A method for optimizing the collection and transfer routes and cycles of rural domestic waste

Abstract

The present invention provides a method for optimizing the routes and cycles for the collection and transfer of rural domestic waste. Combining the estimation of the amount of domestic waste generated and the characteristics of the waste by residents in rural and pastoral areas, the method simulates the routes for the collection and transfer of domestic waste based on an ant colony algorithm. Time cost replaces the original route distance, and additional economic costs such as fuel consumption, including the route length, are fully considered to optimize the routes for the collection and transfer of waste. This method improves transportation efficiency while saving economic costs, fully utilizes existing resources, improves the efficiency of domestic waste collection and transfer, and has good adaptability to rural and pastoral areas of the Qinghai-Tibet Plateau. It provides a scientific basis for achieving optimal disposal of rural domestic waste and building a stable and long-term mechanism.

Description

Technical Field

[0001] The present invention relates to the field of garbage collection and transportation, and in particular to a method for optimizing the collection and transportation routes and cycles of rural domestic garbage. Background Art

[0002] Rural domestic waste is a comprehensive waste stream generated by residents in rural and pastoral areas during their daily lives. Domestic waste pollution can adversely impact residents' health and the ecological environment. Therefore, rural domestic waste management is a key area of ​​environmental improvement for both urban and rural residents. However, the configuration of a domestic waste collection and transfer system in rural and pastoral areas is a weak link in environmental infrastructure development. Most rural areas primarily utilize a domestic waste management model of "village collection, town (village) transfer, and county treatment." However, rural and pastoral settlements in different regions prioritize different aspects of this model.

[0003] In the Qinghai-Tibet Plateau, rural and pastoral settlements are scattered, residents have unique lifestyles and production patterns, and the ecological environment is fragile. Waste management suffers from inadequate management, inadequate facilities, a lack of social awareness and funding, and low environmental awareness among villagers. The lack of scientific and effective disposal of rural domestic waste poses a serious challenge to the ecological carrying capacity.

[0004] Therefore, it is urgent to take ecological benefits, social benefits and economic benefits as optimization goals, explore the path planning and flexible management measures of a zero-coercion, equalized and low-cost rural domestic waste collection and transportation system, effectively improve the quality of the human living environment in rural and pastoral areas of the Qinghai-Tibet Plateau, and ensure the ecological and environmental safety of ecological barrier areas.

[0005] Currently, research on rural domestic waste collection and transportation is relatively weak, focusing primarily on preliminary discussions of pollution characteristics, transportation models, and treatment technologies. However, research on optimizing domestic waste collection and transportation in rural and pastoral areas of the Qinghai-Tibet Plateau is almost nonexistent. Compared to cities, research on optimizing rural domestic waste collection and transportation systems should not only consider route distances, but also factors such as ecological impacts, living habits, and characteristic components that influence the economic costs and environmental benefits of domestic waste collection and transportation. This should also be considered as an important aspect of equalizing basic environmental public services, while also taking into account the social benefits of environmental equity.

[0006] Therefore, technicians in this field are committed to developing a method for optimizing the collection and transfer routes and cycles of rural domestic waste to address the shortcomings of the above-mentioned existing technologies. Summary of the Invention

[0007] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is that there is currently no public method for optimizing the collection and transportation of domestic waste in rural and pastoral areas of the Qinghai-Tibet Plateau.

[0008] To achieve the above objectives, the present invention provides a method for optimizing the collection and transfer routes and cycles of rural domestic waste. Based on the estimation of the amount of domestic waste generated by farmers and herdsmen and the characteristics of the waste, the method simulates the domestic waste collection and transfer routes in Milin County using an ant colony algorithm.

