Abstract:
A signal/sensor automatically sends a wireless signal upon sensing that a vehicle has been parked. There is also provided a locator for determining a current location and storing the current location upon receiving the wireless signal. The current location may be determined by accessing a GPS service through a GPS receiver. The current location may further be refined by accessing a DGPS service through a DGPS receiver or a wireless communication device. The locator also comprises a compass and a relative direction and bearing indicator. Upon receiving a user request, the locator determines a new current location and determines a current heading with the compass. Next, a relative direction and bearing to the parked vehicle may be determined by a processor on board the locator or by accessing a remote server through the wireless communication device. Last, the relative bearing and direction to the parked vehicle is conveyed to the user through the indicator. Advantageously, a user&#39;s location is stored automatically upon sensing a trigger event without a user&#39;s direct intervention. Furthermore, the locator may remain dormant until it senses the trigger event or until a user requests the location of the parked vehicle. As such, the functionality of the present invention may be unobtrusive yet convenient.

Description:
FIELD OF THE INVENTION 
     This invention is directed generally to the field of human necessities and more specifically to the field of electronic vehicle finders whereby a vehicle&#39;s location is automatically stored upon sensing of a trigger event. 
     BACKGROUND OF THE INVENTION 
     Conventional devices for locating parked vehicles use visual attention devices such as flags, banners, pennants or streamers, which are supported from an antenna, as disclosed in U.S. Pat. No. 4,964,360 (“Henry”), or masts with magnetic bases for attaching to vehicle roofs, as disclosed in U.S. Pat. No. 5,388,546 (“Lombard”). However, these systems are not effective at long distances or in bad weather conditions. 
     Other devices use electronic communication techniques to locate vehicles. U.S. Pat. No. 5,777,580 (“Janky, et. al.”), discloses a mobile vehicle location system comprising a location determination system, such as the Global Positional System (“GPS”), in combination with a transceiver/receiver. In Janky, et al. the vehicle location system resides with the target vehicle. While the vehicle location may be determined by remotely communicating with the location system, the user&#39;s location cannot be known with the same device when the user is outside the vehicle. Accordingly, Janky et. al is unable to determine the relative position of the vehicle to the user. 
     Known location determination devices cooperate with location systems such as GPS, Global Navigation System (“GLONASS”), Global Navigation Satellite System (“GNSS”) or Long Range Navigation (“LORAN”) to provide a user with the latitude and longitude of a location. These devices might be used to direct a user back to a desired location, like the location of a parked vehicle. For instance, if the latitude and longitude of a parked vehicle were input to the navigation instrument, the instrument could readily calculate the distance and bearing to the vehicle. A disadvantage with using these devices to locate a parked vehicle is that the user must know or be able to determine the coordinates of a vehicle and must input this vehicle location into the locator device every time the location of the vehicle changes. 
     Thus there is a need for a more convenient method and apparatus of locating a user&#39;s vehicle. 
     SUMMARY OF INVENTION 
     According to one aspect of the invention, there is provided a method for facilitating returning to a parked vehicle location, comprising, responsive to receiving a wireless indication, obtaining position information of a current location, and storing the current location. 
     According to another aspect of the invention, there is provided an apparatus for facilitating finding of a parked vehicle, comprising a signaller arranged for signalling to indicate a vehicle has been parked, and a locator responsive to the signaller for obtaining and storing a current location upon receiving a signal from the signaller. 
     According to another aspect of the invention, there is provided an apparatus for facilitating returning to a parked vehicle location comprising, a locator responsive to a wireless signal for storing a current location. 
