CN102128631B - Path searching method, navigation server and navigator - Google Patents

Abstract

The invention provides a path searching method on the basis of an effective path chain, which comprises the following steps of: selecting at least one part of a path chain when a terminal point of at least one path chain in the original path net structure is connected with starting points of a plurality of path chains to cause at least one path chain to have a plurality of different path chain travelling time; transforming the original path net structure formed by all the path chains into a new path net structure on the basis of the selected path chain and corresponding travelling time of theplurality of different path chains; and searching the optimal path according to the novel path net structure. After that, the optimal path is reversedly transformed to an optimal transformation path on the basis of the original path net structure, and the optimal transformation path is displayed in the original path net structure. In addition, the invention also provides a navigation server and anavigator used for realizing the path searching method based on the effective path chain.

Description

Method for searching path, navigation server and navigating instrument

Technical field

The present invention relates to airmanship, more specifically, relate to a kind of air navigation aid and navigational system (comprising navigation server and navigating instrument), can in former road network, dynamically search with the effective road of conversion chain and obtain new road network, and carry out route searching based on new road network.The road chain is the representation of real road on map, if a road chain has a plurality of road chain impedances relevant with the flow direction, so just this road chain is called effective road chain.

Background technology

Optimum route search is the core technology in the Vehicular navigation system, according to path computing based on information type, can be divided into that static path calculates and dynamic route calculating.It is according to information calculations optimal paths such as the static information of road such as length, grade, speed limit, charges that static path calculates.It is to calculate optimal path according to dynamic real-time traffic information that dynamic route calculates.Performance element difference according to path computing again can be with navigation and vehicle mounted guidance centered by the automobile navigation branch.The path computing of center navigation is finished by the computing unit that is positioned at navigation server, and the path computing of vehicle mounted guidance is finished by vehicle-mounted computing unit, and the path computing among the present invention both can realize at navigation server, also can realize at car-mounted terminal.

Existing navigational system is based on static information more and carries out path computing.But the jam situation of urban road is dynamic change, so often occur than large deviation based on optimal path computation result and the actual optimum path of static information.Therefore some advanced navigational system propose to calculate optimal path based on Real-time Traffic Information, and the Real-time Traffic Information that utilizes mainly is the information of reflection congestion in road degree.Pass through the average velocity of road chain or on average calculate optimal path as the impedance of road chain hourage as all having mentioned among Japanese Patent Application Publication 2001-352501, U.S. Patent Application Publication 2007/0162222A1, the Chinese patent ZL200510089079.0 with vehicle.The time that vehicle spends by the road chain is called road chain hourage.May be to flow to be correlated with hourage but these navigational system are not considered the road chain, if vehicle was turned right when intersection allowed red light, the vehicle of turning right so will namely be less than and through vehicles for same road chain right-hand rotation vehicle than keeping straight on and the left turning vehicle weak point in the stand-by period of crossing average hourage.So when calculating optimal path based on the Real-time Road degree of blocking up, need to consider the flow direction property of road chain impedance.If consider the flow direction property of road chain impedance, so every road chain just has a plurality of resistance values, and all to require the impedance of road chain or node be single value for the classical path calculation method dijkstra's algorithm of widespread use or A* algorithm in the current navigational system.So road chain impedance that how will the branch flow direction dissolve for traditional single road chain impedance be a problem that must solve.

Be same problem in the intersection delay question essence that the road chain impedance problems that branch flows to and branch flow to, consideration flows to the traffic intersection delay of being correlated with and has been studied a lot of years in the path computing.Current have the intersection delay disposal route that minute flows to when path computing: a. with various flows to the average back of intersection delay add the impedance of approach chain as an additive term; B. add logic limit or logical point; C. utilize the dual graph theoretical treatment to flow to relevant intersection delay.Method a has obliterated the heterogeneite of various flows to intersection delay, is actually to ignore rather than address this problem, and method b makes the network size multiplication, and method c has brought a large amount of extra computation amounts.Method b and c carry out the road network conversion, also can be applied to solve the road chain impedance problems that branch flows to, but need overcome the defective of method itself equally.And method b and method c carry out conversion to whole road network, do not consider validity problem, namely in fact the impedance of some road chain to flow to correlativity very little, namely the resistance difference of each flow direction is very little, is not worth carrying out the road network conversion.So whole road network is not added the conversion of carrying out of differentiation, will inevitably increase road network structure on a large scale or increase calculated amount, cause these methods effectively to be applied in the actual navigational system.

In order to overcome the above problems.The present invention proposes the concept of effective road chain, and effectively the road chain refers to that each flows to the apparent in view road chain of chain resistance difference of setting out on a journey.System of the present invention has the function of the effective road chain in the detection of dynamic road network, effective road chain in the road network is carried out conversion dynamically, to non-effective road chain with the mean value of each flow direction as road chain impedance, road chain resistance value after guaranteeing to handle all is single value, can be used by the path computation algorithm of current extensive employing.The present invention only carries out conversion to effective road chain and has guaranteed can significantly not increase road network scale, can significantly not increase calculated amount, the new road network after the conversion can be applied to classical path search algorithm and guarantee that system proposed by the invention can be applied in the actual navigational system very easily.

Summary of the invention

The objective of the invention is to by dynamically the effective road chain in the road network being carried out conversion, increasing road network scale not significantly, do not increasing under the situation of legacy paths computational algorithm complexity and calculated amount, to flow to relevant road chain hourage or speed as road chain impedance, calculate the point-to-point transmission optimal path.Effectively the road chain refers to that each flows to the apparent in view road chain of chain resistance difference of setting out on a journey.Navigation server of the present invention detects the effective road chain in the current road network at first dynamically, then when user's request path is searched for, only effective road chain in the specific region is carried out conversion, make the road chain and the node that obtain after the conversion only have single resistance value, utilize the existing route computational algorithm to calculate an optimal path at server end or client at last.

During the navigation system computes optimal path, can calculate dissimilar optimal paths according to dissimilar road chain impedances.For example with the road chain length as road chain impedance, the optimal path that obtains so is referred to as shortest path.If as road chain impedance, the optimal path that obtains so is referred to as the fastest path usually with the maximum speed limit of road chain.These two kinds all are based on the optimal path that static information obtains, if the shortest with actual institute spended time is criterion, more than the path that obtains of two kinds of methods often be not optimum, real optimum path should be to be road chain impedance with the real-time road chain degree of blocking up, the optimal path that calculates, so must have system that the chain degree of blocking up in real-time road can be provided, the Floating Car system of introducing as Jap.P. 07-029098 (1995).The Floating Car system is more and more universal in China, but existing Floating Car system all is that only to calculate road chain hourage be a mean value, distinguishes to flow to, and this mean value is suitable for showing the congestion in road degree.But the path computing in the navigational system be flow to relevant, so more accurate hourage according to average road chain according to flowing to the path beguine that relevant road chain calculates hourage.But the impedance that is not the branch flow direction of every road chain has notable difference, so the invention provides a kind of effective road chain pick-up unit, for detection of respectively flowing to impedance in the road network road chain of notable difference is arranged, and is referred to as effective road chain.Because the congestion in road state is dynamic change, so effective road chain pick-up unit can detect the effective road chain in the road network, the effective road chain information in the real-time update system dynamically.

The resistance value that effective road chain is gathered around is not unique, just must carry out conversion to it for path computing and make resistance value unique.The invention provides a kind of road network converting means, can carry out conversion to all effective road chains, obtain new road network after the conversion, in new road network, the resistance value of every road chain is single value, with road chain hourage as road chain impedance, calculate optimal path.

Navigation server feeds back to the user with the optimal path computation result by communicator, and can constantly upgrade user's route according to the effectively variation of road chain in the road network.Navigation server also can a transformation results with effective road chain send to client by communicator, carries out optimal path computation by client oneself.After optimal path computation was come out, the path reciprocal transformation that also needs to calculate was the path that can show in the former road network structure, could show in client's navigating instrument display device like this.

According to a scheme of the present invention, a kind of method for searching path based on effective road chain has been proposed, comprise: cause described No. at least one chain to have a plurality of different road chains during hourage when the terminal point owing to No. at least one chain in the original road network structure links to each other with the starting point of many other road chains, select the part in described No. at least one chain; Based on selected road chain and corresponding a plurality of different road chain hourages thereof, will be transformed to new road network structure by the original road network structure that all road chains constitute; And according to described new road network structure, the search optimal path.

Described method for searching path based on effective road chain can also comprise: described optimal path reciprocal transformation is the transform optimal path based on described original road network structure; And in original road network structure, show described transform optimal path.

Preferably, in described selection step, the road chain that has a plurality of different road chain hourage in the original road network structure can be labeled as candidate road chain, and the road chain that has single road chain hourage in the original road network structure is labeled as non-effective road chain, and can select a part in the chain of described candidate road, be labeled as effective road chain, and the residue road chain in the chain of described candidate road is labeled as non-effective road chain, thereby all the road chains in the original road network structure are divided into effective road chain and non-effective road chain.

More preferably, can select the part in the chain of described candidate road according to the coefficient of variation of each bar candidate road chain, be labeled as effective road chain.

