Cable cutting combination calculation method

Abstract

The invention belongs to the technical field of nuclear power plant engineering installation, and aims to solve the problems of low efficiency and waste caused by manual cable cutting calculation. The invention discloses a cable cutting combination calculation method, which comprises the steps of reading initial information, sorting cable lengths from long to short, finding a cable reel which can accommodate the current cable length and has the shortest residual length, if the cable reel is found, distributing cables to the cable reel, if the cable reel is not found, recording undistributed cables, and if the cable reel is not found, recording the undistributed cables. And outputting the information of the cable which does not find the matched cable reel, outputting the information of the cable which finds the matched cable reel, and outputting a result. The method provided by the invention can overcome material shortage caused by material waste due to manual calculation and cutting of the cable. Through scientific calculation, combination cutting of the cable reel is reasonably planned, materials are saved to the maximum extent, and the cable purchasing cost is reduced.

Description

Technical Field

[0001] This application belongs to the technical field of nuclear power plant engineering installation, and particularly relates to a cable cutting combination calculation method. Background Technique

[0002] For a certain nuclear power project DCS project, 71 cables of a certain type need to be installed and laid in the plant, and the total designed length is 12,716.441 meters. The lengths of these 71 cables are random, ranging from 633.311 meters to 17.769 meters.

[0003] The technology company provided 7 cable reels of this type of cable to the installation company for laying and installation. The lengths of the 7 cable reels are 400, 1000, 2000, 2000, 3000, 3000, and 3000 meters respectively, and the total length is 14,400 meters (greater than the designed total length). The installation company needs to cut out the above 71 cables from the 7 cable reels provided by the technology company for on-site laying and installation. The installation company randomly cut the above 7 cable reels according to the progress requirements of each plant, and cut 70 cables (a total of 71 cables) according to the designed length of each cable. The installation company found that the last cable with a length of 633.311 meters could not be cut out (lack of materials), but there were remainders after cutting the above 7 cable reels, which were relatively short lengths such as 140, 233, 53, 87, 61, and 89 meters.

[0004] The total length of the cable reels provided by the technology company is 1,684 meters greater than the designed total length, but the installation company reported a lack of materials. This is actually a cutting combination calculation problem. When cutting different cable combinations on the same cable reel, the utilization rate is different (the remainder of the cable reel is the least). The installation company did not perform pre-cutting calculations in advance, but randomly cut according to on-site requirements, resulting in a lack of materials in the end. Summary of the Invention

[0005] The purpose of this application is to provide a cable cutting combination calculation method to solve the problems of low efficiency and waste caused by manual calculation of cable cutting.

[0006] To achieve the above purpose, this application provides the following technical solutions:

[0007] This application provides a cable cutting combination calculation method, including:

[0008] Step 1: Read the initial information;

[0009] Step 2: Sort the cable lengths from long to short;

[0010] Step 3: Find the cable reel that can accommodate the current cable length and has the shortest remaining length;

[0011] Step 4: If the cable reel is found, allocate the cable to the cable reel;

[0012] Step 5: If the cable reel is not found, record the unallocated cable;

[0013] Step 6: Output the cable information for which no matching cable reel is found;

[0014] Step 7: Output the cable information for which a matching cable reel is found;

[0015] Step 8: Output the result.

[0016] As an implementable way, in Step 1, the initial information includes cable reel information and cable to be cut information.

[0017] As an implementable way, in Step 2, sort the cables to be cut in descending order of length, and the formula is:

[0018] S = Sort(C2, by v descending)

[0019] In the formula, C2 is a set whose elements are key-value pairs (k, v), k is a string, and v is a double-precision floating-point number; S represents a list, and the elements in it are key-value pairs (k, v) sorted in descending order of value v.

[0020] As an implementable way, Step 3 includes:

[0021] Step 3.1: For each cable c ∈ C;

[0022] Step 3.2: For each cable reel data (k, r) ∈ R;

[0023] Step 3.3: If R(k) ≥ L, execute Step 3.4; otherwise, enter the next loop;

[0024] Step 3.4: If R(k) - L < M, execute Step 3.5; otherwise, enter the next loop;

[0025] Step 3.5: Set M = R(k) - L;

[0026] Step 3.6: Set B = k;

[0027] In the formula, C is the set of sorted cables to be cut; R is the set of cable reels, and each element in it is a key-value pair (k, r), k is the key of the cable reel, and r is the current length; L is the required cable length; M is the minimum remaining length; B is the key of the best cable reel.