[0009] The specific steps include:

[0010] Step 1: Based on the field survey method, calculate the average amount of domestic waste collected and transported according to the tonnage of garbage trucks, and use the improved vehicle tonnage method to estimate the daily amount of domestic waste generated by indigenous peoples y d , the formula is shown in (1):

[0011] y d =y q ×k s ×k c (1)

[0012] In formula (1),

[0013] y q The average daily volume of domestic waste collected and transported by vehicle tonnage, in kilograms per day (kg / d);

[0014] k s is the landfill leachate coefficient;

[0015] k c is the load utilization coefficient of the garbage truck;

[0016] y d Conduct summary statistics to calculate the daily scale of domestic waste collection and transportation at the three levels of "village collection, town transfer, and county treatment";

[0017] Step 2: Based on the ant colony algorithm, the garbage truck is regarded as an ant, and the next node to be visited is determined according to the pheromone concentration on the path connecting each node (residential site). The main variables and parameters are determined, including the number of ants k, nodes i and j, pheromone constant Q, pheromone factor α, heuristic function factor β, pheromone volatility factor ρ, and maximum number of iterations t.

[0018] The number of ants k is the number of garbage trucks working, and its value depends on each township;

[0019] The nodes i and j are garbage collection and transfer points, and their values ​​are determined by each township;

[0020] The pheromone constant Q represents the total amount of pheromone released by the ants in one cycle;

[0021] The pheromone factor α represents the importance of pheromone concentration and the search range of the ant colony;

[0022] The heuristic function factor β reflects the relative importance of heuristic information in guiding ant search, and the strength of the effects of a priori and deterministic factors in the ant colony optimization process;

[0023] The pheromone volatility factor ρ reflects the volatility of the pheromone, and 1-ρ reflects the retention level of the pheromone, which is the pheromone residual coefficient;

[0024] The maximum number of iterations t is the number of times the calculation is repeated to reach the optimal path;

[0025] Step 3: Comprehensively consider the additional economic costs in the process of receiving and transporting, and replace the original path distance with the time cost.

[0026] The calculation of domestic waste collection and transfer routes is as follows:

[0027]

[0028] In formula (2),

[0029] l ij is the length of the road that the garbage truck travels from node i to node j;

[0030] v ij is the speed of the garbage truck;

[0031] Step 4: After all ants complete a cycle, the pheromone concentration on the connection path between each node needs to be updated. The calculation formula is as follows (3) and (4):

[0032] τ ij (t+1)=(1-ρ)τ ij (t)+Δτ ij (3)

[0033]

[0034] In formula (3) and (4),

[0035] represents the pheromone concentration released by the kth ant on the path connecting node i and node j at time t;

[0036] Δτ ij (t) represents the sum of the pheromone concentrations released by all ants on the path connecting node i and node j at time t;

[0037] Based on the ant-week model, global information is used for calculation; the calculation formula is as follows (5):

[0038]

[0039] In formula (5),

[0040] Q is the pheromone constant;

[0041] T k is the time cost of the kth ant traveling from node i to node j; Step 5: Based on the optimal path, optimize the collection and transportation routes and cycles of domestic waste in rural and pastoral areas; taking into account the amount of domestic waste generated in rural and pastoral areas and the existing road network, reduce the frequency of garbage truck collection in months with significantly less domestic waste generation; collect and transport garbage once every 5 days or so in remote areas; and rationally adjust the collection routes to optimize the collection and transportation cycles of domestic waste;

[0042] Furthermore, in step 2, the pheromone constant Q has a value range of 10≤Q≤10000;

[0043] Furthermore, in step 2, the value range of the pheromone factor α is 0≤α≤5;

[0044] Furthermore, in step 2, the value range of the heuristic function factor β is 0≤β≤5;

[0045] Furthermore, in step 2, the pheromone volatility factor ρ has a value range of 0<ρ<1;

[0046] Furthermore, in step 2, the maximum number of iterations t is in the range of 100≤t≤500;

[0047] In a specific embodiment of the present invention, in step 2, the pheromone constant Q is 100;

[0048] In a specific embodiment of the present invention, in step 2, the pheromone factor α is set to 1;

