser emission circuit as described above, and the laser emission method includes: performing an energy storage process on a first energy storage element through a first voltage; performing a second energy charging process on a second energy storage element through a second voltage and a second charging circuit; controlling the second energy storage element to perform a second energy release process so that the laser emits a laser; performing a first energy charging process on the second energy storage element through the first voltage and the first energy storage element; controlling the second energy storage element to perform a first energy release process so that the laser emits a laser.

[0017] In one or more embodiments, the duration of the energy storage process is greater than the sum of the durations of the second energy charging process and the second energy release process; the second energy charging process and the corresponding second energy release process are located in the duration of the same energy storage process of the first energy storage element in the time domain.

[0018] In one or more embodiments, any first energy release process is located during the duration of the energy storage process of the next cycle in the time domain.

[0019] In a third aspect, an embodiment of the present application provides a laser radar, comprising: a shell; a laser emitting circuit as described above, housed in the shell, the laser emitting circuit being used to emit laser; and a receiving module, housed in the shell, being used to receive the laser emitted by the laser emitting circuit.

[0020] The beneficial effects of the present application are as follows: the laser emitting circuit of the embodiment of the present application includes a first charging circuit, an energy conversion circuit, a second charging circuit and an energy release circuit. Among them, the first charging circuit includes a first energy storage element, and the first charging circuit is connected to a first voltage to perform an energy storage process on the first energy storage element; the energy conversion circuit includes a second energy storage element, and the laser emitting circuit performs a first energy charging process on the second energy storage element through the first voltage and the first energy storage element; the energy release circuit includes a laser, and the laser emits light when the second energy storage element releases energy; thus, the laser is emitted with the power provided by the first energy charging process. Secondly, the second charging circuit is connected to a second voltage, and the laser emitting circuit performs a second energy charging process on the second energy storage element through the second voltage and the second charging circuit; the laser emits light when the second energy storage element releases energy; thus, the laser is emitted with the power provided by the second energy charging process. Since the first charging circuit and the second charging circuit charge the second energy storage element independently, it is beneficial for the energy release circuit to quickly perform the second charging process after using the electric energy obtained based on the first charging process to trigger the laser to emit light, and use the electric energy obtained based on the second charging process to trigger the laser to emit light. Therefore, the laser emission circuit provided in the embodiment of the present application is beneficial to improving the current situation where it is difficult to continuously emit lasers of different powers twice, thereby improving the ability to distinguish the reflectivity of different objects at different distances. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] One or more embodiments are exemplarily described by the figures in the corresponding drawings, and these exemplary descriptions are not intended to limit the embodiments. Elements with the same reference numerals in the drawings represent similar elements.

[0022] Figure 1 This is a schematic diagram of the composition block diagram of the laser emission circuit provided in the embodiment of the present application. Figure 1 ;

[0023] Figure 2 This is a schematic diagram of the composition block diagram of the laser emission circuit provided in the embodiment of the present application. Figure 2 ;

[0024] Figure 3 is a schematic diagram of the corresponding relationship between the temperature, the power of the laser emitted by the laser and the second voltage provided in an embodiment of the present application;

[0025] Figure 4 is with Figure 1 The circuit structure corresponding to the laser emission circuit shown in the figure Figure 1 ;

[0026] Figure 5 is with Figure 1 The circuit structure corresponding to the laser emission circuit shown in the figure Figure 2 ;

[0027] Figure 6 is with Figure 1 The circuit structure corresponding to the laser emission circuit shown in the figure Figure 3 ;

[0028] Figure 7 is a flow chart of the laser emission method provided in an embodiment of the present application;

[0029] Figure 8 yes Figure 7 The laser emission method shown is applied to Figure 5 or Figure 6 The circuit structure shown is a schematic diagram of each signal;

[0030] Fig. 9 It is a schematic diagram of the composition block diagram of the laser radar provided in an embodiment of the present application. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and in detail in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the 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.

[0032] It should be noted that, when an element is described as being “connected to” another element, it may be directly connected to the other element, or one or more intervening elements may exist therebetween.

[0033] In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as there is no structural conflict between them.

[0034] Please refer to Figure 1 , Figure 1 Schematic diagram of the composition block diagram of the laser emission circuit provided in the embodiment of the present application. Figure 1 As shown, the laser emitting circuit 100 includes a first charging circuit 10 , a second charging circuit 20 , an energy conversion circuit 30 and an energy release circuit 40 .

[0035] The first energy charging circuit 10 includes a first energy storage element 11, and the first energy charging circuit 10 is used to access the first voltage V1 to perform an energy storage process on the first energy storage element 11. The energy conversion circuit 30 includes a second energy storage element 31, and the laser emission circuit 100 is configured to perform a first energy charging process on the second energy storage element 31 through the first voltage V1 and the first energy storage element 11. The second energy charging circuit 20 is connected to the second energy storage element 31, and is used to access the second voltage V2. The laser emission circuit 100 is also configured to perform a second energy charging process on the second energy storage element 31 through the second voltage V2 and the second energy charging circuit 20. The energy release circuit 40 includes a laser 41, and the laser 41 is connected to the second energy storage element 31, and the laser 41 is configured to emit light when the second energy storage element 31 releases energy. When the first energy charging process starts, the voltage at one end of the first energy storage element 11 connected to the energy conversion circuit 30 is higher than the second voltage V2.

