Abstract:
A battery operated portable device, or “lockator” facilitates location of a parked automobile within having an unknown or forgotten location. The lockator locks, unlocks and locates the automobile with a simplified user interface. The locator has a combined automobile door lock and unlock transmitter and GPS locator. Pressing a lock button both transmits a lock signal and substantially determines the automobile location. Pressing the unlock button transmits the unlock signal and determines the direction back to the location where the lock button was pressed. Left and right icons on the lockator direct the driver back to the vehicle. The icons blink at a rate indicative of the distance to the automobile and indicate if the driver is heading away from the automobile. Measures are take to conserve power drawn from a battery powering the lockator.

Description:
FIELD OF THE INVENTION 
     This invention relates to the field of automotive control and location determination. 
     BACKGROUND OF THE INVENTION 
     Automobile parking lots have grown in size due in part to the development of large department stores and shopping malls. Often times a driver of an automobile parks in the large parking lot for shopping or other business. When the driver returns to the parking lot the driver may not be able to remember the location of the automobile and thus can waste a significant amount of time hunting for the automobile in the large parking lot. Modem automobiles often are manufactured with a key having an attached remote transmitter that allows the driver to remotely lock or unlock the automobile while the automobile is within a limited wireless transmission range. Such remotes are also available on an after market installation basis. Often, the automobile will sound a horn, flash exterior lights or other audio/visual alert when the remote transmitter is activated in the vicinity of the automobile, thereby facilitating location of the automobile within the limited range. Unfortunately, this limited range between the transmitter and automobile and the limited range of the automobile&#39;s audio/visual alert only allows a driver to pinpoint the automobile location if the automobile is close to the driver. This method is of very little use in locating an automobile in a very large parking area or far from the driver. 
     The advent of global positioning systems (GPS) has allowed determination of a location virtually anywhere on the surface of the planet where the GPS signal can be received. However, consumer GPS devices are usually general purpose having a complex user interface an expensive display. Furthermore, many consumer grade GPS receivers have inaccurate pinpoint location and can only guide to a location which is close, but are incapable of pinpoint accuracy. Furthermore, GPS devices typically operate continuously and consume a large amount of power, thus rapidly depleting batteries used to power portable GPS receivers. 
     Thus, what is needed is a simple portable device for locating an automobile which takes advantage of the benefits of both GPS and remote transmitter location determination without rapidly depleting batteries powering the device. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 illustrates a remote transmitter and locator, or “lockator” operating in accordance with the present invention. 
     FIG. 2 shows a block diagram of an apparatus operating in accordance with the present invention. 
     FIG. 3 shows an illustration of the use of a device operating in accordance with the present invention. 
     FIG. 4 shows a flow diagram of a method operating in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 illustrates a remote transmitter and locator, or “lockator” operating in accordance with the present invention. The remote lockator  100  is preferably attached through a chain  102  to a key  104  for starting the automobile. Alternatively the key  104  and lockator  100  could be integrated or the mechanical key portion  104  and chain  102  eliminated. The remote lockator has lock and unlock buttons  106  and  108  for locking and unlocking the automobile. Pressing the lock button within the limited range between the automobile and remote lockator, the limited range may be as great as 30 meters or more, causes the automobile doors to lock. Pressing the unlock button within the limited range causes the automobile doors to unlock. Such locking and unlocking also causes the automobile to generate an audio and visual alert such as tooting the horn and flashing the lights. Such locking and unlocking may also activate and deactivate, respectively, an automobile alarm system. The remote lockator  100  also has a GPS receiver that, in response to pressing the lock button activates the GPS receiver and determines the location of the remote transmitter, which substantially corresponds to the stationary location of the vehicle. This location is indicative of the location of the parked automobile. Thus, the automobile is both locked and its location automatically determined by the single manual act of pressing of the lock button. Since drivers are used to locking their automobiles after parking, coupling locking to location determination automatically facilitates determination of the location of the parked vehicle by the simple act of locking it. Thus, the driver does not need to remember additional steps or operations to record the location of the parked vehicle other than the act of locking it. 
