WO2020113564A1 - 一种激光接收电路及测距装置、移动平台 - Google Patents

一种激光接收电路及测距装置、移动平台 Download PDF

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Publication number
WO2020113564A1
WO2020113564A1 PCT/CN2018/119813 CN2018119813W WO2020113564A1 WO 2020113564 A1 WO2020113564 A1 WO 2020113564A1 CN 2018119813 W CN2018119813 W CN 2018119813W WO 2020113564 A1 WO2020113564 A1 WO 2020113564A1
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Prior art keywords
circuit
laser
photoelectric conversion
pulse signal
conversion circuit
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Application number
PCT/CN2018/119813
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English (en)
French (fr)
Inventor
刘祥
洪小平
Original Assignee
深圳市大疆创新科技有限公司
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Filing date
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Application filed by 深圳市大疆创新科技有限公司 filed Critical 深圳市大疆创新科技有限公司
Priority to PCT/CN2018/119813 priority Critical patent/WO2020113564A1/zh
Priority to CN201880068065.6A priority patent/CN112219330A/zh
Publication of WO2020113564A1 publication Critical patent/WO2020113564A1/zh

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    • 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
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection

Definitions

  • the invention relates to the technical field of circuits, in particular to a laser receiving circuit, a distance measuring device and a mobile platform.
  • Lidar is a radar system that emits laser beams to detect the target's position, speed and other characteristic quantities.
  • the light sensor of the lidar can convert the acquired light pulse signal into an electrical signal, and obtain the time information corresponding to the electrical signal based on the comparator, thereby obtaining the distance information between the lidar and the target.
  • multiple sets of equipment may work at the same time.
  • multiple lidars will work together. During the scanning process, there is a chance that two radars will illuminate each other. In this case, the radar will receive a strong pulsed laser at this time, which may damage the radar's receiving circuit.
  • the current laser receiving circuit and lidar need to be improved to eliminate the above-mentioned various problems and drawbacks.
  • a first aspect of the present invention provides a laser receiving circuit, including: a photoelectric conversion circuit and a protection circuit;
  • the photoelectric conversion circuit is used to receive a laser pulse signal, convert the laser pulse signal into an electrical signal, and output the electrical signal;
  • the protection circuit is used to limit the current of the electrical signal in the photoelectric conversion circuit when the laser pulse signal received by the photoelectric conversion circuit is greater than a set value to prevent damage to the photoelectric conversion circuit.
  • the protection circuit includes a current limiting element, the current limiting element is connected in series with the photoelectric conversion circuit, and the current limiting element includes at least one resistor or inductance.
  • the protection circuit further includes an energy storage circuit, wherein the energy storage circuit is connected in series with the current limiting element and the photoelectric conversion circuit.
  • the energy storage circuit includes at least one capacitor.
  • the protection circuit includes a charging circuit, and the charging circuit is used to charge the energy storage circuit within a first period of time until the voltage of the energy storage circuit is saturated.
  • the energy storage circuit is also used to supply power to the photoelectric conversion circuit when the laser pulse signal received by the photoelectric conversion circuit is equal to or greater than the set value within a second period of time.
  • the energy storage circuit is further configured to: when the laser pulse signal received by the photoelectric conversion circuit is less than the set value within a second period of time, the protection circuit does not supply power to the photoelectric conversion circuit.
  • one end of the photoelectric conversion circuit is electrically connected to one end of the current limiting element, the other end of the photoelectric conversion circuit is electrically connected to the reading circuit, and the other end of the current limiting element is connected to the energy storage
  • One end of the circuit is electrically connected, and the other end of the energy storage circuit is grounded; or;
  • One end of the photoelectric conversion circuit is electrically connected to one end of the energy storage circuit, the other end of the photoelectric conversion circuit is electrically connected to the reading circuit, and the other end of the energy storage circuit is electrically connected to one end of the current limiting element Connect, the other end of the current limiting element is grounded.
  • the charging circuit includes a power source and a first resistor, one end of the first resistor is electrically connected to the power source, and the other end of the first resistor is electrically connected to the protection circuit.
  • the charging circuit includes a transistor, a voltage calibration source, a first resistor, and a second resistor;
  • one end of the first resistor is electrically connected to the power source, and the other end of the first resistor is electrically connected to the base electrode of the triode; the collector electrode of the triode is electrically connected to the power source, and the triode Is electrically connected to one end of the second resistor, the other end of the second resistor is electrically connected to the protection circuit, and one end of the voltage calibration source is electrically connected to the base of the triode, the voltage The other end of the calibration source is electrically connected to the protection circuit.
  • the resistance value of the resistance in the charging circuit is greater than the resistance value of the resistance in the protection circuit.
  • the photoelectric conversion circuit includes a photosensitive sensor for receiving the laser pulse signal and converting the laser pulse signal into an electrical signal.
  • the laser receiving circuit further includes an amplifying circuit, the amplifying circuit is configured to amplify the electrical signal input from the photosensor and output the amplified electrical signal.
  • the photosensitive sensor includes an avalanche photodiode, a cathode of the avalanche photodiode is electrically connected to the protection circuit, and an anode of the avalanche photodiode is connected to an input end of the amplification circuit.
  • the invention also provides a distance measuring device, including:
  • Light emitting circuit used to emit laser pulse signal
  • the laser receiving circuit as described above is used to receive at least part of the laser signal reflected by the laser pulse signal emitted by the light emitting circuit through the object, and convert the received laser signal into an electrical signal;
  • the arithmetic circuit is used for calculating the distance between the object and the distance measuring device according to the sampling result.
  • the number of the light emitting circuits and the number of the laser receiving circuits are at least 2 respectively;
  • Each of the laser receiving circuits is used to receive at least a part of the laser signal reflected by the laser pulse signal emitted from the corresponding light emitting circuit through the object, and convert the received laser signal into an electrical signal.
  • the laser distance measuring device further includes a scanning module
  • the scanning module is used for changing the transmission direction of the laser pulse signal and then exiting.
  • the laser pulse signal reflected by the object is incident on the laser receiving circuit after passing through the scanning module.
  • the scanning module further includes a driver and a prism with an uneven thickness.
  • the driver is used to drive the prism to rotate to change the laser pulse signal passing through the prism to different directions for exit.
  • the scanning module further includes two drivers, and two prisms of uneven thickness arranged in parallel, and the two drivers are respectively used to drive the two prisms to rotate in opposite directions;
  • the laser pulse signal from the laser emitting circuit sequentially passes through the two prisms and then changes the transmission direction and exits.
  • the invention also provides a mobile platform, including:
  • a platform body, the light emitting circuit is installed on the platform body.
  • the mobile platform includes at least one of an unmanned aerial vehicle, a car, and a robot.
  • the present invention provides the above-mentioned laser receiving circuit, distance measuring device and mobile platform to realize the rapid response of the APD to the transient strong light, thereby protecting the APD, and achieving the APD protection without affecting the response of the weak signal.
  • the radar will receive a very strong pulse laser, which will damage the radar's receiving circuit.
  • FIG. 1 is a schematic structural diagram of a laser receiving circuit in the prior art
  • FIG. 2 is a schematic structural diagram of a laser receiving circuit according to an embodiment of the present invention.
  • FIG. 3 is a schematic structural diagram of a laser receiving circuit according to another embodiment of the present invention.
  • FIG. 4 is a schematic frame diagram of a distance measuring device according to an embodiment of the present invention.
  • FIG. 5 is a schematic diagram of an embodiment of a distance measuring device provided by an embodiment of the present invention using a coaxial optical path.
  • the laser will continuously emit lasers in all directions in the space during the scanning process, and the two laser emitters have a probability of illuminating each other. At this time, the receiving system will have to withstand high pulse laser energy, which may damage the receiving system. In the photoelectric conversion circuit.
  • the existing solution mainly places a small-capacity capacitor on the power supply of the photoelectric conversion circuit to limit the energy of a single pulse.
  • the photoelectric conversion circuit cannot quickly respond to the strong light pulse. If the energy of the laser is strong enough, a single pulse may damage the photoelectric conversion circuit; if the capacitance is too small, it will cause the photoelectric conversion circuit to output a large current. The voltage fluctuates, and the voltage across the photoelectric conversion circuit slowly rises after the pulsed light, which causes a long tailing of the readout circuit after the photoelectric conversion circuit, which affects the response of the photoelectric conversion circuit itself.
  • the capacitor will get nF level, but under this capacity, the photoelectric conversion circuit will have an instantaneous energy that is too high when it is exposed to extremely strong light, and the voltage across the capacitor cannot change quickly, causing the photoelectric conversion circuit to be damaged.
  • the present invention provides a laser receiving circuit, including:
  • the photoelectric conversion circuit is used to receive a laser pulse signal, convert the laser pulse signal into an electrical signal, and output the electrical signal;
  • the protection circuit is used to limit the current of the electrical signal in the photoelectric conversion circuit when the laser pulse signal received by the photoelectric conversion circuit is greater than a set value to prevent damage to the photoelectric conversion circuit.
  • the laser receiving circuit is shown in Figure 2:
  • the laser receiving circuit includes a power supply, a photoelectric conversion circuit, and a protection circuit.
  • the power supply is VCC_APD, which serves as the energy supply end of the protection circuit, for example, for charging the protection circuit.
  • the photoelectric conversion circuit includes a photosensitive sensor for receiving an optical pulse signal and converting the optical pulse signal into an electrical signal. After receiving the optical pulse signal, the photoelectric conversion circuit converts the optical pulse signal into an electrical pulse signal.
  • the electrical pulse signal includes a voltage pulse signal or a current pulse signal, and is not limited to a certain one.
  • the photoelectric conversion circuit includes an APD (Avalanche Photodiode).
