Laser ranging method, system, terminal device and storage medium
By acquiring clock pulses of different phases and detecting the level sequence, the delay time of laser ranging is calculated, which solves the problem of limited ranging accuracy in the existing technology and achieves more accurate laser ranging.
Patent Information
- Application Number
- CN202111396293.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-11-23
- Publication Date
- 2025-09-12
- Estimated Expiration
- 2041-11-23
AI Technical Summary
In existing laser ranging technology, due to the period limitation of the reference clock signal, the accuracy of the ranging distance is limited, there is a large error, and accurate distance measurement is impossible.
By acquiring n clock pulses with different phases, the phase difference between two adjacent clock pulses is 180°/n, the time interval Td and delay time Tp are calculated, and the FPGA module is used to detect the level sequence of the rising and falling edges of the clock pulses, estimate the first and second delay times, and then calculate the ranging distance.
It achieves more accurate ranging, reduces ranging errors, and improves the accuracy of laser ranging.
Smart Images
Figure CN114137561B_ABST
Abstract
Description
Technical Field
[0001] The present disclosure generally relates to the field of laser ranging technology, and in particular to a laser ranging method, system, terminal device and storage medium. Background Art
[0002] Laser ranging usually emits a laser beam to the object to be measured and generates a reference signal T at the same time. base , after the laser is reflected by the object to be measured, an echo signal T can be obtained echo By obtaining the time interval T between the reference signal and the echo signal, the ranging distance can be calculated: R max =T*c / 2;
[0003] However, in the prior art, the time interval T between the reference signal and the echo signal is usually calculated based on the reference clock signal clk of the master clock. Since the reference clock signal is triggered by the rising edge, the time interval T calculated based on the reference clock signal clk is actually the time interval between the rising edges of the reference clock signal, that is, T d =m*T clk , m∈N + ; m is the integer value of the counter, T clk is the period of the reference clock signal clk;
[0004] The above formula shows that the approximate time T d The minimum resolution is determined by the master clock, and the measurement accuracy is greatly affected by the clock period T clk Limitation; that is, there is a delay error between the rising edge of the reference signal and the rising edge of the reference clock signal, and there is a delay error between the rising edge of the echo signal and the rising edge of the reference clock signal, which leads to the final ranging distance R max The error is large and the true distance cannot be accurately obtained. Summary of the Invention
[0005] In view of the above-mentioned defects or deficiencies in the prior art, it is desired to provide a laser ranging method, system, terminal device and storage medium that can solve the above-mentioned technical problems.
[0006] In a first aspect, the present application provides a laser ranging method, comprising the following steps:
[0007] Emitting laser light to the object to be measured and generating a reference signal; the laser light is reflected by the object to be measured to form an echo signal;
[0008] receiving the echo signal;
[0009] Get n clock pulses of different phases. The phase difference between two adjacent clock pulses is n≥3;
[0010] Calculate the time interval Td , T d =m*T clk , m∈N + ; Among them, T clk is the period of the reference clock signal, and m is the number of periods of the reference clock signal between the reference signal and the echo signal;
[0011] According to n clock pulses, the first delay time T is estimated s , the first delay time T s is the time difference between the rising edge of the reference signal and the rising edge of the reference clock signal;
[0012] According to n clock pulses, the second delay time T is estimated p , the second delay time T p is the time difference between the rising edge of the echo signal and the rising edge of the reference clock signal;
[0013] According to formula (1), calculate the ranging distance R max ;
[0014]
[0015] According to the technical solution provided in the embodiment of the present application, the first delay time T is estimated. s The specific method is:
[0016] sequentially detecting the levels of the reference signal at rising and falling edges of n clock pulses to generate a first level sequence; wherein the first level sequence has n first level values, and at least one of the n first level values has a high level value;
[0017] According to formula (2), estimate the first delay time T s :
[0018]
[0019] Wherein, j1 is the number of low levels in the first level sequence.
