One of the difficulties encountered when driving in a large or unfamiliar city is locating and returning to one's vehicle after parking. Particularly in the case of rental vehicles, where both the vehicle and city are unfamiliar to the driver, and with the large size of parking garages in malls, hotels and other venues, it can be very difficult for the driver to not only locate the parked vehicle, but also to determine how to return to the location. However, with the development and increased usage of portable navigation systems, such as GPS tracking and mapping devices, the potential exists to use those systems to assist the driver in locating their vehicle after leaving it parked.
For example, U.S. Pat. Nos. 6,392,592 and 6,694,258 to Johnson et al. (“Johnson”) disclose a hand-held car locator device consisting of two parts, a transmitter/receiver in the vehicle, and a fob which is carried by the user. When the user wants to locate the vehicle, they activate the fob, and a signal is sent to the vehicle, which then gets its current location using GPS or similar means, and sends the location back to the fob for the user to see. Johnson also discloses automatic transmission of location to the fob, such as upon locking of the vehicle doors.
Problems with the above-mentioned Johnson patents include the following: it requires that a GPS or similar location tracking unit be located in the vehicle at all times and it requires that the location tracking unit be powered by the vehicle's battery while the vehicle is off, which can present vehicle battery drainage issues. Johnson also requires a fob with (1) transceiver technology, (2) the ability to interpret a signal from a location tracking unit, (3) the ability to display location and/or directional information, and (4) strong transmission signal capabilities—which necessitates a significant power source—in order to effectively contact the tracking unit in the vehicle (as the signal may be issued from a great distance and can be blocked by concrete walls or other such obstructions).
Another example, U.S. Pat. No. 6,407,698 to Ayed (“Ayed”) discloses a method of locating a parked vehicle using a sensor incorporated into the vehicle and a mobile GPS device where the sensor is activated when the vehicle is parked and sends a signal to the GPS device. The GPS device then retrieves the current coordinates on receiving the signal from the sensor. The Ayed method requires modification of the vehicle to incorporate the sensor, as well as possession of a separate mobile GPS device by the user. In Ayed, as the location coordinates are not retrieved by the GPS device until the vehicle is parked, there is also the risk of a failure to connect to the GPS satellites in a timely manner, such that the retrieved coordinates do not correspond to the vehicle's parking location.
As with Johnson, Ayed requires a second device to communicate with the GPS device to determine the location of the parked vehicle. Another problem is the need to modify the vehicle to include sensors to indicate to the locator device that the vehicle is parked, or other devices, such as a cradle, to accommodate the locator device.
Additionally, Ayed requires that the sensors installed in the vehicle have sufficient sophistication and complexity to both accurately and consistently note that the vehicle is parked and to then communicate with the GPS device, creating a risk of failure in that the parking of the vehicle may not be detected by the sensor and, as a result, a failure to communicate the signal to the GPS device.
Yet another example is found in U.S. Pat. No. 6,489,921 issued to Wilkinson (“Wilkinson”). The Wilkinson patent discloses a handheld device (i.e. a keychain fob) which senses when it has been moved out of range of an RF signal tag that is mounted on the vehicle's dashboard near the vehicle's ignition. When the user removes the key (and keychain fob apparatus) from the immediate range of the vehicle's ignition, which is likely indicative of the user being in the process of leaving the vehicle, the RF signal is therefore lost. This signal loss automatically prompts the device to initiate the device's GPS receiver to seek satellite signals and, upon securing said signals, to record the device's coordinates. These coordinates, in turn, are meant to correspond to the location of the user's parked vehicle. When re-activated, the device gets the GPS coordinates for its current location, and calculates the shortest distance to the recorded coordinates. It then displays on-screen an arrow indicating the direction the user should travel to get back to the original coordinates. Once the device is back within range of the RF signal, it disengages and waits for the RF signal to drop below threshold again to resume the process.
Problems with Wilkinson include an issue with apparatus size, as Wilkinson expresses a need for an apparatus with locating technology capabilities that is small enough in size and weight to be placed on a key chain (and thus to be in range of the RF tag that is to be placed by the vehicle's ignition).
Wilkinson and Ayed share a common limitation, in that the process for determining the coordinates of the vehicle is not initiated until after the vehicle is parked. Initiating the locating technology after parking creates a significant risk that the coordinates will not be retrieved in a timely fashion, as the device needs time to secure multiple satellite signals in order to determine its location. By the time the device secures the required satellite signals and calculates its location the user may have walked a significant distance from their vehicle, thus significantly limiting the device's ability to secure an accurate determination of the location of the vehicle. This, in turn, largely undermines the purpose and intent of both of these patents.
A further limitation of both Wilkinson and Ayed as a result of not initiating the process of determining coordinates of the vehicle until after it is parked relates to situations in which the user parks in a location where GPS signals are blocked (for example, in an underground or covered parking garage). In this situation, the portable locator device in Ayed reattempts to obtain a GPS signal a fixed number of times before alerting a user that obtaining a location has failed. As for Wilkinson, the locator device beeps if it is unable to determine the location where the vehicle is parked. While these audible warnings may alert the user of an issue, they do not address the issue. That is, the user will not have any location information for the parked vehicle.
U.S. Pat. No. 6,363,324 to Hildebrant, which has two GPS receivers, one in car and another in the handheld device, and discloses a display using a direction arrow and an elevation marker to indicate the direction to a parked vehicle. The Hildebrant receivers retrieve and store the location coordinates once the vehicle is parked. Hildebrant is limited in that two GPS devices are required.
U.S. Pat. No. 6,791,477 and No. 7,068,163, both issued to Sari et al. (“Sari”). The Sari patents disclose a locator device (key “faub” (sic) or wireless telephone) that retrieves a waypoint from a second device in response to a triggering event such as the parking of a vehicle. The waypoint is determined by the second device using coordinates retrieved prior to the triggering event. Sari is limited in that two GPS devices are required, and that the waypoint is transmitted between devices, creating a risk of a corrupted or missed waypoint.
There is a need for a method of locating a vehicle that uses a single GPS device, ideally in a one-step operation that does not require any modification of the vehicle.
There is also a need for a method of locating a vehicle that functions autonomously, enabling the recording of the vehicle's location on a GPS-enabled device without any user intervention and without the requirement for noteworthy modifications to the vehicle. Ideally, such a method would use a device that is unobtrusive and requires minimal or no modification to the vehicle.
There is further a need for a method of locating a vehicle that does not rely on retrieving coordinates after the vehicle is parked, to increase the likelihood of the coordinates being captured and stored in a timely fashion so that the co-ordinates are in very close proximity to the vehicle's actual location.
It is an object of this invention to partially or completely fulfill one or more of the above-mentioned needs.