Laser distance measuring device

Abstract

The invention provides a laser ranging device, and belongs to the technical field of laser detection and ranging. The system comprises a single photon detection module integrated on a single chip and a processing module electrically connected with the single photon detection module. And the single-photon detection module is integrated with a single-photon detector array, a time measurement unit array and a histogram processing unit, and is used for accumulating and generating a flight time histogram in the chip according to the flight time of returned photons detected for multiple times. The processing module is configured to obtain the time-of-flight histogram from the single photon detection module, perform peak detection on the histogram to determine a signal peak corresponding to the target distance, and calculate the target distance based on the position of the signal peak. By means of on-chip integration and statistical processing, miniaturization and low power consumption of the system are achieved, and the precision and reliability of weak signal distance measurement under the strong noise background are improved.

Description

Technical Field

[0001] This application relates to the field of laser detection and ranging technology, and in particular to a laser ranging device. Background Technology

[0002] Laser ranging technology has been widely used due to its high precision and long-range capabilities. However, when facing distant, low-reflectivity targets or strong ambient light interference, the echo signal of traditional pulsed laser ranging systems is extremely weak, and the signal-to-noise ratio drops sharply, leading to reduced measurement accuracy or even ranging failure.

[0003] To address the problem of weak signal detection, existing technologies have incorporated high-sensitivity detectors such as single-photon avalanche diodes (SPADs). However, current ranging systems based on single-photon detectors generally employ a discrete architecture, where multiple chips, including the single-photon detector, time-to-digital converter, and microprocessor, are separately arranged on a circuit board. This discrete architecture has significant drawbacks: First, the system is bulky and consumes a lot of power, making it difficult to meet the miniaturization and low-power requirements of consumer electronics and portable devices. Second, long-distance signal transmission between chips is prone to introducing noise and clock jitter, limiting the system's timing accuracy and anti-interference capabilities. Finally, traditional processing methods that rely on comparing signal strength with a fixed threshold are highly susceptible to misjudgment in extremely weak single-photon signals and high background noise environments, leading to ranging failures or severely out-of-tolerance accuracy. Summary of the Invention

[0004] The purpose of this application is to provide a laser ranging device to solve the technical problems of existing laser ranging systems based on single-photon detection, which are characterized by large size, high power consumption, low integration, and limited timing accuracy due to the use of multi-chip discrete architecture, as well as the poor reliability and low accuracy of traditional signal processing methods in weak signal and high noise environments.

[0005] To achieve the above objectives, this application provides a laser ranging device, comprising: Laser pulse emission module, used to generate ranging laser signals; The transmitting optical system is used to collimate and shape the laser signal to obtain a first laser signal; Receiving optical system: used to collect the second laser signal reflected from the target and focus it onto the photosensitive surface of the single-photon detection module; A single-photon detection module, integrated on a single chip, comprises: a single-photon detector array for responding to an incident single photon and generating a detection signal; a time measurement unit array corresponding to the single-photon detector array for measuring the time difference between the detection signal and a trigger signal to obtain the photon's flight time; and a histogram processing unit for statistically accumulating the flight times of multiple photons output by the time measurement unit array within the single chip to generate a time-of-flight histogram. The single-photon detection module is connected to the laser pulse emission module; as well as, The processing module is electrically connected to the single-photon detection module and is configured to: acquire the time-of-flight histogram from the single-photon detection module; perform peak detection on the time-of-flight histogram to determine the signal peak corresponding to the target distance; and calculate the target distance based on the position information of the signal peak.

[0006] Furthermore, the laser pulse emitting module includes: It consists of a high-performance dual-channel in-phase Schmitt trigger buffer, an enhanced nitride field-effect transistor, and peripheral circuitry.

[0007] Furthermore, the single-photon detector array is a single-photon avalanche diode array.

[0008] Furthermore, the time measurement unit array is a time-to-digital converter array; or, the time measurement unit array includes a time-to-amplitude converter array and an analog-to-digital converter.

[0009] Furthermore, the single-photon detection module communicates with the processing module through a serial peripheral interface; and after generating the time-of-flight histogram, the single-photon detection module notifies the processing module to read the data through an interrupt signal.

[0010] Furthermore, it also includes: A narrow-bandpass optical filter is disposed in front of the photosensitive surface of the single-photon detector array, the center wavelength of which matches the laser wavelength.