[0020] According to the technical solution provided in the embodiment of the present application, the second delay time T is estimated. p The specific method is:
[0021] sequentially detecting the levels of the echo signals at rising and falling edges of n clock pulses to generate a second level sequence; wherein the second level sequence has n second level values, and at least one of the n second level values has a high level value;
[0022] According to formula (3), estimate the second delay time T p :
[0023]
[0024] Wherein, j2 is the number of low levels in the second level sequence.
[0025] In a second aspect, the present application provides a laser ranging system, comprising:
[0026] A laser output module (1) is used to emit laser light toward an object to be measured; the laser light is reflected by the object to be measured to form an echo signal;
[0027] A signal receiving module, configured to receive the echo signal;
[0028] Master clock, used to output period T clk The reference clock signal;
[0029] The PLL module is configured to control n clock modules to output clock pulses of different phases. The phase difference between two adjacent clock pulses is
[0030] FPGA module, configured for:
[0031] Controlling the laser output module (1) to emit laser light and generate a reference signal;
[0032] receiving the echo signal;
[0033] Calculate the time interval T d , T d =m*T clk , m∈N + ; Wherein, m is the number of cycles of the reference clock signal between the reference signal and the echo signal;
[0034] According to n clock pulses, the first delay time T is estimated s , the first delay time T s is the time difference between the rising edge of the reference signal and the rising edge of the reference clock signal;
[0035] According to n clock pulses, the second delay time T is estimated p , the second delay time T p is the time difference between the rising edge of the echo signal and the rising edge of the reference clock signal;
[0036] According to formula (1), calculate the ranging distance R max ;
[0037]
[0038] According to the technical solution provided in the embodiment of the present application, the FPGA module is further specifically configured to:
[0039] sequentially detecting the levels of the reference signal at rising and falling edges of n clock pulses to generate a first level sequence; wherein the first level sequence has n first level values, and at least one of the n first level values has a high level value;
[0040] According to formula (2), estimate the first delay time T s :
[0041]
[0042] Wherein, j1 is the number of low levels in the first level sequence.
[0043] According to the technical solution provided in the embodiment of the present application, the FPGA module is further specifically configured to:
[0044] sequentially detecting the levels of the echo signals at rising and falling edges of n clock pulses to generate a second level sequence; wherein the second level sequence has n second level values, and at least one of the n second level values has a high level value;
[0045] According to formula (3), estimate the second delay time T p :
[0046]
[0047] Wherein, j2 is the number of low levels in the second level sequence.
[0048] In a third aspect, the present application provides a terminal device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the laser ranging method as described above when executing the computer program.
[0049] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program, which, when executed by a processor, implements the steps of the laser ranging method as described above.
[0050] The beneficial effect of the present application is that: by obtaining n clock pulses of different phases and the phase difference between two adjacent clock pulses is 180° / n; calculating the time interval T d , T d =m*T clk , m∈N + ; Estimate the second delay time T p ; Calculate the ranging distance R max :Rmax =c*(T d +T s -T p ) / 2; so that n clock pulse rising and falling edges can be a clock cycle T clk The average interval is divided into 2n time periods, that is, through time interpolation, the time interval T from the rising edge of the reference signal to the rising edge of the reference clock signal is s , the time interval T from the rising edge of the echo signal to the rising edge of the reference clock signal p These two tiny times smaller than the main control clock cycle are used to quantize a smaller range, thereby making the ranging distance R max More accurate, reduces ranging errors, and realizes accurate laser ranging. BRIEF DESCRIPTION OF THE DRAWINGS
[0051] Other features, objects and advantages of the present application will become more apparent upon reading the detailed description of non-limiting embodiments made with reference to the following drawings:
[0052] Figure 1 A flow chart of a laser ranging method provided in this application;
[0053] Figure 2 for Figure 1 The reference signal T shown base With the echo signal T echo Waveform diagram;
[0054] Figure 3 for Figure 1 The schematic diagram of detecting the first level value of the reference signal at the rising and falling edges of four clock pulses is shown;
[0055] Figure 4 for Figure 1 The schematic diagram of detecting the second level value of the echo signal at the rising and falling edges of four clock pulses is shown;
[0056] Figure 5 A schematic diagram of a laser ranging system provided for this application;
[0057] Figure 6 A schematic diagram of a terminal device provided for this application;
[0058] Numbers in the figure:
[0059] 1. Laser output module; 2. Signal receiving module; 3. Master clock; 4. PLL module; 5. FPGA module. DETAILED DESCRIPTION
[0060] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the relevant invention and are not intended to limit the invention. It should also be noted that, for ease of description, only portions relevant to the invention are shown in the accompanying drawings.
