WO2020142948A1 - 一种激光雷达设备、专用集成电路及测距装置 - Google Patents

一种激光雷达设备、专用集成电路及测距装置 Download PDF

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Publication number
WO2020142948A1
WO2020142948A1 PCT/CN2019/071034 CN2019071034W WO2020142948A1 WO 2020142948 A1 WO2020142948 A1 WO 2020142948A1 CN 2019071034 W CN2019071034 W CN 2019071034W WO 2020142948 A1 WO2020142948 A1 WO 2020142948A1
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Prior art keywords
signal
integrated circuit
unit
time measurement
specific integrated
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PCT/CN2019/071034
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English (en)
French (fr)
Inventor
高明明
梅雄泽
刘祥
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深圳市大疆创新科技有限公司
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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/CN2019/071034 priority Critical patent/WO2020142948A1/zh
Priority to CN201980005044.4A priority patent/CN111758049A/zh
Publication of WO2020142948A1 publication Critical patent/WO2020142948A1/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
    • G01S17/06—Systems determining position data of a target
    • G01S17/08—Systems determining position data of a target for measuring distance only
    • G01S17/32—Systems determining position data of a target for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
    • G01S17/36—Systems determining position data of a target for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated with phase comparison between the received signal and the contemporaneously transmitted signal
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/88—Lidar systems specially adapted for specific applications

Definitions

  • the invention relates to the technical field of electronics, and in particular to a laser radar device, a special integrated circuit and a distance measuring device.
  • Lidar equipment is a device that calculates and obtains the distance, distance change, bearing, etc. from the target to the signal transmission point through the transmission and reception of laser signals.
  • the laser radar device emits a laser beam through the transmitter during range measurement. After encountering the target object, the laser beam undergoes diffuse reflection or reflection, and then returns to the laser receiver and is converted into an electrical signal. After receiving the electrical signal, the laser lidar device calculates the time interval t between sending the laser signal and receiving the laser reflection signal, and then dividing it by 2 and multiplying by the speed of light v to calculate the distance s between the transmitter and the target object; The information of the emission angle of the light pulse can reconstruct the three-dimensional depth information of the target object.
  • Embodiments of the present invention provide a laser radar device, a dedicated integrated circuit, and a distance measuring device, which can integrate a dedicated time measurement unit into a dedicated integrated circuit ASIC, and use the logic clock frequency of the ASIC to perform time calculation to facilitate the implementation of Lidar equipment for accurate distance measurement.
  • an embodiment of the present invention provides a lidar device, including: a transmitter for transmitting a laser transmission signal, a receiver for receiving a laser reflection signal, and an application specific integrated circuit ASIC module, wherein:
  • the application specific integrated circuit ASIC module integrates a processing unit and a time measurement unit, the processing unit is respectively connected to the transmitter and the receiver, the processing unit is connected to the time measurement unit, and the time measurement unit is The receiver is connected;
  • the time measurement unit is configured to record time measurement information of the signal to be measured according to the logic clock of the ASIC module of the dedicated integrated circuit, and the signal to be measured is obtained according to the laser reflection signal received by the receiver;
  • the processing unit is used to control the transmitter and the receiver, and calculate the response time of the signal to be measured according to the time measurement information output by the time measurement unit and the logic clock of the ASIC module of the application specific integrated circuit.
  • an embodiment of the present invention also provides a dedicated integrated circuit, which integrates a processing unit and a time measurement unit, and the processing unit is connected to the time measurement unit;
  • the time measurement unit is used to record time measurement information of the signal to be measured input from the outside according to the logic clock of the ASIC module of the dedicated integrated circuit;
  • the processing unit is configured to calculate the response time of the signal to be measured according to the time measurement information output by the time measurement unit and the logic clock of the ASIC module of the application specific integrated circuit.
  • the embodiments of the present invention use an ASIC to integrate the processing unit and the time measurement unit, and perform related data recording based on the clock frequency of the ASIC, which not only completely implements the integrated processing of a single chip of the laser radar device, but also reduces cost, power consumption, area, and performance Better, more conducive to structural design, and can get more accurate time and other information, specifically can measure the time measurement accuracy of one hundred picoseconds (ps), or even sub-100 ps, to obtain centimeter-level time measurement capabilities, thus more Accurately realize the lidar ranging function.
  • FIG. 1 is a schematic structural diagram of a laser radar device according to an embodiment of the present invention.
  • FIG. 2 is a schematic structural diagram of a time measurement unit according to an embodiment of the present invention.
  • FIG. 3 is a schematic structural diagram of a delay chain implemented by a sampling AND gate according to an embodiment of the present invention
  • FIG. 4 is a schematic diagram of implementation principles of coarse timing and fine timing according to an embodiment of the present invention.
  • 5a is a schematic structural diagram of a comparator and delay measurement circuit according to an embodiment of the present invention.
  • 5b is a schematic structural diagram of another comparator and delay measurement circuit according to an embodiment of the present invention.
  • FIG. 5c is a schematic diagram of the effect of using a comparator to perform a signal under test according to an embodiment of the present invention
  • FIG. 6 is a schematic structural diagram of an ASIC module according to an embodiment of the present invention.
  • FIG. 7 is a schematic structural diagram of a distance measuring device according to an embodiment of the present invention.
  • FIG. 8 is a schematic diagram of an embodiment of the distance measuring device of the present invention using a coaxial optical path.
  • the embodiment of the present invention uses an application specific integrated circuit (Application Specific Integrated Circuit, ASIC) to design the core unit of the lidar device.
  • ASIC Application Specific Integrated Circuit
  • At least the time measurement unit 103 and the processing unit 104 are integrated in the ASIC to obtain an ASIC module, and the time measurement unit 103 is used in the ASIC
  • the time of the signal to be measured is measured under the trigger of the logic clock of the device to obtain the time measurement information of the signal to be measured.
  • the processing unit 104 also integrated on the ASIC can obtain a more accurate response time based on the time measurement information.
  • the response time can be It is used to calculate the reception time of the laser reflection signal corresponding to the signal to be measured, and then obtain more accurate time interval and distance data of the laser radar signal transmission and reception.
  • the logic clock or frequency of the ASIC module can be configured and determined when the ASIC module is integrated.
  • the embodiment of the invention can completely realize the integrated processing of a single chip of the laser radar device, which reduces cost, power consumption, area, performance, and is more conducive to structural design; high integration, and can obtain more accurate time and other information, Specifically, the time measurement accuracy of 100 picoseconds (ps) and even sub-100 ps can be measured to obtain centimeter-level time measurement capabilities, thereby achieving the lidar ranging function more accurately.
  • FIG. 1 is a schematic structural diagram of a laser radar device according to an embodiment of the present invention.
  • the laser radar device includes an emitter 101 for emitting a laser emission signal and a laser reflection signal for receiving Receiver 102 and application specific integrated circuit ASIC module 100.
  • FIG. 1 simply illustrates the structure of the lidar device according to the embodiment of the present invention, and is used to highlight the ASIC module 100 integrating the time measuring unit 103 and the processing unit 104 and the transmitter 101 and receiver of the lidar device. The relationship between 102.
  • the transmitter 101 may include a emitting device for emitting a laser emission signal, and may also include a beam splitter, a prism, a motor, and other components as required.
  • the receiver 102 also includes a receiver that reflects the target. Receiver device for laser reflection signal, as well as beam splitter, prism, motor and other components.
  • a laser radar probe can be shared between the transmitter 101 and the receiver 102, and a laser emission signal and a laser reflection signal can be sent by a built-in transceiver signal switching method.
  • the application specific integrated circuit ASIC module 100 integrates a processing unit 104 and a time measurement unit 103, the processing unit 104 is connected to the transmitter 101 and the receiver 102 respectively, and the processing unit 104 and the time measurement unit 103 Connection, the time measurement unit 103 is connected to the receiver 102; the time measurement unit 103 is used to record time measurement information of the signal to be measured according to the logic clock of the application specific integrated circuit ASIC module 100, and the signal to be measured It is obtained based on the laser reflection signal received by the receiver 102; the processing unit 104 is used to control the transmitter 101 and the receiver 102, and according to the time measurement information output by the time measurement unit 103, an application specific integrated circuit ASIC The logic clock of the module 100 calculates the response time of the signal to be measured.
  • the time measurement unit 103 can accurately measure time information may include three ways, one way is to build a time measurement unit 103 based on the delay measurement circuit to achieve accurate measurement of time information, such as electronic time digital conversion ( Time-to-Digital Converter (TDC) circuit to achieve, by converting the laser reflection signal received by the receiver 102 into a digital signal to obtain the signal to be measured, based on the TDC circuit to achieve accurate measurement of time information; another way is The time measurement unit 103 is constructed based on a comparator plus a delay measurement circuit (such as TDC) to achieve accurate measurement of time information.
  • TDC Time-to-Digital Converter
  • the signal output by the receiver 102 is used as the test Signal; another way is to build a time measurement unit 103 based on an analog-to-digital converter (ADC) to sample the signal output by the receiver 102 during the process of receiving the laser reflection signal to achieve high-speed sampling Accurate measurement.
