Bayes's path planning apparatus and method based on the GPS detection
Technical field:
The present invention relates to a kind of a kind of path planning apparatus and method of adopting based on the deduction of priori of being suitable under actual traffic trip situation, particularly a kind of Bayes's path planning apparatus and method of surveying based on GPS.
Background technology:
Current, GPS (Global Positioning System) should use as positioning navigating device on various vehicles widely, such as onboard navigation system, and the locating and monitoring system of vehicle, Floating Car system of traffic department or the like.On the other hand, the optimal path that obtains of the method for optimizing route in our the various navigational system its path of planning out a kind of shortest path on absolute time or length tolerance often in actual use.Yet because the random character of the real-time traffic of road, the optimal path on the tolerance meaning often is not the priori that meets the driver so like this, and such optimal path often is not the optimal path of our real world yet.
Patent (Chinese patent application number 200410103954.1) is that the time of vehicle and speed are merged a kind of method into path planning, patent (Chinese patent application number 200610036181.9) be a kind of be a kind of paths planning method that transit time is realized with the highway section weight setting, from top this several patents application form, it only is a kind of path optimization method that provides on tolerance (length or time) that some patents about path planning apparatus and method, existing patent about path planning have been arranged at present.These methods all do not have to adopt based on Bayesian priori deduction method comes realizing route planning.
Announced one piece document " taxi experimental knowledge modeling and path planning algorithm " in the volume (404-409 page or leaf) " mapping journal " Augusts 39 in 2010, though some has considered the posterior infromation of taxi, but only be some information to have been arrived under the road on the weights W with following computing formula reduction
I(t)=[μ
1T
I(t)+ μ
2S
i]/μ
3C
I (t)
In essence, this formula is that time and velocity information are passed through this formula, and the w weight setting to the highway section of correspondence, is calculated optimal path by traditional dijkstra method at last.The method of path planning being done in the posterior infromation reduction to the road weights, possessed under the situation of Real-time Traffic Information, is the same with the problem of traditional optimal path method, and it can't avoid the randomness of Real-time Traffic Information.This method is not a kind of priori deduction method, thereby and adopts the calculating of the optimal path planning on the tolerance to distinguish also little on method.Therefore, the document does not form a kind of driver's prior imformation and according to the Bayesian inference road collection of classifying, and carries out path planning in view of the above.
Technical method from the existing path planning of last surface analysis, these are with speed, length, the optimal path method of certain posterior infromation naturalization such as transit time on the tolerance of road weights, a kind of priori deduction method of the driver that really will be familiar with very much the road network traffic is not brought in the path planning system.
Summary of the invention:
Purpose of the present invention is exactly the above-mentioned defective that exists at prior art, a kind of Bayes's path planning apparatus and method of surveying based on GPS is provided, and the inventive method is that a kind of priori that the method that adopts priori to estimate posterior information is simulated the driver is looked for path method; This device utilizes Bayes classifier that driver's priori deduction method is brought in our path planning apparatus, itself is based on the sorter device road network is done after the pattern recognition process and the paths planning method that forms.
Bayes's path planning apparatus of surveying based on GPS of the present invention mainly is divided into two parts of end of probe and center processing end, and wherein end of probe is selected the driver that some are familiar with road traffic condition, the GPS detector is distributed on these drivers' the vehicle; Described center processing end comprises receiver, central control unit, path screening washer, Bayes classifier and the several modules of optimal path computation device:
End of probe wherein: the GPS detector mainly is to come n driver's driving trace is surveyed with the GPS collector;
Described center processing end: central control unit, the data of controlling between other the module transmit; The path screening washer, the GPS tracing point of these driver's vehicles that main basis collects and the starting point and the terminating point of collection recover the path of travelling, and filter out " good " path fast by speed, that expend time in short; Bayes classifier is practiced Bayes classifier according to " good " path training of setting up, and according to the Bayes classifier that trains road is done classification, forms preferential road collection, suboptimum road collection and whole road collection; The optimal path computation device according to three kinds of preferred roads that form, is implemented optimum route search and is calculated, and obtains the optimal path result; Path memory is deposited " good " path collection that the path screening washer is set up; The classification of road storer is deposited three kinds of road collection that Bayes classifier classification back forms.