[0061] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.
[0062] Example 1
[0063] Please refer to Figure 1 The laser ranging method provided in this application includes the following steps:
[0064] S100: emit laser to the object to be measured and generate reference signal T base The laser is reflected by the object to be measured to form an echo signal T echo ;
[0065] Specifically, in this embodiment, the frequency of the laser is 5kHz and the pulse width is 48ns;
[0066] S200: Receive the echo signal T echo ;
[0067] S300: Obtain n clock pulses with different phases. The phase difference between two adjacent clock pulses is
[0068] Specifically, n clock pulses of different phases can be obtained by multiplying and phase shifting the clock through the PLL module; preferably, n ≥ 3; to facilitate the explanation of the technical principles of the present application, this embodiment takes n = 4 as an example, specifically: an external input clock of 125 MHz is input to the input end of the PLL, and the clock is phase shifted four times to obtain four clock pulses of different phases, and the phase difference between two adjacent clock pulses is 45°; respectively:
[0069] The first clock pulse (CLK[1]) has a phase of 0°;
[0070] The second clock pulse (CLK[2]) has a phase of 45°;
[0071] The third clock pulse (CLK[3]) has a phase of 90°;
[0072] The fourth clock pulse (CLK[4]) has a phase of 135°;
[0073] S400: Calculating time interval T d , T d =m*Tclk , m∈N + ; Among them, T clk is the period of the reference clock signal, m is the reference signal T base With the echo signal T echo The number of cycles of the reference clock signal between :
[0074] Specifically, the reference clock signal is output by the master clock, and the reference clock signal clk is triggered by the rising edge, so the time interval T calculated according to the reference clock signal is d is an integer multiple of the reference clock signal period; in the prior art, the time interval T is directly d Using the ranging time as the ranging distance to calculate the ranging distance will result in errors in the ranging distance.
[0075] Specifically, the reference clock signal period and the clock pulse period are both T clk ;
[0076] Specifically, m can be obtained by a counter, for example, m=4, T clk =8ns;
[0077] S500: Estimate a first delay time T based on the n clock pulses s ,like Figure 2 As shown, the first delay time T s is the reference signal T base The time difference between the rising edge and the rising edge of the reference clock signal clk;
[0078] It needs to be further explained that each clock pulse has a rising edge and a falling edge. Since each clock pulse has a different phase, the phase difference between two adjacent clock pulses is 180° / n; therefore, n clock pulse rising edges and falling edges can be used to calculate a clock cycle T. clk The average time period is divided into 2n periods, and the reference signal T is judged by base The first delay time T can be estimated approximately by the time period where the rising edge is located. s ;
[0079] S600: Estimate the second delay time T according to the n clock pulses p ,like Figure 2 As shown, the second delay time T p is the echo signal T echo The time difference between the rising edge and the rising edge of the reference clock signal; Similarly, by judging the echo signal T echo The second delay time T can be estimated approximately by the time period where the rising edge is located. p ;
[0080] S700: Calculate the ranging distance R according to formula (1) max ;
[0081]
[0082] Where c is the speed of light.