[0036] The laser emitting circuit 100 may include two laser emitting processes in a single working cycle. For ease of understanding, the two processes are first isolated and described as follows:

[0037] The first process is: first, the first energy storage element 11 is subjected to an energy storage process by means of the first voltage V1; after the energy storage process is completed, the second energy storage element 31 is subjected to a first energy charging process by means of the first voltage V1 and the first energy storage element 11; after the first energy charging process is completed, the second energy storage element 31 can be released to enable the laser 41 to emit a laser. At this time, the power of the laser emitted by the laser 41 is the power corresponding to the electric energy on the second energy storage element 31 at the end of the first energy charging process. In some embodiments, the end of the energy storage process can be achieved by: presetting the first duration for executing the energy storage process, and the end of the first duration corresponds to the end of the energy storage process. In other embodiments, the end of the first energy charging process can be achieved by: presetting the second duration for executing the first energy charging process, and the end of the second duration corresponds to the end of the first energy charging process.

[0038] The second process is: first, the second energy storage element 31 is subjected to the second energy charging process through the second voltage V2 and the second energy charging circuit 20; after the second energy charging process is completed, the second energy storage element 31 can be released to enable the laser 41 to emit a laser. At this time, the power of the laser emitted by the laser 41 is the power corresponding to the electric energy on the second energy storage element 31 at the end of the second energy charging process. In some embodiments, the end of the second energy charging process can be achieved in the following manner: presetting the third duration for executing the end of the second energy charging process, and the end of the third duration corresponds to the end of the second energy charging process.

[0039] At this point, the process of emitting lasers of different powers twice within the same working cycle of the laser emitting circuit 100 has been realized; and the above two laser emitting processes can be controlled relatively independently, and there may be parts running in parallel in the time domain. For example, since the emission power achieved by the first energy charging process is higher, the above first energy storage process will also be carried out for a longer time, and the energy storage process and the second energy charging process can be run in parallel; for another example, the energy storage process and the energy release process corresponding to the above second energy charging process (the process in which the second energy storage element releases the electrical energy stored in the second energy charging process) can also be run in parallel; that is, the second energy charging process and the corresponding energy release process can be carried out during the duration of the same energy storage process, thereby shortening the time interval between the two laser emitting processes. By continuously repeating the above two processes, it is possible to achieve rapid and continuous multiple emission of lasers of different powers.

[0040] Since the laser emitting circuit 100 has the function of emitting lasers of different powers, a high-power laser can be used for detection when detecting a long-distance target, and a low-power laser can be used for detection when detecting a close-range target. In the related art, a constant power laser is used to emit a target detection. In order to meet the needs of long-distance detection, the laser emitting circuit needs to use a higher emission power; however, when a high-power laser is used to detect a close-range target object, the energy of the echo light is high. Even if the reflectivity of the target object is low, the echo light may still cause the detector to be oversaturated, thereby making the laser radar's ability to distinguish the reflectivity of the target object low. In contrast, the laser emitting circuit 100 provided in the embodiment of the present application can use a low-power laser for close-range detection. In this way, the energy returned by the target object is low, and it is not easy to cause the detector to be oversaturated, thereby enabling the laser radar to more effectively distinguish the reflectivity of the target object.

[0041] In some embodiments, at the beginning of the first charging process, the voltage of the first energy storage element 11 at the end connected to the second energy storage element 31 is the sum of the first voltage V1 and the voltage of the first energy storage element 11. In the second charging process, the voltage of the second charging circuit at the end connected to the second energy storage element 31 is a constant second voltage V2.

[0042] On the one hand, by configuring the voltage at the output end of the first energy storage element 11 to be the sum of the first voltage V1 and the voltage of the first energy storage element 11 at the beginning of the first charging process, the first voltage V1 can be boosted to serve as the charging voltage of the second energy storage element 12, which can provide a higher transmission power and improve the efficiency of charging, that is, the charging efficiency is high. On the other hand, by configuring the second voltage V2 to be constant, the stability of the charging process of the second energy storage element 31 can be maintained, and the actual charging energy of the second energy storage element 31 can be made close to or equal to the target charging energy set based on demand, so that the power of the laser emitted by the laser 41 is close to or equal to the target power. It can be seen that this process can control the power of the emitted laser more accurately, that is, the control accuracy is higher. In short, the first charging process is a higher voltage charging process with higher charging efficiency, and the second charging process is a lower voltage charging process with higher charging accuracy. It should be noted that the phrase “in the second charging process, the voltage at the end of the second charging circuit connected to the second energy storage element 31 is a constant second voltage V2” stated in the present application document means that in the cycle of a single second charging process, the second voltage V2 is constant, and does not mean that the second voltage V2 is always constant during the entire working process of the laser radar; in two adjacent second charging processes, the second voltages V2 corresponding to the two second charging processes may be different.

[0043] In some embodiments, at the beginning of the first energy charging process, the voltage at the output end of the first energy storage element is 3 to 20 times the second voltage V2. By significantly staggering the power that can ultimately be provided to the laser by the first energy charging process and the second energy charging process, it is also beneficial to control the duration of the first energy storage process and / or the first energy charging process differently, so that the power provided to the laser by the first energy charging process can be high power of different power values ​​(such as 1W and 0.1W), and is also staggered with the low power (such as 0.01W) provided to the laser by the second energy charging process, making the emission mode of the laser emission circuit 100 more flexible.

