Laser frequency modulation parameter calibration method and device, electronic equipment and storage medium

Abstract

The invention is suitable for the technical field of radar, and provides a laser frequency modulation parameter calibration method and device, electronic equipment and a storage medium. The calibration method comprises the following steps: firstly, acquiring an output voltage range of a DAC (Digital-to-Analog Converter), determining an optional modulation bandwidth of a laser according to the output voltage range, determining a DAC code value matrix corresponding to the optional modulation bandwidth according to the resolution ratio of the DAC because the bandwidths are different and the corresponding DAC code value ranges are different, and secondly, calibrating the optional modulation bandwidth according to the DAC code value matrix. The method comprises the steps of obtaining a modulation frequency residual error under a corresponding selectable modulation bandwidth through solving, determining the modulation linearity corresponding to each selectable modulation bandwidth according to the selectable modulation bandwidth and the modulation frequency residual error under the selectable modulation bandwidth, and finally determining the optimal modulation linearity. And determining the target modulation bandwidth and the target code value range so as to calibrate the laser. According to the scheme, the laser can provide an accurate and reliable measurement result by calibrating the frequency modulation parameter of the laser.

Description

Technical Field

[0001] This application belongs to the field of radar technology, and particularly relates to a calibration method, device, electronic device and storage medium for laser modulation parameters. Background Art

[0002] A lidar is a sensor that obtains the distance to a target by measuring the time of a laser beam reflected by the target. Frequency Modulated Continuous Wave (FMCW) lidar uses frequency modulation technology to accurately measure distance and speed by changing the frequency of the laser signal. FMCM lidar is widely used in fields such as autonomous driving, long-distance ranging, and high-precision map construction.

[0003] In related technologies, an FMCW lidar calculates the target distance by measuring the echo time of the laser signal. During the frequency modulation process, high-precision distance measurement can be achieved by measuring the phase difference of the frequency change. And since the frequency of the laser echo is affected by the target speed, the target speed can be measured by analyzing the speed information of the frequency change. When an FMCW lidar calculates the target distance by measuring the echo time of the laser signal, the accuracy of the frequency modulation parameters directly affects the precise relationship between the laser signal frequency and the distance.

[0004] Therefore, there is an urgent need to provide a calibration method for laser modulation parameters to ensure that the lidar system can provide accurate and reliable measurement results in various application scenarios by calibrating the laser modulation parameters, meeting the requirements of practical applications. Summary of the Invention

[0005] Embodiments of this application provide a calibration method, device, electronic device and storage medium for laser modulation parameters, which can ensure that the lidar system can provide accurate and reliable measurement results in various application scenarios by calibrating the laser modulation parameters, meeting the requirements of practical applications.

[0006] In a first aspect, embodiments of this application provide a calibration method for laser modulation parameters. The laser includes a digital-to-analog conversion module DAC. The calibration method includes:

[0007] Obtain the output voltage range of the digital-to-analog conversion module, and determine the optional modulation bandwidth of the laser according to the output voltage range;

[0008] For each of the optional modulation bandwidths, determine the DAC code value matrix corresponding to each optional modulation bandwidth according to the resolution of the digital-to-analog conversion module;

[0009] Determine the modulation frequency residual corresponding to the optional modulation bandwidth according to the DAC code value matrix.

[0010] Determine the modulation linearity corresponding to each of the optional modulation bandwidths according to the optional modulation bandwidth and the modulation frequency residual at the optional modulation bandwidth.

[0011] Determine the optional modulation bandwidth corresponding to the optimal modulation linearity among all the modulation linearities as the target modulation bandwidth, and determine the DAC code value range corresponding to the target modulation bandwidth as the target code value range to calibrate the laser.

[0012] Optionally, in a possible implementation, obtain the output voltage range of the digital-to-analog conversion module, and determine the optional modulation bandwidth of the laser according to the output voltage range.

[0013] For each of the optional modulation bandwidths, determine the DAC code value matrix corresponding to each of the optional modulation bandwidths according to the resolution of the digital-to-analog conversion module.

[0014] Determine the modulation frequency residual at the corresponding optional modulation bandwidth according to the DAC code value matrix.

[0015] Determine the modulation linearity corresponding to each of the optional modulation bandwidths according to the optional modulation bandwidth and the modulation frequency residual at the optional modulation bandwidth.

[0016] Determine the optional modulation bandwidth corresponding to the optimal modulation linearity among all the modulation linearities as the target modulation bandwidth, and determine the DAC code value range corresponding to the target modulation bandwidth as the target code value range to calibrate the laser.

[0017] Optionally, in a possible implementation, the determining the optional modulation bandwidth of the laser according to the output voltage range includes:

[0018] Determine the maximum modulation bandwidth of the laser according to the maximum value, minimum value of the output voltage and the electro-optic modulation parameters of the laser.

[0019] Determine the range of the optional modulation bandwidth according to the maximum modulation bandwidth and a preset minimum modulation bandwidth.

[0020] Determine the optional modulation bandwidth of the laser according to the range of the optional modulation bandwidth and the number of preset optional modulation bandwidths.

[0021] Optionally, in a possible implementation, the determining the DAC code value matrix corresponding to each of the optional modulation bandwidths according to the resolution of the digital-to-analog conversion module includes:

[0022] Determine the number of input code values of the digital-to-analog conversion module according to the resolution of the digital-to-analog conversion module;

[0023] Determine the number of code value combinations corresponding to the optional modulation bandwidth according to the optional modulation bandwidth and the number of input code values of the digital-to-analog conversion module;

[0024] Determine the number of columns of the DAC code value matrix according to the number of optional modulation bandwidths;

[0025] Determine the number of rows of the DAC code value matrix according to the number of code value combinations corresponding to the optional modulation bandwidth;

[0026] Determine the DAC code value matrix corresponding to each optional modulation bandwidth according to the DAC code value range corresponding to each optional modulation bandwidth and the number of columns and rows of the corresponding DAC code value matrix.