At this moment, chain i in candidate road is at the coefficient of variation L of t in the period _i(t) can calculate according to the following equation:

L _i(t)＝S _i(t)/A _i(t)

Wherein, S _i(t) expression candidate road chain i is at the t standard deviation of a plurality of road chain hourage in the period, A _i(t) expression candidate road chain i is at the t mean value of a plurality of road chain hourage in the period.

Here, coefficient of variation threshold value A L (t) can be that all n bar candidate road chains are at the mean value of the coefficient of variation of t in the period

$\mathrm{AL}\left(t\right)=\underset{i}{\overset{n}{\mathrm{\Σ}}}{L}_i\left(t\right)/n.$

Perhaps, coefficient of variation threshold value A L (t) can be that previously selected n bar represents candidate road chain at the mean value of the coefficient of variation of t in the period

$\mathrm{AL}\left(t\right)=\underset{i}{\overset{n}{\mathrm{\Σ}}}{L}_i\left(t\right)/n.$

Perhaps, coefficient of variation threshold value A L _j(t) can be all n that have the chain grade j that goes the same way mutually with candidate road chain i _jBar candidate road chain is at the mean value of the coefficient of variation of t in the period

$A{L}_j\left(t\right)=\underset{i}{\overset{n_j}{\mathrm{\Σ}}}{L}_i\left(t\right)/n_j.$

Perhaps, chain i in candidate road is at the coefficient of variation L of t in the period _i(t) can calculate according to the following equation:

L _i(t)＝V _i(t) _max-V _i(t) _min

Wherein, V _i(t) _MaxBe illustrated in the main road chain Average Travel Speed of candidate road chain i in the t period, V _i(t) _MinBe illustrated in the minimal path chain Average Travel Speed of candidate road chain i in the t period.

Preferably, in described search step, if beginning or end is positioned at the non-endpoint location of effective road chain, then described starting point or the residing effective road of described terminal point chain can be updated to non-effective road chain, transformation rule according to non-effective road chain, upgrade described starting point or the residing effective road of described terminal point chain in the described new road network structure, then, search for optimal path again.

Preferably, with candidate road chain or effectively the road chain step that is updated to non-effective road chain can comprise: the mean value that calculates a plurality of road chain hourage of described candidate road chain or described effective road chain, as the road chain hourage of described non-effective road chain, and many records about described candidate road chain or described effective road chain in road chain-Lu chain table hourage are merged the single record that is updated to about described non-effective road chain.

Preferably, a plurality of different road chain of described No. at least one chain can be hourage flow to relevant.

Preferably, in described shift step, can adopt dual graph method or virtual limit method, described original road network structure is transformed to described new road network structure.

According to another aspect of the present invention, a kind of navigation server has been proposed, comprise: road chain selecting arrangement, be used for causing described No. at least one chain to have a plurality of different road chains during hourage when the terminal point owing to No. at least one chain of original road network structure with the starting point of many other road chains is continuous, select the part in described No. at least one chain; The road network converting means is used for will being transformed to new road network structure by the original road network structure that all road chains constitute based on selected road chain and corresponding a plurality of different road chain hourages thereof; And path calculation device, be used for according to described new road network structure the search optimal path.

Preferably, described navigation server can also comprise: the path reverse mapping device, and being used for described optimal path reciprocal transformation is transform optimal path based on described original road network structure; And dispensing device, be used for described transform optimal path is sent to navigating instrument.

Preferably, described road chain selecting arrangement can be labeled as candidate road chain with the road chain that has a plurality of different road chain hourage in the original road network structure, and the road chain that has single road chain hourage in the original road network structure is labeled as non-effective road chain, and can select a part in the chain of described candidate road, be labeled as effective road chain, and the residue road chain in the chain of described candidate road is labeled as non-effective road chain, thereby all the road chains in the original road network structure are divided into effective road chain and non-effective road chain.

More preferably, described road chain selecting arrangement can be selected the part in the described at least one candidate road chain according to the coefficient of variation of each bar candidate road chain, is labeled as effective road chain.

At this moment, described road chain selecting arrangement according to the following equation calculated candidate road chain i at the coefficient of variation L of t in the period _i(t):

L _i(t)＝S _i(t)/A _i(t)

Wherein, S _i(t) expression candidate road chain i is at the t standard deviation of a plurality of road chain hourage in the period, A _i(t) expression candidate road chain i is at the t mean value of a plurality of road chain hourage in the period.

Here, described road chain selecting arrangement can be calculated as coefficient of variation threshold value A L (t) all n bar candidate road chains at the mean value of the coefficient of variation of t in the period

$\mathrm{AL}\left(t\right)=\underset{i}{\overset{n}{\mathrm{\Σ}}}{L}_i\left(t\right)/n.$

Perhaps, described road chain selecting arrangement can be calculated as coefficient of variation threshold value A L (t) previously selected n bar and represent candidate road chain at the mean value of the coefficient of variation of t in the period

$\mathrm{AL}\left(t\right)=\underset{i}{\overset{n}{\mathrm{\Σ}}}{L}_i\left(t\right)/n.$

Perhaps, described road chain selecting arrangement can be with coefficient of variation threshold value A L _j(t) be calculated as all n that have the chain grade j that goes the same way mutually with candidate road chain i _jBar candidate road chain is at the mean value of the coefficient of variation of t in the period

$A{L}_j\left(t\right)=\underset{i}{\overset{n_j}{\mathrm{\Σ}}}{L}_i\left(t\right)/n_j.$

Perhaps, described road chain selecting arrangement according to the following equation calculated candidate road chain i at the coefficient of variation L of t in the period _i(t):

L _i(t)＝V _i(t) _max-V _i(t) _min

Wherein, V _i(t) _MaxBe illustrated in the main road chain Average Travel Speed of candidate road chain i in the t period, V _i(t) _MinBe illustrated in the minimal path chain Average Travel Speed of candidate road chain i in the t period.

Preferably, if beginning or end is positioned at the non-endpoint location of effective road chain, then described path calculation device can also be used for: described starting point or the residing effective road of described terminal point chain are updated to non-effective road chain, transformation rule according to non-effective road chain, upgrade described starting point or the residing effective road of described terminal point chain in the described new road network structure, then, search for optimal path again.

Preferably, described road chain selecting arrangement or described path calculation device, at the candidate road chain that will be updated to non-effective road chain or effective road chain, can calculate the mean value of a plurality of road chain hourage of described candidate road chain or described effective road chain, as the road chain hourage of described non-effective road chain, and many records about described candidate road chain or described effective road chain in road chain-Lu chain table hourage are merged the single record that is updated to about described non-effective road chain.

Preferably, a plurality of different road chain of described No. at least one chain can be hourage flow to relevant.

Preferably, described road network converting means can adopt dual graph method or virtual limit method, and described original road network structure is transformed to described new road network structure.

According to another aspect of the present invention, a kind of navigating instrument has been proposed, comprise: road chain selecting arrangement, be used for causing described No. at least one chain to have a plurality of different road chains during hourage when the terminal point owing to No. at least one chain of original road network structure with the starting point of many other road chains is continuous, select the part in described No. at least one chain; The road network converting means is used for will being transformed to new road network structure by the original road network structure that all road chains constitute based on selected road chain and corresponding a plurality of different road chain hourages thereof; And path calculation device, be used for according to described new road network structure the search optimal path.

Preferably, described navigating instrument can also comprise: the path reverse mapping device, and being used for described optimal path reciprocal transformation is transform optimal path based on described original road network structure; And display device, be used at original road network structure, show described transform optimal path.

Preferably, described road chain selecting arrangement can be labeled as candidate road chain with the road chain that has a plurality of different road chain hourage in the original road network structure, and the road chain that has single road chain hourage in the original road network structure is labeled as non-effective road chain, and can select a part in the chain of described candidate road, be labeled as effective road chain, and the residue road chain in the chain of described candidate road is labeled as non-effective road chain, thereby all the road chains in the original road network structure are divided into effective road chain and non-effective road chain.

According to a specific embodiment of the present invention, a kind of method for searching path based on effective road chain has been proposed, comprise: the road chain hourage of obtaining each bar road chain in the original road network structure in real time, each bar road chain has at least one road chain hourage, generates or upgrades road chain-Lu chain table hourage; In described road chain-Lu chain table hourage, the road chain that will have a plurality of road chain hourage is labeled as candidate road chain; At each bar candidate road chain, calculate the coefficient of variation of described candidate road chain; If the coefficient of variation of described candidate road chain greater than coefficient of variation threshold value, then is labeled as effective road chain with described candidate road chain; If the coefficient of variation of described candidate road chain is not more than coefficient of variation threshold value, then described candidate road chain is labeled as non-effective road chain, and calculate the mean value of a plurality of road chain hourage of described candidate road chain, as the road chain hourage of described non-effective road chain, accordingly, many records about described candidate road chain in described road chain-Lu chain table hourage are merged the single record that is updated to about described non-effective road chain; According to described road chain-Lu chain table hourage, will be transformed to new road network structure by the original road network structure that all road chains constitute; According to starting point and terminal point and described new road network structure, the search optimal path.

Described method for searching path based on effective road chain can also comprise: described optimal path reciprocal transformation is the transform optimal path based on described original road network structure; And in described original road network structure, show described transform optimal path.