[0011] Furthermore, the processing module is configured as follows: Peak detection is performed on the time-of-flight histogram, the peak detection including: The time-of-flight histogram is smoothed to suppress noise spikes; as well as, In the smoothed histogram, peak points with values ​​greater than a preset detection threshold are searched and selected as candidate signal peaks.

[0012] Furthermore, the processing module is also configured to: Before smoothing the time-of-flight histogram, the background noise baseline of the time-of-flight histogram is estimated, and the preset detection threshold is determined based on the background noise baseline.

[0013] Furthermore, the processing module is also configured to: For the candidate signal peak, Gaussian function fitting is performed on the data in the neighborhood of the candidate signal peak in the original time-of-flight histogram data, so that the center position of the fitted Gaussian curve is determined as the precise position of the signal peak.

[0014] Compared with the prior art, this application has the following beneficial effects: 1. Miniaturization and low power consumption of the system were achieved. By integrating the single-photon detector, time measurement unit, and histogram processing unit onto a single chip, the system size and power consumption were significantly reduced. The on-chip histogram accumulation method significantly reduced the data transmission bandwidth with the external processor, thereby further reducing system power consumption.

[0015] 2. Improved ranging accuracy and reliability. This application employs a statistical histogram method, effectively extracting weak target signals from strong noise backgrounds through multiple measurements, forming significant signal peaks. Therefore, it maintains high reliability and ranging accuracy even in extremely low signal-to-noise ratio scenarios such as long distances and low reflectivity. Simultaneously, the on-chip integrated timing unit reduces signal jitter introduced by long-distance transmission, ensuring timing accuracy.

[0016] 3. Improved reliability and facilitated mass production. The monolithic integration solution based on standard complementary metal-oxide-semiconductor (CMOS) technology offers excellent consistency and interference immunity, providing a foundation for large-scale, low-cost commercial mass production.

[0017] 4. Expanded application scenarios. Due to its single-photon level detection sensitivity, the system can use low-power lasers that meet human eye safety standards to achieve long-distance ranging, resolving the conflict between high power and human eye safety in traditional laser ranging systems.

[0018] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the device composition of a laser ranging device provided in an embodiment of this application; Figure 2 This is a schematic diagram illustrating the implementation process of a laser ranging device provided in an embodiment of this application; Figure 3 This application provides a schematic diagram of the ranging process of a laser ranging device according to an embodiment of the present application. Figure 4 This is a schematic diagram of a photon arrival time histogram provided in an embodiment of this application; Figure 5 This is a schematic diagram of the SPAD detection chip circuit provided in an embodiment of this application; Figure 6 This is a schematic diagram of the optomechanical interface and envelope provided in an embodiment of this application. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] For specific implementation details, please refer to [link / reference]. Figure 1 , Figure 1 This is a schematic diagram of the device composition of a laser ranging device provided in an embodiment of this application. The device includes: Laser pulse emission module 30 is used to generate ranging laser signals; The transmitting optical system 41 is used to collimate and shape the laser signal to obtain a first laser signal; Receiving optical system 42: used to collect the second laser signal reflected from the target and focus it onto the photosensitive surface of the single-photon detection module; The single-photon detection module 10 integrates on a single chip: a single-photon detector array for responding to an incident single photon and generating a detection signal; a time measurement unit array corresponding to the single-photon detector array for measuring the time difference between the detection signal and the trigger signal to obtain the photon's flight time; and a histogram processing unit for statistically accumulating the flight times of multiple photons output by the time measurement unit array within the single chip to generate a flight time histogram. as well as, The processing module 20 is electrically connected to the single-photon detection module and is configured to: acquire the time-of-flight histogram from the single-photon detection module; perform peak detection on the time-of-flight histogram to determine the signal peak corresponding to the target distance; and calculate the target distance based on the position information of the signal peak.

[0023] Specifically, please refer to Figure 2 The laser pulse emission module 30 is responsible for generating the light source for ranging. In this embodiment, the module can employ a laser diode with a center wavelength of 905 nanometers, driven by a driving circuit based on an enhanced gallium nitride field-effect transistor. The driving circuit can generate high peak power, nanosecond-level narrow pulse laser pulses, which is beneficial for improving ranging resolution and peak power, thereby ensuring long-range detection capability.

[0024] The single-photon detection module 10 drives the laser pulse emission module 30 to emit laser pulse signals, and connects the driving signal to the input terminal of the time measurement unit array as the starting reference for time measurement.

[0025] Specifically, the processing module 20 sets the operating voltage value and drive signal parameters for the laser pulse emission module and sends these parameters to the single-photon detection module. The final laser drive signal is output by the single-photon detection module.