[0027] Optionally, in a possible implementation manner, the determining the modulation frequency residual under the corresponding optional modulation bandwidth according to the DAC code value matrix includes:

[0028] Obtain a DAC gain error curve, where the abscissa of the gain error curve is the DAC code value and the ordinate is the phase voltage error;

[0029] Determine the phase voltage error corresponding to each DAC code value in the DAC code value matrix of the optional modulation bandwidth according to the DAC gain error curve;

[0030] Convert the phase voltage error corresponding to each DAC code value into a corresponding frequency error;

[0031] Perform data processing on all frequency errors to obtain the modulation frequency residual under the corresponding optional modulation bandwidth.

[0032] Optionally, in a possible implementation manner, the determining the modulation linearity corresponding to each optional modulation bandwidth according to the optional modulation bandwidth and the modulation frequency residual under the optional modulation bandwidth includes:

[0033] Determine the root mean square of the modulation frequency residual according to the modulation frequency residual under the optional modulation bandwidth;

[0034] Determine the modulation linearity corresponding to the optional modulation bandwidth according to the root mean square of the modulation frequency residual under the optional modulation bandwidth and the optional modulation bandwidth, and obtain the modulation linearity corresponding to each optional modulation bandwidth.

[0035] Optionally, in a possible implementation, determining the optional modulation bandwidth corresponding to the optimal modulation linearity among all the modulation linearities as the target modulation bandwidth, and determining the range of DAC code values corresponding to the target modulation bandwidth as the target code value range includes:

[0036] Determining the optional modulation bandwidth corresponding to the maximum modulation linearity among all the modulation linearities as the target modulation bandwidth;

[0037] Determining the range of DAC code values corresponding to the target modulation bandwidth as the target code value range.

[0038] Optionally, in a possible implementation, it further includes:

[0039] Controlling the laser to operate according to the target modulation bandwidth and the target code value range to complete the calibration of the laser frequency modulation parameters.

[0040] In a second aspect, an embodiment of the present application provides a calibration device for laser frequency modulation parameters. The laser includes a digital-to-analog conversion module DAC. The calibration device includes:

[0041] An acquisition module, configured to acquire the output voltage range of the digital-to-analog conversion module, and determine the optional modulation bandwidth of the laser according to the output voltage range;

[0042] A matrix determination module, configured to determine, for each of the optional modulation bandwidths, a DAC code value matrix corresponding to each of the optional modulation bandwidths according to the resolution of the digital-to-analog conversion module;

[0043] A residual determination module, configured to determine the modulation frequency residual under the corresponding optional modulation bandwidth according to the DAC code value matrix;

[0044] A linearity determination module, configured to determine the modulation linearity corresponding to each of the optional modulation bandwidths according to the optional modulation bandwidth and the modulation frequency residual under the optional modulation bandwidth;

[0045] A calibration module, configured to determine the optional modulation bandwidth corresponding to the optimal modulation linearity among all the modulation linearities as the target modulation bandwidth, and determine the range of DAC code values corresponding to the target modulation bandwidth as the target code value range to calibrate the laser.

[0046] Optionally, in a possible implementation, the above acquisition module may specifically include:

[0047] A maximum bandwidth determination unit, configured to determine the maximum modulation bandwidth of the laser according to the maximum value, minimum value of the output voltage, and the electro-optic modulation parameters of the laser;

[0048] A range determination unit for determining a range of the optional modulation bandwidth according to the maximum modulation bandwidth and a preset minimum modulation bandwidth;

[0049] An optional bandwidth determination unit for determining an optional modulation bandwidth of the laser according to the range of the optional modulation bandwidth and a preset number of the optional modulation bandwidths.

[0050] Optionally, in a possible implementation manner, the matrix determination module may specifically include:

[0051] An input quantity determination unit for determining a quantity of input code values of the digital-to-analog conversion module according to a resolution of the digital-to-analog conversion module;

[0052] A combination quantity determination unit for determining a quantity of code value combinations corresponding to the optional modulation bandwidth according to the optional modulation bandwidth and the quantity of input code values of the digital-to-analog conversion module;

[0053] A column number determination unit for determining a column number of the DAC code value matrix according to the number of the optional modulation bandwidths;

[0054] A row number determination unit for determining a row number of the DAC code value matrix according to the quantity of code value combinations corresponding to the optional modulation bandwidth;

[0055] A code value matrix determination unit for determining a DAC code value matrix corresponding to each optional modulation bandwidth according to a DAC code value range corresponding to each optional modulation bandwidth and the column number and the row number of the corresponding DAC code value matrix.

[0056] Optionally, in a possible implementation manner, the residual determination module may specifically include:

[0057] A curve acquisition unit for acquiring a DAC gain error curve, where an abscissa of the gain error curve is a DAC code value and an ordinate thereof is a phase voltage error;

[0058] A voltage error determination unit for determining a phase voltage error corresponding to each DAC code value in the DAC code value matrix of the optional modulation bandwidth according to the DAC gain error curve;

[0059] An error conversion unit for converting the phase voltage error corresponding to each DAC code value into a corresponding frequency error;

[0060] An error processing unit for performing data processing on all frequency errors to obtain a modulation frequency residual corresponding to the optional modulation bandwidth.

[0061] Optionally, in a possible implementation manner, the linearity determination module may specifically include:

[0062] A root mean square determination unit, configured to determine the root mean square of the modulation frequency residual according to the modulation frequency residual under the optional modulation bandwidth;

[0063] A linearity calculation unit, configured to determine the modulation linearity corresponding to the optional modulation bandwidth according to the root mean square of the modulation frequency residual under the optional modulation bandwidth and the optional modulation bandwidth, and obtain the modulation linearity corresponding to each optional modulation bandwidth.

