Abstract:
A method is used to identify a plurality of tires of a motor vehicle by location allowing a sensed parameter of each of the plurality of tires to be monitored. The method incorporates the use of a central receiver, a plurality of sensors, a plurality of transmitters and a mobile training unit. The method includes the steps of moving the mobile training unit to a location adjacent one of the plurality of tires. Once there, the operator inputs manually the location of one of the plurality of tires with respect to the motor vehicle. The mobile training unit transmits the location to the adjacent sensor. The sensor identification is paired with the location in the sensor to create paired data. The method concludes with transmitting the paired data from the sensor to the central receiver allowing the central receiver to identify one of the plurality of tires by the paired data when the transmitter of one of the plurality of tires transmits a signal based on the identification signal and the parameter sensed by one of the plurality of sensors.

Description:
BACKGROUND ART 
     1. Field of the Invention 
     The invention relates to a method for monitoring parameters of tires of a motor vehicle. More specifically, the invention relates to a method for monitoring parameters of each tire of the motor vehicle in an energy efficient manner. 
     2. Description of the Related Art 
     Systems have been developed to monitor parameters of tires for motor vehicles. These systems use sensors mounted inside the tires of the motor vehicle to directly measure the parameters desired. These sensors then transmit the information to a receiver on the motor vehicle to be displayed for the operator of the motor vehicle. Because tires are rotated and periodically changed, a common problem with these systems is identifying from which tire location the transmission is emanating. 
     Methods for determining sensor location have been devised. Many of these methods involve having the receiver initiate a training mode. In the training mode, a controller transmits to each of the sensors inside the tires to transmit a signal to the receiver in a predetermined order, e.g., right-front, left-front, left-rear and right-rear. The operator of the vehicle must go to each tire and initiate the transmission of the signal from that particular tire. Requiring the operator to follow a particular tire transmission pattern when training the system oftentimes leads to errors. This is because the receiver receives four different signals and operates under the assumption that the transmission of those signals was in the proper order. 
     U.S. Pat. No. 6,414,592 discloses one solution for the training mode of the monitoring system. In this reference, a manually actuated transmitter creates a manual input location identification. The sensor within the tire receives the manually input location identification and stores that information and transmits this information every time the sensor is queried. When the position of the tire is changed, the manually input location identification is changed at that time. This system operates when the sensor identifies itself, its location and then transmits the parameter it senses. In this reference, the sensed parameter is pressure. 
     Because the sensor contemplated in this reference is located within the tire, it relies on a battery for its power. Transmitting the location of the sensor consumes battery power and is often redundant. More specifically, the sensor transmits its location every time it transmits a parameter signal, regardless of whether the tire has been rotated to a new position or not. Should the battery exhaust its potential, the tire must be removed from the wheel and the battery must be replaced. Operators of motor vehicles tend to consider this system non-operational due to its high maintenance and the time and cost associated with replacing the batteries. 
     SUMMARY OF THE INVENTION 
     A method identifies a plurality of tires of a motor vehicle by location to sense a parameter of each of the plurality of tires. The method incorporates the use of a central receiver, a plurality of sensors, a plurality of transmitters and a mobile training unit. The method includes the steps of moving the mobile training unit to a location adjacent one of the plurality of tires. Once there, the operator inputs manually the location of one of the plurality of tires with respect to the motor vehicle. 
     A sensor identification is retrieved from one of the plurality of sensors at the one of the plurality of tires. The location information and the sensor identification for that particular sensor are paired together to create paired data. The paired data is then transmitted from the sensor to the central receiver allowing the central receiver to identify one of the plurality of tires by the paired data when the transmitter of the one of the plurality of tires transmits a signal based on the identification signal and the parameter sensed by the one of the plurality of sensors. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Advantages of the invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: 
     FIG. 1 is a top view of a motor vehicle, partially cut away, utilizing the inventive method; 
     FIG. 2 is a block diagram of the mobile training unit; 
     FIG. 3 is a block diagram of the sensor and transmitter located in each tire of the motor vehicle; 
     FIG. 4 is a block diagram of the central receiver located within the motor vehicle; and 
     FIGS. 5A through 5C are logic diagrams for one embodiment of the inventive method. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, a monitoring assembly is generally indicated at  10 . The monitoring assembly  10  is hosted by a motor vehicle  12 . The motor vehicle  12  includes a front driver side tire  14 , a front passenger side tire  16 , a rear driver side tire  18 , a rear passenger side tire  20  and a spare tire  22  (the tires  14 - 22 ). The motor vehicle  12  also includes a passenger compartment  24  having a steering wheel  26  disposed in front of a driver seat (not shown). 
