A shared parking space allocation method considering composite demand

Abstract

The present invention discloses a shared parking space allocation method considering composite demands, which belongs to the field of smart parking technology, and the steps are: obtaining shared parking demand information in residential areas at night; determining the parking space information available for shared parking in urban commercial areas at night, including the number of rentable parking spaces, the start time and the end time of shared parking; setting assumptions for the shared parking space allocation problem considering composite demands; taking the maximum profit of shared parking operators as the objective function, constructing a shared parking space allocation optimization model considering composite demands, setting the constraints of the model; using genetic algorithms to solve the model; calculating the number of charging piles installed and the parking space ratio. The present invention can not only alleviate the parking and charging difficulties in residential areas during the peak period of nighttime parking, but also improve the utilization rate of parking spaces in commercial areas at night, so that parking resources are reasonably allocated, and to a certain extent, it also promotes the development of electric vehicles, and then promotes the development of green transportation.

Description

Technical Field

[0001] The present invention belongs to the technical field of smart parking, and in particular relates to a shared parking space allocation method taking complex demands into consideration. Background Art

[0002] As the number of fuel vehicles and electric vehicles continues to grow, the problem of parking difficulties still exists. The number of electric vehicles is growing rapidly, but the number of charging piles is far from enough to meet the charging needs of electric vehicle owners. Compared with fuel vehicles, electric vehicles take a long time to charge and cannot be completed quickly. Therefore, electric vehicle owners usually charge their vehicles during periods when the vehicles are idle for a long time, such as at night, during the day on weekdays, or during leisure time on weekends. Charging behavior often occurs at the same time as parking behavior. There are few private charging piles in my country, and some electric vehicle owners even use unsafe methods such as privately pulling wires to charge, which poses a hidden danger to the safety of residential areas. my country's public charging piles are built based on public parking lots, but most public parking lots still have not installed charging piles. In addition, some residential areas have insufficient parking space planning, which makes it difficult for residents to park during the peak parking period at night. At the same time, commercial areas often have a large number of vacant parking spaces at night, and residential areas have the characteristics of overall stable parking space demand, stable parking time zone, and stable charging demand at night. This temporal and spatial complementarity and stability provide the possibility for shared parking between residential and commercial areas.

[0003] At present, most studies have only studied the shared parking problem of fuel vehicles, and there are few studies on the shared parking problem of electric vehicles and fuel vehicles. Most of the research on shared parking is based on private parking spaces in residential areas, and there are few studies on public parking spaces such as parking lots in commercial areas. At present, most of the research on the allocation of shared parking spaces considering complex needs is to share the charging parking spaces that have been equipped with charging piles, without considering the construction of charging piles.

[0004] The present invention takes the idle parking spaces at night in urban commercial parking lots without charging piles installed as the research object, takes the maximum profit of operators as the objective function, establishes a mathematical model, determines the allocation scheme of shared parking, the number of charging piles installed, and the berth ratio of charging berths to ordinary berths when compound demand and ordinary demand coexist, evaluates the model with revenue, berth utilization rate, demand acceptance rate, and charging pile utilization rate as evaluation indicators, analyzes the optimal ratio of charging berths to ordinary berths under different compound demand numbers, different charging pile investment amounts, and different numbers of rented berths, and determines the optimal berth allocation scheme. It provides new ideas for the practical application of shared parking berth allocation and the determination of the ratio of charging berths to ordinary berths in parking lots. Summary of the invention

[0005] In view of the above-mentioned problems existing in the prior art, the present invention proposes a shared parking space allocation method taking into account complex needs, which is reasonably designed, solves the shortcomings of the prior art and has good effects.

[0006] A shared parking space allocation method considering composite demand includes the following steps:

[0007] S1. Obtaining shared parking demand information in residential areas at night, including the start time and end time of ordinary demand, the start time and end time of compound demand, and the required power;

[0008] The ordinary demand is the demand for only parking service; the compound demand is the demand for both parking service and charging service;

[0009] S2. Collect information on parking spaces available for shared parking at night in urban commercial areas, including the number of rentable parking spaces, the start time and the end time of shared parking;

[0010] S3. Set assumptions for the shared parking space allocation problem considering complex demands;

[0011] S4. Taking the maximum profit of shared parking operators as the objective function, a shared parking space allocation optimization model considering complex demand is constructed, and the constraints of the model are set;

[0012] S5. Using genetic algorithm to solve the model and obtain berth allocation results;

[0013] S6. Calculate the number of charging piles to be installed and the ratio of charging berths to ordinary berths.

