An adaptive separation method for mixed laser pulse trains

Abstract

The present invention relates to an adaptive separation method for a mixed laser pulse sequence, which comprises the following steps: 1) a photoelectric receiver senses the mixed laser signal and converts it into an impulse signal sequence Y(t); 2) an impulse train C with an approximately constant or slowly varying frequency is found in the impulse signal sequence Y(t). j (t) to achieve the separation of the impulse signal sequence Y(t); 3) each time find a C in Y(t) j (t), let Y(t)=Y(t)-C j (t) to update Y(t); 4) Calculate the number of impulse signals Sum in the updated Y(t) Y(t) , if Sum Y(t) =0, go to step 5), if Sum Y(t) ≠0, go to step 2); 5) restore the separated impulse signal sequence to a pulse sequence. This solves the problem of low application efficiency of the precision laser positioning system caused by the existing separation method.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic information signal separation, and relates to a method for separating a mixed laser pulse sequence, and in particular to an adaptive separation method for a mixed laser pulse sequence. Background Art

[0002] The precision laser positioning system is a distributed optoelectronic scanning positioning system for large-scale industrial measurement. It consists of laser transmitters, measurement nodes, a data processor, and a host computer. In practice, to achieve higher measurement accuracy and cover a larger measurement range, multiple laser transmitters are distributed throughout the measurement field. When these laser transmitters are networked for joint measurement, they use rotating laser planes to scan the entire measurement space. The measurement nodes receive the mixed laser signals, separate and identify them, and then determine the node coordinates.

[0003] Existing pulse train separation methods require the prior knowledge of the rotational speed of each laser transmitter in order to separate the signals. In actual measurement sites, hundreds of measurement nodes are distributed. Every change in the rotational speed of a laser transmitter requires re-programming the laser transmitter's rotational period information into each node, a costly task.

[0004] In practice, to avoid this, each laser transmitter has a strict rotation speed requirement, which is required to be as close as possible to the rotation period of the laser transmitter recorded in the node. However, this greatly reduces the application efficiency of the precision laser positioning system.

[0005] In view of the above technical defects of the prior art, there is an urgent need to develop a new method for separating mixed laser pulse sequences. Summary of the Invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and propose an adaptive separation method for mixed laser pulse sequences. This method can automatically decompose the mixed laser pulse sequence perceived by the measurement node into a group of impulse trains that are not strictly stationary or have slowly changing frequencies, thereby greatly improving the application efficiency of the precision laser positioning system.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A method for adaptively separating a mixed laser pulse sequence, characterized by comprising the following steps:

[0009] 1) The photoelectric receiver senses the mixed laser signal and converts it into an impulse signal sequence Y(t);

[0010] 2) Find an impulse train C with an approximately constant or slowly changing frequency in the impulse signal sequence Y(t) j (t), so as to realize the separation of the impulse signal sequence Y(t);

[0011] 3) Find a C in Y(t) each time j (t), let Y(t) = Y(t) - C j (t) to update Y(t);

[0012] 4) Calculate the number of impulse signals Sum in the updated Y(t) Y(t) , if Sum Y(t) =0, go to step 5), if Sum Y(t) ≠0, go to step 2);

[0013] 5) Restore the separated impulse signal sequence to a pulse sequence.

[0014] Preferably, the step 1) is specifically as follows:

[0015] 1.1) The photoelectric receiver converts the sensed mixed laser signal into a pulse signal sequence X(t) through photoelectric conversion and binarization circuit, and records the rising edge time of each pulse signal in the pulse signal sequence X(t). And the pulse width d of each pulse signal k , k = 1, 2, 3…N, represents the sequence number of the pulse signal in X(t);

[0016] 1.2) Calculate the total number N of pulse signals in X(t) and the median time t of each pulse signal in X(t) k ,in, According to t k Get the impulse signal δ(tt of each pulse signal k ), according to δ(tt k ) to obtain the impulse signal sequence

[0017] Preferably, the step 2) is specifically as follows:

[0018] 2.1) Calculate the maximum time scale T of the impulse signal sequence Y(t) max , and set the maximum error offset offset allowed for strict periodicity when Y(t) is separated;

[0019] 2.2) Initialize variables, set m = 1, n = 2;

[0020] 2.3) Record the time t corresponding to the mth and nth impulse signals in Y(t) m and t n, and let C j (t) = δ(tt m )+δ(tt n ), where j represents the number of impulse trains with approximately constant or slowly varying frequencies in Y(t), and its initial value is 0;

[0021] 2.4) Calculation time window W mn ({W mn :a mn ≤W mn ≤b mn}), where a mn =2t n -t m -offset,b mn =2t n -t m +offset, if Y(t) is in W mn If there is an impulse signal within the range of mn If there is no impulse signal, go to step 2.6.