[0049] In a specific embodiment of the present invention, in step 2, the heuristic function factor β is set to 2;

[0050] In a specific embodiment of the present invention, in step 2, the pheromone volatility factor ρ is 0.1;

[0051] In a specific embodiment of the present invention, in step 2, the maximum number of iterations t is 200;

[0052] By adopting the above scheme, the rural domestic waste collection and transfer path and cycle optimization method disclosed in the present invention has the following advantages:

[0053] The rural domestic waste collection and transfer route and cycle optimization method of the present invention combines the estimation of residents' domestic waste generation and waste characteristics, and simulates the domestic waste collection and transfer route based on the ant colony algorithm, replacing the original path distance with time cost, and fully considering additional economic costs such as fuel consumption including path length to optimize the waste collection and transfer route, thereby improving transportation efficiency while reducing economic costs. It can fully utilize existing resources, improve the efficiency of domestic waste collection and transfer, and has good adaptability to rural and pastoral areas of the Qinghai-Tibet Plateau, providing a scientific basis for achieving optimal disposal of domestic waste in rural and pastoral areas of the Qinghai-Tibet Plateau.

[0054] The concept, specific technical solutions and technical effects of the present invention will be further described below in conjunction with specific implementation methods to fully understand the purpose, characteristics and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 This is a schematic diagram of the location and scope of the study area of ​​Example 1 of the present invention;

[0056] Figure 2 This is a graph of household waste generation and removal frequency according to Example 1 of the present invention;

[0057] Figure 3 This is a schematic diagram of the location of the Milin County domestic waste landfill and the amount of domestic waste generated in residential areas according to Example 1 of the present invention;

[0058] Figure 4 This is the optimal domestic waste collection route map for each township in Milin County according to Example 1 of the present invention;

[0059] Figure 5 This is a comparison diagram of the spatial distribution of domestic waste in Milin County before and after optimization of the route of domestic waste in Example 1 of the present invention;

[0060] Figure 6 This is a schematic diagram of the optimization results of the domestic waste collection and transfer routes in Milin County according to Example 1 of the present invention;

[0061] Figure 1 In the figure, a is the geographical location of the case area on the Qinghai-Tibet Plateau; b is the topographic distribution of Milin County;

[0062] Figure 4 Among them, a is Danniang Township; b is Lilong Township; c is Milin Town, Qiangna Township, and Nanyi Luoba Nationality Township; d is Zhaxi Raodeng Township; e is Wolong Town; f is Pai Town;

[0063] Figure 5 Where a is the spatial distribution of the current domestic waste collection and transfer routes; the optimal path spatial distribution based on the improved ant colony algorithm; DETAILED DESCRIPTION

[0064] The following describes several preferred embodiments of the present invention to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, which are for illustrative purposes only and the scope of protection of the present invention is not limited to the embodiments mentioned herein.

[0065] Example 1: A method for optimizing the collection and transfer routes and cycles of rural domestic waste

[0066] Case area: Milin County, located at 28°39′N~29°50′N, 93°07′E~95°12′E, is located in the southeastern part of the Qinghai-Tibet Plateau, southwest of Nyingchi City, and in the middle and lower reaches of the Yarlung Zangbo River; Figure 1 As shown;

[0067] Data involved: including geographic element data, socio-economic and demographic data, domestic waste transfer facility operation and traffic network data; the geographic element data include digital elevation model (DEM), land use map, and administrative division map. DEM data comes from the Resource and Environmental Science Data Center of the Chinese Academy of Sciences, and the raster data accuracy is 30m×30m; the land use map comes from the land use status survey data of the local natural resources management department; the administrative division map is extracted from the land use map, including the boundaries of counties, towns and administrative villages; the socio-economic and demographic data include urban and rural permanent population, tourist population, etc., and come from local ecological environment, cultural tourism, urban management and other departments; the domestic waste transfer facility operation and traffic network data, including landfills and ancillary facilities and roads at all levels, mainly come from local government departments and national basic geographic information data statistics; and data verification is carried out through field surveys;