[0064] Optionally, in a possible implementation manner, the calibration module may specifically include:

[0065] A target bandwidth determination unit, configured to determine the optional modulation bandwidth corresponding to the maximum modulation linearity among all the modulation linearities as the target modulation bandwidth;

[0066] A target range determination unit, configured to determine the DAC code value range corresponding to the target modulation bandwidth as the target code value range.

[0067] Optionally, in a possible implementation manner, the calibration device may further include:

[0068] A control module, configured to control the laser to operate according to the target modulation bandwidth and the target code value range to complete the calibration of the laser frequency modulation parameters.

[0069] In a third aspect, an embodiment of the present application provides an electronic device, including: 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 calibration method of the laser frequency modulation parameters as described above is implemented.

[0070] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, on which a computer program is stored, and characterized in that when the computer program is executed by a processor, the calibration method of the laser frequency modulation parameters as described above is implemented.

[0071] In a fifth aspect, an embodiment of the present application provides a computer program product, which when running on an electronic device, causes the electronic device to execute the calibration method of the laser frequency modulation parameters as described above.

[0072] The beneficial effects of the embodiments of the present application compared with the prior art are:

[0073] The laser frequency modulation parameters in this application include modulation bandwidth and DAC code value range. First, obtain the output voltage range of the DAC. According to the output voltage range, the optional modulation bandwidth of the laser can be determined. Since different bandwidths correspond to different ranges of DAC code values, the DAC code value matrix corresponding to the optional modulation bandwidth can be determined according to the resolution of the DAC. Secondly, according to the DAC code value matrix, the modulation frequency residual corresponding to the optional modulation bandwidth is solved. According to the optional modulation bandwidth and the modulation frequency residual under the optional modulation bandwidth, the modulation linearity corresponding to each optional modulation bandwidth can be determined. Finally, by determining the optimal modulation linearity among all modulation linearities, the target modulation bandwidth and the target code value range are determined, and then the laser is calibrated. The above solution ensures that the lidar system can provide accurate and reliable measurement results in various application scenarios and meets the requirements of practical applications by calibrating the laser frequency modulation parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] In order to more clearly illustrate the technical solutions in the embodiments of this application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0075] Figure 1 is a schematic flowchart of a method for calibrating the laser frequency modulation coefficient provided by an embodiment of this application;

[0076] Figure 2 is a schematic diagram of the gain error curve of the DAC;

[0077] Figure 3 is a schematic structural diagram of a device for calibrating the laser frequency modulation coefficient provided by an embodiment of this application;

[0078] Figure 4 is a schematic structural diagram of an electronic device provided by an embodiment of this application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0079] In the following description, specific details such as specific system structures and technologies are presented for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of this application. However, those skilled in the art should clearly understand that this application can also be implemented in other embodiments without these specific details. In other cases, the detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of this application.

[0080] It should be understood that, as used in the specification of this application and the appended claims, the term "comprising" indicates the presence of the described features, integers, steps, operations, elements and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or their combinations.

[0081] It should also be understood that the term "and / or" as used in the specification of this application and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0082] As used in the specification of this application and the appended claims, the term "if" can be interpreted, depending on the context, as "when", "once", "in response to determining", or "in response to detecting". Similarly, the phrases "if determined" or "if [the described condition or event] is detected" can be interpreted, depending on the context, as meaning "once determined", "in response to determining", "once [the described condition or event] is detected", or "in response to detecting [the described condition or event]".

[0083] In addition, in the description of the specification of this application and the appended claims, the terms "first", "second", "third", etc. are used only for differentiating descriptions and should not be construed as indicating or implying relative importance.

[0084] The reference to "one embodiment" or "some embodiments" etc. described in the specification of this application means that a specific feature, structure or characteristic described in connection with that embodiment is included in one or more embodiments of this application. Thus, statements such as "in one embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments", etc. that appear in different places in this specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "comprising", "including", "having" and their variants all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0085] It should be understood that the magnitude of the sequence numbers of the steps in this embodiment does not mean the sequence of execution is prior or subsequent. The execution sequence of each process should be determined according to its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0086] LiDAR is a sensor that obtains the distance to a target by measuring the time of the laser beam reflected by the target. Frequency Modulated Continuous Wave (FMCW) LiDAR uses frequency modulation technology to achieve precise measurement of distance and speed by changing the frequency of the laser signal. FMCM LiDAR is widely used in fields such as autonomous driving, long-distance ranging, and high-precision map construction.

[0087] In related technologies, FMCW LiDAR calculates the target distance by measuring the echo time of the laser signal. During the frequency modulation process, high-precision distance measurement can be achieved by measuring the phase difference of the frequency change. And since the frequency of the laser echo is affected by the target speed, the target speed can be measured by analyzing the speed information of the frequency change. When FMCW LiDAR calculates the target distance by measuring the echo time of the laser signal, the accuracy of the frequency modulation parameters directly affects the precise relationship between the laser signal frequency and the distance. Therefore, there is an urgent need to provide a calibration method for the laser frequency modulation parameters to ensure that the LiDAR system can provide accurate and reliable measurement results in various application scenarios and meet the requirements of practical applications by calibrating the laser frequency modulation parameters.

