Laser emission circuit, circuit fault detection method and laser radar

Abstract

The embodiment of the invention discloses a laser emission circuit, a circuit fault detection method and a laser radar. The laser emission circuit comprises an energy charging circuit, an energy storage capacitor, an energy release circuit, a light emitting unit, a first voltage comparator and a processor. The first voltage comparator is used for obtaining a first comparison signal according to the voltage of the non-inverting input end of the first voltage comparator and the voltage of the inverting input end of the first voltage comparator; the processor is used for obtaining a first pulse width according to the first comparison signal; the processor is also used for comparing the first pulse width with the first preset pulse width, and obtaining the state information of the laser emission circuit according to the comparison result. Based on the laser emission circuit, the working state of the circuit can be monitored, and the reliability of the laser emission circuit is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of laser radar, in particular to a laser emission circuit, a circuit fault detection method and a laser radar. BACKGROUND

[0002] The laser radar is a precision instrument based on laser pulse ranging and sensing, which has been widely used in automatic driving, industrial mapping, robots and intelligent transportation fields.

[0003] In the laser radar system, in order to ensure that the receiving unit can receive the effective echo signal, it is necessary to monitor the emission power and working state of the laser emission circuit. The conventional fault detection method is to judge the fault state by the current change of the circuit node, but this method needs to set different power resistors for different current sizes, and the circuit topology is complex. SUMMARY

[0004] In order to monitor the working state of the laser emission circuit, the embodiments of the present application disclose a laser emission circuit, a circuit fault detection method and a laser radar.

[0005] In a first aspect, the present application discloses a laser emission circuit, comprising: a charging circuit, an energy storage capacitor, a discharging circuit, a light emitting unit, a first voltage comparator and a processor;

[0006] The first end of the energy storage capacitor is connected with the charging circuit, the first end of the energy storage capacitor is connected with the light emitting unit, the first end of the energy storage capacitor is connected with the discharging circuit, the first end of the energy storage capacitor is connected with the non-inverting input terminal of the first voltage comparator, the output terminal of the first voltage comparator is connected with the processor, and the second end of the energy storage capacitor is grounded.

[0007] The first voltage comparator is used to obtain a first comparison signal according to the voltage of the non-inverting input terminal of the first voltage comparator and the voltage of the inverting input terminal of the first voltage comparator.

[0008] The processor is used to obtain a first pulse width according to the first comparison signal.

[0009] The processor is also used to compare the first pulse width with a first preset pulse width, and obtain state information of the laser emission circuit according to the comparison result.

[0010] In some embodiments, the laser emission circuit further comprises a second voltage comparator; wherein a non-inverting input terminal of the second voltage comparator is connected with the first terminal of the energy storage capacitor, and an output terminal of the second voltage comparator is connected with the processor; the second voltage comparator is configured to obtain a second comparison signal according to a voltage of the non-inverting input terminal of the second voltage comparator and a voltage of an inverting input terminal of the second voltage comparator; the processor is further configured to obtain a second pulse width according to the second comparison signal; and correspondingly, the processor is configured to obtain the state information of the laser emission circuit according to the comparison result comprises that the processor is configured to obtain the state information of the laser emission circuit according to the second pulse width and a second preset pulse width, wherein the comparison result is that the first pulse width is equal to the first preset pulse width.

[0011] In some embodiments, the laser emission circuit further comprises a first gating module, and the light-emitting unit comprises a first laser and a second laser; wherein the first gating module comprises a control terminal, a first switch terminal, a second switch terminal and a third switch terminal, the laser comprises a positive electrode and a negative electrode, the control terminal is connected with the processor, the first switch terminal is connected with the first terminal of the energy storage capacitor, the second switch terminal is connected with the positive electrode of the first laser, the third switch terminal is connected with the positive electrode of the second laser, the negative electrode of the first laser is grounded, and the negative electrode of the second laser is grounded; the processor is further configured to control the first switch terminal and the second switch terminal to be conductive; or the processor is further configured to control the first switch terminal and the third switch terminal to be conductive. The processor can realize addressing of the laser based on the gating module, and then control one of the lasers to emit laser. In addition, the processor can also detect the working state of different lasers one by one based on the gating module.

[0012] In some embodiments, the laser emission circuit further comprises a first gating module and a second gating module, the light emitting unit comprises a first laser, a second laser, a third laser and a fourth laser; wherein the gating module comprises a control end, a first switch end, a second switch end and a third switch end, the laser comprises a positive electrode and a negative electrode, the control end of the first gating module is connected with the processor, the first switch end of the first gating module is connected with the first end of the energy storage capacitor, the second switch end of the first gating module is connected with the positive electrode of the first laser, the second switch end of the first gating module is connected with the positive electrode of the second laser, the third switch end of the first gating module is connected with the positive electrode of the third laser, and the third switch end of the first gating module is connected with the positive electrode of the fourth laser; the control end of the second gating module is connected with the processor, the first switch end of the second gating module is grounded, the second switch end of the second gating module is connected with the negative electrode of the first laser, the second switch end of the second gating module is connected with the negative electrode of the third laser, the third switch end of the second gating module is connected with the negative electrode of the second laser, and the third switch end of the second gating module is connected with the negative electrode of the fourth laser; the processor is further used for controlling the first switch end of the first gating module and the second switch end of the first gating module to be conductive; or the processor is further used for controlling the first switch end of the first gating module and the third switch end of the first gating module to be conductive; or the processor is further used for controlling the first switch end of the second gating module and the second switch end of the second gating module to be conductive; or the processor is further used for controlling the first switch end of the second gating module and the third switch end of the second gating module to be conductive.