[0014] Furthermore, in S3, the assumption conditions specifically include:

[0015] Assumption 1: Ignore the power limitation of the commercial parking lot;

[0016] Assumption 2: Shared parking demand is fixed demand;

[0017] Assumption 3: After charging, the total power of the charging vehicle does not exceed the maximum power of the charging vehicle;

[0018] Assumption 4: At the start of shared parking, there are no cars in the shared parking spaces;

[0019] Assumption 5: All successfully allocated vehicles arrive and leave the shared parking spaces on time according to the shared parking demand time;

[0020] Assumption 6: Shared parking operators choose to install the same low-power charging piles in shared parking spaces, that is, each charging pile has the same charging power, and the charging piles are compatible with charging interfaces with different complex requirements;

[0021] Assumption 7: Before shared parking allocation begins, all shared parking spaces are homogeneous spaces without charging piles installed.

[0022] Furthermore, in S4, taking the maximum profit of shared parking operators as the objective function, a shared parking space allocation optimization model considering composite demands is constructed as follows:

[0023] ;

[0024] In the above formula, the first item represents the revenue brought by the shared parking operator from meeting ordinary demand; the second item represents the parking revenue brought by the shared parking operator from meeting compound demand; the third item represents the charging revenue brought by the shared parking operator from accepting compound demand; the fourth item represents the cost of renting a shared parking space; the fifth item represents the cost of installing a charging pile; the sixth item represents the charging cost of the electricity required to meet compound demand;

[0025] in, is the total revenue, The parking fee per unit time paid by ordinary users. is the quantity of normal demand, The number of shared parking spaces rented. Indicates Is the common demand assigned to Shared parking spaces, , ; For the The parking time required for a normal Parking fees per unit time paid by users with complex needs; is the quantity of composite demand, Indicates Is the composite demand assigned to Shared parking spaces, ; For the The parking time of a compound demand, The charging fee per unit of electricity paid by users with complex demands, The statistically obtained The amount of electricity required for a composite demand, d is the unit time rental for renting a shared parking space, For the The sharing time of a shared parking space, The cost of installing a charging station. The service life of each charging pile. For the Whether each shared parking space is equipped with a charging pile, is the cost per unit of electricity;

[0026] The model needs to meet the following constraints:

[0027] No. A common demand is assigned to at most one shared parking space, that is:

[0028] ;

[0029] No. A composite demand is assigned to at most one shared parking space, namely:

[0030] ;

[0031] Shared parking demands with time conflicts cannot be allocated to the same shared parking space, that is:

[0032] ;

[0033] ;

[0034] ;

[0035] in, Indicates A composite demand and The conflict relationship between the demand time periods of the composite demand, , , Indicates Common needs and The conflict relationship between the demand time periods of ordinary demands, , , Indicates Common needs and The conflicting relationship between the demand time periods of the composite demands;

[0036] If ordinary demand or compound demand is allocated to a shared parking space, the time window constraint of the shared parking space must be met, namely:

[0037] ;

[0038] ;

[0039] in, Indicates A composite demand and The time window affiliation of shared parking spaces, Indicates Common needs and The time window affiliation of shared parking spaces;

[0040] Satisfy the The charging time required for each composite demand is included in the parking time, that is:

[0041] ;

[0042] in, is the power of the charging pile;

[0043] The total cost of installing charging piles should be within the investment range of shared parking operators, that is:

[0044] ;

[0045] in, is the investable amount for charging piles;

[0046] The number of shared parking spaces where charging piles are installed should not exceed the total number of shared parking spaces rented, that is:

[0047] .

[0048] Furthermore, the decision variables , All are 0-1 variables, namely:

[0049] {0,1};

[0050] Jordi The composite demand was successfully assigned to Shared parking spaces, =1, otherwise, =0;

[0051] {0,1};

[0052] Jordi Common requirements were successfully assigned to Shared parking spaces, =1, otherwise, =0;

[0053] When A composite demand and When there is a conflict in the demand time periods of the composite demands, =1, otherwise =0, the expression is:

[0054] ;

[0055] in, For the The start time of shared parking with multiple demands, For the The end time of shared parking with multiple demands, For the The start time of shared parking with multiple demands, For the The end time of shared parking with multiple demands;

[0056] When Common needs and When there is a conflict in the demand time period of a common demand, =1, otherwise =0, the expression is:

[0057] ;

[0058] in, For the The start time of shared parking for common needs, For the The end time of the shared parking with common needs, For the The start time of shared parking for common needs, For the The end time of the commonly needed shared parking;