The road chain of each bar road chain can be hourage flow to relevant.

In described shift step, can adopt dual graph method or virtual limit method, described original road network structure is transformed to described new road network structure.

In described search step, if described starting point or described terminal point are positioned at the non-endpoint location of effective road chain, described starting point or the residing effective road of described terminal point chain can be labeled as non-effective road chain, calculate the mean value of a plurality of road chain hourage of described effective road chain, as the road chain hourage of described non-effective road chain, according to the transformation rule of non-effective road chain, upgrade described starting point or the residing effective road of described terminal point chain in the described new road network structure, then, search for optimal path again.

Candidate road chain i is at the coefficient of variation L of t in the period _i(t) can calculate according to the following equation:

L _i(t)＝S _i(t)/A _i(t)

Wherein, S _i(t) expression candidate road chain i is at the t standard deviation of a plurality of road chain hourage in the period, A _i(t) expression candidate road chain i is at the t mean value of a plurality of road chain hourage in the period.At this moment, coefficient of variation threshold value A L (t) can be that all n bar candidate road chains are at the average letter of the coefficient of variation of t in the period

$\mathrm{AL}\left(t\right)=\underset{i}{\overset{n}{\mathrm{\Σ}}}{L}_i\left(t\right)/n.$

Perhaps, coefficient of variation threshold value A L (t) can be that previously selected n bar represents candidate road chain at the mean value of the coefficient of variation of t in the period

$\mathrm{AL}\left(t\right)=\underset{i}{\overset{n}{\mathrm{\Σ}}}{L}_i\left(t\right)/n.$

Perhaps, coefficient of variation threshold value A L _j(t) can be all n that have the chain grade j that goes the same way mutually with candidate road chain i _jBar candidate road chain is at the mean value of the coefficient of variation of t in the period

$A{L}_j\left(t\right)=\underset{i}{\overset{n_j}{\mathrm{\Σ}}}{L}_i\left(t\right)/n_j.$

Candidate road chain i is at the coefficient of variation L of t in the period _i(t) also can calculate according to the following equation:

L _i(t)＝V _i(t) _max-V _i(t) _min

Wherein, V _i(t) _MaxBe illustrated in the main road chain Average Travel Speed of candidate road chain i in the t period, V _i(t) _MinBe illustrated in the minimal path chain Average Travel Speed of candidate road chain i in the t period.At this moment, coefficient of variation threshold value A L (t) can be predefined.

According to another specific embodiment of the present invention, a kind of navigation server has been proposed, comprise: effective road chain pick-up unit, be used for obtaining in real time the road chain hourage of each bar road chain of original road network structure, each bar road chain has at least one road chain hourage, generate or renewal road chain-Lu chain table hourage, in described road chain-Lu chain table hourage, the road chain that will have a plurality of road chain hourage is labeled as candidate road chain, and at each bar candidate road chain, calculate the coefficient of variation of described candidate road chain; If the coefficient of variation of described candidate road chain greater than coefficient of variation threshold value, then is labeled as effective road chain with described candidate road chain; If the coefficient of variation of described candidate road chain is not more than coefficient of variation threshold value, then described candidate road chain is labeled as non-effective road chain, and calculate the mean value of a plurality of road chain hourage of described candidate road chain, as the road chain hourage of described non-effective road chain, accordingly, many records about described candidate road chain in described road chain-Lu chain table hourage are merged the single record that is updated to about described non-effective road chain; The road network converting means is used for will being transformed to new road network structure by the original road network structure that all road chains constitute according to described road chain-Lu chain table hourage; And path calculation device, be used for according to starting point and terminal point and described new road network structure the search optimal path.

Described navigation server can also comprise: the path reverse mapping device, and being used for described optimal path reciprocal transformation is transform optimal path based on described original road network structure; And dispensing device, be used for described transform optimal path is sent to navigating instrument.

The road chain of each bar road chain can be hourage flow to relevant.

In described shift step, adopt dual graph method or virtual limit method, described original road network structure is transformed to described new road network structure.

If described starting point or described terminal point are positioned at the non-endpoint location of effective road chain, described road network converting means can be labeled as non-effective road chain with described starting point or the residing effective road of described terminal point chain, calculate the mean value of a plurality of road chain hourage of described effective road chain, as the road chain hourage of described non-effective road chain, transformation rule according to non-effective road chain, upgrade described starting point or the residing effective road of described terminal point chain in the described new road network structure, then, search for optimal path again.

Described effective road chain pick-up unit according to the following equation calculated candidate road chain i at the coefficient of variation L of t in the period _i(t):

L _i(t)＝S _i(t)/A _i(t)

Wherein, S _i(t) expression candidate road chain i is at the t standard deviation of a plurality of road chain hourage in the period, A _i(t) expression candidate road chain i is at the t mean value of a plurality of road chain hourage in the period.At this moment, described effective road chain pick-up unit can be calculated as coefficient of variation threshold value A L (t) all n bar candidate road chains at the mean value of the coefficient of variation of t in the period

$\mathrm{AL}\left(t\right)=\underset{i}{\overset{n}{\mathrm{\Σ}}}{L}_i\left(t\right)/n.$

Perhaps, described effective road chain pick-up unit can be calculated as coefficient of variation threshold value A L (t) previously selected n bar and represent candidate road chain at the mean value of the coefficient of variation of t in the period

$\mathrm{AL}\left(t\right)=\underset{i}{\overset{n}{\mathrm{\Σ}}}{L}_i\left(t\right)/n.$

Perhaps, described effective road chain pick-up unit can be with coefficient of variation threshold value A L _j(t) be calculated as all n that have the chain grade j that goes the same way mutually with candidate road chain i _jBar candidate road chain is at the mean value of the coefficient of variation of t in the period

$A{L}_j\left(t\right)=\underset{i}{\overset{n_j}{\mathrm{\Σ}}}{L}_i\left(t\right)/n_j.$

Described effective road chain pick-up unit also according to the following equation calculated candidate road chain i at the coefficient of variation L of t in the period _i(t):

L _i(t)＝V _i(t) _max-V _i(t) _min

Wherein, V _i(t) _MaxBe illustrated in the main road chain Average Travel Speed of candidate road chain i in the t period, V _i(t) _MinBe illustrated in the minimal path chain Average Travel Speed of candidate road chain i in the t period.At this moment, described effective road chain pick-up unit can store predefined coefficient of variation threshold value A L (t).

According to another specific embodiment of the present invention, a kind of navigating instrument has been proposed, comprising: effective road chain information receiving trap, be used for receiving or upgrade road chain-Lu chain table hourage, comprise record about effective road chain hourage in the table at described road chain-Lu chain; The road network converting means is used for will being transformed to new road network structure by the original road network structure that all road chains constitute according to described road chain-Lu chain table hourage; And path calculation device, be used for according to starting point and terminal point and described new road network structure the search optimal path.

Described navigating instrument can also comprise: the path reverse mapping device, and being used for described optimal path reciprocal transformation is transform optimal path based on described original road network structure; And display device, be used at original road network structure, show described transform optimal path.

If described starting point or described terminal point are positioned at the non-endpoint location of effective road chain, described path calculation device can be labeled as non-effective road chain with described starting point or the residing effective road of described terminal point chain, calculate the mean value of a plurality of road chain hourage of described effective road chain, as the road chain hourage of described non-effective road chain, transformation rule according to non-effective road chain, upgrade described starting point or the residing effective road of described terminal point chain in the described new road network structure, then, search for optimal path again.

According to another specific embodiment of the present invention, a kind of navigating instrument has been proposed, comprising: new road network structure receiving trap is used for receiving new road network structure; Path calculation device is used for according to starting point and terminal point and described new road network structure, the search optimal path; The path reverse mapping device, being used for described optimal path reciprocal transformation is transform optimal path based on original road network structure; And display device, be used at original road network structure, show described transform optimal path.

If described starting point or described terminal point are positioned at the non-endpoint location of effective road chain, described path calculation device can be labeled as non-effective road chain with described starting point or the residing effective road of described terminal point chain, calculate the mean value of a plurality of road chain hourage of described effective road chain, as the road chain hourage of described non-effective road chain, transformation rule according to non-effective road chain, upgrade described starting point or the residing effective road of described terminal point chain in the described new road network structure, then, search for optimal path again.

Description of drawings

By below in conjunction with description of drawings the preferred embodiments of the present invention, will make above-mentioned and other purpose of the present invention, feature and advantage clearer, wherein:

Fig. 1 shows the system hardware structure figure of embodiment 1.

Fig. 2 shows the system flowchart of embodiment 1.

Fig. 3 shows the road network structure example of representing with road chain and node.

Fig. 4 shows with the road network structure example after the dual graph method conversion road network structure example shown in Figure 3.

Fig. 5 (a), 5 (b) and 5 (c) show the simplified illustration of road network being carried out conversion with the dual graph method.

Fig. 6 (a), 6 (b) and 6 (c) show the impedance of road network conversion time channel chain and distribute diagram.

Fig. 7 (a), 7 (b) and 7 (c) show with increasing virtual limit method is carried out conversion to road network simplified illustration.

Fig. 8 (a), 8 (b) and 8 (c) show the road network conversion exemplary plot at rotary island crossing.

