WO2011160687A1

WO2011160687A1 - System and method of optimizing and dynamically updating route information

Info

Publication number: WO2011160687A1
Application number: PCT/EP2010/058897
Authority: WO
Inventors: Erik Thomassen; Renatus Van Troost
Original assignee: Tomtom International B.V.
Priority date: 2010-06-23
Filing date: 2010-06-23
Publication date: 2011-12-29

Abstract

Systems and methods of optimizing and dynamically updating route information are described that combine and optimize both on-board and off-board routing in order to transmit real-time and predictive traffic information to a navigation device. A server optimizes a route calculated by a navigation device using dynamic traffic information not available to the device due to hardware constraints, and transmits the optimized route to the device using compression techniques that minimize bandwidth usage.

Description

SYSTEM AND METHOD OF OPTIMIZING AND DYNAMICALLY UPDATING

ROUTE INFORMATION

BACKGROUND OF THE INVENTION

Field of the Invention

[0001] The present invention relates to a system and method of optimizing and dynamically updating route information. This disclosure is related to U.S. Pat. App. No. 61/129,491, and U.S. Pat. App. No. 61/193,027, and their corresponding PCT applications, PCT/EP2009/058131 and PCT/EP2009/058130, respectively, each of which is incorporated herein by reference.

Description of Related Art

[0002] GPS-based navigation devices are widely employed as personal navigation devices (PNDs), such as in-vehicle navigation systems. These devices enable a user to input a start and destination address, then calculate the best route between the two points and display instructions on how to navigate that route. By using the positional information derived from the GPS receiver, the software can determine at regular intervals the position of a pedestrian, vehicle, or other object, can display its current position on a map, and can display and/or vocalize appropriate navigation instructions. Graphics depicting the actions to be accomplished (e.g.,. a left arrow indicating a left turn ahead) can be displayed in a status bar, and also be superimposed over the applicable turns in the roads shown in the map itself. Such devices are referred to herein as "onboard" navigation devices and include navigation devices integrated with the vehicle, such as in-dash devices, and portable devices used in association with a vehicle.

[0003] Map data for these devices comes from specialized map vendors. This map data is specially designed to be used by route guidance algorithms, typically using location data from the GPS device. For example, roads can be defined as lines or vectors, with a starting point, an ending point, and a direction. An entire road may be made up of hundreds of vectors, each uniquely defined by its own starting point, ending point, and direction parameters. A map integrates a set of such road vectors, as well as data associated with each vector (such as speed limit, travel direction, etc.), points of interest (such as shopping malls, airports, hospitals, etc.), road names, and geographic features (such as parks, mountains, rivers, etc.). Each of these map features is typically defined in a coordinate system that corresponds with or relates to the GPS coordinate system, enabling a device's position as determined through a GPS system to be located within a road shown in a map, and for an optimal route to be planned to a destination.

[0004] Hybrid navigation systems, in which an onboard navigation device associated with a vehicle communicates with a remote server-based navigation system, are known. In conventional hybrid navigation systems, the onboard navigation device stores a network graph with static speed information which is used to determine the route between a given origin and destination (O-D pair) of a trip. Dynamic speed information of, for example, traffic incidents, is transmitted from the server system on a cyclic basic (e.g. every x minutes) to the onboard device using a wireless communication channel. The dynamic speed information is used to override the static speed information for stretches ahead of the current position of the vehicle and, in the case where predictive speed information has been transmitted, on more remote stretches of the route as well. The dynamic speed information is then used to optimize the routing from the current vehicle position to the destination. These types of conventional hybrid systems are inefficient and require a large amount of bandwidth on the wireless communication channel.

SUMMARY OF THE INVENTION

[0005] Thus, there is a need in the art for systems and methods of optimizing and dynamically updating route information that combine and optimize both on-board and off-board routing in order to transmit real-time and predictive dynamic speed information to a navigation device. Embodiments of the invention meet those needs and others by providing a server that optimizes a route calculated by a navigation device using dynamic speed information not available to the device due to hardware constraints, and transmits the optimized route to the device using compression techniques that minimize bandwidth usage.