     Pressing the unlock button  108  with a second manual input causes transmission of the unlock signal to the automobile. If the automobile is within the limited range, the vehicle unlocks and an audio/visual alert generated facilitating pinpoint location of the automobile. If the driver is beyond the limited range and continues to hold the unlock button, the GPS receiver powers on and determines the current location of the driver and compares it to the stationary location of the automobile recorded when the lock button was pressed. The orientation of the remote transmitter is determined wherein the chain retainer  110  indicates the heading of the remote transmitter. Other heading indicators may be used, such as the key itself if the key and lockator are integrated, or the heading marker may be otherwise implied in the user interface configuration, or alternately all together eliminated. Thereafter left and right icons  112  and  114  are activated in order to guide the driver to the stationary location. If the vehicle is to the left then the left icon is displayed. If the vehicle is to the right of the heading, then the right icon is displayed. If the vehicle is along the heading then both icons are displayed. The icons may be flashed at a rate indicative of the distance to the automobile wherein the flash rate increases as the driver moves closer to the vehicle. A special alert may be generated if the distance between the driver and the stationary location increases rather than decreases. When the lockator determines that the distance between the driver and the stationary location is sufficiently small, the unlock transmitter is again activated, facilitating pinpoint location of the automobile by the toot of the horn and flash of lights of the automobile audio/visual alert. 
     In alternate embodiments, the lockator may have additional functions and/or buttons including opening doors or trunks and initiating panic alarms. 
     FIG. 2 shows a block diagram of an apparatus operating in accordance with the present invention. Lockator  100  has the aforementioned lock and unlock buttons  106  and  108  as well as left and right icons  112  and  114 . Battery  120  provides power for the functions of the locator. A controller  122  controls the operations of the locator and may be either a microprocessor on an application specific integrated circuit. The lockator includes a lock and unlock transmitter  124  for wirelessly transmitting signals to the automobile, including lock and unlock signals. The locator also includes a GPS receiver  130  for determining location. The GPS receiver may also include an electronic compass for facilitating determination of orientation. Alternatively orientation may be determined by determining location of movements of the locator, or other means know to those familiar with the art. A memory stores the stationary location of the automobile at location  132 , which is determined in response to receiving a manual input at the lock button  106 . The memory also stores current locations and orientation information at location  134 , which is determined in response to a manual input at the unlock button  108 . Direction vector and display control determine a direction vector by comparing the stationary location  132  and the current location and orientation  134  in order to determine a direction vector from the current to the stationary location. From the direction vector, distance information and left and right direction information is determined. A display  138  includes left and right icons  112  and  114  and is preferably two LEDs, one for each icon. Alternative displays are also contemplated, including a LCD or larger multi-function displays, such as a display found on a hand held personal computer integrating the simplified user interface and automotive control functions of the locator. 
     FIG. 3 shows an illustration of the use of a device operating in accordance with the present invention. An automobile  200  is parked in a parking lot. The driver presses the lock button on the locator at stationary location  202 . The lock signal is transmitted, a receiver  201  installed within the automobile  200  receives the lock signal and causes at least one door of the vehicle to lock. Both the vehicle is locked and the GPS location of the lockator is determined, the determined location substantially corresponding to the location of the automobile. Sometime later the driver desires to determine the location of the automobile at location  204 . The unlock button is pressed, since the lockator is beyond the limited range  206 , the unlock transmission is not received by the vehicle. Holding the unlock button causes the GPS receiver to activate and determine current location  204 . The compass determines the heading of the locator to correspond to North. Thereafter direction vector  207  is determined from the orientation  205 , current location  204  and stationary location  202 . Since the direction vector points to the left of the orientation, the left icon  112  is illuminated. Furthermore, the icon blinks at a rate indicative of the distance between locations  202  and  204 . Thereafter, the unlock button is released, the driver walks to the left and again presses the unlock button at location  208 . Since the lockator is still beyond the limited range  206  the unlock transmission is not received by vehicle  200 . Holding the unlock button