Fig. 9 (a) and 9 (b) show the road chain of various intersections and represent example.

Figure 10 shows the example block diagram of path calculation device.

Figure 11 (a), 11 (b) and 11 (c) show head and the tail road chain reciprocal transformation exemplary plot.

Figure 12 (a) and 12 (b) show path reciprocal transformation exemplary plot.

Figure 13 shows the system construction drawing of user's automatic navigator.

Figure 14 shows the system hardware structure figure of the embodiment of the invention 2.

Figure 15 shows the system flowchart of the embodiment of the invention 2.

Figure 16 shows the system hardware structure figure of the embodiment of the invention 3.

Figure 17 shows the system flowchart of the embodiment of the invention 3.

Embodiment

To a preferred embodiment of the present invention will be described in detail, having omitted in the description process is unnecessary details and function for the present invention with reference to the accompanying drawings, obscures to prevent that the understanding of the present invention from causing.

Embodiment 1

Fig. 1 is the system hardware structure figure of the embodiment of the invention 1, and navigation server 1000 comprises effective road chain pick-up unit 100, road network converting means 300, path calculation device 400, path reverse mapping device 600, communicator 700, information-storing device 50.

Fig. 2 is the system flowchart of embodiment 1, and effectively road chain pick-up unit 100 detects effective road chain by analyzing floating car data 110, obtains road chained list 120, and road chained list 120 has comprised the information (step S100) of effective road chain and non-effective road chain.Road network converting means 300 carries out conversion by inquiry road chained list 120 and map datum 130 to the effective road chain in the map, obtains new road net data 140 (step S300).Road chain and node in the new road network all have single value, and the impedance of road chain or node is road chain hourage, utilize path calculation device 400 to calculate optimal path (step S400).Reverse mapping device 600 pairs of optimal paths in path carry out reciprocal transformation, the path is transformed to the path (step S600) that can the map in automatic navigator 800 shows, format map in the automatic navigator 800 format map common and server end is consistent, automatic navigator 800 is to the center requests path computing time, send the version number of the map on current location, destination locations and the automatic navigator 800, calculate optimal path by navigation server 1000, and according to vehicle-mounted end map version optimal path is carried out reciprocal transformation.Last communicator 700 sends to client automatic navigator 800 with optimal path.

Below, will each device in the navigation server 1000 be elaborated.

Effective road chain pick-up unit that is positioned at the center 100 is used for generating and flows to relevant road chain hourage as the impedance of road chain, and detects the road chain and whether have a plurality of resistance values.If the road chain is detected and has a plurality of resistance values (be a plurality of hourage value), this road chain just is marked as effective road chain, and effectively a plurality of resistance values of road chain are recorded in the chained list of effective road, and are as shown in table 1.

Table 1

Road chain numbering	Timestamp	Divide and flow to road chain impedance (hourage) (second)	Be regardless of and flow to average road chain impedance (second)	Road chain whether effectively	Turn direction (being the numbering of next bar road chain)
						1	14:00	30	30	Be	2
1	14:00	20	30	Be	3
						1	14:00	40	30	Be	4
2	14:00		20	Not
						3	14:00		30	Not
4	14:00	30	30	Be	5
						4	14:00	20	30	Be	6
4	14:00	40	30	Be	7
						1	14:05		30	Not
2	14:05		20	Not
						1	14:10		30	Not
…	…	…	…	…	…

Road chain resistance value is dynamic change, and the resistance value of the road chain that the crossing links to each other may be all identical on all directions, also may be inequality, this is time dependent, thus road chain whether effectively the road chain also be dynamic change in time.The road chain is the one section oriented highway section that is divided into out in the real road, and every road all comprises many road chains, and the road of an opposing traffic comprises two road chains at least.

Fig. 3 shows the road network structure example of representing with road chain and node.As shown in Figure 3,2 roads are arranged laterally, 2 roads are vertically arranged, every road all comprises many directed line segments, i.e. the road chain.The point of crossing of road chain is called node.16 road chains altogether among Fig. 3,8 nodes.Preserved the static information of all road chains in the map datum 130, as shape, position, width, length, direction etc., and the connection situation between each road chain.

Can find out that from table 1 and Fig. 3 at 14:00 constantly, road chain 1 is effective road chain, its road chain is divided into three values according to turn direction hourage.Be 30 seconds its hourage when road chain 1 turned to road chain 2, if namely vehicle leaves for road chain 2 from road chain 1, be 30 seconds its hourage on road chain 1 so.Be 20 seconds its hourage when road chain 1 turned to road chain 3, if namely vehicle leaves for road chain 3 from road chain 1, be 20 seconds its hourage on road chain 1 so.It is 40 seconds that road chain 1 turns to the hourage of road chain 4, if namely vehicle leaves for road chain 4 from road chain 1, be 40 seconds its hourage on road chain 1 so.At 14:00 constantly, road chain 2 is not effective road chain, and its road chain has only one hourage, and namely which direction no matter vehicle leave to from road chain 2, and all be 20 seconds its hourage on road chain 2.The road chain degree of blocking up is dynamic change, can find out 14:05 constantly from table 1, and road chain 1 has also become non-effective road chain.

Be that effective road chain pick-up unit 100 utilizes floating car data 110 to detect the concrete exemplary step of effective road chain below:

Step S101: the GPS that the Floating Car system uploads according to Floating Car calculates hourage and the turn direction (be next bar road chain that vehicle travel) of each Floating Car on the chain of road, and the result saves as floating car data 110.Table 2 is the data layout example of floating car data 110.

Table 2

Car number	Current time	The current road of living in of vehicle chain numbering	Vehicle road chain hourage (second)	Turn inside diameter direction (being the numbering of next bar road chain)
					12344	14:00	1	29	2
12345	14:00	1	31	2
					23456	14:00	1	20	3
34567	14:00	1	40	4
					56789	14:00	2	20	101
67890	14:00	2	20	102
					78900	14:00	2	20	103
…	…	…	…	…

Because the Floating Car system is known technology, how calculating road chain hourage is not emphasis of the present invention, for outstanding emphasis of the present invention, no longer introduce the computation process of Floating Car system at this, its ultimate principle can effectively not comprise the Floating Car system in the road chain pick-up unit 100 with reference to Jap.P. 07-029098 (1995) or U.S. Patent Application Publication 2004/0167710A1." current time " time period of expression in the table 2, if the time interval is 5 minutes, current time 14:00 namely represents this time period from 13:55～14:00 so.

Step S102: effectively road chain pick-up unit 100 obtains the hourage of each car on every road chain from floating car data 110, calculates the mean value of the hourage that flows to identical vehicle, as the road chain hourage of this flow direction.For example, during time period 14:00, have two to be numbered 12344 and 12345 Floating Car and all to drive towards road chain 2 on the road chain 1 in the table 2, the road chain was respectively 31 seconds and 29 seconds hourage, mean value is 30 seconds, and the hourage of road chain 1 on the direction that flows to road chain 2 is exactly 30 seconds so.During time period 14:00, flow to road chain 3 and road chain 4 has only a Floating Car respectively from road chain 1 in the table 2, so be exactly the road chain hourage (20 seconds and 40 seconds) of vehicle 23456 and 34567 road chain hourage of these two flow directions.

If in certain time period, do not have real-time floating car data or certain to flow on the chain of road and do not have real time data, just substitute with statistics, statistics is to obtain by the historical floating car data of analyzing on this road chain.If also do not have statistics on this road chain, the data on this road chain just replace with the floating car data of last period or adjacent road chain so.About how the road chain data of completion disappearance are not emphasis of the present invention, so do not describe in detail at this, correlation technique can be with reference to U.S. Patent Application Publication 2004/0167710A1.

Step S103: effective road chain pick-up unit 100 obtains every road chain from floating car data 110 branch flows to the road chain after hourage, and the branch that calculates every road chain again flows to the coefficient of variation of hourage.The coefficient of variation is the ratio of standard deviation and average, and the coefficient of variation computing formula that respectively flows to road chain hourage is as follows:

L _i(t)＝S _i(t)/A _i(t) (1)

L in the formula (1) _i(t) be illustrated in the coefficient of variation of road chain i in the t period, S _i(t) be illustrated in the standard deviation that respectively flows to the vehicle journeys time of road chain i in the t period, A _iWhat (t) be illustrated in road chain i in the t period respectively flows to mean value hourage, or at t mean value of all vehicle journeys times on the road chain i in the period.Calculate the coefficient of variation L of every road chain _i(t) after, use again formula (2) calculate whole road network at the average coefficient of variation AL (t) of t in the period

$\mathrm{AL}\left(t\right)=\underset{i}{\overset{n}{\mathrm{\Σ}}}{L}_i\left(t\right)/n---\left(2\right)$

N represents for the road chain number of calculating average coefficient of variation AL (t) in the formula (2).When calculating average coefficient of variation AL (t), both the coefficient of variation of all n bar road chains can be averaged, also can average by the representational road of a picking part chain, can also be by the rating calculation mean value of road chain, different road chain rating calculation go out a plurality of different average coefficient of variation AL _j(t), j is road chain class letter (formula (2 ')).