  • ADC analog-to-digital converter
  • the signal output by the receiver 102 during the process of receiving the laser reflection signal may be the laser reflection signal itself, or it may be a signal after the laser reflection signal is subjected to some processing such as denoising and filtering.
  • the time measurement unit 103 of the ASIC module 100 is constructed based on a TDC circuit.
  • the time measurement unit 103 includes: a delay measurement circuit, and the delay measurement circuit Including N delay chains, latches and counters; the input of each delay chain is the signal to be tested, each delay chain includes M delay circuits, each delay circuit will delay The signal to be tested is output to the latch, and the delayed signal to be tested is output to the next-stage delay circuit; the latch is effective at the latch clock signal of the ASIC module 100 of the dedicated integrated circuit When the edge appears, record the time measurement information of the signal to be measured. Each delay chain will get the corresponding time measurement information, and a response time can be calculated based on each time measurement information.
  • the receiving time of the laser reflection signal received by the receiver 102 is calculated based on the response time of each delay chain of N. For example, the average response time of N delay chains can be used as the reception time of the laser reflection signal corresponding to the signal to be measured.
  • a latch can be configured for each delay chain, or a latch composed of a large number of register arrays can be configured to store time measurement information of each delay chain separately; the counter is used to record the dedicated integrated circuit The number of valid edges of the latched clock signal of the ASIC module 100; where N is a positive integer greater than or equal to 1, and M is a positive integer greater than or equal to 2.
  • N can be 128, that is, there are 128 sets of delay chains, which will correspond to 128 sets of hardware processing results. Based on the processing results obtained by each delay chain through the following calculation method, it can be averaged, etc. To get the final response time of a signal under test.
  • the input of the time measuring unit 103 is a signal to be measured after processing the laser reflection signal received by the receiver 102, and the signal to be measured may be only a signal that has undergone analog-to-digital conversion processing, for example, converting the laser reflection signal to digital
  • the signal is input into the time measurement unit 103, specifically into the delay chain of the delay measurement circuit in FIG.
  • the time measuring unit 103 uses the logic clock of the ASIC as the latch clock, and records in the latch the level information corresponding to the level signal output by each delay circuit on one or more delay chains. These level information It constitutes the time measurement information corresponding to the delay chain.
  • the time measuring unit 103 is mainly used for fine timing of the response time, and then combining the coarse timing to obtain the response time, so as to finally obtain the reception time of the laser reflection signal.
  • coarse timing plus fine timing for example, when the operating frequency of the ASIC is configured to 500 MHz, each time the count of the coarse timing (i.e., the logical clock) corresponds to 2ns (ns nanoseconds), the
  • the clock period of the ASIC is defined as T ck
  • the count time of the latched clock is defined as the coarse time
  • the measurement accuracy of the coarse timing is T ck
  • the coarse count is defined as C r
  • the obtained coarse timing is C r *T ck .
  • Each delay circuit has a delay of about several ps to hundreds of ps. This delay time varies from different manufacturers and different devices.
  • the delay time of each delay circuit is defined as t d It is known that measurements can be made according to the prior art. Input the signal to be tested into the delay circuit of the delay chain, and it will pass a delay circuit every t d time.
  • the latch occurs at the valid edge of the latched clock signal of the ASIC module 100 of the application specific integrated circuit, if the signal to be measured is a rising edge, the rising edge time measurement information is recorded in the latch, otherwise, The falling edge time measurement information will be recorded in the latch.
  • the processing unit 104 is based on the number of 1s appearing in the rising edge time measurement information (ie C r1 ), the delay time interval of the delay circuit (ie t d ), and the number of records of the counter (That is, C r ), and the clock cycle (that is, Tck) of the latched clock signal of the application specific integrated circuit ASIC module 100, Trising is calculated, and Trising can be regarded as the accurate response time of the signal to be measured, which can be The reception time of the laser reflection signal received as the effective edge of the Cr-th latch clock signal. Since the transmission time of the laser radar transmission signal corresponding to the laser reflection signal is known, the transmission and reception time interval of the signal can be calculated, thereby calculating the accurate distance data of the effective edge time of the Cr- th latched clock signal.
  • the time measurement unit 103 may output the time measurement information recorded in the latch to the processing unit 104 for the processing unit 104 to perform measurement of response time and/or reception time. In other embodiments, the time measurement unit 103 may further integrate a measurement unit, and the measurement unit calculates the response time and/or the reception time.
  • the delay circuit includes but is not limited to using OR2 (two-input OR gate) or AND2 (two-input AND gate).
  • OR2 two-input OR gate
  • AND2 two-input AND gate
  • AND2 includes two inputs and one output, one of which is fixedly connected to a high-level signal, and the other one
  • the input is used to cascade with the output of the previous level, and the output is cascaded with the input of the AND gate of the next level.
  • the output is connected to the register to realize the detection of time measurement information.
  • the delay circuit includes an OR gate
  • one input terminal of one OR gate in the delay chain is fixed at a low level, and the other input terminal of the OR gate inputs the signal to be measured or the previous stage delay
  • the delayed test signal output by the time circuit; the output end of the OR gate outputs the delayed test signal to the latch, and outputs the delayed test signal to the next stage delay Time circuit (next level OR gate), as the input of the next level delay circuit.
  • a delay circuit is formed by OR2.
  • OR2 includes two inputs and one output, one of which is fixedly connected to 0, that is, a low-level signal, and the other input is used to cascade with the output of the previous stage.
  • the input of the next level OR gate is cascaded, and the output is connected to the register at the same time to realize the detection of time measurement information.
  • the input of the first level AND2 or OR2 is connected to the signal to be tested.
  • the physical constraints can be adjusted as needed, the distance between the delay circuits, and the position distribution of the registers can be adjusted, so that the length of the trace in the ASIC module 100 is relatively fixed, and the delay of the trace is relatively uniform.
  • the latch includes: a register array integrated on the application specific integrated circuit ASIC module 100, and the time measurement information is recorded by the register array.
  • the logic detects the above “...111111000000" or “...000000111111", and realizes the edge 1 (fine_cnt of rising/falling edge) corresponding to the rising and falling edges of the signal under test Position detection in order to calculate the response time.
  • coarse timing and fine timing for example, 2ns corresponds to a maximum of 100 delay chains, then the time corresponding to each delay chain is 20ps, which means that the fine timing will be accurate to the picosecond level in nanoseconds, compared to 4G
  • the accuracy of the clock signal of the clock is improved by an order of magnitude.
  • FIG. 4 shows a schematic diagram of the implementation principle of coarse timing and fine timing according to an embodiment of the present invention.
  • the signal is measured corresponding to the returned laser reflection signal to obtain the response time of the corresponding signal to be measured, and then the reception time is calculated based on the response time, and the time interval between the laser emission signal and the laser reflection signal can be obtained by the transmission time and the reception time .
  • the conversion of the laser reflection signal received by the receiver 102 into a signal to be measured may be implemented by an analog-to-digital conversion unit ADC, that is, the application specific integrated circuit ASIC module 100 is also integrated An analog-to-digital conversion unit is provided.
  • the analog-to-digital conversion unit is used to perform analog-to-digital conversion on the signal output from the receiver 102 to obtain a signal to be measured, and output the converted signal to be measured to the time measurement unit 103.
  • the signal output by the receiver 102 may be the received laser reflection signal itself.
  • the analog-to-digital conversion unit can send the converted signals to be tested to N sets of delay chains respectively.
  • multiple analog-to-digital conversion units can be integrated on the ASIC module 100 to perform analog-to-digital conversion on the signal output by the receiver 102 Convert to get the signal to be tested.
  • each analog-to-digital conversion unit separately transmits the signal to be tested to one or more delay chains among the N delay chains.
  • the time measurement unit 103 may include a comparator and the TDC circuit mentioned above.
  • One input of the comparator is the signal to be measured output by the receiver 102 during the process of receiving the laser reflection signal.
  • the other input of the comparator is a reference signal; the comparator generates an output signal according to the level amplitude of the signal under test and the level amplitude of the reference signal output by the receiver 102, and outputs the output signal to all
  • the delay measurement circuit may output an output signal to a delay chain of the delay measurement circuit, for example.
  • the role of the comparator is mainly to sample the signal to be measured at different levels and amplitudes to obtain the sampled signal, while the TDC performs the above-mentioned finely-timed time measurement on the different sampled signals. Samples with different sampled amplitudes may obtain different The time measurement result of the fine timing, and the time measurement result based on the different fine timing can be obtained by a calculation method such as averaging to obtain a more accurate fine timing.
  • the level of the reference signal corresponding to the comparators used is not the same. Of course, there may be a case where the level of the reference signal used between some of the comparators is the same.
  • the method of using a high-speed comparator plus a TDC circuit can be understood as a time sampling method based on a voltage threshold (different voltage thresholds correspond to different level amplitudes). When sampling based on the voltage threshold, there is a correlation between the sampling point and the signal under test. It can be considered that the time information of the signal under test is obtained directly, and the time information of the signal under test thus obtained is more effective and direct.
