Abstract:
A mobile computer that can be borne in a vehicle and that can receive position information may adjust a maximum speed limit to account for unfavorable weather or road conditions and cause the vehicle to automatically reduce speed below the adjusted maximum limit.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to automatically adjusting a maximum speed limit value for road conditions and to automatically reducing a vehicle&#39;s speed to below the adjusted limit. 
     BACKGROUND OF THE INVENTION 
     Electronic roadside signs have been provided to post speed limits. Because the signs can be controlled by a remote facility, the posted speed limits may be easily changed. However, as understood herein these signs are relatively large and require significant infrastructure and cost. 
     SUMMARY OF THE INVENTION 
     A mobile computer that can be borne in a vehicle is configured to receive position information. The computer is also configured to communicate a speed limit associated with the position information and adjusted to account for road conditions to cause a vehicle to automatically reduce speed below an adjusted maximum limit. 
     The mobile computer may be configured to access a database of speed limits. It may further be configured to communicate with a sender of road conditions to receive the road conditions therefrom. The computer can be configured to apply rules to the road condition and to output an adjusted speed limit associated with the position information. 
     Alternatively, the computer can be configured to receive from a base station a speed limit adjusted for road conditions. To this end, an advanced televisions systems committee (ATSC) tuner can be provided in the computer. 
     In another aspect, a tangible computer storage medium is readable by a processor to automatically limit a vehicle maximum speed in response to an upper speed limit modified by application of rules relating to road conditions such that the vehicle may travel at any speed up to but not exceeding the upper speed limit. 
     In still another aspect, a method includes receiving a geographic position and accessing a database of speed limits to determine a nominal speed limit associated with the geographic information. The method also includes accessing current road condition information for the speed limit. If the current road condition information warrants, the method adjusts down the speed limit to render a modified speed limit. 
     The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of a non-limiting system in accordance with present principles; and 
         FIG. 2  is a flow chart of non-limiting logic which may be undertaken by one or more processors executing code elements stored on one or more computer readable media. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring initially to  FIG. 1 , a mobile computer is shown, generally designated  10 , that includes a processor  12  and tangible digital storage medium  14  that may be, without limitation, a magnetic or optical disk drive, a solid state device such as random access memory or read-only memory or flash memory, a removable stick medium or removable floppy disk, etc. The medium  14  and processor  12  may be stored in a computer housing  16  as shown along with a display  18  such as but not limited to a high definition (HD) matrix display or a standard definition cathode ray tube display. The processor  12  may output signals to the display  18  and to one or more audio speakers  20 , and it may receive input from an input device  22  such as one or more of a keypad, keyboard, mouse, etc. 
     As shown in  FIG. 1 , in some embodiments the mobile computer  10  can also include a position receiver  24  such as a global positioning satellite (GPS) receiver that inputs position signals to the processor  12 . Some embodiments of the mobile computer  10  may further include a unidirectional receiver  26  such as but not limited to an advanced televisions systems committee (ATSC) tuner. The processor  12  can cause signals from the receiver  26  to bc presented on the display  18 . In the embodiment shown, the ATSC receiver  26  can also receive non-video data for purposes to be shortly disclosed. 
     In the non-limiting implementation shown in  FIG. 1 , the mobile computer  10  additionally includes a long-range wireless transceiver  28  such as a WiFi transceiver, WIMAX transceiver, or telephone transceiver such as a global system for mobile communication (GSM) transceiver, code division multiple access (CDMA) transceiver or variant, etc. The transceiver  28  communicates with the processor  12 . 
     In some embodiments, the mobile computer  10  can further include a Bluetooth transceiver  30  or other short-range interface useful for communicating with a complementarily configured receiver interface  32  of a vehicle  34 . In this way, signals may be sent from the mobile computer  10  to an engine control module (ECM)  36  or other computer in the vehicle  34 . The ECM  36  typically receives signals from, among other things, a speed sensor  38  onboard the vehicle  34  for control of, e.g., an engine throttle  40  of the vehicle  34  in a cruise control mode. 
     The mobile computer  10  can receive information via one or more of the receiver  26  and transceiver  28  from one or more wireless base stations  42 , each of which typically has a communication interface  44 , processor  46 , and computer readable medium  48 . 
