WO2022061656A1 - 激光测距装置 - Google Patents

激光测距装置 Download PDF

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Publication number
WO2022061656A1
WO2022061656A1 PCT/CN2020/117473 CN2020117473W WO2022061656A1 WO 2022061656 A1 WO2022061656 A1 WO 2022061656A1 CN 2020117473 W CN2020117473 W CN 2020117473W WO 2022061656 A1 WO2022061656 A1 WO 2022061656A1
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Prior art keywords
amplifier
laser
ranging device
buffer
laser ranging
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PCT/CN2020/117473
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English (en)
French (fr)
Inventor
马亮亮
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深圳市大疆创新科技有限公司
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Priority to PCT/CN2020/117473 priority Critical patent/WO2022061656A1/zh
Publication of WO2022061656A1 publication Critical patent/WO2022061656A1/zh

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
    • G01C3/00—Measuring distances in line of sight; Optical rangefinders
    • G01C3/02—Details
    • G01C3/06—Use of electric means to obtain final indication
    • G01C3/08—Use of electric radiation detectors

Definitions

  • the present application generally relates to the field of detection technology, and more particularly to a laser ranging device.
  • a sensor such as avalanche photodiode APD or PIN photodiode
  • the reflected signal also called pulsed light signal
  • the sensor also receives ambient light signals
  • the pulsed light signal appears as a high-frequency signal in the frequency domain, and the ambient light appears as a low-frequency signal, and the signal output by the sensor will be sent to the analog circuit for processing.
  • Ambient light needs to be filtered out during distance measurement to avoid interference to the measurement system.
  • the signal output by the sensor will be sent to the analog circuit for processing.
  • the amplitude of the output of the analog circuit is limited.
  • the ambient light will generate a common mode voltage on the circuit.
  • the amplitude of the pulsed light signal will be limited.
  • the amplitude of the output is different under the light of the light; on the other hand, if the analog circuit uses a multi-stage amplifier circuit, when the direct current (DC) coupling method is used, the common-mode voltage will be amplified together, resulting in the saturation of the second-stage op amp. For this reason, an alternating current (AC) coupling scheme is generally used in the laser measurement circuit. In this scheme, DC and low-frequency signals (ambient light) will be suppressed, but the waveform of the pulsed light will be distorted after passing through the AC coupling circuit, resulting in Performance is affected in some scenarios.
  • DC direct current
  • AC alternating current
  • the present application has been made in order to solve the above-mentioned problems.
  • the present application provides a laser ranging device.
  • the solution proposed by the present application will be briefly described below, and more details will be described in the specific embodiments in conjunction with the accompanying drawings later.
  • a laser ranging device includes a laser, a sensor, at least one amplifier, a buffer and a controlled switch, wherein: the laser is used to emit a laser pulse signal; The sensor is used to convert at least part of the reflected light pulse signal into an electrical signal, and the output end of the sensor is connected to the input end of the first stage amplifier in the at least one amplifier; the buffer includes a storage An energy element and a buffer element, two ends of the energy storage element are respectively connected to the input end and the output end of the buffer element, and the output end of the buffer element is connected to the input end of any stage of the at least one amplifier ; the controlled switch is connected to the output end of the last stage or intermediate stage amplifier in the at least one amplifier, and is connected to the input end of the buffer element; the controlled switch is connected every time the laser emits laser light The signal turns on before and turns off after a predetermined time, and the laser emits the laser signal after the controlled switch is turned off.
  • a laser ranging device includes a laser, a sensor, at least one amplifier, an energy storage element, a buffer and a controlled switch, wherein: the laser is used for emit laser pulse signal; the sensor is used for converting at least part of the reflected signal of the optical pulse signal into an electrical signal, and the output end of the sensor is connected to the input end of the first stage amplifier in the at least one amplifier; The energy storage element is connected to the input end of the buffer, and the output end of the buffer is connected to the input end of any stage of amplifiers in the at least one amplifier; the controlled switch is connected to the at least one amplifier The output terminal of the last stage or intermediate stage amplifier is connected to the energy storage element; the controlled switch is opened each time before the laser emits a laser signal, and is closed after a predetermined time, the controlled switch The laser emits a laser signal after switching off.
  • the laser ranging device performs common-mode voltage calibration before the laser emits a laser signal each time, stores the common-mode voltage on the energy storage element after the common-mode voltage calibration, keeps the feedback loop constant, and disconnects the feedback loop, The laser pulse is sent out again, so that the baseline does not change after the pulse signal passes, so it can suppress the ambient light without affecting the normal pulsed light signal.
  • Figure 1 shows a schematic diagram of the basic principle of laser ranging.
  • FIG. 2 shows a schematic diagram of the influence of ambient light in laser ranging.
  • FIG. 3 shows a schematic structural diagram of a conventional laser ranging device.
  • FIG. 4 shows a schematic structural diagram of another existing laser ranging device.
  • FIG. 5 shows a schematic structural diagram of yet another existing laser ranging device.
  • FIG. 6 shows a schematic structural diagram of a laser ranging device according to an embodiment of the present application.
  • FIG. 7 shows a waveform diagram of a laser signal and a switch signal in a laser ranging device according to an embodiment of the present application.
  • FIG. 8 shows a schematic structural diagram of a laser ranging device according to another embodiment of the present application.
  • FIG. 9 shows a schematic structural diagram of a laser ranging device according to still another embodiment of the present application.
  • FIG. 1 shows a schematic diagram of the basic principle of laser ranging.
  • the laser ranging device includes a laser Laser, a sensor APD, an amplifier TIA and an amplifier AMP, wherein the sensor APD, the amplifier TIA and the amplifier AMP form an analog circuit, and the positive input terminal of the amplifier TIA inputs the reference signal VREF.
  • the laser Laser sends out an optical pulse signal, and the signal of the optical pulse signal reflected by the object to be measured is received by the sensor APD, and the signal output by the sensor APD is amplified by the amplifier TIA and the amplifier AMP.
  • the signal output is used to calculate the distance to be measured.
  • the output waveform of the amplifier AMP should be as shown in the waveform diagram on the right side of Figure 1.
  • FIG. 2 shows a schematic diagram of the influence of ambient light in laser ranging.
  • the laser ranging device includes a laser Laser, a sensor APD, an amplifier TIA and an amplifier AMP, wherein the sensor APD, the amplifier TIA and the amplifier AMP form an analog circuit, and the positive input terminal of the amplifier TIA inputs the reference signal VREF.
  • the laser Laser sends out an optical pulse signal, and the signal of the optical pulse signal reflected by the object to be measured is received by the sensor APD.
  • the sensor APD also receives the ambient light signal.
  • the signal output by the sensor APD is amplified by the amplifier TIA and the amplifier AMP.
  • the waveform of the amplifier AMP output is shown in the waveform diagram on the right side of Figure 2.
  • the ambient light appears as DC in the time domain, and the DC signal will enter the amplifier TIA through the sensor APD and be amplified, resulting in the common mode voltage (DC voltage) and output amplitude of the amplifier AMP output waveform relative to the amplifier AMP shown in Figure 1.
  • the output waveform changes. In this case, the algorithm judgment will be affected. When the ambient light is strong, the analog circuit will be directly saturated and cannot work.
  • the speed of laser emission and reception scanning is getting faster and faster.
  • the ambient light received by the sensor may change rapidly (the received position is constantly changing. Scanning), the DC voltage brought by ambient light will also change rapidly, resulting in low-frequency common-mode voltage changes.
  • the analog circuit included in the general laser ranging device adopts AC coupling or uses a DC feedback loop to suppress ambient light.
  • Figures 3 and 4 show two types of analog circuits in the existing laser ranging device. AC coupling method.
  • the laser ranging device includes a laser Laser, a sensor APD, an amplifier TIA and an amplifier AMP, and a reference signal VREF is input to the positive input end of the amplifier TIA.
  • capacitor C and resistor R are included for AC coupling. Since capacitor C and resistor R are located at the output of amplifier TIA, they are AC coupled after the output signal of amplifier TIA.
  • the common mode voltage of the signal output by the amplifier TIA will change due to the influence of ambient light, but after AC coupling, the output signal of the amplifier AMP is available, and its waveform is shown in the waveform on the right side of Figure 3 shown, the common-mode voltage (also known as the common-mode level) is within the normal range.
  • the laser ranging device includes a laser Laser, a sensor APD, an amplifier TIA and an amplifier AMP, and a reference signal VREF is input to the positive input terminal of the amplifier TIA.
