WO2021213103A1 - Module de photodétection pour radar laser, radar laser et procédé de détection de lumière ambiante - Google Patents

Module de photodétection pour radar laser, radar laser et procédé de détection de lumière ambiante Download PDF

Info

Publication number
WO2021213103A1
WO2021213103A1 PCT/CN2021/082025 CN2021082025W WO2021213103A1 WO 2021213103 A1 WO2021213103 A1 WO 2021213103A1 CN 2021082025 W CN2021082025 W CN 2021082025W WO 2021213103 A1 WO2021213103 A1 WO 2021213103A1
Authority
WO
WIPO (PCT)
Prior art keywords
signal
voltage
triode
current
unit
Prior art date
Application number
PCT/CN2021/082025
Other languages
English (en)
Chinese (zh)
Inventor
刘建峰
向少卿
Original Assignee
上海禾赛科技有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 上海禾赛科技有限公司 filed Critical 上海禾赛科技有限公司
Publication of WO2021213103A1 publication Critical patent/WO2021213103A1/fr

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/483—Details of pulse systems
    • G01S7/486—Receivers
    • G01S7/487—Extracting wanted echo signals, e.g. pulse detection
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
    • G01S17/06—Systems determining position data of a target
    • G01S17/08—Systems determining position data of a target for measuring distance only
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/88—Lidar systems specially adapted for specific applications
    • G01S17/93—Lidar systems specially adapted for specific applications for anti-collision purposes

