CN114594451A

CN114594451A - Laser emission driving circuit, laser radar and laser emission control method

Info

Publication number: CN114594451A
Application number: CN202011403355.7A
Authority: CN
Inventors: 杨松; 赵鑫; 毕云天; 于庆国; 王力威; 向少卿
Original assignee: Hesai Technology Co Ltd
Current assignee: Hesai Technology Co Ltd
Priority date: 2020-12-04
Filing date: 2020-12-04
Publication date: 2022-06-07

Abstract

Laser emission drive circuit, laser radar and laser emission control method, drive circuit is suitable for and is coupled with laser module and energy storage module, the laser module includes a plurality of lasers, laser emission drive circuit includes: power module, drive module, detection module, drive protection module, wherein: the power supply module is suitable for responding to a gating signal and gating a voltage supply path to charge the energy storage module; the driving module is coupled with the laser and is suitable for gating a light emitting loop formed by the energy storage module and the laser based on a trigger signal so that the energy storage module discharges to enable the laser to emit light; the detection module is suitable for detecting the charging signal of the energy storage module, comparing the charging signal with a preset threshold value, outputting a driving control signal based on a comparison result, and triggering the driving protection module to perform circuit protection, so that the energy storage module cannot discharge. The scheme can enhance the safety of the laser radar.

Description

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

Technical Field

The embodiment of the specification relates to the technical field of electronic circuits, in particular to a laser emission driving circuit, a laser radar and a laser emission control method.

Background

Lidar is a sensor that uses laser light to achieve precise ranging. The lidar emits laser pulses which are reflected back when they encounter surrounding objects, and by measuring the time required for the laser to reach and return to each object, the precise distance to the object can be calculated. Laser radars emit thousands of pulses per second, and by collecting these distance measurements, a three-dimensional environmental model, i.e., a point cloud, can be constructed.

The application of the laser radar is very wide, including: autopilot (can be applied to autopilot taxis, passenger cars, trucks, logistics trolleys and the like), mapping, smart city/V2X, robots, security and the like. V2X, namely Vehicle to event, indicates a communication method for the Vehicle to communicate with other things outside, and the "X" may indicate any object capable of communicating with the Vehicle, such as Vehicle-to-Vehicle communication, Vehicle-to-person communication, Vehicle-to-road infrastructure communication, Vehicle-to-cloud network communication, and so on.

Based on the optical characteristics of laser and the core position of the laser radar in the sensor in the applied field, the safety requirement of the laser radar is higher and higher.

Disclosure of Invention

In view of this, embodiments of the present disclosure provide a laser emission driving circuit, a laser radar, and a laser emission control method, so as to perform circuit protection on the laser emission driving circuit and enhance the safety of the laser radar.

First, an embodiment of the present specification provides a laser emission driving circuit, which is suitable for being coupled to a laser module and an energy storage module, where the laser module includes a plurality of lasers, and the laser emission driving circuit includes: power module, drive module, detection module, drive protection module, wherein:

the power supply module is suitable for responding to a gating signal and gating a voltage supply path to charge the energy storage module;

the driving module is coupled with the laser and is suitable for gating a light emitting loop formed by the energy storage module and the laser based on a trigger signal so that the energy storage module discharges to enable the laser to emit light;

the detection module is suitable for detecting the charging signal of the energy storage module, comparing the charging signal with a preset threshold value, outputting a driving control signal based on a comparison result, and triggering the driving protection module to perform circuit protection, so that the energy storage module cannot discharge.

Optionally, the detection module includes: a comparator, comprising: the charging circuit comprises a first input end, a second input end and an output end, wherein the first input end is coupled to the voltage supply path, the second input end is suitable for inputting a threshold signal corresponding to the preset threshold value, the output end is suitable for outputting the driving control signal when the charging signal of the energy storage module, detected by the first input end, is greater than the threshold signal input by the second input end, and the preset threshold value is related to an energy threshold value corresponding to human eye safety protection.

Optionally, the detection module further includes: and the sampling unit is coupled between the voltage supply path and the ground and is coupled with the first input end of the comparator through a voltage division sampling end.

Optionally, the drive protection module comprises: the first switch unit is coupled between the power end of the power supply module and the ground and is suitable for responding to the driving control signal and triggering the power end of the power supply module to stop supplying power.

Optionally, the drive protection module comprises: the second switch unit is coupled between the first end of the energy storage module and the ground and is suitable for responding to the driving control signal and conducting a path between the first end of the energy storage module and the ground.

Optionally, the drive protection module comprises: and the signal bias unit is suitable for responding to the driving control signal and outputting a bias signal to an enabling end of a trigger signal generation module of the driving module so that the trigger signal generation module stops outputting the trigger signal.

Optionally, the laser emission driving circuit further includes: and the digital-to-analog conversion module is coupled between the second input end of the comparator and the threshold signal control end and is suitable for converting the threshold digital signal output by the threshold signal control end into a corresponding threshold analog signal, and the magnitude of the threshold digital signal is positively correlated with the acquired ambient temperature.

Optionally, the laser module comprises a plurality of laser groups, each laser group comprising at least one laser branch;

the energy storage module comprises a plurality of energy storage units, the first ends of the energy storage units are coupled with the laser group, and the second ends of the energy storage units are grounded;

the driving module comprises a plurality of driving units which are respectively coupled with the corresponding laser branches;

the power supply module includes: and each power supply unit is respectively coupled with at least one energy storage unit and the laser group.

Optionally, the laser emission driving circuit further includes: the gating module comprises a plurality of gating units, is coupled between the power supply unit and the first end of the energy storage unit and is suitable for responding to a switching signal to gate the corresponding laser group.

Optionally, the sampling unit includes: a sampling sub-unit, the sampling sub-unit comprising: 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 the ground;

the voltage division sampling end is arranged between the first resistor and the second resistor;

the anode of the second diode is coupled to the divided voltage sampling end, and the cathode of the second diode is coupled to the first input end of the comparator.

Optionally, the outputs of the plurality of power supply units meet.

Optionally, the first input end of the detection module is coupled to the first end of the energy storage unit or the output end of the power supply unit.

Optionally, the power supply unit includes:

an inductor having a first terminal coupled to a voltage supply terminal;

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;

and the first end of the switch unit is coupled to the second end of the inductor and the anode of the first diode, the second end of the switch unit is coupled to the ground, and the switch unit stores energy for the power supply unit or charges the energy storage unit based on the received on-off signal.