  • capacitor C2 and resistor R2 for AC coupling and capacitor C and resistor R are also included. Since the capacitor C2 and resistor R2 are located at the input of the amplifier TIA, the AC coupling is performed before the amplifier TIA. In the example shown in Figure 4, the effects of ambient light are suppressed before entering the amplifier TIA, and the output signal of the amplifier AMP is available with the waveform shown on the right side of Figure 4. However, in this way, when the sensor APD outputs a large current, there will be a serious back channel, and it will take a long time to return to normal. The recovery time depends on the resistance-capacitance (RC) constant.
  • RC resistance-capacitance
  • the pulsed laser signal also referred to as laser signal, pulsed light signal or pulsed signal
  • the capacitor is charged, and after the pulse passes, the capacitor is charged, and a back channel is generated in the process of releasing the charge.
  • This back channel will affect the response of the next pulse, causing the common mode voltage to change, and it will recover after a period of time.
  • the recovery time depends on the value of RC.
  • the received second pulse signal will be affected or even not detected. For the coaxial scheme, this effect cannot be ignored, the internal optical reflection will form the first echo, and the second echo of the near object will be significantly affected or even undetectable.
  • FIG. 5 shows another existing laser ranging device.
  • the laser ranging device includes a laser Laser, a sensor APD, an amplifier TIA, an amplifier AMP and an amplifier DCAMP, and a reference signal VREF is input to the positive input terminal of the amplifier TIA.
  • the amplifier DCAMP is used for feedback.
  • the amplifier DCAMP will output a reverse signal, so that the outputs of the amplifier TIA and the amplifier AMP will change until the output of the amplifier AMP changes.
  • the common-mode voltage reaches the design value, as shown in the waveform on the right side of Figure 5.
  • the amplifier TIA and amplifier AMP are the main signal link and have high bandwidth.
  • the amplifier DCAMP is a DC feedback loop amplifier, which is used to correct low-frequency ambient light signals. It is necessary to use a low-bandwidth feedback loop to ensure that the main amplifier loop does not oscillate. .
  • the laser ranging device shown in Figure 5 effectively solves the problem that the common mode voltage of the amplifier AMP output changes, and the feedback loop will keep the common mode voltage unchanged under strong ambient light; however, its impulse response is similar to AC coupling, After a pulse signal, the output of the amplifier AMP will cause the output of the amplifier DCAMP to respond; however, the bandwidth of the amplifier DCAMP is relatively low, and the time constant of the response is relatively slow. After the pulse signal, the baseline of the signal will change in the opposite direction and maintain a period of time. The time, the duration of which depends on the bandwidth of the amplifier DCAMP, causes the second pulse to be affected.
  • FIG. 6 shows a schematic structural diagram of a laser ranging device according to an embodiment of the present application.
  • the laser ranging device includes a laser Laser, a sensor APD, an amplifier TIA, an amplifier AMP, a buffer and a controlled switch, wherein the buffer includes a buffer element DCAMP and an energy storage element C.
  • the laser ranging device includes two amplifiers TIA and AMP, this is only an example. In practical applications, the laser ranging device may also include one amplifier or more than two amplifiers.
  • the amplifier that is, the laser ranging device may include at least one amplifier. The following description mainly takes the example of including two amplifiers.
  • the laser is used to emit laser pulse signals.
  • the sensor APD is connected under the voltage -HV, and converts at least part of the reflected signal of the optical pulse signal into an electrical signal, and the output end of the sensor APD is connected to the input end of the first stage amplifier in the at least one amplifier.
  • the output of the sensor APD is connected to the negative input terminal of the amplifier TIA, and the positive input terminal of the amplifier TIA is connected to the reference signal VREF1.
  • the buffer includes an energy storage element C and a buffer element DCAMP, two ends of the energy storage element C are respectively connected to the input end and the output end of the buffer element DCAMP, and the output end of the buffer element DCAMP is connected to the input of any stage of the amplifier in the at least one amplifier
  • the output of the buffer element DCAMP is connected to the input of the amplifier TIA, and may also be connected to the input of the amplifier AMP (this example will be described later in conjunction with FIG. 8).
  • a controlled switch is connected to the output of the last or intermediate stage of the at least one amplifier, in the example of FIG. 6 the controlled switch is connected to the output of the amplifier AMP and to the input of the buffer element DCAMP.
  • the controlled switch is turned on before each time the laser Laser emits a laser signal, and is turned off after a predetermined time, and the laser Laser emits a laser signal after the controlled switch is turned off.
  • the laser ranging device includes a controlled switch that can be controlled to open (ie, close) before the laser Laser emits a laser signal each time, that is, the amplifier TIA, the amplifier AMP and the buffer A feedback path is formed. At this time, the laser has not yet sent out a laser signal, and the sensor APD can only detect the ambient light signal. The ambient light signal is output to the forward input end of the buffer element DCAMP after passing through the amplifier TIA and the amplifier AMP.
  • the buffer element DCAMP will output a positive voltage to the negative input terminal of the amplifier TIA (the current is recorded as Ibias) , the amplifier TIA will output a reverse voltage signal to the amplifier AMP to reduce the output voltage of the amplifier AMP, thereby realizing negative feedback, that is, the buffer element DCAMP can correct the common mode voltage of the amplifier AMP to the set common mode voltage VREF.
  • the calibration voltage will be stored on the energy storage element C, the calibration voltage will keep the loop constant, and the amplifier AMP output will remain at the set common mode voltage VREF.
  • the controlled switch can be turned off (ie, disconnected), at which time the laser can emit a laser signal for laser ranging. Since the DC feedback loop has been disconnected, the output of the amplifier AMP The waveform will not affect the operation of the buffer element DCAMP, so that the baseline will not change after the pulse signal, and will not affect the subsequent pulses.
  • the common mode voltage since the common mode voltage is calibrated, the common mode voltage can also be kept constant under different ambient light. In general, the laser ranging device according to the embodiments of the present application can suppress ambient light without affecting the normal pulsed light signal.
  • the buffer may further include a resistor, as shown in FIG. 6 , one end of the resistor is connected to the controlled switch, and the other end of the resistor is connected to the positive input terminal of the buffer element DCAMP.
  • the energy storage element C may be a capacitor
  • the buffer element DCAMP may be a DC amplifier
  • the first stage amplifier namely the amplifier TIA
  • the sensor APD may be an avalanche photodiode.
  • the reference numbers of these elements in the drawings identify their type in this embodiment, it should be understood that in other embodiments, they may also be of other types.
  • the sensor may also be a PIN photodiode
  • the amplifier, buffer, and energy storage element may also be other amplifiers, buffers, and energy storage elements, respectively.
  • the laser ranging device may further include another resistor.
  • the output end of the buffer element DCAMP is connected to the input end of any stage of the at least one amplifier via the resistor.
  • the resistor is connected to the negative input terminal of the amplifier TIA, and the resistor can be used to divide the voltage.
  • the feedback loop is fed back via resistors. In other embodiments, the feedback loop can also feed back the calibrated voltage to any stage of amplifiers via triodes or transistors.
  • the controlled switch is turned on before the laser laser emits the laser signal (as shown in the waveform diagram of the laser signal and the switching signal in FIG. 7 ), and the buffer element DCAMP will at least be turned on when the controlled switch is turned on.
  • the common-mode voltage output by the last stage or intermediate stage amplifier (amplifier AMP) in an amplifier is calibrated and the calibrated voltage is stored on the energy storage element C, which will store the calibrated voltage when the controlled switch is turned off.
  • the controlled switch is turned off, and the laser emits a pulsed light signal,
  • the feedback loop has been disconnected, and the output waveform of the amplifier AMP will not affect the operation of the buffer element DCAMP, so that the baseline change will not be caused after the pulse signal passes, and the subsequent pulse will not be affected.
  • the laser ranging device includes a laser Laser, a sensor APD, an amplifier TIA, an amplifier AMP, a buffer and a controlled switch.
  • the buffer includes an energy storage element C and a buffer element DCAMP.
  • the laser is used to emit laser pulse signals.
  • the sensor APD is used to convert at least part of the reflected light pulse signal into an electrical signal.
  • the output end of the sensor APD is connected to the input end of the first stage amplifier in the at least one amplifier. In the example of FIG. 8 , the output end of the sensor APD is connected to to the input of the amplifier AMP.
  • the buffer includes an energy storage element C and a buffer element DCAMP, two ends of the energy storage element C are respectively connected to the input end and the output end of the buffer element DCAMP, and the output end of the buffer element DCAMP is connected to the input of any stage of the amplifier in the at least one amplifier terminal, in the example of FIG. 8, the output terminal of the buffer element DCAMP is connected to the input terminal of the amplifier AMP.
  • a controlled switch is connected to the output of the last or intermediate stage of the at least one amplifier, in the example of FIG. 8 the controlled switch is connected to the output of the amplifier AMP and to the input of the buffer element DCAMP.