     Advantageously, the present invention stores a user&#39;s location automatically upon sensing a trigger event. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be more clearly understood after reference to the following detailed specification read in conjunction with the drawings wherein: 
     FIG. 1 is a schematic of a parked vehicle locator system; 
     FIG. 2 is a block diagram of a portable locator made in accordance with this invention; 
     FIG. 3 a  is a flowchart illustrating the steps involved in sending a signal to the portable locator; 
     FIG. 3 b  is a flowchart illustrating the steps involved in storing a parked vehicle location in the portable locator; 
     FIG. 4 is a flowchart illustrating the steps involved in conveying parked vehicle location directions to a user; 
     FIG. 5 is a flow chart illustrating alternative steps involved in conveying parked vehicle location directions to a user whereby some functions are performed remotely; 
     FIG. 6 is a flow chart illustrating further alternative steps involved in conveying directions to a stored location to a user whereby a user may store locations other than that of the parked vehicle; 
     FIG. 7 is a block diagram of a portable locator made in accordance with another embodiment of this invention; and 
     FIG. 8 is a block diagram of a portable locator made in accordance with further embodiment of this invention. 
    
    
     Similar reference numerals are used in different figures to denote similar components. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1, a parked vehicle locator, generally designated  10 , includes a portable locator device  12  and a parked vehicle sensor/signal device  14  fixed to a user&#39;s vehicle  15 . Locator device  12  may be a stand alone device such as a compact hand held unit. Alternatively, locator device  12  may be incorporated with another portable electronic device such as a cellular phone, personal communication device, personal data assistant, pager or portable personal computer. 
     Parked vehicle sensor/signal device  14  comprises a trigger event sensor  16  interconnected with an activation signal transmitter  18 . 
     Sensor  16  is disposed in a user&#39;s vehicle to sense a trigger event signifying that the user&#39;s vehicle has been parked. In the preferred embodiment, sensor  16  comprises a photo-electric switch arranged near an interior light of vehicle  15  which, when the driver&#39;s door opens, turns on thereby activating the photo-electric switch causing sensor  16  to signify that vehicle  15  has been parked. It will be appreciated that sensor  16  may be a different type of switch and may be positioned in vehicle  15  so that the switch would switch upon shifting an automatic transmission from drive into park, applying the parking brake, turning off the engine, removing the keys from the ignition, opening the driver&#39;s side door, or any combination of these events. 
     Upon sensing an appropriate trigger event, sensor  16  prompts activation signal transmitter  18  to wirelessly send an identifiable short range signal to portable location device  12 . It will be understood that only a short range signal is needed to contact portable location device  12  since the user is expected to be in (or near) the vehicle with portable locator device  12  when the car is parked. It will also be understood that sensor  16  and activation signal transmitter  18  are to be provided with a power supply (not shown). 
     Although the system described employs an activation signal transmitter which transmits a wireless activation signal, it is contemplated that portable locator  12  could also be removably attached to a cradle (not shown) that is connected to activation signal transmitter  18 . In such a case, it would not be necessary for the activation signal to be wireless. 
     In order to prevent locator device  12  from being prompted by other signal transmitters, activation signal transmitter  18  may modulate the activation signal with a digital marker sequence that only the complementary portable locator device  12  will recognize. 
     As will be explained further, the signal sent by activation signal transmitter  18  may prompt locator device  12  to cooperate with a GPS  20  to determine the vehicle&#39;s current location and store this information for future reference. 
     It will be understood that GPS  20  may alternatively be a GLONASS, LORAN, GNSS, or any other commercially available service, or combination of services, that provides global position information. 
     Referring now to FIG. 2, in one embodiment, portable location device  12  comprises a processor  36  interconnected with an input from a vehicle locator button  22 , memory  24 , a GPS receiver  26 , a wireless communication device  27 , a compass  28 , an information centre  30 , a battery  34 , and a activation signal receiver  32 . 
     By pressing vehicle locator button  22  a user may request that a current location be stored or that bearing and distance information to a previously stored location be provided. Optionally, vehicle locator button  22  may be replaced by any suitable type of user input device such as a keyboard, a pointing device (e.g. mouse), a touch sensitive display, a voice recognition system, a stylus or any combination of such devices. 
     Memory  24 , which may be any standard writeable memory, stores parked vehicle, or other location information. 
     GPS receiver  26  cooperates with a publicly available GPS  20  (FIG. 1) to determine the user&#39;s current location. It will be understood that the reception of GPS receiver  26  may be improved by providing the user&#39;s vehicle with a wireless GPS antenna (not shown) to relay GPS signals inside the vehicle. 