[0059] When Common needs and When there is a conflict in the shared parking demand time period of a composite demand, =1, otherwise =0, the expression is:

[0060] ;

[0061] When The shared parking space sharing time meets the When there is a shared parking time demand with a composite demand, =0, otherwise =1, the expression is:

[0062] ;

[0063] in, and They respectively represent the start time and end time of shared parking in a shared parking space;

[0064] When The shared parking space sharing time meets the When the shared parking time requirement is a normal demand, =0, otherwise =1, the expression is:

[0065] ;

[0066] When there is a composite demand assigned to When there are shared parking spaces, charging piles will be installed in these shared parking spaces. ,otherwise , the expression is:

[0067] .

[0068] Furthermore, in S5, a genetic algorithm is used to solve the model, which specifically includes:

[0069] Firstly, shared parking spaces that can meet the demand are selected according to the demand and constraints, and shared parking spaces that meet the conditions are randomly selected to match the shared parking spaces with the demand, so as to obtain several initial feasible solutions, namely the initial population; the chromosomes are encoded in the form of real number coding, and the genes of the chromosomes are the shared parking space numbers, so as to achieve a one-to-one correspondence between the demand and the allocated shared parking spaces; the fitness of individuals in the population is calculated according to the objective function of the constructed model, and the size of the fitness represents the probability that the individual genes are inherited to the next generation; finally, the population is continuously iterated and updated through selection, crossover and mutation operations, and after reaching the maximum number of iterations, the optimal shared parking space allocation plan is output.

[0070] Furthermore, the S6 specifically includes:

[0071] The calculation formula for the number of charging piles installed Q is:

[0072] ;

[0073] Berth ratio It refers to the ratio of charging spaces to ordinary spaces, which is determined by the shared parking allocation results and the number of shared parking spaces rented by shared parking operators. The calculation formula is as follows:

[0074] ;

[0075] Among them, Q is the number of installed charging piles.

[0076] Beneficial technical effects brought by the present invention:

[0077] The present invention can not only alleviate the parking and charging difficulties during the nighttime parking peak in residential areas, but also improve the utilization rate of parking spaces in commercial areas at night, so that parking resources can be reasonably allocated, and to a certain extent also promote the development of electric vehicles, and then promote the development of green transportation. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 A schematic flow chart of a shared parking space allocation method considering complex demands according to the present invention.

[0079] Figure 2 It is a line graph showing the changes in evaluation indicators under different numbers of berths.

[0080] Figure 3 This is a line graph showing the changes in evaluation indicators under different charging pile investment amounts.

[0081] Figure 4 It is a line chart showing the changes in evaluation indicators under different numbers of composite demands.

[0082] Figure 5 Schematic diagram of the results for the "first come, first served" allocation method.

[0083] Figure 6 This is a schematic diagram of the optimization results of the allocation scheme of the present invention. DETAILED DESCRIPTION

[0084] The specific implementation of the present invention is further described below in conjunction with specific embodiments:

[0085] A shared parking space allocation method considering composite demand, such as Figure 1 As shown, the following steps are included:

[0086] S1. Obtaining shared parking demand information in residential areas at night, including the start time and end time of ordinary demand, the start time and end time of compound demand, and the required power;

[0087] Ordinary demand refers to the demand for only parking services; compound demand refers to the demand for both parking services and charging services;

[0088] S2. Collect information on parking spaces available for shared parking at night in urban commercial areas, including the number of rentable parking spaces, the start time and the end time of shared parking;

[0089] S3. Set assumptions for the shared parking space allocation problem considering complex demands;

[0090] S4. Taking the maximum profit of shared parking operators as the objective function, a shared parking space allocation optimization model considering complex demand is constructed, and the constraints of the model are set;

[0091] S5. Using genetic algorithm to solve the model and obtain berth allocation results;

[0092] S6. Calculate the number of charging piles to be installed and the ratio of charging berths to ordinary berths.

[0093] Specifically, in S3, determining the model assumption conditions specifically includes:

[0094] Assumption 1: Ignore the power limitation of the commercial parking lot;

[0095] Assumption 2: Shared parking demand is fixed demand;

[0096] Assumption 3: After charging, the total power of the charging vehicle does not exceed the maximum power of the charging vehicle;

[0097] Assumption 4: At the start of shared parking, there are no cars in the shared parking spaces;

[0098] Assumption 5: All successfully allocated vehicles arrive and leave the shared parking spaces on time according to the shared parking demand time;

[0099] Assumption 6: Shared parking operators choose to install the same low-power charging piles in shared parking spaces, that is, each charging pile has the same charging power, and the charging piles have wide compatibility to meet different composite needs, that is, they can be compatible with charging interfaces with different composite needs;

[0100] Assumption 7: Before shared parking allocation begins, all shared parking spaces are homogeneous spaces without charging piles installed.