  • the signal input pin 3 of the comparator can be directly connected to the receiver 102, and the received input signal Signal_in is a signal output by the receiver 102, such as a laser reflection signal, of course, it can also pass through a signal processing circuit It is connected to the receiver 102 and receives the signal processed by the signal processing circuit. For example, the signal processing circuit performs processing such as denoising and filtering on the laser reflection signal received by the receiver 102.
  • the signal input pin 4 of the comparator is a reference signal Comparator_Ref, specifically a signal with a certain level amplitude.
  • VCC_COMP at the 6th pin of the comparator and VCC_COMP_IN at the 2nd pin of the comparator represent the power input.
  • the pin 1 of the comparator outputs the compared level signal, specifically, the compared level signal is output to the delay measurement circuit.
  • the output signal of the comparator is high level, otherwise, the output signal is low level.
  • the comparator can be a dedicated comparator, or a differential port can be integrated in the ASIC module to replace the comparator.
  • a multi-voltage threshold comparator and multiple TDC Time measurement by way of circuit. As shown in FIG. 5b, a plurality of comparators and corresponding TDC circuits are included.
  • a signal transmitting unit can also be selected based on the corresponding level amplitude threshold to the comparator Output reference signal, the level amplitude threshold can be configured by the signal transmitting unit, which can be a digital-to-analog converter (DAC) device, and the required level amplitude threshold signal is generated by the DAC device as a reference Signal, and the signal transmitting unit may output different level amplitudes of the reference signals to the comparators based on different level amplitude thresholds.
  • DAC digital-to-analog converter
  • the time measurement unit 103 can also be implemented by a plurality of analog-to-digital conversion units.
  • Time measurement is implemented by a high-speed ADC sampling method.
  • ADC sampling can be understood as an equal interval voltage sampling method based on a time axis.
  • the time and the signal to be measured are independent of each other, and there is no time relationship.
  • the extraction of time information requires a certain extraction algorithm.
  • a pulse model may be established in advance, the pulse shape is restored based on the pulse model and the sampling information sampled by the ADC, and time information (such as response time) is determined based on the restored pulse shape; or, because the pulse edge is linear , You can also directly calculate the time information (such as response time) based on the sampling information.
  • the response time can be comprehensively measured by combining the above-mentioned time measurement method of the comparator plus TDC and the time measurement method of the high-speed ADC.
  • the average of all response times can be obtained as the reception time of the laser reflection signal received by the receiver; the reception time can also be calculated by averaging with different weights; or based on one of the calculated response times
  • the receiver receives the laser reflection signal reception time, and the other response time is used to verify the accuracy of the measurement. For example, when the two get the reception time close based on the measured response time, it means that the measurement is accurate. If the difference is large (Greater than the preset threshold), it is considered that the currently obtained response time or reception time is inaccurate.
  • the embodiment of the invention can realize the integrated processing of a single chip of the laser radar device, which reduces the cost, power consumption, area, performance, is more conducive to structural design, and can obtain more accurate time and other information to obtain the time in the centimeter level
  • the measurement capability can realize the lidar ranging function more accurately.
  • FIG. 6 is a schematic structural diagram of an ASIC module according to an embodiment of the present invention
  • the above-mentioned time measurement unit 602 and a central processing unit CPU 601 that implements the functions of the processing unit are integrated in the ASIC module.
  • Other functional units are also integrated as needed. It can be understood that these other functional units are either used to increase the functions of the lidar equipment or can be implemented on other circuits, such as additionally using an ASIC module or field logic gate array ( field-programmable gate array (FPGA) module.
  • FPGA field-programmable gate array
  • the central processing unit CPU 601 integrated in the ASIC is responsible for overall scheduling and partial function control of the ASIC module, as well as partial algorithm processing and implementation.
  • the CPU 601 may correspond to the above-mentioned processing unit, for example, which can realize the above-mentioned functions of the processing unit.
  • the central processing unit may also be a different functional unit from the above-mentioned processing unit .
  • the CPU is integrated in the system-on-chip (SOC) of the entire ASIC module, which can integrate processing such as advanced reduced instruction set machine (Advanced RISC Machine, ARM) processor, digital signal processor (Digital Signal Processing, DSP), etc.
  • SOC system-on-chip
  • controller area network Controller Area Network
  • IIC Inter-Integrated Circuit
  • the interface unit 603 may be integrated in the ASIC module, and high-speed interfaces such as Ethernet interfaces may be integrated as needed; and/or some low-speed interfaces such as Universal Asynchronous Receiver/Transmitter (UART) ), IIC, CAN, Serial Peripheral (SPI) and other interfaces.
  • UART Universal Asynchronous Receiver/Transmitter
  • IIC IIC
  • CAN Serial Peripheral
  • SPI Serial Peripheral
  • the ADC unit 604 is integrated in the ASIC module for analog-to-digital conversion, including the above-mentioned analog-to-digital conversion of the laser reflection signal received by the receiver.
  • the analog-to-digital conversion unit is also used to perform analog-to-digital conversion on the input clock influence signal about the lidar device, and transmit the converted clock influence signal to the processing unit.
  • the analog-to-digital conversion unit can also be used to collect the current clock influence signal.
  • the clock influence signal may include, for example, external voltage monitoring and temperature monitoring.
  • the integrated processing unit is based on voltage and temperature. When performing the above-mentioned response time calculation, some compensation values can be introduced corresponding to the temperature and/or voltage to more accurately calculate the response time.
  • Integrated on the module is a time-multiplexed analog-to-digital conversion unit.
  • the A/D conversion unit based on time division multiplexing performs different processes in different time periods, for example, 0 ⁇ 1ms for the analog-to-digital conversion of the laser reflection signal A, and 1 ⁇ 2ms for the analog-to-digital conversion of the laser reflection signal B.
  • 1ms instruction pulse is generated inside the A/D conversion unit.
  • an angle measuring unit 605 is further integrated into the application specific integrated circuit ASIC module, and the angle measuring unit 605 is used to measure the angle information of the receiver and/or the transmitter, and obtain the measurement The angle information is output to the processing unit.
  • the receiver and the transmitter include at least one motor, and the rotation of the motor drives the rotation of optical elements such as prisms, so that the transmitter and the receiver can emit laser emission signals and receive laser reflection signals at different angles to realize the area Scan detection.
  • the angle measuring unit 605 is used to measure the angle of the at least one motor to obtain the angle information, determine the signal emission angle, the signal reception angle, etc., so as to realize the motor angle information recording, and then realize the 3D of the detected environment or target reconstruction.
  • the angle information includes: the rotation speed and the rotation angle of the motor calculated by the angle measurement unit 605 according to the duration of the high level in the control signal output to the motor.
  • a control unit 606 is further integrated in the application specific integrated circuit ASIC module, and the control unit 606 is used to control the receiver and the transmitter, specifically including the above-mentioned transmitter or The speed and angle control of the motor corresponding to the receiver, as well as the emission control of the laser emission signal and the reception control of the laser reflection signal, etc.
  • the control unit 606 is used to control any one or more of the transmitter's transmission voltage, compensation parameters, and pulse width of the transmitted signal; the control unit 606 is used to accept the receiver Any one or more of voltage, compensation parameters and receiving gain can be controlled.
  • an algorithm processing unit 607 is further integrated in the ASIC module of the application specific integrated circuit, and the algorithm processing unit 607 is used to calculate the lidar data according to a preset algorithm.
  • the lidar data includes: The emission time of the laser emission signal emitted by the transmitter, the point cloud data corresponding to the laser reflection signal received by the receiver, the response time or the reception time calculated by the processing unit based on the received laser reflection signal Any one or more of.
  • the calculation performed by the algorithm processing unit 607 may include distance calculation, reflectivity calculation, laser angle calculation, sorting, point cloud filtering, image recognition, etc.
  • the algorithm processing unit 607 is further used to calculate the angle of the motor Based on the optical principle, the emission angle of the laser emission signal and the reception angle of the laser reflection signal are calculated.
  • the application specific integrated circuit ASIC module can also be integrated with a compression unit 608. Since the amount of lidar data (such as laser point cloud data) is very large and has high real-time performance, online compression is required to reduce bandwidth , Integrated compression unit can improve the practicality of the entire system.
  • lidar data such as laser point cloud data
  • the application specific integrated circuit ASIC module may also integrate a memory controller such as a DDR controller, a general input/output (GPIO) unit, or a global timestamp. Unit etc.
  • a memory controller such as a DDR controller, a general input/output (GPIO) unit, or a global timestamp. Unit etc.
  • the above-mentioned units can be used as IP cores involved in parallel in the ASIC module.
  • multiple IP cores can be run simultaneously, so that more data can be processed in a unit time.
  • the embodiments of the present invention use an ASIC to integrate the processing unit and the time measurement unit, and perform related data recording based on the clock frequency of the ASIC, which not only completely implements the integrated processing of a single chip of the laser radar device, but also reduces cost, power consumption, area, and performance Better, more conducive to structural design, and can get more accurate time and other information, to obtain centimeter-level time measurement capabilities, so as to more accurately achieve the lidar ranging function.
  • the embodiment of the present invention also provides an application specific integrated circuit ASIC, which can be used as a chip product alone and applied to products such as laser radar products that require high-precision measurement of the time of the signal to be measured.