  • APD Anavalanche Photodiode
  • the electrical pulse signal when the electrical pulse signal is a voltage signal, the electrical pulse signal is at a low level in the first period and is located at the valley of the pulse; the electrical pulse signal is at a high level in the second period The level is at the peak of the pulse.
  • the protection circuit includes a current limiting element.
  • a current limiting element When the APD encounters strong light and generates a large current, a relatively high voltage drop will occur on the current limiting element. After the voltage is reduced, the gain of the APD will decrease, and the output current of the APD will decrease. To prevent the APD instantaneous power is too large, so as to avoid the APD will burn out.
  • the current limiting element is connected in series with the photoelectric conversion circuit
  • the current limiting element includes at least one resistor or inductance for limiting the current in the photoelectric conversion circuit when the optical pulse signal received by the photoelectric conversion circuit is greater than a set value To prevent damage to the photoelectric conversion circuit.
  • the current limiting element in the present invention is not limited to resistance or inductance, and other elements that can play a role in current limiting can be applied to the present application.
  • the current limiting element selects a resistor R2, where the resistor R2 is directly connected in series with the APD, and the current limiting resistor takes a small resistance.
  • the protection circuit further includes an energy storage circuit, wherein the energy storage circuit is connected in series with the current limiting element and the photoelectric conversion circuit.
  • the energy storage circuit includes at least one capacitor C1.
  • the manner in which the capacitor is connected in series with the current limiting element and the photoelectric conversion circuit includes at least the following two types:
  • the first type one end of the photoelectric conversion circuit is electrically connected to one end of the current limiting element, the other end of the photoelectric conversion circuit is electrically connected to the reading circuit, and the other end of the current limiting element is connected to the energy storage One end of the circuit is electrically connected, and the other end of the energy storage circuit is grounded; or;
  • one end of the photoelectric conversion circuit is electrically connected to one end of the energy storage circuit, the other end of the photoelectric conversion circuit is electrically connected to the reading circuit, and the other end of the energy storage circuit is connected to the current limiting One end of the element is electrically connected, and the other end of the current limiting element is grounded.
  • the protection circuit includes a charging circuit, and the charging circuit is used to charge the energy storage circuit within a first period of time until the voltage of the energy storage circuit is saturated.
  • the electrical pulse signal is at a low level in the first period, located at the valley of the pulse, and the charging circuit is used to The energy storage circuit is charged until the voltage of the energy storage circuit is saturated.
  • the electrical pulse signal is at a high level, at the peak of the pulse, and the energy storage circuit is also used during the second period when the laser pulse signal received by the photoelectric conversion circuit is equal to or greater than the setting
  • the photoelectric conversion circuit is powered, the energy on the energy storage circuit is consumed, and the voltage across the capacitor is reduced.
  • the internal gain of the APD will decrease and the output current will decrease, resulting in negative feedback.
  • the APD will not continue to output large currents and cause damage to itself, thus protecting the APD.
  • the energy storage circuit supplies power to the photoelectric conversion circuit until the energy of the energy storage circuit is exhausted, so that the photoelectric conversion circuit is disconnected.
  • the energy storage circuit does not supply power to the photoelectric conversion circuit.
  • the size of the set value is set according to actual needs, wherein at least part of the optical signal that is received by the laser pulse signal emitted by the light emitting circuit and reflected by the object through the object, and the ambient light signal are less than the set value
  • the size of the optical pulse signal directly emitted by the laser must be greater than the set value to ensure that when the lasers are irradiated with each other, the protection circuit will be triggered to supply power to the photoelectric conversion circuit, thereby protecting the APD from damage.
  • the charging circuit includes a power source VCC_APD and a first resistor R1, and one end of the first resistor R1 is electrically connected to the power source VCC_APD. The other end of a resistor R1 is electrically connected to the protection circuit.
  • the protection circuit includes a current limiting element, the current limiting element is a current limiting resistor R2, wherein the energy storage circuit includes a capacitor C1, the photoelectric conversion circuit is an avalanche photodiode APD, wherein the avalanche photodiode APD Is electrically connected to one end of the current limiting resistor R2, the other end of the avalanche photodiode APD is electrically connected to the reading circuit, and the other end of the current limiting resistor R2 is connected to one end of the capacitor C1 of the energy storage circuit Electrically connected, the other end of the capacitor C1 of the energy storage circuit is grounded.
  • the current limiting element is a current limiting resistor R2
  • the energy storage circuit includes a capacitor C1
  • the photoelectric conversion circuit is an avalanche photodiode APD
  • the avalanche photodiode APD Is electrically connected to one end of the current limiting resistor R2
  • the power supply VCC_APD charges the capacitor C1 of the energy storage circuit through the first resistor R1 in the first period.
  • the avalanche photodiode APD receives the optical pulse signal and converts the optical pulse signal into an electrical signal.
  • the working mode of the laser receiving circuit during the second period can be divided into the following two types:
  • the laser receiving circuit works normally at this time, and the current in the laser receiving circuit is a small normal current at this time, due to current limiting
  • the resistance of the resistor R2 is small, so the voltage across the current limiting resistor R2 is also very small, that is, the partial voltage of the current limiting resistor R2 is very small, the voltage across the APD does not change much when receiving the pulse light, and will not affect the APD itself. Has an impact.
  • the value of the capacitor C1 is relatively large, when the received laser pulse signal is a weak signal, the charge released by the capacitor is less, the voltage fluctuation is extremely small, and it will not affect the response of the APD.
  • the laser receiving circuit will not Affected by any influence, it works normally. Among them, the voltage on the storage capacitor hardly changes, and the current response of the APD is normal.
  • the APD encounters a strong laser pulse signal, for example, the intensity of the laser pulse signal is greater than the set value, the strong laser pulse signal generates a large current, and a relatively high voltage drop will occur on the current limiting resistor R2.
  • the APD gain will decrease after the voltage is reduced (because the APD itself has an internal gain (photoelectric conversion has a multiplication effect), the APD gain changes with the voltage, and the APD gain will decrease when the voltage decreases ), so that the output current is reduced, the APD output current is reduced to prevent the APD instantaneous power is too large, to avoid the output of a large current to cause APD damage.
  • the APD will be exposed to unusually strong light, such as a laser control, (at this time the output current will be very large, such as more than 100mA), in this case, the voltage drop on the current limiting resistance R2 is limited, and the APD will still output Large currents cause damage.
  • the energy storage capacitor C1 will continue to provide energy to the APD and deplete its own charge to eventually form an open circuit. Even if the APD continues to be exposed to strong light or cannot recover the high-impedance state, the voltage across the APD It will also be reduced to 0V, thus protecting the APD.
  • the protection circuit does not affect the operation of the APD during normal use, and when subjected to strong light, the current limiting resistor quickly responds to limit the maximum current of the APD first, and then the capacitor The depletion of the charge realizes the extinction of the APD, and then protects the APD to prevent damage due to excessive current.
  • the light emitting device is shown in Figure 3:
  • the laser receiving circuit includes a power supply, a photoelectric conversion circuit, and a protection circuit.
  • the laser receiving circuit includes a power supply, a photoelectric conversion circuit, and a protection circuit.
  • the power supply is VCC_APD, which serves as the energy supply end of the protection circuit, for example, for charging the protection circuit.
  • the photoelectric conversion circuit includes a photosensitive sensor for receiving an optical pulse signal and converting the optical pulse signal into an electrical signal. After receiving the optical pulse signal, the photoelectric conversion circuit converts the optical pulse signal into an electrical pulse signal.
  • the electrical pulse signal includes a voltage pulse signal or a current pulse signal, and is not limited to a certain one.
  • the photoelectric conversion circuit includes an APD (Avalanche Photodiode).
  • APD Anavalanche Photodiode
  • the electrical pulse signal when the electrical pulse signal is a voltage signal, wherein the electrical pulse signal is a low level in the first period and is located at the valley of the pulse; the electrical pulse is in the second period The signal is high and is located at the peak of the pulse.
  • the protection circuit includes a current limiting element.
  • a current limiting element When the APD encounters strong light and generates a large current, a relatively high voltage drop will occur on the current limiting element. After the voltage is reduced, the gain of the APD will decrease, and the output current of the APD will decrease. To prevent the APD instantaneous power is too large, so as to avoid the APD will burn out.
  • the current limiting element is connected in series with the photoelectric conversion circuit
  • the current limiting element includes at least one resistor or inductance for limiting the current in the photoelectric conversion circuit when the optical pulse signal received by the photoelectric conversion circuit is greater than a set value To prevent damage to the photoelectric conversion circuit.
  • the current limiting element in the present invention is not limited to resistance or inductance, and other elements that can play a role in current limiting can be applied to the present application.
  • the current limiting element selects a resistor R3, where the resistor R3 is directly connected in series with the APD, and the current limiting resistor takes a small resistance.
  • the protection circuit further includes an energy storage circuit, wherein the energy storage circuit is connected in series with the current limiting element and the photoelectric conversion circuit.
  • the energy storage circuit includes at least one capacitor C1, and the capacitor C1 is connected in series with the current limiting element and the photoelectric conversion circuit.
  • the manner in which the capacitor is connected in series with the current limiting element and the photoelectric conversion circuit includes at least the following two types:
  • one end of the photoelectric conversion circuit is electrically connected to one end of the current limiting element, the other end of the photoelectric conversion circuit is electrically connected to the reading circuit, and the other end of the current limiting element is connected to the energy storage circuit Is electrically connected at one end, and the other end of the energy storage circuit is grounded; or;
  • One end of the photoelectric conversion circuit is electrically connected to one end of the energy storage circuit, the other end of the photoelectric conversion circuit is electrically connected to the reading circuit, and the other end of the energy storage circuit is electrically connected to one end of the current limiting element Connect, the other end of the current limiting element is grounded.