[0044] In combination with the content of the above embodiment, the above first laser emitting process can be further configured as a process of emitting high-power laser, and the above second laser emitting process can be further configured as a process of emitting low-power laser.

[0045] In some implementations, the power of the low-power laser can be configured to be less than or equal to 1 / 100 of the power of the high-power laser. For example, in a specific embodiment, the power of the high-power laser is configured to be greater than or equal to 1 W, and the power of the low-power laser is configured to be less than or equal to 0.01 W.

[0046] When the power of the laser emitted by the laser 41 is high, a small fluctuation in power has little effect on the detection information obtained after the laser is emitted, and can be ignored. In this case, the first laser emission process in the above text can be used as a process of emitting a high-power laser to improve work efficiency. This method is conducive to long-distance detection. When the power of the laser emitted by the laser 41 is low, a small fluctuation in power will also have a greater impact on the detection information obtained after the laser is emitted. In this case, the second laser emission process in the above text can be used as a process of emitting a low-power laser to maintain a high control accuracy, thereby improving the accuracy of the detection information obtained. This method is conducive to short-distance detection.

[0047] In some embodiments, when the second laser emitting process is configured as a low-power laser emitting process, the second voltage V2 may be temperature compensated to further improve the control accuracy.

[0048] Specifically, Figure 2 As shown, the laser emission circuit 100 also includes a temperature detection circuit 50 and a controller 60. The temperature detection circuit 50 is used to output a detection signal to the controller 60 based on the temperature of the laser 41, and the controller 60 is used to determine the current temperature of the laser 41 according to the detection signal. In some embodiments, the controller 60 can determine the correlation between the emission power of the laser, the temperature of the laser, and the power supply voltage of the laser within a preset temperature range; of course, in other embodiments, the correlation between the emission power, temperature, and power supply voltage of the laser 41 can also be determined in other ways. For example, the correlation can be obtained through the laser performance parameters provided by the laser manufacturer, and this application does not make specific restrictions on this. The controller 60 is also used to determine the current power supply voltage required by the laser 41 based on the emission power of the laser 41 (the emission power is a preset power), the current temperature of the laser 41, and the above-mentioned correlation, and charge the second energy storage element 31 based on the supply voltage. For example, in some embodiments, temperature compensation can be performed for low emission power working scenarios; please combine Figure 3 , when the laser 41 needs to emit laser at low power, such as 0.01W, the controller 60 can determine the power supply voltage required by the laser 41 after obtaining the current temperature of the laser 41 based on the correlation corresponding to the 0.01W emission power, and then set the second voltage V2 to the above-mentioned power supply voltage to charge the second energy storage element 31. Of course, in some other embodiments, temperature compensation can also be performed for high emission power working scenarios, and temperature compensation can also be performed for all emission power working scenarios, which is not specifically limited in this application. It should be noted that the above-mentioned preset temperature range can be set according to the actual application scenario, and the embodiments of the present application do not specifically limit this.

[0049] Figure 3 The schematic diagram of the correlation between the emission power, temperature and supply voltage of the laser 41 when the preset temperature range is [-40°C, 125°C] is shown as an example, and the emission power is 1W, 0.1W and 0.01W respectively. Figure 3 In the figure, the horizontal axis is temperature in °C; the vertical axis is power supply voltage in V. Take the power of the laser emitted by the laser 41 as 0.01W as an example. If the current temperature of the laser 41 is 25°C, the current temperature 25°C and the emission power 0.01W can be mapped to the association relationship of the emission power of 0.01W to determine that the power supply voltage required by the laser 41 at the current temperature is voltage VA1; if the current temperature of the laser 41 changes from 25°C to 30°C, the current temperature 30°C and the emission power 0.01W can be mapped to the association relationship of the emission power of 0.01W to determine that the power supply voltage required by the laser 41 at the current temperature is voltage VA2. In this way, temperature compensation can be performed in each low-power emission scenario, which is conducive to more accurate control of the power of the emitted laser, so as to maintain a high control accuracy, thereby improving the accuracy of the detection information obtained. The temperature compensation process in the high emission power (0.1W and 1W) scenario can refer to the temperature compensation method in the above-mentioned low-power emission scenario, which will not be repeated here.

[0050] It should be noted that if Figure 2 The hardware structure of the laser emitting circuit 100 shown is only an example, and the laser emitting circuit 100 may have more or fewer components than shown in the figure, may combine two or more components, or may have a different component configuration. The various components shown in the figure may be implemented in hardware, software, or a combination of hardware and software including one or more signal processing and / or application-specific integrated circuits.

[0051] Please refer to Figure 4 , Figure 4 An example is shown with Figure 1 A circuit structure corresponding to the block diagram shown in FIG. Figure 4 As shown, the first energy storage element 11 is an inductor, and the first charging circuit 10 further includes a first switching element 12 .

[0052] The first end of the inductor is used to access the first voltage V1 , the first end of the first switch element 12 is connected to the second end of the inductor, and the second end of the first switch element 12 is grounded GND.

