WO2023206891A1 - 信号发射接收系统及其方法 - Google Patents

信号发射接收系统及其方法 Download PDF

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Publication number
WO2023206891A1
WO2023206891A1 PCT/CN2022/115643 CN2022115643W WO2023206891A1 WO 2023206891 A1 WO2023206891 A1 WO 2023206891A1 CN 2022115643 W CN2022115643 W CN 2022115643W WO 2023206891 A1 WO2023206891 A1 WO 2023206891A1
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Prior art keywords
time
delay
signal
starting point
receiving
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PCT/CN2022/115643
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English (en)
French (fr)
Inventor
沈国锋
向少卿
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上海禾赛科技有限公司
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Publication of WO2023206891A1 publication Critical patent/WO2023206891A1/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
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/483—Details of pulse systems
    • G01S7/484—Transmitters
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/483—Details of pulse systems
    • G01S7/486—Receivers
    • G01S7/4861—Circuits for detection, sampling, integration or read-out

Definitions

  • This specification relates to a signal transmitting and receiving system and a method thereof, and in particular to a system and method in which the receiving system and the transmitting system are asynchronous clocks and the scanning starting point is stable.
  • the signal transmitting and receiving system is a commonly used target object detection method. It achieves the purpose of detecting and measuring target objects by sending signals to the target object and detecting the reflected echo signals.
  • Common application examples include lidar that detects target objects by emitting laser beams. Based on the echo signal reflected by the detected target object, the precise distance, orientation, reflectivity and other information of the target object and/or area can be calculated. Compared with other technologies, lidar can better describe complex surface conditions, so it is increasingly used in ranging applications, such as distance measurement in fields such as autonomous driving and industrial automation, and has great market development prospects. .
  • a lidar transmitter usually emits an explosive energy signal emitted by a laser pulse.
  • kick' is the signal with metastable state
  • kick" is the signal after hitting one beat to eliminate the metastable state.
  • the metastable state is eliminated, Steady state, but the rising edge of "kick" is one clock cycle later when the metastable value is 0 than when the substable value is 1.
  • This causes the kick signal synchronized to the receive clock domain to jitter back and forth (the jitter time is an integer multiple of the receive clock period). If this jitter is not suppressed, it will cause jitter before and after the starting point of the received scan.
  • a jitter of 1ns will cause the detected object to have a positional jitter of 15cm, which is unacceptable for lidar with an accuracy of 2 to 3cm. Therefore, for a signal transmitting and receiving asynchronous clock receiving system, it is necessary to solve the problem of unstable scanning starting point to ensure object detection accuracy.
  • the present application discloses a signal transmitting and receiving system, which includes: a transmitting circuit for generating a trigger signal at a triggering time according to a first clock signal and transmitting a detection signal at the transmitting time; and a receiving circuit for receiving the detection signal.
  • the echo signal reflected by the target object, and the trigger signal is received according to the second clock signal and the first receiving channel is enabled at the initial startup moment.
  • the first receiving channel uses the initial startup moment as the time origin to sense Receive the return time of the echo signal; determine a first calculation starting point of the first receiving channel, and determine the return time sensed by the first receiving channel and the transmission time based on the first calculation starting point.
  • the target time difference between the initial start time and the trigger time includes unpredictable jitter delay.
  • determining the target time difference includes: determining a first time difference between the first calculation starting point and the return time; and comparing the first time difference with a pre-calibrated time calibration value Sum to obtain the target time difference.
  • the transmitting circuit also generates a reference signal at the transmitting time, the reference signal has a fixed timing relationship with the transmitting time; and the determining the first calculation starting point further includes: the first receiving The channel determines a reference time based on the reference signal, and determines the first calculation starting point based on the reference time.
  • determining the first calculation starting point based on the reference time includes obtaining an expected scan delay, where the expected scan delay is a preset time delay after the reference time. ;
  • the first receiving channel uses the initial startup time as the time origin: determines the initial timing time; based on the initial timing time and the reference time, determines the compensation delay, the compensation delay includes the jitter delay The offset part; and based on the initial timing moment and the compensation delay, determine the first calculation starting point.
  • determining the initial timing moment includes: determining the initial timing moment based on the initial startup moment.
  • the receiving circuit further includes a second receiving channel, which is enabled at the first startup moment for sensing the echo signal; determining the initial timing moment includes: The initial timing time is determined based on the first startup time. According to some embodiments of the present application, determining the first calculation starting point based on the initial timing moment and the compensation delay includes obtaining a system comprehensive delay, and determining the first calculation starting point based on the compensation delay and the expected scan delay. and the system integrated delay to determine a second delay; based on the initial timing time and the second delay, the first calculation starting point is determined.
  • the receiving circuit further determines a second calculation starting point of the second receiving channel based on the second delay, and determines a second calculation starting point perceived by the second receiving channel based on the second calculating starting point.
  • the receiving circuit further includes a second receiving channel, the second receiving channel starts a pre-enable signal at the first starting moment, and starts the enabling signal at the second starting moment, wherein the The enable signal of the second receiving channel is used to sense the echo signal; the determining the initial timing time includes: determining the initial timing time based on the first startup time.
  • determining the first calculation starting point based on the initial timing moment and the compensation delay includes obtaining a system comprehensive delay, and determining the first calculation starting point based on the compensation delay and the expected scan delay.
  • the second delay is determined with the system integrated delay, and the first calculation starting point is determined based on the initial timing time and the second delay.
  • the receiving circuit further determines the second calculation starting point of the enable signal of the second receiving channel based on the first startup moment and the second delay, and based on The second calculation starting point determines a target time difference between the return time of the echo signal and the transmission time of the enabling signal sensing.
  • obtaining the system comprehensive delay includes: selecting the system comprehensive delay value of the previous scan as the system comprehensive delay value of this scan; determining the first calculation starting point It includes: adding the compensation delay, the expected scan delay and the comprehensive system delay of this scan to obtain an initial second delay, and rounding the initial second delay value to obtain an integer time. unit value, determine the integer time unit value as the second delay value of the current scan, and update the system comprehensive delay of the current scan based on the second delay value of the current scan. , and adding the initial timing time and the second time delay of the current time to obtain the first calculation starting point.
  • the trigger signal is the reference signal
  • the trigger time is the rising edge time of the reference signal
  • the reference time is the falling edge time of the reference signal
  • the trigger signal is different from the reference signal, and there is a fixed timing relationship between the trigger signal and the reference signal; the trigger moment is earlier than the rising edge moment of the reference signal. , and the reference time is the rising edge time or falling edge time of the reference signal.
  • a signal transmitting and receiving method which includes: generating a trigger signal at the triggering time through a transmitting circuit according to the first clock signal and transmitting a detection signal at the transmitting time; and receiving the signal through the receiving circuit according to the second clock signal.
  • the echo signal after the detection signal is reflected by the target object simultaneously receives the trigger signal and enables the first receiving channel at the initial startup moment.
  • the first receiving channel uses the initial startup moment as the time origin to sense and receive To the return time of the echo signal: determine the first calculation starting point of the first receiving channel, and determine the time between the return time sensed by the first receiving channel and the transmission time according to the first calculation starting point.
  • the target time difference wherein the first delay between the initial startup moment and the trigger moment includes unpredictable jitter delay.
  • determining the target time difference between the return time and the transmission time sensed by the first receiving channel according to the first calculation starting point includes: determining the first calculation starting point and The first time difference of the return time; and the target time difference is obtained by summing the first time difference and the pre-calibrated time calibration value.
  • the transmitting circuit also generates a reference signal, the reference signal has a fixed timing relationship with the transmitting moment; and the determining the first calculation starting point further includes: the first receiving channel is based on The reference signal determines a reference time, and based on the reference time, the first calculation starting point is determined.
  • determining the first calculation starting point based on the reference time includes obtaining an expected scan delay, where the expected scan delay is a preset time delay after the reference time. ;
  • the first receiving channel uses the initial startup time as the time origin to determine the initial timing time; based on the initial timing time and the reference time, determine the compensation delay, the compensation delay includes the jitter delay The offset part; and based on the initial timing moment and the compensation delay, determine the first calculation starting point.
  • determining the initial timing moment includes: determining the initial timing moment based on the initial startup moment.
  • the receiving circuit further includes a second receiving channel, which is enabled at the first startup moment for sensing the echo signal; determining the initial timing moment includes: The initial timing time is determined based on the first startup time.
  • determining the first calculation starting point based on the initial timing moment and the compensation delay includes obtaining a system comprehensive delay, and determining the first calculation starting point based on the compensation delay and the expected scan delay.
  • the second delay is determined with the system integrated delay, and the first calculation starting point is determined based on the initial timing time and the second delay.
  • the receiving circuit further determines a second calculation starting point of the second receiving channel based on the first startup moment and the second delay, and determines the third calculation starting point based on the second calculation starting point. The target time difference between the return time of the echo signal sensed by the second receiving channel and the transmission time.
  • the receiving circuit further includes a second receiving channel, the second receiving channel starts a pre-enable signal at the first starting moment, and starts the enabling signal at the second starting moment, wherein the The enable signal of the second receiving channel is used to sense the echo signal; the determining the initial timing time includes: determining the initial timing time based on the first startup time.
  • determining the first calculation starting point based on the initial timing moment and the compensation delay includes obtaining a system comprehensive delay, and determining the first calculation starting point based on the compensation delay and the expected scan delay.
  • the second delay is determined with the system integrated delay, and the first calculation starting point is determined based on the initial timing time and the second delay.
  • the receiving circuit further determines the second calculation starting point of the enable signal of the second receiving channel based on the first startup moment and the second delay, and based on the A second calculation starting point determines a target time difference between the return time of the echo signal and the transmission time of the enabling signal sensing.
  • obtaining the system comprehensive delay includes: selecting the system comprehensive delay value of the previous scan as the system comprehensive delay value of this scan; determining the first calculation starting point It includes: adding the compensation delay, the expected scan delay and the comprehensive system delay of this scan to obtain an initial second delay, and rounding the initial second delay value to obtain an integer time. unit value, determine the integer time unit value as the second delay value of the current scan, and update the system comprehensive delay of the current scan based on the second delay value of the current scan. , and adding the initial timing time and the second time delay of the current time to obtain the first calculation starting point.
  • the trigger signal is the reference signal
  • the trigger time is the rising edge time of the reference signal
  • the reference time is the falling edge time of the reference signal
  • the trigger signal is different from the reference signal, and there is a fixed timing relationship between the trigger signal and the reference signal; the trigger moment is earlier than the rising edge moment of the reference signal. , and the reference time is the rising edge time or falling edge time of the reference signal.
  • the determined calculation starting point of the receiving system is not affected by the cross-clock domain metastability of the receiving system and the transmitting system, and the stability mechanism principle and calculation method of the calculation starting point of this application are Simple and easy to implement, it improves the accuracy of time measurement and the precision of ranging systems. At the same time, it also makes it possible to accumulate multiple scan data on the chip, further increasing the signal-to-noise ratio and improving the ranging capabilities and application scenarios of the receiving chip. In addition, the system and method of the present application make reasonable use of the existing hardware resources of the chip and do not require additional devices to stabilize the scanning starting point of the receiving system.
  • FIG. 1A and Figure 1B respectively list two situations in which the kick signal appears metastable
  • Figure 2 shows a schematic structural diagram of a signal transmitting and receiving system provided according to some embodiments of this specification
  • Figure 3 shows a workflow 300 of a signal transmitting and receiving system disclosed according to some embodiments of this specification
  • Figure 4 shows a signal diagram corresponding to an embodiment of method 300
  • Figures 5A-C show signal diagrams corresponding to another embodiment of method 300
  • Figures 6A-C show signal diagrams corresponding to yet another embodiment of the method 300
  • Figure 7 is a specific example corresponding to the signal diagram shown in Figure 5A.
  • Figure 8 is a specific example corresponding to the signal diagram shown in Figure 6A;
  • Figure 9 is a measurement example of a receiving circuit in the asynchronous clock domain in the prior art.
  • Signal transmitting and receiving system 100; transmitting circuit: 110; first clock signal: 111; receiving circuit: 120; second clock signal: 121; receiving channel: 122; histogram sampler: HDC; time-to-digital converter: TDC; Launch time: t 0 ; initial start time: First calculation starting point: t_TDC_origin ; Second calculation starting point: t_HDC_origin; Return time: t 4 ; Target time difference: TOF; Base time: t 2 ; Initial timing time: t 1 ; Expected scan delay: T 1 ; System comprehensive delay : ⁇ t; second delay: x; compensation delay: ⁇ t; TDC time calibration value: t_TDC_c; HDC time calibration value: t_HDC_c; reference signal: kick; trigger time: t_trigger.
  • Figure 2 shows a schematic structural diagram of a signal transmitting and receiving system 100 provided according to some embodiments of this specification.
  • the signal may be a laser signal
  • the system 100 is an electromagnetic wave radar system
  • the signal may be an electromagnetic wave
  • the system 100 is an ultrasonic radar system
  • the signal may be an ultrasonic signal
  • the system 100 may also be a quantum detection system
  • the signal may be a detection signal related to the quantum detection principle.
  • the system 100 can also be a signal transmitting and receiving system in other forms, which is not limited in this application.
  • lidar will be used as an example to describe the technical solution in this application.
  • those skilled in the art can completely apply the technical solutions in the present application to other examples mentioned above without departing from the essential spirit of the present application.
  • the signal transmitting and receiving system 100 includes a transmitting circuit 110 and a receiving circuit 120 .
  • the transmitting circuit 110 and the receiving circuit 120 are two independently operated circuits that operate according to different clock signals.
