Abstract:
A GNSS-based, bidirectional mobile communication system includes a mobile unit, such as a vehicle or a personal mobile system, with GNSS (e.g., GPS) and Internet (worldwide web) access. A base station also has GNSS and Internet access, and provides differential (e.g., DGPS) correctors to the mobile unit via the Internet. The Internet communications link enables audio and/or video (AV) clips to be recorded and played back by the mobile unit based on its GNSS location. The playback function can be triggered by the mobile unit detecting a predetermined GNSS location associated with a particular clip, which can be GNSS position-stamped when recorded. Alternatively, clips can be generated by utilities and loaded by the application either from a personal computer or automatically over the Internet. Moreover, maps, vehicle travel paths and images associated with particular GNSS-defined locations, such as waypoints, can be updated and position-stamped on the data server. A GNSS-based mobile communication method and a storage medium encoded with a machine-readable code for mobile communications are also provided.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority in U.S. Provisional Patent Application No. 61/043,224, filed Apr. 8, 2008, which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates generally to the implementation of wireless communications for disseminating GNSS-based differential correctors and other position-locating information to mobile units, such as vehicles and personal navigation devices, and for receiving positional, operational and status information for real-time display, all via the Internet (worldwide web). 
         [0004]    2. Description of the Related Art 
         [0005]    Global Navigation Satellite System (GNSS) technology has become increasingly important in navigation, guidance and machine control applications in such varied fields as agriculture, transportation, mining and logistics. The widespread availability of differential correctors from various sources has improved accuracy to sub-centimeter levels using sophisticated differential correction techniques, such as real-time kinematic (RTK). Such finer accuracy and other performance enhancements tend to increase the applicability of differential global positioning systems (DGPS) to various operations and its usefulness on various types of mobile and stationary equipment. DGPS differential corrector distribution has been accomplished by 300 KHz beacon systems, FM transmitters and proprietary radio and satellite links. However, privately-sponsored, proprietary DGPS correction services have ongoing subscription fees. Other differential correction techniques have limited useful ranges and availability. 
         [0006]    RTK correction utilizes carrier phase correction signals from fixed and known base station locations for processing by mobile or rover vehicles equipped with RTK-enabled GNSS receivers. Using RTK, vehicles can be automatically guided along predetermined guide paths to within less than a centimeter of course-variance, i.e. sub-centimeter accuracy navigation. Such higher-accuracy systems are in demand for precision agriculture and other operations. 
         [0007]    Like GNSS, the Internet (worldwide web) has enabled a wide range of applications of increasing sophistication and technical capability. For example, digital telephone networks can interface with the Internet and enable the dissemination of GNSS information, including differential correctors. Commercially-available mapping services provide current, detailed visual content for many geographic regions. Combining these technologies enables triggering AV output derived from mapping services based on GNSS-identified locations, which can be identified by vehicle-mounted GNSS receiver equipment. Moreover, GNSS positioning information and differential correctors can be efficiently disseminated over digital telecommunications systems at relatively low cost and over relatively large areas. 
         [0008]    Various operations can benefit from GNSS-derived information being disseminated among a number of vehicles for purposes of coordinating their activities. For example, agricultural spraying operations with fleets of aerial and/or ground-based vehicles can be coordinated by identifying and marketing treated field areas for centralized control in order to ensure complete coverage and to avoid overlaps. Vehicle routing and travel path information can be collected and disseminated in real-time to avoid collisions in multi-vehicle operations. For example, the flight paths of multiple aircraft can be simultaneously tracked using on-board, GNSS-based receivers and RF transmitters. The aircraft can thus be spaced apart with adequate safety margins for guiding through operations such as aerial spraying and firefighting. 
         [0009]    Heretofore there has not been available a system or a method for combining these technologies with the advantages and features of the present invention. 
       SUMMARY OF THE INVENTION 
       [0010]    In the practice of the present invention, a system and method are provided for the implementation of wireless communication to disseminate GNSS differential correctors, work orders and multimedia data to mobile units, such as ground and air vehicles and personal mobile systems. The system and method also accommodate bidirectional communication for receiving positional, operational and status information for real-time display. The Internet and other network systems can be utilized for data distribution. GNSS position-stamped audio and/or video clips can be generated by the mobile units and uploaded to the system for dissemination. Alternatively, clips generated by utilities can be loaded by the application either from a personal computer or remotely and automatically over the Internet. Trigger events for playing back the clips include proximity of the mobile unit to a predetermined GNSS-based position. Exemplary applications include ground-based and aerial agricultural operations. Other applications include navigation, security, logistics, firefighting, tourism, field inventory control, law enforcement, military and transportation. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a block diagram of a GNSS-based mobile communication system embodying an aspect of the present invention. 