[0013] In some embodiments, the laser emission circuit further comprises a first resistance and a second resistance; wherein the first end of the first resistance is connected with the first end of the energy storage capacitor, the second end of the first resistance is connected with the first end of the second resistance, and the second end of the second resistance is grounded; the second end of the first resistance is connected with the non-inverting input end of the first voltage comparator, and the second end of the first resistance is connected with the non-inverting input end of the second voltage comparator.

[0014] In a second aspect, the embodiments of the present application disclose a circuit fault detection method, the circuit comprising a charging circuit, an energy storage capacitor, a discharging circuit and a light emitting unit, wherein the first end of the energy storage capacitor is connected with the charging circuit, the first end of the energy storage capacitor is connected with the light emitting unit, the first end of the energy storage capacitor is connected with the discharging circuit, and the second end of the energy storage capacitor is grounded, and the method comprises the following steps: obtaining a first comparison signal according to the voltage of the first end of the energy storage capacitor and a first preset voltage; obtaining a first pulse width according to the first comparison signal; comparing the first pulse width with a first preset pulse width, and obtaining state information of the circuit according to a comparison result.

[0015] In some embodiments, the state information of the circuit is obtained according to the comparison result, comprising: determining that the light emitting unit is in a fault state according to the first pulse width and the first preset pulse width, wherein the first pulse width is greater than the first preset pulse width.

[0016] In some embodiments, the method further comprises: obtaining a second comparison signal according to the voltage of the first end of the energy storage capacitor and a second preset voltage; obtaining a second pulse width according to the second comparison signal; and correspondingly, the state information of the circuit is obtained according to the comparison result, comprising: determining that the discharging circuit is in a fault state according to the second pulse width and a second preset pulse width, wherein the second pulse width is greater than the second preset pulse width, and the comparison result is that the first pulse width is equal to the first preset pulse width.

[0017] In some embodiments, the method further comprises: determining that the charging circuit or the energy storage capacitor is in a fault state according to the first pulse width, wherein the first pulse width is equal to zero.

[0018] In a third aspect, the present application discloses a laser radar, comprising a transceiving optical module, a receiving unit and the laser emitting circuit.

[0019] In the laser emitting circuit disclosed by the present application, the voltage of the first pole plate of the energy storage capacitor is monitored based on the voltage comparator, and then the state information of the laser emitting circuit is obtained, so that the real-time monitoring of the working state of the laser emitting circuit can be realized, and the reliability of the laser emitting circuit is effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required by the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application.

[0021] Figure 1 is a structural schematic diagram of a laser emitting circuit disclosed by the embodiments of the present application;

[0022] Figure 2 is Figure 1 the voltage waveform of the first plate of the energy storage capacitor of the laser emission circuit in the normal working state;

[0023] Figure 3 a is Figure 1 the voltage waveform of the non-inverting input terminal of the voltage comparator of the laser emission circuit in the normal working state;

[0024] Figure 3 b is the waveform of the first comparison signal corresponding to Figure 3 a;

[0025] Figure 4 is a flow chart of a circuit fault detection method disclosed in the embodiments of the present application;

[0026] Figure 5 a is Figure 1 the voltage waveform of the non-inverting input terminal of the voltage comparator of the laser emission circuit in the fault state;

[0027] Figure 5 b is the waveform of the first comparison signal corresponding to Figure 5 a;

[0028] Figure 6 a is Figure 1 the voltage waveform of the non-inverting input terminal of the voltage comparator of the laser emission circuit in the fault state;

[0029] Figure 6 b is the waveform of the first comparison signal corresponding to Figure 6 a;

[0030] Figure 7 a is Figure 1 the voltage waveform of the non-inverting input terminal of the voltage comparator of the laser emission circuit in the fault state;

[0031] Figure 7 b is the waveform of the first comparison signal corresponding to Figure 7 a;

[0032] Figure 8 a is Figure 1 the voltage waveform of the non-inverting input terminal of the voltage comparator of the laser emission circuit in the normal state;

[0033] Figure 8 b is Figure 1 the voltage waveform of the non-inverting input terminal of the voltage comparator of the laser emission circuit in the fault state;

[0034] Figure 9 is Figure 1The voltage waveform diagram of the in-phase input end of the voltage comparator when the laser emission circuit is in a fault state;

[0035] Figure 10 The structure schematic diagram of the laser emission circuit disclosed by the embodiment of the present application is shown in FIG. 1.

[0036] Figure 11 The structure schematic diagram of the laser emission circuit disclosed by the embodiment of the present application is shown in FIG. 1.

[0037] The figure mark explanation: 101, the charging circuit; 102, the voltage comparison circuit; 103, the energy storage circuit; 104, the energy release circuit; 105, the light emitting unit; 301, the first gating module; 302, the second gating module. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical scheme and advantages of the present application more clear, the following will combine the drawings to make the embodiment of the present application further detailed description. When the following description relates to the drawings, the same numerals in different drawings represent the same or similar elements unless otherwise indicated. The implementation described in the following exemplary embodiments does not represent all the implementations consistent with the present application. On the contrary, they are only examples of the structure consistent with some aspects of the present application as detailed in the appended claims.