An embodiment of the present specification further provides a lidar, including:

a laser module comprising a plurality of lasers;

the energy storage module is coupled with the laser module and is suitable for charging and discharging;

the laser emission driving circuit is suitable for being coupled with the laser module and the energy storage module, is suitable for supplying power to the energy storage module and driving the laser to emit light, and comprises: power module, drive module, detection module and drive protection module, wherein: the detection module is suitable for detecting a charging signal of the energy storage module, comparing the charging signal with a preset threshold value, outputting a driving control signal based on a comparison result, and triggering the driving protection module to carry out circuit protection;

the control module is suitable for outputting gating signals to the power supply module, gating a voltage supply path and charging the energy storage module; and outputting a trigger signal to the driving module, and controlling the driving module to gate a light-emitting loop formed by the energy storage module and the laser, so that the energy storage module discharges and the laser emits light.

Optionally, the control module is further adapted to record fault information based on the collected driving control signal.

An embodiment of the present specification further provides a laser emission control method, which is adapted to control a laser emission driving circuit, where the laser emission driving circuit is adapted to be coupled to a laser module and an energy storage module, the laser module includes a plurality of lasers, and the laser emission driving circuit includes: the laser emission control method comprises the following steps of:

based on preset emission control parameters, the control module outputs a switching signal to the first end of the power supply module and outputs a trigger signal to the driving module so as to control the laser to emit light;

the drive protection module is used for carrying out circuit protection on the laser emission drive circuit based on a drive control signal, wherein: the driving control signal is generated based on a comparison result of the charging signal of the energy storage module detected by the detection module and a preset threshold value.

Optionally, the laser emission control method further includes: and the control module records fault information based on the driving control signal output by the laser emission driving circuit.

By adopting the laser emission driving circuit in the embodiment of the present specification, the detection module detects the charging signal of the energy storage module, compares the charging signal with the preset threshold, outputs the driving control signal to the driving protection module based on the comparison result, and triggers the driving protection module to perform circuit protection on the laser emission driving circuit, so that the laser can output the energy condition meeting the energy corresponding to the preset threshold, thereby ensuring the normal operation of the laser, and once the charging signal is detected not to meet the preset threshold interval, the detection module immediately triggers the driving protection module to perform circuit protection operation, so that the energy storage module cannot discharge, and the laser cannot emit light, thereby avoiding possible human eye safety risks in advance. And because the detection module can directly trigger the drive protection module to carry out circuit protection, the whole protection circuit is realized based on hardware, so that the influence of a program execution cycle is not limited, and the response speed is high.

Further, fault judgment is carried out through the comparator, and since the preset threshold corresponding to the threshold signal input by the second input end of the comparator is related to the energy threshold corresponding to the eye safety protection, when the comparator detects that the charging signal of the energy storage module is greater than the threshold signal input by the second input end, the output triggers the driving control signal of the driving protection module to carry out circuit protection, so that the laser can be prevented from possibly outputting laser higher than the energy threshold corresponding to the eye safety protection, and the response process is extremely short, so that possible eye safety risks can be avoided in advance, the eye safety is guaranteed, and the use safety of the laser radar is improved.

Furthermore, the first switch unit coupled between the power end of the power supply module and the ground responds to the driving control signal to turn on the path between the power end of the power supply module and the ground, so that the power end stops supplying power, the laser cannot emit light, the safety of human eyes can be guaranteed, and the use safety of the laser and the laser radar using the laser can be improved.

Furthermore, the second switch unit is coupled between the first end of the energy storage module and the ground, and is suitable for responding to the driving control signal and conducting a path between the first end of the energy storage module and the ground, namely, the transmitting end of the laser is grounded, and the laser cannot emit light, so that the safety of human eyes can be guaranteed, and the use safety of the laser and the laser radar using the laser can be improved.

Further, when the charging signal of the energy storage module, which is detected by the detection module, is greater than the preset threshold value, a driving control signal is output to the signal bias unit, and a bias signal is output to an enable end of a trigger signal generation module of the driving module through the signal bias unit in response to the driving control signal, so that the trigger signal generation module stops outputting the trigger signal, and the driving module cannot gate a light-emitting loop formed by the energy storage module and the laser, therefore, the laser cannot emit light, the safety of human eyes can be guaranteed, and the use safety of the laser and a laser radar using the laser can be improved.

Further, threshold value digital signal through digital-to-analog conversion module with threshold value signal control end output converts corresponding threshold value analog signal, because threshold value digital signal's size and the ambient temperature positive correlation who gathers, consequently can adjust accurately along with the ambient temperature's that gathers change threshold value analog signal makes the laser instrument along with ambient temperature's change, also can ensure laser instrument and laser radar's safety in utilization, it is more reliable and more stable.

Further, a gating module is arranged and coupled between the power supply unit and the first end of the energy storage unit through a gating unit, and gates the corresponding laser group in response to a switching signal, the gating module is used as an area switch, and the laser group coupled with the gating module can be integrally controlled through the on and off of the gating module, so that the control logic of the driving module can be simplified.

Further, because the output ends of the plurality of power supply units are crossed, the energy storage units can be respectively supplied with power by different power supply units, a laser can continuously emit a plurality of pulses within a short time, and more accurate measurement is realized. Furthermore, the sampling sub-units are respectively coupled with the corresponding energy storage units, and the voltages of the first ends of the corresponding energy storage units, which are collected by the voltage division sampling ends of the sampling sub-units, are collected to the first input end of the comparator, so that the detection module can realize the sampling of the voltages of the first ends of the energy storage units only by arranging one comparator, thereby simplifying the circuit design and saving the occupied space of a hardware circuit.

Furthermore, the first input end of the detection module may be coupled to the first end of the energy storage unit, or may be coupled to the output ends of the power supply units, and when the output ends of the power supply units intersect, only the intersection point needs to be coupled to the first input end of the detection module, that is, the interaction point is used as the monitoring point of the detection module, so that the number of sampling sub-units may be reduced, and the circuit area may be further saved.

Furthermore, fault information is recorded based on the driving control signal output by the laser emission driving circuit, so that a user can find the fault reason as soon as possible according to the fault information, and the laser emission driving circuit can be maintained more efficiently and quickly.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, it is obvious that the drawings in the following description are only embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a laser emission driving circuit in an embodiment of the present disclosure;

FIG. 2 is a schematic structural diagram of a detection module according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram illustrating a variation curve of a voltage at a monitoring point corresponding to a detection module with time in an embodiment of the present disclosure;

fig. 4a is a schematic structural diagram of a laser emitting circuit in a specific application scenario in an embodiment of the present disclosure;

fig. 4b is a schematic structural diagram of a laser emitting circuit in another specific application scenario in the embodiment of the present disclosure;

FIG. 5a is a schematic diagram of two consecutive pulses from a laser;

FIG. 5b is a schematic diagram of three consecutive pulses from a laser;

FIG. 6 is a timing diagram illustrating the light emission control of the laser emitting circuit shown in FIG. 4 a;

fig. 7 is a waveform diagram of input and output corresponding to a laser emission driving circuit when a fault occurs in an embodiment of the present specification;

fig. 8a is a waveform diagram of monitoring waveforms corresponding to normal operation of a laser in a specific application scenario according to an embodiment of the present disclosure;

fig. 8b is a waveform diagram of monitoring waveforms corresponding to a controller failure in a specific application scenario according to an embodiment of the present disclosure;

fig. 9 is a partial structural schematic diagram of a laser emission driving circuit in an embodiment of the present disclosure;

fig. 10 is a partial structural schematic diagram of another laser emission driving circuit in the embodiment of the present disclosure;

fig. 11 is a waveform diagram of monitoring corresponding to a controller failure in a specific application scenario according to an embodiment of the present disclosure;

FIG. 12 is a schematic structural diagram of a lidar in an embodiment of the present disclosure;

fig. 13 is a schematic view of an unmanned vehicle in an embodiment of the present disclosure.

