Patent Publication Number: US-2021190939-A1

Title: System and method for facilitating position tracking

Description:
FIELD OF THE INVENTION 
     The invention relates to a method and a system for tracking position of an object, and more particularly relates to positioning and navigation control system based on directional signal scanning and measurement method. 
     BACKGROUND OF THE INVENTION 
     Various known navigation and positioning systems enable people in cars, boats, aircraft, and other moveable objects to efficiently travel between given locations. Knowing a precise current geographic location or starting location and a desired destination or ending location enables navigation systems to provide customized directions that indicate which direction that moveable object should travel to reach the destination or ending location. Various known navigation systems use path-planning algorithms that combine knowledge of conduits (such as streets, bridges, or traffic rules), obstacles (such as freeway congestion), and current real-time positioning information to determine and output detailed directions. 
     Various known navigation systems are enhanced through graphical user interfaces that visually depict the surroundings of a current position, identify points of interest, and provide a highlight of a path of travel to reach a destination. In one known example, vehicular navigation systems use the Global Positioning System (widely known as GPS). GPS is a space-based global navigation satellite system (GNSS) that provides reliable location and time information to anyone on or near the earth. 
     One known limitation of existing navigation systems that employ GPS is that they typically need an unobstructed line of sight to multiple (such as four or more) GPS satellites to receive and calculate a geographic position of an object. For this reason, GPS typically does not effectively operate in indoor areas or spaces such as in buildings or other covered structures. Thus, while GPS has become a valued system for outdoor navigation, GPS is generally not ideal for indoor navigation application. 
     Various existing indoor navigation systems use radio or sound waves to determine a current position of a moveable object within an indoor area. One known indoor navigation system determines a location using Received Signal Strength Indicator (“RSSI”) values of multiple Wi-Fi beacons (i.e., IEEE 802.11 access points or radios). This system is configured to use location fingerprinting, which stores samples of RSSI values of received Wi-Fi signals transmitted by a number of locations in a pre-mapped area. In this location fingerprinting system, a processor computes a current location of a moveable object by sampling the RSSI values and performing a look-up search from a database. 
     Another known indoor navigation system determines a location of a moveable object using triangulation of RSSI values of multiple Wi-Fi beacons. This system uses triangulation to compute expected signal strengths at a given location using signal propagation equations that estimate effects of known obstructions and multipath errors. 
     One known problem of using location fingerprinting or triangulation in indoor areas is that both of these methods are limited in accuracy to within a few meters, and tend to worsen with dynamic changes in signal obstructions resulting from human movement or physical obstructions, including for example, walls, shelves, signs, etc. Similar indoor positioning and navigating methods relying on Bluetooth signal or Near Field Communication (“NFC”) signals also experience the same challenges in indoor areas. 
     Since all of these navigation systems have various known issues or problems, the overall need for navigation systems remains an issue largely unaddressed by currently known commercially available navigation systems. Accordingly, a need exists for a new navigation system that does not rely on a satellite or unreliable characteristics of a signal such as signal strength. 
     SUMMARY OF THE INVENTION 
     Accordingly, example embodiments of the present disclosure are provided to substantially obviate one or more problems due to limitations and disadvantages of the related art. Various embodiments of the present disclosure solve the above problems by providing a precise and accurate limited area positioning system that utilizes the location of the beacons and the angle in which the positioning module is located relative to a set of beacons. 
     Generally, a limited area positioning system includes a positioning module, at least two beacons and a processor that is configured to determine the position of the positioning module based on the data gathered from the interaction between the positioning module and each one of the set of beacons. More specifically, the limited area positioning system utilizes a beacon signal emitted from each of the beacons, and may further utilize a module signal from the positioning module, which may be emitted in response to receiving a beacon signal. The coordinate of the positioning module can be identified based on the coordinates of the beacons and the angle of beacon signals emitted from those beacons, which are received at the positioning module. The beacon signal should be a signal that travels in substantially straight line. The limited area positioning system can determine the coordinate of the positioning module based on the coordinates of the beacons and the angle in which the beacon is aligned with the positioning module (i.e., the angle in which the beacon signals from those beacons reaching the positioning module). 
     One aspect of the present disclosure provides systems for self-positioning within a limited area. Example embodiments of the present disclosure, as limited area positioning system, provide systems for determining coordinate of a positioning module based on coordinates of at least two beacons and the angle in which the positioning module is positioned in relation to those beacons. 
     In one embodiment, the limited area positioning system comprises a plurality of beacons. Each of the beacons includes a module signal receiver and a beacon signal transmitter. The actuator is coupled to the beacon signal transmitter so that the angle in which the beacon signal emitted from the beacon signal transmitter can be adjusted. The positioning system is further provided with a positioning module. The positioning module includes a beacon signal receiver and a module signal transmitter. The module signal transmitter is configured to emit a module signal in response to receiving the beacon signal. The positioning system is further provided with a processor that is configured to identify the angle in which the positioning module is located in relation to the beacons. In this regard, the relative angle from the beacon can be determined by obtaining the degree of movement of the actuator. To scan the positioning module, the actuator of the beacon continues to adjust orientation of the beacon signal transmitter while the beacon signal transmitter emits the beacon signal, thereby adjusting the emissive angle of the beacon signal that travels substantially in a straight line. When the beacon signal is received by the beacon signal receiver of the positioning module, the module signal transmitter of the positioning module emits the module signal. The actuator&#39;s movement stops when the beacon&#39;s module signal receiver receives the module signal, and the degree of actuator&#39;s movement from the reference position until the receipt of the module signal would be indicative of the angle in which the positioning module is aligned from that beacon. Since the coordinate of each of the beacons are predefined, the coordinate of the positioning module can be identified when the angles from those beacons to the positioning module is determined. In some embodiments, the processor may be configured to identify the coordinate of the location where at least two beacon signals intersect each other as the coordinate of the positioning module. In some other embodiments, the processor may rely on additional beacon signals for verification or for increased accuracy in determining the location of the positioning module. For instance, the processor may be configured to determine the coordinate of the point where at least three beacon signals intersect each other as the coordinate of the positioning module. 
