Dynamically providing position information of a transit object to a computing device

A system and method for providing position information of a transit object to a computing device is provided. Global positioning satellite (GPS) information of a transit object can be periodically received. For each of some of the GPS information, one or more candidate points of a transit system can be identified based on the GPS information. Using the one or more candidate points, a most likely path of travel can be determined. Additional position points along the most likely path of travel can be extrapolated and transmitted to a computing device.

RELATED APPLICATIONS

This application is related to U.S. patent application Ser. No. 13/672,634, filed Nov. 8, 2012, entitled “Providing On-Demand Services Through Use Of Portable Computing Devices;” the aforementioned application being incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

Current systems for visualizing the position of an object typically display the raw global positioning system (GPS) data of the object on a map. This GPS data is updated and then redisplayed to show the object's new position. In many situations, however, the raw GPS data does not provide an accurate depiction of the actual position and motion of the object.

DETAILED DESCRIPTION

Embodiments described herein provide for a system that delivers real-time (or close to real-time) position and motion information of a transit object to a client application. The system can receive raw global positioning system (GPS) data from a transit device (e.g., a computing device) of a transit object (e.g., a vehicle, a bicycle, a train, etc.) as the transit object moves in position, and can use the data to determine a most likely path of travel of the transit object on an underlying transit system.

In some embodiments, a transit object's operator or driver can use a computing device (e.g., also referred to as a transit device) that can communicate GPS data corresponding its real-time position at a given instance in time to a system. In many cases, such GPS data may not be accurate due to GPS error and/or signal problems. Inaccurate location information of a transit object may be problematic, for example, to an end-user that is using the client application for requesting services.

By fitting the raw GPS data to an underlying transit system, the system can provide a more accurate depiction of the trajectory or movement of a transit object to an end user. A computing device (e.g., also referred to as an observer device) that runs a client application can receive position information of the most likely path of travel of the transit object and present a visualization of the trajectory of the transit object that accurately reflects the actual movement of the transit object to a user.

According to an embodiment, the system can periodically receive raw GPS data from one or more transit devices over a network. Because the position of a transit device corresponds to the position of the corresponding transit object, the GPS data of the transit device can identify the position of the transit object at an instance in time (e.g., a latitude, a longitude, an altitude, etc.). As the transit object moves in real-time, GPS data can be periodically provided to the system at different instances in time thereby providing updated position information indicating the movement of the transit object.

In some embodiments, for each received GPS point, the system can identify one or more candidate points of a transit system (e.g., roads, walkways, railways, shipping routes, flight paths, etc.) that can correspond to a possible position of the transit object for that GPS point. For example, a candidate point identified for a received GPS point can have a latitude and a longitude that is very close (e.g., within a certain distance) to that GPS point. The system can then use or apply one or more transit models in order to determine, for each transit object, the most likely path of travel on the transit system.

A transit device can be a computing device that runs an application configured to communicate with the system. Similarly, an observer device can run a client application also configured to communicate with the system and to present a visualization of the trajectory of the transit object. As described herein, a “transit device” and an “observer device” refer to computing devices that can correspond to desktop computers, cellular devices or smartphones, personal digital assistants (PDAs), laptop computers, tablet devices, television (IP Television), etc., that can provide network connectivity and processing resources for enabling a user to communicate with the system over a network. A transit device can also correspond to taxi meters, other metering devices of a transit object, or custom hardware, etc. Also as used herein, a “transit object” refers to an object that can be in motion, such as, for example, a vehicle (e.g., a sedan, an SUV, a limousine), a motorcycle, a bicycle, a train, a light-rail vehicle, an airplane, a helicopter, a ship, or a person (e.g., an individual walking, jogging, skateboarding).

Still further, the system, for example, can enable services (such as a transportation service, a delivery service, an entertainment service) to be arranged between individuals using a computing device (or observer device) and available service providers that provide services via a transit object. As an example, a user can request a service, such as a transportation or delivery service (e.g., food delivery, messenger service, food truck service, or product shipping) or an entertainment service (e.g., mariachi band, string quartet) using the system, and a service provider, such as a driver, food provider, band, etc. can communicate with the system and/or the user to arrange for the service. As described herein, a “user,” an “end-user,” a “requester,” or a “customer” are invariably used to refer to individuals that are requesting or ordering a service using an application on his or her computing device. Also as described herein, a “provider,” a “service provider,” a “supplier,” or a “vendor” are invariably used to refer to individuals or entities that can provide the service.

In some embodiments, once the system determines the most likely path of travel of a transit object on a transit system, the system can extrapolate additional position points along the most likely path of travel. A set of extrapolated points can then be wirelessly transmitted over a network to a client application stored and operated on an end-user's computing device (e.g., an observer device). The client application can use the set of extrapolated points and present a visualization of the trajectory of the transit object that accurately reflects the actual movement of the transit object to the user.