[0039] The present application discloses a laser emission circuit, which comprises a charging circuit, an energy storage circuit, an energy release circuit, a light emitting unit, a first voltage comparator and a processor. Wherein, the first end of the energy storage capacitor is connected with the charging circuit, the first end of the energy storage capacitor is connected with the light emitting unit, the first end of the energy storage capacitor is connected with the energy release circuit, the first end of the energy storage capacitor is connected with the in-phase input end of the first voltage comparator, the output end of the first voltage comparator is connected with the processor, and the second end of the energy storage capacitor is grounded; the first voltage comparator is used to obtain a first comparison signal according to the voltage of the in-phase input end of the first voltage comparator and the voltage of the inverse input end of the first voltage comparator; the processor is used to obtain a first pulse width according to the first comparison signal; the processor is further used to compare the first pulse width with a first preset pulse width and obtain the state information of the laser emission circuit according to the comparison result. Wherein, the state information of the laser emission circuit comprises that the laser emission circuit is in a normal working state, the charging circuit or the energy storage circuit is in a fault state, and the energy release circuit or the light emitting unit is in a fault state.

[0040] In one example, the laser emission circuit is as shown in FIG. 1. Figure 1As shown, the charging circuit 101 includes an inductor L1 and a first switch S1; the voltage comparison circuit 102 includes a first voltage comparator Comp1; the energy storage circuit 103 includes an energy storage capacitor C1; the energy releasing circuit 104 includes a first resistor R1 and a second switch S2; the light emitting unit 105 includes a laser LD and a third switch S3, wherein the laser LD includes a positive electrode and a negative electrode. Each switch includes a first switch terminal, a second switch terminal and a control terminal. The first terminal of the inductor L1 is connected to a power supply voltage V G , the second terminal of the inductor L1 is connected to the first switch terminal of the first switch S1, and the second switch terminal of the first switch S1 is grounded. The non-inverting input terminal of the first voltage comparator Comp1 is connected to the first plate of the energy storage capacitor C1, and the inverting input terminal of the first voltage comparator Comp1 is connected to a first preset voltage V th , the output terminal of the first voltage comparator Comp1 is connected to a processor, and the second plate of the energy storage capacitor C1 is grounded. The first terminal of the first resistor R1 is connected to the first plate of the energy storage capacitor C1, the second terminal of the first resistor R1 is connected to the first switch terminal of the second switch S2, and the second switch terminal of the second switch S2 is grounded. The positive electrode of the laser LD is connected to the first plate of the energy storage capacitor C1, the negative electrode of the laser LD is connected to the first switch terminal of the third switch S3, and the second switch terminal of the third switch S3 is grounded. The control terminals of the first switch S1, the second switch S2 and the third switch S3 are respectively connected to the processor. In another example, the inverting input terminal of the first voltage comparator Comp1 is connected to the second terminal of the inductor L1, and the non-inverting input terminal of the first voltage comparator Comp1 is connected to the first preset voltage V th , the output terminal of the first voltage comparator Comp1 is connected to the processor. In another example, the laser emission circuit further includes a rectifier diode D1, the anode of the rectifier diode D1 is connected to the second terminal of the inductor L1, and the cathode of the rectifier diode D1 is connected to the first plate of the energy storage capacitor C1. The rectifier diode D1 is used to control the direction of current. In another example, the power supply voltage V G and the first preset voltage V th are provided by at least one power supply, and the processor is used to control the power supply to change the power supply voltage V G and the first preset voltage V th .

[0041] In one embodiment, Figure 1 As shown, the laser emission circuit is in a normal working state, and one working cycle T0 includes a Q1 charging stage, a Q2 energy storage stage, a Q3 light emitting stage and a Q4 energy releasing stage. In one example, the voltage variation of the first plate of the energy storage capacitor C1 is as shown in Figure 2 .

[0042] Q1 charging stage: within time 0 to t1, the processor sends a rectangular pulse signal TX_EN1 to the control end of the first switch S1 to control the conduction of the first switch S1, and the second switch S2 and the third switch S3 are in the off state. Among them, the high level in the rectangular pulse signal TX_EN1 corresponds to the conduction between the first switch end and the second switch end of the first switch S1, and the low level in the rectangular pulse signal TX_EN1 corresponds to the open circuit between the first switch end and the second switch end of the first switch S1. When the first switch S1 is turned on, the processor controls the power supply to connect the first end of the inductor L1 to the power supply voltage V G , the power supply, the inductor L1, the first switch S1 and the ground form a charging circuit, and the power supply charges the inductor L1. By adjusting the duration of the high level in the rectangular pulse signal TX_EN1, the conduction time of the first switch S1 can be controlled, and then the charging time of the inductor L1 can be controlled, the energy size of the charging is changed, and the emission power of the laser LD is adjusted.

[0043] Q2 energy storage stage: within time t1 to t2, the first switch S1, the second switch S2 and the third switch S3 are in the off state, the processor controls the power supply to stop charging, the inductor L1, the energy storage capacitor C1 and the ground form an energy storage circuit, and the inductor L1 transfers the charged energy to the energy storage capacitor C1. The voltage V C1 of the first plate of the energy storage capacitor C1 is increased to the first energy storage voltage V S and remains unchanged.