           [0012]      FIG. 2  is a flowchart of a GNSS-based mobile communication method embodying an aspect of the present invention. 
           [0013]      FIG. 3  is an area map of an aerial spraying operation conducted with the present invention. 
           [0014]      FIG. 4  is a top plan view of a tractor and implement, which comprise an example of a mobile unit of the system. 
           [0015]      FIG. 5  is a side elevational view thereof. 
           [0016]      FIG. 6  is a block diagram of components thereof. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     I. Introduction and Environment 
       [0017]    As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. 
         [0018]    Certain terminology will be used in the following description for convenience in reference only and will not be limiting. For example, up, down, front, back, right and left refer to the invention as oriented in the view being referred to. The words “inwardly” and “outwardly” refer to directions toward and away from, respectively, the geometric center of the embodiment being described and designated parts thereof. Global navigation satellite systems (GNSS) are broadly defined to include GPS (U.S.), Galileo (proposed), GLONASS (Russia), Beidou (China), Compass (proposed), IRNSS (India, proposed), QZSS (Japan, proposed) and other current and future positioning technology using signals from satellites, with or without augmentation from terrestrial sources. Inertial navigation systems (INS) include gyroscopic (gyro) sensors, accelerometers and similar technologies for providing output corresponding to the inertia of moving components in all axes, i.e. through six degrees of freedom (positive and negative directions along transverse X, longitudinal Y and vertical Z axes). Yaw, pitch and roll refer to moving component rotation about the Z, X and Y axes respectively. Said terminology will include the words specifically mentioned, derivatives thereof and words of similar meaning. 
       II. Preferred Embodiment System  2 . 
       [0019]    Referring to the drawings in more detail, the reference numeral  2  generally designates a GNSS-based mobile bidirectional communication system embodying an aspect of the present invention. As shown in  FIG. 1 , the system  2  generally includes a network  4 , which can comprise the Internet (worldwide web) or some other suitable network, such as a LAN or a WAN. A base station  6  can be located at a fixed, known location for differential comparison of GNSS signals received by it with signals received almost simultaneously by a vehicle  8  or a personal mobile system  10  from a GNSS satellite constellation  12  for well-known differential GPS (DGPS) error-correcting techniques. Such techniques include single and double differencing and RTK. Differential correctors can be wirelessly transmitted from the base station  6 , or disseminated wirelessly via the Internet  4 . Signals from the mobile units, e.g., the vehicle  8  and the personal mobile system  10 , can be transmitted to the base station  6 , also via the Internet  4 . Enhanced positioning accuracy can also be achieved by using satellite-based augmentation systems (SBAS). 
         [0020]    An optional data server  14  can also be connected to the Internet  4  and the mobile units  8 ,  10 . The data server  14  can host a wide variety of information, such as commercial mapping service information and utilities. Information provided by Google Earth and similar content providers can be accessed via the Internet  4  for dissemination. The base station  6  can correlate information from various sources, such as the GNSS satellite constellation  12  and the data server  14  for dissemination to the mobile units  8 ,  10 . For example, satellite images, waypoints and other location-specific mapping functions can be downloaded to the base station  6  and associated with their respective GNSS coordinates. Location-specific content can also be supplied via the mobile units  8 ,  10 , which can be equipped with video cameras and other input devices. For example, a mobile unit  8 ,  10  could capture an image and position-stamp the digital recording with the corresponding GNSS data recorded by the mobile unit GNSS receiver. 
         [0021]      FIG. 2  shows a method for mobile communications based on GNSS positioning. From a start  20  the system is initialized at  22 , e.g., by preprogramming and/or preloading the base station  6  and the mobile units  8 ,  10  with program code instructions and/or data. GNSS (GPS) is acquired at step  24  simultaneously by the base station  6  and the mobile units  8 ,  10 , thus enabling differential correction. 
         [0022]    Information clips, such as audiovisual (AV) or utility-generated, are loaded on the data server  14  or other suitable storage at step  26 . The clips can be created on the vehicle  8  or by the personal mobile system  10  for uploading via the Internet  4 . Examples of alternative clip sources, including personal computers (PCs), remote sources and web-based sources, are depicted at step  28 . The clip is GNSS-position stamped at step  30 . A real-time GNSS position is determined by a mobile unit  8 ,  10  at step  32 . For example, a mobile unit  8 ,  10  can be in motion and intermittently determine its GNSS-defined position using its receiver and, optionally, differential correction information from the base station  6  via a wireless-Internet-wireless connection. Control systems associated with the mobile units  8 ,  10  can also store information clips in onboard memory. 