[0083] Working principle: By obtaining n clock pulses with different phases and the phase difference between two adjacent clock pulses is 180° / n; calculate the time interval T d , T d =m*T clk , m∈N + According to the n clock pulses, estimate the first delay time T s According to the n clock pulses, estimate the second delay time T p ; Calculate the ranging distance R max :R max =c*(T d +T s -T p ) / 2; Therefore, n clock pulse rising and falling edges can make a clock cycle T clk The reference signal T is evenly divided into 2n time periods, that is, through time interpolation, base The time interval T from the rising edge to the rising edge of the reference clock signal s , echo signal T echo The time interval T from the rising edge to the rising edge of the reference clock signal clk p These two tiny times smaller than the main control clock cycle are used to quantize a smaller range, thereby making the ranging distance R max More accurate, reduces ranging errors, and realizes accurate laser ranging.
[0084] In a preferred embodiment, the first delay time T is estimated s The specific method is:
[0085] Sequentially detect the reference signal T at the rising edge and falling edge of n clock pulses base generating a first level sequence; wherein the first level sequence comprises n first level values, and at least one of the n first level values comprises a high level value;
[0086] According to formula (2), estimate the first delay time T s :
[0087]
[0088] Wherein, j1 is the number of low levels in the first level sequence.
[0089] To illustrate the principle of this application, take a laser ranging as an example:
[0090] In this embodiment, n=4, the reference signal T base As shown in FIG3, the reference signal T at the rising edge and falling edge of the four clock pulses base The levels are shown in Table 1:
[0091]
[0092] Table-1
[0093] As can be seen from Table 1, the first level sequence is 0111111; the eight first level values in the first level sequence are, from left to right, the reference signal level values corresponding to the rising edges of four clock pulses and the reference signal level values corresponding to the falling edges of four clock pulses;
[0094] It can be seen from the above first level sequence that the number of low levels is 1; the first delay time T s for:
[0095]
[0096] It should be further explained that at least one of the n first level values has a high level value; when the first level sequence is 00000000, it means that the reference signal T is not detected or generated. base , the rising edge and falling edge levels should continue to be detected until at least one of the n first level values has a high level value.
[0097] In a preferred embodiment, the second delay time T is estimated p The specific method is:
[0098] sequentially detecting the levels of the echo signals at rising and falling edges of n clock pulses to generate a second level sequence; wherein the second level sequence has n second level values, and at least one of the n second level values has a high level value;
[0099] According to formula (3), estimate the second delay time T p :
[0100]
[0101] Wherein, j2 is the number of low levels in the second level sequence.
[0102] To illustrate the principle of this application, take a laser ranging as an example:
[0103] In this embodiment, n=4, the echo signal T echo like Figure 4As shown, the echo signal T at the rising edge and falling edge of the four clock pulses echo The levels are shown in Table 1:
[0104]
[0105] Table-2
[0106] As shown in Table 2, the second level sequence is 00111111; the eight second level values in the second level sequence are, from left to right, the echo signal level values corresponding to the rising edges of four clock pulses and the echo signal level values corresponding to the falling edges of four clock pulses;
[0107] From the above second level sequence, we can see that the number of low levels is 2; the second delay time T p for:
[0108]
[0109] Through the first delay time T s And the second delay time T p The distance R can be calculated max :
[0110] Example 2
[0111] This embodiment provides a laser ranging system, such as Figure 5 Shown, including:
[0112] The laser output module 1 is used to emit laser light to the object to be measured; the laser light is reflected by the object to be measured to form an echo signal;
[0113] A signal receiving module 2, configured to receive the echo signal;
[0114] Master clock 3, used to output a period of T clk The reference clock signal;
[0115] The PLL module 4 is configured to control n clock modules to output clock pulses of different phases. The phase difference between two adjacent clock pulses is
[0116] FPGA module 5, configured to:
[0117] Controlling the laser output module 1 to emit laser light and generate a reference signal;
[0118] receiving the echo signal;
[0119] Calculate the time interval T d , T d =m*T clk, m∈N + ; Wherein, m is the number of cycles of the reference clock signal between the reference signal and the echo signal;
