Abstract:
A location apparatus for returning to a user to a location including a system unit configured to compute a location using radio signals, a user interface unit having a display area and first and second buttons, a memory unit, and a computational unit configured to interact with the first and second buttons. The computation unit retrieves a first location from the system unit and stores the first location in the memory unit upon selection of the first button by the user. Further, the computation unit retrieves a second location from the system unit and calculates a relative three-dimensional direction from the second location to the first location upon selection of the second button by the user. The relative three-dimensional direction is graphically represented on the display area of the user interface unit.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is related to the following U.S. application Ser. Nos. 09/575,702 filed on Jul. 12, 2000; 10/167,497 filed on Jun. 13, 2002; 09/575,710 filed on Jul. 25, 2000; and 09/668,162 filed on Sep. 25, 2000. The contents of each of those applications are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates generally to a location device and more specifically to a location system and method using radio-based technology to register a location and then later direct a user back to the registered location.  
         [0004]     2. Discussion of the Background  
         [0005]     Today, many people have trouble remembering how to return to a particular location such as a common meeting place or where they parked their vehicle. This problem will most likely only get worse as the population ages and the aging generation face problems associated with memory loss. Forgetting where a vehicle is parked can be a serious problem in large parking lots such as malls, shopping centers, or amusement parks. Further, not being able to remember how to return to a gathering location after a period of time is also problematic.  
         [0006]     The Global Positioning System (GPS) is an example of a radio-based technology that is used to provide an earth based position using orbiting space satellites. As is well known in the art, currently there are twenty-four GPS space satellites in the GPS constellation orbiting in twelve-hour orbits, 20,200 kilometers above Earth configured such that there are six to eleven GPS satellites visible from any point on the Earth. GPS satellites broadcast specially coded signals that can be processed by GPS receivers. These GPS space satellites transmit on a primary and a secondary radio frequency, referred to as L1 and L2. The frequency of L1 is 1575.42 MHz (154 times the atomic clock) and the frequency of L2 is 1227.6 MHz (120 times the atomic clock). A typical GPS receiver retrieves GPS signals from at least three orbiting GPS space satellites and then calculates an earth based location, generally latitude and longitude coordinates. GPS signals from at least four orbiting GPS space satellites are necessary to calculate a three-dimensional earth based location, such as latitude, longitude and altitude. A GPS receiver calculates its location by correlating the signal delays from the GPS space satellites and combining the result with orbit-correction data sent by the satellites.  
         [0007]     At present, there exist many different types of GPS receivers of varied capabilities which are commonly available for personal and governmental use. Typically, these GPS receivers are intended for navigational use in which the current calculated latitude and longitude location is displayed on some form of a geographic or topographical map. These systems are sometimes bulky and may require the user to manually program the system, such as entering a destination street address.  
         [0008]     Because a typical user of a device intended to help the user remember how to return to a particular location is likely to be concerned about the size and complexity of the device, the device should be lightweight and simple to operate. Thus, a location device should have a simple user interface that is easy to operate with minimal or no user programming required. To this end, the location device should be able to utilize radio-based technology to automatically determine its current location.  
         [0009]     Thus, there exists an unmet need in the art for a lightweight and simple to use location device for registering and returning to a particular location.  
       SUMMARY OF THE INVENTION  
       [0010]     One object of the present invention is to provide a lightweight and simple to use location device for locating a particular location based on a previous registration of that location.  
         [0011]     Another object of the present invention is to provide a device having a simple and intuitive user interface including a button to register the location to which the user wants to return and a button to activate the direction indicators. A user stores the current location ascertained from a radio-based (e.g., GPS) system unit into a memory unit using a registration button. The user later activates the direction indicators to graphically represent a three-dimensional direction from the current location ascertained from the radio-based system to the previously registered location using a direction button.  
         [0012]     Yet another object of the present invention is to provide a device with direction indicators that are active at all times.  
         [0013]     Another object of the present invention is to provide a device that can be implemented in the remote lock of a vehicle key or cellular phone in addition to being a universal device.  
         [0014]     Finally, another object of the present invention is to provide a device and computer product that is incorporated into a PDA or laptop computer capable of sophisticated mapping options. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]     A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:  
         [0016]      FIG. 1  is a block diagram of a location device according to an embodiment of the present invention;  
         [0017]      FIG. 2  is an example of the location device implemented in a vehicle key remote according to an embodiment of the present invention;  
         [0018]      FIG. 3  is a flowchart illustrating the steps of registering a location according to an embodiment of the present invention;  
         [0019]      FIG. 4  is a flowchart illustrating the steps of getting the current location and representing a relative three-dimensional direction to the registered location according to an embodiment of the present invention on direction indicators; and  
         [0020]      FIG. 5A -C are examples of the location device incorporating a simple route-tracking mechanism according to alternate embodiments of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]     Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views.  