     The monitoring assembly  10  includes a central receiver  28  and an antenna  30  electrically connected thereto. It should be appreciated by those skilled in the art that the central receiver  28  and antenna  30  are graphically shown in FIG. 1 at a location proximate the driver seat and steering wheel  26 . Other locations for the central receiver  28  and antenna  30  within the motor vehicle  12  may be acceptable, depending on the design of the monitoring assembly  10 . The central receiver  28  receives signals from the antenna  30 . 
     The monitoring assembly  10  also includes a plurality of sensors  32 , each associated with one of the tires  14 - 22 . Each of the plurality of sensors  32  is located within each of the tires  14 - 22  allowing it to sense a parameter of each of the tires  14 - 22 . A non-exhaustive list of parameters that may be sensed by the sensors  32  include pressure and temperature. 
     The monitoring assembly  10  also includes a mobile training unit  34 . The mobile training unit  34  is selectively connectable with the monitoring assembly  10  through a wireless protocol allowing it to move about the motor vehicle  12  while transmitting data to the central receiver  28  through the antenna  30 . 
     Referring to FIG. 4, the central receiver  28  is shown in greater detail. The central receiver  28  includes a receiver  36  that is electrically connected to the antenna  30  via conductor  38 . The receiver  36  receives signals  40 , then transmits the signals  40  to a controller  42  via an electrical conductor  43 . The controller  42  includes memory  44 , discussed in greater detail subsequently. The central receiver  28  is powered by a power source  46 . The power source  46  is graphically represented and may be a battery, transformer, or a connection to a power generating source, e.g., the alternator of the motor vehicle  12 . 
     Depending on the signals  40  received by the central receiver  28 , an output is generated by the controller  42  and transmitted to a tire condition indicator display  48 . Referring back to FIG. 1, the tire condition indicator display  48  is disposed adjacent the steering wheel  26  at a location visible by the operator of the motor vehicle  12 . While the tire condition indicator display  48  is contemplated as a visual indicator, it should be appreciated by those skilled in the art that an audible indication may be included with the tire condition indicator display  48 . 
     Referring to FIG. 3, one of the plurality of sensors  32  is shown in greater detail. Each of the sensors  32 , mounted to the interior of the tires  14 - 22  through methods known in the art, includes a sensing element  50 . The sensing element  50  receives conditions in the tires  14 - 22  through a port  52 . In one example, the port  52  would be an opening in a sensor housing leading to a diaphragm at the sensing element  50  allowing the sensing element  50  to sense the pressure of the host tire. There may be more than one sensing element  50  in each sensor  32  should more parameters be monitored. 
     The sensing element  50  transmits a signal of the parameter sensed by the sensing element  50  to a sensor controller  54 . The sensor controller  54  generates a signal based on the signal received from the sensing element  50  and transmits that signal to a sensor transmitter  56 . The sensor transmitter  56  transmits the signal  40  using a sensor transmitting antenna  58 . 
     The sensor  32  also includes a training receiver  60  that is also electrically connected to the sensor controller  54 . The training receiver  60  receives signals from a training receiver antenna  62 . The training receiver antenna  62  receives a trainer signal  64 , discussed in greater detail subsequently. 
     The sensor  32  also includes an internal power source  66  that provides power to the sensing element  50  and the sensor controller  54 . The internal power source  66  is the only source of energy available to the sensor  32 . Therefore, the internal power source  66  must be sufficient to supply power to the sensor  32  through the life of the sensor  32 , which should equal or exceed the life of the tire  14 - 22 . If the internal power source  66  is not adequate, the sensor  32  will have to be changed resulting in the dismounting of the tire  14 - 22  from its wheel prematurely. 
     Referring to FIG. 2, the mobile training unit  34  is shown in greater detail. The mobile training unit  34  is a handheld device designed to move to locations disposed adjacent each of the tires  14 - 22 . The mobile training unit  34  includes a power source  68  that may be batteries, rechargeable batteries and the like. The power source  68  provides power to a training controller  70 . The training controller  70  receives inputs from an input keypad  72  and a training receiver  74 . The training controller  70  transmits information to a display  76 , via the input keypad  72 , and a training transmitter  76 . The training transmitter  76  transmits the trainer signals  64  through a training transmission antenna  78 , whereas the training receiver  74  receives signals  40  from a training receiving antenna  80 . 