  • the application specific integrated circuit integrates a processing unit and a time measurement unit, the processing unit is connected to the time measurement unit; the time measurement unit is used to follow the logic clock of the application specific integrated circuit ASIC module, Record time measurement information of the signal to be measured, the signal to be measured is obtained from an externally input signal, and the externally input signal may be a signal output by a receiver of a laser radar device during receiving a laser reflection signal; the processing The unit is used to calculate the response time of the signal to be measured according to the time measurement information output by the time measurement unit and the logic clock of the ASIC module of the application specific integrated circuit.
  • the externally input signal to be measured may refer to the signal output by the receiver of the lidar device mentioned above.
  • the ASIC may also include an analog-to-digital conversion unit, an angle measurement unit, an algorithm processing unit, and other structures.
  • an analog-to-digital conversion unit for a specific implementation of the ASIC, refer to the description of the foregoing embodiment. With reference to the structure shown in FIG. 6, it will not be repeated here.
  • the embodiment of the present invention uses an ASIC for the integration of the processing unit and the time measurement unit, and records data based on the clock frequency of the ASIC, which not only completely implements the integrated processing of a single chip of the laser radar device, but also reduces cost, power consumption, area, and performance. , Is more conducive to structural design, and can get more accurate time and other information, specifically can measure the time measurement accuracy of 100 picoseconds (ps), or even sub-100 ps, to obtain centimeter-level time measurement capabilities, thereby more accurately Realize the lidar ranging function.
  • the distance measuring device may be an electronic device such as a laser radar or a laser distance measuring device.
  • the lidar device and the application specific integrated circuit mentioned in the above embodiments can be applied to the distance measuring device.
  • 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 700 may include a transmitting circuit 710, a receiving circuit 720, a sampling circuit 730 and an arithmetic circuit 740.
  • the transmitting circuit 710 may transmit a sequence of light pulses (for example, a sequence of laser pulses).
  • the receiving circuit 720 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 730 after processing the electrical signal.
  • the sampling circuit 730 may sample the electrical signal to obtain the sampling result.
  • the arithmetic circuit 740 may determine the distance between the distance measuring device 700 and the detected object based on the sampling result of the sampling circuit 730.
  • the distance measuring device 700 may further include a control circuit 750, which can control other circuits, for example, can control the working time of each circuit and/or set parameters for each circuit.
  • a control circuit 750 can control other circuits, for example, can control the working time of each circuit and/or set parameters for each circuit.
  • the distance measuring device shown in FIG. 7 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 housed in the same packaging space.
  • the distance measuring device 700 may further include a scanning module 760 for changing the propagation direction of at least one laser pulse sequence emitted by the transmitting circuit 710.
  • the module including the transmitting circuit 710, the receiving circuit 720, the sampling circuit 730, and the arithmetic circuit 740, or the module including the transmitting circuit 710, the receiving circuit 720, the sampling circuit 730, the arithmetic circuit 740, and the control circuit 750 may be referred to as a measurement A distance module, the distance measuring module may be independent of other modules, for example, the scanning module 760.
  • 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. 8 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 distance measuring 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 203, and is used to collimate the light beam emitted from the emitter 203, and collimate the light beam emitted by the emitter 203 into parallel light to the scanning module.