     The actuator may be implemented with a stepper motor, which is configured to rotate the beacon signal transmitter about the beacon as the axis of that rotation. While the beacon signal must be a signal that exhibit directionality, the module signal need not exhibit directionality. Accordingly, in some embodiments, said beacon signal is a laser based signal or an infrared based signal. In some embodiments, the module signal is a radio frequency based signal. The positioning system may be provided with a database, which stores a look-up table of coordinates that corresponds to a set of potential intersecting points of the beacon signals emitted from the beacons. The database may be provided in the positioning module itself. In some other embodiments, the database storing the look-up table of coordinates that corresponds to a set of potential intersecting points of the beacon signals is provided on a network server. In this case, each of the beacons is provided with a network module to communicate with the network server to provide beacon&#39;s unique identification information, unique identification information of the positioning module associated with the module signal received by the module signal receiver, and the angle of which the beacon signal travels from the respective beacon to the positioning module. 
     In another embodiment, the positioning system is provided with a plurality of beacons, and each beacon is provided with a plurality of beacon signal transmitters. Each of the beacon signal transmitters is configured to transmit a beacon signal in predefined angles about the respective beacon. In other words, each beacon may consists of N number of beacon signal transmitters, and each of the beacon signal transmitter may be configured to transmit the beacon signal in a range of 360/N degrees angle. Each of the beacon signal transmitters may be dedicated to emit the beacon signal in a predetermined limited range of angles. The range of angles covered by one of the beacon signal transmitters may not overlap with the range of angles covered by another one of the beacon signal transmitter of the same beacon. It is preferred that the plurality of beacon signal transmitters provided in a single beacon, collectively, covers the entire 360 degrees about the respective beacon. In this embodiment, the beacon signal may be designed such that it identifies where that beacon signal originates from (i.e., the identification of the beacon as well as the identification of the specific beacon signal transmitter within that beacon). Since each beacon signal transmitter emits the beacon signal only in a predetermined direction (i.e., angle), the identification of the beacon and the identification of the beacon signal transmitter obtained from the beacon signal can indicate the angle in which the beacon is positioned from the positioning module. The beacon&#39;s coordinate is already known, and with the emission angle of the beacon signal from that beacon towards the positioning module, the coordinate of the point where the beacon signals from at least two distinct beacons intersect each other (i.e., the coordinate of the positioning module) can be identified. Further, the positioning system can be configured to determine the coordinate of the point where more than two beacon signals intersect each other, for instance at least three beacon signals, as the coordinate of the positioning module. The intersecting point of the vector of the beacon signals is the location of the positioning module. A hash map of angles and coordinates of the corresponding intersecting point of the vectors of the beacon signals are pre-calculated and stored in a database (look-up table). Accordingly, the processor can identify the coordinate of the positioning module by querying a set of beacon signal transmitter identifications received by the positioning module. 
     In this embodiment, the beacon signal is structured such that it identifies the beacon as well as the beacon signal transmitter where that beacon signal is originated from. The coordinate of the beacon is known, and the identification of the beacon signal transmitter gives away the vector (i.e., emission angle) of the beacon signal emitted from that beacon. In other words, the beacon signal already incorporates the information regarding the angle in which the beacon is positioned relative to the positioning module or the angle in which the positioning module is positioned relative to the beacon associated with that beacon signal. Accordingly, the positioning module does not need to transmit a module signal back to the beacons for determining the angle. Moreover, the beacons do not need to wait for the module signal or actively engage in calculating a coordinate of a positioning module. The beacons only need to transmit the beacon signals, and the coordinate calculation is handled by either the positioning module itself or by a remote server based on the beacon signal information collected by the positioning module. This allows for faster scanning of the positioning module while reducing process power consumption. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a functional schematic diagram of a positioning system of one example embodiment of the present disclosure. 
         FIG. 2A  is a functional schematic diagram of a positioning system of one example embodiment using beacons coupled to an actuator. 
         FIG. 2B  is a flowchart illustrating a method of determining the position of the positioning module according to the embodiments described in  FIG. 2A . 
         FIG. 3A  is a functional schematic diagram of a positioning system of one example embodiment using beacons with a plurality of beacon signal transmitters provided therein. 
         FIG. 3B  is a flowchart illustrating a method of determining the position of the positioning module according to the embodiments described in  FIG. 3A . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Hereinafter, the present invention will be described in more detail with reference to the following Examples. However, these Examples are set forth to illustrate the present invention, and the scope of the present invention is not limited thereto. 