     Referring to FIGS. 5A through 5C, logic diagrams of the inventive method are shown. The method shown in FIG. 5A represent the method utilized by the mobile training unit  34 . The method begins at  86 . The method would begin when the ignition is operated to power the motor vehicle  12 . The mobile training unit  34  is moved to one of the tires  14 - 22 . This step occurs at  86 . The location of the tire  14 - 22  that is being trained is identified at  88 . Identification occurs by the operator of the mobile training unit  34  manually inputting the location of the tire being trained using the input keypad  72 . The input keypad  72  may have as few as five buttons, each identifying one of the five standard locations in which the tires  14 - 22  are located. The input strokes into the input keypad  72  are displayed at  76  ensuring the operator has an opportunity to correct any accidental miskeying. 
     Once the tire location is entered, it is forwarded to the sensor  32  in the tire  14 - 22  at  90 . The mobile training unit  34  then determines whether the sensor  32  responds by return transmission at  92 . If received, it is determined at  94  whether the transmission from the sensor  32  includes the training code. If so, the mobile training unit  34  displays an identification number associated with the trained location at  96  and waits for the mobile training unit  34  to be moved to another tire  14 - 22 , (step  86 ). 
     FIG. 5B represents the method of operation for each of the plurality of sensors  32 . It begins with the sensor  32  resting in standby mode until it receives a transmission from the mobile training unit  34 . This listening step occurs at  98 . It is determined whether the sensor  32  has received a transmission from the mobile training unit  34  at  100 . If the sensor  32  does not receive such a transmission, the sensor  32  operates in a normal manner in which it measure the parameter it is designed to do at  106 . Once measured, it transmits the code, measured information and sensor identification number to the receiver  36  at  108 . 
     If the sensor  32  does receive a transmission from the mobile training unit  34  at  100 , it accepts the identification information transmitted by the mobile training unit  34  at  102 . It then transmits to the mobile training unit  34  the training code, the location information and the sensor identification number at  104 . 
     Referring specifically to FIG. 5C, the receiver  36  is shown to operate a method shown. This method begins at  110  with the receiver  36  waiting for a signal from a sensor  32 . It is determined at  112  whether a signal is received. If not, the method is looped back to the start of the method at  110  and waits to receive a signal from one of the sensors  32 . 
     If a signal is received, it is determined at  114  whether a training code is a part of the transmission. If so, it pairs the tire location information and the identification information of the sensor  32  in memory  44 . The method then loops back to the beginning at  10  where the receiver  36  awaits a new signal from any one of the plurality of sensors  32 . 
     If the transmission received at  114  does not include a training code as a part thereof, it begins to evaluate the data transmitted thereby at  118 . It determines whether the parameter is below a predetermined level at  120 . In FIG. 5C, the parameter is pressure. It should be appreciated by those skilled in the art that other parameters of the tires  14 - 22  may be sensed depending on the data desired to be measured. If the parameter is not below the predetermined level, the method loops back to the beginning at  110  and waits for a new signal from one of the plurality of sensors  32 . If the data received indicates a parameter is below a predetermined amount, the driver of the motor vehicle  12  is notified by generating a warning signal at  122 . The warning signal is generated by the controller  42  and displayed or emitted from the tire condition indicator display  48 . Once the warning signal is generated, the method is looped back to step  110  allowing the central receiver  28  to receive data from any one of the plurality of sensors  32 . 
     The receiver  36  then cycles back to the beginning of the method where it awaits another signal from one of the sensors  32  at  110 . The receiver  36  will cycle through all of signals received from all of the plurality of sensors  32  as they are received thereby. 
     As the central receiver  28  receives the paired data from each sensor  32 , the central receiver  28  can store the paired data in the memory  44 . Therefore, the location of each of the sensors  32  is not stored at the sensor  32 , but at the central receiver  44 . This eliminates the need for each of the plurality of sensors  32  to transmit its respective location every time the sensor may transmit data relating to the condition of each of the tires  14 - 22 . When a location is stored, the central receiver  44  signals the operator by honking the horn, flashing the lights, or other obvious means so that the operator will know that the central receiver  44  has indeed received the information. 
     If the transmission received does include a training code, the location information and sensor identification that defines the paired data is stored into memory at  116 . The method then notifies the operator that the sensor location has been recorded at  124  in a manner similar to that which as discussed above for the notification step  122 . 
     The invention has been described in an illustrative manner. It is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation. 
     Many modifications and variations of the invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the invention may be practiced other than as specifically described.