[0068] Step 1: Based on the field survey method, calculate the average amount of domestic waste collected and transported according to the tonnage of garbage trucks, improve the vehicle tonnage method, and calculate the daily amount of domestic waste generated in rural and pastoral areas. d The estimation formula is shown in (1):

[0069] y d =y q ×k s ×k c (1)

[0070] In formula (1),

[0071] y q The average daily volume of domestic waste collected and transported by vehicle tonnage, in kilograms per day (kg / d);

[0072] k s is the leachate coefficient (can be ignored if direct transportation);

[0073] k cis the load utilization coefficient of the garbage truck;

[0074] y d Conduct summary statistics to calculate the daily scale of domestic waste collection and transportation at the three levels of "village collection, town transfer, and county treatment";

[0075] Step 2: Based on the ant colony algorithm, the garbage truck is regarded as an ant, and the next node to be visited is determined according to the pheromone concentration on the path connecting each node (residential site). The main variables and parameters are determined, including the number of ants k, nodes i and j, pheromone constant Q, pheromone factor α, heuristic function factor β, pheromone volatility factor ρ, and maximum number of iterations t.

[0076] The number of ants k is the number of garbage trucks working, and its value depends on each township;

[0077] The nodes i and j are garbage collection and transfer points, and their values ​​are determined by each township;

[0078] The pheromone constant Q represents the total amount of pheromone released by the ants in one cycle;

[0079] The pheromone factor α represents the importance of pheromone concentration and the search range of the ant colony;

[0080] The heuristic function factor β reflects the relative importance of heuristic information in guiding ant search, and the strength of the effects of a priori and deterministic factors in the ant colony optimization process;

[0081] The pheromone volatility factor ρ reflects the volatility of the pheromone, and 1-ρ reflects the retention level of the pheromone, which is the pheromone residual coefficient;

[0082] The maximum number of iterations t is the number of times the calculation is repeated to reach the optimal path;

[0083] The main variables and parameters of Milin County are shown in Table 1 ;

[0084] Table 1 Main variables and parameters of ant colony algorithm

[0085]

[0086] Step 3: Comprehensively consider the additional economic costs in the process of receiving and transporting, and replace the original path distance with the time cost.

[0087] The calculation of domestic waste collection and transfer routes is as follows:

[0088]

[0089] In formula (2),

[0090] l ijis the length of the road that the garbage truck travels from node i to node j;

[0091] v ij is the speed of the garbage truck;

[0092] Step 4: After all ants complete a cycle, the pheromone concentration on the connection path between each node needs to be updated. The calculation formula is as follows (3) and (4):

[0093] τ ij (t+1)=(1-ρ)τ ij (t)+Δτ ij (3)

[0094]

[0095] In formula (3) and (4),

[0096] represents the pheromone concentration released by the kth ant on the path connecting node i and node j at time t;

[0097] Δτ ij (t) represents the sum of the pheromone concentrations released by all ants on the path connecting node i and node j at time t;

[0098] Based on the ant-week model, global information is used for calculation; the calculation formula is as follows (5):

[0099]

[0100] In formula (5),

[0101] Q is the pheromone constant;

[0102] T k is the time cost of the kth ant traveling from node i to node j;

[0103] Step 5: Based on the optimal route, optimize the collection and transportation routes and cycles for domestic waste in rural and pastoral areas. Considering the amount of domestic waste generated in rural and pastoral areas and the existing road network, reduce the frequency of garbage truck collection in months with significantly lower domestic waste generation. For geographically remote areas, collection should be conducted approximately every five days. Rationally adjust collection routes to optimize the collection and transportation cycles for domestic waste.

