Distance measuring method, distance measuring device and distance measuring equipment

Abstract

The invention provides a distance measurement method, a distance measurement device and distance measurement equipment, and relates to the technical field of distance measurement, and the distance measurement method comprises the steps: obtaining current echo data; determining a waveform state corresponding to the echo data; adjusting the transmitting power of the laser transmitting tube according to the waveform state until the waveform state is in an unsaturated state; and under the condition that the waveform state is in an unsaturated state, determining the current test distance. According to the invention, the current echo data is acquired, then the waveform state corresponding to the echo data is determined, the transmitting power of the laser transmitting tube is adjusted according to the waveform state until the waveform state is in the unsaturated state, and finally the current test distance is determined when the waveform state is in the unsaturated state. By improving the saturated waveform state and adjusting the emission voltage of the laser emission tube, the laser emission power is adjusted, the purpose of adjusting the received laser power is achieved, the saturation state of echo signals is changed, and therefore the stability and precision of distance measurement are remarkably improved.

Description

Technical Field

[0001] This application relates to the technical field of ranging, and particularly to a ranging method, a ranging device, and a ranging equipment. Background Art

[0002] When laser ranging faces target objects with materials of different surface reflection characteristics, due to variables such as the reflectivity, reflection azimuth angle, roughness, and color of the materials of different surface reflection characteristics, the optical power received by the pulsed laser receiving system is severely affected, which seriously affects the ranging accuracy. Summary of the Invention

[0003] The main purpose of the present invention is to provide a ranging method, aiming to suppress the saturation of echo signals and improve the ranging accuracy.

[0004] To achieve the above purpose, the present invention provides a ranging method, which is applied to a ranging equipment. The ranging equipment includes a laser emitting tube. The ranging method includes: Obtain current echo data; Determine the waveform state corresponding to the echo data; Adjust the emission power of the laser emitting tube according to the waveform state until the waveform state is in an unsaturated state; When the waveform state is in an unsaturated state, determine the currently measured distance.

[0005] Optionally, the adjusting the emission power of the laser emitting tube according to the waveform state until the waveform state is in an unsaturated state includes: If the waveform state is a saturated state, reduce the driving voltage of the laser emitting tube according to a preset step size, and the preset step size is dynamically adjusted according to the target reflectivity or environmental optical characteristics; Re-obtain echo data to determine the waveform state of the new echo data until the waveform state is in an unsaturated state.

[0006] Optionally, the if the waveform state is a saturated state, reducing the driving voltage of the laser emitting tube according to a preset step size includes: If the waveform state is a saturated state, calculate the voltage difference between the current driving voltage and the theoretical saturation voltage corresponding to the target reflectivity or environmental optical characteristics; Gradually reduce the driving voltage of the laser emitting tube according to the voltage difference and the preset step size; The re-obtaining echo data to determine the waveform state of the new echo data until the waveform state is in an unsaturated state includes: After adjusting the driving voltage of the laser emitting tube, re-obtain echo data to determine the waveform state of the new echo data; If the waveform state is in the saturation state, the driving voltage of the laser emitting tube is reduced again.

[0007] Optionally, adjusting the emission power of the laser emitting tube according to the waveform state until the waveform state is in the unsaturated state includes: If the waveform state is the saturation state, calculate the voltage difference between the current driving voltage and the theoretical saturation voltage corresponding to the target reflectivity or the environmental optical characteristics; Adjust the driving voltage of the laser emitting tube to within the range of the theoretical saturation voltage according to the voltage difference, so that the waveform state is in the unsaturated state; Re-obtain the echo data to determine the waveform state of the new echo data until the waveform state is in the unsaturated state.

[0008] Optionally, when the waveform state is in the unsaturated state, determining the currently measured distance includes: When the waveform state is in the unsaturated state, record the time difference between the laser pulse emission and the echo signal reception through a timer; Calculate the currently measured distance corresponding to the time difference according to the light speed distance formula.

[0009] Optionally, determining the waveform state corresponding to the echo data includes: Detect the distribution of the echo data at the upper limit of the voltage range; If there are multiple echo data at the upper limit position of the voltage range, determine that the waveform state is the saturation state; If the voltages of the echo data do not reach the upper limit position of the voltage range, determine that the waveform state is the unsaturated state.

[0010] Optionally, the ranging method further includes: Obtain the distance prediction value of the position of the target to be measured; Set the reference voltage according to the distance prediction value, and the reference voltage is the critical saturation voltage set according to the maximum reflectivity target; Set the reference voltage to the upper limit of the voltage range.

[0011] Optionally, the ranging device includes an avalanche diode; The obtaining of the current echo data includes: Receive the laser pulse reflected by the target through the avalanche diode to generate a corresponding echo electrical signal; After amplifying the echo electrical signal, perform digital conversion to generate the current echo data.

[0012] In addition, to achieve the above object, the present invention further provides a ranging device, which includes: a memory, a processor, and a ranging program stored on the memory and executable on the processor, and the ranging program is configured to implement the ranging method as described above.

[0013] In addition, to achieve the above object, the present invention further provides a ranging device, including the above-mentioned ranging device.