  • the collimating element 204 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 convert 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. In this way, it is possible to 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 outside 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 after the first optical element changes and the rotation axis 209 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 215 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 directions 211 and 213, so as to scan the space around the distance measuring device 200.
  • 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 emitter 203 , 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

一种激光雷达设备及专用集成电路，包括用于发射激光发射信号的发射器(101)、用于接收激光反射信号的接收器(102)和专用集成电路ASIC模块(100)，ASIC模块(100)集成了处理单元(104)和时间测量单元(103)，时间测量单元(103)用于按照ASIC模块(100)的逻辑时钟，记录待测信号的时间测量信息；处理单元(104)用于对发射器(101)和接收器(102)进行控制，并根据时间测量单元(103)输出的时间测量信息、ASIC模块(100)的逻辑时钟计算得到待测信号的响应时间。可实现激光雷达设备的单颗芯片集成处理，并且可获得厘米级别的测量能力，更准确地实现激光雷达测距。

Description

一种激光雷达设备、专用集成电路及测距装置 技术领域
本发明涉及电子技术领域，尤其涉及一种激光雷达设备、专用集成电路及测距装置。
背景技术
激光雷达设备是一种通过激光信号的发射和接收来计算获得目标至信号发射点的距离、距离变化、方位等等信息的设备。激光雷达设备在测距时，通过发射器发射出一束激光，激光遇到目标物体后，经过漫反射或反射，返回至激光接收器并转换成电信号。激光激光雷达设备在接收到电信号后，计算发送激光信号、接收激光反射信号的时间间隔t，再除以2，再乘以光速v，即可计算出发射器与目标物体的距离s；结合光脉冲的发射角度信息，便可重建目标物体的三维深度信息。
由上述提及的计算方式可以看出，由于光速v为常数，因此，计算s的准确度则取决于时间间隔t的精度。如何更为精确地计算激光反射信号的接收时间以此来计算准确的时间间隔成为研究的热点问题。
发明内容
本发明实施例提供了一种激光雷达设备、专用集成电路及测距装置，可将专用的时间测量单元集成到专用集成电路ASIC中，利用ASIC的逻辑时钟频率进行时间计算，以便于实现可以更准确地进行测距的激光雷达设备。
一方面，本发明实施例提供了一种激光雷达设备，包括：用于发射激光发射信号的发射器、用于接收激光反射信号的接收器和专用集成电路ASIC模块，其中：
所述专用集成电路ASIC模块，集成了处理单元和时间测量单元，所述处理单元分别与所述发射器和接收器连接，所述处理单元与所述时间测量单元连接，所述时间测量单元与所述接收器相连；
所述时间测量单元，用于按照专用集成电路ASIC模块的逻辑时钟，记录待测信号的时间测量信息，所述待测信号是根据所述接收器接收的激光反射信号得到的；
所述处理单元，用于对发射器和接收器进行控制，并根据时间测量单元输出的时间测量信息、专用集成电路ASIC模块的逻辑时钟计算得到所述待测信号的响应时间。
另一方面，本发明实施例还提供了一种专用集成电路，所述专用集成电路集成了处理单元和时间测量单元，所述处理单元与所述时间测量单元连接；
所述时间测量单元，用于按照专用集成电路ASIC模块的逻辑时钟，记录从外部输入的待测信号的时间测量信息；
所述处理单元，用于根据时间测量单元输出的时间测量信息、专用集成电路ASIC模块的逻辑时钟计算得到所述待测信号的响应时间。
本发明实施例采用ASIC进行处理单元和时间测量单元的集成，基于ASIC的时钟频率进行相关的数据记录，不仅完整地实现激光雷达设备的单颗芯片集成处理，降低成本、功耗、面积、性能更优，更利于结构设计，并且能够得到更为精确的时间等信息，具体能够测量得到百皮秒(ps)，甚至亚百ps的时间测量精度，以获得厘米级别的时间测量能力，从而更加准确地实现激光雷达测距功能。
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是本发明实施例一种激光雷达设备的结构示意图；
图2是本发明实施例时间测量单元的结构示意图；
图3是本发明实施例采样与门实现的延时链的结构示意图；
图4是本发明实施例粗计时和细计时的实现原理示意图；
图5a是本发明实施例一种基于比较器和延时测量电路的结构示意图；
图5b是本发明实施例另一种基于比较器和延时测量电路的结构示意图；
图5c是本发明实施例的基于比较器进行待测信号采用的效果示意图；
图6是本发明实施例一种ASIC模块的结构示意图；
图7是本发明实施例的是本发明实施例的一种测距装置的结构示意图；
图8是本发明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
本发明实施例采用专用集成电路(Application Specific Integrated Circuit，ASIC)来设计激光雷达设备的核心单元，在ASIC中至少集成时间测量单元103和处理单元104得到一个ASIC模块，通过时间测量单元103在ASIC的逻辑时钟的触发下进行待测信号的时间测量，得到待测信号的时间测量信息，同样集成在ASIC上的处理单元104基于该时间测量信息可以得到更为精确的响应时间，该响应时间可以用来计算待测信号对应的激光反射信号的接收时间，进而得到更为精确的激光雷达信号收发时间间隔及距离数据。所述ASIC模块的逻辑时钟或者说频率可以在集成得到ASIC模块时进行配置确定。本发明实施例可以完整地实现激光雷达设备的单颗芯片集成处理，降低成本、功耗、面积、性能更优，更利于结构设计；集成度高，并且能够得到更为精确的时间等信息，具体能够测量得到百皮秒(ps)，甚至亚百ps的时间测量精度，以获得厘米级别的时间测量能力，从而更加准确地实现激光雷达测距功能。
请参见图1，是本发明实施例的一种激光雷达设备的结构示意图，在本发明实施例中，所述激光雷达设备包括用于发射激光发射信号的发射器101、用于接收激光反射信号的接收器102和专用集成电路ASIC模块100。可以理解的是，图1仅简单地对本发明实施例的激光雷达设备进行结构示意，用于突出集成了时间测量单元103和处理单元104的ASIC模块100与激光雷达设备的发射器101和接收器102之间的关系。在一个具体实施例中，发射器101中可包括用于发射激光发射信号的发射器件，还可以根据需要包括分光镜、棱镜、电机等元件，所述接收器102中也包括了接收目标反射的激光反射信号的接收器件，以及分光镜、棱镜、电机等元件。并且所述发射器101和接收器102之间还可以共用一个激光雷达探头，通过内设收发信号切换的方式来发出激光发射信号和接收激光反射信号。在另一个具体实施例中，发射器101和接收器102之间还可以存在一部分共用的光学元件等等。
所述专用集成电路ASIC模块100，集成了处理单元104和时间测量单元103，所述处理单元104分别与所述发射器101和接收器102连接，所述处理单元104与所述时间测量单元103连接，所述时间测量单元103与所述接收器 102相连；所述时间测量单元103，用于按照专用集成电路ASIC模块100的逻辑时钟，记录待测信号的时间测量信息，所述待测信号是根据所述接收器102接收的激光反射信号得到的；所述处理单元104，用于对发射器101和接收器102进行控制，并根据时间测量单元103输出的时间测量信息、专用集成电路ASIC模块100的逻辑时钟计算得到所述待测信号的响应时间。
其中，所述时间测量单元103实现时间信息的精确测量可以包括三种方式，一种方式是基于延时测量电路构建时间测量单元103来实现时间信息的精确测量，例如采用电子学时间数字转换(Time-to-Digital Convertor，TDC)电路来实现，通过将接收器102接收到的激光反射信号转换为数字信号得到待测信号后，基于TDC电路来实现时间信息的精确测量；另一种方式是基于比较器加延时测量电路(例如TDC)的方式构建时间测量单元103来实现时间信息的精确测量，在此方式中，在接收激光反射信号的过程中，接收器102输出的信号作为待测信号；再一种方式是基于模数转换单元(Analog-to-Digital Converter，ADC)构建时间测量单元103对接收器102在接收激光反射信号的过程中输出的信号进行高速采样，来实现时间信息的精确测量。接收器102在接收激光反射信号的过程中输出的信号可以是激光反射信号本身，也可以是对激光反射信号经过一些诸如去噪、滤波等处理后的信号。
在一个实施例中，如图2所示，所述ASIC模块100的所述时间测量单元103是基于TDC电路构建的，所述时间测量单元103包括：延时测量电路，所述延时测量电路包括N个延时链、锁存器以及计数器；每个延时链的输入为所述待测信号，每个延时链中包括M个延时电路，每个延时电路将延时后的待测信号输出至所述锁存器、并将延时后的待测信号输出至下一级延时电路；所述锁存器在所述专用集成电路ASIC模块100的锁存时钟信号的有效沿出现时，记录得到所述待测信号的时间测量信息。每一个延时链会得到相应的时间测量信息，基于每一个时间测量信息可以测算得到一个响应时间。最终基于N各延时链的响应时间计算得到接收器102接收激光反射信号的接收时间。例如N个延时链的响应时间求平均即可作为待测信号对应的激光反射信号的接收时间。
可以为每一个延时链配置一个锁存器，也可以配置由大量的寄存器阵列构成的锁存器用于分别存储每一个延时链的时间测量信息；所述计数器用于记录 所述专用集成电路ASIC模块100的锁存时钟信号的有效沿的个数；其中，N为大于等于1的正整数，M为大于等于2的正整数。在一个实施例中，N可以取128，即存在128套延时链，会对应128套硬件处理结果，基于每一个延时链通过下述计算方式后得到的处理结果，可通过取平均等方式来得到的某个待测信号最终的响应时间。
时间测量单元103的输入为对接收器102接收到的激光反射信号进行处理后的待测信号，该待测信号可以仅仅是进行了模数转换处理后的信号，例如将激光反射信号转换为数字信号输入到时间测量单元103中，具体是输入到图2中延时测量电路的延时链中。时间测量单元103以ASIC的逻辑时钟作为锁存时钟，在锁存器中记录了一个或者多个延时链上的每一个延时电路输出的电平信号对应的电平信息，这些电平信息构成了对应延时链的时间测量信息。在本发明实施例中，时间测量单元103主要用于对响应时间的细计时，再结合粗计时得到响应时间，以便最终得到激光反射信号的接收时间。
