The invention falls under the computer technology field, especially involving a ranking method of urban parking lots based on temporal and spatial features and its device, terminal, and medium.
Due to the rapid increase in vehicle quantity, parking becomes increasingly difficult in many Chinese cities; Spending too much time in finding a parking space not only aggravates traffic but also leads to increased energy consumption, so it is imperative to tackle this serious issue for cities. To this end, a City-wide Parking Guidance System (CPGS) is introduced to guide vehicles to the surrounding parking lots with unoccupied parking spaces, thus achieving rapid and easy parking of vehicles. Just like a search engine, CPGS can transmit the information of the most related parking lots to the parking users based on the keywords they query. As a quantitative assessing and ranking technique, the ranking method is directly used for determining which pages or parking lots are the most related ones based on keywords queried, and each page gets a rank value calculated by the search engine in accordance with the keywords; the higher the rank value is, the most related the page will be; different ranking models will lead to different ranking lists. The pages with more visits on heated websites certainly have a higher ranking than those on unknown websites; even if they have similar keywords, by exchanging links with heated websites with a higher rank value, unknown websites will also experience an increase in their rank value. In fact, a similar phenomenon can be identified during the parking process. If a popular parking lot has been fully occupied, the vehicles heading for it will be parked in the parking lots nearby, so the importance of parking lots shall be evaluated to facilitate ranking computation. Current evaluation of the importance of parking lots is merely based on the analysis of geographic information from temporal or spatial dimension alone, so the evaluation results are of low accuracy; besides, the computation of rank value for parking lots is time-consuming, and the needs of parking users cannot be satisfied.
The invention provides a ranking method of urban parking lots based on temporal and spatial features and its device, terminal, and storage medium, aiming to eliminate inaccurate sequencing of urban parking lots and low success rate of parking by users because an effective sequencing method of urban parking lots is not available based on current technologies.
On the one hand, the invention provides a ranking method of urban parking lots based on temporal and spatial features, and the said method can be explained in the following steps:
Based on public information and geographical relations, all parking lots within the preset urban regions and their static and dynamic information are acquired, wherein the said parking lot information includes static and dynamic information;
In accordance with the said static information of parking lots, a prebuilt service capability model is utilized to calculate the initial service capability of each said parking lot, and the initial service capability ranking of all said parking lots is obtained according to the said initial service capability;
Based on the static and dynamic information of the said parking lots, a prebuilt temporal-spatial transition model is utilized to get the transition probabilities between neighboring parking lots at the moment, and the transition probability matrix is thus obtained in accordance with the said transition probability;
According to the said initial service capability ranking and the said transition probability matrix, the power iteration algorithm is adopted for iterative computation of comprehensive service capability ranking of all said parking lots at the moment until the preset stopping conditions for the iteration are met; then, the said parking lots are ranked based on the said comprehensive service capability ranking.
On the other hand, the invention provides the ranking device for urban parking lots based on temporal and spatial features, and the said device consists of:
A parking lot acquisition unit, which is used for acquiring all parking lots within the preset urban regions and their static and dynamic information based on public information and geographical relations, wherein the said parking lot information includes static and dynamic information;
The first parameter acquisition unit, wherein a prebuilt service capability model is utilized to calculate the initial service capability of each said parking lot in accordance with the said static information of parking lots, and the initial service capability ranking of all said parking lots is obtained according to the said initial service capability;
The second parameter acquisition unit, wherein a prebuilt temporal-spatial transition model is utilized to get the transition probabilities between neighboring parking lots at the moment based on the static and dynamic information of the said parking lots, and the transition probability matrix is thus obtained in accordance with the said transition probability; and
A parking lot ranking unit, wherein the power iteration algorithm is adopted for iterative computation of comprehensive service capability ranking of all said parking lots at the moment according to the said initial service capability ranking and the said transition probability matrix until the preset stopping conditions for the iteration are met; then, all parking lots are ranked based on the said comprehensive service capability ranking.
On the other hand, the invention also provides an intelligent terminal, comprising a memory, a processor, and a computer program stored in the said memory and executable in the said processor, wherein the said steps for the ranking method of the above urban parking lots based on temporal and spatial features are effectuated when the said computer program is executed by the said processor.
On the other hand, the invention also provides a computer-readable storage medium in which the computer program is stored, wherein the said steps for the ranking method of the above urban parking lots based on temporal and spatial features are effectuated when the said computer program is executed by the said processor.
