Abstract:
A system and method for determining a traffic condition of a vehicle includes receiving status information of a plurality of vehicles, the status information including at least a speed of the respective vehicle. An average speed is determined according to the speed included in the status information of a first group of vehicles among the plurality of vehicles satisfying a first condition. An indication of the determined average speed is provided to a driver of a first vehicle.

Description:
FIELD OF THE INVENTION 
   The present invention relates generally to motor vehicles and, more particularly, to a vehicle and method for determining traffic conditions ahead of a vehicle. 
   BACKGROUND OF THE INVENTION 
   To determine traffic conditions on various roads, a driver typically must listen to local traffic news on the radio or television or visit a traffic information site on the Internet. Both of these modes for determining traffic conditions have various drawbacks. First, the traffic conditions reported on the radio, television or the Internet are generally reported late, i.e., the traffic reports refer to conditions as they existed some time before the report is made. Second, the traffic conditions are often reported irregularly or only after relatively long increments of time. In addition, the traffic reports are often limited to certain roads and may not include conditions for a road that a driver intends to take. As a result, when a driver needs to make a decision about which route to take to a destination, the driver may not be able to get the traffic information or only have limited or old traffic information available to make the decision. 
   It would be desirable to have a system for receiving up-to-date and relevant traffic related information. 
   SUMMARY OF THE INVENTION 
   According to an aspect of the invention, a system and a method for determining a traffic condition of a vehicle includes receiving status information of a plurality of vehicles, the status information including at least a speed of the respective vehicle. An average speed is determined according to the speed included in the status information of a first group of vehicles among the plurality of vehicles satisfying a first condition. An indication of the determined average speed is provided to a driver of a first vehicle. 
   Further features, aspects and advantages of the present invention will become apparent from the detailed description of preferred embodiments that follows, when considered together with the accompanying figures of drawing. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a block diagram of a traffic control system consistent with the present invention. 
       FIG. 2  is a flow diagram of a traffic control process consistent with the present invention. 
       FIG. 3  is a block diagram of an alternative communication arrangement for the traffic control system of  FIG. 1 . 
       FIG. 4  is a graphical representation of an exemplary display for a vehicle in the traffic control system of  FIG. 1   
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   Wireless communication between vehicles and to and from other structures and devices can provide for a significant increase in the amount and types of information available to vehicles and drivers, as well as the potential for a variety of new applications and systems ranging from crash avoidance to Internet entertainment systems. Systems such as telephony and Dedicated Short Range Communications (DSRC) are capable of supporting wireless communication between vehicles. For example, using a DSRC system, each vehicle is capable of generating and broadcasting a “Common Message Set” (CMS), which provides each vehicle&#39;s relevant kinematical and location information such as GPS/vehicle position including longitude, latitude, and elevation, heading, velocity, vehicular dimensions, and other related information. The DSRC system can broadcast messages between vehicles using a frequency between about 5 and 6 GHz. In addition, location and speed information can be obtained independent of the DSRC system, such as through the use of forward looking radar. 
   The CMS message can be broadcast as the most frequent message on the control or center channel of the DSRC band, although other messages can also be broadcast over this channel. Unicast messages (i.e., single-sender speaking directly to a single-receiver for mono-to-mono exchanges) can be directed to an alternate channel, and several channels can be designated as either urgent/safety-related channels or service-providing, non-urgent channels. This type of implementation permits OEM&#39;s to send messages only to vehicles of the same manufacturer or make, and create exchanges of information between them outside the central channel of communication. 
   In view of this ability for information to be communicated between vehicles, it is possible to configure a system that enables a vehicle to modify its operation or settings and to notify a driver of settings, situations or conditions relevant to operating a vehicle. For example, it is possible for a driver to adjust a driving route based on location and speed information from other vehicles.  FIG. 1  is a block diagram of a traffic control system consistent with the present invention. As shown in  FIG. 1 , there is a vehicle  1  and a vehicle  2 . The vehicle  1  includes an antenna controller  11 , a GPS antenna  12 , a DSRC antenna  13 , a DSRC processor  14 , a speed sensor  15 , a map database  16 , and a system processor  17 . The vehicle  2  has similar elements including an antenna controller  21 , a GPS antenna  22 , a DSRC antenna  23 , a DSRC processor  24 , a speed sensor  25 , a map database  26 , and a system processor  27 . Although only the two vehicles  1  and  2  are shown, it should be understood that the traffic control system is applicable to more than two vehicles. 