Definitions

  • This application relates to the field of laser detection, in particular to photoelectric detection modules for laser radar, laser radar and ambient light detection methods.
  • Lidar is usually used to detect information about external obstacles, such as the distance between the obstacle and the lidar, and the shape of the obstacle.
  • the lidar includes a transmitting module and a receiving module, and the receiving module includes a photoelectric detection module.
  • the photoelectric detection module usually receives the echo laser signal after the detection laser emitted by the transmitter module hits an obstacle.
  • the present application provides a photoelectric detection module for lidar, including: a photodetection unit, a signal conditioning unit, and a data processing unit; the output end of the photodetection unit is connected to the input end of the signal conditioning unit, The output end of the signal conditioning unit is connected to the input end of the data processing unit; the photodetection unit is used to sense the optical signal incident thereon, and convert the sensed optical signal into an electrical signal, wherein The optical signal incident on it includes the ambient light signal and the echo laser signal generated by the reflection of the laser beam after irradiating the object to be measured; the signal conditioning unit includes an ambient light detection subunit, and the ambient light detection subunit is used for The direct current signal in the electrical signal is detected and the direct current signal is quantified; wherein the direct current signal includes a direct current signal generated by a photodetection unit inducing an ambient light signal; the data processing unit is used to quantify the received The subsequent AC signal and the quantized DC signal are analyzed and processed, and the photode
  • an embodiment of the present application provides a lidar, which includes the photoelectric detection module for lidar described in the first aspect.
  • an embodiment of the present application provides an ambient light detection method, which is used in the photoelectric detection module for lidar described in the first aspect; the method includes: acquiring monotonically rising signals under the control of the same clock signal The reference voltage signal is compared with the count signal of monotonically increasing counting; the reference voltage signal is compared with the actual measured voltage signal output by the current-voltage conversion module; wherein, the current-voltage conversion module is used to convert the photoelectric detection module from the detected ambient light The generated direct current signal is converted into a measured voltage signal; at the moment when the reference voltage signal rises to the same time as the measured voltage signal, the count value corresponding to the count signal at that moment is determined as the target count value; The value determines the intensity of the ambient light of the lidar.
  • the photoelectric detection module for lidar, lidar, and ambient light detection method detect the intensity of the DC signal caused by the ambient light by arranging the ambient light detection subunit in the photoelectric detection module. Therefore, the brightness of the ambient light where the lidar is located can be inferred by detecting the magnitude of the DC signal, which is beneficial to adjust the corresponding parameters of the lidar.
  • FIG. 1 is a schematic structural diagram of a photoelectric detection module for lidar provided by an embodiment of the application
  • FIG. 2 is a schematic circuit structure diagram of an embodiment of a photoelectric detection module for lidar provided by an embodiment of the application;
  • FIG. 3 is a schematic circuit structure diagram of another embodiment of a photoelectric detection module for lidar provided by an embodiment of the application;
  • Fig. 4 is a timing diagram of a multi-channel environmental light detection scheme for a photoelectric detection module of a lidar
  • FIG. 5 is a schematic structural diagram of an implementation circuit of the photoelectric detection module for laser radar shown in FIG. 1 to FIG. 3;
  • FIG. 6 is a schematic flowchart of an embodiment of an ambient light detection method provided by an embodiment of the application.
  • ambient light will affect the detection of the receiving system.
  • the specific expression is that the ambient light forms a current on the photodetector that is proportional to the light intensity. This current value changes with the external light intensity.
  • the range may be from 0.9uA to 17uA (Avalanche Photodetection Unit, APD).
  • APD Automatic Photodetection Unit
  • the wave is a pulse current, and the peak value of the current varies greatly. It varies from a few uA to 1A.
  • the direct current in the photodetector will increase the shot noise (the shot noise of the photogenerated current), that is, the external ambient light will affect the signal noise of the detector. Compare.
  • Part of the prior art detects and quantifies the DC current into a digital signal, and requires the circuit to have two functions, one is the conversion of current to voltage, and the other is the quantization of voltage signals.
  • the commonly used technique in the circuit is to connect a detection resistor in series with the current input branch, and complete the detection of the current value by measuring the voltage difference between the two ends of the series resistor.
  • APD adjustment photodetection unit
  • the above circuit completes the conversion of current to voltage, and has the following two shortcomings.
  • One is that the conversion resistance cannot take a larger resistance value. If it is too large, the common mode rejection of the current will become worse, resulting in an increase in output deviation.
  • the current and transimpedance gain should not be too small, because it is of the same magnitude as the voltage noise, and a voltage that is too small cannot be effectively quantified. Therefore, to ensure effective quantization, further amplification needs to be added. Further amplification will cause the mismatch of the differential amplifier to be further amplified. Taking the smallest effective quantization value as an example, at least two additional stages of amplifiers are required.
  • this circuit for low current detection increases the complexity of the entire detection circuit; second, in order to meet better detection accuracy, the operational amplifier is required to have Good input offset voltage and DC of the measured current will not be shunted inside the detection circuit. No shunt needs to ensure that the equivalent resistance of the positive and negative terminals of the op amp is exactly the same, the proportional error is small and the input of the op amp is small enough, and the resistance needs to be increased.
  • the matching accuracy and the matching accuracy of the op amp input to the tube will greatly increase the area of the circuit and increase the cost.
  • the DC detection of the APD is carried out through the solution in this application.
  • the ramp voltage generating circuit By setting a preset ramp voltage generating circuit related to ambient light in the synchronous logic circuit, the ramp voltage generating circuit generates a preset ramp voltage generation circuit during each ambient light detection time period.
  • a voltage signal Vramp that varies linearly from the minimum voltage value (for example, 0V) to the preset maximum voltage value.