  • the protection circuit includes a charging circuit, and the charging circuit is used to charge the energy storage circuit within a first period of time until the voltage of the energy storage circuit is saturated.
  • the electrical pulse signal is at a low level in the first period, located at the valley of the pulse, and the charging circuit is used to The energy storage circuit is charged until the voltage of the energy storage circuit is saturated.
  • the electrical pulse signal is at a high level, at the peak of the pulse, and the energy storage circuit is also used during the second period when the laser pulse signal received by the photoelectric conversion circuit is equal to or greater than the setting
  • the photoelectric conversion circuit is powered, the energy on the energy storage circuit is consumed, and the voltage across the capacitor is reduced.
  • the internal gain of the APD will decrease and its output current will decrease, resulting in negative feedback.
  • the APD will not continue to output large currents and cause damage to itself, thus protecting the APD.
  • the energy storage circuit supplies power to the photoelectric conversion circuit until the energy of the energy storage circuit is exhausted, so that the photoelectric conversion circuit is disconnected.
  • the energy storage circuit does not supply power to the photoelectric conversion circuit.
  • At least part of the optical signal that is received by the laser pulse signal emitted by the light emitting circuit and reflected by the object through the object and the ambient light signal are less than the set value, and the size of the optical pulse signal directly emitted by the laser is definitely greater than the set value A fixed value to ensure that when the lasers irradiate each other, the protection circuit is triggered to supply power to the photoelectric conversion circuit, so as to protect the APD from damage.
  • the charging circuit includes a power supply VCC_APD, a first resistor R1, a second resistor R2, a transistor Q1, and a voltage calibration source Q2, wherein the first One end of the resistor R1 is electrically connected to the power supply VCC_APD, and the other end of the first resistor R1 is electrically connected to the base of the transistor Q1NPN; the collector of the transistor NPN is electrically connected to the power supply VCC_APD, the transistor The emitter of NPN is electrically connected to one end of the second resistor R2, the other end of the second resistor R2 is electrically connected to one end of the capacitor C1, and one end of the voltage calibration source Q2 is electrically connected to the base of the triode NPN Connected, the other end of the voltage calibration source Q2 is electrically connected to the capacitor C1.
  • the charging circuit composed of the first resistor R1, the second resistor R2, the transistor Q1, and the voltage calibration source Q22 charges C1, wherein the resistance value of the first resistor R1 is larger, and the charging circuit Is used to limit the current in the charging circuit and plays a role in limiting the current.
  • the current of the voltage stabilizing tube Q2 can change in a large range and the voltage is basically unchanged.
  • the stable voltage value generated at both ends at the rated current is used to output a stable voltage to charge the capacitor C1.
  • the avalanche photodiode APD is off and does not generate current, and Since the resistance of the first resistor R1 is large, there is no obvious current in the laser receiving circuit, so the power supply VCC_APD charges the capacitor C1 of the energy storage circuit through the first resistor R1 in the first period.
  • the charging voltage can be made more stable and efficient.
  • the setting of the first resistor can also be used to limit the magnitude of the current.
  • the avalanche photodiode APD receives the optical pulse signal and converts the optical pulse signal into an electrical signal.
  • the working mode of the laser receiving circuit during the second period can be divided into the following two types:
  • the laser receiving circuit works normally at this time, and the current in the laser receiving circuit is a small normal current at this time, due to current limiting
  • the resistance of the resistor R2 is small, so the voltage across the current limiting resistor R2 is also very small, that is, the partial voltage of the current limiting resistor R2 is very small, the voltage across the APD does not change much when receiving the pulse light, and will not affect the APD itself. Has an impact.
  • the value of the capacitor C1 is relatively large, when the received laser pulse signal is a weak signal, the charge released by the capacitor is less, the voltage fluctuation is extremely small, and it will not affect the response of the APD.
  • the laser receiving circuit will not Affected by any influence, it works normally. Among them, the voltage on the storage capacitor hardly changes, and the current response of the APD is normal.
  • the APD encounters a strong laser pulse signal, for example, the intensity of the laser pulse signal is greater than the set value, the strong laser pulse signal generates a large current, and a relatively high voltage drop will occur on the current limiting resistor R2.
  • the APD gain will decrease after the voltage is reduced (because the APD itself has an internal gain (photoelectric conversion has a multiplication effect), the APD gain changes with the voltage, and the APD gain will decrease when the voltage decreases ), so that the output current is reduced, the APD output current is reduced to prevent the APD instantaneous power is too large, to avoid the output of a large current to cause APD damage.
  • the APD will be subjected to unusually strong light, such as laser control, (the output current will be very large at this time, such as more than 100mA).
  • the voltage drop on the current limiting resistance R2 is limited, and the APD will still output. Large currents cause damage.
  • the energy storage capacitor C1 will continue to provide energy to the APD and deplete its own charge to eventually form an open circuit. Even if the APD continues to be exposed to strong light or cannot recover the high-impedance state, the voltage across the APD It will also be reduced to 0V, thus protecting the APD.
  • the protection circuit does not affect the operation of the APD during normal use, and when subjected to strong light, the current limiting resistor quickly responds to limit the maximum current of the APD first, and then the capacitor The depletion of the charge realizes the extinction of the APD, and then protects the APD to prevent damage due to excessive current.
  • the laser receiving circuit further includes an amplifying circuit, the amplifying circuit is configured to amplify the electrical signal input from the photosensor and output the amplified electrical signal.
  • the specific structure of the amplifying circuit can be a structure commonly used in the art.
  • an embodiment of the present invention further provides a distance measuring device, including: a light emitting circuit for emitting a laser pulse signal; a laser receiving circuit according to any one of the above embodiments, for Receiving at least part of the laser signal reflected from the laser pulse signal emitted by the light emitting circuit through the object, and converting the received laser signal into an electrical signal; a sampling circuit for detecting the electrical signal from the laser receiving circuit Sampling is performed to obtain a sampling result; an operation circuit is used to calculate the distance between the object and the distance measuring device according to the sampling result.
  • the distance measuring device is used to sense external environment information, for example, distance information, azimuth information, reflection intensity information, speed information, etc. of the environmental target.
  • the distance measuring device can detect the distance between the detecting object and the distance measuring device by measuring the time of light propagation between the distance measuring device and the detection object, that is, Time-of-Flight (TOF).
  • TOF Time-of-Flight
  • the distance measuring device may also detect the distance between the detected object and the distance measuring device through other techniques, such as a distance measuring method based on phase shift measurement, or a distance measuring method based on frequency shift measurement. There are no restrictions.
  • the distance measuring device 100 may include a transmitting circuit 110, a receiving circuit 120, a sampling circuit 130 and an arithmetic circuit 140.
  • the transmission circuit 110 may transmit a sequence of light pulses (for example, a sequence of laser pulses).
  • the receiving circuit 120 can receive the optical pulse sequence reflected by the detected object, and photoelectrically convert the optical pulse sequence to obtain an electrical signal, which can be output to the sampling circuit 130 after processing the electrical signal.
  • the sampling circuit 130 may sample the electrical signal to obtain the sampling result.
  • the arithmetic circuit 140 may determine the distance between the distance measuring device 100 and the detected object based on the sampling result of the sampling circuit 130.
  • the distance measuring apparatus 100 may further include a control circuit 150, which may control other circuits, for example, may control the working time of each circuit and/or set parameters for each circuit.
  • a control circuit 150 may control other circuits, for example, may control the working time of each circuit and/or set parameters for each circuit.
  • the distance measuring device shown in FIG. 4 includes a transmitting circuit, a receiving circuit, a sampling circuit, and an arithmetic circuit for emitting a beam of light for detection
  • the embodiments of the present application are not limited thereto, and the transmitting circuit
  • the number of any one of the receiving circuit, the sampling circuit, and the arithmetic circuit may also be at least two, for emitting at least two light beams in the same direction or respectively in different directions; wherein, the at least two light paths may be simultaneously
  • the shot may be shot at different times.
  • the light-emitting chips in the at least two emission circuits are packaged in the same module.
  • each emitting circuit includes a laser emitting chip, and the die in the laser emitting chips in the at least two emitting circuits are packaged together and accommodated in the same packaging space.
  • the distance measuring device 100 may further include a scanning module for changing at least one laser pulse sequence emitted by the transmitting circuit to change the propagation direction.
  • the module including the transmitting circuit 110, the receiving circuit 120, the sampling circuit 130, and the arithmetic circuit 140, or the module including the transmitting circuit 110, the receiving circuit 120, the sampling circuit 130, the arithmetic circuit 140, and the control circuit 150 may be referred to as measurement Distance module, the distance measuring module may be independent of other modules, for example, a scanning module.
  • a coaxial optical path may be used in the distance measuring device, that is, the light beam emitted by the distance measuring device and the reflected light beam share at least part of the optical path in the distance measuring device.
  • the distance measuring device may also adopt an off-axis optical path, that is, the light beam emitted from the distance measuring device and the reflected light beam are respectively transmitted along different optical paths in the distance measuring device.
  • FIG. 5 shows a schematic diagram of an embodiment of the distance measuring device of the present invention using a coaxial optical path.
  • the distance measuring device 200 includes a distance measuring module 210.
  • the distance measuring module 210 includes a transmitter 203 (which may include the above-mentioned transmitting circuit), a collimating element 204, and a detector 205 (which may include the above-mentioned receiving circuit, sampling circuit, and arithmetic circuit) and Optical path changing element 206.
  • the ranging module 210 is used to emit a light beam, and receive back light, and convert the back light into an electrical signal.
  • the transmitter 203 may be used to transmit a light pulse sequence.
  • the transmitter 203 may emit a sequence of laser pulses.
  • the laser beam emitted by the transmitter 203 is a narrow-bandwidth beam with a wavelength outside the visible light range.