[0006] One embodiment of the invention provides a hybrid navigation system and method of optimizing and dynamically updating route information. The method preferably comprises calculating a route represented by an origin-destination pair at an onboard navigation device associated with a vehicle from an origin to a destination based on a first road network graph and static speed information stored in the onboard navigation device, transmitting the origin- destination pair to a remote server via a wireless communication channel, determining an optimized route by the remote server based on a second road network graph and dynamic speed information stored in the remote server, encoding the optimized route, transmitting the encoded optimized route to the onboard navigation device, decoding the optimized route, fitting the optimized route to the first road network graph, and displaying the optimized route based on the first road network graph. The system comprises an onboard navigation device, a remote server, a coding module, and a wireless communication channel, configured to carry out the steps of the method.

[0007] Still other aspects, features and advantages of the present invention are readily apparent from the following detailed description, simply by illustrating a number of exemplary embodiments and implementations, including the best mode contemplated for carrying out the present invention. The present invention also is capable of other and different embodiments, and its several details can be modified in various respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature, and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The present invention will be understood more fully from the detailed description given below and from the accompanying drawings of various embodiments of the invention, which, however, should not be taken to limit the invention to the specific embodiments, but are for explanation and understanding only.

[0009] FIG. 1 is a flowchart illustrating a method according to one embodiment.

[0010] FIG. 2 is a schematic representation of a second road network graph including nodes and segments according to one embodiment.

[0011] FIG. 3 is a schematic representation of a route to be encoded within a second road network graph according to one embodiment.

[0012] FIG. 4 is a schematic representation of an optimized shortest route between start and end nodes within a second road network graph according to one embodiment. [0013] FIG. 5 is a schematic representation of location reference points required to completely reference the optimized shortest route of FIG. 5 according to one embodiment.

[0014] FIG. 6 is a flowchart illustrating a method of decoding an optimized route according to one embodiment.

[0015] FIG. 7 is an exemplary segment-and-node graph of a route selected by the method according to one embodiment.

[0016] FIG. 8 is another exemplary segment-and-node graph of a route selected by the method according to one embodiment.

[0017] FIG. 9 is an exemplary system for implementing the method according to one embodiment.

DETAILED DESCRIPTION

[0018] A system and method for optimizing and dynamically updating route information is described. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the exemplary embodiments. It is apparent to one skilled in the art, however, that the present invention can be practiced without these specific details or with an equivalent arrangement. In some instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring the preferred embodiment.

[0019] Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, FIG. 1 is a flowchart 5 illustrating a method for optimizing and dynamically updating route information according to an embodiment. At processing block 10, a route represented by an origin-destination pair (e.g. latitude, longitude coordinates of the origin and destination) is calculated at an onboard navigation device from an origin to a destination based on a first road network graph stored at the device, static speed information stored in the device, and optionally, a preference model selected by a user. The preference model may be, for example, the fastest route, the shortest route, the most inexpensive route, a scenic route, or combinations thereof. For example, the user may enter an origin of 1400 Pennsylvania Ave., Washington D.C., a destination of 100 Summer St., Boston, MA, and select an option for the fastest route available. The navigation device can calculate the fastest route between those two points based on the road network graph stored in the device, along with static speed information stored in the device. Static speed information can be any information available to the onboard navigation device that is indicative of the likely speed and/or time between two points, but is not based on real-time conditions. For example, static speed information can be based on static speed averages, a full historic speed profile data per road stretch of the road network graph, and/or published speed limits for a given segment (or a fraction or multiple thereof). Static speed information can be determined in various manners based on information available over time. Static speed information is stored in the onboard navigation device and does not necessarily reflect current conditions during a trip. The onboard navigation device is associated with a vehicle. The vehicle can be any movable object, such as a pedestrian, car, truck, boat, bicycle, or skateboard

[0020] At processing block 20, the origin-destination pair is transmitted from the onboard navigation device to a remote server via a wireless communication channel. In addition to the origin-destination pair, the navigation device may further transmit probe data collected by the device representing its location at various times, and Can Bus data, such as wiper data, temperature data, weather data, fuel consumption data, etc. "Can Bus" refers to a vehicle bus standard for providing communications between vehicle computing devices. Optionally, this transmission can be encoded, compressed or encrypted, for example, at the navigation device, transmitted to the server, and decoded at the server, in order to minimize bandwidth usage, as is described in further detail herein. The server may then store the decoded transmission information for later use or analysis.