[0044] Q3 light emitting stage: within time t2 to t3, the processor sends a rectangular pulse signal TX_EN3 to the control end of the third switch S3 to control the conduction of the third switch S3, and the first switch S1 and the second switch S2 are in the off state. Among them, the high level in the rectangular pulse signal TX_EN3 corresponds to the conduction of the third switch S3. When the third switch S3 is turned on, the energy storage capacitor C1, the laser LD, the third switch S3 and the ground form a light emitting circuit, and the energy storage capacitor C1 releases part of the stored energy to power the laser LD to emit laser. In the above light emitting stage, the voltage V C1 of the first plate of the energy storage capacitor C1 is decreased from the first energy storage voltage V S to the second energy storage voltage V L and remains unchanged.

[0045] Q4 energy release stage: t3 to t PIn the time period from t0 to t1, the processor sends a rectangular pulse signal TX_EN2 to the control end of the second switch S2 to control the second switch S2 to be turned on, and the first switch S1 and the third switch S3 are in the off state. In the rectangular pulse signal TX_EN2, the high level corresponds to the turn-on of the second switch S2. When the second switch S2 is turned on, the energy storage capacitor C1, the first resistor R1, the second switch S2 and the ground form a discharge circuit, the energy storage capacitor C1 releases the stored residual energy and supplies the first resistor R1, and the first resistor R1 consumes the energy in the form of heat until the voltage V C1 of the first plate of the energy storage capacitor C1 decreases to 0. In another example, the first resistor R1 can be replaced by a light-emitting diode, the anode of the light-emitting diode is connected with the first plate of the energy storage capacitor C1, and the cathode of the light-emitting diode is connected with the first switch end of the second switch S2. The light-emitting diode consumes the energy stored in the energy storage capacitor C1 in the form of light energy until the voltage V C1 of the first plate of the energy storage capacitor C1 decreases to 0.

[0046] In one example, Figure 1 When the laser emission circuit shown in the figure is in a normal working state, the voltage V IN1 at the non-inverting input end of the first voltage comparator Comp1 changes as shown in FIG. Figure 3 a, and the corresponding first comparison signal is as shown in FIG. Figure 3 b. In the figures, V IN1 (the voltage at circuit node A) is equal to V C1 (the voltage at circuit node B), the first preset voltage V th is greater than the second energy storage voltage V L , and is less than the first energy storage voltage V S , the second energy storage voltage V L is greater than 0. Figure 3 In FIG. a, in the time period from 0 to t4 and from t5 to t P , V IN1 is less than the first preset voltage V th , and the first comparison signal output is low. In the time period from t4 to t5, V IN1 is greater than the first preset voltage V th , and the first comparison signal output is high. The processor is used to count the high level duration of the first comparison signal in one working period T0 to obtain the first preset pulse width T th . As shown in FIG. Figure 3 b, the first preset pulse width T th corresponds to the high level duration of the first comparison signal in the time period from t4 to t5.

[0047] In some embodiments, the processor can be a Field-Programmable Gate Array (FPGA), a System on Chip (SoC), a Central Processor Unit (CPU), a Network Processor (NP), a digital signal processing circuit, a Micro Controller Unit (MCU), a Programmable Logic Device (PLD), an Application-Specific Integrated Circuit (ASIC), or any combination thereof, for implementing the relevant functions. The PLD can be a Complex Programmable Logic Device (CPLD), a Generic Array Logic (GAL), or other integrated chips.

[0048] In some embodiments, the switch can be an electronic switch formed by a combination of one or more of a bipolar junction transistor (BJT) or a metal-oxide-semiconductor field-effect transistor (MOSFET), such as an insulated gate bipolar transistor (IGBT) and a gallium nitride (GaN) switch tube. In one example, taking the first switch S1 as an example, the first switch S1 is a BJT triode, the base of the first switch S1 is connected to the processor as a control terminal, the collector of the first switch S1 is connected to the second end of the inductor L1, and the emitter of the first switch S1 is grounded. Or the emitter of the first switch S1 is connected to the second end of the inductor L1, and the collector of the first switch S1 is grounded. The processor sends a pulse signal, such as a rectangular pulse signal, to the control terminal of the first switch S1. When the rectangular pulse signal is high, the emitter and the collector of the first switch S1 are conductive. When the rectangular pulse signal is low, the emitter and the collector are disconnected, and the duration of the high level of the rectangular pulse signal is the conduction time of the first switch S1. In another example, the first switch S1 is a MOSFET, the gate of the first switch S1 is connected to the processor as a control terminal, the drain of the first switch S1 is connected to the second end of the inductor L1, and the source of the first switch S1 is grounded. Or the source of the first switch S1 is connected to the second end of the inductor L1, and the drain of the first switch S1 is grounded. The processor sends a pulse signal, such as a rectangular pulse signal, to the control terminal of the first switch S1. When the rectangular pulse signal is high, the source and the drain of the first switch S1 are conductive. When the rectangular pulse signal is low, the source and the drain are disconnected, and the duration of the high level of the rectangular pulse signal is the conduction time of the first switch S1.

[0049] In some embodiments, the laser LD can be a fiber laser, a vertical-cavity surface-emitting laser (VCSEL), or an edge-emitting laser (EEL).

[0050] Based on Figure 1 As shown in the laser emission circuit, the present application discloses a circuit fault detection method, as shown in the laser emission circuit, comprising: Figure 3 As shown in the laser emission circuit, the present application discloses a circuit fault detection method, as shown in the laser emission circuit, comprising:

[0051] S101, obtaining a first comparison signal according to the voltage of the first end of the energy storage capacitor and the first preset voltage.