  • the collimating element 204 is disposed on the exit optical path of the emitter, and is used to collimate the light beam emitted from the emitter 203, and collimate the light beam emitted from the emitter 203 into parallel light to the scanning module.
  • the collimating element is also used to converge at least a part of the return light reflected by the detection object.
  • the collimating element 204 may be a collimating lens or other element capable of collimating the light beam.
  • the optical path changing element 206 is used to combine the transmitting optical path and the receiving optical path in the distance measuring device before the collimating element 204, so that the transmitting optical path and the receiving optical path can share the same collimating element, so that the optical path More compact.
  • the transmitter 203 and the detector 205 may respectively use respective collimating elements, and the optical path changing element 206 is disposed on the optical path behind the collimating element.
  • the light path changing element can use a small-area mirror to change The transmitting optical path and the receiving optical path are combined.
  • the light path changing element may also use a reflector with a through hole, where the through hole is used to transmit the outgoing light of the emitter 203, and the reflector is used to reflect the return light to the detector 205. This can reduce the blocking of the return light by the support of the small mirror in the case of using the small mirror.
  • the optical path changing element is offset from the optical axis of the collimating element 204. In some other implementations, the optical path changing element may also be located on the optical axis of the collimating element 204.
  • the distance measuring device 200 further includes a scanning module 202.
  • the scanning module 202 is placed on the exit optical path of the distance measuring module 210.
  • the scanning module 202 is used to change the transmission direction of the collimated light beam 219 emitted through the collimating element 204 and project it to the external environment, and project the return light to the collimating element 204 .
  • the returned light is converged on the detector 205 via the collimating element 204.
  • the scanning module 202 may include at least one optical element for changing the propagation path of the light beam, wherein the optical element may change the propagation path of the light beam by reflecting, refracting, diffracting, etc. the light beam.
  • the scanning module 202 includes a lens, a mirror, a prism, a galvanometer, a grating, a liquid crystal, an optical phased array (Optical Phased Array), or any combination of the above optical elements.
  • at least part of the optical element is moving, for example, the at least part of the optical element is driven to move by a driving module, and the moving optical element can reflect, refract, or diffract the light beam to different directions at different times.
  • multiple optical elements of the scanning module 202 may rotate or vibrate about a common axis 209, and each rotating or vibrating optical element is used to continuously change the direction of propagation of the incident light beam.
  • the multiple optical elements of the scanning module 202 may rotate at different rotation speeds, or vibrate at different speeds.
  • at least part of the optical elements of the scanning module 202 can rotate at substantially the same rotational speed.
  • the multiple optical elements of the scanning module may also rotate around different axes.
  • the multiple optical elements of the scanning module may also rotate in the same direction, or rotate in different directions; or vibrate in the same direction, or vibrate in different directions, which is not limited herein.
  • the scanning module 202 includes a first optical element 214 and a driver 216 connected to the first optical element 214.
  • the driver 216 is used to drive the first optical element 214 to rotate about a rotation axis 209 to change the first optical element 214 The direction of the collimated light beam 219.
  • the first optical element 214 projects the collimated light beam 219 to different directions.
  • the angle between the direction of the collimated light beam 219 changed by the first optical element and the rotation axis 109 changes as the first optical element 214 rotates.
  • the first optical element 214 includes a pair of opposed non-parallel surfaces through which the collimated light beam 219 passes.
  • the first optical element 214 includes a prism whose thickness varies along at least one radial direction.
  • the first optical element 214 includes a wedge-angle prism, aligning the straight beam 219 for refraction.
  • the scanning module 202 further includes a second optical element 215 that rotates about a rotation axis 209.
  • the rotation speed of the second optical element 215 is different from the rotation speed of the first optical element 214.
  • the second optical element 215 is used to change the direction of the light beam projected by the first optical element 214.
  • the second optical element 115 is connected to another driver 217, and the driver 217 drives the second optical element 215 to rotate.
  • the first optical element 214 and the second optical element 215 may be driven by the same or different drivers, so that the first optical element 214 and the second optical element 215 have different rotation speeds and/or rotations, thereby projecting the collimated light beam 219 to the outside space Different directions can scan a larger spatial range.
  • the controller 218 controls the drivers 216 and 217 to drive the first optical element 214 and the second optical element 215, respectively.
  • the rotation speeds of the first optical element 214 and the second optical element 215 can be determined according to the area and pattern expected to be scanned in practical applications.
  • Drives 216 and 217 may include motors or other drives.
  • the second optical element 215 includes a pair of opposed non-parallel surfaces through which the light beam passes. In one embodiment, the second optical element 215 includes a prism whose thickness varies along at least one radial direction. In one embodiment, the second optical element 215 includes a wedge angle prism.
  • the scanning module 202 further includes a third optical element (not shown) and a driver for driving the third optical element to move.
  • the third optical element includes a pair of opposed non-parallel surfaces through which the light beam passes.
  • the third optical element includes a prism whose thickness varies along at least one radial direction.
  • the third optical element includes a wedge angle prism. At least two of the first, second and third optical elements rotate at different rotational speeds and/or turns.
  • each optical element in the scanning module 202 can project light into different directions, such as the direction and direction 213 of the projected light 211, thus scanning the space around the distance measuring device 200.
  • the light 211 projected by the scanning module 202 hits the detection object 201, a part of the light is reflected by the detection object 201 to the distance measuring device 200 in a direction opposite to the projected light 211.
  • the returned light 212 reflected by the detection object 201 passes through the scanning module 202 and enters the collimating element 204.
  • the detector 205 is placed on the same side of the collimating element 204 as the emitter 203.
  • the detector 205 is used to convert at least part of the returned light passing through the collimating element 204 into an electrical signal.
  • each optical element is coated with an antireflection coating.
  • the thickness of the antireflection film is equal to or close to the wavelength of the light beam emitted by the emitter 203, which can increase the intensity of the transmitted light beam.
  • a filter layer is coated on the surface of an element on the beam propagation path in the distance measuring device, or a filter is provided on the beam propagation path to transmit at least the wavelength band of the beam emitted by the transmitter, Reflect other bands to reduce the noise caused by ambient light to the receiver.
  • the transmitter 203 may include a laser diode through which laser pulses in the order of nanoseconds are emitted.
  • the laser pulse receiving time may be determined, for example, by detecting the rising edge time and/or the falling edge time of the electrical signal pulse. In this way, the distance measuring device 200 can calculate the TOF using the pulse reception time information and the pulse emission time information, thereby determining the distance between the detection object 201 and the distance measuring device 200.
  • the distance and orientation detected by the distance measuring device 200 can be used for remote sensing, obstacle avoidance, mapping, modeling, navigation, and the like.
  • the distance measuring device of the embodiment of the present invention can be applied to a mobile platform, and the distance measuring device can be installed on the platform body of the mobile platform.
  • a mobile platform with a distance measuring device can measure the external environment, for example, measuring the distance between the mobile platform and obstacles for obstacle avoidance and other purposes, and performing two-dimensional or three-dimensional mapping on the external environment.
  • the mobile platform includes at least one of an unmanned aerial vehicle, a car, a remote control car, a robot, and a camera.
  • the distance measuring device is applied to an unmanned aerial vehicle, the platform body is the fuselage of the unmanned aerial vehicle.
  • the platform body When the distance measuring device is applied to an automobile, the platform body is the body of the automobile.
  • the car may be a self-driving car or a semi-automatic car, and no restriction is made here.
  • the platform body When the distance measuring device is applied to a remote control car, the platform body is the body of the remote control car.
  • the platform body When the distance measuring device is applied to a robot, the platform body is a robot.
  • the distance measuring device is applied to a camera, the platform body is the camera itself.