[0022] 2.5) Record W mn Middle distance 2t n -t m The most recent impulse signal δ(tt w ), tw represents the distance 2t n -t m The moment corresponding to the most recent impulse signal, let C j (t) = C j (t)+δ(tt w ), t m =t n , t n =t w And return to step 2.4);

[0023] 2.6) Determine W mn The lower limit of time 2t n -t m - Whether offset is greater than T max If no, go to step 2.7); if yes, go to step 2.8);

[0024] 2.7) Determine whether n in step 2.3) is greater than N / 2. If not, set n=n+1 and go to step 2.3). If yes, determine δ(tt m ) is the disturbance signal, and let Y(t)=Y(t)-δ(tt m ) Go to step 2.2);

[0025] 2.8) Set j = j + 1 and save C j (t).

[0026] Preferably, the step 5) is specifically as follows:

[0027] 5.1) Record C j Each impulse signal in (t) of Where r=1,2,3…; r represents C j (t) The sequence number of the impulse signal;

[0028] 5.2) Find the t recorded in step 1.2) k and make Equal to t k , and extract the k The corresponding pulse width d k ;

[0029] 5.3) Afterwards, As the pulse width center moment of the pulse signal, Generate a pulse signal for the pulse signal pulse width

[0030] Compared with the prior art, the adaptive separation method of the hybrid laser pulse sequence of the present invention has one or more of the following beneficial technical effects:

[0031] 1. The present invention can automatically decompose the mixed laser pulse sequence perceived by the measurement node into a group of pulse trains that are not strictly stable or have slowly changing frequencies, thereby eliminating the need to specify a strict rotation speed for the laser transmitting station and greatly improving the application efficiency of the precision laser positioning system.

[0032] 2. The separation method of the present invention is simple, practical and easy to promote and apply. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a flow chart of the adaptive separation method of the mixed laser pulse sequence of the present invention. DETAILED DESCRIPTION

[0034] The present invention will be further described below with reference to the accompanying drawings and examples, and the contents of the examples are not intended to limit the scope of protection of the present invention.

[0035] In response to the problem of low application efficiency of precision laser positioning systems, the present invention proposes an adaptive separation method for mixed laser pulse sequences. This method can automatically decompose the mixed laser pulse sequence perceived by the measurement node into a group of impulse trains that are not strictly stationary or have slowly changing frequencies, thereby eliminating the need to specify strict rotation speeds for the laser transmitting station and greatly improving the application efficiency of the precision laser positioning system.

[0036] Figure 1 FIG. 4 is a flow chart showing the adaptive separation method of the mixed laser pulse sequence of the present invention. Figure 1 As shown, the adaptive separation method of the mixed laser pulse sequence of the present invention includes the following steps:

[0037] 1. The photoelectric receiver senses the mixed laser signal and converts it into an impulse signal sequence Y(t).

[0038] After sensing the mixed laser signals emitted by multiple laser transmitters, the photoelectric receiver converts them into a mixed pulse signal sequence through its own photoelectric conversion and binarization circuits. To facilitate the implementation of the present invention, it is necessary to convert the obtained mixed pulse signal sequence into an impulse signal sequence Y(t) to facilitate the separation of the pulse signal sequence.

[0039] In the present invention, the photoelectric receiver senses the mixed laser signal and converts it into an impulse signal sequence Y(t), specifically including:

[0040] 1.1. After the photoelectric receiver senses the mixed laser signals emitted by multiple laser transmitters, it converts the sensed mixed laser signals into a pulse signal sequence X(t) through its own photoelectric conversion and binarization circuit; at the same time, it records the rising edge time of each pulse signal in the pulse signal sequence X(t). And the pulse width d of each pulse signal k , where k = 1, 2, 3…N, represents the sequence number of the pulse signal in X(t).