Some embodiments described herein can generally require the use of computing devices, including processing and memory resources. For example, one or more embodiments described herein may be implemented, in whole or in part, on computing devices such as servers, desktop computers, cellular or smartphones, personal digital assistants (e.g., PDAs), laptop computers, printers, digital picture frames, network equipments (e.g., routers) and tablet devices. Memory, processing, and network resources may all be used in connection with the establishment, use, or performance of any embodiment described herein (including with the performance of any method or with the implementation of any system).

System Description

FIG. 1illustrates an example tracking system, under an embodiment. In particular,FIG. 1illustrates a system that can operate with or as part of another system that enables services to be arranged between parties (e.g., arrange a transport or a delivery between a requester of a service and a service provider). For example, the tracking system can provide a service for a requester by providing a visualization (as close to real-time) of available service providers within the area of the requester. In some examples, system100can periodically receive GPS data from one or more transit devices corresponding to one or more transit objects, determine the most likely path of travel for the one or more transit objects using the GPS data, and provide a set of extrapolated points of the most likely path of travel to an observer device. In this manner, the system can dynamically provide position information of a transit object to a user's computing device so that a smooth and accurate visualization of the trajectory of the transit object can be displayed to the user. A system such as described can be implemented in various contexts.

System100can dynamically provide position information for any type of object that can be in motion (e.g., a vehicle, a bicycle, a boat, a train, etc.) for any corresponding transit system (e.g., roads, walkways, railways, shipping routes, flight paths, etc.). In one example, system100can track bicycle messengers. Because bicycle messengers can ride on certain roads as well as through parks or open fields (but not on freeways or in rivers), the underlying corresponding transit system for bicycle messengers can include some roadways and other paths that vehicles cannot drive on (e.g., the corresponding transit system includes only possible avenues of travel).

In another example, system100can track the movement of trains on particular railways and railroads, i.e., a train's corresponding transit system and/or can track the movement of airplanes in flight patterns and paths, i.e., an airplane's corresponding transit system. The airplane transit system can also take into account no flight zones, for example, or typical paths between airports. System100can also track the movement of vehicles. In general, a vehicle can travel on most roadways and freeways, but only on certain bridges, for example, or only on selective streets through certain parks having streets. Although system100is not limited to vehicles and roadways, for simplicity purposes of this application, system100is described mainly with respect to vehicles that can travel on roadways, i.e., a vehicle's respective transit system.

System100includes a tracking service110, a transit models database140, a transit device interface190, and an observer device interface195. In some implementations, the tracking service110can also include a path of travel (POT) determination120, a transit model determination130, a position extrapolation150, and a data store160. The components of system100can combine to dynamically provide position information of one or more transit objects to one or more observer devices180. For example, the components of system100can be implemented on network side resources, such as on one or more servers. System100can also be implemented through other computer systems in alternative architectures (e.g., peer-to-peer networks, etc.).

As an alternative or addition, some or all of the components of system100can be implemented on client machines or devices, such as through applications that operate on the transit devices170and/or observer devices180. For example, a client application operating on a transit device and/or an observer device can execute to perform one or more of the processes described by the various components of system100. System100can communicate over a network, via a network interface (e.g., wirelessly or using a wire), to communicate with the one or more transit devices170and the one or more observer devices180.

Each of the transit device interface190and the observer device interface195manages communications between system100and the corresponding devices over a network. In some implementations, each of the transit devices170can download, store, and operate an application that can interface with the transit device interface190in order to provide information to and/or receive information from system100via a cellular or Wi-Fi network. Similarly, each of the observer devices180can download, store, and operate an application (e.g., a different application than the application used by a customer, or the same application) that can interface with the observer device interface195in order to provide information to and/or receive information from system100.

For example, the applications can include or use an application programming interface (API), such as an externally facing API, to communicate data with the respective device interfaces190,195. The externally facing API can provide access to system100via secure access channels over the network through any number of methods, such as web-based forms, programmatic access via restful APIs, Simple Object Access Protocol (SOAP), remote procedure call (RPC), scripting access, etc., while also providing secure access methods including key-based access to ensure system100remains secure and only authorized users, service providers, and/or third parties can gain access to system100.

The tracking service110can receive, via the transit device interface190, GPS data171from one or more transit devices170. A transit device170can be a computing device that is located with a transit object (e.g., a vehicle, such as a sedan, a taxi cab, an SUV, etc.) so that its position corresponds to the position of the transit object. As the transit object moves, e.g., is driven along one or more roads, its actual position changes and is measured/identified by one or more sensors of the transit device170(e.g., a GPS component and a magnetometer). The GPS data171that is provided by the transit device170can correspond to position or GPS information of the transit device170determined at different instances in time (e.g., GPS snapshots).

