Pulse phase distance measuring device

Abstract

The invention discloses a pulse phase distance measurement device, and relates to the field of phase distance measurement, in the device, a transmitting module is used for generating a path of pulse laser signal as an inner light path signal to be reflected to a receiving module; generating another path of pulse laser signal and emitting the pulse laser signal to a target object; a local oscillator signal is generated and transmitted to the receiving module; the receiving module is used for receiving the inner light path signal and the outer light path signal, converting the signals into electric signals, mixing the electric signals with the local oscillator signal to obtain a frequency-mixed electric signal, and filtering and amplifying the electric signal; the control processing module is used for acquiring signals from the receiving module to obtain receiving signals, sequentially performing waveform accumulation, median filtering processing and differential processing on the receiving signals to obtain initial phases of wave crests of internal and external optical paths, optimizing the initial phases of the wave crests of the internal and external optical paths by adopting a centroid method and calculating a phase difference of the internal and external optical paths; and the distance between the target object and the target object is calculated. According to the invention, high-reliability measurement can be realized in different environments.

Description

Technical Field

[0001] The present application relates to the field of phase ranging, and in particular to a pulse phase ranging device. Background Art

[0002] Pulse phase ranging technology: by transmitting modulated light waves, receiving signals reflected from the target, measuring the phase difference between the transmitted signal and the received signal, and using the phase difference to calculate the distance to the target. Pulse phase ranging technology is a high-precision ranging method that combines the characteristics of pulse ranging and phase ranging, and can achieve millimeter-level measurement accuracy. Compared with traditional pulse ranging, it can achieve higher accuracy. However, in complex environments, measurement accuracy and performance stability are easily affected. Especially when the external ambient light signal is strong, the signal-to-noise ratio of the signal will deteriorate, affecting the calculation of the signal phase, causing unstable calculations and even erroneous data. Summary of the invention

[0003] The purpose of this application is to provide a pulse phase ranging device that can achieve high-reliability measurement in different environments.

[0004] To achieve the above objectives, this application provides the following solutions: The present application provides a pulse phase ranging device, including a transmitting module, a receiving module and a control processing module; The transmitting module is used to: generate a pulse laser signal, which is reflected to the receiving module as an inner optical path signal; generate another pulse laser signal and emit it to the target object; generate a local oscillator signal and transmit it to the receiving module; wherein the pulse laser signal reflected by the target object is sent to the receiving module as an outer optical path signal; The receiving module is used to: receive the inner optical path signal and the outer optical path signal and convert them into electrical signals, and then mix them with the local oscillator signal to obtain a mixed electrical signal; and perform filtering and amplification processing on the mixed electrical signal; The control processing module is used to: collect signals from the receiving module to obtain a received signal; perform waveform accumulation, median filtering, and differential processing on the received signal in sequence to obtain a preliminary phase of the internal and external optical path peaks; use the centroid method to optimize the preliminary phase of the internal and external optical path peaks, and calculate the internal and external optical path phase difference; based on the internal and external optical path phase difference, calculate the distance to the target object.

[0005] According to the specific embodiments provided by the present application, the present application has the following technical effects: the present application provides a pulse phase ranging device, in which the transmitting module performs laser emission and signal transmission, the receiving module performs signal reception, and then the control processing module performs waveform accumulation, median filtering, and differential processing on the collected received signals in sequence to obtain the preliminary phase of the internal and external optical path peaks; in this step, waveform accumulation and median filtering processing will make the background noise in the signal smaller and smoother, and then differential processing can further reduce the influence of the signal that has become smooth but still has large fluctuations on the peak search, and provide more accurate data for subsequent distance calculation. The centroid method is used to optimize the preliminary phase of the internal and external optical path peaks, determine the precise phase, and calculate the internal and external optical path phase difference; based on the internal and external optical path phase difference, the distance to the target is calculated. So far, the present application realizes the ranging function, and based on the function settings in the control processing module, even in different environments or in strong light interference environments, noise reduction processing can be achieved through waveform accumulation, median filtering, differentiation, and centroid method, thereby achieving stable and reliable measurement and obtaining accurate distance results. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0007] Figure 1 Schematic diagram of a pulse phase ranging device in one embodiment of the present application.

[0008] Figure 2 It is a schematic diagram of a pulse phase ranging device in another embodiment of the present application.

[0009] Figure 3 Schematic diagram of the structure of a distance measuring board in one embodiment of the present application.