     Wireless communication device  27  communicates with wireless network  21  (FIG. 1) to obtain DGPS correction data to improve the accuracy of the GPS data so that the user&#39;s current or stored location may be determined with more precision than could be obtained by using GPS alone. The DGPS service may be available from a satellite, a radio station, a cellular network or any other wireless network. In addition, wireless communication device  27  may access remote server  23  through wireless network  21  to store information and to determine relative bearing and distance for locator device  12  to reduce the hardware requirements of the locator. Wireless communication device  27  may be a cellular phone, a personal communication device, a pager, a DGPS receiver or any other wireless communication device capable of accessing the wireless networks mentioned above. 
     Compass  28  determines the user&#39;s current heading. 
     Information centre  30  conveys bearing and distance information to the user. Information centre  30  is preferably a liquid crystal display (“LCD”) capable of displaying a digital pointer and alphanumeric readout of distance, as shown in FIG.  1 . However, information centre  30  may also be a cathode ray tube, a plasma discharge display, a compact speaker or any other audible or visual means capable of conveying information to the user. 
     Battery  34  provides power to some of the components of portable location device  12 . It will be understood that battery  34  may be a nickel-cadmium, lithium, alkaline or nickel-hydride battery or any other portable source of electric power. 
     Activation signal receiver  32  listens for an activation signal from activation signal transmitter  18 . It will be understood that activation signal receiver may be any type of receiver capable of receiving the signal generated by activation signal transmitter  18 . 
     As described hereafter, processor  36  communicates with the components of locator  12  and determines relative bearing and distance to a stored location by comparing the current location and heading with the stored location. However, remote server  23  may alternatively perform the function of determining relative bearing and distance. 
     When portable locator device  12  is not in operation it remains in a dormant state (“sleep-mode”) to conserve the energy of battery  34 . 
     FIGS. 3 a  and  3   b  illustrate the steps involved in storing a parked vehicle location. 
     Turning now to FIG. 3 a , which illustrates the operation of sensor/signal device  14 , along with FIGS. 1 and 2, in step  44  a trigger event  40  (e.g. the illumination of the vehicle&#39;s interior light) is sensed by trigger event sensor  16 . In step  46 , trigger event sensor  16  prompts activation signal transmitter  18  to send a short range radio frequency signal. 
     Turning now to FIG. 3 b , which illustrates the operation of portable locator  12 , upon receipt of the activation signal in step  48 , activation signal receiver  32  prompts some components in portable locator  12  to wake up in step  50 . After waking up, in step  51  processor  36  verifies the signal (e.g. checks a digital sequence modulation on the carrier wave with a stored sequence) then prompts GPS receiver  26  to attempt to obtain the portable locator&#39;s current location, which will correspond to the parked vehicle location (because portable locator  12  must be in or near the vehicle to be within the range of the activation signal when the vehicle is parked). However, sometimes the GPS signal is blocked by buildings or is too weak for GPS receiver  26  to obtain. If processor  36  is unable to obtain a current location in step  52  it repeats step  51 . After a set number of failed attempts (not shown) locator  12  may warn the user with a signal signifying that it was unable to obtain a current location. In step  54  the portable locator&#39;s current location is stored in vehicle location memory  24  after which, in step  56 , some the components of portable locator  12  return to sleep-mode to conserve energy. 
