Laser emission drive circuit, laser radar and laser emission control method

Abstract

A laser emission drive circuit, a laser radar, and a laser emission control method. The drive circuit is suitable for coupling with a laser module and an energy storage module. The laser module includes multiple lasers. The laser emission drive circuit includes: a power supply module, a drive module, a detection module, and a drive protection module. The power supply module is suitable for activating a voltage supply path in response to a strobe signal to charge the energy storage module. The drive module is coupled to the laser and is suitable for activating a light-emitting circuit formed by the energy storage module and the laser based on a trigger signal, causing the energy storage module to discharge and thus causing the laser to emit light. The detection module is suitable for detecting the charging signal of the energy storage module and comparing it with a preset threshold. Based on the comparison result, the detection module outputs a drive control signal to trigger the drive protection module to perform circuit protection, preventing the energy storage module from discharging. The above scheme can enhance the safety of the laser radar.

Description

Technical Field

[0001] The embodiments of this specification relate to the field of electronic circuit technology, and in particular to a laser emission drive circuit, a laser radar, and a laser emission control method. Background Art

[0002] LiDAR is a sensor that uses lasers to precisely measure distance. LiDAR emits laser pulses that are reflected by surrounding objects. By measuring the time it takes for the laser to reach and return to each object, the precise distance can be calculated. LiDAR emits thousands of pulses per second, and by collecting these distance measurements, a three-dimensional model of the environment, known as a point cloud, is constructed.

[0003] LiDAR has a wide range of applications, including autonomous driving (specifically, autonomous taxis, buses, trucks, and logistics vehicles), mapping, smart cities / V2X, robotics, and security. V2X, or Vehicle-to-Everything, refers to a communication method between vehicles and other external objects. The "X" can represent anything that can communicate with the vehicle, including vehicle-to-vehicle communication, vehicle-to-pedestrian communication, vehicle-to-road infrastructure communication, and vehicle-to-cloud communication.

[0004] Based on the optical properties of lasers and the core position of lidar in sensors in its application fields, the safety requirements for lidar are becoming increasingly higher. Summary of the Invention

[0005] In view of this, the embodiments of this specification provide a laser emission drive circuit, a laser radar, and a laser emission control method to perform circuit protection on the laser emission drive circuit and enhance the safety of the laser radar.

[0006] First, the embodiment of this specification provides a laser emission drive circuit suitable for coupling with a laser module and an energy storage module. The laser module includes multiple lasers. The laser emission drive circuit includes: a power supply module, a drive module, a detection module, and a drive protection module, wherein:

[0007] The power supply module is adapted to enable a voltage supply path in response to a strobe signal to charge the energy storage module;

[0008] The driving module is coupled to the laser and is adapted to switch on a light-emitting circuit formed by the energy storage module and the laser based on a trigger signal, so that the energy storage module discharges, thereby causing the laser to emit light;

[0009] The detection module is adapted to detect the charging signal of the energy storage module and compare it with a preset threshold value, and output a drive control signal based on the comparison result to trigger the drive protection module to perform circuit protection, so that the energy storage module cannot discharge.

[0010] Optionally, the detection module includes: a comparator, including: a first input terminal, a second input terminal and an output terminal, the first input terminal is coupled to the voltage supply path, the second input terminal is suitable for inputting a threshold signal corresponding to the preset threshold value, and the output terminal is suitable for outputting the drive control signal when the charging signal for the energy storage module detected by the first input terminal is greater than the threshold signal input by the second input terminal, and the preset threshold value is related to the energy threshold corresponding to human eye safety protection.

[0011] Optionally, the detection module further includes: a sampling unit coupled between the voltage supply path and ground, and coupled to the first input terminal of the comparator via a voltage-dividing sampling terminal.

[0012] Optionally, the driving protection module includes: a first switch unit, coupled between the power supply terminal of the power supply module and the ground, and adapted to trigger the power supply terminal of the power supply module to stop supplying power in response to the driving control signal.

[0013] Optionally, the driving protection module includes: a second switch unit, coupled between the first end of the energy storage module and the ground, and adapted to connect the first end of the energy storage module and the ground in response to the driving control signal.

[0014] Optionally, the driving protection module includes: a signal bias unit, adapted to output a bias signal to an enable terminal of a trigger signal generating module of the driving module in response to the driving control signal, so that the trigger signal generating module stops outputting the trigger signal.

[0015] Optionally, the laser emission driving circuit also includes: a digital-to-analog conversion module, coupled between the second input terminal of the comparator and the threshold signal control terminal, suitable for converting the threshold digital signal output by the threshold signal control terminal into a corresponding threshold analog signal, and the size of the threshold digital signal is positively correlated with the collected ambient temperature.

[0016] Optionally, the laser module includes a plurality of laser groups, each laser group includes at least one laser branch;

[0017] The energy storage module includes a plurality of energy storage units, wherein a first end of the energy storage unit is coupled to the laser group, and a second end of the energy storage unit is grounded;

[0018] The driving module includes a plurality of driving units, each of which is coupled to a corresponding laser branch;

[0019] The power supply module includes: a plurality of power supply units, each of which is coupled to at least one energy storage unit and a laser group.

[0020] Optionally, the laser emission driving circuit further includes: a gating module, the gating module including a plurality of gating units, coupled between the power supply unit and the first end of the energy storage unit, and adapted to gating a corresponding laser group in response to a switching signal.

[0021] Optionally, the sampling unit includes: a sampling subunit, the sampling subunit includes: a first resistor, a second resistor and a second diode, wherein:

[0022] The first resistor and the second resistor are coupled between a voltage supply path and ground;

[0023] The voltage-dividing sampling terminal is arranged between the first resistor and the second resistor;

[0024] An anode of the second diode is coupled to the voltage-dividing sampling terminal, and a cathode of the second diode is coupled to the first input terminal of the comparator.

[0025] Optionally, the output ends of the multiple power supply units intersect.

[0026] Optionally, the first input terminal of the detection module is coupled to the first terminal of the energy storage unit or the output terminal of the power supply unit.

[0027] Optionally, the power supply unit includes:

[0028] an inductor having a first end coupled to the voltage supply end;

[0029] a first diode, an anode of which is coupled to the second end of the inductor, and a cathode of which is coupled to the first end of the energy storage unit;

[0030] A switch unit, a first end of which is coupled to the second end of the inductor and the anode of the first diode, and a second end of which is coupled to the ground, stores energy for the power supply unit or charges the energy storage unit based on the received on / off signal.

[0031] The embodiment of this specification further provides a laser radar, the laser radar comprising:

[0032] a laser module, comprising a plurality of lasers;

[0033] an energy storage module, coupled to the laser module and suitable for charging and discharging;

[0034] A laser emission drive circuit is adapted to be coupled to the laser module and the energy storage module, and is adapted to power the energy storage module and drive the laser to emit light. The laser emission drive circuit comprises: a power supply module, a drive module, a detection module, and a drive protection module, wherein: the detection module is adapted to detect a charging signal from the energy storage module and compare it with a preset threshold value, and output a drive control signal based on the comparison result, thereby triggering the drive protection module to perform circuit protection;

[0035] The control module is adapted to output a gating signal to the power supply module to enable a voltage supply path to charge the energy storage module; and output a trigger signal to the drive module to control the drive module to enable a light-emitting circuit formed by the energy storage module and the laser, so that the energy storage module discharges and the laser emits light.

[0036] Optionally, the control module is further adapted to record fault information based on the collected drive control signal.