For example, at time t=T1, the transit device170can be at a particular location or GPS point, identified by a latitude and a longitude (e.g., Lat1,Long1). The transit device170can provide the GPS data171that includes a latitude and longitude at time t=T1, as well as the time stamp of the GPS reading (e.g., the time stamp would be t=T1) and a GPS error amount to the POT determination120. In some implementations, the GPS data171can also include a GPS bearing (or magnetometer bearing), or other information, such as nearby Wi-Fi networks, cellular network strength, etc. If the transit object is moving, at time t=T2, the transit device can be at a different location or GPS point, identified by a different latitude and longitude, Lat2and Long2, respectively. This GPS data171is also provided to the tracking service110along with the time stamp (t=T2) and the GPS error amount at this particular GPS measurement. In this manner, the transit device170can periodically take GPS measurements of the current status or position of the transit object (e.g., every three seconds, every four seconds, etc.), and provide these measurements to the tracking service110. In another example, the transit device170can provide GPS data171whenever new or updated GPS measurements are taken or are available.

In some implementations, as the transit object moves and provides updated GPS data171at different instances in time, the POT determination120can maintain a running history of GPS data for each transit object (e.g., for each transit device170). For example, for each transit object, the GPS data171for that transit object can be continually added to a list or table of previously received GPS data. The POT determination120can include a data store or a buffer to store the GPS data171received from the transit devices170. Using the GPS data171at different instances in time, the POT determination120attempts to identify which roadways or highways (when tracking vehicles, for example) the vehicle is actually moving on.

As the POT determination120receives the GPS data171at different instances in time (e.g., receives GPS snapshots), the POT determination120identifies one or more candidate points of a transit system that can correspond to a given GPS point. A candidate point is a point (having a latitude and a longitude reading) corresponding to a location on an underlying transit system. For example, a vehicle transit system, a candidate point can be a point that corresponds to a location on a street or at an intersection between streets. In order to identify one or more candidate points, the underlying transit system must be identified (based on what type of transit object the tracking service110is tracking).

In one implementation, the POT determination120queries121a transit model determination130for one or more appropriate transit models or spatial databases. The POT determination120can use the transit models and/or spatial databases to identify one or more candidate points and to determine the most likely path of travel for a particular transit object. The query121can identify the type of transit object (e.g., a bicycle, a vehicle, an airplane, etc.) that the tracking service110is to track. Based on the type of transit object, the transit model determination130can select, from a transit models database140, one or more selected transit models and/or spatial databases123that can be used by the POT determination120.

For example, the transit models database140can store a variety of transit system spatial databases. Transit system spatial databases are queryable databases identifying different points (e.g., having a latitude and a longitude, and/or an altitude) along paths of transit which a given transit object can use, and information of how the different points connect with other points. Some transit system spatial databases can also include points identifying locations of interests or landmarks.

With respect to vehicles, a vehicle transit system spatial database can include points corresponding to locations on roadways, highways, freeways, etc., and other information related to roadways, such as intersections, one way streets, how the different roads and streets connect to each other, etc. Similarly, with respect to airplanes, an airplane transit system spatial database can include points corresponding to locations along flight paths and what points are boundaries for no flight zones, while for trains, a train transit system spatial database can include points corresponding to locations on railroads and railways, and where/how the railroads connect. Additional spatial databases can be created and/or added to the transit models database140as a result of real life updates and changes.

The POT determination120references a transit system spatial database in order to identify one or more candidate points corresponding to locations on the transit system. As a result, for a particular GPS point for a transit object, a candidate point can be a probable actual (or real-life) position of the transit device170. This can be the best approximated position for the transit object that matches an actual position on the underlying transit system. The POT determination120identifies one or more candidate points because in many cases, a GPS measurement may not be perfectly accurate. This can be a result of bad GPS components of a computing device or a result of bad signals or interference when the GPS reading was taken. Because the GPS data171may not be accurate, the measured (and transmitted) latitude and longitude of a transit device170may not necessarily correspond to the actual position of the transit device170. For example, due to the inconsistencies of a GPS measurement, a given GPS point for a vehicle can identify Lat1, Long1(which corresponds to a building near a street) as the position of the transit device170at a time t=T1, but in reality, the transit device170can be positioned at Lat2, Long2(which corresponds to a location on a street) at time t=T1. Using the position Lat2, Long2would be more accurate in determining the most likely path of travel of the transit device170(especially if Lat1, Long1identified the vehicle to be on a different road than a road that the vehicle was actually traveling on).