Detailed Description

As described in the background section, lidar is the most central sensor device in many fields such as autopilot, mapping, smart city/V2X, robot, security, and the like, and therefore, normal and stable operation of lidar including a lidar transmitting end is a necessary guarantee for normal operation of devices equipped with lidar in each field, however, there is no corresponding monitoring guarantee mechanism for laser transmission of the lidar at present.

Based on this, the embodiments of the present specification provide a corresponding laser emission monitoring and circuit protection scheme, where a detection module is used to monitor a working state of a laser, and output a driving control signal to a driving protection module based on a monitoring result, and trigger the driving protection module to perform circuit protection on a laser emission driving circuit, so that energy output by the laser during light emission can meet a preset requirement, and normal operation of the laser is ensured. In addition, the detection module can directly trigger the drive protection module to protect the circuit of the laser emission drive circuit, and the whole protection circuit is realized on the basis of hardware, so that the influence of a program execution cycle is avoided, and the response speed is high.

For those skilled in the art to better understand the concept and advantages of the embodiments provided in the present specification and the embodiments for implementing the present specification, the following detailed description and examples illustrate the principles of the laser emission driving circuit, the laser emission control method, the lidar and other embodiments provided in the embodiments of the present specification by means of specific embodiments with reference to the accompanying drawings.

First, in some embodiments of the present disclosure, as shown in the schematic structural diagram of the laser emission driving circuit shown in fig. 1, the laser emission driving circuit 10 is adapted to be coupled to the laser module 1A and the energy storage module 1B. Wherein the laser module 1A comprises a plurality of lasers. The Laser may be various types of lasers, such as a Vertical-Cavity Surface Emitting Laser (VCSEL), or an Edge Emitting Laser (EEL), and the scope of the present invention is not limited by the type of the Laser.

In specific implementation, the laser used can be an anode-driven laser, and if the laser array is a laser array, the laser array can be relatively a common-anode-driven laser array; the laser used may also be a cathode driven laser, or in the case of a laser array, a common cathode driven laser array. Fig. 1 is a schematic structural diagram of a laser emission driving circuit applied to a cathode-driven laser in one embodiment of the present specification.

Specifically, with continued reference to fig. 1, the laser emission driving circuit 10 may include: power module 11, drive module 12 and detection module 13 and drive protection module 14, wherein:

the power supply module 11 is adapted to respond to a gating signal S to gate a voltage supply path to charge the energy storage module 1B;

the driving module 12 is coupled to the laser and is adapted to gate a light emitting loop formed by the energy storage module 1B and the laser based on a trigger signal Tr, so that the energy storage module 1B discharges to enable the laser to emit light;

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

In a specific implementation, the detection module 13 may be specifically a voltage detection module, and may also be a current detection module. If the detecting module 13 is a voltage detecting module, it is adapted to detect a voltage signal of the first end of the energy storage unit 1B, compare the voltage signal with a preset threshold voltage Vth, and generate a corresponding driving control signal Vc based on a comparison result, as shown in fig. 2. If the detecting module 13 is a current detecting module, it is adapted to detect a current signal at the first end of the energy storage module 1B, compare the current signal with a preset threshold current Ith, and generate a corresponding driving control signal Ic based on the comparison result. Of course, the detecting module 13 may also detect other circuit parameters, such as the rate of change of current or the rate of change of voltage, so long as the parameters reflect the intensity of the emitted light of the laser.

The driving control signal Vc or Ic may trigger the driving protection module 14 to perform circuit protection. For example, the driving control signal Vc may trigger a switch of the driving protection module 14, so as to perform circuit protection on the laser emission driving circuit 10.

The following description will be made of the working principle of driving a laser to operate by using a laser emission driving circuit in the embodiment of the present specification, taking the specific application of the laser as an example:

when the first control terminal K1 of the power supply module 11 receives the gating signal, gating a voltage supply path, and supplying power to the power supply module 11 from the power supply terminal VIN, where the power supply module 11 stores electric energy; when the first control terminal K1 receives a turn-off signal, the power supply loop 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 driving unit 11 receives the trigger signal through the second control terminal Tr, the light emitting loop formed by the energy storage unit 1B, the laser module 1A, the driving unit 12 and the ground may be gated, and the energy storage unit 1B discharges to make the laser module 1A emit light.

The detection module 13 may be coupled to the voltage supply path, and monitor the charging voltage Vx of the energy storage module 1B, so as to obtain the light emission condition of the laser in the laser module 1A, and trigger the driving control module 14 to perform circuit protection.

By adopting the laser emission driving circuit in the embodiment of the present specification, the detection module 13 detects the charging signal of the energy storage module 1B, compares the charging signal with the preset threshold value, and outputs the driving control signal based on the comparison result, so that the monitoring of the working state of the laser can be realized, the abnormality can be found in time, and the circuit protection can be triggered.

The laser emits light and consumes electric energy, the electric energy stored in the energy storage module can drive the laser to emit light through discharging, the light emitting intensity of the laser is affected, and the energy storage module can discharge after charging is completed, so that whether the next discharging is normal or not can be estimated based on the actual condition of the charging signals (such as charging voltage, charging current and the like of the energy storage module) of the energy storage module before discharging, including whether the discharging is safe or not.

Laser light emitted from a laser has a relatively high power density even in a small emission amount, and is effective for health of living bodies, and for this reason, countries and regions such as the united states, japan, and the european union have established corresponding laser safety standards. Among the injuries caused by laser, the injury to eyes is the most serious. The degree of action on the eyeball will also vary with the wavelength of the laser, and the consequences will also vary.