[0052] In one example, a first comparison signal is obtained based on the voltage at the non-inverting input terminal of the first voltage comparator Comp1 and the voltage at the inverting input terminal of the first voltage comparator Comp1. When the voltage at the non-inverting input terminal is greater than the voltage at the inverting input terminal, the first comparison signal is output as a high level; when the voltage at the non-inverting input terminal is less than the voltage at the inverting input terminal, the first comparison signal is output as a low level.

[0053] S102: Obtain a first pulse width according to the first comparison signal.

[0054] In one example, the duration of the high level in the first comparison signal is counted to obtain the first pulse width T1.

[0055] S103: Compare the first pulse width with the first preset pulse width, and obtain circuit state information according to the comparison result.

[0056] In a working cycle T0, when the laser emission circuit fails, the voltage V C1 Fluctuations will occur, thereby affecting the voltage V at the non-inverting input of the first voltage comparator Comp1. IN1 , so that the first pulse width changes. Therefore, by comparing the first pulse width T1 with the first preset pulse width T th The size relationship of the circuit can be obtained based on the comparison results.

[0057] In one embodiment, according to the first pulse width and the first preset pulse width, it is determined that the light emitting unit 105 is in a fault state (the light emitting unit 105 does not emit laser light in the Q3 light emitting stage), wherein the first pulse width T1 is greater than the first preset pulse width T th In one example, if Figure 5 As shown in a, V IN1 During the Q2 energy storage phase (t1 to t2), the voltage increases to the first energy storage voltage V S , during the Q3 light-emitting phase (t2 to t3), the voltage does not decrease to the second energy storage voltage V L . V IN1 In the Q4 energy release phase (t3 to t P The waveform of the corresponding first comparison signal is as follows: Figure 5 As shown in b, the first pulse width T1 (time period from t4 to t6) is greater than the first preset pulse width T th (t4 to t5 period), and the first comparison signal is between t6 and t P In another example, the light emitting unit 105 and the energy releasing circuit 104 are both in a fault state (the light emitting unit 105 does not emit laser light in the Q3 light emitting stage, and the energy releasing circuit 104 does not consume power in the Q4 energy releasing stage). Figure 6 As shown in a, V IN1During the Q2 energy storage phase (t1 to t2), the voltage increases to the first energy storage voltage V S , V IN1 During the Q3 light-emitting phase (t2 to t3), the voltage does not decrease to the second energy storage voltage V L . V IN1 In the Q4 energy release phase (t3 to t P The waveform of the corresponding first comparison signal is as follows: Figure 5 As shown in b, the first pulse width T1 (t4 to t P time period) is greater than the first preset pulse width T th .

[0058] In one embodiment, a second comparison signal is obtained according to the voltage of the first terminal of the energy storage capacitor and the second preset voltage; a second pulse width T2 is obtained according to the second comparison signal; and correspondingly, circuit state information is obtained according to the comparison result, including: comparing the second pulse width T2 with the second preset pulse width T th2 , determine that the energy release circuit is in a fault state, wherein the second pulse width T2 is greater than the second preset pulse width T th2 The comparison result is that the first pulse width T1 is equal to the first preset pulse width T th In one example, when only the energy release circuit 104 fails, the voltage change of the non-inverting input terminal of the first voltage comparator Comp1 is as follows: Figure 7 As shown in a, since the laser emission circuit is in a normal state during the Q2 energy storage phase and the Q3 light emission phase, the first pulse width T1 is still equal to the first preset pulse width T th At this time, only the first preset pulse width T th To solve this problem, the voltage connected to the inverting input terminal of the first voltage comparator Comp1 is changed from the first preset voltage V th Adjust to the second preset voltage V th2 Among them, the second preset voltage V th2 Greater than zero and less than the second energy storage voltage V L The waveform of the first comparison signal within a working cycle T0 is re-monitored. According to the voltage of the non-inverting input terminal of the first voltage comparator Comp1 and the second preset voltage V th2 , obtain a second comparison signal. According to the second comparison signal, obtain a second pulse width T2. According to the second pulse width T2 and the second preset pulse width T th2 , it is determined that the energy release circuit 104 is in a fault state, wherein the second pulse width T2 ( Figure 8 As shown in b, t7 to t P time period) is greater than the second preset pulse width T th2 ( Figure 8 a, time period from t7 to t8).

[0059] In one embodiment, the circuit fault detection method further includes: determining that the charging circuit 101 or the energy storage circuit 103 is in a fault state (the charging circuit 101 is not charged in the Q1 charging phase or the energy storage capacitor C1 is not stored in the Q2 energy storage phase) based on the first pulse width T1, wherein the first pulse width T1 is equal to zero. Figure 9 As shown, in one working cycle T0, V C1 Close to 0, not reaching the first preset voltage V th The corresponding first comparison signal is output as a low level in one working cycle T0, and the first pulse width T1 is equal to 0.