  • the current-voltage converter outputs the measured voltage value output by the photodetection module according to the measured ambient light intensity. Compare the measured voltage value with Vramp, and determine the actual voltage value corresponding to the obtained ambient light through the comparison result. In this way, the direct current corresponding to the ambient light is determined, and then the intensity of the ambient light is determined.
  • the power consumption of the lidar can be adjusted according to the ambient light, and the power consumption and system complexity can be reduced, and the detection accuracy can be improved on the premise that the lidar can be used to obtain accurate signals of the detected object.
  • FIG. 1 shows a schematic structural diagram of a photoelectric detection module for lidar provided by an embodiment of the present application.
  • the photoelectric detection module for lidar includes: a photodetection unit 11, a signal conditioning unit 12 and a data processing unit 13.
  • the output terminal of the photodetection unit 11 is connected to the input terminal of the signal conditioning unit 12.
  • the output terminal of the signal conditioning unit 12 is connected to the input terminal of the data processing unit 13.
  • the photodetection unit 11 is used to sense the optical signal incident on it and convert the sensed optical signal into an electrical signal.
  • the optical signal incident on it includes the ambient light signal and the laser beam irradiated on the object to be measured. Echo laser signals generated by reflection, but electrical signals may include dark currents in addition to ambient light and echo signals.
  • the signal conditioning unit 12 includes an ambient light detection sub-unit 121 and an AC detection sub-unit 122.
  • the ambient light detection sub-unit 121 is used to detect a DC signal in the electrical signal, quantize the DC signal, and pass the quantization result. Reflects the intensity of ambient light.
  • the AC detection subunit 122 is used to amplify and quantify the AC signal in the electrical signal; wherein, the AC signal includes the AC signal generated by the photoelectric detection unit 11 inducing the echo signal, and the DC signal includes the photoelectric The detection unit 11 senses the DC signal generated by the ambient light signal.
  • the data processing unit 13 is used to analyze and process the received quantized AC signal and quantized DC signal. For example, the data processing unit converts the quantized DC voltage signal into a corresponding DC voltage amplitude.
  • the ambient light detection subunit is provided in the photodetection module to detect the intensity of the DC signal caused by the ambient light. Therefore, the brightness of the ambient light where the lidar is located can be inferred by detecting the magnitude of the DC signal, which is beneficial to adjust the corresponding parameters of the lidar.
  • the signal conditioning unit 12 further includes a bias voltage adjustment subunit 123.
  • the output terminal of the bias voltage adjustment subunit 123 is electrically connected to the anode of the photodetection unit 11; wherein, the bias voltage adjustment subunit 123 is used to adjust the bias voltage of the photodetection unit 11 to compensate for temperature and process deviations. The working current drift of the photodetection unit 11 is calibrated.
  • the bias voltage adjustment sub-unit 123 (DAC, digital-to-analog converter) outputs a voltage VB connected to the anode of the photodetection unit, and the cathode of the photodetection unit is connected to HV, so the voltage difference of the photodetection unit For HV-VB, the target quantity of the photodetection unit is current.
  • FIG. 2 shows a schematic circuit structure diagram of an embodiment of a photoelectric detection module for lidar provided by an embodiment of the present application.
  • the photodetection module may include a photodetection unit 11, a signal conditioning unit 12 and a data processing unit 13.
  • the photodetection unit 11 can be APD, Spad(s) or SiPM.
  • the signal conditioning unit 12 includes an ambient light detection subunit 121 and an AC signal detection subunit 122 as shown in FIG. 1.
  • the photoelectric detection module for lidar may further include a bias voltage adjustment subunit 123 and an AC detection subunit 122 as shown in FIG. 1.
  • the AC detection sub-unit 122 may include a capacitor 1221, an AC current signal amplifier 1222, and an analog-to-digital converter (ADC) 1223. Among them, the capacitor is used to isolate the DC signal.
  • ADC analog-to-digital converter
  • the ambient light detection sub-unit 121 includes a current-voltage conversion module.
  • the input end of the current-voltage conversion module is electrically connected with the anode of the photodetection unit.
  • the output terminal of the current-voltage conversion module is connected with the input terminal of the data processing unit.
  • the current-voltage conversion module includes: a synchronous logic circuit 1211, a ramp voltage generator 1212, a counter 1213, a current-voltage converter 1214, a voltage comparator 1215, and a latch 1216; wherein the output terminal of the photodetection unit 11 is connected to the current -The input terminal of the voltage converter 1214 is connected.
  • the signal output terminal of the synchronous logic circuit can output the same clock signal.
  • the signal output terminal of the synchronous logic circuit 1211 is connected to the input terminal of the ramp voltage generator 1212 and the input terminal of the counter 1213, respectively.
  • the clock signal output by the synchronous logic circuit 1211 controls the ramp voltage generator 1212 and the counter 1213 to work simultaneously.
  • the ramp voltage generator 1212 generates a monotonically rising voltage signal that changes with time under the control of the clock signal output from the counter 1211.
  • the counter 1213 under the control of the clock signal output from the synchronous logic circuit 1211, generates a count value that monotonically increases with time.
  • the inverting input terminal of the voltage comparator 1215 is connected to the output terminal of the current-voltage converter 1214; the non-inverting input terminal of the voltage comparator 1215 is connected to the output terminal of the ramp voltage generator 1212; the latch 1216 The control terminal of is connected to the output terminal of the voltage comparator 1215, and the signal input terminal of the latch 1216 is connected to the output terminal of the counter 1213.
  • the output terminal of the latch is connected to the data processing unit 13 as the output terminal of the current-voltage conversion module.
  • the ramp voltage generator 1212 Under the control of the signal output by the synchronous logic circuit 1211, the ramp voltage generator 1212 generates a ramp voltage signal (Vramp). In each detection period of the ambient light signal, the ramp voltage generator 1212 generates a linearly changing voltage signal from the preset minimum voltage value to the preset maximum voltage value.
  • the counter 1213 counts (Cout) according to a preset counting frequency.