[0037] The embodiments of this specification also provide a laser emission control method, which is suitable for controlling a laser emission drive circuit. The laser emission drive circuit is suitable for coupling with a laser module and an energy storage module. The laser module includes multiple lasers. The laser emission drive circuit includes: a power supply module, a drive module, a detection module, and a drive protection module. The laser emission control method includes:

[0038] Based on preset emission control parameters, the control module outputs a switch signal to the first end of the power supply module and outputs a trigger signal to the driving module to control the laser to emit light;

[0039] The driving protection module performs circuit protection on the laser emission driving circuit based on a driving control signal, wherein the driving control signal is generated based on a comparison result between the charging signal of the energy storage module detected by the detection module and a preset threshold.

[0040] Optionally, the laser emission control method further includes: the control module recording fault information based on the drive control signal output by the laser emission drive circuit.

[0041] The laser emission drive circuit of the embodiment of this specification is used, wherein the charging signal of the energy storage module is detected by a detection module and compared with a preset threshold value. Based on the comparison result, a drive control signal is output to the drive protection module, which triggers the drive protection module to perform circuit protection on the laser emission drive circuit, thereby enabling the laser output to meet the energy conditions corresponding to the preset threshold value, thereby ensuring the normal operation of the laser. Once it is detected that the charging signal does not meet the preset threshold interval, the detection module immediately triggers the drive protection module to perform circuit protection operation, preventing the energy storage module from discharging, and thus preventing the laser from emitting light, thereby avoiding possible human eye safety risks in advance. Moreover, since the detection module can directly trigger the drive protection module to perform circuit protection, the entire protection circuit is based on hardware implementation and is therefore not limited by the influence of the program execution cycle, and the response speed is fast.

[0042] Furthermore, fault judgment is performed through a comparator. Since the preset threshold corresponding to the threshold signal input at the second input end of the comparator is related to the energy threshold corresponding to human eye safety protection, when the comparator detects that the charging signal of the energy storage module is greater than the threshold signal input at the second input end, the output triggers the drive control signal of the drive protection module to perform circuit protection, thereby preventing the laser from outputting a laser that exceeds the energy threshold corresponding to human eye safety protection. In addition, this response process is extremely short, so possible human eye safety risks can be avoided in advance, ensuring human eye safety and improving the safety of lidar use.

[0043] Furthermore, by coupling the first switch unit between the power supply end and the ground of the power supply module, in response to the driving control signal, the path between the power supply end and the ground of the power supply module is turned on, so that the power supply end stops supplying power, thereby making the laser unable to emit light, thereby ensuring the safety of human eyes and improving the safety of the use of the laser and the laser radar using the same.

[0044] Furthermore, by coupling the second switch unit between the first end of the energy storage module and the ground, it is suitable for responding to the driving control signal to connect the first end of the energy storage module and the ground, so that the transmitting end of the laser is grounded and the laser cannot emit light, thereby ensuring the safety of human eyes and improving the safety of the laser and the laser radar using the same.

[0045] Furthermore, when the charging signal of the energy storage module detected by the detection module is greater than the preset threshold value, the drive control signal is output to the signal bias unit. Through the signal bias unit, in response to the drive control signal, the bias signal is output to the enable end of the trigger signal generation module of the drive module, so that the trigger signal generation module stops outputting the trigger signal, making it impossible for the drive module to select the light-emitting circuit formed by the energy storage module and the laser, so the laser cannot emit light, thereby ensuring the safety of human eyes and improving the safety of the use of the laser and the laser radar using it.

[0046] Furthermore, the threshold digital signal output by the threshold signal control terminal is converted into a corresponding threshold analog signal through a digital-to-analog conversion module. Since the size of the threshold digital signal is positively correlated with the collected ambient temperature, the threshold analog signal can be accurately adjusted as the collected ambient temperature changes, so that the laser and the lidar can be used safely and more stably and reliably as the ambient temperature changes.

[0047] Furthermore, a gating module is provided, which is coupled between the power supply unit and the first end of the energy storage unit through the gating unit, and selects the corresponding laser group in response to the switching signal. The gating module serves as a regional switch, and the laser group coupled thereto can be controlled as a whole by turning it on and off, thereby simplifying the control logic of the driving module.

[0048] Furthermore, because the output terminals of the multiple power supply units intersect, different power supply units can power the energy storage units separately, enabling the laser to continuously emit multiple pulses in a relatively short period of time, achieving more accurate measurements. Furthermore, by coupling multiple sampling subunits to corresponding energy storage units, and collecting the voltages of the first terminals of the corresponding energy storage units collected by the voltage-dividing sampling terminals of each sampling subunit to the first input terminal of the comparator, the detection module only needs to include a single comparator to sample the voltages of the first terminals of multiple energy storage units, thereby simplifying the circuit design and saving space occupied by the hardware circuit.

[0049] Furthermore, the first input end of the detection module can be coupled to the first end of the energy storage unit, or can be coupled to the output end of the power supply unit. When the output ends of the power supply units intersect, it is only necessary to couple to the first input end of the detection module at the intersection, that is, the interaction point can be used as the monitoring point of the detection module, thereby reducing the number of sampling sub-units and further saving circuit area.

[0050] Furthermore, based on the driving control signal output by the laser emission driving circuit, fault information is recorded, so that the user can find the cause of the fault as soon as possible according to the fault information, and then perform more efficient and rapid maintenance on the laser emission driving circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0052] Figure 1 This is a schematic diagram of the structure of a laser emission drive circuit in an embodiment of this specification;

[0053] Figure 2 This is a schematic diagram of the structure of the detection module in Example 1 of this specification;

[0054] Figure 3 Schematic diagram of a curve showing changes in voltage over time at a monitoring point corresponding to a detection module in an embodiment of this specification;

[0055] Figure 4a This is a schematic diagram of the structure of a laser emission circuit in a specific application scenario in an embodiment of this specification;

[0056] Figure 4b This is a schematic structural diagram of a laser emission circuit in another specific application scenario in the embodiments of this specification;

[0057] Figure 5a Schematic diagram of two consecutive pulses emitted by a laser;

[0058] Figure 5b Schematic diagram of three consecutive pulses emitted by a laser;

[0059] Figure 6 for Figure 4a The light emission control timing diagram of the laser emission circuit shown;

[0060] Figure 7 This is a diagram of the input and output waveforms corresponding to the laser emission drive circuit in the embodiment of this specification when a fault occurs;

[0061] Figure 8a This is a monitoring waveform diagram corresponding to the normal operation of the laser in the specific application scenario of Example 1 of this specification;

[0062] Figure 8b This is a monitoring waveform corresponding to a controller failure in a specific application scenario of Example 1 of this specification;

[0063] Figure 9 This is a partial structural diagram of a laser emission drive circuit in an embodiment of this specification;

[0064] Figure 10 This is a partial structural diagram of another laser emission drive circuit in an embodiment of this specification;

[0065] Figure 11 This is a monitoring waveform corresponding to a controller failure in a specific application scenario of Example 1 of this specification;

[0066] Figure 12 This is a schematic diagram of the structure of a laser radar in an embodiment of this specification;

[0067] Figure 13 Schematic diagram of an unmanned vehicle in an embodiment of this specification. DETAILED DESCRIPTION

[0068] As mentioned in the background technology section, LiDAR has become the most core sensor device in many fields, including autonomous driving, mapping, smart cities / V2X, robotics, and security. Therefore, the normal and stable operation of LiDAR, including the LiDAR transmitter, is a necessary guarantee for the normal operation of equipment equipped with LiDAR in various fields. However, there is currently no corresponding monitoring and guarantee mechanism for the laser emission of the laser transmitter.