Based on a selected spatial database or model123, the POT determination120can identify, for each (or for some) of the GPS points received at different instances in time (e.g., GPS snapshots), one or more candidate points of the selected transit system. For example, if the tracking service110is tracking vehicles, the selected spatial database123can correspond to the vehicle transit system spatial database, which includes points corresponding to locations on roadways. By referencing the vehicle transit system spatial database, for a given GPS point (e.g., having a latitude and a longitude, a time stamp, a bearing, and a GPS error amount), the POT determination120identifies one or more candidate points (e.g., points corresponding to locations on roadways) that are nearby or close to the measured (and received) GPS point. The candidate point(s) can be identified by searching for points that are within a predetermined distance from the given GPS point at an instance. Depending on implementation, the predetermined distance can be configured or set by an administrator of system100or other users, or can correspond to a GPS error amount for a given GPS point that is provided by the respective GPS component of transit device.

As the transit object moves and provides updated GPS data171at different instances in time to the POT determination120, the POT determination120continues to identify candidate point(s) for each GPS point at each instance in time (or as an alternative, not every GPS point, but for only selected GPS points). The POT determination120can then determine the most likely path of travel based on the identified candidate point(s) on the transit system. In one example, the POT determination120can query121the transit model determination130(at the same time it queried for the spatial database or at a different time) to select other transit models to determine the most likely path of travel. These transit models can use the identified one or more candidate points to make this determination. For example, other transit models stored in the database140include routing engines, physics engines, a hidden Markov model solver, or other models that can be used, individually or in combination, to determine the best or most likely paths of travel of one or more transit objects.

For example, a routing engine, a physics engine, and/or a hidden Markov model solver (or other models) can provide a mechanism that the POT determination120can use to select, from all (or many of) the possible paths of travel, a path of travel as being the most likely path of travel for a transit object. Based on the identified candidate points at each instance in time (corresponding to the each received GPS point), a routing engine and/or the physics engine, for example, can use the time stamps of the GPS points to generate timing distance and travel paths between two points in the transit system. Using this information, the routing engine and/or the physics engine can determine how long it would have (or should have) taken a typical vehicle driving at a particular speed on the road (e.g., based on the speed limit) to get from one GPS point to another GPS point (or one candidate point for a GPS point to another candidate point for a subsequent GPS point). This can provide a better indication as to which path of travel is the most likely travel path of the vehicle (as compared to other travel paths). In another example, a hidden Markov model solver (or other Markov models) can also be used by the POT determination120to determine the most likely path of travel of the transit object.

Because the identified candidate points correspond to only possible positions of the transit device170, the POT determination120considers only possible avenues of travel for the particular type of transit object (e.g., roads for vehicles, roads and walkways for bicycles, railroads for trains) in determining the most likely path of travel. In the case of tracking vehicles, the most likely path of travel can include, for example, Road1to Road2to Road3, etc., while continuing to stay on these roads (e.g., cannot jump between roads). In this manner, the GPS data171of the transit objects can be matched to the underlying transit system and the most likely path of travel can be determined for each of the transit objects.

In some implementations, the determined most likely path of travel125can continue to be stored in a data store160as the POT determination120continues to process the GPS data171(e.g., as the GPS data is continually or periodically received from the transit devices170). The POT determination120can continue to identify one or more candidate points and determine a most likely path of travel until the transit device170stops providing the GPS data171(e.g., shuts off or closes/logs out of the application) or until other triggers are received. For example, if the transit device170is performing a service (e.g., is unavailable) or is out of commission, the transit device170can stop providing the GPS data171to the tracking service110.

The position extrapolation150can generate position data of a transit object based on the determined most likely path of travel125. As an addition or an alternative, the position extrapolation150can retrieve the stored most likely path of travel151from the data store160. Using the most likely path of travel151determined by the POT determination120, the position extrapolation150can extrapolate additional position points along the most likely path of travel.

For example, if a GPS point or candidate point at time t=T1is determined to be a point along the most likely path of travel, and four seconds later at time t=T2, another GPS point or candidate point is determined to be a point along the most likely path of travel, additional extrapolated data points can be generated along the most likely path of travel in between the points at t=T1and t=T2. For each of the extrapolated points, a corresponding extrapolated time stamp can also be generated. Optionally, the bearing or heading can also be included with each extrapolated data point. By generating extrapolated points, additional points that are closer together in time (e.g., one second, a half of a second, or a third of a second, etc., as compared to four seconds) can be provided to the observer device180(via the observer device interface195) so that a visualization of the movement of the transit device can be displayed more smoothly to a user.

The extrapolated data points155are provided to the observer device(s)180via the observer device interface195. An application running on the observer device180(and communicating with system100) can use the extrapolated data points155to display (e.g., as part of a map) the location and trajectory of transit objects in real-time (or as close to real-time). In the example of vehicles, because the extrapolated data points155(which can also include the selected GPS point or candidate point) corresponds to actual locations on roads, highways, and freeways, a graphic (e.g., an image of a vehicle) that represents the transit object can be animated to move on the appropriate roads on the map. This is done by matching the positions identified in the extrapolated data points155to the underlying map displayed on the user's observer device180. In this manner, a smooth visualization of the trajectory of the transit object that accurately reflects the actual movement of the transit object can be presented to a user.