In this invention, the service capability model and temporal-spatial transition model are adopted to get the initial service capability ranking of all parking lots and the transition probability matrix between parking lots at the moment based on all parking lots within the preset urban regions and their static and dynamic information; the power iteration algorithm is utilized to iteratively calculate the comprehensive service capability ranking of all parking lots at the moment in accordance with initial service capability ranking and transition probability matrix until the stopping conditions for the iteration are met; the parking lots are ranked based on comprehensive service capability ranking, thus achieving real-time quantitative computation of service capability of any urban parking lot from the temporal and spatial dimensions, enhancing the assessing accuracy of parking lots' service capability and the ranking effectiveness of parking lots, and playing a key role in parking guidance and parking lot construction and assessment.
In order to present the objects, technical solutions, and advantages of the invention in a more clear way, the invention is further detailed in combination with the appended drawings and embodiments below. It should be understood that specific embodiments described herein just serve the purpose of explaining the invention instead of imposing restrictions on it.
In the following part, specific embodiments are presented for a more detailed description of the invention:
In S101, based on public information and geographical relations, all parking lots within the preset urban regions and their static and dynamic information are acquired, wherein the parking lot information includes static and dynamic information.
This embodiment of the invention applies to on-board units and intelligent mobile terminals, such as on-board computers, mobile phones, smartwatches, etc. Based on public information and geographical relations (such as electronic maps), all parking lots within the preset urban regions and their static and dynamic information are acquired, wherein the parking lot information includes static and dynamic information.
Preferably, a parking lot's static information includes parking service range, the total number of parking spaces, parking prices, and geographical position; parking prices also incorporate the hourly parking prices for different vehicle models and upper limits; in contrast, a parking lot's dynamic information includes the number of parking spaces available at the moment, thus providing a basis for assessing the service capability of parking lots and enhancing the assessing accuracy of service capability.
More preferably, a parking lot's dynamic information also includes the traffic flow on the effective path from the target geographical location of the targeted vehicle to the parking lot (i.e. congestion information), thereby further enhancing the assessing accuracy of service capability.
In S102, in accordance with the static information of parking lots, a prebuilt service capability model is utilized to calculate the initial service capability of each parking lot, and the initial service capability ranking of all parking lots is obtained according to the initial service capability.
In this embodiment of the invention, the service capability of parking lots is mainly assessed from three aspects: parking service range, the total number of parking spaces, and parking prices; parking service range means which kinds of cars can be parked in this parking lot. For example, a shopping mall's parking lot is open to all kinds of vehicles, while a residential community's parking lot only serves the property owners. Relatively speaking, a parking lot with a larger service range is often found with higher service capability; a parking lot with more parking spaces in total also reveals higher service capability. Parking prices are also an important influencing factor for service capability; as a rule, the higher the parking price is, less possibly the parking lot will be chosen and fewer cars there will be; that is to say, a parking lot with higher parking prices has lower service capability, and a parking lot's service capability is embodied in its service capability ranking. Based on the static information (such as parking service range, the total number of parking spaces, parking prices) of parking lots acquired, a prebuilt service capability model can be utilized to calculate the initial service capability of each parking lot. The initial service capability ranking of all parking lots can thus be obtained in accordance with initial service capability, which is expressed as the column vector Pt0=(p10, p20, . . . , pm0)T, wherein T represents the transpose of the vector; p01, p20, and pm0 refer to the initial service capability of the 1st, 2nd and mth parking lot, respectively; Pt0 is the initial service capability ranking of the mth parking lot at time t.
Before adopting the prebuilt service capability model for calculating the initial service capability of each parking lot, preferably, the service capability model for parking lots is constructed based on major influencing factors, which is expressed as
wherein p0i is the initial service capability of the ith parking lot;
xi is the parking service range of the ith parking lot; y is the total number of parking spaces for the ith parking lot, and y is the total number of parking spaces for all parking lots; zi refers to the parking price of the ith parking lot, and z refers to the sum of parking prices of all parking lots; m is the quantity of all parking lots; exp(xi) is the expected parking service range of the ith parking lot, thus improving the plausibility of calculating the parking lot's initial service capability.