For example, when a laser with a wavelength of visible light and near-infrared light enters the eye, the visible light or near-infrared light with a high light concentration and high intensity can be concentrated on the retina by means of the refractive medium in the human eye. At this time, the laser energy density and power density on the retina are instantaneously increased to thousands, even tens of thousands of times, and a large amount of light energy is concentrated on the retina, so that the temperature of the photoreceptor cell layer on the retina is rapidly increased, and the photoreceptor cells are coagulated, denatured and necrotic to lose the sensitization effect. The protein coagulation denaturation caused by overheating when laser light is focused on photoreceptor cells is irreversible damage, and once damaged, the permanent blindness of eyes can be caused. The damage of the far infrared laser to the eye is mainly caused by the cornea, and the damage to the cornea is the heaviest because the laser with the wavelength is almost completely absorbed by the cornea. And the damage of the ultraviolet laser to the eye is mainly to the cornea and the crystalline lens.

However, devices using laser light, such as lidar, have been applied to a plurality of application fields, as mentioned above, and in order to improve the health safety of the operation of the lidar, a corresponding safety monitoring and eye safety protection scheme is required.

As shown in fig. 2, in some embodiments of the present specification, the detection module 13 may include: a comparator 131. With reference to fig. 1 and 2, the comparator 131 includes: a first input terminal, a second input terminal and an output terminal, wherein the first input terminal is coupled to a voltage supply path, and the second input terminal is suitable for inputting a threshold signal Vth corresponding to the preset threshold; the output end is suitable for outputting the driving control signal when the charging signal of the energy storage module 1B detected by the first input end is greater than the threshold signal input by the second input end.

The preset threshold value can be set according to various factors such as laser wavelength emitted by the laser, power density, pulse width and specific circuit protection requirements. For eye safety protection, for example, the preset threshold may be related to an energy threshold corresponding to eye safety protection. For example, if the light emission energy is specified to be not more than several thousand nJ within 5us (the threshold value of each system may be different according to the system condition) for protecting the safety of human eyes, the correspondingly set threshold voltage is 20V, and if the maximum value of the charging voltage of the first end of the energy storage module is 30V this time, it indicates that the laser may emit light unsafe for human eyes next time.

Referring to a variation curve of the charging voltage U at a monitoring point (e.g., the first end of the energy storage unit, or the output end of the power supply module) with time t shown in fig. 3, a curve 31 represents that a peak value of the charging voltage is greater than a preset threshold voltage Vth, so that there is a risk of eye safety; the curve 32 indicates that the peak value of the charging voltage is smaller than the threshold voltage Vth, which indicates that there is no eye safety risk.

In other embodiments of the specification, the corresponding preset threshold may be different based on the characteristic difference of the protected living body, and the preset threshold may be related to the corresponding living body safety protection threshold. The embodiment of the present specification does not limit the specific value of the life safety protection threshold. For example, when the living body is a human being, the threshold voltage th1 may be used; the living body is a cat, and the threshold voltage th2 can be used.

For convenience of understanding, the following description will be given by taking a circuit in which the detection module is a voltage detection type as an example. It is to be understood that the following examples are not intended to limit the scope of the present invention.

In the above embodiments, the signal of the first end of the energy storage module is directly compared with a preset threshold value to determine the fluctuation of the laser when the laser emits laser light. In a specific circuit implementation process, a large high-voltage device needs to be used for driving in consideration of a large supply voltage of the laser, and if the detection module uses a comparator, it is difficult to withstand the voltage (e.g., 40V) at the first end of the energy storage module 1B in consideration of a low-voltage device (usually 5V) of the comparator.

In specific implementation, the voltage of the first end of the energy storage module may not be directly compared with the preset threshold voltage, but a sampling unit is disposed in the detection module, and the sampling unit performs voltage division sampling. Specifically, referring to fig. 2 in combination with fig. 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 ground, and coupled to the first input end of the comparator 131 through a voltage division sampling end, where a voltage sampled through the voltage division sampling end may also reflect a voltage value of the first end of the energy storage module 1B and a fluctuation amplitude of the voltage.

In a specific implementation, the lidar may have a plurality of light-emitting channels, each light-emitting channel may correspond to one laser, each channel emits 1 line of beams, and the lasers are staggered with respect to each other in a vertical direction (that is, a vertical angle of each laser is different), specifically, one line, or a plurality of lines. For each light emitting channel, different detection requirements are required due to the fact that the light emitting channel corresponds to different vertical angles, and therefore different light emitting intensities are required. For example, for the channels of the central beam, it may be desirable to detect farther, and correspondingly, to have greater light intensity, while the channels on both sides are reversed.

In order to realize the round-trip light emission of multiple lasers in a laser radar, for example, the laser module may be provided with one or more laser groups, each laser group includes at least one laser branch, each laser branch corresponds to one light emitting channel, and accordingly, the energy storage module may include multiple energy storage units, and each laser or each laser group may be configured with one energy storage unit. Similarly, each module in the laser emission driving circuit may adaptively set a plurality of circuit units for different lasers or laser groups. Specifically, the driving module may include a plurality of driving units, each of the driving units may be coupled to a corresponding laser branch, and the power supply module may include a plurality of power supply units, each of the power supply units may be coupled to at least one energy storage unit and the laser group.

In order to make the embodiments of the present specification better understood and implemented by those skilled in the art, some specific implementation examples of the light emission driving circuit are given below.

First, referring to the schematic structural diagrams of the laser emitting circuit shown in fig. 4a and 4b, the laser emitting circuit includes a plurality of laser groups LD1, LD2 … LDi-1, LDi, and a plurality of energy storage units C1, C2 … Cn-1, Cn, wherein a first end of each energy storage unit is coupled to one laser group, and a second end of each energy storage unit is grounded. Each energy storage unit is specifically an energy storage capacitor, and it should be noted that in specific implementation, each energy storage unit may also be implemented by other energy storage components. The laser emission driving circuit shown in fig. 4a and 4b includes: the laser driving system comprises a plurality of power supply units A1 and A2 … Am, wherein each power supply unit A1 and A2 … Am can be respectively coupled with one or more laser groups and an energy storage unit, each laser group can be respectively driven by corresponding driver unit groups DR1, DR2 … DRj-1 and DRj, and each driving unit group comprises a plurality of driving units which can respectively correspond to one or more laser branches.

In a specific implementation, a gating module may be further included, with continued reference to fig. 4a and 4B, which may include a plurality of gating cells B1, B2 … Bn-1, Bn, which may be coupled between the power supply unit and the first end of the energy storage unit, adapted to gate respective groups of lasers in response to a switching signal. For example, the gating unit B1 is coupled between the power supply units a1, a2 … Am and the first terminal of the energy storage unit C1, and the gating unit B2 is coupled between the power supply units a1, a2 … Am and the first terminal of the energy storage unit C2. As a more specific example, as shown in fig. 4a and 4b, the driving unit may specifically include driving switches S11, S12, S13, S14, and the like, each of which may be turned on or off by a trigger signal Tr, and the gating unit may specifically include switching tubes P1, P2 … Pn-1, Pn, and the like.