[0069] Based on this, embodiments of this specification provide corresponding laser emission monitoring and circuit protection solutions. In these solutions, a detection module monitors the operating status of the laser and, based on the monitoring results, outputs a drive control signal to a driver protection module, triggering the driver protection module to perform circuit protection on the laser emission driver circuit. This ensures that the laser's output energy meets preset requirements during emission, ensuring the laser's normal operation. Furthermore, because the detection module can directly trigger the driver protection module to perform circuit protection on the laser emission driver circuit, the entire protection circuit is hardware-based and, therefore, is not limited by program execution cycles, resulting in a fast response speed.

[0070] In order to enable those skilled in the art to better understand the concept, advantages and implementation schemes of the solutions provided in this specification, the following refers to the accompanying drawings and uses specific embodiments to describe in detail the principles of the laser emission drive circuit, laser emission control method and laser radar solutions provided in the embodiments of this specification.

[0071] First, in some embodiments of this specification, such as Figure 1The laser emission drive circuit 10 is a schematic structural diagram of a laser emission drive circuit shown in FIG. The laser emission drive circuit 10 is suitable for coupling with a laser module 1A and an energy storage module 1B. The laser module 1A includes multiple lasers. The lasers can be various types of lasers, such as a vertical-cavity surface emitting laser (VCSEL) or an edge emitting laser (EEL). The scope of protection of the present invention is not limited by the type of laser.

[0072] In a specific implementation, the laser used can be an anode-driven laser. If it is a laser array, it can be a relatively common anode-driven laser array; the laser used can also be a cathode-driven laser. If it is a laser array, it can be a relatively common cathode-driven laser array. Figure 1 FIG2 is a schematic structural diagram of a laser emission driving circuit applied to a cathode driven laser in an embodiment of the present specification.

[0073] Specifically, continue to refer to Figure 1 The laser emission driving circuit 10 may include: a power supply module 11, a driving module 12, a detection module 13 and a driving protection module 14, wherein:

[0074] The power supply module 11 is adapted to respond to a selection signal S and select a voltage supply path to charge the energy storage module 1B;

[0075] The driving module 12 is coupled to the laser and is adapted to switch on the light-emitting circuit formed by the energy storage module 1B and the laser based on a trigger signal Tr, so that the energy storage module 1B discharges, thereby causing the laser to emit light;

[0076] The detection module 13 is adapted to detect the charging signal of the energy storage module 1B and compare it with a preset threshold value, and output a driving control signal based on the comparison result to trigger the driving protection module 14 to perform circuit protection, so that the energy storage module cannot discharge.

[0077] In a specific implementation, the detection module 13 can be a voltage detection module or a current detection module. If the detection module 13 is a voltage detection module, it is suitable for detecting the voltage signal of the first end of the energy storage unit 1B and comparing it with a preset threshold voltage Vth, and generating a corresponding drive control signal Vc based on the comparison result, such as Figure 2If the detection module 13 is a current detection module, it is suitable for detecting the current signal at the first end of the energy storage module 1B, comparing it with the preset threshold current Ith, and generating a corresponding drive control signal Ic based on the comparison result. Of course, the detection module 13 can also detect other circuit parameters, such as the rate of change of current or voltage, as long as the parameter can reflect the intensity of the laser light emission.

[0078] The driving control signal Vc or Ic can trigger the driving protection module 14 to perform circuit protection. For example, the driving control signal Vc can trigger the switch of the driving protection module 14 to perform circuit protection on the laser emission driving circuit 10.

[0079] The following uses a specific application of a laser as an example to illustrate the working principle of using the laser emission driving circuit in the embodiment of this specification to drive the laser:

[0080] When the first control terminal K1 of the power supply module 11 receives an enable signal, the voltage supply path is enabled, and power is supplied from the power supply terminal VIN to the power supply module 11, which then stores electrical energy. When the first control terminal K1 receives a disable signal, the power supply circuit from the voltage supply terminal Vin to the power supply module 11 is disconnected, and the power supply module 11 charges the energy storage unit 1B. When the driver module 12 receives a trigger signal via the second control terminal Tr, the light-emitting circuit formed by the energy storage unit 1B, the laser module 1A, the driver module 12, and the ground is enabled, and the energy storage unit 1B discharges, causing the laser module 1A to emit light.

[0081] The detection module 13 can be coupled to the voltage supply path to monitor the charging voltage Vx of the energy storage module 1B, thereby obtaining the light emission status of the laser in the laser module 1A and triggering the drive control module 14 to perform circuit protection.

[0082] The laser emission drive circuit of the embodiment of this specification is adopted, in which the charging signal of the energy storage module 1B is detected by the detection module 13 and compared with a preset threshold value, and a drive control signal is output based on the comparison result, so as to monitor the working status of the laser, detect abnormalities in time, and trigger circuit protection.

[0083] Laser emission consumes electrical energy. The electrical energy stored in the energy storage module can drive the laser to emit light after discharge, affecting the intensity of the laser light. Since the energy storage module needs to be fully charged before it can be discharged, based on the actual charging signal of the energy storage module before discharge (such as the charging voltage and charging current of the energy storage module), it is possible to estimate whether the next discharge is normal, including whether it can be discharged safely. Based on this working principle, in the embodiments of this specification, the voltage of the voltage supply path (such as the first end of the energy storage module, or the output end of the power supply module) is compared with the voltage threshold corresponding to the detection module to determine the charging status of the energy storage module and realize monitoring of the laser light emission function.

[0084] Even small amounts of laser light emitted from a laser have a high power density, which can be harmful to biological health. Consequently, countries and regions such as the United States, Japan, and the European Union have established corresponding laser safety standards. Among the harmful effects of lasers, eye damage is the most serious. Different laser wavelengths can have varying degrees of effect on the eye, leading to different consequences.

[0085] For example, lasers with wavelengths in the visible and near-infrared range have low absorption and high transmission rates in the eye's refractive media. This refractive media has a strong focusing ability. When high-intensity visible or near-infrared light enters the eye, it is focused onto the retina by the refractive media within the eye. At this point, the laser energy density and power density on the retina instantly increase by several thousand or even tens of thousands of times. This massive amount of light energy concentrates on the retina, rapidly raising the temperature of the retinal photoreceptor cells, causing them to coagulate, degenerate, and necrotize, resulting in their loss of photosensitivity. The overheating caused by laser light focusing on photoreceptor cells causes irreversible protein coagulation and denaturation, resulting in permanent blindness. Far-infrared lasers primarily damage the cornea, as these wavelengths are almost entirely absorbed by the cornea, causing the most damage. Ultraviolet lasers, on the other hand, primarily damage the cornea and lens.

[0086] However, as mentioned above, devices using lasers, such as LiDAR, have been used in multiple application fields. In order to improve the health and safety of LiDAR operations, corresponding safety monitoring and eye safety protection solutions are needed.

[0087] like Figure 2 As shown, in some embodiments of this specification, the detection module 13 may include: a comparator 131. Figure 1 and Figure 2The comparator 131 includes: a first input terminal, a second input terminal, and an output terminal. The first input terminal is coupled to a voltage supply path, the second input terminal is suitable for inputting a threshold signal Vth corresponding to the preset threshold value; and the output terminal is suitable for outputting the driving control signal when the charging signal of the energy storage module 1B detected at the first input terminal is greater than the threshold signal input at the second input terminal.

[0088] The preset threshold can be set based on various factors, including the laser wavelength, power density, pulse width, and specific circuit protection requirements of the laser. For example, to ensure eye safety, the preset threshold can be related to the energy threshold corresponding to eye safety protection. For example, if eye safety requires that the luminous energy cannot exceed several thousand nJ within 5 μs (depending on the system conditions, the threshold value can be different for each system), and the corresponding threshold voltage is set to 20V, if the maximum charging voltage at the first terminal of the energy storage module is 30V, it means that the laser may emit light that is unsafe for the human eye next time.