[0088] To solve the above problems, the embodiments of the present application provide a calibration method for laser frequency modulation parameters. In the embodiments of the present application, the laser frequency modulation parameters include the modulation bandwidth and the DAC code value range. Therefore, calibrating the laser frequency modulation parameters means obtaining the optimal modulation bandwidth and the optimal DAC code value range. First, obtain the output voltage range of the DAC. According to the output voltage range, the optional modulation bandwidth of the laser can be determined. Since different bandwidths correspond to different ranges of DAC code values, the DAC code value matrix corresponding to the optional modulation bandwidth can be determined according to the resolution of the DAC. Secondly, according to the DAC code value matrix, solve for the modulation frequency residual corresponding to the optional modulation bandwidth. According to the optional modulation bandwidth and the modulation frequency residual under the optional modulation bandwidth, the modulation linearity corresponding to each optional modulation bandwidth can be determined. Finally, by determining the optimal modulation linearity among all modulation linearities, determine the target modulation bandwidth and the target code value range, and then calibrate the laser. The above solution ensures that the LiDAR system can provide accurate and reliable measurement results in various application scenarios and meet the requirements of practical applications by calibrating the laser frequency modulation parameters.

[0089] The following describes in detail a calibration method, device, electronic device, storage medium, and computer program for laser frequency modulation parameters provided by the present application with reference to the accompanying drawings.

[0090] Step 101, obtain the output voltage range of the digital-to-analog conversion module, and determine the optional modulation bandwidth of the laser according to the output voltage range.

[0091] It should be noted that the calibration method for the laser frequency modulation parameters in the embodiments of the present application can be executed by the calibration device for the laser frequency modulation parameters in the embodiments of the present application. The calibration device for the laser frequency modulation parameters in the embodiments of the present application can be configured in any electronic device to execute the calibration method for the laser frequency modulation parameters in the embodiments of the present application. For example, the calibration device for the laser frequency modulation parameters in the embodiments of the present application can be configured in a laser to obtain more reliable measurement results by calibrating the laser frequency modulation parameters.

[0092] Among them, a digital-to-analog converter (DAC) is used to convert a digital signal into an analog signal. In the embodiments of the present application, the DAC can receive the numerical value of the digital signal at the digital input end, which is usually represented in binary. This binary value can refer to the DAC code value, and the input code value of the DAC represents the numerical value that the DAC will convert into an analog signal. In the DAC, the input code value range is usually limited by the number of bits (i.e., resolution) of the DAC. For example, for an 8-bit DAC, its input code value range is from 0 to 255 (i.e., 2^8 - 1).

[0093] Each input code value corresponds to an analog voltage value output by the DAC. This voltage value is obtained by mapping the input digital code value to the corresponding analog voltage output through the conversion mechanism inside the DAC. Therefore, the output voltage of the digital-to-analog conversion module can be obtained through the digital-to-analog conversion module.

[0094] In the embodiments of the present application, the modulation bandwidth is the speed at which the DAC responds to changes in the input signal, usually measured in Hz. Generally speaking, a larger modulation bandwidth means that the DAC can respond to input changes faster. The relationship between the output voltage range and the modulation bandwidth is that if a faster adjustment of the output is required within a wider voltage range, a higher modulation bandwidth may be needed. Therefore, the optional modulation bandwidth of the laser can be determined according to the output voltage range, and there are multiple optional modulation bandwidths.

[0095] In one possible implementation, determining the optional modulation bandwidth of the laser according to the output voltage range includes:

[0096] Determining the maximum modulation bandwidth of the laser according to the maximum value, minimum value of the output voltage, and the electro-optic modulation parameters of the laser;

[0097] Determining the range of the optional modulation bandwidth according to the maximum modulation bandwidth and the preset minimum modulation bandwidth;

[0098] Determining the optional modulation bandwidth of the laser according to the range of the optional modulation bandwidth and the preset number of optional modulation bandwidths.

[0099] In the embodiments of the present application, the maximum value of the modulation bandwidth may refer to the modulation bandwidth corresponding to the full-scale output of the DAC. For example, the relationship between the maximum modulation bandwidth and the DAC output voltage is as follows:

[0100] B = (V_ max - V_ min ) * β

[0101] Wherein, V_ max is the voltage value corresponding to the maximum code value output by the DAC, that is, the maximum value of the output voltage; V_ min is the voltage value corresponding to the minimum code value output by the DAC, that is, the minimum value of the output voltage; β is the electro-optic modulation parameter of the inherent parameter of the laser, which is related to the characteristics of the laser; B is the maximum modulation bandwidth of the laser.

[0102] Exemplarily, assuming that the preset minimum modulation bandwidth is 2Ghz and the calculated maximum modulation bandwidth is 10Ghz, then the range of the selectable modulation bandwidth is 2Ghz to 10Ghz. Assuming that the number of preset selectable modulation bandwidths is n, where n is a positive integer, then the determined selectable modulation bandwidths of the laser are {B1, B2,... B n}, where B n is 10Ghz, and 2Ghz = B min < B1 < B2 <... < B n .

[0103] In summary, the selectable modulation bandwidths can be obtained as {B1, B2,... B n}.

[0104] Step 102, for each selectable modulation bandwidth, determine the DAC code value matrix corresponding to each selectable modulation bandwidth according to the resolution of the digital-to-analog conversion module.

[0105] Among them, the resolution of the digital-to-analog conversion module may refer to the number of different voltage levels or output values that the DAC can generate. Usually, the resolution is expressed in bits, such as 8 bits, 12 bits, or 16 bits.

[0106] In the embodiments of the present application, for each selectable modulation bandwidth, there is a corresponding DAC code value range. Therefore, a corresponding DAC code value matrix can be established, which means determining the input code values of the DAC under each modulation bandwidth, and these code values will be used to generate analog signals of the corresponding bandwidth, such as generating actual voltage values of the corresponding bandwidth.