         [0023]    At decision box  34  the method determines if the mobile unit  8 ,  10  is in proximity to the GNSS position associated with a respective clip, from which an affirmative decision leads to a playback trigger at step  36  and a waypoint is annotated at step  38 . A negative decision at proximity decision box  34  leads to a decision box for another trigger event at  36 , from which a positive decision leads to the playback trigger  36  and a negative decision cycles back to the GNSS position determination step  32 . An affirmative decision at “CONTINUE?” decision box  42  returns to the GNSS position determination step  32 . A negative decision leads to an end  44 . 
         [0024]    The method described above can be implemented in various modes. For example, input content can be produced and recorded at the mobile units  8 ,  10  by AV or other equipment, providing a simaultaneous image and audio content at a specific GNSS-defined position, i.e. a “georeference.” Such content can include motion and still images and audio annotation. For example, on-the-fly recording of audio and/or video clips can be accomplished by a mobile unit  8 ,  10  on a particular route. Retracing the route can trigger the respective clips upon detecting proximity to the original recording sites, as detected by the GNSS system. For example, the proximity or other trigger event can initiate an output, such as an audio description associated with a particular GNSS-defined position. The clips can comprise any suitable format, such as TIFF or other photo image files and can be used to underlay other content, such as superimposed grids, etc. The clips can be named and cached and/or exported offline, for example, to the data server  14  for posting to the Internet  4  and further dissemination. 
         [0025]    Alternatively, the georeference clips can be downloaded from other sources, such as commercial mapping services and digital photograph sources. For example, the data server  14  can receive clips from multiple vehicles  8  comprising a fleet for dissemination and downloading to other vehicles  8  in the fleet via the Internet  4 . Users can thus obtain automated, real-time, georeference information pertaining to specific waypoints in both audio and video formats. Changed conditions can be monitored over time, for example, crop conditions as an indicator of growth progress. Moreover, triggering conditions can initiate various preprogrammed responses at the mobile units  8 ,  10  and remotely via the telecommunications/Internet connections. Thus, a locally-detected condition can initiate an appropriate response almost anywhere. 
         [0026]    The system  2  can provide bidirectional, interactive communication between mobile units and other Internet-accessible resources, such as mapping services, which can provide real-time, GNSS position-stamped content corresponding to paths traveled by the mobile units. Forward-predicted content can also be communicated based on mobile unit operating parameters such as position, heading and speed. For example, an operator can receive annotated waypoint information for a forward-predicted course of travel, subject to periodic updating based on actual course. Both aerial and ground-based operations can utilize such information corresponding to the predictive mobile unit tracks. 
         [0027]    The range of applications with particular detectable conditions and preprogrammed responses is virtually unlimited. Without limitation, they include:
       tourism with descriptions associated with current position views;   field inventory control, including both generation and use, for describing situations at current positions;   real-time tracking with status information;   display of real-time traffic and speed camera information; and   military and law enforcement applications, allowing rapid real-time updates of status with positional awareness.       
 
         [0033]      FIG. 3  shows a map of an aerial agricultural operation, such as spraying fertilizer, herbicide or pesticide, utilizing the present invention. An area  52  is divided by a grid  54  into multiple sectors  56 , which can be square as shown, or other suitable geometric shapes. The area  52  can be scaled as appropriate to define a field or an entire geographic region. Likewise, the sectors  56  can utilize a pre-existing grid or a system-generated grid with an appropriate scale factor. Treatment areas  58 ,  60  can be predefined with predetermined reference corners  59 ,  61  respectively. For example, an agricultural operation can be initiated by defining the reference corners  59 ,  61  and an appropriate scale determining the XY ranges, from which the number of complete and partial sectors  56  and the area involved can be calculated. Coverages of applied materials, such as fertilizers, herbicides and pesticides, can be calculated. The mobile unit  8  can comprise a cropduster aircraft as shown, for which a flight path  62  is calculated by the system  2 . The mobile unit  8  can generate or download its flight path for storage in its onboard processor, or the flight path can be stored and accessed remotely, for example, from the base station  6  via the Internet and telecommunications connection. The actual flight path can be monitored in real-time throughout the operation using the present invention. Moreover, the flight paths of multiple aircraft can be monitored and displayed to ground-based controllers and the airborne pilots for real-time situational awareness, even in poor visibility conditions. Operations involving multiple aircraft can thus be controlled with a relatively high degree of safety and effectiveness. Still further, the displays in the base station  6  and the aircraft  8  can graphically display in real-time areas treated and remaining, which data can be recorded for documenting the operation. Gaps and overlaps in treatment can thus be minimized or avoided. 
