DESC:FIELD
The present disclosure relates to the field of Global Positioning System (GPS) assisted vehicle tracking, more particularly to correcting GPS trajectory of a moving vehicle.
DEFINITIONS
As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used indicate otherwise.
Waypoint – The term “Waypoint” hereinafter refers to a unique address for any point in the world. GPS units utilize waypoints expressed in mapping formats such as latitude/longitude or the UTM Grid.
Trajectory- The term “Trajectory” hereinafter refers to a path that an object with mass in motion follows through space as a function of time.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Positioning systems are used in almost all modern vehicles for providing navigation information to a vehicle, for example, the preferable route, estimated time of arrival, toll routes and the like. Some of the examples of these positioning systems may include global positioning systems (GPS), inertial-based positioning systems, vision-based positioning systems, and dead-reckoning systems.
In GPS based systems, for example, a position of a GPS device installed on a vehicle is tracked using a group of satellites, which transmit signals to the device at pre-determined time slots. A GPS receiver of the device captures the signals and estimates its relative distance from all the satellites by comparing a time stamp of the signal broadcasting and arrival and assess its position. The GPS receiver typically utilizes a trilateration algorithm for the purpose.
It has been observed that a location determined by the GPS receiver is not always exactly accurate as the assessment is affected by a large number of factors like satellite geometry, multipath effect, atmospheric effects, clock inaccuracies, rounding errors, receiver noise and so forth. Further, position errors are common as the GPS derived position will tend to jump around, even when the vehicle is not moving. The jumping GPS waypoints may be off from the expected trajectory of the vehicle by multiple magnitudes, compared to maximum motion capabilities of the vehicle such as maximum speed, maximum acceleration in given time frame. Due to this, a GPS based navigation system does not give smooth tracking of the vehicle.
There is a constant endeavor towards improving the positioning accuracy of existing GPS-based positioning systems. For example, WAAS (Wide Area Augmentation System) and DGPS (Differential GPS) use additional auxiliary or peripheral modules to supplement the GPS computation. However, such modifications make the existing systems complex and highly expensive, which is not desired.
Therefore, there is felt a need to provide a system and method for correcting GPS trajectory of a moving vehicle which alleviates the above mentioned drawbacks.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
It is an object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
An object of the present disclosure is to provide a system for correcting GPS trajectory of a moving vehicle.
Another object of the present disclosure is to provide a system that eliminates and/or corrects jumping/erroneous GPS waypoints using machine learning and artificial intelligence based techniques.
Yet another object of the present disclosure is to provide a system that improves effective positional accuracy of the GPS waypoints.
Still another object of the present disclosure is to provide a system that smoothens out the GPS trajectory using Kalman filter and its equivalents such as extended Kalman filter, time series filters, and the like.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure envisages a system for correcting GPS trajectory of a moving vehicle, wherein the trajectory is made of GPS waypoints which are generated by a GPS device disposed within the vehicle. The system comprises a sensing unit and a way point correction and estimation unit. The sensing unit, installed in the moving vehicle, is configured to sense location, speed and acceleration of the moving vehicle, and is further configured to generate a corresponding sensed data. The way point correction and estimation unit comprises a data collection module, a waypoint correction module and a trajectory correction module.
The data collection module is configured to communicate with the GPS device and the sensing unit to periodically collect the GPS waypoints and sensed data corresponding to the GPS waypoints.
In an embodiment, the data collection module includes a data retriever and a timer. The data retriever is configured to retrieve the GPS waypoints and the sensed data from the GPS device and the sensing unit respectively. The timer is configured to cooperate with the data retriever to measure a pre-determined time period after the retrieval of the GPS waypoints and the sensed data, and is further configured to generate a trigger signal for retrieving the GPS waypoints and the sensed data after the completion of the pre-determined time period, thereby facilitating periodic collection of the GPS waypoints and the sensed data.
The waypoint correction module is configured to cooperate with the data collection module to identify erroneous GPS waypoints from the received GPS waypoints based on the received sensed data.
In an embodiment, the waypoint correction module uses at least one of artificial intelligence, neural network, and machine learning techniques to identify erroneous GPS waypoints from the received GPS waypoints.
In another embodiment, the waypoint correction module includes a computation unit and an error detector. The computation unit is configured to compute a radius indicative of distance that the vehicle is likely to travel after each of the GPS waypoints based on the received sensed data, and is further configured to plot a circle of the computed radius around the GPS waypoints on the trajectory. The error detector is configured to cooperate with the computation unit to determine the erroneous GPS waypoints by identifying the GPS waypoints which lie outside the plotted circle.