[0053] The first switch element 12 has a first on state and a first off state. When the first switch element 12 is in the first on state, the circuit between the first end and the second end of the first switch element 12 is on, the first voltage V1, the inductor and the first switch element 12 form a loop, and the first voltage V1 charges the inductor; when the first switch element 12 is in the first off state, the circuit between the first end and the second end of the first switch element 12 is disconnected, and the connection between the second end of the inductor and the ground GND is disconnected. At this time, the first voltage V1 and the inductor perform the first charging process on the second energy storage element 31.

[0054] The first switch element 12 may be any controllable switch. Figure 5 As shown, in some embodiments, the first switch element 12 is a first triode, the base of the first triode is used to input the first pulse signal S1, the collector of the first triode is the first end of the first switch element 12, and the emitter of the first triode is the second end of the first switch element 12. Figure 6 As shown, in some embodiments, the first switch element 12 is a first field effect transistor, the gate of the first field effect transistor is used to input the first pulse signal S1, the drain of the first field effect transistor is the first end of the first switch element 12, and the source of the first field effect transistor is the second end of the first switch element 12. In one embodiment, the first field effect transistor is a gallium nitride (GaN) field effect transistor. Since the gallium nitride (GaN) field effect transistor has a higher electron mobility and a lower on-resistance, the gallium nitride (GaN) field effect transistor has excellent performance at high frequencies, which helps to reduce the heat loss of the device during operation and achieve a faster switching speed, thereby improving the overall efficiency of the laser emission circuit 100.

[0055] In the embodiments of the present application, each pulse signal (including the first pulse signal S1 and the second pulse signal S2 to be referred to below) is an electrical signal having discrete variation characteristics in both time and amplitude. In some embodiments, each pulse signal is specifically a rectangular wave, and when the pulse signal is at a low level, the corresponding switch element is disconnected; when the pulse signal is at a high level, the corresponding switch element is turned on. For example, when the first pulse signal S1 is at a low level, the first switch element 12 is disconnected; when the first pulse signal S1 is at a high level, the first switch element 12 is turned on.

[0056] Please continue to refer to Figure 4In some embodiments, the second energy storage element 31 is a capacitor, and the energy conversion circuit 30 includes a first diode 32, the capacitor and a second diode 33. The anode of the first diode 32 is connected to the second end of the first energy storage element 11, the first end of the capacitor is connected to the cathode of the first diode 32, the anode of the second diode 33 is connected to the second end of the capacitor, and the cathode of the second diode 33 is grounded GND.

[0057] In some embodiments, the second charging circuit 20 includes a first resistor 21 and a third diode 22 connected in series. The first end of the first resistor 21 is used to access the second voltage V2, the anode of the third diode 22 is connected to the second end of the first resistor 21, and the cathode of the third diode 22 is connected to the first end of the second energy storage element 31. The first end of the first resistor 21 is the first end of the second charging circuit 20, and the cathode of the third diode 22 is the second end of the second charging circuit 20. It can be understood that in other embodiments of the present application, the positional relationship between the first resistor 21 and the third diode 22 can also be interchanged, as long as the two are connected in series.

[0058] In some embodiments, the energy release circuit 40 includes a laser 41 and a second switch element 42 , and the second energy storage element 31 , the laser 41 and the second switch element 42 are connected in series.

[0059] The second switch element 42 has a second on state and a second off state. When the second switch element 42 is in the second on state, the circuit between the first end and the second end of the second switch element 42 is on, the second energy storage element 31, the laser 41 and the second switch element 42 form a loop, and the second energy storage element 31 is in the energy release process, that is, the second energy storage element 31 discharges the laser 41 to make the laser 41 emit laser light. When the second switch element 42 is in the second off state, the circuit between the first end and the second end of the second switch element 42 is disconnected, and the second energy storage element 31 is in the first energy charging process or the second energy charging process.

[0060] The second switch element 42 may be any controllable switch. Figure 5 As shown, in some embodiments, the second switch element 42 is a second triode, the base of the second triode is used to input the second pulse signal S2, the collector of the second triode is the first end of the second switch element 42, and the emitter of the second triode is the second end of the second switch element 42. Figure 6As shown, in some embodiments, the second switch element 42 is a second field effect transistor, the gate of the second field effect transistor is used to input the second pulse signal S2, the drain of the second field effect transistor is the first end of the second switch element 42, and the source of the second field effect transistor is the second end of the second switch element 42. In one embodiment, the second field effect transistor is a gallium nitride (GaN) field effect transistor. Since the gallium nitride (GaN) field effect transistor has a higher electron mobility and a lower on-resistance, the gallium nitride (GaN) field effect transistor has excellent performance at high frequencies, which helps to reduce the heat loss of the device during operation and achieve a faster switching speed, thereby improving the overall efficiency of the laser emission circuit 100.

[0061] In some embodiments, the anode of the laser 41 is grounded, and the cathode of the laser 41 is connected to the second end of the second energy storage element 31; the first end of the second switch element 42 is connected to the first end of the second energy storage element 31, and the second end of the second switch element 42 is grounded GND.