  • the voltage comparator 1215 When the ramp voltage signal (Vramp) input from the non-inverting input terminal of the voltage comparator 1215 is greater than the voltage signal Vout output by the current-voltage converter, the voltage comparator outputs a control signal for controlling the operation of the latch; the latch The control terminal of the input terminal inputs the control signal, the latch latches the count value input from the signal input terminal at this time, and outputs the latched count value Lout. Lout is a digital code value that does not change over time. The above-mentioned digital code value latched by the latch is controlled by the output of the voltage comparator 1215 at a high level.
  • the voltage comparator 1215 is when the voltage Vramp output by the ramp voltage generator linearly rises from the preset minimum value to the preset maximum value, when the value of Vramp at a certain moment is just greater than (also can be regarded as equal to) the current ⁇
  • the voltage Vout is output by the voltage converter, a high-level signal is output.
  • the data processing unit determines the DC voltage value corresponding to the ambient light signal according to the count value.
  • the ramp voltage generator generates a ramp voltage signal that rises from a preset minimum voltage value to a preset maximum voltage value within a preset sampling time period; the counter increases from a preset counting frequency during the preset sampling time period. Preset the lowest value to the preset highest value count.
  • the above-mentioned preset maximum voltage value is related to the magnitude of the expected ambient light. The stronger the expected ambient light, the greater the maximum voltage value. In specific implementation, the highest voltage value may be slightly higher than or equal to the expected ambient light level.
  • the photodetector used for lidar may include multiple sampling time periods when working.
  • the synchronization signal generated by the synchronization logic circuit controls the ramp voltage generator and the counter to work at the same time.
  • the ramp voltage generator generates a ramp voltage signal from the preset lowest voltage to the preset highest voltage.
  • the count value Cout increases proportionally with time.
  • the current-voltage converter may be various existing converters that convert DC current into DC voltage.
  • the current-voltage converter can input the analog DC current signal produced by the photodetection unit by sensing ambient light, and convert the analog DC current signal into an analog DC voltage signal Vout.
  • the voltage signal Vout output by the current-voltage converter is input to the inverting input terminal of the voltage comparator.
  • the voltage signal Vramp output by the ramp voltage generator is input to the non-inverting input terminal of the voltage comparator. When the voltage signal Vout is greater than the voltage signal Vramp, the voltage comparator outputs a low level. When the voltage signal Vout is less than the voltage signal Vramp, the voltage comparator outputs a high level.
  • the latch When the voltage comparator 1215 outputs a low level, that is, the control terminal of the latch inputs a low level, the latch does not work, and the count value input to the latch 1216 is not latched by the latch.
  • the latch has no output.
  • the voltage comparator 1215 When the voltage comparator 1215 outputs a high level, the control terminal of the latch inputs a high level, and the latch starts to work. At this time, the count value input to the latch 1216 is latched by the latch.
  • the latch can output the count value input into it, and the output value is Lout.
  • Lout can be a binary number.
  • the data processing unit can convert the binary number into a corresponding DC voltage value, or into a DC current amount related to ambient light and dark current, so as to determine information such as the size or intensity of the ambient light.
  • the DC voltage Vout is compared with Vramp.
  • the comparator output voltage Vcmp reverses, and Vcmp triggers the Latch (latch) circuit to latch the Counter current count value output as Lout( Digital code value). Then the corresponding relationship between Vout and Lout at this time is
  • n is the preset counting digits of the counter.
  • VFS is the preset highest voltage value that the ramp voltage generator can generate.
  • I in (DC) is the direct current generated by the photodetector
  • Vout is the direct current voltage value output by the current-voltage converter
  • Rt is the transimpedance gain of the current-voltage converter
  • VFS is the voltage generated by the ramp voltage generator The highest preset voltage
  • Lout is the count value output by the latch
  • n is the preset count number of the above counter.
  • the comparator and Latch used achieve DC quantization.
  • This solution does not require high performance and power consumption.
  • the circuit structure is simple. It is triggered only once when Vramp is greater than Vout, and the ramp voltage is generated before the next measurement. The device, counter and latch are reset, and the number of flips is less, so the power consumption is lower and the system complexity is lower.
  • FIG. 3 shows a schematic circuit structure diagram of another embodiment of a photoelectric detection module for lidar provided by an embodiment of the present application.
  • the circuit structure diagram of the photoelectric detection module for laser radar shown in FIG. 3 includes a plurality of photodetection units 111, 112,... 11N. Each photoelectric detection unit corresponds to a channel. Each channel includes a photoelectric detection unit and a signal conditioning unit. As shown in Fig. 3, the photoelectric detection module for lidar includes signal conditioning units 101, 102, ..., 10N. N is the number of channels, which is an integer greater than 2.
  • Each signal conditioning unit may include an ambient light detection sub-unit, a bias voltage adjustment sub-unit, and an AC detection sub-unit.
  • the ambient light detection sub-unit includes a current-voltage conversion module.
  • the current-voltage conversion module includes a current-voltage converter 1214, a voltage comparator 1215, and a latch 1216;
  • the AC detection sub-unit may include a capacitor 1221, an amplifier 1222, and an analog-to-digital converter 1223.
  • the current-to-voltage conversion modules of the ambient light detection subunits 101, 102,... 10N of multiple channels can share a synchronous logic circuit, a ramp voltage generator, and a counter.
  • Multi-channel ambient light detection sub-units share synchronous logic circuits, ramp voltage generators, and counters, which can save chip area and reduce overall system complexity and power consumption.
  • the non-inverting input of the voltage comparator of the ambient light detection subunit of each of the multiple channels 101, 102, ... 10N is inputted by the same ramp voltage generator.
  • Ramp voltage signal; the input of the signal input terminal of the latch is the count value output by the same counter.
  • FIG. 4 shows a timing diagram of the environmental light detection scheme of the photoelectric detection module of the multi-channel laser radar.
  • Figure 4 shows the timing relationship of Cout, Vramp, Vcmp, and Lout with the quantization of 3 channels as an example.
  • the ramp voltage generator and counter are started, and the voltage Vramp generated by the ramp voltage generator starts from 0V and ramps up with a constant slope.
  • the counter count value (Cout) starts from 0 and increases by 1 on the rising edge of the clock (not shown, each X means the clock changes once).