  • the transmitting circuit 110 may be a laser radar transmitting circuit or a transmitting chip. Under normal operating conditions, the laser transmitting circuit or chip can output laser pulses at a certain frequency; the receiving circuit 120 can be a receiving circuit or receiving chip of a laser radar. Under normal operating conditions, the receiving circuit or The chip can receive the echo signal reflected by the target object, and calculate the time of flight TOF (time of flight) of each laser pulse or target time difference based on the launch time of the emitted laser pulse and the return time of the received echo signal. .
  • time of flight TOF time of flight
  • the transmit circuit 110 includes a first clock signal 111 .
  • the transmitting circuit 110 transmits the detection signal at the transmitting time t 0 according to the first clock signal 111 . Since the transmitting circuit 110 and the receiving circuit 120 operate according to different clock signals, the transmitting circuit 110 also sends a trigger signal to the receiving circuit 120 so that the receiving circuit 120 starts processing the echo signal. scanning. To this end, the transmitting circuit 110 can generate a trigger signal at the t_trigger moment according to the first clock signal 111 and send it to the receiving circuit 120 to enable the receiving channel 122 so that the receiving circuit 120 is ready to receive the echo signal. .
  • the echo signal is the signal after the detection signal is reflected by the target object.
  • the echo signal is the reflected laser light that is reflected back after being irradiated by an object surrounding the radar and captured by the lidar.
  • the trigger signal may be a kick signal as a reference signal, or may be other trigger signals different from the reference signal.
  • t_trigger the generation and emission time
  • t 0 is a certain time after the t_trigger time, and t 0 may also be at the same time as t_trigger. This is explained in detail later in this manual.
  • the receiving circuit 120 includes a second clock signal 121 and a receiving channel 122 .
  • the receiving circuit 120 can detect the trigger signal sent by the transmitting circuit according to the second clock signal 121 .
  • the receiving circuit 120 can enable the receiving channel 122 to start timing and detect the echo signal.
  • the receiving channel 122 may have only one receiving channel, or may have multiple receiving channels, for example, it may be a time-to-digital converter (TDC), or it may be a time-to-digital converter TDC.
  • TDC time-to-digital converter
  • histogram sampler HDC, TDC and HDC are the original receiving channels in the lidar transmitting circuit/chip. TDC and HDC each have their own measurement advantages.
  • TDC is more suitable for the measurement of large signals in the vicinity
  • HDC is more suitable for the measurement of small signals in the distance.
  • TDC and HDC can be used to detect echo signals at the same time, and then the point cloud data can be fused to obtain more accurate echo signal data.
  • FIG. 3 shows a workflow 300 of the signal transmitting and receiving system 100 disclosed according to some embodiments of the present application.
  • the workflow 300 includes the following steps:
  • the transmitting circuit generates a trigger signal at the trigger moment according to the first clock signal, and transmits the detection signal at the transmit moment.
  • the transmitting circuit 110 can generate the trigger signal at the trigger time t_trigger according to the first clock signal 111 and send it to the receiving circuit 120 to enable the receiving channel 122 .
  • the trigger signal may be a reference signal kick, wherein the generation and emission time t_trigger of the rising edge of the reference signal kick and the emission time t 0 of the detection signal may be the same time. , or may be at different times.
  • the transmission time t 0 may be a fixed time after the rising edge of the reference signal kick.
  • the trigger signal trigger can also be another trigger signal different from the reference signal kick, and the generation and emission time t_trigger of the trigger signal trigger is earlier than the reference signal There is a fixed timing relationship between the rising edge moment of signal kick, t_trigger and the rising edge moment of reference signal kick.
  • the receiving circuit receives the trigger signal according to the second clock signal, and enables the first receiving channel at the initial startup moment.
  • the receiving circuit 120 can set the enabling time of the receiving channel 122 according to the second clock signal 121, that is, the initial startup time.
  • the initial start time of receiving channel 122 Detect the echo signal for its time origin.
  • the trigger signal may be a reference signal kick, or may be another trigger signal different from the reference signal kick. Therefore, the receiving circuit 120 may enable the receiving channel according to the reference signal kick, or may enable the receiving channel according to an additional trigger signal. Enable the receive channel.
  • the receiving channel 122 may only include the first receiving channel, such as the time-to-digital converter TDC in Figure 4; it may also include the first receiving channel at the same time, such as the time-to-digital converter in Figures 5A-C.
  • the first receiving channel and the second receiving channel can independently sense the echo signal.
  • the receiving channel may also be other types of measurement channels except TDC and HDC, and the receiving circuit may also include more than two receiving channels. According to the essential spirit of this application, those skilled in the art can completely implement the technical solutions in this application. Apply this to other examples.
  • the TDC enable signal is represented by TDC_en in Figures 4, 5A-C and 6A-C.
  • the receiving circuit 120 can The second receiving channel HDC is then enabled, as shown in FIGS. 5A-C , and the HDC is enabled at the initial timing time t 1 .
  • the TDC is able to sense the initial timing time t 1 , the reference time t 2 and the return time t 4 when the echo signal is received.
  • the receiving circuit 120 can control the second receiving channel to Then the HDC pre-enable signal (HDC_en_pre) is generated, for example, HDC_en_pre is enabled at the first startup time t 1 , as shown in FIGS. 6A-C , and the receiving circuit 120 controls the second receiving channel HDC to start at the first start time t 1 .
  • the second calculation starting point t_HDC_origin enables the HDC enable signal (HDC_en), and HDC_en can sense the echo signal.
  • the receiving chip since the receiving chip has a certain probability of being metastable when synchronizing the trigger signal (such as the reference signal kick), the initial startup moment There is an unpredictable jitter delay between the trigger time t_trigger and the trigger signal trigger, because the receiving channel is based on the initial startup time. To detect the echo signal at its time origin, the unpredictable jitter delay will cause the time origin of the measured echo signal to be unstable, thereby making the measurement results of the echo signal unstable.
  • the first receiving channel uses the initial startup time as the time origin to sense the return time when the echo signal is received; the receiving circuit determines the first calculation starting point of the first receiving channel.
  • the first receiving channel Since the first receiving channel is at the initial startup time When awakened, for the first receiving channel, all subsequent times and time calculations are based on the initial startup time. Measured and calculated for the origin of time.
  • the first receiving channel may first determine the reference time t 2 based on the reference signal kick, and then determine the first calculation starting point t_TDC_origin based on the reference time. .
  • the receiving circuit can obtain the expected scan delay T 1 and the system comprehensive delay ⁇ t, and the first receiving channel can use the initial startup time As the origin of time, determine the initial timing time t 1 and the reference time t 2 .
  • the initial timing time t 1 can be determined in multiple ways. In some embodiments, as shown in FIG. 4 , when the receiving circuit 120 only includes the first receiving channel, the initial timing time t 1 can be based on the initial startup time. It is determined that in some embodiments, the initial timing time t 1 is the initial startup time. In some embodiments, as shown in Figure 5A-C, the receiving circuit 120 includes the first receiving channel and the second receiving channel at the same time, and the second receiving channel is enabled at the first startup moment, so The first receiving channel determines the initial timing time t 1 according to the first starting time. In some embodiments, the first starting time is the initial timing time t 1 . In some embodiments, as shown in FIGS.
  • the receiving circuit 120 includes the first receiving channel and the second receiving channel at the same time, and the second receiving channel is started before the first starting moment.
  • Enable signal HDC_en_pre, and start enable signal HDC_en at the second startup time, and the first receiving channel determines the initial timing time according to the first startup time.
  • the first starting time is the initial timing time t 1 .
  • the expected scan delay T 1 is a delay of a preset length after the reference time t 2 .
  • the expected scan delay T 1 can be set through the system, and the specific value can be determined through testing.
  • the expected scan delay T 1 can be set to a value greater than or equal to zero, such as the case of only the first receiving channel ( Figure 4) or the second receiving channel only enabling the enable Case of signal HDC_en (Fig. 5A-C).
  • the expected scan delay T 1 may be set to a value greater than zero.
  • the reference time t 2 may be the falling edge time of the reference signal kick, and in other embodiments, the reference time t 2 may be the rising edge time of the reference signal kick.
  • the first receiving channel can sense the falling edge time t 2 of the reference signal kick as the reference time ( Figures 4, 5A, 5B, 6A and 6B), or it can sense the rising edge time of the reference signal kick as The reference time ( Figures 5C and 6C). Since the first receiving channel is based on the initial startup time Time is measured as the origin of time, so the reference time t 2 is relative to the initial start time contains a negative jitter error, thereby offsetting the initial start-up time The impact of jitter delay.
  • the receiving circuit can determine the compensation delay ⁇ t based on the initial timing time t 1 and the reference time t 2 .
  • the compensation delay ⁇ t is the difference between the reference time t 2 and the initial timing time t 1 . Because the initial timing time t 1 and the initial startup time The time difference between them is generally fixed, so the compensation delay ⁇ t contains the cancellation part of the jitter delay.
  • the receiving circuit 120 is composed of multiple electrical components. When processing the signal response, each electrical component will have its own errors due to manufacturing, calibration, thermal drift and other reasons. The accumulation of these errors will lead to a systematic error in the response of the receiving circuit 120.
  • the comprehensive delay ⁇ t Therefore, in addition to determining the reference time t 2 and the compensation delay ⁇ t, the receiving circuit 120 also determines the system comprehensive delay ⁇ t in an iterative manner. The specific method is as follows:
  • the initial comprehensive delay value is determined, and the preset expected scan delay T 1 is retrieved. Then at the beginning of each iteration, the system comprehensive delay value in the last scan is selected as the system comprehensive delay value of this scan. If this scan is the initial scan, the system comprehensive delay value of this time is is the initial comprehensive delay value. In some embodiments, the initial comprehensive delay value is zero.
  • the initial second delay x is obtained by summing the compensation delay ⁇ t, the expected scan delay T 1 and the system comprehensive delay ⁇ t of this scan, and rounding the value of the initial second delay x Rounding to obtain an integer time unit value, determining the integer time unit value as the second delay x, and updating the system comprehensive delay ⁇ t of this scan based on the second delay x value.
  • the receiving circuit 120 may determine the first calculation starting point based on the initial timing moment and the second delay x.
  • the first calculation starting point is The sum of the initial timing time t 1 and the second delay x, that is to say, the time after the first receiving channel is delayed by t 1 +x from the enable time of TDC_en is the first time delay of the first receiving channel.
  • the TDC measurement The obtained return time should be minus the first calculation starting point t_TDC_origin value (that is, minus t 1 +x).
  • the receiving circuit 120 further includes the second receiving channel, so step S330 further includes step S331.
  • S331 The receiving circuit determines a second calculation starting point of the second receiving channel according to the second delay.
  • the received circuit 120 further includes the second receive channel, so the receive circuit determines the second calculation starting point t_HDC_origin.
  • the second receiving channel only has the enable signal HDC_en, and the second receiving channel measures the echo signal with the enable moment of the enable signal HDC_en as its time origin, and the receiving circuit measures the echo signal according to the second time delay.
  • the second calculation starting point is determined, specifically, the second calculation starting point t_HDC_origin of the second receiving channel is the time after the enablement time of HDC_en of the second receiving channel is delayed by the second delay x.
  • the second receiving channel detects the echo signal with its enabling moment as the time origin, after determining the second calculation starting point t_HDC_origin, the return time is recalculated using the second calculation starting point t_HDC_origin.
  • the HDC measurement The obtained return time should be minus the second calculation starting point t_HDC_origin value (that is, minus x).
  • the second receiving channel in addition to the enable signal HDC_en, also has a pre-enable signal HDC_en_pre, and the receiving circuit determines the second calculation starting point according to the second delay, specifically the After the enabling moment of HDC_en_pre, the second receiving channel is enabled by delaying the moment after the second delay, that is, the second calculation starting point t_HDC_origin of the second receiving channel.
  • the The second calculation starting point is also the enabling moment of HDC_en, and the second receiving channel measures the echo signal with the second calculation starting point as the time origin.
  • the trigger signal trigger and the reference signal kick may be two different signals.
  • the transmitting circuit provides the trigger signal trigger before the reference signal kick.
  • the delay between the trigger signal trigger and the reference signal kick is fixed, so that the receiving channel of the receiving circuit 120 can trigger before the arrival of the reference signal kick, and obtain the reference moment by measuring the falling edge of the reference signal kick. t 2 .
  • the trigger signal trigger and the reference signal kick are still two different signals.
  • the transmitting circuit 110 provides the trigger signal trigger before the reference signal kick, so that the receiving channel can trigger before the reference signal kick arrives.
  • the receiving circuit may obtain the reference time t 2 by measuring the rising edge of the reference signal kick.
  • the trigger signal trigger and the reference signal kick may be two different signals.
  • the transmitting circuit provides the trigger signal trigger before the reference signal kick.
  • the delay between the trigger signal trigger and the reference signal kick is fixed, so that the TDC and HDC of the receiving circuit 120 can trigger before the arrival of the reference signal kick, and obtain the result by measuring the falling edge of the reference signal kick. Describe the reference time t 2 .
  • the trigger signal trigger and the reference signal kick are still two different signals.
  • the transmitting circuit 110 provides a trigger signal trigger before the reference signal kick, so that the receiving channel can trigger before the reference signal kick arrives.
  • the receiving circuit can obtain the reference time t 2 by measuring the rising edge of the reference signal kick.
  • S340 The receiving circuit determines the target time difference between the return time and the transmission time sensed by the first receiving channel according to the first calculation starting point.
