Summary of the invention
The object of the present invention is to provide a kind of dynamic map management method that data updated is separated with update content that is easy to that is applied on the IP network.
The invention is characterized in that it contains following steps successively:
Step (1.): the initialization map server, set up the map updating form, this table content comprises:
Map sequence number: be used for map of unique mark;
The map address: be used for depositing map on map server in the hard disk the memory location;
Place coordinate: be used for depositing this map pairing position coordinates when showing;
Update time: the newness degree that is used for reflecting map;
Wherein, the ground graphic sequence is that 1 map is deposited initial complete map, cartographic information, sequence is that 2 map is deposited and is up-to-date complete map, the place coordinate information of these two figure is (0,0), and the ground graphic sequence is that 3 later clauses and subclauses are not deposited complete cartographic information, but is used for depositing some later detailed information of each change, as: the highway that certain bar is newly opened, set up the traffic information table, comprising: road name: be used for depositing the name information of highway, and congestion state: be used for depositing the congestion state of highway, wherein use letter " R " representative traffic congestion, " Y " representative is slow, and " G " representative is unimpeded;
Step (2.): the initialization client terminal, foundation comprises: the cartographic information table of map sequence number, map address, place coordinate and update time;
Step (3.): whether client presses access network, according to carrying out following steps:
Step (3.1.): check in the cartographic information table whether be empty, ask for complete cartographic information if sky then sends message to map server;
Step (3.2.):, check then in all maps whether update time is consistent with current system time from the update time of that nearest map of current system time if having at least one map in the cartographic information table; Comprise in the local cartographic information table request message of update time the latest if send early than current system time then to map server the update time of this picture, to be used for inquiring whether have available renewal on the map server; Then report an error when the lastest imformation of this picture is later than the current time in system, and remind the current system time of user's modification; Above-mentioned time ratio is accurate to hour;
Step (3.3.): when the user inquires the traffic information of a certain highway by input equipment, client will send the road condition query message that comprises this road name to server;
Step (4.): after server is received request message from the client, successively according to steps of processing:
Step (4.1.): the type of judging this request message:
If the message of asking for additional detailed map information is map sequence number in the described map updating form that 2 map sends to client terminal then;
If the message that the request map upgrades is then at first obtained the update time that comprises in this message, with this of retrieving map updating form update time, and in will showing all update times send to client terminal early than the cartographic information that comprises update time in the message;
If the road conditions solicited message then according to the road name that comprises in the request message, is inquired about the traffic information table, and the congestion condition of correspondence is sent to client terminal;
Step (5.): when server end no matter when which kind of channel receives that cartographic information changes message, at first determine the content of this change and should change the coordinate of geographic location, and the content that will change deposits in the map updating form, then, be in 2 the complete cartographic information to map updating form kind map sequence number this change content integration, and cover this figure, revise update time simultaneously;
Step (6.): after client receives that map that server sends is asked for the answer of message, deposit this cartographic information in this locality, and with update time, relevant informations such as name map write the cartographic information table;
Step (7.): after client is received the map updating message that server sends, according to the arrangement mode of date descending this map lastest imformation being deposited in respectively in the cartographic information table successively the update time in the message;
Step (8.): after client is received the road condition updating message that server sends, directly and show on the map just that with the congestion condition in different this highway sections of color mark, wherein R be red, Y is a yellow, G is a green;
Step (9.): in the time of the client displayed map, respectively with detailed base map initial in the cartographic information table and all map more new situation be presented on the user interface respectively in overlapping mode according to the coordinate that occurs.
The method that we use simulated roadway to change is tested this method, finds under the frequent situation of revising cartographic information, and average each map updating message that produces and may be come from the density of point between 13K ~ 60K, and most result is about 30K.
Map upgrades the message size dot chart and sees Fig. 4
From realize the result, can find that this method is used minimum renewal cost under the situation of cartographic information frequent variations, satisfied the high real-time of data.
Embodiment
Road must be based upon on the basis of relatively large bandwidth cost in the real-time that the frequent variations of traffic information makes the electronic chart service.The dynamic map management method that designs expense of a kind of end is main contribution of the present invention.
The basic thought of this method is, determine an initial map, and, all changes that take place after it are peeled off separately, so based on this figure, when cartographic information changes, user's needs are downloaded through the part of changing, and will be shown on its stack year former figure, and do not need to download again brand-new map, thereby, finished dynamically updating of electronic chart with smaller cost.
Client map show levels figure sees Fig. 1.
In description of the invention, the change that the server section uses the map updating form to write down map, wherein graphic sequence is that 1 map is initial original map, the ground graphic sequence is that 2 map is for to add later up-to-date map with all changes, this map is used to provide to the user who downloads for the first time map and uses, and remaining clauses and subclauses then is used for storing the lastest imformation of map.And carry out the incremental update service when being used for sending request message for client.
The client basic flow sheet is seen Fig. 2.
The server end basic flow sheet is seen Fig. 3
Stronger service also is put into the row of design to traffic information as a kind of real-time, server will provide the congestion situation of corresponding road section for client, and client will not stored the information of this high real-time, put on the map of this machine but it is directly painted, this change will inquire about next time or restart system after disappear.
Application exemplary plot of the present invention is seen Fig. 5.
The present invention can be by being stored in demonstration to former figure respectively in what change data, be implemented under the frequent situation about changing of cartographic information and satisfy the feature of electronic chart service high real-time, and be particularly suitable for the actual demand of the wide characteristics of cell phone system tail band with less flow cost.