[0101] Specifically, step S4 is as follows: Assume that a shared parking operator plans to rent U shared parking spaces in a commercial parking lot in an old city area at night where no charging piles are installed, the maximum investment amount for the charging piles is C, the service life of each charging pile is D years, and the power of the charging pile is P. , No. Shared parking spaces Shared parking time is [ ], then the sharing time of each shared parking space is ,in and They respectively represent the start time and end time of shared parking in a shared parking space.

[0102] Assume the quantity of normal demand is , the general demand is the demand for parking services only, and the shared parking operator can obtain parking revenue, , the statistics are The parking time required for a normal demand is [ ], the required parking time is ,in and They represent the start and end time of shared parking for normal demand respectively.

[0103] Assume the quantity of composite demand is , the composite demand is the parking demand that requires both parking services and charging services. Shared parking operators can obtain parking revenue and charging revenue, making , the statistics are The parking time period required for a composite demand is [ ], the required parking time is ,in and They represent the start and end time of shared parking with composite demand, and The statistically obtained The amount of electricity required for a composite demand.

[0104] The shared parking operator analyzes the demand information and determines the optimal ratio of charging parking spaces to ordinary parking spaces and the parking space allocation results under a certain number of shared parking spaces. Suppose the unit time rental of the shared parking space by the shared parking operator is The cost per unit of electricity is The cost of installing a charging station is If the shared parking operator allocates ordinary demand to shared parking spaces, it will charge users parking fees. The unit parking fee obtained from ordinary demand users is If the shared parking operator allocates the composite demand to the shared parking space, the user will be charged parking fee and charging fee. The unit time parking fee obtained from the composite demand side is , the charging fee per unit of electricity is ,in , .

[0105] Commercial parking lots have obvious peak and off-peak characteristics, and the off-peak period is fixed, so the parking spaces used for sharing can have the same sharing time. In addition, the parking demand in the commercial area and the parking demand in the surrounding residential areas have obvious temporal and spatial complementarity. At night, commercial parking lots can be used for shared parking to share the parking and charging pressure in the residential areas. The demand allocated to the shared parking spaces must meet the time window constraints of the shared parking spaces provided. If A common need or If the parking time period required by a composite demand exceeds the shared parking time period of the berth, the request will be rejected. , To indicate the A composite demand and The time window affiliation of the shared parking spaces, Common needs and The time window affiliation of shared parking spaces.

[0106] When The shared parking space sharing time meets the When there is a shared parking time demand with a composite demand, =0; otherwise =1; the expression is:

[0107] ;

[0108] When The shared parking space sharing time meets the When the shared parking time requirement is a normal demand, =0; otherwise =1; the expression is:

[0109] ;

[0110] The time windows of various requirements may overlap, so , , To indicate the A composite demand and The conflict relationship between the demand time periods of the composite demand, Common needs and The conflict relationship between the demand time period of the first ordinary demand, Common needs and The conflict relationship between the demand time periods of the composite demand. , ; , ;

[0111] When A composite demand and When there is a conflict in the demand time periods of the composite demands, ;otherwise ; The expression is:

[0112] ;

[0113] in, For the The start time of shared parking with multiple demands, For the The end time of shared parking with multiple demands;

[0114] When Common needs and When there is a conflict in the demand time period of a common demand, =1; otherwise =0; the expression is:

[0115] ;

[0116] in, For the The start time of shared parking for common needs, For the The end time of the commonly needed shared parking;

[0117] When Common needs and When there is a conflict in the demand time periods of the composite demands, =1; otherwise =0;

[0118] ;

[0119] Introducing decision variables:

[0120] Represents composite demand Is it assigned to If the allocation is successful, =1, otherwise, =0;

[0121] Indicates general demand Is it assigned to If the allocation is successful, =1, otherwise, =0.