         [0022]     Referring to  FIG. 1 , a block diagram of the location device according to an embodiment of the present invention is shown. The location device  100  contains four major sub units ( 102 ,  104 ,  106  and  108 ). Radio-based system unit  102  contains a radio frequency receiver along with a system bus interface, not described, and computer software. The radio frequency receiver receives radio frequency signals from radio-based transmitters (e.g., GPS satellites or ground stations). These radio frequency signals are used by the computer software to calculate a current three-dimensional location of the location device. Memory unit  104  contains the non-volatile and volatile memory that is required to operate the location device and its associated software. Memory unit  104  may contain dynamic RAM and flash memory along with ROM. Computational unit  106  includes a CPU which may be implemented as any type of processor including commercially available microprocessors from companies such as Intel, AMD, Motorola, Hitachi and NEC. The Computational unit  106  is configured to store a three-dimensional location ascertained from radio-based system unit  102  into memory unit  104 , to compute a relative three-dimensional direction of the current location of the device relative to the stored location, and to communicate this directional information to user interface unit  108 . User interface unit  108  contains the control logic of the display unit and buttons. All of the units previously described are connected by a system bus.  
         [0023]     Referring to  FIG. 2 , an example of the location device implemented in a vehicle key remote according to an embodiment of the present invention is shown. In this embodiment, a vehicle key remote performs normal vehicle key remote operations in addition to the location operations of the present invention. For instance, door lock button  202  locks the vehicle doors, unlock button  204  unlocks the vehicle doors, trunk open button  206  unlocks and opens the trunk of the vehicle, and button  214  may be used as a panic button to flash the lights and sound the horn of the vehicle. Additionally, in this embodiment, door look button  202  is also used to initiate registration of a location. When the user presses the door lock button  202  longer than some predetermined time, such as two seconds, the current three-dimensional location of the location device is ascertained from the radio-based system unit  102  and stored in memory unit  108 . Activation of the directional indicators is initiated when the user presses button  214 . The current three-dimensional location of the location device is again ascertained from the radio-based system unit  102 . Next, a relative three-dimensional direction is computed from the current location to the previously registered location. The relative three-dimensional direction is then displayed using directional indicators ( 208 ,  210  and  212 ). A user is directed towards a registered location using forward  210   a , left  210   b , right  210   c , back  210   d , up  208  and down  212  indicators. Up  208  and down  212  indicators are used to indicate the registered location altitude relative to the current altitude of the location device. Thus, if the registered location is higher or lower relative to the current altitude of the location device, this difference is indicated by up  208  and down  212  indicators, respectively. Each successive time that button  214  is pressed results in the recalculation and display of the relative three-dimensional direction from the current location to the registered location.  
         [0024]     Optionally, the location device may be configured to periodically calculate and display, for some predetermined period of time after pressing button  214 , the relative three-dimensional direction from the current location to the registered location. Additionally, indicators  208 ,  210  and  212  may optionally be configured with labels indicating their function.  
         [0025]     It is to be understood that  FIG. 2  illustrates just one of the many possible embodiments of the location device and that numerous variations are possible without departing from the scope of the present invention. It is also understood that  FIG. 2  is an example of location device incorporated into a vehicle key remote. If the location device is instead an independent device, then only directional indicators ( 208 ,  210  and  212 ), buttons  202  and  214  are required and may be labeled accordingly. For instance, buttons  202  and  214  may be labeled “Remember Location” and “Get Directions”, respectively.  
         [0026]     Referring to  FIG. 3 , a flowchart of the steps for registering a location according to an embodiment of the present invention is shown. A user activates registration of a location, as shown at Block  300 , by selecting button  202 . At Block  302 , the computational unit attempts to ascertain the current three-dimensional location from the radio-based system unit using an internal radio frequency receiver in communication with radio-based transmitters (e.g., at least four orbiting GPS space satellites or ground stations). This operation will continue, for a predetermined number of attempts, until the current three-dimensional location is ascertained by the radio frequency receiver. Logic Block  304  determines if the current location has been ascertained by the radio frequency receiver. If the current location has not been ascertained, then at Logic Block  310  a determination is made as to whether the number of failures has exceeded a predetermined maximum number of failures. If the maximum number of failures has not been exceeded, then flow continues at Block  302 . Otherwise, as shown at Block  312 , the user is notified that the location device is unable to ascertain the current location. Once the current location is ascertained, it is stored into memory unit  104 , as shown at Block  306 . This operation is referred to as registering a location that the user will later return to. Finally, as shown at Block  308 , the registration steps are completed.  