上述提及的粗计时加细计时的方式主要是指：在一个较大的时间范围(粗计时)内再进行精确时间测量(细计时)，例如，在ASIC的工作频率被配置为500MHz时，每个粗计时的计数时间(即逻辑时钟)对应为2ns(ns为纳秒)，那么在第C r＝100个锁存时钟信号的有效沿出现时，粗计时为200ns，也就是说可以认为此时接收激光反射信号的粗略时间点为200ns，但实际上待测信号的实际时间可能更短，因此，需要对第100个锁存时钟信号的有效沿对应的待测信号进行细计时，以便于在粗计时的基础上确定更精确的响应时间。以下描述了粗计时加细计时的响应时间计算过程。
ASIC的时钟周期定义为T ck，锁存时钟的计数时间被定义为粗时间，粗计时的测量精度为T ck，同时定义粗计数为C r，那么所获得粗计时为C r*T ck。
基于延时链能够得到细计时，每个延时电路大约延时数ps到数百ps，不同厂家、不同器件的这个延时时间有一定差异，每个延时电路延时时间定义为t d为已知，可以根据现有技术进行测量。将待测信号输入到延时链的延时电路内，每t d时间内便会通过一个延时电路。所述锁存器在所述专用集成电路ASIC模块100的锁存时钟信号的有效沿出现时，若待测信号为上升沿，则会在锁存器中记录得到上升沿时间测量信息，否则，会在锁存器中记录得到下降沿时间测量信息。
具体的，锁存时钟信号的有效沿出现时，如果是待测信号的上升沿信号，则在锁存器中会锁存住一串“……111111000000……”信息即上升沿时间测量信息，在此时间测量信息中可以得到前面“1”的个数C r1，由此可获得上升沿的准确时间为：
Trising＝C r*T ck-C r1*t d；
也就是说，所述处理单元104是根据上升沿时间测量信息中出现的1的个数(即C r1)、延时电路的延时时间间隔(即t d)、所述计数器记录的个数(即C r)，以及所述专用集成电路ASIC模块100的锁存时钟信号的时钟周期(即Tck)，计算得到Trising，Trising即可以认为是所述待测信号准确的响应时间，该时间可以作为第Cr个锁存时钟信号的有效沿时接收到的激光反射信号的接收时间。由于该激光反射信号对应的激光雷达发送信号的发射时间为已知，因此可以计算得到信号的收发时间间隔，从而计算得到第C r个锁存时钟信号的有效沿时准确的距离数据。
另外，锁存时钟信号的有效沿出现时，如果是待测信号的下降沿信号，则在锁存器中会锁存住一串“……000000111111……”信息即下降沿时间测量信息，基于该时间测量信息可以得到前面“0”的个数C f1，由此可获得下降沿的准确时间为：
Tfalling＝C r*T ck–C f1*t d；
在一个实施例中，时间测量单元103可以输出锁存器中记录的时间测量信息给处理单元104，以供处理单元104进行响应时间和/或接收时间的测算。在其他实施例中，时间测量单元103也可以进一步集成测算单元，由该测算单元来计算响应时间和/或接收时间。
在一个实施例中，延时电路包括但不限于使用OR2(两个输入的或门)或者是AND2(两个输入的与门)。所述延时电路在包括与门时，所述延时链中一个与门的一输入端固定为高电平，所述与门的另一输入端为所述待测信号或者上一级延时电路输出的延时后的待测信号；所述与门的输出端将延时后的待测信号输出至所述锁存器、并将延时后的待测信号输出至下一级延时电路，作为下一级延时电路(下一级与门)的输入。如图3所示，采用了多个AND2构成了一个延时链，通过AND2构成一个延时电路，AND2包括2个输入，一个输出，其中的一个输入固定接1即高电平信号，另外一个输入用于与上一级 的输出级联，输出与下一级与门的输入级联，同时将输出连接到寄存器上，实现时间测量信息的检测。
所述延时电路在包括或门时，所述延时链中一个或门的一输入端固定为低电平，所述或门的另一输入端输入所述待测信号或者上一级延时电路输出的延时后的待测信号；所述或门的输出端将延时后的待测信号输出至所述锁存器、并将延时后的待测信号输出至下一级延时电路(下一级或门)，作为下一级延时电路的输入。也就是说，通过OR2构成一个延时电路，OR2包括2个输入，一个输出，其中的一个输入固定接0即低电平信号，另外一个输入用于与上一级的输出级联，输出与下一级或门的输入级联，同时将输出连接到寄存器上，实现时间测量信息的检测。其中，第一级AND2或者OR2的输入连接的是待测信号。
在ASIC模块100中，可以根据需要进行物理约束，调整延时电路之间的距离，并调整寄存器的位置分布，可以使得ASIC模块100中的走线长度相对固定，走线延时较为均匀。
所述锁存器包括：集成在所述专用集成电路ASIC模块100上的寄存器阵列，所述时间测量信息是由寄存器阵列记录的。通过锁存阵列，逻辑检测出上述的“……111111000000……”或“……000000111111……”，实现待测信号的上升沿、下降沿对应的边沿1(上升沿/下降沿的fine_cnt)的位置检测，以便于计算出响应时间。基于粗计时和细计时的方式，例如2ns最大对应100个延时链，那么每个延时链对应的时间是20ps，也就是说会在纳秒下细计时精确到皮秒级别，相比4G的时钟clock信号，精度提高一个数量级。
在计算时间间隔时，需要记录激光发射信号的上升沿时刻，由于激光发射信号是激光雷达设备主动发出的，因此发射时间可控，且发射过程中的链路延时比较固定，补偿可近似为一个固定值(补偿值与温度相关)；同时，图4示出了本发明实施例的粗计时和细计时的实现原理示意图，通过粗计时加细计时的时间测量方式，可以对某个激光发射信号对应返回的激光反射信号进行测量，得到对应的待测信号的响应时间，再基于响应时间计算接收时间，通过发射时间和接收时间即可得到激光发射信号和激光反射信号之间的时间间隔t。
在一个实施例中，将接收器102接收到的激光反射信号转换成待测信号可以是通过一个模数转换单元ADC来实现的，也就是说，在所述专用集成电路 ASIC模块100上还集成了模数转换单元，所述模数转换单元用于将所述接收器102输出的信号进行模数转换得到待测信号，并将转换得到的待测信号输出至所述时间测量单元103。在一个实施例中，所述接收器102输出的信号可以是接收到的激光反射信号本身。
所述模数转换单元可以将转换得到的待测信号分别发送给N套延时链，当然也可以在ASIC模块100上集成多个模数转换单元来分别对接收器102输出的信号进行模数转换，得到待测信号。并且每个模数转换单元分别向N个延时链中的一个或者多个延时链传输待测信号。
在一个实施例中，所述时间测量单元103可以包括比较器和上述提及的TDC电路，比较器的一个输入为所述接收器102在接收激光反射信号的过程中输出的待测信号，所述比较器的另一个输入为一参考信号；所述比较器根据接收器102输出的待测信号的电平幅值和参考信号的电平幅值，产生输出信号，并将输出信号输出至所述延时测量电路，例如可将输出信号输出至所述延时测量电路的延时链中。比较器的作用主要在于对待测信号进行不同电平幅度的采样得到采样信号，而TDC则对不同的采样信号进行上述提及的细计时的时间测量，不同采样幅度的采样信号下可能得到不同的细计时的时间测量结果，基于不同的细计时的时间测量结果通过诸如求取平均值的计算方式，能够得到更为精确的细计时。
各比较器所采用的参考信号对应的电平幅度不相同，当然也可以存在部分比较器之间所采用的参考信号对应的电平相同的情况。采用高速比较器加TDC电路的方式，可以理解为基于电压阈值(不同电压阈值对应不同的电平幅度)的时间采样方式。基于电压阈值采样时，其采样点与待测信号之间有相关关系，可以认为直接获取了待测信号的时间信息，如此获得的待测信号的时间信息更加有效直接。
如图5a所示，比较器的信号输入脚3可以直接与接收器102相连，接收到的输入信号Signal_in为所述接收器102输出的信号，比如激光反射信号，当然也可以通过一个信号处理电路与接收器102相连，接收的是经过该信号处理电路进行处理后的信号，例如由该信号处理电路对接收器102接收到的激光反射信号进行去噪、滤波等处理后的信号。比较器的信号输入脚4为一个参考信号Comparator_Ref，具体为一个具有一定电平幅度的信号。所述比较器的第 6引脚的VCC_COMP和所述比较器的第2引脚的VCC_COMP_IN表示电源输入。比较器的引脚1输出比较后的电平信号，具体是将比较后的电平信号输出至延时测量电路。当激光反射信号的电平幅度超过参考信号对应的电平幅度时比较器的输出信号为高电平，否则，输出信号为低电平。比较器可以选用专用比较器，也可以在ASIC模块中集成差分端口以替代比较器。
为了保证获得更为准确、直接的响应时间等时间信息，并且减少由于多变的脉冲信号强度、噪声以及环境带来的不利影响，在一个实施例中可以采用多电压阈值比较器加多路TDC电路的方式来进行时间测量。如图5b所述，包括了多个比较器和对应的TDC电路，为了方便随时调整各个比较器的参考信号的电平幅度，还可以选择一个信号发射单元基于相应的电平幅度阈值向比较器输出参考信号，电平幅度阈值可以通过信号发射单元配置，该信号发射单元可以为一个数字模拟转换器(Digital to analog converter，DAC)器件，由DAC器件产生需要的电平幅度阈值的信号作为参考信号，并且该信号发射单元基于不同的电平幅度阈值输出到各比较器的参考信号的电平幅值可以不相同。基于不同的电平幅度阈值所对应的参考信号达到的采集效果如图5c所示，通过四阈值的比较器后，可以获得脉冲前后沿一共八个采样点的数据，依次分别得到(t1，Vf 01)、(t2，Vf 02)、(t3，Vf 03)、(t4，Vf 04)、(t5，Vf 04)、(t6，Vf 03)、(t7，Vf 02)、(t8，Vf 01)八个采样点的时间-电压信息。同样，可以采用8阈值、12阈值甚至更多阈值的比较器以得到更多的采样点的数据，激光反射信号从一个输入引脚输入，经过N个比较器和TDC，最多可得到2N个采样点，从而保证获取到更为准确的激光反射信号的接收时间。可以理解的是，N值越大，得到的采样点越多，由此获取得到的信号脉冲信息就越丰富，基于延时测量电路而得到的时间信息(如响应时间)就更准确。
在一个实施例中，时间测量单元103还可以通过多个的模数转换单元来实现，由高速ADC的采样方式实现时间测量，ADC采样可以理解为基于时间轴的等间隔电压采样方式，其采样时间与待测信号之间是相互独立的，没有时间关系。对时间信息的提取，需要一定的提取算法实现。在一个实施例中，可预先建立脉冲模型，基于该脉冲模型和ADC采样得到的采样信息还原脉冲形状，基于还原得到的脉冲形状确定时间信息(如响应时间)；或者，由于脉冲边沿是线性的，那么也可以根据采样信息直接计算出时间信息(如响应时间)。
当然，为了保证响应时间的准确，可以结合上述提及的比较器加TDC的时间测量方式和高速ADC的时间测量方式来综合测量响应时间。再进一步地可以求取所有响应时间的平均值，作为接收器接收到的激光反射信号的接收时间；也可以使用不同权重求均值的方式计算接收时间；或者根据其中一个计算得到的响应时间来计算接收器接收到激光反射信号的接收时间，而另一个响应时间用于校验测量的准确性，例如，两者基于测量的响应时间得到接收时间接近时，说明本次测算准确，如果相差较大(大于预设的阈值)，则认为当前得到的响应时间或接收时间不准确。