[0010] Figure 4 This is a schematic diagram of a 5V power supply structure in an embodiment of the present application.

[0011] Figure 5 This is a schematic diagram of a 3.3V power supply structure in an embodiment of the present application.

[0012] Figure 6 This is a schematic diagram of a 2.5V power supply structure in an embodiment of the present application.

[0013] Figure 7 Schematic diagram of various ports of a single-chip microcomputer chip in an embodiment of the present application.

[0014] Figure 8 Schematic diagram of the circuit structure of a phase-locked loop in one embodiment of the present application.

[0015] Fig. 9 Schematic diagram of the circuit structure of a trigger in one embodiment of the present application.

[0016] Fig.10 Schematic diagram of the circuit structure of a receiving boost circuit for controlling an avalanche photodiode in one embodiment of the present application.

[0017] Fig.11 Schematic diagram of the circuit structure of a receiving driving component for driving an avalanche photodiode in one embodiment of the present application.

[0018] Fig.12 This is a schematic diagram of the circuit structure when the laser emits laser in one embodiment of the present application.

[0019] Fig.13 Schematic diagram of the circuit structure of a high-voltage receiving circuit and a transimpedance amplifier circuit for signal processing in one embodiment of the present application. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0021] In order to make the purpose, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0022] In an exemplary embodiment, a pulse phase ranging device is provided, comprising a transmitting module, a receiving module and a control processing module. Figure 1 As shown, the receiving module includes a receiving lens, an avalanche photodiode, a receiving high-voltage circuit and a transimpedance amplifier circuit arranged in sequence; the transmitting module includes a laser, a local oscillator drive circuit, a transmitting drive circuit, a spectroscope, a differential amplifier circuit, a phase-locked loop and a transmitting lens.

[0023] The transmitting module is used to: generate a pulse laser signal, which is reflected to the receiving module as an internal optical path signal; generate another pulse laser signal and emit it to the target object; generate a local oscillator signal and transmit it to the receiving module; wherein the pulse laser signal reflected by the target object is used as an external optical path signal to the receiving module.

[0024] In a specific application example, the first output end of the phase-locked loop is connected to the differential amplifier circuit, the emission drive circuit and the laser in sequence, so that one signal output by the phase-locked loop drives the laser to emit two pulse laser signals. One pulse laser signal is directly reflected to the receiving module through the beam splitter as an inner optical path signal; the other pulse laser signal is emitted to the target object through the emission lens, and then reflected to the receiving module through the target object as an outer optical path signal.

[0025] The second output end of the phase-locked loop is connected to the local oscillator driving circuit, so that another signal output by the phase-locked loop drives the local oscillator driving circuit to generate a local oscillator signal, and transmits it to the receiving module.

[0026] In another specific application example, the pulse phase ranging device also includes a trigger; the trigger is used to: receive a first trigger signal sent by the control processing module, and trigger and control the first output end and the second output end of the phase-locked loop according to the first trigger signal; receive a second trigger signal sent by the control processing module, and according to the second trigger signal, trigger the control processing module to collect signals from the receiving module at intervals of a preset time length.

[0027] Specifically, the phase-locked loop generates two signals that are simultaneously connected to the trigger, generating a trigger signal with a frequency of 1KHz for triggering the control processing module to collect the received signal. The trigger triggers the control processing module to collect the received signal every 1ms. Since the received signal is periodic and continuous, the trigger can ensure that the initial phase of the received signal is consistent, and the time for collecting a cycle of the received signal is accurate and stable.

[0028] The receiving module is used to: receive the inner optical path signal and the outer optical path signal and convert them into electrical signals, and then mix them with the local oscillator signal to obtain a mixed electrical signal; and perform filtering and amplification processing on the mixed electrical signal.

[0029] In a specific application example, the receiving lens is used to collect the external optical path signal to the avalanche photodiode; specifically, the pulsed laser signal returned by the target object is transmitted to the avalanche photodiode through the receiving lens together with the pulsed laser signal reflected inside the optical machine.

[0030] The avalanche photodiode is used to convert the received inner optical path signal and the outer optical path signal into electrical signals, and mix them with the local oscillator signal to obtain a mixed electrical signal.

[0031] The receiving high-voltage circuit is used to filter the mixed-frequency electrical signal to obtain an electrical signal with a frequency of 1 KHz.