[0014] In the embodiment of the present invention, by acquiring the current echo data, determining the waveform state corresponding to the echo data, and adjusting the emission power of the laser emitter according to the waveform state until the waveform state is in an unsaturated state, and finally, when the waveform state is in an unsaturated state, determining the currently measured distance. By improving the saturated waveform state and adjusting the emission voltage of the laser emitter to adjust the emission power, the purpose of adjusting the received laser power is achieved, and the saturation state of the echo signal is changed, thereby significantly improving the stability and accuracy of ranging. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the present application and used together with the specification to explain the principles of the present application.

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 Schematic flowchart of the ranging method according to an embodiment of the present invention; Figure 2 Schematic flowchart of the ranging method according to another embodiment of the present invention; Figure 3 Schematic flowchart of the ranging method according to still another embodiment of the present invention; Figure 4 Schematic flowchart of the ranging method according to yet another embodiment of the present invention; Figure 5 Schematic flowchart of the ranging method according to still another embodiment of the present invention; Figure 6 Schematic flowchart of the ranging method according to another embodiment of the present invention; Figure 7 Schematic flowchart of the ranging method according to still another embodiment of the present invention; Figure 8 Schematic flowchart of the ranging method according to yet another embodiment of the present invention; Figure 9 The structural block diagram of the ranging device of the present invention; Figure 10 The waveform state diagram of the echo signal of the ranging method of the present invention.

[0018] The realization of the object of the present invention, functional features and advantages will be further described with reference to the accompanying drawings in combination with embodiments. Specific embodiments

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Well-known modules, units and their connections, links, communications or operations therebetween are not shown or not described in detail. And the described features, architectures or functions can be combined in any way in one or more embodiments. Those skilled in the art should understand that the following various embodiments are only for illustration, rather than for limiting the protection scope of the present invention. It can also be easily understood that the modules, units or processing methods in the embodiments described herein and shown in the drawings can be combined and designed in various different configurations. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

[0020] For the definitions of various nouns or methods referred to in the following embodiments, unless it is logically impossible to hold, the nouns or methods generally refer to the broad concepts that can be implemented on the premise of the content disclosed in the embodiments. Under such an understanding, various specific lower-level specific definitions of the nouns or methods should be regarded as the content of the present invention, and should not be narrowly understood or prejudicially interpreted on the grounds that the specific definition is not disclosed in the specification. Similarly, on the premise that it can be logically realized, the order of each step in the method is flexible and changeable, and the specific lower-level specific definitions in the broad concepts of various nouns or methods all belong to the protection scope of the present invention.

[0021] Since the pulse laser ranging in the prior art uses a laser to emit laser pulses to the target to be measured during use, and a detector samples the emitted laser pulses to trigger the time measurement system of the rangefinder to start timing. After the optical pulse reaches the target, it is diffusely reflected and returns to the detector of the laser rangefinder, generating a signal to stop timing, and then calculating the target distance according to the speed of light.

[0022] Since different target objects have their own material surface reflection characteristics, variables such as the reflectivity, reflection azimuth angle, roughness, and color of their materials will, to a certain extent, affect the optical power received by the pulsed laser receiving system, causing the echo signals to exhibit different sizes. The echo signals of high-reflectivity or short-distance targets will be in a saturated state, thus affecting the ranging accuracy of the measurement range.

[0023] The main solution of the embodiment of the present application is: by obtaining the current echo data, then determining the waveform state corresponding to the echo data, and adjusting the emission power of the laser emitter according to the waveform state until the waveform state is in an unsaturated state. Finally, when the waveform state is in an unsaturated state, the currently measured distance is determined.

[0024] In this embodiment, for the convenience of description, the ranging device is used as the execution subject for the following elaboration.

[0025] The present application provides a solution. By improving the saturated waveform state, adjusting the emission voltage of the laser emitter to adjust the laser emission power, achieving the purpose of adjusting the received laser power, and changing the saturated state of the echo signal, thereby significantly improving the stability and accuracy of ranging.

[0026] For this reason, the present invention proposes a ranging method. It can be understood that a ranging device for storing and executing the following method is provided in the ranging equipment. The ranging device can be implemented by a main controller, such as an MCU (Microcontroller Unit), a DSP (Digital Signal Process), an FPGA (Field Programmable Gate Array), an SOC (System On Chip), etc.

[0027] In the prior art, when the laser ranging equipment faces target objects with different reflection characteristic materials, due to the reflectivity difference, there is a risk of saturation in the echo signal. When the surface of the target object is a high-reflectivity material, the echo signal exceeds the upper limit of the detection ranging equipment range, causing waveform distortion and data distortion, and finally resulting in deviation of the ranging result. The traditional method uses a fixed emission power mode and cannot effectively cope with the dynamic signal changes in a complex reflection environment.

[0028] To solve the above problems, through research, it is found that the saturation of the echo signal is the key factor restricting the ranging accuracy. By analyzing the correlation between the echo waveform characteristics and the transmission power, a dynamic closed-loop adjustment mechanism is proposed. This mechanism determines whether the system is in the saturation working area by real-time monitoring of the waveform state, and then triggers the power adjustment action. During the power adjustment process, the signal intensity and noise level need to be taken into account to eliminate the saturation phenomenon while maintaining the effective echo.