  • Vramp exceeds the Vout1 voltage of channel 101, the comparator output Vcmp1 flips, and the latch locks the count value 3 of the counter at this moment in Lout1.
  • Vramp exceeds the Vout2 voltage of channel 102, the comparator output Vcmp2 flips, and the latch locks the counter value 80 at this moment in Lout2.
  • Vramp exceeds the Vout3 voltage of channel 103, the comparator output Vcmp3 flips, and the latch locks the count value 253 of the counter at this moment in Lout3.
  • the counter stops counting and the ramp voltage generator stops rising, waiting for the arrival of the next quantization command. Before the next quantization command comes, the latches of each channel are reset, and the counter and ramp voltage generator repeat the actions from t1 to t5.
  • the time t1 may be the time after the laser detection echo is received, or it may be the time before the laser detection echo is received.
  • the ambient light detection subunit can detect the ambient light signal after receiving the laser detection echo strength.
  • time t1, t2, t3, and t4 are all within the time window for measuring APD DC once
  • t1 represents the time when all channels start measurement
  • t5 represents the time when all channels end measurement
  • t2, t3, and t4 represent different channels ( Channel 1, channel 2, channel 3) corresponding to the end value of the measurement time
  • the difference between the end value of the measurement time and t1 is proportional to the value of the DC current on the photoelectric detection unit being detected (the length of time passed) Quantify the current amplitude).
  • the ramp voltage generating circuit by providing a preset ramp voltage generating circuit related to ambient light in the synchronous logic circuit, the ramp voltage generating circuit generates a preset minimum voltage value (for example, 0V) during each period of ambient light detection.
  • a linearly changing voltage signal Vramp to a preset maximum voltage value.
  • the current-voltage converter outputs the measured voltage value output by the photodetection module according to the measured ambient light intensity. Compare the measured voltage value with Vramp, and determine the actual voltage value corresponding to the obtained ambient light through the comparison result. In this way, the direct current corresponding to the ambient light is determined, and then the intensity of the ambient light is determined. Then adjust the relevant parameters of the photodetector according to the ambient light intensity. Therefore, the power consumption of the lidar can be adjusted according to the ambient light, and the power consumption of the lidar can be reduced on the premise that the laser radar can be used to obtain an accurate signal of the detected object.
  • the solution proposed in this application is to use a ramp voltage generator and a counter shared between channels, and a single channel through a comparator and a latch to reduce the overall system complexity and power. Consumption.
  • the comparators and latches used do not require high performance and power consumption.
  • the circuit structure is simple, and only triggers once when Vramp is greater than Vout.
  • the ramp voltage generator, counter and latch are reset before the next measurement starts. The number of flips is less, so the power consumption is lower and the system complexity is lower.
  • FIG. 5 shows a schematic structural diagram of an implementation circuit of the photoelectric detection module for lidar shown in FIGS. 1 to 3.
  • the photodetector is connected to the amplifier AMP of the AC signal detection subunit through a DC blocking capacitor to ensure that DC signals will not flow into the AC signal detection subunit.
  • the current-voltage converter of the bias voltage adjustment sub-unit (DAC) and the ambient light detection sub-unit is integrated.
  • the bias voltage adjusting subunit DAC includes a low voltage adjusting subunit LVDAC and a medium voltage amplifying subunit (medium voltage amplifier);
  • the medium voltage amplifying subunit includes: a direct current source I0, a first transistor M1 , A first operational amplifier A1, a first input resistor R1 and a first feedback resistor R2; wherein one end of the first input resistor R1 is connected to the ground, and the other end is connected to one end of the first feedback resistor R2;
  • the other end of the feedback resistor R2 is electrically connected to the anode of the photodetection unit APD1, the output end of the DC current source, and the drain of the first triode;
  • the cathode of the photodetection unit APD1 is electrically connected to the first high potential HV,
  • the anode of the photodetection unit APD1 is also electrically connected to the output terminal of the direct current source I0; the source of the first transistor M1 is connected to the ground wire,
  • the output terminal of the first operational amplifier is connected to the anode of the photodetection unit; the gate of the first transistor M1 is connected to the output terminal of the first operational amplifier A1; The other end of the input resistor is connected, and the inverting input end of the first operational amplifier is connected to the output end of the low voltage regulator subunit.
  • the current-voltage comparison module includes a second triode M2, a third triode M3, a fourth triode M4, a third resistor R4, a voltage comparator CMP and a latch circuit latch; wherein, the second The gate of the triode M2 is connected to the gate of the first triode M1, the source of the second triode M2 is connected to ground, and the drain of the second triode M2 is connected to the first triode.
  • the gate of the third triode M3 is connected to the gate of the fourth triode M4; the source of the third triode M3 is connected to the second high potential LV1, the third triode The gate of the tube M3 is connected to the drain of the third transistor M3;
  • the source of the fourth transistor M4 is connected to the third high potential LV2; the drain of the fourth transistor M4 is connected to one end of the third resistor R4, and is connected to the voltage comparator CMP Inverting input terminal connection;
  • the non-inverting input terminal of the voltage comparator CMP is connected to the output terminal of the ramp circuit generator, and the output terminal of the voltage comparator CMP is connected to the control terminal of the latch Latch;
  • the signal input end of the latch latch is connected to the output end of the counter, the output end of the latch latch is connected to a data processing unit, and the data processing unit is based on the output end of the latch latch. Determining the direct current voltage corresponding to the direct current;
  • the other end of the third resistor R4 is connected to the ground wire.
  • the ambient light detection subunit of the photoelectric detection module used for the lidar further includes a current compensation module (current compensation); wherein the current compensation module is electrically connected to the bias voltage adjustment subunit and the current-voltage conversion module. connect.
  • the current compensation module includes a second operational amplifier A2, a fifth triode M5, a sixth triode M6, a seventh triode M7, an eighth triode M8, and a ninth triode M9; among them,
  • the non-inverting input terminal of the second operational amplifier A2 is connected to the inverting input terminal of the first operational amplifier A1; the inverting input terminal of the second operational amplifier A2 is connected to the source of the fifth triode and One end of the fourth resistor R3 is electrically connected; the output end of the second operational amplifier A2 is connected to the gate of the fifth transistor M5;