In S103, based on the static and dynamic information of the parking lots, a prebuilt temporal-spatial transition model is utilized to get the transition probabilities between neighboring parking lots at the moment, and the transition probability matrix is thus obtained in accordance with the transition probability.
In this embodiment of the invention, the accessible distances between parking lots can be calculated based on geographical locations among static information of the parking lots; afterwards, the sparking lot network topology is constructed in accordance with accessible distances, and the prebuilt temporal-spatial transition model is adopted to get the transition probability between neighboring parking lots at the moment based on the parking lot network topology and real-time dynamic information (such as the number of parking spaces available at the moment); finally, the transition probability matrix between parking lots is obtained based on the transfer probabilities. As an example,
Preferably, the transition probability model is expressed as
wherein St refers to the transition probability matrix between m parking lots at time t;
represents the parking probability of the ith parking lot; Ei means the total number of parking spaces for the ith parking lot; ei refers to the number of unoccupied parking spaces currently available for the ith parking lot; dij(1≤i≤m, 1≤j≤m, and i≠j) refers to the influence of the distance between the ith parking lot and the jth parking lot on the transition of the targeted vehicle between them. The transition probability model not only takes into account the influencing factors on the distance between parking lots from the spatial dimension but also considers the fact that the number of unoccupied parking spaces changes with time from the temporal dimension, thus enhancing the plausibility and accuracy of transition probability between parking lots. In this case, when the targeted parking lot is fully occupied, the targeted vehicle has to find an alternative parking lot, which can be better simulated by the model. Moreover, a matrix can be utilized to represent this transition probability model, and improve the ranking efficiency of subsequent parking lots.
More preferably, dij can be computed through the equation wherein
is the accessible matrix between m parking lots; Lij is the accessible distance between the ith parking lot and the jth parking lot, thus further enhancing the plausibility and accuracy of transition probability between parking lots.
In S104, according to the initial service capability ranking and the transition probability matrix, the power iteration algorithm is adopted for iterative computation of comprehensive service capability ranking of all parking lots at the moment until the preset stopping conditions for the iteration are met; then, the parking lots are ranked based on the comprehensive service capability ranking.
In this embodiment of the invention, based on the initial service capability ranking P10=(p10, p20, . . . , pm0)T, the transition probability matrix St and the simultaneous equations
the power iteration algorithm is adopted for iterative calculation of comprehensive service capability of all parking lots at the moment until the preset iteration stopping condition |Ptn+1−Pnt|<ε is met; afterward, the service capabilities of the parking lots are ranked from highest to lowest or from lowest to highest based on the comprehensive service capability ranking, wherein ε is the preset sufficiently-small number for characterizing the convergence of iteration results; n is the number of iterations; Pn t refers to the comprehensive service capability ranking obtained from the nth iteration at time t.
In this embodiment of this invention, the service capability model and temporal-spatial transition model are adopted to get the initial service capability ranking of all parking lots and the transition probability matrix between parking lots at the moment based on all parking lots within the preset urban regions and their static and dynamic information; the power iteration algorithm is utilized to iteratively calculate the comprehensive service capability ranking of all parking lots at the moment in accordance with initial service capability ranking and transition probability matrix until the stopping conditions for the iteration are met; the parking lots are ranked based on comprehensive service capability ranking, thus achieving real-time quantitative computation and comparison of service capability of any urban parking lot at any time from the temporal and spatial dimensions, enhancing the assessing accuracy of parking lots' service capability, the computational efficiency of the parking lots' ranking and the ranking effectiveness of parking lots, playing a key role in parking guidance and parking lot construction and assessment, and increasing the success rate of parking by users.
A parking lot acquisition unit 31, which is used for acquiring all parking lots within the preset urban regions and their static and dynamic information based on public information and geographical relations, wherein the parking lot information includes static and dynamic information.
This embodiment of the invention applies to on-board units and intelligent mobile terminals, such as on-board computers, mobile phones, smartwatches, etc. Based on public information and geographical relations (such as electronic maps), all parking lots within the preset urban regions and their static and dynamic information are acquired, wherein the parking lot information includes static and dynamic information.
Preferably, a parking lot's static information includes parking service range, the total number of parking spaces, parking prices, and geographical position; parking prices also incorporate the hourly parking prices for different vehicle models and upper limits; in contrast, a parking lot's dynamic information includes the number of parking spaces available at the moment, thus providing a basis for assessing the service capability of parking lots and enhancing the assessing accuracy of service capability.