[0120] According to n clock pulses, the first delay time T is estimated s , the first delay time T s is the time difference between the rising edge of the reference signal and the rising edge of the reference clock signal;
[0121] According to n clock pulses, the second delay time T is estimated p , the second delay time T p is the time difference between the rising edge of the echo signal and the rising edge of the reference clock signal;
[0122] According to formula (1), calculate the ranging distance R max ;
[0123]
[0124] Specifically, the input end of the laser output module 1 is connected to the output end of the FPGA module 5; the output end of the signal receiving module 2 is connected to the input end of the FPGA module 5;
[0125] Working principle: FPGA module 5 controls the laser output module 1 to emit a laser beam to the object to be measured and simultaneously form a reference signal T base The laser is reflected by the object to be measured to form an echo signal and is emitted to the signal receiving module 2. The signal receiving module 2 sends the received echo signal to the FPGA module 5; the PLL module 4 controls n clock modules to output clock pulses of different phases; the FPGA module 5 receives n clock pulses of different phases; calculates the time interval T d According to the n clock pulses, estimate the first delay time T s According to the n clock pulses, estimate the second delay time T p ; Calculate the ranging distance R max :R max =c*(T d +T s -T p ) / 2; so that n clock pulse rising and falling edges can be a clock cycle T clk The time interval T from the rising edge of the reference signal to the rising edge of the reference clock signal is evenly divided into 2n time periods, that is, through time interpolation, the time interval T from the rising edge of the reference signal to the rising edge of the reference clock signal is s , the time interval T from the rising edge of the echo signal to the rising edge of the reference clock signal p These two tiny times smaller than the main control clock cycle are used to quantize a smaller range, thereby making the ranging distance R maxMore accurate, reduces ranging errors, and realizes accurate laser ranging.
[0126] In a preferred embodiment, the FPGA module 5 is further configured to:
[0127] sequentially detecting the levels of the reference signal at rising and falling edges of n clock pulses to generate a first level sequence; wherein the first level sequence has n first level values, and at least one of the n first level values has a high level value;
[0128] According to formula (2), estimate the first delay time T s :
[0129]
[0130] Wherein, j1 is the number of low levels in the first level sequence.
[0131] In a preferred embodiment, the FPGA module 5 is further configured to:
[0132] sequentially detecting the levels of the echo signals at rising and falling edges of n clock pulses to generate a second level sequence; wherein the second level sequence has n second level values, and at least one of the n second level values has a high level value;
[0133] According to formula (3), estimate the second delay time T p :
[0134]
[0135] Wherein, j2 is the number of low levels in the second level sequence.
[0136] Example 3
[0137] This embodiment provides a terminal device 800, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the laser ranging method described above are implemented.
[0138] like Figure 6As shown, the terminal device 800 includes a central processing unit (CPU) 801, which can perform various appropriate actions and processes according to the program stored in the read-only memory (ROM) 802 or the program loaded from the storage part into the random access memory (RAM) 803. Various programs and data required for system operation are also stored in the random access memory (RAM) 803. The central processing unit (CPU) 801, the read-only memory (ROM) 802 and the random access memory (RAM) 803 are connected to each other via a bus 804. An input / output (I / O) interface 805 is also connected to the bus 804.
[0139] The following components are connected to the input / output (I / O) interface 805: an input section 806 including a keyboard, a mouse, and the like; an output section 807 including devices such as a cathode ray tube (CRT), a liquid crystal display (LCD), and a speaker; a storage section 808 including a hard disk; and a communication section 809 including a network interface card such as a LAN card or a modem. The communication section 809 performs communication processing via a network such as the Internet. A drive is also connected to the input / output (I / O) interface 805 as needed. A removable medium 811, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, and the like, is installed in the drive 810 as needed, so that a computer program read therefrom can be installed into the storage section 808 as needed.