The position extrapolation150can also receive timing information181(via the observer device interface195) from one or more observer devices180in order to adjust or control the timing of the delivery of extrapolated data points155and/or control the amount of extrapolated data to be provided to individual observer devices180. The observer devices180can typically operate off different clocks. For example, observer device180-1can be off by ten seconds from observer device180-2. Similarly, transit devices170can also operate off different clocks. Despite the fact that the clocks of the devices are not in sync, system100provides for a synchronization-free visualization service so that the transit devices170and the observer devices180do not have to be in sync in order for position information to be accurately provided to the observer devices180.

The position extrapolation150can provide a window of extrapolated data points155(e.g., a set of extrapolated data points155) that span a particular duration of time (e.g., ten seconds) for a transit object. This window of extrapolated data points155can have a start time and an end time (which corresponds to a start point and an end point along the determined most likely path of travel). A set of extrapolated data points155(e.g., that spans a duration of ten seconds, or fifteen seconds, etc.) can be beneficial in situations where the observer device180loses a signal or cannot receive subsequent sets of extrapolated data points155from the tracking service110. The application running on the observer device180can continue to display visualization of the transit object for a time until a signal is re-established and an additional extrapolated data points(s)155is received. The position extrapolation150can continue to periodically check/receive the timing information181of the individual observer devices180to adjust or control the timing of the delivery of extrapolated data points155and/or control the amount of extrapolated data to be provided to individual observer devices180. Additionally, based on the timing information181of an observer device180, the position extrapolation150can also determine a delay (e.g., determine how far back in the past to use and provide position points of a transit object) and provide a window of extrapolated data points155of a transit object to the particular observer device180to account for clock discrepancies.

In some implementations, when the position extrapolation150transmits an additional window of extrapolated data points155to the observer device180, this additional window can overlap (e.g., some of the subsequently transmitted extrapolated points can share points previously transmitted) the previously transmitted window. In such a case, the application running on the observer device180can replace or modify the redundant data (e.g., has two data points at the same time t=T5) with the more recently received extrapolated data, and add/append the other more recently received extrapolated data points155to the previously received extrapolated data points155. In this manner, although segments of data can be received at discrete times, the visualization of the transit object can be seamless on the observer device180.

The tracking service110(via the position extrapolation150) can also maintain a database (e.g., using the data store160or other data stores) of user accounts, and can monitor the current location of the transit devices170and the observer devices180. In some examples, only extrapolated data points155of transit objects that are within a certain area or predetermined distance from an observer device180will be transmitted to the observer device180(e.g., within a particular distance, such as 15 mile radius or 20 minutes distance from the observer device180, or within a city limit or metropolitan area that the observer device180is currently located in, etc.).

The tracking service110also provides a fail-safe in situations where one or more components of the tracking service110and/or system100fail. For example, the tracking service110can continue to receive raw GPS data171from the transit device(s)170and directly provide the raw GPS data to the observer device(s)180without processing (e.g., without fitting the GPS data to an underlying transit system) the GPS data. The applications running on the observer devices180can use the raw GPS data to still provide an estimated position of the transit object at the different instances in time. Similarly, if for example, some transit devices are operating off an older application that does not provide GPS error and/or cannot be mapped to a transit system, the raw GPS points can still be provided to system100, which is then (without being processed) transmitted to the observer device(s)180. In this manner, the tracking service110is horizontally scalable by enabling different components of system100to operate on any of different devices and/or operate even when one or more other components fail.

In some variations, some of the components that are described in system100can be provided as being individual components or as being part of the same component. For example, the transit model determination130can be provided as a part of the POT determination120or the position extrapolation150can be provided as a part of the POT determination120. Logic can be implemented with various applications (e.g., software) and/or with hardware of a computer system that implements system100.

Methodology

FIG. 2illustrates an example method for determining a path of travel of a transit object, according to an embodiment. A method such as described by an embodiment ofFIG. 2can be implemented using, for example, components described with an embodiment ofFIG. 1. Accordingly, references made to elements ofFIG. 1are for purposes of illustrating a suitable element or component for performing a step or sub-step being described.

The tracking system periodically receives GPS information from one or more transit devices (step210). The GPS information provided by a transit device can include a latitude and longitude of the transit device, a time stamp, a bearing, and a GPS error amount at a given instances in time. The GPS component of a transit device can determine the GPS error for each measured GPS data (e.g., at each given instance in time). In this manner, as the transit device (and the corresponding transit object) moves and changes position, the transit device can continue to provide the GPS information to the tracking system to indicate new and/or updated positions.