More preferably, a parking lot's dynamic information also includes the traffic flow on the effective path from the target geographical location of the targeted vehicle to the parking lot (i.e. congestion information), thereby further enhancing the assessing accuracy of service capability.
The first parameter acquisition unit 32, wherein a prebuilt service capability model is utilized to calculate the initial service capability of each parking lot in accordance with the static information of parking lots, and the initial service capability ranking of all parking lots is obtained according to the initial service capability.
In this embodiment of the invention, the service capability of parking lots is mainly assessed from three aspects: parking service range, the total number of parking spaces, and parking prices; parking service range means which kinds of cars can be parked in this parking lot. For example, a shopping mall's parking lot is open to all kinds of vehicles, while a residential community's parking lot only serves the property owners. Relatively speaking, a parking lot with a larger service range is often found with higher service capability; a parking lot with more parking spaces in total also reveals higher service capability. Parking prices are also an important influencing factor for service capability; as a rule, the higher the parking price is, less possibly the parking lot will be chosen and fewer cars there will be; that is to say, a parking lot with higher parking prices has lower service capability, and a parking lot's service capability is embodied in its service capability ranking Based on the static information (such as parking service range, the total number of parking spaces, parking prices) of parking lots acquired, a prebuilt service capability model can be utilized to calculate the initial service capability of each parking lot. The initial service capability ranking of all parking lots can thus be obtained in accordance with initial service capability, which is expressed as the column vector Pt0=(p10, p20, . . . , pm0)T, wherein T represents the transpose of the vector; p10, p20, and pm0 refer to the initial service capability of the 1st, 2nd and mth parking lot, respectively; Pt0 is the initial service capability ranking of the mth parking lot at time t.
Before adopting the prebuilt service capability model for calculating the initial service capability of each parking lot, preferably, the service capability model for parking lots is constructed based on major influencing factors, which is expressed as
wherein p0i is the initial service capability of the ith parking lot;
xi is the parking service range of the ith parking lot; yi is the total number of parking spaces for the ith parking lot, and y is the total number of parking spaces for all parking lots; zi refers to the parking price of the ith parking lot, and z refers to the sum of parking prices of all parking lots; m is the quantity of all parking lots; exp(xi) is the expected parking service range of the ith parking lot, thus improving the plausibility of calculating the parking lot's initial service capability.
The second parameter acquisition unit 33, wherein a prebuilt temporal-spatial transition model is utilized to get the transition probabilities between neighboring parking lots at the moment based on the static and dynamic information of the parking lots, and the transition probability matrix is thus obtained in accordance with the transition probability.
In this embodiment of the invention, the accessible distances between parking lots can be calculated based on geographical locations among static information of the parking lots; afterwards, the sparking lot network topology is constructed in accordance with accessible distances, and the prebuilt temporal-spatial transition model is adopted to get the transition probability between neighboring parking lots at the moment based on the parking lot network topology and real-time dynamic information (such as the number of parking spaces available at the moment); finally, the transition probability matrix between parking lots is obtained based on the transfer probabilities.
Preferably, the transition probability model is expressed as
wherein St refers to the transition probability matrix between m parking lots at time t;
represents the parking probability of the ith parking lot; Ei means the total number of parking spaces for the ith parking lot; ei refers to the number of unoccupied parking spaces currently available for the ith parking lot; dij(1≤i≤m, 1≤i≤m, and i≠j) refers to the influence of the distance between the ith parking lot and the jth parking lot on the transition of the targeted vehicle between them. The transition probability model not only takes into account the influencing factors on the distance between parking lots from the spatial dimension but also considers the fact that the number of unoccupied parking spaces changes with time from the temporal dimension, thus enhancing the plausibility and accuracy of transition probability between parking lots. In this case, when the targeted parking lot is fully occupied, the targeted vehicle has to find an alternative parking lot, which can be better simulated by the model. Moreover, a matrix can be utilized to represent this transition probability model, and improve the ranking efficiency of subsequent parking lots.
More preferably, dij can be computed through the equation wherein
is the accessible matrix between m parking lots; Lij is the accessible distance between the ith parking lot and the jth parking lot, thus further enhancing the plausibility and accuracy of transition probability between parking lots.