     Turning now to the drawing,  FIG. 1  shows a functional schematic diagram of one embodiment of a positioning system  100  of the present disclosure that accurately and precisely determines a current location of a movable object OBJ. The limited area can be any suitable indoor area such as, but not limited to, a retail or wholesale store (such as a grocery store), a megastore, a shopping mall, a museum, a school, a hospital, an office building, a residential building, an indoor amusement park, and a storage warehouse. In addition, the limited area may also be certain partially enclosed or restricted outdoor areas (e.g., urban canyons, college campuses, railway stations, etc.), which certain mobile devices may have difficulties in reliably receiving or acquiring sufficient satellite or cellular wireless signals to facilitate or support one or more conventional satellite signal dependent position estimation techniques. Being in a near enclosed space, such as a steep sided valley or a high rise urban environment, reduces the area of sky visible to the GPS receiver. In such situations, the number of satellites that are in direct line of site of the receiver is reduced. Also, receiving GPS signals from a disperse set of satellites is prevented. That is, the satellites used to calculate your location are clustered within a small area of the sky. Highly clustered satellites can result in large positional errors, even up to several hundred meters. Unlike the conventional satellite based GPS, the limited area positioning system  100  described in the present disclosure offers millimeter scale accuracy in near closed environment or even indoors. 
     For instance, in a shopping mall or grocery store environment, the positioning system  100  can provide assistance to customers in locating their desired items within the store. In this embodiment, the movable object OBJ could be a cart that can move around within the store or a device that is carried by a user. The movable object OBJ can be equipped with a means to display to a user the location where the supplies are stocked and help users to navigate toward the designation. The positioning system  100  can also show a navigation route or turn-by-turn directions to areas of the shopping mall or the grocery store where the desired items are located. The positioning system  100  can also track when the user puts the desired items from the shelf to the cart at a location and update the navigation route or directions within the limited area (e.g., shopping mall or grocery store). For instance, the positioning system  100  may be configured to scan the RFID of the item when the movable object OBJ (e.g., cart) reaches the shelf where the item is at. 
     In another embodiment, the positioning system  100  could be used to guide users through a museum. In this embodiment, the positioning system  100  displays a navigation route or turn-by-turn directions to different exhibits in a museum. The positioning system  100  can also enable a user to search for a particular exhibit and display a navigation route or directions to reach the exhibit. The positioning system  100  can also display more information about the exhibit when it detects the user is in proximity to an exhibit. 
     The application of the positioning system  100  is not just limited to indoor environment, but could be used in outdoor areas. For instance, the positioning system  100  of the present disclosure can be used for street vehicle navigation in urban areas so long as beacons can be placed in that area or region. Of course, the movable object OBJ is not limited to a vacuum robot, but may also be lawnmower, air purifier or any other machine, which features automatic maneuvering ability within a scanning area. 
     In the illustrated exemplary embodiments, the positioning system  100  includes a set of beacons  102 A- 102 D, a positioning module  104 , and a processor  106 . The positioning module  104  is configured to communicate with the set of beacons  102 A- 102 D and identify its position in relation to the position of the set of beacons. The positioning module  104  may be coupled to the movable object OBJ, or in some embodiments, the positioning module  104  may be a part of the movable object OBJ. Accordingly, the position of the positioning module  104  changes as the movable object OBJ moves within the scanning area. Each of the beacons is configured to scan and detect the positioning module  104  that is within certain perimeter in the surrounding area of the respective beacon. The processor  106  is configured to communicate with the positioning module  104  and the beacons  102 A- 102 D, and processes the data retrieved at the positioning module  104  and the beacons  102 A- 102 D to provide the position of the positioning module  104  in relation to the beacons  102 A- 102 D. There are only four beacons  102 A- 102 D are depicted in the examples disclosed herein for convenience of explanation. However, it should be noted that additional beacons can be placed as needed to cover a larger area and to increase the positioning accuracy. 
     The positioning system  100  of the present disclosure requires the positioning module  104  to receive beacon signals from at least two beacons BC to determine the position of the positioning module  104 . In a sense, the area covered by at least two beacon&#39;s scanning range defines a block within the targeted area, where the coordinate of the positioning module  104  can be identified. If one of the beacons is positioned too far away from the positioning module  104  and cannot communicate with the positioning module  104 , then the positioning system  100  would not be able to determine the position of the positioning module  104  in that area. Accordingly, the beacons  102 A- 102 D should be positioned around the limited area to maximize the area covered by at least two beacons  102 , and at the same time, minimize the area where the positioning module cannot receive the beacon signal from at least two beacons. In this disclosure, the area where the positioning module  104  cannot communicate with at least two distinct beacons is referred to as the dead spot. 
     The positioning of the beacons  102 A- 102 D may vary based on the type of signals used by the positioning module  104  in communicating with the beacons  102 A- 102 D. As will be described in further detail, the positioning system  100  relies on the angle in which the positioning module  104  is located from the beacon (or the angle in which the beacon is positioned from the positioning module  104 , vice-versa). Accordingly, the beacon signal  108  should be a type of signal that travels in substantially straight line manner. A direct line of sight may be necessary for the beacon signals  108  between the beacons  102 A- 102 D and the positioning module  104 . In this case, the scanning area where the positioning module  104  can determine its position may be limited to the area that provides clear line of sight from the positioning module  104  to at least two of the beacons. In some embodiments, the beacon signal  108  can travel through a wall or other type of obstruction so the beacons BC can identify the angle in which the positioning module  104  is arranged from the beacon  102  even when a direct line of sight is not provided between the beacons  102  and the positioning module  104 . 