For example, referring to diagram300inFIG. 3for illustrative purposes, the tracking system (as described inFIG. 1) is tracking the movement of one or more vehicles (transit objects). As a result, the underlying transit system corresponds to a vehicle transit system. In this case, at time t=T1, a transit device provides GPS information identifying its position GPS1having a latitude and a longitude, a GPS error amount Δ1, and a time stamp t=T1. In this case, although the transit device can be traveling on a road (e.g., the transit object can be a vehicle), due to the GPS measurement inaccuracies, GPS1may not necessarily be shown to be on the road. Similarly, at time t=T2, the transit device provides GPS information identifying its position GPS2having a latitude and a longitude, a GPS error amount Δ2, and a time stamp t=T2, and at time t=T3, the transit device provides GPS information identifying its position GPS3having a latitude and a longitude, a GPS error amount Δ3, and a time stamp t=T3, and so forth. The transit device can continue to provide GPS information as it continues to move. For each of the GPS information at a given instance, the bearing information can also be included (e.g., south, southeast, etc.).

Using the GPS information, the tracking system can identify, for each of the GPS points at a given instance, one or more candidate points of a transit system (step220). The candidate points can be identified by referencing one or more transit system spatial databases and determining which points are nearby or close to the measured (and received) GPS point. In this manner, the inaccuracies of the GPS measurements can be accounted for in determining the most likely path of travel. The candidate point(s) can be identified by searching for points (each having a latitude and a longitude) that are within a predetermined distance or within a GPS error amount from the given GPS point at an instance (sub-step222). The GPS error amount can also vary from point to point as a result of the varying signal quality and/or different interferences at different locations, and can be represented as an ellipse (e.g., where the latitude error and the longitude error can be different) or as a circle (e.g., where the latitude error and the longitude error are equal). As an alternative or an addition, the GPS error amounts can be normalized for each GPS point (see GPS error amount Δ3, which has been normalized to be represented as a circle) in order to perform a search of candidate points within a radius (e.g., a normalized GPS error amount).

Referring again to the example inFIG. 3, the tracking system has selected a vehicle transit system spatial database from a transit models database (e.g., because the tracking system is tracking the movement of vehicles in this example). For each GPS point, the tracking system can identify one or more candidate points corresponding to locations on roadways, highways, freeways, etc., to determine the actual roadway the transit device is actually on. For example, for the GPS point GPS1at time t=T1, three candidate points having latitudes and longitudes, Lat1,Long1, Lat2,Long2, and Lat3,Long3, respectively, have been identified by the tracking system. In this case, GPS1has a GPS error amount Δ1that is larger than the GPS error amounts Δ2and Δ3, thereby encompassing a larger search area for candidate points. As a result, the tracking system identifies that the actual position of the transit device can potentially be on A Street, B Street, and the intersection of B Street and Main Street. For GPS2at time t=T2, two candidate points having latitudes and longitudes, Lat4,Long4, and Lat5, Long5have been identified, respectively, and for GPS3at time t=T3, only one candidate point having latitude and longitude, Lat6,Long6has been identified.

Based on the identified candidate points (and the corresponding time stamps), the tracking system can determine the most likely path of travel of the transit object on the transit system (step230). For example, the tracking system can apply or use one or more transit models, such as routing engines, physics engines, a hidden Markov model solver, or other models, individually or in combination, to determine the best or most likely paths of travel of the transit object. Referring toFIG. 3, the tracking system can determine, for example, that the most likely path of travel of the vehicle (the transit object) is from the following positions: Lat1,Long1to Lat4,Long4, and to Lat6,Long6(see alsoFIG. 4B).

Other paths of travel can be possible based on the candidate points selected. For example, the transit device could have traveled from Lat2,Long2to Lat4,Long4. However, the transit models can take into account the travel times based on the time stamps provided with each GPS point at a given instance in time, in order to better determine the more likely path of travel between Lat1,Long1to Lat4,Long4or Lat2,Long2to Lat4,Long4. For example, the travel time from Lat2,Long2to Lat4,Long4would be much longer than the alternative. Similarly, Lat5,Long5on C Street is also a point along a possible path of travel. Again, using the transit models, such as a hidden Markov model solver, the tracking system can determine that the candidate point Lat5,Long5is unlikely (based on probabilities, timing, etc.) as compared to Lat4,Long4.

FIG. 4Aillustrates an example method for providing position information of a transit object to a computing device, under an embodiment. A method such as described by an embodiment ofFIG. 4can be implemented using, for example, components described with an embodiment ofFIG. 1. Accordingly, references made to elements ofFIG. 1are for purposes of illustrating a suitable element or component for performing a step or sub-step being described. In some implementations, step410ofFIG. 4Acan be automatically performed in response to the most likely path of travel being determined (e.g., after step230ofFIG. 2).