Abstract

一种激光接收电路及测距装置(100,200)、移动平台。激光接收电路包括：光电转换电路和保护电路；光电转换电路用于接收激光脉冲信号，以及将激光脉冲信号转换为电信号，并将电信号输出；保护电路用于在光电转换电路接收的激光脉冲信号大于设定值时对光电转换电路中的电信号进行限流，以防止光电转换电路损坏。激光接收电路、测距装置(100,200)以及移动平台能够实现APD对瞬态强光的快速响应，从而保护APD，在实现APD保护的同时不会对弱信号的响应产生影响，解决了目前雷达收到的很强的脉冲激光会损坏雷达的接收电路的问题。

Description

一种激光接收电路及测距装置、移动平台 技术领域
本发明涉及电路技术领域，尤其涉及一种激光接收电路及测距装置、移动平台。
背景技术
激光雷达是以发射激光束探测目标的位置、速度等特征量的雷达系统。激光雷达的光敏传感器可以将获取到的光脉冲信号转变为电信号，基于比较器获取该电信号对应的时间信息，从而得到激光雷达与目标物之间的距离信息。
在激光测距领域，某些场景下可能会出现多套设备同时工作的情况，比如在自动驾驶领域会有多台激光雷达共同工作，激光雷达在扫描过程中有几率存在两台雷达互相照射的情况，此时雷达将会收到很强的脉冲激光，可能会损坏雷达的接收电路。
因此，需要对目前的激光接收电路和激光雷达进行改进，以消除上述各种问题和弊端。
发明内容
本发明第一方面提供了一种激光接收电路，包括：光电转换电路和保护电路；
所述光电转换电路用于接收激光脉冲信号，以及将所述激光脉冲信号转换为电信号，并将所述电信号输出；
所述保护电路用于在所述光电转换电路接收的所述激光脉冲信号大于设定值时对所述光电转换电路中的电信号进行限流，以防止所述光电转换电路损坏。
可选地，所述保护电路包括限流元件，所述限流元件与所述光电转换电路串联连接，所述限流元件包括至少一个电阻或电感。
可选地，所述保护电路还包括储能电路，其中，所述储能电路与所述限流元件和所述光电转换电路串联连接。
可选地，所述储能电路包括至少一个电容。
可选地，所述保护电路包括充电电路，所述充电电路用于在第一时段内对所述储能电路进行充电，直至所述储能电路的电压饱和。
可选地，所述储能电路还用于在第二时段内当所述光电转换电路接收的激光脉冲信号等于或大于所述设定值时对所述光电转换电路供电。
可选地，所述储能电路还用于在第二时段内当所述光电转换电路接收的激光脉冲信号小于所述设定值时，所述保护电路并不对所述光电转换电路供电。
可选地，所述光电转换电路的一端与所述限流元件的一端电连接，所述光电转换电路的另一端与读取电路电连接，所述限流元件的另一端与所述储能电路的一端电连接，所述储能电路的另一端接地；或者；
所述光电转换电路的一端与所述储能电路的一端电连接，所述光电转换电路的另一端与读取电路电连接，所述储能电路的另一端与所述限流元件的一端电连接，所述限流元件的另一端接地。
可选地，所述充电电路包括电源和第一电阻，所述第一电阻的一端与所述电源电连接，所述第一电阻的另一端与所述保护电路电连接。
可选地，所述充电电路包括三极管、电压校准源、第一电阻和第二电阻；
其中，所述第一电阻的一端与所述电源电连接，所述第一电阻的另一端与所述三极管的基极电连接；所述三极管的集电极与所述电源电连接，所述三极管的发射极与所述第二电阻的一端电连接，所述第二电阻的另一端与所述保护电路电连接，所述电压校准源的一端与所述三极管的基极电连接，所述电压校准源的另一端与所述保护电路电连接。
可选地，所述充电电路中的电阻的阻值大于所述保护电路中的电阻的阻值。
可选地，所述光电转换电路包括光敏传感器，用于接收所述激光脉冲信号，以及将所述激光脉冲信号转换为电信号。
可选地，所述激光接收电路还包括放大电路，所述放大电路用于将从所述光敏传感器输入的电信号放大运算，并将放大运算后的电信号输出。
可选地，所述光敏传感器包括雪崩光电二极管，所述雪崩光电二极管的阴极与所述保护电路电连接，所述雪崩光电二极管的阳极与所述放大电路的输入 端连接。
本发明还提供了一种测距装置，包括：
光发射电路，用于出射激光脉冲信号；
如上述的激光接收电路，用于接收所述光发射电路出射的激光脉冲信号经物体反射回的至少部分激光信号，以及将接收到的所述激光信号转成电信号；
采样电路，用于对来自所述激光接收电路的电信号进行采样，获得采样结果；
运算电路，用于根据所述采样结果计算所述物体与所述测距装置之间的距离。
可选地，所述光发射电路的数量和所述激光接收电路的数量分别为至少2个；
每个所述激光接收电路用于接收来自对应的光发射电路出射的激光脉冲信号经物体反射回的至少部分激光信号，以及将接收到的激光信号转成电信号。
可选地，所述激光测距装置还包括扫描模块；
所述扫描模块用于改变所述激光脉冲信号的传输方向后出射，经物体反射回的激光脉冲信号经过所述扫描模块后入射至所述激光接收电路。
可选地，所述扫描模块还包括驱动器和厚度不均匀的棱镜，所述驱动器用于带动所述棱镜转动，以将经过所述棱镜的激光脉冲信号改变至不同方向出射。
可选地，所述扫描模块还包括两个驱动器，以及两个并列设置的、厚度不均匀的棱镜，所述两个驱动器分别用于驱动所述两个棱镜以相反的方向转动；
来自所述激光发射电路的激光脉冲信号依次经过所述两个棱镜后改变传输方向出射。
本发明还提供了一种移动平台，包括：
上述的测距装置；和
平台本体，所述光发射电路安装在所述平台本体上。
可选地，所述移动平台包括无人飞行器、汽车和机器人中的至少一种。
本发明通过提供上述激光接收电路、测距装置以及移动平台，以实现APD对瞬态强光的快速响应，从而保护APD，在实现APD保护的同时不会对弱信号的响应产生影响，以解决目前雷达将会收到很强的脉冲激光会损坏雷达的接 收电路的问题。
附图说明
为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1是现有技术中的一种激光接收电路的结构示意图；
图2是本发明实施例提供的一种激光接收电路的结构示意图；
图3是本发明另一实施例提供的一种激光接收电路的结构示意图；
图4是本发明实施例提供的一种测距装置的示意性框架图；
图5是本发明实施例提供的测距装置采用同轴光路的一种实施例的示意图。
具体实施方式
下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。
对于激光测距应用，激光器在扫描过程中会不断向空间中的各个方向发出激光，两个激光发射器有概率互相照射，此时接收系统将要承受很高脉冲激光能量，这可能会损坏接收系统中的光电转换电路。
如图1所示，为了避免光电转换电路损坏，现有的方案下主要是在光电转换电路的供电电源上放置小容量电容来限制单个脉冲的能量。但所述方案下存在以下矛盾：
如果电容取太大会导致光电转换电路无法快速响应强光脉冲，如果激光的能量足够强则单个脉冲即有可能损坏光电转换电路；如果电容取得过小会导致光电转换电路输出较大电流后电容的电压出现波动，在脉冲光之后光电转换电路两端的电压缓慢回升、会导致光电转换电路之后的读出电路出现很长的拖尾， 影响光电转换电路本身的响应。
如果电容容量较小时，在经过脉冲电流后光电转换电路两端的电压会很快下跌，但在脉冲电流过后会出现很长的拖尾。一般该电容会取到nF级，但在这种容量下，光电转换电路在受到极强光线照射时会出现瞬时能量过高，电容两端的电压不能迅速变化导致光电转换电路损坏。
为了解决上述问题，本发明提供了一种激光接收电路，包括：
光电转换电路和保护电路；
所述光电转换电路用于接收激光脉冲信号，以及将所述激光脉冲信号转换为电信号，并将所述电信号输出；
所述保护电路用于在所述光电转换电路接收的所述激光脉冲信号大于设定值时对所述光电转换电路中的电信号进行限流，以防止所述光电转换电路损坏。
在本发明的第一实施例中，激光接收电路如图2所示：
其中，所述激光接收电路包括电源、光电转换电路、和保护电路。
其中，电源为VCC_APD，作为保护电路的能量提供端，例如用于为所述保护电路进行充电。
其中，所述光电转换电路包括光敏传感器，用于接收光脉冲信号，以及将所述光脉冲信号转换为电信号。当光电转换电路在接收光脉冲信号之后，将所述光脉冲信号转化为电脉冲信号，所述电脉冲信号包括电压脉冲信号或电流脉冲信号，并不局限于某一种。
可选地，所述光电转换电路包括APD(雪崩光电二极管)。
在本发明的一实施例中，当所述电脉冲信号为电压信号时，其中在第一时段内电脉冲信号为低电平，位于脉冲的波谷处；在第二时段内电脉冲信号为高电平，位于脉冲的峰值处。
其中，所述保护电路包括限流元件，当APD遇到强光产生较大电流时会在限流元件上产生比较高的压降，电压降低后APD的增益会出现下降，APD输出电流降低从而防止APD瞬间功率过大，从而避免APD会烧坏。
可选地，所述限流元件与所述光电转换电路串联连接
在本发明中的实施例中，所述限流元件包括至少一个电阻或电感，用于在所述光电转换电路接收的光脉冲信号大于设定值时对所述光电转换电路中的电流进行限流，以防止所述光电转换电路损坏。需要说明的是，在本发明中所述限流元件并不局限于电阻或电感，其他能够起到限流作用的元件均可应用于本申请。
在第一实施例中，如图2所述，所述限流元件选用电阻R2，其中电阻R2与APD直接串联，限流电阻取小阻值电阻。
可选地，所述保护电路还包括储能电路，其中，所述储能电路与所述限流元件和所述光电转换电路串联连接。
其中，所述储能电路包括至少一个电容C1。
其中，所述电容与所述限流元件和所述光电转换电路串联的方式至少包括以下两种：
第一种：所述光电转换电路的一端与所述限流元件的一端电连接，所述光电转换电路的另一端与读取电路电连接，所述限流元件的另一端与所述储能电路的一端电连接，所述储能电路的另一端接地；或者；