     The beacons  102 A- 102 D may be configured to emit the beacon signal  108  constantly, periodically or on an occurrence of a predefined triggering event. For instance, the beacons  102 A- 102 D may be configured to provide the beacon signal  108  continuously during the operation, in every 10 seconds, every 10 meters of movement by the movable object OBJ or when a sensor that monitors the movable object OBJ measures changes to or in the movable object OBJ (e.g., physical impact is sensed by the movable object OBJ). 
     As will be described in further detail below, the positioning system  100  is configured to determine the angle AG in which the positioning module  104  is positioned in relation to the beacons  102 . The coordinates of the beacons  102  are defined by their placement in the designated area. With a coordinate of a beacon  102  and the detected angle AG of the path of the beacon signal  108  from that beacon  102  towards the positioning module  104 , the coordinates of the points on the path of a given beacon signal  108  can be identified. The positioning module  104  would be on the path of that beacon signal  108 . In other words, the coordinate of the positioning module  104  would be the coordinate of one of the points among the set of points on the path of the beacon signal  108 . The coordinates for the set of points on the path of a given beacon signal  108  to the positioning module  104  can be calculated on-the-fly or may be looked-up from a database storing pre-calculated coordinates for the set of points on the path of that beacon signal  108 . The positioning module  104  may be on the path of another beacon signal  108  emitted from another beacon  102 . The beacon signals  108  from this second beacon BC will intersect with the first beacon signal  108  at the positioning module  104 . Accordingly, the coordinate of the intersecting point of the beacon signals  108  will be coordinate of the positioning module  104 . In other words, there will be a point with the identical coordinate among the coordinates for the points on the path of the first beacon signal  108 A and the coordinates for the points on the path of the second beacon signal  108 B, and this point with the identical coordinate is the coordinate of the positioning module  104 . 
     Identifying the coordinate of the points on the path of a given beacon signal  108  can be calculated by the processor  106 . In embodiments of the positioning system  100  where the coordinates of the points on the path of a given beacon signal  108  is pre-stored in a database, the processor  106  may be configured to search the database for the coordinate of the intersecting point of multiple beacon signals  108 . As shown in  FIG. 1 , the processor  106  may be a standalone processing system that is provided on a separate network server, which is configured to communicate with the positioning module  104 , the set of beacons  102 A- 102 D or with both positioning module  104  and the beacons  102 A- 102 D via various networking means, such as the Internet. In some embodiments, the processor  106  may be integrated with the positioning module  104  or may be integrated with one or more beacons  102 A- 102 D. In other words, the processor  106  is not limited to a single central processing system, but may be provided in some or all of the elements implementing the limited area positioning system  100 . 
       FIG. 2A  is a schematic diagram of an exemplary embodiment of a positioning system  200 , and  FIG. 2B  is a flowchart describing an exemplary operation of the positioning system  200 . As shown in  FIG. 2A , each of the beacons  202 A- 202 B includes a beacon signal transmitter BST and a module signal receiver MSR. The beacons  202 A- 202 B are configured to emit beacon signals  208 A- 208 B, respectively, that is implemented with a type of signal that exhibits directionality (i.e., travels in a specified direction), such as infrared based signal, laser base signal or radio frequency based vertical fan beam signal. In some other embodiments, the beacon signal transmitter BST may be a combination of signal transmitters that emits a first type of beacon signal such as an infrared based signal and a second type of beacon signal such radio frequency based signal. 
     In this embodiment, each of the beacons  202 A- 202 B is provided with an actuator ACT. The actuator ACT is coupled to the beacon signal transmitter BST so that the angle in which the beacon signals  208 A- 208 B emitted from the beacon signal transmitter BST can be adjusted. For instance, the actuator ACT may be implemented with a stepper motor with a predetermined number of steps in a single revolution. For instance, a stepper motor with 51,200 steps per revolution can be used. In this case, each step represents 0.007 degrees of accuracy. 
     To scan the positioning module  204 , the actuator ACT of the beacon  202  continues to adjust orientation of the beacon signal transmitter BST while the beacon signal transmitter BST emits the beacon signal BS, thereby adjusting the emissive angle of the beacon signal  208 A- 208 B that travels substantially in a straight line. 
     The positioning module  204  is provided with a beacon signal receiver BSR and a module signal transmitter MST. The beacon signal receiver BSR, as its name implies, is configured to receive the beacon signals  208 A- 208 B emitted from the beacons  202 A- 202 B. The beacon signal  208  from the beacons  202  is implemented with a type of signal that exhibits directionality (i.e., travels in a specified direction), such as infrared based signal, laser base signal or radio frequency based vertical fan beam signal. Accordingly, the beacon signal receiver BSR can be infrared signal receiver, laser signal receiver or a radio frequency signal receiver. In some embodiments of the positioning system, each beacon is configured to emit two different kinds of beacon signals, for instance, as infrared signal and radio frequency based vertical fan beam signal. In such embodiments, the beacon signal receiver BSR may include a plurality of signal receivers compatible with the different kinds of signals emitted from the beacons. 