   The antenna controller  11  controls the functioning of both the GPS antenna  12  and the DSRC antenna  13 . The GPS antenna  12  is configured to receive information regarding the location of the vehicle  1 . The DSRC antenna  13  is configured to receive information from other vehicles and devices and to transmit information from the vehicle  1 . The received information and the transmitted information can include, for example, kinematical and location information such as GPS/vehicle position, heading, velocity, and vehicular dimensions, as well as status information, such as headlight status (ON/OFF, high brights, etc.), cruise control (ON/OFF) and other settable functions of a vehicle. The vehicle position, based on the GPS, preferably includes a longitude and latitude position, as well as the elevation of the vehicle. The information can be transmitted and received in a predetermined message format such as the CMS. The predetermined message format may be unique to each manufacturer or be a common format for all vehicles. Even in the common format, the predetermined message may include a section or component identifying the manufacturer, which can enable a vehicle to send a message exclusively to other vehicles of the same manufacturer or make. 
   To transmit a message or other information, the DSRC antenna  13  receives control instructions from the antenna controller  11  and transmits the message in accordance with the control instructions. Messages or other information received by the GPS antenna  12  and the DSRC antenna  13  are provided to the antenna controller  11 . In response to the received message, the antenna controller  11  can provide new control instructions to the GPS antenna  12  and the DSRC antenna  13  based on the content of the received message. In addition, the antenna controller provides the received message to the DSRC processor  14 . 
   The DSRC processor  14  is configured to process messages provided from the antenna controller  11  and to generate messages to be transmitted by the DSRC antenna  13 . The DSRC processor  14  is also configured to determine speed and/or traffic information based on the received messages, as well as generate messages for transmission from the DSRC antenna  13 . The DSRC processor  14  can include a processing unit, such as a CPU or microprocessor, a non-volatile storage medium, such as an NVRAM or ROM, and a volatile storage medium, such as RAM. The non-volatile storage preferably includes instructions executed by the processing unit to perform the message processing and generation and other control functions, as will be described in more detail herein. 
   The speed sensor  15  is configured to detect the traveling speed or velocity of the vehicle  1 . The speed sensor  15  can be implemented as any of a number of speed detecting sensors as are known to those skilled in the art. The speed sensor  15  generates an electrical signal indicative of the speed of the vehicle  1  and provides the signal to the DSRC processor  14 , the map database  16 , and the system processor  17 . 
   The map database  16  holds data indicative of the position or location of roadways that can be traveled upon by the vehicle  1 . The map database  16  can be implemented in a non-volatile memory, such as a hard disk driver (HDD), a flash memory, a DVD, etc. The map database  16  may be changeable to update for changes to the roadway or for different geographical locations. For example, the map database  16  for one country may be implemented on one DVD and on another DVD for another country. Data from the map database  16  corresponding to the location of the vehicle  1  can be included in any messages composed by the DSRC processor  14  and transmitted by the DSRC antenna  13 . 
   The system processor  17 , like the DSRC processor  14 , is preferably configured to include a processing unit, a non-volatile storage medium, and a volatile storage medium, such as RAM. The system processor  17  can be configured to perform functions for the vehicle  1  that are not performed by the DSRC processor  14 . The system processor  17  and the DSRC processor  14  can also be configured to work in tandem, capable of performing the same functions as each other. 
   The components of the vehicle  2  are implemented and operate in the same manner as the corresponding components of the vehicle  1 . In particular, the antenna controller  21 , the GPS antenna  22 , the DSRC antenna  23 , the DSRC processor  24 , the speed sensor  25 , the map database  26 , and the system processor  27  are implemented and operate in the same manner as the antenna controller  11 , the GPS antenna  12 , the DSRC antenna  13 , the DSRC processor  14 , the speed sensor  15 , the map database  16 , and the system processor  17 , respectively. 
     FIG. 2  is a flow diagram of a traffic control process consistent with the present invention. In the following description, the process is described in conjunction with the vehicles  1  and  2  of  FIG. 1 . More specifically, the process is described from the standpoint of a message being transmitted to vehicle  2  and received by vehicle  1 , which responds to the received message. It should be understood, however, that the process is applicable to any vehicle capable of communicating wirelessly with other vehicles. 