  • the controlled switch is turned on before each time the laser Laser emits a laser signal, and is turned off after a predetermined time, and the laser Laser emits a laser signal after the controlled switch is turned off.
  • the laser ranging device shown in FIG. 8 is similar in structure to the laser ranging device shown in FIG. 6 , the difference is that the output of the buffer in the laser ranging device shown in FIG. 8
  • the terminal is not connected to the input terminal of the first-stage amplifier TIA, but is connected to the input terminal of the second-stage amplifier AMP; in addition, the laser ranging device shown in FIG. 8 may also include a resistor R1, which is connected to the output of the amplifier TIA. Between the terminal and the input terminal of the amplifier AMP, it is used for a voltage dividing function to adjust the input voltage of the amplifier AMP.
  • the position of the feedback point can be set at the input end of any stage of amplifier (that is, the output end of the buffer element can be connected to the input end of any stage of amplifier);
  • the distance device includes at least two amplifiers, namely a first-stage amplifier (such as amplifier TIA) and other amplifiers (such as amplifier AMP), the output of the buffer element is connected to the input of any one of the other amplifiers, and can be in any of the other amplifiers.
  • a resistor (such as a resistor R1 ) is set between the amplifier (such as amplifier AMP) and the previous stage amplifier (such as amplifier TIA) of any amplifier, so as to play a voltage dividing function.
  • the laser ranging device includes a controlled switch that can be controlled to open (ie, close) before the laser Laser emits a laser signal each time, that is, the amplifier TIA, the amplifier AMP and the buffer A feedback path is formed. At this time, the laser has not yet sent out a laser signal, and the sensor APD can only detect the ambient light signal. The ambient light signal is output to the forward input end of the buffer element DCAMP after passing through the amplifier TIA and the amplifier AMP.
  • the buffer element DCAMP will output a positive voltage to the negative input terminal of the amplifier TIA, and the amplifier TIA will output
  • the reverse voltage signal is sent to the amplifier AMP to reduce the output voltage of the amplifier AMP, thereby realizing negative feedback, that is, the buffer element DCAMP can correct the common mode voltage of the amplifier AMP to the set common mode voltage VREF.
  • the calibration voltage will be stored on the energy storage element C, the calibration voltage will keep the loop constant, and the amplifier AMP output will remain at the set common mode voltage VREF.
  • the controlled switch can be turned off (ie, disconnected), at which time the laser can emit a laser signal for laser ranging. Since the DC feedback loop has been disconnected, the output of the amplifier AMP The waveform will not affect the operation of the buffer element DCAMP, so that the baseline will not change after the pulse signal, and will not affect the subsequent pulses.
  • the common mode voltage since the common mode voltage is calibrated, the common mode voltage can also be kept constant under different ambient light. In general, the laser ranging device according to the embodiments of the present application can suppress ambient light without affecting the normal pulsed light signal.
  • the buffer may further include a resistor, as shown in FIG. 8 , one end of the resistor is connected to the controlled switch, and the other end of the resistor is connected to the negative input terminal of the buffer element DCAMP.
  • the energy storage element C may be a capacitor
  • the buffer element DCAMP may be a DC amplifier
  • the first stage amplifier namely the amplifier TIA
  • the sensor APD may be an avalanche photodiode.
  • the laser ranging device may further include a resistor R2, through which the output end of the buffer element DCAMP is connected to the input end of any stage of the at least one amplifier, in the example of FIG. 8 .
  • resistor R2 is connected to the positive input of amplifier AMP.
  • the feedback loop is fed back via resistors.
  • the feedback loop can also feed back the calibrated voltage to any stage of amplifiers via triodes or transistors.
  • the controlled switch is turned on before the laser laser emits the laser signal, and the buffer element DCAMP outputs the last stage or intermediate stage amplifier (amplifier AMP) in the at least one amplifier when the controlled switch is turned on.
  • the common-mode voltage is calibrated, and the calibrated voltage is stored on the energy storage element C, and the energy storage element C feeds back the calibrated voltage to any amplifier in the at least one amplifier when the controlled switch is turned off, so that it can be To achieve the calibration and maintenance of the common mode voltage; on the other hand, after the controlled switch is turned off, the laser emits a pulsed light signal, and the feedback loop has been disconnected, the output waveform of the amplifier AMP will not affect the work of the buffer element DCAMP, Achieving no baseline change after the pulse signal has passed and will not affect subsequent pulses.
  • the laser ranging device includes a laser Laser, a sensor APD, an amplifier TIA, an amplifier AMP, a buffer DCAMP, a controlled switch, and an energy storage element C.
  • the laser ranging device includes two amplifiers TIA and AMP, this is only an example, and in practical applications, the laser ranging device may also include one amplifier or more than two amplifiers
  • the amplifier that is, the laser ranging device may include at least one amplifier. The following description mainly takes the example of including two amplifiers.
  • the laser is used to emit laser pulse signals.
  • the sensor APD is connected under the voltage -HV, and converts at least part of the reflected light pulse signal into an electrical signal, and the output end of the sensor APD is connected to the input end of the first stage amplifier in the at least one amplifier.
  • the output of the sensor APD is connected to the negative input terminal of the amplifier TIA, and the positive input terminal of the amplifier TIA is connected to the reference signal VREF1.
  • the energy storage element C is connected to the input of the buffer DCAMP, and the output of the buffer DCAMP is connected to the input of any stage of the at least one amplifier.
  • the output of the buffer DCAMP is connected to Amplifier TIA input.
  • the controlled switch is connected to the output of the last or intermediate stage amplifier in the at least one amplifier, in the example of FIG.
  • the controlled switch is turned on before each time the laser Laser emits a laser signal, and is turned off after a predetermined time, and the laser Laser emits a laser signal after the controlled switch is turned off.
  • the laser ranging device includes a controlled switch that can be controlled to open (ie, close) before the laser Laser emits a laser signal each time, that is, the amplifier TIA, the amplifier AMP and the buffer DCAMP forms a feedback path. At this time, the laser has not yet sent out a laser signal, and the sensor APD can only detect the ambient light signal. The ambient light signal is output to the negative input end of the buffer DCAMP after passing through the amplifier TIA and the amplifier AMP.
  • the buffer DCAMP will output the positive voltage to the negative input terminal of the amplifier TIA (the current is recorded as Ibias) , the amplifier TIA will output a reverse voltage signal to the amplifier AMP to reduce the output voltage of the amplifier AMP, thereby realizing negative feedback, that is, the buffer DCAMP can correct the common mode voltage of the amplifier AMP to the set common mode voltage VREF.
  • the calibration voltage will be stored on the energy storage element C, the calibration voltage will keep the loop constant, and the amplifier AMP output will remain at the set common mode voltage VREF.
  • the controlled switch can be turned off (ie, disconnected), at which time the laser can emit a laser signal for laser ranging. Since the DC feedback loop has been disconnected, the output of the amplifier AMP The waveform will not affect the operation of the buffer DCAMP, so that the baseline will not change after the pulse signal, and will not affect the subsequent pulses.
  • the common mode voltage can also be kept constant under different ambient light. In general, the laser ranging device according to the embodiments of the present application can suppress ambient light without affecting the normal pulsed light signal.
  • the energy storage element C may be a capacitor, one end of the capacitor is connected to the input end of the controlled switch and the buffer DCAMP, and the other end of the capacitor is connected to the ground.
  • the buffer DCAMP may be a DC amplifier
  • the first stage amplifier namely the amplifier TIA
  • the sensor APD may be an avalanche photodiode.
  • the buffer DCAMP can also be used as a buffer element to form a buffer together with a resistor (not shown), and two ends of the resistor can be respectively connected to the input terminal and the output terminal of the buffer element.
  • the buffer DCAMP can also be used as a buffer element to form a buffer together with another resistor (not shown), one end of the resistor can be connected to the energy storage element C, and the other end of the resistor can be connected to the input terminal of the buffer element.
  • the laser ranging device may further include a resistor.
  • the output end of the buffer DCAMP is connected to the input end of any stage of amplifiers in the at least one amplifier via the resistor.
  • a resistor is connected to the negative input terminal of the amplifier TIA, and the resistor can be used to divide the voltage.
  • the feedback loop is fed back via resistors. In other embodiments, the feedback loop can also feed back the calibrated voltage of the triode or transistor to any stage of the at least one amplifier.
  • the position of the feedback point can be set at the input end of any stage amplifier (that is, the output end of the buffer element can be connected to to the input of any stage amplifier); if the laser ranging device includes at least two amplifiers, namely the first stage amplifier (such as amplifier TIA) and other amplifiers (such as amplifier AMP), the output end of the buffer DCAMP is connected to other amplifiers At the input end of any amplifier in the amplifier, a resistor can be set between the amplifier (eg, amplifier AMP) and the previous stage amplifier (eg, amplifier TIA) of any amplifier, so as to function as a voltage divider.