[0021] Although described above as wireless, the communication channel transmitting the route may alternatively be fully or partially wired, and can be, for example, a local area network (LAN), wide area network (WAN), a telephone network, such as the Public Switched Telephone Network (PSTN), an intranet, the Internet, or combinations thereof.

[0022] At processing block 30, an optimized route is determined by the remote server based on a second road network graph stored in the server, dynamic speed information stored in the server, and the selected preference model. A second road network graph is used at the remote server because, for example, it may be more up-to-date and accurate than the first road network graph available to the navigation device. Further, the second road network graph may take into account dynamic speed information, such as real-time speed measurements, traffic incidents, delay time, predictive speed information for a period of time, road closures, construction data, traffic load data, and combinations thereof, that is not locally available to the navigation device due to bandwidth constraints and limited onboard processing capabilities. This dynamic speed information can be collected and stored from a variety of sources. For example, real-time speed measurements can be collected by a radar device or camera, or can be inferred from probe data collected from other onboard navigation devices along a similar route. Further, data about delay time, road closures, construction, accidents, and other traffic incidents can be collected and transmitted from traffic helicopters, radio and television news reports, local departments of transportation, etc. Accordingly, "dynamic speed information" is any information about speed and/or time for a trip segment that takes into account current conditions during the trip.

[0023] In one embodiment, the optimized route is determined by the remote server by breaking the second road network graph down into a segment-and-node graph, as described further herein. Using the segment-and-node graph, the remote server is able to map a plurality of routes between the origin and the destination, including a number of alternative routes. Further, the server can associate events and dynamic speed information with particular segments and/or nodes of the graph in order to determine the route that best meets the selected preference model, as well as alternative routes that are available should the first optimized route become unavailable or undesirable. The remote server is able to process this information more efficiently than the navigation device, which has limited on-board hardware resources that may not be capable of executing the complex routing algorithms required to determine best available routes. Additionally, the remote server can have updated road network graphs and dynamic speed information due to its increased resources and bandwidth.

[0024] The remote server determines the optimized route according to the processes described in U.S. Pat. App. No. 61/129,491, and U.S. Pat. App. No. 61/193,027, and their corresponding PCT applications, PCT/EP2009/058131 and PCT/EP2009/058130, respectively, each of which is incorporated herein by reference. Initially in this process, the second network road graph for the network encompassing the origin-destination pair is checked for validity, for example, to ensure that consecutive segments of potential routes are connected and drivable. Once the second network road graph is determined to be valid, the start and end nodes corresponding to the origin and destination points of the optimized route are checked for validity according to certain predetermined data format rules. For example, the start node must have one outgoing segment, and the end node must have one incoming segment. If either of the nodes has none or more than one segment, the node is not valid. In this case, a valid node outside the optimized route is located and the optimized route is adjusted.

[0025] In one embodiment wherein the selected preference model is the shortest distance, the shortest path between the start node and the end node is then determined. Intermediates nodes along the shortest path are identified, and shortest paths between the intermediate nodes are calculated and assigned segments until the path is completely covered by calculated shortest segments. This series of nodes and segments is the optimized route for the shortest distance between the start node and the end node.