The tracking system can extrapolate additional position points along the most likely path of travel (e.g., in addition to the GPS point or candidate point determined to be on the most likely path of travel) (step410). For example, referring to diagram450inFIG. 4B, if a candidate point Lat1,Long1of the GPS point GPS1at time t=T1is determined to be a point along the most likely path of travel (e.g., the darker line from B Street to Main Street), and a duration of time later (e.g., five seconds) at time t=T2, the candidate point Lat4,Long4of GPS point GPS2at time t=T2is determined to be another point along the most likely path of travel, additional extrapolated data points (marked by X's) can be generated along the most likely path of travel in between the points at t=T1and t=T2. Additional points can be extrapolated as the most likely path of travel continues to be determined. For example, points can be extrapolated next between Lat4,Long4and Lat6,Long6. For each of these extrapolated points (marked with X's), having a latitude and a longitude, a corresponding extrapolated time stamp can also be generated. A bearing or heading can also be included with each extrapolated data point.

The extrapolated data is transmitted to one or more observer devices (step420). An application running on the observer device can use the extrapolated data to display (e.g., as part of a map) the location and trajectory of transit objects in real-time (or as close to real-time). In the example of vehicles as shown inFIGS. 3 and 4B, because the extrapolated data (which can also include the selected GPS point or candidate point) corresponds to actual locations on roads, highways, and freeways, a graphic (e.g., an image of a vehicle) that represents the transit object can be animated to move on the appropriate roads on the map. This is done by matching the positions identified in the extrapolated data to the underlying map displayed on the user's observer device. In this manner, a smooth visualization of the trajectory of the transit object that accurately reflects the actual movement of the transit object can be presented to a user.

In one example, the tracking system can also determine or receive timing information from one or more observer devices. Based on the timing information, the tracking system can adjust or control the timing of the delivery of extrapolated data and/or control the amount of extrapolated data to be provided to individual observer devices (sub-step422). Based on the timing information of an observer device, the tracking system can also determine a delay (e.g., determine how far back in the past to use and provide position points of a transit object) and provide a set of extrapolated points of a transit object to the particular observer device to account for clock discrepancies between the system and the observer device.

User Interface Example

FIG. 5illustrates an example user interface illustrating a trajectory of a transit object that is displayed on a computing device, under an embodiment. The user interface500illustrates a user interface that can be provided by a service application running or being operated on an observer device (e.g., a smart phone) and/or a transit device (in some implementations). In one implementation, the user interface500includes a map510and an indicator520representing the current location of the observer device. In the example shown, the user interface500is provided at least in part by a transport service application that a user can use to request for a transport service to be arranged between the user of the observer device and available service providers.

In some implementations, the tracking system can communicate with a fleet of vehicles that can be arranged to provide services for requesters. The GPS data can be received for the fleet of vehicles (e.g., multiple transit objects) and processed by the tracking system. The tracking system can then provide position information (e.g., extrapolated data) of selected transit objects to the respective observer devices based on the geographic location of the observer devices and the transit objects. In this manner, a user of an observer device can see the location and movements of the transit objects in his or her area (and not of objects that he or she does not care about in other areas that are too far to service him or her) to make a more informed decision in requesting a service.

The user interface500can provide a real-time (or close to real-time) visualization of the position and trajectory of one or more transit objects (e.g., in this example, transport service providers) that accurately reflect the actual position and movement of the transit object to a user. Using the extrapolated position data (as discussed with respect toFIGS. 1-4B), the application can present a graphic image of a vehicle, V1, on the map510. The graphic image V1can move along the road (e.g., Market Street) in the manner accurately reflecting the movement of the transit object in real life. Similarly, a second graphic image of a vehicle, V2, can also be presented on the map510and dynamically animated accordingly.

According to an implementation, the graphic images can also vary depending on the transit object. The graphic images can match the type of vehicle, for example, to provide an accurate depiction of the vehicle being a sedan, an SUV, a limousine, etc. Similarly, for other transit objects (e.g., bicycles, trains, airplanes, boats, etc.) on an underlying transit system, respective graphic images can also be presented. In addition, the graphic images can also face (e.g., point) in the correct direction to match the bearing and trajectory of the actual transit object. In the example provided inFIG. 5, V1is shown with the front of the device driving towards the user on Market St, whereas V2is shown with the front of the device driving west on Geary St. In this manner, an accurate depiction of the real-time and actual movement of transit objects can be provided to users in accordance with a service.

Hardware Diagrams

FIG. 6is a block diagram that illustrates a computer system upon which embodiments described herein may be implemented. For example, in the context ofFIG. 1, system100may be implemented using a computer system such as described byFIG. 6. System100may also be implemented using a combination of multiple computer systems as described byFIG. 6.