  • the controlled switch is turned on before the laser laser emits the laser signal, and the buffer DCAMP outputs the last stage or intermediate stage amplifier (amplifier AMP) in the at least one amplifier when the controlled switch is turned on.
  • the common-mode voltage is calibrated, and the calibrated voltage is stored on the energy storage element C, and the energy storage element C feeds back the calibrated voltage to any amplifier in the at least one amplifier when the controlled switch is turned off, so that it can be
  • the calibration and maintenance of the common mode voltage is realized; on the other hand, after a predetermined time (after the calibration of the common mode voltage is completed), the controlled switch is turned off, the laser Laser sends out a pulsed light signal, and the feedback loop has been disconnected, and the amplifier AMP
  • the output waveform will not affect the work of the buffer DCAMP, so that the baseline change will not be caused after the pulse signal passes, and the subsequent pulse will not be affected.
  • the laser ranging device performs common-mode voltage calibration before the laser emits a laser signal each time, stores the common-mode voltage on the energy storage element after the common-mode voltage calibration to keep the feedback loop constant, and disconnects the Open the feedback loop, and then send out the laser pulse, so that the baseline will not change after the pulse signal passes, so it can suppress the ambient light without affecting the normal pulse light signal.
  • the disclosed apparatus and method may be implemented in other manners.
  • the device embodiments described above are only illustrative.
  • the division of the units is only a logical function division. In actual implementation, there may be other division methods.
  • multiple units or components may be combined or May be integrated into another device, or some features may be omitted, or not implemented.
  • Various component embodiments of the present application may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof.
  • a microprocessor or a digital signal processor (DSP) may be used in practice to implement some or all functions of some modules according to the embodiments of the present application.
  • DSP digital signal processor
  • the present application can also be implemented as a program of apparatus (eg, computer programs and computer program products) for performing part or all of the methods described herein.
  • Such a program implementing the present application may be stored on a computer-readable storage medium, or may be in the form of one or more signals. Such signals may be downloaded from Internet sites, or provided on carrier signals, or in any other form.

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Abstract

一种激光测距装置，包括激光器、传感器、至少一个放大器、缓冲器和受控开关，其中：激光器用于出射激光脉冲信号；传感器用于将光脉冲信号经反射的至少部分信号转成电信号，传感器的输出端连接到至少一个放大器中第一级放大器的输入端；缓冲器包括储能元件和缓冲元件，储能元件的两端分别连接到缓冲元件的输入端和输出端，缓冲元件的输出端连接到至少一个放大器中任一级放大器的输入端；受控开关连接到最后一级或中间级放大器的输出端，并连接到缓冲元件的输入端；受控开关在每次激光器发出激光信号之前打开，并在预定时间之后关闭，受控开关关闭之后激光器发出激光信号,能够实现在抑制环境光的同时，不对正常的脉冲光信号造成影响。

Description

激光测距装置
说明书
技术领域
本申请总体上涉及探测技术领域，更具体地涉及一种激光测距装置。
背景技术
在激光测距领域，通常采用传感器(诸如雪崩光电二极管APD或PIN光电二极管)来接收激光器出射的光脉冲信号经反射的信号(也称为脉冲光信号)，同时传感器还会接收环境光信号，脉冲光信号在频域上表现为高频信号，环境光表现为低频信号，传感器输出的信号会一起送入模拟电路进行处理。
环境光在进行距离测量时需要滤除，避免对测量系统产生干扰。传感器输出的信号会一起送入模拟电路做处理，模拟电路的输出的幅值是有限的，环境光在电路上会产生共模电压，此时脉冲光信号的幅值将会受限，在不同的光照下输出的幅值不同；另一方面如果模拟电路使用了多级放大电路，在使用直流(DC)耦合方式时，共模电压将被一起放大，导致第二级运放饱和。为此，激光测量电路中一般使用交流(AC)耦合方案，在这种方案下直流和低频信号(环境光)将会被抑制掉，但是脉冲光在经过AC耦合电路后波形会发生畸变，导致在部分场景下性能受到影响。
发明内容
为了解决上述问题而提出了本申请。本申请提供一种激光测距装置。下面简要描述本申请提出的方案，更多细节将在后续结合附图在具体实施方式中加以描述。
根据本申请的一方面，提供了一种激光测距装置，所述激光测距装置包括激光器、传感器、至少一个放大器、缓冲器和受控开关，其中：所述激光器用于出射激光脉冲信号；所述传感器用于将所述光脉冲信号经反射的至少部分信号转成电信号，所述传感器的输出端连接到所述至少一个放大 器中第一级放大器的输入端；所述缓冲器包括储能元件和缓冲元件，所述储能元件的两端分别连接到所述缓冲元件的输入端和输出端，所述缓冲元件的输出端连接到所述至少一个放大器中任一级放大器的输入端；所述受控开关连接到所述至少一个放大器中的最后一级或中间级放大器的输出端，并连接到所述缓冲元件的输入端；所述受控开关在每次所述激光器发出激光信号之前打开，并在预定时间之后关闭，所述受控开关关闭之后所述激光器发出激光信号。
