Abstract:
A vehicle system and method that include a smart phone for communicating with a vehicle by an authorized user. The vehicle includes an FM transmitter that transmits vehicle information, including an authorization code, using an FM signal. The FM signal is received by the smart phone which deciphers the information, and automatically transmits a command signal back to the vehicle to perform a pre-programmed vehicle operation, such as unlocking the vehicle doors.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of the priority date of U.S. Provisional Patent Application Ser. No. 61/424,488, titled Vehicle Data Services Enabled by Low Power FM Transmission, filed Dec. 17, 2010. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to a vehicle system and method where a vehicle transmits FM signals to a smart phone and, more particularly, to a vehicle system and method where a vehicle transmits vehicle information on an FM frequency band that is received by a smart phone, and where the smart phone transmits a command signal back to the vehicle to perform some operation in response to receiving the FM signal. 
     2. Discussion of the Related Art 
     Modern vehicles typically include a key fob that wirelessly transmits RF command signals to a vehicle controller to perform certain vehicle functions, such as lock the doors, unlock the doors, open the trunk, open the hatch, start the engine, turn on a security light, etc. The vehicle operator will press a particular push button on the key fob that typically has an image of the function that the button provides in order to transmit the command signal to the vehicle. The transmission is coded in such a manner that not only does the command perform a certain operation, but also protects the transmission from being recorded and resent by a third party. Key fobs of this type typically have a limited range, and provide a convenience factor for the vehicle operator. 
     Modern vehicles also typically allow a vehicle driver to set various vehicle devices and systems, such as vehicle mirrors, seats, pedals, radio, etc., to a particular desirable setting, and then allow the driver to record those settings as pre-sets by activating a storing button. If the settings are changed from the last time the vehicle driver drove the vehicle, such as by another vehicle driver, then that vehicle driver can activate the pre-sets, such as by pressing the storing button or another button, so that all of the devices are returned to the desirable position for that driver. A signal transmitted from the key fob identifying the vehicle driver can be used to set the various vehicle devices and system to the pres-set conditions, where the particular key fob is unique to the vehicle driver. 
     Systems have been proposed for a vehicle that cause a vehicle door handle to retract into the vehicle door for security purposes and upon detection of an authorized user will extend the handle to allow the driver to gain access to the vehicle. Current systems that deploy a vehicle handle from a retracted position may require about ten feet between when an authorized vehicle user is detected and when the user arrives at the vehicle to perform the operation satisfactorily. 
     As mentioned above, a typical system that allows a key fob to provide vehicle commands is activated by the vehicle driver or other authorized user using the key fob. It is desirable in some vehicle designs to cause the vehicle to perform the particular function automatically as the user approaches the vehicle, where the user is not required to actively transmit the signal. One known system, referred to as a passive entry passive start (PEPS) system, periodically interrogates or polls the area immediately around the vehicle to detect the key fob using a low frequency (LF) pulsed signal (30-300 kHz) transmitted from the vehicle at a predetermined pulse rate. The pulse width and the pulse rate of the polling signal is set based on how fast the user could be approaching the vehicle and how far from the vehicle it is desirable to first detect the user. When the key fob receives the low frequency pulsed polling signal, and authenticates it, the key fob will automatically transmit a command signal to the vehicle so that the vehicle will perform the particular function that is has been programmed to perform. 
     Low frequency signals are typically used for the key fob polling because they only radiate a short distance. Further, because of the short range of the low frequency pulsed polling signal, it is possible to interrogate directionally, such as at the left or right side of the vehicle or the front or rear of the vehicle. Thus, because the vehicle can know the direction of the approaching user, the vehicle need only open the door for that side. 
     Generating and transmitting low frequency signals typically requires a large amount of current, typically on the order of about 700 mA, for each pulse that is transmitted. Therefore, the amount of time that the vehicle is able to provide the pulsed polling signal at the low frequency before the vehicle battery voltage is reduced to an unacceptable state-of-charge, below which the driver may not be able to start the vehicle, is relatively short, for example, on the order of 12-24 hours. When this time has passed since the last time the vehicle was started, the PEPS system will go into a sleep mode, and not be able to provide the polling signal. 
     SUMMARY OF THE INVENTION 
     In accordance with the teachings of the present invention, a vehicle system and method are disclosed that include a smart phone for communicating with a vehicle by an authorized user. The vehicle includes an FM transmitter that transmits vehicle information, including an authorization code, using an FM signal. The FM signal is received by the smart phone which deciphers the information, and automatically transmits a command signal back to the vehicle to perform a pre-programmed vehicle operation, such as unlocking the vehicle doors. 
     Additional features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  is an illustration of a vehicle system including a vehicle communicating with a smart phone. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The following discussion of the embodiments of the invention directed to a vehicle system including a vehicle that communicates with a smart phone over the FM frequency band is merely exemplary in nature, and is in no way intended to limit the invention or its applications or uses. 
