阅读说明：本技术 一种复合激光测距方法 (Composite laser ranging method ) 是由 黄毅 李明远 于 2020-12-21 设计创作，主要内容包括：本发明公开了一种复合激光测距方法,包括调频测距模式和相位测量模式,包括调频测距模式和相位测量模式,首先采用调频测距模式得到粗测的距离,然后采用相位测量模式测距结合调频测距模式的粗测距离得到精确距离,两者结合得出精准测距；本发明的有益效果是,通过调频测距模式得出粗测距离结合相位测量模式得出精确距离,从而实现精准测距,能够兼顾精度与速度,便于人们进行使用。(The invention discloses a composite laser ranging method, which comprises a frequency modulation ranging mode and a phase measurement mode, wherein the frequency modulation ranging mode and the phase measurement mode are included, firstly, the frequency modulation ranging mode is adopted to obtain a roughly measured distance, then, the phase measurement mode is adopted to measure the distance and combine the roughly measured distance of the frequency modulation ranging mode to obtain an accurate distance, and the two modes are combined to obtain an accurate distance; the invention has the advantages that the rough measurement distance is obtained through the frequency modulation distance measurement mode, the accurate distance is obtained through the phase measurement mode, the accurate distance measurement is realized, the precision and the speed can be considered, and the use by people is convenient.)

1. A composite laser ranging method is characterized by comprising a frequency modulation ranging mode and a phase measurement mode, wherein the frequency modulation ranging mode is adopted to obtain a roughly measured distance, then the phase measurement mode is adopted to range and combine the roughly measured distance of the frequency modulation ranging mode to obtain an accurate distance, and the two modes are combined to obtain the accurate ranging.

2. A composite laser ranging method according to claim 1, characterized in that said frequency modulated ranging mode comprises the following operative steps:

(1) determining a PLL chip which has a fixed input clock signal, wherein a control signal of the PLL chip is controlled by an IIC or SPI communication protocol;

(2) the controller sets the PLL chip to be frequency required to be obtained through the control signal;

(3) outputting a frequency f0 after the signal in the step (2), and dividing the frequency into two frequencies with the same frequency and 90-degree phase difference by a frequency divider, wherein the two frequencies are respectively f1 and f 2;

(4) f1 is then divided into two sub-frequencies, one of which outputs a reference frequency f via the PA_RefThe other branch frequency is input with an I signal carrier, the f2 is input with a Q signal carrier, the I Q signal is two low-frequency signals with the same frequency and 90-degree phase difference, the other branch frequency of f1 and the f2 are respectively modulated with an IQ signal, the other branch frequency of f1 and the f2 are modulated by the IQ signal, and the two paths of modulation signals are accumulated to obtain the carrier wave of the I signalf_I+f₂Then, the laser tube is driven to emit modulated laser through PA output;

(5) after laser emission, the light is reflected back by the object in a diffuse way and received by the APD, and a received signal f is analyzed_I+f₂Mixing the signal with a signal transmitted by the PA so as to obtain a frequency difference value;

(6) and obtaining a rough measurement distance according to the frequency difference.

3. A composite laser ranging method according to claim 2, characterized in that said phase measurement mode comprises the following operative steps:

(1) determining a PLL chip which has a fixed input clock signal, wherein a control signal of the PLL chip is controlled by an IIC or SPI communication protocol;

(2) the controller sets the PLL chip to be frequency required to be obtained through the control signal;

(3) outputting a frequency f3 after the signal in the step (2), and dividing the frequency into two frequencies with the same frequency and 90-degree phase difference by a frequency divider, wherein the two frequencies are respectively f4 and f 5;

(4) f4 is then divided into two sub-frequencies, one of which outputs a reference frequency f via the PA_Ref1Outputting to APD, inputting I signal carrier to another branch frequency, inputting Q signal carrier to f5, IQ signals are two low-frequency signals with same frequency and 90-degree phase difference, modulating another branch frequency of f4 and f5 with IQ signals respectively, modulating another branch frequency of f4 and f5 by I Q signals, accumulating two modulation signals to obtain f_I4+f₅Then, the laser tube is driven to emit modulated laser through PA output;

(5) after laser emission, the light is reflected back by the object and received by the APD, and f is modulated on the APD_Ref1Signal, returned signal f_I4+f₅And f_Ref1After multiplication of the signal, only f remains_I4The low frequency signal of (2);

(6) by calculating f_I4And the phase difference of the I signal is combined with the roughly measured distance, so that the accurate distance is calculated.

4. The composite laser ranging method as claimed in claim 1, wherein the clock signal is an active crystal oscillator or an external input or temperature compensated crystal.