     The module signal transmitter MST may be a transmitter that transmits a signal that radiates without a specific directionality, for instance, a radio frequency signal transmitter. The positioning module  204  is configured to emit a module signal MS upon receiving a beacon signal  208  from any one of the beacons  202 A- 202 B. For purposes of explanation, the positioning module  204  is configured to emit a module signal MS when it receives the beacon signal  208 A emitted from the beacon  202 A. Simply put, a beacon signal  208  activates the positioning module  204  to emit the module signal MS. That is, the positioning module  204  is configured to emit one or more types of module signal MS upon receiving a beacon signal  208  from any one of the beacons  202 A- 202 B. 
     When the beacon signal  208  is received by the beacon signal receiver BSR of the positioning module  204 , the module signal transmitter MST of the positioning module  204  emits the module signal MS. The beacons  202 A- 202 B are configured to stop the actuator&#39;s movement when the beacon&#39;s module signal receiver MSR receives the module signal MS, and the degree of actuator&#39;s movement from the reference position RP until the receipt of the module signal MS would be indicative of the angle AG in which the positioning module  204  is aligned from that beacon  202 . 
     The coordinate of each of the beacons  202 A- 202 B are predefined upon their placement. In conjunction with the angle of the path of beacon signal  208  from the beacon  202  towards the positioning module  204 , the coordinates of a set of points along that path of the beacon signal  208  from the respective beacon  202  can be identified. To the extent that the positioning module  204  is within reach of at least two beacons  202 , the beacon signals from those two beacons  202  will intersect at the point where the positioning module  204  is located. 
     Referring to  FIGS. 2A and 2B , in step S 20 , the beacons  202 A- 202 B start to scan for a positioning module  204  by transmitting the beacon signal  208 A- 208 B, respectively. Herein, the actuator ACT provided in each of the beacons  202 A- 202 B rotates the beacon signal transmitter BST of the beacons  202 A- 202 B, thereby scanning the area for the positioning module  204 . 
     In step S 22 , the positioning module transmits the module signal back to the beacon  202  in response to receiving the beacon signal  208 . For instance, the positioning module  204  emits the module signal MS in response to receiving the beacon signal  208 A from the beacon signal transmitter BST of the first beacon  202 A. In this instance, the module signal MS may be structured so that it is only acceptable by the module signal receiver MSR of the first beacon  202 A. 
     In step S 24 , the first beacon  202 A determines the transmission angle of the beacon signal by calculating the degree of actuator&#39;s rotation from the reference point RP upon receiving the module signal MS from the positioning module  204 . Then, the first beacon  202 A forwards to the processor  206 , the beacon&#39;s identification as well as the information about the determined transmission angle of the beacon signal  208 A from the first beacon  202 A. 
     The steps S 20  through S 24  are repeated until beacon signals from at least two distinct beacons are received by the positioning module  204 . Accordingly, the positioning module  204  emits the module signal MS again in response to receiving the beacon signal  208 B from the beacon transmitter BST of the second beacon  202 B. In this instance, the module signal MS may be structured so that it is only acceptable by the module signal receiver MSR of the second beacon  202 B. Then, the second beacon  202 B forwards to the processor  206 , the beacon&#39;s identification as well as the information about the determined transmission angle of the beacon signal  208 B from the first beacon  202 B. 
     In step  26 , the processor  206  determines the coordinate of the intersecting point of the beacon signals&#39; path when necessary information is received from at least two distinct beacons. More specifically, the first beacon signal  208 A from the first beacon  202 A travels towards the positioning module  204  in the first angle AG 1 , and the second beacon signal  208 B from the second beacon  202 B travels towards the positioning module  204  in the second angle AG 2 . The path of the first beacon signal  208 A and the second beacon signal  208 B is denoted as P 1  and P 2 , respectively. The set of coordinates for the points along the path P 1  of the beacon signal  208 A may be calculated by the processor  206 . Likewise, the set of coordinates for the points along the path P 2  of the beacon signal  208 B may be calculated by the processor  206 . In some embodiments, the set of coordinates for the possible points along the possible paths of the beacon signal from each of the beacons may be pre-calculated and stored in a look-up table for simple retrieval with the beacon&#39;s identification and the beacon signal&#39;s angle identified upon the receipt of the module signal MS from the positioning module  204 . The beacon signal  208 A from the beacon  202 A along the path P 1  and the beacon signal  208 B form the beacon  202 B along the path P 2  intersect each other at the positioning module  204 . Accordingly, the processor  206  is configured to identify a coordinate that is present in both the set of coordinates for the points along the path P 1  as well as the set of coordinates for the points along the path P 2 , which will be the coordinate of the positioning module  204 . 
     Although not depicted in  FIG. 2A , there may be another beacon that is in direct line of sight with the positioning module  204 , and the processor  206  can be configured to search for a coordinate that is present in the set of coordinates for the points along more than two different beacon signal paths (e.g., intersecting point of at least three beacon signals). 
     It should be noted that the processor  206  may be integrated in the positioning module  204 . In this case, the beacons  202 A- 202 B need to provide the angle of the actuator ACT back to the positioning module  204  after the receipt of the module signal MS, and the processor  206  in the positioning module  204  identifies its coordinate from the beacon&#39;s identification information and the associated angle information received from at least two beacons. 