[0060] In one embodiment, in order to monitor the working state of the laser emission circuit within a working cycle T0, the present application discloses the following Figure 10 The laser emission circuit shown. Figure 1 The laser emission circuit shown, Figure 10 A second voltage comparator Comp2 is added. The non-inverting input terminal of the first voltage comparator Comp1 is connected to the first plate of the energy storage capacitor C1, and the inverting input terminal of the first voltage comparator Comp1 is connected to the first preset voltage V th The non-inverting input terminal of the second voltage comparator Comp2 is connected to the first plate of the energy storage capacitor C1, and the inverting input terminal of the second voltage comparator Comp2 is connected to the second preset voltage V th2 The processor is connected to the output end of the first voltage comparator Comp1, and the processor is connected to the output end of the second voltage comparator Comp2. The second voltage comparator Comp2 is used to obtain a second comparison signal according to the voltage at the non-inverting input end of the second voltage comparator Comp2 and the voltage at the inverting input end of the second voltage comparator Comp2; the processor is also used to obtain a second pulse width T2 according to the second comparison signal; accordingly, the processor is used to obtain the state information of the laser emitting circuit according to the comparison result, including: the processor is used to obtain the state information of the laser emitting circuit according to the second pulse width T2 and the second preset pulse width T th2 , obtain the state information of the laser emission circuit, wherein the comparison result is that the first pulse width T1 is equal to the first preset pulse width T th .

[0061] based on Figure 10 The laser emission circuit shown in the figure, the present application discloses a circuit fault detection method, comprising:

[0062] S201 : Obtain a first comparison signal according to a voltage at a first terminal of an energy storage capacitor and a first preset voltage; obtain a second comparison signal according to the voltage at the first terminal of the energy storage capacitor and a second preset voltage.

[0063] S202 : Obtain a first pulse width according to the first comparison signal; and obtain a second pulse width according to the second comparison signal.

[0064] S203, comparing the first pulse width with the first preset pulse width to obtain a first comparison result; comparing the second pulse width with the second preset pulse width to obtain a second comparison result;

[0065] S204 : Obtain circuit status information according to the first comparison result and the second comparison result.

[0066] In one example, according to the first pulse width T1, the first preset pulse width T th , the second pulse width T2 and the second preset pulse width T th2 , determining that the energy release circuit 104 is in a fault state, wherein the first comparison result is that the first pulse width T1 is equal to the first preset pulse width T th The second comparison result is that the second pulse width T2 is greater than the second preset pulse width T th2 In another example, the fault detection method further includes: determining that the light emitting unit 105 is in a fault state according to a first comparison result, wherein the first comparison result is that the first pulse width T1 is greater than the first preset pulse width T th In another example, the fault detection method further includes: determining, based on the first pulse width T1, that the charging circuit 101 or the energy storage circuit 103 is in a fault state, wherein the first pulse width T1 is equal to 0.

[0067] In one embodiment, due to the voltage V of the first plate of the energy storage capacitor C1 C1 It is usually larger than the operating voltage range of the voltage comparator, so a voltage divider resistor is needed to control the voltage at the non-inverting input of the voltage comparator to prevent the voltage from being too large and causing the voltage comparator to fail. In an example, Figure 11 As shown, the laser emission circuit also includes a voltage divider circuit, which includes a second resistor R2 and a third resistor R3, wherein the first end of the second resistor R2 is connected to the first plate of the energy storage capacitor C1, the second end of the second resistor R2 is connected to the first end of the third resistor R3, the second end of the third resistor R3 is grounded, the non-inverting input end of the first voltage comparator Comp1 is connected to the second end of the second resistor R2, and the non-inverting input end of the second voltage comparator Comp2 is connected to the second end of the second resistor R2. The voltage V IN1 =(V C1 × R3) / (R2+R3), where R2 and R3 are the resistance values ​​of the second resistor R2 and the third resistor R3 respectively. Correspondingly, the first preset voltage V th Greater than (V L ×R3) / (R2+R3), less than (V S ×R3) / (R2+R3). The voltage V IN2 =(V C1(V th2 (V L (V

[0068] In one embodiment, the laser emission circuit further comprises a first gating module, the light emitting unit 105 comprises a first laser and a second laser, wherein the gating module is a multi-path analog switch or a multiplexer (MUX), comprising a control end, a first switch end, a second switch end and a third switch end. In one example, the control end of the first gating module is connected with the processor, the first switch end of the first gating module is connected with the first end of the energy storage capacitor, the second switch end of the first gating module is connected with the positive electrode of the first laser, and the third switch end of the first gating module is connected with the positive electrode of the second laser; the negative electrode of the first laser is grounded, and the negative electrode of the second laser is grounded. The processor is further configured to control conduction between the first switch end and the second switch end; or the processor is further configured to control conduction between the first switch end and the third switch end. The processor is configured to control conduction of one light emitting loop, so that the first laser or the second laser emits laser. In another example, the laser emission circuit comprises a first gating module and a second gating module, and the light emitting unit comprises a first laser, a second laser, a third laser and a fourth laser. Wherein the control end of the first gating module is connected with the processor, and the first switch end of the first gating module is connected with the first end of the energy storage capacitor. The second switch end of the first gating module is connected with the positive electrode of the first laser, and the second switch end of the first gating module is connected with the positive electrode of the second laser. The third switch end of the first gating module is connected with the positive electrode of the third laser, and the third switch end of the first gating module is connected with the positive electrode of the fourth laser. The control end of the second gating module is connected with the processor, and the first switch end of the second gating module is grounded. The second switch end of the second gating module is connected with the negative electrode of the first laser, and the second switch end of the second gating module is connected with the negative electrode of the third laser. The third switch end of the second gating module is connected with the negative electrode of the second laser, and the third switch end of the second gating module is connected with the negative electrode of the fourth laser. The processor is further configured to control conduction between the first switch end of the first gating module and the second switch end of the first gating module; or the processor is further configured to control conduction between the first switch end of the first gating module and the third switch end of the first gating module; the processor is further configured to control conduction between the first switch end of the second gating module and the second switch end of the second gating module or the processor is further configured to control conduction between the first switch end of the second gating module and the third switch end of the second gating module, so that one or more of the first laser, the second laser, the third laser or the fourth laser emits laser.