[0122] Charging piles need to be installed to meet the composite demand. Whether a shared parking space is equipped with charging piles depends on whether the space meets the composite demand. To indicate whether a charging pile is installed;

[0123] When there is a composite demand assigned to When there are shared parking spaces, charging piles will be installed in these shared parking spaces. ;otherwise , the expression is:

[0124] ;

[0125] Based on the above analysis, taking the maximum profit of shared parking operators as the objective function, the shared parking space allocation optimization model considering composite demand is constructed as follows:

[0126] ;

[0127] Item 1 represents the revenue from shared parking operators meeting ordinary demands; Item 2 represents the parking revenue from shared parking operators meeting compound demands; Item 3 represents the charging revenue from shared parking operators accepting compound demands; Item 4 represents the cost of renting shared parking spaces; Item 5 represents the cost of installing charging piles; Item 6 represents the charging cost of the electricity required to meet compound demands; is the total revenue.

[0128] The model needs to meet the following constraints:

[0129] The i-th common demand is assigned to at most one shared parking space, that is:

[0130] ;

[0131] The jth composite demand is assigned to at most one shared parking space, namely:

[0132] ;

[0133] Shared parking demands with time conflicts cannot be allocated to the same shared parking space, that is:

[0134] ;

[0135] ;

[0136] ;

[0137] If ordinary demand or compound demand is allocated to a shared parking space, the time window constraint of the shared parking space must be met, namely:

[0138] ;

[0139] ;

[0140] Satisfy the The charging time required for each composite demand is included in the parking time, that is:

[0141] ;

[0142] The total cost of installing charging piles should be within the investment range of shared parking operators, that is:

[0143] ;

[0144] The number of shared parking spaces where charging piles are installed should not exceed the total number of shared parking spaces rented, that is:

[0145] .

[0146] Decision variables , All are 0-1 variables, namely:

[0147] {0,1};

[0148] {0,1};

[0149] Specifically, in step S5, the decision variable of the model is the shared parking space allocation scheme, and the variable is discrete, which belongs to a combinatorial optimization problem. For some complex combinatorial optimization problems, the genetic algorithm can quickly obtain a good optimization result, so the present invention uses the genetic algorithm to solve the model, and the solution steps are as follows: first, according to the demand and constraint conditions, select the shared parking space that can meet the demand, and randomly select the shared parking space that meets the conditions to match the demand, and obtain several initial feasible solutions (i.e., the initial population) in this way. The present invention uses real number coding to encode the chromosome, and the gene of the chromosome is the shared parking space number, so that the demand and the allocated shared parking space can be corresponded one by one, so that the allocation of shared parking spaces can be more intuitively seen. Then, according to the objective function of the constructed model, the fitness of the individuals in the population is calculated, and the size of the fitness represents the probability that the individual gene is inherited to the next generation. Finally, the population is continuously updated through selection, crossover, and mutation operations. After the maximum number of iterations is reached (i.e., Gen reaches the maximum value), the optimal shared parking space allocation scheme is output.

[0150] Specifically, in step S6, the calculation formula for the installed number Q of charging piles is:

[0151] Q= ;

[0152] Berth ratio It refers to the ratio of charging spaces to ordinary spaces, which is determined by the shared parking allocation results and the number of shared parking spaces rented by shared parking operators. The calculation formula is as follows:

[0153] ;

[0154] in, The number of charging piles installed.

[0155] The following is an analysis of the optimization allocation results and parking ratio of shared parking spaces using a parking lot in a commercial area of ​​an old city as an example. Assuming that the sharing time of each parking space is from 8 pm to 8 am the next day, the cost of renting a parking space for a shared parking operator is The cost of installing a charging station is , the estimated service life is D = 10 years, and the power of the charging pile is The charging cost is The parking unit price for general demand is , the parking unit price for composite demand is , the charging unit price is .

[0156] Revenue, berth utilization rate, demand acceptance rate and charging pile utilization rate are used as evaluation indicators to evaluate the model.

[0157] (1) income;

[0158] The revenue is the profit of the shared parking operator, who, as a third-party profit-making organization, expects to maximize the profit.

[0159] The revenue from shared parking is:

[0160] ;

[0161] (2) berth utilization rate;

[0162] The utilization efficiency of shared parking spaces is an important indicator that reflects the usage status of shared parking spaces. The utilization efficiency of shared parking spaces is expressed by the ratio of the utilization time of shared parking spaces to the total sharable time.

[0163] The utilization efficiency of shared parking spaces is:

[0164] ;

[0165] (3) Demand acceptance rate;

[0166] The demand acceptance rate of shared parking is an indicator that reflects the satisfaction of shared parking demand. The demand acceptance rate of shared parking can be expressed as:

[0167] ;

[0168] (4) Utilization rate of charging piles;

[0169] The utilization rate of charging piles reflects the use of charging piles. It is an important indicator of whether charging resources are fully utilized. It can be expressed in the following form:

[0170] ;

[0171] The maximum number of parking demands is set to 300, and the shared parking demand information is randomly generated. Except for the test parameters, other values ​​are the same as the assumptions in the experiment. The changes in the evaluation indicators are analyzed under different shared parking space supply quantities, charging pile investment amounts, and composite demand quantities.