     As will be discussed in detail below, the present invention proposes a technique that leverages, for example, a Bluetooth pairing process between a consumer&#39;s smart phone/consumer electronic (CE) device and a vehicle to secure the communications between the vehicle and the CE device and to determine if the CE device is an authorized device. Bluetooth device pairing is well understood by those trained in the art and can be accomplished by three methods, namely, ‘Just Works’, ‘Alphanumerical Key Entry’ and ‘Out of Band’ key exchange. In all three methods, the pairing devices exchange information including the exchange of private information that is only known to the pairing devices. This private information is used to establish connections in future encounters. For example, when pairing a CE device with a vehicle, the CE device and the vehicle exchange information known only to those two devices. The next time the CE device and vehicle are within the Bluetooth radio frequency range, the devices can automatically establish a Bluetooth session based on the private information that was previously shared between the devices. This invention employs that private information, but in the FM frequency communications band. That is, the CE device and the vehicle exchange the private Bluetooth information over the FM frequency band. Thus, the CE device and the vehicle are able to verify/confirm that the CE device and vehicle are authorized devices. The private information can also be used to secure the data exchange between the CE device and the vehicle through encryption processes that uses the private information as an encryption key, which is well known to those trained in the art. 
       FIG. 1  is an illustration of a vehicle system  10  including a vehicle  12  in communication with a smart phone  14 , which is intended to generally represent the CE device discussed above, that can be carried by an authorized user of the vehicle  12 . The vehicle  12  includes an FM transmitter  16  that transmits a signal  18  in the FM frequency band including various vehicle information and data, such as fuel level, battery state-of-charge, tire pressure, etc. Any information about the vehicle  12  concerning the status of the vehicle  12  can be provided on the signal  18  that may be of interest to the user. The smart phone  14  receives the signal  18  from the vehicle  12  and, as the authorized smart phone  14  for the vehicle  12 , is able to decipher the information and data using a compatible application  34  stored on the phone  14 . The vehicle information can be displayed on a display screen  20  on the phone  14 . The smart phone  14  can use the information from the vehicle  12  in any number of different ways. 
     When the smart phone  14  receives the signal  18 , the application  34  can also cause the phone  14  to send a command signal  22  back to the vehicle  12  to cause the vehicle  12  to automatically perform some predetermined vehicle operation, such as unlocking the vehicle doors, opening a back hatch, rolling down windows, starting the vehicle  12 , etc., without intervention by the user. The vehicle  12  includes various modules that perform various operations on the vehicle  12  in response to receiving the command signal  22 , such as a body control module (BCM)  24  and a vehicle control module  26 , all well known to those skilled in the art. The vehicle  12  can also include security lights  28  and  30  that can be automatically turned on in response to receiving the command signal  22 , and retractable door handles  32  in the doors of the vehicle  12  that can be extended automatically upon receiving the command signal  22 . The application  34  can be tailored for any particular user and any particular vehicle to perform various operations automatically that the user desires. 
     Because most vehicles have FM radios, they are already equipped with the components necessary to be used in association with the FM transmitter  16 , such as an antenna, coaxial cable, etc., to transmit the FM signal  18 . Low power FM transmissions are commonly used on CE portable devices as an audio interface to a vehicle entertainment system to play MP3 signals and otherwise. Thus, the vehicle  12  can be readily equipped to transmit a low power FM signal with specific vehicle information and coding. In one non-limiting embodiment, the FM transmitter  16  transmits the signal  18  about once every second suitable for the purposes described herein. The rate at which the pulses are transmitted could depend on the range and distance that the smart phone  14  can receive the transmissions from the vehicle  12 . The transmission signal  18  would consume about 1 mA of current for each transmission pulse, which is significantly lower than the PEPS polling signal discussed above. 
     The current trend in smart phone technology, such as the current generation of Android phones, is to include FM radios along with the other various systems and applications on the phone. Thus, the smart phone  14  is able to receive and demodulate FM frequencies, and when it receives a particular FM frequency signal transmitted by the vehicle  12 , and includes the proper application  34 , will be able to decode and download information about the vehicle  12  provided on the signal  18 . The application  34  on the smart phone  14  receives the FM signal, checks the vehicle information and code, and if the FM signal is from an authorized vehicle  12 , the phone  14  enables various applications and data exchange with the vehicle  12 . The FCC allows low power FM transmissions without a user license. By complying with the low power requirements of FCC part  15 , the range of the FM transmission signal  18  from the vehicle  12  is limited to the immediate vicinity of the vehicle  12 . 
     Current smart phones do not include FM transmitters, only receivers, and therefore the command signal  16  transmitted from the smart phone  14  back to the vehicle  12  needs to be in some other format other than FM. The present invention contemplates any suitable short range peer-to-peer transmission format, such as Bluetooth™, WiFi™, etc. Also, the smart phone  14  can transmit the command signal  16  to the vehicle  12  through the cellular telephone system including using GM&#39;s Onstar™ system. 
     As will be well understood by those skilled in the art, the several and various steps and processes discussed herein to describe the invention may be referring to operations performed by a computer, a processor or other electronic calculating device that manipulate and/or transform data using electrical phenomenon. Those computers and electronic devices may employ various volatile and/or non-volatile memories including non-transitory computer-readable medium with an executable program stored thereon including various code or executable instructions able to be performed by the computer or processor, where the memory and/or computer-readable medium may include all forms and types of memory and other computer-readable media. 
     The foregoing discussion disclosed and describes merely exemplary embodiments of the present invention. One skilled in the art will readily recognize from such discussion and from the accompanying drawings and claims that various changes, modifications and variations can be made therein without departing from the spirit and scope of the invention as defined in the following claims.