[0026] In some embodiments, the route that best meets the selected preference model may not be the optimized route determined by the remote server. For example, if an accident occurs on the otherwise shortest route, the remote server may determine that the optimized route is a longer route. This longer route may or may not be the "next best" route that fits the criteria of the preference model (i.e. the "next shortest" route). In one embodiment, if the remote server is handling multiple alternative routing requests around an accident, the optimized route may send one vehicle along a first detour, and another along a second, longer, detour, in order to mitigate the potential for further delays, accidents, or detours along either detour route.

[0027] At processing block 40, the optimized route is encoded by converting the start node, end node, and intermediates nodes along the optimized route into binary location reference points (LRPs) using a logical or physical data format, as described in detail in PCT/EP2009/058130, and further herein. The physical data ultimately transmitted is a binary representation of the identified nodes, and contains attribute data so that the appropriate segments can be identified at the onboard navigation device. [0028] At processing block 50, the encoded and optimized route is transmitted to the onboard navigation device. At processing block 60, the optimized route is decoded by extracting the nodes from the transmitted binary data, and performing a validity check, as is described further herein with respect to FIG. 6. Failure of the validity check will result in termination of the process and the reporting of an error. Passage of the validity check indicates that the extracted information is sufficient to resolve the location of the nodes on the second road network graph at the navigation device.

[0029] The encoding and decoding process provides for a variety of benefits, such as privacy and the compression of the route into a smaller sized file that uses less bandwidth. As mentioned above, alternative routes may also be determined by the remote server, and can be encoded and transmitted to the onboard navigation device along with the optimized route using the same encoding and decoding process described above. Encoding and decoding can be performed in any manner depending on bandwidth and resource constraints. In other words, the optimized route can be transmitted in any formant with any type of encryption and/or compression, or without encryption or compression.

[0030] At processing block 70, the optimized route is fit to the first road network graph. This step is necessary to ensure that the optimized route, which was selected and configured based on a second road network graph at the server, is correctly displayed on the first road network graph at the navigation device. A proper fit is achieved by overlaying the extracted nodes of the optimized route onto the corresponding nodes of the first road network graph, and using the transmitted attribute data to identify the appropriate segments that make up the optimized route. Fitting can be accomplished in any manner. For example, if a road segment is not found on the first road network graph, the closest segment to the missing segment on the first road network graph can be used.

[0031] At processing block 80, the optimized route is displayed based on the first road network graph. In addition to the route, the navigation device may also display alternative routes, turn -by-turn instructions for the route from the origin to the destination, and/or an updated estimated time of arrival. Alternative routes, if used, can be calculated by the onboard navigation device based on static speed information, or received from the remote server as described above. Where used, the alternative routes can be ranked or rated according to static and dynamic speed information for those routes, as well as their compliance with the various route requirements, such as the preference model.

[0032] FIGs. 2-5 illustrate the optimization and encoding of the route on the second road network graph. FIG. 2 illustrates a second road network graph according to one embodiment, consisting of 15 nodes and 23 segments (two-way segments are counted twice). The nodes are numbered from 1 to 15. The necessary segment attributes are shown beside each segment using the format <FRC>, <FOW>, <Length (meters)>, wherein FRC represents the functional road class, and FOW represents the form of way. The functional road class can hold eight different values in logical format that represent a main road, a first through sixth class road, or another class road. The form of way can hold eight different values in logical format that represent an undefined form of way, a motorway, a multiple carriageway, a single carriageway, a roundabout, a traffic square, a sliproad, or another form of way. The arrowheads indicate a possible driving direction for each segment.

[0033] The route to be encoded is shown in FIG. 3 using bold lines. The route starts at node 1 and continues over nodes 3, 5, 7, 10, 11 , 13, 14, and ends at node 15. Its total length in the second road network graph is 685 meters. The ordered list of segments and the map to be used during encoding (the second road network graph) serves as input to the coding module of the remote server in order to begin the encoding process, as described further herein.

[0034] FIG. 4 illustrates a shortest path using bold lines. The shortest path has been calculated by the coding module between the start segment (segment between nodes 1 and 3) and the end segment (segment between nodes 14 and 15) of the route. In this example, the shortest path has a length of 725 meters.