     In some other embodiments, the beacon signals  208  in the scanning stage of the positioning module  204  may be structured such that the beacon signals  208  incorporates information indicative of the actuator&#39;s current degree of movement from the reference position RP. That is, the beacon signal  208  may be constantly updated in accordance with the actuator&#39;s current position indicative of the beacon signals&#39; transmission angle AG while scanning for the positioning module  204 . In this embodiment, it is not necessary for the module signal MS to be provided from the positioning module  204  back to the beacons  202 A- 202 B to stop the actuator ACT nor obtain the angle information via another signals sent by the beacons  202 . 
     The positioning module  204  may be provided with the database DB storing the look-up table of the coordinates that are representative of the possible intersecting points of the beacon signals  208 . Alternatively, the positioning module  204  may be provided with a network module to communicate with a network server that includes a database with the look-up table of the coordinates representative of the possible intersecting points of the beacon signals  208  using one or more wireless communication network. The wireless communication network may include, for example, second generation mobile communication networks such as Global System for Mobile communication (GSM), Code Division Multiple Access (CDMA), etc., a mobile internet such as Bluetooth, Wireless Fidelity (Wi-Fi), third generation mobile communication networks such as Wideband Code Division Multiple Access (WCDMA), CDMA2000, etc., fourth generation mobile communication networks such as Long Term Evolution (LTE), LTE-Advanced, and 5th generation mobile communication networks. 
       FIG. 3A  is a schematic diagram of an exemplary embodiment of a positioning system  300 , and  FIG. 3B  is a flowchart describing an exemplary operation of the positioning system  300 . In this embodiment, the positioning system  300  is provided with a plurality of beacons  302 A- 302 B placed around the targeted area to scan for the positioning module  304 . Each of the beacons  302 A- 302 B is provided with a plurality of beacon signal transmitters BST. Each beacon signal transmitter BST is arranged to transmit the beacon signal  308  in a non-overlapping predetermined range of degrees. In other words, there can be provided N number of beacons signal transmitters BST in each of the beacons  302 A- 302 B, and each one of the beacon signal transmitters BST are configured to emit the beacon signal in a range of N/360 degrees. 
     Preferably, each of the beacon signal transmitters BST of a beacon  302  is configured cover less than 1 degree interval. In some embodiments, however, each beacon  302  may be provided with less than 360 beacon signal transmitters BST to reduce the cost and/or to reduce power consumption of the beacon  302 . Of course, additional number of beacon signal transmitters BST may be provided to reduce intervals between the angles covered by each of the beacon signal transmitters BST, thereby reducing the spots that are not scanned by the beacon signals  308 . 
     Each of the beacons  302 A- 302 B is provided with an identification code. Each of the beacon signal transmitters BST of the beacon  302  is also provided with an identification code. Accordingly, the beacon signal  308  can be configured to incorporate the beacon&#39;s identification code and/or the beacon signal transmitter&#39;s identification code. In this embodiment, the transmission angle from the beacon signal transmitter is predefined, and thus the beacon signal transmitter&#39;s identification code serves as the data that is indicative of the angle in which the beacon  302  is positioned relative to the positioning module  304 . In other words, each beacon transmitter&#39;s identification may be associated with a set of coordinates corresponding to a set of points covered by the beacon signal  308  from that particular beacon signal transmitter BST. Rather than indicating the beacon transmitter&#39;s identification information in the beacon signal, in some embodiments, the beacon signal  308  may be structured to indicate the beacon signal&#39;s transmission angle from the respective beacon  302 . 
     The beacon signal  308  may incorporate the information indicative of the beacon&#39;s identification and the beacon signal transmitter&#39;s identification. Alternatively, the beacon signal  308  may incorporate the information indicative of the beacon&#39;s identification and the transmission angle of the beacon signal from the beacon  302 . It should be noted that each beacon  302  is assigned with a predetermined coordinate, and therefore, each of the beacon&#39;s identification is associated with a unique coordinate. 
     The positioning module  304  includes a beacon signal receiver BSR to receive the beacon signals  308 A- 308 B from the beacons  302 A- 302 B. As described above, the beacon signal  308  is unique to a specific beacon signal transmitter BST, which is configured to emit the beacon signal  308  in a predefined range of angles. Accordingly, the beacon signal  308  can be structured to identify the beacon  302  and the beacon signal transmitter BST which the beacon signal  308  is emitted from. A path of the beacon signal  308  from the respective beacon  302  can be determined with the beacon&#39;s coordinate in conjunction with the transmission angle AG of the beacon signal  308  from that beacon  302 . The positioning module  304  may be configured to communicate with the processor  306  for identifying the coordinate of the positioning module  304  based on the information retrieved from the beacon signals  308  collected by the positioning module  304 . 
     As described above, the coordinates of the points along the path of a beacon signal  308  may be predetermined and stored in a look-up table. When the positioning module  304  receives beacon signals from at least two different beacons  302 A- 302 B, the positioning module  304  can be configured to engage the processor  306  to search for a common point that is present in the path of both of those beacon signals  308 A- 308 B. The common point that is present among the set of points along the paths of those beacon signals is the intersecting point of those beacon signals  308 A- 308 B, and this point can be determined as the location of the positioning module  304 . 
     In some embodiments, the processor  306  may be integrated within the positioning module  304  or otherwise provided within the movable object. The database DB storing the look-up tables for the coordinates of the points along each potential path of the beacon signals  308  from a beacon signal transmitter BST may be provided within the memory of the positioning module, or alternatively, provided in a network server that is accessible by the positioning module via a wireless network. 