  • the target time difference between the return time t 4 and the launch time t 0 is the time it takes for the laser to reflect back from its emission, that is, the target time difference TOF ( Figures 4, 5A, and 6A).
  • the receiving circuit first determines a time calibration value t_TDC_c of a first receiving channel, where the time calibration value t_TDC_c is the time difference between the transmission time t0 and the first calculation starting point.
  • the time difference between the first calculation starting point and the return time of the echo signal is not affected by the jitter delay.
  • the time difference from the laser radar's emission time t 0 to the first calculation starting point can be determined through system calibration. During multiple scans, the time calibration value t_TDC_c is fixed.
  • the system 100 may first perform a calibration test on a calibration object with a known fixed distance, thereby obtaining the time calibration value t_TDC_c. In this way, when subsequently calculating the target time difference, the receiving circuit 120 only needs to retrieve the pre-calibrated time calibration value t_TDC_c.
  • a second receiving channel is also included, so step S330 also includes step S341.
  • the receiving circuit determines the target time difference between the return time and the transmission time sensed by the second receiving channel according to the second calculation starting point.
  • the target time difference between the return time t 5 and the emission time t 0 is the time it takes for the laser to reflect back from its emission, that is, the target time difference TOF ( Figures 5A and 6A).
  • the receiving circuit first determines a time calibration value t_HDC_c of the second receiving channel.
  • the time calibration value t_HDC_c is the time difference between the transmitting time t 0 and the second calculation starting point. .
  • the time difference between the second calculation starting point and the return time of the echo signal is not affected by the jitter delay, and the time difference between the laser radar's emission time t 0 and the second calculation starting point (also That is, t_HDC_c) can be determined through system calibration.
  • the time calibration value t_HDC_c is fixed.
  • the system 100 may first perform a calibration test on a calibration object with a known fixed distance, thereby obtaining the time calibration value t_HDC_c. In this way, when subsequently calculating the target time difference, the receiving circuit 120 only needs to retrieve the pre-calibrated time calibration value t_HDC_c.
  • the values t_HDC_c are summed to obtain the time sum, which is the target time difference TOF measured by the second receiving channel. In this way, the measurement process of the second receiving channel is completed. Since the second calculation starting point t_HDC_origin is the initial startup moment that has been eliminated The jitter delay is stable at the moment, so the measurement of the target time difference is stable and accurate.
  • (A) and (B) in Figure 9 are two consecutive scans of the echo signal respectively.
  • the target time difference TOF corresponding to the distance between the target object and the signal transmitting and receiving system 100 is 22 ns.
  • the target time TOF can be determined by emitting a laser beam to the target object at a known distance, or by other methods. The method is obtained and is not limited to this application.
  • the transmitting circuit emits a detection signal at the rising edge of the kick signal, and considers the transmitting time t 0 as the zero time of the first clock signal.
  • the receiving circuit controls TDC and HDC enable respectively.
  • TDC is enabled with a delay of 1.2ns relative to t 0
  • HDC is enabled with a delay of 3.2ns relative to t0
  • the HDC measured The TOF value is 18.8ns.
  • a target object with a known distance can be used to calibrate the TOF value obtained by TDC and the TOF value obtained by HDC.
  • the real TOF value of 22ns is used to calibrate the TDC and TOF values.
  • HDC measurements are calibrated.
  • the obtained TOF value measured by TDC is the same as that measured by HDC.
  • the TOF values are all 22ns.
  • test calibration is usually only performed on the first scan of the lidar, or after a period of time, rather than for every scan. After calibration, the lidar will calibrate the measurement results with the above time calibration value during subsequent scanning of echo signals.
  • the receiving circuit Due to the existence of metastable state, when the receiving circuit synchronizes the kick signal sent by the transmitting circuit during multiple scans, there will be a deviation close to the whole ns. Therefore, the receiving circuit also has a problem when determining the TDC enable moment and HDC enable moment. There will be a deviation close to the whole ns.
  • the delay time corresponding to the TDC enable moment and the HDC enable moment relative to the rising edge of the kick signal has a deviation close to the whole ns during multiple scans. Based on this, it is assumed that in the second scan, the TDC enable time is delayed by 2.2ns from the rising edge of the kick signal, and the HDC enable time is delayed by 4.2ns from the rising edge of the kick signal.
  • the return The time is 19.8ns
  • the return time measured by HDC is 17.8ns.
  • the receiving circuit 120 has a first receiving channel and a second receiving channel.
  • the first receiving channel is specifically TDC
  • the second receiving channel is specifically HDC
  • the trigger signal is a reference signal kick.
  • the first receiving channel TDC_en is at Enabled at time t 1
  • the pre-enable signal HDC_en_pre of the second receiving channel is enabled at time t 1 .
  • it is determined that the enable signal HDC_en of the second receiving channel is enabled at time t_HDC_origin.
  • TDC_en senses the enable moment of HDC_en_pre as the initial timing time t 1 , senses the falling edge moment of the kick signal as the reference time t 2 , and senses the return time t 4 of the echo signal.
  • HDC_en senses the return time t 5 of the echo signal.
  • the target time difference TOF corresponding to the distance of the target object from the signal transmitting and receiving system 100 is 22 ns.
  • the target time TOF can be determined by emitting a laser beam to the target object at a known distance. Determination can also be obtained through other methods, which is not limited to this application.
  • the transmitting circuit emits a detection signal at the rising edge of the kick signal, and considers the transmission time t 0 as the zero time of the first clock signal; the kick signal is a signal with a fixed pulse width, and here it is assumed that its pulse width is 10 ns.
  • the expected scan delay T 1 to 5 ns, and set the delay time of HDC_en_pre enable time relative to TDC_en enable time can be set through the circuit.
  • (A) and (B) in Figure 8 are two consecutive scans of the echo signal.
  • the TDC_en enable time is delayed by 1.2ns relative to the transmit time t 0 in the transmit circuit, that is, relative to the rising edge time of the reference signal kick, that is, it includes the indispensable
  • Initial startup time of estimated jitter delay is 1.2ns, where 1.2ns is based on the time of the first clock signal of the transmitting circuit.
  • TDC_en will use its enabling moment as its zero moment to sense other signals, that is, TDC_en takes the initial startup moment as the time origin, and the measured return time t 4 is 20.8ns. This is because TDC_en delays the transmission time by 1.2ns and starts timing to sense the echo signal.
  • the initial timing time t1 2ns measured by TDC
  • the reference time t2 8.8ns
  • the TDC calculation starting point recalculates the measured value of the echo signal obtained by TDC.
  • the subsequent multiple scans test calibration will no longer be performed, but this time calibration value will be used as the time calibration value in subsequent scans to calculate the target time difference TOF.
  • HDC_en For the histogram sampler HDC, its HDC_en senses the echo signal, and the enable moment of HDC_en is determined according to the technical solution of this application, that is, the receiving circuit controls HDC_en enable after delaying the second delay x after the HDC_en_pre signal enable moment, HDC_en starts measuring the echo signal with its enable moment as the time origin of HDC.
  • the enable moment of HDC_en is delayed by 15.2ns relative to the rising edge of the reference signal kick. Therefore, the echo signal time t' measured by HDC is 6.8ns.
  • the delay time between the enable moment of TDC_en and the rising edge of the reference signal kick is not fixed during multiple scan measurements. There is a deviation close to the whole ns, so it can be assumed that in the second scan due to metastability, the TDC delay is enabled 2.2ns after the rising edge of the reference signal kick (there is a 1ns deviation from the 1.2ns delay in the first scan) , that is, including the initial startup time after the unpredictable jitter delay is 2.2ns.
  • the obtained target time difference TOF value is the same as the target time difference TOF in the last scan.
  • the values are consistent and are not affected by the jitter at the TDC enable moment, which means that the TDC calculation starting point determined according to the technical solution of this application is stable.
  • the starting point that is, the moment when HDC is enabled
  • the starting point of TDC calculation and the starting point of HDC calculation are aligned in time.
  • the receiving circuit and the transmitting circuit are in asynchronous clocks, the receiving circuit has a metastable state when synchronizing the trigger signal, causing the TDC enable time to have a jitter close to the whole ns, but the TDC obtained according to the technical solution of the present application
  • the starting point of calculation and the enabling moment of HDC are stable during multiple measurements.
  • the target time difference obtained by using this stable TDC to calculate the starting point and the enabling moment of HDC is a stable value and will not be affected by jitter caused by metastability. .
  • the technical solution of this application eliminates the problem of jitter of the scanning starting point under the asynchronous clock of the receiving circuit, ensures the stability of the return time measurement results during multiple scans, and improves the measurement accuracy.
  • the TDC calculation starting point and the enabling moment of HDC obtained by the technical solution invented are aligned in time, so that the measurement results of echo signals by TDC and HDC are consistent, and it is also convenient for subsequent measurement results of TDC and HDC. Fusion processing.
  • FIG 7 is an exemplary illustration corresponding to an embodiment of the signal diagram shown in Figure 5A.
  • the receiving circuit 120 has a first receiving channel and a second receiving channel.
  • the first receiving channel is specifically TDC
  • the second receiving channel is specifically HDC.
  • the first receiving channel TDC_en is at Time is enabled
  • the second receiving channel HDC_en is enabled at time t 1 .
  • TDC_en senses the enabling time of HDC_en as the initial timing time t 1 , senses the falling edge time of the kick signal as the reference time t 2 , and senses the return time t4 of the echo signal.
  • HDC_en senses the return time t 5 of the echo signal.
  • the TDC_en enable moment is delayed by 1.2ns relative to the rising edge of the kick signal, that is Therefore TDC is based on The return time t 4 measured for the origin of time is 20.8 ns.
  • the return time t 4 measured by the TDC is 20.8ns.
  • the time difference is the measured value of the echo signal obtained by recalculating the TDC based on the TDC calculation starting point determined according to the technical solution of this application.
  • this TDC time calibration value will be used as the TDC time calibration value in subsequent multiple scans to calculate the target time difference, that is, the TOF value.
  • the time-to-digital converter TDC of the receiving circuit is delayed by 2.2ns after the rising edge of the reference signal kick due to the metastable state, that is, the second scan is caused by the metastable state.
  • There is a 1ns deviation in the TDC enable time during the second scan relative to the TDC enable time during the first scan, which includes the initial startup time after the unpredictable jitter delay. is 2.2ns.
  • HDC is enabled with a delay of 2ns relative to TDC.
  • the target time difference TOF value obtained in the second scan is consistent with the target time difference TOF value in the first scan, and is not affected by the jitter at the TDC enable moment, which means that the TDC calculation determined according to the technical solution described in this application The starting point is stable.
  • the return time t 5 measured by the histogram sampler HDC is 17.8ns.
  • the second time difference is the measured value of the echo signal by HDC during the second scan.
  • the HDC calculation starting point is stable. It can also be seen intuitively from Figure 5 that the starting point of TDC calculation and the starting point of HDC calculation are aligned in time.
  • the time-to-digital converter TDC enable time jitters by several ns due to the metastable state of the trigger signal
  • the calculation starting point obtained according to the method of this application is stable during multiple measurements. With this stable calculation The return time obtained by the starting point is the stable value and will not be affected by the jitter caused by the metastable state. It can be seen that the method of this application eliminates the problem of measuring the starting point jitter under the asynchronous clock of the receiving circuit, and can guarantee the stability during multiple scans. The stability of the measurement results at the return time improves the measurement accuracy.
  • the TDC calculation starting point and the HD calculation starting point obtained by the technical solution invented are aligned in time, so that the measurement results of the target time difference between TDC and HDC are consistent, which facilitates the subsequent fusion processing of the TDC and HDC measurement results.
  • the trigger signal trigger and the reference signal kick are two different signals.
  • the transmitting circuit gives the trigger signal trigger before the reference signal kick.
  • the delay between the trigger signal trigger and the reference signal kick is fixed, so that the TDC and HDC of the receiving circuit can be triggered before the arrival of the reference signal kick, and the reference time t 2 is obtained by measuring the falling edge of the reference signal kick.
  • the trigger signal trigger and the reference signal kick are still two different signals.
  • the transmitting circuit gives the trigger signal trigger before the reference signal kick, so that TDC and HDC can trigger before the reference signal kick arrives.
  • the receiving circuit can obtain the time reference moment t 2 by measuring the rising edge of the reference signal kick.
  • Figures 5B and 5C still show the situation where the trigger signal trigger and the reference signal kick are two different signals.
  • the transmitting circuit gives the trigger signal trigger before the reference signal kick, so that TDC and HDC are enabled successively, and then the receiving circuit can measure the rising edge and falling edge time of the reference signal kick respectively to obtain the reference time t 2 .