[0089] Reference Figure 3 The curve of the charging voltage U at the monitoring point (for example, the first end of the energy storage unit, or the output end of the power supply module) changing with time t is shown. Curve 31 indicates that the peak value of the charging voltage is greater than the preset threshold voltage Vth, and therefore there is a human eye safety risk; curve 32 indicates that the peak value of the charging voltage is less than the threshold voltage Vth, indicating that there is no human eye safety risk.

[0090] In other embodiments of this specification, the corresponding preset thresholds may vary based on the characteristics of the protected life form. The preset thresholds may be related to the corresponding life form safety protection thresholds. This specification does not limit the specific values ​​of the life form safety protection thresholds. For example, if the life form is a human, threshold voltage th1 may be used; if the life form is a cat, threshold voltage th2 may be used.

[0091] For ease of understanding, the following description is given by taking a circuit in which the detection module is a voltage detection type as an example. It should be understood that the following example is not intended to limit the scope of protection of the present invention.

[0092] In the above embodiments, the signal at the first terminal of the energy storage module is directly compared with a preset threshold to determine the magnitude of fluctuations during laser emission. In specific circuit implementations, given the high supply voltage of the laser, a large, high-voltage device is required to drive it. If the detection module uses a comparator, a low-voltage device (typically 5V) would struggle to withstand the voltage at the first terminal of the energy storage module 1B (e.g., 40V).

[0093] In view of this situation, in a specific implementation, instead of directly comparing the voltage at the first end of the energy storage module with the preset threshold voltage, a sampling unit is provided in the detection module to perform voltage division sampling. Figure 2 Combined with Figure 1 The detection module 13 may further include a sampling unit 132, which may be coupled between the first end of the energy storage module 1B and the ground, and coupled to the first input end of the comparator 131 through a voltage divider sampling end. The voltage sampled through the voltage divider sampling end may also reflect the voltage value of the first end of the energy storage module 1B and the voltage fluctuation amplitude.

[0094] In practice, a lidar may have multiple light-emitting channels, each corresponding to a laser. Each channel emits a single beam. These lasers are staggered relative to each other in the vertical direction, i.e., along the lidar's rotational axis (that is, each laser has a different vertical angle). This can be arranged in a single row or multiple staggered rows. Each light-emitting channel has different detection requirements and, therefore, different light intensities, due to its corresponding vertical angle. For example, the center beam channel may require longer detection range and, accordingly, higher light intensity, while the opposite is true for the side channels.

[0095] To achieve, for example, multiple lasers in a laser radar that patrol and emit light, the laser module can be provided with one or more laser groups, each laser group includes at least one laser branch, and each laser branch corresponds to a light-emitting channel. Accordingly, the energy storage module can include multiple energy storage units, and each laser or each laser group can be configured with an energy storage unit. Similarly, each module in the laser emission drive circuit can adaptively set multiple circuit units for different lasers or laser groups. Specifically, the drive module can include multiple drive units, each drive unit can be coupled to the corresponding laser branch respectively, and the power supply module can include multiple power supply units, each power supply unit can be coupled to at least one energy storage unit and a laser group respectively.

[0096] In order to enable those skilled in the art to better understand and implement the embodiments of this specification, some specific implementation examples of the light-emitting driving circuit are given below.

[0097] First, refer to Figure 4a and Figure 4bThe schematic diagram of the laser emission circuit shown includes multiple laser groups LD1, LD2, ..., LDi-1, LDi, and multiple energy storage units C1, C2, ..., Cn-1, Cn. The first end of each energy storage unit is coupled to a laser group, and the second end of each energy storage unit is grounded. Each energy storage unit is specifically a storage capacitor. It should be noted that, in a specific implementation, each energy storage unit can also be implemented using other energy storage components. Figure 4a and Figure 4b The laser emission drive circuit shown includes: multiple power supply units A1, A2...Am, each power supply unit A1, A2...Am can be coupled to one or more laser groups and energy storage units respectively, each laser group can be driven by a corresponding driver unit group DR1, DR2...DRj-1, DRj respectively, each driver unit group includes multiple driver units, which can correspond to one or more laser branches respectively.

[0098] In the specific implementation, a gating module may also be included, and reference is made to Figure 4a and Figure 4b The gating module may include a plurality of gating units B1, B2...Bn-1, Bn. The gating units may be coupled between the power supply unit and the first end of the energy storage unit, and are adapted to gating the corresponding laser group in response to a switch signal. For example, the gating unit B1 is coupled between the first end of the power supply unit A1, A2...Am and the energy storage unit C1, and the gating unit B2 is coupled between the first end of the power supply unit A1, A2...Am and the energy storage unit C2. As a more specific example, Figure 4a and Figure 4b As shown, the driving unit may specifically include driving switches S11, S12, S13, S14, etc. Each driving switch can be turned on or off by a trigger signal Tr. The gating unit may specifically include switch tubes P1, P2...Pn-1, Pn, etc.

[0099] The following first describes the general operating process of the laser emission drive circuit: Each power supply unit in the power supply module can receive the input voltage VIN (i.e., the power supply voltage) and store electrical energy. Then, when the selection unit is turned on, the power supply unit can charge the corresponding energy storage unit, establishing a high voltage on the energy storage unit. Typically, there is no safety protection circuit on the input side, so the input voltage is usually not very high, for example, it can be 5V or 12V, and may not be directly used to drive the laser. In this case, a voltage boost is required. The high voltage established in the energy storage unit can be significantly higher than the input voltage VIN, for example, 60V, which is used to drive the laser LD. After this high voltage is established, the energy storage unit C can drive the laser LD, causing it to emit a laser beam.

[0100] Reference Figure 4aThe following uses the power supply unit A1, gating unit B1, and laser group LD1 as examples to illustrate how the various circuit units work together. Specifically, the power supply unit A1 includes an inductor L1, a first diode D1, and a switch unit M1. A first end of the inductor L1 is coupled to the power supply terminal VIN, a second end of the inductor L1 is connected to the anode of the first diode and the first end of the switch unit M1, and a cathode of the first diode D1 is coupled to the energy storage unit C1 via the gating unit B1.

[0101] In the pre-charging stage, the switch unit M1 can be controlled to close by the selection signal gate1. The closed switch unit M1 is equivalent to a short circuit in the circuit. Therefore, the current generated by the input voltage VIN flows through the inductor L1 and is grounded through the switch unit M1. As the inductor current increases, electrical energy is stored in the inductor L1.

[0102] When pre-charging is completed, the switch unit M1 is disconnected, and the switch P1 in the selection unit B1 can be selected through the high-side driver. At this time, due to the current holding characteristic of the inductor L1, the current flowing through the inductor L1 will not immediately become 0, but slowly change from the current value when charging is completed to 0. In this process, the switch unit M1 has been disconnected and the selection switch P1 is turned on, so the inductor L1 charges the energy storage unit C1, and the voltage across the energy storage unit C1 increases.

[0103] After a high voltage (e.g., 60V) is established on the energy storage unit C1, if the drive switch S11 in the laser branch is turned on, the energy storage unit C1 cannot discharge through the first diode D1 due to the unidirectional conductivity of the first diode D1. Instead, the energy storage unit C1 can only discharge through the loop of the laser LD11 and the drive switch S11. Therefore, current flows through the laser LD11, and the energy storage unit C1 drives the laser LD11 to emit light.