[0172] (1) The impact of the number of rented shared parking spaces on shared parking allocation;

[0173] Without considering investment restrictions, when the demand for shared parking is fixed and the ratio of composite demand to ordinary demand is 1:4, the number of shared parking spaces rented by shared parking operators varies from 50 to 300, with a step length of 50. The parking space ratio and allocation under different numbers of parking spaces are shown in Table 1.

[0174] Table 1 Berth ratio and demand satisfaction under different berth numbers

[0175] ;

[0176] As can be seen from Table 1, as the number of rented parking spaces increases, the number of shared parking needs also gradually increases. The composite demand is fully met when the number of rented parking spaces is 100, and 55 charging piles need to be installed to meet 60 composite demands. The number of charging berths remains unchanged after the composite demand is met, and the number of ordinary berths increases with the increase in the number of rented shared parking spaces. The berth ratio is affected by the number of berths.

[0177] The evaluation indicators under different berth numbers are as follows: Figure 2 As shown in the figure. The berth utilization rate decreases with the increase in the number of berths. This is because the parking time of shared parking demand cannot fully occupy the shared time of shared parking berths. At the same time, the utilization rate of charging piles decreases with the increase in the number of charging piles. After the number of berths is 100 to meet all composite demands, the number of charging piles is fixed and the utilization rate of charging piles also begins to remain unchanged. The demand acceptance rate increases with the increase in the number of berths. When the number of berths increases to 300, the demand acceptance rate is 1, which meets all shared parking demands. When the number of berths increases from 250 to 300, the growth rate of the demand acceptance rate slows down. The revenue of shared parking increases first and then decreases, with the number of berths being 250 as the inflection point. After that, the revenue and berth utilization rate of shared parking decrease significantly. This is because there are too many rented berths, the berth supply is greater than the berth demand, and the oversupply leads to a large number of berths being idle, which further leads to a decrease in revenue and berth utilization rate.

[0178] (2) The impact of charging pile investment on shared parking allocation;

[0179] The demand for shared parking is fixed, and the ratio of compound demand to ordinary demand is 1:4. When the number of shared parking spaces rented is 200, the investment amount of charging piles varies from 182.5 to 547.5, with a step length of 73. Consider the impact of the investment amount of charging piles on the parking space ratio and demand satisfaction;

[0180] Table 2. Berth ratio and demand satisfaction under different charging pile investment amounts

[0181] ;

[0182] The impact of the three situations of charging pile supply less than demand, supply equal to demand, and supply greater than demand on the evaluation index is studied respectively, and the optimal ratio is obtained. Figure 3 It can be seen that the investment amount of charging piles has a smaller impact on berth utilization and demand acceptance rate, but a greater impact on revenue and charging pile utilization, especially when the supply of charging piles is insufficient. When the investment is RMB 1.825 million, RMB 2.555 million and RMB 3.285 million respectively, the number of charging piles that can be installed is less than the number of charging piles required. At this time, the shared parking operators can make the most profit when the parking space ratio reaches 1:7, 7:33 and 9:31 respectively; when the investment reaches RMB 4.015 million, the number of charging piles that can be installed is equal to the number of charging piles required. At this time, the shared parking operators can make the maximum profit when the parking space ratio reaches 11:29. Compared with the case of insufficient investment, the income has increased. Although the utilization rate of charging piles has decreased due to the fact that the charging time of the composite demand is less than the charging time that the charging piles can provide, it still maintains a high level; when the investment is greater than RMB 4.015 million, the number of charging piles that can be installed is greater than the number of charging piles required. In order to avoid waste of charging pile resources, the parking space ratio when the supply of charging piles is equal to the demand is kept unchanged. Therefore, the income, charging pile utilization rate, parking space utilization rate and demand acceptance rate are the same as when the investment is RMB 4.015 million.

[0183] (3) The impact of composite demand quantity on berth allocation;

[0184] Table 3 Berth ratio under different composite demand quantities

[0185] ;

[0186] Without considering investment restrictions, the demand for shared parking is fixed, and the number of shared parking spaces rented by shared parking operators is set to 200. The number of compound demands varies from 30 to 120, with a step length of 30. The ratio and allocation of parking spaces under different numbers of compound demands are shown in Table 3. As the number of compound demands increases, the demand ratio changes, the number of installed charging piles also gradually increases, and the ratio of shared parking spaces under the goal of maximizing the profit of shared parking operators also changes.