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Abstract

本申请提供了信号发射接收系统及其方法。所述系统包括发射电路，用于根据第一时钟信号在触发时刻生成触发信号并在发射时刻发射探测信号；以及接收电路，用于接收所述探测信号经目标物体反射后的回波信号，以及根据第二时钟信号接收所述触发信号并在初启动时刻使能第一接收通道，所述第一接收通道以所述初启动时刻为时间原点，感知接收到所述回波信号的返回时刻；确定所述第一接收通道的第一计算起点，根据所述第一计算起点确定所述第一接收通道感知的所述返回时刻与所述发射时刻之间的目标时差，其中所述初启动时刻相对所述触发时刻之间的第一时延包括不可预估的抖动时延。根据本申请的信号发射接收系统及其方法，能够解决接收系统与发射系统异步时钟时扫描起点抖动的问题，同时也使得片内多次扫描数据累加成为可能，进一步增加信噪比，提升接收芯片测距能力和应用场景。

Description

信号发射接收系统及其方法 【技术领域】
本说明书涉及信号发射接收系统及其方法，尤其涉及一种接收系统与发射系统为异步时钟下的扫描起点稳定的系统及方法。
【背景技术】
信号发射接收系统是一种常用的目标物体探测手段，通过向目标物体发送信号并探测反射回来的回波信号，来达到对目标物体探知和测量的目的。常见的应用实例有如激光雷达通过发射激光光束来探测目标物体，根据探测目标物体反射的回波信号可以测算出目标物体和/或区域的精确距离、方位、反射率等信息。相比其他技术，激光雷达能更好地描述复杂的地表状态，因此其在测距应用上日趋广泛，像是在汽车自动驾驶、工业自动化等领域中进行距离的量测，极具市场发展前景。现有技术中，激光雷达发射器通常发出激光脉冲发射的爆发性能量信号，经反射面反射后被吸收走一部分能量，产生衰减延迟的激光雷达信号，叠加上原信号形成回波。通过精确测量脉冲发射到接收回波的时间，能够精确测量目标距离激光雷达的距离和位置。
一般来说，激光的发送和接收虽然由同一个芯片控制，但是为了提高回波信号的处理能力，设置了从发送接收芯片独立开来的回波处理芯片，形成了异步时钟系统，因此所述回波处理芯片需要检测发送接收芯片发出的基准信号(kick)信号以开始扫描。异步时钟无法保证kick信号与接收时钟(clk)之间的相位关系来满足建立时间(Tsu)和保持时间(Th)的要求，因此检测kick信号时有一定概率会出现亚稳态。图1A和图1B分别列出了kick信号出现亚稳态的两种情况。一般在数字设计上会通过多打几拍kick信号来消除亚稳态，上图kick’为有亚稳态的信号，kick”为打了一拍消除亚稳态后的信号。虽然消除了亚稳态，但是kick”的上升沿在亚稳态值为0时就比亚稳态值为1时晚了一个时钟周期。这导致同步到接收时钟域的kick信号会前后抖动(抖动时间为接收时钟周期的整数倍)。如果不对该抖动进行抑制，则会进而导致接收扫描起点的前后抖动。1ns的抖动就会造成 检测到的物体出现15cm的位置抖动，这对于精度达2～3cm的激光雷达是不可接受的。因此，对于信号发射接收异步时钟接收系统，有必要解决其扫描起点不稳定的问题，以保证物体检测精度。
【发明内容】
本申请一方面公开了一种信号发射接收系统，包括：发射电路，用于根据第一时钟信号在触发时刻生成触发信号并在发射时刻发射探测信号；以及接收电路，用于接收所述探测信号经目标物体反射后的回波信号，以及根据第二时钟信号接收所述触发信号并在初启动时刻使能第一接收通道，所述第一接收通道以所述初启动时刻为时间原点，感知接收到所述回波信号的返回时刻；确定所述第一接收通道的第一计算起点，根据所述第一计算起点确定所述第一接收通道感知的所述返回时刻与所述发射时刻之间的目标时差，其中所述初启动时刻相对所述触发时刻之间的第一时延包括不可预估的抖动时延。
根据本申请的一些实施例，所述确定所述目标时差包括：确定所述第一计算起点与所述返回时刻之间的第一时差；以及将所述第一时差与预先校准的时间校准值求和获得所述目标时差。
根据本申请的一些实施例，所述发射电路在发射时刻还生成基准信号所述基准信号与所述发射时刻具有固定的时序关系；以及所述确定第一计算起点还包括：所述第一接收通道基于所述基准信号确定基准时刻，以及基于所述基准时刻，确定所述第一计算起点。
根据本申请的一些实施例，所述基于所述基准时刻确定所述第一计算起点包括，获取期望扫描时延，所述期望扫描时延为在所述基准时刻之后的预设时长的时延；所述第一接收通道以所述初启动时刻为时间原点：确定初始计时时刻；基于所述初始计时时刻和所述基准时刻，确定补偿时延，所述补偿时延含有所述抖动时延的抵消部分；以及基于所述初始计时时刻、所述补偿时延，确定所述第一计算起点。
根据本申请的一些实施例，所述确定初始计时时刻包括：基于所述初启动时刻确定所述初始计时时刻。
根据本申请的一些实施例，所述接收电路还包括第二接收通道，所述第二接收通道在第一启动时刻使能，用于感知所述回波信号；所述确定初始计时时刻包括：基于所述第一启动时刻确定所述初始计时时刻。根据本申请的一些实施例，所述基于所述初始计时时刻、 所述补偿时延确定所述第一计算起点包括，获取系统综合时延，根据所述补偿时延、所述期望扫描时延和所述系统综合时延确定第二时延；基于所述初始计时时刻、所述第二时延，确定所述第一计算起点。
根据本申请的一些实施例，所述接收电路还根据所述第二时延确定所述第二接收通道的第二计算起点，并根据所述第二计算起点确定所述第二接收通道感知的所述回波信号的返回时刻与所述发射时刻之间的目标时差。
根据本申请的一些实施例，所述接收电路还包括第二接收通道，所述第二接收通道在第一启动时刻启动前使能信号，并在第二启动时刻启动使能信号，其中所述第二接收通道的所述使能信号用于感知所述回波信号；所述确定初始计时时刻包括：基于所述第一启动时刻确定所述初始计时时刻。
根据本申请的一些实施例，所述基于所述初始计时时刻、所述补偿时延确定所述第一计算起点包括，获取系统综合时延，根据所述补偿时延、所述期望扫描时延和所述系统综合时延确定第二时延，基于所述初始计时时刻、所述第二时延，确定所述第一计算起点。根据本申请的一些实施例，所述接收电路还根据所述第一启动时刻和所述第二时延确定所述第二接收通道的所述使能信号的所述第二计算起点，并根据所述第二计算起点确定所述使能信号感知的所述回波信号的返回时刻与所述发射时刻之间的目标时差。
根据本申请的一些实施例，所述获取所述系统综合时延包括：选定上一次扫描的系统综合时延值为本次扫描的系统综合时延值；所述确定所述第一计算起点包括：将所述补偿时延、所述期望扫描时延以及所述本次扫描的系统综合时延相加获得初始第二时延，将所述初始第二时延值四舍五入取整获得整数时间单位值，确定所述整数时间单位值为所述本次扫描的所述第二时延值，基于所述本次扫描的所述第二时延值更新所述本次扫描的系统综合时延，以及将所述初计时时刻同所述当前时刻的所述第二时延相加，得到所述第一计算起点。
根据本申请的一些实施例，所述触发信号为所述基准信号，所述触发时刻为所述基准信号的上升沿时刻，以及所述基准时刻为所述基准信号的下降沿时刻。
根据本申请的一些实施例，所述触发信号不同于所述基准信号，所述触发信号与所述基准信号之间具有固定的时序关系；所述触发时刻早于所述基准信号的上升沿时刻，以及所述基准时刻为所述基准信号的上升沿时刻或者下降沿时刻。
本申请另一方面公开了一种信号发射接收方法，包括：根据第一时钟信号，通过发射电路在触发时刻生成触发信号并在发射时刻发射探测信号；以及根据第二时钟信号，通过接收电路接收所述探测信号经目标物体反射后的回波信号，同时接收所述触发信号并在初启动时刻使能第一接收通道，所述第一接收通道以所述初启动时刻为时间原点，感知接收到所述回波信号的返回时刻：确定所述第一接收通道的第一计算起点，根据所述第一计算起点确定所述第一接收通道感知的所述返回时刻与所述发射时刻之间的目标时差，其中，所述初启动时刻相对所述触发时刻之间的第一时延包括不可预估的抖动时延。
根据本申请的一些实施例，所述根据所述第一计算起点确定所述第一接收通道感知的所述返回时刻与所述发射时刻之间的目标时差包括：确定所述第一计算起点与所述返回时刻的第一时差；以及将所述第一时差与预先校准的时间校准值求和获得所述目标时差。
根据本申请的一些实施例，所述发射电路还生成基准信号，所述基准信号与所述发射时刻具有固定的时序关系；以及所述确定第一计算起点还包括：所述第一接收通道基于所述基准信号确定基准时刻，以及基于所述基准时刻，确定所述第一计算起点。
根据本申请的一些实施例，所述基于所述基准时刻确定所述第一计算起点包括，获取期望扫描时延，所述期望扫描时延为在所述基准时刻之后的预设时长的时延；所述第一接收通道以所述初启动时刻为时间原点，确定初始计时时刻；基于所述初始计时时刻和所述基准时刻，确定补偿时延，所述补偿时延含有所述抖动时延的抵消部分；以及基于所述初始计时时刻、所述补偿时延，确定所述第一计算起点。
根据本申请的一些实施例，所述确定初始计时时刻包括：基于所述初启动时刻确定所述初始计时时刻。
根据本申请的一些实施例，所述接收电路还包括第二接收通道，所述第二接收通道在第一启动时刻使能，用于感知所述回波信号；所述确定初始计时时刻包括：基于所述第一启动时刻确定所述初始计时时刻。
根据本申请的一些实施例，所述基于所述初始计时时刻、所述补偿时延确定所述第一计算起点包括，获取系统综合时延，根据所述补偿时延、所述期望扫描时延和所述系统综合时延确定第二时延，基于所述初始计时时刻、所述第二时延，确定所述第一计算起点。 根据本申请的一些实施例，所述接收电路还根据所述第一启动时刻和所述第二时延确定第二接收通道的第二计算起点，并根据所述第二计算起点确定所述第二接收通道感知的所述回波信号的返回时刻与所述发射时刻之间的目标时差。
根据本申请的一些实施例，所述接收电路还包括第二接收通道，所述第二接收通道在第一启动时刻启动前使能信号，并在第二启动时刻启动使能信号，其中所述第二接收通道的所述使能信号用于感知所述回波信号；所述确定初始计时时刻包括：基于所述第一启动时刻确定所述初始计时时刻。
根据本申请的一些实施例，所述基于所述初始计时时刻、所述补偿时延确定所述第一计算起点包括，获取系统综合时延，根据所述补偿时延、所述期望扫描时延和所述系统综合时延确定第二时延，基于所述初始计时时刻、所述第二时延，确定所述第一计算起点。根据本申请的一些实施例，所述接收电路还根据所述第一启动时刻和所述第二时延确定第二接收通道的所述使能信号的所述第二计算起点，并根据所述第二计算起点确定所述使能信号感知的所述回波信号的返回时刻与所述发射时刻之间的目标时差。
根据本申请的一些实施例，所述获取所述系统综合时延包括：选定上一次扫描的系统综合时延值为本次扫描的系统综合时延值；所述确定所述第一计算起点包括：将所述补偿时延、所述期望扫描时延以及所述本次扫描的系统综合时延相加获得初始第二时延，将所述初始第二时延值四舍五入取整获得整数时间单位值，确定所述整数时间单位值为所述本次扫描的所述第二时延值，基于所述本次扫描的所述第二时延值更新所述本次扫描的系统综合时延，以及将所述初计时时刻同所述当前时刻的所述第二时延相加，得到所述第一计算起点。
根据本申请的一些实施例，所述触发信号为所述基准信号，所述触发时刻为所述基准信号的上升沿时刻，以及所述基准时刻为所述基准信号的下降沿时刻。
根据本申请的一些实施例，所述触发信号不同于所述基准信号，所述触发信号与所述基准信号之间具有固定的时序关系；所述触发时刻早于所述基准信号的上升沿时刻，以及所述基准时刻为所述基准信号的上升沿时刻或者下降沿时刻。
根据本申请提供的信号发射接收系统及其方法，所确定的接收系统的计算起点不受接收系统与发射系统跨时钟域亚稳态的影响，且本申请的计算起点的稳定机制原理和计算方法简单，易于实现，提高了时间测量的准确性和测距系统的精度。同时也使得片内多次扫 描数据累加成为可能，进一步增加了信噪比，提升了接收芯片测距能力和应用场景。此外，本申请的系统和方法合理利用了芯片现有的硬件资源，不需要设置额外的器件来稳定接收系统的扫描起点。
【附图说明】
为了更清楚地描述本说明书实施例中的技术方案，下面将对实施例描述所需要的附图作简单介绍，显而易见地，下述附图仅仅示例本说明书的一些实施例，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，根据这些附图也可以获得其他的附图和/或其他实施例。
图1A和图1B分别列出了kick信号出现亚稳态的两种情况；
图2示出了根据本说明书的一些实施例提供的一种信号发射接收系统的结构示意图；
图3示出了根据本说明书的一些实施例公开的信号发射接收系统的工作流程300；
图4示出了方法300的一种实施例所对应的信号图；
图5A-C示出了方法300的另一种实施例所对应的信号图；
图6A-C示出了方法300的还一种实施例所对应的信号图；
图7是对应于图5A所示信号图的具体示例；以及
图8是对应于图6A所示信号图的具体示例；
图9是现有技术中异步时钟域下接收电路的测量示例。
附图标号说明：
信号发射接收系统：100；发射电路：110；第一时钟信号：111；接收电路：120；第二时钟信号：121；接收通道：122；直方图采样器：HDC；时间数字转换器：TDC；发射时刻：t 0；初启动时刻：
Figure PCTCN2022115643-appb-000001
第一计算起点：t_TDC_origin ；第二计算起点：t_HDC_origin；返回时刻：t 4；目标时差：TOF；基准时刻：t 2；初始计时时刻：t 1；期望扫描时延：T 1；系统综合时延：δt；第二时延：x；补偿时延：Δt；TDC时间校准值：t_TDC_c；HDC时间校准值：t_HDC_c；基准信号：kick；触发时刻：t_trigger。