[0107] In a possible implementation manner, the specific process of determining the DAC code value matrix corresponding to each selectable modulation bandwidth according to the resolution of the digital-to-analog conversion module for each selectable modulation bandwidth may include:

[0108] Determine the number of input code values of the digital-to-analog conversion module according to the resolution of the digital-to-analog conversion module;

[0109] Determine the number of code value combinations corresponding to the optional modulation bandwidth according to the optional modulation bandwidth and the number of input code values of the digital-to-analog conversion module;

[0110] Determine the number of columns of the DAC code value matrix according to the number of optional modulation bandwidths;

[0111] Determine the number of rows of the DAC code value matrix according to the number of code value combinations corresponding to the optional modulation bandwidth;

[0112] Determine the DAC code value matrix corresponding to each optional modulation bandwidth according to the DAC code value range corresponding to each optional modulation bandwidth and the number of columns and rows of the corresponding DAC code value matrix.

[0113] In the embodiments of the present application, to determine the DAC code value matrix corresponding to the optional modulation bandwidth, first determine the number of DAC input code values. For example, for a 10-bit DAC, the number of its input code values is 1024; then, according to the optional modulation bandwidth and the number of input code values, determine the number of code value combinations corresponding to the optional modulation bandwidth. For example, if the DAC full-scale output is 2V and the maximum modulation bandwidth of the laser is 2 GHz, when corresponding to the maximum modulation bandwidth of 2 GHz, the number of corresponding code value combinations is 1, that is, 1 - 1024; if the optional modulation bandwidth is 1 GHz, the corresponding code value combinations are 1 - 512, 512 - 1024, with a total of 512 combinations; if the optional modulation bandwidth is 500 MHz, the corresponding code value combinations are 1 - 256, 768 - 1024, with a total of 768 combinations.

[0114] Among them, the number of columns of the DAC code value matrix is the number of optional modulation bandwidths, and the number of rows of the DAC code value matrix is the number of code value combinations corresponding to the optional modulation bandwidth.

[0115] Exemplarily, for the optional modulation bandwidth B i , the form of its DAC code value matrix can be:

[0116]

[0117] Among them, n is the number of optional modulation bandwidths, m is the number of code value combinations corresponding to the optional modulation bandwidth, and code is the input code value of the DAC.

[0118] In the embodiments of the present application, the number of code value combinations corresponding to different optional modulation bandwidths is different. Therefore, each optional modulation bandwidth corresponds to a DAC code value matrix.

[0119] Step 103, determine the modulation frequency residual under the corresponding optional modulation bandwidth according to the DAC code value matrix.

[0120] Among them, the modulation frequency refers to the frequency in the modulation signal. For a digital signal processing system, it usually refers to the frequency in the analog signal output by the DAC. This frequency can be adjusted by the input code value of the DAC.

[0121] Among them, the modulation frequency residual refers to the difference between the actual modulation frequency and the expected modulation frequency. It should be understood that for each optional modulation bandwidth, the expected modulation frequency is determined.

[0122] In the embodiment of the present application, according to the DAC code value in the DAC code value matrix, the output phase voltage error can be calculated, and then the modulation frequency residual can be calculated.

[0123] In a possible implementation manner, determining the modulation frequency residual corresponding to the optional modulation bandwidth according to the DAC code value matrix includes:

[0124] Obtain the DAC gain error curve, where the abscissa of the gain error curve is the DAC code value and the ordinate is the phase voltage error;

[0125] According to the DAC gain error curve, determine the phase voltage error corresponding to each DAC code value in the DAC code value matrix of the optional modulation bandwidth;

[0126] Convert the phase voltage error corresponding to each DAC code value into the corresponding frequency error;

[0127] Perform data processing on all frequency errors to obtain the modulation frequency residual corresponding to the optional modulation bandwidth.

[0128] In the embodiment of the present application, the DAC gain error curve can be obtained through experiments or simulations, that is, by changing the input code value of the DAC, measuring the corresponding actual output voltage, and according to the expected voltage corresponding to the input code value, the phase voltage error of the actual output voltage compared with the expected voltage can be obtained. Then, by plotting a curve with the DAC code value as the abscissa and the phase voltage error as the ordinate, the DAC gain error curve can be obtained. This DAC gain error curve is usually a linear function curve, which can be referred to Figure 2 The schematic diagram of the DAC gain error curve shown, and its function expression can be:

[0129] ΔV = code * α + γ

[0130] Among them, ΔV is the phase voltage error, code is the DAC code value, α is the coefficient, and γ represents other possible biases or non-linear errors.

[0131] Therefore, according to the DAC gain error curve, the phase voltage error corresponding to each DAC code value in the DAC code value matrix of the selectable modulation bandwidth is determined. Then, through the conversion relationship between the phase voltage error and the frequency error: Δf = ΔV * β, the frequency error Δf corresponding to each DAC code value in the DAC code value matrix can be obtained. ij . Finally, for all Δf ij , data processing is performed, and the modulation frequency residual corresponding to the selectable modulation bandwidth can be obtained.

[0132] Step 104: Determine the modulation linearity corresponding to each selectable modulation bandwidth according to the selectable modulation bandwidth and the modulation frequency residual under the selectable modulation bandwidth.

[0133] In the embodiment of the present application, the modulation linearity corresponding to the selectable modulation bandwidth is related to the ratio of the modulation frequency residual to the selectable modulation bandwidth. Therefore, the modulation linearity corresponding to each selectable modulation bandwidth can be determined according to the selectable modulation bandwidth and the modulation frequency residual under the selectable modulation bandwidth.