     Referring to  FIG. 3A  and  FIG. 3B , the operation of the positioning system  300  is described. In step S 30 , beacons  302 A- 302 B formulates the beacon signals  308  so that each beacon signal  308  comprises the information regarding identification of the beacon  302  and the identification of the beacon signal transmitter BST. In some other embodiments, the information regarding the beacon signal&#39;s transmission angle may be incorporated in the beacon signal  308 . In the example depicted in  FIG. 3A , the beacon signal  308 A from the beacon signal transmitter BST 1  of the beacon  302 A is structured so that the signal is indicative of the identification of the beacon  302 A and the identification of the beacon signal transmitter BST 1 . Likewise, the beacon signal  308 B is structured so that it comprises information on the identification of the beacon  302 B and the identification of the beacon signal transmitter BST 4  of that beacon  302 B. Other beacon signals  308  emitted from their respective beacon signal transmitters BST are structured to incorporate information regarding the respective beacon  302  and the beacon signal transmitter BST. 
     As mentioned, the degree in which the beacon signal  308  can be emitted from each individual beacon signal transmitter BST of a beacon  302  is predefined. Therefore, the information on the identification of the beacon  302  and the beacon signal transmitter BST can be easily translated into the transmission angle of the beacon signal  308  associated with such identification information. In some embodiments, however, the beacon signal  308  can be structured in such a way that it provides the raw information, such as the beacon&#39;s coordinate and the transmission angle of the beacon signal  308  from that beacon  302  when using the positioning system  300  in a time critical applications (e.g., navigation for automobile). 
     In step S 32 , the beacons  302 A- 302 B scan the area for the positioning module  304  by radiating the beacon signal  308  from their beacon signal transmitters BST. Here, the beacons  302 A- 302 B may be configured to radiate the beacon signals  308  from constantly during the operation or in predetermined periodic intervals. The scanning operation of this step S 32  is repeated until the positioning module  304  receives at least two beacon signals  308  at its beacon signal receiver BSR. 
     When the positioning module  304  obtains at least two beacon signals  308 A- 308 B, the positioning module  304  activates the processor  306  to determine the coordinate of the positioning module  304  in step S 34 . 
     In this embodiment, the beacon signal may be designed such that it identifies where that beacon signal originates from (i.e., the identification of the beacon as well as the identification of the specific beacon signal transmitter within that beacon). Since each beacon signal transmitter emits the beacon signal only in a predetermined direction (i.e., angle), the identification of the beacon and the identification of the beacon signal transmitter obtained from the beacon signal can indicate the angle in which the beacon is positioned from the positioning module. The beacon&#39;s coordinate is already known, and with the emission angle of the beacon signal from that beacon towards the positioning module, the coordinate of the point where the beacon signals from at least two distinct beacons intersect each other (i.e., the coordinate of the positioning module) can be identified. 
     The processor  306  determines the coordinate of the intersecting point of the beacon signals&#39; path when necessary information is received from the beacons  302 A- 302 B. More specifically, the first beacon signal  308 A from the first beacon  302 A travels towards the positioning module  304  along the path P 1 , and the second beacon signal  308 B from the second beacon  302 B travels towards the positioning module  304  along the path P 2 . 
     In performing the step S 34 , the processor  306  may calculate a set of coordinates for the points along the path P 1  of the beacon signal  308 A. Likewise, the set of coordinates for the points along the path P 2  of the beacon signal  308 B may be calculated by the processor  306 . In some embodiments, the set of coordinates for the possible points along the possible paths of the beacon signal from each of the beacon signal transmitters BST of the beacons  302  may be pre-calculated and stored in a look-up table for simple retrieval from the database DB by querying the beacon&#39;s identification and the beacon signal transmitter&#39;s identification. The positioning module  304  may be equipped with a network module, which allows the positioning module  304  to provide information collected from the beacon signals  308 A and  308 B to the network server where the processor  306  and the database DB is provide. 
     The positioning module  304  received the beacon signal  308 A from the beacon  302 A along the path P 1  and the beacon signal  308 B form the beacon  302 B along the path P 2 , which means they intersect each other at the location where the positioning module  304  is. Accordingly, the processor  306  may identify the coordinate of the common point along the path P 1  and the path P 2 , which will be the coordinate of the positioning module  304 . 
     For increased accuracy, the positioning system  300  can be configured to determine the coordinate of the point where more than two beacon signals intersect each other, for instance three or more beacon signals, as the coordinate of the positioning module  304 . The intersecting point of the vector of the beacon signals  308  is the location of the positioning module. A hash map of angles and coordinates of the corresponding intersecting point of the vectors of the beacon signals  308  can be pre-calculated and stored in a database DB (look-up table). Accordingly, the processor  306  can identify the coordinate of the positioning module  304  by querying a set of beacon signal transmitter identifications received by the positioning module. 