根据本申请的另一方面，提供了一种激光测距装置，所述激光测距装置包括激光器、传感器、至少一个放大器、储能元件、缓冲器和受控开关，其中：所述激光器用于出射激光脉冲信号；所述传感器用于将所述光脉冲信号经反射的至少部分信号转成电信号，所述传感器的输出端连接到所述至少一个放大器中第一级放大器的输入端；所述储能元件连接到所述缓冲器的输入端，所述缓冲器的输出端连接到所述至少一个放大器中任一级放大器的输入端；所述受控开关连接到所述至少一个放大器中的最后一级或中间级放大器的输出端，并连接到所述储能元件；所述受控开关在每次所述激光器发出激光信号之前打开，并在预定时间之后关闭，所述受控开关关闭之后所述激光器发出激光信号。
根据本申请实施例的激光测距装置通过每次在激光器发出激光信号之前进行共模电压校准，在共模电压校准后保存在储能元件上保持反馈环路恒定，并断开反馈环路，再发出激光脉冲，实现在脉冲信号过后不会导致基线变化，因而能够实现在抑制环境光的同时，不对正常的脉冲光信号造成影响。
附图说明
图1示出激光测距的基本原理的示意图。
图2示出激光测距中受环境光影响的示意图。
图3示出现有的一种激光测距装置的结构示意图。
图4示出现有的另一种激光测距装置的结构示意图。
图5示出现有的再一种激光测距装置的结构示意图。
图6示出根据本申请一个实施例的激光测距装置的结构示意图。
图7示出根据本申请实施例的激光测距装置中的激光信号和开关信号的波形图。
图8示出根据本申请另一个实施例的激光测距装置的结构示意图。
图9示出根据本申请再一个实施例的激光测距装置的结构示意图。
具体实施方式
为了使得本申请的目的、技术方案和优点更为明显，下面将参照附图详细描述根据本申请的示例实施例。显然，所描述的实施例仅仅是本申请的一部分实施例，而不是本申请的全部实施例，应理解，本申请不受这里描述的示例实施例的限制。基于本申请中描述的本申请实施例，本领域技术人员在没有付出创造性劳动的情况下所得到的所有其它实施例都应落入本申请的保护范围之内。
在下文的描述中，给出了大量具体的细节以便提供对本申请更为彻底的理解。然而，对于本领域技术人员而言显而易见的是，本申请可以无需一个或多个这些细节而得以实施。在其他的例子中，为了避免与本申请发生混淆，对于本领域公知的一些技术特征未进行描述。
应当理解的是，本申请能够以不同形式实施，而不应当解释为局限于这里提出的实施例。相反地，提供这些实施例将使公开彻底和完全，并且将本申请的范围完全地传递给本领域技术人员。
在此使用的术语的目的仅在于描述具体实施例并且不作为本申请的限制。在此使用时，单数形式的“一”、“一个”和“所述/该”也意图包括复数形式，除非上下文清楚指出另外的方式。还应明白术语“组成”和/或“包括”，当在该说明书中使用时，确定所述特征、整数、步骤、操作、元件和/或部件的存在，但不排除一个或更多其它的特征、整数、步骤、操作、元件、部件和/或组的存在或添加。在此使用时，术语“和/或”包括相关所列项目的任何及所有组合。
为了彻底理解本申请，将在下列的描述中提出详细的步骤以及详细的结构，以便阐释本申请提出的技术方案。本申请的较佳实施例详细描述如下，然而除了这些详细描述外，本申请还可以具有其他实施方式。
图1示出激光测距的基本原理的示意图。如图1所示，激光测距装置 中包括激光器Laser、传感器APD、放大器TIA和放大器AMP，其中传感器APD、放大器TIA和放大器AMP构成模拟电路，放大器TIA的正输入端输入参考信号VREF。其中，激光器Laser发出光脉冲信号，光脉冲信号经被测距物体反射后的信号被传感器APD接收，传感器APD输出的信号经放大器TIA和放大器AMP放大后的信号输出，以用于计算被测距物体距离激光测距装置的距离。在没有环境光(也称为背景光)干扰的情况下，放大器AMP输出的波形应该是如图1右侧的波形图所示的。
图2示出激光测距中受环境光影响的示意图。如图2所示，激光测距装置中包括激光器Laser、传感器APD、放大器TIA和放大器AMP，其中传感器APD、放大器TIA和放大器AMP构成模拟电路，放大器TIA的正输入端输入参考信号VREF。其中，激光器Laser发出光脉冲信号，光脉冲信号经被测距物体反射后的信号被传感器APD接收，传感器APD还同时接收环境光信号，传感器APD输出的信号经放大器TIA和放大器AMP放大后的信号输出，放大器AMP输出的波形如图2右侧的波形图所示的。环境光在时域上表现为直流，直流信号将会通过传感器APD进入放大器TIA并被放大，导致放大器AMP输出波形的共模电压(直流电压)和输出幅值相对于图1所示的放大器AMP输出的波形发生变化。这种情况下将会影响算法判断，在环境光较强的时候将会导致模拟电路直接饱和，无法工作。
此外，随着激光测距装置分辨率的不断提高，激光发射和接收扫描的速度越来越快，在遇到明暗交替的环境中，传感器收到的环境光可能快速变化(接收的位置在不断扫描)，环境光带来的直流电压也将会快速变化，产生低频的共模电压变化。
为了解决该问题，一般激光测距装置包括的模拟电路会采用AC耦合或者使用DC反馈环路，抑制环境光，图3和图4示出了现有的激光测距装置中模拟电路的两种交流耦合方式。
如图3所示，激光测距装置中包括激光器Laser、传感器APD、放大器TIA和放大器AMP，放大器TIA的正输入端输入参考信号VREF。此外，还包括用于进行交流耦合的电容器C和电阻器R。由于电容器C和电阻器R位于放大器TIA的输出端，因此是在放大器TIA的输出信号之后进行交 流耦合。在图3所示的示例中，受环境光影响，放大器TIA输出的信号共模电压会发生变化，但经过交流耦合之后，放大器AMP的输出信号可用，其波形如图3右侧的波形图所示的，共模电压(也称为共模电平)在正常范围内。
如图4所示，激光测距装置中包括激光器Laser、传感器APD、放大器TIA和放大器AMP，放大器TIA的正输入端输入参考信号VREF。此外，还包括用于进行交流耦合的电容器C2和电阻器R2、以及电容器C和电阻器R。由于电容器C2和电阻器R2位于放大器TIA的输入端，因此是在放大器TIA之前即进行交流耦合。在图4所示的示例中，环境光的影响在进入放大器TIA之前即被抑制，放大器AMP的输出信号可用，其波形如图4右侧的波形图所示的。但是，这种方式在传感器APD输出大电流时会有比较严重的回沟，需要很长时间才能恢复正常，恢复的时间取决于电阻电容(RC)常数。
如图3和图4所示的激光测距装置都会遇到一个本质的问题，即脉冲激光信号(也可简称为激光信号、脉冲光信号或脉冲信号)在经过交流耦合后会在交流耦合的电容上充电，脉冲过去后电容上带有电荷，在电荷被释放掉过程中产生一个回沟，这个回沟会影响下一次脉冲的响应，导致共模电压发生变化，经过一段时间收才会恢复正常，恢复时间取决于RC的取值。在恢复过程中，接收到的第二个脉冲信号将会受到影响，甚至探测不到。对于共轴方案这种影响是不可忽视的，内部的光学反射将会形成第一次回波，此时近处物体的第二次回波将会受到显著影响甚至无法被测到。
图5示出现有的另一种激光测距装置。如图5所示，激光测距装置中包括激光器Laser、传感器APD、放大器TIA、放大器AMP和放大器DCAMP，放大器TIA的正输入端输入参考信号VREF。在图5所示的示例中，使用放大器DCAMP进行反馈，在放大器AMP输出的共模电压发生变化时放大器DCAMP将会输出反向信号，使放大器TIA和放大器AMP的输出发生改变，直到放大器AMP的共模电压达到设计值，如图5右侧的波形图所示的。其中放大器TIA和放大器AMP为主信号链路，带宽较高，放大器DCAMP为DC反馈环路放大器，用来校正低频的环境光信号，需要使用低带宽的反馈环路保证主放大环路不发生震荡。
图5所示的激光测距装置有效解决了放大器AMP输出共模电压发生变化的问题，在强环境光下反馈环路将会保持共模电压不变；但是它的脉冲响应与AC耦合类似，在一个脉冲信号后放大器AMP的输出将会导致放大器DCAMP的输出产生响应；但是放大器DCAMP的带宽比较低，响应的时间常数比较慢，脉冲信号过后会导致信号的基线产生反方向的变化并维持一段时间，维持的这段时间取决于放大器DCAMP的带宽，导致第二个脉冲可能受到影响。
为了解决上述问题，本申请提供了一种激光测距装置，下面结合图6到图9来描述。图6示出了根据本申请一个实施例的激光测距装置的结构示意图。如图6所示，激光测距装置包括激光器Laser、传感器APD、放大器TIA、放大器AMP、缓冲器和受控开关，其中缓冲器包括缓冲元件DCAMP和储能元件C。此处，虽然在图6中示出了激光测距装置包括两个放大器TIA和放大器AMP，但这仅是示例性的，在实际应用中，激光测距装置也可以包括一个放大器或者两个以上的放大器，即激光测距装置可以包括至少一个放大器。下文中主要以包括两个放大器为例来描述。