[0029] It should also be understood that, with reference to Figure 9 , the ranging method of this embodiment is applied to a ranging device, and the ranging device includes a laser emitting tube.

[0030] Based on the above content, with reference to Figure 1 and Figure 10 , in an embodiment of the present invention, the ranging method includes steps S100 - S400, where: S100. Obtain the current echo data; S200. Determine the waveform state corresponding to the echo data; S300. Adjust the emission power of the laser emitting tube according to the waveform state until the waveform state is in the unsaturated state; S400. When the waveform state is in the unsaturated state, determine the currently measured distance.

[0031] Among them, the waveform state refers to the distribution characteristics of the echo signal within the voltage range, and it can be judged by detecting whether the signal peak continuously stays at the upper limit of the range. For example, when three consecutive sampling values reach the maximum value of the analog-to-digital converter, it is determined as the saturation state. Among them, the emission power adjustment refers to controlling the light intensity output by changing the driving voltage of the laser tube, and it can be achieved by gradually reducing the voltage or directly jumping to the theoretical value, and the theoretical value is pre-calculated according to the target reflectivity model.

[0032] Among them, the device continuously collects the digitized echo signal generated by the reflected laser, and identifies whether there is saturation by statistically analyzing the peak distribution. When continuous over-range signals are detected, the control unit immediately reduces the driving voltage to reduce the laser emission intensity so that the echo amplitude returns to the effective detection range. After adjustment, the signal is re-collected for state verification, and the loop iteration is performed until a stable unsaturated waveform is obtained. Finally, based on the time-of-flight method, the round-trip time difference of the optical pulse is calculated, and the accurate distance value is obtained by conversion.

[0033] Among them, as Figure 10 shown, when both signal 1 and signal 2 are in the saturated waveform state, it is necessary to adjust the emission power of the laser emitting tube until the waveform reaches the unsaturated state of signal 3.

[0034] Among them, as Figure 9As shown, the emission optical power is adjusted by adjusting the voltage of the emission high-voltage module. After the laser reaches the measured target, it is reflected back and reaches the light-receiving circuit, where it is received by an avalanche diode and converted into electrical energy. Then, after being amplified by the amplifier circuit, it is converted into a digital signal by a high-speed ADC, collected by the FPGA and transmitted to the MCU. The MCU analyzes and detects the received echo signal and calculates the distance. The FPGA also controls the laser emission and time counting functions. Before a measurement, the target is predicted first, the reflectivity of the target is predicted, and the emission voltage is changed to adjust the laser emission power to find the emission voltage that is most suitable for the current target reflection, and then the adjusted voltage is used for measurement. By adjusting the voltage of the laser tube, the laser emission power is changed, the saturation of the echo signal is suppressed, and the discrimination accuracy of the echo signal is improved.

[0035] Compared with the prior art, the traditional solution requires manual intervention to adjust device parameters when encountering a high-reflection target, while the ranging method of this embodiment realizes full-automatic closed-loop control. The prior art uses a fixed threshold to judge saturation, which is prone to misjudgment. This embodiment improves the reliability of state recognition through continuous sampling point analysis. The conventional power adjustment method has the risk of overshoot oscillation. This embodiment combines a theoretical model with a step-by-step adjustment strategy to ensure rapid convergence.

[0036] Through the above technical means, this embodiment realizes adaptive ranging for targets with different reflection characteristics, and eliminates the measurement error caused by signal saturation. The system can autonomously maintain the echo signal in the optimal detection range, ensure the ranging accuracy in a complex optical environment, and at the same time avoid the cumbersome operation of manual parameter adjustment.

[0037] In this embodiment, by obtaining the current echo data, then determining the waveform state corresponding to the echo data, and adjusting the emission power of the laser emitter according to the waveform state until the waveform state is in an unsaturated state. Finally, when the waveform state is in an unsaturated state, the distance of the current test is determined. By improving the saturated waveform state, the emission voltage of the laser emitter is adjusted to adjust the laser emission power, so as to adjust the received laser power, change the saturation state of the echo signal, and thus significantly improve the stability and accuracy of ranging.

[0038] Optionally, referring to Figure 2 , another embodiment of the present invention provides a ranging method. Based on the above Figure 1 shown embodiment, adjusting the emission power of the laser emitter according to the waveform state until the waveform state is in an unsaturated state includes steps S310-S320, where: S310. If the waveform state is a saturated state, reduce the drive voltage of the laser emitter according to a preset step size, and the preset step size is dynamically adjusted according to the target reflectivity or environmental optical characteristics; S320. Re-obtain the echo data to determine the waveform state of the new echo data until the waveform state is in an unsaturated state.