[0104] In 2020, the amount of domestic waste collected and transported by various villages and towns in Milin County was 265.43 tons. The daily domestic waste production of residents in the county was about 8.07 tons / day. The amount of domestic waste generated in each month is shown in the table below. Figure 2 ;

[0105] Milin County’s domestic waste treatment facility is the Milin County’s domestic waste landfill, with a designed storage capacity of 84,000 m3, a designed service life of 15 years, a daily processing capacity of 11 tons, and a daily transportation distance of approximately 985.26 km. Its geographical location is closely related to Milin County’s road traffic and residential waste production. Figure 3 As shown. Daily processing time is from 9 am to 5 pm. There are 42 garbage trucks in total, with a collection frequency of 8 times / day. A garbage truck collection cycle takes 30 to 40 minutes, and they work in shifts. Milin County's existing domestic waste collection and transportation system is centered around the landfill. Garbage trucks depart from the treatment station, collect domestic waste from various villages and bring it to the township, and then send it to the landfill for treatment.

[0106] In this embodiment 1, the optimization method of the present invention is used to obtain the optimal domestic waste collection path for each township in Matlab software. Figure 4 As shown;

[0107] Qiangna Township and Nanyi Luoba Township are close to the Milin County municipal solid waste landfill and are located on the east and west sides of Milin Town, respectively. Most of their villages are located on both sides of traffic arteries. They are numerous and densely distributed compared to other townships, and have good transportation conditions. Therefore, the domestic waste collection routes of these villages are comprehensively planned to improve the operating efficiency of garbage trucks. The transfer point in Danniang Township is located between the collection points of each village. Therefore, two garbage trucks are dispatched daily to Baila Village and Mailang Village to operate simultaneously, shortening the garbage collection time. Pai Town is located on the north side of the Yarlung Zangbo Grand Canyon. The roads are greatly restricted by the terrain. It is necessary to set up routes on both sides of the Yarlung Zangbo River. At the same time, containerized garbage trucks are deployed to operate during the peak tourist season from March to July to September. Tongburong Village, northwest of Zhaxi Raodeng Township, is located in a remote area. The daily garbage collection cost of garbage trucks is high and the efficiency is low, so it is considered to be collected every five days. The improved ant colony algorithm was applied to the route optimization of rural domestic waste collection and transfer in Milin County. The average daily transportation mileage of garbage trucks was 919.02 km, which reduced the average daily transportation mileage of garbage trucks by 66.24 km. Periodic adjustment based on the optimized collection and transfer route shortened the average daily transportation mileage by 28.53%, saving a total of 31.20% of economic costs.

[0108] The comparison of transport mileage and cost before and after optimization is shown in Table 2, and the comparison of spatial distribution is shown in Figure 5 ;

[0109] Table 2 Comparison of domestic waste collection and transportation distance and cost before and after optimization

[0110]

[0111]

[0112] The amount of domestic waste generated by residents in Milin County is shown to be large from November to February and from May to August each year, which is 9.01 tons and 12.48 tons higher than usual respectively. The amount generated in other months is small. Therefore, it is necessary to adjust the frequency of garbage truck collection and transportation accordingly, flexibly respond to seasonal fluctuations, and maximize the use of garbage trucks to achieve the optimization of the domestic waste collection and transportation cycle. The results after optimization are compared. Figure 6 ;

[0113] This shows that the cycle optimization method of the present invention can reduce the transfer distance, reduce the transfer cost, save time and improve the efficiency of garbage truck removal, which has practical significance;

[0114] To sum up, this patented technical solution, combined with the estimation of the amount of domestic waste generated by rural and pastoral residents and the characteristics of the waste, simulates the domestic waste collection and transfer routes based on the ant colony algorithm, replaces the original path distance with time cost, and fully considers additional economic costs such as fuel consumption including path length to optimize the garbage collection and transfer routes, thereby improving transportation efficiency while reducing economic costs. It can make full use of existing resources, improve the efficiency of domestic waste collection and transfer, and has good adaptability to rural and pastoral areas of the Qinghai-Tibet Plateau, providing a scientific basis for achieving the optimal disposal of rural domestic waste and building a stable and long-term mechanism.