         [0027]     Referring to  FIG. 4 , a flowchart of the steps for getting the current location and representing a relative three-dimensional direction to the registered location on direction indicators is shown. The user activates directions, shown at Block  400 , by selecting button  214 . At Block  402 , the computational unit attempts to ascertain the current three-dimensional location from the radio-based system unit again using the internal radio frequency receiver in communication with radio-based transmitters (e.g., at least four orbiting GPS space satellites or ground stations). This operation will continue, for a predetermined number of attempts, until the current three-dimensional location is ascertained by the radio frequency receiver. Logic Block  404  determines if the current location has been ascertained by the radio frequency receiver. If the current location has not been ascertained, then at Block  414  a determination is made as to whether the number of failures has exceeded a predetermined maximum number of failures. If the maximum number of failures has not been exceeded, then flow continues at Block  402 . Otherwise, as shown at Block  416 , the user is notified that the location device is unable to ascertain the current location. Once the current location is ascertained, at Block  406 , the previously stored location is retrieved from memory unit  104 . Next, the relative three-dimensional direction from the current location to the registered location is calculated by the computational unit, as shown at Block  408 . At Block  410 , the three-dimensional direction is graphically displayed on the user interface using forward, left, right, back, up and down directional indicators. Finally, as shown at Block  412 , the direction steps are completed.  
         [0028]     Referring to  FIG. 5A , an alternate embodiment of the location device incorporating a simple route-tracking mechanism is shown. According to this embodiment, multiple locations may be registered by a user. Each registered location is associated with a unique location number that is visually represented in Location Number display  502 . The first registered location, also referred to as the starting location, is identified by a location number of  0 . Memorize button  504  stores the location number, the current location, and the direction that a user is currently facing. The location number is then automatically incremented. Back button  506  decrements the location number and retrieves its associated registered location and direction. By repeatedly pressing Back button  506 , the user is able to rotate through each of the stored locations. Show button  514  activates the relative three-dimensional directional indicators ( 508 ,  510 , and  512 ) which thereafter light up as necessary to direct a user towards a registered location. While the user is being directed towards a registered location, the light intensity of the directional indicators ( 508 ,  510 , and  512 ) is varied, if necessary, to indicate a primary heading. For example, where a user facing north is being directed in a North-North-East direction, the forward  510   a  and right  510   c  directional indicators are simultaneously illuminated with forward  510   a  having a greater light intensity than right  510   c , thereby providing the user with a visual indication of a primarily northern heading. Directional indicators  510  (forward  510   a , left  510   b , right  510   c , back  510   d ) light up simultaneously when the user has arrived at a registered location. Because the registered location may only be accurate to within several feet or more, the original direction that the user was facing when the Memorize button  504  was pressed may be helpful in locating an exact location. Thus, upon arrival to a registered location, Facing Direction indicator  518  illuminates when the user faces the original direction registered when Memorize button  504  was pressed. Determining whether the user is facing the same registered direction may be implemented using a conventional internal compass configured to determine a direction relative to a magnetic north, not shown. Alternatively, as shown in  FIG. 5B , directional indicators  510  (forward  510   a , left  510   b , right  510   c , back  510   d ) flash one or more times when the user has arrived at a registered location and additionally light up as necessary to indicate the original direction registered when Memorize button  504  was pressed. The Erase All button  516  allows the user to clear all previously stored locations and acts as a reset. When the user presses the optional Erase All button  516  longer than some predetermined time, such as two seconds, all previously stored locations are cleared and the location number is set to 0. Additionally, a reset is performed when the user uses the Back button  506  to go back to the starting location and then presses Memorize button  504 , thereby eliminating the need for Erase All button  516 . Further, as shown in  FIG. 5C , the location device may be configured with a distance display  520  to display the distance to a registered location. In this configuration, distance display  520  indicates 0 when the user has arrived at a registered location.  
         [0029]     Although the interface is described in terms of the buttons, the operation can be done using the voice command. Also, the response can be voice response instead of the arrows. Therefore, a person can not only register the location, he can register a short message when memorizing a location so that the location number and his voice can be associated.  
         [0030]     Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.