The following first describes the rough operation of the laser emission driving circuit: each power supply unit in the power supply module can receive an input voltage VIN (namely, a power supply voltage) and store electric energy, and then when the gating unit is switched on, the power supply unit can charge the corresponding energy storage unit, and high voltage is established on the energy storage unit. Normally, there is no safety protection circuit on the input side, so the input voltage is usually not very high, for example, it may be 5V or 12V, and it may not be directly used to drive the laser, and in this case, it needs to be boosted. The high voltage built up on the energy storage unit may be significantly higher than the input voltage VIN, for example 60V, for driving the laser LD. After the high voltage is built up, the energy storage unit C may drive the laser LD to emit a laser beam.

Referring to fig. 4a, how the circuit units cooperate is illustrated with the power supply unit a1, the gating unit B1, and the laser group LD 1. As a specific example, the power supply unit a1 includes an inductor L1, a first diode D1, and a switching unit M1, wherein a first terminal of the inductor L1 is coupled to the power supply terminal VIN, a second terminal of the inductor L1 is connected to an anode of the first diode and a first terminal of the switching unit M1, and a cathode of the first diode D1 is coupled to the energy storage unit C1 through the gating unit B1.

During the pre-charging phase, the switching unit M1 may be controlled to be closed by the gate signal gate1, and the closed switching unit M1 may be equivalent to a short circuit in circuit, so that the current generated by the input voltage VIN flows through the inductor L1 and is grounded through the switching unit M1, and as the inductor current increases, the inductor L1 stores electric energy.

When the pre-charging is completed, the switch unit M1 is turned off, and the switch P1 in the gating unit B1 can be gated by the high-side driver, at this time, because of the current holding characteristic of the inductor L1, the current flowing through the inductor L1 does not immediately become 0, but slowly changes from the current value at the time of completion of charging to 0, in this process, the switch unit M1 is already turned off, and the gating switch P1 is turned on, so the inductor L1 charges the energy storage unit C1, and the voltage across the energy storage unit C1 rises.

After a high voltage (e.g. 60V) has been built up in the energy storage unit C1, if the driving switch S11 in the selected laser branch is turned on, due to the unidirectional conductivity of the first diode D1, the energy storage unit C1 cannot discharge through the first diode D1, and can only discharge through the loop of the laser LD11 and the driving switch S11, so that a current flows through the laser LD11, and the energy storage unit C1 drives the laser LD11 to emit light.

When the energy storage unit C1 finishes discharging, the switch unit M1 is closed again, the driving switch S11 is opened, and the cycle of pre-charging, charging and discharging is performed again, so that the laser L11 is continuously driven to emit light.

In the field of lidar, there is the concept of pulse coding. Each laser may emit multiple pulses in succession to achieve multi-pulse encoding of the laser. With regard to coding, in particular, it means that each laser emits n (n ≧ 2) pulses at a time, which is an operation against crosstalk.

There are many cases where the parameters are changed at the time of encoding. For example, where the pulse widths of 2 pulses may be different (as shown in FIG. 5a, where pulse 1 has a smaller width than pulse 2), the time intervals between the preceding and following pulses may be different (as shown in FIG. 5b, where Δ t1 ≠ Δ t2), and the amplitudes of the pulses are different (as shown in FIG. 5a, pulse 2 has a higher amplitude than pulse 1)The number of pulses is different (shown as double pulses in fig. 5a and triple pulses in fig. 5 b). For example, laser radar A emits double pulses, laser radar B also emits double pulses, the time interval Δ t between the double pulses of the two laser radars_A≠Δt_BIn this way, lidar a will only receive or specifically process the echo at the interval Δ t1 ″ between the double pulses, and will not treat the echo of lidar B as its own echo.

In some practical applications, the power supply module may include 3 power supply units, 4 gating units, and 4 laser groups, i.e., m is 3, n is 4, and i is 4, each laser continuously emits 3 pulses at a time.

In order to make the skilled person better understand and implement the laser multi-pulse emission, how to cooperate 16 lasers by 3 power supply units, 4 gating units and 4 laser groups is described below.

Referring to the timing diagram of the light emission control of the laser emitting circuit shown in fig. 6, in conjunction with fig. 4a and 6, first at time t1, assuming that the power supply unit a1 has completed charging the energy storage unit C1, a high voltage is established across the energy storage unit C1 (as shown by the waveform before time t 1).

At time t1, the controller controls the drive switch S11 to close by 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 circuit including the laser LD11 and the drive switch S11, and current flows through the laser LD11, so that the laser LD11 emits pulse 1. It should be noted that, since the discharge speed of the laser is very fast, the high voltage on the energy storage unit C1 drops much in the almost instant from fig. 6, and therefore, the gradual voltage drop process is not shown in fig. 6.

After discharging at Time t1, entering coding Time Δ t1 (actually, the Time interval between pulse 1 and pulse 2), and until Time t2, the coding Time may be set, and if the interval between pulse 1 and pulse 2 is 20ns, the detector will determine that the pulse is transmitted by the radar only when detecting that the interval between the two received pulses is 20ns, and then will perform subsequent processing to further calculate Time of Flight (ToF) and distance, which is called coding Time, so as to prevent signal crosstalk. And, after the discharging is finished at time t1, the power supply unit a1 enters the energy storage time, the controller controls the switch unit M1 to be closed, the inductor L1 starts to have current to flow through the inductor L1 and the switch unit M1 under the action of the input voltage VIN, and the inductor L1 is charged and stored with energy again. And after the pre-charging is finished, waiting for the next charging and boosting of one energy storage unit in the energy storage module.

At time t2, assume that power supply unit A2 has already stored energy. At this time, the controller ensures that the gate switch P1 is closed and at the same time controls the switch unit M2 to be opened, and the inductor L2 in the power supply unit a2, due to its characteristic of maintaining current thereon, will discharge through the first diode D2, the gate switch P1 and the energy storage unit C1, thereby charging the energy storage unit C1, and gradually building a high voltage thereon. At time t3, the high voltage build-up on energy storage cell C1 is complete. At this time, the controller controls the drive switch S11 to be closed, and the other drive switches S12, S13, and S14 to be opened. At this time, the energy storage unit C1 will discharge through the circuit including the laser LD11 and the drive switch S11, and current flows through the laser LD11, so that the laser LD11 emits pulse 2.