【具体实施方式】
参考图2，图2示出了根据本说明书的一些实施例提供的一种信号发射接收系统100的结构示意图。比如，若所述系统100是激光雷达系统，则所述信号可以是激光信号；若所述系统100是电磁波雷达系统，则所述信号可以是电磁波；若所述系统100是超声波雷 达系统，则所述信号可以是超声波信号；所述系统100还可以是量子探测系统，则所述信号可以是与量子探测原理相关的探测信号。当然，所述系统100还可以是其他形式的信号发射接收系统，本申请不做限制。本申请中将以激光雷达作为例子来描述本申请中的技术方案。然而本领域技术人员完全可以根据本申请中的技术方案将之应用在上述其他例子中而不偏离本申请的实质精神。
所述信号发射接收系统100包括发射电路110和接收电路120。其中，所述发射电路110和所述接收电路120是两个独立操作的电路，根据不同的时钟信号进行操作。比如，所述发射电路110可以是激光雷达的发射电路或者发射芯片。在正常工作状态下，所述激光发射电路或者芯片可以向外以一定频率输出激光脉冲；所述接收电路120可以是激光雷达的接收电路或者接收芯片，在正常工作状态下，所述接收电路或者芯片可以接收由目标物体反射回来的回波信号，并根据发射激光脉冲的发射时刻和接收到回波信号的返回时刻来计算每一束激光脉冲的飞行时间TOF(time of flight)或者叫目标时差。
所述发射电路110包括第一时钟信号111。在一些实施例中，所述发射电路110根据所述第一时钟信号111在发射时刻t 0发射出探测信号。由于所述发射电路110和所述接收电路120根据不同的时钟信号进行操作，因此发射电路110还要向所述接收电路120发送触发信号以使所述接收电路120启动对所述回波信号的扫描。为此，所述发射电路110可以根据所述第一时钟信号111在t_trigger时刻产生触发信号并发送给所述接收电路120来使能接收通道122，以便接收电路120准备好接收所述回波信号。所述回波信号为所述探测信号经目标物体反射后的信号。比如在激光雷达的例子中，所述回波信号为出射激光照射到雷达周边物体后反射回来并被激光雷达捕捉到的反射激光。所述触发信号可以是作为基准信号的kick信号，也可以是不同于基准信号的其他触发信号。其中触发信号的产生和发出时刻t_trigger与探测信号的所述发射时刻t 0之间具有固定时序关系，例如t 0在t_trigger时刻之后一定时间，t 0也可以与t_trigger是同时刻的。这点在本说明书的后面进行详细介绍。
所述接收电路120包括第二时钟信号121和接收通道122。所述接收电路120能够根据所述第二时钟信号121检测由所述发射电路发出的所述触发信号。通过接收所述触发信号，所述接收电路120可以使能所述接收通道122，以便开始计时并探测所述回波信号。比如，所述接收通道122可以只有一个所述接收通道，也可以有多个所述接收通道，例如可以是 时间数字转换器TDC(time-to-digital converter)，也可以是时间数字转换器TDC和直方图采样器HDC，TDC和HDC均是激光雷达发射电路/芯片内原有的接收通道。TDC和HDC各有其测量优势，TDC更适用于近处大信号的测量，HDC更适用于远处小信号的测量。可以利用TDC和HDC同时对回波信号进行检测，再对点云数据进行融合处理，就可以得到更为精准的回波信号数据。
图3示出了根据本申请的一些实施例公开的信号发射接收系统100的工作流程300，工作流程300包括以下步骤：
S310：发射电路根据第一时钟信号在触发时刻生成触发信号，并在发射时刻发射探测信号。
如前所述，所述发射电路110可以根据所述第一时钟信号111在所述触发时刻t_trigger产生所述触发信号并发送给所述接收电路120来使能所述接收通道122。如图4、图5A、图6A所示，所述触发信号可以是基准信号kick，其中所述基准信号kick上升沿的产生和发出时刻t_trigger与所述探测信号的发射时刻t 0可以是同时刻的，也可以是不同时刻的，例如所述发射时刻t 0可以在所述基准信号kick上升沿的后面固定时刻。如图5B、图5C、图6B、图6C所示，所述触发信号trigger也可以是不同于所述基准信号kick的其他触发信号，且所述触发信号trigger的产生和发出时刻t_trigger早于基准信号kick上升沿时刻，t_trigger和基准信号kick上升沿时刻之间具有固定的时序关系。
S320：接收电路根据第二时钟信号接收所述触发信号，并在初启动时刻使能第一接收通道。
如前所述，所述接收电路120能够根据所述第二时钟信号121，设置接收通道122的使能时刻，即初启动时刻
Figure PCTCN2022115643-appb-000002
接收通道122以初启动时刻
Figure PCTCN2022115643-appb-000003
为其时间原点进行回波信号的探测。如前所述，所述触发信号可以是基准信号kick，也可以是不同于基准信号kick的其他触发信号，因此，接收电路120可以根据基准信号kick使能接收通道，也可以根据额外的触发信号使能接收通道。在一些实施例中，所述接收通道122可以仅包括第一接收通道，如图4中的时间数字转换器TDC；也可以同时包括第一接收通道，如图5A-C中的时间数字转换器TDC，和第二接收通道，如图5A-C中的直方图采样器HDC，所述第一接收通道和所述第二接收通道均可以独立感知所述回波信号。所述接收通道也可以是除TDC和HDC外的其他类型测量通道，接收电路也可以包含两个以上的接收通道，依据本申请的实质精神， 本领域技术人员完全可以根据本申请中的技术方案将之应用在其他例子中。所述TDC使能信号在图4、图5A-C和图6A-C中以TDC_en表示。在一些实施例中，所述接收电路120能够在所述初启动时刻
Figure PCTCN2022115643-appb-000004
之后使能所述第二接收通道HDC，如图5A-C所示，在所述初始计时时刻t 1使能HDC。在一些实施例中，所述TDC能够感知所述初始计时时刻t 1、所述基准时刻t 2和接收到所述回波信号的返回时刻t 4。在一些实施例中，所述接收电路120能够控制所述第二接收通道在所述初启动时刻
Figure PCTCN2022115643-appb-000005
之后生成HDC前使能信号(HDC_en_pre)，例如在第一启动时刻t 1时刻使能HDC_en_pre，如图6A-C所示，并且所述接收电路120控制所述第二接收通道HDC在所述第二计算起点t_HDC_origin使能HDC使能信号(HDC_en)，HDC_en可以感知所述回波信号。
如前所述，由于接收芯片在同步触发信号(比如基准信号kick)时有一定的概率存在亚稳态，导致所述初启动时刻
Figure PCTCN2022115643-appb-000006
同触发信号trigger的触发时刻t_trigger之间存在不可预估的抖动时延，由于接收通道是以初启动时刻
Figure PCTCN2022115643-appb-000007
为其时间原点探测回波信号，不可预估的抖动时延将导致测量回波信号的时间原点不稳定，进而使得对回波信号的测量结果不稳定。
S330：所述第一接收通道以所述初启动时刻为时间原点感知接收到所述回波信号的返回时刻；所述接收电路确定所述第一接收通道的第一计算起点。
由于第一接收通道是在初启动时刻
Figure PCTCN2022115643-appb-000008
被唤醒的，对于第一接收通道，后续所有的时间以及时间计算均是以初启动时刻
Figure PCTCN2022115643-appb-000009
为时间原点进行测量和计算的。
为了确定第一接收通道TDC的所述第一计算起点t_TDC_origin，第一接收通道可以首先基于所述基准信号kick确定基准时刻t 2，然后再基于所述基准时刻，确定所述第一计算起点t_TDC_origin。具体地，所述接收电路可以获取期望扫描时延T 1和系统综合时延δt，所述第一接收通道可以以所述初启动时刻
Figure PCTCN2022115643-appb-000010
为时间原点，确定初始计时时刻t 1和基准时刻t 2。
所述初始计时时刻t 1的确定方法可以有多种。在一些实施例中，如图4所示，当所述接收电路120只包括所述第一接收通道时，所述初始计时时刻t 1可以根据所述初启动时刻
Figure PCTCN2022115643-appb-000011
确定，在一些实施例中，所述初始计时时刻t 1即为所述初启动时刻
Figure PCTCN2022115643-appb-000012
在一些实施例中，如图5A-C所示，所述接收电路120同时包括所述第一接收通道和所述第二接收通道，所述第二接收通道在第一启动时刻使能，所述第一接收通道根据所述第一启动时刻来确定所述 初始计时时刻t 1。在一些实施例中，所述第一启动时刻即为所述初始计时时刻t 1。在一些实施例中，如图6A-C所示，所述接收电路120同时包括所述第一接收通道和所述第二接收通道，所述第二接收通道在所述第一启动时刻启动前使能信号HDC_en_pre，并在第二启动时刻启动使能信号HDC_en，所述第一接收通道根据所述第一启动时刻确定所述初始计时时刻。在一些实施例中，所述第一启动时刻即为所述初始计时时刻t 1。
在一些实施例中，所述期望扫描时延T 1为在所述基准时刻t 2之后的预设时长的时延。所述期望扫描时延T 1可以通过系统进行设定，具体数值可以通过测试来确定。在一些实施例中，所述期望扫描时延T 1可以设为大于等于零的数值，例如只有所述第一接收通道的情形(图4)或者所述第二接收通道仅使能所述使能信号HDC_en的情形(图5A-C)。在另一些实施例中，所述期望扫描时延T 1可以设为大于零的数值。
在一些实施例中，所述基准时刻t 2可以为所述基准信号kick的下降沿时刻，而在另一些实施例中，所述基准时刻t 2可以为所述基准信号kick的上升沿时刻。比如，所述第一接收通道可以感知所述基准信号kick的下降沿时刻t 2为基准时刻(图4、5A、5B、6A和6B)，也可以感知所述基准信号kick的上升沿时刻为所述基准时刻(图5C和6C)。由于所述第一接收通道是以所述初启动时刻
Figure PCTCN2022115643-appb-000013
为时间原点进行时间测量的，因此所述基准时刻t 2相对于初启动时刻
Figure PCTCN2022115643-appb-000014
来说含有负的抖动误差，从而抵消掉所述初启动时刻
Figure PCTCN2022115643-appb-000015
的抖动时延的影响。
在确定了所述基准时刻t 2后，所述接收电路便可以基于所述初始计时时刻t 1和所述基准时刻t 2，确定补偿时延Δt。在一些实施例中，所述补偿时延Δt为所述基准时刻t 2与所述初始计时时刻t 1的差值。因为所述初始计时时刻t 1与所述初启动时刻
Figure PCTCN2022115643-appb-000016
之间的时间差一般是固定的，因此补偿时延Δt就含有所述抖动时延的抵消部分。
接收电路120是由多个电器元件组成，每个电器元件在处理信号响应的时候会因制造、校准、热漂移等原因出现自身的误差，这些误差累积起来会导致接收电路120在响应上的系统综合时延δt。因此，除了确定所述基准时刻t 2和所述补偿时延Δt外，所述接收电路120还要通过迭代的方式确定所述系统综合时延δt。具体方法如下：
首先确定初始综合时延值，并调取预先设置的所述期望扫描时延T 1。然后在每次迭代开始时，选定上一次扫描时的系统综合时延值为本次扫描的系统综合时延值，若本次扫描为初始扫描，则本次的所述系统综合时延值为所述初始综合时延值，在一些实施例中，所 述初始综合时延值为零。将所述补偿时延Δt、所述期望扫描时延T 1以及所述本次扫描的系统综合时延δt求和获得初始第二时延x，将所述初始第二时延x的值四舍五入取整获得整数时间单位值，确定所述整数时间单位值为所述第二时延x，以及基于所述第二时延x值更新本次扫描的系统综合时延δt。
在完成了上述参数的确定后，所述接收电路120可以基于所述初始计时时刻和所述第二时延x确定所述第一计算起点，在一些实施例中，所述第一计算起点为初始计时时刻t 1与所述第二时延x之和，也就是说第一接收通道在TDC_en的使能时刻延迟t 1+x后的时刻即为所述第一接收通道的所述第一计算起点t_TDC_origin。由于所述第一接收通道是以其使能时刻作为时间原点探测回波信号，因此在确定所述第一计算起点t_TDC_origin后，以所述第一计算起点t_TDC_origin对返回时刻进行重新计算，TDC测得的所述返回时刻应该减去所述第一计算起点t_TDC_origin值(即减去t 1+x)。在一些实施例中，所述接收电路120还包括所述第二接收通道，因此步骤S330还包括步骤S331。
S331：所述接收电路根据所述第二时延确定所述第二接收通道的第二计算起点。