     FIG. 4 illustrates a flow chart of the steps involved in locator  12  conveying parked vehicle location directions to a user. Referring to FIGS. 1,  2  and  4 , in step  60  a user presses vehicle locator button  22  which prompts some components in portable vehicle locator  12  to wake up in step  62 . Upon waking up, in step  64  processor  36  performs steps  51  and  52  as set out in FIG. 3 b  and attempts to obtain the user&#39;s current location by accessing GPS  20 . In step  65 , processor  36  prompts wireless communication device  27  to access a DGPS service to obtain DGPS correction data for both the user&#39;s current location and parked vehicle location stored in memory  24 . Processor  36  then utilizes this DGPS correction data to refine the precision of the user&#39;s current location and parked vehicle location. Next, processor  36  in step  66  obtains the locator&#39;s current heading from compass  28  and in step  67  retrieves the parked vehicle location stored in memory  24 . Next, in step  68  processor  36  determines the relative distance and bearing to the user&#39;s parked vehicle by comparing the current location and heading with the parked vehicle location stored in vehicle location memory  22 . In step  70  the relative distance and bearing information are conveyed to the user through information centre  30 . In step  72 , processor  36  determines whether vehicle locator button  22  is still depressed after a prescribed period of time. If vehicle locator button  22  is still depressed processor  36  returns to step  64  to provide the user with updated relative distance and bearing information. In this way, if the user keeps vehicle locator button  22  depressed the user will receive continuous periodic updates of relative distance and bearing information without having to press vehicle locator button  22  repetitively. If vehicle locator button  22  is no longer depressed after the prescribed period of time then some of the components return to sleep mode in step  74 . 
     In an alternative embodiment, illustrated in FIG. 5, the function of determining relative bearing and distance as well as refining position precision using DGPS correction data, performed by processor  36 , may be performed by remote server  23  instead. Accordingly, with reference to step  69  in FIG. 5, processor  36  prompts wireless communication device  27  to access remote server  23  to obtain DGPS correction data, refine position and determine relative distance and bearing the user&#39;s vehicle. 
     In another embodiment, illustrated in FIG. 6, if the vehicle locator button  22  is still depressed after a prescribed period of time in step  76 , instead of updating the relative distance and bearing information and conveying this information to the user, as previously described in steps  67 ,  68  and  70 , processor  36  may proceed to step  54  and store the locator&#39;s current location by overwriting the parked vehicle location already stored in memory  24 . In this alternative embodiment, the user can press vehicle locator button  22  for a short period of time to obtain relative distance and bearing information and can press the vehicle locator button  22  for an extended period of time to store a new current location in memory  24 . In this way, the user can utilise memory  24  to store locations other than the location of the user&#39;s parked car. However, with only one memory location, once the new current location is stored in memory  24 , the location of the parked vehicle will no longer be available. 
     With reference to FIG. 7, a modified portable locator  112  is provided with optional memory registers  24   b ,  24   c  and  24   n  and corresponding optional location buttons  22   b ,  22   c  and  22   n . The steps set out in FIG. 5 are followed mutatis mutandis, when a user presses one of the optional locator buttons  22   b ,  22   c , or  22   n . More particularly, when the user presses one such button for a short period of time, relative distance and bearing information is obtained between the locator&#39;s current location and the stored location in the optional memory register  24   b ,  24   c  or  24   n  which corresponds to the button which was pushed. The user may also press one of the optional locator buttons  22   b ,  22   c  or  22   n  for an extended period of time to store a new current location in corresponding memory register  24   b ,  24   c ,  24   n  by overwriting the location that was previously stored in that memory register. In this way, vehicle location memory  24  remains devoted to storing the user&#39;s parked vehicle location but the user may use other memory registers  24   b ,  24   c ,  24   n  to store other locations which may be of interest to the user. 
     With reference to FIG. 8, in another embodiment a modified portable locator  212 , as shown in FIG. 2, may be provided with an optional street number and street comer locator table  35 . Locator table  35  tabulates static terrestrial features, such as addresses and street comers, with their corresponding GPS coordinates. With portable locator  212 , when a user requests relative bearing and distance to a stored location, in addition to the steps previously provided, processor  36  may also determine and display the street address or comer nearest to the stored location by cross-referencing the GPS coordinates of the stored location with the nearest GPS coordinate stored in locator table  35 . Although FIG. 8 shows that locator table  35  is stored in portable locator  212 , it may also be stored in remote server  23  where it may be accessed through wireless network  21  by wireless communication device  27 . 
     Although the system described relies upon information from a DGPS in addition to a GPS, where the information from the primary positioning system (e.g. a GPS) is considered sufficiently accurate, no correction data is required. In such a case, wireless communication device  21  may be optional. 
     Numerous other modifications, variations, and adaptations may be made to the particular embodiments of the invention described above without departing from the scope of the invention, which is defined in the claims.