[0026] The optical system 40 includes a transmitting optics section (transmitting optics system 41) and a receiving optics section (receiving optics system 42). The transmitting optics section (e.g., a collimating lens group) shapes and collimates the laser beam emitted by the laser pulse transmitting module 30 to reduce its divergence angle, thereby concentrating the energy onto a distant target. The receiving optics section (e.g., a converging lens group) collects the extremely weak echo photons diffusely reflected from the target and focuses them onto the photosensitive surface of the single-photon detection module 10. As a preferred embodiment, to suppress ambient light noise, a narrow-bandpass optical filter can be placed before the photosensitive surface of the single-photon detection module 10. The center transmission wavelength of this filter matches the wavelength of the laser pulse (e.g., 905 nm), while the bandwidth is as narrow as possible (e.g., 10 nm). This selectively allows signal photons reflected from the target to pass through while significantly filtering out ambient light of other wavelengths, thereby significantly improving the system's signal-to-noise ratio.

[0027] The power management module 50 is responsible for providing stable and reliable power to the entire system. It typically includes circuits such as DC-DC converters and low-dropout linear regulators to convert external input power (such as batteries) into different voltages required by various modules in the system. For example, it provides logic voltage and drive voltage to the processing module 20 and the laser pulse emission module 30, and provides the required bias high voltage to the single-photon detection module 10.

[0028] The core of this embodiment lies in the architecture and division of labor between the single-photon detection module 10 and the processing module 20. The single-photon detection module 10, as a key component of the technical solution of this application, is characterized by its high degree of monolithic integration. For example... Figure 2 As shown, this module integrates a single-photon detector array 11, a time measurement unit array 12, and a histogram processing unit 13 on a single semiconductor chip (e.g., a chip manufactured using standard complementary metal-oxide-semiconductor processes). This monolithic integrated design effectively overcomes the technical bottlenecks inherent in traditional discrete solutions, such as large size, high power consumption, and susceptibility to interference.

[0029] In this embodiment, the single-photon detector array 11 can be composed of multiple single-photon avalanche diodes. Each single-photon avalanche diode operates in Geiger mode, possessing the ability to detect a single photon and generate a macroscopic avalanche current pulse, thereby achieving extreme detection sensitivity. The array design can increase the total photosensitive area and improve photon capture efficiency.

[0030] The time measurement unit array 12 and the single-photon detector array 11 are physically adjacent and correspond one-to-one. Each time measurement unit can be a high-precision time-to-digital converter. When the processing module 20 controls the single-photon detection module to send a trigger signal (TRIG), all time measurement units are synchronously started to begin timing; when any detector in the single-photon detector array 11 responds to an incident photon and generates a detection signal, its corresponding time measurement unit stops timing and outputs a digital value representing the photon's flight time. It is understandable that because the time measurement unit array 12 and the detector array 11 are integrated on the same chip, the signal transmission path is extremely short, effectively avoiding clock jitter and noise interference introduced by long board-level traces, ensuring picosecond-level high-precision timing.

[0031] The histogram processing unit 13 is the core unit for implementing on-chip statistical functions; it can be a dedicated digital signal processing core or a hardened logic circuit. This unit receives each photon time-of-flight value output from the time measurement unit array 12 and performs statistical accumulation in a static random access memory (SRAM) within the chip. This memory is divided into a series of time units, each corresponding to a very small time window. Based on the received time-of-flight value, the histogram processing unit 13 increments the count value of the corresponding time unit by one. Through thousands of repeated measurements, a complete time-of-flight histogram is constructed within the single-photon detection module 10.

[0032] The processing module 20 can be a general-purpose microcontroller unit or a field-programmable gate array (FPGA), primarily responsible for controlling the entire ranging process and performing final data computation. This module communicates with the single-photon detection module 10 via an electrical connection; in this embodiment, this connection can be a high-speed serial peripheral interface. The processing module 20 sends configuration commands to the single-photon detection module 10 through this interface, such as setting the number of measurement repetitions. After the single-photon detection module 10 completes the preset number of measurements and generates a complete histogram, it sends an interrupt request to the processing module 20 via a dedicated interrupt signal line (INT). Upon receiving the interrupt, the processing module 20 reads the entire histogram data array from the single-photon detection module 10 into its internal memory via the serial peripheral interface. Subsequently, the processing module 20 executes a peak detection algorithm on the histogram data to determine the signal peaks formed by the accumulation of target echo signal photons, and finally calculates the precise distance to the target based on the position information of the signal peaks.