本发明实施例可以实现激光雷达设备的单颗芯片集成处理，降低成本、功耗、面积、性能更优，更利于结构设计，并且能够得到更为精确的时间等信息，以获得厘米级别的时间测量能力，更准确地实现激光雷达测距功能。
再请参见图6，是本发明实施例的一种ASIC模块的结构示意图，在该ASIC模块中集成了上述提及的时间测量单元602、以及实现所述处理单元的功能的中央处理器CPU601，还根据需要集成了其他功能单元，可以理解的是，这些其他功能单元或者是用于增加激光雷达设备的功能，或者可以在其他的电路上实现，例如另外采用一个ASIC模块或者现场逻辑门阵列(field-programmable gate array，FPGA)模块来实现。在本法实施例中，集成在ASIC模块中的其他的功能单元及其功能描述如下。
在一个实施例中，集成在ASIC中的中央处理器CPU601负责ASIC模块整体的调度和部分功能控制，以及部分算法处理、实现。该CPU601例如可以与上述提及的处理单元相对应，其能够实现所述处理单元的上述功能，当然在其他实施例中，该中央处理器也可以与上述提及的处理单元为不同的功能单元。CPU集成在整个ASIC模块的片上系统(System on Chip，SOC)中，可以整合诸如进阶精简指令集机器(Advanced RISC Machine，ARM)处理器、数字信号处理器(Digital Signal Processing，DSP)等处理器，或者其他一些低功耗控制处理器，各个处理器与外部传感器或其他处理平台通过接口对接，如通过控制器局域网络(Controller Area Network，CAN)接口、集成电路总线(Inter-Integrated Circuit，IIC)、以太网接口等对接，可以实现完整的单芯片解决方案。
在一个实施例中，可以在ASIC模块中集成接口单元603，可以根据需要 集成高速接口，例如以太网接口；和/或集成一些低速接口，例如通用异步收发传输器(Universal Asynchronous Receiver/Transmitter，UART)、IIC、CAN、串行外设接口(Serial Peripheral Interface，SPI)等接口。
在一个实施例中，在ASIC模块中集成ADC单元604用于模数转换，包括上述提及的可以对接收器接收到的激光反射信号进行模数转换。所述模数转换单元还用于对输入的关于所述激光雷达设备的时钟影响信号进行模数转换，并将转换后的时钟影响信号传输给所述处理单元。所述模数转换单元还可以用来采集当前的时钟影响信号。所述时钟影响信号例如可以包括：外部的电压监测、温度监测等。集成的处理单元基于电压和温度，在进行上述的响应时间计算时可以对应于温度和/或电压引入一些补偿值，以更为准确地进行响应时间的计算，其中，在所述专用集成电路ASIC模块上集成的是分时复用的模数转换单元。基于时分复用的模数转换单元，在不同的时间段执行不同的处理，例如在0～1ms用于激光反射信号A的模数转换、在1～2ms用于激光反射信号B的模数转换，在模数转换单元内部产生1ms的指示脉冲。
在一个实施例中，所述专用集成电路ASIC模块中还集成了角度测量单元605，所述角度测量单元605用于测量所述接收器和/或所述发射器的角度信息，并将测量得到的角度信息输出给所述处理单元。所述接收器和发射器上包括至少一个电机，通过电机的转动来带动棱镜等光学元件的转动，从而使得发射器和接收器可在不同的角度发射激光发射信号和接收激光反射信号，实现区域扫描检测。而所述角度测量单元605用于测量所述至少一个电机的角度来得到角度信息，确定信号发射角度、信号接收角度等，以便于实现电机角度信息记录，进而实现所探测的环境或者目标的3D重建。在一个实施例中，所述角度信息包括：由所述角度测量单元605根据对电机输出的控制信号中高电平的持续时间计算得到的电机的转速和转动角度。
在一个实施例中，所述专用集成电路ASIC模块中还集成了控制单元606，所述控制单元606用于对所述接收器和所述发射器进行控制，具体包括上述提及的发射器或接收器对应的电机的转速、角度控制，以及激光发射信号的发射控制和激光反射信号的接收控制等。在一个实施例中，所述控制单元606用于对发射器的发射电压、补偿参数、发射信号脉冲宽度中的任意一种或多种进行控制；所述控制单元606用于对接收器的接受电压、补偿参数、接收增益中的 任意一种或多种进行控制。
在一个实施例中，所述专用集成电路ASIC模块中还集成了算法处理单元607，所述算法处理单元607用于根据预置的算法对激光雷达数据进行计算，所述激光雷达数据包括：所述发射器发射的激光发射信号时的发射时间、所述接收器接收到的激光反射信号对应的点云数据、所述处理单元基于所述接收到的激光反射信号计算得到的响应时间或接收时间中的任意一个或者多个。所述算法处理单元607实现的运算可以包括距离计算，反射率计算，激光角度计算，排序，点云滤波，图像识别等；在一个实施例中，所述算法处理单元607还用于根据电机角度和光学原理计算得到激光发射信号的发射角度以及激光反射信号的接收角度等。
在一个实施例中，所述专用集成电路ASIC模块中还可以集成压缩单元608，由于激光雷达数据(例如激光点云数据)的数据量非常大、且实时性高，需要进行在线压缩以降低带宽，集成压缩单元可以提高整个系统的实用型。
在其他的一些实施例中，所述专用集成电路ASIC模块中还可以集成内存控制器例如ddr控制器，通用输入/输出(General Purpose Input Output，GPIO)单元等，还可以集成全局的时间戳timestamp单元等。
上述的各个单元可以作为在ASIC模块中并行涉及的IP核，在ASIC模块可以让多个IP核同时运行，这样在单位时间内能够处理更多的数据。
本发明实施例采用ASIC进行处理单元和时间测量单元的集成，基于ASIC的时钟频率进行相关的数据记录，不仅完整地实现激光雷达设备的单颗芯片集成处理，降低成本、功耗、面积、性能更优，更利于结构设计，并且能够得到更为精确的时间等信息，获得厘米级别的时间测量能力，从而更加准确地实现激光雷达测距功能。
本发明实施例还提供了一种专用集成电路ASIC，该ASIC可以单独作为一个芯片产品，应用到激光雷达产品等需要对待测信号的时间进行高精度测量的产品中。在一个实施例中，所述专用集成电路集成了处理单元和时间测量单元，所述处理单元与所述时间测量单元连接；所述时间测量单元，用于按照专用集成电路ASIC模块的逻辑时钟，记录待测信号的时间测量信息，所述待测信号是根据外部输入的信号得到的，外部输入的信号可以是激光雷达设备的接收器在接收激光反射信号的过程中输出的信号；所述处理单元，用于根据时间 测量单元输出的时间测量信息、专用集成电路ASIC模块的逻辑时钟计算得到所述待测信号的响应时间。其中，所述外部输入的待测信号可以是指上述提及的由激光雷达设备的接收器输出的信号。所述ASIC除了包括所述处理单元、时间测量单元以外，还可以包括模数转换单元、角度测量单元、算法处理单元等等结构，所述ASIC的具体实现可参看前述实施例的描述，具体可以参考图6所示的结构，在此不再赘述。
本发明实施例采用ASIC进行处理单元和时间测量单元的集成，基于ASIC的时钟频率作数据记录，不仅完整地实现激光雷达设备的单颗芯片集成处理，降低成本、功耗、面积、性能更优，更利于结构设计，并且能够得到更为精确的时间等信息，具体能够测量得到百皮秒(ps)，甚至亚百ps的时间测量精度，以获得厘米级别的时间测量能力，从而更加准确地实现激光雷达测距功能。
本发明实施例还提供了一种测距装置，该测距装置可以是激光雷达、激光测距设备等电子设备。在一个实施例中，上述实施例中提及的激光雷达设备和专用集成电路可以应用在测距装置上。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7所示的测距装置700对测距的工作流程进行举例描述。
如图7所示，测距装置700可以包括发射电路710、接收电路720、采样电路730和运算电路740。
发射电路710可以发射光脉冲序列(例如激光脉冲序列)。接收电路720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730。采样电路730可以对电信号进行采样，以获取采样结果。运算电路740可以基于采样电路730的采样结果，以确定测距装置700与被探测物之间的距离。
可选地，该测距装置700还可以包括控制电路750，该控制电路750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7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7所示的电路，测距装置700还可以包括扫描模块760，用于将发射电路710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710、接收电路720、采样电路730和运算电路740的模块，或者，包括发射电路710、接收电路720、采样电路730、运算电路740和控制电路750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760。
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8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203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204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8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8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8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209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215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，例如方向211和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203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。
以上所揭露的仅为本发明部分实施例而已，当然不能以此来限定本发明之权利范围，因此依本发明权利要求所作的等同变化，仍属本发明所涵盖的范围。

Claims (41)

  1. 一种激光雷达设备，其特征在于，包括：用于发射激光发射信号的发射器、用于接收激光反射信号的接收器和专用集成电路ASIC模块，其中：
    所述专用集成电路ASIC模块，集成了处理单元和时间测量单元，所述处理单元分别与所述发射器和接收器连接，所述处理单元与所述时间测量单元连接，所述时间测量单元与所述接收器相连；