  • the other end of the fourth resistor R3 is connected to the ground wire;
  • the drain of the fifth transistor M5 is electrically connected to the gate and the drain of the sixth transistor M6 and the gate of the seventh transistor M7;
  • the source of the sixth transistor M6 is electrically connected to the fourth high potential LV3; the gate of the sixth transistor M6 is connected to the gate of the seventh transistor M7;
  • the source of the seventh triode M7 is electrically connected to the fifth high potential LV4; the drain of the seventh triode M7 is electrically connected to the drain of the eighth triode M8;
  • the source of the eighth triode M8 is connected to the ground, and the gate is electrically connected to the gate of the ninth triode M9; the drain of the eighth triode M8 is connected to the 83rd
  • the grid of the pole tube M8 is electrically connected;
  • the source of the ninth transistor M9 is connected to the ground, and the drain is electrically connected to the drain of the fourth transistor M4.
  • DAC output voltage range is 0 ⁇ M(V), M>0.
  • the voltage output by the DAC is used to adjust the bias voltage of the photodetector.
  • DAC is composed of two parts of circuits, one is LVDAC (low voltage DAC), and the other is MV amplifier (medium voltage amplifier).
  • the MV amplifier includes A1, R1, R2, I0, and M1.
  • A1 is an operational amplifier.
  • R1 and R2 are input resistance and feedback resistance, respectively.
  • I0 is a direct current source.
  • M1 is the output NMOS.
  • the gain of the MV amplifier is (1+R2/R1).
  • the open loop impedance of the MV amplifier is the resistance ro of the M1 tube in parallel with the output impedance of the current source I0, which is approximately ro.
  • the IV Converter circuit that is, the current-voltage converter, consists of two parts. One is a resistive load current mirror circuit composed of M2, M3, M4, and R4. The second is a constant current compensation circuit (Current Compensation) with groups A2, R3, M5, M6, M7, M8, and M9.
  • the direct current generated by the photodetector is I in (DC)
  • the direct current flowing through M1 is I0+I in (DC)
  • the gates of M1 and M2 are connected, and the two form a current mirror circuit
  • M3 And M4 also constitute a current mirror, continue to mirror the current of M2 to M4, assuming that the proportional relationship between the working current of M1 and M2 is p1, and the proportional relationship between the working current of M3 and M4 is p2, then the current I4 of M4 is
  • I4 is the working current of M4
  • I3 is the working current of M3
  • I1 is the working current of M1
  • I in (DC) is the direct current generated by the photodetector
  • I0 is the current generated by the direct current source.
  • the current of M4 forms a voltage on R4.
  • the output voltage Vout of the current-voltage converter I-V Converter
  • R4 represents the resistance value of resistor R4.
  • Vout is proportional to I in (DC) and has a DC voltage term related to I0.
  • Vdac is the output voltage of the voltage regulation unit
  • I0' represents the direct current component that has nothing to do with the Vdac voltage
  • ⁇ is the pre-determined proportional coefficient
  • I9 is the working current of the ninth transistor M9;
  • R4 represents the resistance value of the resistor R4;
  • Vlvdac is the output voltage of the low voltage DAC (LVDAC);
  • R3 represents the resistance value of the resistor R3.
  • Vout output is approximately independent of the Vdac voltage.
  • the requirement for the resistance ratio is not high.
  • a smaller ratio can be selected to ensure that the image error is small, and a larger R4 resistance value can be selected to ensure sufficient transimpedance gain.
  • the implementation circuit of the photoelectric detection module for lidar adopts the current mirror method to realize the conversion of the DC current converted by the ambient light into the DC voltage by the photoelectric detection unit, and uses the current mirror method to indirectly detect the conversion environment of the photodetection unit The direct current obtained by the light does not change the direct current working state of the photodetection unit.
  • a current compensation module is used to compensate the non-linearity of the current mirror caused by the output voltage of the bias adjustment subunit, and improve the DC detection accuracy of the photodetection unit.
  • An embodiment of the present application also provides a lidar.
  • the lidar includes the photoelectric detection module for lidar provided by the embodiment shown in one of FIGS. 1 to 3.
  • FIG. 6 shows an ambient light detection method used in the photoelectric detection module for lidar provided by the embodiment shown in one of FIGS. 1 to 4.
  • the ambient light detection method includes the following steps:
  • Step 601 Obtain a monotonically increasing reference voltage signal and a monotonically increasing counting signal under the control of the same clock signal, and the reference voltage signal monotonically increasing between a preset minimum voltage value and a preset maximum voltage value.
  • Step 602 Compare the reference voltage signal with the measured voltage signal output by the current-voltage conversion module; wherein the current-voltage conversion module is used to convert the DC current signal generated by the photoelectric detection module from the detected ambient light into a measured voltage signal.
  • Step 603 At the moment when the reference voltage signal rises to the same time as the actual measured voltage signal, the count value corresponding to the count signal at that moment is determined as the target count value.
  • Step 604 Determine the intensity of the ambient light of the lidar according to the target count value.
  • the data processing unit can determine the magnitude of the direct current corresponding to the ambient light through the above-mentioned count value, and then determine the magnitude of the ambient light.
  • each sampling period for example, the same synchronous clock signal output by the synchronous logic unit is used to control the ramp voltage generator to work synchronously with the counter.
  • the analog voltage signal output by the current-voltage conversion module can be input to the inverting input terminal of the voltage comparator; the ramp voltage signal output from the output terminal of the ramp voltage generator can be input to the non-inverting input terminal of the comparator.
  • the analog voltage signal has a preset relationship with the current signal generated by the photodetection module inducing ambient light.
  • the voltage comparator When the ramp voltage signal rises to the analog voltage signal, the voltage comparator outputs a control signal to control the operation of the latch, and the latch latches the current corresponding count value of the counter input from the input terminal , And output the latched count value to the data processing unit.
  • step 601 to step 604 reference may be made to the description part of the embodiment shown in FIG. 2 and FIG. 3, which will not be repeated here.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Electromagnetism (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Optical Radar Systems And Details Thereof (AREA)