在一些实施例中，所接收电路120还包括所述第二接收通道，因此所述接收电路确定所述第二计算起点t_HDC_origin。在一些实施例中，第二接收通道仅有使能信号HDC_en,第二接收通道以使能信号HDC_en的使能时刻为其时间原点测量回波信号，所述接收电路根据所述第二时延确定所述第二计算起点，具体是第二接收通道在HDC_en的使能时刻延迟所述第二时延x后的时刻即第二接收通道的所述第二计算起点t_HDC_origin。由于所述第二接收通道是以其使能时刻作为时间原点探测回波信号，因此在确定所述第二计算起点t_HDC_origin后，以所述第二计算起点t_HDC_origin对返回时刻进行重新计算，HDC测得的所述返回时刻应该减去所述第二计算起点t_HDC_origin值(即减去x)。在一些实施例中，所述第二接收通道除存在使能信号HDC_en外，还具有前使能信号HDC_en_pre，所述接收电路根据所述第二时延确定所述第二计算起点，具体是所述第二接收通道在HDC_en_pre的使能时刻后，延迟所述第二时延后的时刻即所述第二接收通道的所述第二计算起点t_HDC_origin进行使能，在这种情况下，所述第二计算起点也正是HDC_en的使能时刻，所述第二接收通道以所述第二计算起点为时间原点测量回波信号。
在一些实施例中，如在图5B中，所述触发信号trigger与所述基准信号kick可以为两个不同的信号。所述发射电路在所述基准信号kick之前给出所述触发信号trigger。所 述触发信号trigger和所述基准信号kick之间的延迟固定，使得所述接收电路120的接收通道能够在基准信号kick到来之前进行触发，并通过测量基准信号kick的下降沿获得所述基准时刻t 2。在一些实施例中，如在图5C中，所述触发信号trigger仍然与所述基准信号kick是两个不同的信号。所述发射电路110在所述基准信号kick之前给出所述触发信号trigger，使得接收通道能够在基准信号kick到来之前进行触发。所述接收电路可以通过测量所述基准信号kick的上升沿获得所述基准时刻t 2。
在一些实施例中，如在图6B中，所述触发信号trigger与所述基准信号kick可以为两个不同的信号。所述发射电路在所述基准信号kick之前给所述出触发信号trigger。所述触发信号trigger和所述基准信号kick之间的延迟固定，使得所述接收电路120的TDC和HDC能够在基准信号kick到来之前进行触发，并通过测量所述基准信号kick的下降沿获得所述基准时刻t 2。在一些实施例中，如在图6C中，所述触发信号trigger仍然与所述基准信号kick是两个不同的信号。所述发射电路110在所述基准信号kick之前给出触发信号trigger，使得接收通道能够在基准信号kick到来之前进行触发。接收电路可以通过测量所述基准信号kick的上升沿获得所述基准时刻t 2。
S340：所述接收电路根据所述第一计算起点确定所述第一接收通道感知的所述返回时刻与所述发射时刻之间的目标时差。
以激光雷达为例，所述返回时刻t 4与所述发射时刻t 0的目标时差为激光从出射到反射回来所经历的时间，即目标时差TOF(图4、5A、6A)。
在这一步中，在首次扫描时所述接收电路首先确定一个第一接收通道的时间校准值t_TDC_c，所述时间校准值t_TDC_c为所述发射时刻t0到所述第一计算起点之间的时间差。所述第一计算起点与所述回波信号的返回时刻之间的时间差并不受抖动时延的影响，激光雷达的所述发射时刻t 0到所述第一计算起点的时间差(也就是t_TDC_c)可以通过系统校准来确定，在多次扫描时，所述时间校准值t_TDC_c都是固定不变的。具体地，比如所述系统100在使用之前可以先对着具有已知固定距离的校准物进行校准检测，从而获得所述时间校准值t_TDC_c。这样在后续计算目标时差时，所述接收电路120只需调取预先校准的所述时间校准值t_TDC_c值即可。
接着，所述接收电路首先确定所述第一计算起点同所述返回时刻t4的第一时差t，t＝t 4-t_TDC_origin，之后将所述第一时差t与所述时间校准值t_TDC_c求和获得时间和， 所述时间和为第一接收通道测得的目标时差TOF。这样便完成了第一接收通道的测量过程。由于计算起点t_TDC_origin是已经消除了初启动时刻
Figure PCTCN2022115643-appb-000017
的抖动时延的稳定时刻，因此对目标时差的测量是稳定而准确的。在一些实施例中，还包括第二接收通道，因此步骤S330还包括步骤S341。
S341：所述接收电路根据所述第二计算起点确定所述第二接收通道感知的所述返回时刻与所述发射时刻之间的目标时差。
以激光雷达为例，所述返回时刻t 5与所述发射时刻t 0的目标时差为激光从出射到反射回来所经历的时间，即目标时差TOF(图5A、6A)。
在这一步中，在首次扫描时所述接收电路首先确定一个第二接收通道的时间校准值t_HDC_c，所述时间校准值t_HDC_c为所述发射时刻t 0到所述第二计算起点之间的时间差。所述第二计算起点与所述回波信号的返回时刻之间的时间差并不受抖动时延的影响，激光雷达的所述发射时刻t 0到所述第二计算起点之间的时间差(也就是t_HDC_c)可以通过系统校准来确定，在多次扫描时，所述时间校准值t_HDC_c都是固定不变的。具体地，比如所述系统100在使用之前可以先对着具有已知固定距离的校准物进行校准检测，从而获得所述时间校准值t_HDC_c。这样在后续计算目标时差时，所述接收电路120只需调取预先校准的所述时间校准值t_HDC_c值即可。
接着，所述接收电路首先确定所述第二计算起点与所述返回时刻t 5的第二时差t’，t’＝t 5-t_HDC_origin，之后将所述第二时差t’与所述时间校准值t_HDC_c求和获得时间和，所述时间和为所述第二接收通道测得的目标时差TOF。这样便完成了所述第二接收通道的测量过程。由于所述第二计算起点t_HDC_origin是已经消除了初启动时刻
Figure PCTCN2022115643-appb-000018
的抖动时延的稳定时刻，因此对目标时差的测量是稳定而准确的。
下面就以具体的示例来解释图5、图6实施例中能够稳定扫描起点的原理。
为了清楚的阐明本申请技术方案对接收电路的接收通道扫描起点的稳定机制，首先介绍不采用本申请所述技术方案，在接收电路和发射电路处于跨时钟状态时，亚稳态导致的扫描起点抖动对回波信号测量结果的影响。
参照图9，图9中的(A)和(B)分别是对回波信号的两次连续的扫描。首先假定目标物体与所述信号发射接收系统100之间的距离对应的目标时差TOF为22ns，该目标时刻TOF具体可以通过向已知距离的目标物体发射激光光束的方式来确定，也可以通过其他方式获 得，这里不作为本申请的限定。同时假定所述发射电路在kick信号的上升沿时刻发出探测信号，并将发射时刻t 0认为是第一时钟信号的零时刻。接收电路在同步到发射电路发出的基准信号后，分别控制TDC和HDC使能。假定在第一次扫描时(图9(A))，TDC相对于t 0延迟1.2ns使能，HDC相对于t 0延迟3.2ns使能，那么TDC测得的探测信号的返回时刻即为20.8ns(这是由于TDC延迟信号发射时刻1.2ns之后才开始计时测量，因此对于真实值为22ns的回波信号，TDC测得的TOF值时22-1.2＝20.8ns)，相应地，HDC测得的TOF值是18.8ns。在首次扫描时，为了保证结果的准确，可以利用已知距离的目标物体对上述TDC获得的TOF值和HDC获得的TOF值进行校准，对于本例而言就是利用22ns的真实TOF值对TDC和HDC的测量值进行校准。可以得到TDC的时间校准值t_TDC_c＝1.2ns，和HDC的时间校准值t_HDC_c＝3.2ns，采用校准值对TDC和HDC的测量值进行校准后，所得到的TDC测得的TOF值和HDC测得的TOF值均为22ns。在实际应用中，通常仅在激光雷达的首次扫描时进行测试校准，或者间隔一段时间后进行校准，而不会针对每次扫描都进行校准。在校准后，激光雷达在后续对回波信号的扫描过程中，都将以上述时间校准值对测量结果进行校准。
由于亚稳态的存在，导致在多次扫描时接收电路在同步由发射电路发出的kick信号时，会出现接近整ns的偏差，从而接收电路在确定TDC使能时刻和HDC使能时刻时也会有接近整ns的偏差，在本示例中即对应TDC使能时刻和HDC使能时刻相对于kick信号的上升沿的延迟时间在多次扫描时存在近整ns的偏差。基于此，假定在第二次扫描时，TDC使能时刻延迟kick信号上升沿时刻2.2ns，HDC使能时刻延迟kick信号上升沿时刻4.2ns，因此对于22ns时刻的回波信号TDC测得的返回时刻为19.8ns，HDC测得的返回时刻为17.8ns。采用前述确定的时间校准值对本次扫描结果进行校准，可以分别得到TDC测量得到的TOF＝19.8+t_TDC_c＝19.8+1.2＝21ns，HDC测量得到的TOF＝17.8+t_HDC_c＝17.8+3.2＝21ns。与第一次扫描时的测量结果进行对比可知，第二次扫描时得到的TOF值均与准确TOF值有1ns的偏差，而这1ns的偏差正是由于亚稳态导致的TDC和HDC扫描起点的抖动产生的，扫描起点的抖动在多次扫描时使得接收电路对TOF值的测量不准确。
对于本申请技术方案参照图8进行解释，图8为对应于图6A所示信号图实施方案的示例性说明。接收电路120中具有第一接收通道和第二接收通道，第一接收通道具体为TDC，第二接收通道具体为HDC，触发信号为基准信号kick。接收电路在同步到发射电路发出的 基准信号kick后，使得第一接收通道TDC_en在
Figure PCTCN2022115643-appb-000019
时刻使能，第二接收通道的前使能信号HDC_en_pre在t 1时刻使能。根据本申请技术方案确定第二接收通道的使能信号HDC_en在t_HDC_origin时刻使能。TDC_en感知HDC_en_pre的使能时刻作为初始计时时刻t 1，感知kick信号的下降沿时刻作为基准时刻t 2，感知回波信号的返回时刻t 4。HDC_en感知回波信号的返回时刻t 5。在图8所示的示例性说明中，假定目标物体离信号发射接收系统100的距离对应的目标时差TOF为22ns，该目标时刻TOF具体可以通过向已知距离的目标物体发射激光光束的方式来确定，也可以通过其他方式获得，这里不作为本申请的限定。同时假定发射电路在kick信号的上升沿时刻发出探测信号，并将该发射时刻t 0认为是第一时钟信号的零时刻；kick信号为固定脉宽的信号，这里假定其脉宽为10ns。首先设定期望扫描时延T 1为5ns，设定HDC_en_pre使能时刻相对于TDC_en使能时刻的延迟时间固定为2ns，该延迟时间具体可以通过电路进行设定。图8中的(A)和(B)分别是对回波信号的两次连续的扫描。
假定在第一次扫描时(图8中的(A))，TDC_en使能时刻相对于发射电路中的发射时刻t 0，即相对于基准信号kick上升沿时刻延迟1.2ns，也就是包括了不可预估的抖动时延的初启动时刻
Figure PCTCN2022115643-appb-000020
为1.2ns，其中
Figure PCTCN2022115643-appb-000021
为1.2ns是基于发射电路的第一时钟信号的时间而言的。而对于第一接收通道TDC本身，TDC_en会以其使能时刻作为其零时刻进行其他信号的感知，即TDC_en以初启动时刻为时间原点，测得的返回时刻t 4是20.8ns，这是由于TDC_en延迟发射时刻1.2ns开始计时来感知回波信号，因此对于22ns的回波信号，TDC_en测得的返回时刻是22-1.2＝20.8ns。根据本申请的技术方案，在第一次扫描时初始化δt＝0，TDC测得的初始计时时刻t 1＝2ns,基准时刻t 2＝8.8ns，确定补偿时延Δt＝t 2-t 1＝6.8ns。计算第二时延x＝round(Δt+T 1+δt)＝round(6.8+5+0)＝12ns，其中round(·)为四舍五入取整函数。更新系统综合时延δt＝x-Δt-T 1＝12-6.8-5＝0.2ns。根据初始计时时刻t 1和第二时延x可以得到TDC的第一计算起点为t_TDC_origin＝t 1+x＝2+12＝14ns。由于TDC使能时刻相对于发射时刻延迟1.2ns，因此TDC测量得到的返回时刻t4为20.8ns。计算第一时差t，也就是TDC计算起点为t_TDC_origin与返回时刻t 4之间的时间差，t＝t 4-t_TDC_origin＝20.8-14＝6.8ns，该第一时差即为根据本申请技术方案确定的TDC计算起点重新计算获得的TDC对回波信号的测量值。在第一次扫描时可以利用已知距离的目标物体对上述TDC获得的测量值(即第一时差)进行测试校准，可以得到TDC的时间校准值t_TDC_c＝22-6.8＝15.2ns。在后续的 多次扫描中，将不再进行测试校准，而是以此次时间校准值作为后续扫描时的时间校准值来计算目标时差TOF。在本次扫描时，根据确定的时间校准值和TDC测得的第一时差可以确定TDC测得的目标时差TOF＝t+t_TDC_c＝6.8+15.2＝22ns。
对于直方图采样器HDC，其HDC_en感知回波信号，根据本申请的技术方案确定的HDC_en的使能时刻，即接收电路在HDC_en_pre信号使能时刻之后延迟第二时延x后控制HDC_en使能，HDC_en以其使能时刻作为HDC的时间原点开始进行回波信号的测量，HDC_en的使能时刻相对于基准信号kick上升沿延迟15.2ns
Figure PCTCN2022115643-appb-000022
因此HDC测得的回波信号时刻t’为6.8ns，同样测试校准可得HDC的时间校准值t_HDC_c＝t_TDC_c＝22-6.8＝15.2ns，经过校准后HDC测得的TOF＝t’+t_HDC_c＝6.8+15.2＝22ns。
第二次扫描时(图8中的(B))，由于亚稳态的存在，在多次扫描测量时，TDC_en的使能时刻与基准信号kick上升沿之间的延迟时间并不固定，会有接近整ns的偏差，因此这里可以假定在第二次扫描由于亚稳态导致TDC延迟于基准信号kick上升沿后2.2ns使能(与第一次扫描时的1.2ns延迟有1ns的偏差)，即包括了不可预估的抖动时延后初启动时刻