[0104] When the energy storage unit C1 is completely discharged, the switch unit M1 is closed again and the driving switch S11 is disconnected, and the cycle of pre-charging, charging, and discharging is entered again, continuously driving the laser L11 to emit light.

[0105] In the field of LiDAR, there is a concept called pulse coding. Each laser can emit multiple pulses continuously, achieving multi-pulse coding of the laser. Specifically, coding means that each laser emits n (n ≥ 2) pulses at a time, which is a method to prevent crosstalk.

[0106] During encoding, the parameters that can be changed can be of various types. For example, the widths of two pulses can be different (e.g. Figure 5a As shown, the pulse width of pulse 1 is smaller than that of pulse 2), the time intervals between the two pulses can be different (such as Figure 5b As shown, where Δt1≠Δt2), the amplitude of the pulse is different (such as Figure 5a As shown, pulse 2 has a higher amplitude than pulse 1), the number of pulses is different (e.g. Figure 5a Shown is a double pulse, Figure 5b For example, LiDAR A emits a double pulse, and LiDAR B also emits a double pulse. The time interval Δt between the double pulses of the two LiDARs is A ≠Δt B In this way, LiDAR A will only receive or process the echo of the double pulses with an interval of Δt1" between them, and will not regard the echo of LiDAR B as its own echo.

[0107] In some practical applications, the power supply module may include 3 power supply units, 4 gating units, and 4 laser groups, that is, m=3, n=4, i=4, and each laser continuously emits 3 pulses each time.

[0108] To enable those skilled in the art to better understand and implement laser multi-pulse emission, the following describes how 3 power supply units, 4 gating units, and 4 laser groups, a total of 16 lasers, work together.

[0109] Reference Figure 6 The light emission control timing diagram of the laser emission circuit shown in FIG. Figure 4a and Figure 6 First, at time t1, it is assumed that the power supply unit A1 has completed charging the energy storage unit C1, and a high voltage is established on the energy storage unit C1 (as shown in the waveform before time t1).

[0110] At time t1, the controller controls the drive switch S11 to close through the trigger signal Tr11, and the other drive switches S12, S13, and S14 are all open. At this time, the energy storage unit C1 will discharge through the loop including the laser LD11 and the drive switch S11, and the current flows through the laser LD11, so the laser LD11 emits pulse 1. It should be noted that since the discharge speed of the laser is very fast, Figure 6 In the process, the high voltage on the energy storage unit C1 drops a lot almost instantly, so Figure 6 The process of voltage gradually decreasing over time is not shown.

[0111] After discharging at time t1, the device enters encoding time Δt1 (actually the time interval between pulses 1 and 2) until time t2. This encoding time is configurable. If the interval between pulses 1 and 2 is 20ns, the detector will only confirm that the pulse was transmitted by the radar and perform subsequent processing to calculate the time of flight (ToF) and distance when the interval between the two received pulses is 20ns. This is called the encoding time and prevents signal crosstalk. Furthermore, from the end of discharge at time t1, power supply unit A1 enters the energy storage time. The controller closes switch unit M1, and current begins to flow through inductor L1 and switch unit M1 under the action of input voltage VIN, recharging and storing energy in inductor L1. After pre-charging is complete, the device waits for the next charging and voltage boosting of one of the energy storage modules.

[0112] At time t2, it is assumed that power supply unit A2 has completed energy storage. At this time, the controller ensures that the selection switch P1 is closed, and at the same time controls the switch unit M2 to be disconnected. The inductor L2 in the power supply unit A2, due to its characteristic of maintaining the current thereon, will discharge through the first diode D2, the selection switch P1, and the energy storage unit C1, thereby charging the energy storage unit C1 and gradually building up a high voltage thereon. At time t3, the high voltage on the energy storage unit C1 is completely established. At this time, the controller controls the drive switch S11 to be closed, and the other drive switches S12, S13, and S14 to be disconnected. At this time, the energy storage unit C1 will discharge through the loop including the laser LD11 and the drive switch S11. The current flows through the laser LD11, and the laser LD11 emits pulse 2.

[0113] After discharging at time t3, the laser enters encoding time Δt2 (actually, the time interval between pulses 2 and 3, which is also configurable. This allows the laser to emit three pulses with two configurable intervals. This reduces the probability of the encoding interval overlapping with the current radar, enhancing the radar's anti-interference capability). From the moment discharge ends at time t3, power supply unit A2 enters the charging and energy storage period. The controller closes switch unit M2, and current flows through inductor L2 and switch unit M2 under the influence of input voltage VIN, recharging and storing energy in inductor L2. After energy storage is complete, the laser waits for the next step to charge and boost the voltage of one of the energy storage module's capacitors.

[0114] At time t4, assuming that power supply unit A3 has completed energy storage, the controller ensures that the gate switch P1 is closed and controls the switch unit M3 to be open. Therefore, due to its characteristic of maintaining current, the inductor L3 in power supply unit A3 will discharge through the first diode D3, the gate switch P1, and the energy storage unit C1, thereby charging the energy storage unit C1 and gradually building up a high voltage across it.

[0115] At time t5, the high voltage on energy storage cell C1 is established. The controller closes drive switch S11 and opens other drive switches S12, S13, and S14. Energy storage cell C1 then discharges through the circuit comprising laser LD11 and drive switch S11. Current flows through laser LD11, causing it to emit pulse 3.

[0116] As described above, from time t1 to t5, power supply units A1, A2, and A3 sequentially charge energy storage unit C1 corresponding to laser group LD1, establishing a high voltage across it. After establishing a high voltage across energy storage unit C1, the controller controls drive switch S11 to close, thereby driving laser LD11 connected to drive switch S11 three times, emitting pulses 1, 2, and 3, completing a single detection and light emission process for laser LD11. After charging and boosting energy storage unit C1, each power supply unit enters the energy storage inductor pre-charge period, storing electrical energy in it in preparation for the next charge and boost to one of the energy storage units in the energy storage module.

[0117] The time interval between pulse 1 and pulse 2 is the encoding time Δt1 + the charging time of capacitor C1, and the time interval between pulse 2 and pulse 3 is the encoding time Δt2 + the charging time of capacitor C1. The encoding time Δt1 and the encoding time Δt2 can be the same or different. In addition, the encoding time of different lasers can be set to be different from each other, so that multi-pulse encoding can be achieved. After receiving the radar echo, the receiving end of the laser radar can decode the pulse based on the time interval between each pulse to know which laser's emission pulse it corresponds to.

[0118] Figure 6 The schematic diagram shows that each laser emits three pulses during a single light detection process. Those skilled in the art will readily appreciate that the scope of protection of the present invention is not limited thereto. Each laser may emit a fewer or more pulses during a single light detection process. When a fewer number of pulses are emitted, for example two pulses, then according to a pre-set emission sequence, at time t5, the controller may control the drive switch S12 to close, thereby discharging the energy storage unit C1 through the laser LD12 and the drive switch S12, driving the laser LD12 to emit a light pulse.

[0119] When more pulses are emitted, after pulse 3, the energy storage unit C1 can be recharged by the power supply unit A1 that was charged the earliest, and then the laser LD11 is driven to generate pulse 4. The above process is repeated until the laser LD11 emits a preset number of pulses.

[0120] After the laser LD11 finishes emitting, the above process is repeated to drive the laser LD12 to emit light and emit a preset number of pulses.

[0121] It can be understood that in the process of driving the laser LD12, the control of the power supply unit and the control of the selection switch P1 are basically similar to those in the process of driving the laser LD11. The difference is that the controller needs to control the driving switch S12 to be closed in order to drive the laser LD12.