其中，激光器Laser用于出射激光脉冲信号。传感器APD连接在电压-HV下，将光脉冲信号经反射的至少部分信号转成电信号，传感器APD的输出端连接到至少一个放大器中第一级放大器的输入端，在图6的示例中，传感器APD的输出连接到放大器TIA的负输入端，放大器TIA的正输入端连接参考信号VREF1。缓冲器包括储能元件C和缓冲元件DCAMP，储能元件C的两端分别连接到缓冲元件DCAMP的输入端和输出端，缓冲元件DCAMP的输出端连接到至少一个放大器中任一级放大器的输入端，在图6的示例中，缓冲元件DCAMP的输出端连接到放大器TIA的输入端，也可以连接到放大器AMP的输入端(该示例稍后结合图8来描述)。受控开关连接到至少一个放大器中的最后一级或中间级放大器的输出端，在图6的示例中，受控开关连接到放大器AMP的输出端，并连接到缓冲元件DCAMP的输入端。受控开关在每次激光器Laser发出激光信号之前打开，并在预定时间之后关闭，受控开关关闭之后激光器Laser发出激光信号。
在本申请的实施例中，激光测距装置包括受控开关，该受控开关可受控以在激光器Laser每次发出激光信号之前打开(即闭合)，也就是放大器 TIA、放大器AMP和缓冲器形成反馈通路，此时，激光器Laser尚未发出激光信号，传感器APD仅可以探测到环境光信号，该环境光信号经过放大器TIA和放大器AMP后输出至缓冲元件DCAMP的正向输入端。如果放大器AMP输出的共模电压大于设置共模电压VREF(即缓冲元件DCAMP的负向输入端的参考电压)，缓冲元件DCAMP将输出正向的电压给放大器TIA的负输入端(电流记为Ibias)，放大器TIA将会输出反向电压信号给放大器AMP，使放大器AMP的输出电压降低，从而实现负反馈，即缓冲元件DCAMP可以把放大器AMP的共模电压校正到设置共模电压VREF。在共模电压校准完成后，校准电压将保存在储能元件C上，校准电压将会保持环路恒定，放大器AMP输出保持在设置共模电压VREF。由于储能元件C与反馈网络结合在一起，因而储能元件C的电压比较稳定，开关的电荷注入影响比较小。此外，在共模电压校准完成后，受控开关可以关闭(即断开)，此时激光器Laser可以发出激光信号以进行激光测距，由于DC反馈环路已被断开，因此放大器AMP的输出波形将不会影响缓冲元件DCAMP的工作，实现在脉冲信号过后不会导致基线变化，不会对后续的脉冲产生影响。此外，由于经过了共模电压校准，因此也可实现共模电压在不同的环境光下保持不变。总体上，根据本申请实施例的激光测距装置可以实现在抑制环境光的同时，不对正常的脉冲光信号造成影响。
在本申请的实施例中，缓冲器还可以包括电阻器，如图6所示的，电阻器的一端连接到受控开关，另一端连接到缓冲元件DCAMP的正输入端。在本申请的实施例中，储能元件C可以为电容器，缓冲元件DCAMP可以为直流放大器，第一级放大器即放大器TIA可以为跨阻放大器，传感器APD可以为雪崩光电二极管。虽然在附图中这些元件的标号均标识了其在该实施例中的类型，但应理解，在其他实施例中，它们还可以是其他的类型。例如，传感器也可以为PIN光电二极管，放大器、缓冲器、储能元件也分别可以是其他的放大器、缓冲器、储能元件。
在本申请的实施例中，激光测距装置还可以包括另一电阻器，如图6所示的，缓冲元件DCAMP的输出端经由该电阻器连接到至少一个放大器中任一级放大器的输入端，在图6的示例中，该电阻器连接到放大器TIA的负输入端，该电阻器可以用于起到分压作用。在该实施例中，反馈环路 经由电阻器进行反馈。在其他实施例中，反馈环路也可经由三极管或晶体管校准后的电压反馈至任一级放大器。
总体上，在本申请的实施例中，受控开关在激光器Laser发出激光信号之前打开(如图7的激光信号和开关信号波形图所示的)，缓冲元件DCAMP在受控开关打开时将至少一个放大器中的最后一级或者中间级放大器(放大器AMP)输出的共模电压进行校准，并将校准后的电压存储在储能元件C上，储能元件C在受控开关关闭时将校准后的电压反馈至任一级放大器，从而可以实现共模电压的校准与保持；另一方面，在经过预定时间之后(共模电压完成校准后)，受控开关关闭，激光器Laser发出脉冲光信号，而反馈环路已被断开，放大器AMP的输出波形将不会影响缓冲元件DCAMP的工作，实现在脉冲信号过后不会导致基线变化，不会对后续的脉冲产生影响。
下面结合图8描述根据本申请另一个实施例的激光测距装置的结构示意图。如图8所示，激光测距装置包括激光器Laser、传感器APD、放大器TIA、放大器AMP、缓冲器和受控开关。其中，缓冲器包括储能元件C和缓冲元件DCAMP。其中，激光器Laser用于出射激光脉冲信号。传感器APD用于将光脉冲信号经反射的至少部分信号转成电信号，传感器APD的输出端连接到至少一个放大器中第一级放大器的输入端，在图8的示例中，传感器APD的输出连接到放大器AMP的输入端。缓冲器包括储能元件C和缓冲元件DCAMP，储能元件C的两端分别连接到缓冲元件DCAMP的输入端和输出端，缓冲元件DCAMP的输出端连接到至少一个放大器中任一级放大器的输入端，在图8的示例中，缓冲元件DCAMP的输出端连接到放大器AMP的输入端。受控开关连接到至少一个放大器中的最后一级或中间级放大器的输出端，在图8的示例中，受控开关连接到放大器AMP的输出端，并连接到缓冲元件DCAMP的输入端。受控开关在每次激光器Laser发出激光信号之前打开，并在预定时间之后关闭，受控开关关闭之后激光器Laser发出激光信号。
在本申请的实施例中，图8所示的激光测距装置与图6所示的激光测距装置结构类似，不同之处在于，图8所示的激光测距装置中的缓冲器的输出端连接的不是第一级放大器TIA的输入端，而是连接第二级放大器 AMP的输入端；此外，图8所示的激光测距装置还可以包括电阻器R1，其连接在放大器TIA的输出端与放大器AMP的输入端之间，用于起到分压作用，以调整放大器AMP的输入电压。因此，在根据本申请实施例的激光测距装置中，反馈点的位置可以设置在任一级放大器的输入端(即缓冲元件的输出端可以连接到任一级放大器的输入端)；如果激光测距装置包括至少两个放大器，即第一级放大器(如放大器TIA)和其他放大器(如放大器AMP)，在缓冲元件的输出端连接到其他放大器中任一放大器的输入端，可以在该任一放大器(如放大器AMP)与该任一放大器的前一级放大器(如放大器TIA)之间设置一个电阻器(诸如电阻器R1)，以起到分压作用。
在本申请的实施例中，激光测距装置包括受控开关，该受控开关可受控以在激光器Laser每次发出激光信号之前打开(即闭合)，也就是放大器TIA、放大器AMP和缓冲器形成反馈通路，此时，激光器Laser尚未发出激光信号，传感器APD仅可以探测到环境光信号，该环境光信号经过放大器TIA和放大器AMP后输出至缓冲元件DCAMP的正向输入端。如果放大器AMP输出的共模电压大于设置共模电压VREF(即缓冲元件DCAMP的负向输入端的参考电压)，缓冲元件DCAMP将输出正向的电压给放大器TIA的负输入端，放大器TIA将会输出反向电压信号给放大器AMP，使放大器AMP的输出电压降低，从而实现负反馈，即缓冲元件DCAMP可以把放大器AMP的共模电压校正到设置共模电压VREF。在共模电压校准完成后，校准电压将保存在储能元件C上，校准电压将会保持环路恒定，放大器AMP输出保持在设置共模电压VREF。由于储能元件C与反馈网络结合在一起，因而储能元件C的电压比较稳定，开关的电荷注入影响比较小。此外，在共模电压校准完成后，受控开关可以关闭(即断开)，此时激光器Laser可以发出激光信号以进行激光测距，由于DC反馈环路已被断开，因此放大器AMP的输出波形将不会影响缓冲元件DCAMP的工作，实现在脉冲信号过后不会导致基线变化，不会对后续的脉冲产生影响。此外，由于经过了共模电压校准，因此也可实现共模电压在不同的环境光下保持不变。总体上，根据本申请实施例的激光测距装置可以实现在抑制环境光的同时，不对正常的脉冲光信号造成影响。
在本申请的实施例中，缓冲器还可以包括电阻器，如图8所示的，电阻器的一端连接到受控开关，另一端连接到缓冲元件DCAMP的负输入端。在本申请的实施例中，储能元件C可以为电容器，缓冲元件DCAMP可以为直流放大器，第一级放大器即放大器TIA可以为跨阻放大器，传感器APD可以为雪崩光电二极管。虽然在附图中这些元件的标号均标识了其在该实施例中的类型，但应理解，在其他实施例中，它们还可以是其他的类型。
在本申请的实施例中，激光测距装置还可以包括电阻器R2，缓冲元件DCAMP的输出端经由该电阻器R2连接到至少一个放大器中任一级放大器的输入端，在图8的示例中，电阻器R2连接到放大器AMP的正输入端。在该实施例中，反馈环路经由电阻器进行反馈。在其他实施例中，反馈环路也可经由三极管或晶体管校准后的电压反馈至任一级放大器。
总体上，在本申请的实施例中，受控开关在激光器Laser发出激光信号之前打开，缓冲元件DCAMP在受控开关打开时将至少一个放大器中的最后一级或中间级放大器(放大器AMP)输出的共模电压进行校准，并将校准后的电压存储在储能元件C上，储能元件C在受控开关关闭时将校准后的电压反馈至至少一个放大器中的任一级放大器，从而可以实现共模电压的校准与保持；另一方面，受控开关关闭后，激光器Laser发出脉冲光信号，而反馈环路已被断开，放大器AMP的输出波形将不会影响缓冲元件DCAMP的工作，实现在脉冲信号过后不会导致基线变化，不会对后续的脉冲产生影响。
下面结合图9描述根据本申请再一个实施例的激光测距装置的结构示意图。如图9所示，激光测距装置包括激光器Laser、传感器APD、放大器TIA、放大器AMP、缓冲器DCAMP、受控开关和储能元件C。此处，虽然在图9中示出了激光测距装置包括两个放大器TIA和放大器AMP，但这仅是示例性的，在实际应用中，激光测距装置也可以包括一个放大器或者两个以上的放大器，即激光测距装置可以包括至少一个放大器。下文中主要以包括两个放大器为例来描述。