Figure PCTCN2022115643-appb-000023
为2.2ns。TDC_en以初启动时刻
Figure PCTCN2022115643-appb-000024
为时间原点，测得的回波信号的返回时刻t 4为19.8ns，初始计时时刻t 1＝2ns,基准时刻t 2＝7.8ns。根据初始计时时刻t 1和基准时刻t 2可以确定补偿时延Δt＝t 2-t 1＝5.8ns，与第一次扫描时Δt＝6.8ns相比，第二次扫描时的补偿时延Δt＝5.8ns，含有了亚稳态导致的抖动影响，即含有了所述抖动时延的抵消部分。将上一次扫描时更新的系统综合时延作为本次扫描时的系统综合时延δt＝0.2ns。计算第二时延x＝round(Δt+T 1+δt)＝round(5.8+5+0.2)＝11ns，以此更新系统综合时延δt＝11-5.8-5＝0.2ns。根据本申请的技术方案得到的TDC的第一计算起点为t_TDC_origin＝t 1+x＝2+11＝13ns。由于TDC_en使能时刻，即初始计时时刻
Figure PCTCN2022115643-appb-000025
包括了不可预估的抖动时延，同上一次测量比发生了变动，相对于基准信号kick上升沿时刻延迟2.2ns，因此TDC测得的返回时刻t 4＝19.8ns。以本申请所确定的TDC计算起点来返回时刻，即计算TDC的第一计算起点t_TDC_origin与返回时刻t 4之间的时间差，即第一时差，为t＝19.8-t_TDC_origin＝19.8-13＝6.8ns。采用前述确定的时间校准值t_TDC_c对TDC测得的第一时差进行校准，可以得到目标时差TOF＝t_TDC_c+t＝15.2+6.8＝22ns，得到的目标时差 TOF值与上一次扫描时的目标时差TOF值一致，并未受到TDC使能时刻抖动的影响，即说明根据本申请的技术方案所确定的TDC计算起点是稳定的。
接收电路控制HDC_en在HDC_en_pre使能时刻之后延迟x时间进行使能，并以HDC_en的使能时刻作为其测量的时间原点，由于HDC_en的使能时刻相对于基准信号kick的上升沿时刻延迟15.2ns，因此HDC测量得到的返回时刻t’＝6.8ns。采用前述确定的时间校准值t_HDC_c对HDC测得的回波信号时刻进行校准，可以得到目标时差TOF＝t_HDC_c+t’＝15.2+6.8＝22ns。可知HDC在第二次扫描时得到的目标时差TOF值与第一次扫描时得到的目标时差TOF值一致，并未受到亚稳态的影响，即说明根据本申请的技术方案所确定的HDC扫描起点(即HDC使能时刻)是稳定的。另外，根据图4也可以直观的看到，TDC的计算起点和HDC计算起点在时间上是对齐的。
可见，虽然由于接收电路与发射电路处于异步时钟，使得接收电路在同步触发信号时存在亚稳态而导致TDC的使能时间存在接近整ns的抖动，但根据本申请的技术方案所得到的TDC计算起点和HDC的使能时刻在多次测量时是稳定的，以该稳定的TDC计算起点和HDC的使能时刻获得的目标时差也就是稳定值，并不会受到亚稳态导致的抖动影响。由此可见，本申请的技术方案消除了接收电路异步时钟下的扫描起点抖动的问题，在多次扫描时能够保证返回时刻测量结果的稳定，提高了测量精度。同时发明的技术方案所获得的TDC计算起点和HDC的使能时刻在时间上是对齐的，从而使得TDC和HDC对回波信号的测量结果是一致的，也便于后续对TDC和HDC测量结果的融合处理。
图7是对应于图5A所示信号图实施方案的示例性说明。接收电路120中具有第一接收通道和第二接收通道，第一接收通道具体为TDC，第二接收通道具体为HDC。接收电路在同步到发射电路发出的基准信号kick后，使得第一接收通道TDC_en在
Figure PCTCN2022115643-appb-000026
时刻使能，第二接收通道HDC_en在t 1时刻使能。TDC_en感知HDC_en的使能时刻作为初始计时时刻t 1，感知kick信号的下降沿时刻作为基准时刻t 2，感知回波信号的返回时刻t4。HDC_en感知回波信号的返回时刻t 5。探测信号、回波信号、基准信号的假定与图4一致，即假定kick信号的上升沿时刻为第一时钟的零时刻，在kick信号的上升沿时刻发出探测信号，探测信号与探测信号之间的准确TOF值为22ns，kick信号的脉宽为10ns。设定期望扫描时延T 1为5ns。首先设定直方图采样器HDC的使能信号HDC_en使能时刻相对于时间数字转换器TDC的使能 信号TDC_en使能时刻的延迟时间固定为2ns，即
Figure PCTCN2022115643-appb-000027
图7中的(A)和(B)分别是对回波信号的两次连续的扫描。
假定在第一次扫描时(图7中的(A))，TDC_en使能时刻相对于kick信号上升沿时刻延迟1.2ns，即
Figure PCTCN2022115643-appb-000028
因此TDC以
Figure PCTCN2022115643-appb-000029
为时间原点测得的返回时刻t 4是20.8ns。根据本申请的技术方案，初始化系统综合时延δt＝0，TDC测得的初始计时时刻t 1＝2ns,基准时刻t 2＝8.8ns，补偿时延Δt＝t 2-t 1＝6.8ns。由此可以确定第二时延x＝round(Δt+T 1+δt)＝round(6.8+5+0)＝12ns，其中round(·)为四舍五入取整函数。据此更新系统综合时延δt＝12-6.8-5＝0.2ns。根据本申请的方案得到的TDC计算起点t_TDC_origin＝t 1+x＝2+12＝14ns。
由于时间数字转换器TDC使能时间延迟于基准信号kick上升沿1.2ns，因此TDC测得的返回时刻t 4为20.8ns。以TDC计算起点t_TDC_origin对回波信号测量结果进行重新计算，计算TDC计算起点t_TDC_origin与返回时刻t 4的时间差，即第一时差，为t＝20.8-t_TDC_origin＝20.8-14＝6.8ns，该第一时差即为根据本申请技术方案确定的TDC计算起点重新计算获得的TDC对回波信号的测量值。在首次扫描时同样利用已知距离的目标物体对上述TDC的测量值(即第一时差)进行测试校准，可以得到TDC的时间校准值t_TDC_c＝22-6.8＝15.2ns。在后续的扫描中，将不再进行测试校准，而是以此次TDC时间校准值作为后续多次扫描时的TDC时间校准值来计算目标时差，即TOF值。在本次扫描时，根据确定的TDC时间校准值和TDC测得的第一时差可以确定TDC测得的目标时差TOF＝t+t_TDC_c＝6.8+15.2＝22ns。
由于直方图采样器HDC的使能时刻t 1相对于基准信号kick上升沿时刻延迟3.2ns，HDC以其使能时刻作为时间原点进行回波信号的测量，因此HDC测得的返回时刻t 5为18.8ns，HDC计算起点t_HDC_origin＝x＝12ns，计算HDC计算起点t_HDC_origin与返回时刻t 5的时间差为第二时差t’＝t 5-t_HDC_origin＝18.8-12＝6.8ns，该第二时差即为根据本申请技术方案确定的HDC计算起点重新计算获得的HDC对回波信号的测量值。同样在首次扫描时对HDC测得的第二时差进行校准可得HDC的时间校准值t_HDC_c＝22-6.8＝15.2ns。在后续的扫描中，将不再进行测试校准，而是以此次HDC时间校准值作为后续多次扫描时的HDC时间校准值来计算目标时差，即TOF值。在本次扫描时，根据确定的HDC时间校准值和HDC测得的第二时差可以确定HDC测得的目标时差TOF＝t’+t_HDC_c＝6.8+15.2＝22ns。
在第二次扫描时(图7中的(B))，假定由于亚稳态导致接收电路时间数字转换器TDC延迟于基准信号kick上升沿2.2ns后使能，即由于亚稳态导致第二次扫描时TDC使能时刻相对于第一次扫描时TDC使能时刻存在1ns的偏差，即包括了不可预估的抖动时延后初启动时刻
Figure PCTCN2022115643-appb-000030
为2.2ns。HDC相对于TDC延迟2ns使能，TDC测得的初始计时时刻t 1＝2ns,基准时刻t 2＝7.8ns,补偿时延Δt＝t 2-t 1＝5.8ns。将上一次扫描时更新的系统综合时延作为本次扫描时的系统综合时延δt＝0.2n。四舍五入取整计算得到第二时延x＝round(Δt+T 1+δt)＝round(5.8+5+0.2)＝11ns，进而更新系统综合时延δt＝11-5.8-5＝0.2ns，得到的TDC计算起点为t_TDC_origin＝t 1+x＝2+11＝13ns。由于TDC使能时刻相对于基准信号kick上升沿时刻延迟2.2ns，即初启动时刻
Figure PCTCN2022115643-appb-000031
为2.2ns，因此TDC测得的返回时刻t 4为19.8ns，即T 2＝19.8ns。以TDC计算起点对返回时刻测量结果进行重新计算，得到第二次扫描时的第一时差为t＝t 4-t_TDC_origin＝19.8-13＝6.8ns，该第一时差即为第二次扫描时TDC对回波信号的测量值。采用前述确定的TDC时间校准值t_TDC_c，对根据TDC计算起点重新计算得到第一时差进行校准后，可以确定TDC测得的目标时差TOF＝t_TDC_c+t＝15.2+6.8＝22ns。可知第二次扫描时得到的目标时差TOF值与第一次扫描时的目标时差TOF值一致，并未受到TDC使能时刻抖动的影响，即说明根据本申请所述的技术方案确定的TDC计算起点是稳定的。
对于直方图采样器HDC，其使能时刻t 1相对于基准信号kick延迟4.2ns.因此直方图采样器HDC测得的返回时刻t 5为17.8ns。根据本申请技术方案确定的HDC计算起点为t_HDC_origin＝x＝11ns，根据确定的HDC计算起点对HDC测得的回波信号进行重新计算，即计算HDC计算起点t_HDC_origin与返回时刻t 5的时间差为第二时差为t’＝t 5-t_HDC_origin＝18.8-11＝6.8n，该第二时差即在第二次扫描时HDC对回波信号的测量值。采用前述确定的HDC时间校准值t_HDC_c，对根据HDC计算起点重新计算得到第二时差进行校准，可以得到HDC测得的目标时差TOF＝t’+t_HDC_c＝6.8+15.2＝22ns。可知HDC在第二次扫描时得到的目标时差TOF值与第一次扫描时得到的目标时差TOF值一致，并未受到HDC使能时刻抖动的影响，即说明根据本申请所述的技术方案确定的HDC计算起点是稳定的。根据图5也可以直观的看到，TDC计算起点和HDC计算起点在时间上是对齐的。
可见，虽然由于触发信号的亚稳态使得时间数字转换器TDC使能时间有几个ns的抖动，但根据本申请的方法得到的计算起点在多次测量时是稳定的，以该稳定的计算起点获得的 返回时刻也就是稳定值，并不会受到亚稳态导致的抖动影响，由此可见，本申请方法消除了接收电路异步时钟下的测量起点抖动的问题，在多次扫描时能够保证返回时刻测量结果的稳定，提高了测量精度。同时发明的技术方案所获得的TDC计算起点和HD计算起点在时间上是对齐的，从而使得TDC和HDC对目标时差的测量结果是一致的，便于后续对TDC和HDC测量结果的融合处理。
基于同样的原理，图5、6中的其他实施方式也能完成同样的消除测量起点抖动的问题。比如在图6B中，触发信号trigger与基准信号kick是两个不同的信号。发射电路在基准信号kick之前给出触发信号trigger。触发信号trigger和基准信号kick之间的延迟固定，使得接收电路的TDC和HDC能够在基准信号kick到来之前进行触发，并通过测量基准信号kick的下降沿获得基准时刻t 2。图6C中仍然是触发信号trigger同基准信号kick是两个不同的信号的情况。发射电路在基准信号kick之前给出触发信号trigger，使得TDC和HDC能够在基准信号kick到来之前进行触发。接收电路可以通过测量基准信号kick的上升沿获得时间基准时刻t 2。同样地，图5B、5C仍然是触发信号trigger同基准信号kick是两个不同的信号的情况。发射电路在基准信号kick之前给出触发信号trigger，使得TDC和HDC先后使能，然后接收电路可以分别测定基准信号kick的上升沿和下沿时间获得基准时刻t 2。
上述对本说明书特定实施例进行了描述。其他实施例在所附权利要求书的范围内。在一些情况下，在权利要求书中记载的动作或步骤可以按照不同于实施例中的顺序来执行并且仍然可以实现期望的结果。另外，在附图中描绘的过程不一定要求示出特定顺序或者连续顺序才能实现期望的结果。在某些实施方式中，多任务处理和并行处理也是可以的或者是可能有利的。
综上所述，在阅读本详细公开内容之后，本领域技术人员可以明白，前述详细公开内容可以仅以示例的方式呈现，并且可以不是限制性的。尽管这里没有明确说明，本领域技术人员可以理解本说明书需求囊括对实施例的各种合理改变，改进和修改。这些改变，改进和修改旨在由本说明书提出，并且在本说明书的示例性实施例的精神和范围内。
此外，本说明书中的某些术语已被用于描述本说明书的实施例。例如，“一个实施例”，“实施例”和/或“一些实施例”意味着结合该实施例描述的特定特征，结构或特性可以包括在本说明书的至少一个实施例中。因此，可以强调并且应当理解，在本说明书的各个部 分中对“实施例”或“一个实施例”或“替代实施例”的两个或更多个引用不一定都指代相同的实施例。此外，特定特征，结构或特性可以在本说明书的一个或多个实施例中适当地组合。