         [0034]    The system  2  can be programmed to automatically compute and select best-fit solutions for specific operations using auto-select functions for such variables as: starting corners  59 ,  61 ; scale; grid  54  location and spacing; and XY ranges. Other variables involved in such auto-select functions include: equipment parameters (e.g. speed, turning radius, swath width, etc.); treatment area  58 ,  60  configurations; materials being applied; ambient conditions; etc. Data from previous operations can be stored for reuse in subsequent operations, e.g., from season-to-season in agricultural operations. 
         [0035]    The communication system  2  can be applied to various equipment configurations for a wide range of applications. Such applications include equipment and components used in road construction, road maintenance, earthworking, excavation, mining, transportation, manufacturing, logistics, etc. For example, and without limitation on the generality of useful applications of the communication system  2 ,  FIGS. 4-6  show an agricultural mobile unit  8  comprising a motive component  106  connected to a working component  108  through an optional articulated connection or hitch  110 . Also by way of example, the motive component  106  can comprise a tractor and the working component  108  can comprise a ground-working implement, such as the sprayer shown. The tractor  106  can include a graphical user interface (GUI)/display  107  for displaying video clips, guidance, field maps and other content to the operator. 
         [0036]    The mobile communication system  2  can be implemented with a tractor  106  including a microprocessor  112  connected to the GUI/display  107 , which can be original equipment manufacture (OEM) general-purpose components, or special-purpose for the system  2 . The tractor  106  also includes a steering wheel  116  for operating a hydraulic steering system  118 . A position sensor  120  is connected to the steering wheel  116  and provides an output corresponding to its position. The components can be connected and external communications can be provided by suitable networks, buses, hardwired and wireless connections, a controller area network (CAN)  158  as shown, serial connections and virtualization technology (VT). 
         [0037]    A position/heading (vector) sensor  128  can be mounted externally on the tractor  106 , e.g. on its roof, and includes a pair of antennas  130  connected to a GNSS receiver  132 . The GNSS receiver  132  disclosed herein can be adapted for various satellite navigational systems, and can utilize a variety of satellite based augmentation systems (SBAS). Technology is also available for continuing operation through satellite signal interruptions, and can be utilized with the system  2 . The antennas  130  can be horizontally aligned transversely with respect to a direction of travel of the tractor  106 , i.e. parallel to its X axis. The relative positions of the antennas  130  with respect to each other can thus be processed for determining yaw, i.e. rotation with respect to the vertical Z axis. The sensor  128  also includes a direction sensor  134  and inertial sensors  136 ,  138  and  140  for detecting and measuring inertial movement with respect to the X, Y and Z axes corresponding to yaw, roll and pitch movements in six degrees of freedom. Signals from the receiver  132  and the sensors  134 ,  136 ,  138  and  140  are received and processed by the microprocessor  112  based on how the system  2  is configured and programmed. 
         [0038]    The implement (working component)  108  can optionally be equipped with an implement GNSS receiver  146  connected to an implement microprocessor  148  for steering the implement  108  independently of the tractor  106  via an implement steer subsystem  150 . An optional articulated connection  110  can be provided between the tractor  106  and the implement  108 . Examples of such an articulated connection and an implement steering system are described in U.S. Pat. No. 6,865,465 and U.S. Pat. No. 7,162,348, which are incorporated herein by reference. The implement  108  can comprise any of a wide range of suitable implements, such as planting, cultivating, harvesting and spraying equipment. For example, spraying applications are commonly performed with a boom  152 , which can be equipped for automatic, selective control of multiple nozzles  154  and other boom operating characteristics, such as height, material dispensed, etc. Automatic boom control  156  can be utilized, for example, to selectively activate and deactivate individual spray nozzles  154  whereby overspraying previously treated areas can be avoided by the system  2  keeping track of previously treated areas and turning off the nozzles  154  when those areas are reached in an overlapping swath situation, which occasionally occurs in connection with irregularly shaped parcels, near field boundaries and in other operating situations. 
         [0039]    It is to be understood that the invention can be embodied in various forms, and is not to be limited to the examples discussed above.