[0115] The above describes in detail the preferred embodiments of the present invention. It should be understood that numerous modifications and variations based on the concepts of the present invention can be made by those skilled in the art without inventive effort. Therefore, any technical solution that can be derived by those skilled in the art based on the concepts of the present invention through logical analysis, reasoning, or limited experimentation based on the existing technology should be within the scope of protection defined by the claims.

Claims

1. A method for optimizing the collection and transfer routes and cycles of rural domestic waste, characterized in that: The steps include: Step 1: Based on the field survey method, calculate the average daily volume of domestic waste collected according to the tonnage of garbage trucks, and use the improved vehicle tonnage method to estimate the daily volume of domestic waste generated by indigenous peoples. , the formula is shown in (1): （1） In formula (1), The average daily volume of domestic waste collected and transported by vehicle tonnage, in kilograms per day (kg / d); is the landfill leachate coefficient; is the load utilization coefficient of the garbage truck; right Conduct summary statistics and sequentially calculate the daily scale of domestic waste collection and transportation at the three levels of "village collection, town transfer, and county treatment"; Step 2: Based on the ant colony algorithm, the garbage truck is regarded as an ant, and its next visit node is determined according to the pheromone concentration on the path connecting each settlement; the main variables and parameters are determined, including the number of ants. , pheromone factors , heuristic function factor , pheromone volatile factors , maximum number of iterations ; The number of ants The number of garbage trucks on duty is determined by each township; described It is a garbage collection and transfer point, and its value depends on each township; described ; The pheromone factor , The heuristic function factor It reflects the relative importance of heuristic information in guiding ant search, and the strength of the effects of a priori and deterministic factors in the ant colony's optimization process; The pheromone volatility factor Reflects the volatility of pheromones, 1- It reflects the level of pheromone retention and is the pheromone residual coefficient; The maximum number of iterations The number of times the calculation is repeated to reach the optimal path; Step 3: Comprehensively consider the additional economic costs in the process of receiving and transporting, and replace the original path distance with the time cost. The calculation of domestic waste collection and transfer routes is as follows (2): （2） In formula (2), For garbage truck slave node To Node Length of the road traversed; is the speed of the garbage truck; Step 4: After all ants complete a cycle, the pheromone concentration on the connection path between each node needs to be updated. The calculation formula is as follows (3) and (4): （3） （4） In formula (3) and (4), express Moment Only ants on the node With node the concentration of pheromones released along the connecting pathway; express All ants are at the node With node The sum of the pheromone concentrations released along the connecting path; Based on the ant-week model, global information is used for calculation; the calculation formula is as follows (5): （5） In formula (5), Q is the pheromone constant; for The time cost between Step 5: Based on the optimal route, optimize the collection and transportation routes and cycles of domestic waste in rural and pastoral areas; combine the amount of domestic waste generated in rural and pastoral areas with the existing road network to reduce the frequency of garbage truck collection in months when the amount of domestic waste generated is significantly less; collect and transport garbage in remote areas about once every 5 days; reasonably adjust the collection routes to optimize the cycle of domestic waste collection and transportation.

2. The rural domestic waste collection and transfer route and cycle optimization method according to claim 1, wherein step 2 is characterized in that: described The value range is 10 ≤ ≤ 10000; The pheromone factor The value range is 0 ≤ ≤ 5; The heuristic function factor The value range is 0 ≤ ≤ 5; The pheromone volatility factor The value range is 0 < < 1; The maximum number of iterations The value range is 100 ≤ ≤ 500.

3. The rural domestic waste collection and transfer route and cycle optimization method according to claim 1, wherein in step 2, described The value is 100; The pheromone factor The value is 1; The heuristic function factor The value is 2; The pheromone volatility factor The value is 0.1; The maximum number of iterations The value is 200.

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