[0041] 1.2. Calculate the total number N of pulse signals in X(t) and calculate the median time t of each pulse signal in X(t) k ,in, Afterwards, according to t k Get the impulse signal δ(tt of each pulse signal k ), according to δ(tt k ) to obtain the impulse signal sequence

[0042] 2. Find an impulse train C with an approximately constant or slowly changing frequency in the impulse signal sequence Y(t) j (t), so as to realize the separation of the impulse signal sequence Y(t).

[0043] In the present invention, the impulse trains C with approximately constant or slowly varying frequencies are found in the impulse signal sequence Y(t). j (t), thereby achieving the separation of the impulse signal sequence Y(t).

[0044] In the present invention, the following steps are performed to find an impulse train C with an approximately constant or slowly changing frequency in the impulse signal sequence Y(t): j (t):

[0045] 2.1. Calculate the maximum time scale T of the impulse signal sequence Y(t) max , and set the maximum error offset offset allowed for strict periodicity when Y(t) is separated.

[0046] 2.2. Initialize variables, set m=1, n=2.

[0047] 2.3. Record the time t corresponding to the mth and nth impulse signals in the impulse signal sequence Y(t) m and t n , and let C j (t) = δ(tt m )+δ(tt n ), where j represents the order of the impulse trains with approximately constant or slowly varying frequencies in Y(t), and its initial value is 0.

[0048] 2.4. Calculation time window W mn {W mn :a mn ≤W mn ≤b mn}), where a mn =2t n -t m -offset,b mn =2t n -t m +offset, if Y(t) is in W mn If there is an impulse signal within the range of mn If there is no impulse signal, proceed to step 2.6.

[0049] 2.5. Record W mn Middle distance 2t n -t m The most recent impulse signal δ(tt w ), tw represents the distance 2t n -t m The moment corresponding to the most recent impulse signal, let C j (t) = C j (t)+δ(tt w ), t m =t n , t n =t w And return to step 2.4.

[0050] 2.6. Determine W mn The lower limit of time 2t n -t m - Whether offset is greater than T max If no, go to step 2.7; if yes, go to step 2.8.

[0051] 2.7. Determine whether n in step 2.3 is greater than N / 2. If not, set n=n+1 and go to step 2.3. If yes, determine δ(tt m ) is the disturbance signal, and let Y(t)=Y(t)-δ(tt m ) Go to step 2.2;

[0052] 2.8. Set j = j + 1 and save C j (t).

[0053] 3. Find a C in Y(t) each time j (t), let Y(t) = Y(t) - C j (t) is used to update Y(t), so as to facilitate the next separation of Y(t).

[0054] 4. Calculate the number of impulse signals Sum in the updated Y(t) Y(t) , if Sum Y(t) =0, go to step 5. If Sum Y(t) ≠0, go to step 2.

[0055] In the present invention, through this step, it can be determined whether the impulse signal still exists in the updated Y(t). If the impulse signal still exists, the updated Y(t) is substituted into step 2 to start the next separation, and the process continues until the impulse signal no longer exists in the updated Y(t), thereby achieving the separation of Y(t). If the impulse signal does not exist, the process proceeds to step 5 for processing.

[0056] Through the above steps, we finally get:

[0057]

[0058] In the formula, each C j (t) is an impulse train with an approximately constant or slowly varying frequency. j represents the number of impulse trains found, which is at most n. R(t) represents the disturbance signal in Y(t). It can be obtained by subtracting C from the original aliased impulse train. j At the measurement site, R(t) may be the reflection of ambient light or a short-lived signal from a transmitter that cannot be used.

[0059] 5. Restore the separated impulse signal sequence to a pulse sequence.

[0060] Since what is obtained after separation is a separated impulse signal, it is also necessary to restore the separated impulse signal sequence to a pulse sequence.

[0061] In the present invention, restoring the separated impulse signal sequence to a pulse sequence specifically includes:

[0062] 5.1. Record each impulse string C after separation j Each impulse signal in (t) of Where r = 1, 2, 3…; r represents the impulse train C j (t) is the sequence number of the impulse signal.

[0063] 5.2. Find the t recorded in step 1.2 k and make Equal to t k , extract the t k The corresponding pulse width d k .