5. The composite laser ranging method as claimed in claim 1, wherein the input frequency of the IQ signal is 100Hz to 10 MHz.

6. The composite laser ranging method as claimed in claim 1, wherein the clock signal input adopts a single sideband modulation method.

7. The composite laser ranging method as claimed in claim 1, wherein the clock compensation value of the PLL is 0-5 GHZ.

Technical Field

The invention relates to the technical field of laser ranging, in particular to a composite laser ranging method.

Background

With the development of science and technology and the progress of technology, the manufacturing industries of high-end equipment such as aerospace equipment, ocean engineering equipment, high-technology ships, advanced rail transit equipment, high-grade numerical control machines, robot equipment and the like have strict requirements on the performances such as precision, range, measuring speed and the like of large-scale three-dimensional precision measurement; the existing laser scanning measurement technology needs to be matched with a mechanical scanning device to carry out point-by-point measurement on a target, so that measurement precision and measurement speed cannot be taken into consideration in the measurement process; in view of the defects in the prior art, a composite laser ranging method is designed, so that the requirements on precision and speed are met.

Disclosure of Invention

Because the existing distance measuring method cannot take the measurement precision and the measurement speed into consideration, the composite laser distance measuring method is designed on the basis of the defects of the prior art, the measurement precision is accurate, the measurement speed is high, and the composite laser distance measuring method is convenient for people to use.

The technical scheme of the invention is that the composite laser ranging method comprises a frequency modulation ranging mode and a phase measurement mode, wherein the frequency modulation ranging mode is firstly adopted to obtain a roughly measured distance, then the phase measurement mode is adopted to measure the distance and combine the roughly measured distance of the frequency modulation ranging mode to obtain an accurate distance, and the two modes are combined to obtain the accurate distance measurement.

In addition to the technical solution, the frequency modulation ranging mode includes the following steps:

(1) determining a PLL chip which has a fixed input clock signal, wherein a control signal of the PLL chip is controlled by an IIC or SPI communication protocol;

(2) the controller sets the PLL chip to be frequency required to be obtained through the control signal;

(3) outputting a frequency f0 after the signal in the step (2), and dividing the frequency into two frequencies with the same frequency and 90-degree phase difference by a frequency divider, wherein the two frequencies are respectively f1 and f 2;

(4) f1 is then divided into two sub-frequencies, one of which outputs a reference frequency f via the PA_RefInputting an I signal carrier at the other branch frequency, inputting a Q signal carrier at f2, carrying out modulation operation on IQ signals which are two low-frequency signals with the same frequency and 90-degree phase difference, respectively carrying out modulation operation on the other branch frequency of f1 and the other branch frequency of f2 and the IQ signals, modulating the other branch frequency of f1 and the other branch frequency of f2 by using the IQ signals, and accumulating the two paths of modulation signals to obtain f_I+f₂Then, the laser tube is driven to emit modulated laser through PA output;

(5) after laser emission, the light is reflected back by the object in a diffuse way and received by the APD, and a received signal f is analyzed_I+f₂Mixing the signal with a signal transmitted by the PA so as to obtain a frequency difference value;

(6) and obtaining a rough measurement distance according to the frequency difference.

To further supplement the technical solution, the phase measurement mode comprises the following working steps:

(1) determining a PLL chip which has a fixed input clock signal, wherein a control signal of the PLL chip is controlled by an IIC or SPI communication protocol;

(2) the controller sets the PLL chip to be frequency required to be obtained through the control signal;

(3) outputting a frequency f3 after the signal in the step (2), and dividing the frequency into two frequencies with the same frequency and 90-degree phase difference by a frequency divider, wherein the two frequencies are respectively f4 and f 5;

(4) f4 is then divided into two sub-frequencies, one of which outputs a reference frequency f via the PA_Ref1Outputting to APD, inputting I signal carrier to another branch frequency, inputting Q signal carrier to f5, IQ signals are two low-frequency signals with same frequency and 90-degree phase difference, modulating another branch frequency of f4 and f5 with IQ signals respectively, modulating another branch frequency of f4 and f5 with IQ signals, accumulating two modulation signals to obtain f_I4+f₅Then, the laser tube is driven to emit modulated laser through PA output;

(5) after laser emission, the light is reflected back by the object and received by the APD, and f is modulated on the APD_Ref1Signal, returned signal f_I4+f₅And f_Ref1After multiplication of the signal, only f remains_I4The low frequency signal of (2);

(6) by calculating f_I4And the phase difference of the I signal is combined with the roughly measured distance, so that the accurate distance is calculated.

In addition to the technical scheme, the clock signal adopts an active crystal oscillator or an external input or temperature compensation crystal.

The technical proposal is further supplemented, and the input frequency of IQ signals is 100Hz-10 MHz.