[0187] Evaluation indicators under different demand ratios are as follows: Figure 4 As shown in the figure. The change in the number of compound demands has little effect on the parking space utilization rate and demand acceptance rate. The impact on the utilization rate of charging piles is determined by the amount of electricity required to meet the compound demands. The number of compound demands has a greater impact on the revenue of shared parking operators. As the number of compound demands increases, the revenue gradually increases.

[0188] In order to verify the effectiveness of the model of the present invention, a simulation experiment was designed based on the idle characteristics of parking spaces at night, and compared with the "First Come First Service" (FCFS) allocation method. Assuming that there are three compound demands and seven ordinary demands for parking vehicles in the commercial area among the demand users, the statistical shared parking demand information is shown in Table 4. A shared parking operator plans to rent 8 parking spaces for sharing, and other values ​​are the same as those assumed in the experiment;

[0189] Table 4 Shared parking demand information

[0190] ;

[0191] contrast Figure 5 and Figure 6 It can be seen from the allocation scheme that under the condition of renting the same number of parking spaces, the allocation scheme proposed by the present invention can meet all composite demands when the operator's profit is the largest, but does not meet the ordinary demand 8. Three charging piles need to be installed, and the ratio of charging berths to ordinary berths is 3:5; the first-come-first-served model can meet the two composite demands 1 and 2 and all ordinary demands, but does not meet the composite demand 3. Two charging piles need to be installed, and the ratio of charging berths to ordinary berths is 1:3. The demand acceptance rate of the two allocation methods is the same, both of which are 90%. Although the utilization rate of charging piles in this model is reduced by 9% compared with the "first-come-first-served" method, this allocation scheme earns 27 yuan more than the "first-come-first-served" method, and the utilization rate of parking spaces is increased by 4%. The allocation method proposed by the present invention can meet most of the parking demands when the profit of the shared parking operator is the largest, and make the shared parking spaces and the installed charging piles obtain higher utilization efficiency. Compared with the "first-come-first-served" model, it meets more composite demands, which can effectively alleviate the existing problems of "difficult parking" and "difficult charging" in residential areas, and improve the utilization rate of parking spaces in commercial parking lots at night.