causes the GPS receiver to determine the current location  208 . The compass determines the orientation of the locator to correspond to west. Thereafter, an new direction vector is determined (not shown). Since the direction vector points to the right of the orientation, the right icon  112  is illuminated. Furthermore, the right icon blinks at a faster rate at location  208  relative to the blink rate at location  204  because the vehicle is now closer. Thereafter, the unlock button is again released deactivating the GPS receiver. The driver walks to the right and again presses the unlock button at location  210 . Since the lockator is still beyond the limited range  206  the unlock transmission reception by vehicle  200 , it is not received. Holding the unlock button causes the GPS receiver to determine the current location  210 . The compass determines the orientation of the locator to correspond to north. Thereafter, a new direction vector is determined (not shown). Since the direction vector points in substantial coincidence with the orientation, both left and right icons  110  and  112  are illuminated. Furthermore, both icons blinks at a faster rate at location  210  relative to the blink rate at location  208  because the vehicle is now closer. If the driver continues to hold the unlock button and walk towards the vehicle, the blink rate will increase. When the lockator determines the unlock signal is likely to be received, corresponding to the distance being within circle  206 , the unlock signal is continuously transmitted for as long as the unlock button is pressed. When the automobile receives the unlock signal, the doors are unlocked and audio/visual alert generated by tooting the horn and flashing the lights. Since many commercial GPS receivers are not able to accurately pinpoint a location, the selective transmission of the unlock signal allows the driver to pinpoint the location of the vehicle when it is close, but does not expend power continuously transmitting the unlock signal when the vehicle is far from the driver. 
     It should be noted that a special alert may be generated if the distance to the stationary location increases rather than decreases. For example, if the orientation is south instead of north at location  210  and the driver proceeded south then the special alert would be generated. The special alert is preferably alternate flashing of the left and right icons. This gives the driver a clear indication of heading in the wrong direction. 
     FIG. 4 shows a flow diagram of a method operating in accordance with the present invention. In step  300 , the lock button is pressed by a manual input from the driver. Step  300  determines if a manual input is received at the lock button by being pressed. If true the lock signal is transmitted, the GPS receiver activated, location determined and saved in the stationary location and the GPS receiver deactivated at steps  302 - 310 . Note that the GPS receiver is activated only long enough to determine the stationary location and then automatically deactivated, thereby conserving lockator battery power. 
     If the lock button is not pressed at step  300  then step  312  checks for the unlock button to be pressed. Steps  300  and  312  are repeated until either button is positively pressed. Upon receiving a second manual input of pressing the unlock button, step  314  transmits the car unlock signal. The transmission may occur for a predetermined time, or the signal may be sent a preset number of times and the transmission of the signal terminated. If at step  316  the unlock button is not pressed then step  318  deactivates the GPS receiver, which is a non-event because it remained inactive in this portion of the example, and steps  300  and  312  are repeated. Thus, if the driver is close to the automobile, pressing the unlock button results in the doors unlocking and the driver observing the horn tooting and light flashing alert of the automobile. The driver then releases the unlock button in response thereto. Because of the delay associated with step  314 , the GPS receiver is never activated, thereby conserving lockator battery power. If the unlock button remains pressed, the driver has not likely heard the horn toot or seen the light flash and is thus likely far away from the automobile. In response, the GPS receiver is activated at step  320 , the current location is determined at step  324 , and the distance to the stationary location of step  306  determined at step  324 . Step  326  sets the icon blink rate in response to the distance determined at step  324 . The blink rate may be linearly or nonlinearly related to the distance and includes frequency or duty cycle modulation. The preferred blink rate has a constant frequency of one blink per second with an ON time of 95% if the lockator is substantially close to a 5% ON duty cycle if the lockator is more than one thousand yards away, with a linear variation there between. Step  328  determines if the distance to the automobile is increasing and generates a special alert. This is done by comparing distance from a new current position with the distance from a prior current position, if the new distance is substantially greater, by a predetermined amount of one yard for example, then the special alert is generated. The special alert may be the alternate flashing of the left and right icons, flashing of a third icon (not shown) or an audio alert. 