[0032] The transimpedance amplifier circuit is used for: amplifying the mixed-frequency electrical signal after filtering processing.

[0033] The control processing module is used for: collecting signals from the receiving module to obtain a received signal; performing waveform accumulation, median filtering processing, and differential processing on the received signal in sequence to obtain a preliminary phase of the inner and outer optical path wave peaks; optimizing the preliminary phase of the inner and outer optical path wave peaks by using the centroid method, and calculating the phase difference between the inner and outer optical paths; calculating the distance to the target object based on the phase difference between the inner and outer optical paths.

[0034] In a specific application example, the control processing module is composed of a single-chip microcomputer, and the single-chip microcomputer is also used for: (1) Controlling the local oscillator driving circuit through a DAC (Digital Audio Compress, digital-to-analog converter) to change the magnitude of the local oscillator signal.

[0035] (2) Generating a first PWM (Pulse width modulation, pulse width modulation) signal through a timer to control the emission driving circuit, and further changing the laser power of the pulsed laser signal.

[0036] (3) Controlling the phase-locked loop through IIC (Inter-Integrated Circuit, integrated circuit bus) to generate multiple high-frequency and low-frequency signals; that is, the phase-locked loop is controlled by the single-chip microcomputer to generate two signals with a frequency difference of 1 KHz.

[0037] (4) After receiving the trigger signal sent by the trigger, performing signal acquisition from the receiving module through an ADC (Analog-to-digital converter, analog-to-digital converter). Specifically, after being triggered by the 1 KHz trigger signal of the trigger, the single-chip microcomputer acquires the received signal after circuit amplification and filtering through the ADC.

[0038] (5) Generating a second PWM signal through a timer to change the amplification factor of the avalanche photodiode by regulating the driving voltage, so that the wave peaks of the inner and outer optical path signals received by it reach a suitable height without saturation or being too weak.

[0039] In another specific application example, within the control processing module, the step of calculating the distance to the target object based on the phase difference between the inner and outer optical paths includes: (1) Using the following formula to calculate the preliminary distance L to the target object 1 : ; where P 1 、P 2 is the phase difference between the inner and outer optical paths of two low-frequency pulsed laser signals, ld It is the length that can be measured by one cycle corresponding to the difference frequency of two low-frequency pulsed laser signals.

[0040] (2) Based on the preliminary distance to the target, determine the frequency of the high-frequency pulsed laser signal, and then calculate the internal and external optical path phase difference P of the two high-frequency pulsed laser signals. 3 .

[0041] (3) Use the following formula to calculate the distance value L between the target object and the high-frequency signal: 2 : ; Among them, l 3 It is the length that can be measured by one cycle corresponding to the difference frequency of two high-frequency pulsed laser signals.

[0042] (4) Use the following formula to calculate the final distance L to the target object: ; where N is Round up.

[0043] In another specific application example, the pulse phase ranging device also includes a power management module; the power management module is used to generate voltages of different sizes (such as 3V, 5V, etc.) to power the laser, the receiving high-voltage circuit in the receiving module, and the transimpedance amplifier circuit.

[0044] In an exemplary embodiment, the pulse phase ranging device of the present application can be as follows: Figure 2 The distance measuring board is set as shown in the figure; among them, GD32F103Rxxx is the model of the single-chip microcomputer chip used in the control processing module. LCD is a liquid crystal display screen, which is used to display the final distance between the targets. HV is a high-voltage driver, which is used to drive an avalanche photodiode, i.e., APD. PLL is a phase-locked loop, TIA is a transimpedance amplifier circuit, LD refers to a laser, and target refers to a target object. In addition, the buzzer is used to prompt the user to start or end a task. In practical applications, low-pass filtering can be performed first, and then TIA can be used for amplification processing; it can also be adjusted as needed.

[0045] In practical applications, the distance measuring board can be connected to the keypad through a connector; different keys are provided on the keypad to realize different functions, such as continuous measurement and single measurement. Figure 3 shown.

[0046] Corresponding to the power management module mentioned above, different voltages can be generated. When the voltage is 5V, for example Figure 4 As shown; when the voltage is 3.3V, Figure 5 As shown; when the voltage is 2.5V, Figure 6 shown.