The trajectory correction module is configured to cooperate with the waypoint correction module to smoothen out the trajectory by estimating correct GPS waypoints, and by replacing the erroneous GPS waypoints with the correct GPS waypoints.
In an embodiment, the trajectory correction module is implemented using Kalman filter.
In another embodiment, the trajectory correction module includes a corrector module and a smoothening module. The corrector module is configured to cooperate with the error detector to determine the correct GPS waypoints, wherein the correct GPS waypoints lie on the plotted circle. The smoothening module is configured to cooperate with the corrector module to smoothen out the trajectory by replacing the erroneous GPS waypoints with the correct GPS waypoints.
The way point correction module and the trajectory correction module are implemented using one or more processors.
The present disclosure envisages a method for correcting a trajectory of a moving vehicle on a generated by a GPS device disposed within the vehicle.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
A system for correcting GPS trajectory of a moving vehicle and a method thereof, of the present disclosure will now be described with the help of the accompanying drawing, in which:
Figure 1 illustrates a block diagram of a system for correcting a GPS trajectory of a moving vehicle;
Figure 2 illustrates a flow diagram depicting steps involved in a method for correcting GPS trajectory of a moving vehicle;
Figures 3a, 3b, 3c and 3d illustrate corrected GPS trajectories achieved using the system of present disclosure;
Figure 4 illustrates elimination of erroneous GPS waypoints and estimation of correct GPS waypoints using the system of present disclosure; and
Figure 5 illustrates a smoothened trajectory as an output of the system of present disclosure.
LIST OF REFERENCE NUMERALS
100 system
102 sensing unit
104 way point correction and estimation unit
106 data collection module
108 GPS device
110 waypoint correction module
112 trajectory correction module
114 data retriever
116 timer
118 computation unit
120 error detector
122 corrector module
124 smoothening module
DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details, are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open ended transitional phrases and therefore specify the presence of stated features, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, elements, components, and/or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.
As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed elements.
A system for correcting GPS trajectory of a moving vehicle and a method thereof of the present disclosure, is described with reference to Figure 1 through Figure 5. The trajectory is made of GPS waypoints generated by a GPS device (108) disposed within the vehicle.
Referring to Figure 1, the system for correcting GPS trajectory of a moving vehicle (hereinafter referred as “system”) (100) comprises a sensing unit (102) and a way point correction and estimation unit (104).
The sensing unit (102), installed in the moving vehicle, is configured to sense location, speed and acceleration of the moving vehicle, and is further configured to generate a corresponding sensed data.
In an embodiment, the acceleration is either sensed through sensor or derived from the speed. In another embodiment, the location of the moving vehicle is also sensed.
The way point correction and estimation unit (104) comprises a data collection module (106), a waypoint correction module (110) and a trajectory correction module (112). The data collection module (106) is configured to communicate with the GPS device (108) and the sensing unit (102) to periodically collect the GPS waypoints and sensed data corresponding to the GPS waypoints.
In an embodiment, the data collection module (106) includes a data retriever (114) and a timer (116). The data retriever (114) is configured to retrieve the GPS waypoints and the sensed data from the GPS device (108) and the sensing unit (102) respectively. The timer (116) is configured to cooperate with the data retriever (114) to measure a pre-determined time period after the retrieval of the GPS waypoints and the sensed data, and is further configured to generate a trigger signal for retrieving the GPS waypoints and the sensed data after the completion of the pre-determined time period, thereby facilitating periodic collection of the GPS waypoints and the sensed data.
The waypoint correction module (110) is configured to cooperate with the data collection module (106) to identify erroneous GPS waypoints from the received GPS waypoints based on the received sensed data.
In an embodiment, the waypoint correction module (110) uses at least one of artificial intelligence, neural network, and machine learning techniques to identify erroneous GPS waypoints from the received GPS waypoints.
In another embodiment, the waypoint correction module (110) includes a computation unit (118) and an error detector (120). The computation unit (118) is configured to compute a radius indicative of distance that the vehicle is likely to travel after each of the GPS waypoints based on the received sensed data, and is further configured to plot a circle of the computed radius around the GPS waypoints on the trajectory. The error detector (120) is configured to cooperate with the computation unit (118) to determine the erroneous GPS waypoints by identifying the GPS waypoints which lie outside the plotted circle.
The trajectory correction module (112) is configured to cooperate with the waypoint correction module (110) to smoothen out the trajectory by estimating correct GPS waypoints, and by replacing the erroneous GPS waypoints with the correct GPS waypoints.
In an embodiment, the trajectory correction module (112) is implemented using Kalman filter where Kalman filter can be extended to any variations of Kalman filter.