    所述时间测量单元，用于按照专用集成电路ASIC模块的逻辑时钟，记录待测信号的时间测量信息，所述待测信号是根据所述接收器接收的激光反射信号得到的；
    所述处理单元，用于对发射器和接收器进行控制，并根据时间测量单元输出的时间测量信息、专用集成电路ASIC模块的逻辑时钟计算得到所述待测信号的响应时间。
  2. 如权利要求1所述的激光雷达设备，其特征在于，
    所述时间测量单元包括：延时测量电路，所述延时测量电路包括N个延时链、锁存器以及计数器；
    每个延时链的输入为所述待测信号，每个延时链中包括M个延时电路，每个延时电路将延时后的待测信号输出至所述锁存器、并将延时后的待测信号输出至下一级延时电路；
    所述锁存器在所述专用集成电路ASIC模块的锁存时钟信号的有效沿出现时，记录得到所述待测信号的时间测量信息；
    所述计数器用于记录所述专用集成电路ASIC模块的锁存时钟信号的有效沿的个数；
    其中，N为大于等于1的正整数，M为大于等于2的正整数。
  3. 如权利要求2所述的激光雷达设备，其特征在于，所述时间测量单元包括比较器，比较器的一个输入为所述接收器在接收激光反射信号的过程中输出的待测信号，所述比较器的另一个输入为一参考信号；
    所述比较器根据接收器输出的待测信号的电平幅值和参考信号的电平幅 值，产生输出信号，并将输出信号输出至所述延时测量电路。
  4. 如权利要求3所述的激光雷达设备，其特征在于，各比较器所采用的参考信号对应的电平幅值不相同。
  5. 如权利要求3所述的激光雷达设备，其特征在于，所述时间测量单元还包括信号发射单元，所述信号发射单元产生参考信号输出至所述比较器。
  6. 如权利要求5所述的激光雷达设备，其特征在于，所述信号发射单元输出到各比较器的参考信号的电平幅值不相同。
  7. 如权利要求2-6任一项所述的激光雷达设备，其特征在于，
    所述锁存器在所述专用集成电路ASIC模块的锁存时钟信号的有效沿出现时，若待测信号为上升沿，则记录得到上升沿时间测量信息，否则，记录得到下降沿时间测量信息。
  8. 如权利要求2-6任一项所述的激光雷达设备，其特征在于，所述锁存器包括集成在所述专用集成电路ASIC模块上的寄存器阵列，所述时间测量信息是由寄存器阵列记录的。
  9. 如权利要求2所述的激光雷达设备，其特征在于，所述延时电路包括与门，所述与门的一输入端固定为高电平，所述与门的另一输入端输入所述待测信号或者上一级延时电路输出的延时后的待测信号；所述与门的输出端将延时后的待测信号输出至所述锁存器、并将延时后的待测信号输出至下一级延时电路，作为下一级延时电路的输入。
  10. 如权利要求2所述的激光雷达设备，其特征在于，所述延时电路包括或门，所述或门的一输入端固定为低电平，所述或门的另一输入端输入所述待测信号或者上一级延时电路输出的延时后的待测信号；所述或门的输出端将延时后的待测信号输出至所述锁存器、并将延时后的待测信号输出至下一级延时 电路，作为下一级延时电路的输入。
  11. 如权利要求7所述的激光雷达设备，其特征在于，
    所述处理单元，用于根据上升沿时间测量信息中出现的1的个数、延时电路的延时时间间隔、所述计数器记录的个数，以及所述专用集成电路ASIC模块的锁存时钟信号的时钟周期，计算得到所述待测信号的响应时间。
  12. 如权利要求1所述的激光雷达设备，其特征在于，在所述专用集成电路ASIC模块上还集成了模数转换单元，所述模数转换单元用于将所述接收器在接收激光反射信号的过程中输出的信号进行模数转换得到待测信号，并将得到的待测信号发送给所述时间测量单元。
  13. 如权利要求12所述的激光雷达设备，其特征在于，在所述专用集成电路ASIC模块上集成的是分时复用的模数转换单元。
  14. 如权利要求12或13所述的激光雷达设备，其特征在于，所述模数转换单元还用于对输入的关于所述激光雷达设备的时钟影响信号进行模数转换，并将转换后的时钟影响信号传输给所述处理单元。
  15. 如权利要求14所述的激光雷达设备，其特征在于，所述时钟影响信号包括：温度信号和/或电压信号。
  16. 如权利要求1所述的激光雷达设备，其特征在于，所述专用集成电路ASIC模块中还集成了角度测量单元，所述角度测量单元用于测量所述接收器和/或所述发射器的角度信息，并将测量得到的角度信息输出给所述处理单元。
  17. 如权利要求16所述的激光雷达设备，其特征在于，所述发射器和/或所述接收器包括至少一个电机，所述角度测量单元用于测量所述至少一个电机的角度来得到所述角度信息。
  18. 如权利要求17所述的激光雷达设备，其特征在于，所述角度信息包括：由所述角度测量单元根据对电机输出的控制信号中高电平的持续时间计算得到的电机的转速和转动角度。
  19. 如权利要求1-18任一项所述的激光雷达设备，其特征在于，所述专用集成电路ASIC模块中还集成了算法处理单元，所述算法处理单元用于根据预置的算法对激光雷达数据进行计算；
    所述激光雷达数据包括：所述发射器发射的激光发射信号时的发射时间、所述接收器接收到的激光反射信号对应的点云数据、所述处理单元基于所述接收到的激光反射信号计算得到的响应时间中的任意一个或者多个。
  20. 如权利要求1-18任一项所述的激光雷达设备，其特征在于，所述处理单元是集成在所述专用集成电路ASIC模块上的片上系统SOC单元。
  21. 一种专用集成电路，其特征在于，所述专用集成电路集成了处理单元和时间测量单元，所述处理单元与所述时间测量单元连接；
    所述时间测量单元，用于按照专用集成电路ASIC模块的逻辑时钟，记录待测信号的时间测量信息，所述待测信号是根据外部输入的信号得到的；
    所述处理单元，用于根据时间测量单元输出的时间测量信息、专用集成电路ASIC模块的逻辑时钟计算得到所述待测信号的响应时间。
  22. 如权利要求21所述的专用集成电路，其特征在于，
    所述时间测量单元包括：延时测量电路，所述延时测量电路包括N个延时链、锁存器以及计数器；
    每个延时链的输入为所述待测信号，延时链中每个延时电路中包括M个延时电路，每个延时电路将延时后的待测信号输出至所述锁存器、并将延时后的待测信号输出至下一级延时电路；
    所述锁存器在所述专用集成电路ASIC模块的锁存时钟信号的有效沿出现时，记录得到所述待测信号的时间测量信息；
    所述计数器用于记录所述专用集成电路ASIC模块的锁存时钟信号的有效 沿的个数；
    其中，N为大于等于1的正整数，M为大于等于2的正整数。
  23. 如权利要求22所述的专用集成电路，其特征在于，所述时间测量单元包括比较器，所述比较器的一个输入为待测信号，所述比较器的另一个输入为一参考信号；
    所述比较器根据输入的待测信号的电平幅值和参考信号的电平幅值，产生输出信号，并将输出信号输出至所述延时测量电路。
  24. 如权利要求23所述的专用集成电路，其特征在于，各比较器所采用的参考信号对应的电平幅值不相同。
  25. 如权利要求23所述的专用集成电路，其特征在于，所述时间测量单元还包括信号发射单元，所述信号发射单元输出的信号作为所述比较器的参考信号。
  26. 如权利要求25所述的专用集成电路，其特征在于，所述信号发射单元输出到各比较器的参考信号的电平幅值不相同。
  27. 如权利要求22-26任一项所述的专用集成电路，其特征在于，
    所述锁存器在所述专用集成电路ASIC模块的锁存时钟信号的有效沿出现时，若待测信号为上升沿，则记录得到上升沿时间测量信息，否则，记录得到下降沿时间测量信息。
  28. 如权利要求22-26任一项所述的专用集成电路，其特征在于，所述锁存器包括集成在所述专用集成电路ASIC模块上的寄存器阵列，所述时间测量信息是由寄存器阵列记录的。
  29. 如权利要求22-26任一项所述的专用集成电路，其特征在于，所述延时电路包括与门，所述与门的一输入端固定为高电平，所述与门的另一输入端 为所述待测信号或者上一级延时电路输出的延时后的待测信号；所述与门的输出端将延时后的待测信号输出至所述锁存器、并将延时后的待测信号输出至下一级延时电路，作为下一级延时电路的输入。
  30. 如权利要求22-26任一项所述的专用集成电路，其特征在于，所述延时电路包括或门，所述或门的一输入端固定为低电平，所述或门的另一输入端输入所述待测信号或者上一级延时电路输出的延时后的待测信号；所述或门的输出端将延时后的待测信号输出至所述锁存器、并将延时后的待测信号输出至下一级延时电路，作为下一级延时电路的输入。
  31. 如权利要求27所述的专用集成电路，其特征在于，
    所述处理单元，用于根据上升沿时间测量信息中出现的1的个数、延时电路的延时时间间隔、所述计数器记录的个数，以及所述专用集成电路ASIC模块的锁存时钟信号的时钟周期，计算得到所述待测信号的响应时间。
  32. 如权利要求21所述的专用集成电路，其特征在于，在所述专用集成电路ASIC模块上还集成了模数转换单元，所述模数转换单元用于将外部输入的信号进行模数转换得到所述待测信号，并将得到的待测信号发送给所述时间测量单元。
  33. 如权利要求32所述的专用集成电路，其特征在于，在所述专用集成电路ASIC模块上集成的是分时复用的模数转换单元。
  34. 如权利要求32或33所述的专用集成电路，其特征在于，所述模数转换单元还用于对关于所述专用集成电路的时钟影响信号进行模数转换，并将转换后的时钟影响信号传输给所述处理单元。
  35. 如权利要求34所述的专用集成电路，其特征在于，所述时钟影响信号包括：温度信号和/或电压信号。
  36. 如权利要求21所述的专用集成电路，其特征在于，所述专用集成电路ASIC模块中还集成了角度测量单元，所述角度测量单元用于测量激光雷达设备中接收器和发射器的角度信息，并将测量得到的角度信息输出给所述处理单元。
  37. 如权利要求36所述的专用集成电路，其特征在于，所述角度测量单元用于测量激光雷达设备中接收器和发射器中包括的电机的角度来得到所述角度信息。
  38. 如权利要求37所述的专用集成电路，其特征在于，所述角度信息包括：由所述角度测量单元根据对电机输出的控制信号中高电平的持续时间计算得到的电机的转速和转动角度。
  39. 如权利要求21-38任一项所述的专用集成电路，其特征在于，所述专用集成电路ASIC模块中还集成了算法处理单元，所述算法处理单元用于根据预置的算法对激光雷达数据进行计算；
    所述激光雷达数据包括：激光雷达设备的发射器发射激光发射信号时的发射时间、激光雷达设备的接收器接收到的激光反射信号对应的点云数据、所述处理单元基于所述接收到的激光反射信号计算得到的响应时间中的任意一个或者多个。
  40. 如权利要求21-38任一项所述的专用集成电路，其特征在于，所述处理单元是集成在所述专用集成电路ASIC模块上的片上系统SOC单元。
  41. 一种测距装置，其特征在于，所述测距装置包括如权利要求1至20任一项所述的激光雷达设备。
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