[0192] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A shared parking space allocation method considering complex demands, characterized in that: The following steps are involved: S1. Obtaining shared parking demand information in residential areas at night, including the start time and end time of ordinary demand, the start time and end time of compound demand, and the required power; The ordinary demand is the demand for only obtaining parking services; Compound demand refers to the parking demand that requires both parking service and charging service. S2. Collect information on parking spaces available for shared parking at night in urban commercial areas, including the number of rentable parking spaces, the start time and the end time of shared parking; S3. Set assumptions for the shared parking space allocation problem considering complex demands; S4. Taking the maximum profit of shared parking operators as the objective function, a shared parking space allocation optimization model considering complex demand is constructed, and the constraints of the model are set; S5. Using genetic algorithm to solve the model and obtain berth allocation results; S6. Calculate the number of charging piles to be installed and the ratio of charging berths to ordinary berths; In S3, the assumptions specifically include: Assumption 1: Ignore the power limitation of the commercial parking lot; Assumption 2: Shared parking demand is fixed demand; Assumption 3: The total power of the electric vehicle after charging does not exceed the maximum power of the charging vehicle; Assumption 4: At the start of shared parking, there are no cars in the shared parking spaces; Assumption 5: All successfully allocated vehicles arrive and leave the shared parking spaces on time according to the shared parking demand time; Assumption 6: Shared parking operators choose to install the same low-power charging piles in shared parking spaces, that is, each charging pile has the same charging power, and the charging piles are compatible with charging interfaces with different complex requirements; Assumption 7: Before the shared parking allocation begins, all shared parking spaces are homogeneous spaces without charging piles installed; In S4, taking the maximum profit of shared parking operators as the objective function, the shared parking space allocation optimization model considering the composite demand is constructed as follows: ； In the above formula, the first item represents the revenue brought by the shared parking operator from meeting ordinary demand; the second item represents the parking revenue brought by the shared parking operator from meeting compound demand; the third item represents the charging revenue brought by the shared parking operator from accepting compound demand; the fourth item represents the cost of renting a shared parking space; the fifth item represents the cost of installing a charging pile; the sixth item represents the charging cost of the electricity required to meet compound demand; in, is the total revenue, The parking fee per unit time paid by ordinary users. is the quantity of normal demand, The number of shared parking spaces rented. Indicates Is the common demand assigned to Shared parking spaces, , ; For the The parking time required for a normal Parking fees per unit time paid by users with complex needs; is the quantity of composite demand, Indicates Is the composite demand assigned to Shared parking spaces, ; For the The parking time of a compound demand, The charging fee per unit of electricity paid by users with complex demands, The statistically obtained The amount of electricity required for a composite demand, d is the unit time rental for renting a shared parking space, For the The sharing time of a shared parking space, The cost of installing a charging station. The service life of each charging pile. For the Whether each shared parking space is equipped with a charging pile, is the cost per unit of electricity; The model needs to meet the following constraints: No. A common demand is assigned to at most one shared parking space, that is: ； No. A composite demand is assigned to at most one shared parking space, namely: ； Shared parking demands with time conflicts cannot be allocated to the same shared parking space, that is: ； ； ； in, Indicates A composite demand and The conflict relationship between the demand time periods of the composite demand, , , Indicates Common needs and The conflict relationship between the demand time periods of ordinary demands, , , Indicates Common needs and The conflicting relationship between the demand time periods of the composite demands; If ordinary demand or compound demand is allocated to a shared parking space, the time window constraint of the shared parking space must be met, namely: ； ； in, Indicates A composite demand and The time window affiliation of shared parking spaces, Indicates Common needs and The time window affiliation of shared parking spaces; Satisfy the The charging time required for each composite demand is included in the parking time, that is: ； in, is the power of the charging pile; The total cost of installing charging piles should be within the investment range of shared parking operators, that is: ； in, is the investable amount for charging piles; The number of shared parking spaces where charging piles are installed should not exceed the total number of shared parking spaces rented, that is: 。 2. A shared parking space allocation method considering complex demands according to claim 1, characterized in that: Decision variables , All are 0-1 variables, namely: {0,1}； Jordi The composite demand was successfully assigned to Shared parking spaces, =1, otherwise, =0; {0,1}； Jordi Common requirements were successfully assigned to Shared parking spaces, =1, otherwise, =0; When A composite demand and When there is a conflict in the demand time periods of the composite demands, =1, otherwise =0, the expression is: ； in, For the The start time of shared parking with multiple demands, For the The end time of shared parking with multiple demands, For the The start time of shared parking with multiple demands, For the The end time of shared parking with multiple demands; When Common needs and When there is a conflict in the demand time period of a normal demand, =1, otherwise =0, the expression is: ； in, For the The start time of shared parking for common needs, For the The end time of the shared parking with common needs, For the The start time of shared parking for common needs, For the The end time of the shared parking with common demand; When Common needs and When there is a conflict in the shared parking demand time period of a composite demand, =1, otherwise =0, the expression is: ； When The shared parking space sharing time meets the When there is a shared parking time demand with a composite demand, =0, otherwise =1, the expression is: ； in, and They respectively represent the start time and end time of shared parking in a shared parking space; When The shared parking space sharing time meets the When the shared parking time requirement is a normal demand, =0, otherwise =1, the expression is: ； When there is a composite demand assigned to When there are shared parking spaces, charging piles will be installed in these shared parking spaces. ,otherwise , the expression is: 。 3. A shared parking space allocation method considering complex demands according to claim 2, characterized in that: In S5, a genetic algorithm is used to solve the model, which specifically includes: Firstly, shared parking spaces that can meet the demand are selected according to the demand and constraints, and shared parking spaces that meet the conditions are randomly selected to match the shared parking spaces with the demand, so as to obtain several initial feasible solutions, namely the initial population; the chromosomes are encoded in the form of real number coding, and the genes of the chromosomes are the shared parking space numbers, so as to achieve a one-to-one correspondence between the demand and the allocated shared parking spaces; the fitness of individuals in the population is calculated according to the objective function of the constructed model, and the size of the fitness represents the probability that the individual genes are inherited to the next generation; finally, the population is continuously iterated and updated through selection, crossover and mutation operations, and after reaching the maximum number of iterations, the optimal shared parking space allocation plan is output.

4. A shared parking space allocation method considering complex demands according to claim 3, characterized in that: The S6 specifically includes: The calculation formula for the number of charging piles installed Q is: ； Berth ratio It refers to the ratio of charging spaces to ordinary spaces, which is determined by the shared parking allocation results and the number of shared parking spaces rented by shared parking operators. The calculation formula is as follows: ； Among them, Q is the number of installed charging piles.

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