[0033] For specific implementation details, please refer to [link / reference]. Figure 3 The system first completes the initialization of all modules (including the basic configuration of laser emission, detection, and processing modules); then it measures the ambient temperature (to provide a basis for temperature compensation of laser diode, SPAD and other modules), and the processing module uniformly sets the pulse parameters (such as frequency and pulse width) of the laser pulse emission module, the SPAD operating voltage of the single photon detection module 10, the preset number of measurements and other core parameters.

[0034] Afterwards, the processing module 20 continuously detects the ranging command from the host computer via UART; if no command is received, the detection state is maintained; if a command is received, the laser pulse emission module 30 drives the laser diode to emit laser (which is collimated and shaped by the emission optical system 41 and then directed toward the target), and at the same time, the single photon detection module 10 synchronously starts the timing process.

[0035] After the laser beam is reflected from the target, it is collected by the receiving optical system 42 and focused onto the photosensitive surface of the SPAD in the single-photon detection module. The SPAD performs single-photon detection, and the TDC (Time-to-Digital Converter) simultaneously measures the time of flight. Within a set time window, if the SPAD detects a photon, the TDC records the time of flight; if no photon is detected, it is marked "No count this time," and the count for this test is recorded as 0. A histogram is generated based on all measurement results.

[0036] The processing module 20 continuously counts the number of measurements to determine if the preset number of pulses has been reached. If not, it returns to the "emit laser and time" step to repeat the operation. If the preset number of pulses has been reached, the single-photon detection module 10 accumulates all time-of-flight data within the chip to generate a histogram. The processing module 20 further reads the histogram for signal processing, calculates target information using peak detection, and then uses an algorithm to compensate for temperature, noise, and other factors on the distance value (this process is completed by the algorithm unit of the processing module). Finally, the processing module outputs the ranging result to the host computer via UART.

[0037] It is evident that the entire processing is the result of the laser pulse emission module, the transmitting / receiving optical system, the single-photon detection module, and the processing module each performing their respective functions and cooperating with each other. Through the closed loop of "emission-detection-data processing-output", accurate ranging based on the device structure is achieved.

[0038] It should be noted that the photon arrival time histogram is as follows: Figure 4 As shown, the horizontal axis represents the Time-of-Flight (TOF) value calculated by TDC, and the vertical axis represents the count, indicating the number of signal photons aggregated within the same time unit. After accumulating N pulses, Figure 4 The flight time T_peak is the target time T, where 1029 is the target time, and 83 is the number of photons gathered in this time unit.

[0039] The histogram is then read and signal processed, and the target distance is calculated using the peak detection method. This peak detection algorithm uses a sliding window mean method combined with a Gaussian fitting algorithm, and also integrates a background noise removal algorithm - by selecting the time period in the histogram where there is no target echo to calculate the background noise level; if multiple peaks are identified, the distances of multiple targets can be calculated simultaneously.

[0040] Finally, the formula for calculating the target distance is D=(c * T_peak*TDC per unit time) / 2 (where c is the speed of light).

[0041] It should be noted that the laser ranging described in this invention is a cyclical process of "emission-accumulation-resolution". Through thousands or even tens of thousands of repeated measurements, the laser ranging system forms a significant signal peak with excellent signal-to-noise ratio in the histogram. By accurately locating the TOF position and count of the peak using an algorithm (the sliding window filtering combined with Gaussian fitting algorithm used in this invention), the distance to the target can be calculated. This algorithm effectively suppresses echo signal noise, enabling high-precision measurement of long-distance or low-reflectivity targets even with extremely low echo photon flux.

[0042] In a specific implementation, this application provides an embodiment, the core of which is a monolithically integrated SPAD detection chip (model number: SP5662), the circuit schematic of which is shown in Figure 5.

[0043] When the system is working, the single-photon detection module 10 drives the laser diode (LD) to emit laser pulse signals, and the laser beam is collimated and shaped by the emitting optical system; the receiving optical system collects the weak light signals reflected from the target and focuses them onto the photosensitive surface of the SPAD; the chip directly outputs the preprocessed histogram data for the signal processing module to perform the final calculation of the distance value and distance compensation.