[0122] The above driving process is performed on the laser LD13 and the laser LD14 respectively until all the lasers in the first group have finished emitting light.

[0123] Similarly, the laser group LD2 is driven to emit light. In this process, it is necessary to ensure that the gate switches P1, P3, and P4 are disconnected.

[0124] Repeat the above process to drive the lasers in the laser group LD3 and the laser group LD to emit light. After the last laser LD44 in the laser group LD4 finishes emitting light, start driving the first laser LD11 to be triggered in the laser group LD1 again.

[0125] Multi-line mechanical laser radar is often used in the field of unmanned driving. Figure 13 The schematic diagram of the self-driving car shown includes a car body 1301 and a laser radar 1302 located on top of the car body. As an active detection laser product, laser radars are required to meet certain eye safety standards when sold in various regions around the world. Generally speaking, the energy of the laser pulse / pulse train is required to not exceed a certain threshold. To this end, this requirement can be met through circuit design and control strategies. However, according to some standards, such as the international laser level certification standard IEC 60825-1:2014, it is necessary not only to ensure eye safety in the absence of system faults, but also to ensure that the energy of the pulse / pulse train emitted by the laser product cannot exceed the threshold corresponding to the product's eye safety level in the event of a single point fault.

[0126] The conventional solution to the above requirements is to use sensors to collect laser pulse energy, and then use a controller to determine whether it exceeds a threshold. If so, appropriate measures are taken. However, in practical applications, there are two problems:

[0127] 1) The accuracy of the luminous flux test is low. Laser intensity is typically detected using an avalanche photodiode (APD) and an amplifier circuit. However, the output characteristics of an APD are significantly affected by its own consistency and the environment. Therefore, this method of detecting laser pulse energy has low accuracy.

[0128] 2) Laser pulses are extremely short, typically in the nanosecond range. Even if the threshold design includes a lead time (for example, the eye safety threshold is 300nJ, while the monitoring threshold is set at 200nJ), there will be no time to react after a fault is detected.

[0129] The inventors have analyzed the failure modes and circuit protection solutions of the laser emission drive circuit, which may cause the luminous energy to exceed a preset threshold due to circuit failure, and will illustrate them through specific embodiments below.

[0130] Reference Figure 4a and Figure 4b For example, the gating units P1~Pn may be short-circuited, and the faulty energy storage unit may be charged at the same time as other energy storage units are charged, resulting in the faulty energy storage unit having an excessively high voltage after charging. When it discharges, it may cause the laser's luminous energy to exceed the human eye safety threshold. For another example, the input voltage VIN is overvoltage. For another example, a controller (such as an FPGA) failure may cause the signal value given by the gate end for driving the switch units M1-Mn in the power supply module to be too large, thereby taking too long to charge the inductor Lx, and correspondingly causing excessive charging energy to the energy storage unit Cx. The laser LD has an open circuit failure, and the laser LD in the faulty branch does not emit light when it should, resulting in the laser LD in the next branch emitting light with excessively high high-voltage energy, and the luminous energy exceeds the human eye safety threshold.

[0131] Take the laser open circuit fault as an example, refer to Figure 7 The graph shows the voltage signal of the energy storage cell changing over time when the laser is open-circuited. When the circuit is operating normally, the maximum voltage of the energy storage cell Cx is approximately 30.30V. When a laser experiences an open-circuit fault, the charging process continues, but discharge through the laser is impossible. This is because the circuit can only discharge through self-discharge. After three charges, the voltage of the energy storage cell Cx rises to 45.62V. Before the next light-emitting sequence begins, the self-discharge voltage of the circuit drops. After the next light-emitting sequence begins, the voltage of the first pulse is higher than normal due to the energy stored in capacitor Cx, posing a risk to human eye safety.

[0132] In the scenario where the controller failure causes the gate signal value received by the strobe end of the power supply module to be too large, causing eye safety risks, the corresponding monitoring waveform diagram when the gate signal value is normal is as follows Figure 8aAs shown, the monitoring waveform when the Gate signal value is too large is as follows Figure 8b As shown, the corresponding relationship between the gate terminal signal value, the monitoring point voltage Vx, and the optical power waveform is shown. Figure 8a and Figure 8b By comparison, it can be seen that when the gate-end signal value is too large, the corresponding maximum value of the monitoring point voltage Vx also increases. Under normal circumstances, the corresponding optical power PW does not exceed the human eye safety threshold TH. However, when the gate-end signal value is too large, the monitored optical power PW exceeds the human eye safety threshold, so there is a safety risk to human eye health.

[0133] When other faults cause eye safety risks, the waveforms are different from the above example waveforms, but they all cause the voltage across the energy storage unit Cx to rise.

[0134] In order to meet the eye safety requirements in the event of a single point failure, in the embodiment of this specification, a detection module detects the output signal of the first end of the energy storage module during discharge and compares it with a preset threshold. Based on the comparison result, a drive control signal is output to directly trigger the drive protection module to perform safety protection to ensure eye safety.

[0135] Reference Figure 9 The laser emission drive circuit 90 includes the following components: Figure 4a and Figure 4b In addition to the power supply module and the driving module shown, the device may also include a detection module 91 and a driving protection module 92. The detection module 91 may include a sampling unit 911 and a comparator 912. The sampling unit may be coupled between the first terminal of the energy storage unit and the ground, and coupled to the first input terminal of the comparator via a voltage-dividing sampling terminal.

[0136] In the specific application process, combined with the structural characteristics of the multi-coded laser emission drive circuit, such as Figure 4a As shown, the intersection of multiple power supply units can be selected as the monitoring point, that is, at the output end X of each power supply unit, as shown in Figure 4a This is because when the gate unit is turned on, the voltage at the intersection is the voltage across the energy storage unit Cx.

[0137] If there is no connectivity between the monitoring points, multiple sampling sub-units can be set for the unconnected monitoring points, each coupled with a corresponding energy storage unit, such as Figure 4b As shown, the monitoring point is set at the first end of each energy storage unit, that is, Figure 4b The monitoring points X1, X2...Xn in . As an optional example, Figure 9As shown, the sampling subunit 9111 may include a first resistor R1, a second resistor R2, and a second diode D2, wherein: the first resistor R1 and the second resistor R2 are coupled between the first terminal of the corresponding energy storage unit and ground; the voltage-dividing sampling terminal X-div is disposed between the first resistor R1 and the second resistor R2; the anode of the second diode D2 is coupled to the voltage-dividing sampling terminal X-div, and the cathode of the second diode D2 is coupled to the first input terminal of the comparator 912. The sampled voltages are combined by the second diodes D2 in multiple sampling subunits 9111, and each sampling subunit 9111 shares a single comparator, which can simplify circuit design and save hardware circuit space.

[0138] Continue to refer to Figure 9 In a specific implementation, the driving protection module 92 may include a first switch unit 921, which may be coupled between the power supply terminal of the power supply module and the ground, and is suitable for triggering the power supply terminal of the power supply module to be grounded in response to the driving control signal. In a specific implementation, the controller 9A may be coupled to the power supply terminal VIN through the power enable terminal LBB_EN. Therefore, the power enable terminal LBB_EN may be coupled through the first switch unit 921. In this way, the voltage value of the output terminal X of the power supply unit obtained by sampling is compared with a preset threshold value through the sampling unit 911. When the sampled value exceeds the threshold value, the MOS tube in the first switch unit 921 is turned on, the LBB_EN enable terminal is pulled down, the gate terminal gate controls the switch unit to be disconnected, and the voltage terminal VIN stops supplying power.