   As shown in  FIG. 2 , the vehicle  2  first prepares a CMS message (step  202 ). As described above, the CMS message can include kinematical and location information such as GPS/vehicle position (including, e.g., latitude, longitude, and elevation), heading, velocity, and vehicular dimensions, as well as other status information. With reference to  FIG. 1 , the DSRC processor  24  of the vehicle  2  collects the information for forming the CMS message. The information collected includes, for example, velocity data from the speed sensor  25 , location information from the GPS antenna  22  and/or the map database  26 , and other relevant information about the operation and settings of the vehicle  2 . The collected information is formatted into the CMS message format. Although the CMS message format is preferable, other message formats, either common to all automobile manufacturers or unique to particular manufacturers can be used instead. Further, in addition to the collected information, the message is formatted to include a unique identifier for the vehicle  2  so that other vehicles receiving the message can distinguish the origin of the message from messages received from other vehicles. The CMS message can be prepared at predetermined time intervals, such as every minute. 
   The vehicle  2  broadcasts the CMS message (step  204 ). To broadcast the message, the DSRC processor  24  provides the CMS message to the antenna controller  21 , which controls the DSRC antenna  23  to broadcast the message. The CMS message is broadcast at least to vehicles in the vicinity of the vehicle  2 . Additionally, the CMS message can be broadcast to other structures, such as antenna towers or other communication devices, which can forward or broadcast the CMS message to more vehicles that may be outside of the broadcast range of the DSRC antenna  23 . 
   For example,  FIG. 3  shows a block diagram of an alternative communication arrangement for the traffic control system of  FIG. 1 . As shown in  FIG. 3 , the vehicle  1  and a plurality of vehicles  2 -N are traveling on a roadway  45 . Adjacent to the roadway  45  are a series of roadside units (RSUs)  30  and  35 . Although only the two RSUs  30  and  35  are shown, it should be understood that there can be many RSUs located adjacent to the roadway  45 , such as one for every fixed distance, e.g., one per mile. The RSU  35  is located close to the vehicles  2 -N, and the RSU  30  is located close to the vehicle  1 . In operation, the RSU  35  receives CMS messages from the vehicles  2 -N, and forwards those messages to a traffic control operations center (TOC)  40 . The TOC  40  receives the messages, and processes them to determine traffic control information, as will be described in greater detail herein. The TOC  40  may be configured in a manner similar to the DSRC  14  including being configured to determine traffic control information based on location and velocity data received from various vehicles. The TOC  40  then transmits a message to the RSU  30 , which forwards the message from the TOC  40  to the vehicle  1 . The vehicle  1  is thus able to determine traffic control information based on information from the vehicles  2 -N, even if the vehicle  1  is unable to receive messages directly from the vehicles  2 -N. 
   Returning to  FIGS. 1 and 2 , the vehicles in the broadcast range of the DSRC antenna  23 , including the vehicle  1 , receive the CMS message from the vehicle  2  (step  206 ). At vehicle  1 , the CMS message is received by the DSRC antenna  13  and provided to the antenna controller  11 , which transfers the message to the DSRC processor  14 . The message from the vehicle  2  may be received directly from the DSRC antenna  23 , via another vehicle, such as a vehicle between the vehicles  1  and  2 , or via a receiver/transmitter that can receive messages from vehicles and retransmit them to other vehicles or other receiver/transmitters. The DSRC processor  14  is configured to understand the format and content of the received CMS message and to process it accordingly. 
   The received CMS message includes an identifier of the vehicle transmitting the CMS message, in this case vehicle  2 . The identifier enables the DSRC processor  14  to distinguish which vehicle sent the CMS message and to collect the most up-to-date information about each vehicle transmitting CMS messages to the vehicle  1 . The information from the CMS messages can be stored in a memory coupled to or implemented in the DSRC processor  14 . When a new CMS message is received, the DSRC processor  14  can update the information stored in the memory or, if it is the first CMS message received from a vehicle, store all of the information in the memory. The information can be stored, for example, in the form of a spreadsheet or table with a line for each vehicle, each line having the identifier of the vehicle and some or all of the information in the CMS message. Accordingly, for each vehicle sending a CMS message to the vehicle  1 , the DSRC processor  14  may store each vehicle&#39;s location, heading, speed, dimensions and other status settings. 
   In response to the received CMS message, the DSRC processor  14  determines if the CMS message indicates that the vehicle  2  is traveling on the same road as the vehicle  1  (step  208 ). To determine if the two vehicles are traveling on the same road, the DSRC processor  14  uses the location information of the vehicle  1  derived from the GPS data received by the GPS antenna  12  and the location information (GPS data and/or data from map database  26 ) of the vehicle  2  from the received CMS message. The location of each vehicle is used as an input to the map database  16 . Based on the location of each vehicle in reference to the map database  16 , it is possible to determine if both vehicles are traveling on the same road. In addition to determining if the vehicles are on the same road, the reference to the map database  16  can also be used to determine if the vehicle  2  is ahead of or behind the vehicle  1 . Furthermore, if the road has multiple lanes, the location information of the vehicle  2  can preferably be used to determine in which lane the vehicle  2  is traveling, e.g. the left, center, or right lane. To identify the lane, it may be possible to use differential corrections via the RSUs  30 , use a more accurate GPS band, or rely on internal map-matching. 