其中，激光器Laser用于出射激光脉冲信号。传感器APD连接在电压-HV下，将光脉冲信号经反射的至少部分信号转成电信号，传感器APD的 输出端连接到至少一个放大器中第一级放大器的输入端，在图9的示例中，传感器APD的输出连接到放大器TIA的负输入端，放大器TIA的正输入端连接参考信号VREF1。储能元件C连接到缓冲器DCAMP的输入端，缓冲器DCAMP的输出端连接到至少一个放大器中任一级放大器的输入端，在图9所示的示例中，缓冲器DCAMP的输出端连接到放大器TIA的输入端。受控开关连接到至少一个放大器中的最后一级或中间级放大器的输出端，在图9的示例中，受控开关连接到放大器AMP的输出端，并连接到储能元件C。受控开关在每次激光器Laser发出激光信号之前打开，并在预定时间之后关闭，受控开关关闭之后激光器Laser发出激光信号。
在本申请的实施例中，激光测距装置包括受控开关，该受控开关可受控以在激光器Laser每次发出激光信号之前打开(即闭合)，也就是放大器TIA、放大器AMP和缓冲器DCAMP形成反馈通路，此时，激光器Laser尚未发出激光信号，传感器APD仅可以探测到环境光信号，该环境光信号经过放大器TIA和放大器AMP后输出至缓冲器DCAMP的负向输入端。如果放大器AMP输出的共模电压大于设置共模电压VREF(即缓冲器DCAMP的正向输入端的参考电压)，缓冲器DCAMP将输出正向的电压给放大器TIA的负输入端(电流记为Ibias)，放大器TIA将会输出反向电压信号给放大器AMP，使放大器AMP的输出电压降低，从而实现负反馈，即缓冲器DCAMP可以把放大器AMP的共模电压校正到设置共模电压VREF。在共模电压校准完成后，校准电压将保存在储能元件C上，校准电压将会保持环路恒定，放大器AMP输出保持在设置共模电压VREF。此外，在共模电压校准完成后，受控开关可以关闭(即断开)，此时激光器Laser可以发出激光信号以进行激光测距，由于DC反馈环路已被断开，因此放大器AMP的输出波形将不会影响缓冲器DCAMP的工作，实现在脉冲信号过后不会导致基线变化，不会对后续的脉冲产生影响。此外，由于经过了共模电压校准，因此也可实现共模电压在不同的环境光下保持不变。总体上，根据本申请实施例的激光测距装置可以实现在抑制环境光的同时，不对正常的脉冲光信号造成影响。
在本申请的实施例中，储能元件C可以为电容器，电容器的一端连接到受控开关和缓冲器DCAMP的输入端，电容器的另一端连接到地。在本 申请的实施例中，缓冲器DCAMP可以为直流放大器，第一级放大器即放大器TIA可以为跨阻放大器，传感器APD可以为雪崩光电二极管。虽然在附图中这些元件的标号均标识了其在该实施例中的类型，但应理解，在其他实施例中，它们还可以是其他的类型。
在本申请的实施例中，缓冲器DCAMP还可以作为缓冲元件，与电阻器(未示出)共同构成缓冲器，该电阻器的两端可以分别连接到缓冲元件的输入端和输出端。此外，缓冲器DCAMP还可以作为缓冲元件，与又一电阻器(未示出)共同构成缓冲器，该电阻器的一端可以连接到储能元件C，另一端可以连接到缓冲元件的输入端。
在本申请的实施例中，激光测距装置还可以包括电阻器，如图9所示的，缓冲器DCAMP的输出端经由该电阻器连接到至少一个放大器中任一级放大器的输入端，在图9的示例中，电阻器连接到放大器TIA的负输入端，电阻器可以用于起到分压作用。在该实施例中，反馈环路经由电阻器进行反馈。在其他实施例中，反馈环路也可经由三极管或晶体管校准后的电压反馈至至少一个放大器中的任一级放大器。
此外，与图8所示的激光测距装置类似的，在根据本申请实施例的激光测距装置中，反馈点的位置可以设置在任一级放大器的输入端(即缓冲元件的输出端可以连接到任一级放大器的输入端)；如果激光测距装置包括至少两个放大器，即第一级放大器(如放大器TIA)和其他放大器(如放大器AMP)，在缓冲器DCAMP的输出端连接到其他放大器中任一放大器的输入端，可以在该任一放大器(如放大器AMP)与该任一放大器的前一级放大器(如放大器TIA)之间设置一个电阻器，以起到分压作用。
总体上，在本申请的实施例中，受控开关在激光器Laser发出激光信号之前打开，缓冲器DCAMP在受控开关打开时将至少一个放大器中的最后一级或中间级放大器(放大器AMP)输出的共模电压进行校准，并将校准后的电压存储在储能元件C上，储能元件C在受控开关关闭时将校准后的电压反馈至至少一个放大器中的任一级放大器，从而可以实现共模电压的校准与保持；另一方面，在经过预定时间之后(共模电压完成校准后)，受控开关关闭，激光器Laser发出脉冲光信号，而反馈环路已被断开，放大器AMP的输出波形将不会影响缓冲器DCAMP的工作，实现在脉冲信 号过后不会导致基线变化，不会对后续的脉冲产生影响。
以上示例性地示出了根据本申请实施例的激光测距装置。基于上面的描述，根据本申请实施例的激光测距装置通过每次在激光器发出激光信号之前进行共模电压校准，在共模电压校准后保存在储能元件上保持反馈环路恒定，并断开反馈环路，再发出激光脉冲，实现在脉冲信号过后不会导致基线变化，因而能够实现在抑制环境光的同时，不对正常的脉冲光信号造成影响。
尽管这里已经参考附图描述了示例实施例，应理解上述示例实施例仅仅是示例性的，并且不意图将本申请的范围限制于此。本领域普通技术人员可以在其中进行各种改变和修改，而不偏离本申请的范围和精神。所有这些改变和修改意在被包括在所附权利要求所要求的本申请的范围之内。
本领域普通技术人员可以意识到，结合本文中所公开的实施例描述的各示例的单元及算法步骤，能够以电子硬件、或者计算机软件和电子硬件的结合来实现。这些功能究竟以硬件还是软件方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可以对特定的应用来使用不同方法来实现所描述的功能，但是这种实现不应认为超出本申请的范围。
在本申请所提供的几个实施例中，应该理解到，所揭露的设备和方法，可以通过其它的方式实现。例如，以上所描述的设备实施例仅仅是示意性的，例如，所述单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，例如多个单元或组件可以结合或者可以集成到另一个设备，或一些特征可以忽略，或不执行。
在此处所提供的说明书中，说明了大量具体细节。然而，能够理解，本申请的实施例可以在没有这些具体细节的情况下实践。在一些实例中，并未详细示出公知的方法、结构和技术，以便不模糊对本说明书的理解。
类似地，应当理解，为了精简本申请并帮助理解各个发明方面中的一个或多个，在对本申请的示例性实施例的描述中，本申请的各个特征有时被一起分组到单个实施例、图、或者对其的描述中。然而，并不应将该本申请的方法解释成反映如下意图：即所要求保护的本申请要求比在权利要求中所明确记载的特征更多的特征。更确切地说，如相应的权利要求书所反映的那样，其发明点在于可以用少于某个公开的单个实施例的所有特征 的特征来解决相应的技术问题。因此，遵循具体实施方式的权利要求书由此明确地并入该具体实施方式，其中权利要求本身都作为本申请的单独实施例。
本领域的技术人员可以理解，除了特征之间相互排斥之外，可以采用任何组合对本说明书(包括伴随的权利要求、摘要和附图)中公开的所有特征以及如此公开的任何方法或者设备的所有过程或单元进行组合。除非另外明确陈述，本说明书(包括伴随的权利要求、摘要和附图)中公开的特征可以由提供相同、等同或相似目的的替代特征来代替。
此外，本领域的技术人员能够理解，尽管在此所述的一些实施例包括其它实施例中所包括的某些特征而不是其它特征，但是不同实施例的特征的组合意味着处于本申请的范围之内并且形成不同的实施例。例如，在权利要求书中，所要求保护的实施例的任意之一都可以以任意的组合方式来使用。
本申请的各个部件实施例可以以硬件实现，或者以在一个或者多个处理器上运行的软件模块实现，或者以它们的组合实现。本领域的技术人员应当理解，可以在实践中使用微处理器或者数字信号处理器(DSP)来实现根据本申请实施例的一些模块的一些或者全部功能。本申请还可以实现为用于执行这里所描述的方法的一部分或者全部的装置程序(例如，计算机程序和计算机程序产品)。这样的实现本申请的程序可以存储在计算机可读存储介质上，或者可以具有一个或者多个信号的形式。这样的信号可以从因特网网站上下载得到，或者在载体信号上提供，或者以任何其他形式提供。
应该注意的是上述实施例对本申请进行说明而不是对本申请进行限制，并且本领域技术人员在不脱离所附权利要求的范围的情况下可设计出替换实施例。在权利要求中，不应将位于括号之间的任何参考符号构造成对权利要求的限制。本申请可以借助于包括有若干不同元件的硬件以及借助于适当编程的计算机来实现。在列举了若干装置的单元权利要求中，这些装置中的若干个可以是通过同一个硬件项来具体体现。单词第一、第二、以及第三等的使用不表示任何顺序。可将这些单词解释为名称。
以上所述，仅为本申请的具体实施方式或对具体实施方式的说明，本 申请的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本申请揭露的技术范围内，可轻易想到变化或替换，都应涵盖在本申请的保护范围之内。本申请的保护范围应以权利要求的保护范围为准。