After discharge at time t3, the code time Δ t2 (actually, the time interval between pulse 2 and pulse 3, which may also be set so that the laser emits 3 pulses, has 2 settable intervals so that the probability of code interval coinciding with the current radar is smaller and the radar has stronger interference rejection) is entered until time t 4. And the discharging is finished from the time t3, the power supply unit a2 enters the charging energy storage time, the controller controls the switch unit M2 to be closed, the inductor L2 starts to have current flow under the action of the input voltage VIN through the inductor L2 and the switch unit M2, and the inductor L2 is charged and stored with energy again. And after the energy storage is finished, waiting for the next time of charging and boosting one capacitor of the energy storage module.

At time t4, assume that power supply unit A3 has already stored energy. At this time, the controller ensures that the gate switch P1 is closed while the control switch unit M3 is opened, and therefore, the inductor L3 in the power supply unit A3, due to its property of maintaining current thereon, 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 a high voltage thereon.

At time t5, the high voltage build-up on energy storage cell C1 is complete. At this time, the controller controls the drive switch S11 to be closed, and the other drive switches S12, S13, and S14 to be opened. At this time, the energy storage unit C1 will discharge through the circuit including the laser LD11 and the drive switch S11, and current flows through the laser LD11, so that the laser LD11 emits pulse 3.

As described above, from time t1 to time t5, the power supply unit a1, the power supply unit a2, and the power supply unit A3 sequentially charge the energy storage unit C1 corresponding to the laser group LD1, and a high voltage is established thereon. After the high voltage is built on the energy storage unit C1, the controller controls the driving switch S11 to close, so that the laser LD11 connected with the driving switch S11 is driven three times to emit pulse 1, pulse 2 and pulse 3, and a detection light emitting process of the laser LD11 is completed. After the energy storage unit C1 is charged and boosted, each power supply unit enters the energy storage inductor pre-charging time, stores electric energy thereon, and prepares to charge and boost one of the energy storage units in the energy storage module next time.

The time interval between the pulse 1 and the pulse 2 is the encoding time delta t1+ the charging time of the capacitor C1, and the time interval between the pulse 2 and the pulse 3 is the encoding time delta t2+ the charging time of the capacitor C1. The encoding time Δ t1 and the encoding time Δ t2 may be the same or different. In addition, the encoding time can be set to be different from one laser to another, so that multi-pulse encoding can be realized. After receiving the radar echo, the receiving end of the laser radar can decode the pulse according to the time interval between each pulse to acquire the transmitting pulse corresponding to which laser.

Fig. 6 schematically illustrates the emission of three pulses during one emission detection of each laser, and those skilled in the art will readily appreciate that the scope of the present invention is not limited thereto. A single emission detection process for each laser may emit a fewer or greater number of pulses. When a smaller number of pulses, for example two pulses, are transmitted, then at time t5 according to the preset transmission timing, the controller may control the driving switch S12 to close, so that the energy storage unit C1 discharges through the laser LD12 and the driving switch S12, and drives the laser LD12 to emit a light pulse.

When a greater number of pulses are transmitted, after pulse 3, the energy storage unit C1 may be recharged by the power supply unit a1 which was charged the earliest, and then the laser LD11 is driven, producing pulse 4. The above process is repeated until the laser LD11 emits a preset number of pulses.

After the laser LD11 finishes emitting, the above process is repeated, and the laser LD12 is driven to emit light, emitting a predetermined number of pulses.

It is understood that the control of the power supply unit, the control of the gate switch P1, in driving the laser LD12 is substantially similar to that in driving the laser LD11, except that: the controller needs to control the driving switch S12 to close to drive the laser LD 12.

The above driving process is performed for the laser LD13 and the laser LD14, respectively, until all the lasers of the first group emit light.

Similarly, the drive laser group LD2 emits light. In this process, it is necessary to ensure that the gate switches P1, P3, P4 are turned off.

The above process is repeated, and the laser group LD3 and the lasers in the laser group LD are driven to emit light. After the last laser LD44 in the laser group LD4 finishes lighting, the driving of the first laser LD11 to be triggered in the laser group LD1 is restarted.

Multiline mechanical lidar is commonly used in the field of unmanned vehicles, and referring to the schematic diagram of an unmanned vehicle shown in fig. 13, includes a vehicle body 131 and a lidar 132 located on the top of the vehicle body. As an active detection laser product, laser radars are sold in various regions of the world and need to meet certain eye safety standards. In general, the energy of the laser pulse/burst is required not to exceed a certain threshold. To this end, the requirements can be met by circuit design and control strategies. However, according to some standards, such as the international certification standard IEC 60825-1:2014 for laser ratings, it is not only necessary to ensure eye safety in the case of a system without failure, but also necessary that the energy of the pulses/pulse trains emitted by the laser product cannot exceed the corresponding threshold value of the eye safety rating of the product in the case of a single point failure.

In response to the above requirements, the conventional solutions are: and acquiring laser pulse energy by adopting a sensor, judging whether the laser pulse energy exceeds a threshold value by a controller, and taking corresponding measures after the laser pulse energy exceeds the threshold value. However, in practical applications, there are two problems:

1) the accuracy of the mode for testing the luminous flux is low. An Avalanche Diode (APD) and an amplifier circuit are usually used to detect the laser intensity, but the output characteristics of the APD are greatly affected by the consistency and environment, so the accuracy of detecting the laser pulse energy by this method is low.

2) The laser pulses are extremely short in time, typically in the order of nanoseconds. The design of the instant threshold is added with a lead (for example, the threshold of the safety requirement of human eyes is 300nJ, and the monitoring threshold is set to be 200nJ), and the lead can not react in time after the fault is detected.

The inventor analyzes a failure mode that the light emitting energy exceeds a preset threshold value due to a circuit fault of the laser emission driving circuit and a circuit protection scheme thereof, and the following description is provided by a specific embodiment.

Referring to fig. 4a and 4b, for example, the gating units P1 to Pn may be short-circuited, and may charge the failed energy storage unit while charging other energy storage units, so that the voltage of the failed energy storage unit after charging is too high, and the light emitting energy of the laser may exceed the eye safety threshold when discharging; as another example, the input voltage VIN is over-voltage; as another example, a controller (e.g., FPGA) fails, which may cause the value of the signal provided by the gate terminal for driving the switch unit M1-Mn in the power supply module to be too large, so that the inductor Lx is charged for too long, and accordingly, the energy storage unit Cx is charged with too much energy; the laser LD has an open circuit fault, the laser LD of the fault branch does not emit light when the laser LD of the fault branch should emit light, so that the high-voltage energy is too high when the laser LD of the latter branch emits light, and the light-emitting energy exceeds the safety threshold of human eyes.