第二种：所述光电转换电路的一端与所述储能电路的一端电连接，所述光电转换电路的另一端与读取电路电连接，所述储能电路的另一端与所述限流元件的一端电连接，所述限流元件的另一端接地。
进一步，所述保护电路包括充电电路，所述充电电路用于在第一时段内对所述储能电路进行充电，直至所述储能电路的电压饱和。当所述光电转换电路件光脉冲信号转化为电脉冲信号时，在第一时段内电脉冲信号为低电平，位于脉冲的波谷处，所述充电电路用于在第一时段内对所述储能电路进行充电，直至所述储能电路的电压饱和。
在第二时段内电脉冲信号为高电平，位于脉冲的峰值处，所述储能电路还用于在第二时段内当所述光电转换电路接收的激光脉冲信号等于或大于所述设定值时对所述光电转换电路供电，消耗储能电路上的能量，使电容两端的电压降低。当电容两端的电压降低时APD的内部增益会下降从而使其输出电流降低，形成负反馈，APD则不会持续输出大电流导致自身损害，从而对APD 起到保护作用。当光电转换电路接收的激光脉冲信号特别强烈时，储能电路对所述光电转换电路供电，直至所述储能电路的能量耗尽，以使所述光电转换电路断路。在所述第二时段内当所述光电转换电路接收的光脉冲信号小于设定值时，所述储能电路并不对所述光电转换电路供电。
其中，所述设定值的大小根据实际需要进行设定，其中常规的接收所述光发射电路出射的激光脉冲信号经物体反射回的至少部分光信号，以及环境光信号均小于该设定值，并且激光器直接发射的光脉冲信号的大小肯定大于该设定值，以保证当激光器互相照射时会触发所述所述保护电路对所述光电转换电路供电，从而保护APD不会损坏。
在本发明的第一实施例的示例中，如图2所示，所述充电电路包括电源VCC_APD和第一电阻R1，所述第一电阻R1的一端与所述电源VCC_APD电连接，所述第一电阻R1的另一端与所述保护电路电连接。
所述保护电路包括限流元件，所述限流元件为限流电阻R2，其中，所述储能电路包括电容C1，所述光电转换电路为雪崩光电二极管APD，其中，所述雪崩光电二极管APD的一端与所述限流电阻R2的一端电连接，所述雪崩光电二极管APD的另一端与读取电路电连接，所述限流电阻R2的另一端与所述储能电路的电容C1的一端电连接，所述储能电路的电容C1的另一端接地。
如图2所示，其中，所述第一电阻R1取比较大的阻值，在脉冲的间隙(第一时段)时，所述雪崩光电二极管APD为关断状态，并不会产生电流，又由于所述第一电阻R1的阻值较大，所述激光接收电路中没有明显的电流，因此在第一时段电源VCC_APD通过第一电阻R1为储能电路的电容C1充电。
在第二时段时，雪崩光电二极管APD接收光脉冲信号并将光脉冲信号转化为电信号，其中，在第二时段所述激光接收电路的工作方式可以分为以下两种：
第一，当所述光电转换电路接收的所述激光脉冲信号小于设定值时，激光接收电路此时正常工作，此时所述激光接收电路中的电流为较小的正常电流，由于限流电阻R2的阻值较小，因此限流电阻R2的两端的电压也很小即限流 电阻R2的分压很小，APD两端的电压在收到脉冲光时变化不大，不会对APD本身的响应产生影响。此外，由于电容C1的取值相对较大，在接收的所述激光脉冲信号为弱信号时电容释放的电荷较少电压波动极小，也不会对APD的响应产生影响，激光接收电路不会受到任何影响，正常工作，其中，储能电容上的电压几乎没有变化，APD的电流响应正常。
第二，当APD遇到强烈的激光脉冲信号时，比如激光脉冲信号的强度大于设定值，强烈的激光脉冲信号产生较大电流，此时会在限流电阻R2上产生比较高的压降，使得APD两端的电压降低，电压降低后APD的增益会出现下降(由于APD本身是存在内部增益的(光电转换具有倍增效应)，APD的增益随电压变化，当电压降低时APD的增益会下降)，从而使输出电流降低，APD输出电流降低从而防止APD瞬间功率过大，避免输出很大的电流导致APD损坏。
进一步，在某些状态下APD会受到异常强的光照，例如激光器对照，(此时输出电流会非常大比如超过100mA)，在该情况下限流阻值R2上的压降有限，APD依然会输出很大的电流导致损坏。此时，为了避免所述情况，储能电容C1会持续为APD提供能量并将自身的电荷耗尽，以最终形成断路，即使APD持续受到强光照射或无法恢复高阻状态，APD两端的电压也会降低到0V，从而实现对APD的保护。
综上两种工作方式可以看到，在正常使用时该保护电路并不会对APD的工作产生影响，而在受到强光时首先由限流电阻快速响应限制APD的最大电流，随后通过将电容的电荷耗尽实现对APD的熄灭，进而对所述APD进行保护，防止电流过大损坏。
本发明的第二实施例中，光发射装置如图3所示：
其中，所述激光接收电路包括电源、光电转换电路、和保护电路。其中，所述激光接收电路包括电源、光电转换电路、和保护电路。
其中，电源为VCC_APD，作为保护电路的能量提供端，例如用于为所述保护电路进行充电。
其中，所述光电转换电路包括光敏传感器，用于接收光脉冲信号，以及将 所述光脉冲信号转换为电信号。当光电转换电路在接收光脉冲信号之后，将所述光脉冲信号转化为电脉冲信号，所述电脉冲信号包括电压脉冲信号或电流脉冲信号，并不局限于某一种。
可选地，所述光电转换电路包括APD(雪崩光电二极管)。
在本发明第二实施例的一示例中，当所述电脉冲信号为电压信号时，其中在第一时段内电脉冲信号为低电平，位于脉冲的波谷处；在第二时段内电脉冲信号为高电平，位于脉冲的峰值处。
其中，所述保护电路包括限流元件，当APD遇到强光产生较大电流时会在限流元件上产生比较高的压降，电压降低后APD的增益会出现下降，APD输出电流降低从而防止APD瞬间功率过大，从而避免APD会烧坏。
可选地，所述限流元件与所述光电转换电路串联连接
在本发明中的实施例中，所述限流元件包括至少一个电阻或电感，用于在所述光电转换电路接收的光脉冲信号大于设定值时对所述光电转换电路中的电流进行限流，以防止所述光电转换电路损坏。需要说明的是，在本发明中所述限流元件并不局限于电阻或电感，其他能够起到限流作用的元件均可应用于本申请。
示例性地，如图3所述，所述限流元件选用电阻R3，其中电阻R3与APD直接串联，限流电阻取小阻值电阻。
可选地，所述保护电路还包括储能电路，其中，所述储能电路与所述限流元件和所述光电转换电路串联连接。
其中，所述储能电路包括至少一个电容C1，所述电容C1与所述限流元件和所述光电转换电路串联连接。
其中，所述电容与所述限流元件和所述光电转换电路串联的方式至少包括以下两种：
第一，所述光电转换电路的一端与所述限流元件的一端电连接，所述光电转换电路的另一端与读取电路电连接，所述限流元件的另一端与所述储能电路的一端电连接，所述储能电路的另一端接地；或者；
所述光电转换电路的一端与所述储能电路的一端电连接，所述光电转换电 路的另一端与读取电路电连接，所述储能电路的另一端与所述限流元件的一端电连接，所述限流元件的另一端接地。
进一步，所述保护电路包括充电电路，所述充电电路用于在第一时段内对所述储能电路进行充电，直至所述储能电路的电压饱和。当所述光电转换电路件光脉冲信号转化为电脉冲信号时，在第一时段内电脉冲信号为低电平，位于脉冲的波谷处，所述充电电路用于在第一时段内对所述储能电路进行充电，直至所述储能电路的电压饱和。
在第二时段内电脉冲信号为高电平，位于脉冲的峰值处，所述储能电路还用于在第二时段内当所述光电转换电路接收的激光脉冲信号等于或大于所述设定值时对所述光电转换电路供电，消耗储能电路上的能量，使电容两端的电压降低。当电容两端的电压降低时APD的内部增益会下降从而使其输出电流降低，形成负反馈，APD则不会持续输出大电流导致自身损害，从而对APD起到保护作用。当光电转换电路接收的激光脉冲信号特别强烈时，储能电路对所述光电转换电路供电，直至所述储能电路的能量耗尽，以使所述光电转换电路断路。在所述第二时段内当所述光电转换电路接收的光脉冲信号小于设定值时，所述储能电路并不对所述光电转换电路供电。
其中，常规的接收所述光发射电路出射的激光脉冲信号经物体反射回的至少部分光信号，以及环境光信号均小于该设定值，并且激光器直接发射的光脉冲信号的大小肯定大于该设定值，以保证当激光器互相照射时会触发所述所述保护电路对所述光电转换电路供电，从而保护APD不会损坏。
在本发明的第一实施例的示例中，如图3所示，所述充电电路包括电源VCC_APD、第一电阻R1、第二电阻R2，三极管Q1、电压校准源Q2，其中，所述第一电阻R1的一端与所述电源VCC_APD电连接，所述第一电阻R1的另一端与所述三极管Q1NPN的基极电连接；所述三极管NPN的集电极与所述电源VCC_APD电连接，所述三极管NPN的发射极与所述第二电阻R2的一端电连接，所述第二电阻R2的另一端与电容C1的一端电连接，所述电压校准源Q2的一端与所述三极管NPN的基极电连接，所述电压校准源Q2的另一端与所述电容C1电连接。
在该实施例中，由第一电阻R1、第二电阻R2，三极管Q1、电压校准源Q22组成的充电电路为C1进行充电，其中，所述第一电阻R1的电阻值较大，在充电电路中用于限制充电电路中的电流，起到限流的作用。
其中，稳压管Q2其电流可在很大范围内变化而电压基本不变的现象，通过额定电流时两端产生的稳定电压值，以用于输出稳定的电压对所述电容C1进行充电。
如图3所示，其中，所述第一电阻R1取比较大的阻值，在脉冲的间隙(第一时段)时，所述雪崩光电二极管APD为关断状态，并不会产生电流，又由于所述第一电阻R1的阻值较大，所述激光接收电路中没有明显的电流，因此在第一时段电源VCC_APD通过第一电阻R1为储能电路的电容C1充电。此外，由于稳压管Q2的设置，可以使所述充电的电压更加稳定和高效。第一电阻的设置还可以用于限制电流的大小。
在第二时段时，雪崩光电二极管APD接收光脉冲信号并将光脉冲信号转化为电信号，其中，在第二时段所述激光接收电路的工作方式可以分为以下两种：