[0035] FIG. 5 shows the lines in bold that are selected for the location reference points along the shortest path. The first LRP points to the segment from node 1 to 3 and indicates the start of the optimized route. The second LRP points to the segment from node 10 to 1 1, and can be used to avoid deviation from the optimized route. The last LRP points to the segment from node 14 to 15, and indicates the end of the optimized route. [0036] FIG. 6 is a flowchart 100 representing the process of decoding the optimized route by the onboard navigation device once it is received from the remote server. At processing block 102, the incoming optimized route is received at the onboard navigation device in the form of binary data (or other machine-readable representation, such as XML), resulting from the encoding process by the remote server and structured according to the physical data format. At processing block 104, a validity check is performed. Failure of this step results in termination of the decoding process, and the reporting of an error as shown at processing block 124. Because the encoding process and the reduction of the optimized route to physical format is a lossy process, the information extracted from the binary data may not be as accurate as it was prior to the encoding process.

[0037] After validating the data and providing a list of decoded LRPs and their attributes at processing block 112, the decoder then begins processing each LRP in the list at processing block 1 14 to determine candidate nodes for each LRP. Candidates nodes are determined by using the LRP coordinates (represented in latitude, longitude) to identify the nearest node(s) appearing in the first road network graph stored at the onboard navigation device (represented generally as a digital map at block 118). At processing block 120, nodes that are further than a predetermined threshold value from the LRPs are eliminated.

[0038] At processing block 122, candidate segments for each of the LRPs are identified. If the decoder fails to identify a candidate segment for any of the LRPs, then the decoding process is terminated and an error is reported, as shown at processing block 124. If the decoder identifies candidate segments for all of the LRPs, a list of the candidate nodes and segments existing in the first road network graph is generated at processing block 126.

[0039] In one embodiment of the invention, more than one candidate node and/or segment is identified for each LRP. In this embodiment, the candidate nodes and/or segments can be rated or ranked. Accordingly, at processing block 128, a rating function is applied to the lists of candidate nodes and/or segments according to their compliance with the attributes of the LRP. A rating function of portion thereof specific to nodes may include some measure of the distance od candidates to the physical or geographic position of the decoded LRP. A rating function or portion thereof specific to candidate segments may include some means of assessing the correlation between the type of candidate segment identified and those represented in the decoded data, as well as some beating of those candidate and identified segments. One skilled in the art will appreciate that many different mathematical and/or statistical bases exist for executing these types of rating functions.

[0040] At processing block 130, most suitable candidates nodes and segments are identified. The most suitable segments are used in the shortest path calculation at processing block 132. The shortest path calculation is performed on each successive pair of LRPs, starting with the first and second LRPs represented by arrow 134. The shortest path algorithm determines a route through the first road network graph, represented generally as digital map 118, using the most likely candidate nodes and segments. Each determined shortest path is then validated at processing block 136 by determining a path length value between the start node and end node of that path, then comparing the path length value to the distance to next location reference point ("DNP") attribute specified in the data for each LRP, as indicated by arrow 138. The DNP measures the distance between two consecutive LRPs along the optimized route. If the path length value is within the DNP interval specified by the attribute data, the associated shortest path is validated. At processing block 140, a concatenated format (i.e., an ordered list of all the segments present in the complete path) in the first road network graph is provided, and at processing block 142, the concatenated shortest path is trimmed according to the retrieval (represented by arrow 144) and extraction of offset values at processing block 110.

[0041] FIG. 7 represents another route that has been broken down into segments and nodes according to an embodiment in order that the route may be optimized by the server using dynamic speed information. A segment-and-node route represents a continuous route within a road network, with the route being expressible as a list of segments (AB, BC, CD, DE, EF, FG) that are consecutively ordered and separated by nodes (A, B, C, D, E, F, G) that represent intersections, potentially where an alternative route may be taken. The route broken down into segments and nodes and selected based on the user-selected preference model.