Abstract

Module de photodétection pour un radar laser, radar laser et procédé de détection de lumière ambiante. Le module de photodétection pour un radar laser comprend une unité de photodétection (11), une unité de conditionnement de signal (12) et une unité de traitement de données (13). Une extrémité de sortie de l'unité de photodétection (11) est connectée à une extrémité d'entrée de l'unité de conditionnement de signal (12). Une extrémité de sortie de l'unité de conditionnement de signal (12) est connectée à une extrémité d'entrée de l'unité de traitement de données (13). L'unité de photodétection (11) est utilisée pour détecter un signal optique incident sur cette dernière, et convertir le signal optique détecté en un signal électrique. L'unité de conditionnement de signal (12) comprend une sous-unité de détection de lumière ambiante (121). La sous-unité de détection de lumière ambiante (121) est utilisée pour détecter un signal de courant continu dans le signal électrique, et quantifier le signal de courant continu. L'unité de traitement de données (13) est utilisée pour analyser le signal de courant continu quantifié reçu. La luminosité de la lumière ambiante là où se trouve le radar laser peut être déduite en fonction de l'amplitude du signal de courant continu détecté, de manière à régler un paramètre correspondant du radar laser.
PCT/CN2021/082025 2020-04-23 2021-03-22 Module de photodétection pour radar laser, radar laser et procédé de détection de lumière ambiante WO2021213103A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202010329779.7 2020-04-23
CN202010329779.7A CN113552556A (zh) 2020-04-23 2020-04-23 用于激光雷达的光电探测模块、激光雷达和环境光检测方法

Publications (1)

Publication Number Publication Date
WO2021213103A1 true WO2021213103A1 (fr) 2021-10-28

Family

ID=78129491

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/082025 WO2021213103A1 (fr) 2020-04-23 2021-03-22 Module de photodétection pour radar laser, radar laser et procédé de détection de lumière ambiante

Country Status (2)

Country Link
CN (1) CN113552556A (fr)
WO (1) WO2021213103A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115980708A (zh) * 2023-03-21 2023-04-18 北醒（北京）光子科技有限公司 一种激光雷达的强光保护系统及方法