应当理解，在本说明书的实施例的前述描述中，为了帮助理解一个特征，出于简化本说明书的目的，本说明书将各种特征组合在单个实施例、附图或其描述中。然而，这并不是说这些特征的组合是必须的，本领域技术人员在阅读本说明书的时候完全有可能将其中一部分设备标注出来作为单独的实施例来理解。也就是说，本说明书中的实施例也可以理解为多个次级实施例的整合。而每个次级实施例的内容在于少于单个前述公开实施例的所有特征的时候也是成立的。
本文引用的每个专利，专利申请，专利申请的出版物和其他材料，例如文章，书籍，说明书，出版物，文件，物品等，可以通过引用结合于此。用于所有目的的全部内容，除了与其相关的任何起诉文件历史，可能与本文件不一致或相冲突的任何相同的，或者任何可能对权利要求的最宽范围具有限制性影响的任何相同的起诉文件历史。现在或以后与本文件相关联。举例来说，如果在与任何所包含的材料相关联的术语的描述、定义和/或使用与本文档相关的术语、描述、定义和/或之间存在任何不一致或冲突时，使用本文件中的术语为准。
最后，应理解，本文公开的申请的实施方案是对本说明书的实施方案的原理的说明。其他修改后的实施例也在本说明书的范围内。因此，本说明书披露的实施例仅仅作为示例而非限制。本领域技术人员可以根据本说明书中的实施例采取替代配置来实现本说明书中的申请。因此，本说明书的实施例不限于申请中被精确地描述过的实施例。

Claims (28)

  1. 一种信号发射接收系统，其特征在于，包括：
    发射电路，用于根据第一时钟信号在触发时刻生成触发信号并在发射时刻发射探测信号；以及
    接收电路，用于接收所述探测信号经目标物体反射后的回波信号，以及根据第二时钟信号接收所述触发信号并在初启动时刻使能第一接收通道，所述第一接收通道以所述初启动时刻为时间原点，感知接收到所述回波信号的返回时刻；
    确定所述第一接收通道的第一计算起点，
    根据所述第一计算起点确定所述第一接收通道感知的所述返回时刻与所述发射时刻之间的目标时差，
    其中所述初启动时刻相对所述触发时刻之间的第一时延包括不可预估的抖动时延。
  2. 如权利要求1所述的信号发射接收系统，其特征在于，所述确定所述目标时差包括：
    确定所述第一计算起点与所述返回时刻之间的第一时差；以及
    将所述第一时差与预先校准的时间校准值求和获得所述目标时差。
  3. 如权利要求1所述的信号发射接收系统，其特征在于，所述发射电路还生成基准信号，所述基准信号与所述发射时刻具有固定的时序关系；以及
    所述确定第一计算起点还包括：
    所述第一接收通道基于所述基准信号确定基准时刻，以及
    基于所述基准时刻，确定所述第一计算起点。
  4. 如权利要求3所述的信号发射接收系统，其特征在于，所述基于所述基准时刻确定所述第一计算起点包括，获取期望扫描时延，所述期望扫描时延为在所述基准时刻之后的预设时长的时延；所述第一接收通道以所述初启动时刻为时间原点：
    确定初始计时时刻；
    基于所述初始计时时刻和所述基准时刻，确定补偿时延，所述补偿时延含有所述抖动时延的抵消部分；以及
    基于所述初始计时时刻、所述补偿时延，确定所述第一计算起点。
  5. 如权利要求4所述的信号发射接收系统，其特征在于，所述确定初始计时时刻包括：
    基于所述初启动时刻确定所述初始计时时刻。
  6. 如权利要求4所述的信号发射接收系统，其特征在于，所述接收电路还包括第二接收通道，所述第二接收通道在第一启动时刻使能，用于感知所述回波信号；
    所述确定初始计时时刻包括：
    基于所述第一启动时刻确定所述初始计时时刻。
  7. 如权利要求6所述的信号发射接收系统，其特征在于，所述基于所述初始计时时刻、所述补偿时延确定所述第一计算起点包括，获取系统综合时延，根据所述补偿时延、所述期望扫描时延和所述系统综合时延确定第二时延；基于所述初始计时时刻、所述第二时延，确定所述第一计算起点。
  8. 如权利要求6或7所述的信号发射接收系统，其特征在于，所述接收电路还根据所述第二时延确定所述第二接收通道的第二计算起点，并根据所述第二计算起点确定所述第二接收通道感知的所述回波信号的返回时刻与所述发射时刻之间的目标时差。
  9. 如权利要求4所述的信号发射接收系统，其特征在于，所述接收电路还包括第二接收通道，所述第二接收通道在第一启动时刻启动前使能信号，并在第二启动时刻启动使能信号，其中所述第二接收通道的所述使能信号用于感知所述回波信号；
    所述确定初始计时时刻包括：
    基于所述第一启动时刻确定所述初始计时时刻。
  10. 如权利要求9所述的信号发射接收系统，其特征在于，所述基于所述初始计时时刻、所述补偿时延确定所述第一计算起点包括，获取系统综合时延，根据所述补偿时延、所述期望扫描时延和所述系统综合时延确定第二时延，基于所述初始计时时刻、所述第二时延，确定所述第一计算起点。
  11. 如权利要求9或10所述的信号发射接收系统，其特征在于，所述接收电路还根据所述第一启动时刻和所述第二时延确定所述第二接收通道的所述使能信号的所述第二计算起点，并根据所述第二计算起点确定所述使能信号感知的所述回波信号的返回时刻与所述发射时刻之间的目标时差。
  12. 如权利要求7或10所述的信号发射接收系统，其特征在于，所述获取所述系统综合时延包括：选定上一次扫描的系统综合时延值为本次扫描的系统综合时延值；
    所述确定所述第一计算起点包括：
    将所述补偿时延、所述期望扫描时延以及所述本次扫描的系统综合时延相加获得初始第二时延，
    将所述初始第二时延值四舍五入取整获得整数时间单位值，
    确定所述整数时间单位值为所述本次扫描的所述第二时延值，
    基于所述本次扫描的所述第二时延值更新所述本次扫描的系统综合时延，以及
    将所述初计时时刻同所述当前时刻的所述第二时延相加，得到所述第一计算起点。
  13. 如权利要求1-3任一所述的信号发射接收系统，其特征在于，
    所述触发信号为所述基准信号，
    所述触发时刻为所述基准信号的上升沿时刻，以及
    所述基准时刻为所述基准信号的下降沿时刻。
  14. 如权利要求1-3任一所述的信号发射接收系统，其特征在于，
    所述触发信号不同于所述基准信号，所述触发信号与所述基准信号之间具有固定的时序关系；
    所述触发时刻早于所述基准信号的上升沿时刻，以及
    所述基准时刻为所述基准信号的上升沿时刻或者下降沿时刻。
  15. 一种信号发射接收方法，其特征在于，包括：
    根据第一时钟信号，通过发射电路在触发时刻生成触发信号并在发射时刻发射探测信号；以及
    根据第二时钟信号，通过接收电路接收所述探测信号经目标物体反射后的回波信号，同时接收所述触发信号并在初启动时刻使能第一接收通道，所述第一接收通道以所述初启动时刻为时间原点，感知接收到所述回波信号的返回时刻：
    确定所述第一接收通道的第一计算起点，
    根据所述第一计算起点确定所述第一接收通道感知的所述返回时刻与所述发射时刻之间的目标时差，
    其中，所述初启动时刻相对所述触发时刻之间的第一时延包括不可预估的抖动时延。
  16. 如权利要求15所述的信号发射接收方法，其特征在于，所述根据所述第一计算起点确定所述第一接收通道感知的所述返回时刻与所述发射时刻之间的目标时差包括：
    确定所述第一计算起点与所述返回时刻的第一时差；以及
    将所述第一时差与预先校准的时间校准值求和获得所述目标时差。
  17. 如权利要求15所述的信号发射接收方法，其特征在于，所述发射电路还生成基准信号，所述基准信号与所述发射时刻具有固定的时序关系；以及
    所述确定第一计算起点还包括：
    所述第一接收通道基于所述基准信号确定基准时刻，以及
    基于所述基准时刻，确定所述第一计算起点。
  18. 如权利要求17所述的信号发射接收方法，其特征在于，所述基于所述基准时刻确定所述第一计算起点包括，获取期望扫描时延，所述期望扫描时延为在所述基准时刻之后的预设时长的时延；所述第一接收通道以所述初启动时刻为时间原点，
    确定初始计时时刻；
    基于所述初始计时时刻和所述基准时刻，确定补偿时延，所述补偿时延含有所述抖动时延的抵消部分；以及
    基于所述初始计时时刻、所述补偿时延，确定所述第一计算起点。
  19. 如权利要求18所述的信号发射接收方法，其特征在于，所述确定初始计时时刻包括：
    基于所述初启动时刻确定所述初始计时时刻。
  20. 如权利要求18所述的信号发射接收方法，其特征在于，所述接收电路还包括第二接收通道，所述第二接收通道在第一启动时刻使能，用于感知所述回波信号；
    所述确定初始计时时刻包括：
    基于所述第一启动时刻确定所述初始计时时刻。
  21. 如权利要求20所述的信号发射接收方法，其特征在于，所述基于所述初始计时时刻、所述补偿时延确定所述第一计算起点包括，获取系统综合时延，根据所述补偿时延、所述期望扫描时延和所述系统综合时延确定第二时延，基于所述初始计时时刻、所述第二时延，确定所述第一计算起点。
  22. 如权利要求20或21所述的信号发射接收方法，其特征在于，所述接收电路还根据所述第一启动时刻和所述第二时延确定第二接收通道的第二计算起点，并根据所述第二计算起点确定所述第二接收通道感知的所述回波信号的返回时刻与所述发射时刻之间的目标时差。
  23. 如权利要求18所述的信号发射接收方法，其特征在于，所述接收电路还包括第二接收通道，所述第二接收通道在第一启动时刻启动前使能信号，并在第二启动时刻启动使能信号，其中所述第二接收通道的所述使能信号用于感知所述回波信号；
    所述确定初始计时时刻包括：
    基于所述第一启动时刻确定所述初始计时时刻。
  24. 如权利要求23所述的信号发射接收方法，其特征在于，所述基于所述初始计时时刻、所述补偿时延确定所述第一计算起点包括，获取系统综合时延，根据所述补偿时延、所述期望扫描时延和所述系统综合时延确定第二时延，基于所述初始计时时刻、所述第二时延，确定所述第一计算起点。
  25. 如权利要求23或24所述的信号发射接收方法，其特征在于，所述接收电路还根据所述第一启动时刻和所述第二时延确定第二接收通道的所述使能信号的所述第二计算起点，并根据所述第二计算起点确定所述使能信号感知的所述回波信号的返回时刻与所述发射时刻之间的目标时差。
  26. 如权利要求21或24所述的信号发射接收方法，其特征在于，所述获取所述系统综合时延包括：选定上一次扫描的系统综合时延值为本次扫描的系统综合时延值；
    所述确定所述第一计算起点包括：
    将所述补偿时延、所述期望扫描时延以及所述本次扫描的系统综合时延相加获得初始第二时延，
    将所述初始第二时延值四舍五入取整获得整数时间单位值，
    确定所述整数时间单位值为所述本次扫描的所述第二时延值，
    基于所述本次扫描的所述第二时延值更新所述本次扫描的系统综合时延，以及
    将所述初计时时刻同所述当前时刻的所述第二时延相加，得到所述第一计算起点。
  27. 如权利要求15-17任一所述的信号发射接收方法，其特征在于，
    所述触发信号为所述基准信号，
    所述触发时刻为所述基准信号的上升沿时刻，以及
    所述基准时刻为所述基准信号的下降沿时刻。
  28. 如权利要求15-17任一所述的信号发射接收方法，其特征在于，
    所述触发信号不同于所述基准信号，所述触发信号与所述基准信号之间具有固定的时序关系；
    所述触发时刻早于所述基准信号的上升沿时刻，以及
    所述基准时刻为所述基准信号的上升沿时刻或者下降沿时刻。
PCT/CN2022/115643 2022-04-30 2022-08-29 信号发射接收系统及其方法 WO2023206891A1 (zh)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180299249A1 (en) * 2017-04-13 2018-10-18 Leica Geosystems Ag High-resolution distance measurement by means of interferometry
CN110809704A (zh) * 2017-05-08 2020-02-18 威力登激光雷达有限公司 Lidar数据获取与控制
CN113534173A (zh) * 2020-04-14 2021-10-22 上海禾赛科技有限公司 激光雷达、使用其的探测方法以及平动扫描方法
CN114280573A (zh) * 2021-12-09 2022-04-05 上海禾赛科技有限公司 激光雷达及其测量目标反射率的方法和系统

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180299249A1 (en) * 2017-04-13 2018-10-18 Leica Geosystems Ag High-resolution distance measurement by means of interferometry
CN110809704A (zh) * 2017-05-08 2020-02-18 威力登激光雷达有限公司 Lidar数据获取与控制
CN113534173A (zh) * 2020-04-14 2021-10-22 上海禾赛科技有限公司 激光雷达、使用其的探测方法以及平动扫描方法
CN114280573A (zh) * 2021-12-09 2022-04-05 上海禾赛科技有限公司 激光雷达及其测量目标反射率的方法和系统

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