In another embodiment, the trajectory correction module (112) includes a corrector module (122) and a smoothening module (124). The corrector module (122) is configured to cooperate with the error detector (120) to determine the correct GPS waypoints, wherein the correct GPS waypoints lie on the plotted circle. The smoothening module (124) is configured to cooperate with the corrector module (122) to smoothen out the trajectory by replacing the erroneous GPS waypoints with the correct GPS waypoints.
The way point correction module (110) and the trajectory correction module (112) are implemented using one or more processors.
In an embodiment, the way point correction and estimation unit (104) can be installed in a user device.
In another embodiment, the way point correction and estimation unit (104) can be located remotely on a server.
The processors disclosed herein may be general-purpose processors, Field Programmable Gate Arrays (FPGAs), Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), and/or the like. The processors may be configured to retrieve data from and/or write data to a memory/repository. The memory/repository can be for example, a random access memory (RAM), a memory buffer, a hard drive, a database, an erasable programmable read only memory (EPROM), an electrically erasable programmable read only memory (EEPROM), a read only memory (ROM), a flash memory, a hard disk, a floppy disk, cloud storage, and/or so forth.
Figure 2 illustrates a flow diagram of a method (200) for correcting GPS trajectory of a moving vehicle, wherein the trajectory is made of GPS waypoints generated by a GPS device (108) disposed within the vehicle.
The method (200) includes the following steps:
• Step 202: sensing, by a sensing unit (102) installed in the moving vehicle, location, speed and acceleration of the moving vehicle;
• Step 204: generating, by the sensing unit (102) installed in the moving vehicle, a corresponding sensed data;
• Step 206: periodically collecting, by a data collection module (106) of a way point correction and estimation unit (104), the GPS waypoints and sensed data corresponding to the GPS waypoints;
• Step 208: identifying, by a waypoint correction module (110) of the way point correction and estimation unit (104), erroneous GPS waypoints from the received GPS waypoints based on the received sensed data; and
• Step 210: smoothening out, by a trajectory correction module (112) of the way point correction and estimation unit (104), the GPS trajectory by estimating correct GPS waypoints and by replacing the erroneous GPS waypoints with the correct GPS waypoints.
Figures 3a, 3b, 3c and 3d illustrate the original trajectories (raw data) generated by the GPS device (108) and modified/correct trajectories generated by the system (100). In the corrected trajectories, the erroneous GPS (or jumping GPS (JGPS)) are eliminated.
Figure 4 refers to the elimination of erroneous GPS waypoints and estimation of the correct GPS waypoints which helps in providing a clean trajectory that the user can follow while driving the vehicle. For example, as shown in the figure 4, the point is A is the nth GPS way point. The waypoint correction module (110) computes a radius indicative of distance that the vehicle is likely to travel after the (n-1)th GPS waypoint based on the received location, speed and acceleration data (i.e. sensed data). The waypoint correction module (110) then plots a circle of said computed radius around said (n-1)th GPS waypoint on said trajectory to determine whether the nth GPS waypoint is erroneous or not. For determining if a GPS waypoint is erroneous, the waypoint correction module (110) checks if it lies outside said plotted circle. The trajectory correction module (112) estimates the correct position of nth GPS waypoint, wherein said correct GPS waypoint lies on said plotted circle. The trajectory is smoothened out by replacing said erroneous GPS waypoint with said correct GPS waypoint. The trajectory correction module (112) corrects the point A to A’ to be at the most expected distance and in the most expected direction based on the last location. In an embodiment, the trajectory correction module (112) may smoothen the overall GPS trajectory by means of a Kalman filter, particularly an extended Kalman filter. The Kalman filter may filter the GPS waypoints considering the fact that the moving vehicle cannot experience acceleration beyond a certain physical limit. The filter may be tunable according to user requirements.
The filter can be configured to use the previous state (last location of the vehicle) to estimate probabilistically current position and velocity. In other words, it uses the previous state to predict the position of the next phase and assumes that the previous state is correct.
For example, if the trajectory has alternate waypoints about a line then the waypoint correction module (110) determines said erroneous GPS waypoints. For smoothening the trajectory, the trajectory correction module (112) considers parameters such as acceleration of the vehicle, acceleration of the vehicle at a previous instant, and the change in RPM of the vehicle. A smoothened trajectory as an output of the trajectory correction module (112) is shown in Figure 5.