[0134] In a possible implementation manner, determining the modulation linearity corresponding to each selectable modulation bandwidth according to the selectable modulation bandwidth and the modulation frequency residual under the selectable modulation bandwidth includes:

[0135] Determine the root mean square of the modulation frequency residual according to the modulation frequency residual under the selectable modulation bandwidth;

[0136] Determine the modulation linearity corresponding to the selectable modulation bandwidth according to the root mean square of the modulation frequency residual under the selectable modulation bandwidth and the selectable modulation bandwidth, and obtain the modulation linearity corresponding to each selectable modulation bandwidth.

[0137] Exemplarily, the specific process of determining the root mean square of the modulation frequency residual can be: Assume that all the obtained frequency errors are {Δf1, Δf2, Δf3,... Δf (n-1) , Δf n}, then the root mean square of the modulation frequency residual is:

[0138] Δf rms = sqrt(Δf1 2 + Δf2 2 +... + Δf n 2 )

[0139] After obtaining the root mean square of the modulation frequency residual, the modulation linearity corresponding to the selectable modulation bandwidth can be obtained through the following calculation formula. The calculation formula is:

[0140] R = (1 - Δf rms / B) * 100%

[0141] where R is the modulation linearity, Δfrms Δfrms is the root mean square of the modulation frequency residual, and B is the optional modulation bandwidth.

[0142] It should be understood that from the above calculation formula, it can be obtained that the larger the optional modulation bandwidth B is, the better the frequency modulation linearity of the laser is; the root mean square of the modulation frequency residual Δf rms The smaller it is, the better the frequency modulation linearity of the laser is.

[0143] Step 105: Determine that the optional modulation bandwidth corresponding to the optimal modulation linearity among all modulation linearities is the target modulation bandwidth, and determine the DAC code value range corresponding to the target modulation bandwidth as the target code value range to calibrate the laser.

[0144] In the embodiment of the present application, the optional modulation bandwidth corresponding to the optimal modulation linearity is the target modulation bandwidth, that is, the modulation bandwidth required for calibration. After determining the target modulation bandwidth, the target code value range corresponding to the target modulation bandwidth can be determined according to the target modulation bandwidth, and the laser can be calibrated using the target modulation bandwidth and the target code value range.

[0145] In a possible implementation manner, since the larger the optional modulation bandwidth B is, the better the frequency modulation linearity of the laser is; the smaller the root mean square of the modulation frequency residual Δfrms is, the better the frequency modulation linearity of the laser is. Therefore, the linewidth characterization value Δf rms / B is smaller, and its corresponding linearity is good. Therefore, the above step 105 may include:

[0146] Determine that the optional modulation bandwidth corresponding to the maximum modulation linearity among all modulation linearities is the target modulation bandwidth;

[0147] Determine the DAC code value range corresponding to the target modulation bandwidth as the target code value range.

[0148] In a possible implementation manner, the calibration method further includes controlling the laser to operate according to the target modulation bandwidth and the target code value range to complete the calibration of the laser frequency modulation parameters.

[0149] In an embodiment of the present application, first, by obtaining the output voltage range of the DAC, the optional modulation bandwidth of the laser is determined. Since different bandwidths correspond to different ranges of DAC code values, the DAC code value matrix corresponding to the optional modulation bandwidth can be determined according to the resolution of the DAC. Secondly, according to the DAC code value matrix, the modulation frequency residual corresponding to the optional modulation bandwidth is obtained. Based on the optional modulation bandwidth and the modulation frequency residual under the optional modulation bandwidth, the modulation linearity corresponding to each optional modulation bandwidth can be determined. Finally, by determining the optimal modulation linearity among all modulation linearities, the target modulation bandwidth and the target code value range are determined, and then the laser is calibrated. The above solution ensures that the lidar system can provide accurate and reliable measurement results in various application scenarios and meets the requirements of practical applications by calibrating the frequency modulation parameters of the laser.

[0150] Corresponding to the calibration method of the laser frequency modulation parameters in the above embodiment, Figure 3 FIG. shows a schematic structural diagram of a calibration device for laser frequency modulation parameters provided by an embodiment of the present application. For the sake of convenience of description, only the parts related to the embodiment of the present application are shown.

[0151] See Figure 3 , the calibration device 300 includes:

[0152] An acquisition module 301, configured to acquire the output voltage range of the digital-to-analog conversion module, and determine the optional modulation bandwidth of the laser according to the output voltage range;

[0153] A matrix determination module 302, configured to determine the DAC code value matrix corresponding to each optional modulation bandwidth according to the resolution of the digital-to-analog conversion module for each optional modulation bandwidth;

[0154] A residual determination module 303, configured to determine the modulation frequency residual corresponding to the optional modulation bandwidth according to the DAC code value matrix;

[0155] A linearity determination module 304, configured to determine the modulation linearity corresponding to each optional modulation bandwidth according to the optional modulation bandwidth and the modulation frequency residual under the optional modulation bandwidth;

[0156] A calibration module 305, configured to determine that the optional modulation bandwidth corresponding to the optimal modulation linearity among all modulation linearities is the target modulation bandwidth, and determine that the DAC code value range corresponding to the target modulation bandwidth is the target code value range to calibrate the laser.

[0157] In an embodiment of the present application, the above acquisition module 301 may specifically include:

[0158] A maximum bandwidth determination unit, configured to determine the maximum modulation bandwidth of the laser according to the maximum value, minimum value of the output voltage, and the electro-optic modulation parameters of the laser;

[0159] A range determination unit, configured to determine a range of selectable modulation bandwidths according to the maximum modulation bandwidth and a preset minimum modulation bandwidth;

[0160] An optional bandwidth determination unit, configured to determine the selectable modulation bandwidth of the laser according to the range of selectable modulation bandwidths and the preset number of selectable modulation bandwidths.