[0047] like Figure 7 As shown, it is a schematic diagram of each port of the single-chip microcomputer chip used in the control processing module of this application. In this chip, the PA1 port is an IO port, which realizes power supply control and is set high when powered on. The PA2 port and the PA3 port are Bluetooth connection serial ports. The PA4 port is DAC laser power control. The PA5 port is DAC intrinsic signal drive control. The PA6 port is ADC intermediate frequency echo signal acquisition. The PA7 port is ADC charging status detection. The PB0 port is a timer, and the local oscillator signal high voltage control. The PB1 port realizes ADC battery power detection. The PB2 port realizes Bluetooth chip selection. The PB10 port realizes Bluetooth reset. The PA11 port realizes interrupt and trigger signal acquisition. The PA9 port is the debug serial port TX. The PA10 port is the debug serial port RX. The PA13 port and the PA14 port are program download ports. The PB5 port is an IO port, which realizes display screen reset. The PB6 port and the PB7 port are I2C display screen communication. The PB8 port and the PB9 port are I2C phase-locked loop communication.

[0048] like Figure 8 As shown, the circuit structure of the phase-locked loop is: the first end of the chip U4 is connected to the seventh end and grounded via the capacitor C20; the first end of the chip U4 is connected to VCC via the inductor L4; the first end of the chip U4 is also connected to the capacitor C18, the capacitor C18 is a decoupling capacitor, and the blank space next to the capacitor C18 means that a capacitor has been removed; the second end of the chip U4 is connected to the first end of the chip Y1 and then grounded; the third end of the chip U4 is connected to the third end of the chip Y1 and then grounded; the fourth end of the chip U4 is connected to the PLL_I2C_SCL contact; the fifth end of the chip U4 is connected to the PLL_I2C_SDA contact; the sixth end of the chip U4 is connected to the CLK_LD contact; the tenth end of the chip U4 is connected to the CLK_LO contact; the eighth end of the chip U4 is grounded.

[0049] The chip U4 is a phase-locked chip; the chip Y1 is a passive crystal oscillator, which provides a high-precision fixed-frequency clock for the phase-locked loop; the PLL_I2C_SCL contact and the PLL_I2C_SDA contact are communication interfaces between the phase-locked loop and the control processing module MCU, which are used to control the frequency output of the phase-locked loop; the CLK_LD contact and the CLK_LO contact represent two signals with different frequencies generated by the phase-locked loop, which are sent to the transmitting drive circuit and the local oscillator drive circuit respectively.

[0050] like Fig. 9As shown, the circuit structure of the trigger is: the first end of the chip U5 is connected to the CLK_LO contact via a resistor R13; the second end of the chip U5 is grounded; the third end of the chip U5 is connected to the CLK_LD contact via a resistor R14; the CLK_REF contact is connected to one end of the resistor R37; the other end of the resistor R37 is connected to VCC after being connected in series with a resistor R12; the other end of the resistor R37 is also connected to the fourth end of the chip U5 and then to ground via a capacitor C22; the fifth and sixth ends of the chip U5 are connected and then to VCC via a resistor R11; the fifth and sixth ends of the chip U5 are connected and then to ground via a capacitor C21; the chip U5 is a trigger chip, and the CLK_REF contact is a trigger mixing signal, which serves as a starting reference for signal echo acquisition.

[0051] like Fig.10 As shown, the receiving boost circuit for controlling the avalanche photodiode is a BOOST boost circuit, and its circuit structure is: the APD_HV contact is grounded via the resistor R17, and the APD_HV contact is also connected to the first end of the resistor R15 and the first end of the capacitor C25 respectively, and the second end (the other end) of the resistor R15 is respectively connected to the cathode of the diode D3 and the first end of the capacitor C55; the second end (the other end) of the capacitor C25 is respectively connected to the second end (the other end opposite to the first end) of the capacitor C55 and one end of the resistor R23; the anode of the diode D3 is respectively connected to one end of the inductor L7 and the drain of the field effect transistor Q5, and a resistor R20 is arranged between the source and the gate of the field effect transistor Q5; the gate of the field effect transistor Q5 is connected to the HV_ADJ contact; the other end of the inductor L7 is connected in series with the inductor L6 and then connected to VCC; the capacitor C24 is an input filter capacitor, which is arranged between the inductor L6 and the inductor L7 and is grounded.