The parking lot ranking unit 34, wherein the power iteration algorithm is adopted for iterative computation of comprehensive service capability ranking of all parking lots at the moment until the preset stopping conditions for the iteration are met according to the initial service capability ranking and the transition probability matrix; then, the parking lots are ranked based on the comprehensive service capability ranking.
In this embodiment of the invention, based on the initial service capability ranking Pt0=(p10, p20, . . . , pm0)T, the transition probability matrix St and the simultaneous equations
the power iteration algorithm is adopted for iterative calculation of comprehensive service capability of all parking lots at the moment until the preset iteration stopping condition |Ptn+1−Pn t|<ε is met; afterwards, the service capabilities of the parking lots are ranked from highest to lowest or from lowest to highest based on the comprehensive service capability ranking, wherein ε is the preset sufficiently-small number for characterizing the convergence of iteration results; n is the number of iterations; Pn t refers to the comprehensive service capability ranking obtained from the nth iteration at time t.
In this embodiment of the invention, various units of the ranking device for urban parking lots based on temporal and spatial features can be achieved through corresponding hardware or software units, while various units can serve as independent software or hardware units or can be integrated into a software and hardware unit, wherein the invention is not restricted in this respect.
In this embodiment of the invention, the intelligent terminal 4 consists of a processor 40, a memory 41, and a computer program 42 stored in the memory 41 and executable on the processor 40. When processor 40 executes the computer program 42, the steps in the above embodiments of the ranking method for urban parking lots based on temporal and spatial features are effectuated, such as S101 to S104 in
In this embodiment of this invention, the service capability model and temporal-spatial transition model are adopted to get the initial service capability ranking of all parking lots and the transition probability matrix between parking lots at the moment based on all parking lots within the preset urban regions and their static and dynamic information; the power iteration algorithm is utilized to iteratively calculate the comprehensive service capability ranking of all parking lots at the moment in accordance with initial service capability ranking and transition probability matrix until the stopping conditions for the iteration are met; the parking lots are ranked based on comprehensive service capability ranking, thus achieving real-time quantitative computation and comparison of service capability of any urban parking lot at any time from the temporal and spatial dimensions, enhancing the assessing accuracy of parking lots' service capability and the ranking effectiveness of parking lots, playing a key role in parking guidance and parking lot construction and assessment, and increasing the success rate of parking by users.
Intelligent terminals in this embodiment of the invention can be on-board computers, mobile phones, smartwatches, etc. When the processor 40 in the intelligent terminal 4 executes the computer program 42, the steps of effectuating the ranking method for urban parking lots based on temporal and spatial features have been described in the above method embodiments, and will not be further elaborated here.
In this embodiment of the invention, a computer-readable storage medium is presented, provided with a computer program. When the computer program is executed by the processor, the steps in the ranking method embodiments for urban parking lots based on temporal and spatial features are effectuated, such as S101 to S104 in
In this embodiment of this invention, the service capability model and temporal-spatial transition model are adopted to get the initial service capability ranking of all parking lots and the transition probability matrix between parking lots at the moment based on all parking lots within the preset urban regions and their static and dynamic information; the power iteration algorithm is utilized to iteratively calculate the comprehensive service capability ranking of all parking lots at the moment in accordance with initial service capability ranking and transition probability matrix until the stopping conditions for the iteration are met; the parking lots are ranked based on comprehensive service capability ranking, thus achieving real-time quantitative computation and comparison of service capability of any urban parking lot at any time from the temporal and spatial dimensions, enhancing the assessing accuracy of parking lots' service capability and the ranking effectiveness of parking lots, playing a key role in parking guidance and parking lot construction and assessment, and increasing the success rate of parking by users.
In this embodiment of the invention, the computer-readable storage medium comprises any physical device or recording medium, such as ROM/RAM, disc, compact disc, flash memory, and other memories.
The said embodiments just represent the best embodiments of this invention, but do not serve the purpose of restricting this invention; any revision, equivalent replacement, or improvement made within the spirit and principle of this invention is included in the protection scope of this invention.
This application is a national stage application of PCT/CN2019/087081. This application claims priority from PCT Application No. PCT/CN2019/087081, filed May 15, 2019, the content of which is incorporated herein in the entirety by reference.
Filing Document | Filing Date | Country | Kind |
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PCT/CN2019/087081 | 5/15/2019 | WO | 00 |