[0062] By reversely connecting the laser 41 relative to the first voltage V1, when the electric energy in the inductor is transferred to the capacitor, the laser 41 will not be mistakenly illuminated due to the current flowing through the laser 41, thereby reducing the risk of light leakage of the laser 41, so as to improve the stability and reliability of the operation of the laser emission circuit 100. It can be understood that even if the present embodiment is described by taking the laser 41 and the second switch element 42 as an example of being arranged at both ends of the second energy storage element 31, it should be understood that the present application is not limited to this, as long as the three are connected in series and the laser 41 is not triggered to light up during the first charging process and the second charging process; for example, in some other embodiments of the present application, the first end of the second switch element 42 is connected to the first end of the second energy storage element 31, the anode of the laser 41 is connected to the second end of the second switch element 42, and the cathode of the laser 41 is grounded.

[0063] The following Figure 4 The principle of the circuit shown is explained, and the two laser emitting processes are still explained separately.

[0064] In the first laser emission process, first, the first switch element 12 is turned on, and the first voltage V1, the first energy storage element 11 and the first switch element 12 form a loop, and the first voltage V1 charges the first energy storage element 11 to perform the energy storage process. After the energy storage process is completed, the first switch element 12 is turned off, and the loop of the first voltage V1, the first energy storage element 11 and the first switch element 12 is disconnected, and the first voltage V1, the first energy storage element 11, the first diode 32, the second energy storage element 31 and the second diode 33 form a loop, and the first voltage V1 and the voltage of the first energy storage element 11 together charge the second energy storage element 31 to perform the first energy charging process. After the first energy charging process is completed, the first switch element 12 is turned on, and the first voltage V1, the first energy storage element 11 and the first switch element 12 form a loop again, and the first voltage V1 continues to charge the first energy storage element 11 to perform the energy storage process of the next cycle; the second switch element 42 is turned on, the second energy storage element 31, the second switch element 42 and the laser 41 form a loop, and the second energy storage element 31 discharges to the laser 41 through the second switch element 42 to make the laser 41 emit laser; that is, the first energy release process of this cycle can be carried out during the continuation of the energy storage process of the next cycle.

[0065] In the second laser emitting process, the second voltage V2, the first resistor 21, the third diode 22, the second energy storage element 31 and the second diode 33 form a loop, and the second voltage V2 charges the second energy storage element 31 to perform the second energy charging process. After the second energy charging process is completed, the second switch element 42 is turned on, the second energy storage element 31, the second switch element 42 and the laser 41 form a loop, and the second energy storage element discharges to the laser 41 through the second switch element 42, so that the laser 41 emits laser light.

[0066] Thus, the process of emitting lasers of different powers twice in succession has been realized. Moreover, the two processes of emitting lasers may have a parallel running part, thereby shortening the time interval between the two emitting lasers, so as to realize the process of emitting lasers of different powers twice in rapid succession.

[0067] In practical applications, when the laser emitting circuit 100 is switched from a state where it has never been run (i.e., a state where the above two laser emitting processes are not performed) to a state where it is run (i.e., a state where the above two laser emitting processes are performed), first, both the first voltage V1 and the second voltage V2 are powered on to provide power. Next, the first switching element 12 is turned on so that the first voltage V1 charges the first energy storage element 11 to perform the energy storage process for the first time. At the same time, the second voltage V2 charges the second energy storage element 31 to perform the second energy charging process for the first time. After the second energy charging process is completed, the second switching element 42 is turned on, and the second energy storage element 31 discharges to the laser 41 through the second switching element 42, so that the laser 41 emits a laser for the first time. Afterwards, after the energy storage process is completed, the first switching element 12 is turned off, and the first voltage V1 and the voltage of the first energy storage element 11 together charge the second energy storage element 31 to perform the first energy charging process for the first time. It can be understood that the energy storage process can start before the second energy charging process, or start at the same time as the second energy charging process; the energy storage process ends only after the laser 41 completes the laser emission. After the first energy charging process is completed, the second switch element 42 is turned on, and the second energy storage element 31 discharges to the laser 41 through the second switch element 42, so that the laser 41 emits laser light for the second time. If the moment when the first energy charging process ends is the moment when the second energy storage element 31 has just been charged to the highest voltage, the first switch element 12 is turned on at the end of the first energy charging process, so that the first voltage V1 charges the first energy storage element 11 to perform the energy storage process for the second time; if the moment when the first energy charging process ends is later than the moment when the second energy storage element 31 has just been charged to the highest voltage, the first switch element 12 is turned on when the second energy storage element 31 has just been charged to the highest voltage (at this time, the first energy charging process has not yet ended), so that the first voltage V1 charges the first energy storage element 11 to perform the energy storage process for the second time; in this case, after the first energy charging process is completed, the process of the second energy storage element 31 discharging to the laser 41 through the second switch element 42 is in the continuous process of the energy storage process of the next cycle in the time domain. At the same time, the second voltage V2 charges the second energy storage element 31 to perform the second energy charging process for the second time. After the second energy charging process is completed, the second switch element 42 is turned on, and the second energy storage element 31 discharges to the laser 41 through the second switch element 42, so that the laser 41 emits the laser for the third time. Afterwards, after the energy storage process is completed, the first switch element 12 is turned off, and the first voltage V1 and the voltage of the first energy storage element 11 together charge the second energy storage element 31 to perform the first energy charging process for the second time. After the first energy charging process is completed, the second switch element 42 is turned on, and the second energy storage element 31 discharges to the laser 41 through the second switch element 42, so that the laser 41 emits the laser for the fourth time... and so on, it is possible to achieve rapid and continuous multiple emission of lasers of different powers.By emitting lasers of different powers, it is helpful to measure echo energies of different energies to identify the reflectivity energy of different objects at different distances, thereby improving the ability to distinguish the reflectivity of different objects at different distances.