[0069] In one embodiment, as Figure 11As shown, the laser emission circuit includes a light-emitting unit 105, a first gating module 301, and a second gating module 302. The light-emitting unit 105 includes 4x5 lasers. The first gating module 301 includes a control terminal, a first switch terminal, a second switch terminal, a third switch terminal, a fourth switch terminal, and a fifth switch terminal. The control terminal of the first gating module 301 is connected to the processor. The first switch terminal of the first gating module 301 is connected to the first plate of the energy storage capacitor C1. The second switch terminal of the first gating module 301 is connected to the positive electrode of the five lasers in the first row. The third switch terminal of the first gating module 301 is connected to the positive electrode of the five lasers in the second row. The fourth switch terminal of the first gating module 301 is connected to the positive electrode of the five lasers in the third row. The fifth switch terminal of the first gating module 301 is connected to the positive electrode of the five lasers in the fourth row. The second gating module 302 includes a control terminal, a first switch terminal, a second switch terminal, a third switch terminal, a fourth switch terminal, a fifth switch terminal, and a sixth switch terminal. The first switch terminal of the second gating module 302 is grounded. The control terminal of the second gating module 302 is connected to the processor. The second switch terminal of the second gating module 302 is connected to the negative electrode of the four lasers in the first column. The third switch terminal of the second gating module 302 is connected to the negative electrode of the four lasers in the second column. The fourth switch terminal of the second gating module 302 is connected to the negative electrode of the four lasers in the third column. The fifth switch terminal of the second gating module 302 is connected to the negative electrode of the four lasers in the fourth column. The sixth switch terminal of the second gating module 302 is connected to the negative electrode of the four lasers in the fifth column. In one example, during the Q3 light-emitting stage, the processor is configured to send a rectangular pulse signal to the first gating module 301 and the second gating module 302, wherein the high level of the rectangular pulse signal corresponds to the conduction between the first switch terminal and the second switch terminal of the first gating module 301 and the conduction between the first switch terminal and the second switch terminal of the second gating module 302. The energy storage capacitor C1, the first gating module, one laser (first row first column), the second gating module, and the ground form a light-emitting loop, so that the laser in the first row and the first column emits laser. In another example, the processor is further configured to control the first gating module 301 and the second gating module 302, so that at least two lasers emit laser simultaneously. By controlling the first gating module 301 and the second gating module 302 through the processor, the addressing of the laser array can be realized to control the emission timing of different lasers. In addition, by controlling the first gating module 301 and the second gating module 302 through the processor, fault detection can be performed for a single laser in the laser array within one working period T0 of the laser emission circuit.

[0070] In one embodiment, the laser radar comprises the transceiving optical module, the receiving unit, and the laser emission circuit in any of the above embodiments. In one example, the laser radar is a mechanical laser radar or a semi-solid laser radar, comprising a brushless motor or a two-dimensional galvanometer, etc. The processor is further configured to control the brushless motor or the two-dimensional galvanometer to stop working according to the detected fault state of the laser emission circuit. In another example, the laser radar is a solid laser radar, and the laser emission circuit is, as shown in FIG. 3, a planar laser emission chip comprising a plurality of VCSELs, and the receiving unit is a planar receiving chip comprising a plurality of single photon avalanche diodes (SPADs), and the laser emitted by one VCSEL is received by one or more SPADs based on the transceiving optical module. The processor is configured to control the laser emitted by the one or more VCSELs by the first gating module 301 and the second gating module 302. Figure 11

[0071] In the description of the present application, it should be understood that, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used herein describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can represent the three cases of A alone, A and B together, and B alone. The character " / " generally represents an "or" relationship between the associated objects. The singular form "a", "an" is also intended to include the plural form, unless the context clearly indicates otherwise. When the terms "comprise" and / or "include" are used in the specification, it means that the features, elements and / or components are present, but do not exclude the presence or addition of one or more other features, elements, components and / or combinations thereof, i.e. any and all combinations of one or more related listed items are included. The ordinal numbers such as "first" and "second" cited in the embodiments of the present application are only for identification, and do not refer to other meanings such as specific order or imply relative importance.

[0072] ​In the present application, unless specifically stated and limited otherwise, the "on" or "under" of a first feature to a second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "on", "above" and "under" of a first feature to a second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The "under", "below" and "under" of a first feature to a second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature. The specific meanings of the above terms can be understood according to the specific circumstances by those of ordinary skill in the art. "One or more embodiments" used herein does not refer to the same embodiment, but combines specific features, structures or properties in any suitable manner. The above is only the preferred embodiment of the present application, and is not used to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A laser emitting circuit, characterized in that: It includes a charging circuit, an energy storage capacitor, an energy release circuit, a light emitting unit, a first voltage comparator and a processor; Wherein, the first end of the energy storage capacitor is connected to the charging circuit, the first end of the energy storage capacitor is connected to the light-emitting unit, the first end of the energy storage capacitor is connected to the energy release circuit, the first end of the energy storage capacitor is connected to the non-inverting input end of the first voltage comparator, the output end of the first voltage comparator is connected to the processor, and the second end of the energy storage capacitor is grounded; The first voltage comparator is configured to obtain a first comparison signal according to a voltage at a non-inverting input terminal of the first voltage comparator and a voltage at an inverting input terminal of the first voltage comparator; The processor is configured to obtain a first pulse width according to the first comparison signal; The processor is further configured to compare the first pulse width with a first preset pulse width, and obtain state information of the laser emitting circuit according to a result of the comparison.