[0042] In practice, as shown in FIG. 7, the user may select an origin represented by node A and destination represented by node G and select the shortest trip distance as the preference model. The navigation device may initially assign the user to travel the route represented by segments AB, BC, CD, DE, EF, and FG, consecutively. However, when the server receives this transmitted route, it may amend the route so that the user travels along segments AB, BC, CF, and FG, consecutively, due to dynamic traffic data available to the server. The server may route the user along deviation segment CF instead of segments CD, DE, and EF, due to, for example, construction, road closures, traffic incidents, and/or a high traffic load on one or more of segments CD, DE, and/or EF. The server may also route the user along deviation segment CF instead of segments CD, DE, and EF, for reasons unrelated to dynamic traffic data, such as a calculation by the server that deviation segment CF is shorter in distance than segments CD, DE, and EF.

[0043] Once the route is amended, the server may calculate updated travel and arrival times to encode and transmit to the navigation device along with the optimized route. Updated travel and arrival times may depend on the bias of historic speed information on the navigation device and the server, and the bias between the historic and real-time traffic patterns, as influenced by the amount of bandwidth usage needed to keep such information up to date.

[0044] FIG. 8 illustrates a route with an origin represented by node H and a destination represented by node T, broken down into segments (HI, IJ, JP, PS, ST) and nodes (H, I, J, P, S, T). In this example, all available deviation segments JK, JK, LM, MP, J , NO, OP, OQ, QR, and RS on the route are also identified by the server and illustrated. As the navigation device approaches node J, the server can check segment JP for dynamic traffic data. If the road represented by segment JP is closed, the server can transmit the amended route represented by segments JK, KL, LM, and MP, consecutively, to the device as a possible detour. If the server has already transmitted the amended route represented by segments JK, KL, LM, and MP, to multiple other navigation devices as a detour, the server may instead transmit the amended route represented by segments JN, NO, and optionally OP, to the device as a detour in order to balance the traffic load on each of the detours and mitigate any delays on the detours. To further mitigate delays caused by multiple vehicles attempting to merge from the detours at node P, the server may continue routing some vehicles traveling along segments JN and NO to OQ, QR, and RS, consecutively, in order to merge further down the route. [0045] FIG. 9 illustrates system of an embodiment for effecting the functions described above. Remote server 210 is connected over wireless communication channel 240 to a plurality of onboard navigation devices 250. Remote server 210 is configured to determine an optimized route based on a second road network graph and dynamic speed information stored at the remote server. Remote server 210 may further be configured to calculate the dynamic speed information based on probe data associated with one or more navigation devices. Remote server 210 is typically a computer system, and may be an HTTP (Hypertext Transfer Protocol) server, such as an Apache server.

[0046] Remote server 210 includes memory 220 and processor 230, which are in communication with one another. In one embodiment, memory 220 stores the second road network graph, dynamic speed information, transmitted probe data and can bus data, and/or origin-destination pairs. Memory 220 may be any type of storage media that may be volatile or non-volatile memory that includes, for example, read-only memory (ROM), random access memory (RAM), magnetic disk storage media, optical storage media, flash memory devices, and zip drives. Processor 230 effects the various determination functions of remote server 210, and includes a coding module configured to encode and decode data, such as the optimized route, as described above.

[0047] As previously noted, wireless communication channel 240 may be a local area network (LAN), wide area network (WAN), a telephone network, such as the Public Switched Telephone Network (PSTN), an intranet, the Internet, or combinations thereof. The plurality of onboard navigation devices 250 may be personal navigation devices, satellite devices, or computer-readable mediums on other computing devices, such as personal computers, laptops, personal digital assistants (PDAs), cell phones, netbooks, thin clients, and the like. The plurality of onboard navigation systems 250 are characterized in that they are capable of being connected to wireless communication channel 240.