[0161] In an embodiment of the present application, the above-mentioned matrix determination module 302 may specifically include:

[0162] An input quantity determination unit, configured to determine the quantity of input code values of the digital-to-analog conversion module according to the resolution of the digital-to-analog conversion module;

[0163] A combination quantity determination unit, configured to determine the quantity of code value combinations corresponding to the selectable modulation bandwidth according to the selectable modulation bandwidth and the quantity of input code values of the digital-to-analog conversion module;

[0164] A column number determination unit, configured to determine the number of columns of the DAC code value matrix according to the quantity of selectable modulation bandwidths;

[0165] A row number determination unit, configured to determine the number of rows of the DAC code value matrix according to the quantity of code value combinations corresponding to the selectable modulation bandwidth;

[0166] A code value matrix determination unit, configured to determine the DAC code value matrix corresponding to each selectable modulation bandwidth according to the DAC code value range corresponding to each selectable modulation bandwidth and the number of columns and rows of the corresponding DAC code value matrix.

[0167] In an embodiment of the present application, the above-mentioned residual determination module 303 may specifically include:

[0168] A curve acquisition unit, configured to acquire a DAC gain error curve, where the abscissa of the gain error curve is the DAC code value and the ordinate is the phase voltage error;

[0169] A voltage error determination unit, configured to determine the phase voltage error corresponding to each DAC code value in the DAC code value matrix of the selectable modulation bandwidth according to the DAC gain error curve;

[0170] An error conversion unit, configured to convert the phase voltage error corresponding to each DAC code value into a corresponding frequency error;

[0171] An error processing unit, configured to perform data processing on all frequency errors to obtain the modulation frequency residual corresponding to the selectable modulation bandwidth.

[0172] In an embodiment of the present application, the above-mentioned linearity determination module 304 may specifically include:

[0173] A root mean square determination unit, configured to determine the root mean square of the modulation frequency residual according to the modulation frequency residual under an optional modulation bandwidth;

[0174] A linearity calculation unit, configured to determine the modulation linearity corresponding to an optional modulation bandwidth according to the root mean square of the modulation frequency residual under the optional modulation bandwidth and the optional modulation bandwidth, and obtain the modulation linearity corresponding to each optional modulation bandwidth.

[0175] In an embodiment of the present application, the above calibration module 305 may specifically include:

[0176] A target bandwidth determination unit, configured to determine the optional modulation bandwidth corresponding to the maximum modulation linearity among all modulation linearities as the target modulation bandwidth;

[0177] A target range determination unit, configured to determine the DAC code value range corresponding to the target modulation bandwidth as the target code value range.

[0178] In an embodiment of the present application, the above calibration device 300 may further include:

[0179] A control module, configured to control the laser to operate according to the target modulation bandwidth and the target code value range, so as to complete the calibration of the laser frequency modulation parameters.

[0180] In actual use, the calibration device for laser frequency modulation parameters provided in the embodiment of the present application may be configured in any electronic device to execute the foregoing calibration method for laser frequency modulation parameters.

[0181] It should be noted that for the information interaction, execution process, etc. between the above devices / units, since they are based on the same concept as the method embodiment of the present application, their specific functions and the technical effects brought, for details, please refer to the method embodiment part, and will not be elaborated here.

[0182] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the above division of each functional unit and module is used as an example. In actual application, the above functions may be allocated to different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment may be integrated into a processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit. The above integrated unit may be implemented in the form of hardware or in the form of a software functional unit. In addition, the specific names of the functional units and modules are only for the convenience of mutual distinction and do not limit the protection scope of the present application. The specific working process of the units and modules in the above system may refer to the corresponding process in the foregoing method embodiment, and will not be elaborated here.

[0183] See Figure 4 , which shows a schematic structural diagram of an electronic device provided in an embodiment of the present application. As shown in Figure 4 , the electronic device 400 in this embodiment includes: at least one processor 410( Figure 4 only one is shown in), a memory 420, and a computer program 421 stored in the memory 420 and executable on the at least one processor 410. When the processor 410 executes the computer program 421, the steps in the calibration method embodiment of the above laser frequency modulation parameters are implemented.

[0184] It should be noted that the electronic device 400 may refer to computing devices such as lidar, desktop computers, notebooks, palmtop computers, and cloud servers. The electronic device may include, but is not limited to, a processor 410 and a memory 420. Those skilled in the art can understand that Figure 4 merely examples of the electronic device 400 do not constitute a limitation on the electronic device 400, and may include more or fewer components than shown in the figure, or combine certain components, or different components. For example, it may also include input / output devices, network access devices, etc.

[0185] The so-called processor 410 may be a central processing unit (CPU), and the processor 410 may also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), off-the-shelf programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0186] The memory 420 may be an internal storage unit of the electronic device 400 in some embodiments, such as a hard disk or memory of the electronic device 400. The memory 420 may also be an external storage device of the electronic device 400 in other embodiments, such as a plug-in hard disk equipped on the electronic device 400, a Smart Media Card (SMC), a Secure Digital (SD) card, a Flash Card, etc. Further, the memory 420 may include both the internal storage unit of the electronic device 400 and an external storage device. The memory 420 is used to store an operating system, application programs, a Boot Loader, data, and other programs, such as program codes of the computer program. The memory 420 may also be used to temporarily store data that has been output or will be output.

[0187] In the above embodiments, the descriptions of the various embodiments have their own focuses. For parts not detailed or recorded in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0188] Those of ordinary skill in the art can realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. A professional technician can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0189] In the embodiments provided in this application, it should be understood that the disclosed device / electronic device and method can be implemented in other ways. For example, the device / electronic device embodiments described above are merely illustrative. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of the devices or units can be in an electrical, mechanical, or other form.

[0190] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0191] In addition, the functional units in the various embodiments of the present application may be integrated into one processing unit, may exist physically separately for each unit, or two or more units may be integrated into one unit. The above-mentioned integrated units may be implemented in the form of hardware or in the form of software functional units.