Further complementing the technical scheme, the clock signal input adopts a single sideband modulation method.

Further supplementing the technical scheme, the clock compensation value of the PLL is 0-5 GHZ.

The FMCW ranging and phase ranging can be realized through PLL + IQ single-side band modulation, the FMCW ranging and the phase ranging can be matched with the ranging in precision and speed measurement, the ranging is accurate, the precision is high, and the FMCW ranging and the phase ranging are practical; and the sine signal is directly output, a filter circuit is reduced, interference signals are reduced, and the use by people is facilitated.

Drawings

FIG. 1 is a flow chart of the operation of the present invention.

Detailed Description

In order to make the technical solution more clear to those skilled in the art, the technical solution of the present invention will be described in detail below with reference to fig. 1:

according to the invention, firstly, frequency modulation distance measurement is carried out, then phase distance measurement is adopted, and finally the two are combined and compared to obtain a more accurate distance; the technical scheme of the invention is detailed as follows:

a composite laser ranging method comprises a frequency modulation ranging mode and a phase measurement mode, wherein the frequency modulation ranging mode is adopted to obtain a roughly measured distance, then the phase measurement mode is adopted to range and combine the roughly measured distance of the frequency modulation ranging mode to obtain an accurate distance, and the two modes are combined to obtain the accurate ranging.

The frequency modulation distance measurement mode comprises the following working steps:

(1) determining a PLL chip which has a fixed input clock signal, wherein a control signal of the PLL chip is controlled by an IIC or SPI communication protocol;

(2) the controller sets the PLL chip to be frequency required to be obtained through the control signal;

(3) outputting a frequency f0 after the signal in the step (2), and dividing the frequency into two frequencies with the same frequency and 90-degree phase difference by a frequency divider, wherein the two frequencies are respectively f1 and f 2;

(4) f1 is then divided into two sub-frequencies, one of which outputs a reference frequency f via the PA_RefThe other branch frequency is input with an I signal carrier, the f2 is input with a Q signal carrier, the IQ signals are two low-frequency signals with the same frequency and 90-degree phase difference, the other branch frequency of the f1 and the f2 are respectively modulated with the IQ signals, the other branch frequency of the f1 and the f2 are modulated by the IQ signals, and the two paths of modulation signals are accumulated and then are input with the I signal carrierTo obtain f_I+f₂Then, the laser tube is driven to emit modulated laser through PA output;

(5) after laser emission, the light is reflected back by the object in a diffuse way and received by the APD, and a received signal f is analyzed_I+f₂Mixing the signal with a signal transmitted by the PA so as to obtain a frequency difference value;

(6) and obtaining a rough measurement distance according to the frequency difference.

The phase measurement mode comprises the following working steps:

(1) determining a PLL chip which has a fixed input clock signal, wherein a control signal of the PLL chip is controlled by an IIC or SPI communication protocol;

(2) the controller sets the PLL chip to be frequency required to be obtained through the control signal;

(3) outputting a frequency f3 after the signal in the step (2), and dividing the frequency into two frequencies with the same frequency and 90-degree phase difference by a frequency divider, wherein the two frequencies are respectively f4 and f 5;

(4) f4 is then divided into two sub-frequencies, one of which outputs a reference frequency f via the PA_Ref1Outputting to APD, inputting I signal carrier to another branch frequency, inputting Q signal carrier to f5, IQ signals are two low-frequency signals with same frequency and 90-degree phase difference, modulating another branch frequency of f4 and f5 with IQ signals respectively, modulating another branch frequency of f4 and f5 with IQ signals, accumulating two modulation signals to obtain f_I4+f₅Then, the laser tube is driven to emit modulated laser through PA output;

(5) after laser emission, the light is reflected back by the object and received by the APD, and f is modulated on the APD_Ref1Signal, returned signal f_I4+f₅And f_Ref1After multiplication of the signal, only f remains_I4The low frequency signal of (2);

(6) by calculating f_I4And the phase difference of the I signal is combined with the roughly measured distance obtained by the frequency modulation distance measurement mode, so that the accurate distance can be calculated, and the distance measurement accuracy is higher than any one of the I signal and the I signal.

The clock signal adopts an active crystal oscillator or an external input or temperature compensation crystal.

The input frequency of the IQ signal is further defined, and the input frequency of the IQ signal is 100Hz-10 MHz.

Further complementing the technical scheme, the clock signal input adopts a single sideband modulation method.

Wherein the clock compensation value of the PLL is 0-5 GHZ.

The technical solutions described above only represent the preferred technical solutions of the present invention, and some possible modifications to some parts of the technical solutions by those skilled in the art all represent the principles of the present invention, and fall within the protection scope of the present invention.