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115240579A (zh) * 2022-07-28 2022-10-25 京东方科技集团股份有限公司 环境光检测电路及检测方法、显示装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101236444A (zh) * 2007-01-30 2008-08-06 夏普株式会社 恒流源、斜坡电压发生电路、a/d转换器
US20080308716A1 (en) * 2006-07-19 2008-12-18 Byren Robert W Automatic photodiode biasing circuit
CN104969539A (zh) * 2013-02-27 2015-10-07 索尼公司 固体摄像器件、固体摄像器件驱动方法和电子设备
CN109839639A (zh) * 2019-02-27 2019-06-04 宁波舜宇车载光学技术有限公司 激光雷达和减少环境光干扰的激光雷达系统及其探测方法
CN110530515A (zh) * 2019-08-23 2019-12-03 上海禾赛光电科技有限公司 光电探测电路、激光雷达和控制方法
CN110940987A (zh) * 2018-09-20 2020-03-31 欧姆龙(上海)有限公司 用于光电检测系统的控制装置及方法、光电检测系统

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN206442567U (zh) * 2016-11-17 2017-08-25 深圳市光峰光电技术有限公司 一种光源亮度控制系统、光源系统及投影设备

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080308716A1 (en) * 2006-07-19 2008-12-18 Byren Robert W Automatic photodiode biasing circuit
CN101236444A (zh) * 2007-01-30 2008-08-06 夏普株式会社 恒流源、斜坡电压发生电路、a/d转换器
CN104969539A (zh) * 2013-02-27 2015-10-07 索尼公司 固体摄像器件、固体摄像器件驱动方法和电子设备
CN110940987A (zh) * 2018-09-20 2020-03-31 欧姆龙(上海)有限公司 用于光电检测系统的控制装置及方法、光电检测系统
CN109839639A (zh) * 2019-02-27 2019-06-04 宁波舜宇车载光学技术有限公司 激光雷达和减少环境光干扰的激光雷达系统及其探测方法
CN110530515A (zh) * 2019-08-23 2019-12-03 上海禾赛光电科技有限公司 光电探测电路、激光雷达和控制方法

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115980708A (zh) * 2023-03-21 2023-04-18 北醒（北京）光子科技有限公司 一种激光雷达的强光保护系统及方法
CN115980708B (zh) * 2023-03-21 2023-06-02 北醒（北京）光子科技有限公司 一种激光雷达的强光保护系统及方法

Also Published As

Publication number Publication date
CN113552556A (zh) 2021-10-26

Similar Documents

Publication Publication Date Title
WO2021213103A1 (fr) Module de photodétection pour radar laser, radar laser et procédé de détection de lumière ambiante
US20190141265A1 (en) Sample and hold based temporal contrast vision sensor
Zheng et al. A linear dynamic range receiver with timing discrimination for pulsed TOF imaging LADAR application
Ma et al. A 66-dB Linear Dynamic Range, 100-dB· $\Omega $ Transimpedance Gain TIA With High-Speed PDSH for LiDAR
Zheng et al. High sensitivity and wide dynamic range analog front-end circuits for pulsed TOF 4-D imaging LADAR receiver
WO2017016469A1 (fr) Circuit préamplificateur de mesure de photons
CN105548848A (zh) 用于测量击穿电压的装置、设备及方法
CN114114212B (zh) 脉冲信号的放大电路、回波信号接收系统及激光雷达
EP2936207B1 (fr) Circuits de lecture pour réseaux de photomultiplicateur multi-canaux
Zheng et al. A CMOS peak detect and hold circuit with auto-adjust charging current for NS-scale pulse ToF lidar application
CN107329133B (zh) 矫正型成像激光雷达接收器及信号处理方法
Zheng et al. A linear-array receiver AFE circuit embedded 8-to-1 multiplexer for direct ToF imaging LiDAR applications
US11320521B2 (en) Light sensor and sensing method thereof comprising a control circuit to operate diodes of plural sensing sub-pixels in a Geiger mode or in an avalanche linear mode according to intensity of ambient light
CN113093211A (zh) 一种驱动激光系统
CN110044479B (zh) 一种基于无时钟电流舵dac结构的硅光电倍增管
CN111337147A (zh) 一种像素级激光脉冲检测与测量电路
Maj et al. 23552-channel IC for single photon counting pixel detectors with 75 µm pitch, ENC of 89 e− rms, 19 e− rms offset spread and 3% rms gain spread
CN110389617A (zh) 电流减法电路
CN111273260B (zh) 一种脉冲激光测距系统晶体管型接收电路距离测量精度提高方法
CN219392540U (zh) 一种测距设备及其高压生成电路
RU2790350C1 (ru) Способ расширения диапазона измеряемых токов преобразователем аналоговых сигналов
CN113238204A (zh) 一种激光脉冲检测与测量输入级电路
CN218772021U (zh) 一种增益可控的放大电路及激光雷达
US20180091129A1 (en) Circuit sommateur
CN109471009B (zh) 偏流值检测电路和单光子探测器强光攻击检测电路、方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21792343

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21792343

Country of ref document: EP

Kind code of ref document: A1

122 Ep: pct application non-entry in european phase

Ref document number: 21792343

Country of ref document: EP

Kind code of ref document: A1