[0048] In use, when a user of one of the plurality of onboard navigation devices 250 enters an origin, a destination, and/or a preference model, onboard navigation device 250 calculates a route represented by an origin-destination pair between the two points based on static speed information for a first network graph and the preference model, if selected. The origin- destination pair is transmitted from onboard navigation device 250 to remote server 210 over wireless communication channel 240. For example, a signal is transmitted from one of the onboard navigation devices 250, the signal having a destination address (e.g., address representing the server), content (e.g. an origin-destination pair), and a return address (e.g. address representing the onboard navigation device that sent the content). Processor 230 determines and optimized route based on a second road network graph and dynamic speed information stored at memory 220, such as, for example, real-time speed measurements, traffic incidents, delay time, predictive speed information for a period of time, road closures, construction data, traffic load data, or combinations thereof, for the entire second road network graph. Further, processor 230 includes a coding module that encodes the optimized route in order to compress it, and transmits the optimized route to onboard navigation device 250 via wireless communication channel 240. Onboard navigation device 250 fits the optimized route to the first road network graph, and displays the optimized route to the user based on the first road network graph.

[0049] It should be noted that the server as illustrated and discussed herein has various modules which perform particular functions and interact with one another. It should be understood that these modules are merely segregated based on their function for the sake of description and represent computer hardware and/or executable software code which is stored on a computer-readable medium for execution on appropriate computing hardware. The various functions of the different modules and units can be combined or segregated as hardware and/or software stored on a computer-readable medium as above as modules in any manner, and can be used separately or in combination. The described devices can be a single hardware device or plural devices. For example, the onboard navigation device can include a separate memory device.

[0050] It should be understood that processes and techniques described herein are not inherently related to any particular apparatus and may be implemented by any suitable combination of components. Further, various types of general purpose devices may be used in accordance with the teachings described herein. It may also prove advantageous to construct specialized apparatus to perform the method steps described herein. The present invention has been described in relation to particular examples, which are intended in all respects to be illustrative rather than restrictive. Those skilled in the art will appreciate that many different combinations of hardware, software, and firmware will be suitable for practicing the present invention.

[0051] Other implementations of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. Various aspects and/or components of the described embodiments may be used singly or in any combination. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.

Claims

What is claimed is:

1. A hybrid navigation system comprising:

an onboard navigation device associated with a vehicle configured to calculate a route represented by an origin-destination pair for the vehicle, said onboard navigation device having a database of static speed information for a first road network graph;

a remote server configured to determine an optimized route based on a second road network graph and dynamic speed information stored at the remote server;

a coding module configured to encode and decode the optimized route;

a communication channel configured to receive and transmit data between the onboard navigation device, the remote server, and the coding module, wherein the data includes at least one of the origin-destination pair and the optimized route; and

a fitting module configured to fit the optimized route to the first road network graph.

2. The system of claim 1 , wherein the route and the optimized route are determined based on a preference model that is at least one of a fastest route, a shortest route, and a most inexpensive route.

3. The system of claim 1 , wherein the static speed information is at least one of an average link speed measurement per road stretch and a daily speed profile per road stretch.

4. The system of claim 1 , wherein the wireless communication channel is further configured to receive and transmit at least one of probe data and Can Bus data.

5. The system of claim 4, wherein the remote server is further configured to calculate the dynamic speed information based on probe data associated with one or more navigation devices.

6. The system of claim 4, wherein the Can Bus data includes at least one of wiper data, temperature data, weather data, and fuel consumption data.

7. The system of claim 1, wherein the dynamic speed information includes at least one of real-time speed measurements, traffic incidents, delay time, predictive speed information for a period of time, road closures, construction data, and traffic load data.

8. The system of claim 1 , wherein the onboard navigation device is further configured to display turn-by-turn instructions for at least one of the calculated route and the optimized route.

9. The system of claim 1 , wherein at least one of the calculated route and the optimized route are represented by a plurality of segments and nodes.

10. The system of claim 1 , wherein the coding module is further configured to compress and decompress the optimized route.