$A{L}_j\left(t\right)=\underset{i}{\overset{n_j}{\mathrm{\Σ}}}{L}_i\left(t\right)/n_j---\left(2^{,}\right)$

Step S104: effective road chain pick-up unit 100 coefficient of variation L with every road chain _i(t) compare with average coefficient of variation AL (t), with coefficient of variation L _i(t) the road chain greater than average coefficient of variation AL (t) is labeled as effective road chain, coefficient of variation L _i(t) be labeled as non-effective road chain (with the mean value of hourage of a plurality of flow directions hourage (be regardless of and flow to the chain impedance of average road) as non-effective road chain) smaller or equal to the road chain of average coefficient of variation AL (t), and finally generate the road chained list shown in the table 1.If average coefficient of variation AL _j(t) be chain grade along separate routes, when calculating so the road chain of different brackets will with the average coefficient of variation AL of corresponding grade _j(t) compare.

In addition, in above-mentioned steps S103 and S104, the coefficient of variation can also be the difference that each minute of same road chain flows to speed.Effectively chain pick-up unit 100 branch that obtains every road chain from floating car data 110 in road flows to the road chain after hourage, again the road chain average velocity that flows to according to the branch of every road chain of length computation of road chain.Therefore, the road chain i with a plurality of flow directions has a plurality of branches at t and flows to road chain average velocity in the period, and the maximum road chain average velocity of definition is V _i(t) _Max, minimum road chain average velocity is V _i(t) _Min, at this moment, can be with this road chain i at the coefficient of variation L of t in the period _i(t) be defined as

L _i(t)＝V _i(t) _max-V _i(t) _min (2”)

If coefficient of variation L _i(t) greater than the coefficient of variation threshold value A L (t) of a default, as AL (t)=10km/h, so just road chain i can be labeled as effective road chain.

A road network converting means 300 that is positioned at the center with reference to the effective road chain in the road chained list shown in the table 1, carries out conversion to the effective road chain in the former map road network, and the mode of conversion both can be the dual graph method, also can adopt the method that increases virtual limit.When adopting the dual graph method, effective road chain original in the new road network is converted into effective node.It is new road chain that new connecting line between effective node is taken as, and each new road chain has only single road chain hourage.When adopting the method that increases virtual limit, effective road chain transformaiton is many road chains, and every road chain has only single road chain hourage.Be the concrete exemplary step of carrying out the road network conversion below:

Step S201: select the effective road chain in the map.Be not that every road chain all is effective road chain in the map, need reference arm chained list (as table 1), effective road chain that will be arranged in map is picked out.

Step S202: at select effective road chain among the step S201, carry out conversion with dual graph method or the method that increases virtual limit, the dual graph method mainly contains two characteristics: a) represent the limit with point, and keep all properties on limit; B) represent to turn to behavior with the limit.The feature that increases virtual limit method is: a) deletion former effective road chain, the attribute of former effective road chain is comprised in b in the newly-increased virtual limit) newly-increased virtual limit represents to turn to behavior.

Below, illustrate earlier and how with the dual graph method road network to be carried out conversion.

Fig. 4 is the figure that obtains after the road network dualistic transformation among Fig. 3.

Because Fig. 3 is comparatively complicated to the conversion of Fig. 4, for the purpose of simplifying the description, Fig. 5 (a) has simplified the road network structure among Fig. 3.Among Fig. 5 (a), suppose that road chain 1 has three different road chain impedances (road chain hourage), for example, but reference table 1.By the dual graph method, the road chain 1,2,3,4 among Fig. 5 (a) is transformed to the point 1,2,3,4 among Fig. 5 (b), and the line 12,13,14 between them represents vehicle respectively and turns to road chain 2,3,4 from road chain 1.The road chained list is updated in the table 1, and the content after the renewal is as shown in table 3.

Table 3

Road chain numbering	Timestamp	Divide and flow to road chain impedance (hourage) (second)	Be regardless of and flow to average road chain impedance (second)	Road chain whether effectively	Turn direction (being the numbering of next bar road chain)
						*1	14:00		0	Not
12	14:00		30	Not
						13	14:00		20	Not
14	14:00		40	Not
						*2	14:00		20	Not
*3	14:00		30	Not
						*4	14:00	30	30	Be	5
*4	14:00	20	30	Be	6
						*4	14:00	40	30	Be	7

* 1 expression road chain 1 has been transformed into node 1, and the node impedance is 0.

* 2 expression road chains 2 have been transformed into node 2, and have kept all properties of road chain 2.

* 3 expression road chains 3 have been transformed into node 3, and have kept all properties of road chain 3.

* 4 expression road chains 4 have been transformed into node 4, and have kept all properties of road chain 4.

Road chain 12,13,14 road chain impedance equal the impedance that road chain 1 makes progress in various flows among Fig. 5 (a), and the impedance that is about to three flow directions of road chain 1 is assigned on three road chains, guarantees that every impedance on the chain of road is single value.Fig. 5 (b) mid point 2 is the logic limit to point 40 connection, and resistance value own is 0, and expression point 2 annexations to point 40 only, this annexation are that the annexation of road chain 2 and node 40 is inherited from Fig. 5 (a).In like manner, Fig. 5 (b) mid point 4 and the connection of putting between 90 also are the logic limits, and point 3 and the connection of putting between 60 also are the logic limits, and point 1 and the connection of putting between 20 also are the logic limits, and impedance all is 0.

Further, if the road chain 4 among Fig. 5 (a) also is effective road chain, arranged three different road chain hourages, the node 4 among Fig. 5 (b) just has a plurality of resistance values so, and Fig. 5 (b) just should further be transformed to Fig. 5 (c).Road chain 5,6,7 among Fig. 5 (b) is transformed to the point 5,6,7 among Fig. 5 (c), and the line 45,46,47 between they and the point 4 represents vehicle respectively and turns to road chain 5,6,7 from node 4 (former road chain 4).After the conversion, the resistance value of point 4 becomes 0.Fig. 5 (c) mid point 5 is the logic limit to point 80 connection, and itself is without any resistance value, and expression point 5 annexations to point 80 only, this annexation are that the annexation of road chain 5 and node 80 is inherited from Fig. 5 (a).In like manner, Fig. 5 (c) mid point 7 and the connection of putting between 120 also are the logic limits, and point 6 and the connection of putting between 100 also are the logic limits, all do not have impedance.Fig. 5 (b) mid point 4 and the logic limit of putting between 90 are deleted in Fig. 5 (c).After the road network conversion, road chained list (table 3) is updated, and the content after the renewal is as shown in table 4.

Table 4

Road chain numbering	Timestamp	Divide and flow to road chain impedance (hourage) (second)	Be regardless of and flow to average road chain impedance (second)	Road chain whether effectively	Turn direction (being the numbering of next bar road chain)
						*1	14:00		0
12	14:00		30	Not
						13	14:00		20	Not
14	14:00		40	Not
						*2	14:00		20	Not
*3	14:00		30	Not
						*4	14:00		0
45	14:00		30	Not
						46	14:00		20	Not
47	14:00		40	Not

* 4 expression road chains 4 have been transformed into node 4, and the node impedance is 0.

Road chain 45,46,47 road chain impedance equal the impedance that road chain 4 makes progress in various flows among Fig. 5 (a), and the impedance that is about to three flow directions of road chain 4 is assigned on three road chains, guarantees that every impedance on the chain of road is single value.

Point newly-generated after the conversion is referred to as available point, and newly-generated limit (except the logic limit) is referred to as effective edge.The impedance of effective edge is effective in a plurality of hourages in the chain of road in the former road network, the impedance of available point in two kinds of situation, if available point is to be come by the effective road chain transformaiton that is transformed, its impedance is made as 0 so, as the node 1 among Fig. 5 (b).If available point is to come with being transformed the road chain transformaiton that effective road chain links to each other, its impedance is made as the hourage of former road chain so, and as the node 4 among Fig. 5 (b), its impedance this moment might not be unique, because former road chain might also be effective road chain.Need further carry out conversion this moment, all is unique up to the impedance of newly-generated available point.

For example, supposing to have only among Fig. 6 (a) road chain 1 and road chain 4 is that effective road chain (has a plurality of hourage of value, road chain 1 is respectively 120,140,130 to road chain 2,4,3 value hourage, road chain 4 is respectively 450,470,460 to road chain 5,7,6 value hourage), road chain 2,3,5,6, hourage of 7 are respectively 20,30,50,60,70, can have arbitrary unit above-mentioned hourage, for unification, is unit with the second in this instructions.Numeral in Fig. 6 (a) bracket is resistance value (value hourage), and the impedance of having arrived available point 2 newly-generated among Fig. 6 (b) and 3 so is 20 and 30 respectively just, and the impedance of available point 1 is 0.But the resistance value of available point 4 is not unique, need further be transformed to the form of Fig. 6 (c).Arrived among Fig. 6 (c), newly-generated available point 5,6,7 impedance be not for being 50,60,70, and the resistance value of available point 4 becomes 0, and newly-generated effective edge 45,46,47 impedance are respectively 450,460,470.So far, newly-generated available point 1,2,3,4,5,6,7 impedance all are unique values, and the road network conversion of Fig. 6 (a) is finished.

Below, illustrate again and how with increasing virtual limit method road network to be carried out conversion.