   Instead of checking if the vehicle  2  is on the same road, a check can be made if the vehicle  2  is traveling on a road of interest. For example, the driver of the vehicle  1 , with reference to the map database  16  or other navigational system, may be interested in traffic information on a different roadway than the one on which the vehicle  1  is currently traveling. The driver can select the roadway of interest, and a check is made as to whether the vehicle  2  is traveling on the selected road. In this manner, the driver of the vehicle  1  can get traffic control information for both the current roadway as well as other roadways that the driver may want to use. 
   If the two vehicles are not on the same road, then the DSRC processor  14  can check if information is already stored for the vehicle  2  and update any new information. If the DSRC processor  14  determines that both vehicles are on the same road, then it checks to determine if the vehicles have the same vector (step  210 ). The vector corresponds to the heading or direction in which the vehicle is traveling. The CMS message from the vehicle  2  preferably includes the heading or direction in which the vehicle  2  is traveling. In general, even if the vehicle  2  is ahead of the vehicle  1 , the traffic related information that can be derived from the vehicle  2  is more relevant if the vehicle  2  is traveling in substantially the same direction as the vehicle  1 . In other words, if the vehicle  2  is traveling in a substantially different direction than the vehicle  1 , such as in the opposite direction, then any traffic related information derived from the vehicle  2  is not that relevant to the vehicle  1 . The vectors of the vehicles  1  and  2  need not be identical or exactly the same. Rather, the vectors can be considered the same or substantially the same if the difference in the vectors is less than some threshold, such as a predetermined number of degrees. The threshold can be a fixed value or can be changed by a driver, dealer, or manufacturer. 
   If the driver had selected a road of interest other than the road on which the vehicle  1  is traveling, then the driver can also designate the desired heading on the road of interest. If the vehicle  2  is on the road of interest, then instead of determining if the vehicles  1  and  2  are traveling in the same direction, a check is made to determine if the vehicle  2  is traveling in the same direction as the desired heading. 
   If the vehicles  1  and  2  are not traveling in the same direction, then no action is taken. If they are traveling in the same direction, however, then the DSRC processor  14  calculates an average lane speed (step  212 ). If the road on which the vehicle  1  is traveling has only one lane or if the received information from the other vehicles cannot be used to distinguish between lanes of a multi-lane road, then the average lane speed simply corresponds to an average road speed. In general, the average lane (or road) speed corresponds to an average speed of vehicles traveling ahead of the vehicle  1 . To calculate the average lane speed, the DSRC processor  14  can use the vehicle speeds, the vehicle locations, or a combination of the two. It is also possible to give different weightings to the vehicle speeds depending upon a varying parameter, such as the distance between the vehicle  1  and each vehicle or the type of vehicle. The DSRC processor  14  preferably calculates the average lane speed using the speed of the vehicle  2  and the location of the vehicle  2 , as well as the speed and location of other vehicles that are also traveling ahead of the vehicle  1  in the same direction. The location information used to calculate the average lane speed may include its location relative to the vehicle  1  to determine the distance between them and the lane in which it is traveling. The information for the calculation can be derived from the received CMS message transmitted from the vehicle  2 . In addition, the average lane speed is preferably calculated by using the information received from the vehicle  2 , as well as similar information from other vehicles traveling in the same lane as vehicle  2 . In this manner, the average lane speed is calculated in accordance with a speed of each vehicle traveling in the same lane on the same roadway as the vehicle  1  and positioned ahead of vehicle  1 . In addition, it is possible to calculate an average lane speed for each lane of the roadway in which the vehicle  1  is traveling. 
   More preferably, the DSRC processor  14  can use a formula, such as equation (1), to calculate the average lane speed:
 
 LS   x =Σ( d   i   *s   i   /d   f )   (1)
 
wherein LS x  is the average speed in lane x, x being a lane in which each of the first group of vehicles is traveling, d i  is the distance to a respective one of the first group of vehicles, s i  is the speed of a respective one of the first group of vehicles, and d f  is the sum of the distances from the first vehicle to each of the first group of vehicles. In accordance with equation 1, an average speed of vehicles traveling in a particular lane ahead of the vehicle  1  can be determined. Further, by including the distance to the vehicle  1  as part of the calculation, a weighting is given to each vehicle in accordance with the distance. More particularly, as shown in equation (1), as the distance from the vehicle  1  increases, the weight given to that vehicle&#39;s speed in determining the average lane speed also increases. In this manner, the speed of a vehicle farther ahead of the vehicle  1  is given greater weight as its speed is more indicative of the traffic conditions that the vehicle  1  will face.