[0044] Combination Figure 5 The schematic diagram of the SPAD detector chip circuit, its pin connections and functions are as follows: Pin 12 (INT) of U2 (SP5662) is the interrupt output flag pin, which is active low and connected to the signal processing module; Pin 14 (nRESET) and Pin 22 (OTT) of U2 are connected to the signal processing module respectively to control the startup and reset of U2; Pin 1 (VSPAD) of U2 is connected to the power management module and receives a high voltage input. Pin 3 (TRIG) of U2 is connected to the laser pulse emission module, which outputs a high repetition rate, extremely narrow pulse width and adjustable laser diode drive signal; Pins 7, 8, 9, and 11 (SS, SCLK, MISO, MOSI) of U2 are connected to the signal processing module, acting as a slave device to interact with the signal processing module via the four-wire SPI communication protocol, thereby enabling parameter setting, startup, and operation control of the SPAD detection module.

[0045] In a specific implementation, this application provides another embodiment, which discloses a specific application scheme of the laser ranging system of the present invention in industrial ranging sensors. This scheme takes monolithically integrated SPAD detection technology as its core (the core component is the SP5662 single-photon detector), and through targeted hardware selection, structural design and performance optimization, it accurately adapts to the industrial scenario's requirements for "long distance, high precision, and low power consumption" ranging. The specific configuration and performance characteristics are as follows: In terms of hardware and structural adaptation, this industrial ranging sensor first adopts, for example... Figure 6The optical-mechanical interface and envelope design shown ensure that the system can be stably integrated into the installation space of industrial equipment, meeting the mechanical adaptability requirements of industrial scenarios. A 905nm laser is selected as the light source, which can be precisely matched with the narrowband optical filter built into the system—allowing only 905nm signal photons reflected by the target to pass through, significantly filtering out ambient light noise of other wavelengths, and improving the system's signal-to-noise ratio from a hardware perspective. The core detection component adopts the SP5662 single-photon detector, which, relying on its monolithically integrated SPAD array, time measurement unit (TDC), and histogram processing unit, achieves efficient capture and high-precision timing of weak echo photons from distant targets in industrial scenarios, as well as on-chip time-of-flight histogram preprocessing, laying the foundation for subsequent distance calculation.

[0046] In terms of core ranging performance, the system fully leverages the high sensitivity of single-photon detection: in typical industrial environments with visibility ≥10km and humidity ≤60%, the ranging capability for typical industrial targets such as buildings can reach ≥1200m, meeting the needs of long-distance industrial detection; the ranging accuracy is optimized in stages according to the distance range, with accuracy ≤±0.25m when the distance is ≤50m, ≤±0.5m when 50m<L≤100m, ≤±1m when 100m<L≤300m, and ≤±2m when 300m<L≤2000m. This graded high accuracy is due to the system's histogram peak detection algorithm (combining sliding window smoothing and Gaussian fitting) and background noise removal technology (calculating the background noise through the no-echo period), effectively offsetting the impact of signal attenuation and noise interference on accuracy during long-distance transmission; the ranging frequency supports multiple adjustable levels of single-shot, 1Hz, 2Hz, 3Hz, and 4Hz, which can be flexibly switched according to the measurement efficiency requirements of industrial scenarios.

[0047] Furthermore, relying on histogram multi-peak analysis capabilities, the system supports multi-target ranging functionality—it can identify multiple independent signal peaks from the time-of-flight histogram and simultaneously calculate the distances to multiple targets (such as multi-layered structures, obstacles, and the target itself in industrial scenarios) along the laser path, expanding its adaptability to complex industrial environments. In terms of power consumption control, thanks to the optimization of "inter-chip signal transmission loss and data bandwidth" by the monolithic integrated design, the system's standby power consumption is ≤0.3W, and the average power consumption under 3.3V power supply is ≤0.8W, meeting the requirements of long-term low-power operation of industrial equipment.

[0048] Specifically, compared to traditional laser ranging technology, the innovation of this invention is not simply the use of a high-sensitivity SPAD detector, but rather the construction of a complete, synergistically optimized system-level solution around the SPAD. The advantages of this invention are: Extreme miniaturization: By integrating SPAD, TDC and histogram accumulation unit onto a single chip, a revolutionary "chip as system" architecture is achieved, completely eliminating the volume redundancy of discrete components, enabling the system to be integrated into micro-terminal devices such as mobile phones and telescopes.

[0049] High performance maintained: While achieving miniaturization, the extreme detection sensitivity at the single-photon level is retained, and the signal jitter is greatly reduced due to on-chip timing, thus achieving high-precision ranging at the centimeter level over long distances.