第一，当所述光电转换电路接收的所述激光脉冲信号小于设定值时，激光接收电路此时正常工作，此时所述激光接收电路中的电流为较小的正常电流，由于限流电阻R2的阻值较小，因此限流电阻R2的两端的电压也很小即限流电阻R2的分压很小，APD两端的电压在收到脉冲光时变化不大，不会对APD本身的响应产生影响。此外，由于电容C1的取值相对较大，在接收的所述激光脉冲信号为弱信号时电容释放的电荷较少电压波动极小，也不会对APD的响应产生影响，激光接收电路不会受到任何影响，正常工作，其中，储能电容上的电压几乎没有变化，APD的电流响应正常。
第二，当APD遇到强烈的激光脉冲信号时，比如激光脉冲信号的强度大于设定值，强烈的激光脉冲信号产生较大电流，此时会在限流电阻R2上产生比较高的压降，使得APD两端的电压降低，电压降低后APD的增益会出现下降(由于APD本身是存在内部增益的(光电转换具有倍增效应)，APD的增益随电压变化，当电压降低时APD的增益会下降)，从而使输出电流降低，APD输出电流降低从而防止APD瞬间功率过大，避免输出很大的电流导致APD损坏。
进一步，在某些状态下APD会受到异常强的光照，例如激光器对照，(此时输出电流会非常大比如超过100mA)，在该情况下限流阻值R2上的压降有限，APD依然会输出很大的电流导致损坏。此时，为了避免所述情况，储能电容C1会持续为APD提供能量并将自身的电荷耗尽，以最终形成断路，即使APD持续受到强光照射或无法恢复高阻状态，APD两端的电压也会降低到0V，从而实现对APD的保护。
综上两种工作方式可以看到，在正常使用时该保护电路并不会对APD的工作产生影响，而在受到强光时首先由限流电阻快速响应限制APD的最大电流，随后通过将电容的电荷耗尽实现对APD的熄灭，进而对所述APD进行保护，防止电流过大损坏。
进一步，所述激光接收电路还包括放大电路，所述放大电路用于将从所述光敏传感器输入的电信号放大运算，并将放大运算后的电信号输出。其中，所述放大电路的具体结构可以选用本领域常用的结构。
在另一个实施例中，本发明实施例还提供了一种测距装置，包括：光发射电路，用于出射激光脉冲信号；上述实施例中的任一项所述的激光接收电路，用于接收所述光发射电路出射的激光脉冲信号经物体反射回的至少部分激光信号，以及将接收到的所述激光信号转成电信号；采样电路，用于对来自所述激光接收电路的电信号进行采样，获得采样结果；运算电路，用于根据所述采样结果计算所述物体与所述测距装置之间的距离。
在一种实施方式中，测距装置用于感测外部环境信息，例如，环境目标的距离信息、方位信息、反射强度信息、速度信息等。一种实现方式中，测距装置可以通过测量测距装置和探测物之间光传播的时间，即光飞行时间(Time-of-Flight，TOF)，来探测探测物到测距装置的距离。或者，测距装置也可以通过其他技术来探测探测物到测距装置的距离，例如基于相位移动(phase shift)测量的测距方法，或者基于频率移动(frequency shift)测量的测距方法，在此不做限制。
为了便于理解，以下将结合图4所示的测距装置100对测距的工作流程进行举例描述。
如图4所示，测距装置100可以包括发射电路110、接收电路120、采样电路130和运算电路140。
发射电路110可以发射光脉冲序列(例如激光脉冲序列)。接收电路120可以接收经过被探测物反射的光脉冲序列，并对该光脉冲序列进行光电转换，以得到电信号，再对电信号进行处理之后可以输出给采样电路130。采样电路130可以对电信号进行采样，以获取采样结果。运算电路140可以基于采样电路130的采样结果，以确定测距装置100与被探测物之间的距离。
可选地，该测距装置100还可以包括控制电路150，该控制电路150可以实现对其他电路的控制，例如，可以控制各个电路的工作时间和/或对各个电路进行参数设置等。
应理解，虽然图4示出的测距装置中包括一个发射电路、一个接收电路、一个采样电路和一个运算电路，用于出射一路光束进行探测，但是本申请实施例并不限于此，发射电路、接收电路、采样电路、运算电路中的任一种电路的数量也可以是至少两个，用于沿相同方向或分别沿不同方向出射至少两路光束；其中，该至少两束光路可以是同时出射，也可以是分别在不同时刻出射。一个示例中，该至少两个发射电路中的发光芯片封装在同一个模块中。例如，每个发射电路包括一个激光发射芯片，该至少两个发射电路中的激光发射芯片中的die封装到一起，容置在同一个封装空间中。
一些实现方式中，除了图4所示的电路，测距装置100还可以包括扫描模块，用于将发射电路出射的至少一路激光脉冲序列改变传播方向出射。
其中，可以将包括发射电路110、接收电路120、采样电路130和运算电路140的模块，或者，包括发射电路110、接收电路120、采样电路130、运算电路140和控制电路150的模块称为测距模块，该测距模块可以独立于其他模块，例如，扫描模块。
测距装置中可以采用同轴光路，也即测距装置出射的光束和经反射回来的光束在测距装置内共用至少部分光路。例如，发射电路出射的至少一路激光脉冲序列经扫描模块改变传播方向出射后，经探测物反射回来的激光脉冲序列经过扫描模块后入射至接收电路。或者，测距装置也可以采用异轴光路，也即测 距装置出射的光束和经反射回来的光束在测距装置内分别沿不同的光路传输。图5示出了本发明的测距装置采用同轴光路的一种实施例的示意图。
测距装置200包括测距模块210，测距模块210包括发射器203(可以包括上述的发射电路)、准直元件204、探测器205(可以包括上述的接收电路、采样电路和运算电路)和光路改变元件206。测距模块210用于发射光束，且接收回光，将回光转换为电信号。其中，发射器203可以用于发射光脉冲序列。在一个实施例中，发射器203可以发射激光脉冲序列。可选的，发射器203发射出的激光束为波长在可见光范围之外的窄带宽光束。准直元件204设置于发射器的出射光路上，用于准直从发射器203发出的光束，将发射器203发出的光束准直为平行光出射至扫描模块。准直元件还用于会聚经探测物反射的回光的至少一部分。该准直元件204可以是准直透镜或者是其他能够准直光束的元件。
在图5所示实施例中，通过光路改变元件206来将测距装置内的发射光路和接收光路在准直元件204之前合并，使得发射光路和接收光路可以共用同一个准直元件，使得光路更加紧凑。在其他的一些实现方式中，也可以是发射器203和探测器205分别使用各自的准直元件，将光路改变元件206设置在准直元件之后的光路上。
在图5所示实施例中，由于发射器203出射的光束的光束孔径较小，测距装置所接收到的回光的光束孔径较大，所以光路改变元件可以采用小面积的反射镜来将发射光路和接收光路合并。在其他的一些实现方式中，光路改变元件也可以采用带通孔的反射镜，其中该通孔用于透射发射器203的出射光，反射镜用于将回光反射至探测器205。这样可以减小采用小反射镜的情况中小反射镜的支架会对回光的遮挡。
在图5所示实施例中，光路改变元件偏离了准直元件204的光轴。在其他的一些实现方式中，光路改变元件也可以位于准直元件204的光轴上。
测距装置200还包括扫描模块202。扫描模块202放置于测距模块210的出射光路上，扫描模块202用于改变经准直元件204出射的准直光束219的传输方向并投射至外界环境，并将回光投射至准直元件204。回光经准直元件204 汇聚到探测器205上。
在一个实施例中，扫描模块202可以包括至少一个光学元件，用于改变光束的传播路径，其中，该光学元件可以通过对光束进行反射、折射、衍射等等方式来改变光束传播路径。例如，扫描模块202包括透镜、反射镜、棱镜、振镜、光栅、液晶、光学相控阵(Optical Phased Array)或上述光学元件的任意组合。一个示例中，至少部分光学元件是运动的，例如通过驱动模块来驱动该至少部分光学元件进行运动，该运动的光学元件可以在不同时刻将光束反射、折射或衍射至不同的方向。在一些实施例中，扫描模块202的多个光学元件可以绕共同的轴209旋转或振动，每个旋转或振动的光学元件用于不断改变入射光束的传播方向。在一个实施例中，扫描模块202的多个光学元件可以以不同的转速旋转，或以不同的速度振动。在另一个实施例中，扫描模块202的至少部分光学元件可以以基本相同的转速旋转。在一些实施例中，扫描模块的多个光学元件也可以是绕不同的轴旋转。在一些实施例中，扫描模块的多个光学元件也可以是以相同的方向旋转，或以不同的方向旋转；或者沿相同的方向振动，或者沿不同的方向振动，在此不作限制。
在一个实施例中，扫描模块202包括第一光学元件214和与第一光学元件214连接的驱动器216，驱动器216用于驱动第一光学元件214绕转动轴209转动，使第一光学元件214改变准直光束219的方向。第一光学元件214将准直光束219投射至不同的方向。在一个实施例中，准直光束219经第一光学元件改变后的方向与转动轴109的夹角随着第一光学元件214的转动而变化。在一个实施例中，第一光学元件214包括相对的非平行的一对表面，准直光束219穿过该对表面。在一个实施例中，第一光学元件214包括厚度沿至少一个径向变化的棱镜。在一个实施例中，第一光学元件214包括楔角棱镜，对准直光束219进行折射。
在一个实施例中，扫描模块202还包括第二光学元件215，第二光学元件215绕转动轴209转动，第二光学元件215的转动速度与第一光学元件214的转动速度不同。第二光学元件215用于改变第一光学元件214投射的光束的方向。在一个实施例中，第二光学元件115与另一驱动器217连接，驱动器217 驱动第二光学元件215转动。第一光学元件214和第二光学元件215可以由相同或不同的驱动器驱动，使第一光学元件214和第二光学元件215的转速和/或转向不同，从而将准直光束219投射至外界空间不同的方向，可以扫描较大的空间范围。在一个实施例中，控制器218控制驱动器216和217，分别驱动第一光学元件214和第二光学元件215。第一光学元件214和第二光学元件215的转速可以根据实际应用中预期扫描的区域和样式确定。驱动器216和217可以包括电机或其他驱动器。