[0039] Among them, the preset step size refers to the change amplitude of the driving voltage adjusted each time. It can be implemented by using a dynamic step size algorithm calculated based on the difference between the target reflectivity and the ambient light intensity. For example, step size parameters are generated according to the reflectivity difference and the change amplitude of the ambient light intensity. The target reflectivity refers to the ratio parameter of the laser reflected by the surface of the object to be measured, which can be calculated by inverting through a pre-calibrated reflectivity database or by measuring the echo signal intensity in real time. The ambient optical characteristics refer to the background light intensity and spectral distribution in the current environment, and the ambient light data can be collected by a photoelectric sensor and converted into an interference intensity evaluation value. The dynamic adjustment means optimizing the step size according to the reflectivity and ambient light parameters fed back in real time. For example, when the reflectivity is higher than the threshold or the ambient light interference increases, the voltage adjustment step size is automatically increased.

[0040] Among them, when it is detected that the waveform corresponding to the echo data is in a saturated state, the ranging device calculates the preset step size based on the real-time parameters of the target reflectivity and the ambient optical characteristics. For example, a smaller step size is used when the reflectivity is higher or the ambient light is weaker. Subsequently, the driving voltage is gradually decreased according to this step size. After each adjustment, the laser emission is triggered again and new echo data is collected. By repeatedly executing the voltage adjustment and waveform state detection until the echo waveform gets out of the saturated state. During this process, the adjustment amplitude of the driving voltage is dynamically adapted to the target object characteristics and environmental conditions, avoiding problems such as excessive adjustment times or insufficient adjustment caused by a fixed step size.

[0041] Compared with the prior art, the traditional scheme usually adjusts the driving voltage with a fixed step size, which is likely to cause a sharp increase in the number of adjustments or fail to effectively eliminate saturation in scenarios with large reflectivity differences. This embodiment significantly improves the voltage adjustment efficiency by introducing a dynamic coupling mechanism of reflectivity and ambient light parameters, making the step size adapt to the target object characteristics and ambient interference intensity. At the same time, since signal attenuation caused by excessive adjustment is avoided, the echo waveform can be more reliably controlled within the non-saturated range.

[0042] By the above technical means, this embodiment solves the problems of low ranging efficiency and error accumulation caused by a fixed voltage adjustment step size in the prior art. Through the dynamic step size mechanism, waveform saturation can still be quickly eliminated in the case of strong reflection targets or complex optical environments, ensuring that the ranging system can stably obtain effective echo signals in various scenarios. In addition, this scheme avoids the energy loss caused by multiple ineffective adjustments in the traditional method and extends the service life of the laser emission tube.

[0043] Optionally, referring to Figure 3 , another embodiment of the present invention provides a ranging method based on the above Figure 2In the illustrated embodiment, if the waveform state is the saturation state, the driving voltage of the laser emitting tube is decreased according to a preset step size, including steps S311 - S312, where: S311. If the waveform state is the saturation state, calculate the voltage difference between the current driving voltage and the theoretical saturation voltage corresponding to the target reflectivity or the environmental optical characteristics; S312. Decrease the driving voltage of the laser emitting tube step by step according to the voltage difference and the preset step size.

[0044] The re - acquisition of the echo data to determine the waveform state of the new echo data until the waveform state is in the non - saturation state includes steps S321 - S322, where: S321. After adjusting the driving voltage of the laser emitting tube, re - acquire the echo data to determine the waveform state of the new echo data; S322. If the waveform state is in the saturation state, re - decrease the driving voltage of the laser emitting tube.

[0045] Among them, the current driving voltage refers to the voltage value actually output by the laser emitting tube in the saturation state, which can be realized by real - time acquisition through a voltage sensor and is used to characterize the actual state of the current laser emission power. The theoretical saturation voltage refers to the critical voltage value calculated according to the target reflectivity or the environmental optical characteristics, which can be realized by feedback from a reflectivity database or an optical sensor and is used to reflect the ideal voltage range required to avoid echo signal saturation in the current environment. The voltage difference refers to the numerical difference between the current driving voltage and the theoretical saturation voltage, which can be realized by subtraction operation or table - look - up comparison and is used to quantify the amplitude of the driving voltage that needs to be adjusted. The preset step size refers to the gradient change amount of the driving voltage adjusted each time, which can be realized by a dynamic step - size algorithm or an adaptive step size based on the difference ratio and is used to balance the adjustment speed and stability. Step - by - step decrease refers to the operation mode of gradually reducing the driving voltage in stages, which can be realized by multi - cycle iterative control or piece - wise linear regulation to avoid signal distortion caused by voltage mutation.

[0046] Among them, when the waveform state of the echo data is determined to be saturated, first calculate the theoretical saturation voltage according to the target reflectivity or the environmental optical characteristics. For example, on the metal surface with a higher reflectivity, the theoretical saturation voltage may be lower than the theoretical value of ordinary materials. Subsequently, obtain the voltage difference by comparing the current driving voltage with the theoretical value, and determine the adjustment amplitude each time according to the preset step size. For example, if the voltage difference is 5V and the preset step size is 1V, the driving voltage will be decreased step by step in five times. After each adjustment, re - collect the echo data and detect the waveform state. If saturation still exists, continue to decrease the driving voltage. This process continues until the waveform state enters the non - saturation region, at which time the voltage adjustment is stopped and the distance calculation module is started.