[0139] Continue to refer to Figure 9 In other embodiments of this specification, the driver protection module 90 may include a signal biasing unit 922 adapted to, in response to the drive control signal, output a bias signal to the enable terminal of the trigger signal generating module (not shown) of the driver module, causing the trigger signal generating module to stop outputting the trigger signal. In specific implementations, the trigger signal generating module may be part of the laser emission driver circuit, or it may be an independent device, circuit, or component outside of the laser emission driver circuit. For example, the trigger signal generating module may be a pulse signal generator.

[0140] When the output signal of the first end of a certain energy storage unit detected by the detection module 91 during discharge is greater than the preset threshold, a drive control signal is output to the signal bias unit 922. Through the signal bias unit 922, in response to the drive control signal, a bias signal is output to the enable end of the trigger signal generation module of the driver module, so that the trigger signal generation module stops outputting the trigger signal, so that the driver module cannot select the light-emitting circuit formed by the energy storage module and the laser, so that the laser cannot emit light, thereby ensuring the safety of human eyes and improving the safety of the use of the laser and the laser radar using it. As an optional example, the signal bias unit 922 may include a third resistor R3, the first end of the third resistor R3 may be coupled to the output end of the detection module and the enable end of the signal generation module, and the second end of the third resistor R3 is grounded.

[0141] In a specific implementation, the drive control signal can also be fed back to the controller 9A. The controller 9A records the fault information based on the drive control signal, so that the user can find the cause of the fault as soon as possible according to the fault information, and then the laser emission drive circuit can be maintained more efficiently and quickly.

[0142] Reference Figure 10 The figure shows a partial structural diagram of another laser emission driving circuit in the embodiment of this specification. The differences between the laser emission driving circuit 100 and the laser emission driving circuit are specifically reflected in the following aspects:

[0143] As an optional example, the controller is specifically implemented by a Field Programmable Gate Array (FPGA) chip.

[0144] The driving protection module 102 may include a second switch unit 1023 coupled between the first end of the energy storage module (ie, the monitoring point X) and the ground, and adapted to connect the first end of the energy storage module to the ground in response to the driving control signal.

[0145] In response to the driving control signal, the second switching unit 1023 can connect the first end of the energy storage module to the ground, that is, it can ground the transmitting end of the laser, and the laser cannot emit light, thereby ensuring the safety of human eyes and improving the safety of the laser and the laser radar using the laser.

[0146] Continue to refer to Figure 10The laser emission drive circuit may also include a digital-to-analog converter (DAC) module 103, which may be coupled between the second input terminal of the comparator and the threshold signal control terminal and adapted to convert the threshold digital signal outputted by the threshold signal control terminal into a corresponding threshold analog signal, wherein the magnitude of the threshold digital signal is positively correlated with the collected ambient temperature. In a specific implementation, the ambient temperature may be collected by a temperature sensor and fed back to the FPGA chip 10A. The FPGA chip 10A may obtain a corresponding threshold value based on the ambient temperature, and output a threshold digital signal through the threshold signal control terminal. The threshold digital signal is then converted by the DAC module 103 into a corresponding threshold analog signal, thereby enabling the preset threshold value to be adjusted according to the ambient temperature.

[0147] The threshold digital signal output by the threshold signal control terminal is converted into a corresponding threshold analog signal through the DAC module. Since the size of the threshold digital signal is positively correlated with the collected ambient temperature, the threshold analog signal can be accurately adjusted as the collected ambient temperature changes. This ensures that the laser and lidar are safe to use and more stable and reliable as the ambient temperature changes.

[0148] In a specific implementation, two or more corresponding embodiments of the driving protection module may be used in combination to further improve its reliability.

[0149] Reference Figure 11 As shown in the monitoring waveform corresponding to the controller failure, at time Tp, the controller fails and the gate signal value is too large. At this time, the detection module can detect that the voltage of the monitoring point Vx is greater than the preset voltage threshold Vth, and the output end of the comparator outputs a high level. Through the signal bias module, a bias signal can be output to the enable end of the trigger signal generation module of the driving module, so that the trigger signal generation module stops outputting the trigger signal, thereby making the corresponding laser not emit light, and further making the optical power PW emitted by the laser lower than the preset human eye safety threshold.

[0150] Depend on Figure 11 It can be seen that even in the event of a circuit failure, the laser can still be guaranteed to meet the eye safety requirements.

[0151] The embodiments of this specification also provide a laser radar that can be applied to the above-mentioned laser emission drive circuit. As mentioned above, the laser radar may have multiple light-emitting channels, each of which may correspond to a laser, and each channel emits a beam. These lasers are staggered relative to each other in the vertical direction, that is, along the axis of rotation of the laser radar (that is, the vertical angle of each laser is different). Specifically, they can be arranged in one row or in multiple rows. For each light-emitting channel, due to the corresponding different vertical angles, there will be different detection requirements, and thus corresponding different light-emitting intensities. For example, for the channel of the middle beam, you may want to detect farther, and accordingly, you want a stronger light intensity, while the opposite is true for the channels on both sides.

[0152] like Figure 12 As shown, in the embodiment of this specification, the laser radar 120 includes: a laser module 121, a laser emission drive circuit 122, a control module 123 and an energy storage module 124, wherein:

[0153] The laser module 121 may include multiple lasers;

[0154] an energy storage module 124 coupled to the laser module 121 and adapted for charging and discharging;

[0155] The laser emission driving circuit 122 may include a power supply module (not shown), a driving module (not shown), a detection module (not shown), and a driving protection module (not shown), wherein: the detection module is adapted to detect the charging signal of the energy storage module and compare it with a preset threshold value, and output a driving control signal based on the comparison result to trigger the driving protection module to perform circuit protection. For specific implementation, please refer to the aforementioned embodiment and will not be repeated here;

[0156] The control module 123 is suitable for outputting a selection signal to the power supply module in the laser emission drive circuit 122, selecting the voltage supply path, and charging the energy storage module 124; outputting a trigger signal to the drive module of the laser emission drive circuit 122, controlling the drive module to select the light-emitting circuit formed by the energy storage module and the laser, so that the energy storage module discharges and the laser emits light.

[0157] The specific implementation of the energy storage module 124 and the specific electrical connection relationship between the energy storage module 124 and the laser emission drive circuit 122 and the laser module 121 can refer to the detailed description of the aforementioned laser emission drive circuit embodiment.

[0158] In a specific implementation, in addition to outputting a control signal to the corresponding driver of the laser emission drive circuit based on the preset emission control parameters, the control module 123 can also record fault information based on the collected drive control signal, specifically the fault time information, and based on the fault time, determine the possible faults and fault locations of the corresponding branch and the corresponding laser emission drive circuit.

[0159] The embodiments of this specification also provide a corresponding laser emission control method for controlling a laser emission drive circuit, wherein the laser emission drive circuit may include a power supply module, a drive module, a detection module, and a drive protection module. The specific implementation of the laser emission drive circuit can be referred to the aforementioned embodiments. Corresponding to the laser emission drive circuit, the following control method can be used in the embodiments of this specification:

[0160] Based on preset emission control parameters, the control module can output a switch signal to the first end of the power supply module in the laser emission drive circuit, and output a trigger signal to the drive module in the laser emission drive circuit to control the laser to emit light;

[0161] The driving protection module performs circuit protection on the laser emission driving circuit based on a driving control signal, wherein the driving control signal is generated based on a comparison result between the charging signal of the energy storage module detected by the detection module and a preset threshold.

[0162] The specific control process can be found in the above-mentioned embodiment, which will not be described in detail here.

[0163] In a specific implementation, the control module may further record fault information based on the driving control signal output by the laser emission driving circuit.