[0050] Low power consumption and high efficiency: On-chip histogram accumulation technology significantly reduces the data communication bandwidth between the chip and the main controller, solving the power consumption bottleneck caused by massive photon data processing and enabling the system to meet the battery life requirements of portable devices. At the same time, this method does not rely on the "decisiveness" of a single photon, but on the "statistics" of a large number of photon events. The real target echo signal will form a significant "peak" at a specific time unit of the histogram, while random noise is uniformly distributed.

[0051] High reliability and mass production capability: Based on standard CMOS technology, the monolithic integration solution has good system consistency, strong anti-interference capability, and the potential for large-scale, low-cost production.

[0052] Expanding the application limits of laser ranging technology: Due to its single-photon sensitivity, it can use extremely low-power lasers to achieve long-distance ranging while meeting human eye safety standards, thus resolving the contradiction between "high power" and "safety" in traditional laser ranging systems.

[0053] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0054] It should be noted that in the description of this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this application, unless otherwise stated, "multiple" or "more" means at least two.

[0055] It should be understood that when an element is referred to as "fixed to" or "set on" another element, it may be directly on the other element or may have an intervening element present at the same time; when an element is referred to as "connected to" another element, it may be directly connected to the other element or may have an intervening element present at the same time. In addition, the term "connected" as used herein may include wireless connections; the word "and / or" as used includes any unit and all combinations of one or more of the associated listed items.

[0056] Any process or method description in the flowchart or otherwise herein can be understood as: representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0057] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0058] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0059] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0060] The storage media mentioned above can be read-only memory, disk, or optical disk, etc.

[0061] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0062] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A laser range finder device, characterized by, The application relates to a laser ranging system. The laser ranging system comprises: a laser pulse emission module for generating a ranging laser signal; a transmitting optical system for collimating and shaping the laser signal to obtain a first laser signal; a receiving optical system for collecting a second laser signal reflected from a target and converging the second laser signal onto a light-sensitive surface of a single-photon detection module; a single-photon detection module integrated on a single chip and comprising: a single-photon detector array for responding to incident single photons and generating detection signals; a time measurement unit array corresponding to the single-photon detector array for measuring time differences of the detection signals relative to a trigger signal to obtain time of flight of photons; and a histogram processing unit for statistically accumulating time of flight of a plurality of photons output by the time measurement unit array inside the single chip to generate a time of flight histogram; 2. The laser ranging device of claim 1, wherein the single-photon detection module is connected to the laser pulse emission module; and a processing module electrically connected to the single-photon detection module, configured to:

3. The laser ranging device of claim 1, wherein obtain the time of flight histogram from the single-photon detection module; 4. The laser ranging device of claim 1, wherein perform peak detection on the time of flight histogram to determine a signal peak corresponding to a target distance; and 5. The laser ranging device of claim 1, wherein, calculate the target distance based on position information of the signal peak.

6. The laser ranging device of claim 1, wherein, The laser pulse emission module comprises: a high-performance two-way in-phase Schmitt trigger buffer and an enhanced nitrogenized field effect transistor and peripheral circuit.

7. The laser ranging device of claim 1, wherein, The single-photon detector array is a single-photon avalanche diode array. The time measurement unit array is a time-to-digital converter array or comprises a time-to-amplitude converter array and an analog-to-digital converter. The single-photon detection module communicates with the processing module through a serial peripheral interface; and after generating the time of flight histogram, the single-photon detection module notifies the processing module to read data through an interrupt signal. The application further comprises: a narrow-band optical filter arranged in front of the light-sensitive surface of the single-photon detector array, the center wavelength of the narrow-band optical filter matching a laser wavelength.

8. The laser ranging device of claim 7, wherein, The processing module is configured to: perform peak detection on the time of flight histogram, the peak detection comprising:

9. The laser ranging device according to claim 7 or 8, characterized in that performing smoothing processing on the time of flight histogram to suppress noise peaks; and searching for a peak point with a value greater than a preset detection threshold in the histogram after the smoothing processing as a candidate signal peak. The processing module is further configured to: estimate a background noise baseline of the time of flight histogram before performing the smoothing processing on the time of flight histogram, and determine the preset detection threshold according to the background noise baseline. The processing module is further configured to: for the candidate signal peak, perform Gaussian function fitting on data in a neighborhood of the candidate signal peak in original time of flight histogram data to determine a center position of a fitted Gaussian curve as an accurate position of the signal peak.

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