[0047] Compared with the prior art, traditional methods usually adopt a fixed step size or a single large adjustment of the driving voltage, which is prone to insufficient or excessive voltage adjustment due to sudden changes in environmental reflectivity, thereby causing multiple ineffective cycles or signal distortion. In this embodiment, by dynamically calculating the theoretical saturation voltage and implementing hierarchical adjustment based on the difference, it is possible to more accurately match the environmental characteristics, reduce the number of adjustments while avoiding signal saturation, and improve the response speed of the ranging device.

[0048] Through the above technical means, this embodiment effectively solves the problem of echo signal saturation caused by reflectivity differences. Through the dynamic hierarchical voltage adjustment mechanism, it ensures that the echo signals of targets with different materials are always within the resolvable range, thereby improving the ranging accuracy and the environmental adaptability of the device.

[0049] Optionally, referring to Figure 4 , another embodiment of the present invention provides a ranging method. Based on the above Figure 1 shown embodiment, adjust the emission power of the laser emitter according to the waveform state until the waveform state is in an unsaturated state, including steps S330 - S350, where: S330. If the waveform state is a saturated state, calculate the voltage difference between the current driving voltage and the theoretical saturation voltage corresponding to the target reflectivity or environmental optical characteristics; S340. Adjust the driving voltage of the laser emitter to within the theoretical saturation voltage range according to the voltage difference, so that the waveform state is in an unsaturated state; S350. Re - obtain the echo data to determine the waveform state of the new echo data until the waveform state is in an unsaturated state.

[0050] Among them, the theoretical saturation voltage refers to the critical voltage threshold calculated through a physical model based on the target reflectivity or environmental optical parameters, which can be realized through a preset reflectivity - voltage mapping table or an environmental light compensation algorithm. Its role is to provide a scientific basis for voltage adjustment to avoid blind adjustment. The voltage difference refers to the quantitative deviation between the current driving voltage and the theoretical saturation voltage, which can be realized through the difference operation of the voltage signal collected by the analog - to - digital converter. Its role is to determine the adjustment amplitude to quickly eliminate the saturation phenomenon. The theoretical saturation voltage range refers to the driving voltage range that allows the echo signal to be in the linear response interval, which can be realized by experimentally calibrating the upper and lower voltage limits corresponding to targets with different reflectivities. Its role is to ensure that the dynamic range of the signal - processing ranging device adapts to the current measurement conditions.

[0051] Among them, when it is detected that the echo data is continuously distributed at the upper limit of the voltage range, by comparing the current driving voltage with the voltage reference value output by the theoretical model, the voltage difference to be adjusted is calculated. Subsequently, the driving voltage of the laser emitting tube is adjusted to the theoretical saturation voltage range at one time. For example, when it is detected that the driving voltage is higher than the theoretical value, it is directly set to the theoretical value. Immediately after the voltage adjustment, a new round of echo signal acquisition is started, and the adjustment effect is confirmed by verifying whether the newly obtained waveform has left the saturation region. If the saturation phenomenon still exists, the calculation and adjustment process is repeated until the unsaturated condition is met.

[0052] Compared with the prior art, the existing methods usually adopt a step-by-step voltage regulation method with a fixed step size and require multiple iterations to reach the target voltage. In this embodiment, the adjustment amplitude is directly determined by calculating through the theoretical model, eliminating the time loss of repeated trial and error in the traditional method. For example, the traditional method needs to gradually reduce the voltage and repeatedly detect, while this embodiment predicts the required voltage value through the physical model, achieving the effect that the ideal working range can be reached with a single adjustment.

[0053] By the above technical means, this embodiment effectively solves the problem of response delay caused by low voltage regulation efficiency of traditional ranging devices, and significantly shortens the elimination time of the saturation state. Especially when facing a target with a high reflectivity, this solution can quickly adjust the ranging device to the optimal working state, avoiding the extension of the measurement period caused by multiple voltage regulations, thereby ensuring the real-time and continuous nature of the ranging process.

[0054] Optionally, referring to Figure 5 , another embodiment of the present invention provides a ranging method. Based on the above Figure 1 -shown embodiment, when the waveform state is in an unsaturated state, the currently measured distance is determined, including steps S410 - S420, where: S410. When the waveform state is in an unsaturated state, record the time difference between the emission of the laser pulse and the reception of the echo signal through a timer; S420. Calculate the currently measured distance corresponding to the time difference according to the light speed distance formula.

[0055] Among them, the timer recording the time difference means using a hardware module with a high-precision timing function. It can use a clock counter chip (such as TDC) in an embedded ranging device, or be implemented through a timer in the FPGA module of the ranging device, and its timing accuracy can reach the nanosecond level. The light speed distance formula calculation means based on the product relationship between the time difference and the light speed. It can be performed by a preset floating-point operation module in the processor, and the calculation formula is that the distance is equal to the light speed multiplied by the time difference and then divided by two.