Suppose that road chain 1 is effective road chain among Fig. 7 (a), increased by three virtual road chains 12,13,14 among Fig. 7 (b), delete road chain 1 simultaneously.The resistance value of road chain 12 is the impedance that the impedance of road chain 1 adds road chain 2, and the resistance value of road chain 13 is the impedance that the impedance of road chain 1 adds road chain 3, and the resistance value of road chain 14 is the impedance that the impedance of road chain 1 adds road chain 4.After the road network conversion, the road chained list is updated in the table 1, and the content after the renewal is as shown in table 5.

Table 5

Road chain numbering	Timestamp	Divide and flow to road chain impedance (hourage) (second)	Be regardless of and flow to average road chain impedance (second)	Road chain whether effectively	Turn direction (being the numbering of next bar road chain)
						12	14:00		30+20	Not
13	14:00		20+30	Not
						14	14:00		40+30	Not
2	14:00		20	Not
						3	14:00		30	Not
4	14:00	30	30	Be	5
						4	14:00	20	30	Be	6
4	14:00	40	30	Be	7
						…

Further, if road chain 4 also is effective road chain, further be transformed to the road network shown in Fig. 7 (c).Deletion road chain 14 and road chain 7 increase road chain 145,146,147.The impedance of road chain 145 is road chain 1,4,5 impedance sum.The impedance of road chain 146 is road chain 1,4,6 impedance sum.The impedance of road chain 147 is the impedance sum of road chain 14,7 ( road chain 1,4,7 namely).After the road network conversion, road chained list (table 5) is updated, and the content after the renewal is as shown in table 6.

Table 6

Road chain numbering	Timestamp	Divide and flow to road chain impedance (hourage) (second)	Be regardless of and flow to average road chain impedance (second)	Road chain whether effectively	Turn direction (being the numbering of next bar road chain)
						12	14:00		30+20	Not
13	14:00		20+30	Not
						2	14:00		20	Not
3	14:00		30	Not
						145	14:00		40+30+50	Not
146	14:00		40+20+60	Not
						147	14:00		40+40+70	Not
5	14:00		50	Not
						6	14:00		60	Not
7	14:00		70	Not
						…

After table 7 has provided and with dual graph method and virtual limit method road network has been carried out conversion, the number of node and road chain in the road network.

Table 7

Road network	The node number	Road chain number
			Former road network, Fig. 5 (a) and Fig. 7 (a)	8	7
The dual graph method, Fig. 5 (b)	11	10
			The dual graph method, Fig. 5 (c)	13	12
Virtual limit method, Fig. 7 (b)	8	9
			Virtual limit method, Fig. 7 (c)	8	10

Use the method that increases virtual limit to carry out the road network conversion as can be seen, the road network scale after the conversion is littler than adopting the dual graph method.But the impedance computation on newly-increased virtual limit is more complicated, need carry out summation operation to the impedance of a plurality of roads chain in the former road network.When particularly many continuous effective road chains being carried out conversion, need carry out summation operation repeatedly.For balance road network scale and calculated amount, can adopt following strategy: when the intersection has only isolated effective road chain, use virtual limit method that effective road chain is carried out conversion, when effective road of intersection chain is continuous two or more, adopt the dual graph method.

Step S203, by above two step S201 and S202, the effective road chain in the original path network is converted into new effective edge and available point, and each effective edge and available point have only single resistance value, a plurality of values can not arranged simultaneously.Road chain and node in the road network after the conversion all have only single value, just can handle with classical dijkstra's algorithm or A* algorithm.Because road network is digraph, the road chain all is directive, so if the impedance of new available point is not 0, its resistance value can be appended to this point so serves as in the effective edge impedance of outlet end points, for example the impedance of Fig. 6 (c) mid point 5 is included in the effective edge 45, then the impedance of effective edge 45 increases to 500 by 450, and the impedance of point 5 is 0.Through this step, the impedance of all nodes all is 0 in the road network after the conversion.

To the initialization setting of node impedance, be an optional step when step S203 just influences path computing.

According to up-conversion step, not only can carry out conversion to common crossroad, can also be to irregular intersection, carry out conversion if any intersection of rotary island etc.

Fig. 8 (a) is depicted as the crossing that typically comprises rotary island, and rotary island is expressed as node when road calculates, and is depicted as the rotary island road network structure of expressing with node and the combination of road chain as Fig. 8 (b).1 node is arranged, and 5 flow into road chains and 5 and flow out the road chains, just than common crossroad Duo 1 flow out road chain and 1 inflow road chain.Suppose that road chain 112 is effective road chains, structure was shown in Fig. 8 (c) after applying virtual limit method was carried out the road network conversion, and the dotted line among Fig. 8 (c) is newly-increased virtual limit.

Fig. 9 (a) and 9 (b) show the road chain of various intersections and represent example.Various forms of intersections in theory, around can being expressed as a node road chain of some inflows and the road chain of outflow are arranged, difference is the quantity variance of road chain, so aforementioned road network map function goes for effective road chain of various intersections.

The congestion status of actual road network is dynamic the variation, so navigation server 1000 need regularly upgrade the road chained list, and according to the new road chained list road network of remapping.Congestion status is the process of a gradual change, when upgrading the road chained list, is not that the validity of every road chain all can change at every turn, for example some road chain probably continuously several hrs all be effective road chain.Therefore, need carry out conversion to all effective road chains during except road network conversion first, under other situation, only need newly-increased effective road chain is carried out the road network conversion, cross and last till that current effective road chain no longer carries out the road network conversion, only upgrades its resistance value for conversion.For the effective road chain that lost efficacy, in time delete its transformation results, recover original road chain structure.By this gradual road network transform method, can further reduce the calculated amount of road network converting means 300 each road network conversion.

Be positioned at destination, departure place/current location information that the path calculation device 400 of navigation server 1000 is uploaded according to vehicle-mounted end, based on new road network, calculate optimal path.In the new road network with road chain hourage as road chain impedance, the impedance of node also is the road chain hourage in the former road network.The optimal path that path calculation device 400 adopts traditional Dijkstra or A* algorithm to calculate is the shortest path hourage.The congestion status of road is real-time change, be that the road chain is constantly to change hourage, path calculation device 400 should be able to be according to the renewal of road chained list before the user reaches home, again be user's calculating path, and the path after will upgrading sends to the user, and whether the user can select in navigation procedure more new route certainly.

The departure place of vehicle and destination may be to be positioned at middle-of-chain position, road not necessarily at the end points of road chain, furthermore may be to be positioned at middle-of-chain position, effective road.Effectively can become many road chains after chain pathway chain transformaiton device 300 conversion of road, if user's terminus is on the chain of effective road, a starting point just becomes a plurality of starting points, a terminal point also becomes a plurality of terminal points, this just makes path calculation device 400 will carry out repeatedly path computing, obtain a plurality of path computing results, and therefrom select optimal path.The difference of aforementioned a plurality of starting points is the difference of turn direction in fact just, and vehicle can only be to keep to the side to stop after arriving the destination, and the meaning of repeatedly calculating according to a plurality of starting points and terminal point is also little.

Therefore, the present invention comprises a head and the tail chain reciprocal transformation unit, road 410 in path calculation device 400, as shown in figure 10.If the terminus of path computing is positioned at the non-endpoint location of effective road chain, head and the tail chain reciprocal transformation unit, road 410 is former road chain or node with the road chain reciprocal transformation that is come by effective road chain transformaiton in the new road network just so, and with average hourage of road chain as road chain impedance, guarantee the uniqueness of road chain resistance value.Then, again by path-calculating element 420 search optimal paths.

Figure 11 (a), 11 (b) and 11 (c) show head and the tail road chain reciprocal transformation exemplary plot.Supposing that the vehicle starting point among Figure 11 (a) is positioned on effective road chain 4, is 1/3 of road chain 4 length to road chain 4 terminal points distance.In the new road network after conversion (Figure 11 (b)), the vehicle starting point has three places, lays respectively on the road chain 45,46,47, and these three road chains overlap geographically, and just the road chain is different hourage.Before the path computing, head and the tail chain reciprocal transformation unit, road 410 carries out reciprocal transformation to these three road chains, and the result is shown in Figure 11 (c) after the conversion, and the vehicle starting point is positioned at node 4, node 4 is by 4 conversion of road chain, so the impedance of node 4 is 1/3 of 4 average hourages of road chain.Starting point has only one when so just having guaranteed path computing, if terminal point also on effective road chain, adopts so with quadrat method and carries out reciprocal transformation, terminal point also has only one when guaranteeing path computing.The reciprocal transformation of the 410 pairs of starting points in head and the tail chain reciprocal transformation unit, road, terminal point is only effective at the active user, only when calculating active user's path, come into force temporarily, invalid to other user, this conversion can not changed the new road net data 140 that exists as global data.

If the computing power of navigation server 1000 is very strong certainly, can bear the calculated amount that multipath calculates, the reciprocal transformation of not carrying out head and the tail road chain so also is fine, and path calculation device 400 is still chosen an optimal path and offered the user from mulitpath.

The road chain that comprises in the optimal path that path calculation device 400 calculates and nodal information all are based on new road net data 140, and the map on the automatic navigator is original map, and aforementioned optimal path can not directly be shown to the user.The invention provides a path reverse mapping device 600, optimal path is transformed to path based on road chain and nodal information in the original map.