Claims (23)

  1. 一种激光测距装置，其特征在于，所述激光测距装置包括激光器、传感器、至少一个放大器、缓冲器和受控开关，其中：
    所述激光器用于出射激光脉冲信号；
    所述传感器用于将所述光脉冲信号经反射的至少部分信号转成电信号，所述传感器的输出端连接到所述至少一个放大器中第一级放大器的输入端；
    所述缓冲器包括储能元件和缓冲元件，所述储能元件的两端分别连接到所述缓冲元件的输入端和输出端，所述缓冲元件的输出端连接到所述至少一个放大器中任一级放大器的输入端；
    所述受控开关连接到所述至少一个放大器中的最后一级或中间级放大器的输出端，并连接到所述缓冲元件的输入端；
    所述受控开关在每次所述激光器发出激光信号之前打开，并在预定时间之后关闭，所述受控开关关闭之后所述激光器发出激光信号。
  2. 根据权利要求1所述的激光测距装置，其特征在于，所述缓冲元件在所述受控开关打开时将所述至少一个放大器中最后一级放大器输出的共模电压进行校准，并将校准后的电压存储在所述储能元件上，所述储能元件在所述受控开关关闭时将所述校准后的电压反馈至所述至少一个放大器中的任一级放大器。
  3. 根据权利要求2所述的激光测距装置，其特征在于，所述储能元件在所述受控开关关闭时经由电阻器、三极管或晶体管将所述校准后的电压反馈至所述至少一个放大器中的任一级放大器。
  4. 根据权利要求1-3中的任一项所述的激光测距装置，其特征在于，所述缓冲元件的输出端连接到所述至少一个放大器中所述第一级放大器的输入端。
  5. 根据权利要求1-3中的任一项所述的激光测距装置，其特征在于，所述激光测距装置包括至少两个放大器，且还包括第一电阻器，所述至少两个放大器包括第一级放大器和其他放大器，所述缓冲元件的输出端连接到所述其他放大器中任一放大器的输入端，所述第一电阻器连接在所述任一放大器与所述任一放大器的前一级放大器之间。
  6. 根据权利要求1-5中的任一项所述的激光测距装置，其特征在于，所述储能元件为电容器。
  7. 根据权利要求1-6中的任一项所述的激光测距装置，其特征在于，所述缓冲元件为直流放大器。
  8. 根据权利要求1-7中的任一项所述的激光测距装置，其特征在于，所述缓冲器还包括第二电阻器，所述第二电阻器的一端连接到所述受控开关，所述第二电阻器的另一端连接到所述缓冲元件的输入端。
  9. 根据权利要求1-8中的任一项所述的激光测距装置，其特征在于，所述激光测距装置还包括第三电阻器，所述缓冲元件的输出端经由所述第三电阻器连接到所述至少一个放大器中任一级放大器的输入端。
  10. 根据权利要求1-9中的任一项所述的激光测距装置，其特征在于，所述传感器为雪崩光电二极管。
  11. 根据权利要求1-10中的任一项所述的激光测距装置，其特征在于，所述第一级放大器为跨阻放大器。
  12. 一种激光测距装置，其特征在于，所述激光测距装置包括激光器、传感器、至少一个放大器、储能元件、缓冲器和受控开关，其中：
    所述激光器用于出射激光脉冲信号；
    所述传感器用于将所述光脉冲信号经反射的至少部分信号转成电信号，所述传感器的输出端连接到所述至少一个放大器中第一级放大器的输入端；
    所述储能元件连接到所述缓冲器的输入端，所述缓冲器的输出端连接到所述至少一个放大器中任一级放大器的输入端；
    所述受控开关连接到所述至少一个放大器中的最后一级或中间级放大器的输出端，并连接到所述储能元件；
    所述受控开关在每次所述激光器发出激光信号之前打开，并在预定时间之后关闭，所述受控开关关闭之后所述激光器发出激光信号。
  13. 根据权利要求12所述的激光测距装置，其特征在于，所述缓冲元件在所述受控开关打开时将所述至少一个放大器中的最后一级或中间级放大器输出的共模电压进行校准，并将校准后的电压存储在所述储能元件上，所述储能元件在所述受控开关关闭时将所述校准后的电压反馈至所述 至少一个放大器中的任一级放大器。
  14. 根据权利要求13所述的激光测距装置，其特征在于，所述储能元件在所述受控开关关闭时经由电阻器、三极管或晶体管将所述校准后的电压反馈至所述至少一个放大器中的任一级放大器。
  15. 根据权利要求12-14中的任一项所述的激光测距装置，其特征在于，所述缓冲器的输出端连接到所述至少一个放大器中所述第一级放大器的输入端。
  16. 根据权利要求12-14中的任一项所述的激光测距装置，其特征在于，所述激光测距装置包括至少两个放大器，且还包括第一电阻器，所述至少两个放大器包括第一级放大器和其他放大器，所述缓冲器的输出端连接到所述其他放大器中任一放大器的输入端，所述第一电阻器连接在所述任一放大器与所述任一放大器的前一级放大器之间。
  17. 根据权利要求12-16中的任一项所述的激光测距装置，其特征在于，所述储能元件为电容器，所述电容器的一端连接到所述受控开关和所述缓冲器的输入端，所述电容器的另一端连接到地。
  18. 根据权利要求12-17中的任一项所述的激光测距装置，其特征在于，所述缓冲器包括缓冲元件和第四电阻器，所述第四电阻器的两端分别连接到所述缓冲元件的输入端和输出端。
  19. 根据权利要求18所述的激光测距装置，所述缓冲元件为直流放大器。
  20. 根据权利要求18或19所述的激光测距装置，其特征在于，所述缓冲器还包括第二电阻器，所述第二电阻器的一端连接到所述储能元件的一端，所述第二电阻器的另一端连接到所述缓冲元件的输入端。
  21. 根据权利要求12-20中的任一项所述的激光测距装置，其特征在于，所述激光测距装置还包括第三电阻器，所述缓冲器的输出端经由所述第三电阻器连接到所述至少一个放大器中任一级放大器的输入端。
  22. 根据权利要求12-21中的任一项所述的激光测距装置，其特征在于，所述传感器为雪崩光电二极管。
  23. 根据权利要求12-22中的任一项所述的激光测距装置，其特征在于，所述第一级放大器为跨阻放大器。
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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN206710917U (zh) * 2017-01-13 2017-12-05 广州腾德同普光电科技有限公司 基于apc和恒温智能控制的激光半导体物证发现装置
CN108566524A (zh) * 2018-01-31 2018-09-21 深圳市光微科技有限公司 像素单元、图像传感器芯片、成像系统、像素单元的形成方法以及深度信息测算方法
CN108603758A (zh) * 2015-11-30 2018-09-28 卢米诺技术公司 具有分布式激光器和多个传感器头的激光雷达系统和激光雷达系统的脉冲激光器
CN110927737A (zh) * 2019-11-26 2020-03-27 华中科技大学 一种多频调制激光动态目标测距测速系统及方法
CN211505895U (zh) * 2018-09-27 2020-09-15 深圳市大疆创新科技有限公司 激光发射装置、峰值保持电路、测距装置和移动平台
WO2020182591A1 (en) * 2019-03-08 2020-09-17 Osram Gmbh Component for a lidar sensor system, lidar sensor system, lidar sensor device, method for a lidar sensor system and method for a lidar sensor device

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108603758A (zh) * 2015-11-30 2018-09-28 卢米诺技术公司 具有分布式激光器和多个传感器头的激光雷达系统和激光雷达系统的脉冲激光器
CN206710917U (zh) * 2017-01-13 2017-12-05 广州腾德同普光电科技有限公司 基于apc和恒温智能控制的激光半导体物证发现装置
CN108566524A (zh) * 2018-01-31 2018-09-21 深圳市光微科技有限公司 像素单元、图像传感器芯片、成像系统、像素单元的形成方法以及深度信息测算方法
CN211505895U (zh) * 2018-09-27 2020-09-15 深圳市大疆创新科技有限公司 激光发射装置、峰值保持电路、测距装置和移动平台
WO2020182591A1 (en) * 2019-03-08 2020-09-17 Osram Gmbh Component for a lidar sensor system, lidar sensor system, lidar sensor device, method for a lidar sensor system and method for a lidar sensor device
CN110927737A (zh) * 2019-11-26 2020-03-27 华中科技大学 一种多频调制激光动态目标测距测速系统及方法

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