Taking the laser open circuit fault as an example, refer to the graph of the voltage signal of the energy storage unit changing with time when the laser is open circuit shown in fig. 7. When the circuit normally works, the maximum voltage of the energy storage unit Cx is about 30.30V. When one laser has an open-circuit fault, the charging process is continued and the laser cannot discharge, because the voltage of the energy storage unit Cx is raised to 45.62V only through self-discharge of the circuit and three times of charging. Before the next light-emitting sequence starts to charge, the self-discharge voltage of the circuit drops, and after the next light-emitting sequence starts to charge, the voltage value of the first pulse is higher than the normal value due to the electric energy in the capacitor Cx, so that the risk of causing eye safety exists.

Aiming at the situation that the gate end signal value received by the gate end of the power supply module is too large due to the controller fault, so that the human eye safety risk is caused. A schematic diagram of a corresponding monitoring waveform when a signal value at a Gate end is normal is shown in fig. 8a, and a monitoring waveform when the signal value at the Gate end is too large is shown in fig. 8b, where a corresponding relationship among the signal value at the Gate end, a monitoring point voltage Vx and a waveform of optical power is shown, as can be seen from comparison between fig. 8a and fig. 8b, a maximum value of the corresponding monitoring point voltage Vx is also increased when the signal value at the Gate end is too large, a corresponding optical power PW does not exceed a human eye safety threshold TH under a normal condition, and when the signal value at the Gate end is too large, a monitored optical power PW exceeds a human eye safety threshold, so that a safety risk exists in human eye health.

When other faults cause eye safety risks, the waveforms are different from the above example waveforms, but all result in a voltage rise across the energy storage unit Cx.

In order to meet the requirement of eye safety under the condition of single-point failure, in the embodiment of the specification, the detection module detects an output signal of the first end of the energy storage module during discharging, the output signal is compared with a preset threshold value, and a driving control signal is output based on a comparison result to directly trigger driving protection for safety protection, so that the eye safety is guaranteed.

Referring to the schematic partial structure diagram of the laser emission driving circuit shown in fig. 9, the laser emission driving circuit 90 may further include a detection module 91 and a driving protection module 92 in addition to the power supply module and the driving module shown in fig. 4a and 4 b. The detection module 91 may include a sampling unit 911 and a comparator 912, and the sampling unit may be coupled between the first terminal of the energy storage unit and ground and coupled to a first input terminal of the comparator through a voltage division sampling terminal.

In a specific application process, in combination with the structural features of the multi-coding laser emission driving circuit, as shown in fig. 4a, an intersection point of a plurality of power supply units may be selected as a monitoring point, that is, at an output terminal X of each power supply unit, such as monitoring points X1 and X2 … Xn in fig. 4 a. This is because when the gating unit is turned on, the voltage at the junction is the voltage across the energy storage unit Cx.

If there is no communication between the monitoring points, for the monitoring points without communication, a plurality of sampling sub-units may be disposed, and respectively coupled to the corresponding energy storage units, as shown in fig. 4b, and the monitoring points are disposed at the first ends of the energy storage units, i.e., the monitoring points X1 and X2 … Xn in fig. 4 b. As an alternative example, as shown in fig. 9, 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 end of the corresponding energy storage unit and the ground; the voltage division sampling end X-div is arranged between the first resistor R1 and the second resistor R2; the anode of the second diode D2 is coupled to the divided voltage sampling terminal X-div, and the cathode of the second diode D2 is coupled to the first input terminal of the comparator 912. The sampling voltage is converged by the second diodes D2 in the sampling subunits 9111, and each sampling subunit 9111 shares one comparator, so that the circuit design can be simplified, and the occupied space of a hardware circuit is saved.

With continued reference to fig. 9, in an 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 adapted to trigger the power supply terminal of the power supply module to be grounded in response to the driving control signal, in an implementation, the controller 9A may be coupled to the power supply terminal VIN through a power enable terminal LBB _ EN, and therefore, the power enable terminal LBB _ EN may be coupled through the first switch unit 921, so that the sampled voltage value of the output terminal X of the power supply unit is compared with a preset threshold value through the sampling unit 911, when the sampled value exceeds the threshold value, the MOS transistor in the first switch unit 921 is turned on, the LBB _ EN enable terminal is pulled down, and the gate terminal gate controls the switch unit to be turned off, and then the voltage terminal VIN stops supplying power.

With continued reference to fig. 9, in other embodiments of the present disclosure, the driving protection module 90 may include a signal bias unit 922, which is adapted to output a bias signal to an enable terminal of a trigger signal generation module (not shown) of the driving module in response to the driving control signal, so that the trigger signal generation module stops outputting the trigger signal. In a specific implementation, the trigger signal generating module may be a part of the laser emission driving circuit, or may be an independent device, circuit or device other than the laser emission driving circuit. For example, the trigger signal generation module may be specifically a pulse signal generator.

When the output signal detected by the detection module 91 when the first end of a certain energy storage unit discharges is greater than the preset threshold value, the detection module outputs a driving control signal to the signal bias unit 922, and the signal bias unit 922 responds to the driving control signal and outputs a bias signal 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, and the driving module cannot gate the light-emitting loop formed by the energy storage module and the laser, and therefore, the laser cannot emit light, so that the safety of human eyes can be guaranteed, and the use safety of the laser and the laser radar using the laser is improved. As an optional example, the signal bias unit 922 may include a third resistor R3, a first end of the third resistor R3 may be coupled to the output terminal of the detection module and the enable terminal of the signal generation module, and a second end of the third resistor R3 is grounded.

In specific implementation, the driving control signal can be fed back to the controller 9A, and the controller 9A records fault information based on the driving control signal, so that a user can find a fault reason as soon as possible according to the fault information, and further, the laser emission driving circuit can be maintained more efficiently and quickly.

Referring to a schematic partial structure diagram of another laser emission driving circuit in the embodiment shown in fig. 10, the differences between the laser emission driving circuit 100 and the laser emission driving circuit are embodied in the following aspects:

as an alternative example, the controller is specifically implemented by a Field Programmable Gate Array (FPGA) chip.

In the driving protection module 102, a second switch unit 1023 may be included, which is coupled between the first end of the energy storage module (i.e. the monitoring point X) and the ground, and is adapted to conduct a path between the first end of the energy storage module and the ground in response to the driving control signal.

The second switch unit 1023 responds to the driving control signal, can turn on the first end of the energy storage module and the path of the ground, that is, can enable the transmitting end of the laser to be grounded, and the laser cannot emit light, so that the safety of human eyes can be guaranteed, and the use safety of the laser and the laser radar using the laser can be improved.

With continued reference to fig. 10, the laser emission driving circuit may further 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 is adapted to convert the threshold Digital signal output by the threshold signal control terminal into a corresponding threshold Analog signal, where the magnitude of the threshold Digital signal is positively correlated to the collected ambient temperature. In specific implementation, the ambient temperature can be collected by the temperature sensor and fed back to the FPGA chip 10A, the FPGA chip 10A can obtain a corresponding threshold according to the ambient temperature, and output a threshold digital signal through the threshold signal control terminal, and convert the threshold digital signal into a corresponding threshold analog signal by the DAC module 103, so that the preset threshold can be adjusted according to the ambient temperature.