[0052] like Fig.11As shown in the figure, it is the circuit structure of the receiving driving component for driving the avalanche photodiode. Among them, the inductor L13 is a magnetic bead, which is used to suppress the high-frequency noise in the power supply. The capacitor C28 and the capacitor C29 are bypass capacitors for filtering; U6 is a voltage-adjustable low-voltage difference linear regulator LDO, which is used to drive the local oscillator signal. Signals of different frequencies require different voltage values. Resistors R25, 26 and 27 divide the voltage, and the output voltage is adjusted through DAC. Capacitors C31 and C32 are used as output filter capacitors, and resistor R24 ​​is a magnetic bead to suppress the noise of the subsequent circuit. LDO amplifies the high-frequency signal emitted by PLL through capacitors C50, C30, inductor L19, capacitor C34, resistor R30 and transistor U7 to reach the threshold of APD photoelectric conversion. In the circuit from CLK_LO to transistor U7, multiple inductors and capacitors form an LC filter network to filter out high-frequency noise and achieve impedance matching, and at the same time realize high-frequency pulse waveform modulation with U6 and transistor U7.

[0053] like Fig.12 The figure shows the circuit structure when the laser emits laser. Among them, inductor L16, capacitor C52 and resistor R49 perform differential modulation on the signal sent by PLL to generate pulses, improve the steepness of the signal edge through resonance characteristics, and optimize the pulse quality. Inductor L15 filters high-frequency noise, and FL1 suppresses common-mode noise to ensure signal integrity. Transistor U15 modulates, shapes and amplifies the signal. The circuit around U12 is connected to the laser feedback pin to control the laser power and the stability of the emission signal.

[0054] like Fig.13 As shown in the figure, it is a circuit structure for receiving high-voltage circuit and transimpedance amplifier circuit for signal processing. The figure mainly shows the signal receiving circuit. Resistor R40 and capacitor C72 are input filters to filter out high-frequency noise and improve the signal-to-noise ratio. Resistor R67, resistor R66 and capacitor C33 form a transimpedance amplifier with the first stage of U13 to ensure signal gain. Resistor R64 and capacitor C64 frequency compensation suppress parasitic oscillation and improve signal stability. Resistor R61 and resistor R63 are bias resistors to provide a stable bias voltage for the op amp. Resistor R48, resistor R51 and capacitor C59, capacitor C60 suppress the high-frequency noise of the amplified signal.

[0055] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0056] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A pulse phase ranging device, characterized in that: The pulse phase ranging device includes a transmitting module, a receiving module and a control processing module; The transmitting module is used to: generate a pulse laser signal, which is reflected to the receiving module as an inner optical path signal; generate another pulse laser signal and emit it to the target object; generate a local oscillator signal and transmit it to the receiving module; wherein the pulse laser signal reflected by the target object is sent to the receiving module as an outer optical path signal; The receiving module is used to: receive the inner optical path signal and the outer optical path signal and convert them into electrical signals, and then mix them with the local oscillator signal to obtain a mixed electrical signal; and perform filtering and amplification processing on the mixed electrical signal; The control processing module is used to: collect signals from the receiving module to obtain a received signal; perform waveform accumulation, median filtering, and differential processing on the received signal in sequence to obtain a preliminary phase of the internal and external optical path peaks; use the centroid method to optimize the preliminary phase of the internal and external optical path peaks, and calculate the internal and external optical path phase difference; based on the internal and external optical path phase difference, calculate the distance to the target object.

2. The pulse phase ranging device according to claim 1, characterized in that: The receiving module includes a receiving lens, an avalanche photodiode, a receiving high-voltage circuit and a transimpedance amplifier circuit which are arranged in sequence; The receiving lens is used to: collect the external optical path signal to the avalanche photodiode; The avalanche photodiode is used to: convert the received inner optical path signal and the outer optical path signal into electrical signals, and mix them with the local oscillator signal to obtain a mixed electrical signal; The receiving high-voltage circuit is used to: filter the mixed-frequency electrical signal; The transimpedance amplifier circuit is used to amplify the mixed-frequency electrical signal after filtering.

3. The pulse phase ranging device according to claim 1, characterized in that: The transmitting module includes a laser, a local oscillator driving circuit, a transmitting driving circuit, a spectroscope, a differential amplifier circuit, a phase-locked loop and a transmitting lens; The first output end of the phase-locked loop is connected to the differential amplifier circuit, the emission drive circuit and the laser in sequence, so that one signal output by the phase-locked loop drives the laser to emit two pulse laser signals; Among them, one pulse laser signal is directly reflected to the receiving module through the beam splitter as an inner optical path signal; another pulse laser signal is emitted to the target object through the transmitting lens, and then reflected to the receiving module through the target object as an outer optical path signal; The second output end of the phase-locked loop is connected to the local oscillator driving circuit, so that another signal output by the phase-locked loop drives the local oscillator driving circuit to generate a local oscillator signal, and transmits it to the receiving module.