       FIG. 2  shows logic in accordance with present principles that may be executed by one or more of the processors above accessing computer-readable instructions on one or more of the above-described computer readable media. Commencing at block  50 , information pertaining to the current geographic position of the mobile device  10  (and, hence, any vehicle  34  in which it happens to be disposed) is received by the position receiver  24 . In some embodiments the receiver  24  may be mounted directly in the vehicle and not on the mobile device  10 , in which case the position can be sent from the ECM  36  to the processor  12  of the mobile device  10  using, e.g., the Bluetooth transceiver  30 . 
     At block  52 , a speed limit database is accessed to determine the published speed limit for the current position received at block  50 . The processor  12  may access the medium  14  within the mobile device  10  for this purpose, or the base station processor  46  may access the database as it may be stored on, e.g., the medium  48  in the base station  42 . The base station  42  may then send the relevant speed limit (i.e., the speed limit for the current position) to the mobile device  10 . 
     Proceeding to block  54 , current road condition information (including weather information, which affects road condition) is accessed. For this purpose, the base station  42  may send road condition information to the mobile device  10  via, e.g., the tuner  26  or the long range transceiver  28 , or the subsequent logic at block  56  may be executed internally at the base station  42 . In any case, the road condition information may be accessed from, e.g. a state road condition information server on the Internet or a National Oceanic and Atmospheric Administration (NOAA) weather information site or other appropriate source. 
     At block  56 , the published (“nominal”) speed limit can be adjusted in accordance with the road condition information received at block  54 . Typically, the published maximum limit is reduced for less than optimum road conditions; it is never increased. The rules for adjusting the speed limit may be universal or the rules may differ for each road or group of roads. The rules may be statistic-based or empirical. 
     By way of non-limiting example, a published speed limit of 65 mph may be reduced by 10 mph any time rain is indicated at block  54  for any and all roads having posted speed limits of 65. Or, the limit may be reduced by 5 mph for one road and 10 mph for another, different road when rain is indicated. Freezing rain mat result in greater reduction in speed limit. 
     Yet again, if statistics on one road indicate that most accidents occur in the rain at speeds in excess of 50 mph, while statistics on another road indicate that most accidents occur in the rain at speeds in excess of 40 mph, the speed limit for the first road may adjusted down to 45 mph while the speed limit for the second road may be adjusted down to 35 mph. 
     As further non-limiting examples, if road conditions indicate a single lane closure in the vicinity, a 10 mph reduction in speed limit may be effected, whereas a two lane closure may result in a 20 mph reduction. Statistics may be used in establishing these reduction amounts, e.g., if statistics show that on a 65 mph highway, a single lane closure leads to a spike in accidents at average speeds of 55 mph and greater, the speed limit may be adjusted down to 50 mph (i.e., reduced by 15 mph from the otherwise “nominal” limit) for single lane closures on that road. As mentioned above, such a rule may be universally applied or applied on a road by road basis. 
     The logic at block  56  may be executed by the mobile device  10 , in which case the processor  12  receives the road condition information at block  54  from, e.g., a base station  42 . Or, the logic at block  56  may be executed by the base station  42  and then the adjusted speed limit sent to the mobile device  10  using the above-described transmission paths. 
     At block  58 , the adjusted limit is presented on the display  18 /speakers  20 . In this way, no large roadside signage is required, and the speed limit may be dynamically changed and presented to the driver. Further, not only may a government agency change the published, “nominal” speed limit directly, but present principles envision an automatic reduction in the speed limit presented to the driver based on less than optimum road conditions. 
     Also at block  58 , the speed of the vehicle  34  may be automatically reduced to be no greater than the adjusted speed limit. To this end, the mobile device processor  12  may communicate the adjusted speed limit to the ECM  36  using, e.g., the Bluetooth transceiver  30 , with the ECM then controlling the throttle  40  to ensure that the speed of the vehicle as indicated by the speed sensor  38  does not exceed the speed limit as adjusted for road conditions at block  56 . 
     While the particular AUTOMATIC SPEED LIMIT ADJUST FOR ROAD CONDITIONS is herein shown and described in detail, it is to be understood that the subject matter which is encompassed by the present invention is limited only by the claims.