[0164] In the embodiments of this specification, the control module may be implemented by a digital logic device, a single chip microcomputer, a central processing unit (CPU), an FPGA, or the like.

[0165] Although the embodiments of the present invention are disclosed above, the present invention 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 invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A laser emission drive circuit, suitable for coupling with a laser module and an energy storage module, wherein the laser module includes a plurality of lasers, characterized in that: The laser emission drive circuit includes: a power supply module, a drive module, a detection module, and a drive protection module, wherein: The power supply module is adapted to enable a voltage supply path in response to a selection signal to charge the energy storage module. The power supply module includes a power supply unit, which includes: an inductor, a first end of which is coupled to a voltage supply end; a first diode, an anode of which is coupled to a second end of the inductor, and a cathode of which is coupled to a first end of the energy storage module; a switch unit, a first end of which is coupled to the second end of the inductor and the anode of the first diode, and a second end of which is coupled to ground, and stores energy for the power supply unit or charges the energy storage module based on a received on / off signal; The driving module is coupled to the laser and is adapted to switch on a light-emitting circuit formed by the energy storage module and the laser based on a trigger signal, so that the energy storage module discharges, thereby causing the laser to emit light; The detection module is suitable for detecting the charging signal of the energy storage module and comparing it with a preset threshold value. When the charging signal is greater than the preset threshold value, the detection module outputs a drive control signal to trigger the drive protection module to perform circuit protection, so that the energy storage module cannot discharge to the laser on the light-emitting circuit, wherein the charging signal includes the electrical signal provided by the power supply module to the energy storage module before the energy storage module discharges.

2. The laser emission driving circuit according to claim 1, characterized in that: The detection module includes: a comparator including: a first input terminal, a second input terminal and an output terminal, the first input terminal is coupled to the voltage supply path, the second input terminal is suitable for inputting a threshold signal corresponding to the preset threshold value, and the output terminal is suitable for outputting the drive control signal when the charging signal for the energy storage module detected by the first input terminal is greater than the threshold signal input by the second input terminal, and the preset threshold value is related to the energy threshold corresponding to human eye safety protection.

3. The laser emission driving circuit according to claim 2, wherein: The detection module further includes a sampling unit coupled between the voltage supply path and the ground, and coupled to the first input terminal of the comparator via a voltage-dividing sampling terminal.

4. The laser emission driving circuit according to claim 3, characterized in that: The driving protection module includes: a first switch unit, coupled between the power supply terminal of the power supply module and the ground, and adapted to trigger the power supply terminal of the power supply module to stop supplying power in response to the driving control signal.

5. The laser emission driving circuit according to claim 3, characterized in that: The driving protection module includes: a second switch unit coupled between the first end of the energy storage module and the ground, and adapted to connect the first end of the energy storage module and the ground in response to the driving control signal.

6. The laser emission driving circuit according to claim 3, characterized in that: The driving protection module includes: a signal bias unit, adapted to output a bias signal to an enable terminal of a trigger signal generating module of the driving module in response to the driving control signal, so that the trigger signal generating module stops outputting the trigger signal.

7. The laser emission driving circuit according to claim 2, characterized in that: Also includes: The digital-to-analog conversion module is coupled between the second input terminal of the comparator and the threshold signal control terminal, and is suitable for converting the threshold digital signal output by the threshold signal control terminal into a corresponding threshold analog signal, and the magnitude of the threshold digital signal is positively correlated with the collected ambient temperature.

8. The laser emission driving circuit according to any one of claims 3 to 6, characterized in that: The laser module includes a plurality of laser groups, each laser group includes at least one laser branch; The energy storage module includes a plurality of energy storage units, wherein a first end of the energy storage unit is coupled to the laser group, and a second end of the energy storage unit is grounded; The driving module includes a plurality of driving units, each of which is coupled to a corresponding laser branch; The power supply module includes: a plurality of power supply units, each of which is coupled to at least one energy storage unit and a laser group.

9. The laser emission driving circuit according to claim 8, characterized in that: Also includes: The gating module includes a plurality of gating units, coupled between the power supply unit and the first end of the energy storage unit, and is adapted to gating corresponding laser groups in response to a switch signal.

10. The laser emission driving circuit according to claim 9, characterized in that: The sampling unit includes: a sampling subunit, and the sampling subunit includes: a first resistor, a second resistor and a second diode, wherein: The first resistor and the second resistor are coupled between a voltage supply path and ground; The voltage-dividing sampling terminal is arranged between the first resistor and the second resistor; An anode of the second diode is coupled to the voltage-dividing sampling terminal, and a cathode of the second diode is coupled to the first input terminal of the comparator.

11. The laser emission driving circuit according to claim 10, characterized in that: The output ends of the multiple power supply units intersect.

12. The laser emission driving circuit according to claim 11, characterized in that: The first input terminal of the detection module is coupled to the first terminal of the energy storage unit or the output terminal of the power supply unit.

13. A laser radar, characterized in that: include: a laser module, comprising a plurality of lasers; an energy storage module, coupled to the laser module and suitable for charging and discharging; A laser emission drive circuit is suitable for coupling with the laser module and the energy storage module, and is suitable for powering the energy storage module and driving the laser to emit light. The laser emission drive circuit includes: a power supply module, a drive module, a detection module and a drive protection module, wherein: the power supply module includes a power supply unit, and the power supply unit includes: an inductor, a first end coupled to the voltage supply end; a first diode, an anode coupled to the second end of the inductor, and a cathode coupled to the first end of the energy storage module; a switch unit, a first end coupled to the second end of the inductor and the anode of the first diode, and a second end coupled to the ground, which stores energy for the power supply unit or charges the energy storage module based on the received on-off signal; the detection module is suitable for detecting the charging signal of the energy storage module and comparing it with a preset threshold value. When the charging signal is greater than the preset threshold value, the detection module outputs a drive control signal to trigger the drive protection module to perform circuit protection; wherein the charging signal includes an electrical signal provided by the power supply module to the energy storage module before the energy storage module is discharged; The control module is adapted to output a gating signal to the power supply module to enable a voltage supply path to charge the energy storage module; and output a trigger signal to the drive module to control the drive module to enable a light-emitting circuit formed by the energy storage module and the laser, so that the energy storage module discharges and the laser emits light.

14. The laser radar according to claim 13, characterized in that The control module is further adapted to record fault information based on the collected drive control signal.

15. A laser emission control method, characterized in that: Suitable for controlling a laser emission drive circuit, the laser emission drive circuit is suitable for coupling with a laser module and an energy storage module, the laser module includes multiple lasers, the laser emission drive circuit includes: a power supply module, a drive module, a detection module and a drive protection module, the power supply module includes a power supply unit, and the power supply unit includes: an inductor, a first end coupled to a voltage supply end; a first diode, an anode coupled to the second end of the inductor, and a cathode coupled to the first end of the energy storage module; a switch unit, a first end coupled to the second end of the inductor and the anode of the first diode, and a second end coupled to ground, which stores energy for the power supply unit or charges the energy storage module based on a received on-off signal; the laser emission control method includes: Based on preset emission control parameters, the control module outputs a switch signal to the first end of the power supply module and outputs a trigger signal to the driving module to control the laser to emit light; The drive protection module performs circuit protection on the laser emission drive circuit based on a drive control signal, wherein: the drive control signal is generated when the charging signal of the energy storage module detected by the detection module is greater than a preset threshold, wherein the charging signal includes an electrical signal provided by the power supply module to the energy storage module before the energy storage module discharges.

16. The laser emission control method according to claim 15, characterized in that: Also includes: The control module records fault information based on the driving control signal output by the laser emission driving circuit.

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