[0028] As an implementable way, among all the cable reels with the current length at least L, find the key of the cable reel that makes the difference between the current length and the required length the smallest, which is expressed as: B = arg k min{rk -L|(k, r k ) ∈ R, r k ≥ L}。

[0029] As an implementable way, among all the cable reels with a current length of at least L, find the minimum difference between the current length and the required length, expressed as: M = min{r k -L|(k, r k ) ∈ R, r k ≥ L}。

[0030] As an implementable way, in step 4, after determining a cable reel, record the cutting result, update the remaining length of the cable reel, and mark it as successfully matched; in step 5, when it is determined that a cable is not successfully matched to a cable reel, add the relevant information of the cable to the set of unmatched cables.

[0031] As an implementable way, in step 6, add the information of all the unmatched cables line by line to the data table to construct a data table containing the information of all the unmatched cables.

[0032] As an implementable way, in step 7, construct and record the cutting results of each cable reel, including the number, original length, remaining length of each cable reel, and the numbers and lengths of all the cut cables.

[0033] As an implementable way, in step 8, the output results include the cable reel and the numbers and lengths of the cables cut on it, the numbers and lengths of the cables that could not be cut, and the remaining amounts of each cable reel.

[0034] Compared with the prior art, the cable cutting combination calculation method provided by this application has the following beneficial effects:

[0035] The method provided by this application can overcome the shortage of materials caused by waste of materials in manual calculation of cable cutting. Through scientific calculation and reasonable planning of the combined cutting of cable reels, materials can be saved to the greatest extent and the cable procurement cost can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of this application, the following will briefly introduce the drawings required in the technical description.

[0037] Figure 1 is the flowchart of the cable cutting combination calculation method provided by this application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] The following will be further described in detail through specific embodiments.

[0039] Such as Figure 1As shown in the figure, an embodiment of the present application provides a combined calculation method for cable cutting, including the following steps:

[0040] Step 1: Read the initial information;

[0041] Step 2: Sort the cable lengths from long to short;

[0042] Step 3: Find the cable reel that can accommodate the current cable length and has the shortest remaining length;

[0043] Step 4: If a suitable cable reel is found, allocate the cable to this cable reel;

[0044] Step 5: If no suitable cable reel is found, record the unallocated cable;

[0045] Step 6: Output the cable information for which no matching cable reel is found;

[0046] Step 7: Output the cable information for which a matching cable reel is found;

[0047] Step 8: Output the result.

[0048] In Step 1, read (input) the cable reel information and read (input) the cable information to be cut.

[0049] In Step 2, sort the cables to be cut from long to short. The mathematical formula is expressed as:

[0050] S = Sort(C2, by v descending)

[0051] In the formula, C2 is a set whose elements are key-value pairs (k, v), k is a string, and v is a double-precision floating-point number. S is a list, and the elements in it are key-value pairs (k, v) arranged in descending order of value v.

[0052] In Step 3, find the best cable reel in a set of cable reel data. The remaining length of this cable reel is the smallest after cutting off the specified length. The calculation method is described as follows:

[0053] Let: C be the set of cables to be cut that have been sorted; R be the set of cable reels, where each element is a key-value pair (k, r), k is the key of the cable reel, and r is the current length; L be the length of the required cable; M be the minimum remaining length; B be the key of the best cable reel.

[0054] The mathematical representation of the calculation steps is as follows:

[0055] Step 3.1: For each cable c ∈ C;

[0056] Step 3.2: For each cable reel data (k, r) ∈ R;

[0057] Step 3.3: If R(k) ≥ L, execute step 3.4, otherwise enter the next loop;

[0058] Step 3.4: If R(k)-L <M执行步骤3.5,否则进入下一循环;

[0059] Step 3.5: Set M = R(k) - L;

[0060] Step 3.6: Set B=k.

[0061] The above process can be described as an optimization problem, where the goal is to minimize M, the remaining cable length after cutting. The constraint is R(k) ≥ L, which means that a cable drum is only considered if its length is at least equal to the required length.

[0062] In a more compact form, it can be written as:

[0063] B=arg k min{r k -L|(k,r k )∈R,r k ≥L}; (Formula 1)

[0064] M=min{r k -L|(k,r k )∈R,r k ≥L}; (Formula 2)

[0065] Formula 1 is: Among all cable reels whose current length is at least L, find the key of the cable reel that minimizes the difference between the current length and the required length;

[0066] Formula 2 is: Among all cable reels whose current length is at least L, find the minimum difference between the current length and the required length.