     In some of the embodiments described in  FIG. 3A-3B , the beacon signal  308  is structured such that it identifies the beacon  302  as well as the specific beacon signal transmitter BST that emitted the beacon signal  308 . The coordinates of the beacons  302 A- 302 B are known, and the identification of the beacon signal transmitter BST 1  of the beacon  302 A and BST 4  of the beacon  302 B provides the vector (i.e., transmission angle) of the beacon signals  308 A- 308 B emitted from the respective beacons  302 A- 302 B. In other words, the beacon signal  308 A- 308 B already incorporates the information regarding the angle in which the beacons  302 A- 302 B are positioned relative to the positioning module  304  (in other words, the angle in which the positioning module  304  is positioned relative to the beacons  302 A- 302 B associated with those beacon signals  308 A- 308 B. Here, the positioning module  304  does not need to transmit a module signal back to the beacons  302 A- 302 B for determining the transmission angle of the beacon signals  308 A- 308 B. Moreover, the beacons  302 A- 302 B do not need to wait for the module signal or actively engage in the calculation of a coordinate of a positioning module  304 . Instead, the beacons  302 A- 302 B only need to transmit the beacon signals  308  from the beacon signal transmitters BST provided therein, and the coordinate calculation is handled by either the positioning module  304  itself of by a remote server based on the information incorporated in the beacon signals  308  collected by the positioning module  304 . This allows for faster scanning of the positioning module while reducing process power consumption. 
     In some embodiments, each beacon signal transmitter BST may be coupled to an actuator for adjusting the transmission angle TA of the beacon signal  308  from each of the beacon signal transmitter BST. For instance, the actuator may be implemented with a stepper motor with 51,200 steps per revolution can be used to rotate the beacon. In this case, each step represents 0.007 degrees of accuracy. In this way, the entire 360 degrees around each beacon  302  can be scanned with less number of beacon signal transmitters BST. For instance, a beacon signal transmitter BST 4  may be configured to emit the beacon signal 60 degrees from the reference point RP. The beacon signal transmitter may be coupled to an actuator that swings the orientation of the beacon signal transmitter ±5 degrees. In this example, the beacon signal transmitter BST 4  can cover 55 degrees to 65 degrees from the reference point RP. If the beacon signal transmitter&#39;s orientation has changed −3 degrees, then this must be compensated when determining the angle in which the beacon  302 B is positioned in relation to the positioning module  304 . The amount of swing by the actuator can be considered when incorporating the angle information within the beacon signal  308 B. The beacon signal  308 B may incorporate the information indicative of the beacon&#39;s identification, the beacon signal transmitter&#39;s identification as well as the compensation amount (e.g., −3 degrees). Alternatively, the beacon signal  308 B may incorporate the information indicative of the beacon&#39;s identification and the adjusted angle of the beacon signal  308 B from the beacon  302 B. 
     In some embodiments, the beacon itself may be configured to rotate so that the entire 360 degrees around the beacon can be scanned with the beacon signals from the beacon signal transmitters provided therein. For instance, the beacon may be coupled to a stepper motor. By way of example, a stepper motor with 51,200 steps per revolution can be used to rotate the beacon. In this case, each step represents 0.007 degrees of accuracy. In this case, the amount of beacon&#39;s rotation should be considered in determining the angle in which the beacon is positioned in relation to the positioning module. In this example, not the individual beacon signal transmitter BST, but the beacon  302  itself may be coupled to an actuator. In this case, the amount of rotation RT of the beacon  302 A should be considered when structuring the beacon signal  308 A from each of the beacon signal transmitters BST from that beacon  302 A. Similar to the previous example, the beacon signal  308 A may incorporate the information indicative of the beacon signal transmitter&#39;s identification as well as the information regarding the amount of beacon&#39;s rotation RT from the reference position RP. 
     Foregoing instructions and the various data described herein for various applications may be stored in files and transmitted using a variety of computer-readable media. A file in a computing device is generally a collection of data stored on a computer readable medium, such as a storage medium, a random access memory and the likes. 
     A computer-readable medium includes any medium that participates in providing data (e.g., instructions), which may be read by a computer. Such a medium may take many forms, including, but not limited to, non-volatile media, volatile media, etc. Non-volatile media include, for example, optical or magnetic disks and other persistent memory. Volatile media include dynamic random access memory (DRAM), which typically constitutes a main memory. Common forms of computer-readable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, any other magnetic medium, a CD-ROM, DVD, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, a RAM, a PROM, an EPROM, a FLASH-EEPROM, any other memory chip or cartridge, or any other medium from which a computer can read. 
     All terms used in the claims are intended to be given their plain and ordinary meanings as understood by those skilled in the art unless an explicit indication to the contrary in made herein. In particular, use of the singular articles such as “a,” “the,” “said,” etc. should be read to recite one or more of the indicated elements unless a claim recites an explicit limitation to the contrary. 
     The term “exemplary” is used herein in the sense of signifying an example, e.g., a reference to an “exemplary widget” should be read as simply referring to an example of a widget. 
     The adverb “approximately” modifying a value or result means that a shape, structure, measurement, value, determination, calculation, etc. may deviate from an exact described geometry, distance, measurement, value, determination, calculation, etc., because of imperfections in materials, machining, manufacturing, sensor measurements, computations, processing time, communications time, etc. 
     In the drawings, the same reference numbers indicate the same elements. Further, some or all of these elements could be changed. With regard to the media, processes, systems, methods, etc. described herein, it should be understood that, although the steps of such processes, etc. have been described as occurring according to a certain ordered sequence, such processes could be practiced with the described steps performed in an order other than the order described herein. It further should be understood that certain steps could be performed simultaneously, that other steps could be added, or that certain steps described herein could be omitted. In other words, the descriptions of processes herein are provided for the purpose of illustrating certain embodiments, and should in no way be construed so as to limit the claimed invention.