In one implementation, computer system600includes processing resources, such as a processor610, main memory620, ROM630, storage device640, and communication interface650. Computer system600includes at least one processor610for processing information and a main memory620, such as a random access memory (RAM) or other dynamic storage device, for storing information and instructions to be executed by the processor610. Main memory620also may be used for storing temporary variables or other intermediate information during execution of instructions to be executed by processor610. Computer system600may also include a read only memory (ROM)630or other static storage device for storing static information and instructions for processor610. A storage device640, such as a magnetic disk or optical disk, is provided for storing information and instructions.

The communication interface650can enable the computer system600to communicate with one or more networks680(e.g., cellular network) through use of the network link (wireless or wire). Using the network link, the computer system600can communicate with one or more computing devices, and one or more servers. In some variations, the computer system600can be configured to receive sensor data (e.g., such as GPS data) from one or more transit devices (e.g., belonging to service providers) via the network link. The sensor data652can be processed by the processor610and can be stored in, for example, the storage device640. The processor610can process the sensor data652of a transit device in order to determine a most likely path of travel of a transit object corresponding to the transit device. Extrapolated position information654can be transmitted to one or more observer devices over the network680to enable an application running on the observer device to use the position information654to present a visualization of the actual movement of the transit object.

Computer system600can also include a display device660, such as a cathode ray tube (CRT), an LCD monitor, or a television set, for example, for displaying graphics and information to a user. An input mechanism670, such as a keyboard that includes alphanumeric keys and other keys, can be coupled to computer system600for communicating information and command selections to processor610. Other non-limiting, illustrative examples of input mechanisms670include a mouse, a trackball, touch-sensitive screen, or cursor direction keys for communicating direction information and command selections to processor610and for controlling cursor movement on display660.

Examples described herein are related to the use of computer system600for implementing the techniques described herein. According to one embodiment, those techniques are performed by computer system600in response to processor610executing one or more sequences of one or more instructions contained in main memory620. Such instructions may be read into main memory620from another machine-readable medium, such as storage device640. Execution of the sequences of instructions contained in main memory620causes processor610to perform the process steps described herein. In alternative implementations, hard-wired circuitry may be used in place of or in combination with software instructions to implement examples described herein. Thus, the examples described are not limited to any specific combination of hardware circuitry and software.

FIG. 7is a block diagram that illustrates a mobile computing device upon which embodiments described herein may be implemented. In one embodiment, a computing device700may correspond to a mobile computing device, such as a cellular device that is capable of telephony, messaging, and data services. The computing device700can correspond to each of a transit device and an observer device. Examples of such devices include smartphones, handsets or tablet devices for cellular carriers. Computing device700includes a processor710, memory resources720, a display device730(e.g., such as a touch-sensitive display device), one or more communication sub-systems740(including wireless communication sub-systems), input mechanisms750(e.g., an input mechanism can include or be part of the touch-sensitive display device), and one or more location detection mechanisms (e.g., GPS component)760. In one example, at least one of the communication sub-systems740sends and receives cellular data over data channels and voice channels.

The processor710is configured with software and/or other logic to perform one or more processes, steps and other functions described with implementations, such as described byFIGS. 1-5, and elsewhere in the application. Processor710is configured, with instructions and data stored in the memory resources720, to operate a service application as described inFIGS. 1-5. For example, instructions for operating the service application in order to display user interfaces, such as a user interface described inFIG. 4, can be stored in the memory resources720of the computing device700.

From the viewpoint of a service provider, a service provider operating a transit device (such as a computing device700) can operate a service application so that sensor data, such as location/position data765, can be determined from the GPS component760. This location/position data765can then be wirelessly transmitted to the system via the communication sub-systems740. From the viewpoint of an end-user, a user can operate the service application in order to receive position information745of one or more transit objects from the system (via the communication sub-systems740).

The processor710can provide content to the display730by executing instructions and/or applications that are stored in the memory resources720. In some examples, one or more user interfaces715can be provided by the processor710, such as a user interface for the service application, based at least in part on the received position information745of the one or more transit objects. WhileFIG. 7is illustrated for a mobile computing device, one or more embodiments may be implemented on other types of devices, including full-functional computers, such as laptops and desktops (e.g., PC).

It is contemplated for embodiments described herein to extend to individual elements and concepts described herein, independently of other concepts, ideas or system, as well as for embodiments to include combinations of elements recited anywhere in this application. Although embodiments are described in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments. As such, many modifications and variations will be apparent to practitioners skilled in this art. Accordingly, it is intended that the scope of the invention be defined by the following claims and their equivalents. Furthermore, it is contemplated that a particular feature described either individually or as part of an embodiment can be combined with other individually described features, or parts of other embodiments, even if the other features and embodiments make no mentioned of the particular feature. Thus, the absence of describing combinations should not preclude the inventor from claiming rights to such combinations.