[0067] The above two formulas together describe the process of finding the best cable reel among a set of cable reels, where the best cable reel is the one that minimizes the remaining length after cutting the required length of cable.

[0068] In step 4, after determining an optimal cable drum, the cutting result is recorded, the remaining length of the cable drum is updated, and it is marked as a successful match.

[0069] In step 5, when it is determined that a cable is not successfully matched to a suitable cable reel, relevant information of the cable is added to a set of unmatched cables for subsequent processing or display.

[0070] In step 6, the information of all unmatched cables is added line by line to the data table to construct a data table containing the information of all unmatched cables for subsequent display or processing.

[0071] In step 7, the cutting results of each cable reel are constructed and recorded, including the number, original length, remaining length of each cable reel, and the numbers and lengths of all cut cables.

[0072] In step 8, the results are output to Excel. All results are output, including the cable reel number and the numbers and lengths of the cables cut on it, the numbers and lengths of the cables that could not be cut, and the remaining amount information of each cable reel.

[0073] Therefore, through the above reasonable planning of the combined cutting of cable reels, this embodiment can achieve the maximum material saving and reduce the cable procurement cost.

[0074] The above are only the specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered by the protection scope of the present application.

Claims

1. A combined calculation method for cable cutting, characterized in that, Including: Step 1: Read the initial information; Step 2: Sort the cable lengths from long to short; Step 3: Find the cable reel that can accommodate the current cable length and has the shortest remaining length; Step 4: If the cable reel is found, assign the cable to the cable reel; Step 5: If the cable reel is not found, record the unassigned cable; Step 6: Output the cable information for which no matching cable reel is found; Step 7: Output the cable information for which a matching cable reel is found; Step 8: Output the result.

2. The cable cutting combination calculation method according to claim 1, wherein In Step 1, the initial information includes cable reel information and cable information to be cut.

3. The cable cutting combination calculation method according to claim 1, characterized in that In Step 2, sort the cables to be cut from long to short, and the formula is: S = Sort(C2, by v descending) In the formula, C2 represents a set whose elements are key-value pairs (k, v), where k is a string and v is a double-precision floating-point number; S represents a list whose elements are key-value pairs (k, v) sorted in descending order by value v.

4. The cable cutting combination calculation method according to claim 1, characterized in that Step 3 includes: Step 3.1: For each cable c ∈ C; Step 3.2: For each cable reel data (k, r) ∈ R; Step 3.3: If R(k) ≥ L, execute Step 3.4; otherwise, enter the next loop; Step 3.4: If R(k) - L < M, execute Step 3.5; otherwise, enter the next loop; Step 3.5: Set M = R(k) - L; Step 3.6: Set B = k; In the formula, C represents the set of sorted cables to be cut; R represents the set of cable reels, where each element is a key-value pair (k, r), k is the key of the cable reel, and r is the current length; L represents the required cable length; M represents the minimum remaining length; B represents the key of the best cable reel.

5. The cable cutting combination calculation method according to claim 4, characterized in that, Among all current cable reels with a length of at least L, find the key of the cable reel that minimizes the difference between the current length and the required length, expressed as: B = arg k min{r k - L|(k, r k ) ∈ R, r k ≥ L}.

6. The cable cutting combination calculation method according to claim 4, wherein, Among all current cable reels with a length of at least L, find the minimum difference between the current length and the required length, expressed as: M = min{r k - L | (k, r k ) ∈ R, r k ≥ L}.

7. The cable cutting combination calculation method according to claim 1, characterized in that In Step 4, after determining a cable reel, record the cutting result, update the remaining length of the cable reel, and mark it as successfully matched; in Step 5, when it is determined that a cable is not successfully matched to a cable reel, add the relevant information of the cable to the set of unmatched cables.

8. The cable cutting combination calculation method according to claim 1, wherein In Step 6, add the information of all unmatched cables line by line to the data table to construct a data table containing the information of all unmatched cables.

9. The cable cutting combination calculation method according to claim 1, characterized in that In Step 7, construct and record the cutting results of each cable reel, including the number, original length, remaining length of each cable reel, and the numbers and lengths of all cut cables.

10. The cable cutting combination calculation method according to claim 1, wherein In Step 8, the output result includes the cable reel and the numbers and lengths of the cables cut on it, the numbers and lengths of the cables that cannot be cut, and the remaining amount information of each cable reel.

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