     Thereafter, step  332  determines the orientation of the lockator. This may be done with a electronic compass on an integrated circuit or successive GPS location measurements or other means known to those familiar with the art. Thereafter the direction vector to the vehicle is determined relative to the orientation of the lockator, as shown by arrow  207  of FIG.  3 . If the direction is to the left or right, then the left or right icon is set to blink at the blink rate of step  326 . If the vector is in substantial coincidence with the vector, then step  338  sets both left and right icons to blink at the blink rate of step  326 . Step  340  determines if the lockator&#39;s current position is close to the stationary position, if so, the unlock signal is transmitted from the lockator&#39;s transmitter for a predetermined time or number of unlock signals. Transmission of the unlock signal causes the automobile to generate an alert. This advantage is helpful for either of at least two reasons. First the GPS location system may not be accurate enough to pinpoint the location of the automobile, in which case the automobile alert provides a second locating system which facilitates the driver precisely locating the automobile after the GPS system brings the driver in close. Second, even if the GPS system is able to pinpoint the stationary location, the automobile alert could prove a substantially more convenient user interface than the lockator&#39;s left/right user interface in pinpointing the location of the automobile because of the driver&#39;s ears and eyes can more naturally locate the automobile. Furthermore, the stationary position may substantially albeit not precisely correspond to the location of the automobile because the lock button may be pressed a distance away from the automobile, the automobile alert may better facilitate the pin point location of the automobile by the driver when the driver is close. 
     Thereafter, step  316  is returned to and steps  320  to  340  are repeated until the unlock button is released. Upon release of the unlock button the GPS receiver is deactivated. The driver may press and hold the unlock button allowing constant update of the left and right icon display. Although this may increase battery power consumption, the driver may rotate position left or right in response to the icons until both icons are ON indicating the direction of the vehicle, with the blink rate indicating the distance to the vehicle. By taking a few steps in the indicated direction, the driver may be assured that the distance to the vehicle is being reduced by the absence of a special alert. The continued blinking of the icons at an increasing duty cycle indicates the driver is traveling closer to the vehicle. In an alternate embodiment the left and right icons may be eliminated in favor of an icon that indicates simply that the distance is increasing or decreasing. 
     It should be noted that the lockator&#39;s operation facilitates conservation of battery power. The transmitter is only powered ON in response to pressing the lock or unlock buttons, and automatically powers off. Similarly, the GPS receiver only powers ON in response to the lock button being pressed and automatically switches OFF after determining the stationary location. Also, the GPS receiver only powers ON after the unlock button is pressed and held, giving the driver time to listen or observer the automobile&#39;s alert, before the GPS receiver is powered ON. Thereafter, the GPS receiver remains ON for so long as the unlock button is pressed. However, the unlock transmitter is inhibited until the distance to the automobile is such that the unlock signal is likely to be received, thereby conserving power. It should be further noted that the locator and lock/unlock receiver incorporated in the automobile may be either original equipment in a new automobile, or incorporated on an after market basis. The after market allows the lockator to be used with existing vehicles which do not have integral GPS systems. 
     Numerous alternate embodiments are within the scope of the invention. For example, the lockator could have a third unlock button for continuously transmitting the unlock signal when pressed. This would be useful if the driver knew the location of the vehicle and did not require the activation of the GPS receiver, thereby conserving lockator battery power. In this embodiment, step  314  could optionally be eliminated. In yet another alternate embodiment, if the automobile had an integral GPS receiver, the stationary location could be determined by the automobile&#39;s GPS receiver and communicated electronically to the lockator when the vehicle&#39;s ignition was stopped or the key and lockator assembly removed, thereby conserving power required for the lockator&#39;s GPS receiver to determine the stationary position. The manual act by the driver of turning off the vehicle&#39;s ignition or key removal is also indicative of the vehicle being in a stationary mode and thus having a stationary location. The stationary location could be communicated through a detachable connector or through a wireless communication protocol such as Bluetooth or 902.11b. In yet another embodiment, the simple manual act of the driver opening the door and/or walking away from the vehicle with the lockator could be a sufficient manual input to either cause communication of the stationary location from the automobile or cause the lockator to determine the stationary location. In yet another embodiment, another type of location/orientation determining system may be used, other than GPS. 
     Thus, what is provided is a simple portable device for locating an automobile which takes advantage of the benefits of both GPS and remote transmitter location determination without rapidly depleting batteries powering the device.