[0068] In some embodiments, the first voltage V1 connected to the first charging circuit 10 is lower than the second voltage V2 connected to the second charging circuit 20. Therefore, before the energy storage process is performed, that is, before the inductor stores electrical energy, the third diode 22 can be kept forwardly conductive because the second voltage V2 is greater than the first voltage V1, thereby maintaining the normal execution of the second charging process.

[0069] Please refer to Figure 7 , Figure 7 Flowchart of the laser emission method provided in some embodiments of the present application. The laser emission method is applied to the laser emission circuit 100 in any embodiment of the present application. Figure 7 As shown, the laser emission method includes the following method steps:

[0070] Step 701: performing energy storage on a first energy storage element by applying a first voltage.

[0071] Step 702: Perform a second charging process on the second energy storage element through a second voltage and a second charging circuit.

[0072] Step 703: Control the second energy storage element to perform a second energy release process to enable the laser to emit laser.

[0073] Step 704: Perform a first energy charging process on the second energy storage element through the first voltage and the first energy storage element.

[0074] Step 705: Control the second energy storage element to perform a first energy release process to enable the laser to emit laser.

[0075] Please refer to Figure 8 , Figure 8 An example is shown Figure 7 The laser emission method shown is applied to Figure 5 or Figure 6 The laser emitting circuit 100 shown in FIG. 1 is a schematic diagram of various signals in the laser emitting circuit 100. Figure 7 The method shown and Figure 8 The signal shown and Figure 6 The circuit structure shown in the figure is used as an example to illustrate. Figure 8In the figure, the horizontal axis is time and the vertical axis is voltage. The three curves from top to bottom are respectively the first pulse signal S1, the second pulse signal S2 and the voltage V31 at both ends of the second energy storage element 31; the dotted lines parallel to the horizontal axis are respectively 1 (used to indicate a high level), 0 (used to indicate a low level), 1 (used to indicate a high level), 0 (used to indicate a low level), the voltage V3 at the first end of the second energy storage element 31 in the first charging process, the second voltage V2 and 0 (used to indicate 0V) from top to bottom.

[0076] Specifically, before the time T1, the second energy storage element 31 has completed the first energy charging process, and the voltage V31 of the second energy storage element 31 is the voltage V3, which is the voltage after the first voltage V1 is boosted.

[0077] At time T1, step 701 is executed, specifically, the first pulse signal S1 is switched from a low level to a high level, the first switch element 12 is turned on, the first voltage V1, the first energy storage element 11 and the first switch element 12 form a loop, the first voltage V1 charges the first energy storage element 11, and the energy storage process is executed. While executing step 701, since the voltage V31 of the second energy storage element 31 is already the voltage V3, that is, the first charging process of the second energy storage element 31 has been completed, and the voltage V3 is higher than the second voltage V2, the second energy storage element 31 will not be charged by the second voltage V2 and the second charging circuit 20 at this time.

[0078] Until the moment T2, since the voltage V31 of the second energy storage element 31 is already the voltage V3, the voltage V31 of the second energy storage element 31 has met the condition for emitting laser, then step 705 can be performed first, specifically, the second pulse signal S2 is switched from a low level to a high level, the second switch element 42 is turned on, and the second energy storage element 31, the second switch element 42 and the laser 41 form a loop. The second energy storage element 31 discharges to the laser 41 so that the laser 41 emits a laser, and the voltage V31 of the second energy storage element 31 is reduced to 0. Since the voltage V31 of the second energy storage element 31 is the voltage after the first voltage V1 is boosted, the power of the laser emitted by the laser 41 at this time can be configured as high power. Until the moment T3, the second pulse signal S2 is switched from a high level to a low level, the second switch element 42 is turned off, and the laser 41 stops emitting laser.

[0079] At time T3, step 702 is executed. Specifically, since the first switch element 12 is turned on and the second switch element 42 is turned off, the first energy charging circuit 10 is performing the above energy storage process. The second voltage V2, the first resistor 21, the third diode 22, the second energy storage element 31 and the second diode 33 form a loop. The second voltage V2 charges the second energy storage element 31, that is, the second energy charging process is performed. The voltage V31 of the second energy storage element 31 increases from 0 to the second voltage V2.

[0080] Until time T4, step 703 is performed, specifically, the second pulse signal S2 is switched from a low level to a high level, the second switch element 42 is turned on, and the second energy storage element 31, the second switch element 42 and the laser 41 form a loop. The second energy storage element 31 discharges to the laser 41 so that the laser 41 emits a laser, and the voltage V31 of the second energy storage element 31 is reduced to 0. Since the voltage V31 of the second energy storage element 31 is the second voltage V2 (which is a constant voltage), the power of the laser emitted by the laser 41 at this time can be configured to be low power to improve the control accuracy. Until time T5, the second pulse signal S2 is switched from a high level to a low level, the second switch element 42 is turned off, and the laser 41 stops emitting a laser.