4. The pulse phase ranging device according to claim 3, characterized in that: The pulse phase ranging device also includes a trigger; The trigger is used to: receive a first trigger signal sent by the control processing module, and trigger and control the first output end and the second output end of the phase-locked loop according to the first trigger signal; Receive a second trigger signal sent by the control processing module, and trigger the control processing module to collect signals from the receiving module at intervals of a preset time according to the second trigger signal.

5. The pulse phase ranging device according to claim 4, characterized in that: The control processing module is also used for: Controlling the local oscillator driving circuit through DAC to change the magnitude of the local oscillator signal; Generate a first PWM signal to control the emission drive circuit, thereby changing the laser power of the pulsed laser signal; Controlling the phase-locked loop via IIC; After receiving the trigger signal sent by the trigger, the signal is collected from the receiving module through the ADC.

6. The pulse phase ranging device according to claim 1, characterized in that: In the control processing module, the step of calculating the distance to the target object based on the internal and external optical path phase difference includes: Use the following formula to calculate the initial distance L1 to the target: ; Among them, P1 and P2 are the phase differences between the inner and outer optical paths of two low-frequency pulsed laser signals, l d It is the length that can be measured by one cycle corresponding to the difference frequency of two low-frequency pulsed laser signals; Based on the preliminary distance to the target object, the frequency of the high-frequency pulsed laser signal is determined, and then the internal and external optical path phase difference P3 of the two high-frequency pulsed laser signals is calculated; Use the following formula to calculate the distance value L2 between the target object and the high-frequency signal: ; Wherein, l3 is the length that can be measured by one cycle corresponding to the difference frequency of two high-frequency pulsed laser signals; Use the following formula to calculate the final distance L to the target: ; where N is Round up.

7. The pulse phase ranging device according to claim 3, characterized in that: The pulse phase ranging device also includes a power management module; The power management module is used to generate voltages of different magnitudes to power the laser, the receiving high-voltage circuit in the receiving module, and the transimpedance amplifier circuit.

8. The pulse phase ranging device according to claim 3, characterized in that: The circuit structure of the phase-locked loop is: After the first end of the chip U4 is connected to the seventh end, it is grounded via the capacitor C20; the first end of the chip U4 is connected to VCC via the inductor L4; the first end of the chip U4 is also connected to the capacitor C18, and the capacitor C18 is a decoupling capacitor; The second end of the chip U4 is connected to the first end of the chip Y1 and then grounded; The third end of the chip U4 is connected to the third end of the chip Y1 and then grounded; The fourth end of the chip U4 is connected to the PLL_I2C_SCL connection point; the fifth end of the chip U4 is connected to the PLL_I2C_SDA connection point; the sixth end of the chip U4 is connected to the CLK_LD connection point; the tenth end of the chip U4 is connected to the CLK_LO connection point; The eighth terminal of the chip U4 is grounded; The chip U4 is a phase-locked chip; the chip Y1 is a passive crystal oscillator; the PLL_I2C_SCL contact and the PLL_I2C_SDA contact are communication interfaces between the phase-locked loop and the control processing module; the CLK_LD contact and the CLK_LO contact represent two signals with different frequencies, which are sent to the transmitting drive circuit and the local oscillator drive circuit respectively.

9. The pulse phase ranging device according to claim 4, characterized in that: The circuit structure of the trigger is: The first end of the chip U5 is connected to the CLK_LO connection point via the resistor R13; the second end of the chip U5 is grounded; the third end of the chip U5 is connected to the CLK_LD connection point via the resistor R14; The CLK_REF contact is connected to one end of the resistor R37; the other end of the resistor R37 is connected in series with the resistor R12 and then connected to VCC; the other end of the resistor R37 is also connected to the fourth end of the chip U5 and then grounded via the capacitor C22; After the fifth and sixth terminals of the chip U5 are connected, they are connected to the VCC via the resistor R11; after the fifth and sixth terminals of the chip U5 are connected, they are also grounded via the capacitor C21; The chip U5 is a trigger chip, and the CLK_REF contact is a trigger mixing signal.

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