1 1. A method of optimizing and dynamically updating route information, the method comprising:

calculating a route represented by an origin-destination pair at an onboard navigation device associated with a vehicle from an origin to a destination based on a first road network graph and static speed information stored in the onboard navigation device;

transmitting the origin-destination pair to a remote server via a communication channel; determining an optimized route by the remote server based on a second road network graph and dynamic speed information stored in the remote server;

encoding the optimized route;

transmitting the encoded optimized route to the onboard navigation device;

decoding the optimized route;

fitting the optimized route to the first road network graph; and

displaying the optimized route based on the first road network graph.

12. The method of claim 1 1, wherein the route and the optimized route are determined based on a preference model that is at least one of a fastest route, a shortest route, and a most inexpensive route.

13. The method of claim 1 1, wherein the static speed information is at least one of static speed average data and full historic speed profile data per road stretch of the road network.

14. The method of claim 1 1, wherein the step of transmitting the origin-destination pair to a remote server further comprises transmitting at least one of probe data and Can Bus data.

15. The method of claim 14, wherein the Can Bus data includes at least one of wiper data, temperature data, weather data, and fuel consumption data.

16. The method of claim 11 , wherein the dynamic speed information includes at least one of real-time speed measurements, traffic incidents, delay time, predictive speed information for a period of time, road closures, construction data, and traffic load data.

17. The method of claim 16, further comprising:

encoding the dynamic speed information;

transmitting the dynamic speed information to the onboard navigation device; and decoding the dynamic speed information.

18. The method of claim 17, wherein the dynamic speed information is transmitted to the on board navigation device only when the same dynamic speed information has not been previously transmitted to the onboard navigation device.

19. The method of claim 1 1 , further comprising:

calculating an alternative route by the remote server using the origin-destination pair; optimizing the alternative route based on the second road network graph and the dynamic speed information;

encoding the alternative route;

transmitting the encoded alternative route to the onboard navigation device;

decoding the alternative route;

fitting the alternative route to the first road network graph; and

displaying the alternative route by the onboard navigation device.

20. The method of claim 19, wherein the dynamic speed information includes at least one of real-time speed measurements, traffic incidents, delay time, predictive speed information for a period of time, road closures, and construction data.

21. The method of claim 1 1 , further comprising displaying turn-by-turn instructions for at least one of the calculated route and the optimized route on the onboard navigation device.

22. The method of claim 1 1 , wherein at least one of the calculated route and the optimized route is represented by a plurality of segments and nodes.

23. The method of claim 1 1, wherein the steps of encoding the optimized route and decoding the optimized route include compressing the optimized route and decompressing the optimized route, respectively.

24. An onboard navigation device associated with a vehicle comprising:

memory configured to store static speed information and a first road network graph; and a processor configured to calculate a route represented by an origin-destination pair for the vehicle based on the static speed information and the first road network graph;

a communication module configured to transmit the origin-destination pair to a remote server and receive an optimized route calculated by the remote server based on dynamic speed information stored in the remote server;

a coding module configured to encode and decode at least one of the origin-destination pair and the optimized route; and

25. The onboard navigation device of claim 24, wherein the route is calculated based on a preference model that is at least one of a fastest route, a shortest route, and a most inexpensive route.

26. The onboard navigation device of claim 24, wherein the static speed information is at least one of an average link speed measurement per road stretch and a daily speed profile per road stretch.

27. The onboard navigation device of claim 24, further comprising a display configured to display the optimized route based on the first road network graph.

28. The onboard navigation device of claim 27, wherein the display is further configured to display turn-by-turn instructions for at least one of the calculated route and the optimized route.

29. The onboard navigation device of claim 24, wherein at least one of the calculated route and the optimized route are represented by a plurality of segments and nodes.

30. The onboard navigation device of claim 24, wherein the memory is further configured to store at least one of probe data and Can Bus data.

31. The onboard navigation device of claim 30, wherein the Can Bus data includes at least one of wiper data, temperature data, weather data, and fuel consumption data.

32. The onboard navigation device of claim 24, wherein the dynamic speed information includes at least one of real-time speed measurements, traffic incidents, delay time, predictive speed information for a period of time, road closures, construction data, and traffic load data.