[0081] At time T5, since the first pulse signal S1 remains at a high level, the first field effect transistor 12 remains turned on, that is, the energy storage process has not yet ended, so step 702 will be executed again at this time, specifically, the second switch element 42 is turned off, the second voltage V2, the first resistor 21, the third diode 22, the second energy storage element 31 and the second diode 33 form a loop, and the second voltage V2 charges the second energy storage element 31, that is, the second energy charging process is performed. The voltage V31 of the second energy storage element 31 increases from 0 to the second voltage V2 and remains at the second voltage V2.

[0082] Until time T6, step 704 is executed, specifically, since the first pulse signal S1 switches from a high level to a low level, the first switch element 12 is turned off, the loop of the first voltage V1, the first energy storage element 11 and the first switch element 12 is disconnected, and the energy storage process of the first voltage V1 charging the first energy storage element 11 ends; accordingly, the first energy charging process begins, and the voltage V31 of the second energy storage element 31 continues to increase from the second voltage V2. Until time T7, the voltage V31 of the second energy storage element 31 increases to the voltage V3. After that, the voltage V31 of the second energy storage element 31 is kept at the voltage V3 unchanged.

[0083] Until time T8, the operation performed at time T1 is repeated. That is, step 701 is performed again. Specifically, the first pulse signal S1 is switched from a low level to a high level, the first switch element 12 is turned on, and the first voltage V1 charges the first energy storage element 11 to perform the energy storage process. While executing step 701, since the voltage V31 of the second energy storage element 31 is already the voltage V3, that is, the first energy charging process of the second energy storage element 31 has been completed, and the voltage V3 is higher than the second voltage V2, the second energy storage element 31 will not be charged by the second voltage V2 and the second charging circuit 20 at this time. Until time T9, the operation performed at time T2 is repeated, that is, step 705 is executed. Specifically, the second pulse signal S2 is switched from a low level to a high level, the second switch element 42 is turned on, and the second energy storage element 31 discharges to the laser 41 to make the laser 41 emit laser, and the voltage V31 of the second energy storage element 31 is reduced to 0, ... and so on. The above operation is repeated continuously to realize the process of alternating switching of emitting lasers of different powers, which helps to measure echo energies of different energies to identify the reflectivity energy of different objects at different distances, thereby improving the ability to distinguish the reflectivity of different objects at different distances. Secondly, when emitting high-power laser, the voltage V31 of the second energy storage element 31 is obtained by boosting the first voltage V1, so the voltage V31 of the second energy storage element 31 can quickly reach a voltage that meets the emission requirements, thereby achieving rapid laser emission with high working efficiency; when emitting low-power laser, the voltage V31 of the second energy storage element 31 is a constant second voltage V2, so that the power of the emitted laser can be controlled more accurately, the control accuracy is higher, and the accuracy of the detection information obtained is also higher.

[0084] In some implementations, the duration of the energy storage process is greater than the sum of the durations of the second energy charging process and the second energy release process. The second energy charging process and the corresponding second energy release process are located in the duration of the same energy storage process of the first energy storage element in the time domain.

[0085] by Figure 8 Take the signal shown as an example. The duration between time T1 and time T6 is the duration of the energy storage process; the duration between time T3 and time T5 is the sum of the durations of the second energy charging process and the second energy release process. The duration between time T1 and time T6 is greater than the duration between time T3 and time T5, and the duration between time T3 and time T5 is within the duration between time T1 and time T6 (that is, the second energy charging process and the corresponding second energy release process are located in the duration of the same energy storage process of the first energy storage element in the time domain), thereby ensuring that the second energy charging process and the second energy release process can be performed normally without being affected by the first energy charging process, so as to maintain the stability of the operation of the laser emitting circuit 100.

[0086] In some embodiments, any first energy release process is located during the duration of the energy storage process of the next cycle in the time domain.

[0087] Still Figure 8 Take the signal shown as an example. The duration between time T9 and time T10 corresponds to the first energy release process, and the first energy release process corresponds to the energy storage process corresponding to the duration between time T1 and time T6 in the time domain. The next energy storage process of the energy storage process corresponding to the duration between time T1 and time T6 is the energy storage process corresponding to the duration between time T8 and time T11. Among them, the duration between time T9 and time T10 corresponds to the first energy release process, that is, the energy storage process corresponding to the duration between time T8 and time T11.

[0088] Please refer to Fig. 9 , Fig. 9 This is a schematic diagram of the structure of the laser radar provided in the embodiment of the present application. Fig. 9 As shown, the laser radar 1000 includes a laser emitting circuit 100, a receiving module 200 and a housing 300 in any embodiment of the present application. The laser emitting circuit 100 and the receiving module 200 are both accommodated in the housing 300. The laser emitting circuit 100 is used to emit laser light, and the receiving module 200 is used to receive the laser light emitted by the laser emitting circuit 100.

[0089] The laser radar provided in this application can be applied to any device that requires laser detection, such as vehicles. The laser radar can detect parameters such as the distance and speed between the vehicle and the obstacle. The vehicle detects nearby obstacles such as other cars, static objects on the roadside, and suddenly approaching flying objects through the laser radar system, so that the vehicle can plan a path based on the detected information to avoid collision with obstacles.