[0064] 5.3, Order Afterwards, As the pulse width center moment of the pulse signal, Generate a pulse signal for the pulse signal pulse width

[0065] The adaptive separation method of the mixed laser pulse sequence of the present invention can automatically decompose the mixed laser pulse sequence perceived by the measurement node into a group of pulse trains that are not strictly stable or have slowly changing frequencies, thereby eliminating the need to specify a strict rotation speed for the laser launch station and greatly improving the application efficiency of the precision laser positioning system.

[0066] The above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications based on the above description are possible. It is not possible to enumerate all embodiments here. Any obvious variations or modifications arising from the technical solutions of the present invention remain within the scope of protection of the present invention.

Claims

1. An adaptive separation method for mixed laser pulse trains, characterized in that: The following steps are involved: 1) The photoelectric receiver senses the mixed laser signal and converts it into an impulse signal sequence Y(t); 2) Find an impulse train C with an approximately constant or slowly changing frequency in the impulse signal sequence Y(t) j (t), so as to realize the separation of the impulse signal sequence Y(t); 3) Find a C in Y(t) each time j (t), let Y(t) = Y(t) - C j (t) to update Y(t); 4) Calculate the number of impulse signals Sum in the updated Y(t) Y(t) , if Sum Y(t) =0, go to step 5), if Sum Y(t) ≠0, go to step 2); 5) Restore the separated impulse signal sequence to a pulse sequence.

2. The method for adaptive separation of mixed laser pulse sequences according to claim 1, characterized in that: The step 1) is specifically as follows: 1.1) The photoelectric receiver converts the sensed mixed laser signal into a pulse signal sequence X(t) through photoelectric conversion and binarization circuit, and records the rising edge time of each pulse signal in the pulse signal sequence X(t). And the pulse width d of each pulse signal k , k = 1, 2, 3…N, represents the sequence number of the pulse signal in X(t); 1.2) Calculate the total number N of pulse signals in X(t) and the median time t of each pulse signal in X(t) k ,in, According to t k Get the impulse signal δ(tt of each pulse signal k ), according to δ(tt k ) to obtain the impulse signal sequence 3. The adaptive separation method of mixed laser pulse sequence according to claim 2, characterized in that: The step 2) is specifically as follows: 2.1) Calculate the maximum time scale T of the impulse signal sequence Y(t) max , and set the maximum error offset offset allowed for strict periodicity when Y(t) is separated; 2.2) Initialize variables, set m = 1, n = 2; 2.3) Record the time t corresponding to the mth and nth impulse signals in Y(t) m and t n , and let C j (t) = δ(tt m )+δ(tt n ), where j represents the number of impulse trains with approximately constant or slowly varying frequencies in Y(t), and its initial value is 0; 2.4) Calculation time window W mn , a mn ≤W mn ≤b mn , where a mn =2t n -t m -offset,b mn =2t n -t m +offset, if Y(t) is in W mn If there is an impulse signal within the range of mn If there is no impulse signal, go to step 2.

6. 2.5) Record W mn Middle distance 2t n -t m The most recent impulse signal δ(tt w ), t w Indicates distance 2t n -t m The moment corresponding to the most recent impulse signal, let C j (t) = C j (t)+δ(tt w ), t m =t n , t n =t w And return to step 2.4); 2.6) Determine W mn The lower limit of time 2t n -t m - Whether offset is greater than T max If no, go to step 2.7); if yes, go to step 2.8); 2.7) Determine whether n in step 2.3) is greater than N / 2. If not, set n=n+1 and go to step 2.3). If yes, determine δ(tt m ) is the disturbance signal, and let Y(t)=Y(t)-δ(tt m )Go to step 2.2); 2.8) Set j = j + 1 and save C j (t).

4. The method for adaptive separation of mixed laser pulse sequences according to claim 3, characterized in that: The step 5) is specifically as follows: 5.1) Record C j Each impulse signal in (t) of Where r=1,2,3…; r represents C j (t) The sequence number of the impulse signal; 5.2) Find the t recorded in step 1.2) k and make Equal to t k , and extract the k The corresponding pulse width d k ; 5.3) Afterwards, As the pulse width center moment of the pulse signal, Generate a pulse signal for the pulse signal pulse width

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