In an operative embodiment, a vehicle is installed with a sensing unit (102) and a GPS device (108). A user driving the vehicle has a way point correction and estimation unit (104) installed in a user device associated with the user. The user is riding the vehicle based on a GPS trajectory generated by the GPS device (108). The sensing unit (102) receives the location, speed and acceleration of the moving vehicle and generates the sensed data. The way point correction and estimation unit (104) periodically collects the GPS waypoints and the corresponding to the sensed data. On receiving the GPS waypoints and the corresponding sensed data, the way point correction and estimation unit (104) identifies the erroneous GPS waypoints and smoothens out the trajectory by estimating correct GPS waypoints, and by replacing the erroneous GPS waypoints with the correct GPS waypoints. The smoothened out trajectory is now followed by the user to ride the vehicle as it is accurate than the earlier provided trajectory.
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of, a system for correcting GPS trajectory of a moving vehicle and a method thereof, which:
• eliminates and/or corrects jumping/erroneous GPS waypoints using machine learning and artificial intelligence based techniques;
• improves effective positional accuracy of the GPS waypoints; and
• smoothens out the GPS trajectory using Kalman filter and its variations.
The foregoing disclosure has been described with reference to the accompanying embodiments which do not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, or group of elements, but not the exclusion of any other element, or group of elements.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.
,CLAIMS:WE CLAIM,
1. A system (100) for correcting GPS trajectory of a moving vehicle, said trajectory being made of GPS waypoints generated by a GPS device (108) disposed within said vehicle, said system (100) comprising:
a sensing unit (102), installed in said moving vehicle, configured to sense location, speed and acceleration of said moving vehicle, and further configured to generate a corresponding sensed data; and
a way point correction and estimation unit (104) comprising:
a data collection module (106) configured to communicate with said GPS device (108) and said sensing unit (102) to periodically collect said GPS waypoints and sensed data corresponding to said GPS waypoints;
a waypoint correction module (110) configured to cooperate with said data collection module (106) to identify erroneous GPS waypoints from said received GPS waypoints based on said received sensed data; and
a trajectory correction module (112) configured to cooperate with said waypoint correction module (110) to smoothen out said trajectory by estimating correct GPS waypoints, and by replacing said erroneous GPS waypoints with said correct GPS waypoints,
wherein said way point correction module (110) and said trajectory correction module (112) are implemented using one or more processors.
2. The system (100) as claimed in claim 1, wherein said waypoint correction module (110) uses at least one of artificial intelligence, neural network, and machine learning techniques to identify erroneous GPS waypoints from said received GPS waypoints.
3. The system (100) as claimed in claim 1, wherein said trajectory correction module (112) is implemented using Kalman filter.
4. The system (100) as claimed in claim 1, wherein said data collection module (106) includes:
• a data retriever (114) configured to retrieve said GPS waypoints and said sensed data from said GPS device (108) and said sensing unit (102) respectively; and
• a timer (116) configured to cooperate with said data retriever (114) to measure a pre-determined time period after said retrieval of said GPS waypoints and said sensed data, and further configured to generate a trigger signal for retrieving said GPS waypoints and said sensed data after said completion of said pre-determined time period, thereby facilitating periodic collection of said GPS waypoints and said sensed data.
5. The system (100) as claimed in claim 1, wherein said waypoint correction module (110) includes:
• a computation unit (118) configured to compute a radius indicative of distance that said vehicle is likely to travel after each of said GPS waypoints based on said received sensed data, and further configured to plot a circle of said computed radius around said GPS waypoints on said trajectory; and
• an error detector (120) configured to cooperate with said computation unit (118) to determine said erroneous GPS waypoints by identifying said GPS waypoints which lie outside said plotted circle.
6. The system (100) as claimed in claim 5, wherein said trajectory correction module (112) includes:
• a corrector module (122) configured to cooperate with said error detector (120) to determine said correct GPS waypoints, wherein said correct GPS waypoints lie on said plotted circle; and
• a smoothening module (124) configured to cooperate with said corrector module (122) to smoothen out said trajectory by replacing said erroneous GPS waypoints with said correct GPS waypoints.
7. A method (200) for correcting GPS trajectory of a moving vehicle, said trajectory being made of GPS waypoints generated by a GPS device (108) disposed within said vehicle, said method (200) comprising:
• sensing (202), by a sensing unit (102) installed in said moving vehicle, location, speed and acceleration of said moving vehicle;
• generating (204), by said sensing unit (102), a corresponding sensed data;
• periodically collecting (206), by a data collection module (106) of a way point correction and estimation unit (104), said GPS waypoints and said sensed data corresponding to said GPS waypoints from said GPS device (108) and said sensing unit (102) respectively;
• identifying (208), by a waypoint correction module (110) of said way point correction and estimation unit (104), erroneous GPS waypoints from said received GPS waypoints based on said received sensed data; and
• smoothening out (210), by a trajectory correction module (112) of said way point correction and estimation unit (104), said trajectory by estimating correct GPS waypoints and by replacing (212) said erroneous GPS waypoints with said correct GPS waypoints.