[0090] The above descriptions are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

[0091] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them. Under the idea of ​​the present application, the technical features in the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order. It should be understood by ordinary technicians in this field that they can still modify the technical solutions recorded in the above embodiments, or replace some of the technical features by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A laser emission circuit, characterized in that: include: A first energy charging circuit, comprising a first energy storage element, wherein the first energy charging circuit is used to access a first voltage to perform an energy storage process on the first energy storage element; an energy conversion circuit connected to the first energy storage element, comprising a second energy storage element, wherein the laser emission circuit is configured to perform a first energy charging process on the second energy storage element through the first voltage and the first energy storage element; a second charging circuit connected to the second energy storage element, the second charging circuit being used to access a second voltage, the laser emission circuit being configured to perform a second charging process on the second energy storage element through the second voltage and the second charging circuit; as well as an energy release circuit, comprising a laser, the laser being connected to the second energy storage element, the laser being configured to emit light when the second energy storage element releases energy; Wherein, when the first energy charging process starts, the voltage at one end where the first energy storage element is connected to the second energy storage element is higher than the second voltage; When the first energy charging process starts, the voltage at the end of the first energy storage element connected to the second energy storage element is the sum of the first voltage and the voltage of the first energy storage element; In the second charging process, a voltage at one end of the second charging circuit connected to the second energy storage element is the constant second voltage.

2. The laser emitting circuit according to claim 1, characterized in that: The first energy storage element is an inductor, and the first charging circuit further includes a first switching element; The first end of the inductor is used to access the first voltage, the first end of the first switch element is connected to the second end of the inductor, and the second end of the first switch element is grounded; The first switch element has a first on state and a first off state. In the first on state, the circuit between the first end and the second end of the first switch element is conducted, and the first charging circuit charges the inductor through the first voltage. In the first off state, the circuit between the first end and the second end of the first switch element is disconnected, and the first voltage and the inductor perform the first charging process on the second energy storage element.

3. The laser emitting circuit according to claim 2, characterized in that: The first switch element is a first transistor, the base of the first transistor is used to input a first pulse signal, the collector of the first transistor is a first end of the first switch element, and the emitter of the first transistor is a second end of the first switch element; Alternatively, the first switching element is a first field effect transistor, the gate of the first field effect transistor is used to input the first pulse signal, the drain of the first field effect transistor is the first end of the first switching element, and the source of the first field effect transistor is the second end of the first switching element.

4. The laser emitting circuit according to claim 1, characterized in that: The second energy storage element is a capacitor, and the energy conversion circuit includes a first diode, the capacitor and a second diode; The anode of the first diode is connected to the first energy storage element, the first end of the capacitor is connected to the cathode of the first diode, the anode of the second diode is connected to the second end of the capacitor, and the cathode of the second diode is grounded.

5. The laser emitting circuit according to claim 1, characterized in that: The second charging circuit includes a first resistor and a third diode connected in series; The first end of the first resistor is used to access the second voltage, the anode of the third diode is connected to the second end of the first resistor, and the cathode of the third diode is connected to the first end of the second energy storage element.

6. The laser emitting circuit according to claim 1, characterized in that: The energy release circuit includes the laser and a second switch element, wherein the second energy storage element, the laser and the second switch element are connected in series; The second switch element has a second on state and a second off state. In the second on state, the circuit between the first end and the second end of the second switch element is conductive, and the second energy storage element is in an energy release process. In the second off state, the circuit between the first end and the second end of the second switch element is disconnected, and the second energy storage element is in the first energy charging process or the second energy charging process.

7. The laser emitting circuit according to claim 6, characterized in that: The anode of the laser is grounded, and the cathode of the laser is connected to the second end of the second energy storage element; the first end of the second switch element is connected to the first end of the second energy storage element, and the second end of the second switch element is grounded.

8. The laser emitting circuit according to claim 7, characterized in that: The second switch element is a second triode, the base of the second triode is used to input the second pulse signal, the collector of the second triode is the first end of the second switch element, and the emitter of the second triode is the second end of the second switch element; Alternatively, the second switching element is a second field effect transistor, the gate of the second field effect transistor is used to input the second pulse signal, the drain of the second field effect transistor is the first end of the second switching element, and the source of the second field effect transistor is the second end of the second switching element.

9. The laser emitting circuit according to claim 1, characterized in that: The first voltage connected to the first charging circuit is lower than the second voltage connected to the second charging circuit.

10. A laser emitting method, characterized in that: Applied to the laser emitting circuit according to any one of claims 1 to 9, the laser emitting method comprises: Performing an energy storage process on the first energy storage element by using the first voltage; Performing a second energy charging process on the second energy storage element by using the second voltage and the second energy charging circuit; Controlling the second energy storage element to perform a second energy release process so that the laser emits laser light; Performing a first energy charging process on the second energy storage element by using the first voltage and the first energy storage element; The second energy storage element is controlled to perform a first energy release process so that the laser emits laser.

11. The laser emitting method according to claim 10, characterized in that: The duration of the energy storage process is greater than the sum of the durations of the second energy charging process and the second energy releasing process; The second energy charging process and the corresponding second energy releasing process are located in the duration of the same energy storage process of the first energy storage element in the time domain.

12. The laser emitting method according to claim 11, characterized in that: Any of the first energy release processes is located during the continuation of the energy storage process of the next cycle in the time domain.

13. A laser radar, characterized in that: include: case; The laser emitting circuit according to any one of claims 1 to 9, housed in the housing, the laser emitting circuit being used to emit laser light; as well as The receiving module is housed in the housing and is used for receiving the laser emitted by the laser emitting circuit.

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