[0140] In particular, according to an embodiment of the present invention, the above reference process Figure 1 The described process can be implemented as a computer software program. For example, embodiment 1 of the present invention includes a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network via a communication portion and / or installed from a removable medium. When the computer program is executed by the central processing unit (CPU) 801, the above-mentioned functions defined in the system of the present application are performed.
[0141] Example 4
[0142] This embodiment provides a computer-readable storage medium having a computer program. When the computer program is executed by a processor, the steps of the laser ranging method described above are implemented.
[0143] It should be noted that the computer-readable medium described in the present invention can be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media can include, but are not limited to, an electrical connection having one or more conductors, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present invention, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In the present invention, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. This propagated data signal can take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transport a program for use by or in conjunction with an instruction execution system, apparatus, or device. Program code embodied on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wireline, optical fiber cable, RF, or any suitable combination thereof.
[0144] The flowcharts and block diagrams in the accompanying drawings illustrate the possible implementation architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present invention. In this regard, each box in the flowchart or block diagram can represent a module, program segment, or a part of code, and the above-mentioned module, program segment, or a part of code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, and the combination of boxes in the block diagram or flowchart, can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.
[0145] The units described in the embodiments of the present invention may be implemented via software or hardware, and may also be located within a processor. The names of these units, in some cases, do not limit the units themselves. The units or modules described may also be located within a processor. For example, a processor may be described as including a laser output module, a signal receiving module, a master control clock, a PLL module, and an FPGA module.
[0146] The names of these units or modules do not, under certain circumstances, constitute limitations on the units or modules themselves;
[0147] As another aspect, the present application also provides a computer-readable medium, which may be included in the electronic device described in the above embodiment; or may exist independently without being assembled into the electronic device. The above computer-readable medium carries one or more programs, and when the above one or more programs are executed by an electronic device, the electronic device implements the laser ranging method in the above embodiment.
[0148] For example, the electronic device may implement Figure 1 As shown in:
[0149] S100: emitting laser light toward an object to be measured and generating a reference signal; the laser light is reflected by the object to be measured to form an echo signal;
[0150] S200: receiving the echo signal;
[0151] S300: Obtain n clock pulses with different phases. The phase difference between two adjacent clock pulses is
[0152] S400: Calculating time interval T d , T d =m*T clk , m∈N + ; Wherein, m is the number of cycles of the reference clock signal between the reference signal and the echo signal;
[0153] S500: Estimate a first delay time T based on the n clock pulses s , the first delay time T s is the time difference between the rising edge of the reference signal and the rising edge of the reference clock signal;
[0154] S600: Estimate the second delay time T according to the n clock pulses p , the second delay time T p is the time difference between the rising edge of the echo signal and the rising edge of the reference clock signal;
[0155] S700: Calculate the ranging distance R according to formula (1) max ;
[0156]
[0157] It should be noted that although several modules or units of the device for action execution are mentioned in the detailed description above, this division is not mandatory. In fact, according to the embodiments of the present disclosure, the features and functions of two or more modules or units described above can be concretized in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided into multiple modules or units to be concretized.
[0158] Furthermore, although the steps of the method of the present disclosure are described in a particular order in the accompanying drawings, this does not require or imply that the steps must be performed in this particular order, or that all steps shown must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps.
[0159] Through the description of the above embodiments, those skilled in the art can easily understand that the example embodiments described herein can be implemented by software, or by combining software with necessary hardware.
[0160] The above description is merely a preferred embodiment of the present application and an illustration of the technical principles employed. Those skilled in the art should understand that the scope of the invention herein is not limited to the technical solutions formed by the specific combination of the above-mentioned technical features, but also encompasses other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the inventive concept. For example, a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features having similar functions disclosed in this application.