[0192] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it may be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes of the above-mentioned embodiment methods of the present application can also be completed by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, the steps of the above-mentioned various method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disc, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc. It should be noted that the content included in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals.

[0193] All or part of the processes of the above-mentioned embodiment methods of the present application can also be completed by a computer program product. When the computer program product runs on an electronic device, the electronic device can execute the steps of the above-mentioned various method embodiments when executed.

[0194] The above-mentioned embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A calibration method for the frequency modulation parameters of a laser, characterized in that, The laser includes a digital-to-analog conversion module DAC; the calibration method includes: Obtain the output voltage range of the digital-to-analog conversion module, and determine the optional modulation bandwidth of the laser according to the output voltage range; For each of the optional modulation bandwidths, determine the DAC code value matrix corresponding to each optional modulation bandwidth according to the resolution of the digital-to-analog conversion module; Determine the modulation frequency residual corresponding to the optional modulation bandwidth according to the DAC code value matrix; Determine the modulation linearity corresponding to each optional modulation bandwidth according to the optional modulation bandwidth and the modulation frequency residual under the optional modulation bandwidth; Determine the optional modulation bandwidth corresponding to the optimal modulation linearity among all the modulation linearities as the target modulation bandwidth, and determine the target code value range corresponding to the target modulation bandwidth to calibrate the laser.

2. The calibration method according to claim 1, wherein, The determining the optional modulation bandwidth of the laser according to the output voltage range includes: Determine the maximum modulation bandwidth of the laser according to the maximum value, minimum value of the output voltage and the electro-optic modulation parameters of the laser; Determine the range of the optional modulation bandwidth according to the maximum modulation bandwidth and the preset minimum modulation bandwidth; Determine the optional modulation bandwidth of the laser according to the range of the optional modulation bandwidth and the preset number of optional modulation bandwidths.

3. The calibration method according to claim 1, wherein The determining the DAC code value matrix corresponding to each optional modulation bandwidth according to the resolution of the digital-to-analog conversion module for each of the optional modulation bandwidths includes: Determine the number of input code values of the digital-to-analog conversion module according to the resolution of the digital-to-analog conversion module; Determine the number of code value combinations corresponding to the optional modulation bandwidth according to the optional modulation bandwidth and the number of input code values of the digital-to-analog conversion module; Determine the number of columns of the DAC code value matrix according to the number of the optional modulation bandwidths; Determine the number of rows of the DAC code value matrix according to the number of code value combinations corresponding to the optional modulation bandwidth; Determine the DAC code value matrix corresponding to each optional modulation bandwidth according to the DAC code value range corresponding to each optional modulation bandwidth and the number of columns and rows of the corresponding DAC code value matrix.

4. The calibration method according to claim 1, characterized in that, The determining the modulation frequency residual corresponding to the optional modulation bandwidth according to the DAC code value matrix includes: Obtain the DAC gain error curve, the abscissa of the gain error curve is the DAC code value, and the ordinate is the phase voltage error; Determine the phase voltage error corresponding to each DAC code value in the DAC code value matrix of the optional modulation bandwidth according to the DAC gain error curve; Convert the phase voltage error corresponding to each DAC code value into the corresponding frequency error; Perform data processing on all the frequency errors to obtain the modulation frequency residual corresponding to the optional modulation bandwidth.

5. The calibration method according to claim 1, wherein The determining the modulation linearity corresponding to each optional modulation bandwidth according to the optional modulation bandwidth and the modulation frequency residual under the optional modulation bandwidth includes: Determine the root mean square of the modulation frequency residual according to the modulation frequency residual under the optional modulation bandwidth; Determine the modulation linearity corresponding to the optional modulation bandwidth based on the root mean square of the modulation frequency residuals under the optional modulation bandwidth and the optional modulation bandwidth, and obtain the modulation linearity corresponding to each optional modulation bandwidth.

6. The calibration method according to claim 1, wherein Determining the optional modulation bandwidth corresponding to the optimal modulation linearity among all the modulation linearities as the target modulation bandwidth, and determining the DAC code value range corresponding to the target modulation bandwidth as the target code value range, includes: Determine the optional modulation bandwidth corresponding to the maximum modulation linearity among all the modulation linearities as the target modulation bandwidth; Determine the DAC code value range corresponding to the target modulation bandwidth as the target code value range.

7. The calibration method according to any one of claims 1 to 6, characterized in that, Further includes: Control the laser to operate according to the target modulation bandwidth and the target code value range to complete the calibration of the laser frequency modulation parameters.

8. A calibration device for the frequency modulation parameters of a laser, characterized in that, The laser includes a digital-to-analog conversion module DAC; the calibration device includes: An acquisition module, configured to acquire the output voltage range of the digital-to-analog conversion module, and determine the optional modulation bandwidth of the laser according to the output voltage range; A matrix determination module, configured to determine the DAC code value matrix corresponding to each optional modulation bandwidth according to the resolution of the digital-to-analog conversion module for each optional modulation bandwidth; A residual determination module, configured to determine the modulation frequency residuals corresponding to the optional modulation bandwidth according to the DAC code value matrix; A linearity determination module, configured to determine the modulation linearity corresponding to each optional modulation bandwidth according to the optional modulation bandwidth and the modulation frequency residuals under the optional modulation bandwidth; A calibration module, configured to determine the optional modulation bandwidth corresponding to the optimal modulation linearity among all the modulation linearities as the target modulation bandwidth, and determine the DAC code value range corresponding to the target modulation bandwidth as the target code value range to calibrate the laser.

9. An electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, the method described in any one of claims 1-7 is implemented.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, the method described in any one of claims 1-7 is implemented.

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