[0056] Among them, when the ranging device determines that the waveform of the echo data is in an unsaturated state, it immediately triggers a timer to start recording the laser pulse emission time. After the avalanche diode receives the reflected laser signal, the timer stops running and outputs the time difference. The processor inputs the time difference into a preset operation module and performs real-time calculations in combination with the speed of light constant, and finally outputs an accurate distance value. The entire process ensures seamless connection between time measurement and distance calculation through the coordinated cooperation of hardware triggering and software calculation.

[0057] Compared with the prior art, traditional ranging devices still directly calculate the distance value when the signal is saturated, resulting in deviation of the time difference data due to signal distortion. The ranging method of this embodiment performs distance calculation after confirming that the waveform is unsaturated, avoiding timing errors caused by signal overload. At the same time, by combining high-precision timing and real-time operation, the reliability of the ranging data is significantly improved.

[0058] Through the above technical means, this embodiment effectively solves the problem of reduced ranging accuracy caused by echo signal saturation, and can stably output accurate distance values in scenarios with different reflectivity targets. This solution realizes the improvement of the robustness of the ranging device in complex environments by optimizing the coordinated mechanism of the timing and calculation links.

[0059] Optionally, referring to Figure 6 , another embodiment of the present invention provides a ranging method. Based on the above Figure 1 -shown embodiment, determine the waveform state corresponding to the echo data, including steps S210-S230, where: S210. Detect the distribution of the echo data at the upper limit of the voltage range; S220. If there are multiple echo data at the upper limit position of the voltage range, determine that the waveform state is a saturated state; S230. If the voltages of the echo data do not reach the upper limit position of the voltage range, determine that the waveform state is an unsaturated state.

[0060] Among them, the upper limit of the voltage range refers to the maximum voltage value that the analog-to-digital converter can measure. The maximum value of 255 of an 8-bit analog-to-digital converter can be used as the range upper limit. Whether signal saturation occurs is judged by comparing the digital value of the echo signal with this upper limit value. Among them, that multiple consecutive echo data reach the range upper limit means that the values of three or more adjacent sampling points are all equal to the maximum value, which can be realized by a sliding window algorithm or a point-by-point comparison algorithm. This can effectively distinguish between short-term noise interference and true signal saturation phenomena and avoid misjudgment. Among them, the determination logic of the saturated state is to detect that multiple consecutive points reach the upper limit, rather than a single peak exceeding the threshold, thereby reducing the probability of false triggering caused by instantaneous noise or interference and improving the accuracy of state judgment.

[0061] Among them, after the echo signal output by the analog-to-digital converter is acquired in digital form, first, the signal waveform is scanned point by point to detect whether the values of three consecutive sampling points reach 255. If so, it is determined that the received signal has exceeded the upper limit of the range of the analog-to-digital converter. At this time, the signal is in a saturated state and cannot accurately reflect the true amplitude change of the echo signal. At this time, it is necessary to trigger the transmit power adjustment mechanism, such as reducing the driving voltage of the laser emitter, to avoid continuous saturation of the signal in subsequent measurements. If the values of all sampling points are lower than 255, it is determined that the signal is not saturated and can directly enter the time difference calculation stage. For example, in a laser ranging scenario, when the target reflectivity is high, the intensity of the echo signal may exceed the range of the analog-to-digital converter, resulting in truncation of the signal top. At this time, multiple consecutive sampling points show a fixed maximum value, and this feature is used to reliably identify the saturated state.

[0062] Compared with the prior art, traditional signal saturation detection usually only judges whether a single sampling point reaches the upper limit, but transient interference or noise may cause a single sampling point to reach the maximum value, resulting in misjudgment. By detecting the saturation of multiple consecutive sampling points, accidental interference can be effectively filtered, and the robustness of state judgment can be improved. For example, when using the threshold comparison method in the prior art, incorrect adjustment may be triggered by single-pulse noise, while in this embodiment, the misjudgment probability is reduced by at least one order of magnitude through the continuous point detection mechanism.

[0063] Through the above technical means, this embodiment can accurately distinguish true signal saturation from instantaneous noise interference, ensure distance calculation in the unsaturated state of the signal, and thus improve the credibility of the ranging result. Especially in the scenarios of high-reflectivity targets or short-distance measurements, this scheme can effectively avoid waveform distortion caused by signal truncation, providing a reliable data basis for subsequent power adjustment and time difference calculation.

[0064] Optionally, referring to Figure 7 , another embodiment of the present invention provides a ranging method. Based on the above Figure 6 -shown embodiment, the ranging method further includes steps S500-S700, where: S500. Obtain the distance prediction value of the position of the target to be measured; S600. Set the reference voltage according to the distance prediction value, and the reference voltage is the critical saturation voltage set according to the target with the maximum reflectivity; S700. Set the reference voltage as the upper limit of the voltage range.

[0065] As Figure 9 shown, the setting range of the reference voltage is the highest driving voltage of the target within 20 meters, and the initial voltage loading is completed through the cooperation of the MCU and the FPGA.