Claims
1. A laser ranging method, characterized in that: The following steps are involved: Emitting laser light to the object to be measured and generating a reference signal; the laser light is reflected by the object to be measured to form an echo signal; receiving the echo signal; Get n clock pulses of different phases. The phase difference between two adjacent clock pulses is , n≥3; Calculating time intervals Td , Td = m * Tclk , m ∈ N +; where Tclk is the period of the reference clock signal, m is the number of cycles of the reference clock signal between the reference signal and the echo signal; Estimate the first delay time based on n clock pulses Ts , the first delay time Ts is the time difference between the rising edge of the reference signal and the rising edge of the reference clock signal; Estimate the second delay time based on n clock pulses Tp , the second delay time Tp is the time difference between the rising edge of the echo signal and the rising edge of the reference clock signal; According to formula (1), calculate the ranging distance R max; (one).
2. The laser ranging method according to claim 1, characterized in that: The method for estimating the first delay time Ts is specifically as follows: sequentially detecting the levels of the reference signal at rising and falling edges of n clock pulses to generate a first level sequence; wherein the first level sequence has n first level values, and at least one of the n first level values has a high level value; According to formula (2), the first delay time Ts is estimated: (two) in, j 1 is the number of low levels in the first level sequence.
3. The laser ranging method according to claim 1, wherein: The method for estimating the second delay time Tp is specifically as follows: sequentially detecting the levels of the echo signals at rising and falling edges of n clock pulses to generate a second level sequence; wherein the second level sequence has n second level values, and at least one of the n second level values has a high level value; According to formula (3), the second delay time Tp is estimated: (three) in, j 2 is the number of low levels in the second level sequence.
4. A laser ranging system, characterized in that: include: A laser output module (1) is used to emit laser light toward an object to be measured; the laser light is reflected by the object to be measured to form an echo signal; A signal receiving module (2) is used to receive and output the echo signal; A master clock (3) is used to output a reference clock signal with a period of Tclk; The PLL module (4) is configured to control n clock modules to output clock pulses of different phases, and the phase difference between two adjacent clock pulses is , n≥3; FPGA module (5), configured to: Controlling the laser output module (1) to emit laser light and generate a reference signal; receiving the echo signal; Calculating time intervals Td , Td = m * Tclk , m ∈ N +; in, m is the number of cycles of the reference clock signal between the reference signal and the echo signal; Estimate the first delay time based on n clock pulses Ts , the first delay time Ts is the time difference between the rising edge of the reference signal and the rising edge of the reference clock signal; Estimate the second delay time based on n clock pulses Tp , the second delay time Tp is the time difference between the rising edge of the echo signal and the rising edge of the reference clock signal; According to formula (1), calculate the ranging distance R max; (one).
5. The laser ranging system according to claim 4, characterized in that: The FPGA module (5) is further specifically configured to: sequentially detecting the levels of the reference signal at rising and falling edges of n clock pulses to generate a first level sequence; wherein the first level sequence has n first level values, and at least one of the n first level values has a high level value; According to formula (2), estimate the first delay time Ts : (two) in, j 1 is the number of low levels in the first level sequence.
6. The laser ranging system according to claim 4, characterized in that: The FPGA module (5) is further specifically configured to: sequentially detecting the levels of the echo signals at rising and falling edges of n clock pulses to generate a second level sequence; wherein the second level sequence has n second level values, and at least one of the n second level values has a high level value; According to formula (3), estimate the second delay time Tp : (three) in, j 2 is the number of low levels in the second level sequence.
7. A terminal device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the laser ranging method according to any one of claims 1 to 3 are implemented.
8. A computer-readable storage medium having a computer program, characterized in that: When the computer program is executed by a processor, the steps of the laser ranging method according to any one of claims 1 to 3 are implemented.
Citation Information
Patent Citations
Multichannel photon counting laser radar receiver possessing real-time door control function
CN105911536A
distance measuring device
DE4133196A1