Bayes's paths planning method of surveying based on GPS of the present invention may further comprise the steps:
(1), end of probe is obtained the trip empirical data with the GPS detector;
(2), the center control end obtains track data and the realizing route planning by handle a series ofly from the GPS detector, may further comprise the steps:
(2.1) obtain the path collection of " good " on the priori with the path screening washer: mainly recover the path of travelling, and filter out " good " path fast by speed, that expend time in short according to the GPS tracing point of these driver's vehicles that collect and the starting point and the terminating point of collection;
(2.2) practice Bayes classifier according to " good " path training of setting up, road is done classification, form preferential road collection, suboptimum road collection and whole road collection according to the Bayes classifier that trains;
(2.3) calculate optimal path in the optimal path computation device, central control unit is regarded the preferential road collection of above-mentioned three classes as the triple-decker network and is input to the optimal path computation device, obtains the optimal path result;
Above-mentioned path screening washer mainly is made up of comparison controller, coupling computing module and buffer three parts:
A) in the coupling computing module, the driver's who collects according to end of probe the GPS track and the starting point and the terminating point of record, with map-matching method it is matched the road corresponding highway section, and join according to adjacent road section and to obtain the path that forms between each starting point and the terminating point, the path collection that the coupling computing module obtains is input in the comparison counter;
B) in comparison controller, elder generation can obtain list according to the journey time of the total length and the GPS record of every paths
The average passage rate v that paths superior rolling stock travels
Single, by with the mean value V of all path passage rates
Average overallCompare, according to v
Single〉=V
Average overallCan obtain the path of " good " on the priori, it is included in " good " the path collection, and put in the path memory.
Above-mentioned Bayes classifier mainly is made of data divider, roadway characteristic maker, Bayes controller, road topology device and buffer;
A) " good " path is inputed to data divider, dispenser is divided into " good " path collection T1 of peak period and " good " path collection T2 of non-peak period according to the time attribute in path with it;
B) in the roadway characteristic maker,, the frequency of all paths through same road section e taken statistics to all " good " path collection;
C) in the roadway characteristic maker, calculate on the road network all nodes between shortest path, and obtain intermediary's centrality of road section e thus.
D) from road network data, select a part and come out, utilize the Bayes controller to come the road section classification is obtained preferential road collection, suboptimum road collection and Ordinary Rd collection as the training data of Bayes controller;
E) in the road topology detecting device,, the preferential road collection of this three class of its generation is put in the classification of road storer according to three road collection that step d) obtains.
The invention has the beneficial effects as follows: this patent is exactly to utilize this driver that the priori of the real-time traffic situation of road network is inferred, construct Bayes classifier and formed preferential identification to road network, a kind of path planning apparatus and the method that form based on this preferential identification, it can provide different optimal paths respectively according to the priori of peak period, non-peak period in different traffic slots.This device and method has good practicality, and can be integrated into flexibly in the various navigational system based on road traffic.
Description of drawings:
Accompanying drawing 1 is the principle schematic of device of the present invention;
Accompanying drawing 2 is synoptic diagram of path of the present invention screening washer;
Accompanying drawing 3 is the process flow diagrams in screening washer screening " good " path, path of the present invention;
Accompanying drawing 4 is synoptic diagram of Bayes classifier of the present invention;
Accompanying drawing 5 is Bayes schematic flow sheets of road collection of the present invention;
Accompanying drawing 6 is optimal path computation process flow diagrams of the present invention.
Embodiment:
The concrete embodiment of this device is as follows:
The enforcement of end of probe:
Obtain the trip empirical data with the GPS detector.Select n needs are the driver that the area road net of path analysis is familiar with very much, the GPS detector is contained on this n driver's the car, write down the trip data of its every day, wrap with GPS
Draw together the starting point and the terminating point in its trip path.Cumulative record is after their trip path a period of time (such as one month) like this, according to GPS detector and the record thereof on these driver's vehicles that Real-time Road is familiar with, obtains n experience driver's trip GPS track data.
Center processing end implementation step:
The data transmission of whole center processing end intermodule is controlled by central control unit, and the steps flow chart of operation is also controlled by central control unit.Provide Bayes's paths planning method that the center processing end is realized below sequentially.
1 usefulness path screening washer obtains the path collection of " good " on the priori, and this module mainly is made up of comparison controller, coupling computing module and buffer three parts, and its structural representation is seen " mistake! Do not find Reference source." its process flow diagram sees " mistake! Do not find Reference source.”
The GPS track data that central control unit obtains gathering from the GPS detector.
1a) in the coupling computing module, the driver's who collects according to end of probe the GPS track and the starting point and the terminating point of record, with map-matching method it is matched the road corresponding highway section, and join according to adjacent road section and to obtain the path that forms between each starting point and the terminating point.The path collection that the coupling computing module obtains is input in the comparison counter.