Threshold value digital signal who outputs threshold value signal control end through the DAC module converts corresponding threshold value analog signal, because threshold value digital signal's size and the ambient temperature positive correlation who gathers, consequently can adjust accurately along with the change of the ambient temperature who gathers threshold value analog signal makes the laser instrument is along with ambient temperature's change, also can ensure laser instrument and laser radar's safety in utilization, more reliable and more stable.

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

Referring to a monitoring waveform diagram corresponding to the controller in the case of a fault shown in fig. 11, at the time of Tp, the controller fails, a 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 a preset voltage threshold Vth, the output end of the comparator outputs a high level, and the signal offset module can output an offset signal 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, a corresponding laser does not emit light, and the optical power PW emitted by the laser is lower than a preset human eye safety threshold.

As can be seen from fig. 11, even in the event of a circuit failure, the laser can still be guaranteed to meet the requirements of human eye safety.

The embodiment of the present specification further provides a laser radar to which the above laser emission driving circuit may be applied, as described above, the laser radar may have a plurality of light emitting channels, each light emitting channel may correspond to one laser, each channel emits 1 wire harness, and the lasers are staggered with respect to each other in a vertical direction (that is, a vertical angle of each laser is different) in a direction along a rotation axis of the laser radar, specifically, may be one column, and may also be multiple columns staggered. For each light emitting channel, different detection requirements are required due to the fact that the light emitting channel corresponds to different vertical angles, and therefore different light emitting intensities are required. For example, for the channels of the central beam, it may be desirable to detect farther, and correspondingly, to have greater light intensity, while the channels on both sides are reversed.

As shown in fig. 12, in the present embodiment, laser radar 120 includes: laser module 121, laser emission drive circuit 122, and control module 123 and energy storage module 124, wherein:

the laser module 121 may include a plurality of lasers;

an energy storage module 124 coupled to the laser module 121 and adapted to be charged and discharged;

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 a charging signal of the energy storage module, compare the charging signal with a preset threshold, output a driving control signal based on a comparison result, and trigger the driving protection module to perform circuit protection, and specific implementation can refer to the foregoing embodiments, which are not described herein again;

the control module 123 is adapted to output a gating signal to a power supply module in the laser emission driving circuit 122 to gate a voltage supply path, so as to charge the energy storage module 124; and outputting a trigger signal to a driving module of the laser emission driving circuit 102, and controlling the driving module to gate a light emitting loop formed by the energy storage module and the laser, so that the energy storage module discharges and the laser emits light.

For a specific implementation of the energy storage module 124 and a specific electrical connection relationship between the laser emission driving circuit 122 and the laser module 121, reference may be made to the detailed description of the foregoing laser emission driving circuit embodiment.

In specific implementation, the control module 123 may output a control signal to a corresponding driver of the laser emission driving circuit based on a preset emission control parameter, and may also record fault information based on the collected driving control signal, specifically may record fault time information, and may determine a fault and a fault position that may exist in a corresponding branch and a corresponding laser emission driving circuit based on the fault time.

The embodiment of the present specification further provides a corresponding laser emission control method, which is used for controlling a laser emission driving circuit, where the laser emission driving circuit may include a power supply module, a driving module, a detection module, and a driving protection module, and specific implementation of the laser emission driving circuit may refer to the foregoing embodiment. Corresponding to the laser emission driving circuit, in the embodiment of the present specification, the following control method may be adopted:

the control module can output a switching signal to a first end of the power supply module in the laser emission driving circuit and output a trigger signal to a driving module in the laser emission driving circuit based on preset emission control parameters so as to control the laser to emit light;

The specific control process can be described with reference to the foregoing embodiments, and is not described herein again.

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

In the embodiments of the present disclosure, the control module may be specifically implemented by a digital logic device, a single chip, a Central Processing Unit (CPU), an FPGA, and the like.

Although the embodiments of the present invention have been disclosed, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A laser emission driver circuit adapted to be coupled to a laser module and an energy storage module, the laser module including a plurality of lasers, the laser emission driver circuit comprising: power module, drive module, detection module, drive protection module, wherein:

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

3. The laser emission driving circuit according to claim 2, wherein the detection module further comprises: and the sampling unit is coupled between the voltage supply path and the ground and is coupled with the first input end of the comparator through a voltage division sampling end.

4. The laser emission driving circuit according to claim 3, wherein the driving protection module comprises: the first switch unit is coupled between a power end of the power supply module and ground and is adapted to trigger the power end 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, wherein the driving protection module comprises: the second switch unit is coupled between the first end of the energy storage module and the ground and is suitable for responding to the driving control signal and conducting a path between the first end of the energy storage module and the ground.

6. The laser emission driving circuit according to claim 3, wherein the driving protection module comprises: and the signal bias unit is suitable for responding to the driving control signal and outputting a bias signal to an enabling end of a trigger signal generation module of the driving module so that the trigger signal generation module stops outputting the trigger signal.

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

8. The laser emission driver circuit according to any of claims 3 to 6, wherein the laser module comprises a plurality of laser groups, each laser group comprising at least one laser branch;

9. The laser emission driving circuit according to claim 8, further comprising: the gating module comprises a plurality of gating units, is coupled between the power supply unit and the first end of the energy storage unit and is suitable for responding to a switching signal to gate the corresponding laser group.

10. The laser emission driving circuit according to claim 9, wherein the sampling unit includes: a sampling sub-unit, the sampling sub-unit comprising: a first resistor, a second resistor, and a second diode, wherein:

11. The laser emission driving circuit according to claim 10, wherein output terminals of the plurality of power supply units meet.

12. The laser emission driving circuit of claim 11, wherein 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. The laser emission driving circuit according to claim 8, wherein the power supply unit includes:

an inductor, a first terminal coupled to the voltage supply terminal;

and the first end of the switch unit is coupled with the second end of the inductor and the anode of the first diode, the second end of the switch unit is coupled with the ground, and the switch unit stores energy for the power supply unit or charges the energy storage unit based on the received on-off signal.

14. A lidar, comprising:

a laser module comprising a plurality of lasers;

15. The lidar of claim 14, wherein the control module is further adapted to record fault information based on the collected drive control signal.

16. A laser emission control method adapted to control a laser emission driving circuit, the laser emission driving circuit adapted to be coupled to a laser module and an energy storage module, the laser module including a plurality of lasers, the laser emission driving circuit comprising: the laser emission control method comprises the following steps of:

17. The laser emission control method according to claim 16, further comprising:

and the control module records fault information based on the driving control signal output by the laser emission driving circuit.