 
   As communication between vehicles begins more commonplace, such as with DSRC communication, there will be a lag in which initially many if not most vehicles do not communicate with other vehicles. It is likely that specific manufacturers will begin to make the communication a standard feature of each vehicle. In view of this likelihood, the lane speed average can be calculated by giving a preference to vehicles of the same manufacture or some other criteria for giving preference. Such a calculation is shown by equation (2):
 
 LS   x =[Σ( d   i   *s   i   /d   if )+ C   j *(Σ( d   j   *s   j   /d   jf )]/(1 +C   j )  (2)
 
wherein LS x  is the average speed in lane x, x being the lane in which each of a first group of vehicles is traveling, the first group being non-preferred vehicles, d i  is the distance to a respective one of the first group of vehicles, s i  is the speed of a respective one of the first group of vehicles, d if  is the sum of the distances from the first vehicle to each of the first group of vehicles, C j  is a weighting factor for the second group of vehicles, the second group being preferred vehicles, d j  is the distance to a respective one of the second group of vehicles, s j  is the speed of a respective one of the second group of vehicles, and d jf  is the sum of the distances from the first vehicle to each of the second group of vehicles.
 
   Returning to  FIG. 2 , after calculating the average lane speed, the calculated average is compared to a previously calculated average (step  214 ). The comparison is made to determine if they are sufficiently different. For example, the just-calculated and previously calculated average lane speeds are sufficiently different if the difference between them exceeds a threshold, such as 2 MPH. This threshold can be a fixed value or can be changeable, such as by a driver, manufacturer, or dealer. 
   If the just-calculated and previously calculated average lane speeds are not different, then it is checked whether an information request has been made (step  216 ). An information request is a request from the driver of the vehicle  1  for information about the vehicle  1  or based on information received by the vehicle  1 , such as traffic control information. To make the request, the driver may make a selection through an interface in the vehicle  1 , such as by pressing a button or making a request through an audible command. For example, the vehicle  1  may have an information screen, such as part of its navigation system, that the user can use to make the information request. If no information request has been made, then nothing is done, and the vehicle  1  awaits for another message to be received. 
   If the information request is made, or if the just-calculated and previously calculated average lane speeds are different, then the average lane speed information is displayed (step  218 ). The information can be displayed, for example, on an information display panel in the vehicle  1 .  FIG. 4  is a graphical representation of an exemplary information display panel. As shown in  FIG. 4 , the average lane speed is displayed to the driver for each of the three lanes of the roadway on which the vehicle  1  is traveling. Instead of an information display panel, the vehicle  1  may have a heads up display (HUD), such as ones used to display current vehicle speed, to show the average lane speed information. The display of the average lane speed information can also be done in response to a change in speed by the vehicle  1  or in response to any drop in the calculated average lane speed. 
   In accordance with the present invention, a vehicle can receive vehicle speed, location, and heading information from other vehicles traveling on the same roadway. The information can be received via a wireless system, such as a DSRC system or radar. Based on the location information, it can be determined if the vehicle sending the message is ahead of the vehicle receiving the message, positioned on the same roadway, and in the same or different lane. Based on the heading information, it can be determined if the vehicle sending the message is traveling in substantially the same direction. If on the same roadway and traveling in the same direction, the speed of the vehicle transmitting the message can be used to determine an average speed for vehicles on the roadway or even on each lane of the roadway. 
   By providing the average speed information, the driver can make appropriate driving adjustments. For example, the driver could be alerted that traffic is slowing well before seeing brake-lights and avoid the use of emergency braking. The driver can also use the information to navigate quickly through construction zones or bottlenecks. In addition, if the information indicates a substantial slowing on the roadway, the driver can exit the roadway and avoid potential bumper-to-bumper gridlock. In addition to this utility, the ability to provide this type of speed information to drivers should come at a minimal cost. Vehicles will increasingly have such wireless communication implemented. The only cost will derive from the programming and processing power used to collect, analyze, and average the sensed vehicle speeds. 
   The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light in the above teachings or may be acquired from practice of the invention. The embodiments (which can be practiced separately or in combination) were chosen and described in order to explain the principles of the invention and as practical application to enable one skilled in the art to utilize the invention in various embodiments and with various modifications are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.