在一个实施例中，第二光学元件215包括相对的非平行的一对表面，光束穿过该对表面。在一个实施例中，第二光学元件215包括厚度沿至少一个径向变化的棱镜。在一个实施例中，第二光学元件215包括楔角棱镜。
一个实施例中，扫描模块202还包括第三光学元件(图未示)和用于驱动第三光学元件运动的驱动器。可选地，该第三光学元件包括相对的非平行的一对表面，光束穿过该对表面。在一个实施例中，第三光学元件包括厚度沿至少一个径向变化的棱镜。在一个实施例中，第三光学元件包括楔角棱镜。第一、第二和第三光学元件中的至少两个光学元件以不同的转速和/或转向转动。
扫描模块202中的各光学元件旋转可以将光投射至不同的方向，例如投射的光211的方向和方向213，如此对测距装置200周围的空间进行扫描。当扫描模块202投射出的光211打到探测物201时，一部分光被探测物201沿与投射的光211相反的方向反射至测距装置200。探测物201反射的回光212经过扫描模块202后入射至准直元件204。
探测器205与发射器203放置于准直元件204的同一侧，探测器205用于将穿过准直元件204的至少部分回光转换为电信号。
一个实施例中，各光学元件上镀有增透膜。可选的，增透膜的厚度与发射器203发射出的光束的波长相等或接近，能够增加透射光束的强度。
一个实施例中，测距装置中位于光束传播路径上的一个元件表面上镀有滤光层，或者在光束传播路径上设置有滤光器，用于至少透射发射器所出射的光束所在波段，反射其他波段，以减少环境光给接收器带来的噪音。
在一些实施例中，发射器203可以包括激光二极管，通过激光二极管发射 纳秒级别的激光脉冲。进一步地，可以确定激光脉冲接收时间，例如，通过探测电信号脉冲的上升沿时间和/或下降沿时间确定激光脉冲接收时间。如此，测距装置200可以利用脉冲接收时间信息和脉冲发出时间信息计算TOF，从而确定探测物201到测距装置200的距离。
测距装置200探测到的距离和方位可以用于遥感、避障、测绘、建模、导航等。在一种实施方式中，本发明实施方式的测距装置可应用于移动平台，测距装置可安装在移动平台的平台本体。具有测距装置的移动平台可对外部环境进行测量，例如，测量移动平台与障碍物的距离用于避障等用途，和对外部环境进行二维或三维的测绘。在某些实施方式中，移动平台包括无人飞行器、汽车、遥控车、机器人、相机中的至少一种。当测距装置应用于无人飞行器时，平台本体为无人飞行器的机身。当测距装置应用于汽车时，平台本体为汽车的车身。该汽车可以是自动驾驶汽车或者半自动驾驶汽车，在此不做限制。当测距装置应用于遥控车时，平台本体为遥控车的车身。当测距装置应用于机器人时，平台本体为机器人。当测距装置应用于相机时，平台本体为相机本身。
本发明实施例中所使用的技术术语仅用于说明特定实施例而并不旨在限定本发明。在本文中，单数形式“一”、“该”及“所述”用于同时包括复数形式，除非上下文中明确另行说明。进一步地，在说明书中所使用的用于“包括”和/或“包含”是指存在所述特征、整体、步骤、操作、元件和/或构件，但是并不排除存在或增加一个或多个其它特征、整体、步骤、操作、元件和/或构件。
在所附权利要求中对应结构、材料、动作以及所有装置或者步骤以及功能元件的等同形式(如果存在的话)旨在包括结合其他明确要求的元件用于执行该功能的任何结构、材料或动作。本发明的描述出于实施例和描述的目的被给出，但并不旨在是穷举的或者将被发明限制在所公开的形式。在不偏离本发明的范围和精神的情况下，多种修改和变形对于本领域的一般技术人员而言是显而易见的。本发明中所描述的实施例能够更好地揭示本发明的原理与实际应用，并使本领域的一般技术人员可了解本发明。
本发明中所描述的流程图仅仅为一个实施例，在不偏离本发明的精神的情况下对此图示或者本发明中的步骤可以有多种修改变化。比如，可以不同次序的执行这些步骤，或者可以增加、删除或者修改某些步骤。本领域的一般技术人员可以理解实现上述实施例的全部或部分流程，并依本发明权利要求所作的等同变化，仍属于发明所涵盖的范围。

Claims (21)

  1. 一种激光接收电路，其特征在于，包括：光电转换电路和保护电路；
    所述光电转换电路用于接收激光脉冲信号，以及将所述激光脉冲信号转换为电信号，并将所述电信号输出；
    所述保护电路用于在所述光电转换电路接收的所述激光脉冲信号大于设定值时对所述光电转换电路中的电信号进行限流，以防止所述光电转换电路损坏。
  2. 根据权利要求1所述的激光接收电路，其特征在于，所述保护电路包括限流元件，所述限流元件与所述光电转换电路串联连接，所述限流元件包括至少一个电阻或电感。
  3. 根据权利要求2所述的激光接收电路，其特征在于，所述保护电路还包括储能电路，其中，所述储能电路与所述限流元件和所述光电转换电路串联连接。
  4. 根据权利要求3所述的激光接收电路，其特征在于，所述储能电路包括至少一个电容。
  5. 根据权利要求3所述的激光接收电路，其特征在于，所述保护电路包括充电电路，所述充电电路用于在第一时段内对所述储能电路进行充电，直至所述储能电路的电压饱和。
  6. 根据权利要求3所述的激光接收电路，其特征在于，所述储能电路还用于在第二时段内当所述光电转换电路接收的激光脉冲信号等于或大于所述设定值时对所述光电转换电路供电。
  7. 根据权利要求3所述的激光接收电路，其特征在于，所述储能电路还用于在第二时段内当所述光电转换电路接收的激光脉冲信号小于所述设定值时，所述保护电路并不对所述光电转换电路供电。
  8. 根据权利要求3所述的激光接收电路，其特征在于，所述光电转换电路的一端与所述限流元件的一端电连接，所述光电转换电路的另一端与读取电 路电连接，所述限流元件的另一端与所述储能电路的一端电连接，所述储能电路的另一端接地；或者；
    所述光电转换电路的一端与所述储能电路的一端电连接，所述光电转换电路的另一端与读取电路电连接，所述储能电路的另一端与所述限流元件的一端电连接，所述限流元件的另一端接地。
  9. 根据权利要求5所述的激光接收电路，其特征在于，所述充电电路包括电源和第一电阻，所述第一电阻的一端与所述电源电连接，所述第一电阻的另一端与所述保护电路电连接。
  10. 根据权利要求5所述的激光接收电路，其特征在于，所述充电电路包括三极管、电压校准源、第一电阻和第二电阻；
    其中，所述第一电阻的一端与所述电源电连接，所述第一电阻的另一端与所述三极管的基极电连接；所述三极管的集电极与所述电源电连接，所述三极管的发射极与所述第二电阻的一端电连接，所述第二电阻的另一端与所述保护电路电连接，所述电压校准源的一端与所述三极管的基极电连接，所述电压校准源的另一端与所述保护电路电连接。
  11. 根据权利要求5所述的激光接收电路，其特征在于，所述充电电路中的电阻的阻值大于所述保护电路中的电阻的阻值。
  12. 根据权利要求1所述的激光接收电路，其特征在于，所述光电转换电路包括光敏传感器，用于接收所述激光脉冲信号，以及将所述激光脉冲信号转换为电信号。
  13. 根据权利要求12所述的激光接收电路，其特征在于，所述激光接收电路还包括放大电路，所述放大电路用于将从所述光敏传感器输入的电信号放大运算，并将放大运算后的电信号输出。
  14. 根据权利要求11所述的激光接收电路，其特征在于，所述光敏传感器包括雪崩光电二极管，所述雪崩光电二极管的阴极与所述保护电路电连接，所述雪崩光电二极管的阳极与所述放大电路的输入端连接。
  15. 一种测距装置，其特征在于，包括：
    光发射电路，用于出射激光脉冲信号；
    如权利要求1至14任一项所述的激光接收电路，用于接收所述光发射电路出射的激光脉冲信号经物体反射回的至少部分激光信号，以及将接收到的所述激光信号转成电信号；
    采样电路，用于对来自所述激光接收电路的电信号进行采样，获得采样结果；
    运算电路，用于根据所述采样结果计算所述物体与所述测距装置之间的距离。
  16. 根据权利要求15所述的测距装置，其特征在于，所述光发射电路的数量和所述激光接收电路的数量分别为至少2个；
    每个所述激光接收电路用于接收来自对应的光发射电路出射的激光脉冲信号经物体反射回的至少部分激光信号，以及将接收到的激光信号转成电信号。
  17. 根据权利要求15或16所述的测距装置，其特征在于，所述激光测距装置还包括扫描模块；
    所述扫描模块用于改变所述激光脉冲信号的传输方向后出射，经物体反射回的激光脉冲信号经过所述扫描模块后入射至所述激光接收电路。
  18. 根据权利要求17所述的测距装置，其特征在于，所述扫描模块还包括驱动器和厚度不均匀的棱镜，所述驱动器用于带动所述棱镜转动，以将经过所述棱镜的激光脉冲信号改变至不同方向出射。
  19. 根据权利要求18所述的测距装置，其特征在于，所述扫描模块还包括两个驱动器，以及两个并列设置的、厚度不均匀的棱镜，所述两个驱动器分别用于驱动所述两个棱镜以相反的方向转动；
    来自所述激光发射电路的激光脉冲信号依次经过所述两个棱镜后改变传输方向出射。
  20. 一种移动平台，其特征在于，包括：
    权利要求15至19任一项所述的测距装置；和
    平台本体，所述光发射电路安装在所述平台本体上。
  21. 根据权利要求20所述的移动平台，其特征在于，所述移动平台包括无人飞行器、汽车和机器人中的至少一种。
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