[0066] Among them, the predicted distance value refers to the expected distance range between the target object and the ranging device estimated through pre-scanning or historical data. It can be achieved by pre-detecting using the time-of-flight method or estimating by selecting the target area based on the image recognition algorithm, and is used to guide the initial setting of the reference voltage. The reference voltage refers to the initial driving voltage set based on the critical saturation voltage value corresponding to the maximum reflectivity of the target, which can be obtained by looking up the preset reflectivity-voltage correspondence table or dynamically generated based on the target material database, and is used to avoid directly entering the saturation state during the acquisition of the echo signal. The cooperation between the MCU and the FPGA means that the microcontroller unit and the field-programmable gate array achieve voltage parameter loading through bus communication. The SPI protocol can be used to transmit voltage control instructions and trigger the FPGA to perform digital-to-analog conversion, ensuring that the voltage regulation process has low latency characteristics.

[0067] Among them, during the startup phase, the ranging device first obtains the position information of the target object through pre-scanning, and estimates the target distance range based on the pre-scanning result. For example, for a short-range target within 20 meters, the highest driving voltage that may cause signal saturation is calculated according to the preset reflectivity model as the reference value. This reference value sends a control instruction from the MCU to the FPGA, and the FPGA controls the digital-to-analog conversion module to output the corresponding driving voltage, so that the laser emitting tube starts to work at the critical saturation voltage. This cooperation mechanism enables the voltage loading process to be initialized within milliseconds without manual intervention, effectively shortening the device response time.

[0068] Compared with the prior art, traditional ranging devices usually start with a fixed driving voltage, and are prone to multiple voltage adjustments due to signal saturation when facing high-reflectivity targets and / or short-range targets. In this embodiment, the reference voltage is dynamically set by predicting the target distance, and the initial voltage is directly adjusted to be close to the theoretical saturation critical point. For example, for high-reflectivity targets such as white walls, the reference voltage can be automatically reduced to 85% of the critical value. This active pre-adjustment method reduces the number of voltage calibration times from an average of 5 - 7 times to 1 - 2 times, significantly improving the ranging efficiency.

[0069] Through the above technical means, this embodiment effectively solves the problem of signal saturation caused by high-reflectivity targets and short-range targets. By combining distance prediction with critical voltage presetting, the ranging device can obtain an effective echo signal during the first sampling. The dynamic loading mechanism of the reference voltage avoids the delay caused by repeated trial-and-error adjustments in the traditional method, and can still maintain stable ranging accuracy and response speed in a complex reflection environment.

[0070] It should be noted that the ranging device in this embodiment includes an avalanche diode.

[0071] Based on the above circuit structure, referring to Figure 8 , another embodiment of the present invention provides a ranging method, based on the above Figure 1In the illustrated embodiment, the obtaining of the current echo data includes steps S110 - S120, where: S110. Receive the laser pulse reflected by the target through an avalanche diode to generate a corresponding echo electrical signal; S120. After amplifying the echo electrical signal, perform digital conversion to generate the current echo data.

[0072] Among them, an avalanche diode refers to a semiconductor device that uses the avalanche breakdown effect to convert an optical signal into an electrical signal. It can be manufactured using silicon - based or germanium - based materials and enhances the output current through a multiplication effect under weak optical signals. The high sensitivity of this device helps to capture effective echo signals in low - reflectivity or long - distance scenarios. The echo electrical signal refers to the analog electrical signal output by the avalanche diode, which can be converted from current to voltage through a transimpedance amplifier to form a voltage waveform corresponding to the light intensity. Amplification refers to the gain processing of the electrical signal, which can be achieved by a multi - stage operational amplifier circuit. By adjusting the amplification factor, the signal is adapted to the input range of the subsequent analog - to - digital converter. Digital conversion refers to the conversion of an analog signal into a digital signal, which can be achieved by an analog - to - digital converter. For example, it is completed by combining a sample - and - hold circuit and a successive - approximation - type converter, enabling the echo signal to be analyzed by a digital processor.

[0073] Among them, during the ranging process, after the avalanche diode receives the laser pulse reflected by the target, a weak current signal proportional to the light intensity is generated. This current signal is converted into a voltage signal through a transimpedance amplifier and then adjusted to the effective input range of the analog - to - digital converter through a multi - stage amplification circuit. The analog - to - digital converter quantifies the analog voltage at a fixed sampling rate to generate digital echo data containing time and amplitude information. Due to the high - gain characteristic of the avalanche diode, even when the target reflectivity is low or the ambient light interference is strong, the echo signal can still be effectively extracted, avoiding ranging failures caused by signal loss. The digitized data can be directly used for waveform state analysis. For example, by detecting the number of consecutive high - level signals in the digital signal, it can be determined whether it is in a saturated state, providing a basis for subsequent power adjustment.

[0074] Compared with the prior art, traditional ranging devices usually use ordinary photodiodes as receiving elements, which have low sensitivity and rely on complex external compensation circuits in weak - light scenarios, resulting in a decrease in the response speed of the ranging device. In this embodiment, an avalanche diode is used as the core receiving device, and the signal strength is directly enhanced through the internal carrier multiplication effect, avoiding the noise and delay introduced by external compensation circuits. In addition, the position of the analog - to - digital converter in the signal chain is optimized, and digitalization can be completed immediately after signal amplification, preventing interference to the analog signal during long - distance transmission and ensuring the integrity of the echo data.