Figure 12 (a) and 12 (b) show path reciprocal transformation exemplary plot.Dotted line shown in Figure 12 (a) is wherein a section of certain optimal path, is shown as the dotted path among Figure 12 (b) after reciprocal transformation.

Real road is constantly to change, and map is in constantly upgrading, and the version of the map in each user's automatic navigator 800 may not be consistent, and path reverse mapping device 600 is wanted and can be carried out reciprocal transformation at the map of different editions.This just needs the user when serving to the center requests route searching, except departure place, destination information are provided, also will provide vehicle-mounted map version information.The road chain that comprises in the optimal path after 600 reciprocal transformations of path reverse mapping device and nodal information all are based on format map in user's automatic navigator 800, by communicator 700 these routing informations are sent to user's automatic navigator 800.

Figure 13 is the structural drawing of user's automatic navigator 800.Communicator 810 is used for communicating by letter of automatic navigator 800 and navigation server 1000, and the communications between each installs in the automatic navigator 800.GPS locating device 820 is used for determining the current position of user, the optimal path that the navigation server 1000 that path guiding device 830 receives for preservation communicator 810 calculates, and according to user's current location, cartographic information and routing information generation driving guidance information, as navigation screen and sound.Output display device 840 is presented to the driver with navigation screen and sound that path guiding device 830 generates.User input apparatus 850 is used for receiving user's setting, as the destination being set, other parameter of automatic navigator 800 is set etc.The user will send navigation server 1000 to by communicator 810 to the setting of destination.

Embodiment 2

Path computation function is finished by navigation server 1000 in previous embodiment 1 of the present invention, so do not have path calculation device in the automatic navigator 800 among Figure 13.But path computation function also can be arranged in automatic navigator (embodiment 2), and the path calculation device among Fig. 1 400 and path reverse mapping device 600 just must move on in the automatic navigator 800 so.

Figure 14 is the navigation server 1000 of the embodiment of the invention 2 and the structural drawing of automatic navigator 810.1000 of navigation servers at Figure 14 comprise effective road chain pick-up unit 100 and road network converting means 300.The new road net data that road network converting means 300 generates sends to automatic navigator 800 through communicator 700.

Increased path calculation device 400 and path reverse mapping device 600 in the automatic navigator 800 of Figure 14, that introduces among the principle of work of these two devices and the embodiment 1 is the same, is that the installation site is at vehicle-mounted end.

Figure 15 is the system flowchart of embodiment 2.Navigation server 1000 is responsible for detecting effective road chain, is generated the road chained lists, the effective road chain in the conversion road network then, and the request according to automatic navigator 800 at last sends new road net data to vehicle-mounted end.Automatic navigator 800 receives new road net data by step S810, and step S400 calculates optimal path according to the destination of user's input, and step S600 carries out reciprocal transformation with optimal path, makes optimal path to show in original map.Step S830 is according to routing information and vehicle current location, generates guiding driver's navigation information, as " the 50 meters right-hand rotations in the place ahead " etc.

The communicator 810 of automatic navigator 800 need be downloaded new road net data from navigation server, carries out path computing according to new road net data then.The download of new road net data generally need spend some times, the computing power of automatic navigator 800 is also not as navigation server 1000, if reduce data download and the calculated amount of automatic navigator 800, can be according to user's terminus position, download new road net data selectively, for example the path calculation device in the automatic navigator 800 400 is that road chain impedometer is calculated an initial path with the road chain length earlier, (for example only download this initial path new road net data on every side then, with the distance of initial path smaller or equal to 15km), after download is finished, recomputate optimal path according to the road chain impedance in the new road network again.Delimit the download scope of road net data, except adopting the method for initial path, can also adopt other method, for example, being limited to the download scope of road net data with starting point and terminal point is in the scope of circumscribed circle of circumscribed square of circle of diameter.In process of downloading, automatic navigator 800 also bootable driver is driven according to original route earlier, removes to upgrade navigation way with optimal path on the way then.This method can reduce driver's stand-by period.

Embodiment 3

In embodiments of the invention 3, the road network converting means 300 of the navigation server 1000 of previous embodiment 2 also is installed in the automatic navigator 800, finish road network conversion work by automatic navigator 800,1000 of navigation servers are responsible for generating the road chained list that comprises effective road chain.

Figure 16 shows the navigation server 1000 of the embodiment of the invention 3 and the structural drawing of automatic navigator 810.Because the function of each module all is described in detail in embodiment 1, repeat no more here.

Figure 17 is the system flowchart of the embodiment of the invention 3.In navigation server 1000, generate the road chained list by effective road chain pick-up unit 100, and continue to upgrade.Communicator 810 in the automatic navigator 800 is downloaded the road chained list, generates new road net data by road network converting means 300, and path calculation device 400 calculates optimal path, and reverse mapping device 600 pairs of optimal paths in path carry out reciprocal transformation.Path guiding device 830 generates guiding driver's navigation information.Output display device 840 is presented to the driver with navigation screen and sound that path guiding device 830 generates.

Effectively the download of road chain data generally need spend some times, the computing power of automatic navigator 800 is also not as navigation server 1000, if reduce data download and the calculated amount of automatic navigator 800, can be according to user's terminus position, selectively download effective road chain data, for example the path calculation device in the automatic navigator is that road chain impedometer is calculated an initial path with the road chain length earlier, (for example only download this initial path effective road chain data on every side then, with the distance of initial path smaller or equal to 15km), when carrying out the road network conversion, automatic navigator 800 also only the road network around this initial path is carried out conversion, after conversion is finished, recomputate optimal path according to the road chain impedance in the new road network again.Delimit the scope of road network conversion, except adopting the method for initial path, can also adopt other method, for example, being limited to the scope of road network conversion with starting point and terminal point is in the scope of circumscribed circle of circumscribed square of circle of diameter.In the downloading process of effective road chain, automatic navigator 800 also bootable driver is driven according to original route earlier, removes to upgrade navigation way with optimal path on the way then.This method can reduce driver's stand-by period.

In addition, in above description, at each embodiment, a plurality of cellular construction examples or step example have been enumerated, though the inventor indicates example associated with each other as much as possible, this does not also mean that must there be corresponding relation in these examples according to corresponding label.Need only between the given condition of selected cellular construction example or step example and do not have contradiction, can be in different embodiments, select the not corresponding example of label to constitute corresponding technical scheme, such technical scheme also should be considered as within the scope of the invention involved.

In addition, the present invention also can be implemented as the computer executable instructions in the computer-readable medium.Computer-readable medium comprises wherein to be stored or has comprised mechanized data or can comprise the medium of all kinds of the data of any kind that can be read by computing machine or processing unit.Computer-readable medium is including, but not limited to following storage medium: for example, magnetic storage medium (for example, ROM, floppy disk, hard disk etc.), light reads medium (CD-ROM (compact disc-ROM) for example, DVD (digital universal disc), CD-RW etc.), mix magneto-optic disk, organic dish, system storage (ROM (read-only memory), random access memory), the volatibility of nonvolatile memory such as flash memory or other any kinds or nonvolatile memory, other semiconductor mediums, dielectric, electromagnetic medium, infrared ray, and as other communication medias such as carrier wave the transmission of the Internet or other computing machine (for example, by).But communication media is realized computer-readable instruction, data structure, program module usually or as carrier wave or comprise other data in the modulation signals such as other transmission mediums of any information-delivery media.Can comprise as wireless mediums such as radio frequency, infrared ray microwaves and as wire mediums such as cable networks as computer-readable mediums such as communication medias.In addition, the computer-readable code that is distributed in by in the computing machine of network connection can be stored and be carried out to computer-readable medium.Computer-readable medium also comprises and is in the disposal system or is distributed in this locality of being arranged in disposal system or the computer-readable medium of the collaborative or interconnection of a plurality of disposal systems of far-end.The present invention can comprise the computer-readable medium that stores data structure on it, and described data structure comprises a plurality of fields that comprise the data of representing technology of the present invention.

So far invention has been described in conjunction with the preferred embodiments.Should be appreciated that those skilled in the art can carry out various other change, replacement and interpolations under the situation that does not break away from the spirit and scope of the present invention.Therefore, scope of the present invention is not limited to above-mentioned specific embodiment, and should be limited by claims.

Claims (24)

1. method for searching path based on effective road chain comprises:

Cause described No. at least one chain to have a plurality of different road chains during hourage when the terminal point owing to No. at least one chain in the original road network structure links to each other with the starting point of many other road chains, select the part in described No. at least one chain,

Wherein

The road chain that has a plurality of different road chain hourage in the original road network structure is labeled as candidate road chain, and the road chain that has single road chain hourage in the original road network structure is labeled as non-effective road chain, and according to the coefficient of variation of each bar candidate road chain, select the part in the chain of described candidate road, be labeled as effective road chain, and the residue road chain in the chain of described candidate road is labeled as non-effective road chain, thereby all the road chains in the original road network structure are divided into effective road chain and non-effective road chain;

Based on selected effective road chain and corresponding a plurality of different road chain hourages thereof, will be transformed to new road network structure by the original road network structure that all road chains constitute; And

According to described new road network structure, the search optimal path.