1b) in comparison controller, earlier according to the Hang journey Shi Jian ⊿ t between the total length L of every paths and this path are from the starting point to the terminating point, by v
Single=L/ ⊿ t can obtain the average passage rate v of individual paths
SingleCalculate all travel speeds of GPS in a certain period T then, according to the average V of the passage rate in all paths in this period
Average overallSet a threshold value.Compare v
SingleWith V
Average overallRelation.If v
Single〉=V
Average overall, think that then this path is the path of " good " on the priori, includes it in " good " the path collection, and put in the path memory; If v
Single﹤ V
Average overall, think that then this path is not the path of " good " on the priori, gives up it.After forming the path collection of be over " good " at last, the notice central control unit deposits the path collection of these " good " in the path memory in.
2 usefulness Bayes classifiers are done classification to road network, obtain three kinds of preferred road collection.Bayes classifier mainly is made of these several parts of data divider, roadway characteristic maker, Bayes controller, road topology device and buffer, and its structure is as " mistake! Do not find Reference source " shown in, its flow process is as " mistake! Do not find Reference source " shown in.
" good " path collection that central control unit obtains from path memory is input to Bayes classifier.
2a) " good " path is inputed to data divider, dispenser is divided into " good " path collection T1 of peak period and " good " path collection T2 of non-peak period according to the time attribute in path with it.Following step 2b--2e implements T1 and T2 respectively, obtains the preferential road collection of peak period three classes different with non-peak period.
2b) in the roadway characteristic maker, to all " good " path collection, the frequency of all paths through same road section e taken statistics, promptly different paths is every through once identical road section, and its frequency attribute f (e) adds 1, and f (e) initial value is 0.Do on average through the speed of road section according to all " good " paths, be designated as v (e).
2c) in the roadway characteristic maker, calculate on the road network all nodes between shortest path, all shortest paths add up to N.According to the number of times c (e) of all shortest paths, calculate the centrality B of intermediary (e)=c (e)/N of highway section e through each road section e.
2d) selecting a part from road network data comes out as the training data of Bayes controller.According to 2b) and 2c) in feature f (e), the v (e) of the road e that obtains and the parameter that B (e) estimates the Bayes controller.Determined after the Bayes controller parameter, utilized the Bayes controller to come the road section classification is obtained preferential road collection E according to its feature f (e), v (e) and B (e) in all roads
1, suboptimum road collection E
2With Ordinary Rd collection E
3
2e) in the road topology detecting device, according to step 2d) three road collection obtaining, from E
1Beginning calculates E
1The maximum strong subnet C that is communicated with
1With E
1In not at C
1Road join E again
2In, calculate E
2The maximum strong subnet C that is communicated with
2Like this, we make G
1=C
1As preferential road collection, make G
2=C
1+ C
2As suboptimum road collection, G
3Be all road collection of whole road networks conducts.Like this, we just obtain by G
1, G
2, G
3The preferential road collection of three classes that forms.
Central control unit is put into the preferential road collection of this three class of its generation in the classification of road storer after the step of Bayes classifier is finished.
3 according to the preferential road collection of the classification at peak period T1 and non-peak period T2 that forms in the step 2, calculates optimal path respectively in the optimal path computation device.Because for the road collection of T1 and T2, its calculation procedure all is the same, like this, in the following description T1 and T2 is not distinguished.Its flow process is seen " mistake! Do not find Reference source.”
Central control unit is regarded the preferential road collection of three classes as the triple-decker network and is input to the optimal path computation device.Determine optimal path to be determined starting point and terminating point in road network.Several steps below in the optimal path computation device, implementing:
3a) from G
iBegin forward and reverse search optimal path from the initial sum terminating point respectively in the layer;
If 3b) at G
iIn layer forward and the reverse search, the node on the optimum subpath also is present in corresponding G
I-1In the layer, be designated as S respectively
I-1, T
I-1, so just jump back to step 3a), and i subtracts 1, promptly at G
I-1Middle execution in step 3a).If in forward and reverse search, there is not such node on the optimum subpath) so with regard to execution in step 3c;
If 3c) subpath of the subpath of forward lookup and reverse search can not meet at same point, continue execution in step 3b so), if may converge a bit, execution in step 3d so);
3d) subpath that converges every layer of calculating forms last experience optimal path.
In this device, end of probe equipment GPS detector is assemblied on selected driver's vehicle with the form of hardware, and can preserve the GPS track data of its vehicle.The center processing end device can be under any operating system platform, utilize any programming language, utilize software mode to realize, also can adopt suitable hardware to realize, have good practicality, and can be integrated into flexibly in the various navigational system based on road traffic.