[0075] Through the above technical means, the present embodiment can stably obtain echo signals with high signal-to-noise ratio in target scenarios of different reflectivity materials, effectively solving the problems of signal saturation or attenuation caused by differences in target surface characteristics. The cooperative work of the avalanche diode and digital conversion enables the ranging device to accurately capture the arrival time of laser pulses in a complex optical environment, thereby improving the reliability of distance calculation.

[0076] The present invention also provides a ranging device, which includes: a memory, a processor, and a ranging program stored on the memory and executable on the processor. The ranging program is configured to implement the ranging method as described above.

[0077] It should be noted that since the ranging device of the present invention is based on the above ranging method, the embodiments of the ranging device of the present invention include all the technical solutions of all the embodiments of the above ranging method, and the achieved technical effects are also exactly the same, so they will not be elaborated here.

[0078] The present invention also provides a ranging equipment, which includes the ranging device as described in the above embodiment.

[0079] It should be noted that since the ranging equipment of the present invention is based on the above ranging device, the embodiments of the ranging equipment of the present invention include all the technical solutions of all the embodiments of the above ranging device, and the achieved technical effects are also exactly the same, so they will not be elaborated here.

[0080] It should be noted that in this article, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or system. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article or system including that element.

[0081] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0082] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-described example methods can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art can be embodied in the form of a software product. This computer software product is stored in a storage medium as described above (such as ROM / RAM, magnetic disk, optical disc), and includes several instructions for causing a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in various embodiments of the present invention.

[0083] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A ranging method, applied to a ranging device, the ranging device comprising a laser emitting tube, characterized in that, The ranging method includes: Obtaining current echo data; Determining the waveform state corresponding to the echo data; Adjusting the emission power of the laser emitter according to the waveform state until the waveform state is in an unsaturated state; Determining the currently measured distance when the waveform state is in an unsaturated state.

2. The ranging method according to claim 1, wherein The adjusting the emission power of the laser emitter according to the waveform state until the waveform state is in an unsaturated state includes: If the waveform state is a saturated state, reducing the drive voltage of the laser emitter by a preset step length, and the preset step length is dynamically adjusted according to the target reflectivity or environmental optical characteristics; Re-obtaining echo data to determine the waveform state of the new echo data until the waveform state is in an unsaturated state.

3. The ranging method according to claim 2, characterized in that The if the waveform state is a saturated state, reducing the drive voltage of the laser emitter by a preset step length includes: If the waveform state is a saturated state, calculating the voltage difference between the current drive voltage and the theoretical saturation voltage corresponding to the target reflectivity or environmental optical characteristics; Gradually reducing the drive voltage of the laser emitter according to the voltage difference and the preset step length; The re-obtaining echo data to determine the waveform state of the new echo data until the waveform state is in an unsaturated state includes: After adjusting the drive voltage of the laser emitter, re-obtaining echo data to determine the waveform state of the new echo data; If the waveform state is in a saturated state, reducing the drive voltage of the laser emitter again.

4. The ranging method according to claim 1, wherein The adjusting the emission power of the laser emitter according to the waveform state until the waveform state is in an unsaturated state includes: If the waveform state is a saturated state, calculating the voltage difference between the current drive voltage and the theoretical saturation voltage corresponding to the target reflectivity or environmental optical characteristics; Adjusting the drive voltage of the laser emitter to within the theoretical saturation voltage range according to the voltage difference to make the waveform state in an unsaturated state; Re-obtaining echo data to determine the waveform state of the new echo data until the waveform state is in an unsaturated state.

5. The ranging method according to claim 1, characterized in that The determining the currently measured distance when the waveform state is in an unsaturated state includes: When the waveform state is in an unsaturated state, recording the time difference between the laser pulse emission and the echo signal reception through a timer; Calculating the currently measured distance corresponding to the time difference according to the light speed distance formula.

6. The ranging method according to claim 1, wherein, The determining the waveform state corresponding to the echo data includes: Detecting the distribution of the echo data at the upper limit of the voltage range; If there are multiple echo data at the upper limit position of the voltage range, determining that the waveform state is a saturated state; If the voltages of the echo data do not reach the upper limit position of the voltage range, determining that the waveform state is an unsaturated state.

7. The ranging method according to claim 6, wherein, The ranging method further includes: Obtaining a distance prediction value of the point to be measured of the target; Setting a reference voltage according to the distance prediction value, and the reference voltage is a critical saturation voltage set according to the maximum reflectivity target; Setting the reference voltage to the upper limit of the voltage range.

8. The ranging method according to claim 1, characterized in that, The ranging device includes an avalanche diode; The obtaining of the current echo data includes: Receiving, by the avalanche diode, a laser pulse reflected by a target to generate a corresponding echo electrical signal; After amplifying the echo electrical signal, performing digital conversion to generate the current echo data.

9. A ranging device, characterized in that, The ranging apparatus includes: a memory, a processor, and a ranging program stored on the memory and executable on the processor, the ranging program being configured to implement the ranging method according to any one of claims 1 to 8.

10. A ranging device, characterized in that, It includes the ranging apparatus according to claim 9.

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