2. the method for searching path based on effective road chain according to claim 1 also comprises:

Be transform optimal path based on described original road network structure with described optimal path reciprocal transformation; And

In original road network structure, show described transform optimal path.

3. the method for searching path based on effective road chain according to claim 1 is characterized in that:

Candidate road chain i is at the coefficient of variation L of t in the period _i(t) calculate according to the following equation:

L _i(t)＝S _i(t)/A _i(t)

Wherein, S _i(t) expression candidate road chain i is at the t standard deviation of a plurality of road chain hourage in the period, A _i(t) expression candidate road chain i is at the t mean value of a plurality of road chain hourage in the period.

4. the method for searching path based on effective road chain according to claim 3 is characterized in that:

Coefficient of variation threshold value A L (t) is that all n bar candidate road chains are at the mean value of the coefficient of variation of t in the period

$\mathrm{AL}\left(t\right)=\underset{i}{\overset{n}{\mathrm{\Σ}}}{L}_i\left(t\right)/n.$

5. the method for searching path based on effective road chain according to claim 3 is characterized in that:

Coefficient of variation threshold value A L (t) is that previously selected n bar represents candidate road chain at the mean value of the coefficient of variation of t in the period

$\mathrm{AL}\left(t\right)=\underset{i}{\overset{n}{\mathrm{\Σ}}}{L}_i\left(t\right)/n.$

6. the method for searching path based on effective road chain according to claim 3 is characterized in that:

Coefficient of variation threshold value A L _j(t) be all n that have the chain grade j that goes the same way mutually with candidate road chain i _jBar candidate road chain is at the mean value of the coefficient of variation of t in the period

${\mathrm{AL}}_j\left(t\right)=\underset{i}{\overset{n_j}{\mathrm{\Σ}}}{L}_i\left(t\right)/n_j.$

7. the method for searching path based on effective road chain according to claim 1 is characterized in that:

Candidate road chain i is at the coefficient of variation L of t in the period _i(t) calculate according to the following equation:

L _i(t)＝V _i(t) _max-V _i(t) _min

Wherein, V _i(t) _MaxBe illustrated in the main road chain Average Travel Speed of candidate road chain i in the t period, V _i(t) _MinBe illustrated in the minimal path chain Average Travel Speed of candidate road chain i in the t period.

8. according to the described method for searching path based on effective road chain of one of claim 1～7, it is characterized in that:

In described search step, if beginning or end is positioned at the non-endpoint location of effective road chain, then

Described starting point or the residing effective road of described terminal point chain are updated to non-effective road chain,

According to the transformation rule of non-effective road chain, upgrade described starting point or the residing effective road of described terminal point chain in the described new road network structure,

Then, search for optimal path again.

9. according to the described method for searching path based on effective road chain of one of claim 1～7, it is characterized in that:

With candidate road chain or effectively the road chain step that is updated to non-effective road chain comprise:

Calculate the mean value of a plurality of road chain hourage of described candidate road chain or described effective road chain, as the road chain hourage of described non-effective road chain, and

Many records about described candidate road chain or described effective road chain in road chain-Lu chain table hourage are merged the single record that is updated to about described non-effective road chain.

10. according to the described method for searching path based on effective road chain of one of claim 1～7, it is characterized in that:

The a plurality of different road chain of described No. at least one chain be hourage flow to relevant.

11. according to the described method for searching path based on effective road chain of one of claim 1～7, it is characterized in that:

In described shift step, adopt dual graph method or virtual limit method, described original road network structure is transformed to described new road network structure.

12. a navigation server comprises:

Road chain selecting arrangement, be used for causing described No. at least one chain to have a plurality of different road chains during hourage when the terminal point owing to No. at least one chain of original road network structure with the starting point of many other road chains is continuous, select the part in described No. at least one chain

Wherein, described road chain selecting arrangement

The road chain that has a plurality of different road chain hourage in the original road network structure is labeled as candidate road chain, and the road chain that has single road chain hourage in the original road network structure is labeled as non-effective road chain, and

The coefficient of variation according to each bar candidate road chain, select the part in the chain of described candidate road, be labeled as effective road chain, and the residue road chain in the chain of described candidate road is labeled as non-effective road chain, thereby all the road chains in the original road network structure are divided into effective road chain and non-effective road chain;

The road network converting means is used for will being transformed to new road network structure by the original road network structure that all road chains constitute based on selected road chain and corresponding a plurality of different road chain hourages thereof; And

Path calculation device is used for according to described new road network structure, the search optimal path.

13. navigation server according to claim 12 also comprises:

The path reverse mapping device, being used for described optimal path reciprocal transformation is transform optimal path based on described original road network structure; And

Dispensing device is used for described transform optimal path is sent to navigating instrument.

14. navigation server according to claim 12 is characterized in that:

Described road chain selecting arrangement according to the following equation calculated candidate road chain i at the coefficient of variation L of t in the period _i(t):

L _i(t)＝S _i(t)/A _i(t)

Wherein, S _i(t) expression candidate road chain i is at the t standard deviation of a plurality of road chain hourage in the period, A _i(t) expression candidate road chain i is at the t mean value of a plurality of road chain hourage in the period.

15. navigation server according to claim 14 is characterized in that:

Described road chain selecting arrangement is calculated as all n bar candidate road chains at the mean value of the coefficient of variation of t in the period with coefficient of variation threshold value A L (t)

$\mathrm{AL}\left(t\right)=\underset{i}{\overset{n}{\mathrm{\Σ}}}{L}_i\left(t\right)/n.$

16. navigation server according to claim 14 is characterized in that:

Described road chain selecting arrangement is calculated as previously selected n bar with coefficient of variation threshold value A L (t) and represents candidate road chain at the mean value of the coefficient of variation of t in the period

$\mathrm{AL}\left(t\right)=\underset{i}{\overset{n}{\mathrm{\Σ}}}{L}_i\left(t\right)/n.$

17. navigation server according to claim 14 is characterized in that:

Described road chain selecting arrangement is with coefficient of variation threshold value A L _j(t) be calculated as all n that have the chain grade j that goes the same way mutually with candidate road chain i _jBar candidate road chain is at the mean value of the coefficient of variation of t in the period

${\mathrm{AL}}_j\left(t\right)=\underset{i}{\overset{n_j}{\mathrm{\Σ}}}{L}_i\left(t\right)/n_j.$

18. navigation server according to claim 12 is characterized in that:

Described road chain selecting arrangement according to the following equation calculated candidate road chain i at the coefficient of variation L of t in the period _i(t):

L _i(t)＝V _i(t) _max-V _i(t) _min

Wherein, V _i(t) _MaxBe illustrated in the main road chain Average Travel Speed of candidate road chain i in the t period, V _i(t) _MinBe illustrated in the minimal path chain Average Travel Speed of candidate road chain i in the t period.

19. according to the described navigation server of one of claim 12～18, it is characterized in that:

If beginning or end is positioned at the non-endpoint location of effective road chain, then described path calculation device also is used for:

Described starting point or the residing effective road of described terminal point chain are updated to non-effective road chain,

According to the transformation rule of non-effective road chain, upgrade described starting point or the residing effective road of described terminal point chain in the described new road network structure,

Then, search for optimal path again.

20. according to the described navigation server of one of claim 12～18, it is characterized in that:

Described road chain selecting arrangement or described path calculation device, at the candidate road chain that will be updated to non-effective road chain or effective road chain,

Calculate the mean value of a plurality of road chain hourage of described candidate road chain or described effective road chain, as the road chain hourage of described non-effective road chain, and

Many records about described candidate road chain or described effective road chain in road chain-Lu chain table hourage are merged the single record that is updated to about described non-effective road chain.

21. according to the described navigation server of one of claim 12～18, it is characterized in that:

The a plurality of different road chain of described No. at least one chain be hourage flow to relevant.

22. according to the described navigation server of one of claim 12～18, it is characterized in that:

Described road network converting means adopts dual graph method or virtual limit method, and described original road network structure is transformed to described new road network structure.

23. a navigating instrument comprises:

Road chain selecting arrangement, be used for causing described No. at least one chain to have a plurality of different road chains during hourage when the terminal point owing to No. at least one chain of original road network structure with the starting point of many other road chains is continuous, select the part in described No. at least one chain

Wherein, described road chain selecting arrangement

The road chain that has a plurality of different road chain hourage in the original road network structure is labeled as candidate road chain, and the road chain that has single road chain hourage in the original road network structure is labeled as non-effective road chain, and

The coefficient of variation according to each bar candidate road chain, select the part in the chain of described candidate road, be labeled as effective road chain, and the residue road chain in the chain of described candidate road is labeled as non-effective road chain, thereby all the road chains in the original road network structure are divided into effective road chain and non-effective road chain;

The road network converting means is used for will being transformed to new road network structure by the original road network structure that all road chains constitute based on selected road chain and corresponding a plurality of different road chain hourages thereof; And

Path calculation device is used for according to described new road network structure, the search optimal path.

24. navigating instrument according to claim 23 also comprises:

The path reverse mapping device, being used for described optimal path reciprocal transformation is transform optimal path based on described original road network structure; And

Display device is used at original road network structure, shows described transform optimal path.

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