2. The circuit according to claim 1, wherein: The laser emission circuit further includes a second voltage comparator; Wherein, the non-inverting input terminal of the second voltage comparator is connected to the first terminal of the energy storage capacitor, and the output terminal of the second voltage comparator is connected to the processor; The second voltage comparator is configured to obtain a second comparison signal according to a voltage at a non-inverting input terminal of the second voltage comparator and a voltage at an inverting input terminal of the second voltage comparator; The processor is further configured to obtain a second pulse width according to the second comparison signal; Correspondingly, the processor is used to obtain the status information of the laser emitting circuit based on the result of the comparison, including: the processor is used to obtain the status information of the laser emitting circuit based on the second pulse width and the second preset pulse width, wherein the result of the comparison is that the first pulse width is equal to the first preset pulse width.

3. The circuit according to claim 2, characterized in that The laser emission circuit further includes a first gating module, and the light emitting unit includes a first laser and a second laser; Wherein, the first gating module includes a control end, a first switch end, a second switch end and a third switch end, the laser includes a positive electrode and a negative electrode, the control end is connected to the processor, the first switch end is connected to the first end of the energy storage capacitor, the second switch end is connected to the positive electrode of the first laser, the third switch end is connected to the positive electrode of the second laser, the negative electrode of the first laser is grounded, and the negative electrode of the second laser is grounded; The processor is further configured to control conduction between the first switch terminal and the second switch terminal; or The processor is further configured to control conduction between the first switch terminal and the third switch terminal.

4. The circuit according to claim 2, characterized in that The laser emission circuit further comprises a first gating module and a second gating module, and the light emitting unit comprises a first laser, a second laser, a third laser and a fourth laser; Wherein, the gating module includes a control end, a first switch end, a second switch end and a third switch end, the laser includes a positive electrode and a negative electrode, the control end of the first gating module is connected to the processor, the first switch end of the first gating module is connected to the first end of the energy storage capacitor, the second switch end of the first gating module is connected to the positive electrode of the first laser, the second switch end of the first gating module is connected to the positive electrode of the second laser, the third switch end of the first gating module is connected to the positive electrode of the third laser, and the third switch end of the first gating module is connected to the positive electrode of the fourth laser; The control end of the second gating module is connected to the processor, the first switch end of the second gating module is grounded, the second switch end of the second gating module is connected to the cathode of the first laser, the second switch end of the second gating module is connected to the cathode of the third laser, the third switch end of the second gating module is connected to the cathode of the second laser, and the third switch end of the second gating module is connected to the cathode of the fourth laser; The processor is further configured to control conduction between the first switch terminal of the first gating module and the second switch terminal of the first gating module; or The processor is further configured to control conduction between the first switch terminal of the first gating module and the third switch terminal of the first gating module; or The processor is further configured to control conduction between the first switch terminal of the second gating module and the second switch terminal of the second gating module; or The processor is further configured to control conduction between the first switch terminal of the second gating module and the third switch terminal of the second gating module.

5. The circuit according to claim 2, characterized in that The laser emission circuit further includes a first resistor and a second resistor; Wherein, the first end of the first resistor is connected to the first end of the energy storage capacitor, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is grounded; The second end of the first resistor is connected to the non-inverting input end of the first voltage comparator, and the second end of the first resistor is connected to the non-inverting input end of the second voltage comparator.

6. A circuit fault detection method, wherein the circuit includes a charging circuit, an energy storage capacitor, an energy release circuit and a light emitting unit, wherein: The first end of the energy storage capacitor is connected to the charging circuit, the first end of the energy storage capacitor is connected to the light-emitting unit, the first end of the energy storage capacitor is connected to the energy release circuit, and the second end of the energy storage capacitor is grounded. The method includes: Obtaining a first comparison signal according to the voltage of the first terminal of the energy storage capacitor and a first preset voltage; obtaining a first pulse width according to the first comparison signal; The first pulse width is compared with a first preset pulse width, and state information of the circuit is obtained according to a result of the comparison.

7. The method according to claim 6, characterized in that Obtaining the state information of the circuit according to the comparison result includes: According to the first pulse width and the first preset pulse width, it is determined that the light emitting unit is in a fault state, wherein the first pulse width is greater than the first preset pulse width.

8. The method according to claim 7, characterized in that The method further comprises: Obtaining a second comparison signal according to the voltage at the first terminal of the energy storage capacitor and a second preset voltage; obtaining a second pulse width according to the second comparison signal; Correspondingly, the status information of the circuit obtained according to the result of the comparison includes: determining that the energy release circuit is in a fault state according to the second pulse width and the second preset pulse width, wherein the second pulse width is greater than the second preset pulse width, and the result of the comparison is that the first pulse width is equal to the first preset pulse width.

9. The method according to claim 6, characterized in that The method further comprises: According to the first pulse width, it is determined that the charging circuit or the energy storage capacitor is in a fault state, wherein the first pulse width is equal to zero.

10. A laser radar, characterized in that: It comprises a transceiver optical module, a receiving unit and a laser emitting circuit as claimed in any one of claims 1 to 5.

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